bluuebunny/crossref_metadata_2025 huggingface dataset:
Struktur Penalaran Kolom Opini dalam Surat Kabar dan Pemanfaatannya sebagai Pengembangan Bahan Ajar Menulis Teks Eksposisi
Authors: Perwitasari Wahyu Rahmalia , Kurniawan Khaerudin
Published: May 2023

This study aims to analyze the pattern of paragraph reasoning found in national newspapers to be used as a guide for students in writing texts valid and quality exposition in terms of reasoning. These include, a) the structure of reasoning in opinion texts, b) variations of reasoning in opinion texts, and c) the benefits of reasoning in opinion texts as teaching materials for writing exposition texts. This research design uses a qualitative method with a narrative study. Opinion texts used as data sources in this study are opinion texts published in the newspapers Kompas, Media Indonesia and Sindo.. The results of this study are, a) the structure of reasoning contained in each of these newspapers, which consists of establishment, proof, and conclusion; b) the variations of reasoning found in the three newspapers include Sindo having 33 deductive reasoning, 16 inductive reasoning, 4 inerative reasoning, and 3 mixed reasoning; Kompas which has 40 paragraphs with deductive reasoning, 11 inductive reasoning patterns, 4 mixed reasoning patterns, and 1 inerative paragraph reasoning pattern; and Media Indonesia which has a total of 44 deductive reasoning patterns, 10 inductive reasoning paragraph patterns, 4 paragraphs with mixed reasoning patterns, and 4 paragraphs with inerative reasoning patterns c) reasoning in opinion texts in national newspapers can be used as a supplement to exposition text teaching materials in learning Indonesian at the senior high school level in class X in KD 4.4.
Riesgo de exposición a la Covid-19 en auxiliares de enfermería, enfermeras y médicos de un hospital universitario ante la pandemia
Authors: Sánchez-Herrero Héctor , Montserrat-Capella Dolors , Revuelta-Zamorano Manuel , Santano-Magariño Almudena , Rodríguez de la Pinta Mª Luisa , Solís Muñoz Monserrat
Published: May 2023

Objetivo principal: Los profesionales sanitarios fueron los trabajadores más afectados por Covid-19, especialmente durante las primeras oleadas. El objetivo del estudio es evaluar la percepción del riesgo de exposición al Covid-19, información recibida y participación laboral entre enfermeros, médicos y auxiliares de enfermería. Metodología: Se realizó un estudio transversal mediante una encuesta epidemiológica entre enfermeras, médicos y auxiliares de enfermería de un hospital universitario. Se realizó una validación de aspecto y contenido, un pretest cognitivo y un pilotaje de la encuesta epidemiológica con treinta sujetos. Se realizó un análisis descriptivo utilizando media y desviación estándar (DE) para las variables cuantitativas y las frecuencias absolutas (n) y relativas (%) para variables cualitativas. Se aplicó el test chi-cuadrado y el test ANOVA para evaluar la asociación de las respuestas con las variables: sexo, tipo de trabajador, área de trabajo y actividad en Unidades Covid-19. Resultados principales: Las enfermeras, médicos y auxiliares de enfermería trabajaban principalmente en áreas asistenciales y en unidades de alto riesgo de exposición. Los auxiliares de enfermería y las enfermeras tenían una mayor percepción de riesgo. Las enfermeras estaban menos implicadas en la organización, pero se sentían más apoyadas por sus compañeros. Los médicos se sentían más apoyados por sus superiores y mejor atendidos cuando tenían problemas de salud. Conclusión principal: Las enfermeras y auxiliares de enfermería presentaron mayor percepción de riesgo, las enfermeras se implicaron menos en la organización de la atención sanitaria, mientras que los médicos se sintieron más apoyados por sus superiores.
A Study of Spirit of Zhejiang Entrepreneurs, Enterprise Innovation and Enterprise Growth in China
Authors:   Asia Metropolitan University, Malaysia., GANG HAN
Published: May 2023

The purpose of this paper is to take Zhejiang entrepreneurs as the object, constructs a research model of “entrepreneurship-enterprise innovation-enterprise growth”, collects sample data by questionnaire survey, and makes an empirical analysis to explore the influence of the Spirit of Zhejiang Entrepreneurs on enterprise growth and the intermediary effect of enterprise innovation between them. Based on the quantitative research design, the main findings and conclusions of this paper are as follows: First, each dimension of the Spirit of Zhejiang Entrepreneurs has a direct role in promoting the growth of enterprises, and the spirit of innovation has the strongest role in promoting the growth of enterprises. In addition, the contractual spirit of private enterprises promotes the growth of enterprises more strongly than that of state-owned enterprises. Secondly, each dimension of the Spirit of Zhejiang Entrepreneurs has an obvious positive promotion effect on technological innovation and business model innovation, and the spirit of risk-taking has a stronger promotion effect on business model innovation of state-owned enterprises than private enterprises. Third, technological innovation and business model innovation have an obvious role in promoting the growth of enterprises, which is more obvious in private enterprises. Fourth, technological innovation and business model innovation play an obvious intermediary role between the Spirit of Zhejiang Entrepreneurs and enterprise growth. For the implication of this study, among them, the Spirit of Zhejiang Entrepreneurs mainly influences the growth of state-owned enterprises through the intermediary role of business model innovation. Finally, combined with theoretical analysis and empirical research, the research results are further discussed, and the corresponding countermeasures to promote the healthy growth of Zhejiang enterprises are put forward from the perspective of carrying forward the excellent the Spirit of Zhejiang Entrepreneurs and promoting the innovation and development of enterprises.
Prescribed energy saddle-point solutions of nonlinear indefinite problems
Authors: Il'yasov Yavdat , Da Silva Edcarlos Domingos , Da Silva Maxwell Lizete
Published: May 2023

