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Based on the solution of the Wigner–Boltzmann (WB) equation, quantum correction in the drift-diffusion (DD) model is proposed. The new model, which is a form of the quantum DD model, can show quantum phenomena such as tunneling and quantum repulsion. To evaluate the proposed model, potential barrier and potential wells are simulated. Simulation results show the electron tunneling through and repulsion from the potential barrier.

The use of mobile devices is increasing to exceeds millions of users and has become an important part of daily life. This wide spread has provided new advantages for a wide range of applications. In learning settings, the term M-Learning is considered the latest type of electronic learning introduced as a result of the mobile revolution in which new learning options are provided through mobile applications. This paper presents a review of M-Learning and summarises the main advantages as well as the potential challenges of mobile learning through mobile applications

In this paper a new 3-D analytical model for the potential distribution in nano-scaled lightly doped trigate silicon on insulator MOSFETs in the subthreshold regime, is proposed. This model is derived by solving 3-D Poisson s equation and using parabolic potential distribution assumption between lateral gates. The proposed analytic model is investigated and compared with the obtained results from 3-D simulations using ATLAS device simulator. It is demonstrated that analytic solution has a good accuracy to predict potential distribution along the silicon body.

A new discretization scheme for the current density in the hydrodynamic model is presented. This scheme is an extension of the Scharfetter–Gummel (S–G) method and is derived without neglecting the convective term in the current density. Simulation of two model n–i–n diodes shows that this method gives better numerical results than the conventional upwind and S–G methods.

Cloud computing technology is one of the newest technologies widely used by consumers globally due to its advantages. One of the common advantages is that users can get access to applications and their own files and data on demand. However, there are privacy concerns which discourage users from being active in cloud computing. This paper attempts to investigate the factors that influence consumers’ willingness to use cloud computing services by using a quantitative research approach. A total of 340 cases were gathered from a sampled population of students. Based on SPSS analysis, the study found that perceived privacy control, perceived effectiveness of privacy policy, and information privacy concerns in a cloud computing environment have significant influence on users’ willingness to use cloud computing services.

The Liouville equation for the distribution function is solved and a series solution for the Wigner distribution function is derived. In this solution, potential is nonlocal so that the distribution function in each point is influenced by the potential of the entire space. By computing the carrier density, an effective classical potential is defined. In a quantum system this effective potential replaces the classical potential. Based on the solution of the Liouville equation a novel set of three-dimensional quantum hydrodynamic equations (QHD) is derived. The form of the resulting QHD equations is similar to the classical hydrodynamic (HD) equations but there are explicit quantum corrections which appear in the pressure tensor of electron gas and energy density.

This paper presents radio-frequency (RF) modeling of p-n-p-n double-gate tunneling field-effect transistors (TFETs). The p-n-p-n TFETs are evaluated for various RF parameters such as cut-off frequency, maximum oscillation frequency, gate-source capacitance, gate-drain capacitance, channel resistance, and transconductance. Direct comparisons of high-frequency performances and extracted parameters are made with conventional TFETs. A nonquasistatic radio-frequency model has been used, along with SPICE simulations to investigate p-n-p-n TFETs with RF parameters extracted from TCAD simulation Y-parameters. The results show excellent agreements with the TCAD simulation results for the high frequency range up to the cut-off frequency for the millimeter-wave applications.

Background: Using garlic is widespread in Iran and other countries as a medicine and a natural spice. Garlic is a potential inhibitor for food pathogens. Foods contaminated with pathogens pose a potential danger to the consumer’s health. The use of garlic can increase the shelf life and decrease the possibilities of food poisoning and spoilage in processed foods. Objectives: The aim of this study was to investigate the antibacterial effect of garlic aqueous extract on growth of Staphylococcus aureus bacteria. Materials and Methods: In this study, the garlic aqueous extract was prepared under sterile conditions and was added in 1, 2, and 3 mL to 100g hamburger samples. A group of samples was prepared to be used as treatment sample, while a group was stored at 4°C and -18°C. The samples were kept in refrigerator for one and two weeks and they were frozen for one, two and three months and then subjected to microbial tests. Results: Statistical evaluation of the first and second week samples indicated a significant growth decreased by all the 1, 2, and 3-mL extracts. In treatment of one, two and three-month samples, the growth of S. aureus was significantly decreased by the 2 and 3-mL extracts. The 1-mL extract was effective in decreasing the growth, and a significant difference was observed in treatments with 2 and 3-mL extracts. However, there was no significant difference between the two and three-month samples, though they were significantly different from the one-month samples. After evaluations, treatment with the 2-mL extract was found to be the best one. Conclusions: Garlic aqueous extract has antibacterial properties against S. aureus present in hamburger. Moreover, garlic aqueous extract can be used not only as a flavor but also as a natural additive for hamburger. In addition, garlic has antibacterial properties against other Gram-positive and Gram-negative bacteria, which must be investigated in further studies.

