On-off Conditions Research Articles

Suppressed current collapse and improved threshold voltage stability of AlGaN/GaN HEMT via O2 plasma treatment

A comprehensive study about the effects of O2 plasma treatment on the dynamic performance of AlGaN/GaN high electron mobility transistors (HEMTs) is presented. The drain current transient spectroscopy indicated a much decelerated and mitigated current degradation process for the HEMT with O2 plasma treatment. Upon negative gate bias stressing, current collapse of 10.7 % and minor threshold voltage shift of 0.16 V were achieved by O2 plasma treatment. In addition, current collapse ratio of the HEMTs as a function of stress/recovery time showed that the HEMT with O2 plasma treatment had a superior performance in various on-off conditions. Particularly in high-frequency switching events, current collapse ratio was reduced from about 50 % to 0.2 %. At last, the quality of AlGaN/metal interface with O2 plasma treatment is demonstrated by capacitance-frequency measurements, with the interface trap density Dit is estimated to be 1.39 × 1012 cm−2 eV−1. These results indicate that GaN HEMT with O2 plasma treatment is a promising technology in power switching applications.

Fast on-off jet control of aerosol jet printing (AJP) using internal rotary valve

Aerosol jet printing (AJP) has been used in additive manufacturing sectors because it has advantages over conventional printing due to its capability of micro-pattern printing on various surfaces including a non-flat (3D) substrate with higher aspect ratio. Since the aerosol systems rely on continuous jet stream, one of the key issues is how to control the on-off of the jets to obtain desired patterns. An external shuttering system outside the nozzle was used to block the jet on non-printing regions. However, there are some downsides, for example, non-optimal stand-off distance due to mechanical interference, unwanted accumulation of the ink on the shutter, and possible mechanical interference when printing on curved surface or surfaces with protrusions. The purpose of this study is to develop AJP system with an internal rotary valve to eliminate the problems of the external shutter. The proposed internal two-way rotary valve can select the jet direction for printing or diverting the jet stream to the air. However, there was jetting delay because it takes time to stabilize the internal pressure. This delay results in non-uniform printing especially when resuming printing from off. In this study, we investigate the pressure behaviors of the flow cell under internal shutter on-off conditions and proposed a new flow rate control method capable of fast on-off control for uniform printing.

Automated reasoning of vehicle brake-force: a fuzzy inference system model

Automatic regulation of vehicle braking system is very crucial to control vehicle speed, keep it on its track, and avoid any collision. A traditional binary control for brake system is not appropriate as the on-off conditions induce unpleasant feelings to the passengers. Control engineering technique may solve this problem but does not reflect artificial intelligence in terms of human reasoning behaviour. Although, a few study on fuzzy-based automated brake-force reasoning has been conducted showing the superiority over all the techniques, comparisons among various defuzzification methods are rarely found in the literature. Thus, the objective of this study is to design a fuzzy-based architecture for automated brake-force reasoning system through comparative analysis among various defuzzification approaches. The model takes two inputs as linguistic variables, the speed and the vehicular distance, and the output of the system is the required brake-force. The Mamdani fuzzy inference system (MFIS) is applied in designing the fuzzy architecture for automated brake-force prediction. The output fuzzy set is defuzzified with five defuzzification methods and analysed through observations. The results manifest that out of the five defuzzification approaches, the centroid and bisector methods demonstrate most satisfactory outputs and could be chosen for real system application.

Speech Characteristics of Patients with Parkinson's Disease-Does Dopaminergic Medications Have a Role?

Objective The present study aimed to investigate the effects of dopaminergic medication on voice, speech motor functions, and motor impairment in patients with Parkinson's disease (PD). Materials and Methods Twenty-five individuals (16 males and 9 females) with PD underwent comprehensive assessment of voice, speech, and motor functions in levodopa medication ON and medication OFF conditions. Age- and gender-matched healthy controls were recruited to compare speech and acoustic parameters. Multi-Dimensional Voice Program (MDVP) from Computerized Speech Laboratory (Model: 4500) was utilized for acoustic analysis of voice and the Voice Handicap Index (VHI) for the self-assessment of vocal function. Frenchay Dysarthria Assessment (FDA-2) and Unified Parkinson's Disease Rating Scale-III (UPDRS III) were used to evaluate speech motor and motor functions, respectively. Statistical Analysis The mean and standard deviation were used as descriptive statistics measures. Raw scores were obtained for FDA-2, DRS, VHI, MDVP parameters, and UPDRS-III in either medication condition. The Wilcoxon signed-rank test was performed to determine the statistical significance of the above measures in both genders across the medication conditions. Spearman's rank correlation coefficient was used to determine the relationship between motor speech function and motor impairment and between VHI and MDVP parameters across both medication conditions. The interrater reliability rating was established using Cohen's kappa. Results An improvement in lip and laryngeal functioning was found in the medication ON over medication OFF state in both males and females with PD. A few frequency and amplitude-related measures improved in the medication-ON state over the medication-OFF state. UPDRS-III scores reduced from the OFF state to the ON state, and no change in dysarthria severity or VHI was found in either gender or medication condition. No correlation was found between speech motor function and motor function or between VHI and acoustic parameters of voice in either medication condition. Conclusions Improvement in motor symptoms with levodopa was predominantly observed when compared with the minor improvements in a few aspects of speech motor function and vocal parameters. The results of this study suggest the need for speech therapy as a nonpharmacological treatment method for speech impairments in PD.