A minimax variational method for finding mountain pass-type solutions with prescribed energy levels is introduced. The method is based on application of the Linking Theorem to the energy-level nonlinear Rayleigh quotients which critical points correspond to the solutions of the equation with prescribed energy. An application of the method to nonlinear indefinite elliptic problems with nonlinearities that does not satisfy the Ambrosetti-Rabinowitz growth conditions is also presented.
Existence of solutions to steady Navier-Stokes equations via a minimax approach
Authors: Fereidooni Amin , Moameni Abbas , Grewal Anant
Published: May 2023

Our objective in this paper is to develop and utilize a minimax principle for proving the existence of symmetric solutions for the stationary Navier-Stokes equations. Notwithstanding its application to symmetric solutions in this paper, our minimax principle is broad enough to capture other types of solutions provided the equation and the external force are compatible under a family of operations including but not limited to being invariant by compact groups. The subset of functions compatible under this family of operations is not required to be a linear subspace, and being a closed convex set suffices for our purpose.
Growth properties of solutions of complex differential equations with entire coefficients of finite (alpha,beta,gamma)-order
Authors: Belaidi Benharrat , Biswas Tanmay
Published: May 2023

In this article, we investigate the complex higher order linear differential equations in which the coefficients are entire functions of (α, β, γ)-order and obtain some results which improve and generalize some previous results of Tu et al. [29] as well as Belaidi [1, 2, 3].
SYNTHESIS AND CHARACTERIZATION OF MECHANICAL AND PHYSICAL PROPERTIES OF FALSE BANANA (ʾƏNÄSÄTƏ) FIBER REINFORCED COMPOSITE MATERIAL
Authors: Belay Taye  , Zewdie Alemayehu
Published: May 2023

The use of environmentally friendly materials has recently been promoted due to increased awareness of environmental issues. To offer a better world for future generations, we must decide what we will utilize and serve today. When resources and products reach the end of their useful lives, resource preservation and degradation become issues. Biodegradable products manufactured from renewable resources address these issues. This research aims to develop a biodegradable resource of false banana (ʾənäsätə) fiber as reinforcement with polyester resin composite material manufactured by hand layup method at room temperature. The mechanical and physical properties of the produced sample were investigated. include tensile, flexural, impact strength, and water absorption. The fiber surface was treated with NaOH alkaline in distilled water solution. In composites, the fiber orientations were 0o, 90o, 45o/-45o, 0o/90o, and chopped, at 40% fiber volume fraction. The sample's production process was performed successfully. A chopped sample is an easier manufacturing process relative to the other. As the result, 0o fiber direction scored the highest tensile strength, which is 181.41MPa. In the flexural and impact strength test, a 90o oriented fiber was observed with the highest value, which is 81.43 MPa and 9.75 joules, respectively. The samples were immersed in distilled water until saturated. The highest percentage of water absorption was 45o/-45o oriented fiber. Many researchers have recently shown interest in natural fiber composites material for aerospace and automotive applications, such as aircraft radomes and interior cabin components, as well as remarks on natural fiber composites' future trends and problems. This article provides readers with a positive perspective and piques industry players' interest in the potential of using natural fiber composites in aerospace applications to improve current aerospace material performance, particularly in terms of lightweight and environmental sustainability. Keywords: Composite, Fiber, Manufacturing, Matrix, Reinforcement, Sustainability
"EUROPEAN COMMUNICATION IN THE DIGITAL ERA. A CASE STUDY ON THE AUDIOVISUAL SERVICES OF THE EUROPEAN COMMISSION. "
Authors:   Babeș-Bolyai University, Nistor Cristina , Beuran Rareș ,   Babeş-Bolyai University
Published: May 2023

The European Union’s media communication system has been changing rapidly during the latest years due both to new trends in media industry and also due the euro-scepticism wave expressed by some EU member states. The paper first provides a background on the main perspectives of media industry and public communication. Further, the paper refers to EU’s communication strategies, with a focus on the recent digital initiatives. As for the case study, the authors will conduct an analysis on the Audiovisual Services of the European Union (the video, photo and audio services), in terms of identifying the updated approach imposed by professional media industry and by the consumption preferences of the new segments of audiences in the digital era.
A Debate on Environmental Management Accounting
Authors:   Politehnica University Timişoara, Sîrbu Roxana Mihaela , Vartolomei Mihaela ,   Politehnica University Timişoara
Published: May 2023

Environmental Management Accounting (EMA) refers to a set of accounting and performance tools dedicated to companies’ actions towards improvement of their environmental impact. Furthermore, EMA deals exclusively with the company’s internal costs, as it does not include the external costs of individuals, society, or the economic environment over which the company has no decision-making power. It is recognised that EMA is a relatively new tool in environmental management, which can be defined as the identification, collection, estimation, analysis, internal reporting, and use of information regarding materials and energy flow and environmental costs for both conventional and environmental decision-making process within an organisation. Thus, EMA incorporates and integrates two of the three milestones of sustainable development (environmental and economics dimensions), as they relate to an organisation’s internal decisional process.
Themenauswahl und Lernziele im Fach Cultură și civilizație germană an rumänischen Hochschulen
Authors:   Lucian Blaga University Sibiu, Stancu Andrea Susanne
Published: May 2023

Viele rumänische Universitäten bieten im Rahmen fremdsprachiger Studienangebote Lehrveranstaltungen zur Landeskunde (Cultură și civilizație) an, die in der Regel als Vorlesungen und/oder Seminare durchgeführt werden. Gegenstand dieses Beitrags sind die unterschiedlichen Themenbereiche, Lernziele und Materialien, die fünf Lehrplänen deutschsprachiger Studiengänge entstammen. Die Untersuchung berücksichtigt hierbei deutschsprachige Studiengänge von sowohl philologischen als auch von ingenieur- und wirtschaftswissenschaftlichen Studienangeboten aus den Städten Bukarest, Jassy, Temeswar und Hermannstadt, wodurch ein möglichst breites Spektrum an fachspezifischen Ausbildungsmöglichkeiten abgedeckt wird, das ein umfangreicheres Bild des Landeskundeunterrichts an rumänischen Einrichtungen zu verschaffen vermag.
Legal Aspects Concerning Prostitution
Authors:   Politehnica University Timişoara, Gașpar Cristian-Marian , Luminosu Caius ,   Politehnica University Timişoara
Published: May 2023

This research aims to draw attention to the phenomenon of prostitution both from a legal, social and economic point of view. The study first presents the contemporary social phenomenon, followed by a brief history and the current situation. Subsequently, the legal classification in the New Romanian Criminal Code is presented and two comparative studies of two states (Germany and the Kingdom of the Netherlands) are presented, where prostitution operates in legal forms, with a separate legal regime of application. In the last part of the research is presented the management of prostitution phenomenon in Romania and the conclusion.
HOW MUCH IS INFOTAINMENT THE NEW NEWS?
Authors:   Babeş-Bolyai University, Melinescu Nicolae
Published: May 2023

Infotainment has become a new approach to news reporting lately and introduced into the public sphere matters that seemed hard to crack, especially in terms of economic, financial and political analysis. The inner structure of news production has changed in terms of gathering, processing and disseminating novelties and in the way in which the public evaluated the shifts in m edia planning biased towards commercialization and entertainment. The «new news» will probably share the fate of the so called new media (actually, new digital platforms that took over the signs and their significance from print, radio, cinematography and television): groundbreaking experiences will become gradually goods and gains of the journalistic trade while the useless ones will be shaken off in the media industry’s search for new approaches to reality and truth.
An Eclectic Approach to Islamization of Knowledge: Models and Perspectives
Authors: Dr Ahmad Labeeb Tajudeen
Published: May 2023

Islamization paradigm began in the late seventies and received a very strong impetus in both the Arab world and Muslim countries, as well as Muslim communities in the western world. Two seemingly divergent schools of thought emerged to provide the steering theoretical underpinnings for the Islamization of education project. However, a full application of Islamization theories as propounded by the two schools of thought has been difficult due to several emergent factors. The continued interest and participation of Muslim universities in the western global ranking of universities, continued increase in the number of Muslim countries that are participating in the non-Islamic based international assessment of students, non-existent of internationally recognized Islamic examination bodies as alternatives to the western bodies are all a telltale to the impossibility of full application of Islamization theories in the contemporary time. In its theoretical part, this paper suggests an eclectic approach to the Islamization of education, based on the Shari’ah principle of adopting lesser evil, and aims to create a synergy between multiple theories to form a single coherent and applicable system of education. The paper further suggests models for the application of such an eclectic approach to Islamization of education. In its empirical part, perspectives of stakeholders on the proposed models were explored to ascertain their best choice of model. The novelty of this paper lies in exposing practitioners to the possible models of Islamization of education amidst the limiting contemporary factors which may render the Islamization of education project as a mere caricature.
Design of Manual Flame Weeder
Authors:   Agiculture Engineering, the Kavery Engineering College, Mercheri, Tamilnadu, India., S Kousika , A Madhumitha , K Sudharsanapriya , J Swetha
Published: May 2023

Weed is one of the important factors in productivity loss in agricultural. It is a major problem in both conventional and organic production systems. The presence of weeds in the crop shared all the important nutrients that were required for the growth of the crop. Weed reduces crop production by 31.5% overall, with 36.5% in kharif and 22.7% in rabi. Weed management has become a highly labor-intensive activity, which is the reason for decreased yields and high costs. Moreover, the lack of skilled labor and weed-resistant herbicides severely impact the agriculture sector and food production, hence increasing the need for automation in agriculture. Flame weeding is an alternative method of weed control. Essentially, it is a supplement to other physical and mechanical processes used in organic production. Weed control costs have a large share of the total cost of crop production. This study aimed to investigate hand weed hoeing’s cost-effectiveness, accompanied by inter-row cultivation and flame weeding applied in organic maize production using two different machines to determine the economically best solution. For this purpose, the prototype flame weeder and commercial flame-weeding machinery were used. Key Word: Flaming, Flame Weeding, Butane, Weed, Crop, Heat
La confiance dans la communication publique des acteurs territoriaux : cas des zones arides de Douz et Menzel Habib en Tunisie
Authors: Mzioudet Faillon Balkis
Published: May 2023

Les changements des territoires et des territorialités interpellent différentes lectures de la confiance et de l’identité. Ainsi, fédérer les acteurs autour d’un projet commun renforce-t-il le sentiment d’appartenance et permet-il de reconstruire la confiance. Notre travail nous conduit à mettre l’accent sur la dynamique de la confiance en fonction de l’évolution de l’identité et des changements territoriaux et à examiner le système identité, communication et territoire. Ce processus interroge l’émergence d’une nouvelle identité authentique, reconnue et valorisée (dans les espaces frontaliers partageant des valeurs proches) par les acteurs territoriaux notamment la population locale dans les zones arides, fragiles et menacées en Tunisie. Comment l’identité s’ajuste-t-elle face aux différentes mutations socio-économiques et politiques ? Nous nous sommes basées sur des observations et des entretiens afin de mettre l’accent sur la valorisation de la confiance territoriale, l’adhésion et l’appartenance citoyenne au territoire, marquées par le respect des principes d’homogénéité et de continuité. Les questions sur les politiques de la communication publique et territoriale soulignent l’importance de la confiance territoriale et l’authenticité identitaire pour impliquer la population locale dans les projets de développement. Les plans de développement misent sur la valorisation territoriale à travers l’amélioration de l’infrastructure régionale, l’encouragement de l’investissement privé, la préservation de l’identité régionale du Sud tunisien. Comment s’articule la confiance autour des questions communicationnelles et identitaires ?
Transition démocratique et transition numérique : Les défis des institutions des droits de l’Homme et de gouvernance au Maroc
Authors: Maroub Fadoua , Bendahan Mohamed
Published: May 2023

Depuis 1999, la transition politique au Maroc s’est construite sur une double dynamique. D’abord, une dynamique de légitimation de la gouvernance à travers la mise en place d’un calendrier électoral régulier et propre et ensuite, une dynamique de réhabilitation de la confiance et de renouvellement des termes du débat public à travers la mise en place des institutions des droits de l’Homme et de la gouvernance. Après le printemps arabe (2011) et les mouvements de contestations, ces institutions ont dû revoir leur façon de communiquer en investissant les nouveaux espaces publics de légitimation et de débat, ainsi que les réseaux sociaux. Un changement pour lequel ces dernières ne sont pas tout à fait prêtes.
Tourisme durable et RSE : entre identité sociale des professionnels et sentiment d’efficacité.
Authors: HOUENOUHO Catherine , FOINTIAT Valérie , GLIDJA Judith , Tisserant Pascal
Published: May 2023

Cette recherche réalisée auprès d’un échantillon de 14 professionnels du tourisme durable en France (composé d’agences de voyage, d’associations et de fédérations), a pour objectif, sur la base d’une méthode particulière nommée Investigateur Multistade de l’Identité Sociale (IMIS), d’identifier les niveaux d’engagement perçus des participants en termes de pratiques du tourisme durable. Le niveau d’engagement participe à la construction d’une identité sociale positive conduisant à un sentiment de performance ou d’efficacité personnelle. Les résultats de l’étude montrent une adéquation entre l’identité sociale endossée en lien avec le niveau d’engagement dans le tourisme durable et l’estime de Soi qui sur le plan théorique conduit au sentiment d’efficacité personnelle.
Logistique et le développement durable dans la grande distribution : cas de la région de Souss-Massa
Authors: MANSSORI Saïd , EL HAMRI Mohamed Hicham
Published: May 2023

Le mouvement de la RSE est récemment devenu l’un des plus innovants qui accompagne la grande distribution. La relation est solidement établie entre ce mouvement et les perspectives de développement dudit secteur. En effet, la RSE fait l’objet de plusieurs investigations et interprétations entre divers acteurs, à l’échelle mondiale. Ce qui entraine l’émergence de tensions qui s’exercent autour de ses enjeux et finalités, relativement aux conséquences des activités de ces acteurs y compris les entreprises. Il s’agit donc d’un mouvement qui influencera et régénérera la construction de nouvelles pratiques d’entreprise et aidera par conséquent à développer le principe de l’amélioration continue de l’entreprise.
La contribution de l’audit social à l’amélioration de la performance organisationnelle : Cas des PME exportatrices marocaines
Authors: LAGOUBI Sara , BALHADJ Said
Published: May 2023

Aujourd’hui, le rôle du capital humain en tant que facteur clé de succès de l’entreprise n’est plus à démontrer. Les entreprises cherchent constamment à améliorer leurs pratiques managériales dans le but d’accroitre leur performance. L’audit social, en permettant d’évaluer la performance des ressources humaines, devient un tremplin pour l’efficacité du capital humain de l’entreprise et en l’occurrence la performance de cette dernière. Notre recherche ambitionne d’interroger la place de l’audit social dans les PME marocaines, et surtout de mettre en évidence la contribution de l’audit social à l’amélioration de la performance organisationnelle à travers une étude exploratoire sur la pratique de ce dernier au sein desdites entreprises.
L’irrigation traditionnelle : un système ingénieux du patrimoine oasien entre archaïsme et capitalisme. Cas des palmeraies du Jbel Bani, Maroc
Authors: FAOUZI Hassan
Published: May 2023

Le présent travail a pour objet l’étude des systèmes d’irrigation traditionnels ou coutumiers et leur devenir. L’article réfléchit aussi sur la valorisation de ces systèmes d’irrigation comme vecteur d’attractivité territoriale. L’objectif est d’aborder les enjeux de la conservation des systèmes hydrauliques paysans qui commencent à être étouffés par la gestion moderne. Les mutations récentes appellent à une revalorisation des pratiques et des savoir-faire locaux qui, tant sur le plan socioéconomique qu’écologique, sont les mieux adaptés aux contraintes actuelles.
Les plantes médicinales : ressources patrimoniales pour le développement territorial au Maroc ?
Authors: CHBANI IDRISSI Fadwa , BOUJROUF Said
Published: May 2023

Les plantes médicinales constituent une part importante de la biodiversité au niveau mondial, et contribuent encore d’une manière exceptionnelle à l'évolution de nombreuses thérapies traditionnelles. Ces systèmes de connaissances traditionnelles ont commencé à disparaître avec le temps en raison de la rareté des documents écrits et des revenus relativement faibles dans ces traditions. D’une manière générale, les plantes médicinales ont été affrontées à relever plusieurs défis liés à la reconnaissance, la documentation, l’inventaire, la mise en valeur ainsi que leur considération en tant que ressource patrimoniale. Afin de relever ces défis et de maximiser leur impact sur la population locale, il est important de déclencher le processus de patrimonialisation des plantes médicinales en tant que ressources patrimoniales pour un développement territorial. Pour ce faire, nous avons mené une analyse documentaire à travers, d’abord, l’implication des différentes bases de données en ligne, livres et thèses afin d'obtenir, de rassembler et de synthétiser les informations disponibles sur divers aspects fondamentaux relatifs aux plantes médicinales dans le monde entier d’une façon générale, et au Maroc d’une façon particulière, et ensuite, à travers la mobilisation de plusieurs recherches sur terrain, menées par nos équipes dans le cadre de trois projets scientifiques sur l’étude des terroirs. L’analyse montre que le Maroc a déjà franchi des pas considérables dans la structuration de la filière des plantes médicinales, mais le déclenchement de leur processus de patrimonialisation de cette filière permettrait encore l’émergence cette ressource, de son ancrage territorial dans de nouvelle configuration et identité ainsi qu’une mobilisation des parties prenantes autour d’une initiative préliminaire commune dans le cadre de projets de territoire. Les dit-projets peuvent être, éventuellement, portés par des acteurs aussi bien locaux, que nationaux et/ou internationaux.
Exploring the Feasibility of a Power-Generating Pulsed Nuclear Magnetic Nozzle
Authors:   Department of Mechanical and Aerospace Engineering, University of Alabama in Huntsville, Schilling Nathan , Cassibry Jason ,   Department of Mechanical and Aerospace Engineering, University of Alabama in Huntsville, Adams Robert ,   National Aeronautics and Space Administration, George C. Marshall Space Flight Center
Published: May 2023

Crewed missions to Mars and robotic missions to the gas giant planets are challenging because of the current lengthy trip times (2 years to Mars, ~20+ years to the gas giants) with current propulsion technology. These trips endanger astronauts due to the harmful effects of radiation and microgravity and represent a significant fraction of a PI’s (Principal Investigator's) lifespan for uncrewed gas giant missions. To make these trips safer and more reliable, trip times need to be reduced dramatically. Pulsed nuclear fusion propulsion systems promise to reduce these trip times down to 1-3 months for the Mars mission and 1-4 years for gas giant missions. However, widespread use of these systems is hampered by many technical factors, including efficient conversion of directed jet power for thrust and generation of input power for fusion reactor operation. To address both challenges, the present authors propose using the novel power-generating magnetic nozzle; this nozzle uses high-strength magnetic fields for thrust generation and low-strength fields for power generation. Most approaches in the literature consider the effect of either the high-strength fields or the low-strength fields but, for this work, the authors would like to show their combined effect. To address this, we use two computational tools in tandem from prior work: the Smoothed Particle Fluid with Maxwell equation solver (SPFMax) and a plasma flux compression generator code. The former will determine the effect of the high-strength fields and the latter will determine the effect of the low-strength fields. Combined, they show the effect on thrust, efficiency, and power generation. The present authors find that the inclusion of a power-generation system reduces nozzle efficiency by 7% and thrust by the same amount, however, this is a relatively small reduction. The authors also confirm prior work regarding non-dimensional scaling parameters of the power generation system. These results reduce the technical risk associated with these nozzles, hopefully allowing for their application in current concepts/programs, make interplanetary trips safer and more reliable, and allowing humanity to venture out and explore the solar system. Keywords: Mars, Plasma, Magnet, Nuclear, Power
The Effect of the Spanish Nuclear Phase-out on the Electricity Market
Authors: Roldan Fernandez Juan Manuel , Serrano Gonzalez Javier , Fiestas Chevez Jose Hugo , Burgos Payan Manuel , Riquelme Santos Jesus Manuel
Published: May 2023

