bluuebunny/crossref_metadata_2025_split huggingface dataset:
RESEARCH AND EXPERIMENTAL STUDIES OF STRESS-STRAIN STATE OF DISCRETE-CONTINUAL HARDENED MACHINE PARTS
Authors: Veretelnik Oleg , Tkachuk Mykola M. , Kravchenko Serhii , Saverska Mariia , Kutsenko Serhii , Grabovskiy Andrey , Klochkov Illia , Tkachuk Mykola А. 
Published: December 2021

Research and experimental studies of stress-strain state of discrete-continual hardened machine parts are presented in this work. This hardening method is distinguished by incorporation of numerous hard spots into the surface layer of one of the bodies. Meanwhile the other part is covered by a continuous corundum layer. Correspondingly, a network of microchannels for lubricant is formed between the bodies. Furthermore the contact loads are intensified in the vicinity of the harder material in the discrete zones. As a result the strength and durability of the loaded parts is increased. The technological parameters of the hardening process have great impact on the resulting characteristics. In particular, this concern the shape of the discrete hardening zones and the material properties of the corundum layer. These factors were varied in stress-strain analyses of the contacting bodies. The dependence of the stress-strain state characteristics on the varied parameters was established. The justified recommendations regarding the technological parameters of the discrete-continual hardening have been developed.
Keywords: stress-strain state, discrete-continual hardening, contact interaction, finite element method, contact pressure, machine parts
Characteristics of diatomite-alginate-Fe3O4 composite as a phosphate adsorbent
Authors: Pasenko Olexander , Frolova Liliya , Shunkin Ihnat 
Published: December 2021

Technological approaches to the use of diatomaceous earth as a raw material for the creation of composite adsorbents for wastewater treatment from phosphate ions are analysed. It is shown that the developed surface of diatomite can be used to create a granular adsorbent, and iron (III) oxides (magnetite, goethite, lepidocrocite, ferrihydrite, hematite and goethite) are environmentally safe, cheap, economically feasible modifiers. Emphasis is placed on the possibility of obtaining magnetic granules due to the formation of magnetite. The use of the deposition method for the formation of the applied granular adsorbent is proposed.
The influence of diatomite concentration on the static strength of granules was established. It is determined that the diameter of the nozzle is also an important factor. The selected technical solutions are aimed at solving the problems of granule hardening and ensuring high adsorption activity. Experimental studies of the synthesis and granulation of the composite adsorbent alginate - diatomaceous earth - magnetite have shown that an increase in the content of diatomaceous earth leads to a natural increase in the size of the granules. When increasing the diameter of the nozzle from 1.5 mm to 3.5 mm, for example, the size of the granules 1.5-4.0 (dc = 1.5 mm), 2.0-5.0 mm (dc = 3.0 mm) and 2.5-5.0 mm (dc = 3.5 mm). The diatomaceous earth content of more than 20% does not allow to carry out high-quality granulation on the experimental installation due to the increase in the viscosity of the suspension. The relationship between the size of gel granules and dried. The process of application of the active magnetic phase of the adsorbent is investigated. The dependence of the quality of the granulation process on the solid phase content is established. The measured static strength of the adsorbent granules is in the range of 17 - 25 kPa. It is established that the composite adsorbent with the applied layer of magnetite has magnetic properties. The adsorption of PO43- anions from aqueous solutions was studied. For the adsorbent alginate - diatomite and alginate - diatomite - Fe3O4 - the adsorption capacity is 4 and 9 mg PO43- / g, respectively. The obtained composite adsorbents have a set of functional properties that are promising for use in modern water purification and purification systems.
Photocatalytic activity of oxide systems based on doped d-elements of titanium alloys
Authors: Sakhnenko Mykola , Stepanova Iryna , Zyubanova Svitlana , Djenyuk Anatoly , Indykov Sergey 
Published: December 2021

