bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of Serum 25-Hydroxyvitamin D Concentrations With All-Cause and Cause-Specific Mortality Among Individuals With Diabetes
Authors: Wan Zhenzhen , Guo Jingyu , Pan An , Chen Chen , Liu Liegang , Liu Gang
Published: November 2020

OBJECTIVE

The evidence regarding vitamin D status and mortality among people with diabetes is scarce. This study aimed to examine the association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with all-cause and cause-specific mortality among adults with diabetes.

RESEARCH DESIGN AND METHODS

This study included 6,329 adults with diabetes from the Third National Health and Nutrition Examination Survey (NHANES III) and NHANES 2001–2014. Death outcomes were ascertained by linkage to National Death Index records through 31 December 2015. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% CIs for mortality from all causes, cardiovascular disease (CVD), and cancer.

RESULTS

The weighted mean (95% CI) level of serum 25(OH)D was 57.7 (56.6, 58.8) nmol/L, and 46.6% had deficient vitamin D (<50 nmol/L [20 ng/mL]). Higher serum 25(OH)D levels were significantly associated with lower levels of glucose, insulin, HOMA of insulin resistance, HbA1c, blood lipids, and C-reactive protein at baseline (all Ptrend < 0.05). During 55,126 person-years of follow-up, 2,056 deaths were documented, including 605 CVD deaths and 309 cancer deaths. After multivariate adjustment, higher serum 25(OH)D levels were significantly and linearly associated with lower all-cause and CVD mortality: there was a 31% reduced risk of all-cause mortality and a 38% reduced risk of CVD mortality per one-unit increment in natural log-transformed 25(OH)D (both P < 0.001). Compared with participants with 25(OH)D <25 nmol/L, the multivariate-adjusted HRs and 95% CI for participants with 25(OH)D >75 nmol/L were 0.59 (0.43, 0.83) for all-cause mortality (Ptrend = 0.003), 0.50 (0.29, 0.86) for CVD mortality (Ptrend = 0.02), and 0.49 (0.23, 1.04) for cancer mortality (Ptrend = 0.12).

CONCLUSIONS

Higher serum 25(OH)D levels were significantly associated with lower all-cause and CVD mortality. These findings suggest that maintaining adequate vitamin D status may lower mortality risk in individuals with diabetes.
Genetic aspects of biliary atresia etiology
Authors: Isaeva MKh , Belova VA , Korostin DO , Degtyareva AV
Published: November 2020

Biliary atresia (BA) is a cholestatic disorder of infancy that is fatal if untreated. Despite years of study the etiology of BA remains unknown. Three etiopathogenic mechanisms may be involved, such as immune dysregulation, environmental factors and genetic susceptibility. Genetic predisposition is being actively studied. Candidate genes associated with BA in certain populations, genes affecting the cholangiocyte cilia function, as well as genes involved in stress responses have been identified. However, the long-term follow-up of twins with BA suggests that genotype is not of paramount importance for the disease development. Both epigenetic patterns and postzygotic somatic mutations may contribute to etiology of the disease. Recently, some evidence is being accumulated on the possible genetic predisposition to certain outcome of Kasai portoenterostomy performed in patients with BA. However, the presence of a number of factors contributing to the development of the disease makes it difficult to identify the genetic markers.
Perbedaan Hasil Belajar Siswa Menggunakan Model Kooperatif Tipe MM dan TGT dengan bantuan Powerpoint
Authors: Sari Ayu Puspita , Simatupang Lisnawaty
Published: November 2020

Penelitian ini bertujuan untuk mengetahui apakah ada perbedaan hasil belajar siswa menggunakan model kooperatif tipe Make a Match (MM) dan Teams Games Tournament(TGT) dengan bantuan PowerPoint pada pokok bahasan koloid. Sampel yang digunakan sebanyak 2 kelas reguler dengan teknik random sampling (acak) dan masing–masing kelas terdiri atas 40 siswa. Pada kelas eksperimen I diberi pengajaran dengan model kooperatif tipe MM dengan bantuan powerpoint dan pada kelas eksperimen II diberikan pengajaran dengan model TGT dengan bantuan powerpoint. Hasil pengolahan data menunjukkan siswa pada kelas MM memiliki rata – rata nilai pre-tes 51,44 + 17,85 dan post-tes87,62+6,25 dengan rata – rata gain sebesar 73,53%. Sedangkan siswa pada kelas TGT memiliki rata – rata nilai pre-tes 45,25+14,24 dan post-tes83,94+5,58 dengan rata – rata gain sebesar 69,46%. Uji hipotesis dilakukan dengan menggunakan uji t dua pihak dari data hasil belajar dan diperoleh thitung = 2,80  sedangkan ttabel = 1,994 untuk α = 0,05 dan db = 78, sehingga thitung>ttabel. Maka Ha diterima yakni ada perbedaan hasil belajar siswa menggunakan model kooperatif tipe MM dengan bantuan powerpoint dengan model TGTdengan bantuan powerpoint yaitu sebesar 4,07%. Berdasarkan perbandingan peningkatan hasil belajar siswa diperoleh bahwa hasil belajar yang tertinggi yaitu dengan pembelajaran menggunakan model MM.
Pengembangan Penuntun Praktikum Kimia Inovatif Terintegrasi Pembelajaran Berbasis Proyek dan Karakter Pada Materi Koloid
Authors: NAINGGOLAN BAJOKA , HUTABARAT WESLY , GULTOM LIEMMY
Published: November 2020

