bluuebunny/crossref_metadata_2025 huggingface dataset:
Children's Schooling and Parental Migration: Empirical Evidence on the 'Left-behind' Generation in Pakistan
Authors: Iqbal Shahid , Mohyuddin Anwaar , Muazzmi Riaz Ahmad
Published: July 2021

This study examines the long-term effects of parental international migration on the schooling of children left behind in Pakistan. Although parents' migration usually benefits children economically but the lack of parental care may cause relational and psychological problems that may affect children's welfare in the long term. The locale of the present study is district Gujrat where the labor migration is considered as the best viable way to cope with an increasing poverty and the scarcity of public resources for sustaining households' incomes. To gain the objectives of the study, a mix methods approach has been used for the collection and analysis of data. In the present study the impact of migration on the education of the children was measured through their enrolment in school, type of institution and level of investment on education, dropout from the school, level of achievement. The results show that parental migration has a positive impact on the enrolment of children and investment on education, but it has negative impact on the dropout and level of achievement especially in case of boys.
Writing and Responding to Trauma in a Time of Pandemic
Authors: Edwards Laurie , Poe Mya
Published: July 2021

Writing and Responding to Trauma in a Time of Pandemic is a public writing course that was developed in response to an institutional call for a Public Pandemic Teaching Initiative in Summer 2020, which asked faculty to consider how this moment of radical disruption might inform our teaching and deepen our understanding of the relationship between writing, resilience, and response. The course provides a set of complementary, public-facing modules that offer teachers, community partners, and writers the tools to both write about and respond to writing about trauma. The resources, writing prompts, and activities draw from activities we have used in our undergraduate and graduate writing classrooms as well as our interdisciplinary research interests. Together, they support participants in addressing trauma from three perspectives: composing personal healing narratives; framing their personal inquiries within a larger research context; and positioning themselves within the larger community response to the COVID-19 pandemic. Public writing courses, such as Writing and Responding to Trauma in a Time of Pandemic, demonstrate how interdisciplinary collaboration and accessible platforms can provide meaningful institutional responses during times of public health crises.
If They Build It
Authors: Wang Bryan
Published: July 2021

In an undergraduate biochemistry and molecular biology lab course, students designed their own final assignment to communicate their laboratory work to non-disciplinary audiences. A “meta-assignment” guided them as they proposed the content, form, and process requirements. Students strove to develop unique ideas, and all successfully completed their self-assigned projects. Providing students in this class with the freedom, responsibility, and appropriate scaffolding to build their own projects and learning experiences allowed them to interact with their discipline in new ways and enhanced their abilities to design and plan their work, communicate scientific ideas to nonscientists, and think creatively.
Dynamics of Regional Head Elections (Pilkada) in 2020 During the COVID-19 Pandemic
Authors: Johan Mudir , Wahyudi Andi , Irawati Irawati
Published: July 2021

This research examines the problems of regional head elections (pilkada) as a government system that places the people as the sole voters. Pilkada is defined as the General Election to elect pairs of candidates for Regional Head proposed by a Political Party (Parpol) or a combination of political parties and individuals. But the problem is that the implementation of the pilkada in the COVID-19 pandemic has threatened the health of the people and has an impact on the weakening of various sectors, with this situation several agendas in the process of the pilkada stages were violated by candidate pairs such as not implementing health protocols at every stage of registration so that in the 2020 election feels threatened.
Neutrality of The State Civil Apparatus (ASN) in Indonesian Elections
Authors: Ruslihardi Muhammad , Ramadhani Adinda , Wirawati Siska , Rahmah Tuty Ardian , Kusumawardhani Fajarwaty , Nasution Sri Roserdevi , Harcini Harcini
Published: July 2021

The neutrality of ASN has always been a hot topic in various circles. Concern over the alignment of ASN to one of the candidate pairs is the main reason there are three types of politicization of the bureaucracy in Indonesia: First, openly politicization. Second, semi-open politicization, third, closed politicization. By utilizing the votes of civil servants, it is obvious for incumbent candidates with the promise of being given a position or to support their superiors and the mobilization of civil servants during general and regional elections. The politicization of the bureaucracy in Indonesia is still exist, currently politicization can appear from the legislature or from the executive with the aim of perpetuating power. From symptoms ranging from users of state facilities, mobilization of civil servants, compensation for positions, commercialization of positions, recruitment of new civil servants, to removal (depromotion) of regional secretaries. The involvement of the State Civil Apparatus (ASN) in practical politics is obvious because ASN is considered as the easiest way to influence society. The position of ASN is quite strategic and seen in the community, of course, will make it easier for candidates to gain support and have big hopes in the pilkada. The non-neutrality of ASN is certainly in the spotlight amidst the hopes of the community that ASN is able to become a pillar of an example of an honest and fair course of democratization.
Russian aircrews in Africa (eyewitness narrative accounts)
Authors: Ulanova Natalya S.
Published: July 2021