Portugal and Spain are integrated into what is known as the Iberian Electricity Market. Spain participates in this market with significant contribution of energy produced by nuclear plants. In 2022, nuclear energy accounted for 22 % of the total energy generated in Spain. Nuclear power plants sell their energy largely through bilateral contracts, and approximately 20 % is offered in the day-ahead electricity market. By 2035, Spain will phase-out nuclear power producing a structural change of its generation mix. In this paper, we investigate the effect on the day-ahead Iberian electricity market that the gradual removal of nuclear power plants will have on the daily electricity market. The methodology is based on a ceteris paribus approach, where generation conditions are modified by removing nuclear plants and keeping the rest of the variables constant (demand and other generation). Under these conditions, the market is reproduced, estimating how electricity prices change in the day-ahead electricity market. To evaluate the market electricity prices under this new scenario with a total or a partial elimination of nuclear energy generation, it is necessary to use a market model. The existing literature shows various approaches to replicate the electricity market, among which are agent-base modelling, optimization algorithms, artificial intelligence techniques or metaheuristic merit-order methods. Our approach is based on the latter methods, by using actual generation and demand data, the new market generation and demand curves are reconstructed and the new clearing price is obtained. For the most conservative scenario, the results show a price increase of more than 5 % for the first 6 months of 2021. The reason for this increase is that nuclear generation participates in the market by offering its energy at prices close to zero. When this generation is withdrawn, there is a shift to the left of the hourly generation curve producing a new market equilibrium at a point of higher price and lower energy.
A Sustainability-based Approach for Geotechnical Infrastructure
Authors: Pettinaroli Andrea , Susani Stefano , Castellanza Riccardo , Collina Maria Elena , Peirani Matteo , Paoli Riccardo , Romagnoli Francesco
Published: May 2023

Urban growth needs large cities, and the current emphasis on landscape preservation makes using underground spaces both an opportunity and a significant necessity. However, underground construction techniques significantly impact the sustainability of the built environment, including infrastructure systems and their entire supply chains. Nowadays, there is a shortage of quantitative methodologies to assess and measure the sustainability of underground building processes that effectively integrate the three pillars of sustainability (environmental, social, and economic). Thus, this study aims to solve the abovementioned issues by explaining how to incorporate sustainability goals into geotechnical projects to address measure-driven strategies and eco-design-based solutions appropriately. This study illustrates a novel methodology based on the Life Cycle Thinking approach, with a particular emphasis on geotechnical ground improvement techniques. Specifically, the suggested method incorporates the concept of the EU Taxonomy, following the EU Green Deal, with the Envision framework to guide decision-makers toward a more sustainable, resilient, and equitable infrastructure design. In addition, incorporating a cradleto-grave Life Cycle Assessment (LCA) into the suggested methodological approach will improve the quantitative estimation of the performance of construction processes. The definition of the proposed method will provide the guidelines to systematically assess the sustainability of geotechnical infrastructures to allow further the selection of an optimal solution to reduce their impact from an environmental, social, and economic point of view.
An Empirical Approach to Optimize non-linear Problems of Domestic Energy Management Systems
Authors: Carreras Fernando , Kirchsteiger Harald
Published: May 2023

