79 research outputs found
Theoretical treatment of diffusion and kinetics of osmium redox polymer mediated glucose oxidase enzyme electrodes: analytical expression of current density for varying potential.
We present for the first time a mathematical model of osmium redox polymer mediated glucose oxidase enzyme electrodes. This model is based on a system of three coupled nonlinear reaction-diffusion equations under steady-state conditions for biochemical reactions occurring in the biofuel cells that describes the oxidized mediator, oxygen and substrate (Glucose) concentration within the biofuel cell. Simple analytical expressions for the concentration of oxidized mediator, oxygen and substrate and the corresponding current-potential response have been derived for all the values of reaction diffusion parameters using the new homotopy perturbation method (NHPM).The current-potential response in osmium redox polymer mediated glucose oxidase enzyme electrodes is discussed. The analytical results for the concentrations are also compared with numerical results and a satisfactory agreement is noted. The influence of diffusion coefficient of mediator, thickens of the film, turnover rate of Gluocose Oxidase and Michaelis-Menten constant on current-potential curve is also analyzed
Gene delivery using dendrimer/pDNA complexes immobilized in electrospun fibers using the layer-by-layer technique
Tissue engineering is an important branch of regenerative medicine that uses cells, materials (scaffolds), and suitable biochemical and physicochemical factors to improve or replace specific biological functions. In particular, the control of cell behavior (namely, of cell adhesion, proliferation and differentiation) is a key aspect for the design of successful therapeutical approaches. In this study, poly(lactic-co-glycolic acid) (PLGA) fiber mats were prepared using the electrospinning technology (the fiber diameters were in the micrometer range). Furthermore, the electrospun fiber mats thus formed were functionalized using the layer-by- layer (LbL) technique with chitosan and alginate (natural and biodegradable polyelectrolytes having opposite charges) as a mean for the immobilization of pDNA/dendrimer complexes. The polyelectrolyte multilayer deposition was confirmed by fluorescence spectroscopy using fluorescent-labeled polyelectrolytes. The electrospun fiber mats coated with chitosan and alginate were successfully loaded with complexes of pDNA and poly(amidoamine) (PAMAM) dendrimers (generation 5) and were able of releasing them in a controlled manner along time. In addition, these mats supported the adhesion and proliferation of NIH 3T3 cells and of human mesenchymal stem cells (hMSCs) in their surface. Transfection experiments using a pDNA encoding for luciferase showed the ability of the electrospun fiber mats to efficiently serve as gene delivery systems. When a pDNA encoding for bone morphogenetic protein-2 (BMP-2) was used, the osteoblastic differentiation of hMSCs cultured on the surface of the mats was promoted. Taken together, the results revealed that merging the electrospinning technique with the LbL technique, can be a suitable methodology for the creation of biological active matrices for bone tissue engineering
Estimation and compensation of IQ imbalance in SWIPT system
Although there are many articulations of SWIPT architecture implementations, the hardware impairment aspect involved in the SWIPT architecture system is not given much attention. This paper evaluates the performance of SWIPT PS Reciever architecture in the presence of IQ imbalance hardware impairment with 16-QAM transmitter and AWGN channel. The parameters SNR, BER is evaluated in the presence of amplitude, phase imbalance, and PS factor at the SWIPT receiver side. Further, the IQ imbalance is estimated and compensated using a blind compensation algorithm. The system achieved a maximum BER of 10−7 in the presence of amplitude and phase imbalance of 0.2 and 1.6 respectivel
Wireless Power Transfer for Electric Vehicles Application using the Principle of ICPT System
Wireless Power Transfer is method of transferring the power from the power source to the electrical load without the physical contact, by using the principle of magnetic resonance. Due to the increase in the cost of the petroleum product and environmental issues led to development of the Electrical Vehicles (EV’s) globally for transportation. The charging of electric vehicles using wire causes losses therefore, it decrease in efficiency of the system. The preliminary review of the WPT analysis tells that the Inductively Coupled Power Transfer system ICPT is one of the promising and convenient methods for charging the EV’s. The paper is about designing the circuit using the MATLAB Simulink Software .The results for different values of load versus Efficiency of the system of ideal case is been plotted were the maximum efficiency is around 98% assuming the alignment errors as zero. The system parameters and performance equations are coded using MATLAB for Model based design for charging the EV application. Also, efficiency and load curve characteristics are demonstrated. The paper demonstrates the experimental setup of the same for the distance of about 15 cm. Each part of the setup and the components used along with their features has been discussed briefly. The same setup for higher power rating can be implemented in future with design modifications
Kinetic mechanism for modelling of electrochemical mediatedenzyme reactions and determination of enzyme kinetics parameters.
The non-steady state current density for reversible electrochemical coupled with a homogeneous enzyme reaction and a constant potential is presented in this manuscript for the first time. The model is based on non-stationary diffusion equations with semi infinite boundary condition containing a nonlinear term related to the kinetics of an enzymatic reaction. The nonlinear differential equation for the mediator is solved for reversible homogeneous enzyme reaction. Approximate analytical expressions for the concentration of the mediator and corresponding current for non-steady state conditions are derived. Kinetic parameters are also determined such as Michaelis–Menten constants for substrate (KMS) and mediator (KMM) as well as catalytic rate constant (kcat). Upon comparison, we found that the analytical results of this work are in excellent agreement with the numerical (Matlab program) and existing limiting case results. The significance of the analytical results has been demonstrated by suggesting two new graphical procedures for estimating the kinetic parameters from the current densities
A Solar Photovoltaic Performance Monitoring and Statistical Forecasting Model Using a Multi-Layer Feed-Forward Neural Network and Artificial Intelligence
إن الطبيعة الطبوغرافية لسلطنة عمان تجعل نظام الطاقة الشمسية خيارًا قابلاً للتطبيق وموثوقًا لإنتاج الطاقة بكميات كبيرة في سوق الطاقة المتجددة. تشهد العديد من المناطق الصحراوية في عمان مستويات عالية من الإشعاع الشمسي. وهذا مناسب للأنظمة الكهروضوئية لأن كفاءتها تعتمد بشكل أساسي على الإشعاع الشمسي. ومع ذلك، في التطبيقات في الوقت الفعلي، تؤثر العديد من العوامل البيئية على كفاءة الألواح الشمسية وبالتالي على أدائها. في هذه المقالة، تم اقتراح الشبكة الطبيعية (العصبية) الأمامية متعددة الطبقات (MFFN) لتتبع أداء نظام الطاقة الشمسية الكهروضوئية من أجل استبدال أو تحسين أداء نظام الطاقة الشمسية الكهروضوئية بناءً على حالته الحالية. يتم استخدام خوارزمية الانتشار العكسي (BPA) لتدريب MFFN.The topographical nature of the Sultanate of Oman makes the solar power system a viable and reliable option for bulk power production in the renewable energy market. Many desert areas of Oman experience high levels of solar radiation. This is suitable for photovoltaic (PV) systems as their efficiency mainly depends on solar radiation. However, in real-time applications, many environmental factors affect the efficiency of the solar panel and therefore its performance. In this article, the Multilayer Feed Forward Neural Network (MFFN) is proposed to track the solar PV system performance in order to replace or improve the performance of the solar PV system based on its current state. A backpropagation algorithm (BPA) is used to train the MFFN
The analysis and fabrication of a novel tin-nickel mixed salt electrolytic coloured processing and the performance of coloured films for Al-12.7Si-0.7Mg alloy in acidic and alkali corrosive environments.
We present for the first time the analysis and fabrication of a novel Tin-Nickel mixed salt electrolytic coloured processing and the performance of coloured films for Al-12.7Si-0.7Mg alloy. This alloy is a novel alloy containing high silicon aluminum alloy extrusion profile which presents excellent mechanical properties as well as broad market prospects. Nevertheless, this kind of material is urgent in need of surface treatment technology. The orthogonal design and single factor tests were applied to optimize for electrolytic coloured technological conditions. By controlling operation conditions, the uniform electrolytic coloured films with different color were obtained. Analysis of microstructure showed that tin particles had been deposited in the coloured film. The coloured films, about 10 mu m thick, were uniform, dense and firmly attached to the substrate. After the coloured samples were maintained at 400AC for 1 h, or quenched from 300AC to room temperature, the coloured films did not change, demonstrating excellent thermostability and thermal shock resistance. Acid and alkali corrosion tests and potentiodynamic polarization showed that corrosion resistance of coloured sample was much better than those of untreated samples. After 240 h neutral salt spray test, protection ratings and appearance ratings of coloured films were Grade 9
Proposed classification for interproximal contacts of primary molars using CBCT: a pilot study [version 2; referees: 2 approved]
Background: Interproximal contact areas in primary teeth are known to be broader, flatter, and situated more gingivally than in permanent teeth. The objective of the present study was to evaluate the different types of intact interproximal contact areas in primary teeth using cone beam computed tomography (CBCT) among children. Methods: A cross-sectional study was designed with 74 contacts from 28 existing CBCT images of children aged between 3 and 14 years, obtained from the Indian Dental Education Academy, Chennai, India. The shape of the contact area was observed at three levels, the coronal, middle, and apical thirds, in three different sections of CBCT. Prevalence of the types of contact areas was expressed in the form of numbers and percentages. Results: The weighted Cohen’s kappa values for inter-examiner reliability was 0.893 at baseline. Results exhibited four different types of contact areas between the primary molars, namely, O type, X type, I type, and S type, based on the shapes observed; hence, the proposed classification is referred to as OXIS. The most common pattern seen was I (66.2%), followed by X (21.6%), O (9.4%) and the least common was S (2.7%). Conclusion: The three-dimensional evaluation of intact interproximal contact areas between primary molars are of four types, O,X, I and S
Proposed classification for interproximal contacts of primary molars using CBCT: a pilot study [version 1; referees: 2 approved]
Background: Contact areas in primary teeth are known to be broader, flatter, and situated more gingivally than in permanent teeth. The objective of the present study was to evaluate the different types of intact contact areas in primary teeth using cone beam computed tomography (CBCT) among children. Methods: A cross-sectional study was designed with 74 contacts from 28 existing CBCT images of patients aged between 3 and 14 years, obtained from the Indian Dental Education Academy, Chennai, India. The shape of the contact area was observed at three levels, the coronal, middle, and apical thirds, in three different sections of CBCT. The weighted Cohen’s kappa values for inter-examiner reliability was 0.893 at baseline. Prevalence of the types of contact areas was expressed in the form of numbers and percentages. Results: Results exhibited four different types of contact areas between the primary molars, namely, O type, X type, I type, and S type, based on the shapes observed; hence, the proposed classification is referred to as OXIS. The most common pattern seen was I (66.2%), followed by X (21.6%), O (9.4%) and the least common was S (2.7%). Conclusion: The three-dimensional evaluation of intact interproximal contact areas between primary molars are of four types
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