The argument-based validation of a large-scale high-stakes vocabulary test

The purpose of this study was to investigate the validity of the vocabulary subsection of a high-stakes university entrance exam for PhD programs using the argument-based approach. All the three different versions of the test administered in a period of five years and the responses of 12500 test-takers were studied. The study focused on four inferences of domain definition, evaluation, generalization and explanation mainly using corpus linguistics, the Rash measurement model and factor analysis. The results indicated substantial threats to the validity of the test in terms of vocabulary choice, item difficulty, item discrimination, construct representation, and reliability

Growth Optimization of III-N Electronic Devices by Plasma-Assisted Molecular Beam Epitaxy

InAlN has received significant attention due to its great potential for electronic and optoelectronic applications. In particular, $In_{0.18}Al_{0.82}N$ presents the advantage of being lattice-matched to GaN and simultaneously exhibiting a high spontaneous polarization charge, making $In_{0.18}Al_{0.82}N$ attractive for use as the barrier layer in high-electron-mobility transistors (HEMTs). However, in the case of InAlN growth by plasma-assisted molecular beam epitaxy (PAMBE), a strong non-uniformity in the in-plane In distribution was observed for both N-face and metal-face $In_{0.18}Al_{0.82}N$. This compositional inhomogeneity manifests itself as a columnar microstructure with AlN-rich cores (5-10 nm in width) and InN-rich intercolumn boundaries. Because of the large differences between the bandgaps and polarization of InN and AlN, this non-uniformity in InAlN composition could be a source of scattering, leading to mobility degradation in HEMTs. In this work, the growth conditions for high quality lattice-matched InAlN layers on free-standing GaN substrates were explored by plasma-assisted molecular beam epitaxy (PAMBE) in the N-rich regime. The microstructure of N-face InAlN layers, lattice-matched to GaN, was investigated by scanning transmission electron microscopy and atom probe tomography. Microstructural analysis showed an absence of the lateral composition modulation that was previously observed in InAlN films grown by PAMBE. Using same growth conditions for InAlN layer, N-face GaN/AlN/GaN/InAlN high-electron-mobility transistors with lattice-matched InAlN back barriers were grown directly on SiC. A room temperature two-dimensional electron gas (2DEG) mobility of $1100\,cm^2V^{-1}s^{-1}$ and 2DEG sheet charge density of $1.9\times10^{13}\,cm^2$ was measured on these devices. However, the threading dislocation density (TDD) of GaN grown directly on SiC by PAMBE ($\approx2\times10^{10}\,cm^{-2}$) is two orders of magnitude higher than GaN grown by MOCVD on SiC or sapphire ($\approx5\times10^8\,cm^{-2}$). This high TDD can severely degrade the 2DEG mobility, especially at lower 2DEG sheet densities. Relatively low TDD ($\approx5\times10^8\,cm^{-2}$) on MOCVD-grown GaN substrates motivated us to study the growth of N-face GaN-based HEMT structures with InAlN backbarriers on such substrates. Since on-axis GaN-on-sapphire substrates with low threading dislocation density are not available in the N-face orientation, we explored the growth of InAlN on vicinal ($4^{\circ}$ miscut along GaN $10\bar{1}0$) GaN-on-sapphire substrates. The microstructure of $In_{0.18}Al_{0.82}N$ layers grown by PAMBE at different temperatures was studied using scanning transmission electron microscopy (STEM). The cross-sectional and plan-view STEM images revealed lateral variations in the InAlN composition along $10\bar{1}0$ (perpendicular to the step edges), in addition to step bunching in InAlN layers thicker than 10 nm. N-face HEMTs with lattice-matched InAlN backbarriers were then grown on these vicinal substrates with different InAlN thicknesses. Transmission line measurements showed that step bunching and lateral variation of InAlN composition degraded the 2DEG mobility in the directions parallel and perpendicular to the steps. A 2DEG charge density of $1.1\times10^{13}\,cm^{-2}$ and mobility of $1850\,cm^2V^{-1}s^{-1}$ were achieved on a GaN/AlN/InAlN/GaN structure with 7.5 nm thick $In_{0.18}Al_{0.82}N$. By designing a double backbarrier ($In_{0.18}Al_{0.82}N$(7.5 nm)/$Al_{0.57}Ga_{0.43}N$(7 nm)), a 2DEG charge density of $2\times10^{13}\,cm^{-2}$ and mobility of $1360\,cm^2V^{-1}s^{-1}$ were attained, which resulted in a sheet resistance of $230\,\Omega/\square$.Two good measures of the device quality concerning the power loss in power switch and high frequency switch applications are Huang material figure of merit , and Baliga high-frequency figure of merit, respectively, which shows that for any fixed material system, power loss reduces by increasing the mobility of the 2DEG. Therefore, it is very important to understand the source of scattering mechanisms which affect the 2DEG mobility. In this work, we studied effect of decreasing channel thickness or increasing gate reverse bias on charge density and 2DEG mobility in N-face HEMT structure. Our calculations showed that increasing the gate reverse bias and decreasing the channel thickness both reduce the 2DEG mobility. This trend has been observed by experiment as well. Previously, it was believed that increasing the gate reverse bias or decreasing the channel thickness in N-face GaN-based HEMT structures lead to deeper penetration of the 2DEG wavefunction into the barrier, and consequently, higher interface roughness and alloy scattering rates. Although this statement is true, our calculations revealed that the penetration of the 2DEG into the barrier and, therefore, 2DEG mobility limited by alloy and interface roughness scattering mechanisms do not vary significantly by increasing gate reverse bias or decreasing the channel thickness. therefore, these two scattering mechanisms are not enough to explain the significant drop in the 2DEG mobility observed in experiments. We believe that the charged trap states at the AlGaN-GaN interface, where the 2DEG forms, are responsible for this 2DEG mobility reduction

Influence of pH on Heat-Induced Changes in Skim Milk Containing Various Levels of Micellar Calcium Phosphate

The present study investigated the effect of micellar calcium phosphate (MCP) content and pH of skim milk on heat-induced changes in skim milk. Four MCP-adjusted samples, ranging from 67 to 113% of the original MCP content, were heated (90 °C for 10 min) at different pH values (6.3, 6.6, 6.9, and 7.2), followed by determining changes in particle size, turbidity, protein distribution, and structure. The results demonstrate a strong effect of MCP level and pH on heat-induced changes in milk, with the MCP67 samples revealing the greatest thermal stability. Specifically, decreasing MCP content by 33% (MCP67) led to a smaller increase in non-sedimentable κ-casein and a lower decrease in αs2-casein concentrations after heating compared to other samples. Lower MCP content resulted in a moderate rise in the average particle size and turbidity, along with lower loading of β-turn structural component after heating at low pH (pH 6.3). Notably, MCP113 exhibited instability upon heating, with increased particle size, turbidity, and a significant decrease in non-sedimentable αs2-casein concentration, along with a slight increase in non-sedimentable κ-casein concentration. The FTIR results also revealed higher loading of intermolecular β-sheet, β-turn, and random coil structures, as well as lower loading of α-helix and β-sheet structures in MCP-enhanced skim milk samples. This suggests significant changes in the secondary structure of milk protein and greater formation of larger aggregates

Rural Healthcare Workers` Knowledge, Attitude, and Practice toward COVID-19 two years after the pandemic onset: is health literacy training still necessary?

This study aimed to assess the level of knowledge, attitude, and practice regarding the coronavirus disease among Iranian rural and urban healthcare workers. The study population consisted of all healthcare experts and staff working in 38 rural health centers in Iran. An online questionnaire was distributed in November 2021. The anonymous questionnaire was comprised of a series of questions about demographic information; knowledge about COVID-19, the attitudes and preventive practices toward COVID-19. The majority of the participants (92.6%) had appropriate knowledge about COVID-19 disease. Most of the participants (77.2%) had a good attitude toward COVID-19 and 60.3% showed good practice. There was a significant, strong, and positive correlation between knowledge and attitude scores (p valu

Noise Exposure in Workplace and Mtabolic Syndrome; Are They related?