The last decade of the 20th century saw another boom in the supply of Soviet-made civil aircraft to the countries of Africa. Hundreds of highly qualified aviation specialists from all post-Soviet states were involved in its operation and maintenance. Market relations, new for many of them, the aggressive way of doing business on the part of entrepreneurs, as well as the complicated military and political situation in some regions, have led to the formation of a certain type of business and personal relationships. Lessons learned over the thirty years of work in special economic and socio-cultural conditions are still actual.
Nevertheless, this aspect of Russia-Africa relations remains one of the least studied. Analysis of the narratives of the eyewitnesses - pilots, flight engineers, translators - is still the only way to know more about some hallmarks of the African aviation market, which still has a significant shadow segment.
For this study the narratives of a Russian flight engineer who has worked as a flight crew member in various African countries for more than ten years were collected. The recollections presented relate to the first organized trip to South Africa and Mozambique in 1992, and to the later period of private contract work in Angola and Rwanda, and are interesting because they trace the formation of psychological and ethnocultural aspects of business and personal contacts with the employers, local residents and co-workers.
Intentional Design: Reaching the Most Excluded Girls in the Poorest Communities—A Guide for Practitioners and Advocates
Authors: Bruce Judith , Soares Sophie
Published: July 2021

The Intentional Design guide is a sourcebook that offers step-wise technical guidance for utilizing the Intentional Design approach, an evidence-based model for the design of girl-centered programs that generates a cycle of information collection and analysis. The tools outlined in this guide have been applied in sites in 44 countries. Twenty-one detailed field reports—including an extensive discussion of the Abriendo Oportunidades program in Guatemala—set the scene in each context by describing key challenges and problems faced, present how tools were used, and explain the eventual resolutions of the Intentional Design process.
Etude quantitative sur le mariage précoce et le vécu des adolescentes dans la zone d'intervention du projet: Etat des lieux et perspectives
Authors: Kaboré Gisele , Dala Rene , Bado AristideR.
Published: July 2021

L’étude sur le mariage précoce s’est déroulée dans cinq régions du Burkina Faso. Elle avait pour objectif général d’étudier les connaissances, les attitudes, les pratiques et les perceptions du mariage précoce ainsi que le vécu des adolescentes mariées ou non en vue d’orienter les actions du projet. L’analyse des résultats de l’étude montre que la situation des adolescentes n’est pas reluisante. L’ampleur du mariage précoce dans la zone d’étude montre bien que le problème est toujours d’actualité. Au regard des résultats qui découlent de l’étude, les recommandations suivantes peuvent être formulées afin de contribuer à améliorer la situation des adolescentes: sensibiliser davantage les parents, l’entourage et les adolescentes elles-mêmes sur les inconvénients du mariage précoce ; sensibiliser les chefs de ménage, l’entourage et les adolescentes sur le Code des personnes et de la famille ; appuyer financièrement les adolescentes qui souhaitent fréquenter ou poursuivre leurs études ; renforcer la connaissance des adolescentes sur la santé sexuelle et reproductive et mettre à leur disposition des services appropriés ; créer ou renforcer des structures d’accueil pour des formations professionnelles accessibles aux adolescentes ; et faciliter l’accès des adolescentes aux crédits, les sensibiliser sur les activités génératrices de revenus et renforcer leurs capacités en matière de gestion.
Grundlagen ethischer Unternehmensverantwortung
Authors: Schüz Mathias
Published: July 2021

Die Ölpest im Golf von Mexiko, die Kernschmelze von Fukushima, der Dieselabgasskandal, die weltweite Finanzkrise, Klimawandel und Artensterben sowie zahllose weniger bekannte Schädigungen von Mensch und Natur sind das Ergebnis unverantwortlichen Wirtschaftens. Häufig werden Gewinne rücksichtslos maximiert. Die verantwortlichen Akteure sehen nur kurzfristige Vorteile und ignorieren soziale sowie ökologische Risiken. Die negativen Folgen spüren nicht nur die Opfer. In vielen Fällen fallen sie auf die Täter zurück, wenn sich betroffene Anspruchsgruppen bzw. Stakeholder gegen Übervorteilung mit Streiks, öffentlichen Protesten oder Boykottaufrufen wehren. Unternehmen setzen so ihre Reputation und Profitabilität aufs Spiel. Kann ethisches Verhalten in den Chefetagen solche Auswüchse vermeiden? Wenn ja, wie muss ethische Unternehmensverantwortung beschaffen sein, damit sich Geschäftstätigkeiten nicht nur für die Eigentümer, sondern auch auf Gesellschaft und Natur langfristig positiv auswirken? Welche Hilfestellungen gibt es, um nachhaltig ethische Entscheidungen zu treffen? Zahlreiche Publikationen geben auf solche Fragen teils widersprüchliche Antworten. Die vorliegende Ausgabe der «SML essentials» dient als eine Art Wegweiser, der den Kontext und die Grundbegriffe von Ethik, Verantwortung und Nachhaltigkeit im Rahmen von unternehmerischen Aktivitäten klärt. Darüber hinaus gibt sie Gründe an, weshalb es für Unternehmen sinnvoll ist, sich ihrer vollständigen Verantwortung bewusst zu werden. Erst dann können sie frei entscheiden, ob sie sich selbst zum Vorbild ihrer Branche erheben, den Besten nacheifern oder erst mal abwarten möchten. Sie treffen dann ihre Entscheidung mit all ihren möglichen Konsequenzen bewusst und vermeiden so, zum Spielball zufälliger Reaktionen von Stakeholdern wie z.B. Medien, Investoren oder Kunden zu werden. Viele Unternehmen haben aufgrund schlechter Erfahrungen ihre Aktivitäten bereits erfolgreich auf Nachhaltigkeit und ethische Verantwortung ausgerichtet. Sie belegen die Dringlichkeit einer Umorientierung.
Jugend, politische Partizipation und Digitalisierung
Authors: Räss Nora , Differding Ira , Odermatt Jasmin
Published: July 2021

