Search for Tissue Equivalent Materials Based on Exposure and Energy Absorption Buildup Factor Computations

Tissue equivalent materials (TEM) are frequently used in research as a means to determine the delivered dose to patients undergoing various therapeutic procedures. They are used in routine quality assurance and quality control procedures in diagnostic and therapeutic physics. However, very few materials that are tissue equivalent have been developed for use in research at the low photon energies involved in diagnosis radiology. The objective of this study is to describe a series of TEMs designed to radiographically imitate human tissue at diagnostic photon energies. TEMs for adipose, cortical bone, fat, lung, and muscle tissues were investigated in terms of energy absorption and exposure buildup factors for photon energy range 15–150 keV and for penetration depths up to 40 mean free path. BUF was computed based on GP-fitting method. Moreover, we also compared some radiological properties, including the total attenuation and the energy-absorption attenuation, the effective atomic number, and the CT number at 30, 100, and 120 kVp. We found that SB3, Glycerol trioleate, and MS15 perfectly mimic cortical bone, fat, and muscle tissues, respectively. Additionally, AP6 and Stracey latex are good TEM for adipose and lung tissues, respectively. The results of this work should be useful in radiation diagnosis and dosimetry applications for the large physician researcher community.

Retrieval of the land-sea contrast of cloud liquid water path by applying a physical inversion algorithm to combined zenith and off-zenith ground-based microwave measurements

Combined zenith and off-zenith ground-based observations by modern microwave radiometers provide an opportunity to study horizontal inhomogeneities of the humidity field in the troposphere and of the cloud liquid water path (LWP) spatial distribution. However, practical applications are difficult and require thorough analysis of the information content of measurements, assessment of errors of data processing algorithm and the development of the quality control procedures. In this study we analyse the application of our LWP retrieval algorithm based on the inversion of the radiative transfer equation to the problem of detection of the LWP horizontal inhomogeneities by means of ground-based microwave observations in the vicinity of a coastline of a water object of medium size. The study is based on data acquired by the microwave radiometer RPG-HATPRO which is located in the suburbs of St.Petersburg, Russia, at 2.5 km distance from the coastline of the Neva Bay (the Gulf of Finland) and is operating in angular scanning mode in the vertical plane. The retrieval setup is organised in such a way that zenith and off-zenith measurements provide equal sensitivity to atmospheric parameters. The optimal elevation angles for off-zenith observations are selected. The possibility to detect LWP horizontal inhomogeneity, namely the LWP land-sea contrast, for different measurement geometries (elevation angles) and values of cloud base height is analysed. It is shown that ground-based microwave observations in the vicinity of a coastline can be a valuable tool for validation of the space-borne measurements of the LWP land-sea contrast if three principal requirements are met: (a) the multi-parameter physical inversion method is used for retrieving LWP; (b) rigorous bias correction and quality control procedures are applied to the retrieval results; (c) the information on the cloud base height is available. As a result of processing the microwave measurements at the observational site of St.Petersburg State University, the monthly-averaged values of the LWP land-sea difference have been obtained for summer months within the period 2013–2021. For 24 out of 25 months of high quality observations, the LWP land-sea monthly difference is positive (larger values over land and smaller values over water) and can reach 0.06–0.07 kg m−2. The estimations of the LWP land-sea contrast obtained from the ground-based microwave measurements at the observational site of St.Petersburg University are in very good agreement with the values of the LWP land-sea contrast obtained from the multi-year space-borne measurements by the SEVIRI instrument (Spinning Enhanced Visible and InfraRed Imager) in the region of the Neva Bay (the Gulf of Finland) in June and July. For August, the so-called “August anomaly” detected by space-borne observations is not confirmed by the ground-based measurements.

The Effect of Race and Dementia Prevalence on a COVID-19 Infection Control Intervention in Massachusetts Nursing Homes

Background Nursing home (NH) residents, especially those who were Black or with dementia, had the highest infection rates during the COVID-19 pandemic. A 9-week COVID-19 infection control intervention in 360 Massachusetts NHs showed adherence to an infection control checklist with proper personal protective equipment (PPE) use and cohorting was associated with declines in weekly infection rates. NHs were offered weekly webinars, answers to infection control questions, resources to acquire PPE, backup staff, and SARS-CoV-2 testing. We asked whether the effect of this intervention differed by racial and dementia composition of the NHs. Methods Data were obtained from 4 state audits using infection control checklists, weekly infection rates, and Minimum Data Set variables on race and dementia to determine whether adherence to checklist competencies was associated with decline in average weekly rates of new COVID-19 infections. Results Using a mixed-effects hurdle model, adjusted for county COVID-19 prevalence, we found the overall effect of the intervention did not differ by racial composition, but proper cohorting of residents was associated with a greater reduction in infection rates among facilities with ≥20% non-Whites (n = 83). Facilities in the middle (>50%–62%; n = 121) and upper (>62%; n = 115) tertiles of dementia prevalence had the largest reduction in infection rates as checklist scores improved. Cohorting was associated with greater reductions in infection rates among facilities in the middle and upper tertiles of dementia prevalence. Conclusions Adherence to proper infection control procedures, particularly cohorting of residents, can reduce COVID-19 infections, even in facilities with high percentages of high-risk residents (non-White and dementia).

