bluuebunny/crossref_metadata_2025 huggingface dataset:
Nossas fogueiras contemporâneas: padrões normativos de gênero em Elas marchavam sob o Sol de Cristina Judar
Authors: Kuhn Mariana Schulmeister
Published: February 2024

Resumo Padrões estéticos, tabus sobre o corpo feminino, desigualdade entre homens e mulheres, sexualidade, opressões, violência e intolerância são questões presentes nas discussões recentes sobre gênero. A obra Elas marchavam sob o Sol, de Cristina Judar, de forma contestadora e muito original, traz à tona todos esses elementos. Com uma narrativa intimista e fluida, a autora por meio de duas jovens personagens — Ana e Joan — questiona padrões normativos de gênero estabelecidos em nossa cultura e interroga a sua validade e utilidade. O objetivo deste artigo é analisar alguns desses questionamentos levantados ao longo da narrativa, relacionando-os com nosso contexto social. Para que isso fosse possível, foi utilizado o conceito de gênero de Joan Scott (1995) como norteador das reflexões e uma bibliografia que auxiliou no processo de análise, a qual contou com autores como Beauvoir (1970), Pesavento (2003), Saer (2009), Emidio e Gigek (2019).
Associativismo e elites da Magistratura e do Ministério Público
Authors: Engelmann Fabiano
Published: February 2024

Resumo O artigo aborda a conexão entre o associativismo e a produção de elites na Magistratura e no Ministério Público. Partindo-se da comparação de percursos dos presidentes das associações estaduais dessas carreiras, analisou-se, de modo comparado, a relação entre a passagem pela Presidência e a ocupação de postos na cúpula dos tribunais e dos ministérios públicos estaduais. Considerou-se também a ocupação de outros cargos de destaque no âmbito dessas instituições e no quadro das associações nacionais. Os resultados indicam a importância significativa do espaço associativo na produção de lideranças no âmbito dessas instituições, com variações históricas e regionais relevantes.
Review of Tore Rye Andersen, Planetary Pynchon: History, Modernity, and the Anthropocene (Cambridge University Press, 2023), 228 pp.
Authors: Severs Jeffrey
Published: February 2024

n/a
Potential game in parallel transport network with symmetric externalities
Authors: Чиркова Юлия Васильевна , Chirkova Julia
Published: February 2024

The paper considers a model of a transport system with parallel channels and BPR delay functions with symmetric linear externalities. We consider the case where the impact of channel loads to the delay is pairwise symmetric. For this case, it is proved that the game of traffic allocation among channels is potential, and the price of anarchy is limited by the value $\frac{4}{3}$.
Mapping SCS hydrological soil groups over South Africa at terrain unit spatial resolution
Authors: Schulze R E , Schütte S
Published: February 2024

Given the many users in South Africa of the SCS (Soil Conservation Service) hydrograph-generating technique, which requires key soils information, this paper presents a methodology to develop a detailed map (at the spatial resolution of South Africa's 27 491 terrain units) of the SCS runoff-related soil groups. In order to achieve this objective, background is first provided on the soils context within the SCS technique, as well as on the approaches to defining SCS hydrological soil groups, by assigning SCS soil groups to South African soil series. Steps when mapping SCS soil groups across South Africa at terrain unit spatial resolution are then outlined. This is followed by the presentation and interpretation of the detailed terrain unit level map of SCS soil groups for South Africa. The detailed new map illustrates the finer detail across contributing catchments countrywide now obtained from the terrain unit approach, compared to the previous map of SCS soil groups based only on the coarser soil land types.
The value of Association Rule Analysis in understanding serious and fatal road traffic crashes - a case study of the N4 toll road between 2015 and 2019
Authors: Gelderblom A J , Sinclair M
Published: February 2024

In spite of the fact that the road traffic crash fatality rate in South Africa is significantly higher than the global average, the characteristics and causes of road traffic crashes are still not well understood. Without a clear understanding of the characteristics and causes, intelligence-led countermeasures to reduce crashes cannot be developed or applied. The analysis of local South African road crash data is of particular importance in identifying the underlying problems responsible for the high crash rates across the country. While descriptive analyses can be used to present a snapshot of the crash problem, they are largely inadequate when it comes to throwing light on the underlying patterns and relationships between the contributing factors and causes of the crashes themselves. This paper presents a study of the use of Association Rule Analysis (ARA) on data related to crashes on the N4 between Pretoria and the Mozambican border, between 2015 and 2019, to see what added value ARA may offer to standard descriptive analyses of crash data. Apriori Association Rule algorithm was employed on the dataset to identify what contributory factors were not initially evident in the occurrence of serious and fatal crashes. ARA revealed that pedestrians, negligent driving, overtaking and single-vehicle crashes are common factors likely to be present in a serious crash. However, this study found that descriptive statistical analysis and ARA methods are not mutually exclusive, but rather complementary. Where descriptive statistical analysis focuses on summarising and describing data, ARA focuses on identifying relationships and patterns within the data.
Selected trace element concentrations in run-of-mine coal, discard, and coal product, and environmental implications
Authors: Mashishi R.M. , Okonkwo O.J. , Malehase T.
Published: February 2024

