bluuebunny/crossref_metadata_2025_split huggingface dataset:
АЛГОРИТМЫ БЕЗДАТЧИКОВОГО ОТКАЗОУСТОЙЧИВОГО УПРАВЛЕНИЯ ВЕНТИЛЬНО-ИНДУКТОРНЫМ ЭЛЕКТРОДВИГАТЕЛЕМ НАСОСА ДЛЯ ДОБЫЧИ НЕФТИ
Authors: Однокопылов Георгий Иванович , Розаев Иван Андреевич 
Published: May 2020

Актуальность.Нефтегазовая отрасль России сегодня одна из самых быстро развивающихся в стране. Высокие темпы развития предполагают внедрениеновых технологий и значительную модернизацию технологических комплексов, входящих в состав производственной базы. В частности, исполнительных двигателей насосов добычи и транспортировки ископаемого топлива. Надёжное и бесперебойное функционирование двигателя насоса является конкурентным преимуществом. Для снижения вероятных простоев оборудования и недоотпуска нефти предлагается использовать современный вентильно-индукторный электродвигатель в качестве исполнительного двигателя насоса добычи нефти. Существующие разработки показывают конкурентные преимущества этого типа электродвигателя при доработке системы управления и применении алгоритмов отказоустойчивого управления. Повысить отказоустойчивость и расширить области применения вентильно-индукторного электродвигателя позволяет использование бездатчикового управления. На сегодняшний день в технической литературе данная тематика проработана недостаточно глубоко, а математическая и имитационная модели бездатчикового управления вентильно-индукторным электроприводом в аварийном неполнофазном режиме работы ранее рассмотрены не были. Цель: разработка алгоритмов отказоустойчивого бездатчикового управления исполнительным вентильно-индукторным электродвигателем в неполнофазных режимах работы; обеспечение корректности переключения структуры управления при обрыве фазы; повышение отказоустойчивости вентильно-индукторного электродвигателя насоса в аварийных режимах работы путем подключения алгоритмов отказоустойчивого управления при переключении структуры управления. Объект:четырехфазный вентильно-индукторный электродвигатель насоса добычи или транспортировки нефти в аварийных неполнофазных режимах работы. Методы: математическое и имитационное моделирование, программирование в среде MatlabSimulink. Результаты. Разработаны математическая и имитационная модели бездатчикового отказоустойчивого четырехфазного вентильно-индукторного электропривода в аварийном режиме работы. Получен алгоритм бездатчикового отказоустойчивого управления насосом с вентильно-индукторным электродвигателем в аварийном режиме работы. Получены характеристики насоса добычи нефти в неполнофазном режиме работы исполнительного вентильно-индукторного электродвигателя с применением алгоритма отказоустойчивого управления.
Air Heat Pump in Wind Power
Authors: Gretchikhin L. I. , Hutkouski A. I. 
Published: May 2020

An experimental facility has been developed and manufactured to study the disruptive flow in an air heat pump. The propeller of the heat pump does not produce pulling or pushing forces. The external air flow is created by a high speed propeller perpendicular to the plane of rotation of the heat pump propeller and acts as a ventilator. Herewith, a disruptive flow in the back side of the heat pump propeller is being created and conditions for converting the thermal component of the ventilator air flow into electrical energy by an electric power generator are realized. An aerodynamic model of the flow around the propeller blades of the heat pump in mutually perpendicular airflow has been developed. Experimental studies of the operating propeller as a heat pump, taking into account the friction during rotation of the rotor in the stator of the electric generator, were carried out. In order for the air heat pump to perceive the impacting air flow from the ventilator, it must rotate with minimal power. As a result, for two standard twin-bladed propellers mounted on a 100 W engine under the wind generated by the ventilator which speed is 2.17 m/s the conversion factor was 5.04. As the speed of air flow from the ventilator increased, the conversion coefficient decreased sharply. When placing the two specified propellers on a 300 W motor, the minimum pre-rotation power was 5.7 W. In this case, when an air flow speed is of 1.08 m/s, the conversion coefficient reached only 2.93 and also fell sharply with the increase in the air flow speed. When a three-blade propeller with blades was used on a 300 W motor, then situation has changed dramatically. When the motor with a special propeller with a power of 12.1 W was spun and the air flow was formed at a speed of 3.2 m/s, the conversion coefficient was 12.4. With the reduction in the power of the spinup down to 5.9 W and in the speed of the air flow created by the ventilator to 1.7 m/s, the conversion coefficient increased to 14.9. The theoretical calculation of heat pump conversion coefficient is confirmed by experimental data. The conditions under which this coefficient reaches its maximum value are set. Computer modeling of different designs of heat pump propeller blades was performed. It is demonstrated that an air heat pump is a complex open energy system.
Knowledge of malaria prevention and control methods and associated factors among rural households in West Belessa district, North West Ethiopia, 2019.
Authors: Aragie Tsigie Baye 
Published: May 2020

Abstract

Background: In Ethiopia malaria is one of the top ten leading causes of morbidity and mortality. Community knowledge of prevention and control methods had been proven to play an important role in the implementation of effective and sustainable interventions against malaria. This information is limited in the study area. This study aimed to assess knowledge of malaria prevention and control methods and its associated factors among households in West Belessa district, 2019.Methods:Community-based cross-sectional mixed quantitative and qualitative study was conducted from April to June 2019 in West Belessa district, North West Ethiopia. Multistage sampling was used to select an estimated 770 sample size. A structured questionnaire was used for the quantitative component and semi-structured questionnaire for the qualitative component. Quantitative data were collected by interviewing and qualitative data using focus group discussion (FGD). Quantitative data was coded and entered using Epi info software version 7 then exported to SPSS version 20 for analysis. The binary logistic regression model was fitted to identify the associated factors. Odds Ratio (OR) with 95 % Confidence Interval (CI) was used to assess the strength of association. The qualitative data was transcribed manually using the thematic approach.Result:A total of 770 subjects were included in this study with a 99.5% response rate. Of the total respondents, 75.6% had good knowledge of malaria prevention methods. LLINs and IRS were mentioned by 84.7% and 83.7% respectively. Poorest wealth quintiles [AOR= 0.40, 95% CI: 0.23, 0.73], poor wealth quintiles [AOR= 0.38, 95% CI: 0.21, 0.70], and medium wealth quintiles [AOR= 0.41, 95% CI: 0.22, 0.76], living in Menti Kebele [AOR= 3.07, 95% CI 1.85, 5.08], living in Abay tera kebele [AOR= 2.00, 95% CI 1.21, 3.29] were significantly associated with good knowledge. About all of the focused group discussion (FGD) participants agreed that malaria is a preventable disease and mentioned some of the preventive methods.Conclusion: Overall there was relatively high knowledge of malaria prevention and control methods. LLINs and IRS were known malaria prevention methods in West Belessa. Wealth index and respondents living kebele are predictors for knowledge of malaria prevention.
Women’s Experiences of the 1983-85 Ethiopian Great Famine: A Qualitative Study in Kobo Town, North Wollo Zone, Ethiopia
Authors: Arage Getachew , Belachew Tefera , Abera Mubarek , Abdulhay Fedilu , Abdulahi Misra , Abate Kalkidan Hassen 
Published: May 2020

Abstract
Background

In developing countries as women are mostly involved in handling food and feeding, their narrative is expected to generate optimal portrayal of the lived experiences surrounding the times of food shortage. Although there were repeated bouts of food insecurity in Ethiopia, the experiences of households in managing such shocks has never been documented. This qualitative study is aimed exploring and understanding of the lived experiences of women.
Method:

Phenomenology was employed as an approach to document the lived experiences of women about the great Ethiopian famine in Kobo district of North Wollo Zone. In-depth interview lasting for an average of 40 minutes were carried out among 10 key informants (women who survived the great famine). The interview was carried out using semi-structured interview guides with sufficient probes and open ended follow up questions to exhaustively capture the narratives. Texts with similar code were pooled together and presented in narratives using verbatims as illustrations. Texts with similar codes were pooled together and organized into narratives.
Results