The impact of dopaminergic treatment over cognitive networks in Parkinson's disease: Stemming the tide?

Dopamine‐replacing therapies are an effective treatment for the motor aspects of Parkinson's disease. However, its precise effect over the cognitive resting‐state networks is not clear; whether dopaminergic treatment normalizes their functional connectivity‐as in other networks‐ and the links with cognitive decline are presently unknown. We recruited 35 nondemented PD patients and 16 age‐matched controls. Clinical and neuropsychological assessments were performed at baseline, and conversion to dementia was assessed in a 10 year follow‐up. Structural and functional brain imaging were acquired in both the ON and practical OFF conditions. We assessed functional connectivity in both medication states compared to healthy controls, connectivity differences within participants related to the ON/OFF condition, and baseline connectivity of PD participants that converted to dementia compared to those who did not convert. PD participants showed and increased frontoparietal connectivity compared to controls: a pattern of higher connectivity between salience (SN) and default‐mode (DMN) networks both in the ON and OFF states. Within PD patients, this higher SN‐DMN connectivity characterized the participants in the ON state, while within‐DMN connectivity prevailed in the OFF state. Interestingly, participants who converted to dementia also showed higher SN‐DMN connectivity in their baseline ON scans compared to nonconverters. To conclude, PD patients showed higher frontoparietal connectivity in cognitive networks compared to healthy controls, irrespective of medication status, but dopaminergic treatment specifically promoted SN‐DM hyperconnectivity.

A miniaturized frequency reconfigurable antenna with half-mode CRLH-embedded metamaterial arm

Metamaterial properties of a novel half-mode CRLH unit cell are investigated and hence a compact dual-wideband antenna is designed using an array of four unit cells. The negative refraction of the metamaterial cell is utilized to miniature the antenna. A via-free open stub, in combination with an interdigital capacitor, makes the half-mode CRLH unit cell. The proposed antenna operates at both C-band (6.2–6.8 GHz) and X-band (8.5–9.2 GHz). The dual-wideband antenna is enabled with frequency reconfigurability by incorporating RF PIN diode in its ground plane in the next design step. The ON–OFF conditions of the PIN diode electrically switch the antenna into dual-band and single-band modes, respectively. In OFF state of the diode, the antenna behaves as a monopole and operates in single-band mode resonating at C-band (5.9–6.5 GHz) only. The measured results of the fabricated sample are in good agreement with the simulated ones.

Performance study of a DC refrigerator powered by different solar PV modular sets. 2.

This work studies the performance of a refrigerator with a DC compressor motor using Butane as refrigerant, (R600) and PV module as a power source controlled by a battery. This R 600 was used as drop – in refrigerant to replace the original R 134a refrigerant. The refrigerator rated power is 60 Watts, the battery capacity is 21 Amper hour, (Ah), 12 V, connected to either a 70 Wp module or a 100 Wp module. The experiments were carried out using five different conditions for the power connection: battery stand alone with no PV connection; battery fully charged and either connected to the 70 Wp module or the 100 Wp module; and un charged battery connected to either the 100 Wp module or the 70 Wp module. The states of on-off conditions and their effect on the refrigerator inside temperatures and the refrigeration performance parameters settings of evaporation temperature and condensing temperature were mainly monitored in this study. The effect of the low power trips on-off sequence of the refrigerator on the freezer inside temperature and on the load temperatures was one of the main objectives of this study. This study showed that the minimum module capacity that can power the refrigerator with out interruption of the cooling process of the load was the 100 Wp.

