bluuebunny/crossref_metadata_2025 huggingface dataset:
Problems with String Theory in Quantum Gravity
Authors:   Romanian Academy, Sfetcu Nicolae
Published: September 2023

String theory, a framework that aims to reconcile general relativity and quantum mechanics, holds a unique position in the field of quantum gravity. In quantum field theory, the main obstacle is the occurrence of the untreatable infinities in the interactions of the particles due to the possibility of arbitrary distances between the point particles. Strings, as extended objects, provide a better framework, which allows finite calculations. In the realm of theoretical physics, where theories often push the boundaries of human understanding, examining the epistemology of a theory becomes crucial. This article delves into the epistemological aspects of string theory's role in our quest for a unified theory of quantum gravity, exploring the challenges it presents and the insights it offers.
The Influence of Ramadan Fasting on Some Hematological and Biochemical Parameters in Healthy Adult Males
Authors: Mohammed Zahid
Published: September 2023

Objective(s): Ramadan is the Holy month of the Muslims, where they are required to abstain from food and drinksfrom dawn till the beginning of night. This study was conducted in Ramadan to investigate the effect of fasting onhematological incidences, lipid profile, renal and liver function tests among healthy adult males.Methodology: The present study was carried out in Ramadan – 1431 of Higira (August-September 2010). The studysample was 56 healthy adult males. Five samples of blood were taken at five intervals (Before, at day 1, 15, 28 andafter Ramadan). Estimation was done for hematological markers, (hemoglobin, white blood cells count, plateletcount); renal function tests (blood urea, serum uric acid, serum albumin, total serum protein); biochemicalparameters, (blood glucose, total serum cholesterol, serum triacylglyceride, high and low density lipoproteins) andliver function tests (AST, ALT, Alkaline phosphatase, total serum bilirubin).Results: The mean age of the subjects was 48.4 years (SD 7.15) and mean weight was 79.92 kg (SD 7.94). Nosignificant changes were observed in weight, hemoglobin, white blood cell count and platelets count, blood urea andserum albumin values. Whereas, serum uric acid and total serum protein levels were statistically lower during andaŌer Ramadan (P< 0.05, 0.01).Blood levels of glucose showed no significant decrease and serum cholesterol and serum triacylglyceride results werenon-significant at first 2 weeks of Ramadan.The same significant changes (p< 0.05, 0.01) were observed in the lipoprotein at day 15 and 28 of Ramadan. Findingsof liver functions levels showed significant changes. While, total serum bilirubin still with no significant changes duringRamadan.Recommendations: The present study recommends performing more studies with both larger groups and in variouscategories of healthy and unhealthy subjects.
Nosocomial Urinary Tract Infections in Baghdad Teaching Hospital
Authors: Najee Eman
Published: September 2023

Objectives: The objectives of the present study are to identify both, the rate of urinary tract infections (UTI) in medicaland surgical wards in Baghdad Teaching Hospital and the common types of microorganisms that cause this type of NIs,study the resistance of isolated microorganisms to several types of antibiotic and the effect of some disinfectionmaterial like Iodine, chlorhexidine and septicin on the growth of these isolates.Methodology: This is descripƟve study carried out from 1\6\2009 to 1\11\2009. A total of 200 paƟents were admiƩedto medical and surgical wards in Baghdad teaching hospital, paƟents were divided into two group 100 paƟents, insurgical ward and 100 paƟents in medical ward. Some of important information was recorded. Urine samples werecultured on different culture media in order to isolate different pathogenic bacteria. Then, the sensitivity of theseisolates were tested against different antimicrobials, antibiotics (amikacin, ampicillin, cefixime, cefotaxime,cephalexin, gentamycin, nalidixic acid, nitrofuranion, rifimpicin and vancomycin) and the effects of differentdisinfectant solutions with different concentrations; including benzalkonium chloride (septicin, commercial),chlorhexidine and povidoniodine (betadine, commercial), were tested as well on the growth of isolated bacteria.Results: The results show that a high incidence of (UTI) as nosocomial infections appeared in medical and surgicalwards in Baghdad Teaching Hospital and most of paƟents were male at age groups ranged from 46-55 years and 36-45years in medical and surgical ward respectively. The highest rate of UTIs increased in patients who had neededcatheterization procedures in both wards. Gram negative bacteria were commonly p. aeuroginosa and E. coli, lesscommonly gram positive bacteria like methicillin-resistant Satph aureus were isolated as etiologic agents of UTIsinfections in both wards. Moreover, multi-drug resistance for common use antibiotics was observed in most virulentspecies like Pseudomonas aeuroginos and Methicillin resistant Staphylococcus aureus (MRSA). Nitrofurantion was thebest drug for all bacterial isolates. It was obvious that 10-15% of povidione-iodine solution has more effect on thegrowth controlling of pathogenic bacteria, especially Pseudomonas aeuroginos isolates. The results indicatedsignificant differences (p˂0.01) between the effect of SepƟcin and Chlorhexidine on the acƟvity of isolated bacteria.Recommendations: The study recommends that the catheter should be changed every 2 days, especially if signs ofurinary tract infections appear and using antimicrobial catheters and intelligent use of aseptic techniques, and limitingthe use of antibiotics and the use of most effective disinfectant in the exact concentration specified by themanufacture, and the detection antibiotic resistance gene using Polymerase Chain Reaction (PCR) technique.
Quality of Life for Adult Patients with Chronic Obstructive Pulmonary Disease
Authors: Hamzah Maryam , Mansour Khalida
Published: September 2023

