Search

Composite metal oxide catalyst Cu2M9CeOx (M = Fe, Co, Ni) was prepared by citric acid complexation method for NOx reduction. Prepared catalysts activities were tested in a fixed bed reactor for NOx reduction by CO and H2. The sequence of activity of the three catalysts for NOx reduction by CO is: Cu2Co9CeOx > Cu2Fe9CeOx > Cu2Ni9CeOx. The catalytic efficiency of Cu2Co9CeOx increased to 100% at 250 °C. For NO reduction by H2, the sequence of activity follows: Cu2Fe9CeOx > Cu2Co9CeOx > Cu2Ni9CeOx. The catalytic activity of Cu2Fe9CeOx was ranged from 60% to 100% during 250–325 °C. Additionally, characterization was conducted to investigate the physical and chemical properties of Cu2M9CeOx catalysts. In-situ Fourier transform-infrared spectra was also used to study the mechanism of the reaction. The results indicated that Cu-□-Co synergistic oxygen vacancies in Cu2Co9CeOx and unstable CuFe2O4 (spinel) in Cu2Fe9CeOx promote NO reduction. The reasons of activities over different Cu2M9CeOx catalysts were then carefully explored.

Hybrid precoding and combining is a key technique to provide an appropriate antenna gain in millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) systems. In wideband mmWave channels, the analog precoder and combiner is designed in the time domain and remain unchanged over the whole bandwidth. In contrast, digital precoders and combiners are optimized on a per-subcarrier basis which makes the resultant problem very difficult. To solve this problem, we combine the well-known turbo-equalizer with the tabu-search (TS)-algorithm developed in artificial intelligence and propose TS-based joint hybrid precoding and combining scheme to intelligently search the near-optimum pair of hybrid precoder and combiner. Specifically, our scheme consists of two key steps. At first, a base station (BS) and a mobile station (MS) develop the turbo-like (TL)-joint search by using the idea of iterative information exchange between them. Then, to find out the near-optimum pair of hybrid precoder and combiner in each iteration of the TL-joint search, the TS-algorithm is employed. Simulation results are shown to verify the significant sum-rate performance of the proposed solution with low-complexity compared to some existing solutions.

Cocatalysts play a critical role in the activity and stability of photocatalytic systems. Currently, efficient cocatalysts mainly comprise of expensive noble metals. Herein we report a composite photocatalyst consisting of CdS nanorods (NRs) and noble-metal-free cocatalyst NiSe, which efficiently enhances the hydrogen production activity of CdS NRs under visible light. NiSe was synthesized through a facile aqueous solution method and CdS/NiSe NRs composites were prepared by in situ deposition of NiSe on CdS NRs. This provides increased contact between cocatalyst and photosensitizer leading to enhanced electron transfer at the interface of NiSe and CdS. The current photocatalytic system gave the highest hydrogen evolution rate of 340 µmol h−1 under optimal conditions. The enhanced stability of the system was observed for 30 h of irradiation resulting in 14 mmol of hydrogen evolution. The highest AQY of 12% was observed using the 420 nm monochromatic light. In addition, CdS/NiSe NRs showed significant higher H2 evolution rate than that of 1.0 wt% loaded CdS/Pt NRs proving NiSe as highly efficient cocatalyst. Photoluminescence spectra and the photocurrent response were used to confirm the efficient charge transfer at the interface of NiSe and CdS nanorods. The work presented here demonstrates the successful use of an inexpensive, non-noble-metal cocatalyst for enhanced photocatalytic hydrogen production.

As the average age of the population goes higher, the people undergo hip arthroplasty surgery to replace their stiff and painful damaged hip joints. To reduce the risk factor after the surgery we developed a visual aided system in previous works. In order to solve the integration problems of commercial camera with other sensors into the femoral head and to minimize the area and power consumption, in this paper we propose a CMOS image sensor of resolution 200 × 200 specially designed for the application in which each individual pixel measures around 15 μm × 15 μm in size and the image sensor chip size measures about 3.5 mm × 3.5 mm. The proposed sensor is simulated with the input current variations from 2 pA to 100 pA for the individual pixels and the corresponding measurements for each pixel range from 2 mV to 855 mV. Besides, we put forward a new method of pattern detection and recognition in the blood-covered situation, which provides an accurate segmentation of patterns from the blood. All the detected patterns are recognized by generating its right 9-bit binary ID required for the pose estimation calculation. Furthermore, to reduce system power consumption, we implement algorithms on FPGA to process the image data pixel by pixel and transmit it directly to the computer for post-processing. Experimental results show that the pattern detection rate goes as high as 99%, which is 5% better in accuracy compared to the top hat algorithm. The power consumption of the system is 213 mW, which is a 70% decrease compared to our previous work.

