bluuebunny/crossref_metadata_2025 huggingface dataset:
Existence and Uniqueness of Algebraic Closures
Authors: Schwarzweller Christoph
Published: February 2023

This is the second part of a two-part article formalizing existence and uniqueness of algebraic closures, using the Mizar [2], [1] formalism. Our proof follows Artin’s classical one as presented by Lang in [3]. In the first part we proved that for a given field F there exists a field extension E such that every non-constant polynomial p ∈ F [X] has a root in E. Artin’s proof applies Kronecker’s construction to each polynomial p ∈ F [X]\F simultaneously. To do so we needed the polynomial ring F [X
1, X
2, ...] with infinitely many variables, one for each polynomal p ∈ F [X]\F. The desired field extension E then is F [X
1, X
2, …]\I, where I is a maximal ideal generated by all non-constant polynomials p ∈ F [X]. Note, that to show that I is maximal Zorn’s lemma has to be applied.

In this second part this construction is iterated giving an infinite sequence of fields, whose union establishes a field extension A of F, in which every non-constant polynomial p ∈ A[X] has a root. The field of algebraic elements of A then is an algebraic closure of F. To prove uniqueness of algebraic closures, e.g. that two algebraic closures of F are isomorphic over F, the technique of extending monomorphisms is applied: a monomorphism F → A, where A is an algebraic closure of F can be extended to a monomorphism E → A, where E is any algebraic extension of F. In case that E is algebraically closed this monomorphism is an isomorphism. Note that the existence of the extended monomorphism again relies on Zorn’s lemma.
Qualitative Study of the Practices Used in the Implementation of the Quality Management System Within Moroccan Companies
Authors: Fath Khadija , Haddouch Hajar , Bouksour Otmane , Beidouri Zitouni
Published: February 2023

The objective of this article is to show that project management practices present key success factors for implemented a Quality Management System (QMS) in Moroccan companies. In general, the organizations seem to look at the implementation of a quality management system as a project and they employ standard project management tools, albeit to a different extent and in different ways. Following a qualitative study in Morocco, the companies, whatever their sector of activity and size, use different practices in the framework of the project QMS. Information was collected from practicing managers. The data analysis shows that project management practices present a great opportunity for the successful implementation of QMS within Moroccan companies.
Social Capital and Digital Transformation of Startups in Vietnam During the Covid-19 Pandemic: The Mediating Role of Human Capital and Access to Resources
Authors: Nguyen Thi Thuy Quynh , Tran Nha Ghi , Nguyen Tan Trung
Published: February 2023

Based on social network theory, the study explained the digital transformation process of startups in Vietnam during the outbreak of the COVID-19 pandemic. The study examined the relationship between social capital, human capital, access to resources, and digital transformation of startups in Vietnam. The study used Partial Least Squares - Structural Equation Modelling (PLS-SEM) with a sample size of 230 startups managers. The results show that there are positive and statistically significant relationships between social capital, human capital, access to resources, and digital transformation. The results also reveal the partial mediating roles of access to resources and human capital in the relationship between social capital and digital transformation. The results proposed some managerial implications for startups managers in building relationship networks with stakeholders such as government agencies and business partners (customers, competitors, suppliers, and providers of digital platform services). Through managers' social capital, accessible resources and the improvement of human capital have accelerated digital transformation for startups to escape the crisis of the COVID-19 pandemic. Finally, the study presented some limitations and directions for further research.
Technical Study of the Installation of a Watercress Nectar Processor to Reduce Anemia in Adults
Authors: Manrique-Suarez Luis-Alberto , Ochoa-Sotomayor Nancy-Alejandra , Salazar-Robles Héctor-Gavino , Masías Edward José Flores
Published: February 2023

Peru has a diversity of exotic fruits and plants with recognized yields for food and health protection. Nectars are highly consumed food products, made from fruits or vegetables. The objective for the present work was to carry out the technical study of the installation of a watercress nectar processor to reduce anemia in adults; identify the demand, technical requirements for the operation and profitability of the processing facilities. Methodology. The analytical-synthetic method was used; The population of the target market was analyzed, the size of the sample was determined with the coefficient of variation method, (n = 384), the instrument used was the survey; the technical, economic-financial study was carried out. The results were the growth in the demand for nectars of 59.82%, with respect to the economic-financial evaluation, it has been shown that the results are satisfactory for the installation of the plant, with the economic and financial IRR, both rates proving to be attractive. for the project. From the projected income statement for the 2021-2025 period, it can be deduced that for 2025 there was a net profit of S/316,971.39. Other indicators such as the economic and financial NPV, the B/C ratio and the PRI that were satisfactory for the Project, making its execution viable. The conclusion this study was the technical study for the installation of a nectar processing plant to reduce anemia in adults in Lima, which was viable in terms of operation and profitability, taking advantage of its healing and nutritional properties.
Technology of Obtaining Mixed Alternative Fuel Based on Organic Substances for Mining Technological Transport Engines
Authors: Melnyk Vasyl , Romanyshyn Liubomyr , Mosora Yurii , Kotwica Krzysztof
Published: February 2023

In connection with the increase in the price of fuel based on hydrocarbons, the search and use of alternative types of fuel for machines in the mining and oil production industry is quite relevant today. Most of the existing alternative fuels by themselves cannot be considered as ready-to-use motor fuels. One of the ways to solve this problem is to use their mixtures with commercial fuels in certain ratios. This work deals with the development and research of the main characteristics of the mixer for obtaining mixed fuels based on diesel fuel and soybean oil, as well as the results of the study of the physical and operational properties of the obtained mixtures of different volume ratios of diesel fuel and soybean oil. The process of obtaining a mixed alternative fuel based on diesel fuel and soybean oil was implemented on a developed installation consisting of a mixer, the design of which is protected by a patent of Ukraine, and a gear pump. The study of the characteristics of the mixer as part of the installation showed that at a temperature of the components of the alternative fuel of 20°С, with a loss of full pressure on the mixer Δр ≈ (60-65) kPa, the volume consumption of soybean oil reached 10.7.10-6 m3/s. The time of preparation of the fuel mixture in the amount of 195 liters with a content of soybean oil of 10% ranged from 30 to 33 minutes. As research has shown, mixing soybean oil with diesel fuel in the amount of 5-50% vol. provides an improvement in viscosity-temperature properties and makes it possible to use such mixtures in diesel engines without changes in the design of the power supply system and regulation of fuel equipment, which characterizes soybean oil as a promising additive to diesel fuels to improve their technical and operational performance.
Fatigue Life Testing of the Round Link Mining Chains
Authors: Kandzia Ryszard , Szot Mariusz
Published: February 2023

The material fatigue phenomenon consists of progressive material damage through the appearance and development of fractures under the influence of variable, periodically recurring stresses. Engineers designing machinery and structures to be fatigue resistant can gain useful insights about design and material properties by reviewing the literature. In this way, we can avoid costly research, but in the case of complex loading phenomena and the interaction of components, we must carry out such research. Fatigue strength calculations are less accurate than simple static calculations. The wear of link chains is concentrated in three areas, depending on the installation location and function of the individual links, namely: in the joints (the points of contact between two links), on the outer surfaces of the arches and on the outer surfaces of the straight sections of the links. During operation, chains are particularly vulnerable to wear through abrasion, corrosion and fatigue. These ageing factors, which act with varying intensity depending on the properties of the deposit, determine the service life of the chain, unless other unforeseen damage occurs, e.g. "hard" blockage of the chain. In many cases, users are guided by their own subjective criteria for assessing the technical condition of chains, which does not always lead to fully rational decisions regarding the continued use of used chains. To date, there have been no attempts to transfer the results of chain fatigue tests to behaviour of real objects. This paper presents issues related to mining chain fatigue testing. The test results presented are for both new and used chains. The experimental tests conducted at GIG made it possible to solve the problem of applying fatigue test results in industrial practice.
Physical Activity and Selected Psychological Constructs of Intercultural Students in the Field of Physical Education During the Covid-19 Pandemic
Authors: Samełko Aleksandra , Woycikiewicz Marta de Białynia , Kenioua Mouloud
Published: February 2023

The purpose of the study was to compare anxiety, depression, self-efficacy and mood between students at the Faculty of Physical Education in Poland and Algeria during the Third Wave of the COVID-19 Pandemic, as well as to compare the intensity and quantity physical activity. It was also important to examine relationships between self-efficacy and other psychological variables, and self-efficacy and physical activity in the two groups. The following questionnaires were used to assess psychological constructs, self-efficacy and physical activity level: Mood State Profile (POMS), depression (Beck Depression Inventory), anxiety states (STAI), self-efficacy (GSES), a physical activity questionnaire. The research results show that there where statistically significant differences between Polish and Algerian students in anxiety and mood state. There were also statistically significant differences between the groups in the intensity and quantity physical activity. Based on the results of students’ self-efficacy in relation to states of mood, it turned out that anger and vigour are a significant predictor of a sense of self-efficacy of Algerian student, but among polish students only vigour is a significant predictor of a sense of self-efficacy. The comparative study showed statistically significant differences in each of the mood scales. In data on physical activity during the pandemic, all variables showed statistical significance, but physical activity did not turn out to be a significant predictor of psychological variables in the study. It can be assumed that undertaking increased physical activity is a kind of preventive measure in reducing mood disorders and relieving depressive episodes.
Exploring Perceived Learning Among Students of Sports Sciences in Distance Education
Authors: Savaş Buğra Çağatay , Turan Murat
Published: February 2023

The present study aimed to explore the impacts of e-learning, e-learning attitude in sports, and e-learning satisfaction on perceived learning among students of sports sciences. A total of 371 (108 females, 263 males) undergraduate students of sports sciences participated in this correlational study. The data were collected through a demographic information form, the Online Learning Attitude Scale, the Online Learning Attitude Scale-Sports, the Distance Education Satisfaction Survey, and the Perceived Learning Scale. The data were analyzed using descriptive statistics, SEM, Pearson’s correlation test, and multiple regression analysis. The findings revealed that e-learning attitudes and e-learning satisfaction among the participants had significant effects on their perceived learning (p < .05), while their e-learning attitudes in sports did not yield a significant impact on their perceived learning (p > .05). Accordingly, it may be claimed that as students’ e-learning attitudes and e-learning satisfaction increase, their perceived learning levels also increase. In addition to this, the students did not have a positive attitude toward learning applied courses online; therefore, undergraduate applied courses in sports sciences are better conducted face-to-face.
Synthesis of nanoscale zero-valent iron doped carbonized zeolitic imidazolate framework-8 for methylene blue removal in water
Authors: Chen Shuai , Qiao Lemeng , Feng Xuejiao , Huang Yufu , Gao Guilan , Guan Jie , Lin Donghai
Published: February 2023

Nanoscale zero-valent iron-doped carbonized zeolitic imidazolate framework-8 (nZVI/CZIF-8) was prepared by carbonation of ferric nitrate and ZIF-8 at 800 °C and used as an adsorbent to remove methylene blue (MB) from water. The synthesized nZVI/CZIF-8 has a specific surface area of 806.9 m2/g, a pore volume of 0.86 cm3/g and an nZVI content of 1.35%, respectively. Both the nZVI/CZIF-8 and CZIF-8 have identical functional groups of O-H, C-H and C=C. With the increase of CZIF-8 size, MB removal rate increased. The doping of nZVI increased the MB removal percentage from 74.5% for ZIF-8 to 96.2% within 80 min for nZVI/CZIF-8. The MB removal percentage increased with the dosage of nZVI/CZIF-8. The MB adsorption with the adsorbents conforms to the Freundlich adsorption isothermal model and the removal rate fitted well to a pseudo-first-order model. The results demonstrate the feasibility of synthesizing high active and stable nZVI/CZIF-8 particles.
The platelet to lymphocyte ratio in heart failure: a comprehensive review
Authors: Delcea Caterina , Buzea Cătălin Adrian , Vîjan Ancuța Elena , Bădilă Elisabeta , Dan Gheorghe-Andrei
Published: February 2023

Introduction: At the crossroads of heart failure (HF) and systemic inflammation, platelets and lymphocytes are both influenced as well as actively participating in the bidirectional relationship. The platelet to lymphocyte ratio (PLR) could therefore be a marker of severity. This review aimed to assess the role of PLR in HF.

Methods: We searched the PubMed (MEDLINE) database using the keywords “platelet”, “thrombocyte”, “lymphocyte”, “heart failure”, “cardiomyopathy”, “implantable cardioverter defibrillator”, “cardiac resynchronization therapy” and “heart transplant”.

Results: We identified 320 records. 21 studies were included in this review, with a total of 17,060 patients. PLR was associated with age, HF severity, and comorbidity burden.

Most studies reported the predictive power for all-cause mortality.

Higher PLR was associated with in-hospital and short-term mortality in univariable analysis, however, it was not consistently an independent predictor for this outcome. PLR > 272.9 associated an adjusted HR of 3.22 (95%CI 1.56 – 5.68, p<0.001) for 30-day fatality.

During long-term follow-up from 6 months to 5 years, PLR was an independent predictor of mortality in most studies, with cut-off values ranging from > 150 to > 194.97 and adjusted HR from 1.47 (95%CI 1.06 – 2.03, p=0.019) to 5.65 (95%CI 2.47–12.96, p<0.001).

PLR > 173.09 had an adjusted OR 2.89 (95%CI 1.17–7.09, p=0.021) for predicting response to cardiac resynchronization therapy. PLR was not associated with outcomes after cardiac transplant or implantable cardioverter-defibrillator.

Conclusion: Increased PLR could be an auxiliary biomarker of severity and survival prognosis in HF patients.
Wildervanck syndrome: Case report
Authors: Radulescu Luminita , Martu Alexandra , Astefanei Oana , Cozma Sebastian , Martu Cristian
Published: February 2023

BACKGROUND. Wildervanck syndrome was described for the first time in 1952. This rare entity is composed by the oculo-cervico-acoustic triad, which may be more or less complete.

MATERIAL AND METHODS. We present a 5-year-old girl diagnosed with Wildervanck syndrome, exhibiting: Klippel-Feil anomaly (fused cervical vertebrae), Duane Stilling Turk syndrome (bilateral abducens palsy) and congenital bilateral cophosis indicated by ABR.

RESULTS. The CT scan revealed major malformations of the brain and calvarium including the petrous part of both temporal bones. Despite all these brain malformations, the psychological development of the child was nearly normal. As it was previously reported in other cases, the child also presented spina bifida cervicalis and cleft palate. The cause of deafness was bilateral lack of cochleae, making impossible the insertion of the cochlear electrode for hearing rehabilitation. When the patients are discovered late (after 3 years of age), the management of hearing loss is by being taught sign language and lip reading.

CONCLUSION. Any cranio-facial malformation and any delay in speech production impose early attention of the otorhinolaryngologist or audiologist for timely diagnosis and rehabilitation of hearing loss. The imaging examination, especially the high-resolution temporal bone CT-scan, is of paramount importance to be performed in all profound congenital deaf children to evaluate the candidacy to cochlear implantation.
FAKTOR-FAKTOR PEMBENTUK PURCHASE INTENTION PRODUK OTOMOTIF "X"
Authors: Darren Christofen Michael , Tunjungsari Hetty Karunia
Published: February 2023

Produk otomotif merupakan salah satu produk yang mengalami dampak pada masa pandemi COVID-19. Penurunan produktivitas penjualan produk otomotif di Indonesia bahkan telah mendorong pemerintah untuk menetapkan kebijakan khusus terkait pajak pembelian kendaraan bermotor baru di Indonesia. Terlepas dari situasi pandemi, pada dasarnya pemasar produk otomotif tetap perlu mengetahui faktor-faktor yang mendorong pembelian produknya. Tujuan penelitian ini adalah untuk menguji faktor-faktor yang diduga membentuk purchase intention produk otomotif, meliputi brand experience, brand image, brand trust dan brand attachment. Sampel penelitian ini terdiri dari konsumen otomotif merek X yang berada di wilayah Jakarta. Terdapat sebanyak 200 responden yang berpartisipasi dalam survey online yang disebarkan melalui google form. Data yang diperoleh kemudian diolah dengan menggunakan software SMARTPLS3. Hasil penelitian menunjukkan bahwa terdapat pengaruh yang signifikan secara statistik dari brand experience, brand image, brand trust, dan brand attachment pada purchase intention produk otomotif X. Implikasi hasil penelitian secara teoretis dapat memperluas pengetahuan terkait intensi pembelian produk otomotif. Secara praktis, hasil penelitian dapat menjadi masukan bagi produsen produk otomotif dalam menyusun strategi untuk dapat meningkatkan intensi pembelian konsumen.
 
Automotive products are one of the products that have experienced an impact during the COVID-19 pandemic. The decline in sales productivity of automotive products in Indonesia has even prompted the government to establish a special policy regarding the tax on the purchase of new motor vehicles in Indonesia. Apart from the pandemic situation, basically, automotive product marketers still need to know the factors that encourage the purchase of their products. The purpose of this study is to examine the factors that are thought to shape the purchase intention of automotive products, including brand experience, brand image, brand trust and brand attachment. The sample of this study consisted of automotive consumers with the X brand in the Jakarta area. There were as many as 200 respondents who participated in an online survey distributed via google form. The data obtained was then processed using SMARTPLS3 software. The results showed that there was a statistically significant effect of brand experience, brand image, brand trust and brand attachment on purchase intentions of X automotive products. The theoretical implications of the research results can expand knowledge related to factors affecting purchase intentions of automotive products. Practically, the research results can give suggestions for automotive product manufacturers in formulating strategies to escalate consumers' purchase intentions.
PERAN PASSION WIRAUSAHA, PENGETAHUAN KEWIRAUSAHAAN DAN LINGKUNGAN KELUARGA DALAM MENUMBUHKAN INTENSI KEWIRAUSAHAAN
Authors: Livandy Gabriel , Nuringsih Kartika
Published: February 2023

Seiring dengan program pembelajaran kewirausahaan, tujuan penelitian untuk menguji pengaruh passion wirausaha, pengetahuan kewirausahaan dan lingkungan keluarga terhadap intensi berwirausaha mahasiswa Fakultas Ekonomi dan Bisnis di Universitas Tarumanagara, Jakarta. Desain penelitian menggunakan pendekatan deskriptif dan kuantitatif dengan jumlah sampel 310 responden. Metode analisis menggunakan regresi struktural dengan pengolahan data menggunakan Smart-PLS. Hasil menunjukkan ketiga hipotesis diterima yaitu passion wirausaha, pengetahuan kewirausahaan dan lingkungan keluarga berpengaruh positif signifikan terhadap intensi mahasiswa dalam aktivitas kewirausahaan. Ketiganya memiliki kontribusi terhadap pembentukan atau peningkatan intensi mahasiswa dalam kewirausahaan sehingga implementasi selanjutnya dapat dilakukan melalui program Merdeka Belajar Kampus Merdeka (MBKM) agar mahasiswa memiliki wawasan serta makin tertarik mengembangkan aktivitas atau rintisan bisnisnya menjadi aktivitas kewirausahaan secara berkelanjutan.
 
Along with the entrepreneurship learning program, the research objective was to examine the effect of entrepreneurial passion, entrepreneurial knowledge and family environment on the entrepreneurial intentions of students of the Faculty of Economics and Business at Tarumanagara University, Jakarta. The research design used a descriptive and quantitative approach with a sample size of 310 respondents. The analysis method uses structural regression with data processing using Smart-PLS. The results show that the three hypotheses are accepted, namely entrepreneurial passion, entrepreneurial knowledge and family environment, which have a significant positive effect on students' intentions in entrepreneurial activities. All three have contributed to the formation or improvement of student intentions in entrepreneurship so that further implementation can be carried out through the Merdeka Belajar Kampus Merdeka (MBKM) program so that students have insight and are more interested in developing their activities or business startups into sustainable entrepreneurial activities.
PENGARUH EFIKASI DIRI DAN PERILAKU KEWARGAAN ORGANISASIONAL TERHADAP STRES KERJA DENGAN WELL-BEING SEBAGAI VARIABEL MEDIASI
Authors: Ie Mei , Henny Henny
Published: February 2023

Beberapa penelitian menunjukkan bahwa sebagian besar karyawan menghadapi stres yang cukup tinggi dalam menjalankan pekerjaannya. Stres yang tinggi dapat mengakibatkan kesulitan untuk fokus terhadap pekerjaannya. Tujuan penelitian ini adalah untuk mengetahui pengaruh efikasi diri, perilaku kewargaan organisasional, dan well-being terhadap stres kerja. Purposive sampling digunakan sebagai teknik pengambilan sampel yang digunakan dalam penelitian ini. Sampel penelitian adalah sebanyak enam puluh dua orang karyawan pada beberapa perusahaan swasta di Jakarta Barat. Data penelitian diolah dengan menggunakan SmartPLS. Hasil penelitian yang didapat menunjukkan efikasi diri tidak memiliki pengaruh terhadap stres kerja, perilaku kewargaan organisasional memiliki pengaruh negatif dan signifikan terhadap stres kerja, well-being memiliki pengaruh negatif dan signifikan terhadap stres kerja. Selain itu dapat disimpulkan juga bahwa well-being tidak memberikan pengaruh dalam memediasi pengaruh efikasi diri terhadap stres kerja serta well-being memberikan pengaruh yang signifikan dalam memediasi pengaruh perilaku kewargaan organisasional terhadap stres kerja.
 
Several studies have shown that most employees face quite high stress in carrying out their work. High stress can make it difficult to focus on their work. The purpose of this study was to determine the effect of self-efficacy, organizational citizenship behavior, and well-being on work stress. Purposive sampling was used as a sampling technique used in this study. The study sample was sixty-two employees at several private companies in West Jakarta. The research data was processed using SmartPLS. The results of the study obtained showed that self-efficacy has no influence on work stress, organizational citizenship behavior has a negative and significant influence on work stress, well-being has a negative and significant influence on work stress. In addition, it can also be concluded that well-being does not have an influence in mediating the influence of self-efficacy on work stress and well-being has a significant influence in mediating the influence of organizational citizenship behavior on work stress.
Concentration of saturated turbine oil vapors in ship spaces as function of temperature
Authors:   Kuznetsov Naval Academy, St. Petersburg, Russia, Kicha M.A. , Mikhailenko V.S. ,   Kuznetsov Naval Academy, St. Petersburg, Russia, Malovik D.S. ,   Kuznetsov Naval Academy, St. Petersburg, Russia
Published: February 2023

Object and purpose of research. The archival results of the study of the dependence of the concentration of saturated turbine oil vapors in the air of the ship's room on temperature in the range from 15 °С to 110 °С are presented. Subject matter and methods. The method of measuring the mass loss of an equilibrium cell containing the test sample in an air stream with a known temperature and flow rate providing saturation of the air with turbine oil vapors is used. Main results. Experimental data are theoretically justified by a dependency that provides reliable interpolation and extrapolation. Conclusion. The data obtained can be used in calculating the concentration of turbine oil in shipboard and other rooms, as well as for planning similar studies of other turbine oils and other liquids with a low saturated vapor pressure. The data can also be useful in the development of test equipment to test the effectiveness of air filters.
Selection justification for neutral grounding switchboard of electric power system aboard “Arktika” icebreaker
Authors:   Krylov State Research Centre, St. Petersburg, Russia, Grigoryev V.V. , Tsitsikyan G.N. ,   Krylov State Research Centre, St. Petersburg, Russia
Published: February 2023

Object and purpose of research. This paper discusses the capacity of power cables aboard “Arktika” icebreaker to confirm selected resistor rating of neutral grounding switchboard through on-site measurements. Subject matter and methods. Calculations are based on approximate and rigorous expressions. Main results. Numerical results obtained in this study confirmed the correctness of investigated approaches and calculations. Conclusion. Resistor rating for neutral grounding switchboard of “Arktika” icebreaker was selected correctly, which is confirmed by measurement results.
Water depth effect upon motion parameters of submerged body near free surface
Authors:   Sholom-Aleihem Amur State University, Birobidzhan, Russia, Zemlyak V.L. , Kozin V.M. ,   Institute of Mechanical Engineering and Metallurgy, Khabarovsk Federal Research Centre, Far Eastern Branch of Russian Academy of Sciences, Komsomolsk-on-Amur, Russia, Vasilyev A.S. ,   Sholom-Aleihem Amur State University, Birobidzhan, Russia, Chingalaev S.A. ,   Sholom-Aleihem Amur State University, Birobidzhan, Russia
Published: February 2023

Object and purpose of research. This paper discusses motion parameters of submerged body with given shape near the free surface at limited water depth. The purpose of this study was to determine the effect of water depth upon wave-making resistance, uplift force and hydrodynamic moment acting on the body from the side of fluid. Subject matter and methods. The paper relies on simulation procedure, as well as model test techniques and results obtained at the test tank. Numerical simulation was performed in ANSYS software package. Main results. This experimental and theoretical study yielded the parameters of water depth effect upon wave-making resistance, uplift force and hydrodynamic moment taking place when a submerged body runs near free surface. Conclusion. The results of this study could be helpful for horizontal stabilization of submerged body moving at various speeds and various diving depths in shallow water areas.
Self-stabilizing propeller
Authors:   Moscow Aviation Institute, Russia, Shved Yu.V.
Published: February 2023

Object and purpose of research. The solution discussed in this paper is applicable to the propellers (including those with oscillating blades) operating in fluids, and is intended to ensure self-adjustment of blades to the optimal attack angle. Subject matter and methods. Blade self-adjustment to the optimal attack angle was achieved through one of the properties of the boundary layer for viscous flow around the foil system: this layer acquires different thickness at the opposite sides of foils with non-zero installation angle, thus becoming an asymmetric displacement body. The propeller intended to use this property had its blade and a stabilizing foil attached to a common axe so that the rotation axis of both the blade and the foil was between the application points of the hydrodynamic resultant force (i.e. centers of pressure) for the blade with and without the stabilizing foil. The locations of pressure centers were calculated as per the linear theory. This property of the propulsion system was confirmed experimentally. Main results. It was experimentally demonstrated that proper selection of the rotation axis coordinate in a viscous fluid creates a zone of stable attack angles. This zone also exists for symmetric foils arranged one after another with non-zero installation angle. It means that these foils could be used in a fin-type propulsor, but this will require a control device preventing blade lock due to reversal of oscillation direction. In the suggested solution, blade axis is connected with driving rods by means of steering arms, and the driving rods themselves have guides locking blade tips when oscillation direction changes. Conclusion. The solution suggested in this paper has been experimentally validated, and it paves way to introduction of simple but efficient fin-type propulsors. Following this design, the author suggests a flipper with increased propulsion efficiency in a wide range of speeds, as well as a propulsor based on hinged hydrofoils: this design does not need propeller to maintain the speed.
Life before birth: A thematic analysis of memories of coming into life. Part 2: Recollections of fetal life and birth.
Authors: Wade Jenny
Published: February 2023

This article examines a second set of data produced in a thematic analysis of 68 “earliest memory” narratives submitted to an independent website to explore the question: what do people who claim to remember how they came into the world say about their experience prior to and including birth? Part 1 examined the first and largest subset of the data, narratives of an otherworldly existence consistent with Western reincarnation intermission stage 2 experiences, near-death experience accounts and mythic traditions. This article thematically analyzes descriptions of life in the womb, birth, and apparently veridical out-of-body and other paranormal impressions of events surrounding birth, congruent with pre- and peri-natal psychology, especially early trauma. Surfacing and resolving such early memories may have greater potential for healing than treating later life events.
The perceived impact of holotropic breathwork: An interpretive phenomenological analysis.
Authors: Landaeta Farizo Felipe
Published: February 2023

Holotropic Breathwork (HB) is a method of self-exploration developed by Stanislav and Christina Grof. Research has only just begun to investigate the effects of HB, while the possible influence of the context and other features of HB within the experience and its impact have not been studied in depth. This qualitative study investigated the perceived impact of HB on 6 women and 6 men (ages 25-67) in Chile, using Interpretive Phenomenological Analysis (IPA), an emergent method developed specifically to work with these types of subjective issues. Results revealed 10 major themes involving both intrapsychic and relational features prior, during and after HB. Results provide support for some elements of the existing theory and practice of HB, but, given the influence of preparation, the reasons for seeking HB, and the integration of experiences on the perceived impact of HB, revision of some HB procedures may provide better support for workshop attendees.
Life before birth: A thematic analysis of memories of coming into life. Part 1: Recollections of another realm.
Authors: Wade Jenny
Published: February 2023

Autobiographic memories prior to birth remain controversial in psychology because such memories are traditionally believed to begin much later when some sense of self is formed. Prenatal sentience, including fetal learning, occurs in species from arthropods to humans, and evidence for autobiographic memories from pre- and neo-natal humans has typically come from clinical case histories of altered-state regression techniques eliciting records from adults or clinical case histories of children in normal states. This thematic analysis examined 68 “earliest memory” narratives submitted to an independent website to explore the question: what do people who claim to remember how they came into the world say about their experience prior to and including birth? The findings produced two distinct data sets. This article, Part 1, analyzes the majority of the data, narratives that described prenatal existence in an otherworldly realm. The results are consistent with and elaborate findings in established but controversial fields, notably reincarnation research, especially the intermission research, some of it veridical, and near-death experience research. Part 2, a separate article, analyzes a second subset of records that were narratives of fetal experiences, birth, and apparently veridical paranormal perinatal impressions, consistent with the clinical literature on pre- and peri-natal psychology and some of the intermission experience literature.
Analyzing Multi-Channel and Single-Channel on Multi independent Paths of Ad-Hoc Sensor Network
Authors: Abdulazeez Idrees Barzan , Sulaiman Naif Saad , Safar Sulaiman Shian
Published: February 2023

The Ad Hoc routing protocols include the route rediscover algorithms. Thus, a desirable aim for any routing protocol is to design an effective and rapid route recovery technique to rebuild the broken link. This study presents Multiple Node Index in Multi-Channel (MNIMC) and Multiple Node Index in Single-Channel (MNISC) as two novel route discovery techniques. MNIMC integrates multiple pathways and channels to create an alternate path. MNIMC reroutes the data packet via a different route in previously detected channels. Furthermore, it works with numerous link failures. MNIMC nodes are considered multi-transceiver enabled, in contrast to MNISC, which enables several routes and a single channel. Using the Network Simulator 2 (NS2), the MNIMC and MNISC schemes are developed and thoroughly tested. Simulation results demonstrate that the suggested approach improves packet delivery ratio, throughput, and end-to-end latency.
Multiple Global Navigation Satellite Systems Doppler Positioning for Low-Earth-Orbit Satellites
Authors: Pike G. Elisabeth , Ugazio Sabrina , van Graas Frank
Published: February 2023

Multiple global navigation satellite systems (multi-GNSS) Doppler solutions are analyzed for low-Earth-orbit (LEO) satellites. Precise satellite displacement and change-in-clock offset can be calculated using four satellites if an approximate position solution is available. The position can be calculated using seven or more satellites if time is provided. The precise displacement or average velocity at the millimeter-per-second level is based on accumulated carrier-phase measurements. A novel linearized Doppler position and velocity solution smoothed at the millimeter level is presented. The Doppler position solution is combined with a high-accuracy displacement solution in a complementary filter that provides two new benefits: after initialization with a full seven-satellite position solution, the complementary filter can continue with only four satellites; and the short (1 to 5 s) Doppler tracks can be checked for faults before the complementary filter, using displacement techniques requiring five satellites versus the usual eight. The Doppler solutions are evaluated using data from a LEO satellite and contrasted against a multi-GNSS pseudorange solution. Applications of the Doppler solution include satellite maneuver control, formation flight, thruster monitoring, docking, and scientific applications that require satellite motion compensation, such as synthetic aperture radar.
Assessment of Potential Commercial Success of Business Jets with Natural Laminar Flow
Authors: Karpuk Stanislav , Elham Ali
Published: February 2023

The present research investigates the potential application of the natural laminar flow wing technology to business jet market segments from light to long-range jets. A database of existing business jets was generated to determine the range extension as a potential driver of customer interest. A conceptual design of several configurations for each market segment was performed to investigate potential improvements in the aircraft flight range, operating costs, and price changes using the technology. An initial sizing module and a low-fidelity multidisciplinary design optimization were used to size all aircraft. Results demonstrated a 13–30% increase in the flight range depending on the aircraft concept. Long-range jets with natural laminar flow could not achieve significant range extension due to a combination of the design airspeed and maintenance costs. A rapid increase in acquisition prices for all aircraft suggested that super-midsize and large jets that combine relatively low empty weight and high range extension could be more favorable options compared to other segments, but a significant reduction of acquisition costs and an increase in operating flight hours are required to make the technology implementation successful.
Aerodynamic Performance Benefits of Over-the-Wing Distributed Propulsion for Hybrid-Electric Transport Aircraft
Authors: de Vries Reynard , Vos Roelof
Published: February 2023

The goal of this study is to analyze how the aeropropulsive benefits of an over-the-wing distributed-propulsion (OTWDP) system at the component level translate into an aeropropulsive benefit at the aircraft level, as well as to determine whether this enhancement is sufficient to lead to a reduction in overall energy consumption. For this, the preliminary sizing of a partial-turboelectric regional passenger aircraft is performed, and its performance metrics are compared to a conventional twin-turboprop reference for the 2035 timeframe. The changes in lift, drag, and propulsive efficiency due to the OTWDP system are estimated for a simplified unducted geometry using a lower-order numerical method, which is validated with experimental data. For a typical cruise condition and the baseline geometry evaluated in the experiment, the numerical method estimates a 45% increase in the local sectional lift-to-drag ratio of the wing, at the expense of a 12% reduction in propeller efficiency. For an aircraft with 53% of the wingspan covered by the OTWDP system, this aerodynamic coupling is found to increase the average aeropropulsive efficiency of the aircraft by 9% for a 1500 n mile mission. Approximately 4% of this benefit is required to offset the losses in the electrical drivetrain. The reduction in fuel weight compensates for the increase in powertrain weight, leading to a takeoff mass comparable to the reference aircraft. Overall, a 5% reduction in energy consumption is found, albeit with a [Formula: see text] uncertainty due to uncertainty in the aerodynamic modeling alone.
PERANCANGAN APLIKASI INVENTORY BARANG PADA TB. RESTU JAYA KABUPATEN CIAMIS
Authors: Sidiq Maulana , Dwicahya Supriatman Rian
Published: February 2023

TB Restu Jaya adalah usaha yang bergerak dibidang penjualan bahan baku kontruksi bangunan. Dari banyaknya keluar masuk barang dari konsumen dan toko menjadi permasalahan yang harus dihadapi dalam manajemen pengelolaan barang. Pengelolaan barang tersebut masih mengandalkan peran dari manusia yang tidak bisa melakukan pendataan barang yang terbilang banyak. Jika orang tersebut lupa akan menjadi masalah apalagi terkait jenis barang dan jumlah barang akan mempengaruhi kinerja dari toko tersebut. Penelitian ini untuk memudahkan dalam menghitung jumlah barang yang keluar masuk dari toko. Aplikasi pengelolaan aset ini akan bebasis web-based dengan menggunakan bahasa pemerograman php dan MySql sebagai basis datanya. Hasil dari penelitian ini berupa desain basis data yang nantinya akan di implemtasikan pada website yang bisa digunakan untuk pengelolaan barang dalam melakukan stok barang.
SISTEM KONTROL SUHU UNTUK MENGATUR KELEMBAMAN RUANG KANDANG UNTUK MENINGKATKAN HASIL PANEN JANGKRIK DIWILAYAH LINGGASARI KABUPATEN CIAMIS
Authors: Setiawan Tia , Riyadi Slamet
Published: February 2023

Sistem kontrol merupakan teknologi yang digunakan untuk memudahkan aktivitas manusia pada kehidupan sehari-hari, sistem kontrol digunakan pada remote (televisi, AC dan DVD), sistem pengamanan,  pengendali suhu atau temperature, dan lain lain. Sistem kontrol arduino ini bisa diterapkan dalam bidang pertanian dan peternakan, masalah yang terjadi yaitu bagaimana proses pembuatan  kandang jangkrik dengan sistem kontrol suhu kelembaban arduino. Dengan tujuan mengetahui pembuatan kandang jangkrik dengan sistem kontrol suhu kelembaban arduino sehingga masalah yang akan diuraikan dalam pembuatan kandang dengan sistem kontrol suhu dan kelembaban berbasis arduino meliputi Pembuatan kandang dan pengaturan sistem kontrol suhu kelembaban berbasis arduino pada budidaya ternak jangkrik. Penelitian ini kiranya dapat dikembangkan, karna penulis hanya melakukan proses pembuatan sistem kontrol suhu dan kelembaban berbasis arduino pada ruangan kandang ukuran sederhana yaitu panjang 100cm, lebar 40cm, dan tinggi 60cm. Guna menghasilkan sitem kontrol suhu dan kelembaban berbasis arduino dengan pembiayaan yang lebih hemat, rangkaian yang lebih sederhna, dan penggunaan komponen yang menyesuaikan terhadap kebutuhan.
ANALISIS PENJADWALAN PRODUKSI MENGGUNAKAN METODE SHORTEST PROCCESING TIME UNTUK MENINGKATKAN PRODUKTIVITAS KERJA PADA UKM SARTIKA DMS KUJANGSARI DI KOTA BANJAR
Authors: Nazarudin Nanang , Putramas Tegar
Published: February 2023

