bluuebunny/crossref_metadata_2025 huggingface dataset:
Educação Alimentar e nutricional no contexto da promoção da saúde e de práticas alimentares saudáveis
Authors: Abrantes Lívia Carvalho Sette , Da Costa Glauce Dias , Gonçalves Graziele Santos Conceição , Orlando Mayra Willa Campos , Furtado Letícia Xavier , Ribeiro Isabela Egídio
Published: March 2021

A Educação Alimentar e Nutricional (EAN) é uma estratégia adotada pelas políticas públicas em Alimentação e Nutrição, sendo apontada como um importante instrumento que visa promover uma alimentação saudável de modo a estimular a autonomia do indivíduo, respeitando seus costumes e hábitos alimentares, unidos ao prazer de consumir o alimento e garantindo a Segurança Alimentar e Nutricional e o Direito Humano à Alimentação Adequada - DHAA. Sabe-se que hábitos alimentares adequados são imprescindíveis em qualquer idade, mas na infância é fundamental para o crescimento e desenvolvimento fisiológico além de possibilitar um apropriado desenvolvimento cognitivo e psicomotor. E representa também um dos principais fatores de prevenção de enfermidades durante a fase adulta. Assim, o objetivo foi implantar um projeto de promoção da saúde em um bairro carente da cidade de Viçosa – MG. Focado na EAN e baseado nos quatro pilares da educação da UNESCO: Aprender a conhecer, a fazer, a viver e a ser. O projeto foi efetivado com uma média de 100 crianças entre 3 e 12 anos de idade, atendidas por uma instituição filantrópica localizada no bairro. Foram realizadas pesquisas de campo, incluindo grupos de conversas com os pais, funcionários da instituição e com as crianças; visitas às casas das mesmas; aplicação de questionários socioeconômicos e recordatórios alimentares; rodas de conversas com representantes do bairro. Os resultados foram analisados e planos de ação foram elaborados, focando na necessidade da situação avaliada. As ações foram desenvolvidas através da realização de avaliações antropométricas; desenvolvimento de oficinas educativas; subprojetos com as crianças e com o bairro, focando na educação nutricional e alimentar e na melhoria dos hábitos de higiene e saúde. Como resultados, observou-se que as atividades de EAN foram efetivas. Houve redução do desperdício de alimentos das refeições em mais de 50% em algumas turmas e entre 70 e 100 % em outras, dados obtidos através da pesagem do resto ingestão. As oficinas educativas promoveram mudanças no hábito alimentar das crianças, tanto na instituição como em suas casas. Considerando o uso de metodologias ativas e problematizadoras, as ações de EAN obtiveram sucesso, possibilitando perceptíveis mudanças nos hábitos das crianças em relação à saúde e alimentação. Além disso, a estimulação e o despertar do senso crítico frente ao consumo alimentar possibilitou a aceitação de alimentos antes rejeitados, como folhosos, legumes e carnes. O envolvimento dos pais e familiares foi determinante para essa mudança, afetando beneficamente a vida das crianças e a instituição que as acolhe.
Indicadores antropométricos e riscos à saúde da pessoa com deficiência em uma cidade do sul de Minas
Authors: Corrêa Luís Paulo Pires , Pereira Deyliane Aparecida de Almeida
Published: March 2021

O sedentarismo e o hábito alimentar irregular ocasiona o aumento de peso e de gordura corporal no indivíduo, tornando-o mais suscetível a diversas enfermidades, portanto, os indicadores antropométricos contribuem para a predição de possíveis agravos e riscos a saúde das pessoas. Este estudo tem por objetivo identificar e analisar as prevalências e associações dos riscos à saúde das pessoas com deficiência por meio dos indicadores antropométricos (IA). Trata-se de um estudo quantitativo de corte transversal, com característica descritiva, sendo a amostra composta por 23 (correspondente a 69,7% da população deficiente do município) pessoas com deficiência de ambos os sexos, residentes em uma cidade localizada no sul de Minas Gerais. Para coleta de dados foi aferido as medidas antropométricas: massa corporal, estatura, perímetro da cintura e dobras cutâneas, para o cálculo dos indicadores. Pela análise dos dados verifica-se que a idade média é de 41 anos (DP±14) e Percentual de Gordura corporal médio de 35,63 (DP±9,30), sendo que 65,2% encontram-se com excesso de gordura corporal de acordo com a classificação do Índice de Massa corporal (IMC), já pelo Índice de Adiposidade Corporal (IAC) 85,7% apresentam este quadro. Quando analisado a Razão Cintura Quadril (RCQ) e Relação Cintura/estatura (RCE) 91,3% das pessoas com deficiência apresentam risco para o desenvolvimento de doenças crônico-cardiovasculares. Os resultados apresentados neste estudo demonstram altas prevalências de obesidade, sobrepeso e de risco para possíveis doenças crônico-degenerativas devido à falta de hábitos saudáveis de vida, como a prática de atividade física e o controle alimentar adequado, o que pode ocasionar em grande incidência a agravos e gastos em saúde. Portanto, ressalta-se a importância da criação de estratégias em políticas públicas no município para o incentivo da prática de atividades físicas para pessoas com deficiência e de reeducação alimentar com profissionais capacitados e, observa-se a relevância do uso de indicadores antropométricos por ser um método simples, de baixo custo e facilmente aplicável a um grande grupo de pessoas para diagnosticar problemas em saúde pública como aumento da gordura corporal e fatores associados.
A resolutividade da prática de grupos educativos por enfermeiros na atenção primária
Authors: Fonseca Mariana Pereira Nunes , Coutinho Fabiana de Andrade , Pimenta Laís , Lourenço Letícia Vieira , Marques Thamires Simão , Moreira Ana Carolina Fiuza
Published: March 2021