The aims of this study is to investigate the effects of functional groups like C C and C OH on variation of higher heating values (HHV) of organic compounds. HHV of fuel hydrocarbons, gaseous and liquids including single bonded and multiple bonded carbons and green tea polyphenols (GTP) were determined by using Bomb Calorimeter. It was observed that, multiple bonded carbon and oxygen bonded carbon i.e. C C and C O result in less carbon reduced state while, also increase endothermicity of reactants by changing hybridization state with more s-character and hence, contribute to lower level of HHV. Besides, hydrogen bonding was also considered as the major cause of the difference in HHV of fuel hydrocarbons having the same molecular formula but different oxygen-bearing functional groups due to structure stabilization. These statements were further supported by the combination of Fourier transform infra-red spectra (FTIR) and HHV calculation of raw GTP (set as a representative of biomass) and its solid products obtained at 250 °C and 350 °C by thermal treatment done by using high temperature tube furnace.

The Jerusalem artichoke (Helianthus tuberosus) is a perennial plant which is adapted to wide climatic conditions ranging from temperate to semiarid regions. Its tubers are alternative to potatoes and it can typically produce 18–28 tons of waste foliage from one hectare which can be exploited for bioenergy via pyrolysis. However, the pyrolytic behavior of its waste was never studied. The present study was focused to assess its potential via pyrolysis, kinetics, thermodynamics, and TG-FTIR-MS based study to produce energy and chemicals. The biomass was subjected to thermal degradation at five heating rates (10, 20, 30, 40, 80 °C/min) under an inert environment. The thermograms showed that the highest rate of thermal transformation was achieved at 270–430 °C. The data were subjected to kinetics and thermodynamics analyses using Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO), Starink and Vyazovkin models. The activation energy (Ea) and pre-exponential factors remained consistent and ranged from 160 to 175 kJ/mol and 1012–1014 s−1 at conversion fractions ranging from α = 0.2 to α = 0.6. The kinetic parameters showed higher statistical confidence with R2 ≥ 0.98 and good agreement among the data obtained through various models. The high heating value (HHV = 18.76 MJ/kg), change in enthalpy (∼ΔH = 150–170 kJ/mol), and Gibbs free energy (ΔG = 158–168 kJ/mol) demonstrated the substantial bioenergy potential of this waste. Moreover, the pyrolytic gases were subjected to Thermogravimetric-Fourier Transformed Infrared Spectroscopy-Mass Spectrometry (TG-FTIR-MS) analyses to identify the nature of products. The detected functional groups showed that the evolved gases contained aldehydes, phenols, carboxylic acids, esters, aromatic hydrocarbons and methane which indicated the substantial potential of this waste to produce energy and chemicals via pyrolysis causing no competition with the food/feed or land for food/feed.

This study illustrated the pyrolysis of banana peel (BP) as a potential waste management solution. Samples were characterized through Fourier transform infrared spectrometry (FTIR), elemental analysis, and high heating value (HHV) calculation. After pyrolysis experiments were performed at different heating rates (10, 20, 30, and 40 °C min−1) by using a thermogravimetric analyzer coupled with FTIR (TG-FTIR), the apparent activation energies were computed with Friedman, Kissinger–Akahira–Sunose (KAS), and Flynn–Wall–Ozawa (FWO) methods, and the evolved gaseous products were analyzed simultaneously. During pyrolysis, BP underwent three devolatilization steps accompanied by the evolution of some major gaseous products, including CO2, CH4, H2O, CH3COOH, C C, C6H5OH, HCOOH, and CH3CH2OH. Among them, C C, CH3COOH, and CO2 accounted for approximately 71.56% of the total gaseous products. Gas evolution was more significantly influenced by the pyrolysis temperature than by the heating rate. Pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) analysis confirmed the presence of some high-energy compounds and valuable chemicals containing aromatic, aldehyde, ketone, and other functional groups. In terms of preliminary energy balance, more than 70% of the total energy output was attributed to the liquid pyrolytic products followed by the solid and gaseous products. The energy recovery ratio of BP pyrolysis was superior to that of other fuel feedstocks. This work provided insights into resolving environmental problems associated with BP management by pyrolyzing BP as a potential source of renewable bioenergy.