An overall theme emerged that the Great Famine was ‘catastrophic and caused severe loss of human life.’ The study identified the following six essential points experienced by the women. All participants agreed that the famine was an unforgettable event in their memories. It lasted for two years and was caused by drought and local civil war affecting all socio-economic groups and all areas around Kobo Town. Pregnant women, lactating mothers and children were specifically affected, the coping strategies used included the sale of non-productive assets (utensils, jewelry, furniture), the mortgaging of farmland or houses, and out-migration. Men were more likely to migrate while women and children were more likely to remain in the household—meaning that the burden of the crisis was mainly shouldered by the women.
Conclusion

The study provided a context- specific understanding of the Ethiopian Great Famine which is one of the most catastrophic events of the 20th century in Ethiopia. The interviews described here call for further research to determine the long-term health and socio-economic impact of the famine.
A novel epigenetic signature for predicting the prognosis of pancreatic ductal adenocarcinoma
Authors: Zhao Zhiming , Li Mengyang , Tan Xianglong , Liu Rong 
Published: May 2020

Abstract
Background

Aberrant DNA methylation is often involved in carcinogenesis. This study is designed to establish an epigenetic signature to predict overall survival (OS) of pancreatic ductal adenocarcinoma (PDAC).
Methods

DNA methylation and RNA-seq data of PDAC patients were downloaded from the Cancer Genome Atlas database, Genotype-Tissue Expression (GTEx), and International Cancer Genome Consortium (ICGC) database. Methylation-related differentially expressed genes (DEGs) were identified using an R package MethylMix. Epigenetic signature and nomogram were established by the LASSO and multivariate Cox regression analysis, respectively. In addition, a joint survival analysis of the gene expression and methylation was performed to identify potential prognostic factors for patients with PDAC.
Results

There were a total of 56 methylation-related DEGs by MethylMix criteria. After LASSO Cox regression analysis, we developed an epigenetic signature composed of five genes according to their methylation level. The signature was able to divide patients into high-risk and low-risk groups, and the OS between the high-and low-risk groups was more significantly different in both training and validation cohort. The signature is independent of clinicopathological variables and indicated better predictive power. Moreover, we developed a novel prognostic nomogram that combines risk scores with three clinicopathological factors. The joint survival analysis of gene expression and methylation revealed that 24 genes could be independent prognostic factors for OS in PDAC.
Conclusions

The qualitative signature and nomogram that predict OS at the individualized level and guide therapy for patients with PDAC.
Mental health among displaced and non-displaced populations in Valledupar, Colombia: Why do inequities continue?
Authors: Monsalve Sonia Diaz , Vargas-Monroy Angélica María , Ariza Jannethe Esmeral , Cuello Ana Maria Oñate , Vera Ana Rosa Ropero , Cuello Juan Carlos Bermudez , Zuleta Lina Arzuaga , Novella Andrés Felipe Cubillos , Quintero Enrique Peñaloza , Ortiz Yesika Natali Fernández , Kroeger Axel 
Published: May 2020

