bluuebunny/crossref_metadata_2025 huggingface dataset:
Ensino profissional e tecnológico na pandemia COVID-19: contexto político e educacional
Authors: Garcia José Antonio Dias , Carvalho Maria das Graças de Souza , Lima Samuel José Fernandes de , Alves Laís Roncato de Carvalho , Silva Aline Guerrera Santos , Oliveira Felipe Santana , Pereira Flávia Helena , Schimidt Fernanda Mateus Queiroz , Mota Kárita Santos da , Almeida Dérica Karoly Evarista , Carvalho Filho Cloves Gomes de
Published: December 2020

Durante o enfrentamento da pandemia pela COVID-19, foi necessário adotar medidas alternativas no contexto político-educacional de modo a manter o ano letivo. O objetivo do estudo foi apresentar as medidas deliberadas pelo setor político na área educacional durante a pandemia e refletir o impacto social dessas medidas no ensino profissional e tecnológico. Nessa revisão qualitativa os artigos, publicados em 2020, foram selecionados nas bases de dados Scielo e Google Acadêmico.  Após revisar as medidas deliberadas pelo setor político-educacional, notou-se que essas foram baseadas em um modelo geral, sem considerar as dificuldades de acesso e a qualidade de ensino a ser ofertado. As instituições de ensino público sinalizaram que uma parcela dos estudantes não possui acesso à internet, o que impacta diretamente no acesso ao ensino de qualidade, aumentando os índices de evasão escolar. Nota-se que as instituições de ensino federal desenvolveram mecanismos internos para incluir os estudantes sem acesso à internet. Contudo, a falta de acesso aos computadores e à internet por estudantes da rede pública é um problema existente desde antes da pandemia. A relação política e social no contexto educacional é complexa. Esforços vêm sendo realizados pela comunidade escolar no sentido de democratizar o ensino para todos os estudantes durante o período de pandemia. Sugerimos que para melhor aplicabilidade do ensino remoto durante a pandemia, deverão ser realizados mais investimentos por parte dos órgãos governamentais no sentido de possibilitar acesso a todos os estudantes da EPT e diminuir os índices de evasão escolar e a desigualdades sociais.
Rheological behavior and texture of corn starch gels (Zea mays), arrowroot (Maranta arundinaceaea L.) and cassava (Manihote sculenta Crantz)
Authors: Araújo Mariana Silva , Afonso Marcus Vinícius da Rocha , Mendes Nathalia da Silva Rodrigues , Souza Adriana Régia Marques de , Silveira Miriam Fontes Araújo , Carvalho Deivis de Moraes
Published: December 2020

The main energy reserve in plants is starch. It is unique among polysaccarides for being in the form of granules. Starch granules are heterogeneous mixtures of amylose and amylopectin. Gelatinization and retrogradation of starch depend on the ratio of amylose to amylopectin, type of crystallinity, along with the sizes and structure of starch granules. The present work determined the rheological behavior in a dynamic state, in terms of sweeping frequency, time and temperature, in addition to the extrusion of corn starch gels and arrowroot and cassava starches. The rheological study demonstrated that in all samples analyzed, whether in a non-gelatinized liquid mixture or in the form of gels, behaved as non-Newtonian fluids independent of time. Non-gelatinized mixtures showed properties of dilating non-Newtonian fluids and the gels of pseudoplastic non-Newtonian fluids. Gels were classified as elastic, as it was found that the storage module is larger than the dissipation module with the storage module decreasing with increasing temperature, and thus temperature dependent. With increased temperature, the gels showed low stability which is characteristic of weak gels. The more elastic the gel, the greater its resistance and the corn starch gel was the most resistant when compared to arrowroot and cassava starch.
Lesões fatais em região crânio-facial em mulheres: análise post-mortem
Authors: Ribeiro Maria Luisa Soares , Laureano Filho José Rodrigues
Published: December 2020

O objetivo desse estudo foi identificar o perfil epidemiológico e padrão dos ferimentos letais em mulheres vítimas de homicídio apresentando lesões na região crânio-facial como causa morte, no período de janeiro a dezembro de 2018. Tratou-se de um estudo transversal, retrospectivo, descritivo realizado através da avaliação de laudos tanatológicos em um instituto de medicina forense. Diante dos critérios de inclusão da pesquisa a amostra foi de 62 casos, com predomínio de mulheres com faixa etária de 19 a 29 anos (46,9%), pardas/pretas (76,9%), acontecendo em dias de semana e realizado em vias públicas. As lesões mais prevalentes foram feitas utilizando o instrumento perfuro-contundente (83,4%), transfixante (43,8%), com ocorrência de fraturas no crânio (81,2%) e em 8,2%. na face. Os resultados apresentaram que o gênero feminino reflete perfil sociodemográfico semelhante ao das vítimas globais de homicídios no país, e o padrão das lesões que provocam a morte de mulheres na crânio-facial é composto de lesões realizadas por instrumento de alta energia que produz importantes danos e fraturas nas estruturas da região.
A Visão Mecanicista de Taylor e Ford presente na Regulamentação da Atividade Docente: um estudo de caso
Authors: Nunes Carlos Henrique dos Santos , Rezende Paula Andréa de Oliveira e Silva , Costa Júnior Edio da
Published: December 2020