The images theory of addiction

Sulkunen, P. (2015). The images theory of addiction. The International Journal Of Alcohol And Drug Research, 4(1), 5-11. doi:http://dx.doi.org/10.7895/ijadr.v4i1.191In everyday language, addiction usually refers to a strong desire that drives people to continue habitual behaviour despite acknowledged harm and their own will to quit. Many theorists and practitioners have long rejected the concept because of its tendency to individualize problem behavior, to focus on treatment rather than prevention, and to limit harmful consequences unduly to a selected group of users. There is no commonly accepted etiology of, or evidence-based treatment for, the condition, and diagnostic definitions are based on syndromes only. This article argues that the objections are not valid if we understand addiction as a generic concept, defined in terms of characteristics shared by several specific types, of which some are called prototypes. Addictions involve neurological adaptations but are not caused by them. They always emerge from culturally regulated behaviours, they are processes rather than on-off conditions, and involve types and pathways that depend on the social conditions in which they evolve. Addicted and normal uses are closely related and governed by images that define the functions, norms, meanings and use-values of the behavior. These will be transformed as addictions develop. The Images Theory of Addiction opens the way to understanding cultural variations in the addictive process, as well as to identify particularly risky images of potentially addictive behaviors. The theory is illustrated with examples from recent comparative studies.

Computational Model of Silicon Carbide JFET Power Device

This paper presents the computation simulation models for silicon carbide (SiC) vertical junction field effect power devices. An analytical, physics based model is capable of accurately replicating the device behavior for the on-off state and transient conditions. The simulation results of the models were validated against measured data obtained from experiments. The current and voltage characteristics of the silicon carbide power device is investigated, the simulation and test results indicate that the switching transient and switching losses are improved compared with the same rated silicon power device. The models developed in this research effort are expected to be valuable tools for power electronic designers in the future.

On-Off Conditions for the Omega Currents Caused by 3 Gaps Along S4 in Shaker K-Channel

We previously have shown that each replacement of a pair of long amino acid residues by short ones at 3 different sequential positions along the arginine thread of S4 in Shaker led to an omega conductance through a proteinaceous leak pore (Gamal El-Din et al., Biophys. J. 96(3) pp. 381a, 2009). For the already known omega current mutation R362S, we showed that it leaks only if paired with the native short A359. In consequence, we found that the paired arginine to serine mutations at the subsequent positions 362,365 and 365,368 also produce omega current. This was taken as evidence that S4 slides in 3 steps through a pore towards the activated state. Each pair of 2 short serines in between the thread of long arginines appears as a gap which allows a leak when in the omega pore. Here, we present further studies of the above mutants over a wider voltage range, in addition with the alpha pore open (434W) to detect the open state with alpha current. We found that S4 in all 3 omega constructs can reach the final open state where omega current has disappeared and alpha current appears. This provides clear evidence that all 3 S4 constructs - despite the arginine-to-serine gap - still proceed to the open state, although at different voltages. We also analyzed in detail the voltage range over which the omega pore remains open, i.e. is occupied by the gap. In the cases where the pore could be closed, the voltage dependence for the closing process was studied. While all constructs close in outward direction, a clear inward directed closing of the omega-pore could so far only be demonstrated for the RR/365,368/SS construct.

Binaural hearing aid communication shown to improve sound quality and localization

Binaural hearing aid communication shown to improve sound quality and localization

Modulated low-level electromagnetic field effects on EEG visual event-related potentials

The aim of this study was experimental investigation of the effects of low-level modulated microwaves on the human central nervous system function using electroencephalo- graphic (EEG) visual event-related potentials. Thirty healthy volunteers were exposed and sham- exposed to the electromagnetic field (EMF) (450 MHz, 0.16 mW/cm 2 ) modulated at 21 Hz frequency during visual oddball tasks. During the task the participants had to distinguish infrequent target stimuli from frequent standard stimuli. Th e task consisted of detecting visually presented random ball-shape stimuli of which 25% were target and 75% standard stimuli, in one task the subject was EMF-exposed and in another task sham-exposed. One task lasted 10 min, during the exposed task the EMF was switched on and off in one-minute intervals, so that the participants performed half of the task in exposed condition (EMF ON) and half of the task without the exposure (EMF OFF). The sham-exposed task was identical to the exposed task, except that the EMF generator was switched off all the time. Thr ee-channel EEG was recorded during all the tasks using electrodes Fz, Pz and Cz. For analysis of the EEG event-related responses, the channel Pz was used. The EEG responses of a task were grouped into four different categories, taking into account the EMF exposure condition (ON, OFF) during the response and the response type (standard, target). The responses were averaged by categories; finally we had four types of average EEG event-related potentials for a task for every subject. The EMF ON and OFF potentials were compared pairwise. The hypothesis was that the EEG event-related potential component latencies, amplitudes and reaction times (RT) of the subjects to the target stimuli are not different in EMF ON and EMF OFF conditions during the same task. There were no statistically significant differences in responses in sham-exposed tasks, neither in standard nor in target-response components. In the exposed task the group mean N100 amplitude (measured from standard response) was -3.41 ± 4.54 µV in EMF ON category and -2.50 ± 4.71 µV in EMF OFF category; this difference was statistically highly significant ( p < 0.00009). Differences in amplitudes, latencies and in RT between EMF ON and OFF conditions of other components were not significant. It is concluded that the modulated microwave effect has stronger impact on early (sensory) components of EEG visual event-related potentials compared with later stages of visual information processing during the oddball task.

