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Background Recently, physical class-attendance of students has drastically reduced in medical schools. Many reasons have been postulated and several remedial measures advocated.Methods In order to improve the students’ attendance in classes, we used a novel method by including a real patient-scenario relating to the day’s topic. We removed the case scenario from the posting of lecture note on Learning Management System (LMS) the previous evening. We also involved the students in the case discussion during the lecture which makes the lecture interactive. Student attendance was reported for three lectures before and after application of the new strategy.Results The student average attendance for both year 3 and year 4 was reported before and after applying the intervention. By statistical analysis of the attendance percentage, there was an increase in the average of attendance and this increase was found highly significant, which indicates an improvement in the student class-attendance after applying the proposed modification in lecture delivery and hand out posting on LMS.Discussion Starting the class with a patient-scenario based on the topic, and motivating the students to participate in the open Q and A discussion makes the lecture more interesting for the students. Since they will face the patients with common problems during their clerkship training, starting in next few months to a year, which makes it more meaningful. By analyzing the class attendance average for a minimum of three classes before and after implementing this intervention, we noticed a significance improvement in the overall attendance for both year 3 and year 4.

Partial shading conditions decreases the output power from photovoltaic systems and causes multiple ‎maximum power points on output characteristics because of the mismatching power losses among the PV ‎modules. The shading pattern, the shaded area and the PV array topology are the main factors which affects the ‎mismatching power losses. The main aim of this paper is to study and enhance the ‎performance of a PV system under different array topologies and partial shading conditions and reach to the ‎most convenient topology. PV array topologies including series, parallel, series-parallel and total-cross-tied are ‎studied. Row, column, narrow, wide, middle and random partial shading patterns are considered at the ‎different PV array topologies. The performance is measured according to the maximum output power, ‎mismatching power losses, fill factor, efficiency, open circuit voltage and short circuit current. The parameters and data specification ‎of Suntech Power STD250-20/Wd‎ PV module are used for the simulation based on MATLAB/Simulink ‎software.‎

Static Synchronous Compensation (STATCOM) is considered as one of the famous modules of the Flexible AC Transmission Systems (FACTS) devices. This paper discusses the optimum voltage control technique using the STATCOM module with the transmission system to overcome the drop and the influence factors for the voltage in the power system. In addition, this paper discusses the impact of using the zigzag transformers with the STATCOM control system to prevent the combination between the STATCOM injection voltage and the harmonics to reach pure voltage compensation. The simulation in this paper uses the MATLAB/Simulink software to introduce the STATCOM operation steps, also the proposed analysis of the distribution system network has been validated with IEEE-14 busbar system as a case study to test the increasing loadability by using STATCOM module for enhancing the power system quality.

This paper presents a detailed study of on-chip spiral inductors with patterned ground shield (PGS) inserted between the spiral inductorand the silicon substrate. This new design has been implemented in source degeneration cascode lownoise amplifier (LNA) circuit to show how the PGS inductors improve the performance of the circuit. An operation in 1.8V supply voltage, source degeneration cascode LNA structure was studied with both technology and PGS inductors. In this paper, the Agilent ADS (Advanced Design System) simulation software and TSMC 0.18μm CMOS process parameters were adopted to achieve the low-cost characteristics and high integration to fit the performance of 2.4 GHz LNA design under IEEE 802.11a specification.According to the co-simulation results, the forward gain (S21) improved from 13.432 to 21.474 dB, and the (S12)is below the typical value of -15dB. The input impedance (S11) and the output impedance (S22) also represented good performance. In addition, the minimum noise figure was quite good. Thus, the LNA circuit with PGS inductorswas better in the availability and the possibility of 802.11a specification.

Power system quality is a vital issue for electricity companies and consumers of low and medium voltage. So as to decrease the generation power from fossil fuel, it is important to depend on the renewable energy sources which consider as low running cost and low environmental aspects as compared with the traditional power generation. Distributed generation (DG) unit can be defined as a small-scale unit that generates the electric power near the location of customers based on renewable energy sources, including wind energy, solar energy, and geothermal energy. Interconnecting DG with the utility grid can contribute by different advantages to the owner, utility, and the final user. DG gives an improved power quality and higher dependability of the distribution system. In any case, the integration of DG with the existing power system has associated several technical, economic, and regulatory questions. This study discusses the effect of using the DGs with the power system focuses on wind power generation for voltage control and power losses reduction. The simulation analysis in this context has been validated with IEEE-12 Busbars distribution power system as an example to shows the voltage control and power losses reduction. The highlight points from this study to advice and recommends the power system designer to consider the wind DGs with the distribution network for enhancing the power system quality.

Wind generation is considered as one of the optimum renewable energy sources due to its more saving running cost, zero-emission, and friendly environment at comparing with the traditional power plants. Using the wind farms with the utility grid can’t reach the optimum compensation during any abnormal condition in the power system. Distributed Static Synchronous Compensators (D-STATCOM) is a power electronic control system to be used with the distribution power network for harmonics current elimination, reactive power compensation, voltage regulation, voltage flicker mitigation, and frequency regulation. D-STATCOM provides effective compensation to the unbalance or the nonlinear loads by injecting the required accurate value at the Point of Common Coupling (PCC) depending on the Voltage Source Converter (VSC). This chapter proposes a design procedure of a high-power D-STATCOM with the distribution network linked with the wind generation for enhancing the power system quality. The proposed simulation in this chapter has been done using the MATLAB/Simulink software for distribution voltage control, loadability, and power loss reduction using the D-STATCOM control techniques with the electrical distribution network.

Worldwide energy consumption is increasing at a faster pace than energy generation because of enhanced industrialization, growing population and, improved living standards. Using the Distributed Generation (DG) near the end consumers can support the electrical grid stability and enhance the power system quality. The DG is consisting of a small-scale technology to generate electrical power near the end consumers, which can be renewable energy or generators. Solar Photovoltaic (PV) system is considered as one of the best renewable energy sources, due to its low running cost and low environmental affection comparing with traditional power plants. The proposed PVDG units are employing maximum power point tracking (MPPT) system to track the maximum power available in PV arrays. The proposed DG system used Particle Swarm Optimization (PSO) technique to optimally allocate the PVDG units for minimum cost, transmission line losses, and improved voltage profile of busbars under different operating conditions. This paper proposes a smart optimization technique employing PSO in the design, operation, and control of the proposed system. Also, the paper discusses the PSO algorithm for optimal DGs sizing and allocations. The simulation in this paper uses the IEEE-7 busbars system with an extension of IEEE-3 busbars as a new remote load. The simulation has been carried out by the power world simulator software to compare the voltage and the power losses with and without PVDGs connected to the system. The simulation results showed an acceptable reduction in generating cost, transmission line losses, and improvement of the busbars voltage profile which proves the success of the proposed system.

Sub-Saharan Africa carries the biggest burden of the human immunodeficiency virus type 1 (HIV-1)/AIDS epidemic and is in an urgent need of an effective vaccine. CD8+ T cells are an important component of the host immune response to HIV-1 and may need to be harnessed if a vaccine is to be effective. CD8+ T cells recognize human leukocyte antigen (HLA)-associated viral epitopes and the HLA alleles vary significantly among different ethnic groups. It follows that definition of HIV-1-derived peptides recognized by CD8+ T cells in the geographically relevant regions will critically guide vaccine development. Here, we study fine details of CD8+ T-cell responses elicited in HIV-1/2-uninfected individuals in Nairobi, Kenya, who received a candidate vaccine delivering conserved regions of HIV-1 proteins called HIVconsv. Using 10-day cell lines established by in vitro peptide restimulation of cryopreserved PBMC and stably HLA-transfected 721.221/C1R cell lines, we confirm experimentally many already defined epitopes, for a number of epitopes we define the restricting HLA molecule(s) and describe four novel HLA-epitope pairs. We also identify specific dominance patterns, a promiscuous T-cell epitope and a rescue of suboptimal T-cell epitope induction in vivo by its functional variant, which all together inform vaccine design.

Sub-Saharan Africa carries the biggest burden of the human immunodeficiency virus type 1 (HIV-1)/AIDS epidemic and is in an urgent need of an effective vaccine. CD8+ T cells are an important component of the host immune response to HIV-1 and may need to be harnessed if a vaccine is to be effective. CD8+ T cells recognize human leukocyte antigen (HLA)-associated viral epitopes and the HLA alleles vary significantly among different ethnic groups. It follows that definition of HIV-1-derived peptides recognized by CD8+ T cells in the geographically relevant regions will critically guide vaccine development. Here, we study fine details of CD8+ T-cell responses elicited in HIV-1/2-uninfected individuals in Nairobi, Kenya, who received a candidate vaccine delivering conserved regions of HIV-1 proteins called HIVconsv. Using 10-day cell lines established by in vitro peptide restimulation of cryopreserved PBMC and stably HLA-transfected 721.221/C1R cell lines, we confirm experimentally many already defined epitopes, for a number of epitopes we define the restricting HLA molecule(s) and describe four novel HLA-epitope pairs. We also identify specific dominance patterns, a promiscuous T-cell epitope and a rescue of suboptimal T-cell epitope induction in vivo by its functional variant, which all together inform vaccine design.

Alteration in cytokine levels, particularly, IL-6, TNF-α, IL-1β and IL-2, has been implicated in the pathogenesis of epilepsy and bipolar disorder. Lamotrigine (LTG), an antiepileptic drug with mood stabilizing properties, has documented immunomodulatory effects. However, its effect on cytokine secretion in vivo has not been examined. Besides, studies have reported inconsistent results of the in vitro effects of LTG on cytokine secretion. Hence, we used murine models of inflammation to characterize the in vivo and the in vitro effects of LTG on the secretion of the aforementioned cytokines, using ELISA. LTG significantly inhibited basal and mitogen-induced IL-6, TNF-α and IL-1β secretion in vivo and in LPS-treated RAW264.7 cells in vitro. In PMs, LTG inhibited basal and LPS-induced IL-6 and TNF-α secretion. Our findings extend the current understanding of the anti-inflammatory properties of LTG and may be relevant to its role in modulating the immune system in epilepsy and bipolar disorder.

Modulation of the immune system has recently been shown to be involved in the pharmacological effects of old antiepileptic drugs and in the pathogenesis of epilepsy. Therefore, the most recent guidelines for immunotoxicological evaluation of drugs were consulted to investigate the immunomodulatory effects of lamotrigine, a newer antiepileptic drug, in BALB/c mice. These included the in vivo effects of lamotrigine on delayed-type hypersensitivity (DTH) response to sheep red blood cell (SRBC) antigens, hemagglutination titer assays and hematological changes. In vitro effects of lamotrigine on ConA-induced splenocyte proliferation and cytokine secretion were assessed. The results showed that lamotrigine treatment significantly increased the DTH response to SRBC in the mouse model of this study. This was accompanied by a significant increase in relative monocyte and neutrophil counts and in spleen cellularity. Lamotrigine significantly inhibited ConA-induced splenocyte proliferation in vitro and it significantly inhibited IL-2 and TNF-α secretion in ConA-stimulated splenocytes. In conclusion, the results demonstrated significant immunomodulatory effects of lamotrigine in BALB/c mice. These data could expand the understanding of lamotrigine-induced adverse reactions and its role in modulating the immune system in epilepsy.

Static Var Compensation (SVC) is consists of power electronics circuits to be used with the electric power system for voltage control. SVC is considered as one of the most important and famous modules from the Flexible AC Transmission System (FACTS) devices. SVC is the economic constraints to affect the real network under variation of system operating conditions to maintain the voltage levels and to control the active and reactive power flows. The controlling system by the thyristors into the SVCs modules is more effective to provide fast-acting reactive power compensation. This paper discusses the optimum voltage control techniques using the SVC module with the transmission line to overcome the drop and the influence factors for the voltage in the power system. This paper uses the MATLAB/Simulink software to introduce the thyristors operation steps at coupling the shunt SVC module with the power system to reach the optimal compensation at the voltage drop in the power system. The simulation in this paper has been carried with IEEE-9 busbar distribution system as an example to shows the difference voltage and the power losses without and with SVC installation with the power system.

BACKGROUND HNSCC is the sixth most common human cancer globally. In Saudi Arabia, HNSCC accounts for seven percent of all newly diagnosed cancer cases. The PIK3CA is one of the most commonly mutated oncogene in human malignancies, including HNSCC. OBJECTIVE The objective of this study is to identify mutations in exon 9 and exon 20 of the PIK3CA gene among Saudi HNSCC patients, determine the frequency of these mutations and correlate with clinical and pathological findings. METHODS Histopathologically confirmed paraffin embedded HNSCC tumor tissues from 48 patients were obtained. Capillary sequencing method was used to sequence exons 9 and 20 of the PIK3CA gene. Concurrently, the expression analysis of the PIK3CA and PTEN genes were performed using real-time PCR. RESULTS Sixty percent of the samples studied were of pharyngeal cancer. A total of seven mutations were identified in exons 9 and 20 of the PIK3CA gene in 14 HNSCC tumor tissue specimens. The seven mutations encompassed one hot spot mutation E542K, a common mutation T1025T and the five novel mutation comprising three missense and two silent mutations. Interestingly, eight out of the 14 samples with a mutation were of patients with pharyngeal cancer. CONCLUSION PIK3CA gene plays a crucial role in carcinogenesis in general and HNSCC in particular. The identification of five novel mutations suggest that Saudis may have different frequencies of somatic genetic alterations that may influence HNSCC compared to other populations.