The concentrations of selected trace elements (As, Cd, Hg, and Pb in run-of-mine (ROM) coal, discard, and coal product were investigated to assess the efficiency of beneficiation in reducing trace element concentrations and ascertain any implications regarding environmental compliance to regulatory frameworks. Samples were collected from a colliery in Mpumalanga Province twice a month for a period of 24 months. The samples were ashed to approximately 0.21 mm, then digested in a mixture of 70% HNO3 and 40% HF and analysed using inductively coupled plasma-mass spectrometry (ICP-MS). Except for Pb, the mean concentration of all elements decreased from the ROM stage to the coal product stage. The order in which trace elements occurred from the highest to lowest throughout the production chain was Pb>As>Hg>Cd. With the exception of Cd, the mean trace element concentrations in the discard were above the total concentration threshold (TCT) set for landfill disposal. The As, Hg, and Cd concentrations in the product were well below the thresholds for all land uses. However, Pb concentrations in the product coal were above legal limits, which is of concern with regard to environmental compliance and the performance and marketability of the product.
Formation and isolation of Clu phospholipid particles v1
Authors: Yuste-Checa Patricia
Published: February 2024

This protocol details how to efficiently make in vitro and isolate Clu-phospholipid particles using purified Clusterin from HEK293E cells (dx.doi.org/10.17504/protocols.io.bvvkn64w) and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC).
Dynamic Multilingual Proficiency: Investigating Variation and Development in Language Abilities
Authors: Alshihry Mona A.
Published: February 2024

The present research aims to examine the dynamic nature of multilingual proficiency, the variability in language skills, and the process of language growth among a heterogeneous group of persons who are proficient in many languages. Utilizing a quantitative research methodology, the present study examines language competence statistics, age of acquisition, and language exposure to elucidate patterns and associations within the context of multilingualism. The results of our study indicate that language competency is not a fixed trait. Specifically, we saw a noteworthy improvement in listening abilities over one year. This highlights the significance of regular exposure to and practice of the language. Nevertheless, it is worth noting that both speaking and writing abilities exhibited a very consistent level of proficiency, indicating the need for focused pedagogical approaches to address these specific domains. Additionally, the research highlights the importance of individual language profiles, since there are significant variances in competence ratings seen across various multilingual groups. The findings of this study provide significant contributions to the field of education, policy-making, and research by providing vital insights for professionals involved in the support and promotion of multilingual persons and the cultivation of successful multilingualism.
Visual Representation of Malaysian Candidates in General Election in Selected Coalition Parties: A Visual Survey on Social Media
Authors: Sazan Darwalis , Al-Smadi Omar Ali , Rahman Nurulhasanah Abdul
Published: February 2024

The 15th General Election was held on November 19, 2022. The warmth of the previous GE-15 (General Election 15) is still being talked about by many today. In the context of elections in Malaysia, the main factors that influence selected coalition parties based on communication strategy involving the manifesto agenda besides its effective visual strategy. The use of visuals is seen as a practical, easy, and fast medium of dissemination to influence audiences within the political party. This study aims to examine the meaning and ideology behind the visual representation of candidates involving Pakatan Harapan (PH), Barisan Nasional (BN), and Perikatan Nasional (PN). Visual Semiotics Theory by Kress and van Leuween (1996) was adapted to study visual characteristics and ideology. The results found PH, BN, and PN attach great importance to the implementation of the principle slogan and positive visual elements in the agenda of their party. As a result, PH emphasizes the principles of progress and integrity, BN emphasizes progress and well-being while PN is seen to emphasize the combination of the principles of PH and BN in their party, which are well-being, integrity, and progress. In this case, PN is seen as more critical and transparent based on a combination of slogan principles compared to PH and BN. Positive visual representations and interesting slogan principles are seen as effective alternatives for ideology dissemination to audiences throughout the election season.
The Theory and Practice of Language Ideologies in Modern Societies: A Case Study
Authors: Lenchuk Iryna , Ahmed Amer
Published: February 2024

One of the consequences of the neo-liberal ideology of language commodification, which emphasizes “economic logic, economic integration, professionalism, and effectiveness” (Budach et al., 2003, p. 610) is the changes imposed in the field of literacy and second language learning. From the cultural capital of an individual and community, language has become a commodifiable resource with its value on economic markets. In the process of language commodification, a higher value is assigned to the official language(s). This leads to devaluing the minority languages and to the unequal distribution of the languages that are used in public spaces of schools and other government institutions. The research reviewed for our case study demonstrates that language ideology of the state, which is based on language commodification and on monoglot “standard” (Silverstein, 1996) in defining the state’s social and pedagogical practices, does not promote social cohesion. On the contrary, this ideology informs discriminatory practices that privilege and legitimize the standard variety of the language of the majority over the minority languages, and one type of literacy over the other.
Creating the Imagined in al-Qartajanni’s Minhajul Bulagha’ wa Sirajul ‘Udaba’: Response to Schoeler
Authors: Al-Osaily Eiad F. , Al-Zu'bi Moath H. , Al-Shara Zaydun A.
Published: February 2024

