127 results on '"CHFS"'
Search Results
2. CHFS: Complex hesitant fuzzy sets‐their applications to decision making with different and innovative distance measures
- Author
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Zeeshan Ali, Tahir Mahmood, Ubaid ur Rehman, and Harish Garg
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Computer Networks and Communications ,Computer science ,Fuzzy set ,computer.software_genre ,Distance measures ,Human-Computer Interaction ,QA76.75-76.765 ,Artificial Intelligence ,Computational linguistics. Natural language processing ,CHFS ,Computer software ,Computer Vision and Pattern Recognition ,Data mining ,P98-98.5 ,computer ,Information Systems - Abstract
The objective of the authors is to establish an innovative concept of the complex hesitant fuzzy set (CHFS), which is the combination of the hesitant fuzzy set and the complex fuzzy set to manage complex and awkward information in the real‐decision theory. The structure and the basic properties of the proposed set are studied in detail. Based on the internal structure of the set and to find the degree of the discrimination between the pairs of the CHFSs, the generalized distance measures and modified generalized distance measures are defined. Several properties and their relationship between them are derived in detail. Also, several cases of the proposed measures are exposed which reduce them to the existing studies. Furthermore, based on these proposed measures, a decision‐making approach is established under the uncertain environment and several numerical examples are given to examine the feasibility and validity of the explored measures. Finally, the credibility of the modified and parameterized distance measures based on CHFSs is verified by comparing them with some existing measures.
- Published
- 2021
3. Application of CAD/CAM technology for surgical treatment of condylar head fractures: A preliminary study
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Denis Chernogorskyi, Tetiana Pavlychuk, Yurii Chepurnyi, Andreas Neff, and Andrii Kopchak
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Orthodontics ,medicine.diagnostic_test ,business.industry ,Physical examination ,CAD ,030206 dentistry ,Condyle ,03 medical and health sciences ,Fixation (surgical) ,0302 clinical medicine ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Occlusion ,medicine ,CHFS ,Original Article ,Clinical significance ,Surgical treatment ,business ,General Dentistry - Abstract
Objectives The aim of the present study was to improve the accuracy and reliability of ORIF in patients with condylar head fractures (CHFs) by developing a design for patient specific fixators, navigation and repositioning guides, as well as the algorithms of their clinical application. Materials and methods 14 patients with 16 CHFs were treated by ORIF with the use of CAD/CAM technology. After virtual reduction of the bony fragments, the appropriate length and diameter of the screws was chosen. In biomechanically unfavorable cases (type p) patient specific reinforcement plates were used together with the positional screws for reinforcement of the bone-fixator system. And in cases of severely comminuted fractures patient specific 3-D plate was applied. Results The CT data, obtained immediately after the operation revealed the good anatomical reduction. Any deviations of the small fragments noted were near 1 mm in all cases. Postoperative clinical examination at 3 months follow up showed good occlusion and mouth opening not less than 3 cm in all patients. The lateral and anterior mobility of the mandible was restored with small limitations of protrusive mobility in 1 case. All the patients were satisfied with the outcomes. Conclusions The application of the CAD/CAM technologies and the new design of the surgical guides and patient specific reinforcement plates for CHFs helps to improve the accuracy and quality of fragments reduction and stability of fixation with minimal risks of intraoperative complications. Clinical relevance CAD/CAM technologies improve the clinical effectiveness of treatment patients with the CHFs.
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- 2020
4. Social Network and Family Entrepreneurship Choice -Empirical Evidence from CHFS
- Author
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Wang Jingxue
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Microeconomics ,Entrepreneurship ,Social network ,business.industry ,Economics ,CHFS ,General Earth and Planetary Sciences ,business ,Empirical evidence ,General Environmental Science - Published
- 2020
5. Inflation Expectation and Consumption: Evidence from CHFS Data
- Author
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Yuxin Diao
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Inflation ,Consumption (economics) ,media_common.quotation_subject ,CHFS ,Economics ,Monetary economics ,media_common - Published
- 2020
6. Tailoring the Charge/Discharge Potentials and Electrochemical Performance of SnO 2 Lithium‐Ion Anodes by Transition Metal Co‐Doping
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Dominic Bresser, Jawwad A. Darr, Ute Kaiser, Alexandra R. Groves, Dorin Geiger, Adele Birrozzi, Jakob Asenbauer, and Thomas E. Ashton
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Materials science ,Dopant ,Doping ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Lithium-ion battery ,Cathode ,Anode ,law.invention ,chemistry ,Chemical engineering ,law ,Electrode ,Electrochemistry ,CHFS ,Lithium ,Electrical and Electronic Engineering - Abstract
It has been shown that the introduction of several transition metal (TM) dopants into SnO2 lithium‐ion battery anodes can overcome the issues associated with the irreversible capacity loss from the conversion reaction of SnO2 and the aggregation of the metallic Sn particles formed upon lithiation. As the choice of the single dopant, however, plays a decisive role for the achievable energy density – precisely its redox potential – we investigate herein TM co‐doped SnO2, prepared by using a readily scalable continuous hydrothermal flow synthesis (CHFS) process, to tailor the dis‐/charge profile and by this the energy density. It is shown that the judicious choice of different elemental doping combinations in samples made via CHFS simultaneously improves the cycling performance and the full‐cell energy density. To support these findings, we realized a lithium‐ion full‐cell incorporating the best performing co‐doped SnO2 as negative electrode and high‐voltage LiNi0.5Mn1.5O4 (LNMO) as positive electrode–to the best of our knowledge, the first full‐cell based on such anode material in combination with LNMO as cathode active material.
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- 2020
7. Exponential and non-Exponential Based Generalized Similarity Measures for Complex Hesitant Fuzzy Sets with Applications
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Ubaid ur Rehman, Tahir Mahmood, and Zeeshan Ali
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0209 industrial biotechnology ,Logic ,Generalization ,Applied Mathematics ,Fuzzy set ,02 engineering and technology ,Management Science and Operations Research ,Industrial and Manufacturing Engineering ,Theoretical Computer Science ,Exponential function ,Algebra ,020901 industrial engineering & automation ,Similarity (network science) ,Artificial Intelligence ,Control and Systems Engineering ,0202 electrical engineering, electronic engineering, information engineering ,CHFS ,020201 artificial intelligence & image processing ,Information Systems ,Mathematics - Abstract
The purpose of this manuscript is to explore the notion of a complex hesitant fuzzy set (CHFS), as a generalization of the hesitant fuzzy set (HFS) and complex fuzzy set (CFS) to cope with the unce...
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- 2020
8. High-throughput Screening of Vanadium (IV) Oxide via Continuous Hydrothermal Flow Synthesis Reactor
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Mai Tran, Jie Li, Elizabeth Rasmussen, and Elena V. Shevchenko
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Crystallinity ,Materials science ,Dynamic light scattering ,Chemical engineering ,Scanning electron microscope ,CHFS ,Nanoparticle ,Supercritical fluid ,Nanomaterials ,Autoclave - Abstract
The synthesis of inorganic nanoparticles using continuous hydrothermal flow synthesis (CHFS) reactor systems is an up-and-coming process to manufacture high-quality nanomaterials with singular control of the experimental parameters on the scale of seconds as opposed to hours. VO2-based systems manufactured using an autoclave reactor lack scalability, and current commercial products feature particle sizes too large for feasible application. In this paper, the detailed implementation of a CHFS system that can operate at and above supercritical water conditions (22.06 MPa at 374˚C) is described. Control over the CHFS system’s temperature, flow rate, and precursor concentration parameters allowed the tunability of size, crystallinity, and shape of VO2 nanoparticles to be investigated across seven studies. The resulting VO2 nanoparticles were characterized for size, shape, morphology, and crystallinity using dynamic light scattering (DLS), scanning electron microscopy (SEM), and x-ray diffraction (XRD). This investigation resulted in new operating procedures that enable the synthesis of high-quality, uniform, spherical, and pure M-phase VO2 nanoparticles under 50 nm in diameter in the residence time of a few seconds. Additionally, the procedure described in this paper is performed in a single step, thus eliminating the tedious post-annealing process.
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- 2021
9. Synthesis and characterization of Cu-BTC metal–organic frameworks onto lignocellulosic fibers by layer-by-layer method in aqueous solution
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Zhiqiang Li, Naruhito Hori, and Akio Takemura
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Materials science ,Aqueous solution ,Polymers and Plastics ,Composite number ,Layer by layer ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Cellulose fiber ,Adsorption ,Chemical engineering ,Specific surface area ,CHFS ,Metal-organic framework ,0210 nano-technology - Abstract
In the present study, lignin-contained cellulosic fiber material as a substrate was used for immobilizing Cu-BTC metal–organic framework, the composite was strategically synthesized using trimesic salts as linker sources. The growth of Cu-BTC onto lignocellulosic fiber was conducted in aqueous solution by a layer-by-layer method, and the effect of preparation temperature, time, and number of layers of Cu-BTC deposition was also investigated. The products were characterized by ATR FT-IR, XRD, and SEM. The results showed that the as-prepared Cu-BTC in water was partially hydrolyzed phase of Cu-BTC prepared in organic solvents. Cu-BTC metal–organic frameworks were homogeneously immobilized on carboxymethylated high yield pulp fibers (CHFs). Increasing the growth temperature and time would enhance the deposit of Cu-BTC onto fiber surface slightly, however increasing the growth layers would promote the deposit ratio significantly (from 26.17 to 68.59%, 2 layers to 6 layers). The specific surface area of synthesized Cu-BTC@CHFs had a distinct promotion compared with unmodified fibers, showing a certain gas adsorption capacity.
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- 2019
10. Facile Interface Design Strategy for Improving the Uvioresistant and Self-Healing Properties of Poly(p-phenylene benzobisoxazole) Fibers
- Author
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Meiyu Li, Long Yu, Zhen Hu, Fei Lu, Yingying Liu, Xinghao Huang, Yudong Huang, Haoze Pan, and Leiyu Wu
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Materials science ,Fabrication ,Graphene ,Composite number ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Thermoplastic polyurethane ,Adsorption ,Chemical engineering ,law ,Poly(p-phenylene) ,CHFS ,General Materials Science ,Fiber ,0210 nano-technology - Abstract
Graphene-based coaxial hybrid fibers (CHFs) with a typical core-sheath structure have attracted extensive attention in recent years because of their potentially excellent mechanical performance. However, direct introduction of the micrometer-thick graphene stack structure on the extremely inert fiber surface with little negative effect has barely been reported so far and is still a great challenge. In the present work, a facile and cost-efficient dimensionally confined hydrothermal reduction, static adsorption, and thermal-assisted shrinkage sequential treatment strategy was developed to fabricate one-dimensional CHFs. The large-scale reduced graphene oxide-metal organic framework (RGO-UIO-66) hybrid layer and poly(p-phenylene benzobisoxazole) (PBO) fiber serve as the sheath part and core part, respectively, and the final product is denoted as PGU-CHFs. The experimental results confirmed that the prepared monofilament composite with thermoplastic polyurethane (PGU-CHF-TPU) exhibited an excellent and stable intrinsically self-healing efficiency (about 85%) over 5 cycles and an extraordinary uvioresistant performance (increased by 128%) compared to those of pristine PBO fibers after 288 h UV aging irradiation. Moreover, the anti-ultraviolet (UV) properties of PGU-CHFs at 96 h are basically at the optimum level among most of the reported literatures at present after comparison. The highly near-infrared photothermal conversion ability and stability of micrometer-thick RGO stack structure and the synergism of RGO-UIO-66 hybrid sheath layer including UV adsorption, shielding attenuation, and reflection are responsible for the satisfactorily interfacial self-healing efficiency and UV-resistance properties of PGU-CHFs, respectively. Considering the diversities and versatilities of RGO and MOFs, the proposed fabrication strategy will promisingly endow PBO fibers with great application potential in the other fields such as fiber-based sensors and smart fibers.
- Published
- 2019
11. Characterization of Natural Cellulosic Fiber from Cereus Hildmannianus
- Author
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R. Rajkumar, Senthil Ganesh Subramanian, and T. Ramkumar
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Materials science ,biology ,Materials Science (miscellaneous) ,02 engineering and technology ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,biology.organism_classification ,01 natural sciences ,Characterization (materials science) ,Cellulose fiber ,Cereus hildmannianus ,Chemical engineering ,CHFS ,Research article ,0210 nano-technology ,0105 earth and related environmental sciences - Abstract
The research article aims to characterize the physicochemical, morphological, thermal and mechanical properties of novel Cereus Hildmannianus Fibers (CHFs) are reported for the first time in this w...
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- 2019
12. Quaternary ferrites by batch and continuous flow hydrothermal synthesis: a comparison
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Paolo Pastore, Charles J. M. Footer, Nicola Dengo, Silvia Gross, Michele Bastianello, Jawwad A. Darr, Stefano Diodati, Denis Badocco, and Liam McCafferty
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Materials science ,Continuous flow ,Spinel ,02 engineering and technology ,General Chemistry ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Chemical engineering ,X-ray photoelectron spectroscopy ,CHFS ,engineering ,Hydrothermal synthesis ,General Materials Science ,0210 nano-technology - Abstract
Crystalline spinel quaternary ferrites MxZn1−xFe2O4 (M = Co, Ni; x = 0.2, 0.35, 0.5, 0.65, 0.8) were synthesised through conventional batch hydrothermal synthesis (HT) at 135 °C as well as via continuous flow hydrothermal synthesis (CHFS). The as prepared compounds were thoroughly characterised from a compositional (ICP-MS, XPS) and structural (XRD) point of view in order to compare the synthetic approaches and achieve a greater understanding of how the chosen approach influences the characteristics of the resulting spinel.
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- 2019
13. Tailoring the electrochemical activity of magnesium chromium oxide towards Mg batteries through control of size and crystal structure
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Soojeong Kim, Timothy T. Fister, Gene M. Nolis, Thomas E. Ashton, Liam McCafferty, Ian D. Johnson, Jawwad A. Darr, John W. Freeland, Hyun Deog Yoo, Jordi Cabana, and Linhua Hu
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Materials science ,Magnesium ,Spinel ,chemistry.chemical_element ,02 engineering and technology ,Electrolyte ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Cathode ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,Chromium ,Chemical engineering ,chemistry ,law ,Ionic liquid ,engineering ,CHFS ,General Materials Science ,0210 nano-technology - Abstract
Chromium oxides with the spinel structure have been predicted to be promising high voltage cathode materials in magnesium batteries. Perennial challenges involving the mobility of Mg2+ and reaction kinetics can be circumvented by nano-sizing the materials in order to reduce diffusion distances, and by using elevated temperatures to overcome activation energy barriers. Herein, ordered 7 nm crystals of spinel-type MgCr2O4 were synthesized by a conventional batch hydrothermal method. In comparison, the relatively underexplored Continuous Hydrothermal Flow Synthesis (CHFS) method was used to make highly defective sub-5 nm MgCr2O4 crystals. When these materials were made into electrodes, they were shown to possess markedly different electrochemical behavior in a Mg2+ ionic liquid electrolyte, at moderate temperature (110 °C). The anodic activity of the ordered nanocrystals was attributed to surface reactions, most likely involving the electrolyte. In contrast, evidence was gathered regarding the reversible bulk deintercalation of Mg2+ from the nanocrystals made by CHFS. This work highlights the impact on electrochemical behavior of a precise control of size and crystal structure of MgCr2O4. It advances the understanding and design of new cathode materials for Mg-based batteries.
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- 2019
14. Adipose tissue-derived stromal vascular fraction for treating hands of patients with systemic sclerosis: a multicentre randomized trial Autologous AD-SVF versus placebo in systemic sclerosis
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Elisabeth Jouve, Chloé Dumoulin, David Bocara, Audrey Cras, Olivier Boyer, Françoise Dignat-George, Julie Brunet, Ygal Benhamou, Isabelle Auquit-Auckbur, Cécile Philandrianos, Nicolas Schleinitz, Veronique Bourgarel, Dominique Casanova, Camille Giverne, Stéphanie Mallet, Rosanna Ferreira, Yves-Marie Pers, Aurélie Daumas, Brigitte Granel, Joseph Château, Florence Sabatier, Hervé Levesque, Maxime Abellan Lopez, Jérôme Larghero, Jean-Robert Harlé, Laurent Arnaud, Jeremy Magalon, Guy Magalon, J. Veran, Arnaud Hot, L. Giraudo, Alexandra Giuliani, Dominique Farge, Hôpital de la Conception [CHU - APHM] (LA CONCEPTION), Centre recherche en CardioVasculaire et Nutrition = Center for CardioVascular and Nutrition research (C2VN), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre d'Investigation Clinique [Hôpital de la Conception - APHM] (CIC), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Institut Paoli-Calmettes, Fédération nationale des Centres de lutte contre le Cancer (FNCLCC)-Fédération nationale des Centres de lutte contre le Cancer (FNCLCC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hôpital de la Conception [CHU - APHM] (LA CONCEPTION), Hôpital Nord [CHU - APHM], Assistance Publique - Hôpitaux de Marseille (APHM), CHU Rouen, Normandie Université (NU), Physiopathologie, Autoimmunité, maladies Neuromusculaires et THErapies Régénératrices (PANTHER), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Hopital Saint-Louis [AP-HP] (AP-HP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Recherche clinique appliquée à l'hématologie (URP_3518), Université Paris Cité (UPCité), McGill University = Université McGill [Montréal, Canada], Service de Médecine Interne [CHU Rouen], Normandie Université (NU)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Endothélium, valvulopathies et insuffisance cardiaque (EnVI), Centre de Recherche en Cancérologie de Marseille (CRCM), Aix Marseille Université (AMU)-Institut Paoli-Calmettes, Fédération nationale des Centres de lutte contre le Cancer (FNCLCC)-Fédération nationale des Centres de lutte contre le Cancer (FNCLCC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Cellules Souches, Plasticité Cellulaire, Médecine Régénératrice et Immunothérapies (IRMB), Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM), Immunologie humaine, physiopathologie & immunothérapie (HIPI (UMR_S_976 / U976)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Cité (UPCité), Hôpital privé Jean Mermoz [Lyon], Hôpital Edouard Herriot [CHU - HCL], and Hospices Civils de Lyon (HCL)
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medicine.medical_specialty ,Population ,Adipose tissue ,Placebo ,Scleroderma ,law.invention ,Rheumatology ,Randomized controlled trial ,law ,Fibrosis ,Internal medicine ,CHFS ,medicine ,Humans ,Pharmacology (medical) ,education ,education.field_of_study ,Scleroderma, Systemic ,Stromal Vascular Fraction ,business.industry ,Stromal vascular fraction ,medicine.disease ,Hand ,Autologous adipose tissue-derived stromal vascular fraction ,[SDV.MHEP.RSOA]Life Sciences [q-bio]/Human health and pathology/Rhumatology and musculoskeletal system ,Adipose Tissue ,Regenerative medicine ,Systemic sclerosis ,business ,Cochin Hand Function Scale - Abstract
Objective To assess the superiority of adipose tissue-derived stromal vascular fraction (AD-SVF) injection into the fingers vs placebo in reducing hand disability in systemic sclerosis (SSc) patients. Methods We performed a double-blind, multicentre, phase II trial from October 2015 to January 2018 in France. SSc patients with a Cochin Hand Function Scale (CHFS) ≥20/90 were randomized 1:1 to receive injection of AD-SVF or placebo. AD-SVF was obtained using the automated processing Celution 800/CRS system. The placebo was lactated Ringer’s solution. The primary efficacy end point was the change of the CHFS score from baseline to 3 months. Secondary efficacy endpoints included the CHFS score at 6 months, hand function, vasculopathy, hand pain, skin fibrosis, sensitivity of the finger pulps, Scleroderma Health Assessment Questionnaire, patients and physician satisfaction, and safety. Results Forty patients were randomized. The AD-SVF and placebo groups were comparable for age, sex ratio, disease duration, skin fibrosis of the hands and main cause of hand disability. After 3 months’ follow-up, hand function significantly improved in both groups with no between-group difference of CHFS (mean change of −9.2 [12.2] in the AD-SVF group vs −7.6 [13.2] in the placebo group). At 6 months, hand function improved in both groups. Conclusion This study showed an improvement of hand function in both groups over time, with no superiority of the AD-SVF. Considering the limits of this trial, studies on a larger population of patients with homogeneous phenotype and hand handicap should be encouraged to accurately assess the benefit of AD-SVF therapy. Trial registration ClinicalTrials.gov, https://clinicaltrials.gov, NCT02558543. Registered on September 24, 2015.
- Published
- 2021
15. Synergistic effects of starch nanoparticles and chitin nanofibers on the stability of oil-in-water Pickering emulsions
- Author
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Nuria C. Acevedo, Yeong-Sheng Lee, and Rodrigo Tarté
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Starch ,Sonication ,Nanofibers ,Nanoparticle ,Chitin ,01 natural sciences ,Analytical Chemistry ,chemistry.chemical_compound ,0404 agricultural biotechnology ,CHFS ,Particle Size ,Chemistry ,010401 analytical chemistry ,Water ,04 agricultural and veterinary sciences ,General Medicine ,040401 food science ,Pickering emulsion ,0104 chemical sciences ,Chemical engineering ,Nanofiber ,Emulsion ,Nanoparticles ,Emulsions ,Food Science - Abstract
Starch nanoparticles (SNPs) and Chitin nanofibers (ChFs) have been recognized to be effective for emulsion stabilization. Hence, the use of multiple solid nanoparticles seems to be a promising approach to improve emulsion stability. This work aims to study emulsions stabilized by a combination of SNPs and ChFs at different concentrations over storage time and different environmental conditions. Sonicated emulsions were found to have a significantly higher stability compared to non-sonicated emulsions. Furthermore, SNP/ChF-stabilized emulsions showed smaller droplet sizes and higher stability within a wide range of temperatures and pH, suggesting a synergistic effect between both particles as stabilizers. The addition of NaCl showed limited impact, particularly in concentrations up to 200 mM, on the improvement of the stability of emulsions. The combined use of SNPs and ChFs allowed emulsion stabilization at lower solid nanoparticles concentrations than when only either SNPs or ChFs were used.
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- 2021
16. Social Capital, Financial Literacy and Lending Behaviour of Farmers with Different Incomes--Evidence Based on CHFS 2015 Data
- Author
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Zhihao Guan
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Evidence-based practice ,media_common.quotation_subject ,Negative binomial distribution ,Geology ,Ocean Engineering ,Literacy ,Microdata (HTML) ,CHFS ,Economics ,Financial literacy ,Demographic economics ,China ,Water Science and Technology ,media_common ,Social capital - Abstract
Using microdata from the China Household Financial Survey Project (CHFS 2015), a negative binomial model is used to study the impact of social capital and financial literacy on the lending behavior of farmers with different incomes. The study found that the positive impact of social capital on the formal borrowing behavior of low- and middle-income farmers was significant, while the impact on informal borrowing behavior and both types of borrowing behavior of high-income farmers were not significant. Financial literacy has a significant positive effect on formal lending behavior only for high-income farmers. Financial literacy has a significant positive effect on formal lending behavior only for high-income farmers.
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- 2020
17. Prognostic factors for long-term results after condylar head fractures: A comparative study of non-surgical treatment versus open reduction and osteosynthesis
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Andreas Neff, Lisa-Marie Scheunemann, Andreas Kolk, Klaus-Dietrich Wolff, Herbert Stimmer, and Florian Grill
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medicine.medical_specialty ,Longitudinal study ,medicine.medical_treatment ,Condyle ,03 medical and health sciences ,Fracture Fixation, Internal ,0302 clinical medicine ,Quality of life ,Mandibular Fractures ,Occlusion ,medicine ,CHFS ,Internal fixation ,Humans ,Longitudinal Studies ,Reduction (orthopedic surgery) ,Osteosynthesis ,business.industry ,Mandibular Condyle ,030206 dentistry ,Prognosis ,Surgery ,Treatment Outcome ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Quality of Life ,Oral Surgery ,business - Abstract
This longitudinal study compared functional, anatomical, and quality of life (QoL) outcomes after closed reduction (CR) versus open reduction and internal fixation (ORIF) of condylar head fractures (CHFs). The aim was to determine predictability of results and to establish prognostic factors for poor outcomes, thus allowing therapeutic decision making between CR and ORIF. All fractures of the non-surgical group were treated by CR with maxillomandibular fixation (CR-MMF) according to an managed analogically. Morphological and functional results were acquired using axiography and clinical functional diagnostics, as well as MRI in problematic cases. Outcomes were compared with those of a collective of patients treated by ORIF with small fragment screws (SFS), according to a uniform standard. A total of 26 patients with 29 unilateral and bilateral CHFs of the non-surgical group were examined over a period of 28.5 months after completion of therapy and compared with a collective of 54 patients with 73 CHFs treated by ORIF. Statistically significant differences were found between both groups in protrusion and mediotrusion on the fracture side, in favour of ORIF. Significantly more patients in the ORIF group were symptom free in terms of the Helkimo dysfunction index and the RDC TMD compared with conservatively treated patients. Associations between Angle class and Helkimo dysfunction index, and between occlusion or number of teeth and pain after CT, could be confirmed. Given their respective indications, both treatment options demonstrated acceptable results in the majority of cases. However, for therapeutic decision making, it is crucial that the long-term results after CR are significantly less predictable. Our study showed only few positive prognostic factors for a stable functional outcome after CR such as isolated CHFs with stable occlusal conditions in younger patients (
- Published
- 2020
18. Enhanced flow boiling in microchannels integrated with supercapillary pinfin fences
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Wenming Li, Zuankai Wang, Yongping Chen, and Chen Li
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Fluid Flow and Transfer Processes ,Microchannel ,Materials science ,Capillary action ,Mechanical Engineering ,Boiling ,Heat transfer ,Flow (psychology) ,Evaporation ,CHFS ,Wetting ,Mechanics ,Condensed Matter Physics - Abstract
In conventional microchannels, the flow boiling performances are strongly affected by the highly transitional two-phase flow regimes. In this study, a novel capillary structure made from micro-pinfin fence has been explored and fabricated in microchannels to rectify the usually chaotic and unstable two-phase flows during boiling processes. A highly stable and efficient single annular two-phase flow regime is demonstrated experimentally and visually on two distinguished fluids: DI-water with high surface tension and completely wetting fluid of HFE-7100. More importantly, sustainable thin film evaporation has been established and resulted in the formation of a highly desirable V-shaped HTC curve, i.e., achieving high HTC at high working heat fluxes. This study aims at systematically characterizing flow boiling on this new microchannel configuration as well as the resulted superior stabilities of flow boiling. The experimental results show that the effective heat transfer rates are up to 92 kW/m2 K at G = 389 kg/m² s on water and 42 kW/m2 K at G = 231 kg/m² s on the HFE7100, respectively. Compared to performance in smooth microchannels, the enhancement of HTC is up to 300%. Without using inlet restrictors, CHFs are enhanced up to 830 W/cm2 and 216 W/cm2, corresponding to enhancements of 437% and 86% on water and HFE-7100, respectively.
- Published
- 2022
19. The suppression effect of easy-to-activate nucleation sites on the critical heat flux in pool boiling
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Dongyan Xu, Yi Liu, and Ming-Chang Lu
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Flow resistance ,Materials science ,Critical heat flux ,General Engineering ,Nucleation ,02 engineering and technology ,Boiling heat transfer ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,Chemical physics ,Boiling ,0103 physical sciences ,CHFS ,Wetting ,0210 nano-technology ,High heat - Abstract
We report experimental studies of the role of easy-to-activate nucleation sites in pool boiling on hybrid hydrophobic-hydrophilic surfaces. Microstructured surfaces with controlled wettability and nucleation sites are designed and fabricated to investigate their individual and collective effects on the boiling heat transfer performance. Our results reveal that excellent critical heat flux (CHF) up to 231.5 W/cm2 is attainable only when the surface has good wettability but is free of easy-to-activate nucleation sites. However, with the presence of easy-to-activate nucleation sites on the boiling surface, only limited CHFs can be achieved irrespective of the surface wettability, suggesting a suppression effect of nucleation sites on the CHF. Based on the previous experimental observation of the dynamic network-like wetting pattern at high heat fluxes, a wetting-deterioration mechanism is proposed to explain the suppression effect of easy-to-activate nucleation sites on the CHF. Easy-to-activate nucleation sites continuously generate bubbles that pose a large flow resistance for the liquid to wet the hot surface and thus lead to early dry-out.
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- 2018
20. Effect of heterogeneous wetting surface characteristics on flow boiling performance
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Kiyofumi Moriyama, Moo Hwan Kim, TaeJoo Kim, Dong In Yu, Hyun Sun Park, Jin Man Kim, and Hyunwoo Noh
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Fluid Flow and Transfer Processes ,Drag coefficient ,Materials science ,Critical heat flux ,020209 energy ,Mechanical Engineering ,Flow (psychology) ,02 engineering and technology ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,Heat flux ,Chemical physics ,Boiling ,0103 physical sciences ,Heat transfer ,0202 electrical engineering, electronic engineering, information engineering ,CHFS ,Wetting - Abstract
A hydrophobic surface promotes bubble nucleation due to hydrophobicity. Thus, a hydrophobic surface has a higher boiling heat transfer coefficient (BHTC) than a hydrophilic surface. In contrast, a hydrophilic surface supplies liquid to a heating surface. This mechanism enhances the critical heat flux (CHF). In this respect, there is a trade-off between a hydrophobic and a hydrophilic surface. In this study, we examined the effect of heterogeneous wetting surfaces on flow boiling performance. We designed four types of hydrophobic stripes; there are two directions, parallel and crossed to the flow, and the width (the pitch) of the hydrophobic stripes in each direction is 3 or 1 mm. In the macro-channel, the flow boiling performance on the surfaces depended on the patterns. The parallel striped surfaces had higher CHFs than the crossed striped surfaces. In addition, the narrow patterns in each direction had higher CHFs than the wide patterns. The difference in BHTC among the parallel striped surfaces was not large, but the difference in BHTC among the crossed striped surfaces was considerable. A visualization technique revealed that the merging and confinement of bubbles were key factors in explaining the boiling characteristics. Considering the drag coefficient and bubble breakup, we suggest appropriate designs of the hydrophobic pattern for the improvement of BHTC and CHF in the flow boiling performance.
