Electromagnetic Pulse Driven Spin-dependent Currents in Semiconductor Quantum Rings

We investigate the non-equilibrium charge and spin-dependent currents in a quantum ring with a Rashba spin orbit interaction (SOI) driven by two asymmetric picosecond electromagnetic pulses. The equilibrium persistent charge and persistent spin-dependent currents are investigated as well. It is shown that the dynamical charge and the dynamical spin-dependent currents vary smoothly with a static external magnetic flux and the SOI provides a SU(2) effective flux that changes the phases of the dynamic charge and the dynamic spin-dependent currents. The period of the oscillation of the total charge current with the delay time between the pulses is larger in a quantum ring with a larger radius. The parameters of the pulse fields control to a certain extent the total charge and the total spin-dependent currents. The calculations are applicable to nano-meter rings fabricated in heterojuctions of III-V and II-VI semiconductors containing several hundreds electrons.Comment: 15pages, 5 figure

Desain Model dan Simulasi PLC-Mikrokontroler sebagai Modul Pembelajaran Berbasis PLC

Programmable Logic Controller (PLC) merupakan suatu piranti yang dibuat sebagai pengganti kumpulan relai-relai mekanik yang digunakan dalam sistem kontrol. PLC berkerja dengan cara membaca instruksi-instruksi dari masukannya. Karena PLC pada umumnya memiliki harga yang cukup mahal dan hanya beberapa orang yang dapat mempelajarinya, maka dibuatlah PLC trainer. PLC trainer dirancang menggunakan mikrokontroler Arduino Uno, modul input (berupa: toggle switch, push button, dan limit switch), dan modul output (berupa: LED, seven segment, motor DC, dan buzzer). PLC trainer juga dilengkapi prototype lampu lalu lintas sebagai modul output simulasi lampu lalu lintas empat arah. PLC trainer memanfaatkan LDmicro untuk membuat pemrograman ladder diagram dengan instruksi-instruksi sesuai dengan keinginan programmer dan menggunakan software Xloader untuk upload program ke Arduino Uno. Dari hasil pengujian diperoleh bahwa mikrokontroler Arduino Uno dapat dimanfaatkan sebagai PLC trainer untuk modul pembelajaran

A Survey of Air-to-Ground Propagation Channel Modeling for Unmanned Aerial Vehicles

In recent years, there has been a dramatic increase in the use of unmanned aerial vehicles (UAVs), particularly for small UAVs, due to their affordable prices, ease of availability, and ease of operability. Existing and future applications of UAVs include remote surveillance and monitoring, relief operations, package delivery, and communication backhaul infrastructure. Additionally, UAVs are envisioned as an important component of 5G wireless technology and beyond. The unique application scenarios for UAVs necessitate accurate air-to-ground (AG) propagation channel models for designing and evaluating UAV communication links for control/non-payload as well as payload data transmissions. These AG propagation models have not been investigated in detail when compared to terrestrial propagation models. In this paper, a comprehensive survey is provided on available AG channel measurement campaigns, large and small scale fading channel models, their limitations, and future research directions for UAV communication scenarios

Securing the Mobile Future: An Extensive Analysis of the Threat Landscape from Mobile Devices User Perspectives

Mobile devices are becoming increasingly popular in the modern era, posing a significant threat to the security of organizations. As a result, mobile devices have become more and more vulnerable to cyberattacks. The current study aims to assess the threat landscape of mobile devices from the perspectives of users, highlighting the importance of user-centered perspectives in designing solutions to mobile security threats. A total of 47 participants of different demographic profiles were recruited as respondents, and the primary data were collected through an online questionnaire. The study concludes with a discussion of the findings’ implications for research and practice in mobile security. The paper outlines the current state of the art in mobile device security, including vulnerability to security threats, privacy risks, trust in security measures, awareness of potential threats, and satisfaction with the security provided by mobile operating systems. The results demonstrated that users are unaware of data protection and mobile device security, which have a substantial impact on an organization’s performance. However, this study lays a foundational perspective for future advancements in security audits, aiming to enhance cybersecurity practices in an increasingly mobile-centric corporate landscape

Evaluation of engineering properties of clayey sand bio-mediated with terrazyme enzyme

Soil stabilization is a practical approach for enhancing the suitability of problematic soil in construction projects. This study focusses on analyzing the impact of the bio-enzyme Terrazyme on the engineering properties of Mirpur soil, which exhibits inadequate performance as subgrade soil, particularly in moist conditions. The study investigates key engineering characteristics, including unconfined compressive strength (UCS), California Bearing Ratio (CBR), maximum dry density (MDD), Atterberg’s Limits, and compressibility index. Additionally, X-Ray Diffraction and SEM analysis were conducted to identify the mineral composition and particle structure of Mirpur soil. It is demonstrated that the incorporation of Terrazyme enhanced the engineering properties of the soil. The findings will contribute to a better understanding of the efficacy of bio-mediated soil stabilization techniques

The Green Synthesis of Silver Nanoparticles from Avena fatua Extract: Antifungal Activity against Fusarium oxysporum f.sp. lycopersici