In this study, the effect of ohmic heating technique on electrical conductivity, water evaporation rate, heating rate, colour parameters, pH and energy consumption of tomato samples was investigated. Ohmic heating was accomplished till the moisture content of the tomato samples reduced from initial moisture content of as 9.33 (dry basis) to a safer level of 2.2. The results of the nonlinear mathematical model including the effects of voltage gradient level and the temperature on the electrical conductivity changes had good agreement (R ≥ 0.955) with the experimental data. Also, it was observed that the electrical conductivity increased along with concentration of tomato samples. The range of electrical conductivity during ohmic heating was 3.19–8.95 (S/m). It was found that processing time decreased from 28.32 to 4.3 min over the voltage gradient range studied (6 to 14 V/cm), which resulted in decreased specific energy consumption from 4.63 to 3.05 (MJ/kg water). Due to increasing of heating rate and water evaporation rate at high voltage gradient, the change of the pH was limited. Samples processed in high voltage gradient had higher L*, b* and hue angle (h), lower a* and Chroma (C) values as compared to low voltage gradient. The optimum value of processing time, pH, colour, specific energy consumption was obtained at 14 V/cm voltage gradient level.

An analytical model for double-gate (DG) tunnel FETs (TFETs) using two-dimensional (2-D) solution of Poisson's equation is presented. We derived analytical expressions for the drain current and sub-threshold swing from the maximum electric field using the Kane model. The model is validated via comparing it with TCAD simulation results for different sets of parameters. The results show a good agreement between the model and simulations. The model well predicts the effects of design parameters, such as gate oxide thickness, body thickness, gate oxide dielectric and channel length, on device characteristics which allows us to gain insight on the device operation.

In this paper, a novel double gate tunnel field effect transistor (DGTFET) configuration with p+-layer in the channel is proposed and investigated. The proposed structure is a Si-channel DGTFET, which has a p+-layer in the channel connected to the P+ source region in order to achieve improved switching and higher ON-current when compared to a conventional TFET. The simulation results of DGTFET with p+-layer in the channel shows excellent characteristics with high I ON /I OFF ratio (about 5×1012) and an average subthreshold slope of about 9 mV/decade over 4 decades of current at room temperature. Results suggest that, the DGTFET with p+-layer in the channel seem to be the most optimal ones to replace MOSFET for ultralow power applications and switching devices.

Establishment of Guinea pig fetal fibroblast cells and their biological evaluation before and after cryopreservation were the main purposes of this study. After determination of the proper age of pregnancy by ultrasonography, 30 days old fetuses of Guinea pigs were recovered. Their skins were cut into small pieces (1 mm2) and were cultured. When reaching 80–90% confluence, the cells were passaged. Cells of the second and eighth passages were cultured in 24-well plates (4×104cells/well) for 6 days and three wells per day were counted. The average cell counts at each time point were then plotted against time and the population doubling time (PDT) was determined. Then, vials of cells (2×106cells/mL) were cryopreserved for 1 month and after thawing, the cell viability was evaluated. The PDT of the second passage was about 23 h and for the eighth passage was about 30 h. The viability of the cultures was 95% in the second passage and 74.5% in the eighth passage. It was shown that the Guinea pig fetal fibroblast cell culture can be established using the adherent culture method while, after freezing, the viability indices of these cells were favorable.