A estrutura das escolas na atualidade está ligada à visão e aos valores dos atores envolvidos no processo de ensino e aprendizagem. A visão mecanicista de Taylor e Ford, no que tange ao controle exercido nas organizações empresariais ao longo do Século XX, contrapõe à visão orgânica da modernidade, presente no processo de ensino e aprendizagem atual e vivenciada pelos docentes em suas atividades laborais. A pesquisa foi desenvolvida em uma instituição pública de nível técnico, tecnológico e superior com os objetivos de: verificar se o Regulamento da Atividade Docente (RAD) continha características mecanicistas das teorias tayloristas e fordistas; compreender o nível de conhecimento dos docentes sobre o RAD e verificar as contribuições do controle exercido pela gestão sobre as atividades dos professores. A metodologia de pesquisa é classificada como descritiva com abordagem qualitativa e estudo de caso. Elaborou-se um levantamento bibliográfico sobre a legislação que norteia a atividade docente na instituição e utilizou-se um questionário estruturado e não disfarçado com questões objetivas e discursivas. Conclui-se que o RAD possui a padronização, a divisão do trabalho e o controle apregoados por Taylor e Ford, devendo ser melhorado para atender aos aspectos individuais da profissão. Evidencia-se que, na busca da produtividade, a gestão deixa à margem a visão orgânica e flexível da sociedade contemporânea e que o instrumento pouco contribui para aperfeiçoamento profissional do docente, para a motivação e melhoria das atividades desenvolvidas e, dentro da organização pesquisada, é utilizado principalmente para atender a legislação em vigor.
A családterápia és a dialógusfilozófia találkozása – 100 éve született Böszörményi-Nagy Iván
Authors: Kelemen Gábor
Published: December 2020

A tanulmány a legnagyobb magyar származású családterapeuta, a munkásságát Ame­rikában kibontó Böszörményi-Nagy Iván (BNI) főbb terápiás újításaival foglalkozik, azok filozófiai alapjainak tükrében. A szerző, kitérve BNI életútjára, bemutatja elméletének filozófiai gyökereit, mindenekelőtt Martin Buber dialógusfilozófiáját, ezen belül az emberi világ rendjét sértő eg­zisz­tenciális bűn koncepcióját. A kontextuális terápiát és annak fő dimenzióját, a méltányosság etikáját kidolgozó BNI abból in­dult ki, hogy a családi élet elválaszthatatlan a kölcsönös megbízhatóság és a cselekvéseinkért vállalt felelősség kérdésétől. A ma­ga idejében úttörő terápiás megközelítés, mindenekelőtt a több szempontú ér­dek­kép­viselet attitűdje és módszere, ma is igen korszerű. Ez az irányvonal minden po­ten­ciálisan érintett személy emberségét, szolidaritását és felelősségét magában foglalja, és mindmáig a pszichoterápiás gyakorlat széles körének szilárd, összehangoló elve maradt.
Örgütsel Adalet ile Bağlılık Kavramlarının Doğası ve İlişkisi: Sağlık Sektörü Bağlamında Bir Araştırma
Authors: ŞAHİN Serap , AYYILDIZ Nazlı
Published: December 2020

Örgütsel adalet ve bağlılık, birey, grup ve örgüt düzeyinde olumlu çıktılar elde edebilmede sağladıkları katkılar nedeniyle hem ulusal hem de uluslararası yazında sıklıkla üzerine çalışılan konulardır. Bu çerçevede, bu çalışma ile sağlık sektöründe çalışanların örgütsel adalet algıları ile örgütsel bağlılıkları arasındaki ilişki açığa çıkartılarak örgütsel adalet algısının örgütsel bağlılık üzerindeki etkisi anket tekniği ile toplanan verilerin analizi sonucunda ortaya konmuştur. Bununla birlikte örgütsel adalet ve bağlılık kavramlarını etkileyen dinamikler gerçekleştirilen derinlemesine görüşmeler aracılığı ile örgütsel bağlam genelinde ve kamu sağlık sektörü özelinde tanımlanmaya çalışılmıştır.
Araştırma sonucunda örgütsel adalet ve alt boyutları olan süreç, dağıtım ve etkileşim adaleti ile örgütsel bağlılık ve alt boyutları olan duygusal, devam ve normatif bağlılık arasında pozitif yönlü anlamlı ilişkiler tespit edilmiş ve örgütsel adaletin örgütsel bağlılığın yordayıcısı olduğu ortaya konmuştur. Çalışanların adalet algılarının ve örgütsel bağlılık düzeylerinin demografik değişkenlere göre farklılaştığı tespit edilmiştir. Derinlemesine görüşmelerden elde edilen bulgular ile ise adalet ve bağlılık kavramları ve ilişkilerinin altında yatan dinamikler açığa çıkartılarak bütünsel ve derinlemesine bir değerlendirme yapılmaya çalışılmıştır. Bununla birlikte, çalışanların adalet algısının geliştirilmesi ve örgüte bağlılığının arttırılabilmesi için öneriler geliştirilmiştir.
Functional Characterization of Primordial Protein Repair Enzyme M38 Metallo-Peptidase From Fervidobacterium islandicum AW-1
Authors: La Jae Won , Dhanasingh Immanuel , Jang Hyeonha , Lee Sung Haeng , Lee Dong-Woo
Published: December 2020