This research aims at refuting Schoeler’s claim that Hazim al-Qartajanni’s critical ideas were merely a repetition of Avicenna’s perspective on poetry. We attempt to shed light on al-Qartajanni contribution to the concept of poetry, which was not mentioned in a frank manner by Aristotle or his interpreters; al-Farabi, Avicenna, and Averroes. This study aims at providing adequate evidence that al-Qartajanni’s concept of imagery has traversed the critical perspectives of Aristotle and his interpreters about the reality of imagery and its role in the creation of poetry.
Building a Parallel Corpus for Chinese Folk Songs Translation Studies: A Case Study of Northern Shaanxi and Hua’er Folk Songs
Authors: Lin Yan , Halim Hazlina Abdul , Jalis Farhana Muslim Mohd
Published: February 2024

Folk songs, collaboratively created by the public and transmitted orally, have gained widespread popularity. The translation of folk songs primarily centers on lyrics translation, a subset of literary translation. Recent advancements in corpus technology have highlighted the significance of corpus-based research approaches for the analysis of literary translation. The corpus method, now employed as a hybrid research approach, enables the generation of quantitative data for descriptive translation studies. Scholars are increasingly using parallel corpora containing both the source text (ST) and the target text (TT) to explore translation universals across diverse texts. Despite the growing body of literature on the translation of Chinese folk songs, most studies have involved straightforward analyses of a limited number of translated texts without the utilization of quantitative approaches. This article aims to bridge this gap by presenting a prospective study on the creation of the Chinese-English Parallel Corpus of Northern Shaanxi and Hua’er Folk Songs (CEPCNSHFS). The study covers essential aspects such as sampling, corpus structure, corpora selection, and corpora processing. Moreover, to assess the practical utility of the CEPCNSHFS, a pilot study was conducted. The primary contributions of this article reside in the potential of the CEPCNSHFS to support diverse research topics, including the exploration of translation language characteristics, styles, and methods employed in translating Northern Shaanxi and Hua’er folk songs, both of which hold significant positions within Chinese folk song traditions.
Investigating the Autonomy Orientations and Perceptions of Saudi EFL Teachers
Authors: Al-Qahtani Abdulaziz
Published: February 2024

This research aims to explore the autonomy orientation of English language teachers in the western province of Saudi Arabia, home to numerous secondary schools. The study, grounded in Self-Determination Theory (SDT), examines the impact of two primary variables: the teachers' genders and their levels of teaching experience. A cohort of 102 Saudi secondary school language teachers participated in the study, with 10 engaging in a qualitative follow-up. Data were collected via a questionnaire and analyzed using statistical techniques such as t-tests and analysis of variance (ANOVA). The findings indicated that the autonomy orientation among Saudi language teachers was moderate, with female teachers showing more supportive tendencies towards their students. Moreover, the study uncovered a discrepancy between the teachers’ autonomy orientations and their perceptions of the concept, attributing their perceived constraints and roles to the national education system. In light of these findings, the study advocates for pre-service and in-service training programs designed to enable English language teachers to foster an autonomy-supportive environment for their students. Additionally, the study calls for further research to deepen the understanding of English language teachers' autonomy orientations in Saudi Arabia and the interplay between autonomy orientation and teachers’ perceptions of autonomy.
Primer registro de anomalía ocular en Carollia perspicillata (Chiroptera: Phyllostomidae) en la República de Panamá
Authors: Guevara-Alvarado Nelson , Díaz-Hernández Yulissa
Published: February 2024

Las anomalías oculares causadas debido a lesiones, enfermedades o mutaciones genéticas generan la pérdida total o parcial de la visión, lo cual afecta el desarrollo y comportamiento normal de los individuos afectados en su entorno natural. En murciélagos, estos casos raramente son reportados. Además, es posible que en ocasiones los investigadores encuentren estas anomalías, pero no son reportadas debido a diversos factores. En este trabajo se documenta por primera vez a un individuo de Carollia perspicillata con anomalía ocular (inflamación ocular) en la República de Panamá, registrado en la Reserva Natural Privada Bunorgandi de la Provincia de Panamá.
Particularidades de la democracia, el multiculturalismo y el ecologismo en los dos ciclos progresistas de Latinoamérica y el Caribe, 1998-2022
Authors: Quintero Leguizamón Juan Felipe , Barbosa Domínguez Jhosman Gerliud
Published: February 2024

En este artículo se problematizan las perspectivas teóricas institucionales y críticas surgidas en América Latina y el Caribe en la era de los gobiernos progresistas alrededor del tema de la democracia y su articulación con el culturalismo y el ecologismo. En los últimos años estos temas han recobrado importancia, puesto que los movimientos ecoterritoriales con sus luchas por la autodeterminación de los pueblos y alrededor de la defensa del medio ambiente han situado nuevas demandas a los Estados nacionales. A partir de un ejercicio cualitativo, vinculado a la teoría crítica, particularmente la latinoamericana, el texto se ajusta a una división cronológica en dos ciclos que obedecen a patrones singulares: el primer ciclo progresista entre 1998 y 2014, y el segundo ciclo desde 2015 hasta 2022, acotado a un balance de la relación gobiernos progresistas-movimientos sociales, desde la continuidad de las prácticas estatales extractivistas y de la resistencia misma que encarnan el multiculturalismo y el ecologismo. Se concluye que la disputa por la democracia se refleja en las construcciones teóricas articuladas al ecologismo y el multiculturalismo, en las propuestas de los movimientos sociales y en los obstáculos que deben afrontar los procesos democráticos y los gobiernos progresistas.
Percepción de la calidad de vida en familias con pacientes pediátricos portadores de vejiga neurogénica
Authors: Rincón-Torres Cesar , Jiménez-Barbosa Wilson Giovanni
Published: February 2024

