bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Molybdenum on Precipitation Behaviour in Austenitic Strip-Cast Steels Containing Niobium
Authors: Jiang Lu , Marceau Ross , Dorin Thomas , Yin Huaying , Sun Xinjun , Hodgson Peter , Stanford Nikki E.
Published: September 2020

Two low-C steels microalloyed with Nb were fabricated by simulated strip casting, one with Mo and the other without Mo. Both alloys were coiled at 900 °C to investigate the effect of Mo on the precipitation behaviour in austenite in low-C strip-cast Nb steels. The mechanical properties results show that during the coiling at 900 °C the hardness of both alloys increases and reaches a peak after 3000 s and then decreased after 10,000 s. Additionally, the hardness of the Mo-containing alloy is higher than that of the Mo-free alloy in all coiling conditions. Thermo-Calc predictions suggest that MC-type carbides exist in equilibrium at 900 °C, which are confirmed by transmission electron microscopy (TEM). TEM examination shows that precipitates are formed after 1000 s of coiling in both alloys and the size of the particles is refined by the addition of Mo. Energy dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS) reveal that the carbides are enriched in Nb and N. The presence of Mo is also observed in the particles in the Nb-Mo steel during coiling. The concentration of Mo in the precipitates decreases with increasing particle size and coiling time. The precipitates in the Nb-Mo steel provide significant strengthening increments of up to 140 MPa, much higher than that in the Nb steel, ~ 96 MPa. A thermodynamic rationale is given, which explains that the enrichment of Mo in the precipitates reduces the interfacial energy between precipitates and matrix. This is likely to lower the energy barrier for their nucleation and also reduce the coarsening rate, thus leading to finer precipitates during coiling at 900 °C.
Evaluation of Heavy Commercial Vehicles Brand Considering Multi-Attribute Indexes in China
Authors: Xiong Xiaoqin , Cheng Aiguo
Published: September 2020

Assessment of brand competitiveness which influences consumer trends and company’s sales performance contributes to business development. This paper elaborates the theories and the main investigations of brand competitiveness, and formulates a comprehensive hierarchical structure integrating multi-attribute indexes, i.e., social, technical, managerial, environmental and cultural criteria. An integrated multi-criterion decision-making (MCDM) model combining with analytic hierarchy process (AHP), grey relational analysis (GRA) and VIKOR is presented to determine the weights of influence criteria and to evaluate brand competitiveness. The utilized integrated methodology has been proved to be valid and practical by the empirical application on three enterprises. The results provide an accurate and effective tool for MCDM problem and also a new guideline for the enterprise development.
Clinical effects of low-dose intravenous ketamine in obstetrics: a systematic review
Authors: Shindyapina Nataliya V. , Marshalov D. V. , Shifman E. M. , Kuligin A. V.
Published: September 2020

Introduction. Over the past decade, there has been increased attention to ketamine, which is associated with the identification of its new effects when using low (less than 1 mg/kg for bolus administration and less than 20 μg/kg/min for prolonged infusion) doses of the drug. In pregnant women, the pharmacokinetics of most drugs change, so the results of studies of low doses of ketamine obtained in other categories of patients may not be reproduced in the obstetric population.

Objectives. Assessment of the clinical effects of various doses and regimens of ketamine administration, within the subanesthetic range, in the perioperative period of cesarean section.

Material and Methods. Publications were searched in the electronic databases PubMed, MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL) by four reviewers independently. The date of the last search query was December 30, 2019.

Results. A total of 18 randomized controlled trials (RCTs) involving 2703 patients were included in the review. The results of this systematic review showed that the administration of low doses of ketamine (in the range of 0.15–0.5 mg/kg) in the perioperative period of cesarean section performed under spinal anesthesia can reduce the intensity of pain and the need for analgesics in the postoperative period. The use of low doses of ketamine under these conditions can also be useful to reduce the severity of chills, itching, and the prevention of postoperative nausea and vomiting, post-puncture headache, and postpartum depression. Doses of less than 0.5 mg/kg appear to be safer and comparatively effective in the prevention of the above complications. However, the small number and high heterogeneity of research does not allow us to draw unambiguous conclusions. The effectiveness of low doses of ketamine in the prevention of these complications with general anesthesia also remains unclear.

Conclusion. Further research and a meta-analysis of the data are necessary to obtain final conclusions.
Acute brain edema after two-sided uncomplicated cranioplasty. Clinical report and literature review
Authors: Lubnin Andrey Yu. , Potapov A. A. , Nikitenkova I. V. , Savin I. A. , Popugaev K. A. , Oshorov A. V.
Published: September 2020

We presented case report of patient with acutely developed brain edema after uncomplicated two-sided cranioplasty and manifested by signs of midbrain herniation. In discussion and review, we analyzed possible mechanism of such complication and possible role of subgaleal drainages.
Predictive role of baroreflex sensitivity in the assessment of perioperative risk. Article
Authors: Zabolotskikh Igor B. , Trembach N. V.
Published: September 2020

