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In this study a mathematical analysis for estimating the performance rate "RP" of wheel type trenching machine was studied. The mathematical analysis quantifies the analysis and resulted in an equation. This mathematical equation was checked under different operating conditions. The practical study of the performance rate showed that the deviation of the theoretical performance rate from the actual performance rate ranged from 5 to 7% for the 60.4 and 90.5 cm trench depth, respectively. The machine field efficiency also ranged between 43 and 50.1% for 90.5 cm and 60.4 cm trench depth respectively [ABSTRACT FROM AUTHOR]

Electrical insulation performance of compressed gas insulated switchgear (GIS) is adversely affected by metallic particle contaminants with a loss of up to 90% of the gas dielectric strength. Such particles play a crucial role in determining the system insulation integrity. Coating of the inside surface of GIS enclosures with a dielectric material such as epoxy resin can alleviate the adverse effect of contaminating metallic particles on the insulation, as the coated electrodes in compressed gas result in a somewhat higher breakdown voltage. Such coatings have the effect of "smoothing" the surface and reducing the pre-breakdown current in the gas gap. Also, in the presence of metallic particles, the electrostatic particle charging is impeded; hence, the maximum particle excursion in a coaxial GIS is significantly reduced for a given applied AC voltage. In this paper, the effect of the dielectric coatings is analyzed with a theoretical model which is confirmed in the high-voltage experiments. The results show the effectiveness of dielectric coating in mitigating the contamination due to the particles. The influence of other factors such as gas pressure and particle size are also discussed. [ABSTRACT FROM PUBLISHER]

Liraglutide and linagliptin are novel drugs for the treatment of diabetes. Antioxidative and neuroprotective effects have been described for both compounds. However, it is not yet known, whether these mechanisms are also protective against diabetic retinal neurodegeneration. We assessed the antioxidative and neuroprotective capabilities of liraglutide and linagliptin as well as the signaling pathways involved, by using C. elegans as a model for glucose-induced neurodegeneration. C. elegans were cultivated under conditions, which mimic clinical hyperglycemia, and treated with 160 μmol/l liraglutide or 13 μmol/l linagliptin. Oxidative stress was reduced by 29 or 78 % and methylglyoxal-derived advanced glycation endproducts (AGEs) by 33 or 22 %, respectively. This resulted in an improved neuronal function by 42 or 60 % and an extended mean lifespan by 9 or 11 %, respectively. Antioxidative and AGE reducing effects of liraglutide and linagliptin were not dependent on v-akt murine thymoma viral oncogene homologue 1/forkhead box O1 (AKT1/FOXO). Neuroprotection by liraglutide was AKT1/FOXO dependent, yet AKT1/FOXO independent upon linagliptin treatment. Both liraglutide and linagliptin exert neuroprotective effects in an experimental model for glucose-induced neurodegeneration, however, the signaling pathways differ in the present study. Further pharmacological intervention with these pathways may help to delay the clinical onset of diabetic retinopathy by preserving neuronal integrity. [ABSTRACT FROM AUTHOR]

Objective: Current guidelines for the treatment of type 2 diabetes focus on pharmacological treatment of glucose and cardio-vascular risk factors. The aim of this prospective randomized controlled intervention study was to examine the effects of a psychosocial intervention on clinical endpoints and risk factors in patients with type 2 diabetes and early diabetic kidney disease. Methods: 110 patients were randomized to receive an 8-week mindfulness-based stress reduction (MBSR) training (n = 53) compared to standard care (n = 57). The study was carried out open-labelled and randomization was performed computer-generated in a 1:1 ratio. Primary outcome of the study was the change in urinary albumin excretion (albumin-creatinine-ratio, ACR); secondary outcomes were metabolic parameters, intima media thickness (IMT), psychosocial parameters and cardiovascular events. Results: 89 patients (42 in control group and 47 in intervention group) were analysed after 3 years of follow-up. After 1 year, the intervention group showed a reduction of ACR from 44 [16/80] to 39 [20/71] mg/g, while controls increased from 47 [16/120] to 59 [19/128] mg/g (p = 0.05). Parallel to the reduction of stress levels after 1 year, the intervention-group additionally showed reduced catecholamine levels (p < 0.05), improved 24 hmean arterial (p < 0.05) and maximum systolic blood pressure (p < 0.01), as well as a reduction in IMT (p < 0.01). However, these effects were lost after 2 and 3 years of follow-up. Conclusions: This is the first study to show that a psychosocial intervention improves cardiovascular risk factors in high risk type 2 diabetes patients. [ABSTRACT FROM AUTHOR]