CO-, W-, MO- and Zn-containing hetero-oxide nanostructured coatings on titanium and its alloys formed by plasma-electrolyte oxidation in galvanostatic mode from alkaline electrolytes were investigated. The morphology of the surface of the formed coatings was studied by scanning microscopy on the Zeiss Evo 40XVP microscope. The phase composition of the obtained coatings was determined on the X-ray diffractometer Drone-2. Photocatalytic activity of ZnO-WO3/TiO2 films, ZnO-MOO3/TIO2, ZnO-Co3O4/TiO2, CoO-WO3/TiO2 tested in a model reaction of decomposition of an aqueous solution of azobye with a concentration of 12,2·10-5 mol/L (MО) at UV irradiation. It is shown that with plasma-electrolyte oxidation of titanium and its alloys in alkaline diphosphate electrolytes in the mode of «drop-down power» forming heterostructural composites with micro-globular surface morphology. The possibility of controlling the phase and elemental composition of oxide layers, as well as the topography of the surface by changing the composition of the electrolyte and the content of individual components, as well as the modes of formation is confirmed. Heteroxide coatings formed in PEO modes differ in composition and surface morphology, but all exhibit photocatalytic properties of varying degrees of activity. The study of the photocatalytic activity of the obtained coatings in the azo dye decomposition reaction by means of UV testing allowed to rank the heteroxide systems according to the specified parameter. Thus, the degree of decomposition of MF on ZnO-WO3/TiO2 films in 50 minutes was 23 %. Metal oxide systems ZnO-Co3O4/TiO2 had similar characteristics of the degree of decomposition – 21 %. The incorporation of CoO and WO3 oxides into the coating composition reduced the catalytic activity of the system to 19 %. The unstable mode of formation of ZnO-MoO3/TiO2 oxides and the low speed of the process have affected the quality of the catalytic coating activity, reduced the degree of decomposition of MO to values of titanium monoxide Ti/TiO2 without dopants. Comparison of quantitative characteristics of the properties of the obtained coatings allowed to determine the effects of dopants, incorporated into metal oxide systems, on their photocatalytic activity.
POTENTIAL ICE CRYSTAL MARKS FROM PENNSYLVANIAN–PERMIAN EQUATORIAL RED-BEDS OF NORTHWEST COLORADO, U.S.A.
Authors: VOIGT SEBASTIAN , OLIVER KARL , SMALL BRYAN J. 
Published: December 2021

ABSTRACTThe Pennsylvanian–Permian Maroon Formation of northwest Colorado is an up to 4,600 m thick succession of mainly siliciclastic continental red-beds deposited in equatorial intermontane basins of the Ancestral Rocky Mountains. Sedimentary surfaces of fluvio-lacustrine to eolian siltstones and fine-grained sandstones from various stratigraphic levels within the Maroon Formation preserve cm-sized straight to gently curved sediment-filled acicular structures referred to five morphological groups: single, branched, stellate, rosette, and bunched. Depositional environment, shape, and size of the structures are most similar to ice crystal marks that result from freezing of water-saturated fine-grained substrate at the sediment-air interface. They differ from other syngenetically produced crystals and crystal pseudomorphs in sedimentary rocks mainly by crystal shape and environmental conditions. The potential ice crystal marks of the Maroon Formation are notable for the fidelity and morphological diversity of the crystal casts and could be a key for the understanding of similar but hitherto often only called enigmatic structures of the sedimentary rock record. The ice crystal mark occurrences in the Maroon Formation suggest that night frost affected lower elevation equatorial areas during the climax of the Late Paleozoic Ice Age and may stimulate research on evolutionary adaptations of early terrestrial biota to overcome significant air temperature fluctuations.
STL Decomposition and SARIMA Model: The Case for Estimating Value-at-Risk of Covid-19 Increment Rate in DKI Jakarta
Authors: Agnes Zahrani  , Aniq A. Rohmawati  , Siti Sa’adah  
Published: December 2021

In this research, we propose an extreme values measure, the Value-at-Risk (VaR) based Seasonal Trend Loess (STL) Decomposition and Seasonal Autoregressive Integrated Moving Average (SARIMA) models, which is more sensitive to the seasonality of extreme value than the conventional VaR. We consider the problem of the seasonality and extreme value for increment rate of Covid-19 forecasting. For stakeholder, government and regulator, VaR estimation can be implemented to face the extreme wave of new positive Covid-19 in the future and minimize the losses that possibly affected in term of financial and human resources. Specifically, the estimation of VaR is developed with the difference lies on parameter estimators of STL and SARIMA model. The VaR has coverage probability as well as close 1-α. Thus, we propose to set α as parameter to estimate VaR. Consequently, the performance of VaR will depend not only on parameter model but also α. Our aim estimates VaR with minimum α based on correct VaR value. Numerical analysis is carried out to illustrate the estimative VaR.
Study on the Bearing Characteristics and Application of the Filling Body in Original Roadway Filling and Nonpillar Driving
Authors: Shi Wenbao , Li Yan , Chang Jucai 
Published: December 2021