Violation of baroreflex sensitivity often accompanies the progression of chronic diseases. Given the fact that baroreflex dysfunction has long been known as a long-term prognostic marker of adverse cardiovascular disease outcomes, interest in the role of baroreflex sensitivity assessment in determining perioperative risk has increased significantly over the past decades. An analysis of the literature showed that for the query “baroreflex” + “anesthesia”, an automatic search in the PubMed database allows you to select 592 research papers, of which only 28 are randomized controlled trials. A significant amount of experimental and clinical data has been accumulated, indicating an important role of baroreflex during the perioperative period. The conducted research allows us to state with confidence the fact that the sensitivity of the baroreflex, equal to 3 ms/mm Hg regardless of the method of its assessment, it is a critical value below which the baroreflex function is associated with an increase in the probability of an adverse outcome, including the development of perioperative complications. The pathophysiological mechanisms underlying the increase in risk with a decrease in baroreflex sensitivity include an increase in the frequency of hemodynamic critical incidents, a greater susceptibility to the negative effects of mechanical ventilation, an increase in the need for infusion-transfusion therapy, a more pronounced pain syndrome and a violation of the immune system. The negative effect of general anesthetics and neuroaxial anesthesia on baroreflex leads to a further increase in risk. Given the role of baroreflex in the pathogenesis of perioperative disorders, the assessment of baroreflex can be a key point of an individual approach to the management of the perioperative period.
Perioperative management of patients with hypertension. Guidelines
Authors: Zabolotskikh Igor B. , Bautin A. E. , Grigoryev E. V. , Gritsan A. I. , Lebedinskii K. M. , Potievskaya V. I. , Rudnov V. A. , Subbotin V. V. , Khoronenko V. E. , Shadrin R. V.
Published: September 2020

This article described the main theses of clinical guidelines of the Russian Federation of Anesthesiologists and Reanimatologists on the perioperative management of patients with arterial hypertension. The classification of hypertension, the principles of stratification of the risk of perioperative complications associated with the patient’s hypertension in the perioperative period are presented. The principles of clinical, instrumental and laboratory diagnosis of the condition of such patients are described. The principles and approaches to the treatment of emergency and critical conditions associated with hypertension are given. An algorithm for the preoperative assessment of the patient and recommendations for planning surgical interventions in patients with arterial hypertension are given. The principles and algorithms of preoperative preparation are described in detail, including antihypertensive therapy, premedication, especially the choice and management of anesthesia, and management of the early postoperative period. All information presented in the article is based on evidence-based medicine data obtained by domestic and foreign researchers.
Evaluation of different plant extracts for effective management of fungal rot of tomato and brinjal in Kashmir Valley
Authors: Koka Jahangir Abdullah , Wani Abdul Hamid , Bhat Mohd Yaqub
Published: September 2020

The aim of present research was focused on the antifungal activities of Prunella vulgaris L and Paeonia suffruticosa Andrews via in vitro approach through agar well diffusion assay at three concentrations (25 uL, 50 uL and 75 uL) against fungi causing diseases in tomato and brinjal. All the concentration of plant extracts showed antimycotic activity against tested pathogenic fungi. Antimycotic activity increased with the increased concentrations of plant extracts. However, higher concentrations proved more effective than lower concentrations. It was revealed from the present study that the ethanolic and aqueous extracts of Prunella vulgaris L showed maximum antimycotic activity against Rhizoctonia solani and least inhibitory effect against Penicillium chrysogenum. It was further revealed from the present study that the ethanolic extract of Paeonia suffruticosa Andrews showed maximum antimycotic activity against Penicillium expansum and least activity against Mucor plumbeus. Whereas the aqueous extract of Paeonia suffruticosa Andrews showed maximum antimycotic activity against Rhizoctonia solani and Penicllium expansum and least inhibitory effect against Mucor plumbeus.
Review of frameworks and tools for urban strategic sanitation planning: considering technology innovations and sustainability
Authors: Spuhler Dorothee , Lüthi Christoph
Published: September 2020

To achieve citywide inclusive sanitation in developing countries, a strategic sanitation planning approach (SSA) needs to provide a variety of technical solutions that respond to different urban realities. Despite the development of various SSA frameworks, sanitation planning still often follows a ‘one-size-fits-all’ approach. Structured decision making (SDM) can help by balancing trade-offs among different solutions. But SDM requires a set of appropriate sanitation options to choose from. Because conventional sewer-based sanitation is often inappropriate, many novel technologies and systems have been developed (e.g. container-based sanitation). While these innovations enhance sustainability, they also increase planning complexity. In this review, we look at available frameworks and tools for SSA and discover a lack of systematic tools for the identification of planning options that are able to consider the growing portfolio of available solutions and multiple sustainability criteria. Therefore, we critically compare 15 tools from which we compile eight qualities that could help any future tool address the current sanitation challenge: it should be comprehensive, automated to deal with a large number of options, systematic, flexible towards future innovation and should consider all sustainability dimensions, make a contextualized evaluation, allow for participation, and consider uncertainties to be applicable ex-ante also for novel technologies.
Comparative analysis of linear and nonlinear equilibrium models for the removal of metronidazole by tea waste activated carbon
Authors: Ebili Peter Emmanuel , Auta Manase , Obayomi Kehinde Shola , Okafor Joseph Onyebuchi , Yahya Muibat Diekola , Faruq Aisha Abubakar
Published: September 2020