Introducción: la calidad de vida es un proceso dinámico que depende fundamentalmente del individuo, sus expectativas, experiencias y desenvolvimiento social. En pacientes pediátricos con vejiga neurogénica (VN), una condición crónica, se altera su calidad de vida (CV) y por ende la de la familia, que generalmente cumple el rol de cuidador principal. Objetivo: explorar la percepción de las familias con pacientes pediátricos con VN sobre su CV. Métodos: estudio descriptivo, de corte transversal cuantitativo. La información se recolectó de las historias clínicas y la aplicación del cuestionario WHOQoL-BREF. Se usaron estadísticas descriptivas con el software SPSS® 22. Los resultados se presentaron en medidas de frecuencia, porcentaje y media con un intervalo de confianza del 95%. Resultados: de 54 familias con pacientes con VN, el 68,52% tuvo como etiología los defectos de tubo neural (mielomeningocele); el 57,41% ha recibido tratamiento no quirúrgico; el 96,3% se encuentra afiliado al régimen subsidiado y el 18,52% de las familias cuenta con un cuidador del Instituto Colombiano de Bienestar Familiar (ICBF). Se realizaron 22 cuestionarios de CV familiar. El 68,18% calificó la CV como moderada y el 54,5% refirió sentirse moderadamente satisfecho con su salud. El dominio mejor valorado fue el psicológico y el menor fue el ambiente. Conclusiones: tener un paciente con enfermedad crónica, en especial con VN, genera un impacto negativo sobre la CV familiar, en especial por cómo las consecuencias y secuelas afectan la vida de los integrantes; y en particular, por las implicaciones económicas y el tiempo que involucra su atención
Effect of Hf on the growth of Al coatings on-martensite ferritic by means of CVD-FBR steels
Authors: Bolívar Francisco Javier , Sánchez Laura , Hierro Maria Pilar , Pérez Francisco Javier
Published: February 2024

In recent decades, there has been a marked interest for increasing the temperature and vapor pressure in the power generation plants with the aim of reducing fuel consumption. So, there would be a reduction in the emissions of pollutants such as CO2, SO2 and NOx. To achieve these improvements, it is required on one hand, to develop new ferritic-martensitic steels with Cr contents between 9-12% and on the other hand, to improve resistance against oxidation of the existing ones by using surface engineering. For this reason, the following work is intended to obtain Al and Al-Hf coatings and evaluate the effect of the addition of Hf to the bed on the growth of the coating of Al. In order to optimize the deposition process, a thermodynamic study was conducted using Themocalc program. Al and Al-Hf layers were deposited at three different temperatures in the range of 500 to 600 º C. The coatings were subsequently characterized by DRX and SEM / EDS. According to the results, it was found that for both cases, the layers were mainly formed by intermetallic compounds Fe2Al5 and FeAl3.
Infl uence of castor oil mix composition on the production of biofuel
Authors: Delgado Arnoldo Emilio , Aperador Chaparro Willian , Silva Gonzalez Jorge Réne
Published: February 2024

Castor oil trans esterifi cation has been evaluated as a source of alternative biodiesel. Three mixtures of biofuel (B5% B10% and B20%) were tested in a diesel engine. Power, fuel consumption, temperature and exhaust emissions were measured. Also, densities, viscosities, refractive indexes and combustion heats of the mixtures were determined. The use of biodiesel mixtures produces an increase of viscosity and fuel consumption, decreasing the heating and engine power, reducing the combustion gases like CO, CO2, sulfur oxides, hydrocarbons, and lowering the opacity of exhaust emissions. Additionally, a balance in the observed diesel engine performance was evidenced by the engine temperatures.
Heavy metal concentration and distribution (Pb, Zn, Cu, Cd and Cr) in urban road sediments
Authors: Zafra Mejía Carlos A. , Temprano González Javier , Tejero Monzón Iñaki
Published: February 2024

This paper displays the obtained results of the collected sediment deposited during 65 days on road surfaces (Torrelavega-Spain). Two types of samples are distinguished: aspired directly and collected after sweeping. For each type of sample it was determined the particle size distribution and heavy metals concentration. The results suggest that the heavy metals concentration tends to increase exponentially form with the decrease in the size fraction. The associated loading of metallic elements exponentially increases with the size fraction.
Synthesis and characterization of functionalized mesostructured silicas with acid sulphonic groups
Authors: Posada John Alexander , Giraldo Oscar Hernán , Cardona Carlos Ariel
Published: February 2024

Hexagonal (MCM-41, SBA-15, and HMS) and cubic (MCM-48) mesostructured silicas were synthesized and functionalized with the propylsulphonic acid group, by grafting and co-condensation methods. Structural conformation, physical-chemistry characterization, and morphology of the materials was performed by XRD, FT-IR, TGA, and SEM techniques. Higher functionalization degrees were reached by co-condensation method, for MCM-48 and SBA-15 mesophases. These higher functionalization degrees lead to less thermally and structurally stable materials than those obtained by the grafting method.
Assessment of moisture damage susceptibility of asphalt mixtures using thermodynamic properties
Authors: Caro-Spinel Silvia , Alvarez-Lugo Allex Eduardo
Published: February 2024