Using of un-symmetrical solid-state control loads leads to huge amount of harmonics fed to the balanced three-phase systems. Dependently, the harmonics cause many problems with un-balanced and distorted supply waveforms. In this paper, three-phase 3-wire balanced source energizes a hybrid electric-unbalanced traction system that fed from two independent rectified single-phase supplies. Both trains are fed from a balanced three-phase 3-wire supply via V/V transformer. A proposed shunt active power filter (SAPF) is introduced to mitigate most of the harmonics and rebalance the supply. Intelligent PI-controller is used with self-tuning to regulate the voltage of the DC-link for the proposed filter. This smart controller and its parameters is tuned and optimized by using intelligent technique with the particle swarm optimization (PSO). PSO is one of the most prevailing methods to solve the non-linear optimization problems. Also, the system includes a hysteresis current regulator for generating the IGBT-triggering pulses of the inverter. The proposed system is designed, simulated and implemented with the help of the Matlab/Simulink software package. The test results are obtained and compared with and without optimization technique. With optimized algorithm, the total harmonic distortion (THD) is minimized; restoring the balance of the system, and the power factor of the supply is improved to unity. However, those results demonstrate that the proposed system is robust to non-linearity and more suitable for harmonic mitigation in electric traction.

The purpose of this paper to overcome the impact of electric and magnetic fields on the Intelligent Electronic Devices (IEDs) in High Voltage (HV) substations. The protection devices are considered one from IEDs in HV substation, that's will affect by this fields, this affection will lead to induced current in the secondary connection cables and all devices, that follows to errors in the measurements and the relay decision for the trip command at the fault occurs. So, the calculation of the fault location by the protection IEDs is not accurate. This paper shows the study results of the electric and magnetic field inside HV substation 500 kV, and the result curves shows how the Electromagnetic Field (EMF) vary under HV busbar 500 kV. This study uses the mathematical calculation with MATLAB software, where, the computation domain considered was the 2D free space case study results of a busbar 500kV in outdoor substation design.

However, wind energy conversion system (WECS) is usually located in rural areas with weak grid connection, in which grid voltage unbalance may arise even during normal operation. The unbalanced grid voltage may be caused by unbalanced transmission line impedance, three-phase unbalanced load, and single-phase high-power load. Hence, the strategies to improve the performance of DFIGs under unbalanced network conditions have obtained a worldwide concern.

The Doubly Fed induction generator (DFIG) is a popular wind turbine system due to its high energy efficiency, reduced mechanical stress on the wind turbine, and relatively low power rating of the connected power electronics converter of low costs [126].

In view of the analysis and investigations presented, one can draw the following main conclusions: The phase angle between grid voltage and current waveforms is changed from leading to lagging within one cycle for step change in reactive component of grid current reference \( i_{\text{gq}}^{*} \). This confirms that, the capability of the GSC control to regulate the grid received reactive power for controlling the system power factor.

The power system stability is the accurate operation of the electric grid by restoring balance after being subjected to an abnormal condition such as fault, line switching, load rejection, and loss of excitation. Protective equipment in high voltage substations should fast and precisely localize the faults. Some abnormal conditions in the power system such as out-of-step (OOS) condition which is not a real fault, but the protection equipment will consider it is. This misjudgment will cause the loss of synchronism between areas within the power system or between interconnected systems and will lead to blackout of the national grid. This paper studied the OOS condition, philosophy of protection relay device and how to avoid the false operation for distance function by Out of Step Blocking (OSB) by using the advanced protection relay, to improve the stability of power system.

This paper discusses the impact of Distributed Generator (DG) on the power system for enhancing the power system quality by improving the voltage profile and power losses reduction. With the increasing on the demand power and the power system extension, the distributed renewable energy technologies are becoming increasingly important in the energy supply systems of many countries. DGs units can be defined as a small-units that generate electric power near to the location of customers based on the renewable energy techniques, including wind energy, solar energy, and geothermal energy. Interconnecting DG to an existing distribution system provides various benefits to several entities as for example the owner, utility and the final user. DG provides an enhanced power quality, higher reliability of the distribution system and can peak shaves and fill valleys. However, the integration of DG into existing networks has associated several technical, economic and regulatory questions. Also, this paper uses the power system IEEE-12 busses for an example to illustrate the voltage control and decreases the active and reactive power losses by adding the wind generation DGs with the distribution network.