Tea waste was carbonized at 400 °C for 45 min and modified with potassium hydroxide (KOH), to enhance the active sites for the adsorption of antibiotics. The developed tea waste activated carbon (TWAC) was used as a novel eco-friendly and cost-effective adsorbent for metronidazole (MZN) removal from aqueous solution. The textural and surface properties of the adsorbent were determined using Brunauer-Emmett-Teller (BET) and FT-Raman analysis. The BET surface was found to have increased from 24.670 to 349.585 after carbonization and KOH modification. The batch experimental parameters were optimized and equilibrium time was found to be 75 min. Linear and non-linear models were carried out on the adsorption isotherm and kinetics to determine the best fit for the adsorption data. The adsorption equilibrium data were well fitted by the Freundlich isotherm and pseudo-second order models, with higher regression correlation (R2) and smaller chi-square (χ2), as predicted by the non-linear model. The thermodynamic results revealed the adsorption of MZN as spontaneous, physical, and consistently exothermic in character. The activation energy value of 7.610 kJ/mol further revealed that the adsorption process is dominated majorly by physical adsorption. The removal of MZN onto TWAC was best described by the non-linear adsorption isotherm and kinetics model.
Minería, comercio internacional e impactos ambientales en el páramo El Rabanal de Samacá, Boyacá
Authors: Buitrago Betancourt Jeffer Dario
Published: September 2020

La minería es una actividad económica que se ha desarrollado por más de un siglo en el Páramo El Rabanal, principalmente en Samacá (Boyacá), uno de los seis municipios que tiene jurisdicción en este ecosistema y que cuenta con apreciables reservas de carbón mineral. Es innegable que la minería ha contribuido a la generación de empleo, al impulso del comercio regional y a la financiación de algunas obras sociales para beneficio de la población local. No obstante, durante la última década (2009-2018), debido al repunte de los precios internacionales del carbón y el coque, las actividades de exploración y de explotación se han intensificado, ocasionando una alta presión antrópica al páramo. Por tal razón, desde la perspectiva del pensamiento ambiental, con base en un análisis de la literatura disponible, en el presente artículo se analizan algunos efectos    e impactos ambientales derivados del incremento coyuntural de la producción carbonífera en el Páramo El Rabanal, durante la última década.
COVID-19 and the Gendered Use of Emojis on Twitter: Infodemiology Study
Authors: Al-Rawi Ahmed , Siddiqi Maliha , Morgan Rosemary , Vandan Nimisha , Smith Julia , Wenham Clare
Published: September 2020

Background

The online discussion around the COVID-19 pandemic is multifaceted, and it is important to examine the different ways by which online users express themselves. Since emojis are used as effective vehicles to convey ideas and sentiments, they can offer important insight into the public’s gendered discourses about the pandemic.

Objective

This study aims at exploring how people of different genders (eg, men, women, and sex and gender minorities) are discussed in relation to COVID-19 through the study of Twitter emojis.

Methods

We collected over 50 million tweets referencing the hashtags #Covid-19 and #Covid19 for a period of more than 2 months in early 2020. Using a mixed method, we extracted three data sets containing tweets that reference men, women, and sexual and gender minorities, and we then analyzed emoji use along each gender category. We identified five major themes in our analysis including morbidity fears, health concerns, employment and financial issues, praise for frontline workers, and unique gendered emoji use. The top 600 emojis were manually classified based on their sentiment, indicating how positive, negative, or neutral each emoji is and studying their use frequencies.

Results

The findings indicate that the majority of emojis are overwhelmingly positive in nature along the different genders, but sexual and gender minorities, and to a lesser extent women, are discussed more negatively than men. There were also many differences alongside discourses of men, women, and gender minorities when certain topics were discussed, such as death, financial and employment matters, gratitude, and health care, and several unique gendered emojis were used to express specific issues like community support.

Conclusions

Emoji research can shed light on the gendered impacts of COVID-19, offering researchers an important source of information on health crises as they happen in real time.
Cybersecurity Risks in a Pandemic
Authors: Williams Christina Meilee , Chaturvedi Rahul , Chakravarthy Krishnan
Published: September 2020

Cybersecurity threats are estimated to cost the world US $6 trillion a year by 2021, and the number of attacks has increased five-fold after COVID-19. Although there is substantial literature on the threats technological vulnerabilities have on the health care industry, less research exists on how pandemics like COVID-19 are opportunistic for cybercriminals. This paper outlines why cyberattacks have been particularly problematic during COVID-19 and ways that health care industries can better protect patient data. The Office for Civil Rights has loosened enforcement of the Health Insurance Portability and Accountability Act, which, although useful in using new platforms like Zoom, has also loosened physical and technical safeguards to cyberattacks. This is especially problematic given that 90% of health care providers had already encountered data breaches. Companies must implement well-defined software upgrade procedures, should use secure networks like virtual local area networks, and conduct regular penetration tests of their systems. By understanding factors that make individuals, health care organizations, and employers more susceptible to cyberattacks, we can better prepare for the next pandemic.
The Effect of the COVID-19 Pandemic on Health Care Workers’ Anxiety Levels: Protocol for a Meta-Analysis (Preprint)
Authors: Zhang Lunbo , Yan Ming , Takashima Kaito , Guo Wenru , Yamada Yuki
Published: September 2020