Abstract
Original roadway filling and nonpillar driving can effectively solve the difficulty facing mining replacement in the stope of deep mines. As the bearing characteristics of the filling body in the original roadway play a crucial role in the structural stability of the overlying strata, with the recovery and geological conditions of 62210 working face in Xinzhuangzi Coal Mine, Huainan Mining Group, China, as the background, this study analyzed the stability characteristics of the filling body in the original roadway through comprehensive research methods of theoretical analysis, laboratory tests, and onsite monitoring. The results disclose that the filling body in the original roadway should boost early strength, strong bearing capacity, and long-term weakening. When the water-cement ratios are 1 : 1, 1.5 : 1, 2 : 1, 2.5 : 1, and 3 : 1, the strengths of the filling body are 1.12 MPa, 0.93 MPa, 0.57 MPa, 0.33 MPa, and 0.21 MPa at 2 h and 5.63 MPa, 4.66 MPa, 2.87 MPa, 1.65 MPa, and 1.02 MPa at 48 h, respectively. The strengths surge by 5 times within 2 d on the whole and reach the maximum at about 7 d, i.e., 8.12 MPa, 6.91 MPa, 6.60 MPa, 3.95 MPa, and 2.20 MPa, respectively. As time goes, the water content of the filling body gradually decreases and the compressive strength plunges. This demonstrates that the rapid solidification material with a high water content can satisfy the requirements of the bearing characteristics of the original roadway filling body. With reference to numerical simulation and the data monitored onsite, it can be known that the filling body in the original roadway can support the roof effectively and control the surrounding rock deformation of newly excavated roadways in the lower section. The research results provide theoretical guidance for coal mining under similar geological conditions and serve as reference for safe and efficient coal mining.
Integrative Analyses of Whole-Transcriptome Sequencing Reveals CeRNA Regulatory Network of mRNAs, lncRNAs, miRNAs and circRNAs in Pulmonary Hypertension Treated with FGF21
Authors: Li Xiuchun , Cai Haijian , Zhang Chi , Zhang Yaxin , Wang Xinghong , Song Lanlan , Zhang Jianhao , Lin Jin , Tong Shuolan , Wang Liangxing , Huang Xiaoying 
Published: December 2021

Abstract
Noncoding RNAs have been shown to play important roles in hypoxic pulmonary hypertension (HPH). Our preliminary data showed that HPH is attenuated by fibroblast growth factor 21 (FGF21) administration. Therefore, we further investigated the whole transcriptome RNA expression patterns and interactions in a mice HPH model treated with FGF21. By whole-transcriptome sequencing, differentially expressed mRNA, miRNA, lncRNA, and circRNA were successfully identified in normoxia (Nx) vs. hypoxia (Hx) and Hx vs. hypoxia + FGF21 (Hx + F21). Through intersection and predictive analysis, differentially co-expressed mRNA, miRNA, lncRNA, and circRNA were selected, followed by functional enrichment analysis. MAPK signaling pathway and epigenetic modification were enriched and may play fundamental roles in the therapeutic effects of FGF21. A ceRNA regulatory network was constructed with miR-7a-5p, miR-449c-5p, miR-676-3p and miR-674-3p as the core. Then the quantitative real time-PCR validation results were consistent with the results of whole-transcriptome sequencing. This study may provide potential biomarkers, pathway and ceRNA regulatory network in HPH treated with FGF21.
Assessment of Breeding Practice and Statues of Estrus Synchronization and Mass Insemination Conception Rate of Dairy Cattle in North Shewa Zone, Ethiopia.
Authors: mekonnen Sharew , Bestha Simret , Banerjee Sandip 
Published: December 2021

