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Chronic subdural hematoma (CSDH) is a frequently encountered neurosurgical disease among the elderly. The mainstay treatment involves surgical evacuation, but recurrence rates of approximately 13% pose complications. Adjuvant treatments, including tranexamic acid (TXA), have been explored, yet consensus on their efficacy and safety in elderly patients remains uncertain. The study aims to examine the role of TXA as adjunctive therapy in reducing CSDH recurrence and explore any potential association between TXA use and thrombotic events in this patient population. The systematic review and meta-analysis adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and Cochrane Handbook standards, searching databases up to July 2023 for randomized controlled trials and propensity-matched cohorts evaluating adjuvant TXA. The primary outcome was CSDH recurrence, and the secondary outcome was thrombosis risk, measured as relative risks. A total of 6 studies were included, comprising 1403 patients with CSDH who underwent surgical treatment. Four studies were randomized controlled trials, while the other 2 were propensity-matched cohorts. The overall pooled relative risk for CSDH recurrence in the TXA group compared to the control group was 0.41 (95% confidence interval [0.29–0.59], P < 0.01), indicating a significant reduction in recurrence with TXA treatment. In conclusion, our study indicates that adjuvant TXA may help reduce CSDH recurrence in elderly patients undergoing surgical treatment. However, the study has limitations and there is a need for further research to validate these findings. [ABSTRACT FROM AUTHOR]

This article, titled "Management of Brain Stem Cavernomas in the Setting of Multiple Intracranial Cavernomas: A Retrospective Analysis of Single Institutional Experience," explores the impact of multiple cerebral cavernomas on the management of brain stem cavernomas. The study analyzed electronic records from 2007 to 2023 and selected patients with multiple intracranial cavernomas, dividing them into two groups: those with only brain stem cavernomas and those with both brain stem and non-brain stem cavernomas. The study found that the risk of brain stem cavernoma bleeding was higher in the group with multiple cavernomas compared to the group with only brain stem cavernomas. However, there was no significant difference in outcomes between the two groups after a two-year follow-up period. [Extracted from the article]

Background: The nucleoside transport capabilities of the human equilibrative nucleoside transporter-3 (hENT3) are disrupted by mutations in SLC29A3 (10q22.2), which are genes for the nucleoside transporter and are the cause of the unusual autosomal recessive disease known as H syndrome. As a result, histiocytic cells invade a number of organs. Case presentation: A 17-year-old Syrian male was admitted to the internal medicine department with a one-month history of polyuria, polydipsia, general weakness, and pallor. He had a history of progressive bilateral sensorineural hearing loss and failure to gain weight for three years. Physical examination revealed various abnormalities, including scrotal mass, small penis and testicles, absence of pubic and axillary hair, joint abnormalities, short stature, hallux valgus, fibrous protrusion near the navel, and hyperpigmented non-itchy painful skin plaques. Clinical signs along with laboratory test results confirmed hyperglycemia, primary hypogonadism, osteopenia, and growth hormone deficiency. After a review of the relevant medical literature, this patient's presentation of hyperglycemia with hypogonadism, hyperpigmentation, hallux valgus, hearing loss, hematological abnormalities, and short stature suggested the diagnosis of H syndrome. The patient received treatment with insulin and testosterone, leading to a significant improvement in his presenting symptoms. Conclusions: H syndrome is a very rare condition, and the fact that the first case has only recently been reported in Syria serves to emphasize how rare it is. H Syndrome should be suspected if a patient has short stature with signs of hyperglycemia and other endocrine and cutaneous abnormalities. We are reporting this case to increase physicians' awareness of this exceedingly rare and unique syndrome. [ABSTRACT FROM AUTHOR]

Background: Malignant mesotheliomas are rare, yet highly malignant tumors. Mesotheliomas are tumors that develop from mesothelial surfaces, with the pleura being the most common, followed by the peritoneum. The diagnosis of malignant peritoneal mesothelioma (MPM) is usually established when the disease is advanced, owing to the nonspecific clinical appearance and abdominal symptoms. Initially, MPM was treated with palliative systemic chemotherapy, with or without palliative surgery. However, cytoreductive surgery (CRS) combined with bidirectional intraoperative chemotherapy (BDIC) has recently emerged as a treatment option for MPM. BDIC creates a bidirectional chemotherapy gradient in the peritoneal tumor cells through the simultaneous use of intraperitoneal and intravenous chemotherapy. CRS, combined with BDIC (CRS-BDIC), allows the complete elimination of residual tiny tumor cells after complete removal of the visible tumor nodules. Case Report: Herein, we present a case of a 51-year-old woman with MPM and chronic kidney disease (CKD) stage 3b. Her treatment consisted of neoadjuvant chemotherapy and immunotherapy, followed by CRS-BDIC using intraperitoneal cisplatin and doxorubicin, and intravenous ifosfamide. The surgery was successful, with no immediate complications or decline in the patient's kidney function. On follow up 2 months later, the patient denies suffering any chemotherapy-related adverse effects, and her kidney profile remains stable. Conclusions: In conclusion, nephrotoxicity, a known adverse effect of cisplatin and ifosfamide, might not be a contraindication for the use of these potentially nephrotoxic drugs in CRS-BDIC in patients with renal impairment. [ABSTRACT FROM AUTHOR]