Wie stark sich Jugendliche an politischen Prozessen oder Diskussionen beteiligen, hängt von verschiedenen Faktoren wie beispielsweise dem Geschlecht oder dem Bildungshintergrund ab. Das steht dem Prinzip der Demokratie entgegen, wonach sich alle gleichberechtigt einbringen können sollen. Der Dachverband der Schweizer Jugendparlamente DSJ geht in dieser Studie der Frage nach, wie zugänglich digitale Partizipationsplattformen heute sind und wie diese ausgestaltet sein müssten, um möglichst alle jungen Menschen zu erreichen. Die Studie ist eine von insgesamt drei Studien, die im Rahmen des Projekts «Bürger und Institutionen angesichts der Digitalisierung der Demokratie in der Schweiz» im Auftrag von TA-SWISS erarbeitet worden sind. Sie beleuchten die Auswirkungen der Digitalisierung auf die Demokratie aus unterschiedlichen Blickwinkeln: Während der DSJ die Voraussetzungen für die digitale Partizipation junger Menschen untersucht, entwickelt das Dezentrum drei mit spekulativen Objekten illustrierte Zukunftsszenarien. Diese regen zum Nachdenken über wünschenswerte wie auch unerwünschte Formen der digitalen Demokratie in der Zukunft an. gfs.bern hingegen betrachtet den gesamten demokratischen Prozess und legt dabei den Schwerpunkt auf die Meinungsbildung und deren Beeinflussung durch digitale Medien.
Pectoralis major myo-parenchymal flap for local reconstruction of partial mastectomy defects: Description of a new technique
Authors: Hussein Osama , Roshdy Sameh , Hamdy Omar , Denewer Adel
Published: July 2021

INTRODUCTION: Breast conservation is the standard of care for early breast cancer. Several oncoplastic approaches have been described for the reconstruction of partial breast defects. The multiplicity of techniques indicates that the ideal reconstructive technique is yet to be identified. There has been a recent emphasis on minimizing the magnitude of surgery. In this report, we describe our experience using the pectoralis major muscle to fill relatively large post-tumorectomy breast defects. PATIENTS AND TECHNIQUE: Nine patients were operated on for malignant breast lesions. Tumorectomy resection with surgical margin rendered a 40–50% breast defect. The parenchymal defect was repaired with an advancement muscle flap of the ipsilateral pectoralis major muscle. RESULTS: All patients experienced a non-eventful postoperative course. The early cosmetic outcome was excellent in four patients, good in another four, and fair in one patient. CONCLUSION: The pectoralis major flap is useful for local repair of upper half partial breast defects in non-ptosed, cup A–B breasts.
Complex uncertain differential equations with application to time integral
Authors: Jia Zhifu , Liu Xinsheng
Published: July 2021

In this paper, we propose complex uncertain differential equations (CUDEs) based on uncertainty theory. In order to describe the evolution of complex uncertain phenomenon related to belief degrees, we apply the complex Liu process to CUDEs. Firstly, we pose a concept of a linear CUDE and prove that homogeneous linear CUDE and general linear CUDE have solutions. Then, we prove existence and uniqueness theorem of a special CUDE. Further, we design a numerical algorithm to obtain inverse uncertainty distribution of the solution. Finally, as an application, we analyse the inverse uncertainty distributions of time integral of CUDEs and design numerical algorithms to obtain inverse uncertainty distributions of time integral.
Fuzzy modelling and control of project cash flows
Authors: Kuchta Dorota , Zabor Adam
Published: July 2021

An analysis of the scientific literature on project cash flow control and fuzzy modelling shows that project cash flows are modelled using only basic approaches drawn from fuzzy theory, which may distort the credibility of the model. In this paper, we therefore propose to use the whole spectrum of fuzzy arithmetic, and to select operations that suit the nature of the cash flows in question, their dependencies and the preferences of the project manager. An analysis of the literature also shows that in practically all existing models of project costs and cash flow management, project costs and cash flows are treated at a very high level of generality (without considering the various types of project, factors influencing their variability and signals warning of imminent cash-related problems), and estimations are not updated on an ongoing basis throughout the duration of the project. The results of a survey performed with the participation of 100 project managers show that this simplistic view of project cash flows may be distorting, and cannot guarantee the development of an efficient project cost and cash flow control system. We propose an approach that at least partially compensates for these drawbacks: it differentiates between types of project cash flows and the factors and triggers affecting changes in cash flows. Two case studies are used for a an initial verification of the approach. The paper concludes with suggestions for further research perspectives.
Global research publications on systemic use of off-label and unlicensed drugs: A bibliometric analysis (1990–2020)
Authors: Sweileh Waleed M.
Published: July 2021