BACKGROUND

The COVID-19 pandemic has been declared a public health emergency of international concern; this has caused excessive anxiety among health care workers. In addition, publication bias and low-quality publications have become widespread, which can result in the dissemination of unreliable findings.

OBJECTIVE

This paper presents the protocol for a meta-analysis with the following two aims: (1) to examine the prevalence of anxiety among health care workers and determine whether it has increased due to the COVID-19 pandemic, and (2) to investigate whether there has been an increase in publication bias.

METHODS

All related studies that were published/released from 2015 to 2020 will be searched in electronic databases (Web of Science, PubMed, PsyArXiv, and medRxiv). The risk of bias in individual studies will be assessed using the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) checklist. The heterogeneity of the studies will be assessed using the I2 statistic. The effect size (prevalence rates of anxiety) and a 95% CI for each paper will also be calculated. We will use a moderator analysis to test for the effect of COVID-19 on health care workers’ anxiety levels and detect publication bias in COVID-19 studies. We will also assess publication bias using the funnel plot and Egger regression. In case of publication bias, if studies have no homogeneity, the trim-and-fill procedure will be applied to adjust for missing studies.

RESULTS

Database searches will commence in November 2020. The meta-analysis will be completed within 2 months of the start date.

CONCLUSIONS

This meta-analysis aims to provide comprehensive evidence about whether COVID-19 increases the prevalence of anxiety among health care workers and whether there has been an increase in publication bias and a deterioration in the quality of publications due to the pandemic. The results of this meta-analysis can provide evidence to help health managers to make informed decisions related to anxiety prevention in health care workers.

INTERNATIONAL REGISTERED REPORT

PRR1-10.2196/24136
The Rising Role of Individual and Society in the Development of International Security and the Advancement of Technology; a Southern Case Study
Authors: Pratama Aditya , Rizani Lardo Naifa , Alexander Togu
Published: September 2020

The emergence of Industrial Revolution 4.0 brings uncertainty in the development of InternationalRelations. In the context of international security, the south region is the epicentre of the development, especially with the concern of continual security issues that can be started or settled through the advancement of technology. However, the concept of International Security itself does not facilitate the change that currently occurs in the international world through industry 4.0. The role of the state is recognized as an upper hand over the role of individuals and society in international relations. Industrial Revolution 4.0 stresses the significance of autonomous and interconnectivity through advanced technology. On top of that, technology has been spread to the people globally. The existence of the internet helps people to expand their capacity as an individual. The aforementioned concept extends the role of individuals and society in international relations. This influence brings uncertainty to the traditional approach of International securitythus giving way for other viable approaches. This research utilizes the postmodernism approach as outlined by Jim George with a focus on the concept of Critical Social Movement by R.B.J. Walker to provide new insights for International Relations and security studies. This will be complimented several findings of security issues in the global south that illustrate the empowerment of individuals and society through the advancement of technology and their role in international security. With its emphasis on the role of individuals and society and its statement on the unpredictability of International Relations, this approach is, therefore, essential in comprehending the discourse of International Security in the era of industry 4.0.
Rohingya Influx and Changing Gender Perception among the Host Community: the Context of Cox’s Bazar of Bangladesh
Authors: Mohiuddin Mohammad
Published: September 2020

The paper aims to understand the causes of changing gender perception in Cox’s Bazar district of Bangladesh after the Rohingya influx. Rohingyas have been playing a significant role in the life and attitude of host communities. The study revealed that Rohingya people and their culture are blending with the local people and culture which eventually is affecting the existing hosts’ tradition and practice. Even this blending is restructuring the socio-economic and religion-cultural practices of the host people. On the other hand, NGOs and INGOs are offering jobs to local women and girls. This opportunity though benefiting the stakeholders’ family is ultimately breaking the long-practiced social and religious structure of the society. By and large, the host people are conservative. Women and girls wear veils and they have no practice to work or job by going outside. So, this type of economic, societal, and cultural empowerment of women and girls sometimes contrasts with religious and social long drilled practices in the host area. Further, families who could not afford to manage any job in the camp feel frustrated and sometimes play a negative impression on the women's and girls’ mobility and job. Hence, the key question of the article is to know why the perception of gender in the host area is changing after the Rohingya arrivals. Methodologically, this is explorative research that followed the qualitative method instrumented with the Case studies, Key Informant Interviews (KIIs), and Focus Group Discussions (FGDs). The paper has also endeavored to address the changing nature of women’s empowerment and gender dimension in the host area that occurred after the Rohingya influx which is not explored yet. Therefore, this study can be a fairy source for posterior researchers.
The Growing Diversity of Chinese Negotiators during International Negotiations and Updated Negotiation Strategies
Authors: Danya Zhu , Yutong Han
Published: September 2020

