ZnO thickness and ZnTe back contact effect of CdTe thin film solar cell Voc and efficiency progression

CdTe thin film (TF) solar cells are most promising photovoltaic (PV) technology in commercial platform. Back contacts and interface defects related opto-electrical losses are still vital to limit its further technological benefit. TF PV cells shallow recombination and parasitic loss lessening purpose carrier selective back contact with band matching window layers are essential. Beside that back and front contact thickness choice is vital for field associated selective carrier collection and generous optical transmission into the active junction of the cell. It can make variation of cell efficiency. Window and front contact layers band edge variation and back contact thickness effect is analyzed by SCAPS-1D simulation software. ZnO and SnO2 front contact for CdS and CdSe window layers effect are numerically studied for 1 µm CdTe cell. Significance of materials for front contact and its thinness effect on current density while ZnTe back surface field contact thickness effect on open circuit voltage and efficiency are demonstrated. Finally, ZnO/CdS/CdTe/ZnTe cell of 0.925 V open circuit voltage and 19.06% efficiency is achieved for 90 nm of ZnTe with Molybdenum (Mo) back contact.

Maintaining the Link Between Patients and Their Families During the COVID Pandemic Using Visio: Iterative Development and Evaluation

Access to hospitals has been dramatically restricted during the COVID 19 pandemic. As a result, the patients were unable to communicate with their families other than through virtual communication channels. A still significant number of patients, which do not have access to modern videoconference tools, were completely isolated. As a result, the University Hospitals of Geneva decided to implement a Visio conference system inside their patient app ecosystem to allow every patient to remain connected. This article presents the iterative development of the solution in order to respond to the specific timely constraint of the situations as well as its evaluation by the patients and caregivers. Two iterations of the tool have been developed. The first relied on an existing commercial platform whereas the second is a fully integrated solution in our patient app ecosystem. The very positive evaluation at the first stage by more than 300 patients, relatives and caregivers convinced us to invest additional effort to provide a fully integrated solution. The second version, evaluated by 16 patients, confirmed that the Visio reaches its objective of reducing isolation during hospitalization. This initiative is completely in line with the objective of the hospital of providing human centered care.

From Google Doodles to Facebook: Nostalgia and Visual Reconstructions of the Past in Nigeria

In June 2019, Google announced plans to connect Africa to Europe through an undersea internet cable project named Equiano. As a techno-commercial platform, Google’s gesture warrants scrutiny and propels this essay’s analyses of the political connections of Internet spaces that also enable a visual turn in the scholarship of African history. Using the Google search engine and Facebook, Yékú and Ojebode stress the embeddedness of digital technologies in cultural meanings that include visual narratives that visibilize government’s ahistoricism. They conclude by foregrounding the digital labors of Nigerian digital subjects who deploy historical photographs on Facebook as expressions of performative nostalgia.

Multi-Parameter Vital Sign Telemedicine System Using Web Socket for COVID-19 Pandemics

Telemedicine has become an increasingly important part of the modern healthcare infrastructure, especially in the present situation with the COVID-19 pandemics. Many cloud platforms have been used intensively for Telemedicine. The most popular ones include PubNub, Amazon Web Service, Google Cloud Platform and Microsoft Azure. One of the crucial challenges of telemedicine is the real-time application monitoring for the vital sign. The commercial platform is, by far, not suitable for real-time applications. The alternative is to design a web-based application exploiting Web Socket. This research paper concerns the real-time six-parameter vital-sign monitoring using a web-based application. The six vital-sign parameters are electrocardiogram, temperature, plethysmogram, percent saturation oxygen, blood pressure and heart rate. The six vital-sign parameters were encoded in a web server site and sent to a client site upon logging on. The encoded parameters were then decoded into six vital sign signals. Our proposed multi-parameter vital-sign telemedicine system using Web Socket has successfully remotely monitored the six-parameter vital signs on 4G mobile network with a latency of less than 5 milliseconds.

Exploring the factors affecting the use of C2C in Colombia

This study analyses the factors that users of consumer-to-consumer (C2C) commerce value as direct influences in the intention to use and the acceptance of a marketplace. An empirical model is formulated, which integrates three variables that evaluate trust and, in turn, other variables that influence C2C intention and purchases, taking a sample of 686 surveys gathered using the Internet in Colombia. The results show that trust is a fundamental factor in this type of electronic commerce in Colombia, given that C2C users seek intermediation pages with third-party recognition (TPR) and high web quality; similarly, key variables in the adoption of this type of commercial platform include finding low prices and social influence. The perception of trust in this type of electronic commerce is a broader concept that requires the analysis of psychosocial factors. For companies that manage marketplaces, this study allows them to focus on key actions and tools in their websites. This study allows one to get to know the users of this transactional system, specifically for the Latin American region, highlighting the variables that they most consider when engaging in direct commerce between people. The results show that C2C requires marketplaces that guarantee the necessary conditions for a purchase/sale transaction with trust and quality.

Identification of the Movement Algorithm of a Commercial Platform for Helicopter Simulators

The use of flight simulators for pilot training and evaluations is common in the modern aeronautical sector. Whether for airplanes or helicopters, the military and airline companies use this feature to keep their crews operational, safety-oriented and resource-saving. This work presents a proposal for adjusting the washout filter parameters that allows the use of Stewart's platform in helicopter simulators. The identification of the filter parameters was carried out based on tests on an available commercial platform, certified by the company Moog, model MB-E-6DOF/24/1800KG, currently used in the SHEFE helicopter simulator of the Brazilian Army. The work dealt with the physiological aspects of the human vestibular system and its dynamics. Subsequently, the methods for choosing the filter model, and configuration parameters are presented. Three series of tests were carried on the commercial platform and in a real helicopter prepared with special flight test instrumentation. The tests were completed, and the motion platform filter adjustments were made to minimize errors between the movement cues perceived by the pilot in the aircraft and the flight simulator. The results of this work will be used as a basis for the development of a national movement platform for another flight simulator in the development phase.

Longitudinal Serological Analysis and Neutralizing Antibody Levels in Coronavirus Disease 2019 Convalescent Patients

Background Understanding the longitudinal trajectory of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies is crucial for diagnosis of prior infection and predicting future immunity. Methods We conducted a longitudinal analysis of coronavirus disease 2019 convalescent patients, with neutralizing antibody assays and SARS-CoV-2 serological assay platforms using SARS-CoV-2 spike (S) or nucleocapsid (N) antigens. Results Sensitivities of serological assays in diagnosing prior SARS-CoV-2 infection changed with time. One widely used commercial platform that had an initial sensitivity of >95% declined to 71% at 81–100 days after diagnosis. The trajectories of median binding antibody titers measured over approximately 3–4 months were not dependent on the use of SARS-CoV-2 N or S proteins as antigen. The median neutralization titer decreased by approximately 45% per month. Each serological assay gave quantitative antibody titers that were correlated with SARS-CoV-2 neutralization titers, but S-based serological assay measurements better predicted neutralization potency. Correlation between S-binding and neutralization titers deteriorated with time, and decreases in neutralization titers were not predicted by changes in S-binding antibody titers. Conclusions Different SARS-CoV-2 serological assays are more or less well suited for surveillance versus prediction of serum neutralization potency. Extended follow-up should facilitate the establishment of appropriate serological correlates of protection against SARS-CoV-2 reinfection.