Descriptive research and development using the ADDIE method aims to Innovatiive develop project-based and character practical guides of Colloidal material according with BSNP standards. The sample of 2 lecturers and 2 chemistry teachers, practical guides for Erlangga (A), Bumi Aksara (B), Pudak Saintifk (C), 26  students XI IPA-5 (experiment) and 26 students XI IPA-6 (control) at the  Medan 3th Senior High School. Data was processed descriptively, obtained the results of feasibility validation contents 3.53; language 3.46; presentation of 3.50, score of 3.53, average of 3.32; it means that the  practical guides resulting from the development is very valid according to the BSNP standard. Data analysis with ANOVA, obtained the average scores of student outcomes in experimen > control class or 81.5% > 73.8%. Then the average phsychomotor scores of experimen was larger than control class or 84, 64 > 82.78. In addition, the affective scores of experimen was larger than control class or  78.42 > 76.38. The hypothesis tested with one way ANOVA at the significant level of α  0.05, and found that tcount> ttable, (4.536 > 1.697). It is concluded that the Innovative Chemistry Practicum Guides developped is highly very good, suitable for use in Senior High School.
DESAIN INTEGRASI PEMBELAJARAN DENGAN PENILAIAN ABAB 21 SESUAI DENGAN KURIKULUM 2013
Authors: LUBIS ASNARNI , LUBIS NAZRIANI
Published: November 2020

Berdasarkan road map penelitian di Universitas Muslim Nusantara (UMN) Al Washliyah dibidang IPPK untuk menganalisis kesulitan dalam K13 dan model pembelajaran karakter, dalam hal ini diketahui belum mencapai kebutuhan pada tahun 2020 artinya sangat diperlukan penyelesaian masalah yang dihadapi. Tujuan khusus penelitian ini adalah merumuskan konsep perencanaan kesesuaian kebutuhan mahasiswa dalam memberikan faktor kesulitan keterbatasan mahasiswa dalam mengaplikasi pembelajaran K13 berbasis karakter di FKIP UMN Al Washliyah. Metode Penelitian adalah penelitian pengembangan dengan desain ADDIE. Populasi Penelitian adalah seluruh mahasiswa Tahun Ajaran 2018/2019 FKIP UMN AW, dengan demikian sampel diambil acak, Sampel yang digunakan adalah mahasiswa yang akan melaksanakan Magang III FKIP UMN Al Washliyah sebanyak sampel adalah 70 mahasiswa. Teknik pengumpulan data adalah angket dan wawancara, dengan teknik analisa adalah analisis faktor IBM SPSS 22 for Windows. Hasil pada tahun pertama pada tahapan analisis, diketahui mahasiswa mengalami kesulitan dan ketidakpahaman, tidak mampu mendesain pembelajaran serta penilaian abad 21, selanjutnya tahapan desain diperlukan modul untuk meningkatkan kinerja mahasiswa mengikuti program Magang III.
Pengaruh Model Pembelajaran Kooperatif Team Games Tournament (TGT) Berbantuan Media Teka–Teki Silang (TTS) Terhadap Hasil Belajar Dan Motivasi Siswa Pada Materi Tata Nama Senyawa Di Kelas X SMA Swasta Parulian 1 Medan
Authors: WARUWU AGUS MARTNUS , SUSANTI NORA
Published: November 2020

This study aims to determine student learning outcomes with the cooperative learning model TGT assisted by crossword puzzles on compound nomenclature material. Learning outcomes data collection tool used objective tests totaling 20 questions that have been tested for validity, difficulty level, different power, and reliability with an r value of 0.92. The results of data analysis showed an increase in student learning outcomes in the experimental class by 81.66% higher when compared to the control class by 75%. The average value of learning outcomes in the experimental class was 81.66 ± 9.17, while the average value of student learning outcomes in the control class was 75 ± 8.88. The results of the one-tailed t test were obtained tcount> t table (3.29> 1.67) so that Ha was accepted. This means that the learning outcomes of students in the experimental class are higher than those of the control class. The sum of students' motivation in the experimental class is initial motivation of 86.8, while final motivation is 96. This shows that the Team Games Tournament (TGT) cooperative learning model assisted by crossword media can improve learning outcomes and student motivation, and make a positive contribution to learning outcomes.
KEBERHASILAN BELAJAR SISWA SMA PADA MATERI AJAR LAJU REAKSI MELALUI PEMBELAJARAN BERBASIS MASALAH MENGGUNAKAN WEBLOG
Authors: Sinaga Eko Martin , Silalahi Albinus
Published: November 2020

This study aims to show: (1) the difference between the student learning outcomes taught by the PBL model using weblog media (PBL-WM)  and taught by the same learning model but not using the media (PBL); (2) the correlation between student learning motivation and PBL-WM improvement; (3) differences in student learning motivation  based on PBL-WM and PBL. The sample studied was class XI student of SMA Negeri 1 Percut Sei Tuan in the academic year 2019/2020 on the reaction rate teaching in 2013 curriculum. The instrument that used by test (learning outcome) and non-test (motivation). The results showed the average increase in PBL-WM was 74.7; while the average increase in PBL was 62,658. The average student motivation based on PBL-WM was 85.92; while the average student motivation based on PBL was 78.45. The statistical analysis results of SPSS 22.0 at α=5% can be stated that (1) PBL-WM was higher than PBL; (2) there was a significant correlation between student learning motivation and increase in PBL-WM , with a correlation coefficient of 0.925 and the contribution of learning motivation to increase PBL-WM of 85.5% while 14.5% was influenced by other factors; (3) student motivation based on PBL-WM  was higher than PBL.
Pengajaran Materi Kesetimbangan Kimia Menggunakan Pembelajaran Problem Based Learning Disertai Macromedia Flash Hasil Pengembangan
Authors: Nainggolan Bajoka , Mutiah Raudatus
Published: November 2020

This research is a research and development (R&D) using ADDIE (Ananlysis, design, development, implementation and evaluate) method, aimed at developing Macromedia Flash learning media and knowing the improvement of students' chemistry learning outcomes. The sample consisted of 3 chemistry validator lecturers, macromedia flash, class XI  Science -1 (27 students) for the experimental class and XI  Science -2 (27 students) for the control class from High School Muhammadiyah 1 Medan. Learning in the experimental class problem-based learning model (PBL) with Macromedia Flash is the result of development, and in the PBL control class without Macromedia Flash. Macromedia Flash validation developed using the BSNP instrument, obtained an average content worth of 4.39; language 4.66; presentation 4.39; and graphic 4.33; on average all aspects are 4.44 (very feasible category). Learning outcomes data were processed descriptively and analyzed with one-party t-test, obtained an increase in student chemistry learning outcomes with the experimental class gain 80.00%, and the control class 72.00%. Hypothesis testing obtained tcount> ttable is 4.396 > 1.672. Conclusions that the application of macromedia flash learning media as a result of development in PBL can significantly improve student learning outcomes in equilibrium material in class XI Science High School.
Steady Stokes flow of a non-Newtonian Reiner-Rivlin fluid streaming over an approximate liquid spheroid
Authors: Jaiswal Bharat Raj
Published: November 2020

The investigation is carried out to study steady Stokes axisymmetrical Reiner-Rivlin streaming flow over a fixed viscous droplet, and this droplet to be deformed sphere in shape. As boundary conditions, vanishing of radial velocities, continuity of tangential velocities and shear stresses at the droplet surface are used. The very common configuration of approximate sphere governed by polar equation $\tilde{r} =a[1 +\alpha_m \vartheta_m(\zeta)]$ has been considered for the study to $o(\varepsilon)$ describing the distortion. Based on the Stokes approximation, an analytical investigation is achieved in the orthogonal curve linear framework in an unbounded region of a Reiner-Rivlin fluid. In constraining cases, some earlier noted outcomes are obtained. Also, the yielded outcomes for the drag have been compared with solution existing in the literature. Further, the change for both force and pressure are evaluated with deflection w.r.t. the parameters of interest and shown through table and graphs.
Exploring challenges faced by parents of children with tuberculosis to achieve treatment success
Authors: Awaluddin SMaria , Ismail Nurhuda , Yasin Siti Munira , Zakaria Yuslina , Mohamed Zainudin Norzila , Kusnin Faridah , Mohd Yusoff Mas Ahmad Sherzkawee , Razali Asmah
Published: November 2020

Introduction: Parents play an essential role in the success of their children’s tuberculosis (TB) treatment. They faced many challenges from the initial children’s health status changes until completing the TB treatment. The challenges were also described as perceived barriers, according to the Health Belief Model (HBM). This study aims to explore parents’ experiences on the challenges in achieving a successful TB treatment for their child in two districts of Selangor, Malaysia.

Methods: The research was carried out using the phenomenology study design. In-depth interviews were conducted among purposely sample primary caregivers of children with TB disease who have completed TB treatment or still under treatment. MyTB version 2.1 data were sought from TB Unit, Selangor Health State Department for Klang and Petaling districts. The participants were selected based on the registration year of 2017 to 2019. The collected data was considered as achieving its saturation level if no new themes arise from the latest interviews session. The R-based Qualitative Data Analysis (RQDA) package version 0.2-8 was used for thematic data analysis.

Results: The total number of participants in this study was fifteen mothers of children with TB disease. There were six main themes identified from this study, which were health symptoms challenges, TB investigation challenges, personal challenges, healthcare facilities challenges, administration medication challenges, and community challenges.

Conclusions: Understanding the challenges faced by parents of children with TB disease is vital for improving the TB services and providing the required psychosocial support to the children’s family.
Co-Occurrence of Trichotillomania and Polycystic Ovarian Syndrome: A Case Report
Authors: Ismail Ismaliza , Wan Ismail Wan Salwina , Md. Nor Norazirah , Lee Voon Yee , Zainuddin Ani Amelia
Published: November 2020

Trichotillomania (TTM) or hair pulling disorder is characterized by repetitive pulling of hair on the body whereas Polycystic Ovarian Syndrome (PCOS) is a metabolic-endocrine disorder, manifested by irregular menstrual cycle and clinical hyperandrogenism. Both disorders commonly occur in young females. TTM and PCOS may be related and share the same pathophysiology. We reported a case of a teenager with TTM and PCOS, which were triggered by stress. Neurobiological mechanism may explain the co-occurrences between TTM and PCOS. Further research in the neurobiology of TTM and PCOS may better explain the cooccurrences between the two disorders.
MARKOV CHAIN ANALYSIS, METODE ALTERNATIF DALAM MENGUKUR TINGKAT ELEKTABILITAS PESERTA PEMILU MELALUI TAGAR: STUDI KASUS PEMILIHAN PRESIDEN INDONESIA TAHUN 2019
Authors: Durrah Fara Inka , Anwar Samsul , Siregar Latifah Rahayu
Published: November 2020

Tingkat elektabilitas merupakan informasi yang sangat penting bagi peserta pemilihan umum (pemilu) baik calon legislatif maupun eksekutif. Selama ini, elektabilitas seorang kandidat diukur melalui survei yang dilakukan beberapa waktu sebelum masa tenang pemilihan. Selain membutuhkan biaya yang besar, terdapat rentang waktu antara survei dengan hari pemungutan suara sehingga hasilnya berpotensi bias. Oleh karena itu, dibutuhkan sebuah metode alternatif yang dapat digunakan sebagai pembanding dari hasil survei elektabilitas. Penelitian dengan memanfaatkan informasi melalui media sosial menjadi semakin relevan seiring dengan semakin banyaknya pengguna media sosial di Indonesia. Salah satu pendekatan yang cukup menjanjikan dalam mengukur elektabilitas peserta pemilu dengan memanfaatkan media sosial adalah Markov Chain Analysis (MCA). Selain berbiaya rendah, MCA juga dapat mengukur tingkat elektabilitas pada hari pemungutan suara yang tidak dapat dilakukan melalui survei. Sebagai ilustrasi, penelitian ini mengaplikasikan MCA pada pemilihan presiden (pilpres) 2019. Penelitian ini bertujuan untuk mengukur tingkat elektabilitas terhadap kedua pasangan calon di media sosial melalui tagar utama pendukung masing-masing paslon (#2019tetapjokowi dan #2019gantipresiden). Hasil penelitian menunjukkan bahwa pada hari pemungutan suara, diprediksi jumlah penyebutan #2019gantipresiden di media sosial akan lebih banyak daripada #2019tetapjokowi. Meskipun berbeda dengan hasil perhitungan resmi pada pilpres 2019, metode MCA merupakan metode alternatif berbiaya rendah yang berpotensi dikembangkan untuk mengukur tingkat elektabilitas peserta pemilu pada masa yang akan datang. Pemilihan dan penambahan tagar yang representatif merupakan kunci penting dalam meningkatkan akurasi hasil analisis MCA.
Ranks, Subdegrees and Suborbital graphs of the product action of Affine Groups
Authors: Agwanda Siahi Maxwell , Kimani Patrick , Kamuti Ireri
Published: November 2020

The action of affine groups on Galois field has been studied.  For instance,  studied the action of on Galois field for  a power of prime.  In this paper, the rank and subdegree of the direct product of affine groups over Galois field acting on the cartesian product of Galois field is determined. The application of the definition of the product action is used to achieve this. The ranks and subdegrees are used in determination of suborbital graph, the non-trivial suborbital graphs that correspond to this action have been constructed using Sims procedure and were found to have a girth of 0, 3, 4 and 6.
Effect of Social Capital on Firm Performance: An Empirical Study of Small Enterprises in Sri Lanka
Authors: Lakse Mudiyanselage Chandralatha Subasinghe Menike
Published: November 2020

The purpose of this study is to examine the impact of social capital on the performance of Small Enterprises (SEs) in an emerging economy, Sri Lanka. The study adopts a survey design and cross-sectional data collected by administering 200 questionnaires conducting face to face interviews. The social capital was measured by three dimensions namely, structural, relational, and conative social capital. The data were analyzed using Partial Least Squares-Structural Equation Modelling. The results show that structural and cognitive social capital had a positive significant impact on the performance of SEs while relational social capital had demonstrated a negative statistically significant impact on the performance of SEs. This implies that the managers of SEs emphasize the social capital as a means to a source of finance and resources and access to business and market information by maintaining close ties with the stakeholders to achieve a competitive advantage. The findings will be useful for the owners/managers of SEs who should share their knowledge, opportunities, and resources with their suppliers, customers as well as employees of the organization such that they should try to share their goals and achieve success together with parties who are related and interested in the business.
AD946 and AF371 antibodies recognize a His-tagged recombinant protein by immunofluorescence
Authors: Lima Wanessa C , Cosson Pierre
Published: November 2020

AD946 and AF371 antibodies against the His tag recognize a His-tagged human TAC protein by immunofluorescence in paraformaldehyde-fixed HeLa cells.
RB155, RB156 and RB189 antibodies recognize a peptide from the D. discoideum Tsg101 protein by ELISA
Authors: Gerstenmaier Lilli , Hagedorn Monica
Published: November 2020

The recombinant antibodies RB155, RB156 and RB189 detect by ELISA a fragment of the D. discoideum Tsg101 fused to a GST protein.
AI334 and AQ806 antibodies recognize the spike S protein from SARS-CoV-2 by immunofluorescence
Authors: Marchetti Anna , Hammel Philippe
Published: November 2020

The recombinant antibodies AI334 and AQ806 detect by immunofluorescence the spike S protein from SARS-CoV-2.
The RB596 antibody recognizes a linear epitope from the spike S protein from SARS-CoV-2
Authors: Farrera-Soler Lluc , Daguer Jean-Pierre , Barluenga Sofia , Winssinger Nicolas
Published: November 2020

The recombinant antibody RB596 recognizes a linear epitope (residues 973-984, ISSVLNDILSRL) from the SARS-CoV-2 spike S protein.
Monoclonal antibodies RB139 and RB142 recognize citrullinated LL37 by immunofluorescence in histological sections in Systemic lupus erythematosus (SLE) and Rheumatoid arthritis (RA)
Authors: Lande Roberto , Alivernini Stefano , Tolusso Barbara , Spadaro Francesca , Falchi Mario , Palazzo Raffaella , Pietraforte Immacolata , Chizzolini Carlo , Giannakakis Kostantino , Spinelli Francesca Romana , Alessandri Cristiano , Conti Fabrizio , Gremese Elisa , Frasca Loredana
Published: November 2020