This paper presents a comparative assessment of the susceptibility to moisture damage for different combinations of Colombian asphalt binders and aggregates. The methodology applied focuses on the calculation of the Moisture Damage Index (MDI) for different asphalt binder-aggregate systems. This index has been estimated using thermodynamic properties (i.e., surface free energy) of the involved materials. The results suggest that: (i) the type of aggregate has a larger infl uence on the fi nal mixture resistance to moisture damage, compared to the role of the type of asphalt binder and (ii) the modifi cation processes used in the production of different types of modifi ed asphalt binders generate asphalt binder-aggregate systems with a wide range of resistance to moisture damage. Finally, the results of this study prove that the thermodynamic characterization of paving materials can effi ciently be used for material selection during the initial stage of mixture design.
Model of frequency selective fading
Authors: Pedraza Luis , Hernández Cesar , Ballesteros Dora María
Published: February 2024

In this paper a mathematical analysis of the frequency selective fading produced by multipath propagation is presented, as well as recent techniques to reduce the effects of this phenomenon as: the diversity of antennas, the Rake receiver, the adaptive equalization and OFDM (Orthogonal frequency division multiplexing).
Decolorization of textile wastewater using the white rot fungi anamorph R1 of Bjerkandera sp.
Authors: Osorio Echavarría Juliana , Vidal Benavides Ana Isabel , Quintero Díaz Juan Carlos
Published: February 2024

Decolorization of synthetic and industrial wastewaters from textile industry by the anamorph R1 of white rot fungiBjerkandera sp. was evaluated. The presence of NaCl and Na2CO3 wastewater concentration and treatment with non-sterile wastewater on decolorization were analyzed. In addition, the decolorization effect on wastewater toxicity was analyzed with Vibrio fischerias target microorganism. The presence of salts in the treatment increased the lignin peroxidase activity from 5 to 20 U/L, without detriment of manganese peroxidase activity which remained at 70 U/L, also. The presence of salts also enhances dye adsorption degree over fungi biomass, improving the decolorization by the two mechanisms, degradation and adsorption. In hipersaline synthetic wastewater, the percentage of decolorization was 75%. The decolorization treatment of sterile textile effluents reached 65% in 8 days and the toxicity reduction was 58% with respect to untreated textile effluents. In non-sterile textile effluents, only 40% of decolorization was obtained. The presence of contaminant microorganisms which compete by substrate and increase pH by fungus metabolism, were likely the main causes of low decolorization.
Detection and tracking of human movement based on the motion vectors estimation
Authors: Hernández García Josué , Morita Hiroshi , Nakano Miyatake Mariko , Pérez Meana Héctor
Published: February 2024

This paper proposes a human and vehicle motion detection and tracking system, based on motion vectors, which is able to discriminate between allowed and not allowed movements without the intervention of any human operator. Evaluation results show the desirable features of proposed method.
Automatic selection of parameters in LLE
Authors: Valencia Aguirre Juliana , Álvarez Meza Andrés Marino , Daza Santacoloma Genaro , Acosta Medina Carlos Daniel , Castellanos Domínguez Germán
Published: February 2024

Locally Linear Embedding (LLE) is a nonlinear dimensionality reduction technique, which preserves the local geometry of high dimensional space performing an embedding to low dimensional space. LLE algorithm has 3 free parameters that must be set to calculate the embedding: the number of nearest neighbors k, the output space dimensionality m and the regularization parameter a. The last one only is necessary when the value of k is greater than the dimensionality of input space or data are not located in general position, and it plays an important role in the embedding results. In this paper we propose a pair of criteria to find the optimum value for the parameters kand a, to obtain an embedding that faithfully represent the input data space. Our approaches are tested on 2 artificial data sets and 2 real world data sets to verify the effectiveness of the proposed criteria, besides the results are compared against methods found in the state of art.
From pre-conceptual schemas to OO-Method
Authors: Zapata Jaramillo Carlos Mario , Ruiz Carmona Luz Marcela , Pastor Oscar
Published: February 2024

OO-Method is an object-oriented method for automated code generation. In order to develop a software application by using OO-Method, the analyst must subjectively create the diagrams included in OO-Method. In this task the analyst must invest too much effort. On the other hand, Pre-conceptual Schemas are controlled-language-based diagrams for knowledge representation. Also, Pre-conceptual Schemas are previous diagrams to conceptual schemas and they are designed for automatically obtaining UML diagrams. In this paper, we take advantage of Pre-conceptual Schemas and we propose a set of rules for obtaining OO-Method diagrams from these Schemas. We also exemplify the proposal with a case study.
Study of hydration of cement pastes added with used catalytic cracking catalyst (FCC) from a colombian refinery
Authors: Trochez Jenny Johanna , Torres Agredo Janneth , Mejía de Gutiérrez Ruby
Published: February 2024