Adoptive T-cell immunotherapy is a promising approach to manage and maintain relapse-free survival of leukemia patients, especially following allogeneic stem cell transplantation. Post-transplant adoptive immunotherapy using cytotoxic T lymphocytes (CTLs) of the donor origin provide graft-versus-tumor effects, with or without graft-versus-host disease. Myeloid leukemias express immunogenic leukemia associated antigens (LAAs); such as WT-1, PRAME, MAGE, h-TERT and others, most of them are able to induce specific T cell responses whenever associated with the proper co-stimulation. We investigated the ability of a LAA-expressing hybridoma cell line to induce CTL clones in PBMCs of HLA-matched healthy donors in vitro. The CTL clones were induced by repetitive co-culture with LAAs-expressing, HLA-A*0201(+) hybrid cell line, generated by fusion of leukemia blasts to human immortalized APC (EBV-sensitized B-lymphoblastoid cell line; HMy2). The induced cytotoxic T cell clones were phenotypically and functionally characterized by pentamer analysis, IFN-γ release ELISPOT and cellular cytotoxicity assays. All T cell lines showed robust peptide recognition and functional activity when sensitized with HLA-A*0201-restricted WT-1235-243, hTERT615-624 or PRAME100-108 peptides-pulsed T2 cells, in addition to partially HLA-matched leukemia blasts. This study demonstrates the feasibility of developing multi-tumor antigen-specific T cell lines in allogeneic PBMCs in vitro, using LAA-expressing tumor/HMy2 hybrid cell line model, for potential use in leukemia adoptive immunotherapy in partially matched donor-recipient setting.

Purpose: To evaluate the in vitro antiproliferative activity of the extracts of the three plants against a panel of human tumor cell lines representing the most common types of cancer in Jordan, viz, breast and colorectal and skin cancers. Methods: The methanol extracts of the aerial parts of the three plants ( Arbutus andrachne L., Chrysanthemum coronarium L., and Teucrium polium L.) were prepared and assessed for antiproliferative activity against six human tumor cell lines (A375.S2, WM1361A, CACO-2, HRT18, MCF-7, T47D) using 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide MTT cell proliferation assay. Results: C. coronarium extract, at the concentration range of 25 to 400 μg/mL, significantly inhibited (10 – 50 %) the proliferation of the 6 cell lines in a dose-dependent manner, whilst the extracts of the other two plants exhibited weak antiproliferative activity (2 – 10 % inhibition). The half-maximal inhibitory concentration (IC 50 ) values of C. coronarium extract against the six cell lines were in the range of 75.8 to 138.5 μg/mL. Conclusion: The methanol extract of the aerial parts C. coronarium possesses a relatively potent antiproliferative activity and therefore might be a potential source of natural compounds that can be developed into new antineoplastic agents. Keywords: Antiproliferative , Arbutus andrachne L., Chrysanthemum coronarium L., Teucrium polium L. Jordan flora, Medicinal plants, Cancer, Antineoplastic

Fusions of dendritic cells (DCs) and tumour cells have been shown to induce protective immunity to tumour challenge in animal models, and to represent a promising approach to cancer immunotherapy. The broader clinical application of this approach, however, is potentially constrained by the lack of replicative capacity and limited standardisation of fusion cell preparations. We show here that fusion of ex vivo tumour cells isolated from patients with a range of haematological malignancies with the human B-lymphoblastoid cell line (LCL), HMy2, followed by chemical selection of the hybridomas, generated stable, self-replicating human hybrid cell lines that grew continuously in tissue culture, and survived freeze/thawing cycles. The hybrid cell lines expressed HLA class I and class II molecules, and the major T-cell costimulatory molecules, CD80 and CD86. All but two of 14 hybrid cell lines generated expressed tumour-associated antigens that were not expressed by HMy2 cells, and were therefore derived from the parent tumour cells. The hybrid cell lines stimulated allogeneic T-cell proliferative responses and interferon-gamma release in vitro to a considerably greater degree than their respective parent tumour cells. The enhanced T-cell stimulation was inhibited by CTLA4-Ig fusion protein, and by blocking antibodies to MHC class I and class II molecules. Finally, all of five LCL/tumour hybrid cell lines tested induced tumour antigen-specific cytotoxic T-cell responses in vitro in PBL from healthy, HLA-A2+ individuals, as detected by HLA-A2-peptide pentamer staining and cellular cytotoxicity. These data show that stable hybrid cell lines, with enhanced immunostimulatory properties and potential for therapeutic vaccination, can be generated by in vitro fusion and chemical selection of B-LCL and ex vivo haematological tumour cells.

Tumour-specific cytotoxic T-cells (CTL) are important anti-cancer immune effectors. Most tumour cells, however, do not stimulate effective anti-tumour immune responses, in vivo or in vitro. To enhance tumour cell immunogenicity, we fused human tumour cells from haematological malignancies with the B-lymphoblastoid cell line (LCL), HMy2, to generate a panel of long-lived, self replicating LCL/tumour hybrid cell lines. The LCL/tumour hybrid cell lines expressed HLA class I and class II molecules, CD80 and CD86, and a range of known tumour associated antigens (TAAs). In vitro stimulation of PBLs from healthy, HLA-A2+ individuals by hybrid cell lines induced tumour antigen-specific CTLs to TAAs, including survivin, MAGE-A1, NY-ESO-1 and WT-1. Individual hybrid cell lines simultaneously induced CTL to multiple TAAs. In vitro stimulation of PBL from 2 patients with acute myeloid leukaemia by autologous LCL/tumour hybrid cell lines induced CTL capable of killing the patient's own tumour cells. Our data show, for the first time, that hybrid cell lines formed by fusion of HMy2 cells and haematological tumour cells induce tumour- and tumour antigen-specific cytotoxic T-cell responses in vitro. Hybrid cell lines such as those described may represent novel reagents for use in the immunotherapy of haematological malignancies.

This paper presents a load-frequency control (LFC) design using the model predictive control (MPC) technique in a multi-area power system in the presence of wind turbines (WTs). In the studied system, the controller of each local area is designed independently such that the stability of the overall closed-loop system is guaranteed. A frequency response model of the multi-area power system including WTs is introduced, and physical constraints of the governors and turbines are considered. The model was employed in the MPC structures. Digital simulations for a two-area power system are provided to validate the effectiveness of the proposed scheme. The results show that with the proposed MPC technique the overall closed-loop system performance shows robustness in the face of uncertainties due to governor and turbine parameter variation and load disturbances. A performance comparison between the proposed controller with WTs and MPC without WTs and a classical integral control scheme is carried out, confirming the superiority of the proposed MPC technique with WTs. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

This paper aims to develop a method of field orientation scheme for controlling both active and reactive powers of a DFIG (double fed induction generator) driven by a wind turbine. The controlled system consists of a wind turbine that drives a DFIG connected to the utility grid through AC-DC-AC link. The control method is based on the theory of controlling the e d and e q axes components of voltage and current for both rotor side and line side converters using PI controllers. The main control objective is to regulate the dc link voltage for operating at the maximum available wind power. A mathematical dynamic model of a DFIG driven by a wind turbine system is presented. Digital simulation has been carried out in order to evaluate the effectiveness of the proposed system. The results confirm that good steady state and dynamic performances of the proposed system has been achieved under different types of wind speed variations.

This paper presents a linear parameter estimation technique used toestimate the rotor resistance, self inductance of the rotor winding,stator resistance and the stator leakage inductance of an inductionmotor. Such estimation is important for achieving high estimationperformance of induction motor drives. The parameters estimationmodel expresses the relationships of the dynamic machine model interms of measurable stator voltages, currents and motor speed. Thismodel is represented by a linear regression equation from whichmachine parameters can be obtained using a recursive least squares(RLS) estimation algorithm. Simulation results are presented tovalidate the proposed estimation algorithm with reasonable accuracy ofthe estimated parameters regardless of load conditions. Comparisonsbetween experimental and calculated steady-state performances usingthe estimated parameters are also presented.

This paper presents the improvement of generation quality for a wind energy conversion scheme using artificial neural network (ANN). High generation quality means that, the induction generator generate voltages and frequency at nominal specified values, under all operating conditions, determined by various wind speeds and loads. The scheme consists of a three-phase induction generator driven by a horizontal axis wind turbine and interfaced to an isolated load. A static VAR compensator (SVC) is connected at the induction generator terminals to regulate its voltage. The mechanical power input is controlled by regulating the blade pitch-angle. Both blade pitch-angle and firing angle are adjusted using an ANN to improve the generation quality for a wind energy conversion scheme. The proposed ANN training is based on suitable values of SVC firing angles and blade pitch-angles of the wind turbine, for achieving a high generation quality at different operating conditions. The training data is obtained by using Newton-Raphson method to generate voltages and frequency at nominal specified values. The simulation results prove that, the wind energy conversion scheme, with the proposed ANN, gives good power generation quality over wide range of wind speeds and loads.