Abstract
BackgroundAssisted reproductive biotechnology like oestrus synchronization mass insemination(OSMI), and artificial insemination (AI) are the most important bio techniques for improving the reproductive and productive performance of dairy cattle including enhancing overall profit in Ethiopia. In North Shewa zone different study were conducted. However, there is no study conducted on breeding practice, and status of OSMI conception rate of dairy cattle. Therefore the aim of this study to assess breeding practice, and status of OSMI conception rate of dairy cattle in North Shewa zone.MethodsOut of 27 districts, three district and 135 respondents were selected purposive followed by random sampling techniques per each district. Data were analyzed using SPSS version 20 and Ms-Excel (2010).ResultMilk yield, High growth rate, body weight, fertility and udder size were the major traits perceived by farmers. Breed preference of the respondents were HHFC and HFC in Basonaworena and Angolelanatera ranked first. Breeding objective and rearing system of cattle were milk production with sale of calves and all cattle categories reared together except HHFC and lactating cows respectively. Most of the respondents were used AI mating system due to rapid genetic improvement. HHFC and HJERC bulls breed were not available in the study area as a result alternative strategies taken by the respondents was take cows in other kebele. Reproductive performance of dairy cattle per district and breeds were statistically significant. 86.6% of respondents were not maintained mating and pedigree records due to lack of awareness. Heat detection problem and AIT efficiency were the major factor that affect CR in OSMI program. The perception and satisfaction of farmer on CR of OSMI (34.4%) was not good and (67.1%) not satisfied respectively. The selection criteria of cows for OSMI program (58.9%) of respondents were not aware. The status of CR and NSPC per district, breed and year were vary (p<0.05) in table16 in OSMI program.ConclusionIn conclusion that the status of CR was increasing starting 2013/14-2015/16 in OSMI. In addition creation of farmer’s awareness on breeding aspects as well as OSMI is mandatory. Finally empowering the AI technician efficiency and procurement of the necessary facilities should be in place before implementing an OSMI.
Analysis of the Cooling Effect of Urban Green Spaces in Mitigating Micro-climate Change Using Geospatial Techniques in Adama City, Central Ethiopia
Authors: Merga Biratu Bobo , Tabor Kenate Worku , Alemu Girma 
Published: December 2021

Abstract
Nowadays, addressing urban climate in urban planning through mapping has got world-wide attention. Greening urban environment is one of the best mechanisms to combat the effects of micro-climate change. Therefore, this study aims at analyzing the cooling effects of Urban Green Spaces (UGS) in mitigating micro-climate change in Adama City with special emphasis on land surface temperature variation with respective to vegetation cover for the last two decades i.e. from 2000 to 2020. Three different remotely sensed data of Landsat7 ETM+ (2000 and 2010) as well as Landsat8 OLI/TIRS (2020) were used in the study. The consistent land surface temperature data were retrieved from Landsat7 ETM+ and Landsat8 OLI/TIRS using mono window and split window algorithms, respectively. Regression and correlation analysis among Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI) and Normalized Difference Built-up Index (NDBI) were also performed in Statistical Package for Social Science (SPSS V23). The study reveals that the proportion of Urban Green Spaces (UGS) to other land use/land cover particularly, dense vegetation cover were reduced from 29.3Km2(21.20%) in 2000 to 18.17Km2 (13.15%) in 2020. The main land dynamic process, which could considerably contribute to the increase in Land Surface Temperature, was the rapid expansion of built-up areas in the study area. The model produced through multiple linear regression analysis clearly indicates that the two urban parameters (built up and green areas) contributed 75.2% of the Land Surface Temperature (LST) variations in Adama City. The cooling efficiency (CE) and the threshold value of efficiency (TVoE) of green space in Adama City were calculated as 5.5 ± 0.5 ha. This finding implies that when Adama City municipality implements urban planning, allocating a green space area of 5.5 ± 0.5 ha reduces surface temperature by about 2.85 0C which is the most efficient to reduce heat effects. The study suggests that strengthening of plan execution capacity, public participation in urban planning and strengthening the development of urban green spaces as an important strategy to mitigate the effects of micro-climate change.
Advance Aerobic Granular Sludge Development for the Treatment of Low Strength Wastewater
Authors: Basri Hazlami Fikri , Anuar Aznah Nor , Halim Mohd Hakim Ab , Yuzir Muhammad Ali 
Published: December 2021