The aim of the this study was to have a comparison between Zataria multiflora and Rosemarinus officinalis extracts on quality of minced frozen silver carp preserved in cold storage temperature -18°C for six months. In this research, one control and three treatments of minced silver carp were prepared as Tr1 (+ Zataria), Tr2 (+Rosemary) and Tr3 (mixed with Rosemary and Zataria) all in normal packaging. After quick freezing of samples in the spiral freezer they were preserved in cold storage temperature -18°C for six months. In this period, the changes of Peroxide Value, Total Volatile Nitrogen, Tio Barbituric Acid and Free Fatty Acids in all treatments were measured based on a predetermined schedule. The results of this investigation showed a significant effect of anti-oxidant in all treatments (p

Background: Leptin and adiponectin are two hormones, which are released from adipocytes in order to control energy expenditure. Both hormones are also involved in glucose homeostasis through control of insulin secretion from pancreatic islets. Since Pdx1, PPARγ, and foxm1 play important roles in islets function, it is essential to understand how these genes are regulated in the islets of Langerhans. Objectives: We have designed an experiment to identify the effect of leptin and adiponectin treatment on Pdx1, PPARγ, and foxm1 transcription. Materials and Methods: Islets were isolated from adult male rats by collagenase and incubated with different concentrations of leptin and adiponectin for 24 hours. Next, by means of real time PCR, we evaluated the gene transcription related to a housekeeping gene. The effect of leptin and adiponectin on insulin secretion was evaluated by ELISA. Results: Leptin decreased PPARγ transcription and insulin secretion, while adiponectin significantly increased Pdx1 and PPARγ transcription and insulin secretion in rat islets. The transcription of foxm1 did not change in the islet cells treated with leptin or adiponectin. Conclusions: These findings indicate the possibility that Pdx1 and PPARγ transcription is a mediator of leptin and adiponectin function in control of insulin secretion and glucose homeostasis in pancreatic islets.

In this paper a high performance double gate tunnel field effect transistor (DG-TFET) is proposed. Band gap engineering is achieved in order to improve the device performance. This novel TFET is formed from variable band gap materials with 20 nm channel length to enhance on current and reach to low off-current. With precise selection of mole fraction in materials, Al0.5Ga0.6As and In0.85Ga0.15As are designated to all region in the device and important characterises of TFET are optimized. Low sub threshold swing below 60 mv/dec Ion/Ioff ratio as high as 1012 are the result of the simulation.

In this paper a hetero-junction tunnel field effect transistor (HJ-TFET) with the channel length of 20 nm has been introduced and simulated in which the source/channel hetero-junction is AlxGa1-xAs/InxGa1-xAs. With precise selection of the mole fraction this hetero-junction, excellent device operation has been achieved. With optimized mole fraction and doping value in the source and the channel regions, on-state current as high as 18 μA/μm and very low off-state current of 10-18 is attained. Moreover in the proposed TFET Ion/Ioff ratio is 1013 which is very high. Also sub-threshold swing of 30 mv/decade is achieved which is well below 60 mv/decade.

The comprehensive optical-electrical-gain-thermal self-consistent model of the 1.55 μm AlGaInAs Photonic Crystal vertical cavity surface emitting diode lasers (PhC VCSELs) with buried tunnel junction (BTJ) has been applied to optimize its threshold characteristics. It shows that, for 5 μm devices, the room temperature (RT) threshold current equal to only 0.59 mA and maximum operating temperature equal to as much as 380 K. Results suggest that, the 5 μm AlGaInAs PhC VCSELs seem to be the most optimal ones for light sources in high performance optical communication systems.

The aim of the investigation was to determine the changes in fatty acids profile and chemical quality indexes of Red Tilapia fillets during frozen storage at -18°C. The fish were filleted by hand. The prepared fillets were then placed to the polyamide pouches and stored at -18°C for 150 days. Fatty acid profile, sensory properties and chemical quality indices were determined for a five month period. Results showed that 29 fatty acids were identified in the fresh and frozen samples. Polyunsaturated fatty acids (PUFA) were found higher than saturated fatty acids (SFA) in fresh samples but after 150 days of frozen storage this ratio became reverse. Oleic acid and Linoleic acid were the major MUFA (mono unsaturated fatty acids) and PUFA in fresh and frozen samples, respectively. The ratio of n3/n6 decreased from 0.59 to 0.49. The thiobarbituric acid value (TBA. Mg malondialdehyde/kg) increased significantly (p

In recent decades, the usages of robots in variety of industries have been increased. Self-directed robots have appeared in human lives, specifically, in the areas related to the lives of elderly. The population of old people is significantly growing worldwide. Therefore, there the demand for personal care robots is increasing. The aim of this demand is to enhance the opportunity of mobility and promote independence. In the future, robots care will be in very near contact with people lives. But, what caring roles will robots have at home in the future before old persons? It depends not only on the kinds of robots but also those facets of ageing which are discussed in the paper. This article probes the part and function of robots care in the lifecycle of older adults. It contemplates on the advantages and disadvantages of robots application in human life.

