Evaluation of the Sorption Capacity of a Maleic Acid Copolymer Towards Gold(III) Ions and Production of Catalytically Active Gold Nanoparticles on Its Base

Two spectrophotometric approaches are suggested for the assessment of the concentration of gold(III) cations in an aqueous solution: direct recording of the optical density of gold cations and galvanic substitution of silver atoms in polymer-stabilized silver nanoparticles with gold cations. The sorption capacity of a maleic acid copolymer towards gold cations is estimated. A colloidal composite containing gold nanoparticles is obtained from the polymeric gold salt. The catalytic properties of the resulting polymer-stabilized nanogold are studied in the aerobic oxidation of glucose to gluconic acid.

Murmur on top of the head: bioprosthetic mitral valve insufficiency

In 1961, K Merendino ‘in pure curiosity’, while tracking the murmur of mitral regurgitation, placed his stethoscope ‘on the vertex of the head’, and ultimately led to a medical curiosity and exam finding that not only bears his name, but awes medical learners at all stages of their careers. Merendino and colleagues collected seven such cases of the ‘Murmur on Top of the Head’ building on the work of others who provided a detailed description of mitral regurgitation and noted murmur radiation to the neck and cervical/lumbosacral spine. The majority of patients suffered from rheumatic heart disease or subacute bacterial endocarditis in native heart valves. Here, we report on a case of the ‘Murmur on Top of the Head’ and provide the reader/listener with a direct recording of the ‘Merendino murmur’ (as well as its spinal correlate) in an elderly woman with a bioprosthetic mitral valve.

Arabic as a Foreign Language: Phonological Analysis of Speech Sounds Produced by Students

The aim of this paper is to expose the potential difficulties encountered by students learning Arabic as a foreign language (AFL) with a focus on sounds production. The research design was descriptive-analytic. The data was obtained using direct recording and interviews. The sample included 27 AFL students at the Arabic Institutes at IMSIU and KSU. The work on this research is twofold: first, the paper reports on teachers' and learners' views on the general difficulties encountered by students learning Arabic, focusing on those in post-secondary school getting ready for tertiary education. Secondly, the paper analyzes their speech for pronunciation errors found in sounds production. The results show that learners generally had no problem expressing themselves, but they had some pronunciation issues with some specific Arabic sounds. The results also show that the students attempt different methods to overcome pronunciation difficulties. Teachers were aware of these difficulties, and they had their own methods to help improve students' pronunciation of unfamiliar sounds. The findings show that traditional ways of teaching Arabic sounds are not enough, and difficulties could still exist, as shown by the phonological analysis of sounds environments. The study suggests that implementing an eclectic approach, leveraging the use of technology, could help AFLs to improve their pronunciation.   

Online Political Communication of Youth from Russian Megapolises

Youth remains one of the most active groups of Internet users. The purpose of the study is to identify the features of the use of various social networks, Internet channels and messengers in online political communication of young people from Russian megacities. The research paper presents the results of an online survey of this socio-demographic group conducted in January 2021 among roughly 1700 respondents from 17 Russian megacities as well as the results of an expert survey dated January 2021, namely, non-standardized expert interviews with 21 experts, including scholars, political technologists, government officials, members of political organizations and civil activists. Every fourth young respondent spends over 8 hours in the Internet space daily with about 43% of all young people spending from 4 to 8 hours. Social networks such as VKontakte (91.4%), Instagram (70.6%), YouTube Internet channel (74.9%), WhatsApp (66.4%) and Telegram (59.2%) are most in demand. The interest in Tik Tok is gradually growing (38.8%). Experts believe that the promising channel of online political communication with the aim of online political mobilization is the social network Clubhouse, which allows group voice chats and a strict selection of group members, but does not allow direct recording. Only every fourth representative of young people shows a high interest in the political situation. About 45% use Emoji to assess posts on a political topic, but only every fourth respondent gives comments and discusses political problems. Every fourth representative of young people does not take any political actions in the online space.

STUDY OF DIRECT LASER RECORDING OF MICRO-RELIEF ON A TWO-LAYER a-Si/Ag STRUCTURE

This paper presents the results of direct laser recording on a two-layer amorphous silicon / silver structure deposited on a glass substrate by magnetron sputtering. The absorption spectra of a-Si films of various thicknesses and a glass substrate are investigated. A method is proposed for direct laser recording of microstructures by focused radiation of a single-mode semiconductor laser with a wavelength of λ = 405 nm on a two-layer a-Si / Ag medium from the side of a glass substrate. The formation of the micro relief is studied during direct recording by semiconductor laser pulses with λ = 405 nm on the a-Si layer. Parameters of two-layer structure a-Si / Ag for direct laser recording are optimized.

Tdnn-Based Engine In-Cylinder Pressure Estimation from Shaft Velocity Spectral Representation

Pressure is one of the essential variables to give information about engine condition and monitoring. Direct recording of this signal is complex and invasive, while angular velocity can be measured. Nonetheless, the challenge is to predict the cylinder pressure using the shaft kinematics accurately. In this paper, a time-delay neural network (TDNN), interpreted as a finite pulse response (FIR) filter, is proposed to estimate the in-cylinder pressure of a single-cylinder internal combustion engine (ICE) from fluctuations in shaft angular velocity. The experiments are conducted over data obtained from an ICE operating in 12 different states by changing the angular velocity and load. The TDNN’s delay is adjusted to get the highest possible correlation-based score. Our methodology can predict pressure with an R2 >0.9, avoiding complicated pre-processing steps.