The NA23_RS08100 gene of Fervidobacterium islandicum AW-1 encodes a keratin-degrading β-aspartyl peptidase (FiBAP) that is highly expressed under starvation conditions. Herein, we expressed the gene in Escherichia coli, purified the recombinant enzyme to homogeneity, and investigated its function. The 318 kDa recombinant FiBAP enzyme exhibited maximal activity at 80°C and pH 7.0 in the presence of Zn2+. Size-exclusion chromatography revealed that the native enzyme is an octamer comprising a tetramer of dimers; this was further supported by determination of its crystal structure at 2.6 Å resolution. Consistently, the structure of FiBAP revealed three additional salt bridges in each dimer, involving 12 ionic interactions that might contribute to its high thermostability. In addition, the co-crystal structure containing the substrate analog N-carbobenzoxy-β-Asp-Leu at 2.7 Å resolution revealed binuclear Zn2+-mediated substrate binding, suggesting that FiBAP is a hyperthermophilic type-I IadA, in accordance with sequence-based phylogenetic analysis. Indeed, complementation of a Leu auxotrophic E. coli mutant strain (ΔiadA and ΔleuB) with FiBAP enabled the mutant strain to grow on isoAsp-Leu peptides. Remarkably, LC-MS/MS analysis of soluble keratin hydrolysates revealed that FiBAP not only cleaves the C-terminus of isoAsp residues but also has a relatively broad substrate specificity toward α-peptide bonds. Moreover, heat shock-induced protein aggregates retarded bacterial growth, but expression of BAP alleviated the growth defect by degrading damaged proteins. Taken together, these results suggest that the viability of hyperthermophiles under stressful conditions may rely on the activity of BAP within cellular protein repair systems.
Lung Adenocarcinoma Harboring EGFR Kinase Domain Duplication (EGFR-KDD) Confers Sensitivity to Osimertinib and Nivolumab: A Case Report
Authors: Li Jie , Yan Junrong , Cao Ran , Du Guanjun , Zhao Guofang
Published: December 2020

Background

Kinase domain duplication of EGFR (EGFR-KDD) is a rare oncogenic driver alteration and serves as a potential therapeutic target. Its effect on EGFR–tyrosine kinase inhibitors (TKIs), especially the third-generation drug Osimertinib, and immune checkpoint inhibitors (ICIs) remains inconclusive.

Case Presentation

A 45-year old male with lung adenocarcinoma progressed with liver metastasis after receiving pemetrexed and cisplatin as adjuvant chemotherapy. Targeted next-generation sequencing (NGS) identified an EGFR-KDD in the resected left upper lung. Icotinib was used in the following treatment and the liver metastasis was found to shrink but the progression-free survival (PFS) only lasted for 4 months with the appearance of right hepatic metastasis. Meantime, the same EGFR-KDD was identified in the left hepatic re-biopsy. Afterward, the patient benefited from the third-line therapy of Osimertinib with a PFS as long as 21 months. Then he progressed with enlarged mediastinal lymph nodes, and targeted NGS consistently identified EGFR-KDD, as well as a new RELN p.G1774E mutation. Given the continually increasing tumor mutation burden (TMB, 3.4 mutation/Mb) and PD-L1 expression-based tumor proportion score (TPS, 1%), Nivolumab was used as the fourth-line salvage therapy, which lead to considerable efficacy, with decreased blood carcinoembryonic antigen (CEA), regressed mediastinal lymph nodes, and reduced liver metastases.

Conclusions

Our case provided direct evidence to support the role of Osimertinib in the treatment of EGFR-KDD, as well as added valuable insights into application of immune-based therapeutics in the specific subgroups bearing EGFR alteration(s).
Ten Years of ‘Flying the Flag’: An Overview and Retrospective Consideration of the Active School Flag Physical Activity Initiative for Children—Design, Development & Evaluation
Authors: Belton Sarahjane , Britton Úna , Murtagh Elaine , Meegan Sarah , Duff Christina , McGann Jamie
Published: December 2020

Whole-school physical activity (PA) promotion programmes are recommended to increase youth PA. Evaluation of programmes is essential to ensure practice is guided by evidence. This paper evaluates the Active School Flag (ASF), a whole-school PA promotion programme in Ireland, using the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework. ASF was evaluated across three levels—(1) administration, (2) application, (3) outcomes—using a mixed-methods case study design. Existing data sources were reviewed, the programme coordinator was interviewed, and a pilot study was conducted to investigate impact on 3rd and 5th class students (3 schools, n = 126 students, age range 8–12 years). In-school Moderate to Vigorous Physical Activity (MVPA; by accelerometery), motivation for PA (BREQ), PA self-efficacy (PASES), school affect and peer social support (Kidscreen27) were measured pre-programme (0 months), post-programme (8 months), and at retention (12 months). Teacher perceptions of classroom behaviour (CBAST) were also measured pre- and post-programme. ASF has been successful in engaging 46% of primary schools nationally. Students’ in-school moderate–vigorous PA increased in all pilot-study schools from pre-programme to retention (η2 = 0.68–0.84). ASF programme design facilitates implementation fidelity, adoption and maintenance through buy in from schools and government stakeholders. ASF presents as an effective PA promotion programme in the short-to-medium term for primary schools. This RE-AIM evaluation provides evidence of ASF effectiveness, alongside valuable findings that could support programme improvement, and inform future similar programmes.
Gastroschisis: A State-of-the-Art Review
Authors: Bhat Vishwanath , Moront Matthew , Bhandari Vineet
Published: December 2020

Gastroschisis, the most common type of abdominal wall defect, has seen a steady increase in its prevalence over the past several decades. It is identified, both prenatally and postnatally, by the location of the defect, most often to the right of a normally-inserted umbilical cord. It disproportionately affects young mothers, and appears to be associated with environmental factors. However, the contribution of genetic factors to the overall risk remains unknown. While approximately 10% of infants with gastroschisis have intestinal atresia, extraintestinal anomalies are rare. Prenatal ultrasound scans are useful for early diagnosis and identification of features that predict a high likelihood of associated bowel atresia. The timing and mode of delivery for mothers with fetuses with gastroschisis have been somewhat controversial, but there is no convincing evidence to support routine preterm delivery or elective cesarean section in the absence of obstetric indications. Postnatal surgical management is dictated by the condition of the bowel and the abdominal domain. The surgical options include either primary reduction and closure or staged reduction with placement of a silo followed by delayed closure. The overall prognosis for infants with gastroschisis, in terms of both survival as well as long-term outcomes, is excellent. However, the management and outcomes of a subset of infants with complex gastroschisis, especially those who develop short bowel syndrome (SBS), remains challenging. Future research should be directed towards identification of epidemiological factors contributing to its rising incidence, improvement in the management of SBS, and obstetric/fetal interventions to minimize intestinal damage.
An Approach to Early Detection of Metabolic Syndrome through Non-Invasive Methods in Obese Children
Authors: Molina-Luque Rafael , Ulloa Natalia , Gleisner Andrea , Zilic Martin , Romero-Saldaña Manuel , Molina-Recio Guillermo
Published: December 2020

Background: Metabolic Syndrome (MetS) has a high prevalence in children, and its presence increases in those with a high BMI. This fact confirms the need for early detection to avoid the development of other comorbidities. Non-invasive variables are presented as a cost-effective and easy to apply alternative in any clinical setting. Aim: To propose a non-invasive method for the early diagnosis of MetS in overweight and obese Chilean children. Methods: We conducted a cross-sectional study on 221 children aged 6 to 11 years. We carried out multivariate logistic regressions, receiver operating characteristic curves, and discriminant analysis to determine the predictive capacity of non-invasive variables. The proposed new method for early detection of MetS is based on clinical decision trees. Results: The prevalence of MetS was 26.7%. The area under the curve for the BMI and waist circumference was 0.827 and 0.808, respectively. Two decision trees were calculated: the first included blood pressure (≥104.5/69 mmHg), BMI (≥23.5 Kg/m2) and WHtR (≥0.55); the second used BMI (≥23.5 Kg/m2) and WHtR (≥0.55), with validity index of 74.7% and 80.5%, respectively. Conclusions: Early detection of MetS is possible through non-invasive methods in overweight and obese children. Two models (Clinical decision trees) based on anthropometric (non-invasive) variables with acceptable validity indexes have been presented. Clinical decision trees can be applied in different clinical and non-clinical settings, adapting to the tools available, being an economical and easy to measurement option. These methods reduce the use of blood tests to those patients who require confirmation.
Exploring the Spectrum of Kidney Ciliopathies
Authors: Santoni Matteo , Piva Francesco , Cimadamore Alessia , Giulietti Matteo , Battelli Nicola , Montironi Rodolfo , Cosmai Laura , Porta Camillo
Published: December 2020

Ciliopathies are a group of multi-organ diseases caused by the disruption of the primary cilium. This event leads to a variety of kidney disorders, including nephronophthisis, renal cystic dysplasia, and renal cell carcinoma (RCC). Primary cilium contributes to the regulation of the cell cycle and protein homeostasis, that is, the balance between protein synthesis and degradation by acting on the ubiquitin-proteasome system, autophagy, and mTOR signaling. Many proteins are involved in renal ciliopathies. In particular, fibrocystin (PKHD1) is involved in autosomal recessive polycystic kidney disease (ARPKD), while polycystin-1 (PKD1) and polycystin-2 (PKD2) are implicated in autosomal dominant polycystic kidney disease (ADPKD). Moreover, primary cilia are associated with essential signaling pathways, such as Hedgehog, Wnt, and Platelet-Derived Growth Factor (PDGF). In this review, we focused on the ciliopathies associated with kidney diseases, exploring genes and signaling pathways associated with primary cilium and the potential role of cilia as therapeutic targets in renal disorders.
Conceptual Model of Measuring MHEI Efficiency
Authors: Gundić Ana , Županović Dino , Grbić Luka , Baric Mate
Published: December 2020

Modern societies, new technical equipment and technology confirm the importance of knowledge acquisition in everyday life, especially in economy. An education system is a non-profit system. Since it strongly affects economic efficiency, its quantification becomes a very complex process. In order to make the quantification process possible, this paper analyses the already existing criteria for measuring efficiency in higher education systems. The already existing models of measuring educational efficiency are universal and do not analyse different professions’ specific qualities. In this paper, models of measuring educational efficiency were analysed separately, whereas their interrelations were not a part of the analysis. A conceptual model of measuring maritime higher education institutions’ (hereinafter: MHEI) efficiency was proposed on the basis of the above-mentioned analysis. All the evaluation criteria relevant for MHEI and their interrelations were determined.
An Anonymous Mutual Authentication Scheme for RFID-Based Transportation System
Authors: Ji Sai , Liu Shuai , Wang Chen , Qi Rongxin , Shen Jian
Published: December 2020