Emergency ratings have been introduced for operating transmission lines safely and supplying current capacity efficiently, as well as controlling load flow when line faults occur. In this article, short-term emergency ratings are calculated by using a thermal equilibrium equation for bared conductors in double-circuit transmission lines. Overhead transmission lines installed in double circuit have been extensively utilized worldwide to enhance power transmission. Such lines show various advantages in increasing transmission capacity and decreasing power loss as well as being operated flexibly during a contingency. Even when a fault occurs in one circuit, the healthy circuit can supply power continuously during an emergency without outage. The utilization of such double-circuit transmission lines during normal and/or emergency operations is described. Maximum normal operating current based on fault duration, maximum allowable temperature of conductor, and thermal line ratings is evaluated. Several performances of dip/clearance affecting short-term emergency rating are also presented. [ABSTRACT FROM PUBLISHER]

The use of the CO(2) laser in the management of oral dysplastic lesions has become a more common practice. Very few studies have evaluated recurrence, residual disease malignant transformation, and overall outcome in patients undergoing such a procedure. In this prospective study, a total of 123 oral dysplastic lesions from 77 consecutive patients were treated with the CO(2) laser (resection and/or ablation). The average age was 58 ± 4.8 years. The patients' recovery was uneventful and no complications were reported. Comparisons with the clinical and histopathological features and rate of recurrence as well as malignant transformation were made. The patients were followed-up for a mean of 6.4 years, and biopsies taken in case of changes suggestive of malignant development. Homogenous leukoplakias were identified in 31 patients, non-homogenous leukoplakias in 34 patients, whereas 12 patients had erythroplakias. Ex- and life-long smokers formed 88.3% of the recruited patients. While people who currently smoke and drink formed 55.8% of the cohort. Erythroplakias were solely identified in heavy life-long smokers. The most common identified primary anatomical locations were the lateral border of tongue, floor of mouth, and buccal mucosa. Moderate dysplasia was identified in 42 patients while 18 patients had severe dysplasia. Laser resection margins in selected cases (68 patients) were clear in 53 and showed mild-moderate dysplasia in the involved margins. The rate of recurrence had no significant association with the location but the severity of epithelial dysplasia. The rate of first recurrence after laser surgery was approximately 19.5%. Malignant transformation was observed in eight patients (10.4%), in the tongue and the floor of mouth. Recurrence and malignant transformation was mainly identified in erythroplakias and non-homogenous leukoplakias. Laser resection/ablation is recommended for oral dysplasia to prevent not only recurrence and malignant transformation but also postoperative oral dysfunction encountered by other conventional modalities. [ABSTRACT FROM AUTHOR]

The presence of distributed generation in electrical distribution systems greatly modifies their traditional structure. Overcurrent coordination studies in distribution systems using circuit breakers, reclosers, and fuses have been conducted using two methodologies that were based on constant magnitudes and directions of overcurrents, from the main source toward the end users. These techniques cannot be of general application when distributed generation is involved. The proposed methodology allows overcurrent coordination studies for non-constant, two-source currents. The application results are provided in both graphical and numerical forms. Several examples are given where the potentiality of the new methodology can be assessed, explaining the process for circuit breaker/fuse, fuse/fuse, and recloser/fuse coordination. The method can be applied to any overcurrent coordination study including non-constant, cyclic loads. [ABSTRACT FROM AUTHOR]

An analysis of DC-DC converter-driven direct ethanol fuel cell systems is presented. The output voltage characteristics of two systems—boost-driven and buck-boost-driven systems—are compared. Experimental results show that direct ethanol fuel cells exhibit variable non-linear impedances as a function of frequency. It is shown that DC-DC converter-driven direct ethanol fuel cell systems do not exhibit a predictable output as a function of duty cycle alone, in both boost and buck-boost configurations. The analysis shows that Ni-foam anode direct ethanol fuel cell and Ni-mesh anode direct ethanol fuel cell output voltage characteristics become nearly identical at switching frequencies beyond 6 kHz. [ABSTRACT FROM AUTHOR]

An overcurrent coordination methodology is proposed for non-constant, two-source currents in distribution systems with distributed generation. Results are given in graphical form, where the potentiality of the methodology can be assessed for circuit breaker/fuse, fuse/fuse, and recloser/fuse coordination. The method can be applied to any overcurrent coordination study, including non-constant, cyclic loads. [ABSTRACT FROM AUTHOR]