A diabetes mellitus (DM) é um distúrbio metabólico crônico, comum nos consultórios da atenção primária do Rio de Janeiro. Caracterizada pela disfunção metabólica da glicose, é responsável pelo desenvolvimento de neuropatias que configura o principal fator causal de ulcerações e amputações ocasionando prejuízos tanto emocionais ao usuário quanto financeiro ao município. Nesse sentido, é fundamental que durante o atendimento ao usuário diabético na atenção primária garanta não só o controle clínico da glicemia, mas também a vigilância dos pés através do exame clínico. No entanto, diante do elevado ritmo de atendimentos, por vezes a avaliação dos pés nem sempre é realizada durante a consulta. Dessa forma, é necessário que a equipe técnica lance mão de outras estratégias de abordagem aos usuários, de modo a garantir a abordagem integral e preventiva. Descrever a experiência de um grupo sobre pé diabético realizado em uma Unidade Básica de Saúde. A partir da discussão em uma reunião de equipe a respeito de grupos que devem ser prioritários, identificou-se a necessidade de se realizar um grupo de pé diabético. O grupo contou com onze usuários, sendo a oito mulheres e três homens, com faixa etária entre 40 e 80 anos. O grupo aconteceu em uma Clínica da Família, localizada no bairro Penha, no município do Rio de Janeiro. A atividade foi coordenada por duas enfermeiras residentes contando com o apoio de um agente comunitário de saúde, em uma quinta-feira no mês de junho de 10h00min ás 12h00min. A atividade foi separada em dois momentos: o primeiro com uma apresentação de slides estimulando a participação dos usuários, trazendo questões pertinentes da diabetes, ressaltando as complicações e orientações a respeito dos cuidados com os pés, estimulando principalmente o autocuidado. O segundo momento foi contemplado pela avaliação dos pés através do teste de sensibilidade, utilizando os monofilamentos. Os usuários mostraram-se interessados pelo assunto, participando, trazendo dúvidas e contribuições de experiências vivenciadas. Ao final todos aceitaram realizar o teste de sensibilidade, uma vez que perceberam a importância do cuidado com os pés para impedir complicações evitáveis e além disso, pudemos identificar aqueles que apresentaram alguma perda da sensibilidade. É notório que a prevenção por meio do exame frequente dos pés de pessoas com diabetes, que pode ser realizado tanto pelo médico como pela enfermeira, é de vital importância para a redução das complicações. Além disso, se torna evidente a importância do rastreamento das pessoas com diabetes, para identificar as com maior risco para ulceração nos pés, que podem se beneficiar com as orientações profiláticas, incluindo o estímulo ao autocuidado.
Influence of Sedation on the Detection Rate of Early Cancer and Precancerous Lesions During Diagnostic Upper Gastrointestinal Endoscopies: A Multicenter Retrospective Study
Authors: Zhou Jiawei , Li Zhen , Ji Rui , Wang Peizhu , Zhang Aijun , Wu Kangkang , Liu Chengxia , Niu Qiong , Chu Yanliu , Su Xiufeng , Zuo Xiuli , Li Yanqing
Published: March 2021

INTRODUCTION:

The influence of sedation on the endoscopic detection rate of upper gastrointestinal (UGI) early cancer (EC) and precancerous lesions, including high-grade intraepithelial neoplasia (HGIN) and low-grade intraepithelial neoplasia, has not been assessed. The aim of this research is to assess whether the use of sedation can help improve the detection rate of UGI EC and precancerous lesions. The second objective is to evaluate its potential influencing factors.

METHODS:

The study includes 432,202 patients from a multicenter database from January 2012 to July 2019. Information on endoscopic findings and histology biopsies was obtained from endoscopy quality-control system. Associations of sedation with the detection rate of EC and precancerous lesions were assessed.

RESULTS:

The sedation group has a higher detection rate of UGI EC and HGIN compared with the no-sedation group, whereas the detection rate of low-grade intraepithelial neoplasia was similar between the 2 groups. There were more cases examined by using staining, image enhancement, or magnifying techniques in the sedation group (P < 0.001). And, the mean observation time was also longer in the sedation group (P < 0.001). The type 0-IIb esophageal HGIN and EC cases were significantly increased in the sedation group. No significant difference was detected on lesion subtypes for gastric HGIN and EC according to the Paris classification. More gastric HGIN and EC were detected at gastric body in the sedation group (P = 0.001).