In traditional transportation, each driver usually relies on their experience to determine an appropriate route, which may shorten the driving time and transport cost. However, this may also lead to a waste of time in traffic jams or due to other problems. In recent years, by introducing Internet of Things technology into the transportation system, traffic condition data can be collected and analyzed in real-time, which makes it easier for drivers to choose appropriate routes. However, the transmitted data may be intercepted or falsified, especially in untrusted public communication channels. Some schemes have been proposed to protect personal data, while they are vulnerable to some known attacks. Therefore, we propose a mutual authentication scheme for session key agreement and information encryption before transmitting personal data. This scheme can correctly identify vehicles and information. The Burrows–Abadi–Needham logic proof and our security discussion demonstrate that this authentication scheme can resist the various known attacks, including de-synchronization, the replay attack and the reader lost attack, which is solved for the first time in this field. Compared with some typical schemes, the performance analysis shows that this new scheme realizes a balance between security and computing costs.
PA-LIRS: An Adaptive Page Replacement Algorithm for NAND Flash Memory
Authors: Wang Fangjun , Jiang Xianliang , Huang Jifu , Chen Fuguang
Published: December 2020

NAND flash memory is increasingly widely used as a storage medium due to its compact size, high reliability, low-power consumption, and high I/O speed. It is important to select a powerful and intelligent page replacement algorithm for NAND flash-based storage systems. However, the features of NAND flash, such as the asymmetric I/O costs and limited erasure lifetime, are not fully taken into account by traditional strategies. In order to address these existing shortcomings, this paper suggests a new page replacement algorithm, called probability-based adjustable algorithm onlow inter-reference recency set (PA-LIRS). PA-LIRS completely exploits the “recency” and “frequency” information simultaneously to make a replacement decision. PA-LIRS gives a greater probability to clean pages and a smaller probability to dirty pages when evict selection happens. In addition, this proposed algorithm dynamically adjusts the parameter based on the workload pattern to further improve the I/O performance of NAND flash memory. Through a series of comparative experiments on various types of synthetic traces, the results show that PA-LIRS outperforms the previous studies in most cases.
Clarification of Catalytic Effect on Large Stretchable and Compressible Rubber Dye-Sensitized Solar Cells
Authors: Shimada Kunio , Kikura Hiroshige , Ikeda Ryo , Takahashi Hideharu
Published: December 2020

Rubber involving magnetic compound fluid (MCF) and TiO2 is effective in dye-sensitized solar cells (DSSCs) to create large efficacy. Wearable and portable solar cells made of MCF rubber are the most desirable as soft materials in robots or flexible devices, and they are further desirable because they have self-generated power and power supply with sensing. Therefore, we investigated the effect of TiO2 catalysts on the photovoltaic effect of MCF rubber DSSCs under large tension and compression. The characteristics of the built-in electricity and photoelectricity were clarified experimentally. The experimental results were explained by a chemical–photovoltaic mechanism involving the behavior of dye, electrolytes, water, and rubber molecules, as well as a catalytic effect of the metal component of the MCF on Ni, Fe3O4, and TiO2. Once we are able to produce solar cells that have large tension and compression, the present experimental results and the model of the chemical–photovoltaic mechanism will be of great interest.
Dynamic Modelling of Causal Relationship between Energy Consumption, CO2 Emission, and Economic Growth in SE Asian Countries
Authors: Chontanawat Jaruwan
Published: December 2020

Southeast Asian region is fast growing in terms of economy with rapid population growth, high energy consumption, and pollution. Understanding these linkages are crucial to guidance of appropriate policy. This study aims to examine the causal relationship between energy consumption with economic growth and CO2 emissions of the four selected Asian countries, namely Indonesia, Malaysia, Philippines, and Thailand between the years 1971–2017 using Johansen cointegration method combined with Granger causality model. The results found the evidence of cointegration in all countries implying a long-run relationship among energy consumption, economy and pollution exists. The causality main results show the evidence of unidirectional causality running from economic growth to energy consumption in Indonesia, Malaysia, and Thailand, while the opposite direction was found in Philippines. The results of Indonesia, Malaysia, and Thailand support “conservative hypothesis” suggesting that energy conservation policies could be adopted in these countries as it would not constrain growth of the economies. Whereas the results of Philippines appear to support “growth hypothesis” implying that energy is a key driver to stimulate economy. Limiting the use of energy could affect the economy. Instead, the policies, therefore, should focus on promoting other alternative energy source such as renewable energy in order to maintain sustainable growth.
Harmonic Overvoltage Analysis of Electric Railways in a Wide Frequency Range Based on Relative Frequency Relationships of the Vehicle–Grid Coupling System
Authors: Liu Qiujiang , Sun Binghan , Yang Qinyao , Wu Mingli , He Tingting
Published: December 2020