In the last decades, the application of robots in variety of industries has remarkably been increased. Self-governing robots have been employed in various fields of human life, particularly in that of old and very young people. It is assumed that in the succeeding years, personal care robots will be in an intimate relation with human beings. But, what caring responsibilities will the future robots have before children at home? This is directly related to the kinds of robots as well as those aspects of getting old that are the matter of question. Among the topics that are germane to robot carers, Child-care is the least discussed one. In this article the duties of care robots in the life of youth is investigated. It studies the benefits of the application of robots in daily life along with the negative points, perils, and anxieties that rise from the application. In this article, we examine the benefits of the usage of robots in the child life. Besides, we will discuss the disadvantages, dangers and fears that are related to child-robot connections. In the end, we will recommend some useful points.

In this paper, a silicon–on–insulator (SOI) p–n–p–n tunneling field–effect transistor (TFET) with a silicon doped hafnium oxide (Si:HfO2) ferroelectric gate stack is proposed and investigated via 2D device simulation with a calibrated nonlocal band–to–band tunneling model. Utilization of Si:HfO2 instead of conventional perovskite ferroelectrics such as lead zirconium titanate (PbZrTiO3) and strontium bismuth tantalate (SrBi2Ta2O9) provides compatibility to the CMOS process as well as improved device scalability. By using Si:HfO2 ferroelectric gate stack, the applied gate voltage is effectively amplified that causes increased electric field at the tunneling junction and reduced tunneling barrier width. Compared with the conventional p–n–p–n SOI TFET, the on–state current and switching state current ratio are appreciably increased; and the average subthreshold slope (SS) is effectively reduced. The simulation results of Si:HfO2 ferroelectric p–n–p–n SOI TFET show significant improvement in transconductance (∼9.8X enhancement) at high overdrive voltage and average subthreshold slope (∼35% enhancement over nine decades of drain current) at room temperature, indicating that this device is a promising candidate to strengthen the performance of p–n–p–n and conventional TFET for a switching performance.

Background : There has been some evidence that proteins are potentially excellent source of antioxidants, antihypertensive and antimicrobial peptides and enzymatic hydrolysis is an effective method to release these peptides from protein molecules. The functional properties of protein hydrolysates depends on the protein substrate, the specificity of the enzymes, the conditions used during proteolysis, degree of hydrolysis, and the nature of peptides released including molecular weight, amino acid composition, and hydrophobicity. Context and purpose of this study : The biomass of Kluyveromyces marxianus was considered as a source of ACE inhibitory, antioxidant and antimicrobial peptides. Results : Autolysis and enzymatic hydrolysis were completed respectively, after 96 h and 5 h. Overall, trypsin (18.52% DH) and chymotrypsin (21.59% DH) treatments were successful in releasing antioxidant and ACE inhibitory peptides. Autolysate sample (39.51% DH) demonstrated a poor antioxidant and ACE inhibitory activity compared to trypsin and chymotrypsin hydrolysates. The chymotrypsin 3-5 k Da (301.6±22.81 μM TEAC/mg protein) and trypsin< 3 kDa (280.16±39.16) permeate peptide fractions showed the highest DPPH radical scavenging activity. The trypsin