Toward Optimal Control of a Multivariable Magnetic Levitation System

In the paper, a comparative case study covering different control strategies of unstable and nonlinear magnetic levitation process is investigated. Three control procedures are examined in order to fulfill the specified performance indices. Thus, a dedicated PD regulator along with the hybrid fuzzy logic PID one as well as feed-forward neural network regulator are respected and summarized according to generally understood tuning techniques. It should be emphasized that the second PID controller is strictly derived from both arbitrary chosen membership functions and those ones selected through the genetic algorithm mechanism. Simulation examples have successfully confirmed the correctness of obtained results, especially in terms of entire control process quality of the magnetic levitation system. It has been observed that the artificial-intelligence-originated approaches have outperformed the classical one in the context of control accuracy and control speed properties in contrary to the energy-saving behavior whereby the conventional method has become a leader. The feature-related compromise, which has never been seen before, along with other crucial peculiarities, is effectively discussed within this paper.

DEVELOPMENT OF METHODOLOGICAL TOOLS FOR INTERNAL CONTROL TO INCREASE THE EFFICIENCY OF USE OF FIXED ASSETS

The basis of the material and technical base of the functioning of enterprises are fixed assets. Therefore, the effective organization of accounting and internal control of operations with fixed assets is one of the important tasks facing the management of any enterprise. The purpose of the study is to improve the methodological tools for internal control of the movement of fixed assets at the enterprise, which contribute to the effective assessment of the accounting system and the conduct of control and analytical procedures. To improve the methodological support of internal control of the movement of fixed assets, an internal control working document (ICWD) “Test for assessing the accounting system of fixed assets” was developed, which allows you to identify critical areas of accounting with a high level of risk and determine the means necessary for conducting control procedures. The ICWD “Report on the presence and safety of fixed assets” and “Checking the execution of primary documents for the disposal of fixed assets” developed in the course of research allow the collection of information to confirm the reality of the articles of the financial statements; to establish the reliability of the facts of disposal of fixed assets and to guarantee the quality of original source documentation. To carry out control measures when checking the depreciation of fixed assets, testing should be carried out on the basis of the “Test for checking the correctness of depreciation” developed by the ICWD, using which you can promptly identify violations in the procedure for calculating depreciation. The proposed working documents will make it possible to carry out control procedures, accumulate evidence that can be used in the formation of a report on the results of the audit and the development of recommendations to improve the efficiency of the financial and economic activities of the enterprise

Locomotive Reliability Assessment Method

The authors describe the analysis of the current state of the problem under consideration. A definition of "averaged failure flow parameter" is given. The periods of traction rolling stock life cycle are considered. The assumption of event distribution laws exponentiality is introduced, which makes it possible to obtain expressions of the main reliability indices in the analytical form. The work of depot service locomotives to ensure the required reliability and readiness of the rolling stock during their normal operation has been assessed. The introduction of the term "readiness" into the modern practice of traction rolling stock reliability estimation is considered. The initial data for calculating the indexes of locomotive uptime and readiness are presented. Calculated values of readiness and no-failure indices of electric locomotives in operation are obtained. The calculated values of internal and technical availability coefficients are compared with similar indicators established by technical specifications. Control procedures were performed to determine the compliance of each set of locomotives (EP1, 2ES4K) with the uptime requirements. As a result of comparing the calculated values of internal and technical availability factors (for electric locomotives EP1 and 2ES4K with analogous values set by specifications (EP1 and 2ES4K) it was determined that the surveyed locomotives comply with the established availability requirements. As a result of control procedures to determine the compliance of each set of EP1 and 2ES4K locomotives with the uptime requirements, it was determined that the set of 2ES4K electric locomotives for the run in question does not fully comply with the uptime requirement. And the set of EP1 electric locomotives meets the reliability requirements, but the error value is higher than 20%. To clarify both events, it is necessary to increase the mileage interval of the locomotives and repeat the procedure for determining compliance with the uptime requirements. The method of assessing the uptime and readiness of locomotives during their normal operation makes it possible to identify existing shortcomings in the operation of rolling stock and to form measures to improve the quality of rolling stock operation.