Harmonic overvoltage in electric railway traction networks can pose a serious threat to the safe and stable operation of the traction power supply system (TPSS). Existing studies aim at improving the control damping of grid-connected converters, neglecting the impedance frequency characteristics (IFCs) of the actual TPSS. The applicable frequency range of these studies is relatively low, usually no more than half of the switching frequency, and there is a large gap with the actual traction network harmonic overvoltage frequency range of 750 Hz–3750 Hz. In this paper, first, the IFCs of the actual TPSS in the wide frequency range of 150 Hz–5000 Hz are obtained through field tests, and the resonant frequency distribution characteristics of TPSS are analyzed. After that, the aliasing effect of the sampling process and the sideband effect of the modulation process of the digital control of the grid-connected converter are considered. Based on the relative relationships among the inherent resonant frequency of the TPSS, sampling frequency and switching frequency, an impedance matching analysis method is proposed for the wide frequency range of the vehicle–grid coupling system. By this method, the sampling frequency and switching frequency can be decoupled, and the harmonic overvoltage of traction network in the frequency range of two times switching frequency and above can be directly estimated. Finally, the method proposed in this paper is validated by the comparative simulation analysis of seven different cases.
Proton Exchange Membrane Hydrogen Fuel Cell as the Grid Connected Power Generator
Authors: Ahmed Koushik , Farrok Omar , Rahman Md Mominur , Ali Md Sawkat , Haque Md Mejbaul , Azad Abul Kalam
Published: December 2020

In this paper, a proton exchange membrane fuel cell (PEMFC) is implemented as a grid-connected electrical generator that uses hydrogen gas as fuel and air as an oxidant to produce electricity through electrochemical reactions. Analysis demonstrated that the performance of the PEMFC greatly depends on the rate of fuel supply and air supply pressure. Critical fuel and air supply pressures of the PEMFC are analysed to test its feasibility for the grid connection. Air and fuel supply pressures are varied to observe the effects on the PEMFC characteristics, efficiency, fuel supply, and air consumption over time. The PEMFC model is then implemented into an electrical power system with the aid of power electronics applications. Detailed mathematical modelling of the PEMFC is discussed with justification. The PEMFC functions as an electrical generator that is connected to the local grid through a power converter and a transformer. Modulation of the converter is controlled by means of a proportional-integral controller. The two-axis control methodology is applied to the current control of the system. The output voltage waveform and control actions of the controller on the current and frequency of the proposed system are plotted as well. Simulation results show that the PEMFC performs efficiently under certain air and fuel pressures, and it can effectively supply electrical power to the grid.
Strategies to Foster Competition for the Market in the Urban Bus Sector in Developing Countries
Authors: de Carvalho Gabriel Stumpf Duarte , Marques Rui Cunha
Published: December 2020

Different mechanisms have been adopted by developed and developing countries over the last decades to provide urban bus services. Although competitive tendering has been considered the standard method to procure urban bus services, it cannot be treated as a ready-made solution. Contracts are incomplete by nature and, after the tender, to avoid ex-post opportunism they must be properly monitored. Additionally, developing countries, in general, have weak regulatory bodies and limited capacity to oversee public contracts. This paper aims to review the literature to gather actions that can increase the competition in public tenders and improve service quality during the life of the contract in developing countries.
Achilles Tendon Rupture: Mechanisms of Injury, Principles of Rehabilitation and Return to Play
Authors: Tarantino Domiziano , Palermi Stefano , Sirico Felice , Corrado Bruno
Published: December 2020

The Achilles tendon is the thickest, strongest and largest tendon in the human body, but despite its size and tensile strength, it frequently gets injured. Achilles tendon ruptures (ATRs) mainly occur during sports activities, and their incidence has increased over the last few decades. Achilles tendon tears necessitate a prolonged recovery time, sometimes leaving long-term functional limitations. Treatment options include conservative treatment and surgical repair. There is no consensus on which is the best treatment for ATRs, and their management is still controversial. Limited scientific evidence is available for optimized rehabilitation regimen and on the course of recovery after ATRs. Furthermore, there are no universally accepted outcomes regarding the return to play (RTP) process. Therefore, the aim of this narrative review is to give an insight into the mechanism of injuries of an ATR, related principles of rehabilitation, and RTP.
Experimental and Numerical Assessment of the Hot Sheet Formability of Martensitic Stainless Steels
Authors: Birnbaum Peter , Meza-García Enrique , Landgraf Pierre , Grund Thomas , Lampke Thomas , Kräusel Verena
Published: December 2020

Hot formed sheet components made of Martensitic Stainless Steels (MSS) can achieve ultra-high strengths in combination with very high corrosion resistance. This enables to manufacture complex lightweight sheet components with longer lifespan. Nevertheless, the hot formability of MSS sheets has not been accurately evaluated considering high temperatures and complex stress and strain states. In this work, the hot sheet formability of three MSS alloys under thermomechanical process conditions was investigated. Initially, mechanical properties of this sheet material were determined by uniaxial tensile test. Finite Element Method (FEM) simulation of a hot deep drawing process was performed under consideration of thermo physical calculated material models using the software JMatPro® and Simufact Forming® 15.0. The resulting strains and cooling rates developed locally in the work piece during the forming process were estimated. The numerical results were validated experimentally. Round cups were manufactured by hot deep drawing process. The resulting maximum drawing depth and hardness were measured. In general, all three alloys developed very good formability at forming temperatures between 700 and 900 °C and increased hardness values. However, they are highly susceptible to chemical composition, austenitization temperature, dwell time, and flange gap. A statistic approach is given to explain the correlation between hardness and its influencing factors.
Development of Mechanisms for Automatic Correction of Industrial Complex Tools in the Preprocessing of Laser Welding for Small-Scale and Piece Production Using Computer Vision
Authors: Dmitry Rodionov , Alexander Lyukhter , Valery Prokoshev
Published: December 2020

This paper is devoted to the development and improvement of mechanisms for the functioning of an automated system for correcting the points of the planned trajectory of the tool of a laser robotic welding complex in the pre-process. Correction of the points of the planned trajectory is carried out in two stages: in the first stage, the focal laser radiation is corrected; in the second stage, the position of the tool is corrected. Correction of the focal laser radiation is carried out in conjunction with the automated focusing of the camera by moving the tool of the industrial complex along its own axis. The functioning of position correction mechanisms is based on methods for recognizing the edges of the gap line to be welded from the image obtained from the charge-coupled device (CCD) camera. The edges of the gap to be welded in the image are segmented using threshold selection. The boundaries of the threshold selection segment are the extreme values of the pixel distribution of the entire image in brightness. For unambiguous recognition of the desired edges based on the segmentation result, the features defining them as a pair of continuous, conditionally parallel lines are formalized. Relative to the recognized pair of edges, the correct position of the planned trajectory point relative to the current position of the welding head is determined. To transfer the correct position, we formalized the calculation model and chose an arbitrary point in the flat image in the workspace laser robotic welding complex, considering the orientation of the tool and the position of the camera. The results obtained made it possible to develop a correction system and successfully test it in the industrial complex.
Diffusion Limit of Multi-Server Retrial Queue with Setup Time
Authors: Nazarov Anatoly , Moiseev Alexander , Phung-Duc Tuan , Paul Svetlana
Published: December 2020

In the paper, we consider a multi-server retrial queueing system with setup time which is motivated by applications in power-saving data centers with the ON-OFF policy, where an idle server is immediately turned off and an off server is set up upon arrival of a customer. Customers that find all the servers busy join the orbit and retry for service after an exponentially distributed time. For this model, we derive the stability condition which depends on the setup time and turns out to be more strict than that of the corresponding model with an infinite buffer which is independent of the setup time. We propose asymptotic methods to analyze the system under the condition that the delay in the orbit is extremely long. We show that the scaled-number of customers in the orbit converges to a diffusion process. Using this diffusion limit, we obtain approximations for the steady-state probability distribution of the number of busy servers and that of the number of customers in the orbit. We verify the accuracy of the approximations by simulations and numerical analysis. Numerical results show that the retrial system under the limiting condition consumes more energy than that with an infinite buffer in front of the servers.
Proanthocyanidins Should Be a Candidate in the Treatment of Cancer, Cardiovascular Diseases and Lipid Metabolic Disorder
Authors: Wang Tsz Ki , Xu Shaoting , Li Shuang , Zhang Yunjian
Published: December 2020

The conventional view of using medicines as routine treatment of an intractable disease is being challenged in the face of extensive and growing evidence that flavonoids in foods, especially proanthocyanidins (PAs), can participate in tackling fatal diseases like cancer, cardiovascular and lipid metabolic diseases, both as a precautionary measure or as a dietary treatment. Although medical treatment with medicines will remain necessary in some cases, at least in the short term, PAs’ function as antioxidant, anti-inflammatory drugs, signal pathway regulators remain critical in many diseases. This review article demonstrates the physical and biological properties of PAs, summarizes the health benefits of PAs found by researchers previously, and shows the possibility and importance of being a dietary treatment substance.
In Praise of God: Sport as Worship in the Practice and Self-Understanding of Elite Athletes
Authors: Ellis Robert , Weir J. Stuart
Published: December 2020

The relationships between sport and religion have been examined from a number of perspectives, and parallels between sporting activity and worship are often observed, positively or negatively. Elite sports participants often perform religious gestures and many speak of their sporting performance in terms of their religious faith, including the assertion that it constitutes an act of worship. The authors begin by considering the nature of Christian worship, examining worship as a phenomenon, key biblical and theological ideas, the relationship of worship to sacred places and times, and the relation of worship to everyday life. The self-understanding of elite athletes of faith is then considered, as articulated in interviews collected over several years with one of the authors and in other published statements. This data is then mapped back on to the previously considered ideas of worship. The article suggests that, while the correspondence may not be complete or exact, there is good reason to take seriously the claims of elite athletes of faith that their sporting performance should be regarded as an act of worship.
Producing Omega-3 Polyunsaturated Fatty Acids: A Review of Sustainable Sources and Future Trends for the EPA and DHA Market
Authors: Oliver Laura , Dietrich Thomas , Marañón Izaskun , Villarán Maria Carmen , Barrio Ramón J.
Published: December 2020

Omega-3 polyunsaturated fatty acids (Omega-3 PUFA) are recognized as being essential compounds for human nutrition and health. The human body generates only low levels of Omega-3 PUFA. Conventional sources of Omega-3 PUFA are from marine origin. However, the global growth of population combined with a better consumer understanding about healthy nutrition leads to the fact that traditional sources are exhausted and therefore not enough to satisfy the demand of Omega-3 PUFA for human diet as well as aquaculture. Microalgae cultivated under heterotrophic conditions is increasingly recognized as a suitable technology for the production of the Omega-3 PUFA. The high cost of using glucose as main carbon source for cultivation is the main challenge to establish economical feasible production processes. The latest relevant studies provide alternative pathways for Omega-3 PUFA production. As preliminary results show, volatile fatty acids (VFA) recovered from waste stream could be a good alternative to the use of glucose as carbon source in microalgae cultivation. The purpose of this paper is to highlight the actual situation of Omega-3 PUFA production, sources and market request to provide a summary on sustainable sources that are being investigated as well as present and future market trends in Omega-3 market.
Analysis of the German Industry to Determine the Resource Potential of CO2 Emissions for PtX Applications in 2017 and 2050
Authors: Zitscher Tjerk , Neuling Ulf , Habersetzer Antoine , Kaltschmitt Martin
Published: December 2020