Renin-angiotensin system blockade retards the progression of diabetic and non-diabetic chronic kidney disease of the native kidneys. Though most patients suffer from a significant renal insufficiency (chronic kidney disease stage III) and a concomitant heart disease after renal transplantation, there is up to now no evidence supporting the use of inhibitors of the renin-angiotensin system in these patients. We wish to summarize the available evidence on the use of inhibitors of the renin-angiotensin system after renal transplantation. We specifically discuss potential beneficial as well as adverse effects of a renin-angiotensin system blockade. In addition, we review their influence on morphologic and biochemical markers as well as on renal function, graft and patient survival after renal transplantation. [ABSTRACT FROM AUTHOR]

The outcome of simultaneous pancreas–kidney (SPK) transplantation in type 1 diabetes has dramatically improved in recent years because of optimized surgical techniques and new immunosuppressive drug regimens. Normoglycemia is followed by stabilization or even regression of diabetic lesions, i.e., of heart and kidneys. However, these effects are only visible after more than five yr of normoglycemia (achieved by a functioning allograft). This is also a likely explanation for the conflicting results of studies that investigated patient or kidney graft survival in SPK transplantation compared to kidney transplantation alone. Most studies had too short follow-up periods, i.e., less than five yr, to compare effectively different transplant strategies in patients with type 1 diabetes and therefore failed to discover a survival benefit in favor of simultaneously transplanted patients. Recent data now indicate that, with a longer follow-up, there is an increasing survival benefit for simultaneously transplanted patients compared to patients who received a single kidney transplant. This is paralleled by the comparison of simultaneously transplanted patients to patients who received a single kidney transplant from a living donor. A survival benefit for the combined procedure was here visible after 10 yr of follow-up. We give a short overview on SPK transplantation, with a focus on the effects of this procedure on diabetic complications as well as patient and kidney graft survival. [ABSTRACT FROM AUTHOR]

Objective: Markers reliably identifying vascular damage and risk in diabetic patients are rare, and reports on associations of serum adiponectin with macrovascular disease have been inconsistent. In contrast to existing data on serum adiponectin, this study assesses whether urinary adiponectin excretion might represent a more consistent vascular damage marker in type 2 diabetes.Research Design and Methods: Adiponectin distribution in human kidney biopsies was assessed by immunohistochemistry, and urinary adiponectin isoforms were characterized by Western blot analysis. Total urinary adiponectin excretion rate was measured in 156 patients with type 2 diabetes who had a history of diabetic nephropathy and 40 healthy control subjects using enzyme-linked immunosorbent assay. Atherosclerotic burden was assessed by common carotid artery intima-media-thickness (IMT).Results: A homogenous staining of adiponectin was found on the endothelial surface of glomerular capillaries and intrarenal arterioles in nondiabetic kidneys, whereas staining was decreased in diabetic nephropathy. Low-molecular adiponectin isoforms ( approximately 30-70 kDa) were detected in urine by Western blot analysis. Urinary adiponectin was significantly increased in type 2 diabetes (7.68 +/- 14.26 vs. control subjects: 2.91 +/- 3.85 microg/g creatinine, P = 0.008). Among type 2 diabetic patients, adiponectinuria was associated with IMT (r = 0.479, P < 0.001) and proved to be a powerful independent predictor of IMT (beta = 0.360, P < 0.001) in multivariable regression analyses. In a risk prediction model including variables of the UK Prospective Diabetes Study coronary heart disease risk engine urinary adiponectin, but not the albumin excretion rate, added significant value for the prediction of increased IMT (P = 0.007).Conclusions: Quantification of urinary adiponectin excretion appears to be an independent indicator of vascular damage potentially identifying an increased risk for vascular events. [ABSTRACT FROM AUTHOR]

This article addresses part of a study of the coordination between overcurrent protection and the voltage sag ride-through capability of sensitive equipment connected to customer facilities. The research is extended to utility/distributed generation interconnection. The objective is to develop an intelligent methodology for fast detection of the islanding operation. The algorithm should account for the available distributed generation power, reconnection availability, and event duration. [ABSTRACT FROM AUTHOR]

In this research, the output voltage characteristics of two DC power sources are compared. Both nickel-cadmium DC-DC buck converter and direct ethanol fuel cell DC-DC buck converter systems are experimentally evaluated over a selected switching frequency range. The output voltage characteristics of two types of direct ethanol fuel cell DC-DC buck converter systems are determined. Experimental results are compared to simulations of Fourier-series models of each DC system. The output voltage obtained through simulation and the theoretical output voltage of each system are identical. [ABSTRACT FROM AUTHOR]

Voltage sags are among the most important power quality events due to their economic effect on all types of customers, especially industrial users. Normal contactors would open when a voltage sag of given depth, duration, phase-jump, and starting angle takes place. Results given here were obtained from a series of experimental tests carried out on six contactors with dissimilar characteristics and manufacturers. The traditional immunity curves (or time/voltage characteristics) were obtained. The tested contactors show similar behavior, with very small variations. A few tests were conducted to analyze the increase in contact voltage drop due to voltage sag presence in order to investigate the contacts welding under rated-current conditions. [ABSTRACT FROM AUTHOR]

The operation of distributed generation as an island is still the subject of discussion between utilities and customers, both as owners of distributed generators. For the utility company, operation in an island of generators (islanding) whose control is in the consumers' hands, could cause a high risk of equipment failure and compromise personnel safety. Thus, utilities are normally opposed to islanding and demand immediate disconnection in case of power supply shutdown. On the other hand, for customers who own distributed generation, islanding can represent the continuity of operation under conditions of reduced power, lower power quality, and limited production capability with much smaller economic losses to those who would experience deep voltage sags or total blackout. [ABSTRACT FROM AUTHOR]

The objective of the integrated technology roadmapping methodology STAR® outlined in this paper is to enable companies to align their technology acquisition programmes to meet their business objectives. STAR® has three phases: a preliminary phase involving the setting up of an enterprise framework; a technology data collection phase; and a project creation and assessment phase. STAR® utilises the analytic hierarchy process to rank company technology requirements, several non-financial factors to determine the alignment of proposed projects and visual representations to select a portfolio of projects. Project evaluations have demonstrated that statistically significantly different project selection outcomes arise from the additional non-financial factors included in STAR®. Elements of STAR® are being implemented at a major collaborator, and it is planned to implement the whole STAR® methodology within a year. An integrated enterprise level roadmapping methodology such as STAR® offers an objective way of selecting and evaluating projects and, later, of re-evaluating and improving the process. [ABSTRACT FROM AUTHOR]

The p75 neurotrophin receptor (p75NTR) has been shown to appear in the plasma of diabetic rats, possibly indicating diabetic neuropathy. The aim of this study was to use a semi-quantitative assay for human plasma p75NTR to investigate whether this receptor is a marker of peripheral diabetic neuropathy (DPN) and autonomic cardiovascular neuropathy (CAN) in type 2 diabetic patients. Eighty type 2 diabetic patients and 25 controls without diabetes were analysed for p75NTR immunoreactivity by western blot analysis. DPN was assessed using the Neuropathy Disability Score (NDS). Cardiovascular autonomic function was detected using a standardised analysis of heart rate variability. Three distinct p75NTR signals were detectable in human plasma at ∼75, ∼51 and ∼24 kDa, representing the full length receptor (FL) and its intracellular domain (ICD) and extracellular domain (ECD), respectively. Levels of total plasma p75NTR immunoreactivity in patients with type 2 diabetes were similar to those in controls. Type 2 diabetic patients had significantly higher plasma levels of ICD and lower levels of ECD. However, there were no correlations of total p75NTR immunoreactivity or ECD or ICD immunoreactivity with NDS or aspects of CAN. Levels of the ECD of p75NTR are reduced and levels of the ICD are increased in the plasma of type 2 diabetic patients. None of the p75NTR subunits identified in human plasma seem to be a marker of peripheral or autonomic neuronal function in patients with type 2 diabetes. [ABSTRACT FROM AUTHOR]

This research introduces an intelligent adaptive fuzzy system with a self learning function, that could be installed to monitor electrical equipment or systems and self-learn the trend of events leading to the failure of the monitored system. The self-learning process is accomplished using adaptive neuro-fuzzy techniques. The article includes details of the development of the new tool and the results of applying the technique to a test case based on a practical application and real site data. Wavelet de-noising is used as the filtering technique for pre-preparation of data before introducing it to the fuzzy predictor. [ABSTRACT FROM AUTHOR]

Nearly 80% of customer complaints about power quality (PQ) are related to voltage sags. Voltage sags due to short-circuit faults are detected and their effect is detrimental hundreds of miles away from the fault location. Overcurrent protection must be done taking PQ issues into account. By transforming the voltage/time immunity curve into a current/time curve it can be coordinated with the normal time/current characteristic (TCC) of protective devices. Having the SE immunity curve, the TCC of protective devices, and the fault occurrence index, a complete evaluation of the whole power-quality and overcurrent-protection interaction can be assessed. [ABSTRACT FROM AUTHOR]

Overcurrent protection must be done taking power quality (PQ) issues into account. A new methodology is presented, which allows the transformation of the voltage/ time immunity curve into a current/ time curve that can be easily coordinated with the normal time/ current characteristic (TCC) of protective devices. The presence of transformers changes the voltage-sag magnitude, which can be considered in the proposed methodology. [ABSTRACT FROM AUTHOR]

This article presents one of the possible mitigating measures for industries—having distributed generation (DG)—by using a rigid/nonrigid link between the industrial system and utility system. The double-function circuit breaker will be on rigid connection under steady-state, passing to nonrigid state—while a distant voltage sag is taking place—in order to avoid (or reduce) the DG backfeeding to the system. By controlling the DG energy fed to the system, voltage sag magnitude could be mitigated, which would improve the sensitive-equipment ride-through capability during the event. The task could be accomplished more efficiently and economically using energy storage equipment such as a flywheel or battery bank. Simple calculations are presented, which show the technical and economical improvement when applying the concept to a case of highly automated industrial plant. [ABSTRACT FROM AUTHOR]

A summary of the literature about the effect of unbalanced supply voltage on induction motors is presented. An experimental study was carried out, where rotor currents of a wound-rotor induction motor were measured under different unbalance conditions with respect to positive and negative sequence voltage magnitudes and phase angles. Rotor overcurrent is not a function of the angle between positive and negative voltage components. Effect of rotor overcurrent is under-estimated by the measured stator overcurrent, and rotor currents are closely similar. The currently used unbalanced-voltage derating factors do not seem to consider rotor winding heating, which is only applicable to squirrel-cage rotors. [ABSTRACT FROM AUTHOR]

A method utilizing the Prony algorithm and ANNs has been presented earlier to locate faults on radial lines with high accuracy. This work extends the application to loop systems. Fault simulation is implemented using the ATP-EMTP. The loop system is presented by a line with generator units on both ends. The proposed method accounts for the anticipated changes in the traveling wave characteristics. The proposed modifications are limited to the type of ANN inputs. The scheme structure was preserved to match the radial line scheme. The modified scheme is proven to have good accuracy in locating faults with different fault resistances varying from 2 to 40 ohms. [ABSTRACT FROM AUTHOR]

Since the publication of two case reports that are considered to represent the first clinical demonstration of iatrogenic adrenal insufficiency, it has been the generally accepted practice to cover steroid-treated patients undergoing surgery with glucocorticoids in the perioperative period. Both the inclusion criteria for the patients and the extent of the substitution pattern have been selected on an empirical rather than on a rational basis. Scientific advances over the past 50 years in the knowledge of the hypothalamic-pituitary-adrenal system's physiology and the molecular mechanism of action of its biologically active components are, for the most part, not reflected in current clinical practice and instead seem to be ignored. Clinical and experimental evidence suggests, however, that even glucocorticoid-treated patients undergoing surgery do not require maximum stress doses of hydrocortisone, which should be reserved for the treatment of sepsis. With regard to the broad spectrum of efficacy of glucocorticoids and their side effects, revision and modification of the historical regimen appear prudent. [ABSTRACT FROM AUTHOR]

This study examined a possible association of the T/G polymorphism at nucleotide 94 in the adiponectin gene with the prevalence of diabetic complications. The study was performed in 696 patients with type 1 diabetes and type 2 diabetes. Genotyping was performed by means of polymerase chain reaction and subsequent cleavage by using SmaI restriction endonuclease. The 94G/G genotype was significantly more prevalent in patients with type 2 diabetes (2.2%) than in type 1 diabetics (0.0%) (p = 0.02), whereas no differences were found for frequencies of the 94T/T and the 94G/T genotypes, respectively. In patients with type 1 diabetes, 45 of 239 patients were heterozygous for the 94T/G polymorphism (carrier rate (CR): 18.8%; allele frequency (AF): 0.094). In type 2 diabetics, 71 of 457 patients were heterozygous and 10 patients were homozygous for the 94G/G genotype (CR: 17.7%; AF: 0.10). No association with diabetic nephropathy, diabetic neuropathy or diabetic retinopathy was found for either genotype in patients with type 1 and type 2 diabetes. The 94T/G polymorphism in the adiponectin gene is not associated with diabetic complications. The significance of a higher prevalence of the G allele in type 2, compared to type 1 diabetes remains to be clarified. [ABSTRACT FROM AUTHOR]

The article presents a study of the faulty performance of low-inductance VSI-fed PM brushless DC motors under stator inter-turn short circuits. Performance characteristics of the drive system are obtained under normal operation through a discrete-time, lumped-parameter network model. The model is modified to accommodate a short circuit across certain number of turns on one stator phase. Fault current is introduced as an additional state variable in fault cases. A comparative study between system performance under healthy and faulty operations is conducted. Faulty performance is experimentally measured via a specialty wound machine at different operating conditions and various numbers of shorted turns. Good agreement between analytical and experimental results is obtained. Findings of this work can be used to develop fault detection schemes of the system under consideration. [ABSTRACT FROM AUTHOR]

This article presents an overview of diagnostic principles of incipient faults in electric machines and drive systems. Applications of AI tools in automating the task of fault detection are also highlighted. Operating principles of CSI–fed PM brushless DC motors are briefly introduced. A summary of an extensive study of automatic fault diagnosis and location in CSI–fed PM brushless DC motor drives, based on adaptive neuro–fuzzy inference systems (ANFIS), is reported. A sample of ANFIS testing cases and acceptable matching between simulated and measured performances of the drive show effectiveness of the proposed methodologies. [ABSTRACT FROM AUTHOR]

Voltage sags mainly caused by line faults in transmission and distribution systems have become one of the most important power quality problems facing industrial and commercial customers, as well as utilities. Voltage sags are normally described by characteristics of both magnitude and duration. Phase-angle changes that greatly affect several electronic equipment should be taken into account in identifying and characterizing the sag phenomenon. In this article, voltage sags due to line faults, such as three phase-to-ground, single line-to-ground, and line-to-line faults, for fault impedance (resistance) variation are firstly characterized by using symmetrical component analysis. Different line fault types, fault resistance magnitudes, and their effect on voltage sag magnitude variations together with phase-angle jumps are examined. In order to verify the analyzed results, simulations based on power circuit models are presented. The described methodology is useful in short-circuit studies by giving a quick qualitative assessment of the voltage sag magnitude and phase jump when fault resistance is changed between its extreme values. [ABSTRACT FROM AUTHOR]

Electrical insulation performance of compressed gas insulated switchgear (GIS) and gas insulated transmission line (GITL) system is adversely affected by metallic particle contaminants. Dielectric coatings help to improve the insulation performance in several ways. For example, it is known that dielectric coated electrodes in compressed gas give a somewhat higher breakdown voltage. Such coatings have the effect of “smoothing” the surface and reducing the pre-breakdown current in the gas gap. Also, in the presence of metallic particle contamination, the electrostatic particle charging is impeded; hence, the maximum particle excursion in a coaxial GIS/GITL is significantly reduced for a given applied AC voltage. A simple particle charging model, however, has some significant shortcomings. For example, the charge exchange mechanism between the particle and the electrodes is poorly understood and very complex to model. In this article, the dynamics of a wire particle in a coaxial GITL system with coated electrodes under AC voltage is studied using a computational algorithm. The possibility of SF 6 gas insulation breakdown due to the presence of metallic contaminants was computed at different applied voltages and gas pressures. Results of laboratory experiments conducted at Chalmers University to verify the computational outcome are presented. [ABSTRACT FROM AUTHOR]

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β-adrenergic receptors (β-ARs) are of key importance for the regulation of lipolysis and thermogenesis by catecholamines. Genetic defects in expression or function ofβ1-β2- and/orβ3-AR could affect energy homeostasis and predispose an individual towards the development of obesity. We therefore investigated the possible association of polymorphisms in theβ-adrenergic receptor genes with early onset obesity.Frequencies of the following variants were assessed in extremely obese children and healthy underweight controls: Gly/Ser in codon 49 and Arg/Gly in codon 389 of theβ1-AR, Arg/Gly in codon 16 and Gln/Glu in codon 27 of theβ2-AR, Trp/Arg in codon 64 of theβ3-AR.The Ser49 allele in theβ1-AR gene was found at a frequency of 0.131 in obese and 0.136 in lean subjects (p = 0.835), while the Gly389 allele in theβ1-AR had a frequency of 0.319 in obese and 0.328 in lean subjects (p = 0.802). Gly16 in theβ2-AR was found with a frequency of 0.590 in obese and 0.611 in lean subjects (p = 0.591) and the Glu27 allele in theβ2-AR had a frequency of 0.380 in obese and 0.420 in lean subjects (p = 0.298).We did not detect significant differences for allele and carrier frequencies of individual polymorphisms. Together with previously obtained data on genotype distribution of aβ3-AR variant in the same study group, no significant differences were found between obese and lean subjects for the distribution of individuals with variants in none, one, two or all threeβ-ARs. Our data make it unlikely that polymorphisms inβ-ARs are involved in the pathogenesis of early onset obesity. [ABSTRACT FROM AUTHOR]