JOURNAL/ajgast/04.03/00000434-202106000-00022/inline-graphic1/v/2023-07-18T070803Z/r/image-tiff

DISCUSSION:

Sedation may improve the endoscopic detection rate of EC and HGIN in the UGI tract probably through enhancing the use of accessary endoscopic techniques, prolonging observation time, and taking more biopsies in different locations (see Visual Abstract, Supplementary Digital Content 2, http://links.lww.com/AJG/B926).
Risk and Risk Score Performance of Hepatocellular Carcinoma Development in Patients With Hepatitis B Surface Antigen Seroclearance
Authors: Park Yewan , Lee Jeong-Hoon , Sinn Dong Hyun , Park Jun Yong , Kim Minseok Albert , Kim Yoon Jun , Yoon Jung-Hwan , Kim Do Young , Ahn Sang Hoon , Kang Wonseok , Gwak Geum-Youn , Paik Yong-Han , Choi Moon Seok , Lee Joon Hyeok , Koh Kwang Cheol , Paik Seung Woon
Published: March 2021

INTRODUCTION:

Hepatocellular carcinoma (HCC) can develop among chronic hepatitis B patients after hepatitis B surface antigen (HBsAg) seroclearance. However, whether HCC risk after HBsAg seroclearance differs between antiviral therapy (AVT)-induced or spontaneous seroclearance cases and ways to identify at-risk populations remain unclear.

METHODS:

A retrospective cohort of 1,200 adult chronic hepatitis B patients who achieved HBsAg seroclearance (median age: 56 years; 824 men; 165 with cirrhosis; 216 AVT-induced cases) were analyzed. The risk of HCC after HBsAg seroclearance and the performance of 6 HCC prediction models were assessed.

RESULTS:

During a median of 4.8 years of follow-up (range: 0.5–17.8 years), HCC developed in 23 patients (1.9%). The HCC incidence rate was higher in the AVT-induced cases than that in the spontaneous cases (3.9% vs 0.9% at 5 years). AVT and cirrhosis were independent factors associated with HCC, with HCC incidence rates of 0.5%, 1.2%, 4.0%, and 10.5% at 5 years for spontaneous/no-cirrhosis, AVT-induced/no-cirrhosis, spontaneous/cirrhosis, and AVT-induced/cirrhosis patients, respectively. Among the 6 predictive HCC models tested, Chinese University-HCC score (0.82) showed the highest C-statistics, which was followed by guide with age, gender, HBV DNA, core promoter mutations and cirrhosis (0.81).

DISCUSSION:

AVT-induced HBsAg seroclearance was associated with higher HCC risk, especially for patients with cirrhosis, indicating that they need careful monitoring for HCC risk. The HCC risk models were able to stratify the HCC risk in patients with HBsAg seroclearance.
Electronic Education at the Faculty of Nuclear Sciences and Physical Engineering
Authors: Vaněček D. , Klement V.
Published: March 2021

This paper deals with the current issue of electronic education, and is based on a study of Internet support for education at the Faculty of Nuclear Sciences and Physical Engineering at the Czech Technical University in Prague.The goal of the study was to establish to what extent and in what ways electronic support for education is utilized at FNSPE CTU. In order to answer these questions, a questionnaire was conducted at the faculty. We will present the outcomes here.
Treatment of Biogas for Use as Energy
Authors: Koller J.
Published: March 2021

The biogas generated in biogas plants offers significant potential for the production of energy from renewable energy sources. The number biogas plants in the Czech Republic is expected to exceed one hundred in the near future. Substrates from agriculture, industry and municipal wastes are used for biogas production. Biogas plants usually use co-generation units to generate electricity and heat. Increased effectiveness can be achieved by using heat as a source of energy for producing renewable natural gas.
On multiple M2-brane model(s) and its N=8 Superspace Formulation(s)
Authors: Bandos I. A.
Published: March 2021

We give a brief review of Bagger-Lambert-Gustavsson (BLG) model, with emphasis on its version invariant under the volume preserving diffeomorphisms (SDiff3) symmetry. We describe the on-shell superfield formulation of this SDiff3 BLG model in standard N = 8, d = 3 superspace, as well as its superfield action in the pure spinor N = 8 superspace. We also briefly address the Aharony-Bergman-Jafferis-Maldacena (ABJM/ABJ) model invariant under SU(M)k × SU(N)−k gauge symmetry, and discuss the possible form of their N = 6 and, for the case of Chern-Simons level k = 1, 2, N = 8 superfield equations.
Gause Symmetry and Howe Duality in 4D Conformal Field Theory Models
Authors: Todorov I.
Published: March 2021

It is known that there are no local scalar Lie fields in more than two dimensions. Bilocal fields, however, which naturally arise in conformal operator product expansions, do generate infinite Lie algebras. It is demonstrated that these Lie algebras of local observables admit (highly reducible) unitary positive energy representations in a Fock space. The multiplicity of their irreducible components is governed by a compact gauge group. The mutually commuting observable algebra and gauge group form a dual pair in the sense of Howe. In a theory of local scalar fields of conformal dimension two in four space-time dimensions the associated dual pairs are constructed and classified.The paper reviews joint work of B. Bakalov, N. M. Nikolov, K.-H. Rehren and the author.
Algebraic Solutions in Open String Field Theory – a Lightning Review
Authors: Schnabl M.
Published: March 2021

In this short paper we review basic ideas of string field theory with the emphasis on the recent developments. We show how without much technicalities one can look for analytic solutions to Witten’s open string field theory. This is an expanded version of a talk given by the author over the last year at a number of occasions1 and notably at the conference Selected Topics in Mathematical and Particle Physics in honor of Prof. JiˇrLi Niederle’s 70th birthday.
Subjective Evaluation of Audiovisual Signals
Authors: Fikejz F.
Published: March 2021

This paper deals with subjective evaluation of audiovisual signals, with emphasis on the interaction between acoustic and visual quality. The subjective test is realized by a simple rating method. The audiovisual signal used in this test is a combination of images compressed by JPEG compression codec and sound samples compressed by MPEG-1 Layer III. Images and sounds have various contents. It simulates a real situation when the subject listens to compressed music and watches compressed pictures without the access to original, i.e. uncompressed signals.
Influence of Climatic Cycles on Properties of Leadfree Solders
Authors: Tučan M. , Žák P.
Published: March 2021

This paper presents complex climatic tests performed in the laboratory of climatechnology of the Department of Electrotechnology. More specifically, it presents the results of climatic shocks administered to specimens of Sn-Pb and leadfree solders, and compares the results.While the experimental results are negative regarding the use of electrical resistance as a method for tracking degradation of the joints, the research has provided a large number of specimens that can be examined for structural changes in the solder after climatic stress.
Barriers to Energy Efficiency – Focus on Transaction Costs
Authors: Valentová M.
Published: March 2021

This paper assesses the main barriers that prevent economic energy efficiency potential from being realized. The main barriers discussed here include energy prices (and prices of technology), limited access to capital, lack of information, incorrect risk assessment (i.e. setting a discount rate), the principal-agent problem and transaction costs. Transaction costs are analyzed in greater detail, as they are one way or another related to all of the barriers mentioned here. Based on the analysis, there is a discussion of implications for effective policy making. These are specially needed for transaction costs, where the availability of empirical data is very limited.
Root Asymptotics for the Eigenfunctions of Univariate Differential Operators
Authors: Shapiro B.
Published: March 2021

This paper is a brief survey of the research conducted by the author and his collaborators in the field of root asymptotics of (mostly polynomial) eigenfunctions of linear univariate differential operators with polynomial coefficients.
Application of Wavelet Transform for Image Denoising of Spatially and Time Variable Astronomical Imaging Systems
Authors: Blažek M. , Anisimova E. , Páta P.
Published: March 2021

We report on our efforts to formulate algorithms for image signal processing with the spatially and time variant Point-Spread Function (PSF) and inhomogeneous noise of real imaging systems. In this paper we focus on application of the wavelet transform for denoising of the astronomical images with complicated conditions. They influence above all accuracy of the measurements and the new source detection ability. Our aim is to test the usefulness ofWavelet transform (as the standard image processing technique) for astronomical purposes.
Robotic Astronomy and the BOOTES Network of Robotic Telescopes
Authors: Castro-Tirado A. J.
Published: March 2021

The Burst Observer and Optical Transient Exploring System (BOOTES), started in 1998 as a Spanish-Czech collaboration project, devoted to a study of optical emissions from gamma ray bursts (GRBs) that occur in the Universe. The first two BOOTES stations were located in Spain, and included medium size robotic telescopes with CCD cameras at the Cassegrain focus as well as all-sky cameras, with the two stations located 240 km apart. The first observing station (BOOTES-1) is located at ESAt (INTA-CEDEA) in Mazag´on (Huelva) and the first light was obtained in July 1998. The second observing station (BOOTES-2) is located at La Mayora (CSIC) in M´alaga and has been operating fully since July 2001. In 2009 BOOTES expanded abroad, with the third station (BOOTES-3) being installed in Blenheim (South Island, New Zealand) as result of a collaboration project with several institutions from the southern hemisphere. The fourth station (BOOTES-4) is on its way, to be deployed in 2011.
X-ray Transient Sources (Multifrequency Laboratories) The Case of the Prototype A0535+26/HDE 245770
Authors: Giovannelli F. , Sabau-Graziati L.
Published: March 2021

The goal of this paper is to discuss the behaviour of the X-ray transient source A0535+26 which is considered for historical reasons and for the huge amount of multifrequency data, spread over a period of 35 years, as the prototype of this class of objects. Transient sources are formed by a Be star — the primary — and a neutron star X-ray pulsar — the secondary — and constitute a sub-class of X-ray binary systems. We will emphasize the discovery of low-energy indicators of high-energy processes. They are UBVRI magnitudes and Balmer lines of the optical companion. Particular unusual activity of the primary star — usually at the periastron passage of the neutron star – indicates that an X-ray flare is drawing near. The shape and intensity of X-ray outbursts are dependent on the strength of the activity of the primary. We derive the optical orbital period of the system as 110.856 ± 0.02 days. By using the optical flare of December 5, 1981 (here after 811205-E) that triggered the subsequent X-ray outburst of December 13, 1981, we derive the ephemeris of the system as JD Popt−outb = JD0 (2, 444, 944) ± n(110.856 ± 0.02). Thus the passage of the neutron star at the periastron occurs with a periodicity of 110.856 ± 0.02 days and the different kinds of X-ray outbursts of A0535+26 — following the definitions reported in the review by Giovannelli & Sabau-Graziati (1992) — occur just after ∼ 8 days. The delay between optical and X-ray outbursts is just the transit time of the material coming out from the optical companion to reach the neutron star X-ray pulsar. The occurrence of X-ray “normal outbursts”, “anomalous outbursts” or “casual outbursts” is dependent on the activity of the Be star: “quiet state: steady stellar wind”, “excited state: stellar wind plus puffs of material”, and “expulsion of a shell”, respectively. In the latter case, the primary manifests a strong optical activity and the consequent strong X-ray outburst can occur in any orbital phase, with a preference at the periastron passage of the neutron star, because of its gravitational effects on the Be star.
Czech Participation in the INTEGRAL Satellite: A Review
Authors: Hudec R. , Blažek M. , Hudcová V.
Published: March 2021

The ESA INTEGRAL satellite, launched in October 2002, is the first astrophysical satellite of the European Space Agency ESA with Czech participation. The results of the first 7 years of investigations of various scientific targets e.g. cataclysmic variables, blazars, X-ray sources, and GRBs with the ESA INTEGRAL satellite with Czech participation are briefly presented and discussed.
Czech Participation in International X-Ray Observatory (IXO)
Authors: Hudec R. , Pína L. , Maršíková V. , Inneman A. , Skulinová M. , Míka M.
Published: March 2021

Here we describe the recent status of Czech participation in the IXO (International X-ray Observatory) space mission, with emphasis on the development of new technologies and test samples of X-ray mirrors with precise surfaces, based on new materials, and their applications in space. In addition, alternative X-ray optical arrangements are investigated, such as Kirkpatrick-Baez systems.
On the Intrinsic Simplicity of Spectral Variability of GRBs
Authors: Chernenko A.
Published: March 2021

In this paper we present a Multi-Scale Correlation Analysis (MSCA) of the light curves of gamma-ray bursts recorded in different energy ranges. This analysis allows us to identify time intervals where emission variability can be reduced to a single physical parameter and can therefore be robustly attributed to a single physical emitter. The properties of these intervals can then be investigated separately, and the spectral properties of individual emitters can be analysed. The signatures of hidden dynamical relations between individual emitters are also discussed.
Advanced Processing of Images Obtained from Wide-field Astronomical Optical Systems
Authors: Řeřábek M. , Páta P.
Published: March 2021

The principal aim of this paper is to present a general view of the special optical systems used for acquiring astronomical image data, commonly referred to as WFC or UWFC (Ultra Wide Field Camera), and of their transfer characteristics. UWFC image data analysis is very difficult in general, not only because the systems have so-called space variant (SV) properties. Images obtained from UWFC systems are usually incorrectly presented due to a wide range of optical aberrations and distortions. The influence of the optical aberrations increases towards the margins of the field of view. These aberrations distort the point spread function of the optical system and rapidly cut the accuracy of the measurements. This paper deals with simulation and modelling of the UWFC optical systems used in astronomy and their transfer characteristics.
Quantum Moment Map and Invariant Integration Theory on Quantum Spaces
Authors: Castro O. Osuna , Wagner E.
Published: March 2021

It is shown that, on the one hand, quantum moment maps give rise to examples for the operator-theoretic approach to invariant integration theory developed by K.-D. Kürsten and the second author, and that, on the other hand, the operator-theoretic approach to invariant integration theory is more general since it also applies to examples without a well-defined quantum moment map.
The Velocity Tensor and the Momentum Tensor
Authors: Lanczewski T.
Published: March 2021

This paper introduces a new object called the momentum tensor. Together with the velocity tensorit forms a basis for establishing the tensorial picture of classical and relativistic mechanics. Some properties of the momentum tensor are derived as well as its relation with the velocity tensor. For the sake of clarity only two-dimensional case is investigated. However, general conclusions are also valid for higher dimensional spacetimes.
Some Formulas for Legendre Functions Induced by the Poisson Transform
Authors: Shilin I. A. , Nizhnikov A. I.
Published: March 2021

Using the Poisson transform, which maps any homogeneous and infinitely differentiable function on a cone into a corresponding function on a hyperboloid, we derive some integral representations of the Legendre functions.
Relation between Cutting Surface Quality and Alloying Element Contents when Using a CO2 Laser
Authors: Litecká J. , Fabianová J. , Pavlenko S.
Published: March 2021

This paper deals with the influence of material content on changes in the quality parameters of the cutting surface when cutting with a laser. The study focuses on experiments to find the effect of material structure and cutting parameters on surface roughness, Vickers microhardness and precision of laser cutting. The experimental results are shown in graphs which illustrate the suitability of materials for achieving required cutting surface quality parameters. These results can be used for optimizing production in practical applications using a laser cutting machine.
Practical Implementation of Animation for Students of Pedagogical Studies at MIAS CTU in Prague
Authors: Vaněček D. , Jirsa J.
Published: March 2021

This paper shows computer animation as a teaching and learning instrument in technical education. Our aim is to show good practice in creating computer animations. The paper includes an example, which can serve as a practical guide for teachers of technical subjects.
Singularities in Structural Optimization of the Ziegler Pendulum
Authors: Kirillov O. N.
Published: March 2021

Structural optimization of non-conservative systems with respect to stability criteria is a research area with important applications in fluid-structure interactions, friction-induced instabilities, and civil engineering. In contrast to optimization of conservative systems where rigorously proven optimal solutions in buckling problems have been found, for nonconservative optimization problems only numerically optimized designs have been reported. The proof of optimality in non-conservative optimization problems is a mathematical challenge related to multiple eigenvalues, singularities in the stability domain, and non-convexity of the merit functional. We present here a study of optimal mass distribution in a classical Ziegler pendulum where local and global extrema can be found explicitly. In particular, for the undamped case, the two maxima of the critical flutter load correspond to a vanishing mass either in a joint or at the free end of the pendulum; in the minimum, the ratio of the masses is equal to the ratio of the stiffness coefficients. The role of the singularities on the stability boundary in the optimization is highlighted, and an extension to the damped case as well as to the case of higher degrees of freedom is discussed.
Introduction to Modeling of Buying Decisions
Authors: Gruenwald O.
Published: March 2021