LL37 is a natural antibiotic, but is also a molecule with pleiotropic functions as well as an immune-modulator. LL37 is produced by epithelial cells and is present in neutrophils’ granules. LL37 alone, or in complex with DNA, can activate inflammatory pathways in psoriasis, systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). In this work, we describe the capacity of two recombinant monoclonal antibodies, RB139 and RB142, previously shown to specifically recognize LL37 in its citrullinated form (cit-LL37) by ELISA, to detect LL37 by immunofluorescence in human inflamed tissues derived from SLE and RA patients. Such antibodies represent previously unavailable tools to detect the presence, the citrullinated state and the exact localization of cit-LL37 in human tissues in health and disease.
ANALIZA PROPADA NAPONA U POJEDINIM TAČKAMA PRENOSNE MREŽE SRBIJE
Authors: Hrubenja Miron
Published: November 2020

U ovom radu se razmatraju propadi napona prilikom simulacije kvara na različitim udaljenos­tima. Rezultate simulacije upoređujemo sa rezultatima realnih merenja. Cilj je da se rezultati simulacije na približno istoj udaljenosti mesta kvara kao i u realnom sistemu što manje razlikuju od merenja u realnom sistemu. Razmatranja su izvršena na osnovu realnih snimaka uređajem mikroprocesorske zaštite SIPROTEC 47SA611, dok su rezultati simulacije dobijeni na osnovu modela dalekovoda modelovanog u programskom paketu MATLAB.
UPOREDNA ANALIZA ALATA ZA UPRAVLJANJE API-JIMA
Authors: Krivokapić Marija
Published: November 2020

Ovај rad se bavi uporednom analizom sledeća tri alata: Akana, Apigee i 3Scale. Osnovnih 6 koraka koji su sastavni deo životnog ciklusa jednog API-ja je odrađeno u svakom od navedena 3 alata, ne bi li se utvrdilo koji je najlakši za upotrebu i koji pruža najviše mogućnosti.
NAMJENSKI JEZIK I OKRUŽENJE ZA MODELOVANJE GREŠAKA U PROIZVODNIM PROCESIMA I GENERISANJE DOKUMENTACIJE FMEA
Authors: Ivanišević Đorđije
Published: November 2020

U industriji se trenutno događa četvrta revolucija čiji cilj je da upotrebom savremenih tehnologija odgovori na zahtjeve tržišta za brzom adaptacijom proizvoda, a posljedično i procesa proizvodnje. U situaciji kada se proizvodni procesi brzo mijenjaju, mogu se pojaviti greške koje je teško predvidjeti što povećava cijenu troškova proizvodnje. U ovom radu predstavljeni su namjenski jezik i okruženje za modelovanje grešaka u proizvodnim procesima, koji bi mogli uticati na povećanje stepena automatizacije i smanjenje cijene troškova proizvodnje. Na osnovu modela proizvodnih procesa koji su rezultat upotrebe predloženog namjenskog jezika moguće je automatski generisati dokumentaciju FMEA i time skratiti vrijeme potrebno za ručno pisanje dokumentacije i smanjiti broj grešaka koji se u takvom procesu javlja.
Geometrical Representation of Gas Properties
Authors:   Department of Chemistry, International Hellenic University, 65404 Kavala, Greece, Kosheleva Ramonna , Kyzas George , Mitropoulos Athanasios
Published: November 2020

The perfect gas equation, laws, principles and processes as well as the van der Waals equation for real gases are represented geometrically. Intensive and extensive properties and the standard temperature and pressure (STP) condition are shown too. Plane geometry offers a supplementary method to the piston formulation for explaining and visualizing gas properties. Several difficulties and misconceptions of students may thus be resolved.
Failure Characteristics and Stability Control of Roadway Surrounding Rocks under Different Lateral Pressure Coefficients
Authors:   Key Laboratory of Safe and Effective Coal Mining, Ministry of Education, Anhui University of Science and Technology, Huainan 232001, China, Chen Zhiyu , Yin Zhiqiang , Chang Jucai , Shi Wenbao , Peng Xingqiu
Published: November 2020

The stability control of mining roadways is crucial in ensuring the safe and efficient mining of deep coal resources. Given the effect of mining stress on the working face, the support scheme of such roadways, which is designed based on the original in-situ stress parameters, often presents support-related problems. A mining roadway on the 1131 working face of Zhujidong Coal Mine in the Huainan mining area, China was taken as the engineering background of this study. To explore the influence of mining stress on the stability control of this roadway, the 2-dimensional (2D) Particle Flow Code (PFC) numerical simulation software was used to perform a simulation study on the stress distribution characteristics and deformation failure laws of the surrounding rocks under the change in the roadway lateral pressure coefficient caused by the mining stress. An improved support scheme that considers the influence of varying lateral pressure coefficient on the mining roadway was then proposed. Results show that when the lateral pressure coefficient increased from 1 to 1.4, the maximum principal stress (61.2 MPa) is observed at 2.9 m inside the roof of the surrounding rocks in the roadway. When the lateral pressure coefficient decreases from 1 to 0.4, the maximum principal stress (46.2 MPa) is observed at 2.2 m inside the surrounding rock of sidewalls of the roadway, and failure occurs. These findings suggest that the deformation and failure of surrounding rocks are affected regardless of the lateral pressure coefficient increase or decrease. On this basis, the lengths of the anchor bolts in the roof and sidewalls in the original support method are increased from 2,200 mm to 3,000 mm and 2,500 mm, respectively. The field monitoring results indicate that the improved support method mitigates the deformation and realizes the stability control of the roadway surrounding rocks. The findings of this study could provide a scientific basis for the parameter design of roadway support.
Analysis of Stiffness Reduction Coefficient of Conventionally Reinforced Concrete Coupling Beams on the Bias of Strut-and-Tie Model
Authors:   College of Civil Engineering, Hunan City University, Yiyang 413000, China, Hu Zhangqi , Lv Weirong , Wu Yusheng , Zhang Miao
Published: November 2020