This paper aims at developing a method of rotor resistance estimation for speed sensorless indirect vector controlled induction motor drive taking the effect of magnetic flux saturation into account. A mathematical dynamic model of an induction motor as influenced by magnetic circuit saturation is presented. Moreover, a modified structure of indirect vector controller scheme is proposed which involves the saturated value of the magnetizing inductance. In this scheme, an effective online method for rotor resistance estimation is based on a modified model reference adaptive system (MRAS) to achieve high-precise control in a wide range of motor speed. The motor speed is estimated from the difference between the estimated synchronous speed and slip speed. The online magnetizing inductance estimation algorithm to operate within the rotor resistance estimation is presented. Digital simulations have been carried out in order to evaluate the effectiveness of the proposed sensorless drive system. The results have proven excellent steady-state and dynamic performances of the drive system, which confirms validity of the proposed scheme.

This paper proposes the application of H ∞ synthesis to design a robust controller for regulating the volta ge and frequency of a wind generation system. The controlled system consi sts of a wind turbine that drives an induction generator connected to the utility grid through asynchronous AC-DC-AC link. The main control object ive is to regulate the DC link voltage and to track and extract maximu m available wind power. This is accomplished via controlling the fir ing angles of the rectifier and the inverter. The complete nonlinear dynamic model of the system has been described and linearized around an operating point. Also, the design problem of the H ∞ controller has been formulated in a standard form with emphasis on the selection of the weighting functions that reflect robustness and performance goals. The proposed system has the advantages of robustness against model uncertai nties and external disturbances, fast response and the ability to reje ct noise. The performance of the wind generation system with the proposed controller has been tested through a step and sinusoidal chang es in reference input power. In addition, detuned system parameters are a ssumed. Simulation results confirm that good dynamic performance of th e proposed wind energy scheme has been achieved.

This paper investigates the use of the linear quadratic Gaussian controller to control the voltage and frequency of a wind energy conversion scheme. This scheme cosists of a wind turbine and induction generator connected to the utility grid via AC-DC-AC asynchronous link. The control objective aims to regulate the rectifier output voltage and track the maximum available wind power. This is accomplished via controlling the firing angles of the rectifier and the inverter. The complete nonlinear dynamic model of the system has been described and linearized arround an operating point. The standard Kalman filter technique has been employed to estimate the full states of the system. The computational burden has been minimized to a great extent by computing the optimal state feedback gains and the Kalman state space model off-line. The proposed controller has the advantages of robustness, fast response and good performance. The wind energy scheme with the proposed controller has been tested through a step change in wind speed. Simulation results show that accurate tracking performance of the proposed wind energy scheme has been achieved. Moreover, this scheme is robust against the parameters variation and eliminates the influence of modeling and measurement noises.

A novel sensorless vector controlled induction motor drive system is presented in this paper. In this system, compensation of the drift components of the stator voltage vector is done by offset voltage vector estimation to improve the low-speed drive characteristics. The motor speed is estimated from the difference between the estimated synchronous and slip speed. An effective on-line method for estimating both stator and rotor resistances is introduced in this system to achieve high-precision control at low-speed. The estimation method for rotor resistance is based on the error signal between the command value of reactive power and its actual value being based on stator voltage and current measurements. On the other hand, the error between the magnitude of the stator current command and its measured value is used to estimate the stator resistance variations from its set value. This paper clarifies that the low-speed estimation is possible with stator and rotor resistance estimation and the zero-speed control is achieved under load condition. Simulation results are provided to demonstrate smooth steady-state operation and high dynamic performance of the drive system at very low-speed and at zero-speed.

This paper presents a robust controller design based on Q-parameterization theory for the automatic generation control problem of a power system. This controller is used in order to achieve both robust stability and good dynamic performance against the variation of system parameters. In the Q-parameterization method, the set of all stabilizing controllers of the power system is characterized by a free parameter Q. This free parameter is chosen to satisfy robust stability and other design requirements. Simulation results have confirmed the effectiveness of the proposed controller.