Energy management system for domestic houses comprising photovoltaic energy production and battery electrical storage combined with time-variant electricity prices use to be controlled mean numerical optimization algorithms. The modelling of the system comprises the different involved devices, energy flows and their constrains, and an objective function, which parametrizes the object of the optimization (usually the minimization of the operative costs and/or the CO2 emissions). The solution of the optimization problem provides the optimal operation (charging/discharging) of the battery along the prediction horizon considered. Power inverter efficiencies are usually modelled by assuming that they have constant values, and hence, that charging and discharging energy-flows lie on the most probably operating region of the inverter. A more realistic modelling of the power inverter efficiencies should consider a non-linear parametrization of the efficiency curves. This consideration converts the optimization problem into a non-linear one. It this paper, we propose a method to solve non-linear optimization problems means iterations of linear optimization problems. At the first step, an optimization problem will be solved by using the values of the efficiencies of the battery inverter provided by the manufacturer for the values. The values of the solution of that problem will be the seed of an iterative process: with help of measured (dis)charging power curves and the optimized (dis)charging energy flows, new values of (dis)charging efficiencies will be determined, and a new optimization problem will be defined and solved. The process stops after a certain number of iterations, or once a convergence is achieved. The results of the experimentation show that the modified method improves the performance of the system by reducing the operative costs with respect to the original method. The results summarized in the table correspond to a whole year with a 15-minutes time resolution and a 24-hour prediction horizon. The second method has the same time-steps, and for each time step triggers an iterative process. Simulations were implemented in Matlab and run on a COREi7 processor (8th generation) platform with 16 GB RAM. A wide experimentation by selecting representative cases with shorter periods (one week) will be done. The main objective of these selected cases is to analyze the dependencies between both methods under different circumstances (seven consecutive days of the year with maximal and minimal solar radiation, seven consecutive days of the year with maximal and minimal standard deviation of the buy and sell prices).
Comparison of Most Popular Buildings Performance Simulation Tools
Authors: Albatayneh Aiman , Albadaineh Renad
Published: May 2023

A critical procedure in sustainable building design is the building energy performance assessment, which has significant implications for global energy consumption and climate change. This study compares three simulation software programs for a photovoltaic system on a building’s roof. The low-rise residential buildings in three East Mediterranean cities (Amman, Mafraq, and Aqaba) represent moderate drywarm, semiarid, and humid subtropical climate zones were compared using three simulation software programs (IES-VE, DesignBuilder, REVIT) for a typical building with PV on the roof and the second scenario without a PV system installed on the roof. This investigation aims to evaluate the shading effect of the PV system on a building’s roof structure by calculating the total electrical load required to maintain thermal comfort inside the building. The final results showed significant discrepancies between the three software for the base building design and the PV system on the roof, with a range of around 50 %. This highlights the importance of evaluating and calibrating different simulation tools and using them with a great deal of caution.
Impact Assessment of Steel Circularity Scenarios: Case Study of Steel Radiator based on Life Cycle Assessment (LCA) Methodology
Authors: Paoli Riccardo , Feofilovs Maksims , Romagnoli Francesco
Published: May 2023

Steel is one of the most used materials in the industry and the building sector. Its production causes severe environmental impacts due to direct emissions within extraction and processing stages (e.g. CO, SOx, NOx, and PM2), the intensive use of primary resources, contamination of wastewater, and significant amounts of hazardous and solid waste. In this context, the purpose of the current study is to perform a life cycle analysis (LCA) of four different types of steel used in the manufacturing of a steel-based radiator, namely: standard steel as a baseline scenario, steel with a recycling fraction of 40 % of scrap, steel with a recycling fraction of 60 % of scrap, fully recycled steel from scraps, and a hypothetical ‘Carbon-free’ steel production process. The baseline scenario relies on data from an existing company producing steel radiators. The LCA study is conducted within SimaPro 9.4 software with data obtained from the Ecoinvent 3.8 database and adjusted according to the defined scenarios and the functional unit of ‘1 kg of steel’. The environmental impact is assessed according to EN 15804 requirements for construction product sustainability. The results have shown that standard steel has the highest impact (176.87 μPt), followed by 40 % scrap steel (137.46 μPt), 60 % scrap steel (104.36 μPt), ‘carbon-free’ steel (76.14 μPt), and 100 % scrap steel (38.17 μPt). The climate change indicator is found to be one of the most sensitive for steel production. The selection of ‘carbon-free’ or 100 % scrap steel permits a decrease of impacts by 70 % and 84 %, respectively. The study concludes that the choice of steel is a fundamental point in reducing the environmental impact of construction products such as steel-made radiators within the whole life cycle perspective. Furthermore, the results obtained through the EN 15804 method, tailored explicitly for the Environmental Product Declaration (EPD), can be reused or taken as a starting point for further studies in the environmental labelling sector.
KxKali v0.1: A Work-in-Progress Tool for Streamlining Thermal Comfort Evaluation in Building Design and Occupancy
Authors: Otaegi Jorge , Hernández-Minguillón Rufino Javier , Rodríguez-Vidal Iñigo
Published: May 2023