Using plant extracts as eco-friendly reducing and stabilizing agents for the synthesis of nanoparticles has gained significant attention in recent years. The current study explores the green synthesis of silver nanoparticles (AgNPs) using the Avena fatua extract and evaluates their antifungal activity against Fusarium oxysporum f.sp. lycopersici (Fol), a fungal plant pathogen. A green and sustainable approach was adopted to synthesize silver nanoparticles before these nanoparticles were employed for anti-fungal activity. The primary indication that AgNPs had formed was performed using UV-vis spectroscopy, where a strong peak at 425 nm indicated the effective formation of these nanoparticles. The indication of important functional groups acting as reducing and stabilizing agents was conducted using the FTIR study. Additionally, morphological studies were executed via SEM and AFM, which assisted with more effectively analyzing AgNPs. Crystalline behavior and size were estimated using powder XRD, and it was found that AgNPs were highly crystalline, and their size ranged from 5 to 25 nm. Synthesized AgNPs exhibited significant antifungal activity against Fol at a concentration of 40 ppm. Furthermore, the inhibitory index confirmed a positive correlation between increasing AgNPs concentration and exposure duration. This study suggests that the combined phytochemical mycotoxic effect of the plant extract and the smaller size of synthesized AgNPs were responsible for the highest penetrating power to inhibit Fol growth. Moreover, this study highlights the potential of using plant extracts as reducing and capping agents for the green synthesis of AgNPs with antifungal properties. The study concludes that A. fatua extract can synthesize antifungal AgNPs as a sustainable approach with robust antifungal efficacy against Fol, underscoring their promising potential for integration into plant protection strategies

TAT-peptide conjugated repurposing drug against SARS-CoV-2 main protease (3CLpro): potential therapeutic intervention to combat COVID-19

The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that originated in Chinese city of Wuhan has caused around 906,092 deaths and 28,040,853 confirmed cases worldwide (WHO, 11 September, 2020). In a life-threatening situation, where there is no specific and licensed anti-COVID-19 vaccine or medicine available; the repurposed drug might act as a silver bullet. Currently, more than 211 vaccines, 80 antibodies, 31 antiviral drugs, 35 cell-based, 6 RNA-based and 131 other drugs are in clinical trials. It is therefore utter need of the hour to develop an effective drug that can be used for the treatment of COVID-19 before a vaccine can be developed. One of the best-characterized and attractive drug targets among coronaviruses is the main protease (3CL^{pro}). Therefore, the current study focuses on the molecular docking analysis of TAT-peptide^{47–57} (GRKKRRQRRRP)-conjugated repurposed drugs (i.e., lopinavir, ritonavir, favipiravir, and hydroxychloroquine) with SARS-CoV-2 main protease (3CL^{pro} to discover potential efficacy of TAT-peptide (TP) - conjugated repurposing drugs against SARS-CoV-2. The molecular docking results validated that TP-conjugated ritonavir, lopinavir, favipiravir, and hydroxychloroquine have superior and significantly enhanced interactions with the target SARS-CoV-2 main protease. In-silico approach employed in this study suggests that the combination of the drug with TP is an excelling alternative to develop a novel drug for the treatment of SARS-CoV-2 infected patients. The development of TP based delivery of repurposing drugs might be an excellent approach to enhance the efficacy of the existing drugs for the treatment of COVID-19. The predictions from the results obtained provide invaluable information that can be utilized for the choice of candidate drugs for in vitro, in vivo and clinical trials. The outcome from this work prove crucial for exploring and developing novel cost-effective and biocompatible TP conjugated anti-SARS-CoV-2 therapeutic agents in immediate future

Assessing Climate Sensitivity to Urban Land-Use Changes in Iraq

Iraq has been suffering from a continuing rise in surface air temperature, causing a general deterioration in ecosystems. Land-use climate sensitivity focuses on how changes in land cover (e.g., deforestation, urbanization, or agricultural expansion affect local or regional climate conditions, particularly surface temperatures. Using yearly data on built-up areas and air temperature over the period (1971-2022), this sensitivity is assessed based on alterations in built-up areas for three Iraqi cities-Basrah, Baghdad, and Mosul, as well as for the entire country of Iraq. The time series of the areal yearly averages for air temperatures was analyzed. Standardized Euclidean distance and linear regression models were used to assess the effect of built-up changes and temperature trends, respectively. The results revealed that the trend in Iraq has positively increased, with a value of 0.07°C/year. The results also illustrate that alterations in built-up areas have contributed to the increase in yearly temperature in Basrah and Baghdad, but not in Mosul, which seems to be more affected by global warming and land cover changes. Urbanization plays a significant role in shaping the social, economic, and environmental landscapes of Baghdad and Basrah

Ischaemic stroke and peripheral artery disease

Objective: To determine the frequency of atherosclerosis by ankle brachial index in patients with an ischaemic stroke and to assess the association of carotid artery stenosis and ankle brachial index in ischaemic stroke. Methods: This cross-sectional study was conducted at Abbasi Shaheed Hospital, Karachi, from July 2011 to May 2014, and comprised patients with ischaemic stroke. The patients were classified according to the Asian stroke criteria for classification of brain infarction. Primary outcome measures included carotid artery stenosis and ankle brachial index. The other independent variables were age, gender, body mass index and waist circumference. SPSS 20 was used for data analysis. Results: A total of 327 patients were enrolled. The overall mean age was 57.612.8 years. Besides, 168(51.3%) participants were males. Peripheral artery disease was found in 60(18.3%) patients. Mild carotid artery stenosis was found in 182(55.6%) patients, moderate in 140(42.8%), severe in 3(0.9%) and complete occlusion in 2(0.6%) patients. In patients having mild carotid artery stenosis, 32(17.5%) had peripheral artery disease, whereas in patients with moderate carotid artery stenosis, 25(17.8%) had peripheral artery disease. Conclusion: Abnormally low ankle brachial index suggesting subclinical peripheral artery disease was 18%. Keywords: Ischaemic stroke, Peripheral artery disease, Ankle brachial index, Carotid artery stenosis. (JPMA 67: 1138; 2017)sch_pod67pub4830pub

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability