bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improvement of methods for calculating thermal characteristics of loop air heaters
Authors: Yurko Volodymyr , Ganzha Anton , Tarasenko Oleksandra , Tiutiunyk Larysa 
Published: March 2021

Utilization of heat from gases leaving the waelz process is a promising way to increase its energy efficiency and environmental safety. Taking into account the gas dustiness, the most rational is the use of a loop air heater, which is a multi-pass and multi-section heat exchanger with a complex mixed scheme of coolant movement. In modern conditions, when the methods and means of calculation of such devices are simplified, the task of obtaining improved methods and means of calculation, determining the efficiency and reliability of their work is relevant.
Two mathematical models of the process of heat transfer and hydroaerodynamics in a multi-pass tubular air heater with a cross-circuit of coolants are used. The developed models for the loop air heater are based on the main methods of thermal calculation: a simpler method of correction factor to the average logarithmic temperature pressure and a discrete P-NTU method, which allows obtaining local thermal characteristics of the surface. Diagrams of distribution of heat transfer coefficients, heat transfer, local temperatures of flue gases, air and pipe walls are constructed. The influence of dust and dust particle size on heat transfer is determined. When the flue gas dust is 50 g/Nm3 and with a dust particle size of 1 μm, the heat transfer coefficient increases by 12 %. The application of the air heater design with different schemes of coolant movement is substantiated.
The developed universal methods allow determining the thermal productivity of heat exchangers and obtaining the distribution of local temperature characteristics on the heating surface. It is also possible to identify places of possible overheating of the heat exchange surface and the course of corrosion processes, taking into account the design of recuperators, operating conditions, operating modes and different schemes of coolant movement
Design and development of a new portable roof gutter for electricity production
Authors: Alwan Omar Hussein , Mustafa Faiz. F. , Ghaeb Nebras H. , Sabry Ahmed H. 
Published: March 2021

Despite a sufficient energy supply, harvesting energy from rainfall is essential for intelligent water management. A significant part is still untapped or little exploited, which is the renewable energy produced from rainwater. This paper proposes a portable gutter of the rainwater energy harvesting system to provide electricity that may be sufficient for powering lights and charging cell phones in rainy locations with limited electricity. A prototype is designed and tested to determine the feasibility of rainwater as a source of renewable energy. The aim is to minimize and respectively suspend the use of fossil energy sources, as well as decrease the percentage of pollution as it is a cause of global warming. The system prototype consisted of a gutter assembly that collected and funneled water from the roof to a downspout. The turbine was connected through a gearbox to a DC motor serving as the generator. The device is optimal during high rainfall intensities that produce larger flow rates. A smart algorithm has been applied, which is salutary to keep the system working and has the ability to control the flow of collected rainfall water. Also, this system is useful to install and use in the rural area where the national grids are not common and the level of rainfall is high. The applied system utilized and installed in more than one hundred premises can produce more than 4 kWh for one rain. In some countries such as Malaysia, the average number of rainy days is 250 days a year, so the use of this system in 100 premises can help to provide 80 MWh to the national grid yearly. The system is characterized by simplicity of design and lack of complexity in addition to ease of installation and cheapness, which is the basis for the availability of this system for use by everyone
LSB steganography strengthen footprint biometric template
Authors: Khudher Israa Mohammed 
Published: March 2021

Steganography is the science of hiding secret data inside another data type as image and text. This data is known as carrier data; it lets people interconnect secretly. This suggested paper aims to design a Steganography Biometric Imaging System (SBIS). The system is constructed in a hybridization manner between image processing, steganography, and artificial intelligence techniques. During image processing techniques the system receives RGB foot-tip images and preprocesses the images to get foot-template images. Then a chain code is illustrated for personal information within the foot-template image by Least Significant Bit (LSB). Accurate recognition operation is performed by artificial bee colony optimization (ABC). The automated system was tested on a live-took about ninety RGB foot-tip images known as the cover image and clustered to nine clusters that authorized visual database. The Least Significant Bit method transforms the foot template to a stego image and is stored on a stego visual database for further use. Features database was constructed for each stego footprint template. This step converts the image to quantities data and stored in an Excel feature database file. The quantities data was used at the recognition stage to produce either a notification of rejection or acceptance. At the acceptance choice, the corresponding stego foot-tip template occurrence was retrieved, it is corresponding individual data were extracted and cluster position on the stego template visual database. Indeed, the foot-tip template is displayed. The suggested work consequence is affected by the optimum feature selection via the artificial bee colony optimization usage and clustering, which declined the complication and subsequently raised the recognition rate to 93.65 %. This rate competes out the technique over others’ techniques in the field of biometric recognition
Designing a computerized information processing system to build a movement trajectory of an unmanned aircraft
Authors: Kvasnikov Volodymyr , Ornatskyi Dmytro , Graf Maryna , Shelukha Oleksii 
Published: March 2021

This paper addresses the issue of developing a computerized system for processing information in the construction of the trajectory of an unmanned aircraft (UAC), a remotely-piloted aviation system (RPAS), or another robotic system. Resolving this task involves the neural network learning algorithms based on the mathematical model of movement.
The construction of such a trajectory between two specified destinations has been considered that provides for the possibility of bypassing static and dynamic obstacles. The specified trajectory is divided into several smaller parts. The possibility of restructuring when changing the position of obstacles in space has been considered. A UAC flight control algorithm has been developed, which implies training a neural network for bypassing obstacles of different sizes.
To predict the development of the situation when an object moves between two specified points in space, it is proposed to use the Q-Learning algorithm. It has been shown that the smallest number of steps required for moving along a specified trajectory is 18, the largest is 273 steps. In case of distortion during data transmission, the training of the neural network makes it possible to reduce the possibility of collision with obstacles by improving the accuracy and speed of information transfer between the on-board computer and operator. A system of the video support to moving objects was modeled; dependence charts of the normalized frame size at different parameter values were built. Using the charts makes it possible to determine the function of the maneuver intensity. Existing neural network learning methods such as CNN and LSTM were compared. It has been proven that the success rate reaches 74 % when using CNN only, while it amounts to 92 % at the hybrid application of CNN+LSTM. The simulation results have demonstrated the high efficiency of the developed algorithm
Constructing the models of programmed flight for path calculation in designing tactical and anti-aircraft guided missiles
Authors: Chubarov Anton 
Published: March 2021

Several models of programmed flight have been constructed to perform calculations on flight path optimization in designing tactical and anti-aircraft-guided missiles. The developed models are based on the determination of interrelated programmed values of altitude and the flight path angle depending on the range which have a differential relationship. The combination of flight altitude and flight-path angle programs allows the users to simulate the steady flight of a guided missile to the calculated endpoint using the methods of proportional control.
Good correspondence of the developed models to the physics of flight was shown by assessing the quality of approximation of the developed models of flight paths of anti-aircraft guided missiles obtained using other known models. The obtained approximation error was less than 5 % which indicates a good correspondence of the developed models to the physics of flight.
Compliance of the developed models of programmed flight with the intended purpose and the advantage over the most common known models were proved by optimizing the flight paths of the anti-aircraft-guided missile. In most of the considered calculation cases, the value of the objective function was improved to 2.9 %. The flight path was optimized using a genetic algorithm.
The developed models have a simple algebraic form and a small number of control parameters are presented in a ready-to-use form and do not require refinement for a concrete task. This allows them to be implemented in design practice without spending much time to speed up the calculation of optimal design variables and optimal flight paths of tactical and anti-aircraft-guided missiles
Effects of the rate of natural gas production on the recovery factor during carbon dioxide injection at the initial gas-water contact
Authors: Matkivskyi Serhii 
Published: March 2021

The object of research is gas condensate reservoirs, which is being developed under the conditions of the manifestation of the water drive of development and the negative effect of formation water on the process of natural gas production. The results of the performed theoretical and experimental studies show that a promising direction for increasing hydrocarbon recovery from fields at the final stage of development is the displacement of natural gas to producing wells by injection non-hydrocarbon gases into productive reservoirs. The final gas recovery factor according to the results of laboratory studies in the case of injection of non-hydrocarbon gases into productive reservoirs depends on the type of displacing agent and the level heterogeneity of reservoir. With the purpose update the existing technologies for the development of fields in conditions of the showing of water drive, the technology of injection carbon dioxide into productive reservoirs at the boundary of the gas-water contact was studied using a digital three-dimensional model of a gas condensate deposit. The study was carried out for various values of the rate of natural gas production. The production well rate for calculations is taken at the level of 30, 40, 50, 60, 70, 80 thousand m3/day. Based on the data obtained, it has been established that an increase in the rate of natural gas production has a positive effect on the development of a productive reservoir and leads to an increase in the gas recovery factor. Based on the results of statistical processing of the calculated data, the optimal value of the rate of natural gas production was determined when carbon dioxide is injected into the productive reservoir at the boundary of the gas-water contact is 55.93 thousand m3/day. The final gas recovery factor for the optimal natural gas production rate is 64.99 %. The results of the studies carried out indicate the technological efficiency of injecting carbon dioxide into productive reservoirs at the boundary of the gas-water contact in order to slow down the movement of formation water into productive reservoirs and increase the final gas recovery factor.
Use of plasmapheresis in treatment of patients with unfavorable anamnestic pregnancy outcomes coupled to antiphospholipid antibodies
Authors: Eremeeva D. R. , Zainulina M. S. , Dolgova Yu. S. , Shakhaliev R. A. , Silvanovich O. A. , Pavlova L. A. 
Published: March 2021

Aim: to evaluate efficacy of plasmapheresis combined with low molecular weight heparins (LMWH) and acetylsalicylic acid (ASA).Materials and Methods. 327 plasmapheresis sessions were performed for 75 patients: 17 (22.6 %) patients during preparation for pregnancy, 11 (19.0 %) pregnant women in the first trimester, 33 (56.9 %) pregnant women in the second trimester, and 34 (58.6 %) pregnant women in the third trimester. Study inclusion criteria were as follows: high titers of antiphospholipid antibodies (APA) as well as included non-inclusion criteria in pregnant women with miscarriages and unfavorable anamnestic pregnancy outcome. 36 (62.1 %) women had pregnancy loss in anamnesis. All patients received low-dose ASA and LMWH therapy; 15 (25.86 %) pregnant women also received courses of intravenous immunoglobulins in the first and second trimesters.Results. 47 pregnant women had delivery, whereas 10 of women had pregnancy in progress. Term delivery was in 40 (85.1 %) patients, so that 23 (48.9 %) pregnant women had delivery per vias naturales. The average weight of the fetus was 3364.00 ± 393.76 g, height - 52.13 ± 1.82 cm. In 100 % cases, Apgar score was 8 points. 24 (51.1%) pregnant women had delivery via cesarean section. The average blood loss comprised 528.64 ± 166.10 ml. The average fetal weight in group after surgical delivery was 2982.14 ± 582.88 g, average height - 49.14 ± 4.09 cm, the Apgar score - 7.69 ± 0.47 points. Preterm births were observed in 7 (14.9%) cases, all via cesarean section. In 1 case, early fetal death was at gestational age of 8/9 weeks; according to the karyotyping data, a fetal chromosomal abnormality was detected. No severe obstetric complications were observed.Conclusions. Combining plasmapheresis with low dose LMWH and ASA therapy demonstrated high efficacy in treating obstetric APS manifested as high percentage of favorable pregnancy outcomes and low number of obstetric complications.
Pulmonary function tests: a study among healthy individuals of different age groups in Akhnoor Tehsil
Authors: Sharma Chandan , Badyal Ashima 
Published: March 2021

<p><strong>Background:</strong> Pulmonary function tests may be affected by many factors like age, gender, race and body surface area of an individual. Lung functions decline throughout adult life, and healthy people are no exception. Aging is a universal progressive decline, but it is not a disease. The present study was done with an aim to establish the age effect on lung function test of healthy non-smoking people belonging to the rural belt of Jammu region.</p><p><strong>Methods: </strong>A prospective study was conducted on 180 patients attending the OPD of department of medicine, sub-district hospital Akhnoor. With age ranging from 11 to 70 years, healthy individuals, non-smokers were selected for the study. Pulmonary tests like forced vital capacity (FVC), forced expiratory volume in 1<sup>st</sup> second (FEV<sub>1</sub>) and peak expiratory flow rates (PEFR) were conducted.</p><p><strong>Results:</strong> Younger population had a high value for FEV<sub>1</sub> and PEFR showed a rise among age groups: 11-20, 21-30 and 31-40 years, reaching up to 7.23±1.75 (L/sec), and then declining to reach 3.93±0.98 (L/sec) for the age group: &gt;60 years. Almost all parameters showed a resembling ascends and decline with ageing. Lung function has further variability in older people, depending upon lung capacity at maturation time. This study was quite in line with the most of the research findings in the field, but done under a different social set up.</p><p><strong>Conclusions:</strong> Considerable differences in the respiratory patterns of healthy individuals with ageing suggest that pulmonary function tests have to become a part of routine health examinations in elderly population.</p><p><strong> </strong></p>
Pembelajaran Fisika Menggunakan Model Discovery Learning Berbasis Edutainment
Authors: Winarti Wahyu Tri , Yuliani Hadma , Rohmadi Mukhlis , Septiana Nurul 
Published: March 2021

Pembelajaran fisika merupakan pembelajaran mengenai gejala-gejala alam dan berusaha menemukan hubungan antara kenyataan di alam. Perlu adanya model dan metode yang dapat membantu menerangkan gejala alam tersebut dalam proses pembelajaran fisika. Salah satu model yang diharapkan cocok dengan karakteristik pembelajaran fisika yaitu model discovery learning berbasis edutainment. Penelitian ini bertujuan: (1) untuk mendeskripsikan kelebihan dan kekurangan dari model discovery learning berbasis edutainment; dan (2) untuk mendeskripsikan penerapani model discovery learning berbasis edutainment dalam pembelajaran fisika. Metode pengumpulan data pada penelitian ini adalah studi literatur dan kajian pustaka, data penelitian ini menggunakan jenis data sekunder, kemudian data yang diperoleh tersebut diolah dengan analisis isi. Hasil penelitian menunjukkan bahwa: (1) Model discovery learning berbasis edutainment dapat menjadikan peserta didik aktif dalam kegiatan belajar dan menyenangkan. Namun, memerlukan waktu yang cukup lama dalam pembelajarannya dan kurang efektif digunakan dalam kelas besar; dan (2) Pada pembelajaran fisika, model discovery learning berbasis edutainment digunakan untuk memahami materi yang cukup sulit dengan cara yang menyenangkan.Physics learning is learning about natural phenomena and trying to find the relationship between reality in nature. It is necessary to have models and methods to explain these natural phenomena in the physics learning process. One model that is expected to match physics learning characteristics is the discovery learning model based on edutainment. This study aims: (1) To describe the advantages and disadvantages of the discovery learning model based on edutainment models; (2) To describe the application of the discovery learning model based on edutainment models in physics learning. The data collection method in this research is a literature study and literature review. This research data use secondary data, then the data obtained is processed by content analysis. The results showed that: (1) Discovery learning model based on edutainment could make students active in learning activities because it is fun; however, the learning process requires a long time and is less effective when used in a class with a large number of students; and (2) In physics learning, the discovery learning model based on edutainment is used to understand difficult material in a fun way.
20(S)-Panaxadiol Enhances Hemostatic Effect on Activated Platelet by Affecting Calcium Signaling
Authors: Zhang He , Su Wenjie , Yang Chunhui , Tang Xiaolei , Pan Daian , Zhang Yuyao , Zhao Daqing , Qi Bin , Li Xiangyan 
Published: March 2021

Abstract
Background: Panax notoginseng (Burk.) F.H. Chen has long been used to stop bleeding for hundreds of years in China. At present, only dencichine and notoginsenoside Ft1 showed the hemostatic effect. Other ingredients from Panax notoginseng need to be further investigated. This study evaluates the hemostatic effect of 20(S)-panaxadiol (PD) and reveals its mechanism. Methods: We performed an in vivo study to measure PD on the hemostatic effect of mouse tail amputation and liver scratch models, and routine blood. Plasma coagulation parameters were measured using a blood analyzer. Platelet aggregation rate and adenosine triphosphate (ATP) release were analyzed by platelet aggregometer. Subsequently, degranulation marker P-selectin (CD62P), PAC-1 (activated GP IIb/IIIa receptor marker), the concentrations of cytosolic Ca2+ ([Ca2+]i) and cyclic adenosine monophosphate (cAMP) were also assessed. Results: PD shorted bleeding time on the mouse tail amputation and liver scratch models and mainly increased blood platelet count in the rats after subcutaneous injection of 4 h. Meanwhile, PD decreased APTT, increased FIB content, and directly induced platelet aggregation. In the absence of Ca2+, PD promoted the increase of [Ca2+]i and ATP, slightly increased CD62P expression and PAC-1 binding of platelets. After the addition of Ca2+, PD treatment markedly promoted platelet activation by releasing ATP level, increasing CD62P expression and PAC-1 binding, and decreasing cAMP level in platelets. Besides, PD increased phosphorylation of phosphoinositide 3-kinase (PI3K), protein kinase B (PKB or Akt), and glycogen synthase kinase 3β (GSK3β) in human platelets. Excitingly, PD-induced changes included platelet aggregation, a decrease of the cAMP content, and the increases of ATP, CD62P and PAC-1, which were significantly reversed by vorapaxar, which showed a similar function as thrombin. Conclusions: PD is an essential hemostatic ingredient in Panax notoginseng for promoting hematopoiesis and thrombopoiesis. PD induces platelet aggregation by affecting calcium signaling and activating PI3K/Akt/GSK3β signaling pathway, which could contribute to the new insight for the treatment of hemorrhagic disease.
Genome-Wide mRNA Profiling Identifies&nbsp;&nbsp;the NRF2- Regulated Lymphocyte Oxidative Status in Patients with Silicosis
Authors: zhao yingzheng , Xu Guangcui , Li Haibin , Chang Meiyu , Xiong Cheng , Tao Yingjun , Guan Yi , Li Yuchun , Yao Sanqiao 
Published: March 2021

Abstract
BackgroundThe immunomodulatory abnormalities of silicosis are related to the lymphocyte oxidative state. The potential effect of antioxidant therapy on silicosis may depend on the variation in nuclear factor erythroid 2-related factor 2 (NRF2)-regulated antioxidant genes in peripheral blood mononuclear cells (PBMCs). As NRF2 is a redox-sensitive transcription factor, its possible roles and underlying mechanism in the treatment of silicosis need to be clarified.MethodsIn this study, the lymphocyte oxidative state was investigated by evaluating NRF2 expression and NRF2-dependent antioxidative genes in PBMCs from patients with silicosis. Key differentially expressed genes (DEGs) and signaling pathways were identified utilizing RNA sequencing (RNA-Seq) and bioinformatics technology. Gene set enrichment analysis was used to identify the differences in NRF2 signaling networks between patients with silicosis and healthy controls.ResultsThe number of monocytes increased significantly through cytology detection in patients with silicosis. Furthermore, RNA-Seq findings were confirmed using quantitative polymerase chain reaction and revealed that NRF2-regulated DEGs were associated with glutathione metabolism, transforming growth factor-β, and the extracellular matrix receptor interaction signaling pathway in PBMCs from patients with silicosis. The top 10 hub genes were identified by PPI analysis: SMAD2, MAPK3, THBS1, SMAD3, ITGB3, integrin alpha-V (ITGAV), von Willebrand factor (VWF), BMP4, CD44, and SMAD7.ConclusionsThese findings suggest that NRF2 signaling regulates the lymphocyte oxidative state and may contribute to fibrogenic responses in human PBMCs. Therefore, NRF2 might serve as a novel preventive and therapeutic candidate for silicosis.