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- 2018
21. Room temperature vanadium dioxide–carbon nanotube gas sensors made via continuous hydrothermal flow synthesis
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Michael Powell, Dustin Bauer, Ian D. Johnson, Gwyn P. Evans, Dougal P. Howard, Jawwad A. Darr, and Ivan P. Parkin
- Subjects
Nanotube ,Materials science ,Vanadium ,chemistry.chemical_element ,02 engineering and technology ,Carbon nanotube ,010402 general chemistry ,01 natural sciences ,Hydrothermal circulation ,law.invention ,law ,Materials Chemistry ,CHFS ,Electrical and Electronic Engineering ,Instrumentation ,Nanocomposite ,Metals and Alloys ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,Chemical engineering ,0210 nano-technology ,Carbon - Abstract
Vanadium dioxide–carbon nanotube (VO2–CNT) nanocomposite materials were produced via a continuous hydrothermal flow synthesis (CHFS) method. The composites were made in a single step from CHFS using dispersions of commercially available single-walled carbon nanotubes (SWCNTs) or multi-walled carbon nanotubes (MWCNTs) in a metal salt solution (aq.). The room temperature gas sensing characteristics of the VO2-CNT nanocomposites were investigated and compared with sensors of CHFS-made VO2 without added carbon. The VO2-CNT nanocomposites were found to display high sensitivity to H2O vapour, showing excellent potential as humidity sensors. Furthermore, p-type responses to ammonia gas were observed, with the VO2 (no carbon) sensors showing the largest response. Overall, surface composition and microstructure were found to greatly influence sensor responses to H2O vapour and NH3 gas.
- Published
- 2018
22. Rational Design of Covalent Heptazine Frameworks with Spatially Separated Redox Centers for High‐Efficiency Photocatalytic Hydrogen Peroxide Production
- Author
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Haifeng Lv, Xiaojun Wu, Jun Cheng, Hangxun Xu, Lei Wang, and Hao Cheng
- Subjects
Materials science ,Heptazine ,Mechanical Engineering ,Photochemistry ,Redox ,Catalysis ,Molecular engineering ,Artificial photosynthesis ,Chemical energy ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,CHFS ,Photocatalysis ,General Materials Science - Abstract
The redox reaction centers in natural organisms conducting oxygenic photosynthesis are well arranged in a physically separated manner to convert sunlight into chemical energy efficiently. Mimicking natural photosynthesis via precisely constructing oxidative and reductive reaction centers within photocatalysts is ideal for enhancing catalytic performances in artificial photosynthesis. In this study, new covalent heptazine frameworks (CHFs) with spatially separated redox centers are rationally designed for photocatalytic production of H2 O2 from water and oxygen without using any sacrificial agents. Both experimental and computational investigations indicate that the two-electron oxygen reduction reaction occurs on the heptazine moiety, whereas the two-electron water oxidation reaction occurs on the acetylene or diacetylene bond in the CHFs. This unique spatial separation feature is critical for enhancing charge separation and achieving efficient H2 O2 production. Meanwhile, the measured exciton binding energy of the diacetylene-containing polymer is merely 24 meV. Under simulated solar irradiation, the rationally designed CHFs can achieve a solar-to-chemical conversion efficiency of 0.78%, surpassing previously reported photocatalytic materials. This study establishes a molecular engineering approach to construct periodically arranged and spatially separated redox centers in single-component polymer photocatalysts, representing a hallmark to create more exciting polymer structures for photocatalysis moving forward. This article is protected by copyright. All rights reserved.
- Published
- 2021
23. Face-to-face crosslinking of graphdiyne and related carbon sheets toward integrated graphene nanoribbon arrays
- Author
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Xingfa Gao and Xiaomei Shen
- Subjects
Materials science ,Passivation ,Graphene ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Triple bond ,01 natural sciences ,0104 chemical sciences ,law.invention ,Unpaired electron ,Zigzag ,chemistry ,Nanoelectronics ,law ,CHFS ,General Materials Science ,0210 nano-technology ,Carbon - Abstract
The fabrication of graphene nanoribbon (GNR) arrays in which GNRs have precise widths and edge configurations is critical for the practical application of graphene-based materials into nanoelectronics. Using density functional theory calculations, we study and establish the structural and chemical relationship for three well-known carbon nanostructures: GNRs, graphdiyne and related carbon sheets, and carbon honeycomb frameworks (CHFs). Graphdiyne and related carbon sheets containing C C triple bonds can be chemically converted into the corresponding CHFs through the face-to-face crosslinking reactions of their triple bonds. The yielded CHFs are thermodynamically stable and intrinsically incorporate orderly-aligned GNR arrays. The incorporated GNRs have either armchair or zigzag edges, depending on the A- or Z-type crosslinking reactions the carbon sheets undergo. CHFs incorporating zigzag edged GNRs can have ferromagnetic ground states with unpaired electrons located at the zigzag edges. The edges of CHFs derived from graphdiyne-like carbon sheets, including unpaired electrons localized at zigzag edges, are chemically inert against O 2 and H 2 passivation. Therefore, the face-to-face crosslinking reactions of graphdiyne and related carbon sheets may serve as a promising way to design and synthesize 3D carbon architectures that integrate orderly-aligned and edge-protected GNR arrays with atomically precise structures.
- Published
- 2017
24. Upscaling permeability for reservoir-scale modeling in bioturbated, heterogeneous tight siliciclastic reservoirs: Lower Cretaceous Viking Formation, Provost Field, Alberta, Canada
- Author
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Diana M. Allen, Amy I. Hsieh, and James A. MacEachern
- Subjects
Hydrogeology ,010504 meteorology & atmospheric sciences ,Stratigraphy ,Tight oil ,Alberta canada ,Geology ,010502 geochemistry & geophysics ,Oceanography ,01 natural sciences ,Cretaceous ,Permeability (earth sciences) ,Geophysics ,CHFS ,Economic Geology ,Siliciclastic ,Geotechnical engineering ,Petrology ,Scale model ,0105 earth and related environmental sciences - Abstract
Variations in bed- and bedset-scale permeability in bioturbated siliciclastic rocks result in heterogeneity that is difficult to model at a reservoir scale. This paper presents a technique to upscale permeability, such that the permeabilities of the bioturbated zones are explicitly included in the upscaled values. Study of 28 cored wells of the Lower Cretaceous Viking Formation in the Provost Field, Alberta, Canada integrated sedimentologic and ichnologic features to define recurring bed-/bedset-scale hydrofacies (HFs) characterized by a geometric mean permeability derived from plug samples. Permeability was upscaled by calculating equivalent vertical and horizontal permeabilities for composite hydrofacies (CHFs) using expressions for layered media. The equivalency of the vertical and horizontal permeability values assigned to the CHFs against those of the HFs was evaluated using a simple numerical flow model. Reservoir-scale flow was then simulated along a hydrogeological cross-section that was constructed using the CHFs. The resulting flow regime was consistent with flows simulated using published permeability estimates from tight reservoir units of the Viking Formation. This approach has the potential, therefore, for upscaling permeability for reservoir-scale modeling in tight oil and gas reservoirs, and more broadly in reservoirs where permeability is highly variable at the bed/bedset scale.
- Published
- 2017
25. Flow boiling transient critical heat flux tests with stainless steel and FeCrAl: Transient correlation implementation, model calibration, and sensitivity analysis
- Author
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Soon K. Lee and Nicholas R. Brown
- Subjects
Fluid Flow and Transfer Processes ,Materials science ,Atmospheric pressure ,Critical heat flux ,Mechanical Engineering ,Pressurized water reactor ,Mechanics ,Condensed Matter Physics ,law.invention ,Subcooling ,Superheating ,law ,Volumetric heat capacity ,CHFS ,Transient (oscillation) - Abstract
Steady-state and transient internal-flow critical heat flux (CHF) experiments were carried out under two flow conditions, at atmospheric pressure, on 316 stainless steel (316-SS) and iron-chromium-aluminum (FeCrAl) tubes. Slow power transients at a low mass flow ( 300 k g / m 2 − s ) with very low subcooling ( X e = − 0.0054 ) generated premature CHFs, which were prevented by faster power transients and high mass flow ( 1 , 000 k g / m 2 − s ). The measured transient CHFs increased linearly with increasing power transients, compared with the steady-state CHF. Yet, the wall superheat at the CHFs decreased with faster power transients. Transient CHF correlations highlighting heterogeneous spontaneous nucleation were calibrated to the measured CHFs and compared with other existing correlations. Transient CHF multipliers were acquired from pool and flow boiling empirical CHF correlations that were generated. The multipliers were applied to the RELAP5-3D nuclear system code to analyze the discrepancies between the measured data and the predicted CHF and post-CHF behavior, which improved peak cladding temperature predictions by 24.6%. A variance-based global sensitivity study perturbing the experimental uncertainties and cladding material thermal properties showed the diminishing influence of flow boiling heat transfer with increasing power transients, highlighting the significance of the volumetric heat capacity for the cladding integrity during transients. Transient CHF correlations were applied to the most limiting design basis accident: a hot-zero-power reactivity-initiated accident on a generic pressurized water reactor RELAP5-3D model.