Gene expression in the rodent brain is dependent on exercise. However, our findings regarding this fact are inadequate. The aim of this study was to evaluate the effect of exercise intensity on changes in factors involved in neuronal differentiation and plasticity in the hippocampus of adult male rats. Thus, the effects of 2 weeks treadmill running at of low (11 m/min) and high (25 m/min) intensities, 30 min/day for 14 consecutive days on the expression of two genes, microRNA-124 and neuron restrictive silencer factor/RE1-silencing transcription factor (REST) as well as changes of two proteins of brain-derived eurotrophic factor (BDNF) and tyrosine kinase B (TrkB) were analysed. Using quantitative real-time PCR techniques have shown that both exercise intensities reduced the expression of REST (31% in low exercise intensity, 52% in high exercise intensity) and elevated the expression of miR-124 (3.8-fold in low exercise intensity, 11.9-fold in high exercise intensity)significantly (P≤0.05). This suggests that exercise probably through the changes in these genes is involved in neuronal differentiation in the hippocampus of rats. BDNF and TrkB levels were measured by ELISA. Exercise, at low intensity, increased TrkB (4.51 ng/L vs. 3.73 ng/L) and BDNF (11.97 ng/L vs. 11.08 ng/L) proteins significantly (P≤0.05), while at high intensity,the changes in comparison with the control group were not significant. Expression levels during the exercise programme with high intensity were dramatic for miR-124 and less dramatic for REST compared with low intensity exercise programme.

The cerebellum has been considered a key structure for the processes involved in sensorimotor integration ultimately leading to motor planning and execution of coordinated movement. Thus, motor deficits and behavioral changes can be associated with cerebellar degeneration.Here, the chemical neurotoxin pyridine-2,3-dicarboxylic acid (quinolinic acid, QA) used to create partially cerebellar degeneration in adult Wistar rats suitable for use in stem cell transplantation studies. Stereotaxicaly administration of QA (0.2 mmol) in the right cerebellar hemisphere (folia VI) caused noticeable motor disturbance in all treated animals. Forty-eights hours after causing lesion, rat bone marrow-derived mesenchymal stem cells (MSCs) were transplanted into damaged cerebellar hemisphere. We investigated the role of MSC transplantation in forms of motor and non-motor learning that involves the cerebellum and its neuroprotective effects in Purkinje cells loss.CM-Dil labeling showed that the transplanted MSCs survived and migrated in the cerebellum 6 weeks after transplantation. The MSC-transplanted group showed markedly improved functional performance on the rotating rod test (P≤0.0001) and beam walking test (P≤0.0001) during 6 weeks compared with the controls. For non-motor learning, we used passive avoidance learning test in 3 weeks after transplantation. The results showed that MSC transplantation prevented the development of memory deficit caused by cerebellar degeneration (P≤0.001). Stereological analysis in 6 weeks after transplantation showed that QA significantly decreases Purkinje cells in vehicle-treated rats and MSC transplantation is neuroprotective and decreases Purkinje cell loss in MSC-treated rats (P≤0.0001).The results indicate that transplantation of MSCs can significantly reduce the behavioral and neuroanatomical abnormalities of these animals during 6 weeks after engraftment. According to results of this assay, cell therapy by means of bone marrow-derived adult stem cells promises for treatment of cerebellar diseases.

Nowadays, vicissitude in administrative systems through Performance Measurement (PM) is one of the necessary and inevitable subjects, on which the improvement of efficiency and effectiveness in banking systems depend greatly. In this paper, we focused on efficiency analysis of Tejarat bank branches in order to propose the corrective actions on utilizing resources. Hence, we compute the efficiencies of units based on input-oriented CCR model with three approaches which differ on combination method of inputs and outputs and then rank them by Anderson & Peterson (AP) model. The results represent that the CCR model based on confined fuzzy weights presents the high level of accuracy in identifying efficient units as well as giving useful information on improving the inefficient branches.

Spermatogenesis is supported by a certain type of stem cell known as spermatogonial stem cell (SSC), which transforms information to the next generation. There is currently a wide acceptance of the great potential applications of SSCs for infertility treatment and production of transgenic farm animals. However, rodents are the only thoroughly studied mammals with respect to SSCs due to presence of specific antibodies for SSC markers such as PLZF and THY1 or germ cell marker such as VASA. However, limited information is available about the specific markers of SSCs in farm animals. Moreover, while it is generally believed that stem cell markers are mainly conserved among mammalian species, it is not clear if SSC markers have also remained conserved during species evolution. Through comparative immunohistochemical analysis of testis tissue of sheep, and goats with mice, rats and cattle, for which the original antibodies were rose, this study suggests that, despite the long evolutionary distance which exists between rodents and farm animals, germ cells and SSC markers may have remained conserved between these species. In addition, the results of this study suggest that these antibodies can be used to isolate, propagate and further explore SSCs in goat or sheep and possibly other species.