Estrogen receptor (ER) α expression and associated signaling is a major driver of over two-thirds of all breast cancers (BC). ER targeting strategies are typically used as a first-line therapy in patients with steroid receptor positive (SR+) disease. Secondary resistance to anti-estrogenic agents may occur with clonal expansion and disease progression. Mechanisms underlying hormone resistance are an expanding field of significant translational importance. Cross-talk with other nuclear hormones, receptors, and signaling pathways, including thyroid hormones (TH) and their receptors (THRs), have been shown to promote endocrine therapy resistance in some studies. We have shown that TH replacement therapy (THRT) was independently and significantly associated with higher rates of relapse and mortality in SR positive (+), node-negative (LN-) BC patients, whereas it showed no association with outcomes in SR negative (-) patients. LN-, SR+ patients receiving THRT and tamoxifen had the worst outcomes, suggesting a pro-carcinogenic interaction that significantly and independently shortened survival and increased mortality. Using in vivo and in vitro models, we previously showed hormonal cross-talk, altered gene signaling, target gene activation, and resistance to tamoxifen in the presence of TH. In this report, we show TH ± E2 ± tamoxifen inhibits cell cycle control signaling, reduces apoptosis, and enhances cell proliferation, tumor growth, tamoxifen resistance, and clonal expansion. Mechanistically these changes involve numerous genes and pathways, including critical cell cycle regulatory proteins and genes identified using various molecular methods. These studies facilitate a greater mechanistic understanding of the biological and molecular impact of TH on SR+ BC. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the anti-sickling activity of Senna alexandrina, Aerva javanica, and Ficus palmate extracts. Methods: The leaves were extracted with water and methanol. The anti-sickling effect of extracts was determined using blood from 20 sickle cell disease (SCD) patients by mixing it with 500 and 1000 μg/mL of extract. The treated blood samples were then examined under a light microscope. The osmotic fragility of erythrocytes was determined using 4 mL (0 – 0.9 %) buffered saline mixed with 1 mL extract (500 μg/mL) and 0.05 mL sickled red blood cells (RBCs). Results: Aerva javanica extract significantly (p < 0.0001) reduced the percentage of sickle cells compared to control. The sickle-shaped cells were 29.47 % when treated with 125 μg/mL concentration of methanol extract of A. javanica that was further decreased to 0.35 % on increasing the concentration to 500 μg/mL. A similar trend was also observed with extracts of F. palmata. Extracts had protective effect on erythrocyte osmotic fragility. Results of comet assay suggested that extracts did not damage DNA. Conclusion: These plant extracts have promising anti-sickling activity and protect erythrocyte osmotic fragility. However, in vivo studies are required to validate these results and for further development of the extracts for therapeutic use. [ABSTRACT FROM AUTHOR]

The objective of this paper is to study and define some algebraic curves with neutrosophic variables in neutrosophic real field R(I), where we study what are the relationships between classical algebraic curves and neutrosophic algebraic curves depending on the geometric isometry (AH-Isometry). [ABSTRACT FROM AUTHOR]

The search for sustainable but environmentally friendly medium of harnessing energy for the automotive industry has led to the evolution of various energy generating and converting devices. One of such energy converting device is fuel cells. Despite the merits associated to the performance of proton exchange membrane (PEM) fuel cells, issues relating to the cost and remaining useful life prediction still persist hence impeding their further commercialization especially in the automotive industry. In spite of the progress made by the research community in developing various predictive models in order to mitigate these challenges, the accuracy of these developed models has lately become active research direction. The current study explored the accuracy of recurrent neural network, bi recurrent neural network, combined convolutional neural network and bi recurrent neural network in predicting the remaining useful life of a PEM fuel cell. The presence of the convolutional neural network was mainly to ensure pre – processing of the bi recurrent neural network for the extraction of high level features. To reduce the possibility of overfitting, a dropout approach coupled with callback technique is adopted. Validation of the model was executed based on an experimental data. The outcome of the investigation highlighted the key role of the convolutional neural network in improving the accuracy of the recurrent neural network. Comparing the root mean square error (RMSE) and mean absolute percentage error (MAPE) of the present model with other models, the developed model yielded the least values indicating a higher accuracy. For instance, the relative error showed a least value of 0.12 for the combined convolutional neural network and bi recurrent neural network compared to the long short term memory with 2.61 reported in previous studies. • Evaluation of various existing predictive models for PEM fuel cells is studied. • Convolutional neural network accuracy in predicting the rate of degradation for PEM fuel cell is captured. • The developed predictive model have higher accuracy compared to other models. • Future studies should explore further combination of various predictive models and the effect on the accuracy. [ABSTRACT FROM AUTHOR]

The rising significance of the field of biopolymers has driven the rapid progress of this distinctive class of polymeric materials in the past decades. Biodegradable polymers have acquired much attention because they play an essential role in humans' lives due to their specific tunable electrical conductivity and biodegradability characteristics, making them fascinating in many applications. Herein, we debated the recent progress in developing biodegradable polymers and their applications. Initially, we introduce the basics of conducting and biodegradable polymers, trailed by debates about the effective strategies currently used to develop biopolymers. Special importance will focus on the uses of biodegradable polymers in drug delivery and tissue engineering, as well as wound healing, demonstrating the recent findings, and uses of several biodegradable polymers in modern biological uses. In this review, we have provided comprehensive viewpoints on the latest progress of the challenges and future prospects involving biodegradable polymers' advancement and commercial applications. [ABSTRACT FROM AUTHOR]

Parathyromatosis is a rare cause of recurrent primary hyperparathyroidism that often follows surgical removal of the parathyroid gland. Foci of parathyromatosis are most commonly found in the neck, mediastinum, and sites of autotransplantation. A 36-year-old male with renal failure and prior parathyroidectomy presented with generalized bone pain, for which laboratory investigations revealed hyperparathyroidism. Preoperative coil localization was utilized followed by thoracoscopy using fluoroscopy for resection of ectopic parathyroid tissue. The specimen was sent to histopathology, which revealed multiple nodules of hypercellular parathyroid tissue, consistent with the diagnosis of parathyromatosis. Parathyromatosis is a rare cause of recurrent hyperparathyroidism, with surgical removal being the only curative option. Follow-up is essential as it can commonly recur. [ABSTRACT FROM AUTHOR]

Background: Ventilator Associated Pneumonia (VAP) is a common hospital acquired infection that occurs as complication in patients who are connected to Mechanical Ventilation (MV). Nurses in intensive care unit (ICU) should be updated with the latest evidence-based practice to prevent such complication. This study aimed to assess improvement of the nurses' awareness toward ventilator-associated pneumonia based on latest evidence guidelines. Methods: A quantitative pretest-posttest design has been conducted. Using a convenience sample of 58 nurses who are working in the ICU were recruited. Tools: A self-administrative questionnaire was adapted to assess the nurse's knowledge about VAP and VAP prevention bundle. Results: The results highlighted that all ICU nurses had improvement of knowledge level pre-post regarding VAP (p <0.001), VAP prevention (p <0.001), and the overall knowledge score improvement revealed significantly higher after the educational program (p <0.001). Conclusion: Periodic refreshing on-services education program should be provided to nurses in ICU to improve their knowledge and to maintain high level of information, moreover hospital policies should include updated guidelines for VAP prevention bundle and protocol from international evidence. [ABSTRACT FROM AUTHOR]

There is limited information on use of laser in complex percutaneous coronary interventions (PCI). We examined the impact of laser on the outcomes of balloon uncrossable and balloon undilatable chronic total occlusion (CTO) PCI. We reviewed baseline clinical and angiographic characteristics and procedural outcomes of 4845 CTO PCIs performed between 2012 and 2020 at 32 centers. Of the 4845 CTO lesions, 752 (15.5%) were balloon uncrossable (523 cases) or balloon undilatable (356 cases) and were included in this analysis. Mean patient age was 66.9 ± 10 years and 83% were men. Laser was used in 20.3% of the lesions. Compared with cases in which laser was not used, laser was more commonly used in longer length occlusions (33 [21, 50] vs. 25 [15, 40] mm, p = 0.0004) and in-stent restenotic lesions (41% vs. 20%, p < 0.0001). Laser use was associated with higher technical (91.5% vs. 83.1%, p = 0.010) and procedural (88.9% vs. 81.6%, p = 0.033) success rates and similar incidence of major adverse cardiac events (3.92% vs. 3.51%, p = 0.805). Laser use was associated with longer procedural (169 [109, 231] vs. 130 [87, 199], p < 0.0001) and fluoroscopy time (64 [40, 94] vs. 50 [31, 81], p = 0.003). In a contemporary, multicenter registry balloon uncrossable and balloon undilatable lesions represented 15.5% of all CTO PCIs. Laser was used in approximately one-fifth of these cases and was associated with high technical and procedural success and similar major complication rates. [Display omitted] • Information on laser use in complex percutaneous coronary interventions is limited. • Balloon uncrossable/undilatable lesions represented 15% of chronic total occlusions. • Laser was used in approximately one-fifth of these cases. • Laser was associated with higher technical and procedural success rates. • Laser was associated with similar major cardiac complication rates. [ABSTRACT FROM AUTHOR]

Objective: The outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in octogenarians and nonagenarians have received limited study. Methods: We compared in‐hospital outcomes of CTO PCI between patients ≥80 vs. <80‐years‐old in 6233 CTO PCIs performed between 2012 and 2020 at 33 U.S. and international centers. Results: There were 415 octogenarians and nonagenarians in our study (7% of the total population). Compared with younger patients, octo‐ and nonagenarians were less likely to be men (73% vs. 83.2%, p < 0.0001) and more likely to have atrial fibrillation (27% vs. 12%, p < 0.0001) and prior coronary artery bypass graft surgery (CABG) (43% vs. 29%, p < 0.0001). They were more likely to have CTOs with moderate/severe calcification (71% vs. 46%, p < 0.0001), but had similar mean J‐CTO scores (2.5 ± 1.3 vs. 2.4 ± 1.3, p = 0.08). They had lower technical and procedural success (82.2% vs. 86.3%, p = 0.0201; 80.3% vs. 84.8%, p = 0.016, respectively) and higher incidence of in‐hospital major adverse cardiovascular events (3.4% vs. 1.8%, p = 0.021). On multivariable analysis PCI in octo‐ and nonagenarians was not independently associated with technical and procedural success or with in‐hospital MACE. Conclusion: CTO PCI is feasible in octo‐ and nonagenarians, although success rates are lower, and the risk of complications is higher compared with younger patients, likely related to more comorbidities and higher coronary lesion complexity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel nanocatalysts with oxygen vacancies were synthesized using carbothermal reduction. • Various techniques characterized catalyst structure and morphology. • Oxygen vacancies and doping reduce gaps, improve mobility, and suppress recombination. • The results showed improved degradation of pollutants and high stability for the photocatalysts. Nanostructured photocatalysts based on cobalt and molybdenum-doped TiO 2 composite materials were developed to enhance photocatalytic performance. The creation of defects through partial carbothermal reduction resulted in materials with lower band gaps, improving efficiency. The carbon lattice facilitated electron movement and inhibited electron-hole recombination, while the large surface area of the nanosheets enhanced catalyst effectiveness. The materials were characterized using XRD, FTIR, Raman spectroscopy, FESEM, and UV–Vis spectroscopy. The degradation of arsenazo 3 dye was used to evaluate the catalysts, with all three showing efficient degradation. The TiO 2 -Mo-C catalyst exhibited the highest degradation rate (99.8%). Kinetic data indicated that the photodegradation followed pseudo-first-order and Langmuir-Hinshelwood kinetics. Remarkably, the reaction rate constant (k C = 41.61 mg L-1 min−1) and adsorption equilibrium constant (K LH = 1.26 × 10-3 L mg−1) of the TiO 2 -Mo-C catalyst were significantly superior to other catalysts. These photocatalysts demonstrated excellent stability and reusability over six cycles. [ABSTRACT FROM AUTHOR]