A discrete-time model is used to simulate performance of PM brushless DC motor drives under normal and faulty operations. Normal conditions included perfect and imperfect commutations as well as noisy operation. Faulty operation was considered an open-circuit fault on one phase of the stator windings. Current waveform of the motor-DC link is monitored and processed using continuous wavelet transform to derive suitable diagnostic indices. An adaptive neuro-fuzzy inference system (ANFIS) is trained based on indices extracted under various operating conditions in order to automate the diagnosis process. The developed ANFIS yielded a perfect diagnosis of the fault. A good agreement between simulation and experimental results is achieved. [ABSTRACT FROM AUTHOR]

Epidermal growth factor receptor 1 (EGFR-1) overexpression is usually described as linked with a worse prognosis in a variety of tumours of epithelial origin. However, its role in ovarian cancer is still controversial. The aim of the present study was to analyse the prognostic impact of EGFR-1 in a retrospective series of 93 stage III-IV primary ovarian epithelial tumours. All patients, enrolled in a multicentre GINECO prospective clinical trial, were treated with the same platinum-based combination chemotherapy, and were followed up with a median of 69 months. Epidermal growth factor receptor 1 plasma membrane expression, assessed by immunohistochemistry on paraffin-embedded tissues, was correlated with clinical parameters as well as immunohistochemical expression results of HER-2 (c-erbB-2), BAX, BCL-2, p53 and anti-Ki-67, previously studied in the same series of patients. Positive immunostaining for EGFR-1 was seen in 31 of the 93 analysed cases (33%). No correlation was found between EGFR-1 expression and clinical parameters. No correlation was found between EGFR-1 expression and other biological markers, except for HER-2, which was limit for significance. Indeed, among the EGFR-1-negative cases, 10.3% expressed HER-2, whereas the HER-2-expressing tumours accounted for 27.6% of EGFR-1-positive cases (P=0.06). Epidermal growth factor receptor 1 overexpression had no prognostic impact on both overall and progression-free survival through univariate and multivariate analyses. The potential effect of EGFR-1 and HER-2 co-expression on targeted therapy against EGFR-1 and/or HER-2 molecules has to be further analysed. [ABSTRACT FROM AUTHOR]

An adaptive neuro-fuzzy inference classifier based on the discrete wavelet transform (DWT) to recognize the type of power quality (PQ) disturbances is presented. The DWT, using the multi-resolution signal decomposition (MSD), can transfer power disturbance characteristics into the time-frequency domain. The energy of the signal decomposed to frequency sub-bands can be used to extract feature parameters for classifying various disturbances. The proposed classifier was designed using four feature parameters that consist of energy concentration level and its mean value, mean energy of the signal, and an auxiliary parameter determined by the rms value and pulse detection. The proposed classifier shows good recognizing efficiency for ten types of PQ events, including one double event disturbance. [ABSTRACT FROM AUTHOR]

Voltage sag produced by induction motor starting current is one of the main causes of sensitive equipment dropout. The use of a motor starter reduces the voltage sag depth but increases its duration. The subsequent connection to full voltage produces a new sag separated from the first one by a few seconds. A simple method is presented that allows transforming the information of starting current/time characteristics to voltage sag depth/time characteristics that are directly comparable with the sensitive equipment susceptibility curves (CBEMA and other curves). The methodology also allows consideration of motor repetitive starts as well as different starting cycles. [ABSTRACT FROM AUTHOR]

The Irish Electricity Supply Board's (ESB) Shannon Hydro Electric Scheme joined the ranks of world-recognized engineering feats on 29 July 2002 when it received Milestone and Landmark Awards to mark its 75th Anniversary. The Shannon Scheme was officially opened at Parteen Weir on 22 July 1929. One of the largest engineering projects of its day, it was successfully executed by Siemens to harness the Shannon River. It subsequently served as a model for large-scale electrification projects worldwide. Operated by the Electricity Supply Board of Ireland, it had an immediate impact on the social, economic and industrial development of Ireland and continues to supply significant power beyond the end of the 20th century. [ABSTRACT FROM PUBLISHER]