In this paper numerical optimum base doping for minimum base transit time is presented. The bandgap-narrowing effect, high-injection effect, and carrier velocity saturation at the base edge of the base collector junction, and also doping and field dependence of mobility, are considered. Many doping profile are investigated including, linear, exponential doping concentration, we assumed uniform, exponentially and Gaussian doping profiles. Base transit time is investigated numerically for optimum base doping profile.

This paper presents the 3.4-GHz wideband bandpass filter using coupled compact microstrip-line that the bandwidth of this filter is approximately 55 percent of the central frequency at the return loss of 7.2 dB The parallel-coupled lines at the two sides are longitudinally stretched so as to raise the frequency dispersive coupling degree with the coupling peak near the center of the UWB. The main advantages of this filter are its small size, low cost, high quality factor and low radiation loss.

Recently, Ad Hoc networks are getting more popularity since their ease of deployment. These networks do not have any pre-existing infrastructures and users of such a network are relieved from a centralized administration. Since an Ad Hoc network consists of wireless host which may be mobile, its topology changes dynamically. Such an environment requires special routing protocols which are different with those used in fixed networks. A variety of routing protocols capable of adapting Ad Hoc networks topologies have been proposed. This thesis presents studying of five famous wireless Ad Hoc routing protocols which are WRP, DSR, FSR, LAR and DREAM. Simulation results have been used to compare efficiency and effectiveness of above-mentioned routing protocols. The Simulation results show that on-demand protocols are better suited for mobile Ad Hoc networks. They generate less control overhead messages and manage the mobility of nodes more efficiently. However they produce extra delay in acquiring routes which reduces their efficiency in delivering real-time traffic. Also it can be seen that all of the protocols operates much better with the group mobility model than with the random waypoint model.

In this paper we propose a new dual gate SOI-MOSFET in order to reduce short-channel effects (SCEs). In the proposed structure, the bias of the second gate which is near the drain is dependent on the drain voltage. To investigate transistor characteristics, a two-dimensional (2-D) analytical model for the surface potential variation along the channel is developed. A comparison between our structure and the single-gate (SG) SOI MOSFET demonstrates that short channel effects like, hot carriers effect and the drain induced barrier lowering (DIBL) are reduced considerably in the proposed structure.

In this paper the effects of random distribution fluctuations of dopants in the channel of a nano-scale SOI-MOSFET are investigated via simulations. Simulations are performed using energy balance model. According to obtained results, the threshold voltage is subjected to variations due to non-uniform distribution of dopants under the gate.

In this paper a new transistor of dual-gate (DG) silicon-on- insulator (SOI) MOSFET is presented. The objects of this paper are to use a voltage difference between the two gates to screen the drain voltage and therefore reduce short channel effects (SCEs). In this transistor the surface potential exhibits a step function, which causes the screening of the drain potential. This results in suppressed SCEs such as the hot-carrier effect and decreasing off-current with respect to shrinking of channel length. The obtained results of our transistor are compared to single gate (SG) SOI MOSFET that shows the DG SOI MOSFET performance is superior. The transistor has been simulated by SILVACO software.

The drift-diffusion (DD) model is not accurate for simulation of submicrometer semiconductor devices. Using RBF NN, a neuro space mapping is proposed to DD model parameters. The DD model with mapped parameters can produce accurate simulation results of the hydrodynamic model. Simulations of a n-i-n diode confirm the ability of the proposed method for submicron device simulation.

The drift-diffusion (DD) model is not accurate for simulation of sub-micrometer semiconductor devices. Using RBF NN, a neuro space mapping is proposed to DD model parameters. The DD model with mapped parameters can produce accurate simulation results of the hydrodynamic model. Simulations of a SOI-MOSFET confirm the ability of the proposed method for submicron device simulation.