BACKGROUND: Governmental regulations of drug registration and licensing are not always followed by healthcare providers. OBJECTIVE: To explore the global research growth and patterns on systemic use of off-label and unlicensed drugs to gain knowledge about the magnitude of the problem and the main research themes encountered in this field. METHODS: SciVerse Scopus was searched for papers on off-label and unlicensed drug use from 1990 until December 31, 2020, without any language limitations. A bibliometric methodology was adopted to present the following indicators: top-cited documents, the most productive countries, top active journals, international research collaboration, the most frequent author keywords, and research themes. RESULTS: The search query returned 1320 papers with an h-index of 66, published in 721 different journals. The Hospital Pharmacy journal ranked first (n = 43, 3.3%). In total, 5777 authors (median = 3) from 85 different countries contributed to the retrieved papers. The USA (n = 381, 28.9%) ranked first, followed distantly by Germany and Italy. The percentage of documents with international authors for active countries was from 8.8% for China to 42.3% for the Netherlands. The most frequent author keyword next to off-label was children/pediatrics. The keyword unlicensed was less frequently encountered than that for off-label. Major research themes in the retrieved papers focused on off-label drug use in hospitalized children/pediatrics, biological drugs such as rituximab and rFVIIa, psychiatric disorders, regulations, and questionnaire-based knowledge/attitude studies among community pharmacists and physicians. CONCLUSIONS: Research activity on off-label drug use has witnessed a general increase in the past two decades. The major research theme was off-label drug use in hospitalized children/pediatrics/neonates. The USA and certain European countries made a major contribution to this field.
Prevalence of urinary incontinence in a cohort of women with obesity
Authors: Trotti Giulia , Aspesi Valentina , De Ambroggi Lorena , Cimolin Veronica , Seitanidis Ionathan , Brugliera Luigia , Capodaglio Paolo
Published: July 2021

INTRODUCTION: Urinary incontinence (UI) is frequently associated with obesity. The prevalence of the different UI types in women with obesity remains scarcely investigated and controversial. OBJECTIVE: The goal of this study was to investigate the prevalence of the different types of UI (stress urinary incontinence, SUI, urge, UUI, or mixed, MUI) in a large sample of female patients with obesity by means of a specific questionnaire and non-invasive tests. METHODS: In this observational study, 248 obese female patients (BMI≥30 Kg/m2, age: 62.8 + 10.9 years) admitted to hospital from April 2019 to September 2019 for a multidisciplinary rehabilitation program were recruited for this study. The International Consultation on Incontinence Questionnaire - short form (ICIQ-sf) was used to screen the presence of symptoms of UI and to differentiate the different UI types. Patients with ICIQ-sf score≥4, were asked to undertake the Pad Test for quantifying urine leaks under stress. RESULTS: 61.69% of our sample presented UI symptoms. The prevalence of UI appears to be lower in younger age groups (57% in 31–46 years of age and 52% in 47–62 years of age) and higher (69%) between 63 and 79 years of age. MUI was the most frequent form (57.5%), followed by UUI (21.5%) and SUI (20.9%). SUI was most prevalent in younger participants (31–46 years old). CONCLUSION: This study demonstrated that UI has a high prevalence in females with obesity and it is not an exclusive concern of older women. This high prevalence calls for specific rehabilitation interventions within multidisciplinary programs.
Role of Fibroblast Growth Factor-23 in Coronary Slow Flow Phenomenon Pathogenesis
Authors: Oktaviandani Welly , Taufik Indrajaya  , Ali Ghanie  , Erwin Sukandi
Published: July 2021

The phenomenon of angina chest pain without significant epicardial coronary artery stenosis, but accompanied by a slowdown in coronary blood flow is often found in patients with symptoms of acute coronary syndrome who undergoing invasive coronary angiography. This phenomenon of slow coronary blood flow is then called the coronary slow flow phenomenon (CSFP). The pathogenesis mechanism of CSFP remains unclear. The pathogenesis of CSFP is thought to be multifactorial. Endothelial dysfunction, small vessel disease, inflammation, renin system angiotensin aldosterone, atherosclerosis are thought to be involved in the pathogenesis of CSFP. Cardiovascular disease incidence and death were associated with elevated levels of Fibroblast growth factor-23 (FGF-23). High levels of FGF-23 can lead to formation of blood vessel calcification, left ventricular hypertrophy, arterial stiffness, endothelial dysfunction, increased inflammatory markers and elevated levels of angiotensin II. It is suspected that FGF-23 has a role in this event other than as a regulator of bone and mineral metabolism. This literature review aims to determine the relationship between fibroblast growth factor-23 and the pathophysiology of CSFP. Based on the broad role of FGF-23, it is possible that FGF-23 is involved in the pathogenesis of CSFP.
Az ENSZ-békefenntartáshoz kapcsolódó információszerző/hírszerző tevékenység kialakulása, fejlődése és kihívások
Authors: Németh Gábor
Published: July 2021