The aim of the present work was to evaluate the performance of polypropylene (PP)/sisal fiber (SF)/banana fiber (BF) and chitosan-based hybrid (chitosan(CS)/SF)/BF) composite materials for the adsorptive removal of cadmium (Cd) ions from water waste. Polypropylene is harnessed for its importance in forming strong composite materials for various applications. Chitosan biopolymer encloses a great deal of amino and hydroxyl groups, which provide effective removal of Cd ions from wastewater. The batch adsorption studies proved that the removal of Cd ions was pH-dependent and attained optimum at pH 5.5 for both the composites. Langmuir and Freundlich models were applied for the obtained experimental values. Based on the R2 values, it was evidenced that the adsorption process was best fitted with the Freundlich isotherm than Langmuir. The sorption capacity of CS/SF/BF hybrid composite (C max = 419 mg/g) is higher than PP/SF/BF composite (C max = 304 mg/g), and allows multilayer adsorption. Kinetics studies revealed that the pseudo-second-order model was followed during the removal of Cd ion from wastewater. The overall evaluation proved that though both the adsorbents are suitable for the removal of Cd ions, the efficiency of CS-based ternary composite material is better than PP-based composite. [ABSTRACT FROM AUTHOR]

Piping is an essential component of processing plants that transfers process fluids from one piece of equipment to another. To detect the unpredictable deterioration of piping systems, periodic or continuous pipe inspection for wall loss is conducted, which determines when preventative or corrective maintenance activities, usually replacements, should be done. Therefore, it is necessary to develop an optimal maintenance strategy to replace piping systems to reduce the overall maintenance expenditure and avert the effects of pipe failure. Most of the literature in this field concentrates on maintenance activities executed during decision-making. This paper investigates creating a system and tool to assist decision-makers in evaluating and selecting the optimal moment to replace a deteriorating pipe based on the current state of the piping system. Considering that preventative replacement of the pipeline is done during a scheduled shutdown, also referred to as a turnaround, this paper investigates making a preventative replacement ruling two turnaround cycles ahead. We account for the varying thickness at different monitoring locations of two piping systems in a refinery by applying a nonstationary gamma process with random effects. We employ the Markov decision process (MDP) and the value iteration algorithm to determine the most effective maintenance replacement policy. The outcome of our analysis is an optimal maintenance policy that minimizes the cost of maintenance. Practical Applications: This paper's practical use is to aid in maintenance planning in refineries, midstream or pipelines, chemical plants, and gas facilities by planning piping replacement in two shut-down cycles ahead of time. The pipe wall is classified into states ranging from the present thickness reading to the retirement thickness. The likelihood of transiting from one state to another is calculated based on the corrosion rate. Given that the pipe wall thickness is classified into states, the current wall thickness, transitional probabilities, and preventative and corrective maintenance costs, including lost profit opportunity, can be inputted into the model to help decision-makers decide if it is optimal to replace the piping in the subsequent two shut-down cycles. This policy will assist in reducing the risk of a pipe failure, which has financial, safety, and environmental consequences. It is also critical not to replace a still-in-good-shape pipe. This model may be customized to pipe systems in the various petrochemical sectors with known retirement thicknesses to estimate the risk of operating near the retirement thickness. [ABSTRACT FROM AUTHOR]

Key Clinical Message: However, it is noteworthy that certain patients with minor functional limitations in their hand may have experienced undiagnosed thumb hypoplasia during their childhood years. These individuals may have successfully adapted to their condition without seeking medical intervention and may express a preference for nonintervention (as in this case). Thumb hypoplasia is a congenital underdevelopment of the thumb, accounting for 5%–15% of congenital hand disorders. It occurs equally among both genders and can affect both thumbs. The condition is categorized using Blauth's classification with Type I being the mildest form. We report a 23‐year‐old Syrian male presented with a bilateral restriction in opposition movement when using a pen or razor. Clinical examination and x‐ray imaging revealed a bilateral Type I hypoplastic thumb with bilateral minimal hypoplasia of the toes. Despite the surgical treatment options available, the patient opted not to undergo surgery due to his adaptation to his condition. Hypoplastic thumb Type I is a congenital condition characterized by underdevelopment of the thumb. Bilateral thumb hypoplasia with toes hypoplasia is extremely rare. A full systemic evaluation should be done due to its associations with other syndromic manifestations and treatment options are discussed concerning the best functional outcomes and patient preferences. [ABSTRACT FROM AUTHOR]

Abstract The process of extracting lipids from high-moisture Scenedesmus quadricauda microalgae biomass disrupted with microwave was examined. The study showed that microwave pre-treatment is effective in algae cell rupture while microwave power was found to be a significant factor to enhance the degree of cell disruption. Though microwave pre-treatment time had some effect, the degree of cell rupture seemed to decrease after a certain pre-treatment time. The total lipid from Scenedesmus quadricauda sp. were extracted using a mixture methanol and sulphuric acid as an organic solvent. In addition, it was discovered that microwave pre-treatment enhances the disruption of microalgae cells to attain a high level of lipid yields. Optimal lipid yield obtained in this study was 49% at power 600 W, heating time of 8 min and extraction time of 3.5 h. Highlights • Microwave pre-treatment enhanced the lipid recovery from Scenesdemus quadricauda. • Variation on reaction time between 3 and 4 h has no significant effect on lipid recovery. • Optimum recovered lipid yield of 49% was achieved from a microwave-pretreated alga at 600 W for 8 min. [ABSTRACT FROM AUTHOR]

Polymer matrix composites are excellent materials for a variety of industrial applications. They have superior mechanical, thermal and electrical properties, making them preferable to traditional materials such as metal. To make polymer matrix composite materials, thermosetting, elastomers and thermoplastic polymers are mainly the three types of polymers that can be utilized as matrices. In comparison to thermosetting and elastomers polymers, carbon fiber reinforced thermoplastic (CFRTP), is the subject of this research, are gaining popularity in many industrial sectors due to its recyclability, simplicity of processing, good characteristics, flexibility, and less production time. This review covers conventional and state-of-the-art manufacturing techniques of CFRTP. Moreover, the potential and existing of CFRTP's application as well as the techniques of carbon fiber recovery and recycling methods of such materials were also examined. Overall, this study considers the research and development on manufacturing CFRTP and recycling techniques of polymer composites to recover carbon fiber materials. [Display omitted] • Conventional and state-of-the-art manufacturing techniques of carbon fiber reinforced thermoplastic were investigated. • The potential and existing of carbon fiber reinforced thermoplastic application were reviewed. • Techniques of carbon fiber recovery and recycling methods of polymer composites materials were examined. [ABSTRACT FROM AUTHOR]

The present study investigates the effect on methane production from waste paper when co-digested with macroalgal biomass. Both feedstocks were previously mechanically pretreated to reduce their particle size. The study was planned according two factors: the feedstock to inoculum (F/I) ratio and the waste paper to macroalgae (WP/MA) ratio. The F/I ratios checked were 0.2, 0.3 and 0.4 and the WP/MA ratios were 0:100, 25:75, 50:50, 75:25 and 100:0. The highest methane yield (386 L kg −1 VS added ) was achieved at an F/I ratio of 0.2 and a WP/MA ratio of 50:50. A biodegradability index of 0.87 obtained in this study indicates complete conversion of feedstock at an optimum C/N ratio of 26. Synergistic effect was found for WP/MA 25:75, 50:50 and 75:25 mixing ratios compared with the substrates mono-digestion. [ABSTRACT FROM AUTHOR]

A number of sophisticated techniques, such as NMR imaging and γ-ray attenuation, have now been used to study moisture transport in porous construction materials. This paper presents initial developments in the application of discretized, electrical conductivity measurements as a relatively simple technique to monitor water movement within cover-zone concrete. Using a 3-phase model and the Archie relationship for porous rock formations, conductivity measurements are used to evaluate moisture-content profiles during water ingress and, through the use of Boltzmann's transformation, it is shown that these profiles collapse onto a master-curve . Having obtained the master-curve during absorption, the capillary transport coefficient (D θ ) can then be obtained; however, the current work focuses on presenting the methodology as an alternative testing technique. [ABSTRACT FROM AUTHOR]

In order to increase the methane yield from biomass, this paper investigates the mechanical pretreatment effect of a Hollander beater on the anaerobic digestion process of Pelvetia canaliculata macroalgae using a response surface methodology (RSM). Higher values on methane yield were obtained at lower F/I ratios, with an increase up to 2.5-fold at an F/I value of 0.3. A multi-objective optimization study was carried out with the aim of maximizing the methane yield while minimizing the pretreatment time. An optimum methane yield of 283 ml/gVS was obtained for 50 min pretreatment time and a ratio F/I of 0.3, which represents an increase of 45% compared to non-pretreated algae. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of soil depths (0-30, 30-60, and 60-90 cm) and landcover changes on selected physicochemical properties in soils transformed from a secondary forest status to plantation status for the cultivation of rubber and oil palm aged 5 and 15 years. Soil physicochemical properties; bulk density (Bd), pH, soil organic matter (SOM), total organic carbon (TOC), total organic nitrogen (TON), and their corresponding isotopes; and d13C and d15N were determined by conventional methods. The results showed that the content of SOM (3.39%) at 0-30 cm was significantly greater than those of the 30-60 and 60-90 cm depths. The same pattern was demonstrated by the content of TOC and TON. With respect to land use, the secondary forest had significantly greater SOM content than the rubber and oil palm plantations aged 5 years. The same pattern was also observed for the content of TOC and TON by land use. Similarly, the d13C value of -26.85% was greatest at the 0-30 cm depth, while by land use the oil palm aged 5 years had the greatest d13C. Conversely, the d15N value of 4.21% was significantly greater at the 60-90 cm depth compared to the 30-60 (1.78%) and the 0-30 cm (-2.03%) depths. The negative value of d15N revealed the sources (N was a product of multiple variables such as N fixation, precipitation, rainstorm, and the use of chemical fertilizers), and the limited nitrogen content in the study area. In conclusion, this study demonstrated that the conversion of secondary forest to plantation enhanced the mineralization of soil organic matter and increased SOC concentrations at the sub soil. Therefore, the conversion of the secondary forest to the oil palm plantations must have resulted in a positive effect by contributing to greater soil organic carbon content. [ABSTRACT FROM AUTHOR]

Background. The use of game-based learning strategies in higher education has shown promise to increase student motivation and achievement. Little is known about which game mechanics are most appropriate and effective for learners at different academic levels.Aim. This article examines teacher selection and implementation of game mechanics in 27 courses from middle school to higher education designed with game-based learning.Method. 27 educators participated in an open-ended survey on the design of their course. Measures included an open response survey on patterns and design of game mechanics with results validated through member checking.Results. Findings included different choices of game attritubes and game elements in courses in middle school, high school, and higher education. Teacher selection and inclusion of game mechanics changed over time to better meet the needs of students.Conclusions. The structure of game-based learning at different levels will vary to meet the developmental and academic needs of students, but more work is needed in determining which strategies are most effective for learning. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this paper is to explore the impact of the Kijima Type II imperfect repair model on the availability of repairable systems (RS). Since many individuals are interested in measuring the extent to which the system will be available after it has been run for a long time, the specific interest in this study is in the steady-state (limiting) availability behavior of such systems. Furthermore, the authors study the impact of age-based preventive maintenance (PM) on the RS performance.Design/methodology/approach Because of the complexity of the underlying assumptions of the Kijima Type II model, the authors use simulation modeling to estimate the system availability. Based on preliminary simulation results, the availability function achieves a steady-state value greater than zero. The system steady-state availability is then estimated from the simulation output by computing the average of the availability estimates beyond the initial transient period. Next, the authors develop a meta-model to convert the system reliability and maintainability parameters into the coefficients of the limiting availability estimate without the simulation effort. Using a circumscribed central composite experimental design, the authors confirm the accuracy of the meta-model.Findings The results show that the meta-model is robust, and provides good estimates of the system limiting availability. Also, the authors find that when using a Kijima Type II model for a system repair process, age-based PM can improve the steady-state availability value. Therefore, an optimal age-based PM policy that maximizes the system’s steady-state availability can be identified.Originality/value In practice, it is important to study the system steady-state availability because many individuals, i.e. engineers, are more interested in measuring the extent to which the system will be available after it has been run for a long time. Therefore, this study represents a significant addition to the body of knowledge related to virtual age modeling, in that it incorporates a Kijima type II model and considers system steady-state availability. [ABSTRACT FROM AUTHOR]

In the anaerobic digestion of lignocellulosic materials such as waste paper, the accessibility of microorganisms to the fermentable sugars is restricted by their complex structure. A mechanical pretreatment with a Hollander beater was assessed in order to reduce the biomass particle size and to increase the feedstock’ specific surface area available to the microorganisms, and therefore improve the biogas yield. Pretreatment of paper waste for 60 min improves the methane yield by 21%, from a value of 210 ml/gVS corresponding to untreated paper waste to 254 ml/gVS. 30 min pretreatment have no significant effect on the methane yield. A response surface methodology was used to evaluate the effect of the beating time and feedstock/inoculum ratio on the methane yield. An optimum methane yield of 253 ml/gVS was achieved at 55 min of beating pretreatment and a F/I ratio of 0.3. [ABSTRACT FROM AUTHOR]

This paper discusses new experimental work investigating the change in pH of the electrolyte of individual cells in Lead-Acid batteries during discharge with a view to predicting cell polarity reversal and thereby pre-empting potentially catastrophic failure in batteries. The discharge tests were carried out on batteries which were classified as ‘new’ and ‘aged’ as a means of indicating their state of health. A new pH phenomenon has been recorded for the first time in this paper as evidenced by experimental results including measurement of half-cell potentials. The trends observed during the discharge tests could be used as additional means of indicating impending cell reversal in series connected lead-acid cells. [ABSTRACT FROM AUTHOR]

Measuring soil carbon dioxide efflux is a challenging task even when it is performed using respiration chambers. While gas samples are taken, measurement deviations become more evident according to the used chamber design especially when external disturbances occur. This paper studies the carbon dioxide concentration profiles within the top soil layers, and investigates the controlling factors affecting the process. The considered factors are diffusion, temperature and viscosity. The efflux equation is discussed and then it is linked with the soils geotechnical parameters, while a relationship between the Reynolds number within the soil and efflux is found. Emphasis on the importance of the external geometrical design considerations is shown through studying external boundary layer effects due to the chamber outer shell shape and how it interacts with blowing winds. Chamber stability on site of deployment is also of a significant importance considering external blowing winds. Internal geometrical considerations are linked with the flow turbulence within the dynamic chambers. It is highly recommended that respiration chamber designers need to work in parallel with a multidisciplinary team in order to make a chamber design that ensures the least disturbance to occur at the location of study. [ABSTRACT FROM AUTHOR]

Grass is being considered as a potential feedstock for biogas production, due to its low water consumption compared to other crops, and the fact that it can be cultivated in non-arable lands, avoiding the direct competition with food crops. However, biogas production is limited by the characteristics of the feedstock; in particular its complex lignocellulosic structure. Hence, different pretreatment methods are being investigated for grass structure disruption before undergoing the anaerobic digestion process. The aim of this paper is to review current knowledge on pretreatment techniques used for grassland biomass. Pretreatment techniques were categorized into mechanical, microwave, thermal, chemical and biological groups. The effect of the application of each studied methods on the biogas yield and on the energy balance is discussed. A further comparison between the covered techniques was revealed. [ABSTRACT FROM AUTHOR]