This paper analyzes the effect of the incorporation of industrial waste from an oil refinery in Colombia, known as used catalytic cracking catalyst (FCC), in the hydration process of cementitious pastes. For this purpose, ordinary Portland cement pastes (OPC) added in percentages of 10 and 20% of FCC were prepared. The pozzolanic reactivity of the material and type of hydration products were determined by X-ray diffraction (XRD) and thermogravimetric analysis (TG / DTG). Additionally, the heat of hydration released was determined based on the standard ASTM C186. The results indicate that the hydration process of FCC blended cement is strongly exothermic as a consequence of its pozzolanic activity. The main phases present in the blended cement system were the calcium silicate hydrates (CSH gel), calcium aluminate hydrates (CAH) y calcium aluminosilicate hydrates (CASH), similar to the products obtained in metakaolin blended cement pastes.
Signal compression in radar using FPGA
Authors: Escamilla Hernández Enrique , Kravchenko Víctor , Ponomaryov Volodymyr , Duchen Sánchez Gonzalo , Hernández Sánchez David
Published: February 2024

We present the hardware implementation of radar real time processing procedures using a simple, fast technique based on FPGA (Field Programmable Gate Array) architecture. This processing includes different window procedures during pulse compression in synthetic aperture radar (SAR). The radar signal compression processing is realized using matched filter, and classical and novel window functions, where we focus on better solution for minimum values of side-lobes. The proposed architecture exploits the parallel computing resources of FPGA devices to achieve better computation speed. Experimental investigations have shown that the best results for pulse compression performance have been obtained using atomic functions, improving the performance of the radar system in the presence of noise, obtaining small degradation in range resolution. Implementation of the signal processing in the radar system for real time mode is discussed here and the effectiveness of the proposed hardware architecture has been justified.
A robust watermarking technique based on image normalization
Authors: Cedillo Hernández Manuel , Nakano Miyatake Mariko , Pérez Meana Héctor
Published: February 2024

This paper presents a robust watermarking method against geometric distortions and several other signal processing schemes. In the proposed watermarking method, image normalization is used to get geometric invariant features. The watermark embedding and detection process are carried out in the Discrete Cosine Transform (DCT) domain. A DCT based texture classification is used to classify each image block to embed a stronger as possible watermark, while maintaining watermark imperceptibility. The proposed watermarking scheme is a public watermarking, where the original image is not available for watermark detection. The experimental results show the watermark imperceptibility and robustness against geometric distortion such as rotation, scaling and various other Affine transformation, and common signal processing schemes, such as JPEG compression, Gaussian and impulsive noise contamination.
The negative sequence impedance as fault indicator in induction motors
Authors: Villada Fernando , Cadavid Diego Raúl , Aedo José Edinson , Benavides Bernardo Andrés , Velilla Esteban
Published: February 2024

An algorithm to detect inter-turn faults in induction motors based on the negative sequence impedance is presented in this paper. The implementation through a digital prototype is also explained and its results are tested using a 3 Hp induction motor designed to induce inter-turn faults. It is concluded that the robustness of the algorithm can detect incipient faults from five turns, and it is a good tool for predictive maintenance of induction motors.
Modelamiento del motor de inducción para estudios de cortocircuitos entre espiras del estator
Authors: Cadavid Diego Raúl , Villada Fernando , Velilla Esteban
Published: February 2024

En este trabajo se presenta la implementación en Matlab del modelo del motor de inducción para realizar estudios de cortocircuitos entre espiras del estator. Para este propósito se usan los bloques del Simulink y los parámetros requeridos por el modelo son obtenidos a partir de la norma IEEE112. Se presentan los resultados teóricos, se muestra la aplicación del modelo en la determinación de la corriente de secuencia negativa como indicador de falla y se describen los resultados de la aplicación experimental a un motor de inducción de 2 Hp el cual se ha acondicionado para realizar corto entre espiras. Se concluye el buen desempeño del modelo al permitir obtener con precisión variables indicativas de fallas en el devanado estatórico de un motor de inducción.
Análisis del cortocircuito entre espiras de un motor de inducción tipo jaula de ardilla mediante la aplicación del método de elementos finitos (mef)
Authors: Díaz-Sánchez Darío , Díaz-Sánchez Rodrigo , Amaya Martha Cecilia , Palacios Jairo
Published: February 2024

En este artículo se realiza el análisis del par y la impedancia de secuencia inversa con la evolución de una falla de cortocircuito entre espiras de un devanado estatórico de un motor de inducción tipo jaula de ardilla de 3HP, 220V.
Evaluation of nitrogen oxide emissions and smoke opacity in a HSDI diesel engine fuelled with palm oil biodiesel
Authors: Agudelo John , Benjumea Pedro , Villegas Adriana Patricia
Published: February 2024

In this paper, an experimental study evaluating engine performance, nitrogen oxide emissions (NOx) and smoke opacity of a HSDI (high speed direct injection) diesel engine fuelled with neat palm oil biodiesel (POB) is presented. Tests were performed in a bench-mounted automotive diesel engine operating under steady state conditions. Conventional diesel fuel was taken as base line or reference fuel. Results show that at full-load operation POB led to a power output decrease between 10% and 17% and an effective specific fuel consumption increase between 14% and 22%. At full-load and low engine speeds an increase of 20% in NOx emissions was measured. However, at the same torque rating and high engine speeds a 6% decrease in such emissions was obtained. At partial-load, NOx emissions always increased using POB, this effect being more pronounced at low speeds. On the other hand, smoke opacity significantly decreased (between 40% and 80%) regardless of engine load. According to the experimental results POB fuelling reduced engine power output, increased fuel consumption, increased slightly efficiency, always decreased smoke opacity, and reduced or increased NOx emissions depending on the engine operation mode.
Desempeño dinámico y energético de un autobús operando con gas natural vehicular
Authors: Agudelo John , Moreno Ricardo , Pérez Juan
Published: February 2024