Objective(s): To determine the quality of life for adults with a chronic obstructive pulmonary disease.Methodology: A descriptive study was carried out on (80) patients with a chronic obstructive pulmonary disease fromDecember 2008 through October 2009 with special inclusion criteria (adult paƟents from 18 years and above excludethe patients who suffer complication related of disease and from psychological problems and other chronic illnesses.The data were analyzed through the application of descriptive data analysis approach and inferential data approach.Result: The study indicated that the determination of QoL for COPD depended on the level of effect .The gradesaccording to R.S are: "high" effect of disease in the physical, level of independence and environmental domain and"moderate" in the psychological domain, social domain and "low" in the spiritual domain. Finally the study revealedthat there is significant association between (types of smoking, occupation after disease, family history) with totalscore QOL and no significance with sex, age, marital status, educational level, income.Recommendation: The study recommended that the establishment of pulmonary rehabilitation centers for chronicobstructive pulmonary disease, an educational programs and manual guide should be distributed to the chronicobstructive pulmonary disease patients.
Effectiveness of a dietary education program upon hypertensive clients' information
Authors: Khaleel Maher , Hassan Hakima
Published: September 2023

Objective: To determine the effectiveness of a dietary educational program upon the hypertensive client’sinformation.Methodology: The sample of the study consists of (60) hypertensive clients who attended Al Anbar Health Office –AlAndalus Health Center during the period of the study from the14th of March 2010 to the 30th of September 2010. Thesample is divided into two groups; study group (30) hypertensive clients who received dietary educational programand control group (30) hypertensive clients who received a routine care from the center. Three major instrumentswere used; these instruments included (1) knowledge test which was applied on both groups pretest and eight weekspost-test (2) questions to know what they eat in the last 24 hours in the main meals and in between meals (snacks)which were applied on both groups pretest and eight weeks post-test (3) Body Mass Index measurement was appliedon both groups pre-test and eight weeks post-test.Results: The results show that there is highly significant difference concerns the decrease of BMI in post- test forhypertensive clients in the study group than the control group marked improvement in dietary status of the studygroup compared to the control group. The results of our study also show that there is a significant difference betweenstudy group and control group in post-test regarding the adequate grain vegetable fruit. Meat, poultry, and fish (MPF)and Nuts, seeds, and legumes (NSL) intake daily.Recommendations: The study recommends that all hypertensive clients should be involved in the application ofnutritional educational programme which was developed in this study.
Sistemas de amortização no regime de juros simples
Authors: Lachtermacher Prof. Dr. Gerson , Faro Prof. Dr. Clovis de
Published: September 2023

No sistema Financeiro de Habitação, as modalidades de financiamento mais empregadas são a Tabela Price, o Sistemas de Amortizações Constantes e, mais recentemente, tendo sido introduzido pela Caixa Econômica Federal, o Sistema de Amortizações Crescentes (SACRE). Entretanto, por serem fundamentados no regime de juros compostos, tem sido corrente decisões judiciais determinando suas respectivas substituições segundo os ditames do regime de juros simples. Contemplando tais eventualidades, desenvolve-se uma metodologia geral que possibilita, em cada caso, a determinaçãonumérica da correspondente evolução do plano de financiamento.
Consistência financeira no regime de juros simples
Authors: Lachtermacher Prof. Dr. Gerson , Faro Prof. Dr. Clovis de
Published: September 2023

No sistema Financeiro de Habitação, as modalidades de financiamento mais empregadas são a Tabela Price, o Sistemas de Amortizações Constantes e, mais recentemente, tendo sido introduzido pela Caixa Econômica Federal, o Sistema de Amortizações Crescentes (SACRE). Entretanto, por serem fundamentados no regime de juros compostos, tem sido corrente decisões judiciais determinando suas respectivas substituições segundo os ditames do regime de juros simples. Contemplando tais eventualidades, desenvolve-se uma metodologia geral que possibilita, em cada caso, a determinação numérica da correspondente evolução do plano de financiamento.
Os desafios da cultura de inovação para o desenvolvimento de projetos no ensino médio
Authors: Jacubavicius Prof. Dr. Celso , Mastria Prof. Lucas Gonçalves
Published: September 2023

Uma proposta que garanta, entre outros objetivos específicos, a efetividade de um método de potencialização das capacidades de aprendizagem de jovens cursando o ensino médio e a maximização dos resultados frente aos recursos escolares deve ter uma base metodológica rígida, uma aplicação factível e apresentação de propostas finais efetivas. Assim é o que se apresenta neste relato: uma aplicação de Design Thinking, comumente aplicado em desenvolvimento de novos produtos em diversas áreas de negócios, é aqui utilizado como forma de aprendizagem ativa na criação de produtos com alunos de ensino médio através de uma plataforma de desenvolvimento, mão na massa nas etapas de construção e, como fechamento, apresentação dos projetos e seus resultados no modelo de elevator pitch. Como parte dos objetivos específicos da pesquisa, é possível, também, comparar esta atividade com o DSR (Design Science Research) aplicado nas indústrias em projetos de engenharia de produção.
A implementação da economia circular nas empresas
Authors: Campi Isabela Gomes , Sousa Prof. Dr. Euzébio Jorge Silveira de
Published: September 2023

Este artigo aborda a Economia Circular como um novo paradigma em sustentabilidade, substituindo o modelo linear que extrai, produz, utiliza e descarta recursos naturais. Seu objetivo é criar um ciclo contínuo de produção, consumo e reciclagem, reduzindo a dependência de recursos finitos e minimizando resíduos e emissões. A Economia Circular impulsiona o desenvolvimento sustentável com modelos inovadores e consumidores responsáveis, sendo essencialpara enfrentar desafios ambientais e sociais. Será apresentada a Política Nacional de Resíduos Sólidos (PNRS), principal regulamento sobre o gerenciamento de resíduos no Brasil, bem como os desafios na reestruturação organizacional e mudança de paradigmas na sua implementação. Serão abordados os benefícios da Economia Circular através de modelos de negócios inovadores e consumidores responsáveis. Por fim, destacaremos a importância da transição para a Economia Circular na preservação dos recursos naturais e construção de um desenvolvimento sustentável.
O impacto do covid-19 na receita tributária e condição financeira de Manaus – AM
Authors: Boalento Geovana Pimentel , Constantino Anderson Pascoal , Silva Wellington Prattes da , Henrique Prof. Dr. Marcelo Rabelo , Saporito Prof. Dr. Antonio
Published: September 2023

O Brasil é caracterizado por ser um Estado de Direito, ou seja, uma sociedade civil politicamente e juridicamente organizada. Realizar as ações próprias do Estado, como: defesa, Justiça, saúde, habitação, educação, saneamento básico entre outros, o Estado precisa de recursos financeiros. Considerando o exposto anteriormente, a presente pesquisa busca analisar os impactos da pandemia na arrecadação tributária, com foco no ISSQN, e a condição financeira de Manaus. Assim sendo, a pergunta de pesquisa é: “Qual o impacto gerado condição financeira e na arrecadação do ISSQN no munícipio de Manaus, em decorrência da crise do COVID-19?. Conclui-se que a cidade de Manaus- AM sofreu forte impacto pelo COVID-19, fenômeno este evidenciado nos estudos de arrecadações mensal de ISSQN. Verificou-se que nos meses em que medidas restritivas severas foram tomadas, a arrecadação sofreu variação negativa comparada ao ano anterior. Entretanto, foi notável que no resultado agregado anual, compensado pela alta arrecadação no mês de dezembro, período festivo e de flexibilização nas medidas, Manaus teve uma variação positiva, quando comparada com a arrecadação tributária anual de 2019.
Unlocking the Path to Inclusive Growth: Examining the Impact of Financial Inclusion in Developing Economies
Authors:   Bangladesh Bank, Head Office, Dhaka 1000, Bangladesh, Banik Banna
Published: September 2023

This empirical research study explores the influence of financial inclusion (FI) on long-term economic growth within a dataset comprising 50 developing countries over the period from 2010 to 2022. Sustainable per capita economic growth, defined as an annual growth rate of a minimum of 7%, serves as a representative measure for sustained economic growth, while the growth rate of branches of bank and ATMs per 0.1 million people functions as a proxy for FI. Employing panel data models, our findings suggest a positive correlation between FI and sustained economic growth, although this relationship does not attain statistical significance. We also employ robust endogeneity-consistent estimation techniques, including the two-step system and differenced Generalized Method of Moments (GMM) approaches, and our results consistently indicate that financial inclusion, as measured by bank branches and ATM outreach, does not appear to be a significant driver of economic growth. Consequently, central banks and governments are encouraged to formulate and implement more effective strategies and initiatives aimed at enabling greater access and utilization of financial services among unbanked populations, with the potential to yield tangible benefits from financial inclusion and consequently foster higher growth rates in developing nations.
Space-time behavior for radiative hydrodynamics model with or without heat conduction
Authors: Liu Mengqian , Wu Zhigang
Published: September 2023

We consider space-time behaviors of smooth solutions for the radiative hydrodynamics system with or without heat conduction in the whole space \(R^3\) by using Green's function method. This result exhibits the generalized Huygens' principle as the classical compressible Navier-Stokes equations [3,26], which is different from the Hamer model for radiating gases in [36].