European Commission has set clear targets for 2020 regarding energy and environment policy; these targets include 20% cut in greenhouse gas emissions against the 1990 levels. It is believed that adopted strategy has encouraged the renewable energy applications during the last two decades. Moreover, measurement deviations of carbon dioxide flux occurring in respiration chambers has been seen of a great importance to explain the biochemical parameters affecting the climate change issue. This is attributed on many occasions to chamber design constraints and the way they are coupled with the studied site location. This is illustrated by external disturbances whereby when they happen while gas measurements are taken measurement deviations become more evident. This paper surveys the different soil physical, biological and geotechnical parameters and links them to meteorological ones. Consequently it explores their direct and indirect effects to the produced soil efflux. Furthermore this paper proposes several soil temperature models according to the studied case constraints to see what affects soil efflux production. Moreover a clear understanding of what affects the measurement process was achieved through surveying all the internal and external pressure parameters and how they influence the chamber in relation to time. The conclusion is that respiration chamber designers need to preserve chamber internal temperature and pressure to be equal to the outer atmosphere for the case of stabile external conditions. For the case of unstable external conditions design counter measures are incorporated. Furthermore the appropriate gas sensor needs to be selected professionally with emphasis on the importance of installation location inside the chamber. Likewise soil bacterial type and soil temperature also has an influence on efflux production. [ABSTRACT FROM AUTHOR]

Condition-based maintenance (CBM) is a maintenance strategy that collects and assesses real-time information, and recommends maintenance decisions based on the current condition of the system. In recent decades, research on CBM has been rapidly growing due to the rapid development of computer-based monitoring technologies. Research studies have proven that CBM, if planned properly, can be effective in improving equipment reliability at reduced costs. This paper presents a review of CBM literature with emphasis on mathematical modeling and optimization approaches. We focus this review on important aspects of the CBM, such as optimization criteria, inspection frequency, maintenance degree, solution methodology, etc. Since the modeling choice for the stochastic deterioration process greatly influences CBM strategy decisions, this review classifies the literature on CBM models based on the underlying deterioration processes, namely discrete- and continuous-state deterioration, and proportional hazard model. CBM models for multi-unit systems are also reviewed in this paper. This paper provides useful references for CBM management professionals and researchers working on CBM modeling and optimization. [ABSTRACT FROM AUTHOR]

Vertical axis wind turbines (VAWTs) have gained popularity in the last few decades due to their numerous advantages when deployed in urban areas. Despite this, Vertical axis wind turbines have complex aerodynamics, dynamic stall, hence lower performance. Low/zero starting torque, noise, visual impact, as well as blade safeness are further hurdles when they are fitted into the physical environment. Due to these pertinent issues that comes to play in a vertical axis wind turbine, the current investigation explores an augmented vertical axis wind turbine (AVAWT) having a rotor and a stator. The outcome of the study highlighted the effect of mesh density and the type of turbulence model selected in the determination of the forces being exerted on the blade using computational fluid dynamics. Investigation into the effect of time steps showed lesser effect of this parameter on the performance of the blade computationally. The newly developed augmented turbine blades improved the output power by 1.35 times in comparison to an open rotor. The shape for the conical surface and the stator blade impacted the performance as well. Furthermore, it was deduced that there was higher dynamic stall for scenarios where the tip speed ratios were lower. The study showed the importance of the stator in a vertical axis wind turbine in ensuring that the incoming wind attains some acceleration as well as creating a lower pressure outlet but overall aids in the improvement of the power and torque coefficients by more than 36%. • Effect of mesh density on vertical axis turbine blade design using CFD is presented. • Power and torque coefficient increased by more than 36%. • The speed of the wind has direct correlation to the stator design. [ABSTRACT FROM AUTHOR]

The reliance on fossil fuels is one of the most challenging problems that need to be dealt with vigorously in recent times. This is because using them is not sustainable and leads to serious environmental issues, such as: air pollution and global warming. This condition affects economic security and development. An alternative to fossil fuel is highly possible which will be more environmentally friendly, sustainable and efficient as well. Among all the different technologies associated with renewable energy, fuel cell technologies represent one of the most promising technological advancement to curb the situation. In this paper, an overview of the technology and its advantages and disadvantages compared with competitive technologies was revealed. The application of different fuel cell types in the stationary and portable sectors was covered. Furthermore, recent challenges and promising developments of current fuel cell technologies in different studied applications were reviewed. Some possible solutions to the challenges were named in this paper for both the portable and stationary fuel cell applications. The paper further seeks to expose the world to the current progress made in the fuel cell industry up to date and possible areas that needs intensified research and modifications to make the fuel cell industry more vibrant and buoyant. [ABSTRACT FROM AUTHOR]

The demand for clean power source which can be used to run the various types of vehicles on the road is increasing on a daily basis due to the fact that high emissions released from internal combustion engine play a significant role in air pollution and climate change. Fuel cell devices, particularly Proton Exchange Membrane (PEM) type, are strong candidates to replace the internal combustion engines in the transport industry. The PEMFC technology still has many challenges including high cost, low durability and hydrogen storage problems which limit the wide-world commercialization of this technology. In this paper, the fuel cell cost, durability and performances challenges which are associated with using of fuel cell technology for transport applications are detailed and reviewed. Recent developments that deal with the proposed challenges are reported. Furthermore, problems of hydrogen infrastructure and hydrogen storage in the fuel cell vehicle are discussed. [ABSTRACT FROM AUTHOR]