En este artículo se calculó la potencia teórica requerida por un vehículo para cuatro casos de funcionamiento (2 velocidades y dos pendientes diferentes) con la ayuda de la dinámica longitudinal. Mediciones experimentales del consumo instantáneo de combustible, en conjunto con las potencias teóricas permitieron hallar la eficiencia energética global de un bus con motor a gas natural. Al aumentar la pendiente de la carretera o aumentar la velocidad del bus, la eficiencia energética global se incrementó. La variación de la pendiente de 0 a 7% hizo cambiar la eficiencia de 25,4 a 27,6% mientras que el cambio de velocidad de 15 a 40 km/h hizo que la eficiencia pasara de 25,9 a 27,1%. Para los rangos seleccionados de velocidad y pendiente, la eficiencia presentó un incremento al aumentar velocidad y pendiente, siendo un poco mayor con la pendiente.
Experimentos de combustión con cascarilla de arroz en lecho fluidizado para la producción de ceniza rica en sílice
Authors: Martínez-Ángel Juan Daniel , Pineda-Vásquez Tatiana Gissette , López-Zapata Juan Pablo , Betancur-Vélez Mariluz
Published: February 2024

A fin de contribuir con la valorización de residuos agrícolas que presentan dificultades de disposición, la utilización de energéticos renovables y la obtención de formas de energía más limpias y amigables con el medio ambiente, fue investigada la combustión de cascarilla de arroz en un reactor de lecho fluidizado burbujeante y atmosférico. La metodología consistió en evaluar la influencia de altos excesos de aire, en la obtención de gases calientes y ceniza con altos contenidos de sílice en estado amorfo. Excesos de aire en el rango de 40% al 125%, mostraron que los valores cercanos al límite inferior establecido (40%) favorecieron temperaturas superiores a 700ºC en el interior del reactor, dando origen a mayores eficiencias de conversión de la cascarilla, pero disminuyendo el potencial amorfo de la sílice contenida en la ceniza. Comportamiento contrario fue evidenciado en el límite superior del exceso de aire. Las concentraciones de los gases del proceso mostraron relativa variabilidad para cada condición de operación. Para el caso del CO, fueron reportadas emisiones promedio de 200ppm (en una base seca del 11% de O2), para los excesos de aire comprendidos entre 40% y 82,5%.
The influence of the mineralogical composition of waterproof varnish layer of rutile electrodes on porosity in underwater wet welding
Authors: Queiroz Alexandre , Caires-Pereira Ezequiel , Perdomo Lorenzo , Quintana Rafael
Published: February 2024

Waterproof varnish coated rutile electrodes are used frequently in the underwater wet welding because of their good technological behavior. An alternative to improve its behavior would be to incorporate chemicalcompounds to the waterproof varnish layer. In the present work the results obtained with the addition of an exothermic pyrometallurgical mixture in the first waterproof varnish layer of rutile electrode types 6013 and 7024 are presented. Depending on the temperature of coating, the proposed pyrometallurgical mixture provides oxygen by stages altering the partial pressure of hydrogen of surrounding means. The carrying chemical oxygen element in the pyrometallurgical mixture is reduced until its elementary state, interacting later with the metal in weld pool as deoxidizer. All this process offers a favorable energetic balance to the welding process. Welds were performed at 50 meters deep with electrodes having traditional varnish and varnish with additions. The technological behavior, amount of porous, metallographic structure and chemical composition were measured. For the E6013 electrodes the porosity was reduced to 16% while for the E7024 by 59%.
Prototipo de sistema en lazo cerrado para administración de anestesia intravenosa
Authors: Ruiz-Rada Jorge Andrés , Fernández Juan Manuel , Hernández-Valdivieso Alher Mauricio
Published: February 2024

En este artículo se presenta el desarrollo de un sistema en lazo cerrado de administración de anestesia intravenosa. Para lograr esto se implementan diferentes subsistemas: un modelo multicompartimental de distribución de fármacos en el cuerpo humano, un algoritmo para determinar la curva de velocidades a las que debe infundirse el anestésico Propofol para obtener el efecto de anestesia general, un protocolo de comunicación para enviar el vector de velocidades a una bomba de infusión convencional y un lazo derealimentación para controlar todo el sistema a partir del índice bi-espectral que se utiliza como indicador de la profundidad de anestesia. El resultado final es un instrumento versátil, con prestaciones similares a las de equipos comerciales y con una interfaz interactiva, que facilita la operación por parte del anestesiólogo desde un computador convencional.
Personalización de contenidos en sistemas hipermedia educativos adaptativos: una revisión
Authors: Cobaleda Luz , Duitama Freddy
Published: February 2024