For more information see https://ejde.math.txstate.edu/Volumes/2023/60/abstr.html
ESTADO COMO PRODUTOR DE SERVIÇOS DE SAÚDE NO BRASIL
Authors: Caputo Weiss Xavier Beatriz , Mascarenhas Guzella Matheus , De Souza Lima Marcos César
Published: September 2023

Este artigo busca analisar a atuação do Estado brasileiro como produtor de serviços de saúde. A intenção não é, de qualquer forma, valorar alternativas ao modelo brasileiro ou solucionar problemas advindos desta atuação estatal. Ao contrário, visa-se descrever ao papel do Estado, em suas três esferas, como um produtor de serviços de saúde, que visa benefícios e malefícios do modelo hodierno. A despeito de não ser o objetivo deste trabalho apresentar um eventual modelo “melhor”, fornecer sistemas diversos, de forma exemplificativa, para estabelecer um panorama ao leitor sobre o modo como o Estado brasileiro atua na saúde e o modo como outros países aplicam seus sistemas.
READING MOTIVATION APPROACH UTILIZED BY PUBLIC ELEMENTARY SCHOOL TEACHERS OF CLUSTER III ALAMINOS CITY DIVISION
Authors: Allam Jomar
Published: September 2023

This study was conducted to determine the level of utilization of the reading motivation approaches by public elementary school teachers in Cluster III of Alaminos City Division during the school year 2019 - 2020. Specifically, it delved on determining the profile of the respondents, the level of utilization of teachers on the reading motivation approaches, and the level of seriousness of the problems encountered by the teachers in utilizing the reading motivation approaches. Likewise, it determined the significance of the difference of the level of utilization of the public elementary schools on the reading motivation approaches across their profile variables. Moreover, it determined if the level of seriousness of the problems encountered in utilizing the reading motivation approaches differ significantly across the respondent-teachers’ profile variables. The study made use of the descriptive-survey method of research with the FivePoint Likert Questionnaire as the main tool used in gathering pertinent data to this study.
WORK-LIFE BALANCE AND TEACHER ENGAGEMENT IN PRIVATE SENIOR SECONDARY SCHOOLS IN RIVERS STATE, NIGERIA
Authors: Kelechi Obasi Kenneth , Ginikachi Adieme Franca
Published: September 2023

This study examined work-life balance and teacher engagement in private secondary schools in Rivers State. Three research questions and three hypotheses guided the study. The study adopted a correlation research design with a population of 7,143 teachers (2,676 males and 4,467 females) in all the 275 private secondary schools in Rivers State.  The sample size of 714 teachers was drawn through proportionate stratified random sampling technique, which represents 10% of the population. Two self-designed instruments entitled: “Work-life Balance Questionnaire (WLBQ)” and “Teacher Engagement Questionnaire (TEQ)” were used for data collection. The instruments were in two sections – A and B. Section A consisted of the demographic factors while Section B contained the variables that were used to elicit information from the respondents. The Section B contained 20 items on Work-life Balance and 15 items on Teacher Engagement respectively. Face and content validities were ensured by experts in the relevant areas. The Cronbach’s Alpha reliability method was used to establish the internal consistency, and indexes of .79 for WLBQ and .83 for TEQ were established respectively. Research questions 1 and 2 were answered using simple regression while research question 3 was answered using multiple regression. Hypotheses 1 and 2 were tested with t-test associated with simple regression while hypothesis 3 was tested using ANOVA associated with multiple regression at 0.05 alpha level. The findings of the study revealed, among others, that work-life balance significantly and jointly predicted teacher engagement to a very low extent in secondary schools in Rivers State. Based on the findings, it was recommended, among others, that both employers and school managers should create flexible work environments that promote work-life balance for teachers so as to motivate them to perform optimally for the attainment of the educational goals.
Comparing the effectiveness of online and traditional learning in computer related fields
Authors: Bashllari Silva , Korbi Klea , Skëndaj Alba , Plaku Evis
Published: September 2023

The traditional classroom environment is gradually losing its monopoly as the sole setting of learning. Digital learning is becoming an attractive model across the higher education spectrum as new innovative information technologies have become widely available. Online learning is used as a tool that improves learning performance while combating the reduction in resources. This work presents a novel study focusing on estimating the efficiency of online learning in comparison to traditional learning for computer related fields in education institutions in Albania. A survey is conducted to estimate the impact that the learning modality has on students enrolled in computer technology related fields. The study focuses on measuring the role that intrinsic factors, teaching practices, learning intentions and programming expertise have on the perceived usefulness and the efficacy of online learning. Measuring the role and effect of the learning modality will be important to estimating whether students and higher level education institutions are ready to shift towards online learning, or to integrate it into the current traditional framework. The results of our study are useful to have a better understanding of the benefits of online learning alongside with the challenges that need to be addressed in order to improve the teaching experience and outcomes.
The effect of coronavirus in the stock market
Authors: Cani Klea , Pojani Brendon
Published: September 2023

Living in the era of globalization made the spread of the virus to affect the entire world’s economy. The stock market plays a huge role in the well-going of the economy and for this reason the changes that have happened due the pandemic affected on everyone's lives.Stock market is a perfect investment for all because saving in the stock market is the safest way to produce returns over time that can surpass inflation and now it is being affected by the virus. It is a fact that the stock market and the economy are related together. Many industries have been badly hit by the virus but also some other companies have had major benefits and for this reason the financial market changed directly in an unexpected way. So the market itself reacts to these changes and also should continue to deal with problems that have existed in it before the virus. Many of the problems surfacing now are actually derived from the great crisis that happened in 2008. Recession might happen if the situation goes on for too long but there are facts that also throw this down.
The behavior of organizational and political leader
Authors: Shqau Gjergji
Published: September 2023

This article aims to study the behavior of political and organizational leaders as well as identify common areas and differences between them. Four objectives have been set for this and it is thought that the methodology used will be as effective as possible in achieving the goal and objectives. Organizational leadership has been studied in companies with experience and expertise, with the results of the work of leaders, while political leadership is mainly focused on the behavior of political leaders during their tenure. Organizational and political leaders have been studied not only currently but mainly in the past. This constitutes a difficulty in reaching accurate conclusions, but not an inability to observe leadership behaviors and traits. Various research techniques and methods have been used to gather information, including data processing. At the end of the article are given the conclusions, the conclusions and some recommendations for both types of leaders.
Un enfoque sistemático normativo sobre la libertad de trabajo a mérito de los procedimientos administrativos disciplinarios en la Policía Nacional del Perú
Authors: Romero Luján Carmela Rosalía , Ludeña González Gerardo Francisco , Cueva Quezada Nilton Isaias
Published: September 2023

El objetivo del estudio fue analizar de qué forma se vulnera la libertad de trabajo al personal policial que cuenta con procedimientos administrativo disciplinarios pendientes. El diseño empleado fue cualitativo y el alcance descriptivo. La muestra la conformaron datos de revistas indexadas Scielo, Redalyc, Dialnet, y Proquest, la técnica es la recopilación materializada correspondientes a las variables la vulneración a la libertad del trabajo y procedimiento administrativos disciplinarios en la Policía Nacional del Perú. De la misma forma, se efectuó la revisión de producción científica disponible para su descarga gratuita, filtrando las palabras claves “libertad de trabajo”, “procedimiento administrativo disciplinario”, “derechos fundamentales”, “derecho al trabajo”, “limitación de derechos”. Como resultados de la presente investigación se evidencio que la normativa vigente de la PNP en cuanto a la libertad de trabajo limita a los efectivos policiales a pasar a la situación de retiro a solicitud, cuando estos se encuentren sometidos a un procedimiento administrativo disciplinario por infracciones “Muy Graves a la Ley de Régimen Disciplinario de la PNP”. Concluyendo que dicha Ley colisiona con la Constitución Política del Perú en el extremo del derecho a la libertad de trabajo.
Eficiencia y eficacia en la ejecución de obras públicas: Un análisis critico
Authors: Huamani Macedo Ximena Yurema , Prudenci Cuela Fausto Enrique , Vértiz Carlos Dania Doritza , Cernaqué Miranda Ofelia Carol , Tarco Sánchez Armando
Published: September 2023

El objetivo del presente artículo fue conocer los resultados de las variables eficiencia y eficacia en la ejecución de obras públicas, que permita plantear acciones correctivas e identificar oportunidades de mejora mediante políticas públicas. Referente a la metodología utilizada, se realizó un artículo de revisión bibliográfico con enfoque mixto donde se presenta un proceso analítico y empírico de información existente más relevante de los últimos 5 años de revistas indexadas en base de datos confiables, teniendo como resultados inadecuados niveles de eficiencia y eficacia en la ejecución de obras públicas, dado principalmente por variaciones de plazo y presupuesto, las causas de estas variaciones se deben a múltiples factores externos e internos que varían en mayor y menor medida en países en desarrollo y desarrollados, siendo mayor en países en vías de desarrollo, por lo que es necesario implementar acciones de planeamiento estratégico, capacitación en elaboración de términos de referencia y/o especificaciones técnicas y actualizar el marco normativo a fin de mejorar el bienestar y calidad de vida en las personas y un mayor crecimiento económico y desarrollo de los países.
XIX Congreso Internacional en Innovación Tecnológica Informática - XIX CIITI 2021
Authors: De Vincenzi Marcelo , Darín Susana , Maccarini Marcela , Pons Claudia
Published: September 2023

El XIX Congreso Internacional de Innovación Tecnológica Informática, CIITI, de la Facultad de Tecnología Informática y su Centro de Investigación, CAETI, de la Universidad Abierta Interamericana, UAI, es un espacio para la difusión, promoción y reflexión sobre la importancia de la innovación tecnológica informática como factor de competitividad. El mismo se desarrolló de forma virtual en la plataforma del congreso el jueves 30 de septiembre de 2021.

 

El eje conductor del XIX CIITI 2021 fue “Fast Lane del Futuro Digital”, el cual aborda los caminos tecnológicos trazados por las empresas, el estado y la academia en la autopista de la innovación tecnología informática para alcanzar las demandas de un mundo vertiginoso, líquido y digital propuesto por la cuarta revolución tecnológica. Las buenas prácticas y el constante espíritu emprendedor de los actores protagonistas de esta revolución tecnológica, aplicados en los procesos de construcción de conocimiento y productivos, han favorecido en el corto plazo, la aceleración en la obtención de logros sorprendentes y resultados extraordinarios, valiéndose de la aplicación de tecnologías inmersivas, híbridas y ubicuas como la Inteligencia Artificial, Blockchain, Realidad Aumentada, Internet de las Cosas, en entornos colaborativos, inclusivos y participativos en búsqueda de mejoras de la democratización de acceso a la información e igualdad de oportunidades.
Influence Of Printing Parameters In FFF Of Metal Filaments
Authors: Mueller Christian , Folkert Patrick
Published: September 2023

In this manuscript the influence of two different printing parameters in Fused Filament Fabrication (FFF) Additive Manufacturing process on mechanical properties of metal feedstock-based green parts is investigated. The influence of printing parameters on mechanical properties of sintered parts was analysed in [1], but it is obvious that the additional process steps of debinding and sintering alter the test results and as well might alter the conclusions drawn from such experiment, compared with testing the green parts instead. Both the nozzle temperature 135 - 145 °C and flow 100 - 105 % in the FFF process were found to have statistically significant influence on tension and elongation at break.
Process development of a Ti-6Al-4V-10wt%WC metal matrix composite using selective laser melting
Authors: Mthembu Noluthando , Sacks Natasha
Published: September 2023

In this study the influence of laser power and scanning speed was investigated on the development of a Ti-6Al-4V alloy reinforced with 10wt%WC to form a metal matrix composite. Response surface methodology was used for both the design of experiments and results analyses. The laser power was varied between 95 and 195W while the scanning speed was varied between 600 and 1000mm/s. Cubic samples were deposited using a continuous alternating meander scanning pattern which was selected after initial optimization of the Ti-6Al-4V alloy. Density, porosity, and Vickers micro-hardness (transverse and longitudinal directions) were measured, while the microstructure was studied using x-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Relationships were established between the measured material properties and the deposition parameters in order to find the optimal deposition parameters for the composite.
Multi-Material Laser-Based Powder Bed Fusion Of Steels And Ni-based Superalloy
Authors: Li Xiaoshuang , Gianfolcaro Nicolas , Chaoqun Zhang , Malik Shadab
Published: September 2023

The emerging multi-material additive manufacturing technology enables the production of components with region specific properties via a single-step manufacturing process. One of various advantages is to combine high performance and high-cost materials with low performance and low-cost materials. In the present study, the selected Inconel 625 superalloy and common 316L steel were additively manufactured by laser-based powder bed fusion. Regardless of the presence of material boundary, a continuous scanning strategy was used to optimize processing parameters for both materials with the assistance of artificial intelligence. It turned out that it is feasible to make fully dense parts with a single set of parameters. Intensive material mixing at the interface shown in the SEM results indicates sound metallurgical bonding. In addition to great manufacturability, the manufacturing speed was greatly improved up to two times by employing large hatch spacing coupled with proper laser powder, scanning speed and layer thickness.
Development Of An Invar Strengthened By Ni3Nb-Gamma'' Phase Precipitation Suitable For Additive Manufacturing
Authors: Giroud Tiphaine , Egea Philippe , Vikner Peter , Vivès Solange , Mayer Charlotte
Published: September 2023

Stellar® InvHard is a Nb-enriched Invar designed for additive manufacturing (Laser Powder Bed Fusion). It will be launched on the market in 2023. Compared to Invar 36, Stellar® InvHard exhibits increased mechanical strength while maintaining a low coefficient of thermal expansion. The hardening of this alloy is inspired by superalloys 706 and 718 strengthened by Ni3Nb-γ'' phase that precipitates in the austenitic matrix; also containing carbides and Nb-rich δ phase. The precipitation of the γ'' phase can be controlled through annealing and aging treatment’s optimization, leading to a hardness in a range: 300-420 HV and the effect on coefficient of thermal expansion increase is limited thanks to the small size of such precipitates. Insights on microstructure and processability will also be presented along to coefficient of thermal expansion.
Modelling The First Compaction Stage Of A Metallic Powder By Rearrangement During Load Assisted Sintering: Oedometric Experiment And DEM Simulation
Authors: Mamykin Petr , Chateau-Cornu Jean-Philippe , Bernard Frederic
Published: September 2023

This study examines the possibility of simulating the rearrangement stage of 316L steel powder using a modified cam-clay model. The oedometric compression tests were carried out at up to 900°C using an SPS device. Unlike clay soils, the virgin consolidation line is non-linear, with a slope dependent on volumetric deformation. The dependency of the slope is characterized at different temperatures and a consolidation law under isostatic pressure is proposed. The initial pressure at which the virgin powder starts to densify plastically was successfully adjusted. This adjustment was made using density measurements obtained after HIP interrupted tests performed on the same powder encapsulated in a spherical container. The complete consolidation law can be implemented in FEM simulations to take into account the rearrangement stage in the densification of industrial parts. The second part aims at determining the optimal simulation parameters for oedometric cold pressing of the powder powder using the discrete element method. The simulation uses the Hertz-Mindlin contact model and the Spherical Johnson-Kendall-Roberts model to account for powder particle adhesion. Simulation parameters have been optimised through iterative refinement. The particle size distribution is measured experimentally by sieving. For this size distribution, the values determined for the simulation parameters were 5 nanoseconds for the minimum time step, 0.002 for the friction coefficient and 0.36 for the adhesion coefficient. These parameters ensure accurate representation of the powder behaviour in monotonic compression but the simulation lacks of efficiency when unloading-reloading stages are applied.
Tooth Contact Analysis of Powder Metal Gears under Consideration of Local Material Properties
Authors: Hellenbrand Gerrit , Mevissen Dieter , Brimmers Jens , Brecher Christian
Published: September 2023

An efficient gear design requires minimal safety margins to realise a full material utilization in terms of the load carrying capacity. This leads to a necessity of increasingly accurate calculation methods for the load carrying capacity of gears. In this paper, a method for the stress calculation in the tooth contact of surface densified powder metal gears considering local material properties is presented. The approach to integrate the densification profile is realized, based on an image-processing tool that analyses metallographic microsections. These profiles serve as an input for an FE-based tooth contact analysis with consideration of the local material properties. Parallel, the fully densified surface area is calculated with an analytical approach and the results are compared to the results of the numerical calculation to build up a calculation method, with a combined approach for the resulting stress depth profile.
Nickel-Zirconia Laminates Prepared by Selective Powder Deposition and FAST/SPS Sintering
Authors: Neirinck Bram , Huang Shuigen , Vleugels Jozef , Li Xiaoshuang
Published: September 2023

Co-fired devices were developed in the late 50’s as a robust option for high power / high temperature electronics. As the name suggest, they were obtained by simultaneously sintering different materials, often an insulating ceramic substrate with a conductive metal on top. Since these devices were first conceived there have been significant developments in processing and sintering technologies. This paper addresses a potential alternative approach to create High temperature Co-fired Ceramics (HTCC’s). Commercially pure nickel and yttria-stabilized zirconia powder layers with a controlled thickness were deposited in graphite dies using Selective Powder Deposition (SPD). These layers were subsequently pre-compacted in the die and consolidated using FAST/SPS sintering. The results show that crack-free laminates of fully dense metal and ceramic layers can be obtained. The metal sections are electrically insulated from one another, demonstrating the possibility to generate conductive tracks/circuits, while using a relatively uncomplicated deposition process and high-speed sintering.
Analysis Of Boron Behavior In The High-Temperature Ni-Based PM HIP Superalloys By The Use Of A Firstly Proposed TTT Diagram
Authors: Shulga A.V.
Published: September 2023

Based on the results of a multiscale experimental study of the behavior of boron, carbon, and micro-structure of HIP PM compacts of the high temperature Ni-based superalloys, during various heat treatments, as well as compression and tensile tests, performed in particular by the method autora-diography, was constructed the firstly proposed TTT diagram. Study of boron and carbon behavior in relation to microstructure was carried out by direct methods track autoradiography on boron and activation autoradiography on carbon, metallography, SEM, EDX, OIM methods. Formation of solid solution of boron, segregation of boron, and precipitation of borides, in particular, along grain bound-aries as a result of heat treatment of compacts, have been revealed and analyzed. Therefore, the time -temperature conditions for the precipitation of the boride phase were determined as the main parameters of the proposed TTT-diagram of the boride phase in comparison with the TTT-diagrams of the carbide and gamma-prime phases.
Sintering Simulation Framework As A Virtual Design And Process Optimisation Tool For Sustainable Sinter-based Additive Manufacturing
Authors: Abburi Venkata Kiranmayi , Gao Siwen
Published: September 2023

Sinter-based additive manufacturing (AM), especially Metal Binder Jetting (MBJ) is emerging as an economical AM technology for cheaper metal parts production. Although sinter-based manufacturing has been around for over half a century, the design freedom and specific process characteristics of MBJ necessitate reliable sintering simulation. A validated simulation tool provides greater understanding of the underlying material behaviour necessary for design optimisation, process control and standardisation. Using Simufact Additive MBJ module, the macroscopic shrinkage and deformation behaviour of the material during MBJ sintering are predicted accurately. The simulation predictions are used to automatically generate pre-compensated part geometry such that the part tolerances are within quality specification after sintering. Other quality control strategies such as live setters/supports can also be assessed to identify the best strategy for a given geometry, material and process parameter combination. The simulation framework as a virtual design tool is validated on industry relevant geometries with experimental investigation.
Tailored PM Steel Materials For Heat Treatment Using A Simulation Tool To Predict The Hardenability
Authors: Sundaram Maheswaran Vattur , Andersson Michael
Published: September 2023

The performance of PM steels is directly related to the material properties which is a consequence of the input alloying addition and processes involved. However, it is of significance to understand the hardenability requirements, specific to the component size/dimensions and the selected material for the specific heat treatment (HT) processes where gas and oil are used for quenching. Processes such as sinter-hardening, casehardening, and through-hardening are commonly performed to enhance the performances. In this work, quenching simulations were performed and a tool for hardenability calculation is developed with respect to the materials, components size, and different quenching mediums. For given component dimensions this tool predicts the suitable material and the cooling rate required to transform the microstructure into fully martensitic. This allows for minimising the number of trials required for optimising the HT process for PM steels.
Examination of Special Education Teachers' Opinions on the Problems They Experience and the Solution of the Problems
Authors: Özgen Vildan , Ulutaş Mehmet
Published: September 2023

In this study, the problems experienced by special education teachers according to their opinions, the source of the problems and their expectations were tried to be revealed. In this study, which was conducted to identify the problems and expectations of special education teachers who work in the country and have an important place, it is aimed to improve the quality of special education by developing solution proposals.