The gate turn-off (GTO) thyristor, which has very high voltage and high current ratings compared with other power semiconductor devices, is especially competitive in high-power applications; however, the GTO requires relatively complicated gate drive circuit, has slow switching frequency, and suffers from reverse-bias second breakdown. These factors hinder its popular use. Cascode configuration promises to free the GTO from its drawbacks, especially through the use of a readily available high-voltage insulated-gate bipolar transistor (IGBT) with a simple gate drive circuit. Consisting of two separate kinds of power switches, the cascode switch combines the best characteristics of both technologies. This switch proves to be a better candidate for high-power applications. In general, MOSFETs have advantages over BJTs and GTOs in driving simplicity, switching speed, and second breakdown ruggedness. Thus, MOSFETs are popular for use in cascode switches with BJTs or GTOs, simplifying the drive requirement or increasing switching speed. This paper documents the switching performance of the different power semiconductor devices used in an IGBT-gated GTO-cascode switch. The cascode switch was tested and simulated using SPICE. Experimental waveforms are presented and show good agreement with simulation results. [ABSTRACT FROM AUTHOR]

This letter proposes a gaming model with coalition among producers in subgroups for the market setting with multiple producers. The possible number of coalitions is obtained for a total number of N(N≥3) producers. The generic spatial gaming model with coalition has a vector as its objective function, with each vector element representing a coalition profit. Various constraints are formulated, including the spatial constraints (e.g., the DC power flow equations). The Cournot gaming strategy is adopted. A small system is used for testing the model with satisfactory results. [ABSTRACT FROM PUBLISHER]

ABET Engineering Criteria 2000 has encouraged changes in engineering education. The deregulation of the electric power industry is also causing changes in the types of jobs power engineers take upon graduation. This paper describes efforts by power faculty at Kansas State University to provide students more hands-on active learning experience with power systems and machinery. A summary of the power curriculum is provided. The courses affected include an energy conversion course required of all electrical engineering students, and a new power laboratory course required of students taking the electric power option. Examples of student assignments are provided. Observations and discussion of the in-class experiences are provided. The paper describes work done and in progress to convert the traditional power courses into studio-type courses in which instruction can flow from lecture to laboratory to computer demonstration formats with ease. Future plans for the project are also discussed. [ABSTRACT FROM AUTHOR]

The relationship between distribution system protection schemes and overcurrents, and thus voltage sags, is presented. Sources of interruptions and voltage sags are also reported. The Computer Business Equipment Manufacturing Association (CBEMA) curve is described and adopted as most representative of sensitive equipment capability to withstand voltage sags. A short introduction of the protection parameters, like types of faults, protection device characteristics, and fault prevention, is presented. The six main sag mitigation measures are analyzed, studying their main advantages and drawbacks, with some given examples. The main emphasis is given to the recloser fast tripping elimination, dead time reduction, and the improving of the protection operating speed. Changes in protection criteria and circuit layout can avoid some sensitive equipment dropouts. [ABSTRACT FROM AUTHOR]

Increased oxidative stress and subsequent activation of the transcription factor NF-kB has been linked to the development of late diabetic complications. To determine whether oxidative stress dependent NF-kB activation is evident in patients with diabetic nephropathy we used an Electrophoretic Mobility Shift Assay based semiquantitative detection system which enabled us to determine NF-kB activation in ex vivo isolated peripheral blood mononuclear cells. We examined 33 patients with diabetes mellitus (Type I and Type II). Patients with diabetic nephropathy showed higher NF-kB binding activity in Electrophoretic Mobility Shift Assays and stronger immunohistological staining for activated NF-kBp65 than patients without renal complications. NF-kB binding activity correlated with the degree of albuminuria ( r = 0.316) and with thrombomodulin plasma concentrations ( r = 0.33), indicative for albuminuria associated endothelial dysfunction. In a 3 day intervention study in which 600 mg of the antioxidant thioctic acid (α-lipoic acid) per day were given to nine patients with diabetic nephropathy oxidative stress in plasma samples was decreased by 48 % and NF-kB binding activity in ex vivo isolated peripheral blood mononuclear cells by 38 %. [ABSTRACT FROM AUTHOR]