Az Egyesült Nemzetek Szervezete (ENSZ) békefenntartó tevékenysége sokat változott az elmúlt évtizedek alatt, az első misszió indulása, 1948 óta. A békefenntartó missziók személyi állománya számos kihívással szembesült, illetve szembesül napjainkban is feladatainak ellátása során.A 21. századi békeműveletekbe vezényelt katonák, rendőrök, civil szakértők bonyolult biztonsági környezetben teljesítenek szolgálatot. Olyan kihívásokkal kell megküzdeniük, mint a nemzetközi szervezet missziói elleni terrortámadások, a válságövezetekben jelen levő szervezett bűnözés, ellenséges fegyveres csoportok, a helyi civil lakosság védelme, ellenük elkövetett háborús és emberiség elleni bűncselekmények elkövetőinek törvény elé állítása stb. Ezeket a kihívásokat csak akkor képes az ENSZ eredményesen kezelni, az adott misszió mandátumában meghatározott feladatokat végrehajtani, ha rendelkezik megfelelő hírszerzési támogatással. A békefenntartó tevékenységet mint egyéb nemzeti katonai, rendvédelmi műveleteket csak akkor lehet hatékonyan tervezni, szervezni, végrehajtani, ha a döntésekhez rendelkezésre állnak a szükséges háttérinformációk, a megfelelő hírszerzési támogatási rendszer.
A Brief Overview of Digital Military Systems Used in the Armies of NATO Member Countries
Authors: Török Péter
Published: July 2021

Today’s wars have undergone significant change. These changed military operations have changed the way armies are deployed, including the role and responsibilities of soldiers. New tools are needed to overcome the new challenges. 21st century soldiers need 2 1st century equipment to perform their duties. Aproject is present in several NATO (North Atlantic Treaty Organisation) member states army to develop individual equipment systems for dismounted soldiers equipped with modern military equipment, which are in the pilot phase, under introduction or authorised. I present these briefly in my publication.
Resenha: A Luta De Classes No Agrário Brasileiro E A Construção Das Organizações Políticas Camponesas
Authors: Souza Leonardo Figueiredo de
Published: July 2021

Sabe-se que desde o início da colonização europeia no Brasil, que teve seu inicio no século XVI, até o capitalismo do século XXI, a história do campesinato brasileiro é marcada por inúmeros conflitos com grandes latifundiários e com o Estado. Desse modo, nesta resenha buscamos discutir como os pesquisadores Gilberto Marques e Indira Marques tratam no livro “Luta Camponesa e Reforma Agrária no Brasil a história da luta camponesa no país”, trazendo reflexões sobre as ações do Estado diante dos conflitos e o desenvolvimento das organizações dos trabalhadores do campo.
Papermaking properties of bacterial nanocellulose produced from mother of vinegar, a waste product after classical vinegar production
Authors: LAVRIC GREGOR , MEDVESCEK DASA , SKOCAJ MATEJ
Published: July 2021

Bacterial nanocellulose (BNC) has gained a lot of attention in recent years due to its nano-size-derived properties. Although it is essentially chemically similar to plant-derived cellulose, it has smaller size and is enriched in free hydroxyl groups, which greatly improve mechanical properties of reinforced paper. However, although BNC has some unique features, it comes at a high price. In this paper, we introduce a new solution for BNC production. We have isolated bacterial nanocellulose directly from agro-industrial waste—mother of vinegar—and used it in the production of paper sheets. We show here that paper sheets made with the addition of only 10% bacte-rial nanocellulose from mother of vinegar substantially improved basic mechanical as well as printing properties of paper.
Creasing severity and reverse-side cracking
Authors: PANEK JOEL C. , SMITH SWAN D. , COFFIN DOUGLAS W.
Published: July 2021

Crease cracking can be detrimental to the functionality and appearance of paperboard-based pack-aging. The effect of creasing severity on the degree of reverse-side crease cracking (bead-side of the crease) of paperboard was investigated. Samples were creased with a range of rule and channel geometries, and the cracking degree was quantified as the percent of cracked length relative to the total length of the crease. The cracking degree was typically below 5% at low crease penetration depths, but was exponentially higher beyond a critical penetration depth. A rule and channel combination with a wider clearance shifted the critical depth to larger values.
The creasing severity parameter, termed the creasing draw, converged the cracking degree data from different rule and channel combinations to a single curve. The creasing draw was derived from the same analytical expres-sions as the transverse shear strain and quantifies the length of paper that is drawn into the channel during creasing. The critical draw is defined as the draw at which cracking becomes greater than 5%, which corresponds with the point at which cracking becomes exponential. The critical draw is a material/system parameter that defines the level below which cracking is minimal.
Effects of a PFI refiner’s operational parameters on the swellability of recycled fiber
Authors: SHEN XIAONING , LI BO , MO WENXUAN , CHAI XIN-SHENG
Published: July 2021

This paper presents data on the effects of operational parameters (number of revolutions, linear pressure, and gap) of the PFI refiner on the swellability of recycled fiber, which was characterized by water retention value (WRV). The results showed that the increase of recycled fiber’s WRV was proportional to the number of revolutions and the linear pressure, but inversely proportional to the gap. The mathematical relation between these parameters and the fiber WRV could be described by an empirical model for gaps greater than 0.1 mm. Scanning electron microscopic images of fiber morphology showed that the basic framework of fibers could be maintained with the gap greater than 0.1 mm, but was destroyed with smaller gaps. This model provides a technical reference for quantitative control of refining treatment and an effective method for improving recycled fiber quality.
Alternative “green” lime kiln fuels: Part I—Pulping/recovery byproducts
Authors: HART PETER W.
Published: July 2021