The production and use of crude oil-based materials, e.g., fossil fuels and bulk chemicals of organic origin, results in an increasing level of CO2 emissions within the atmosphere. One way to reduce such CO2 emissions is to substitute them with synthetic fuels and bulk chemicals. For the production of such CO2 neutral materials, CO2 from various sources can serve as a carbon source. Against this background, this paper analyses and quantifies CO2 emissions released from German industry branches today (2017) and potentially in the future (2050) after a complete defossilization has been achieved. Thus, for the classification of CO2 emissions from the respective industries in 2050, alternative techniques and manufacturing processes are analyzed that might lead to a reduction in energy- and process-related CO2 emissions. Additionally, the individual production sites of the analyzed industries are determined at postcode level and a CO2 potential on NUTS3 level has been developed. Based on this, two scenarios for future CO2 emissions are developed. This shows that, in 2017, the analyzed German industrial sectors emitted almost 143 Mt CO2. By 2050, the overall emissions can be decreased by about 77 Mt to 117 Mt CO2 depending on the implementation level of alternative technologies.
A Multi-Sensor Comparative Analysis on the Suitability of Generated DEM from Sentinel-1 SAR Interferometry Using Statistical and Hydrological Models
Authors: Mohammadi Ayub , Karimzadeh Sadra , Jalal Shazad Jamal , Kamran Khalil Valizadeh , Shahabi Himan , Homayouni Saeid , Al-Ansari Nadhir
Published: December 2020

Digital elevation model (DEM) plays a vital role in hydrological modelling and environmental studies. Many essential layers can be extracted from this land surface information, including slope, aspect, rivers, and curvature. Therefore, DEM quality and accuracy will affect the extracted features and the whole process of modeling. Despite freely available DEMs from various sources, many researchers generate this information for their areas from various observations. Sentinal-1 synthetic aperture radar (SAR) images are among the best Earth observations for DEM generation thanks to their availabilities, high-resolution, and C-band sensitivity to surface structure. This paper presents a comparative study, from a hydrological point of view, on the quality and reliability of the DEMs generated from Sentinel-1 data and DEMs from other sources such as AIRSAR, ALOS-PALSAR, TanDEM-X, and SRTM. To this end, pair of Sentinel-1 data were acquired and processed using the SAR interferometry technique to produce a DEM for two different study areas of a part of the Cameron Highlands, Pahang, Malaysia, a part of Sanandaj, Iran. Based on the estimated linear regression and standard errors, generating DEM from Sentinel-1 did not yield promising results. The river streams for all DEMs were extracted using geospatial analysis tool in a geographic information system (GIS) environment. The results indicated that because of the higher spatial resolution (compared to SRTM and TanDEM-X), more stream orders were delineated from AIRSAR and Sentinel-1 DEMs. Due to the shorter perpendicular baseline, the phase decorrelation in the created DEM resulted in a lot of noise. At the same time, results from ground control points (GCPs) showed that the created DEM from Sentinel-1 is not promising. Therefore, other DEMs’ performance, such as 90-meters’ TanDEM-X and 30-meters’ SRTM, are better than Sentinel-1 DEM (with a better spatial resolution).
Lower Limb Exoskeleton Gait Planning Based on Crutch and Human-Machine Foot Combined Center of Pressure
Authors: Yang Wei , Zhang Jiyu , Zhang Sheng , Yang Canjun
Published: December 2020

With the help of wearable robotics, the lower limb exoskeleton becomes a promising solution for spinal cord injury (SCI) patients to recover lower body locomotion ability. However, fewer exoskeleton gait planning methods can meet the needs of patient in real time, e.g., stride length or step width, etc., which may lead to human-machine incoordination, limit comfort, and increase the risk of falling. This work presents a human-exoskeleton-crutch system with the center of pressure (CoP)-based gait planning method to enable the balance control during the exoskeleton-assisted walking with crutches. The CoP generated by crutches and human-machine feet makes it possible to obtain the overall stability conditions of the system in the process of exoskeleton-assisted quasi-static walking, and therefore, to determine the next stride length and ensure the balance of the next step. Thus, the exoskeleton gait is planned with the guidance of stride length. It is worth emphasizing that the nominal reference gait is adopted as a reference to ensure that the trajectory of the swing ankle mimics the reference one well. This gait planning method enables the patient to adaptively interact with the exoskeleton gait. The online gait planning walking tests with five healthy volunteers proved the method’s feasibility. Experimental results indicate that the algorithm can deal with the sensed signals and plan the landing point of the swing leg to ensure balanced and smooth walking. The results suggest that the method is an effective means to improve human–machine interaction. Additionally, it is meaningful for the further training of independent walking stability control in exoskeletons for SCI patients with less assistance of crutches.