Thermal comfort evaluation is crucial in the design of buildings, as it impacts the well-being and productivity of building occupants. Many national regulations and international standards provide guidelines for assessing thermal comfort. In order to simplify this process, we have developed a program called KxKali, which is intended to evaluate thermal comfort based on temperature and relative humidity data input using the adaptative comfort model of EN 16798. The current version of the software, v0.1, is only able to accept data from computer simulation using the official Spanish simulation software HULC and performs graphing and counting automatically, without the need for the user to edit, modify or handle any data manually. By using HULC as the source of input data, the tool can take advantage of the software’s established reputation and acceptance among professionals in the building design industry in Spain, streamlining the comfort evaluation process by eliminating the need to generate input data manually, or using additional software. However, future versions are planned to accept data from other software and also monitored data. In addition, there are plans to implement the evaluation of thermal comfort following other regulations. The ultimate goal of this project is to convert KxKali into a user-friendly and widely accessible web-app that professionals can use in the design phase without performing any additional work apart from what they are already doing for energetic certification, which may improve building design by allowing architects and engineers to quickly evaluate different thermal comfort scenarios and optimize their design for comfort, and also facilitate the process of post-occupancy evaluations (POE). The goal of this presentation is to show the current capabilities of the KxKali tool, and to obtain feedback from other specialists on how to improve it and make it more widely useful. In the paper, the limitations of using simulation data from HULC and the ongoing developments of KxKali such as accepting monitoring data and converting it into a web-app will be discussed. Additionally, the paper will showcase mockups of the future web-app version of the tool, providing a glimpse into its intended user interface, and the expected reporting and output.
Modelling the Electric Bus Charging Network Requirements for HVAC Purposes
Authors: Rubenis Aivars , Šeļegovskis Raimunds
Published: May 2023

Wider use of electric buses is hindered by necessity to provide cabin heating for the passengers during winter months, which in cold climates uses up as much energy as driving, thus significantly reducing bus driving range and requiring larger traction batteries, which are expensive. When the lifetime operational costs are included, unless they are heavily subsidized, the battery electric buses have troubles competing with internal combustion engine (ICE) buses in cold weather conditions. For typical ICE buses, the power capacity for heaters is in the range of 50 kW. It would be possible to increase the driving range by using heat accumulators to provide energy for vehicle thermal requirements. These heat accumulators could be recharged in bus stops using wireless charging to minimize battery size. This article describes the results of a mathematical model developed to determine optimum wireless charging power requirements for heat accumulators. The model is created for public transportation system in Riga city based on weather data in years 2017–2022 to provide passenger thermal comfort. The model simulates energy flows for bus movement and heating purposes using worst-case scenario approach. The model analysed 198 916 bus stop data, which were pertinent for weekday travels in Riga city. The analysis covered 1716 individual bus stops and 448 routes. The results showed that the charging availability during the day varied from 3 % to 55 % and on average the total energy needed for heating would be 75.6 kWh. However, in the worst-case scenario, the number rises to 237 kWh making the system too expensive for practical applications. During the research there is a very limited availability of research regarding bus heating requirements. Most of the research on thermal comfort in busses are done in hot climate and consequently mostly concerns air conditioning. The thermal comfort research about cold weather is predominantly about buildings and indoor comfort and could not directly apply, as clothing should be considered. Also, the research shows that the temperatures for comfort are lower for short haul vehicles than for the long-haul ones. All these factors strongly indicate that current conventions on temperature requirements for buses are outdated and coming from ICE buses where the heat came from the engine and was free. Therefore, the next studies should include field research analysing passenger thermal comfort levels in buses in winter to explore if there are additional opportunities for energy savings in bus HVAC systems.
Optimization of the Performance of a Cross-flow Gas Mixer for a Partial Oxidation Reactor Through Numerical Modelling
Authors: Klevs Martins , Geza Vadims , Jakovičs Andris , Rodin Leonid
Published: May 2023

Efficient mixing of gases has many different applications in science and engineering. Gas mixers are often used in chemical reactors that use pre-mixed gases in their reaction process. In this work, we vary the geometry of a mixer in order to maximize the uniformity of the mixed gases. The mixing happens in several pipes that have small cross-flow inlets on the sides that stimulate turbulent mixing. The mixer geometry is varied by changing the configuration of the small cross-flow inlets on the pipes, and the mixing quality is quantified by the distribution of gases at certain distances from the cross-flow inlets. The flow was modelled by using open-source finite volume code. We show that standard RANS k-ϵ steady state numeric models greatly overestimate the mixing rate between different gasses, as it ignores transient changes in the flow. Transient simulations using a LES turbulence model show that the gas concentrations in the mixing pipe exhibit a pulsating behavior. The amount and the configuration of the cross-flow inlets play a significant role in how the gases mix and how the concentrations vary over time. The resulting mixer geometry will be used as a part of a partial oxidation reactor design in the future.
Accelerating Microorganism Strain Selection for Enhanced Productivity: A Review of Microdroplet Technology Solutions for Screening Mutant and GMO Strains
Authors: Spalvins Kriss , Kusnere Zane , Raita Svetlana , Berzina Indra , Feldmane Linda , Mika Taras
Published: May 2023

This article reviews state-of-the-art microdroplet technological solutions for screening microorganisms mutant and GMO strains. Microorganisms used in the production of various products – single-cell protein, single-cell oil, enzymes, pigments and other bioactive compounds – can always be improved and their properties enhanced to increase the production of products of interest, to simplify microbial cultivation process, improve efficiency or adapted strains to use cheaper raw materials such as agroindustrial by-products. Microorganisms can be improved using either classical mutagenesis techniques or genetic engineering methods. Regardless of the selected method for mutant or GMO creation, during the process most promising microorganism strains must be selected, which is usually a slow and labour-intensive process. The use of microdroplets is a promising technological solution to speed up strain selection. This review looks at the latest developments in microdroplet technology, compares their variations, and identifies future prospects.