This paper is the first of a two-part series on “green” lime kiln fuels. The first part of this work reviews the use of pulp mill and recovery byproducts as either full or partial replacement of oil or natural gas in the kiln. The second part reviews the use of various forms of woody biomass, bio-oils, gasification, and hydrogen as potential carbon neutral or carbon-free lime kiln fuels.
GREEN BIOSYNTHESIZED SILVER NANOPARTICLES MEDIATED BY TRICHOSANTHES CUCUMERINA EXTRACT AND ITS BIOLOGICAL ACTIVITIES
Authors: Bello Oluwasesan M. , Shema Abdulsalam Shehu , Saulawa Aisha Ibrahim
Published: July 2021

Biosynthesized Nanoparticles especially from plants are a new research trend nowadays. In this study, green biosynthesis of silver nanoparticles (TCAgNPs) employing Trichosanthes cucumerina methanol leaf extract was realized. The antioxidant and anti-inflammatory activities of both the methanol extract of T. cucumerina and TCAgNPs were carried out and compared. Indomethacin and ascorbic acid were employed as a positive control for these activities respectively.  Fourier transform infrared spectroscopy (FT-IR) scanning electron microscopy (SEM) and Ultraviolet-visible spectroscopy were employed to characterize the formation of TCAgNPs. The TCAgNPs showed absorption bands at around 340-440 nm which is a distinctive band for Ag Nanoparticles and functional groups accountable for Ag nanoparticles synthesized by plants were noticed in the FTIR. TCAgNPs were spherical in morphology as seen from the SEM images.  TCAgNPs displayed better antioxidant and anti-inflammatory activities at 400 ug/ml (9.79±0.58) as compared with its polar extracts (7.74±0.58) but both the polar part (52.06±1.27) and TCAgNPs (61.72±2.54) were better in anti-inflammatory activity when compared with the positive control indomethacin (antiinflammatory) (48.30±0.23). This study revealed that AgNPs from plants can find germaneness in food, drugs, environmental sciences and drugs.
Analysis of Sources for Information Gathering before Visiting a Festival in the Case of Generation Z
Authors: Iványi Tamás
Published: July 2021

In recent years, festivals have become an essential part of summer activities for many members of Generation Z. Programs that last several days also mean significant financial burden for young people, so they gather information from multiple sources before decision-making. The purpose of the study is to examine which information sources – especially social media – and which motivations have become significant in the context of festival tourism's decision process.An online survey was conducted as part of and exploratory research over four consecutive years dealing with the use of information sources and the importance of the music festivals' characteristics targeting the Hungarian Generation Z attendees of festivals. Besides the descriptive statistics cluster analysis and ANOVA tables were used.It can be emphasized that in the case of festival tourism, the influence and usage of social media, relying on the opinions of acquaintances and friends is much more significant in the decision-making phase than in the case of traditional tourism. The program and the leading performers are not the only important factors, but meeting friends, the atmosphere of the festival, and reasonable value for money are also significant. Three groups of users could be identified: those who are mainly browsing official websites and search engines, those who try to make decisions based on earlier experiences, and those who are also looking at social media sites and digest several types of content to make the decision. Organisers of festivals should understand the differences among these groups to create better communication strategies.
Модель переноса импульса при высокоскоростном ударе
Authors:   Московский технологический университет, Москва, Россия, Головешкин В. А. ,   ФГБУН Институт прикладной механики РАН, Мягков Н. Н. ,   ФГБУН Институт прикладной механики РАН
Published: July 2021

An analytical mechanical model of the ejection arising from a high-velocity impact of a rigid projectile on a semi-infinite target is constructed, and an estimate is given of the ejection mass and the effect of momentum amplification transmitted to the target upon impact. The effect of the momentum amplification is caused by the ejection of target fragments in the 148 direction opposite to the direction of flight of the projectie. At present, there is a steady interest in the study of this effect. This is due, in particular, to the possible use of the effect for deflecting a potentially dangerous object (asteroid) approaching the Earth by means of an impact spacecraft using the effect of momentum amplification. The model presented in this work is constructed in approximation of plane deformation using the minimum number of parameters of the projectiler and target materials. Equations for the mass of the ejection and the increment of the target momentum are obtained, depending on the depth of penetration of the projectile. The model takes into account the dependence of the emission angle of the ejection fragments on the penetration depth of the projectile. It is shown that the model adequately describes the ejection momentum, the rate of change in the ejection momentum, and the ejection mass depending on the penetration depth of the projectile. The possibility of representing the momentum and mass of the ejection by scaling ratios is checked both for the ratio of the densities of the projectile and the target ptρρ, and for the dynamic parameter 20ttVYγρ= (0V - impact velocity, tY - yield stress of the target), in which the proportionality coefficient depends only on the shape of the projectile. It was found that scaling with respect to the dynamic parameter γ takes place at сγγ>, where 330сγ≈ that, e.g., for aluminum gives the value 02.5 km/scV =.
Две модели резинокордного слоя
Authors:   ФГБОУ ВО «Московский государственный университет им. М.В. Ломоносова», Москва, Россия, Шешенин С. В. , Ду Икунь ,   ФГБОУ ВО «Московский государственный университет им. М.В. Ломоносова», Москва, Россия
Published: July 2021