Abstract
Background: During the long-lasting civil war in Colombia involving several armed groups, the year 2002 marked a peak of violent activities displacing thousands of people mainly from rural to urban areas, causing social disruption and prolonged poverty. In 2015, the Colombian national survey on mental health provided a first overview of mental health problems of victimized families and individuals (macro level). The here presented study aimed at analysing ongoing inequalities regarding displaced and non-displaced populations in Cesar State (micro level), one of the most affected areas by the armed conflict.Methods: An interview survey was conducted among 211 displaced families and 181 non-displaced families in 2 adjacent compounds with several five-storey buildings in the outskirts of Valledupar, the capital of Cesar State in Colombia. The questionnaires were developed together with and applied by staff of the health and social services of the departmental secretary of health. The 15 interviewers conducted additionally in-depth interviews and participant observations.Results: The peak of internal displacement occurred around the year 2002, affecting disproportionally more the afro-descendent and indigenous populations. However, the marginalization of previously displaced persons is still ongoing. The living conditions in the neighbourhood of the displaced community were quite precarious in terms of lack of security, continuous noise, drug trafficking and poor connection with public transport. Consequently, psycho-emotional problems were more frequent among the displaced compared to the non-displaced neighbourhood. The displaced had experienced more violent acts (intended murder, threat, murder of a family member and kidnapping) and had subsequently a larger number of emotional symptoms (fright, headache, nervousness, depression, sleeplessness). Other stress factors like economic problems, severe disease or death of family members and unemployment prevailed in the community of displaced persons compared to the non-displaced. Non-displaced lived in a more protected environment and were less exposed to violence and stress, although belonging to a similarly low socio-economic stratum.
How on-the-job training improves general practice service teams’ understanding of GPs’ roles in China: A qualitative case study
Authors: Xia Yinghua , Chen Xi , Liu Shi-Xing , Zhang Xi , Lin Dong-mei , Hong Zi-hui , He Qun 
Published: May 2020

Abstract
Backgroud:

China has introduced series of policies to improve the professional self-image of GPs, however, Chinese general practitioners (GPs) generally have a low professional identity. This study evaluated the effects of on-job-training for medical health professionals that focuses on the recognition of GPs’ roles.
Methods

At a representative training base in Guangdong Province, the most economically developed province in Southern China, 62 workers from community health service centers underwent training for 6 months according to a before-after self-controlled design. A specific module related to professional value recognition was integrated into the training course. Trainees were invited to participate in the open-ended self-questionnair survey. Thematic analysis was used to explore themes within the data. Kappa test was used to compare consistency of career prospects before and after the training.
Results

Before training, participants generally lacked a full and clear understanding of the professional responsibilities of GPs. After the training, participants showed increased awareness of six aspects of general medical practice including a broad understanding of the term, disease treatment, disease prevention, service mode, role of general services in promoting public health, and role of GPs in a service team. Moreover, 84% of participants had a positive opinion of GPs’ career prospects and 90.3% preferred general practice to specialization as a career choice after the training. Current GPs preferred to become a specialist mainly for the higher salary, but current specialists preferred to be a GP for self-growth and sense of community.
Conclusions

These results demonstrate that appropriate on-the-job training can improve GPs’ professional identity in China, and should therefore be included in policies and integrated into programs for medical health professionals.
Coal quality prediction based on multi-feature fusion of flotation foam images
Authors: Bai Yateng , Ma Xiaoping 
Published: May 2020

Abstract
Coal flotation monitoring cannot provide real-time feedback on the yield and ash of coal preparation products because it is influenced by the subjective nature of artificial judgment of coal preparation status and the lag of product quality testing of coal preparation. This paper aims to extract the texture, colour and shape features of floating foam images using various image processing methods, such as colour space, wavelet transform, greyscale co-occurrence matrix and edge operator, and to quantify the characterisation of various characteristic parameters on the basis of the indicative effect of floating foam characteristics on the quality of coal preparation products. The correlation between image features and the yield and ash of flotation products is studied, and a regression prediction model of coal preparation yield and ash was established by combining various image feature parameters using machine learning methods. Experimental results show that the proposed method can realise the real-time monitoring of coal mine flotation and effectively predict coal quality.
Geranylgeraniol in Bone Cement Rescues Osteoclasts from the Toxic Effects of Pamidronate and Restores Function
Authors: Feldman George J , Yagnik Adarsh , Taub Daniel , Diecidue Robert 
Published: May 2020