Several studies confirmed the association of diabetes, hypertension, hyperlipidemia, obesity and high body mass index (BMI) on hearing loss among the general population. We think that same with the general population, we might have same association among workers that exposed with noise exposure in their workplaces. Therefore, this study aimed to examine the relationship between metabolic syndrome and noise-induced hearing loss among workers of the Iranian automobile industry. The present survey was performed on 606 workers of an Iranian automobile product factory. According to Noise exposure measurement, we divided workers into the noise-exposed (≥ 85 dB) and unexposed

Self-Assessment of Clinical Skills in Medical Internship

Background and Objectives: Self-assessment of clinical performance in a clinical setting is defined as the process of collecting internal and external data, interpreting the data on personal performance, and comparing them with a set of standards. The current study aimed at analyzing self-assessment of clinical skills among medical interns at Kerman University of Medical Sciences, Kerman, Iran, and determining the relationship between practical skills and theoretical knowledge. Methods: The current cross sectional, descriptive, analytical study was conducted in 2014 on a total of 141 interns from Kerman University of Medical Sciences selected via census sampling. Data were collected using a checklist including the main procedural skills of medical students and analyzed using the Mann-Whitney and the Kruskal-Wallis tests with SPSS. Results: The majority of participants were female (n = 79; 56%). The mean score of males‘ clinical skills was higher than that of females, and the difference was statistically significant (P = 0.001). Analysis of the relationship between internship duration and clinical skill scores showed that the mean score of interns who had completed 6 months of their internship was higher than that of the ones who had not; the difference was statistically significant (P = 0.001). Conclusions: Since the performance of future general practitioners highly depends on their learning and mastery of clinical skills, acquisition of these essential skills during internships is an important objective of medical students. Correct and complete training of clinical skills, especially during internships, is integrated into the medical curriculum, although its implementation requires careful planning and compliance with the medical standards. Keywords: Internship Period, Medical Students, Self-Assessment, Clinical Skill

Neck and Back Pain Prevalence in Workers of Iranian Steel industries at 2015

Work related musculoskeletal disorders (WMSDs) are considered as the main cause of occupational complications and disability in developing countries. In Iranian steel companies, workers commonly are directly involved in the production process and physical activities such as manual material handling and awkward postures. Present study was performed for assessment of neck and back pain prevalence among workers of four Iranian steel industries. Study participants in our cross sectional study, were randomly selected from workers of four Iranian steel industries. Data of neck and back pain were gathered by Nordic questionnaire. Logistic regression was used for controlling confounding variables and determining independent predictors of neck and back pain among study workers. Among study workers, prevalence of neck and back pain in a recent year were 18.40% and 13.90% respectively. Age (p≤0.02) and job experience (p≤0.00) had significant association with neck pain. Age, sex, BMI, and job duration were not known as an independent predictor of neck or back pain. Neck and back pain prevalence in steel industries were happened whit higher rate compared to most of other countries. Next studies will suggest for determining work related risk factors of WMSDs in workers and designing preventive strategies

Role of Rice Farming in Development Risk of Musculoskeletal Disorders Among Rice Farmers: a Prospective Study in 2013

Farming as job, had some activities or work task such as strenuous physical tasks and high levels of manual labor in farming job, which can increase risk of MSDs among farmers. Present study with prospective design designed for assessment role of rice farming in developmental risk of MSDs among Iranian rice farmers. Present prospective study was performed on 75 rice farmers of Babol city in Iran and 75 participants without history of rice farming, during March 2013 until September 2013. At the beginning of the study, participants did not have any musculoskeletal complaints in each of their body parts. Study exposure in the present study was working in the rice farming workplace for one rice farming period which at least lasted for four months. Frequency of MSDs had been assessed by Nordic questionnaire at three follow-up points. We followed 75 rice farmers of Babol city as expose and compare them with 75 participants without history of rice farming. Within the six months follow-up, MSDs complaints in 38 (50.66%), 61 (81.33%) and 47 (63.51%) rice farmers had been reported respectively in upper limbs, spinal and lower limbs regions. In the present study, rice farming was reported as a risk factor for MSDs in the spinal region and lower limbs

Neuromarketing: a review of research and implications for marketing

In this research, we reviewed existing studies which used neuromarketing techniques in various fields of research. The results revealed that most attempts in neuromarketing have been made for business research. This research provides important results on the use of neuromarketing techniques, their limitations and implications for marketing research. We hope that this research will provide useful information about the neuromarketing techniques, their applications and help the researchers in conducting the research on neuromarketing with insight into the state-of-the-art of development methods