Breker layers in a pneumatic tire are an important part in the tire construction. These layers have a metal cord resulting in substantial bending stiffness. When homogenizing such layers, a “shave” method is applied to the breaker layer. This results in a thinner layer having adequate stiffness in both tension and bending. In this work, a phenomenological approach is used to obtain the effective properties of a homogeneous anisotropic hyper elastic material of an equivalent layer. Two models utilize transverse isotropic or orthotropic potential used to describe the homogenized properties. Comparison is made between these models for the “shaved” rubber-cord layer based on numerical experiments. In both cases, the potentials are built on the basis of the Treloar or Mooney potentials. Note that in the case of an inhomogeneous thin layer, the traditional definition of homogenization needs to be modified. In previous works of the authors, it was proposed to determine 3D averaged elastic properties of a layer by surrounding it with a homogeneous material. This makes it possible to correctly take into account the fact that the boundary effect from the upper to lower surfaces that penetrates through the whole periodicity cell. A set of local problems formulated for the periodicity cell is proposed. This set is sufficient for determining elastic potential material parameters. Nonlinear local problems on a periodic cell are solved and the material constants of the elastic potential are determined. The applicability of the orthotropic potential (second model) is determined for the “shaved” layer. It was found that orthotropic properties are manifested relative to longitudinal shears. The results show the suitability of the proposed potential and the scheme for determining the material parameters.
Усиление внутреннего слоя многослойного композита базальтопластиком в виде сотовой структуры
Authors:   Филиал Самарского государственного университета путей сообщения в г. Саратове (филиал СамГУПС в Саратове), Саратов, Россия, Пономарева Г. П. , Попова И. М. ,   Филиал Самарского государственного университета путей сообщения в г. Саратове (филиал СамГУПС в Саратове), Саратов, Россия, Сладков О. М. ,   Филиал Самарского государственного университета путей сообщения в г. Саратове (филиал СамГУПС в Саратове), Саратов, Россия, Пономарев М. В. ,   Саратовский филиал ООО «Газпром проектирование», Саратов, Россия, Гончарова Т. П. ,   Филиал Самарского государственного университета путей сообщения в г. Саратове (филиал СамГУПС в Саратове), Саратов, Россия, Хитрова Н. В. ,   Филиал Самарского государственного университета путей сообщения в г. Саратове (филиал СамГУПС в Саратове), Саратов, Россия
Published: July 2021

In our studies we present a multilayer structure consisting of outer layers of two-ply basalt composed of basalt fabric impregnated with an epoxy compound and an inner layer of polyurethane reinforced with basalt, having the same composition, formed in conjugate hexagonal prisms, and forming a cellular framework. The main part describes the technological sequence of obtaining basalt face layers, basalt hexagonal cellular frame, and filling it with a liquid reaction mass of rigid polyurethane system. The formation of a single multilayer composite structure is shown. We also present the results of the experimental research of strength of a laminated composite and its inner layer without facing layers when tested for static bending with concentrated load increasing at a constant rate and compression testing up to 10% of relative deformation. It describes the effect of the size of hexagonal prismatic cells of the frame on the physical and mechanical characteristics of the middle layer. The reduction of the cell size results in the increase of the composite strength. The dependence of the composite density on the size of the cells of the basalt frame has been studied.
Влияние дополнительной термической обработки газофазных неоднородных поверхностных слоев на остаточные напряжения и адгезионную прочность стали
Authors:   Московский автомобильно-дорожный государственный технический университет «МАДИ», Белашова И. С. ,   ФГБОУ ВО «Московский авиационный институт (национальный исследовательский университет)», Бибиков П. С. ,   ФГБОУ ВО «Московский авиационный институт (национальный исследовательский университет)»
Published: July 2021

The article presents the results of a study of the surface layers obtained by the deposition of organometallic chromium compounds on the base metal, and the structural changes occurring in them when exposed to additional heat treatment in the form of subsequent annealing. It is noted that the type of coating and its structure primarily depend on the deposition temperature; therefore, there are three main types - kinetic, transitional and diffusional. Each such type of surface layer is determined by its own mechanism of formation, and as the temperature changes, one transforms into another. The metastable state of such surfaces, which are supersaturated solid solutions, upon additional heat treatment leads to significant structural changes and the formation of a nanostructured composite layer. The possibility of obtaining nano-modified layers by forming the structure of a matrix solution with dispersed-dissolved secondary nano-sized particles of chromium carbides is shown. The modes at which crystallization of the amorphous phase begins with the release of nano-sized particles of chromium and chromium carbides have been determined. The modes with the maximum and minimum levels of residual stresses, which directly affect the performance of products, have been established, and the effect of additional annealing on the distribution of residual stresses has been studied. It is shown that the process of crystallization of the amorphous phase during annealing and the parallel process of coagulation of carbides causes the appearance and growth of residual stresses. The influence of residual stresses on the adhesion strength of surface layers, which largely depends on the main parameters of heat treatment - temperature and time, has been investigated. Comparison of adhesion strength before and after annealing showed that the overall level of adhesion strength during heat treatment of coatings decreases insignificantly, by 7-10%.
Задачи о дисперсии волн в неоднородных волноводах: методы решения (обзор). Часть I
Authors:   ФГБУН Институт прикладной механики РАН, г. Москва, Россия, Жаворонок С. И.
Published: July 2021