COVID-19 Infection in Pregnancy: A Review

Coronavirus disease 2019 (COVID-19), which is a highly contagious viral illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a catastrophic effect on the world's demographics, resulting in more than 3.8 million deaths worldwide, and establishing itself as the most serious global health crisis since the 1918 influenza pandemic. Several questions remain unanswered regarding the effects of COVID-19 disease during pregnancy. Although most infections are mild in high-risk populations, severe disease frequently leads to intubation, intensive care unit admission, and, in some cases, death. Hormonal and physiological changes in the immune and respiratory systems, cardiovascular function, and coagulation may affect the progression of COVID-19 disease in pregnancy. However, consequences of coronavirus infection on implantation, fetal growth and development, labor, and newborn health have yet to be determined, and, consequently, a coordinated global effort is needed in this respect . Principles of management concerning COVID-19 in pregnancy include early isolation, aggressive infection control procedures, oxygen therapy, avoidance of fluid overload, consideration of empiric antibiotics (secondary to bacterial infection risk), laboratory testing for the virus and co-infection, fetal and uterine contraction monitoring, prevention and / or treatment of thromboembolism early mechanical ventilation for progressive respiratory failure, individualized delivery planning, and a team-based approach with multispecialty consultations. This review focuses on COVID-19 during pregnancy, its management, and the area where further investigations are needed to reduce the risk to mothers and their newborns.

Redefining Global Economic Thinking for the Welfare of Society

This chapter examines the legal and financial control issues regarding compliance with labor legislation. On the one hand, the legal analysis shows that legislation is one of the main factors influencing the financial control practice for compliance with labour legislation. On the other hand, the problems and specifics of the control procedures applied by the General Labor Inspectorate Executive Agency in Bulgaria are presented. The overall inspection process is presented sequentially, analyzing the individual stages that the control procedures go through. The problems and the specifics of carrying out an independent inspection activity by the agency are presented, and the peculiarities of carrying out joint control activities with executive bodies or their administrative structures by the specialized administration are examined. Different types of factors that influence the implementation of control procedures by the General Labor Inspectorate Executive Agency in Bulgaria are considered.

An Exploratory Study of Consumers’ Travel-Related Concerns About COVID-19

This study explores consumers’ travel-related concerns about the COVID-19 pandemic via YouTube comments. Drawing on the risk perception theory and adopting a Markov Chain approach, this study demonstrates the topics that consumers discussed and empirically illustrates perceived risk in the tourism and hospitality industry via sentiment analysis across four sectors: recreation and entertainment, accommodation, transportation, and food and beverages. Results indicate discussion regarding travel-related videos is not only limited to travel-related topics but also includes a broad perspective of social, political, and historical topics. For instance, hotels have a new function as quarantine facilities with effective disease control procedures and social responsibility for public health. Additionally, health, performance, financial, social, and psychological risks are identified. Whereas the presence of travelers is typically regarded as positive, travelers during the crisis are regarded as “irresponsible” and “selfish” individuals who spread the virus and endanger public health. This shift of perception calls for both the industry and academia at large to educate people about the importance of disease control and rebuild travelers’ image and reputation. Recommendations to reduce the perceived risk in each sector are also provided.

Implementasi Kurikulum Pendidikan Pada Program Studi Lalu Lintas Udara di Politeknik Penerbangan Makassar (Studi Evaluasi Materi Aerodrome Control Procedures)

Perguruan tinggi sebagai salah satu bentuk satuan pendidikan yang memberikan pengetahuan akademik dan atau profesional harus mampu memberikan layanan dan menghasilkan keluaran yang berkualitas melalui program-program strategis. Lulusannya diharapkan mampu mengatasi masalah di atas. Banyak faktor yang dapat mempengaruhi mutu perguruan tinggi seperti dosen, sarana prasarana, kurikulum dan proses belajar mengajar, serta sistem penilaian. Begitu pula parameter kualitas pendidikannya, baik dilihat dari segi input, process, product, maupun outcome selalu berubah dari waktu ke waktu.. Tujuan penelitian ini mengetahui apa input, transformasi, output dan outcome dari hasil pelaksanaan kurikulum di program studi Manajemen Lalu Lintas Udara. Metoda dalam pengumpulan data melalui wawancara yang berupa tanya jawab secara langsung kepada informan perwakilan alumni dan dosen dan dengan observasi yang kemudian dilanjutkan analisis data sehingga data akan lebih terarah pada permasalahan yang sudah ditentukan sebelumnya. Teknik yang digunakan dalam menganalisis untuk penelitian ini yaitu diskriptif kualitatif.