In this paper, a symmetric dual-emitter LBJT (SDE LBJT) structure on TFSOI substrates has been designed and simulated, and suitable doping profiles are used for improving LBJT performance. Simulations show that the device has good DC characteristics. The SDE LBJT with a base length of 0.2µm can achieve a current gain over 1500, which is 7.5 times improvement in current gain, in comparison to the LBJT reported previously. Also has good current drive and high frequency capability. These results indicate that the SDE LBJT structure is suitable for many low power mixed mode applications.

In this paper, a simple and accurate analytical model for current-voltage and Transconductance characteristics of Al m Ga 1−m /GaN modulation doped field effect transistors (MODFETs) devices is presented. In proposed model, the effects of spontaneous and piezoelectric polarization at the hetero-interface and gate-voltage dependence of the Fermi level are considered. Variation of drain current after saturation, parasitic resistance of drain and source, field-dependent mobility, are contained in the model and gate to source dependant is utilized for the low field mobility. By implement model in MATLAB current-voltage characteristics and transconductance have been obtained. The agreement between the model and experimental result validate the proposed analytical model.

In this paper a two-dimensional (2-D) analytical model for the surface potential variation along the channel in a fully depleted dual?gate silicon-on-insulator MOSFETs is proposed to investigate the short-channel effects (SCEs). We demonstrate that the surface potential in the channel region exhibits a step function which causes the screening of the drain potential by the gate near the drain resulting in suppressed SCEs like hot-carrier effect and drain-induced barrier-lowering (DIBL).

In this paper the effect of the gate length on the operation of SOI-MOSFETs is evaluated via simulations. Three transistors with gate lengths 100, 200 and 500 nm are simulated. Simulations show that with a fixed channel length, when the gate length is increased, the curve slope ID-VGS is increased, and therefore the transistor trans-conductance increases. Moreover, with increasing the gate length, the effect of the drain voltage on the drain current is reduced, which results in decreasing of the drain induced barrier lowering (DIBL).

In order to reduce short channel effects, a new dual gate SOI MOSFET is proposed. In the proposed structure, a second gate is used with a drain dependent bias to screen the drain voltage and consequently reduce the threshold voltage reduction due to drain induced barrier lowering. Simulations show considerable improvement in short channel effects.

This paper presents a radio-frequency (RF) small-signal model for the hetero-gate-dielectric p-n-p-n tunnel field-effect transistor (HG p-n-p-n TFET) that includes the charge conservation capacitance and the substrate parameters. The HG p-n-p-n TFET is evaluated in terms of various RF parameters, including the cut-off frequency, the maximum oscillation frequency, capacitances, resistances, conductances, and transport time delay. The extracted small-signal parameters and RF performance values are compared with those of the low-κ p-n-p-n TFET. A nonquasistatic RF small-signal model has been used along with SPICE simulations and small-signal parameters that were extracted from the simulated device Y-parameters to simulate the HG p-n-p-n TFET. It is confirmed using the Y-parameters and the extracted parameters that this model with the extracted charge conservation capacitance and substrate parameters is valid in the high frequency range up to 100 GHz. In addition, it is shown that a significant circuit performance error may be introduced if the charge conservation capacitance and the substrate parameters are not considered appropriately.

Intermediate-moisture figs obtained by rehydration of dried figs are more suitable for direct consumption. Colour and texture are the most important quality attributes, which influence the acceptability of this product. In this research the kinetic of color and texture changes in rehydrated figs were studied as a function of time and temperature (25-90 °C). All hunter colour parameters (L*, a* and b*) were used to estimate the extent of colour change during rehydration. Results indicated that among different kinetic models, a combined kinetic model provided the best fit. Moreover, texture development kinetics over all temperature ranges were satisfactorily described by means of first-order kinetic model compared with second-order, Weibull and Peleg models. Model parameters including texture softening (k) and residual constant (A) values were calculated which also confirmed the decrease in firmness of the dried figs due to the plasticization effect of water intake. The Arrhenius model described well the temperature dependence of the reaction rate constant for colour and texture parameters, Intermediate-moisture figs obtained by rehydration of dried figs are more suitable for direct consumption. Colour and texture are the most important quality attributes, which influence the acceptability of this product. In this research the kinetic of color and texture changes in rehydrated figs were studied as a function of time and temperature (25-90 °C). All hunter colour parameters (L*, a* and b*) were used to estimate the extent of colour change during rehydration. Results indicated that among different kinetic models, a combined kinetic model provided the best fit. Moreover, texture development kinetics over all temperature ranges were satisfactorily described by means of first-order kinetic model compared with second-order, Weibull and Peleg models. Model parameters including texture softening (k) and residual constant (A) values were calculated which also confirmed the decrease in firmness of the dried figs due to theplasticization effect of water intake. The Arrhenius model described well the temperature dependence of the reaction rateconstant for colour and texture parameters.Keywords: Dried figs; Rehydration; Kinetics model; Colour; Texture