UKM Sartika DMS adalah usaha kecil menengah yang terletak didaerah sagaran kujangsari kota banjar jawa barat, UKM ini memproduksi produk opak oven,jenis produknya ada 2 macam yaitu opak lonjong dan opak bulat, proses produksi dilakukan setiap harinya agar dapat memenuhi permintaan pelanggan dalam melakukan produksinya pada umkm terdapat suatu masalah dimana pesanan pelanggan mengalami keterlambatan sehingga membuat kepuasan konsumen kurang terpenuhi,penjadwalan produksi merupakan hal yang penting bagi setiap industri agar perusahaan dapat meminimkan ongkos produksi serta mempercepat waktu produksi agar dapat mencapai efisiensi dan efektivitas kegiatan produksi serta tercapainya target produksi. pada penelitian kali ini peneliti ingin memecahkan masalah pada UKM ini dengan analisis penjadwalan produksi menggunakan metode shortest processing time, dengan adanya penjadwalan produksi UKM dapat mengurangi  keterlambatan pesanan. Berdasarkan hasil penelitian, didapat perbandingan penjadwalan menggunakan metode Shortest Procesing Time menghasilkan waktu penyelesaian total sebanyak 24 Hari dan Utilitas sebesar 60% jumlah keterlambatan pun 0, Sedangkan jika menggunakan metode FCFS menghasilkan waktu penyelesaian total sebanyak 28 Hari dan Utilitas sebesar 52 % dan rata rata jumlah keterlambatan 1 hari. Hasil tersebut menunjukan bahwa penjadwalan produksi menggunakan metode Shortest Procesing Time mampu meminimumkan keterlambatan pesanan dan juga memaksimalkan sumber daya yang ada UKM Sartika DMS Kujangsari
USULAN RANCANGAN RUTE DISTRIBUSI MENGGUNAKAN METODE BRANCH AND BOUND UNTUK MEMINIMUMKAN BIAYA TRANSPORTASI PADA UKM RAKA EGG DI PANGANDARAN
Authors: Kurnia Yusup , Nurdiansyah Apep
Published: February 2023

Telur ayam ras merupakan salah satu komoditi ekonomi yang lahir karena adanya permintaan yang cukup banyak dari konsumen. UKM RAKA EGG yang bergerak di sektor peternakan ayam ras petelur yang berada di daerah Pangandaran lebih Tepatnya di Desa Cigugur Kecamatan Cigugur. UKM Raka Egg sudah mempunyai banyak pelanggan yang tersebar di 5 Desa di daerah tersebut, namun perusahaan ini belum begitu memperhatikan system pendistribusian yang mereka jalankan, masalah ini dikarenakan ketidaktahuan mereka tentang sistem pendistribusian yang mencakup efektifitas, tepat waktu, dan mudah untuk di capai. Pemecahan masalah dalam penelitian ini yaitu bagaimana penentuan rute yang optimal menggunakan metode Branch and Bound. Hasil perhitungan menggunakan metode branch and bound telah melakukan penghematan total jarak tempuh yang awalnya 73,3 Km menjadi 53,5 Km dan menghemat biaya oprasional bahan bakar dari Rp.59,755 – Rp 45,475 = Rp, 14,280. HAsil tersebut menunjukan bahwa penentuan rute pendistribusian menggunakan metode Branch and bound mampu meminimumkan jarak yang mempengaruhi ke penghematan biaya pendistribusian pada UKM RAKA EGG di Pangandaran.
PENJADWALAN PRODUKSI KERAJINAN TAS BAMBU DENGAN MENGGUNAKAN METODE SORTEST PROCESSING TIME (SPT) PADA UKM KREASI BAMBU DI LEUWISARI TASIKMALAYA
Authors: Kurnia Yusup , Ramdani Deni
Published: February 2023

UKM Kreasi Bambu adalah Perusahaan yang bergerak di bidang kerajinan bambu yang memproduksi aneka kerajinan terutama tas bambu  sistem penjadwalan  di UKM saat ini masih belum ada penjadwalan. Dalam hal ini perusahaan sering mengalami kesulitan untuk memenuhi permintaan konsumen secara tepat waktu.. Berdasarkan hal tersebut maka tujuan penelitian ini untuk mengoptimalkan proses produksi dengan menggunakan metode sortest prosesing time (SPT). metode ini membandingkan hasil perhitungan rata-rata waktu penyelsaian pesanan dan total waktu keterlambatan. Hasil dari penelitian ini ternyata metode SPT merupakan metode yang optimal dengan nilai waktu penyelsaian 254,53 menit total keterlambatan 0 menit dan mempunyai utilits 55% di minggu pertama. upaya yang dapat dilakukan oleh UKM Kreasi Bambu untuk membuat penjadwalan produksi yang optimal dapat menggunakan metode spt  karna selain terbukti mempunyai nilai yang lebih baik dari metode sebelumnya, metode ini juga sangat sesuai dengan UKM Kreasi Bambu yang menerapkan make to order dimana penyesuain pesanan pelanggan sesuai dengan lead time yang ada.