En un Sistema Hipermedia Adaptativo Educativo (SHAE), la información que describe a los estudiantes y su comportamiento son elementos significativos para el soporte personalizado que se pueda brindar. Este artículo hace una reseña de los SHAE, analiza la manera como usan diversas características del estudiante en el proceso de adaptación y hace un especial énfasis en los avances logrados en combinar la información del usuario individual con los grupos que se conformen; elemento que cobra relevancia en aquellasocasiones que el SHAE disponga de limitada información individual del usuario.
Optimum design of an acetylated starch plant from Manihot esculenta Crantz, variety INIVIT-Y-93-4
Authors: Acosta-Solares Amanda , Pérez-Navarro Omar , Sánchez-Cabrera Ernesto , Pérez-Díaz Jorge Luis
Published: February 2024

Considering the applicability and added value of acetylated starches, it is necessary to find technological variants to obtain them with favorable technical-economic results and energetic and environmental compatibility. The objective of the work is to optimize economic and dynamic indicators of profitability of acetylated starch production, by considering as optimization criteria the productive capacity, the degree of substitution and the temperature of the drying air, establishing the design of the installation in optimal conditions. Technologies adopted from the mechanized native starch processes were selected, and the design and development of the slurry heating, acetylation, and pneumatic drying stages were proposed. A composite central experimental design was generated for profit (P), net present value (NPV), and internal rate of return (IRR), and the quadratic models obtained through the Response Surface Methodology were optimized. For the evaluation of the indicators, the economic indexes of the process were determined, after technological selection, material and energy balances, and technological design. The optimum operating parameters are achieved at a production capacity of 12.57 tcassava/d, degree of substitution of 0.505 and 124.98 °C in the air supply to the pneumatic dryer. Under these conditions, the production of acetylated starch requires larger volume acetylators  than for acetylated gelatinized starch process, but the technological requirements of gelatinized pulp are eliminated, achieving remarkable energy efficiency with pneumatic drying.
Multi Objective Optimization of FDM Parameters Using Taguchi Grey Relation Analysis for PLA Specimen
Authors:   Gujarat Technological University, Ahmedabad, Gujarat, India, Patel Khushbu , Acharya Shailee ,   SVIT, Gujarat, India, Acharya G. D. ,   Aatmiy University, Rajkot, Gujarat, India
Published: February 2024

Polylactic acid (PLA), is a thermoplastic polyester that has many uses in both consumer goods and industrial settings. The mechanical characteristics of PLA specimens created using Fused deposition modeling (FDM), a cost-effective 3D printing process, including tensile strength, shore hardness, and dimensional precision, have been studied for use in specialised engineering applications. Layer height, infill density, and printing speed are the choices made for the specimen’s 3D printing. Design of experiments use Taguchi’s L9 orthogonal array. Using analysis of variance (ANOVA), designers can determine the relative importance and percentage contribution of each process parameter to each answer. Using Taguchi method while conducting test for individual responses result shows that for tensile strength printing speed is 70 mm/s, layer height 0.2mm and 40% infill density as optimum parameters while for the hardness it is 60 mm/s,0.3mm and 40%, and for the dimensional deviation found 60 mm,0.2 mm, 40% respectively. Proposed TGRA method found optimum parameter for all the responses in single test as printing speed is 70 mm/s, layer height 0.3 mm and 40% infill density also validated by conducting confirmation test. Finally, a superior specimen with all-around mechanical characteristics is fabricated using Taguchi based grey relational analysis (TGRA) as a multi-objective optimization technique.
General Exact Analytical Expressions for Rotation and Displacement of a Timoshenko Beam Under Variable Loads with Validation
Authors:   Department of Basic Science and Related Studies, Mehran University of Engineering and Technology, Jamshoro, Sindh 76020, Pakistan, Channa Hafeezullah , Shaikh Muhammad Mujtaba ,   Department of Basic Science and Related Studies, Mehran University of Engineering and Technology, Jamshoro, Sindh 76020, Pakistan, Malik Kamran ,   Department of Basic Science and Related Studies, Mehran University of Engineering and Technology, Jamshoro, Sindh 76020, Pakistan
Published: February 2024

The researchers involved in the field of applied mathematics mostly project the efficient and viable solutions of those problems in which have practical applications in science and engineering. The Timoshenko beam model (TBM) is described by a system of ordinary differential equations where the expressions of rotation and displacement of the beam are ultimately required. Most of the work on analytical solutions of beam problems in literature focuses the elastic and Euler-Bernoulli beams, whereas for the TBM the numerical solutions are usually preferred. The analytical expressions for the TBM exist for only very basic load cases and are also not general for any load function. In this paper, we attempt to suggest a novel protocol based on expressing a load function by a polynomial or its power series development, and then use it to develop general analytical expressions for the rotation and displacement of a fixed TBM which is not load specific. The proposed general equations can provide ease of access and handling for the practitioners working in applied mathematics, structural engineering and mechanical vibrations as the developed equations can be used with only constant inputs to tailor particular expressions of rotation and displacement profiles of a fixed TBM under any variable load. For performance evaluations of the proposed general equations, we have also obtained particular expressions for some important variable loads, like: linearly varying loads ((LVLs): triangular and trapezoidal and quadratically varying loads (QVLs): parabolic/square and circular loads. Finally, the proposed protocol for generalization has been validated for fixed elastic beams under uniformly distributed loads (UDLs), and the results match exactly with those expressions available in literature. The contributions of this study, on one hand provide ready, direct and exact general expressions for the rotation and displacement profiles of a fixed TBM, while on the other hand the solution of such problem is achieved with quite negligible computational overhead, execution time and software implementations.