Buying decision models of customers to adjust the competitiveness of organizations have been a challenge for marketing disciplines for several generations. This topic has been explored by researchers and academics in past years, and quite an extensive theoretical base exists with a number of approaches for dealing with this challenge.This paper presents some approaches for creating a customer decision model, and provides experimental results from an electronic investigation intended to build the Kano Model; to prove an ability to understand the modeling principle; and to find out the interpretation of the examined demand in a specific market segment involving students of a technical university. The last section of the paper contains a brief introduction to Choice-Based Modeling with Choice-Based Conjoint Analysis (CBC), which was tailored for modeling purchasing decisions.
Performance of Beams Made of Low-cost Self-compacting Concrete in an Aggressive Environment
Authors: Safan M. A.
Published: March 2021

Self-Compacting Concrete mixes (SCC) incorporating silica fume, fly ash and dolomite powder were used in casting two groups of beams. The beams in one group were stored in an open environment, while those in the other group were subjected to salt attack and successive wet/drying cycles. The beams were stored for about one year under a sustained load. The structural performance of the stored beams was evaluated by testing the specimens under four-point loading until failure. The results indicated that the low-cost SCC mixes showed comparable structural behavior with respect to the corresponding control mixes in a normal environment. Different SCC mixes in a corrosive environment yielded a different structural performance, depending on the composition of the fillers.
Advances in Modern Capacitive ECG Systems for Continuous Cardiovascular Monitoring
Authors: Schommartz A. , Eilebrecht B. , Wartzek T. , Walter M. , Leonhardt S.
Published: March 2021

The technique of capacitive electrocardiography (cECG) is very promising in a flexible manner. Already integrated into several everyday objects, the single lead cECG system has shown that easy-to-use measurements of electrocardiograms are possible without difficult preparation of the patients. Multi-channel cECG systems enable the extraction of ECG signals even in the presence of coupled interferences, due to the additional redundant information. Thus, this paper presents challenges for electronic hardware design to build on developments in recent years, going from the one-lead cECG system to multi-channel systems in order to provide robust measurements - e.g. even while driving an automobile.
GRS 1758–258: RXTE Monitoring of a Rare Persistent Hard State Black Hole
Authors: Obst M. , Pottschmidt K. , Lohfink A. , Wilms J. , Böck M. , Smith D. M. , Tomsick J. A. , Kreykenbohm I.
Published: March 2021

GRS 1758–258 is the least studied of the three persistent black hole X-ray binaries in our Galaxy. It is also one of only two known black hole candidates, including all black hole transients, which shows a decrease of its 3-10 keV flux when entering the thermally dominated soft state, rather than an increase.We present the spectral evolution of GRS 1758–258 from RXTE-PCA observations spanning a time of about 11 years from 1996 to 2007. During this time, seven dim soft states are detected. We also consider INTEGRAL monitoring observations of the source and compare the long-term behavior to that of the bright persistent black hole X-ray binary Cygnus X-1. We discuss the observed state transitions in the light of physical scenarios for black hole transitions.
2005–2010 Multiwavelength Campaing of OJ287
Authors: Valtonen M. , Sillanpää A.
Published: March 2021

The light curve of quasar OJ287 extends from 1891 up today without major gaps. This is partly due to extensive studies of historical plate archives by Rene Hudec and associates, and partly due to several observing campaigns in recent times. Here we summarize the results of the 2005–2010 observing campaign, in which several hundred scientists and amateur astronomers took part. The main results are the following: (1) The 2005 October optical outburst came at the expected time, thus confirming the General Relativistic precession in the binary black hole system, as was originally proposed bySillanp¨a¨a et al. (1988). At the same time, this result disproved the model of a single black hole system with accretion disk oscillations, as well as several toy models of binaries without relativistic precession. In the latter models the main outburst would have been a year later. No particular activity was seen in OJ287 in 2006 October. (2) The nature of the radiation of the 2005 October outburst was expected to be bremsstrahlung from hot gas at a temperature of 3 × 105 K. The reason for the outburst is a collision of the secondary on the accretion disk of the primary, which heats the gas to this temperature. This was confirmed by combined ground based and ultraviolet observations using the XMM-Newton X-ray telescope. (3) A secondary outburst of the same nature was expected at 2007 September 13. Within the accuracy of the observations (about 6 hours), it started at the correct time. Thus the prediction was accurate at the same level as the prediction of the return of Halley’s comet in 1986. Due to the bremsstrahlung nature of the outburst, the radiation was unpolarised, as expected. (4) Further synchrotron outbursts were expected following the two bremsstrahlung outbursts.They came as scheduled between 2007 October and 2009 December. (5) Due to the effect of the secondary on the overall direction of the jet, the parsec scale jet was expected to rotate in the sky by a large angle around 2009. This rotation has been seen in high frequency radio observations. The OJ287 binary black hole system is currently our best laboratory for testing theories of gravitation. Using OJ287, the correctness of General Relativity has now been demonstrated up to second Post-Newtonian order, higher than has been possible using binary pulsars.
Structural Variability of 3C 111 on Parsec Scales
Authors: Grossberger C. , Kadler M. , Wilms J. , Müller C. , Beuchert T. , Ros E. , Ojha R. , Aller M. , Aller H. , Angelakis E. , Fuhrmann L. , Nestoras I. , Schmidt R. , Zensus J. A. , Krichbaum T. P. , Ungerechts H. , Sievers A. , Riquelme D.
Published: March 2021