Assessment of the Oyo State Teaching Service Commission Interactive Learning Platforms during COVID-19 Lockdown in Nigeria

The study assessed the member response rate to the Oyo state teaching service commission (TESCOM) interactive learning platforms during the COVID-19 lockdown in Nigeria. The study adopted a descriptive survey research design. The sample comprised 3,388 respondents drawn from five online learning platforms (Arts, science, commercial, general and staffroom). Two instruments, Response Rate Factor Questionnaire-Survey monkey (r = 0.83) and participant online direct recording (π = 0.76), were used to collect data at three different intervals. Frequency counts and analysis of variance were used to analyse the data collected. Those online at the time of data collection were 59 (5.2%) for science, 23 (4.3%) for arts, 24 (6.4%) for commercial, 84 (7.4%) for general study and 96 (48.5%) in the staff room platform. A significant difference in member response rate was observed across the learning platforms [F(4,10) = 4.374; p= 0.027< 0.05]. Bonferroni post hoc analysis shown by mean plot revealed that general studies platform had the highest mean score (M=169.0) in terms of members response online followed by staffroom (M=79.0) and lastly commercial platform (M=32.67). It was deduced from the findings that members across the TESCOM interactive learning platforms do not respond online the same way by participating on the respective interactive platform to which they belong. Therefore, TESCOM should ensure that teachers and students actively engage in online learning platforms for better teaching and learning.

Security, usability, and biometric authentication scheme for electronic voting using multiple keys

We propose electronic voting authentication scheme, which is a key management mechanism for electronic voting system intended to limit the number of attacks on a polling station and strengthen the security control. The motivation is to diversify security requirements of messages exchanged between polling stations. There are different types of messages exchanged between polling stations and each type of message has different security needs. A security mechanism developed on the basis of a single key is not enough to ensure the diverse security needs of voting network. In electronic voting authentication scheme, every polling station is responsible to support three different types of keys. These are global key, pairwise key, and individual key. The global keys are public keys shared with all polling stations in the voting network. The pairwise key can be used for communication with polling stations. Individual keys will be used for communication with the server. To ensure authentication of local broadcast, electronic voting authentication scheme uses one-way key chains in a well-organized way. The support of source authentication is a visible advantage of this scheme. We examine the authentication of electronic voting authentication scheme on numerous attack models. The measurement demonstrates that electronic voting authentication scheme is very operative in protecting against numerous elegant attacks such as wormhole attack, Sybil attack, and HELLO Flood attack. The proposed system is evaluated and the results demonstrate that the proposed system is practical and secure as compared to the direct recording electronic and manual systems.

RAVE: comprehensive open-source software for reproducible analysis and visualization of intracranial EEG data

Direct recording of neural activity from the human brain using implanted electrodes (iEEG, intracranial electroencephalography) is a fast-growing technique in human neuroscience. While the ability to record from the human brain with high spatial and temporal resolution has advanced our understanding, it generates staggering amounts of data: a single patient can be implanted with hundreds of electrodes, each sampled thousands of times a second for hours or days. The difficulty of exploring these vast datasets is the rate-limiting step in discovery. To overcome this obstacle, we created RAVE (“R Analysis and Visualization of iEEG”). All components of RAVE, including the underlying “R” language, are free and open source. User interactions occur through a web browser, making it transparent to the user whether the back-end data storage and computation is occurring on a local machine, a lab server, or in the cloud. Without writing a single line of computer code, users can create custom analyses, apply them to data from hundreds of iEEG electrodes, and instantly visualize the results on cortical surface models. Multiple types of plots are used to display analysis results, each of which can be downloaded as publication-ready graphics with a single click. RAVE consists of nearly 50,000 lines of code designed to prioritize an interactive user experience, reliability and reproducibility.

Analisa Sistem Pencatatan Dan Monitoring Piutang Leasing

This research was made with the aim to help companies in controlling receivables. The study was conducted on companies engaged in the sale and purchase of motorcycles. These companies act as suppliers of goods and collaborate with credit financing institutions or what is commonly called leasing. Every credit sale will form a lease receivable that must be paid by the related leasing party. In general, many receivables have not been paid from the due date of the agreement. This impedes the company's financial productivity. From these problems, researchers create a system that can be used to meet the needs of the company, in relation to receivables. Researchers create a system that can improve performance to be more effective and dynamic, especially to record the daily control of receivables, namely by using the Leasing Accounts Recording and Monitoring System. The design of recording and monitoring systems for receivables is made using the direct recording method. Systems development methods using the R & D. Method stages in the R & D method include potential problems, information gathering, product design, design validation, design improvement, product testing, product revision, trial use, mass product manufacturing. The design of a monitoring system for leasing receivables billing, can help companies control receivables. Leasing Receivables Recording and Monitoring System can minimize receivables losses.