- Published
- 2021
26. Social Interaction and Entrepreneurial Intention: An Empirical Investigation for China
- Author
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Xiaolian Liu, Meng Chen, Isaac Kofi Mensah, and Xiaobing Huang
- Subjects
Entrepreneurship ,General Arts and Humanities ,05 social sciences ,Social Sciences ,General Social Sciences ,Social relation ,AZ20-999 ,0502 economics and business ,Economics ,CHFS ,History of scholarship and learning. The humanities ,050211 marketing ,Classical economics ,China ,050203 business & management - Abstract
This article investigates the impact of social interactions on household entrepreneurial behavior using the data of the China Family Finance Survey (CHFS) in 2015. The results show that social interaction has a positive influence on household entrepreneurship. More social interactions are associated with a higher likelihood of participating in both business and agricultural entrepreneurship. Moreover, the positive effect of social interaction on entrepreneurship increases with the relaxation of financial constraints faced by households. Finally, entrepreneurship is more motivated by social interaction for women than men. The results obtained in the benchmark are testified to be reliable after addressing the potential endogeneity of social interactions and using a different regression method.
- Published
- 2021
27. Time effect on wetting transition of smart surface and prediction of the wetting transition for critical heat flux in pool boiling
- Author
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Kiyofumi Moriyama, TaeJoo Kim, Dong In Yu, Hyun Sun Park, Moo Hwan Kim, and Jin Man Kim
- Subjects
Fluid Flow and Transfer Processes ,Materials science ,Critical heat flux ,020209 energy ,Mechanical Engineering ,Thermodynamics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Contact angle ,Heat flux ,Wetting transition ,Boiling ,0202 electrical engineering, electronic engineering, information engineering ,CHFS ,Wetting ,0210 nano-technology ,Nucleate boiling - Abstract
A smart surface that is a TiO 2 -coated surface (TCS) is a hydrophobic surface initially, but becomes a hydrophilic surface when heated. Therefore, such a surface can be used to enhance both boiling heat transfer (BHT) and critical heat flux (CHF) in pool boiling. In the present study, the time effect of the wetting transition of TCS was focused on. The CHF on TCS was enhanced more when the holding time of the heat flux in high-temperature regime was increased. By observing changes in contact angles on TCS through heat treatment in air, it was found that the wetting transition was affected not only by the temperature, but also by the time. Thus, a variation of the receding contact angle was correlated in the form of an exponential function. The suggested empirical correlation includes temperature and time, and it describes the transition of the receding contact angle. The correlation was also used to predict the CHF on TCS in pool boiling. As a result, CHFs on TCS could be explained using the correlation.
- Published
- 2017
28. Nano-grained SnO2/Li4Ti5O12 composite hollow fibers via sol-gel/ electrospinning as anode material for Li- ion batteries
- Author
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Tata N. Rao, Neha Y. Hebalkar, Anulekha K. Haridas, and Chandra Shekhar Sharma
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,Materials Science (miscellaneous) ,Analytical chemistry ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Lithium-ion battery ,Electrospinning ,0104 chemical sciences ,Dielectric spectroscopy ,Anode ,chemistry.chemical_compound ,Fuel Technology ,Nuclear Energy and Engineering ,chemistry ,X-ray photoelectron spectroscopy ,Chemical engineering ,CHFS ,Lithium ,0210 nano-technology ,Lithium titanate - Abstract
The high capacity of SnO2 (tin oxide) and high rate capability of Li4Ti5O12 (lithium titanate, LTO) were pooled together for engineering a composite Li ion anode material in hollow fiber edifice by sol-gel/electrospinning. The electrospun porous precursor composite hollow fibers (CHFs) were heat treated either in air (SnO2/LTOA) or argon (SnO2/LTOAr) atmosphere to control grain size, porosity and presence of Ti3+ content. The morphological study performed using Field Emission Scanning Electron Microscopy and Transmission Electron Microscopy revealed smaller grain size (5–10 nm) for SnO2/LTOAr CHFs. Further, X-Ray Diffraction and X- Ray Photoelectron Spectroscopy studies illustrated a significant variation in the crystallinity and the elemental oxidation states in these CHFs respectively. Brunauer-Emmett-Teller measurements exposed the presence of high surface area and pore volume in SnO2/LTOAr CHFs. Further, the half-cell galvanostatic charge-discharge performances of SnO2/LTOAr CHFs at 1 C rate revealed a stable specific capacity of 300 mA h/g for 110 cycles with 90% capacity retention. The stable and high capacity of SnO2/LTOAr CHFs were corroborated to the presence of smaller grain size, high porosity and conductive Ti3+ providing faster lithium ion diffusion when compared to SnO2/LTOA CHFs. Electrochemical Impedance Spectroscopy study confirmed low impedances in SnO2/LTOAr CHFs due to low charge transfer and electrolyte resistances. Moreover, Li ion full-cell study performed using LiFePO4 (LFP) cathode (3 V), delivered a specific capacity of 230 mAh/g at 0.1 C rates. The excellent electrochemical performance of SnO2/LTOAr CHFs in both half-cell and full-cell modes illustrated the significance of sol-gel/electrospinning in synthesizing high performance Lithium ion batteries in a cost effective and scalable way.
- Published
- 2017
29. Effects of outlet subcoolings and heat generation rates on transient critical heat flux for subcooled flow boling of water in a vertical tube
- Author
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Koichi Hata, Qiusheng Liu, Katsuya Fukuda, and Makoto Shibahara
- Subjects
Fluid Flow and Transfer Processes ,Materials science ,Critical heat flux ,020209 energy ,Flow (psychology) ,Thermodynamics ,02 engineering and technology ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,Subcooling ,Flow conditions ,Flow velocity ,Heat generation ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,CHFS ,Tube (fluid conveyance) - Abstract
Critical heat fluxes (CHFs) for subcooled flow boiling of water in a vertical tube due to steady and exponentially heat inputs were measured. The platinum tube with an inner diameter of 2.0 mm and a length of 94.8 mm was placed vertically in the experimental water loop. The upward flow velocity was approximately 2.5 m/s and the outlet subcooling ranged from 18 to 48 K. The heat generation rate was varied exponentially to investigate the effect of e-folding time on the CHFs. As an experimental result, the CHFs increased with a decrease in the e-folding time. When the e-folding times were longer, the CHFs were almost constant, whereas the CHFs increased for shorter e-folding times. The CHFs were independent on outlet subcoolings at low flow conditions. Moreover, it was considered that the explosive-like CHF occurred when the inner surface temperature of the tube exceeded the lower limit of heterogeneous spontaneous nucleation (HSN) temperature.
- Published
- 2017
30. Correlation of high critical heat flux during flow boiling for water in a small tube at various subcooled conditions
- Author
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Koichi Hata, Katsuya Fukuda, Makoto Shibahara, and Qiusheng Liu
- Subjects
Materials science ,Critical heat flux ,020209 energy ,General Chemical Engineering ,Thermodynamics ,02 engineering and technology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Subcooling ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Flow velocity ,Boiling ,0202 electrical engineering, electronic engineering, information engineering ,CHFS ,Weber number ,Tube (fluid conveyance) ,Nucleate boiling - Abstract
High critical heat fluxes (CHFs) for subcooled boiling of water in a small tube were investigated experimentally. A platinum tube with an inner diameter of 1.0 mm and a length of 40.9 mm was used in the experiment. The upward flow velocity, the subcooling of water, and the outlet pressure of the experimental tube were varied to enable a parametric study of the CHFs. The flow velocity ranged from 9 to 13 m/s and the inlet subcooling ranged from 69 to 148 K. The boiling number decreased with increasing Weber number. The boiling number is also dependent on a non-dimensional parameter and the density ratio of liquid to vapor. A correlation for the high CHF of the small tube was obtained based on the experimental data. Finally, the high CHF correlation was evaluated using the CHF data obtained by other researchers.
- Published
- 2017
31. Rapid synthesis of graphene quantum dots using a continuous hydrothermal flow synthesis approach
- Author
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Suela Kellici, David J. Morgan, Tobias Heil, Paolo Coppo, John Acord, Nicholas P. Power, and Basudeb Saha
- Subjects
Materials science ,Graphene ,General Chemical Engineering ,Nanotechnology ,02 engineering and technology ,General Chemistry ,Limiting ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Fluorescence ,Hydrothermal circulation ,0104 chemical sciences ,law.invention ,Flow (mathematics) ,Quantum dot ,law ,CHFS ,QD ,Particle size ,0210 nano-technology - Abstract
A rapid, continuous, environmentally benign and innovative approach is employed for the synthesis of green fluorescent graphene quantum dots (GQD) with low cytotoxicity by utilising a Continuous Hydrothermal Flow Synthesis (CHFS) process as an efficient cutting tool in combination with calix[4]arene tetrasulfonic acid (SCX4) as an effective particle size limiting agent.
- Published
- 2017
32. Steady and transient critical heat flux for subcooled water in a mini channel
- Author
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Katsuya Fukuda, Koichi Hata, Makoto Shibahara, and Qiusheng Liu
- Subjects
Fluid Flow and Transfer Processes ,geography ,geography.geographical_feature_category ,Materials science ,Critical heat flux ,020209 energy ,Mechanical Engineering ,Flow (psychology) ,Thermodynamics ,02 engineering and technology ,Condensed Matter Physics ,Inlet ,01 natural sciences ,010305 fluids & plasmas ,Subcooling ,Flow velocity ,Heat generation ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,CHFS ,Tube (fluid conveyance) - Abstract
The transient critical heat fluxes (CHFs) were measured for water flowing in a small vertical tube with exponentially increasing heat inputs. A stainless steel tube (SUS 304) with an inner diameter of 1.0 mm and a length of 47.4 mm was used as a test tube, which was mounted vertically in the experimental water loop. In the experiment, the upward flow velocity ranged from 9.4 to 13.4 m/s and the inlet subcooling ranged from 85 to 145 K. The heat generation rate was exponentially increased as a function of Q0exp(t/τ). The period of the heat generation rate was ranged from 82 ms to 30 s. Experimental results indicated that the CHFs increased with decreasing period of heat generation rates and increasing flow velocity. For shorter periods of the heat generation rate, the CHFs were significantly higher. The CHFs were affected by the period of the heat generation rate and flow velocities. The empirical correlations of the transient CHFs for the small tube were obtained based on the experimental data.
- Published
- 2017
33. Si-doped zinc oxide transparent conducting oxides; nanoparticle optimisation, scale-up and thin film deposition
- Author
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Claire J. Carmalt, Peter Marchand, Dougal P. Howard, Ivan P. Parkin, and Jawwad A. Darr
- Subjects
Spin coating ,Materials science ,Dopant ,Metallurgy ,Analytical chemistry ,Oxide ,Nanoparticle ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Zinc ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Electrical resistivity and conductivity ,Materials Chemistry ,CHFS ,Thin film ,0210 nano-technology - Abstract
Silicon-doped zinc oxide, Zn1−xSixOy, transparent conducting oxide nanoparticles were prepared using a laboratory scale (production rate of 60 g h−1) continuous hydrothermal flow synthesis (CHFS) process in the dopant range 0.25 to 3.0 at% Si. The resistivity of the materials was assessed as pressed heat-treated pellets, revealing that the sample with the lowest resistivity (3.5 × 10−2 Ω cm) was the 0.25 at% Si doped ZnO sample. The synthesis of this optimum composition was then scaled up to 350 g h−1 using a larger pilot plant CHFS process. Spin coating of a slurry of the resulting nanopowder made on the pilot plant, followed by an appropriate heat-treatment, produced a thin film with an optical transmission >80% and a low resistivity of 2.4 × 10−3 Ω cm, with a carrier concentration of 1.02 × 1020 cm−3 and a mobility of 11 cm2 V−1 s−1. This is a factor of almost twenty times improvement in the resistivity versus the analogous pressed, heat-treated pellet.
- Published
- 2017
34. Reliability, Validity, and Sensitivity to Change of the Cochin Hand Functional Disability Scale and Testing the New 6-Item Cochin Hand Functional Disability Scale in Systemic Sclerosis
- Author
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Răzvan Capotă, Victor Stoica, Hermina A. Györfi, Carina Mihai, Ana Maria Gheorghiu, A. E. Matei, Mihai Bojinca, and Raida Oneaţă
- Subjects
Adult ,Male ,medicine.medical_specialty ,Intraclass correlation ,Severity of Illness Index ,Scleroderma ,03 medical and health sciences ,Disability Evaluation ,Young Adult ,0302 clinical medicine ,Rheumatology ,Cronbach's alpha ,Interquartile range ,Surveys and Questionnaires ,medicine ,CHFS ,Humans ,030212 general & internal medicine ,skin and connective tissue diseases ,030203 arthritis & rheumatology ,Scleroderma, Systemic ,business.industry ,Construct validity ,Reproducibility of Results ,Anthropometry ,medicine.disease ,Hand ,Scale (social sciences) ,Physical therapy ,Female ,business - Abstract
Systemic sclerosis (SSc) is a chronic autoimmune disease causing complex hand disability. A reliable tool for hand function assessment in SSc is the Cochin Hand Functional Disability Scale (CHFS). More recently, a short-form CHFS of 6 items (CHFS-6) has been developed. Objectives To validate the CHFS and the new CHFS-6 in Romanian patients with SSc. Patients and methods Consecutive patients with SSc who completed the CHFS were included. All patients were assessed according to the recommendations of the European Scleroderma and Research Trials and also completed the Scleroderma Health Assessment Questionnaire and the Hand Mobility in Scleroderma questionnaire. Finger range-of-motion distances were measured. Results Seventy patients, 63 female and 7 male patients (age median, 53.0 years; interquartile range [IQR], 21.0 years), were included. Twenty seven had diffuse cutaneous involvement (dcSSc). Median CHFS and CHFS-6 at baseline were 25.0 (IQR, 37.0) and 8.0 (IQR, 13.0), respectively.The internal consistency (Cronbach α = 0.96, respectively, 0.90, in all 70 patients) and test-retest reliability (intraclass correlation coefficient = 0.98 for both, in 38 patients) of both CHFS and CHFS-6 were excellent. The CHFS-6 had a very high correlation with the CHFS. There were moderate to good correlations with Hand Mobility in Scleroderma, Scleroderma Health Assessment Questionnaire, and the anthropometric measurements (construct validity). In patients with early dcSSc with a second evaluation, we found good to moderate sensitivity to change (standardized response mean of 0.8 and effect size of 0.4 for CHFS, and standardized response mean of 1.1 and effect size of 0.6 for CHFS-6). Conclusions The CHFS and CHFS-6 are valid and easy-to-use tools for hand involvement in SSc, which can be used in clinical or research setting.
- Published
- 2019
35. Condylar remodeling after osteosynthesis of fractures of the condylar head or close to the temporomandibular joint
- Author
-
Andreas Neff, Jonas Apitzsch, Ingo Fischer, Linda Skroch, Felicián Kozolka, and Axel Meisgeier
- Subjects
Cone beam computed tomography ,medicine.medical_treatment ,Implant removal ,Condyle ,03 medical and health sciences ,Fracture Fixation, Internal ,0302 clinical medicine ,stomatognathic system ,Mandibular Fractures ,medicine ,CHFS ,Internal fixation ,Humans ,Reduction (orthopedic surgery) ,Orthodontics ,Osteosynthesis ,Temporomandibular Joint ,business.industry ,Mandibular Condyle ,030206 dentistry ,Temporomandibular joint ,Open Fracture Reduction ,medicine.anatomical_structure ,Treatment Outcome ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Surgery ,Oral Surgery ,business - Abstract
Condylar head fractures (CHFs) are increasingly treated by open reduction and internal fixation (ORIF). However, there are no reports on the three-dimensional postoperative volumetric transformation of the condyle, especially with regard to fragmented cases. Protruding hardware can lead to severe complications, so the goal of this study was to examine the amount of condylar bony resorption occurring after ORIF.Included were surgically treated CHFs with eligible cone beam computer tomography (CBCT) datasets immediately after ORIF (T1) and after implant removal (T2), plus fractures of the condylar neck and base as a reference. 2D vertical and 3D volume changes of the condylar head after ORIF of CHFs were evaluated by CBCT datasets transformed into 3D models for 3D volumetric assessment using Slicer freeware.Among a total of 50 fractures (38 patients), including 41 CHFs (ORIF with titanium positional screws, including 15 minor and 12 major fragmented cases) plus nine extracapsular fractures (eight upper neck and one base fracture), postoperative condylar volume decreased by a mean of 0.27 cm³ (median 0.25 cm³; SD 0.23 cm³) or 16% (median 14%; SD 11%). Major fragmented CHFs showed significantly higher resorption rates (p 0.001, range 8-42%). Age correlated with a decrease in condylar volume (mean 2.4% per 10 years of age, (p = 0.011). No significant correlation could be established between loss of condylar volume and fracture localization. A protrusion of metallic implants was seen in 20% of the assessed cases.Due to substantial volume changes of the condylar head occurring after ORIF, protrusion of implants (both metallic and resorbable) needs to be taken into consideration. An early removal of metallic ostheosyntesis material (around 4 months after ORIF) is strongly recommended to avoid adverse short- and long-term effects.
- Published
- 2019
36. Enhanced pool boiling of dielectric and highly wetting liquids - a review on enhancement mechanisms
- Author
-
Ali Sadeghianjahromi, Chi-Chuan Wang, Hafiz Muhammad Ali, and Uzair Sajjad
- Subjects
Materials science ,020209 energy ,General Chemical Engineering ,Nanotechnology ,02 engineering and technology ,Dielectric ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,010406 physical chemistry ,0104 chemical sciences ,Coolant ,Nanofluid ,Natural circulation ,Boiling ,Nano ,0202 electrical engineering, electronic engineering, information engineering ,CHFS ,Wetting - Abstract
Direct cooling with inert and hazards free dielectric liquids may well become the method of choice for thermal management of future electronic systems. Owing to the efficiency of phase-change process and the ease of natural circulation, pool boiling is of great interest for this application. The present review consolidates a large number of pool boiling experimental data for dielectric and other highly wetting liquids subject to engineered surfaces with elaborating the related augmentation mechanisms. Potential micro/nano engineered surfaces are categorized into one-dimensional (either CHF or HTC enhancing) and two-dimensional (both CHF and HTC) enhancement surfaces. The enhancement mechanisms along with the bubble dynamics of these enhanced surfaces are discussed briefly. Furthermore, a general classification of electronics coolants (dielectric, non-dielectric, and nanofluids) along with their thermophysical properties is made; especially the problems associated with the dielectric liquids are discussed. Finally, the potential mechanisms for higher HTCs and CHFs are identified.
- Published
- 2020
37. Nanotechnologies for thermophysics: Heat transfer and crisis phenomena at boiling
- Author
-
Vladimir Serdyukov, Aleksandr N. Pavlenko, and Anton Surtaev
- Subjects
Materials science ,General Engineering ,Nanotechnology ,02 engineering and technology ,Boiling heat transfer ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,Nanofluid ,Boiling ,0103 physical sciences ,Heat transfer ,Thermophysics ,CHFS ,General Materials Science ,Wetting ,0210 nano-technology ,Porosity - Abstract
This article reviews the recent research on the effect of micro- and nanomodified surfaces and coatings on heat-transfer enhancement and critical heat fluxes (CHFs) at boiling. The first part contains a detailed review of papers devoted to investigation of boiling heat transfer and crisis phenomena in nanofluids. The interest in this field is caused by a significant increase in the CHF value at boiling of nanofluid due to the sedimentation of nanoparticles and altered wettability and porosity of heat-releasing surfaces. Possible mechanisms of the increase in CHF and the main disadvantages of using nanofluids in practical applications are discussed. The second part is devoted to various techniques that are used to create micro- and nanostructured heat-exchange surfaces and to research the effect of modified heaters on boiling performance.
- Published
- 2016
38. Using Optimal Test Assembly Methods for Shortening Patient-Reported Outcome Measures: Development and Validation of the Cochin Hand Function Scale-6: A Scleroderma Patient-Centered Intervention Network Cohort Study
- Author
-
Janet L. Poole, Dinesh Khanna, Daphna Harel, Brett D. Thombs, Susan J. Bartlett, Marie-Eve Carrier, Anne A. Schouffoer, Joep Welling, Vanessa L. Malcarne, Luc Mouthon, Linda Kwakkenbos, Maureen Sauve, Alexander W. Levis, Serge Poiraudeau, and Cornelia H. M. van den Ende
- Subjects
030203 arthritis & rheumatology ,medicine.medical_specialty ,business.industry ,Confirmatory factor analysis ,03 medical and health sciences ,0302 clinical medicine ,Rheumatology ,Convergent validity ,Cronbach's alpha ,Item response theory ,Cohort ,Physical therapy ,CHFS ,Medicine ,Patient-reported outcome ,030212 general & internal medicine ,business ,Cohort study - Abstract
Objective: To develop and validate a short form of the Cochin Hand Function Scale (CHFS), which measures hand disability, for use in systemic sclerosis, using objective criteria and reproducible techniques. Methods: Responses on the 18-item CHFS were obtained from English-speaking patients enrolled in the Scleroderma Patient-Centered Intervention Network Cohort. CHFS unidimensionality was verified using confirmatory factor analysis, and an item response theory model was fit to CHFS items. Optimal test assembly (OTA) methods identified a maximally precise short form for each possible form length between 1 and 17 items. The final short form selected was the form with the least number of items that maintained statistically equivalent convergent validity, compared to the full-length CHFS, with the Health Assessment Questionnaire (HAQ) disability index (DI) and the physical function domain of the 29-item Patient-Reported Outcomes Measurement Information System (PROMIS-29). Results: There were 601 patients included. A 6-item short form of the CHFS (CHFS-6) was selected. The CHFS-6 had a Cronbach's alpha of 0.93. Correlations of the CHFS-6 summed score with HAQ DI (r = 0.79) and PROMIS-29 physical function (r = -0.54) were statistically equivalent to the CHFS (r = 0.81 and r = -0.56). The correlation with the full CHFS was high (r = 0.98). Conclusion: The OTA procedure generated a valid short form of the CHFS with minimal loss of information compared to the full-length form. The OTA method used was based on objective, prespecified criteria, but should be further studied for viability as a general procedure for shortening patient-reported outcome measures in health research.
- Published
- 2016
39. Mapping Structure-Composition-Property Relationships in V- and Fe-Doped LiMnPO4 Cathodes for Lithium-Ion Batteries
- Author
-
Ian D. Johnson, Rohit Bhagat, Melanie Loveridge, and Jawwad A. Darr
- Subjects
Doping ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,General Chemistry ,General Medicine ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Lithium-ion battery ,Cathode ,0104 chemical sciences ,Nanomaterials ,Ion ,law.invention ,chemistry ,Chemical engineering ,law ,CHFS ,Hydrothermal synthesis ,Lithium ,0210 nano-technology - Abstract
A series of LiMn1–x–yFexVyPO4 (LMFVP) nanomaterials have been synthesized using a pilot-scale continuous hydrothermal synthesis process (CHFS) and evaluated as high voltage cathodes in Li-ion batteries at a production rate of 0.25 kg h–1. The rapid synthesis and screening approach has allowed the specific capacity of the high Mn content olivines to be optimized, particularly at high discharge rates. Consistent and gradual changes in the structure and performance are observed across the compositional region under investigation; the doping of Fe at 20 at% (with respect to Mn) into lithium manganese phosphate, rather than V or indeed codoping of Fe and V, gives the best balance of high capacity and high rate performance.
- Published
- 2016
40. Layer-by-layer carbon nanotube coatings for enhanced pool boiling heat transfer on metal surfaces
- Author
-
Uiju Jeong, Sung Joong Kim, Wonjoon Choi, Seunghyeon Lee, Gwang Hyeok Seo, Sang Jun Lee, and Sanghyeok Lee
- Subjects
Materials science ,Critical heat flux ,Layer by layer ,02 engineering and technology ,General Chemistry ,Carbon nanotube ,Substrate (electronics) ,Adhesion ,Heat transfer coefficient ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Coating ,law ,CHFS ,engineering ,General Materials Science ,Composite material ,0210 nano-technology - Abstract
Micro/nanotextured coatings have enabled the manipulation of thermal characteristics in pool boiling heat transfer such as the heat transfer coefficient (HTC) and critical heat flux (CHF) because of the ability to optimize bubble formations and departures. However, fabricating such coatings on substrates involves high cost-bulky setup, and is limited by the materials and adhesion properties. Herein, we report layer-by-layer (LbL)-assembled polyethylenimine (PEI)-multi-walled carbon nanotube (MWCNTs) coatings on stainless steel (SS316) to enhance HTC and CHF in pool boiling heat transfer. LbL-assembled PEI-MWCNTs coatings (10, 20, 40 bi-layers) on SS316 were fabricated, whereas bare SS316 substrate and vacuum-filtered MWCNTs coating were prepared as controls. Because of the nano-cavities and the inner-nanoporous structures, LbL coatings showed significant enhancement of HTCs and CHFs compared to bare SS316. Furthermore, denser networks of MWCNTs due to electrostatic bonding and hydrophilic nature of PEI in the LbL coatings could enhance the HTCs and CHFs compared to vacuum-filtered MWCNTs coating. LbL-assembled PEI-MWCNTs of 20 bi-layers showed the highest improvement in HTC, whereas the 40 bi-layers coatings achieved the best enhancement ratio of CHF, (∼147%). Further development of the LbL-assembled coatings on metal surfaces would enable potential applications for thermal management, from micro/nanoscale platforms to macroscale systems.
- Published
- 2016
41. Nine traditional Chinese herbal formulas for the treatment of depression: an ethnopharmacology, phytochemistry, and pharmacology review
- Author
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Zhao-yu Yang, Dandan Feng, Tao Tang, Zian Xia, Yun Wang, Chunhu Zhang, Shu Yang, Piao Zheng, Xiangping Lin, and Yang Wang
- Subjects
pharmacological bioactivity ,medicine.medical_specialty ,antidepressant ,Traditional medicine ,business.industry ,Alternative medicine ,Chinese herbal formula ,Review ,Traditional Chinese medicine ,Pharmacology ,Placebo ,Clinical trial ,traditional Chinese medicine ,03 medical and health sciences ,0302 clinical medicine ,030220 oncology & carcinogenesis ,Pill ,CHFS ,medicine ,phytochemistry ,Antidepressant ,Adverse effect ,business ,030217 neurology & neurosurgery - Abstract
Depression is a major mental disorder, and is currently recognized as the second-leading cause of disability worldwide. However, the therapeutic effect of antidepressants remains unsatisfactory. For centuries, Chinese herbal formulas (CHFs) have been widely used in the treatment of depression, achieving better therapeutic effects than placebo and having fewer side effects than conventional antidepressants. Here, we review the ethnopharmacology, phytochemistry, and pharmacology studies of nine common CHFs: "banxia houpo" decoction, "chaihu shugansan", "ganmaidazao" decoction, "kaixinsan", "shuganjieyu" capsules, "sinisan", "wuling" capsules, "xiaoyaosan", and "yueju". Eight clinical trials and seven meta-analyses have supported the theory that CHFs are effective treatments for depression, decreasing Hamilton Depression Scale scores and showing few adverse effects. Evidence from 75 preclinical studies has also elucidated the multitarget and multipathway mechanisms underlying the antidepressant effect of the nine CHFs. Decoctions, capsules, and pills all showed antidepressant effects, ranked in descending order of efficacy. According to traditional Chinese medicine theory, these CHFs have flexible compatibility and mainly act by soothing the liver and relieving depression. This review highlights the effective treatment choices and candidate compounds for patients, practitioners, and researchers in the field of traditional Chinese medicine. In summary, the current evidence supports the efficacy of CHFs in the treatment of depression, but additional large-scale randomized controlled clinical trials and sophisticated pharmacology studies should be performed.
- Published
- 2016
42. Combined EXAFS, XRD, DRIFTS, and DFT Study of Nano Copper-Based Catalysts for CO2 Hydrogenation
- Author
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Abhishek Kumar Mishra, Roberto Lanza, Jawwad A. Darr, Nathan Hollingsworth, Marco Bersani, Nora H. de Leeuw, Christopher Hardacre, S. F. Rebecca Taylor, Husn-Ubayda Islam, and Kalyani Gupta
- Subjects
Extended X-ray absorption fine structure ,Diffuse reflectance infrared fourier transform ,Chemistry ,Analytical chemistry ,Nanoparticle ,02 engineering and technology ,General Chemistry ,Atmospheric temperature range ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,Chemical engineering ,CHFS ,QD ,Density functional theory ,Formate ,0210 nano-technology - Abstract
Highly monodispersed CuO nanoparticles (NPs) were synthesized via continuous hydrothermal flow synthesis (CHFS) and then tested as catalysts for CO2 hydrogenation. The catalytic behavior of unsupported 11 nm sized nanoparticles from the same batch was characterized by diffuse reflectance infrared fourier transform spectroscopy (DRIFTS), extended X-ray absorption fine structure (EXAFS), X-ray diffraction (XRD), and catalytic testing, under CO2/H2 in the temperature range 25–500 °C in consistent experimental conditions. This was done to highlight the relationship among structural evolution, surface products, and reaction yields; the experimental results were compared with modeling predictions based on density functional theory (DFT) simulations of the CuO system. In situ DRIFTS revealed the formation of surface formate species at temperatures as low as 70 °C. DFT calculations of CO2 hydrogenation on the CuO surface suggested that hydrogenation reduced the CuO surface to Cu2O, which facilitated the formation of formate. In situ EXAFS supported a strong correlation between the Cu2O phase fraction and the formate peak intensity, with the maxima corresponding to where Cu2O was the only detectable phase at 170 °C, before the onset of reduction to Cu at 190 °C. The concurrent phase and crystallite size evolution were monitored by in situ XRD, which suggested that the CuO NPs were stable in size before the onset of reduction, with smaller Cu2O crystallites being observed from 130 °C. Further reduction to Cu from 190 °C was followed by a rapid decrease of surface formate and the detection of adsorbed CO from 250 °C; these results are in agreement with heterogeneous catalytic tests where surface CO was observed over the same temperature range. Furthermore, CH4 was detected in correspondence with the decomposition of formate and formation of the Cu phase, with a maximum conversion rate of 2.8% measured at 470 °C (on completely reduced copper), supporting the indication of independent reaction pathways for the conversion of CO2 to CH4 and CO that was suggested by catalytic tests. The resulting Cu NPs had a final crystallite size of ca. 44 nm at 500 °C and retained a significantly active surface.