Abstract
BackgroundExposed intraoral bone in medically related osteonecrosis of the jaw (MRONJ) is a devastatingly side effect of treatment with nitrogen containing bisphosphonates(NBPs) The pathogenesis of the condition is thought to be caused by NBP inhibition of farnesyl diphosphate synthase (FDPS), a critical enzyme in the mevalonate pathway. This block suppresses the prenylation of factors necessary for the maintenance and survival of osteoclasts. Geranylgeraniol (GGOH), a metabolite in the mevalonate pathway downstream of FDPS, reverses the block NBPs impose on osteoclasts. However, no effective method currently exists to deliver GGOH locally to NBP-induced lesions in the mouth. The purpose of this study is to develop a biocompatible, resorbable and tunable carrier to deliver GGOH intraorally and thereby reverse the damaging effects of MRONJ.MethodsPrimary human oral fibroblasts and RAW264.7 osteoclasts were exposed to pamidronate in vitro and GGOH contained within a bone cement pellet and survival of the cells was measured. The kinetics of release of 3HGGOH from the bone cement was measured.. The resorptive function of osteoclasts exposed to pamidronate with or without GGOH was quantitated by measuring the release of bound fluorescent dye from a CaPO4 coated plate. Resorption areas on this plate were photographed.ResultsHuman gingival fibroblasts exposed to pamidronate (100uM) alone decreased survival by 49% (p<0.001) over 72 hours, 2mM GGOH incorporated into bone cement rescued these cells from the toxic effect of NBP (p=0.0024).Exposure of osteoclasts to 400 and 800uM pamidronate over 72 hours showed a 49% and 69% loss of viability respectively. (p<0.0001 for each concentration). 2mM GGOH incorporated into bone cement increased survival by 247% (p=0.0001) for the cells treated with 800uM pamidronate and 4mM GGOH by 450% (p<0.0001). Pamidronate at both concentrations reduced osteoclast function and 4mM GGOH completely restored resorbtive function. At a powder to liquid ration of 2.5:1 92% of the loaded metabolite was released into medium after in 96 hours.ConclusionsGGOH contained in a bone cement carrier can rescue osteoclast function from the toxic effects of pamidronate. This carrier may be the first step in local delivery of this metabolite in the oral cavity.
The Strategy and Efficacy of Prophylaxis Against Hepatitis B Virus Recurrence After Liver Transplantation in the Era of High Potent Nucleos(t)ide Analogues: A Meta-Analysis
Authors: Li Mingshu , Hou Zhouhua , Yao Guozhu , Tan Deming , Lin Qian 
Published: May 2020

Abstract
Background: High potent nucleos(t)ide analogues (HP NAs) with or without hepatitis B immunoglobulin (HBIG) is the standard prophylactic therapy for avoiding the HBV recurrence after liver transplantation (LT). While the clinical impact of HP NAs-based prophylaxis has not been well documented, the optimal treatment strategy is currently debated. This meta-analysis aims to evaluate clinical outcome of LT recipients under HP NAs-based regimens and investigate different prophylaxis schemes. Methods: We followed PRISMA statement to conduct this study. Two reviewers independently searched relevant literature via PubMed, EMBAES, MEDLINE, Web of Science, and Google Scholar. Studies were included if they observed HBV recurrence under HP NAs-based regimens in patients who received HBV-related LT. Primary and secondary outcome were HBV recurrence, HCC recurrence, all-cause and HBV-recurrence related mortality. Incidence with 95% confidence intervals was aggregated and assess by fixed effect model/random effect model. Subgroup analysis was applied to examine the impact of different treatment strategies. Results: 26 studies (n=2374) were included, with a pooled HBV recurrence rate of 0.92% (95% CI 0.47%-1.48%). Studies with and without HBV viremia or HDV superinfected patients demonstrated comparable HBV recurrence (p=0.25, p=0.69). Recurrence rate under indefinite combination of HP NAs and HBIG was lower than that under HP NAs monotherapy (p=0.0003), and similar to that under NAs plus finite course of HBIG (p=0.53). Pooled HCC recurrence rate was 5.34% (95% CI 0.78%-12.48%). HBV-recurrence related mortality and all-cause mortality were 0.17% (95% CI 0.00%-1.51%) and 7.29% (95% CI 4.42%–10.71%) respectively. Conclusion: Our study suggests HP NAs-based regimens provide satisfactory HBV antiviral prophylaxis and improved long-term outcome for LT recipients. Finite combination of HP NAs and HBIG is an alternative to lifelong dual therapy.