The Middle East Respiratory Syndrome (MERS) has been identified in 2012 and since then outbreaks have been reported in various localities in the Middle East and in other parts of the world. To help predict the possible dynamics of MERS, as well as ways to contain it, this paper develops a mathematical model for the disease. It has a compartmental structure similar to SARS models and is in the form of a coupled system of nonlinear ordinary differential equations (ODEs). The model predictions are fitted to data from the outbreaks in Riyadh (Saudi Arabia) during 2013-2016. The results of model simulations indicate that MERS will eventually be contained in the city. However, the containment time and the severity of the outbreaks depend crucially on the contact coefficients and the isolation rate constant. When randomness is added to the model coefficients, the simulations show that the model is sensitive to the scaled contact rate among people and to the isolation rate. The model is analyzed using stability theory for ODEs and indicates that when using only isolation as the control, the endemic steady state is locally stable and attracting. Numerical simulations with parameters estimated from the city of Riyadh illustrate the analytical results and the model behavior, which may have important implications for the disease containment in the city. Indeed, the model highlights the importance of isolation of infected individuals and may be used to assess other control measures. The model is general and may be used to analyze outbreaks in other parts of the Middle East and other areas. [ABSTRACT FROM AUTHOR]

Myocardial abscess is an extremely rare entity and is often deadly in nature. We present a case of a patient with recent orthotopic liver transplant, on immunosuppression, who presented with cardiac tamponade due to Aspergillus fumigatus pericarditis and associated myocardial abscess. The diagnosis was made based on computed tomography imaging, culture of pericardial fluid for Aspergillus, and transthoracic echocardiography. The patient received antifungal therapy with clinical improvement and documented reduction in abscess size based on repeat echocardiogram. Aspergillus myocardial abscess is an extremely rare diagnosis but should be considered in an immunosuppressed patient presenting with pericardial effusion or ventricular mass. [ABSTRACT FROM AUTHOR]

Many authorities have reached the conclusion that using fossil fuels, as the main source of energy to satisfy the increasing global energy demand, is ultimately unsustainable. This is because of depleting resources, and also because, if this approach is followed, emissions of carbon dioxide would continue to build up. Consequently, research on biofuel, that is fuel made from biomass, derived from materials that were recently living, has attracted attention. In this context, the generation of biofuels from algae shows promise for the following reasons. The algae can be grown quickly, all the materials produced are non-toxic and biodegradable, and during this growth there is an opportunity to cause greenhouse gas fixation. Also, since growing algae does not need arable land, it can be grown without competing with food or feed crops, the fuel derived from it being a “third generation” biofuel. This paper describes different types of algae (microalgae and seaweeds), and presents different technologies employed in making biofuels (biogas and biodiesel) from them. [ABSTRACT FROM AUTHOR]

Biogas is one essential renewable energy source which can replace natural gas after its purification. Biogas is produced from different biomass materials though the anaerobic digestion process. Algae are considered as a feedstock for biogas production, which does not compete with food production and does not need large areas of arable land and fresh water resources. In order to improve the biogas production, pre-treatment techniques have been investigated to disrupt the structure of algae increasing the availability of substrates. In this paper, a review of these pre-treatment methods is presented. Pre-treatment methods are categorised into mechanical, ultrasound and micro-wave, thermal, chemical, biological and combined groups. The effect of the application of each of the studied techniques on the biogas yield and the energy balance is discussed. A comparison of the used techniques is carried out, and discussed. [ABSTRACT FROM AUTHOR]

Abstract: Tube hydroforming is one of the most popular unconventional metal forming processes which is widely used to form various tubular components. By this process, tubes are formed into different shapes using internal pressure and axial compressive loads simultaneously to force a tubular blank to conform to the shape of a given die cavity. In this paper, an overall review of developments in the tube hydroforming study is presented so that other researchers at different parts of the world can use it for further investigations in this area. Initially, analytical studies which predict the sufficient parameters in tube hydroforming process were summarized. Afterwards, a guideline for employing finite element modeling (FEM) in the process analysis was proposed. Factors affecting the output of the process were addressed by many studies which were categorized and reviewed in the present work. Moreover, common types of failure of the process were introduced and improvements to avoid them were mentioned. Furthermore, different optimization algorithms to choose the input parameters that would produce the desired hydroformed component were outlined. [Copyright &y& Elsevier]

Abstract: Bi-layered tubing which consists of two different metallic layers is recommended to use in complex working environments as it offers combined properties that single layer structure does not have. However, in this wok, producing of T-shape bi-layered components using the tube hydroforming process is investigated. In this regard, the bulge height and the wall thickness reduction of the bi-layered hydroformed parts (responses) are modelled as functions of the geometrical factors using the combination of the finite element modelling (FEM) and Response Surface Methodology (RSM) for design of experiments (DOE). The geometrical factors effects and their interactions on the responses were determined and discussed. Based on the resultant models, a multi-response optimization study was conducted. Furthermore, for the optimum solutions, a significant agreement was indicated between the predicted and numerical values. [Copyright &y& Elsevier]

Abstract: Optimization of the operating conditions is one of the most significant studies in the hydroforming process, which affect the forming of successful components. In this work, a finite element model was established for bi-layered tube hydroforming process using ANSYS LS-DYNA pre-processor and LS-DYNA solver in order to predict the most efficient and acceptable operating condition for certain material properties and initial blank geometry. Experiments were conducted to check the model validation and the resultant bulge height and thickness reduction were seen in good agreement with the numerical results. The major failure modes of the process were investigated. Different sets of loading paths (relations between axial feed and internal pressure) were tested and compared to each others. Applying internal pressure in advance of the axial pushing was found to give the best formability for the process. [Copyright &y& Elsevier]