This article aims to extend the notion of successful international negotiations beyond just recognizing personal and national information of the negotiators. We argue that in aggregate, international educational and life experiences of the negotiators abroad from their native/home country bring in different perspectives in the negotiation process. Thus, formulating negotiation plans targeting this specific aspect of negotiators’ profile would enlarge the probability of reaching an agreement among different parties. We particularly use the population of Chinese negotiators who have been educated abroad and/or lived abroad for an extensive length of time to illustrate our proposed mechanism of more successful negotiation process.
Wigner function for SU(1,1)
Authors: Seyfarth U. , Klimov A. B. , Guise H. de , Leuchs G. , Sanchez-Soto L. L.
Published: September 2020

In spite of their potential usefulness, Wigner functions for systems with SU(1,1) symmetry have not been explored thus far. We address this problem from a physically-motivated perspective, with an eye towards applications in modern metrology. Starting from two independent modes, and after getting rid of the irrelevant degrees of freedom, we derive in a consistent way a Wigner distribution for SU(1,1). This distribution appears as the expectation value of the displaced parity operator, which suggests a direct way to experimentally sample it. We show how this formalism works in some relevant examples.Dedication: While this manuscript was under review, we learnt with great sadness of the untimely passing of our colleague and friend Jonathan Dowling. Through his outstanding scientific work, his kind attitude, and his inimitable humor, he leaves behind a rich legacy for all of us. Our work on SU(1,1) came as a result of long conversations during his frequent visits to Erlangen. We dedicate this paper to his memory.
The opportunities of umbrella-type shells
Authors: Krivoshapko Sergey N.
Published: September 2020

Relevance. The necessity of division of umbrella surfaces and surfaces of umbrella type into two separated classes is explained in introduction. Earlier, umbrella surfaces and surfaces of umbrella type were in the same class of surfaces because they consist of the identical fragments lying on the surfaces of revolution. Umbrella surfaces are compound surfaces on the base surface of revolution but umbrella-type surfaces are kinematic surfaces formed by continuous movement of a changing curve and that is why taking into account the methods of construction of these surfaces they were divided in two separate classes. The aim of the work is a collection of main publications on all areas of the investigation of umbrella-type shells. Methods. For the determination of principal results of investigation of umbrella-type shells, it is necessary to know differential geometry of surfaces, structural mechanics of thin shells, and approaches used in architecture of spatial structures. Results. In this article, the principal scientific papers on geometry, strength analysis, and offers of applications of thin-walled shells of umbrella type in building and of reflectors of umbrella type for space apparatuses. The accurate parametric equations of some determined surfaces are presented. The approximated computer models of middle surfaces of the real umbrella shells but in the form of umbrella-type surfaces are given. The examples of determination of stress-strain state of thin-walled shells of umbrella type without dividing of the whole shell in identical fragments are shown. New information and materials already known about shells of umbrella type give reasons to suppose that the shells of this type will be claimed by engineers and architects.
Influence of the foundation bed stiffness on the dynamic properties of the building as of a multi-mass cantilever bar
Authors: Pshenichkina Valeriya A. , Drozdov Vyacheslav V. , Strok Sergey I.
Published: September 2020

Relevance. The study of the interaction of buildings and structures with the base during an earthquake is one of the most important tasks of the theory of earthquake resistance. The response of the structure to seismic impact depends to a large extent on the ratio of the stiffness characteristics of the soil, foundation, and foundation structure. Moreover, taking into account a rather high degree of statistical variability of the characteristics of the soil foundation, it is possible to ensure the required level of safety of a structure only through the use of probabilistic models and a quantitative assessment of the reliability of the construction-base system as a whole. At present, for the calculation of the construction - base system for seismic loads, deterministic discrete models of the finite element method are mainly used. But these models are poorly adapted for probabilistic calculations and require extensive statistical data, which are currently insufficient. Therefore, in problems of reliability assessment, it is advisable to use simplified analytical models, which make it possible to derive the value of the statistical variability of its reaction with relatively small initial information about the system. The aim of the work - based on the well-known solution for the single-mass model to present an analytical solution in the matrix form of the problem of free horizontal vibrations of a multi-mass cantilever rod on the foundation specified by the elastic half-space model. Methods. A study was made of the effect of the compliance of the soil foundation on the frequencies and forms of horizontal vibrations of the structure. A comparison of the results with the calculation performed by the finite element method is given. Results. The obtained solution is intended to conduct a probabilistic calculation of the construction-base system under seismic loads and evaluate its reliability.
Variación de las propiedades térmicas de polvos de carbón en función de la humedad y la distribución del tamaño de grano
Authors: Bautista Ruiz Jorge Hernando , Aperador Chaparro William , Sofía Mejía Aura
Published: September 2020