Antagonistic role of E4BP4 and PAR proteins in the circadian oscillatory mechanism.

E4BP4, a basic leucine zipper transcription factor, contains a DNA-binding domain closely related to DBP, HLF, and TEF, which are PAR proteins. Here, we show that the phase of e4bp4 mRNA rhythm is opposite to that of the dbp, hlf, and tef rhythms in the suprachiasmatic nucleus (SCN), the mammalian circadian center, and the liver. The protein levels of E4BP4 and DBP also fluctuate in almost the opposite phase. Moreover, all PAR proteins activate, whereas E4BP4 suppresses, the transcriptional activity of the reporter gene containing a common binding sequence in transcriptional assays in vitro. An electrophoretic mobility shift assay demonstrated that E4BP4 is not able to dimerize with the PAR proteins, but is able to compete for the same binding sites with them. Furthermore, we showed sustained low e4bp4 and high dbp mRNA levels in mCry-deficient mice. These results indicate that the E4BP4 and PAR proteins are paired components of a reciprocating mechanism wherein E4BP4 suppresses the transcription of target genes during the time of day when E4BP4 is abundant, and the PAR proteins activate them at another time of day. E4BP4 and the PAR proteins may switch back and forth between the on-off conditions of the target genes.

Application of an Alarm and Data Telemetering System For Production Control

Abstract An alarm and data telemetering system was installed in the 30-year-old London field, Illinois, to monitor producing operations. Basic system components includesensing devices, located at waterflood plants, produced water gathering sites, LACT units, tank batteries and lease headers,transmission equipment consisting of field transmitting stations and a telephone cable system, andbase station equipment that includes a digital computer. Alarm sensors are on-off switches installed on electrical loops terminating at field transmission stations. Each transmitting station scans 16 alarm loops and reports the status of each to the base station via an underground network of telephone cable. Oil production and waterflood plant discharge pressure are also transmitted to the base station. Rapid detection of field malfunctions is possible with the computer that is also used to accumulate and report daily and monthly production data. Improved operational efficiency afforded by alarm and data telemetering permitted application in the established, relatively old London field. Introduction An alarm and data telemetering system was incorporated into producing operations at London field, Illinois, approximately 80 miles east of St. Louis, Mo. The computerized London system was engineered to improve over-all operational efficiency. To accomplish this objective the system performs three basic functions. It monitorsoperational status of 1,200 potential problem locations,oil production through lease automatic custody transfer (LACT) units anddischarge pressure at waterflood injection plants. Installation of the alarm and data transmission facility has allowed more efficient use of field personnel since manpower is now essentially relieved of searching for problems, and is directed to the tasks of preventive maintenance and rapid correction of problems when they do occur. This application of alarm and data transmission techniques is significant because London is an older field, in the latter stages of secondary depletion. London was discovered in Oct., 1937, developed on 10- and 20-acre spacing and produced on primary until 1950 when the first waterflood pilot was initiated. Production is from formations of the Chester series, Mississippian system, which, in this area of the Illinois basin, are found at a depth of approximately 1,500 ft. Waterflood operations in the field include 319 leases that extend over an area of about 60 sq miles. Oil production from 924 pumping wells is currently sold through 64 LACT units and 87 conventional tank batteries. Produced water is gathered at 18 sites and pumped to 747 water injection wells from 14 waterflood plants. Eleven water source wells also are used to make up required water injection volumes. Currently, 165,000 bbl of fluid are being handled each day. The London alarm and data telemetering system can be divided into three basic parts: field alarm and data sensors, transmission equipment and base station equipment. All alarm and data sensors are owned and maintained by Humble Oil and Refining Co., while transmitting and base station equipment are owned and maintained by a local telephone company and leased to Humble. Alarm and Data Sensors Alarm sensors installed at London are mechanical-electrical devices that reflect only on-off conditions. Mechanically, the sensors vary depending on the application. Electrically, the sensors are switches that are closed under normal operating conditions. Alarms are indicated when the switches open. Twelve hundred points are alarmed at five basic types of installation throughout the field. JPT P. 19ˆ