Gene expression in the rodent brain is dependent on exercise. However, our findings regarding this fact are inadequate. The aim of this study was to evaluate the effect of exercise intensity on changes in factors involved in neuronal differentiation and plasticity in the hippocampus of adult male rats. Thus, the effects of 2 weeks treadmill running at of low (11 m/min) and high (25 m/min) intensities, 30 min/day for 14 consecutive days on the expression of two genes, microRNA-124 and neuron restrictive silencer factor/RE1-silencing transcription factor (REST) as well as changes of two proteins of brain-derived eurotrophic factor (BDNF) and tyrosine kinase B (TrkB) were analysed. Using quantitative real-time PCR techniques have shown that both exercise intensities reduced the expression of REST (31% in low exercise intensity, 52% in high exercise intensity) and elevated the expression of miR-124 (3.8-fold in low exercise intensity, 11.9-fold in high exercise intensity)significantly (P≤0.05). This suggests that exercise probably through the changes in these genes is involved in neuronal differentiation in the hippocampus of rats. BDNF and TrkB levels were measured by ELISA. Exercise, at low intensity, increased TrkB (4.51 ng/L vs. 3.73 ng/L) and BDNF (11.97 ng/L vs. 11.08 ng/L) proteins significantly (P≤0.05), while at high intensity,the changes in comparison with the control group were not significant. Expression levels during the exercise programme with high intensity were dramatic for miR-124 and less dramatic for REST compared with low intensity exercise programme.

In this paper, the potential impact of drain side-double recessed gate (DS-DRG) on silicon carbide (SiC)-based metal semiconductor field effect transistors (MESFETs) is studied. We investigate the device performance focusing on breakdown voltage, threshold voltage, drain current and dc output conductance with two-dimensional and two-carrier device simulation. Our simulation results demonstrate that the channel thickness under the gate in the drain side is an important factor in the breakdown voltage. Also, the positive shift in the threshold voltage for the DS-DRG structure is larger in comparison with that for the source side-double recessed gate (SS-DRG) SiC MESFET. The saturated drain current for the DS-DRG structure is larger compared to that for the SS-DRG structure. The maximum dc output conductance in the DS-DRG structure is smaller than that in the SS-DRG structure. (Some figures in this article are in colour only in the electronic version)

In this paper, a simple and accurate analytical model for current–voltage and small-signal characteristics of Al m Ga1-m N/GaN modulation doped field-effect transistor (MODFET) devices is presented. For the charge control model, Fermi potential variation with sheet carrier concentration, the infiltration of a two-dimensional electron gas wave function into the spacer layer, and the effects of spontaneous and piezoelectric polarizations at the heterointerface are considered. Also, parasitic source/drain resistances have been incorporated in the analysis. In addition, a suitable drift velocity model and the gate voltage dependence of low-field mobility are used to provide simple and accurate equations for the different characteristics of AlGaN/GaN MODFET devices. By implementing the model in the MATLAB environment, current–voltage characteristics, transconductance, output conductance, capacitance–voltage characteristics, and cutoff frequency have been calculated. A comparison of simulation results with published experimental data for Al0.15Ga0.85N/GaN shows excellent agreement, thereby proving the validity of the model.

The gate tunnelling current of MOSFETs is an important factor in modelling ultra-small devices. In this reported work, the gate tunnelling current in present-generation MOSFETs is studied. Presented is a model for the gate tunnelling current in MOSFETs having ultra-thin gate oxides. In the proposed model, the electron wavefunction at the semiconductor–oxide interface is calculated and inversion charge by assuming the inversion layer as a potential well, including some simplifying assumptions. Then the gate tunnelling current is calculated using the calculated wavefunction. The proposed model results have excellent agreement with experimental results in the literature.