El propósito de este trabajo fue determinar el efecto de la cantidad de agua en las propiedades termofísicas de muestras de polvo de carbón con diferentes granulometrías. Se reporta el calor específico por unidad de volumen (rc) y la conductividad térmica (k) a temperatura ambiente de polvos de carbón térmico al agregarles agua entre el 5% y 50%, porcentaje peso (%wt). Las muestras fueron obtenidas de la mina Cerro Tasajero ubicada en el área metropolitana de Cúcuta, pulverizadas utilizando molino de rodillos y tamizados en malla pasante números 30 (595μm), 50 (297μm) y 100 (149μm). Las propiedades termofísicas se determinaron aplicando el principio físico de flujo lineal transitorio de calor mediante el sistema KD2. El análisis de k y rc se realizó ajustando los datos experimentales a una función logística del tipo . Se encontró que las propiedades termofísicas mejoran al aumentar el porcentaje de agua agregado a las muestras y al disminuir el tamaño de grano de los polvos de carbón.Palabras clave: carbón, distribución de tamaño de grano,función logística, granulometría, KD2, propiedades térmicas.
Evaluación del impacto acústico producido por equipos utilizados en minería subterránea de carbón
Authors: Castro Duque Yesid , Monroy Sepulveda Richard
Published: September 2020

El ruido generado por los equipos utilizados en operaciones y servicios mineros, es uno de los impactos que mayor número de incapacidades produce en los trabajadores que laboran en atmósferas subterráneas. Este estudio de evaluación del impacto ambiental producido por el ruido, se efectuó en varios frentes del sector denominado Inclinado 7, de la mina de carbón San José ubicada en el cerro Tasajero, Municipio de Cúcuta; allí, se realizó la medición del nivel sonoro continuo equivalente Leq del ruido ocupacional producido por equipos como: Ventiladores, electrobombas, martillos picadores (neumáticos) y perforadoras eléctricas. Se valoró la atenuación de este impacto, variando la distancia cada 5m. hasta llegar a 45m de la fuente. Con los resultados obtenidos se proponen medidas de gestión ambiental para el control del ruido y medidas preventivas y correctivas para mejorar el confort y la calidad ambiental bajo tierra.Palabras Clave: Ruido, impacto acústico, gestión ambiental, confort, calidad ambiental subterránea.
Automatic Learning of Ontologies for the Semantic Web: experiment lexical learning
Authors: Puerto Eduard , Aguilar Jose , Rodriguez Tatiana
Published: September 2020

Resumen Este artículo propone el diseño de un sistema para el aprendizaje automático de ontologías e información léxica (System for Automatic Learning of Ontologies and Lexical Information - SALOX) para un Marco Ontológico Dinámico Semántico para la Web Semántica (Dynamic Semantic Ontological Framework for the Semantic Web – DSOFSW). DSOFSW interpreta consultas en lenguaje natural (español) para la Web, y está compuesta por cinco partes: una ontología lingüística para la gramática del español, un lexicón para la información léxica, una base de datos de hechos sobre el sistema de experiencias, una ontología de tareas para los procesos de análisis lingüísticos, y una ontología interpretativa para el contexto. SALOX integra varios métodos, enfoques y técnicas para la extracción de información, descubrimiento y actualización (pragmática (perfil de usuario, conocimiento de contexto), información léxica y de lingüística semántica, etc.) con el fin de actualizar el conocimiento usado para DSOFSW. SALOX tiene un componente que mapea las fuentes de aprendizaje con los métodos de aprendizaje, y otro que actualiza la ontología lingüística y el lexicón del DSOFSW. Específicamente, en este artículo presentamos el diseño de la unidad de aprendizaje de información léxica. Palabras clave: Procesamiento de lenguaje natural, semántica ontológica, aprendizaje de máquina, aprendizaje ontológico, web semántica.AbstractThis paper proposes the design of a System for Automatic Learning of Ontologies and Lexical Information (SALOX) for the Dynamic Semantic Ontological Framework for the Semantic Web (DSOFSW). DSOFSW interprets query in natural language (Spanish) to the web, and is composed by five parts; a linguistic ontology for the grammar of Spanish, a lexicon for the lexical information, a database of facts about the system experiences, a task ontology for the linguistic analysis process, and an interpretative ontology of the context. SALOX integrates several methods, approaches and techniques for information extraction, discovery and actualization (pragmatic (user profile, context knowledge), lexical and semantic linguistic information, etc.) in order to update the knowledge used for DSOFSW. SALOX has a component to map the sources of learning with the learning methods, and another to update the linguistic ontology and the lexicon of the DSOFSW. Specifically, in this paper we present the design of the learning unit of lexical information. Keywords: Natural language processing, ontological semantic, machine learning, ontological leaning, semantic web.
Desarrollo de un módulo didáctico para control angular de un péndulo suspendido
Authors: Moreno Garcia Francisco Ernesto , Becerra Vargas Jose Armando , Ayala Garcia Yulianny Estephany
Published: September 2020

Este trabajo presenta el desarrollo de un módulo didáctico con la implementación de un controlador proporcional – integrativo (PI) en un péndulo suspendido, donde se regula la velocidad de la hélice de forma se obtenga el ángulo deseado y se mantenga estable ante la presencia de perturbaciones adicionadas al péndulo. Además el módulo didáctico, le fue desarrollado un sistema de adquisición de datos con un microcontrolador atmega atmel 328 en comunicación serial con la plataforma matlab® simulink®, la cual permite un monitoreamiento en línea en tiempo real del comportamiento del péndulo para sus posteriores análisis y prácticas a los estudiantes en el área de teoría control e ingeniería. El comportamiento del sistema fue satisfactorio, se alcanzaron respuestas transitorias no mayores a cuatro segundos por parte del controlador PI para estabilizar el sistema ante la presencia de perturbaciones o cambios tipo escalonado en su setpoint.Palabras clave: péndulo, controlador PI.
Model of Recommendation System for for Indexing and Retrieving the Learning Object based on Multiagent System
Authors: Rocha Campos Ronaldo Lima , Lunardi Comarella Rafaela , Azambuja Silveira Ricardo
Published: September 2020

This paper proposes a multiagent system application model for indexing, retrieving and recommendation learning objects stored in different and heterogeneous repositories. The objects within these repositories are described by filled fields using different metadata standards. The searching mechanism covers several different learning object repositories and the same object can be described in these repositories by the use of different types of fields. Aiming to improve accuracy and coverage in terms of recovering a learning object and improve the signification of the results we propose an information retrieval model based on the multiagent system approach and an ontological model to describe the knowledge domain covered.Keywords: AI in education, multi-agent systems, learning objects, recommendation systems.
La Evolución normativa de la ciberseguridad en la Unión Europea y su impacto político a nivel de actores, objetivos y recursos.
Authors: Demurtas Alessandro
Published: September 2020

This article of reflection analyses the normative evolution of cybersecurity in the European Union (EU) during the last years. It also seeks to determine its impact on actors, resources and priorities. The starting hypothesis is that cybersecurity is progressively becoming a priority in the European political agenda, for two reasons. The first is more evident and concerns the growing importance of the cyber dimension in the daily life of all actors of the international system: population, institutions, firms, national and international organizations, governmental and no governmental. The second reason is directly related with the role of the EU institutions in regional integration. EU must provide the framework for the intergovernmental cooperation, the coordination of national actions, resources and strategies of the twenty-seven Members. They share, in the great majority of cases, threats, risks and challenges against their cybersecurity.
La digitalización de las masas y los riesgos del dataísmo
Authors: Álvarez Antelo David , Enríquez Sánchez José María
Published: September 2020

The obsession with data accumulation is behind the exciting purposes put into the possibilities of information and communication technologies. From this single perspective it is usually quite common to talk about opportunities and,  associated with it, challenges. But these challenges are focused on favoring the expansion of these technologies to any area that suits them. In the midst of this exaltation, less attention is paid to the risks of exclusion, but also to the control and domination that this may imply. Precisely counteracting these dangers is one of the great challenges of the Law to safeguard the civil andpolitical guarantees of the members of the democratic society or, otherwise, to contribute to the establishment of totalitarian regimes, equally subject to legality, but not to the idea of justice.This concern is what we will try to make explicit by returning to it about the false dichotomy that is established between freedom and security, on which the so-called criminal law of the enemyabounds and how much this involves the failure of the system of guarantees in a democratic and legal State.
High proportion of mixed virus infections in raspberry plantations in Serbia
Authors: Paunovic Svetlana , Jevremovic Darko
Published: September 2020

Samples of red raspberry (Rubus idaeus L.) from the most important growing
areas in Serbia were analyzed for the presence of four most important
raspberry viruses: raspberry leaf blotch virus (RLBV), raspberry leaf mottle
virus (RLMV), black raspberry necrosis virus (BRNV) and Rubus yellow net
virus (RYNV), and their incidence in individual and mixed infected samples.
Seventy-four samples of eight raspberry cultivars, selected from 32 main
cultivation sites were tested, of which 62 leaf samples showed symptoms that
could be caused by viruses and 12 samples were asymptomatic. The presence of
viruses was tested by appropriate RT-PCR and PCR methods, using
virus-specific primers. All four viruses were detected with highly
significant differences of incidence in a total of 61 infected symptomatic
samples. Infection with one of the four tested viruses was detected in 59.0%
of all infected samples. The most prevalent was RLBV, which was associated
with raspberry leaf blotch disorder in coexistence with its vector raspberry
leaf and bud mite P. gracillis, and it was detected in 70.5% of the infected
samples. It was followed by RYNV with an incidence of 42.6%, BRNV with 36.1%
and RLMV with 9.8% incidence, considering all infected samples. The obtained
results for the first time in Serbia showed a high proportion (41.0%) of
mixed infections involving between two and four viruses. The most common
were infections with two viruses, 68.0% of all mixed-infected samples, and
among them coinfections with RLBV and RYNV (44.0%). Viruses of the raspberry
mosaic complex, BRNV, RYNV and RLMV, including coinfections of 2-3 listed
viruses along with RLBV, were found in a high joined proportion of 14.7% of
all infected samples, i.e. 36.0% of mixed infected samples.
Morphological, cultural and ecological characterization of Monilinia spp., pathogens of stone fruit in Serbia
Authors: Hrustic Jovana , Mihajlovic Milica , Tanovic Brankica
Published: September 2020

Different brown rot pathogens cause similar symptoms on fruit, which makes it
difficult to differentiate them based only on developed symptoms. Therefore,
several methods have been described for accurate identification of Monilinia
species. In spite of the fact that those methods can be reliable, there are
several limitations for their use, and the aim of this study was to find out
if there are any specific characteristics that could be used as additional
features for precise identification and in-depth characterization of
Monilinia species. The results showed that morphological characteristics on
PDA, and mycelium growth rate on PDA medium can be useful characters for
differentiation of Monilinia species since M. fructicola was found to grow
faster than the other two test species, while M. fructigena grew the
slowest. MALT was the optimal medium for M. laxa and M. fructigena isolates,
while PDA medium was optimal for M. fructicola. Regarding an extremely
acidic medium (pH 2), only M. laxa and M. fructicola isolates were able to
grow in it, while M. fructigena isolate was the only that grew in a
moderately alkaline medium (pH 9). Also, the results revealed that the
optimal temperature for M. fructigena and M. fructicola growth was 23oC,
while 28oC was optimal for M. laxa isolate. On the other hand, some
differences in the sensitivity of Monilinia isolates were revealed at
extreme temperatures: M. fructigena isolate was the most sensitive (grew
from 4?C to up to 31?C), while M. fructicola isolate was the most resistant
(grew at 2?C and 34?C). The obtained results inferred that there are no
specific features that can be used for reliable and precise identification
of Monilinia species, but we observed some differences regarding the effects
of extreme temperatures and pH values of culture medium on different
species. Further research, involving more isolates, is needed for a final
conclusion.
Genotoxicity test methods - a tool for DNA and chromosome damage biomonitoring
Authors: Velickova Nevenka , Milev Misko
Published: September 2020

Nowadays, life is highly influenced by intense growth of various industries, high levels of pollution, and other environmental factors with harmful effects on human health. Therefore, cytogenetic monitoring is essential for detection of changes in the structure of chromosomes, which occur because of the effects of various genotoxic agents. In this review, we shall apprize the theoretical and experimental aspects of several tests for assessment of genotoxicity in humans such as Micronucleus assay, Comet assay, Chromosomal aberrations assessment and Sister chromatid exchanges analysis. These methods are accepted by the World Health Organization as standard tests for genotoxicological screening in humans. The methods are sensitive and confirm the cellular genotoxic effects of various genotoxicants.
An experimentally validated control strategy to optimize power generation quality for waste heat recovery system
Authors: Xiao Yanjun , Wang Jing , Zhang Yameng , Meng Zhaozong , Wan Feng , Zhou Wei , Jiang Yunfeng
Published: September 2020

Roots-type engine is suitable for small power generation system fuelled by waste heat. The disorderly fluctuations of the waste heat source upstream of the power generation process and changes in external environmental factors cause the working parameters of the device to change, which makes the speed of roots engine unstable, and the output power quality of the system is not good. For this problem, this paper starts from the control structure and control strategy to improve the adjustment speed and anti-interference ability of the control system. In this contribution, the model transformation of the dynamic work unit of waste heat power generation device from engineering to theoretical model is performed, the temperature of working gas and the speed of output shaft of roots engine are determined as control objects, and the internal mode control strategy is introduced to optimize the controller of the system. Simulation results are in good agreement with the measurements, which verify that the optimized control system can effectively improve the following ability and anti-interference of the system, and shorten the response time.
Aero-engine exhaust gas temperature prediction based on LightGBM optimized by improved bat algorithm
Authors: Li Dingzhe , Peng Jingbo , He Dawei
Published: September 2020

In this paper, an aero-engine exhaust gas temperature prediction model based on LightGBM optimized by the chaotic rate bat algorithm is proposed to monitor aero-engine performance effectively. By introducing chaotic rate, the convergence speed and precision of bat algorithm are improved, which chaotic rate bat algorithm is obtained. The LightGBM is optimized by chaotic rate bat algorithm and it is used to predict exhaust gas temperature. Taking a type of aero-engine for example, some relevant performance parameters from the flight data measured by airborne sensors were selected as input variables and exhaust gas temperature as output variables. The data set is divided into training and test sets, and the CRBA-LightGBM model is trained and tested, and compared with ensemble algorithms such as RF, XGBoost, GBDT, LightGBM, and BA-LightGBM. The results show that the mean absolute error of this method in the prediction of exhaust gas temperature (after normalization) is 0.0065, the mean absolute percentage error is 0.77% and goodness of fit R2 has reached to 0.9469. The prediction effect of CRBA-LightGBM is better than other comparison algorithms and it is suitable for aero-engine condition monitoring.