We discuss the parsec-scale structural variability of the extragalactic jet 3C111 related to a major radio flux density outburst in 2007. The data analyzed were taken within the scope of the MOJAVE, UMRAO, and F-GAMMA programs, which monitor a large sample of the radio brightest compact extragalactic jets with the VLBA, the University of Michigan 26 m, the Effelsberg 100 m, and the IRAM 30m radio telescopes. The analysis of the VLBA data is performed by fitting Gaussian model components in the visibility domain. We associate the ejection of bright features in the radio jet with a major flux-density outburst in 2007. The evolution of these features suggests the formation of a leading component andmultiple trailing components
Influence of the Surface Layer when the CMT Process Is Used for Welding Steel Sheets Treated by Nitrooxidation
Authors: Michalec I. , Marônek M.
Published: March 2021

Nitrooxidation is a non-conventional surface treatment method that can provide significantly improved mechanical properties as well as corrosion resistance. However, the surface layer is a major problem during the welding process, and welding specialists face many problems regarding the weldability of steel sheets. This paper deals with the properties of a nitrooxidized surface layer, and evaluates ways of welding steel sheets treated by nitrooxidation using a Cold Metal Transfer (CMT) process. The limited heat input and the controlled metal transfer, which are considered as the main advantage of the CMT process, have a negative impact on weld joint quality. An excessive amount of porosity is observed,probably due to the high content of nitrogen and oxygen in the surface layer of the material and the fast cooling rate of the weld pool.
FMEA and FTA Analyses of the Adhesive Joining Process using Electrically Conductive Adhesives
Authors: Povolotskaya E. , Mach P.
Published: March 2021

This paper introduces a formulation of appropriate risk estimation methods that can be used for improving of processes in the electronics area. Two risk assessment methods have been chosen with regard to the specifics of adhesive joining based on electrically conductive adhesives. The paper provides a combination of a failure mode and effect analysis (FMEA) and fault tree analysis (FTA) for optimizing of the joining process. Typical features and failures of the process are identified. Critical operations are found and actions for avoiding failures in these actions are proposed. A fault treehas been applied to the process in order to get more precise information about the steps and operations in the process, and the relations between these operations. The fault tree identifies potential failures of the process. Then the effects of the failures have been estimated by the failure mode and effect analysis method. All major differences between failure mode and effect analysis and fault tree analysis are defined and there is a discussion about how to use the two techniquescomplement each other and achieve more efficient results.
Idealized Compression Ratio for a Screw Briquetting Press
Authors: Biath Peter , Ondruška Juraj
Published: March 2021

This paper deals with issues in determining the ideal compression ratio for a screw briquetting press. First, the principles of operation and a basic description of the main parts of a screw briquetting press are introduced. The next section describes the pressing space by means of 3D software. The pressing space was created using a Boolean subtract function. The final section of the paper measures the partial volumes of the pressing chamber in CATIA V5 by function of measuring. The measured values are substituted into the formula for the compression ratio, and the resulting evaluations are presented in the diagram in the conclusion of this paper.
Measurement of O2 in the Combustion Chamber of Apulverized Coal Boiler
Authors: Janeba Břetislav , Kolovratník Michal , Bartoš Ondřej
Published: March 2021

Operational measurements of the O2 concentration in the combustion chamber of a pulverized coal boiler are not yet common practice. Operators are generally satisfied with measuring the O2 concentration in the second pass of the boiler, usually behind the economizer, where a flue gas sample is extracted for analysis in a classical analyzer. A disadvantage of this approach is that there is a very weak relation between the measured value and the condition in specific locations in the fireplace, e.g. the function of the individual burners and the combustion process as a whole. A new extractionline was developed for measuring the O2 concentration in the combustion chamber. A planar lambda probe is used in this approach. The extraction line is designed to get outputs that can be used directly for diagnosis or management of the combustion in the boiler.
Modularity of Pressing Tools for Screw Press Producing Solid Biofuels
Authors: Matúš Miloš , Križan Peter
Published: March 2021

This paper focuses on the development of the newly-patented structure of a screw briquetting machine for compacting biomass into a solid biofuel. The design of the machine is based on the results of a comprehensive study of the complicated process of biomass compaction. The patented structure meets two main goals: the elimination of axial forces, leading to increased lifetime of the bearings, and the new modular design of a pressing chamber and tools with their geometry based on the application of a mathematical model.
Influence of Various Process Parameters on the Density of Sintered Aluminium Alloys
Authors: Laska Mateusz , Kazior Jan
Published: March 2021

This paper presents the results of density measurements carried out on Alumix sintered parts. ECKA Alumix aluminium powders were used because of their wide application in the powder metallurgy industry. The compacts were produced using a wide range of compaction pressures for three different chemical compositions. The compacts were then sintered under a pure dry nitrogen atmosphere at three different temperatures. The heating and cooling rates were the same throughout the entire test. The results showed that the green density increases with compaction pressure, but that sintered density is independent of green density (compaction pressure) for each sintering temperature.
Holding Pressure and Its Influence on Quality in PIM Technology
Authors: Petera Pavel
Published: March 2021