Stiffness reduction coefficient of coupling beams (κ) can reflect the stiffness degradation degree at yield and significantly affect the seismic response and the internal force distribution. However, existing calculation methods do not consider the influencing factors comprehensively and have a limited application scope. To effectively predict the stiffness reduction coefficient of conventionally reinforced concrete coupling beams (CCBs), a simplified analysis model was established, and analysis and parameter modification were also implemented. Then, an equation with comprehensive consideration, wide application, and high accuracy was proposed. The proposed equation was verified by comparison with existing test data and calculation methods, and parametric analysis was performed to investigate the independent factors, including the span–depth ratio, longitudinal reinforcement ratio, stirrup ratio and concrete compressive strength. Results show that the independent factors are related to each other, and the span–depth ratio has the greatest influence on the stiffness reduction coefficient of CCBs. Furthermore, κ significantly increases with the longitudinal reinforcement ratio when the coupling beam has a large span–depth ratio, but the stirrup ratio has a bigger role when the span-depth ratio is small. Finally, on the basis of the analysis results, suggestions are made to improve the stiffness reduction coefficient of CCBs. The study results provide a reference for the design and optimization of shear wall and core tube structures.
Millisecond-delay Intervals in Horizontal Layering Bench Blasting Based on the Evaluation Model of the Entropy Weight Method
Authors:   Shool of Civil & Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China, Zuoming Yin , Desheng Wang , Xinghai Zhang , Xuguang Wang , Zhiheng Dang
Published: November 2020

Millisecond-delay blasting in an open pit is difficult because the development of rock mass horizontal layering and mechanical properties vary widely among rocks. An unreasonable delay time for varied holes and rows often causes poor blasting effects. In this study, the multi-layer rock blasting model in the ANSYS/LS-DYNA software is used to optimize the delay time between holes and rows, improve the blasting effect, and reduce the vibration produced by blasting. The delay time for varied holes and rows is simulated. In line with the evaluation model of the entropy weight method, the maximum effective stress in the three sections is analyzed. The weight coefficient of each index is determined with entropy information theory, and a rock damage model is established. The ratio between the maximum tangential stress of the surrounding rock and the uniaxial compressive strength of the rock and the ratio of the uniaxial compressive strength of the rock to its tensile strength are selected as evaluation indicators. The maximum effective stress in the three sections at different positions between holes and rows is determined and analyzed. The test indicates that the delay time combination of 28 and 100 ms is effective and can avoid the interference of various geological conditions on the blasting effect. In accordance with the evaluation results, this delay time combination is used for field tests. Results demonstrate that the blasting effect of the selected delay time combination is remarkably enhanced, the boulder frequency is low, and the vibration caused by blasting is reduced by 30%. In special geological conditions where the mechanical properties of rocks differ greatly, the evaluation model of the entropy weight method presents crucial advantages in the precise selection of millisecond-delay intervals for horizontal layering bench blasting.
Optimal Supervisory Control of Two Phases Intersection Using Hybrid-based Model Approach
Authors:   Department of Automatic, University of Sidi Bel-Abbes, BP 89, 22000, Sidi Bel-Abbes, Algeria., Tolbi Bilal
Published: November 2020

In the present paper, a hybrid approach that combines modular modelling and Timed Petri Nets model is proposed, the main interest of this combination is to ensure optimal supervisory control of urban traffic flows in two phases intersections of medium-sized cities. Each intersection is considered as a multi-agent system, composed of all agents who represent all physical spaces. The behaviours of interconnected agents are supervised by the Timed Petri Nets model that controls the traffic light cycles according to an optimal timing plan defined by the Continuous Genetic Algorithm. A real two phases intersection in Sidi Bel-Abbes City is presented as an example. The proposed timing plan is compared with the current one using SUMO software for the most important objective functions. Also, the proposed model's behaviour is compared with TSIS-CORSIM software's model, and all obtained experiments results show the effectiveness of the approach and its possibility to be extended and applied to a many-phases intersection.
Design of a 1 t/h Biomass Chain Boiler and ιts Fuel Adaptability Analysis
Authors:   School of Mechanical and Electrical Engineering, Henan Institute of Science and Technology, Xinxiang 453003, China, Chengguo Fu , Yipeng Feng , Yishui Tian , Mingchao Liang , Zhengchuan Zhang
Published: November 2020