Development of novel environment friendly self-crosslinker, which enables polymers crosslinking without thermal treatment, is highly desirable for several industrial scale applications such as paints and dyes. Herein, we reported a one-pot facile synthesis of hyperbranched polyvinylbenzylchloride (HBPVBC) followed by its quaterinization with pyridine. The resulting product (QHBPVBC) was then used as a crosslinker. Detailed characterization of the HBPVBC and QHBPVBC were conducted by nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FTIR) and thermo-gravimetric analysis (TGA). Four different quaterinized crosslinked membranes (QHPs) were prepared by changing the ratio of pyridine to HBPVBC, denoted as QHP-0.25, QHP-0.50, QHP-0.75 and QHP-1.0. Sol-Gel analysis and elemental analysis were used to evaluate the degree of crosslinking and quaterinization of all QHPs. Furthermore, crosslinking effectiveness of QHBPVBC was also demonstrated by introducing QHP-0.50 in sulfonated polyphenyloxide polymer (H+sPPO) structure and observing the mechanical and thermal properties. Initiator-free preparation of QHBPVBC and the self-crosslinking ability in pure aqueous medium at ambient temperature exhibited high effectiveness and environmental-friendly nature. All these outstanding properties facilitated the enhancement of thermal and mechanical properties of linear polymers, making QHBPVBC a potential crosslinker candidate for various industrial applications.

Hybrid precoding has emerged as a promising technique to reduce the hardware cost and complexity in millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) systems. However, due to the drastic increase in the number of user devices and higher data rate demand, new frequency bands (i.e., terahertz (THz) communications) are needed to explore. At THz frequencies, the precoding technique can provide a large beamforming gain, but still, the blockage and high path-loss remain a significant problem. To overcome the blockage problem, in this paper, we introduce the two-way relay design where the well-known two-way amplify-and-forward (AF) relay in THz-MIMO orthogonal frequency-division multiplexing (OFDM) systems is employed. The optimal two-way relay hybrid precoding problem is non-convex due to the practical hardware constraints (i.e., unit-modulus and block-diagonal constraints). To solve this problem, we first propose to use mathematical manipulations to remove the block-diagonal constraints from its analog part and then reformulate the original two-way relay hybrid precoding problem into a quadratic-convex problem with only power constraint. Finally, we obtain the closed-form solution for the two-way relay hybrid precoding problem. Simulation results reveal that our proposed solution can achieve better sum-rate and energy efficiency than existing hybrid schemes. China National Key Research and Development Program [2018YFB0803600]; Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [61801008]; Scientific Research Common Program of Beijing Municipal Commission of EducationBeijing Municipal Commission of Education [KM201910005025]; Chinese Postdoctoral Science FoundationChina Postdoctoral Science Foundation [2020M670074] This work was supported in parts by the China National Key Research and Development Program under Grant 2018YFB0803600, the Natural Science Foundation of China under Grant 61801008, the Scientific Research Common Program of Beijing Municipal Commission of Education under Grant KM201910005025, and the Chinese Postdoctoral Science Foundation under Grant 2020M670074. WOS:000603715900001 2-s2.0-85098334509

Objective: The aim of this study was to evaluate factors affecting oral health related quality of life (OHRQoL) of patients using removable dental prosthesis. Methods: The present study employed a cross sectional analytical design. A total of 200 patients participated and interviewed using a cross sectional analytical design. In the first section of the questionnaire patients were asked about demographic data whereas the second part of the questionnaire assessed medical history, oral habits, smoking status, oral hygiene habits and frequency of dental visit. The questionnaire also collected information regarding patient’s removable prosthesis. Questionnaire of OHIP-DENT (Oral Health Impact Profile) was also employed to measure oral health quality of life (OHRQoL) on the domains of functional limitation (FL), physical pain (P1), psychological discomfort (P2), physical disability (D1), psychological disability (D2), social disability (D3) and handicap (H). Relationships between the demographic, socio-economic and education variables and others OHIP-EDENT scores were explored by comparing mean scores by applying ANOVA Results: The study participants comprised of 107 males (53.5%) and 93 females (46.5%). Regarding oral care, participants reporting to visit their dentist within one year were 40.0%. The highest score was recorded for the functional limitation (FL) domain (15.62±6.6), followed by social disability (D3) (15.23±5.06) and physical pain (P1) (14.28±4.8). The respective scores for physical (D1) and psychological disability (D2) and handicap (H) were 10.47±4.84, 11.32±5.38 and 12.45±4.50 respectively. Conclusions: Removable partial denture patients showed minimum problems with mastication, social compromise and functional discomfort. The oral health quality of life of removable denture patients is significantly influenced by patient education level, socio-economic status, medical conditions, smoking and tobacco use habits. doi: https://doi.org/10.12669/pjms.36.2.1257 How to cite this:Al-Deeb M, Abduljabbar T, Vohra F, Zafar MS, Hussain M. Assessment of factors influencing oral health-related quality of life (OHRQoL) of patients with removable dental prosthesis. Pak J Med Sci. 2020;36(2):213-218. doi: https://doi.org/10.12669/pjms.36.2.1257 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Background Studies assessing clinical and radiographic peri-implant parameters around short dental implants (SDIs) in treated generalized aggressive periodontitis (GAgP) patients are scant. Objectives This 3-year follow-up study aimed to compare the clinical peri-implant and radiographic bone status around SDIs placed in partially edentulous patients treated for GAgP and periodontally healthy patients and to assess the implant success rate between both the groups. Materials and methods A total of seven patients clinically diagnosed with GAgP and seven periodontally healthy patients was included in the clinical study. Forty-eight (29 maxilla; 19 mandible) and 11 (8 maxilla; 3 mandible) SDIs were placed in the GAgP group and healthy group, respectively. Plaque index (PI), bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL) were recorded at six sites around all teeth and implants. Marginal bone loss (MBL) was studied incorporating in a specialized software and examined on a calibrated computer display screen with the help of an image analyzer. Patient satisfaction was recorded using a questionnaire sheet that contained questions regarding esthetics and function of the restorations. Results The implant survival rate after 3 years was 81.25%. BOP and CAL around SDIs of GAgP patients were significantly higher than in periodontally healthy subjects (P = .01) throughout the follow-up. CAL around the teeth of GAgP patients was significantly greater during the follow-up than around the teeth of periodontal healthy subjects (P = .02). The PI and BOP between the teeth and implants showed no statistical significant difference. The mean PD at teeth was 0.4 mm greater than at implants. Implants showed significantly increased attachment loss than teeth (P = .01). The overall mean satisfaction of visual analogue scale was 12.8 ± 1.45. Conclusion This short-term follow-up study indicates SDIs remain functionally stable in the posterior jaws of treated GAgP patients.