- Published
- 2016
43. Pilot plant scale continuous hydrothermal synthesis of nano-titania; effect of size on photocatalytic activity
- Author
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Christopher J. Tighe, Jawwad A. Darr, Neel M. Makwana, Robert I. Gruar, and Paul F. McMillan
- Subjects
Materials science ,Mechanical Engineering ,Inorganic chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Boric acid ,chemistry.chemical_compound ,Pilot plant ,chemistry ,Chemical engineering ,Mechanics of Materials ,Titanium dioxide ,CHFS ,Hydrothermal synthesis ,General Materials Science ,Crystallite ,0210 nano-technology ,Superheated water ,Photocatalytic water splitting - Abstract
A pilot plant scale continuous hydrothermal flow synthesis (CHFS) process was used to control the crystallite size (and surface area) for nano-TiO2 in the range ca. 5–18 nm. In CHFS, a room temperature solution of titanium oxysulfate (and boric acid) was mixed in flow with a feed of potassium hydroxide solution (at 24.1 MPa), and then this combined stream was mixed with a flow of superheated water (at 400 °C and 24.1 MPa) in a confined jet mixer. Nano-TiO2 particles were formed instantly and then cooled inline before being collected as a slurry from the exit of the process. It was observed that the boric acid concentration in the precursor feed affected reaction pH, which in turn, determined the average crystallite size of the nano-TiO2; as the pH increased, larger crystallites were obtained. The nanomaterials were evaluated in a sacrificial photocatalytic water splitting system (hydrogen evolution), and it was found that TiO2 prepared under mildly acidic conditions, yielded the highest photoactivity.
- Published
- 2016
44. Consumption Concept and People’s Choice of Financial Assets: A Research Based on CHFS 2011
- Author
-
Pan Zhu
- Subjects
Consumption (economics) ,Finance ,business.industry ,Research based ,CHFS ,Business - Abstract
As an important part of culture, consumption concept can not only influence people’s attitude about worth and wealth, but also their economical behavior and financial decisions. Based on CHFS2011 database, this paper analyzes the relationship between consumption concept and people’s choice of financial assets. The empirical results of this paper show that those who hold forward and positive consumption concept are more willing to hold risk assets than those who hold traditional and conservative consumption concept.
- Published
- 2016
45. Research on the Influencing Factors of Household Financial Asset Selection Empirical Evidence from China Financial Survey (CHFS) Data
- Author
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Jin Mengyuan and Yang Jie
- Subjects
Financial economics ,Financial asset ,CHFS ,Household finance ,Business ,Empirical evidence ,China ,Selection (genetic algorithm) - Published
- 2018
46. Greener synthesis of propylene carbonate using graphene-inorganic nanocomposite catalysts
- Author
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Martin Vickers, Suela Kellici, Basudeb Saha, Tobias Heil, Adegboyega Isaac Adeleye, and David J. Morgan
- Subjects
Zirconium nitrate ,Materials science ,Nanocomposite ,Inorganic chemistry ,General Chemistry ,Heterogeneous catalysis ,Catalysis ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Propylene carbonate ,CHFS ,Hydrothermal synthesis ,Propylene oxide - Abstract
Continuous hydrothermal flow synthesis (CHFS) has been employed as rapid and cleaner route for the synthesis of a novel, highly efficient graphene-inorganic heterogeneous catalyst, denoted as Ce–La–Zr–GO nanocomposite. The catalyst was used for the direct synthesis of propylene carbonate (PC) from the cycloaddition of carbon dioxide (CO2) and propylene oxide (PO) in the absence of any organic solvents. Ce–Zr–La–GO nanocomposite was synthesized from pre-mixed aqueous solution of cerium, lanthanum, zirconium nitrate and GO (synthesized via conventional Hummers method) under alkaline conditions using the CHFS reactor. The resulting nanocomposite catalyst was heat-treated at various temperatures (773, 973 and 1173 K) and their catalytic properties were assessed. The as-prepared and the corresponding heat-treated catalysts were characterized using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Brunauer–Emmett–Teller (BET) surface area measurements. Effect of various parameters such as heat-treatment temperature, catalyst loading, CO2 pressure, reaction time and temperature was systematically studied to determine the optimum reaction conditions. The optimum reaction condition for the direct synthesis of PC was found at 443 K, 70 bar and 10% (w/w) catalyst loading. Catalyst reusability study was also conducted to investigate the long life stability for the synthesis of PC and it was found that the catalyst could be reused several times without losing it catalytic activity. These studies revealed that Ce–Zr–La–GO nanocomposite catalyst showed high catalytic activity as compared to other reported heterogeneous catalysts with the conversion of PO, selectivity and yield of PC.
- Published
- 2015
47. Trace metals removal through a catalytic hybrid filter during cofiring of different biomass waste materials
- Author
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F.J. García-Frutos, D. Sanz, M.L. Contreras, A. Bahillo, and R. Ramos
- Subjects
Compost ,General Chemical Engineering ,Organic Chemistry ,Energy Engineering and Power Technology ,Electrostatic precipitator ,Cofiring ,engineering.material ,Pulp and paper industry ,Fuel Technology ,Pilot plant ,Fly ash ,engineering ,CHFS ,Environmental science ,Particle size ,Refuse-derived fuel - Abstract
This paper aims at evaluating trace elements (TEs) removal during biomass cofiring in a fluidised bed pilot plant (1 MWth) equipped with a Catalytic Hybrid Filter System (CHFS), as air pollution control device, which combines electrostatic precipitation (ESP) and fabric filter (FF) in a unique approach to develop a compact but highly efficient system. One biomass (olive tree pruning (OP)) and two different waste materials (municipal refuse derived fuel (RDF) and compost (CO)) were employed in the cofiring tests, to evaluate the impact of the fuel in the process. TEs control through the CHFS as well as the effect of this system on mercury speciation, were evaluated. In addition, different factors which may be involved in TEs retention, such as ash matter composition and fly ash particle size, were investigated. Significant removal efficiency was achieved at the CHFS for most TEs studied, even for the most highly volatile TEs such as Hg and Se (40–60%), Cd (50–70%) and Sb (80–90%). Similar trends for TEs capture were observed for both fuel mixtures, obtaining the highest removal rates for Cu, Pb, Cr and Zn. However the retention of most TEs was significantly affected by the fuel employed, as consequence of the different composition and characteristics of ashes generated in each process. The capture of most TEs was seen to be highly influenced by the calcium content in fly ashes, while TEs of higher volatility were seen to be preferably retained in the finest size particles (
- Published
- 2015
48. A modified hydrodynamic model for pool boiling CHF considering the effects of heater size and nucleation site density
- Author
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Chung Te Huang, Chih Hung Huang, Yu Chi Chen, and Ming-Chang Lu
- Subjects
Materials science ,Critical heat flux ,Boiling ,General Engineering ,CHFS ,Nucleation ,Thermodynamics ,Limit (mathematics) ,Condensed Matter Physics ,Instability - Abstract
Boiling is commonly used in daily life and is an efficient heat removal method. During pool boiling, the critical heat flux (CHF) establishes the upper limit of efficient heat removal. Although, numerous studies have explored CHF, its exact mechanisms remain ambiguous. The hydrodynamic instability model is the most prominent CHF model, but it fails to explain the evident dependence of CHF on surface properties. The authors proposed modifying the hydrodynamic model to account for how nucleation site density and finite heater size affect the CHF. The experimental CHF values obtained from evaluating various types of surfaces qualitatively agreed with the predictions of the modified hydrodynamic model. This suggests that the CHFs on these surfaces were due to the hydrodynamic limit.
- Published
- 2015
49. Subcooled Pool Boiling CHFs on Cylinder due to Transient Heat Input
- Author
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Katsuya Fukuda, Jongdoc Park, and Qiusheng Liu
- Subjects
Subcooling ,Materials science ,Boiling ,CHFS ,Cylinder ,Mechanics ,Transient (oscillation) - Published
- 2015
50. Faster File Imaging Framework for Digital Forensics
- Author
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Neha Kishore and Bhanu Kapoor
- Subjects
Disk Imaging ,Cybercrime ,Computer science ,Process (engineering) ,SHA-1 ,Digital forensics ,computer.software_genre ,Criminal investigation ,Digital Forensics ,Digital evidence ,Parallel Algorithms ,CHFS ,Cryptographic hash function ,General Earth and Planetary Sciences ,OpenMP ,Data mining ,Cryptographic Hash Functions ,computer ,General Environmental Science - Abstract
The use of digital forensics tools has become common in typical crime investigations involving computing and communication devices. As with any evidence in criminal investigations, the preservation of digital evidence is of critical importance for the success of the investigation. Cryptographic Hash Functions (CHFs) are used by digital forensic tools to ensure the preservation of digital evidence during the acquisition and analysis of evidence. These tools make the use of the CHFs during the acquisition process to ensure that the created image of the evidence is accurate. The CHFs that are currently in use are serial in nature and can be time consuming when working with the large data sets. We propose a new parallel CHF transformation to speed up the image creation process by a factor of 6.5 over existing methods. We discuss the use of the parallel algorithm in the image creation process and compare the results with the existing sequential methods.
- Published
- 2015
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