The arch is an important component of a biomass boiler. Initial arch design of most boilers is generally gained through manual computation, thus resulting in uncertain reasonability of flue gas flow. Moreover, biomass fuels in the market have instable characteristics, which influence the utilization of biomass energies considerably. To address the problems concerning reasonable flue gas flow caused by the collaborative design of arch and air staging and the combustion adaptability of fuels, a cold modeling experiment of a 1 t/h biomass boiler under different staged air distribution ratios when the rear arch coverage varies was conducted using Fluent software in this study after thermal performance computation and initial structural design of grate and furnace. Furthermore, a boiler performance test based on main fuels and a combustion adaptation test of auxiliary fuels were also performed. The experiments show that the best flue gas flow in the furnace is achieved when the rear arch coverage is 60% and the primary–secondary air distribution ratio is 4:6. The mean boiler efficiency and the mean boiler heat output are 81.26% and 715.76 kW/h by using Pinus koraiensis pellets, wood–straw mixed pellets, and cotton straw briquettes as main fuels; and the tested pollutant emissions are in compliance with the limits of the national standard. The results of the combustion adaptation test reveal that the excessive particle size, the high ash content and the relatively low calorific value of biomass molded fuels are all against the combustion of biomass boilers. Fuel upgrading based on washing process and other methods is suggested. This study can provide references to the performance optimization of traditional small-scale biomass chain heating boilers.
Theoretical and Numerical Study of Shear Strength of Concrete Material
Authors:   School of Civil Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China, Jun Liu , Yuzhou Xiang , Yucheng Xiong , zusong Wu , Chuan He
Published: November 2020

The shear strength of some concrete materials should be analyzed based on elastic-plastic theory in petroleum, water conservancy, tunnel engineering, and so on. The majority of researches concentrate mainly on the tensile and compressive strength of concretes, but few have studied the shear strength. Concrete materials have been increasingly applied broadly to geotechnical engineering. Thus, investigating the shear strength characteristics of concretes is of great importance. To study the characteristics of shear strength of concrete materials, the theoretical relationship between concrete’s compressive and shear strengths was discussed in the uniaxial, biaxial, and triaxial stress states. The concrete strength envelopes under the biaxial and uniaxial compressive strength were studied. Given the concrete shear strength, the overload method and the finite difference software FLAC3D were used to investigate the concrete failure modes and ultimate bearing capacities. Results show that the theoretical formula under the 3D stress-bearing condition is only applicable to the circumstance with equal compressive strengths under the biaxial and uniaxial conditions, which conforms to 3D Mohr’s circle theory. 3D Mohr’s circle theory is not totally applicable to concrete materials where the concrete compressive strength under the biaxial condition is larger than that under the uniaxial condition. Concrete material gains its shear strength 47 percent from its frictional force while the rest form cohesive force. The study results can provide a certain basis and reference for analyzing the shear strength characteristics of concrete materials.
Experiencia inicial en Buenos Aires con la cirugía transoral robótica (TORS)
Authors:   Hospital Italiano de Buenos Aires. Argentina, Busto Eduardo , Patrucco Marta
Published: November 2020

Background: robotic surgery is an alternative to open surgery, CO2 laser microsurgery, or chemoradiation for the upper aero-digestive tract. This system allows surgeons to use the open surgical technique in a minimally invasive approach through the mouth to treat benign and malignant disorders. Different treatments are currently used with similar oncologic outcomes. Objective: the aim of this study was to introduce a surgical tool through transoral approach, report the initial experience with the use of the robotic system, evaluate respiratory and digestive functional preservation and analyze the variables associated with shorter hospital length of stay. Material and methods: A total of 24 patients (13 women and 11 men, mean age 55.08 years [16-82]) were included. Eight patients had chronic inflammatory disease, four had benign tumors and 12 had cancer. The variables considered in robotic surgery were hospital length of stay, place of postoperative care, complications, respiratory and swallowing function and use of reconstructive techniques. Flexible endoscopic evaluation of swallowing was performed to document safe function. Results: mean length of stay was 1.92 days; 83.3% stayed for one day; 79.9% were admitted to the general ward and 20.1% stayed in intensive or intermediate care units. None of the patients required tracheostomy. Healing of the surgical bed occurred by secondary intention. There were no complications. Tongue edema occurred in two patients. Conclusions: robotic surgery favors tumor removal with low morbidity and maximum preservation of healthy tissues while reducing postoperative edema, use of flaps for reconstruction, temporary tracheostomy and hospital length of stay. Flexible endoscopic evaluation of swallowing is useful to determine safe swallowing function. The main limitation of our study is the sample size. It is important to increase the number of patients to evaluate survival and quality of life.
Reducción de la exposición en residentes de Cirugía frente al brote de COVID-19
Authors:   Servicio de Cirugía General Hospital Universitario Austral. Buenos Aires. Argentina, Morales Agustín , Achával Mora , López Meyer Juan Cruz , Vega Carla , Faillace Gerónimo , Iudica Guadalupe , Verde Ezequiel , Chwat Carina
Published: November 2020

The worldwide outbreak of COVID-19 during the first quarter of 2020 constitutes an unprecedented challenge for the health system. The aim is to describe the strategies adopted by residents of General Surgery of a university hospital of Argentina, to safeguard the health of residents, reduce the risk of exposure of surgical patients, maintain continuous academic training and promote teamwork. Minimize resident exposure by dividing the group into two teams that work by fortnights; divide activities, hours within hospital, and shifts equally among residents; use telemedicine for postoperative / ambulatory controls; suspend office activity; organize daily online classes and reviews of published articles. In the context of the COVID-19 pandemic, all means should be used to minimize the risk of exposure in order to optimize human resources. Although these strategies can easily be applied to other residencies, more research is needed to assess their impact on disease transmission, and on the physical and emotional health of health professionals
A finite-element algorithm for Stokes flow through oil and gas production tubing of uniform diameter
Authors: Akanji Lateef T. , Chidamoio Joao
Published: November 2020