Waste biomass is one of the promising feedstocks for bioenergy generation in present era. The aim of present study is to demonstrate Mango peel as a source of bioenergy, bio-based chemical and phenols productions via pyrolysis, thermodynamics and evolved gas analyses. Therefore, samples were characterized through thermogravimetric analyser, Fourier transform infrared spectrometry (FTIR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Pyrolysis experiments were carried out at different heating rates i.e. 10, 20 and 30 °Cmin−1 and thermodynamic parameters were calculated using different kinetic models. The apparent activation energy was found in range of 88 kJ mol−1 to 304 kJ mol−1 with all kinetic models. Evolved gaseous analysis was performed though out pyrolysis and between three temperature intervals for qualitative and quantitative analysis of pyrolytic compounds. Similarly, effect of temperature and heating rate on pyrolytic compounds concentrations were also carried out. Release of several chemicals, aromatics compounds and high phenols concentration i.e. 21.01 % via Py/GC-MS confirms its potential for bioenergy, bio-based chemicals productions and anti-oxidant characteristics associated with phenolic compounds.

The present study proposed successfully TG-FTIR as a novel technique for high quality bio oil production having desirable concentration of targeted products especially phenols and acids. TG-FTIR analysis of pine waste was performed to calculate yield of desirable chemical compounds at different temperature ranged 350−600 °C. While, bio oil was produced at each corresponded temperatures and GC–MS analysis was carried out to support TG-FTIR analysis which showed high consistency. Additionally, efficient extraction of phenolic compounds was performed via complex method using Ca2+ as a complex agent under alkaline conditions which showed that 95 % phenols were extracted successfully. Meanwhile, production of calcium acetate in residue bio oil turns this study highly valuable for future scientific research.

Hyperbranched Poly(amido amine)s (PAMAM) especially those containing disulfide groups have been highly investigated for DNA condensation, drugs and genes delivery. However, the detailed optical properties of PAMAM, intrinsic fluorescence characteristics and their applications for detection of thiols in pure aqueous medium have not been explored yet. Here we report for the first time the detailed investigation of optical properties of PAMAM and their biosensing application in pure aqueous medium. Three PAMAM named as MBAP (without disulfide group), CBAP and HPAP (with disulfide) groups were chosen, synthesized and characterized. Quantum yields of these PAMAM at different pH value were calculated in pure aqueous medium and all the PAMAM were found to be pH sensitive due to presence of tertiary amine and have shown increase in quantum yields in acidic medium. MBAP was not found to be redox sensitive due to the absence of disulfide group while CBAP has shown low redox sensitivity in aqueous medium because of low water solubility. HPAP has shown high redox sensitivity and high quantum yields hence applied for detection of thiols with the limit of detection of 5.29 mM in pure aqueous medium under physiological conditions. These investigations have not only shown the detailed optical properties of extremely important PAMAM but also broadens their application for bioimaging and biosensing.

In this study, density functional theory and time-dependent density functional theory are used to determine how the size of π-conjugated system influences the absorption spectra and non-linear optical (NLO) properties of dyes. Double and triple bonds, as well the benzene rings, are used in conjugated systems. The results of the theoretical computation show that the absorption spectra are gradually broadened and red-shifted with increases in the conjugation length. Theoretical examination of the NLO properties was performed on the key parameters of polarizability and hyperpolarizability. A notable increase in the non-linear optical response was observed with an increase in the conjugation length of the π-spacer.