Introduction: Adoptive T-cell immunotherapy represents a promising approach, as a mean of cancer immunotherapy, for management of different types of malignant tumors. This immunotherapeutic approach has been used with significant clinical benefits in EBV-associated lymphoid disorders, myeloma, and leukemia, in addition to a group of solid tumors. Different studies have demonstrated the probability of generating cytotoxic T-lymphocytes (CTLs) lines to high manufacturing standards, as well as the tolerability and therapeutic benefit of the approach. In our previous studies we verified that the EBV-associated B lymphoblastoid cell line (LCL), HMy2, fusion to hematologic tumor cells and cell lines in vitro produced stable hybridoma cells that grew spontaneously and immortally in tissue culture, expressed relevant tumor partner antigens, and showed an enhanced ability to stimulate allogeneic and semi-autologous T cell responses. Moreover, these studies prospered in the induction of hematologic tumor antigen-specific CTLs in peripheral blood lymphocytes (PBL) from healthy donors, and semi-autologous cancer patients as detected by HLA-A2-peptide pentamer staining and cellular cytotoxicity. In the current study, we aimed to further investigate newly generated solid/HMy2 hybrids for their abilities to stimulate naive HLA-A2+ T cells of healthy donors to induce new relevant TAA-specific, HLA-A2-restricted T cell clones of therapeutic value in management of hepatocellular and pancreatic adenocarcinomas. Materials and methods: Two tumor cell lines (HepG2; HCC cell line, and Panc-1; pancreatic tumor cell line) were used separately in generation of two distinct hybrids by fusion to HMy2, using PEG/ DMSO as fusogen and fusion protocol was followed as mentioned before. Fusion cells' (FCs) growth was selected physically using deferential detachment capabilities and then chemically by 3 days incubation in HAT supplemented growth media (RPMI-1640). Moreover, relevant CD markers and surface TAAs expression of the FCs were investigated to evaluate the fusion efficiency. Hybrid cells' viability under different tissue culture conditions, phenotypic properties (including CD markers, HLAs, and co-stimulatory molecules expression) and relevant TAAs expression profile were assessed using flowcytometric analysis and RT-PCR respectively. Two immunogenic, HLA-A2-restricted and high expressed antigens were selected (GPC3 and CEA for HCC and Panc-1 hybrids respectively) and targeted to induce T cell response against. Subsequently, depending on their phenotype, two FC clones were selected for stimulation of naïve allogeneic T cells, isolated from healthy HLA-A2+ donors, in vitro for several rounds, and the outgrowing T cells were phenotyped and analysed regarding T cell subtype, differentiation pattern, & γ-IFN release, cellular cytotoxic avidity and efficacy as well as HLA-A2-restricted peptide-specificity. Results: The generated hybrid cell lines grew continuously in tissue culture in loosely adherent pattern and expressed CD40, CD80, CD86, HLA class I and HLA class II and the level of expression were higher in the hybrid cell lines than in the parent tumor cells. T cell proliferation assays showed enhanced ability of both fusion clones to stimulate both CD4 and CD8 subtypes of both central and effector cells, however, with slight dominance of effector than central counterparts Two HLA-A2-restricted peptide-specific cytotoxic T cell clones (against HLA-A*02:01-GPC3 144-152 and HLA-A*02:01-CEA 694-702) were produced for the first time using this technique and demonstrated abundant & γ-IFN production and cytotoxic activity upon recognition of their target cells. Conclusion: Hybrid cell lines, such as those described, could be used as cost effective and feasible in vitro stimulators of semi-autologous, antigen-specific CTLs for adoptive T cell immunotherapy for not only hematologic but also for certain solid tumors. Citation Format: Yehia Mohamed, Michael Browning. Immortalized HMy2/solid tumor hybridomas induce two different tumor antigen-specific T cell clones in vitro. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B099.

Field orientation, with autonomous control of reactive power, using PI controller is the most widely used controlling method of doubly-fed induction generators (DFIG). This paper describes a method for separate control of active and reactive power of grid-connected DFIG using PI controller. Using MATLAB/SIMULINK software, the behavior of controller is evaluated during variation of wind speed. Simulation results represent the behavior of controller when facing the variations. This paper first explains the model of DFIG and the second part is explaining field oriented control of DFIG.

Enhancement of fault ride-through (FRT) capability and subsequent improvement of rotor speed stability of wind farms equipped with doubly fed induction generator (DFIG) is the objective of this paper. The objective is achieved by employing a novel FRT scheme with suitable control strategy. The proposed FRT scheme, which is connected between the rotor circuit and dc link capacitor in parallel with Rotor Side Converter, consists of an uncontrolled rectifier, two sets of IGBT switches, a diode and an inductor. In this scheme, the input mechanical energy of the wind turbine during grid fault is stored and utilized at the moment of fault clearance, instead of being dissipated in the resistors of the crowbar circuit as in the existing FRT schemes. Consequently, torque balance between the electrical and mechanical quantities is achieved and hence the rotor speed deviation and electromagnetic torque fluctuations are reduced. This results in reduced reactive power requirement and rapid reestablishment of terminal voltage on fault clearance. Furthermore, the stored electromagnetic energy in the inductor is transferred into the dc link capacitor on fault clearance and hence the grid side converter is relieved from charging the dc link capacitor, which is very crucial at this moment, and this converter can be utilized to its full capacity for rapid restoration of terminal voltage and normal operation of DFIG. Extensive simulation study carried out employing MATLAB/SIMULINK software vividly demonstrates the potential capabilities of the proposed scheme in enhancing the performance of DFIG based wind farms to fault ride-through.