Stokes flow of a Newtonian fluid through oil and gas production tubing of uniform diameter is studied. Using a direct simulation on computer-aided design of discretised conduits, velocity profiles with gravitational effect and pressure fields are obtained for production tubing of different inner but uniform diameter. The results obtained with this new technique are compared with the integrated form of the Hagen–Poiseuille equation (i.e., lubrication approximation) and data obtained from experimental and numerical studies for flow in vertical pipes. Good agreement is found in the creeping flow regime between the computed and measured pressure fields with a coefficient of correlation of 0.97. Further, computed velocity field was benchmarked againstANSYS Fluent; a finite element commercial software package, in a single-phase flow simulation using the axial velocity profile computed at predefined locations along the geometric domains. This method offers an improved solution approach over other existing methods both in terms of computational speed and accuracy.
Productivity analysis for a horizontal well with multiple reorientation fractures in an anisotropic reservoir
Authors: Wang Mingxian , Fan Zifei , Zhao Lun , Xing Guoqiang , Zhao Wenqi , Tan Chengqian
Published: November 2020

Reorientation fractures may be formed in soft and shallow formations during fracturing stimulation and then affect well productivity. The principal focus of this study is on the productivity analysis for a horizontal well with multiple reorientation fractures in an anisotropic reservoir. Combining the nodal analysis technique and fracture-wing method, a semi-analytical model for a horizontal well with multiple finite-conductivity reorientation fractures was established to calculate its dimensionless productivity index and derivative for production evaluation. A classic case in the literature was selected to verify the accuracy of our semi-analytical solution and the verification indicates this new solution is reliable. Results show that for a fixed fracture configuration the dimensionless productivity index of the proposed model first goes up and then remains constant with the increase of fracture conductivity, and optimal fracture conductivity can be determined on derivative curves. Strong permeability anisotropy is a negative factor for well production and the productivity index gradually decreases with the increase of anisotropic factor. As principal fracture angle goes up, horizontal well’s productivity index increases correspondingly. However, the effect of reoriented fracture angle on the productivity index is not as strong as that of principal fracture angle. When reoriented fracture angle is smaller than principal fracture angle, reoriented factor should be as low as possible to achieve optimal productivity index. Meanwhile, well productivity index rises up with the increase of fracture number and fracture spacing, but the horizontal well has optimal reorientation fracture number and fracture spacing to get the economical productivity. Furthermore, the influence of the rotation of one central reorientation fracture on productivity index is weaker than that caused by the rotation of one external reorientation fracture. In addition, the asymmetrical distribution of one or more reorientation fractures slightly affects the productivity index when fracture conductivity is high enough.
COGNITIVE LEARNING TASKS IN VIRTUAL TEAMS
Authors:   Kyiv National Economic University named after Vadym Hetman, Zhukova Liliana
Published: November 2020

The article is devoted to problems of cognitive learning in virtual teams – a new model of Union competences, the development of which is entirely due to the development of technologies in the field of Hi-Tech and Hi-Hume. The purpose of the article is to identify the specifics of cognitive training in virtual teams, as well as to formulate its tasks.
REGULATORY AND LEGAL SUPPORT OF INFORMATION SECURITY IN UKRAINE
Authors:   Lviv University of Business and Law, Malashko Oleksandr , Yesimov Serhii ,   Lviv State University of Internal Affairs
Published: November 2020

The article examines trends in the development of legal regulation of information security in Ukraine in the context of the implementation of the Association Agreement between Ukraine and the European Union. The current information legislation and regulations on information security are analyzed. The tendencies in the legal regulation of information security that took place at the initial stage of the formation of information legislation are revealed. Based on the factors that took place before the adoption of the Doctrine of information security of Ukraine, the laws of Ukraine “On the basic principles of ensuring the cybersecurity of Ukraine”, “On the national security of Ukraine”, in the context of the current legislation, based on the methodology of legal forecasting, it is concluded that in the future the development of normative legal information security will be developed on the basis of by-laws, mainly at the departmental level.
CONTENT OF STATE ACTIVITIES TO ENSURE INFORMATION SECURITY
Authors:   Lviv University of Business and Law, Malashko Oleksandr , Yesimov Serhii ,   Lviv State University of Internal Affairs
Published: November 2020

In the article, in the theoretical and applied aspect, the content of state activities to ensure information security is considered. The analysis of the regulatory and legal framework of the information security system of Ukraine, the structure of public authorities involved in this activity in the context of the state information policy is carried out. On the basis of the Doctrine of Information Security of Ukraine, considered the main aspects of the activities of the Verkhovna Rada of Ukraine, the President of Ukraine, the Cabinet of Ministers of Ukraine, the Ministry of Digital Transformation of Ukraine, the Security Service of Ukraine, the State Special Service for Special Communications and Information Protection of Ukraine and other central executive bodies for the development and improvement of regulatory-legal base and practical implementation of measures aimed at ensuring information security. It is noted that in order to ensure the effective functioning of the information security system of Ukraine, it is necessary to increase the efficiency of the work of structural units for the protection of information in public authorities, organizations and enterprises, which will lead to the optimization of the work of departmental information security systems and increase the efficiency of the functioning of the information security system of Ukraine.