A brief review of the modern state-of-the art and tendencies of further development of various methods of solution of wave dispersion problems in heterogeneous functionally graded elastic waveguides is presented. Main types of functionally graded materials and structures, including gradient thon-walled structures, and their main engineering applications is discussed. The main difficulties of modelling of the stress-strain state of functionally graded shells and plates are pointed, as well as the possible ways to overcome such difficulties. The main theoretical bases of definition of effective constitutive constants of functionally graded materials and their possible estimates used in the practice are considered. Main dependencies of the effective constitutive constants of a functionally graded material on coordinates used for the mathematical modelling of the dynamics are also shown. The statement of the dynamics problem for a functionally graded waveguide and the appropriate statement of the normal wave dispersion problem are pointed. The presented Part I of the review consider some analytical methods of solution of dispersion problems, mainly the matrix ones based on the formulation of the steady dynamics problem in the image space as a first-order ordinary differential equations system. The state vectors corresponding to the useful Cauchy and Stroh formalisms are introduced, and the appropriate governing equations and the boundary conditions on waveguide’s faces are presented. Classical methods for solving the steady dynamics problem for a laminated waveguide are briefly described, which could be a basis for the further approximation of a functionally graded material by a system of layers with constant properties, i.e. the transfer matrix method, its main modifications developed to ensure the stability of calculations, and the global matrix method. Then, the intensively developed last 15 years reverberation matrix method, stiffness matrix method, and the Peano series method are discussed. Some key solutions of the wave dispersion problems for heterogeneous layers are presented; such solutions improve the efficiency of approximation of a functionally graded structure by a laminated one. The implicit solution of the general problem of steady dynamics for a waveguide with arbitrary gradation law is shown. The key features of the discussed matrix methods are pointed briefly as well as their main drawbacks. In the Part II, the main attention will be paid to methods of semi-analytical solution of dispersion problems based on the approximation of a waveguide by an equivalent system with a finite number of degrees of freedom: power series, generalized Fourier series, semi-analytical finite elements. spectral elements, as well as methods based on various theories of plates and shells.
Особенности конструирования углерод-углеродных композитов фрикционного назначения, изготовленных аэродинамическим методом, на основе дискретных волокон
Authors:   ПАО Авиационная корпорация «Рубин», Балашиха, Россия, Кулаков В. В. , Шмелев Д. С. ,   ПАО Авиационная корпорация «Рубин», Балашиха, Россия, Иванова А. Н. ,   ПАО Авиационная корпорация «Рубин», Балашиха, Россия, Голубков А. К. ,   ПАО Авиационная корпорация «Рубин», Балашиха, Россия
Published: July 2021

The designing of carbon-carbon composites (СCС) for friction use is an important problem, since the existing approaches are applicable only to technologies for obtaining materials using continuous fiber in the form of tapes and fabrics and are not suitable for products with chaotic reinforcement by short fibers, the use of which improves the mechanical characteristics of ССС both under static and dynamic influences. Also, this technology has economic advantages due to the use of cheaper raw materials and a significant reduction in the time of the molding stage in the presence of comparable physical, mechanical and frictional properties with CCC based on needle-punching and needle-piercing. To ensure the strength of discretely reinforced friction products, it is necessary to ensure the required effective length of the carbon fiber in the bundles distributed in the volume of the material, due to their evaluation by the degree of separation of the filaments. This article shows the dependence of the critical length of the bundle on the number of its fibers, from which it is found out that the critical length of the bundle sets the minimum threshold value at which the material is able to realize high strength characteristics. These ratios allow us to estimate the minimum necessary rate of separation of the bundle for a given fiber length. this will allow you to realize the maximum strength of the material, taking into account the technological limitations in the rate of separation. Models are also proposed that allow us to evaluate the technological prospects for the manufacture of discretely reinforced carbon-carbon materials for friction purposes and to predict their properties. The effect of additional reinforcement of the inter-joint spaces of the composite material on its wear resistance at high specific friction energies is shown
Hydropower: Projections in a changing climate and impacts by this "clean" source
Authors: Naranjo-Silva Sebastian , Álvarez del Castillo Javier
Published: July 2021

INTRODUCTION: Hydropower is an extensively used renewable source; in 2016, 159 countries reported benefiting; currently, there are around 9,000 projects in operation due to the competitive cost of generating a similar cost such as thermal energy such as coal, oil, or gas in the range of USD 4 - 5 cents US dollars per kilowatt-hour. OBJECTIVE: Investigate the results of hydroelectric development in the face of the changing climate and the generated impacts, making hydropower a subsector of special attention to discussing the global projection. METHOD: Bibliographic review to reflect on the global context of hydroelectricity based on scientific studies. RESULTS: Hydropower projects a 6% decrease for Europe by 2070, from 20% to 50% throughout the Mediterranean, and a reduction in usable capacity in most hydroelectric plants between 61% for the 2040 scenario– 2069 globally. DISCUSSION AND CONCLUSIONS: Globally, hydropower presents a broad vision of the advantages, and little said about the disadvantages and problems, and only there are specific studies that shown various project studied in a general way. It is shown that hydroelectric production has several implications in the face of the changing climate and impacts generated in ecosystems by the deployment of large infrastructures.