The PIM (powder injection molding) process consists of several steps in which faults can occur. The quality of the part that is produced usually cannot be seen until the end of the process. It is therefore necessary to find a way to discover the fault earlier in the process. The cause of defects is very often “phase separation” (inhomogeneity in powder distribution), which can also be influenced by the holding pressure. This paper evaluates the powder distribution with a new method based on density measurement. Measurements were made using various holding pressure values.
Influence of the Amount of Master Alloy on the Properties of Austenitic Stainless Steel AISI 316L Powder Sintered in Hydrogen
Authors: Skaloń Mateusz , Kazior Jan
Published: March 2021

AISI 316L austenitic stainless steel powder was modified with four different amounts of boron (0.1; 0.2; 0.3; 0.4 of wt. %) in the form of MasterAlloy micro-powder, and was sintered in a pure dry hydrogen atmosphere in order to obtain high density sintered samples characterized by a thickened non-porous surface layer. We investigated the influence of the amount of boron on: density, hardness, grain microhardness, porosity, microstructure and surface quality. The study revealed that it is possible by a conventional compacting and sintering process to obtain near full-density sintered samples with a non-porous superficial layer without boride precipitations.
Gated Graphene Electrical Transport Characterization
Authors: Náhlík Josef , Janoušek Michal , Šobáň Zbyněk
Published: March 2021

Graphene is a very interesting new material, and promises attractive applications in future nanodevices. It is a 2D carbon structure with very interesting physical behavior. Graphene is an almost transparent material that has higher carrier mobility than any other material at room temperature. Graphene can therefore be used in applications such as ultrahigh-speed transistors and transparent electrodes. In this paper, we present our preliminary experiments on the transport behavior of graphene at room temperature. We measured the resistivity of Hall-bar samples depending on gate voltage (backgated graphene). Hysteresis between the forward and backward sweep direction was observed.
Hygro-Thermo-Mechanical Analysis of a Reactor Vessel
Authors: Kruis Jaroslav , Koudelka Tomáš , Krejčí Tomáš
Published: March 2021

Determining the durability of a reactor vessel requires a hygro-thermo-mechanical analysis of the vessel throughout its service life. Damage, prestress losses, distribution of heat and moisture and some other quantities are needed for a durability assessment. A coupled analysis was performed on a two-level model because of the huge demands on computer hardware. This paper deals with a hygro-thermo-mechanical analysis of a reactor vessel made of prestressed concrete with a steel inner liner. The reactor vessel is located in Temelín, Czech Republic.
RATA: A method for high-throughput identification of RNA bound transcription factors
Authors: Schmidt Karyn , Buquicchio Frank , S. Carroll Johanna , J. Distel Robert , D. Novina Carl
Published: March 2021

transcription factors is especially challenging due to inefficient RNA immunoprecipitation and low abundance of many transcription factors. Here we describe a highly sensitive, user-friendly, and inexpensive technique called RATA (RNA-associated transcription factor array), which utilizes a MS2-aptamer pulldown strategy coupled with transcription factor activation arrays for identification of transcription factors associated with a nuclear RNA of interest. RATA requires only ~5 million cells and standard molecular biology reagents for multiplexed identification of up to 96 transcription factors in 2–3 d. Thus, RATA offers significant advantages over other technologies for analysis of RNA-transcription factor interactions.
Use of chick neural tube for optimizing the PSM and epithelial somites electroporation parameters: A detailed protocol
Authors: Abu-Elmagd Muhammad
Published: March 2021

Somite myogenesis is one of the crucial early embryonic events that lead to the formation of muscular tissue. A complex of dynamic gene regulatory networks masters this event. To understand and analyze these networks, there remains a genuine need for the use of a reproducible and highly efficient gene transfer technique. In vivo electroporation has proven to be amongst the best approaches in achieving a high level of gene transfer. However, unoptimized electroporation conditions can directly cause varying degrees of cellular damage which may induce abnormal embryonic development as well as changes in the endogenous gene expression. Presegmented mesoderm and epithelial somites are not easy to electroporate. Chick neural tube has served in many functional studies as an ideal experimental model organ which is both robust and easily manipulated. In the current detailed protocol, the neural tube was used as a tool to optimize the electroporation conditions which were subsequently applied in the electroporation of the presegmented mesoderm and epithelial somites. The protocol highlights important notes and hints that enable reproducible results and could be applied in the in vivo electroporation of other chick embryo tissues.
Optimization of small-scale sample preparation for high-throughput OpenArray analysis
Authors: A. Abraham Neeta , C. Campbell Anne , D. Hirst Warren , L. Nezich Catherine
Published: March 2021

OpenArray is one of the most high-throughput qPCR platforms available but its efficiency can be limited by sample preparation methods that are slow and costly. To optimize the sample workflow for high-throughput qPCR processing by OpenArray, small-scale sample preparation methods were compared for compatibility with this system to build confidence in a method that maintains quality and accuracy while using less starting material and saving time and money. This study is the first to show that the Cells-to-CT kit can be used to prepare samples within the dynamic range of OpenArray directly from cultured cells in a single well of a 96-well plate when used together with a cDNA preamplification PCR step. Use of Cells-to-CT produced results of similar quality and accuracy to that of a preparation method using purified RNA in less than half the sample preparation time. While Cells-to-CT samples also exhibited slightly increased variance, which affects the ability of OpenArray to distinguish small differences in gene expression, overall gene expression mean results correlated well between small-scale methods. This work demonstrates that Cells-to-CT with preamplification can be used to reliably prepare samples for OpenArray analysis while saving time, money, and starting material.