Eight school administrators, who work in schools of various types and levels in Aydın province, who were determined by criterion sampling and maximum diversity sampling, which are among the purposeful sampling methods, participated in this study, which is considered in the case study design, which is one of the qualitative research methods. The semi-structured interview form used in the research was shaped by the researchers as a result of the literature review. The data obtained by the face-to-face interview method were analyzed by content analysis. As a result of the analysis of the data, it was determined that special education teachers mostly experienced problems with school management, teaching process, student parents, physical space and other field teachers.

In this study, which is thought to make a significant contribution to increasing the quality of special education given in schools, within the framework of the data obtained, meeting the needs of teaching materials and equipment, providing seminars, courses and distance education services for parents, teachers and school administrators, and communication and communication of school administrators with other field teachers. Suggestions have been developed to carry out activities to increase interaction.
Learning Local History and Culture Through Museum Visits
Authors: Pedroso John Erwin Prado , Gicole Charisse , Sarches Anthony
Published: September 2023

This study described how social studies preservice teachers learn local history and culture through museum visits. It employed a qualitative descriptive research design involving ten social studies preservice teachers selected through purposeful sampling. Data were collected through a written interview and analyzed using thematic analysis. Through museum visits, social studies preservice teachers learned the following: visual driven through images, relics and artifacts, and multimedia presentation; audio/oral driven through curator explanation and peer discussion; text driven through text description; and actual experience-driven through applying learning from exhibits, giving a point of view from the past, and wearing traditional attire. Preservice social studies teachers can learn about local history and culture by visiting museums. This study emphasizes the value of museums in preserving and promoting local heritage and culture, as well as how they can be a valuable resource for learning about local history and culture.
standard measurement in online learning: a rubric as a focus on teaching-learning practices to move up quality education
Authors: Farzana Tasnia
Published: September 2023

The main objective of this paper is to facilitate the 21st century’s quality assurance for learning and distance learning to measure learning outcomes and enable students to achieve skills and knowledge in global transformative education. Technologies in education have provided a common platform for transforming education into online learning practices throughout the global COVID-19 affliction. Accordingly, the transformation of modern technologies in education has opened up many challenges and reliability issues in teaching and learning processes. The paper highlights the rethinking of rubric perceptions, uses, and design in learning, including online learning, in an interactive way to promote quality education. The research methodology involved a systematic review of the literature and data analysis synthesized using both qualitative and quantitative techniques. Rubrics, as an influential assessment instrument in learning, have been applied along with standardizing the quality of students in higher education for almost three decades globally. This study is significant in focusing on the rubric, the practical instrument, which is helpful for great accomplishments and challenging skills, and creativity in tertiary education. Well-designed and carefully designed rubrics and e-rubrics help students become more rational judges of the quality of their work by identifying the essential criteria and targeting the goals and learning outcomes of education. Rubrics enhance students' competency to communicate their ideas effectively, which correlates with the standard of sustainable quality education. Further examination of the rubric is needed to identify the challenges of reliability and authenticity in digital education.
Harnessing AI to Power Constructivist Learning: An Evolution in Educational Methodologies
Authors: Grubaugh Steven , Levitt Greg , Deever Donald
Published: September 2023

This article navigates the confluence of the age-old constructivist philosophy of education and modern Artificial Intelligence (AI) tools as a means of reconceptualizing teaching and learning methods. While constructivism champions active learning derived from personal experiences and prior knowledge, AI’s adaptive capacities seamlessly align with these principles, offering personalized, dynamic, and enriching learning avenues. By leveraging AI platforms such as ChatGPT, BARD, and Microsoft Bing, educators can elevate constructivist pedagogy, fostering enhanced student engagement, self-reflective metacognition, profound conceptual change, and an enriched learning experience. The article further emphasizes the preservation of humanistic values in the integration of AI, ensuring a balanced, ethical, and inclusive educational environment. This exploration sheds light on the transformative potential of inter-twining traditional educational philosophies with technological advancements, paving the way for a more responsive and effective learning paradigm.
An Inquiry into the Evolution of the Project-based Instructional Approach “Three” from “A Program” to “A High-quality Course”
Authors: Li Mengru , Kitili Ike M.
Published: September 2023

Within the context of education reform, there is a pressing need to overhaul and enhance the existing educational approach. As part of this endeavor, it is imperative to establish a more adaptable and multifaceted project-based teaching methodology. However, it is important to acknowledge that this approach also exhibits certain inherent limits, which become increasingly apparent during its implementation. However, it is worth considering if this particular pedagogical approach can effectively address its inherent limits and successfully facilitate the desired transformation and advancement of the educational system. This research aims to examine the efficacy of the “three” teaching approach in facilitating the transition from a mere instructional plan to an effective classroom experience.