Abstract
The aim of the present study was to assess the start-up performance of aerobic granular sludge for the treatment of low-strength (COD <200 mg L−1) domestic wastewater by the application of a diatomite carrier. The feasibility was evaluated in terms of the start-up period and stability of the aerobic granules as well as COD and phosphate removal efficiencies. A single pilot-scale Sequencing Batch Reactor (SBR) was used and operated separately for the control granulation and granulation with diatomite. Complete granulation (granulation rate ≥ 90%) was achieved within 20 days for the case of diatomite with an average influent COD concentration of 184 mg L−1. In comparison, control granulation required 85 days to accomplish the same feat with a higher average influent COD concentration (253 mg L−1). The presence of diatomite solidifies the core of the granules and enhances physical stability. Diatomite granules recorded the strength and SVI of 18 IC and 53 mL/g SS which clearly superior to control granulation (19.3 IC, 81 mL/g SS). Quick start-up and achievement of stable granules lead to an efficient COD (89%) and phosphate removal (74%) in 50 days of bioreactor operation. Interestingly, this study revealed that diatomite has some special mechanism in enhancing the removal of both COD and phosphate. The result of this research implies that the advanced development of granular sludge by using diatomite can provide a promising low-strength wastewater treatment.
Meteorological Drought Analysis Using Global Climate Model and Drought Indicators in West of Iran
Authors: Pakdin Mahsa , Akbari Morteza , Noughani Mohamad Alizadeh 
Published: December 2021

Abstract
Climate change and global warming impact the frequency of droughts and supply systems. Therefore, it is necessary to conduct appropriate studies to evaluate the impact of climate change on weather patterns and drought. For this purpose, data from 6 synoptic stations located in the wet and temperate areas in the Zagros region in western Iran were used to construct four general atmospheric models including BCC-CSM1, CANESM2, HADGEM2-ES, NORESM1-M under representative concentration pathways (RCPs) 2.6, 4.5, and 8.5, for three future periods (2010-2039), (2040-2069) and (2070-2099). Then, spatio-temporal variations of drought severity and frequency were studied in the study area using SPI and SPEI indices in different periods up to 2100. The results showed the spatial extent of areas classified as extremely dry will increase by 47.9% in the first period compared to the base period. In the second and third periods, however, the severely dry class covers more area. Analysis of SPEI showed that drought will be more severe in all future periods. According to SPEI, drought frequency will increase by 2% according to the first period (2010-2039) relative to the base period (1984-2013), and by 0.3% in the second and third periods by 2099. The results of this study indicate that the severity, frequency, and impacts of drought will increase in the study area until the end of the century. Therefore, appropriate measures should be taken to control and reduce its potential effects in the future.
Dental Education During Pandemic – Cross-Sectional Lecturer-Side Evaluation For The Use of Digital Teaching Concepts In German Universities
Authors: Nold Ephraim , Demeter Vivienne , Erdelt Kurt , Edelhoff Daniel , Liebermann Anja 
Published: December 2021

Abstract
Background: The Covid-19 pandemic resulted in significant restrictions on dental teaching. The aim of this investigation was to evaluate the attitudes of faculty members towards digital teaching formats and the effort creating digital lectures. Methods: All German dental faculties were invited from January to April 2021 to the online survey by an anonymous voluntary questionnaire. The questionnaire consisted of 27 questions that could be answered with a visual analog scale, free text answers or with fixed answer options. Data was analyzed using the Kolmogorov-Smirnov test and an exploratory data analysis (α=0.05).Results: Before the pandemic, 24.8% of the participating lecturers were using digital teaching and 64.4% had no previous experience. After the outbreak of the pandemic, more than 80% of the lecturers stated that they offer online lectures (86.1%), online seminars (81.2%), and/or online bedside teaching (33.7%). 88.1% see face-to-face teaching as the preferred teaching format.The lecturers also see the greatest opportunities for interaction in the area of analog teaching and significantly worse in synchronous and asynchronous digital teaching. In the course of the pandemic, respondents' attitudes towards online teaching improved in the median of 24.0 to a median of 50.0. Conclusions: Faculty members have positively changed their attitudes towards online teaching formats over the course of the pandemic. Although they see the greatest learning success in conventional face-to-face teaching formats and the creation of digital lectures is associated with a higher effort, they want more online lessons in the future.