Electrical characteristics of metal-insulator-semiconductor Schottky diodes using a photowashing treatment in AlzGa1-xAs/InGaAs (X=0.75) pseudimorphic high electron mobility transistors

MIS Schottky diodes on Al0.75Ga0.25As/In0.2Ga0.8As PHEMTs were produced using both photowashing and H2O2 treatments. The Schottky contact on the GaAs layer with photowashing and H2O2 treatments showed enhancements of the SBH of about 0.11 and 0.05 eV, respectively. However, on the undoped AlGaAs layer, no further improvement in SBH was observed. After the photowashing treatment, the Ga oxide (Ga2O3) was dominantly created. In the mean time, two types of As oxide (As2O3,As5O2) were mainly produced by the H2O2 treatment, which are distributed uniformly on the GaAs surface. The thickness of the oxide layer formed by both treatments was nearly the same. Applying a representative model, formation of Ga oxide after the photowashing treatment effectively enhanced the SBH.open4

AN INVESTIGATION OF FACTORS RELATED TO SUBJECTIVE MEMORY COMPLAINTS OF OLDER ADULTS DURING THE COVID-19 PANDEMIC

Introduction: The purpose of this research was to determine the individual factors that predict the subjective memory complaints of older adults during the Covid-19 pandemic. Materials and Method: The sample of the study consisted of 356 older adults aged between 60 and 88 years ((x) over bar = 67.03, SD = 5.72). Subjective Memory Complaints Questionnaire, Geriatric Depression Scale-Short Form, The Scale of Loneliness for the Elderly, Quality of Life Scale in Older People, and Socio-Demographic Information Form were administered to the participants. In order to examine the relationships among the variables, correlation analysis was performed. In addition, a hierarchical regression analysis was conducted to determine the variables predicting subjective memory complaints. Results: The subjective memory complaints of this age group were found to be positively related to depression and loneliness levels, while they were discovered to be negatively associated with quality of life. The results of hierarchical regression analysis indicated that each of the variables of gender, perceived socioeconomic status, loneliness, quality of life, and depression included in the analysis at different steps were a significant predictors of subjective memory complaints. Conclusion: Our results showed that there is a need for interventions that will expand social support networks, improve quality of life, and reduce depression levels in order to prevent subjective memory complaints of elderly individuals during the Covid-19 pandemic

Brucellar spondylodiscitis

Spondylodiscitis is among the most frequent and serious complications of brucellosis, and the lumbar spine is the most frequently involved region. This report describes the clinical characteristics of 37 cases and discusses the management problems of brucellar spondylodiscitis. © 2011 ARGOS and Springer-Verlag France

Determination of volatile organic compounds in air by a surface acoustic wave array

This article reports the design and performance of a portable volatile organic compound detection system implemented with a surface acoustic wave array. The system employed electrospray technology for the determination of acetone and methanol. The novel part of this study was the design of the 433MHz surface acoustic wave array. The sensor oscillators were operated at higher frequencies to reduce space and power consumption. The higher frequency also improved the response resolution; however, it created problems including interferences, crosstalk, signal degradation, and noise. Crosstalk was the most important problem and was minimized by the operation of one sensor at a time while the others were muted. Analog and digital circuitry served as the transducer to obtain analyte signals that were processed to produce bar and principal component analysis plots. The system was extensively tested and good results were obtained for qualitative and quantitative measurements.https://doi.org/10.1080/10739149.2015.107513

Acoustoelectric Effect on the Responses of SAW Sensors Coated with Electrospun ZnO Nanostructured Thin Film

In this study, zinc oxide (ZnO) was a very good candidate for improving the sensitivity of gas sensor technology. The preparation of an electrospun ZnO nanostructured thin film on a 433 MHz Rayleigh wave based Surface Acoustic Wave (SAW) sensor and the investigation of the acoustoelectric effect on the responses of the SAW sensor are reported. We prepared an electrospun ZnO nanostructured thin film on the SAW devices by using an electrospray technique. To investigate the dependency of the sensor response on the structure and the number of the ZnO nanoparticles, SAW sensors were prepared with different coating loads. The coating frequency shifts were adjusted to fall between 100 kHz and 2.4 MHz. The sensor measurements were performed against VOCs such as acetone, trichloroethylene, chloroform, ethanol, n-propanol and methanol vapor. The sensor responses of n-propanol have opposite characteristics to the other VOCs, and we attributed these characteristics to the elastic effect/acoustoelectric effect