bluuebunny/crossref_metadata_2025 huggingface dataset:
Osteomielitis Crónica Maxilar. Informe de 4 casos clínicos
Authors: Wintergerst Fish Alberto , Iturralde Espinosa Carlos Javier , De la Riva Parra Vladimir , Reinoso Quezada Santiago
Published: September 2022

La osteomielitis es una enfermedad ósea inflamatoria, comúnmente relacionada a un origen infeccioso por gérmenes piógenos fundamentalmente estafilococos y en algunas ocasiones por estreptococos, neumococos y enterobacterias. Se han establecido diversas clasificaciones y tratamientos para la Osteomielitis, basadas en el comportamiento clínico, características anatomo-patológicas, radiográficas, etiología y patogenia. La osteomielitis crónica es una complicación de la osteomielitis aguda no tratada, manejada inadecuadamente  o como una reacción inflamatoria prolongada de bajo grado.Se presentan 4 casos de osteomielitis crónica en el maxilar tratadas entre 2007 y 2009 mediante terapia antimicrobiana preoperatoriamente con Clindamicina 300mg, IV cada 8 hrs. y Ceftriaxona 1gr. IV cada 12 hrs. quirúrgicamente con hemimaxilectomía subtotal, postoperatoriamente se trata con Penicilina G Procaínica 800,000 UI IM cada 24 hrs. resolviendo satisfactoriamente y sin recidiva actual en todos los casos.
Rehabilitación Protésica Multidisciplinaria. Reporte de un Caso Clínico
Authors: Mendoza Rivera Susana , Ríos Szalay Enrique , Treviño Santos Alejandro , Olivares Tapia Selene
Published: September 2022

En la actualidad la evolución en la Odontología y los cambios en las técnicas protésicas y materiales han hecho que los pacientes demanden más en términos de estética, función y comodidad. Existe una gran demanda de problemas dentofaciales que necesitan de la interacción de distintas disciplinas odontológicas pretendiendo un ideal preventivo, funcional y estético con un elevado método de organización y comunicación, lo que tiene como objetivo común la rehabilitación protésica multidisciplinaria.Un tratamiento multidisciplinario está basado en el diagnostico, la planeación y los procedimientos terapéuticos. La planeación de un tratamiento puede empezar por una visualización del resultado final. Sin un objetivo multidisciplinario los resultados finales podrían estar comprometidos.
Aumento de reborde con mallas de titanio para la rehabilitación con implantes utilizando un modelo estereolitográfico
Authors: Soria Pérez Diana Angélica , Higashida Guerrero Carolina
Published: September 2022

Un adecuado hueso alveolar es crítico tanto para la estética, como para el soporte biomecánico de la prótesis dental. Se han desarrollado varias técnicas para la reconstrucción de defectos en mandíbula y maxilar atróficos. El aumento de reborde óseo es un método exitoso aceptado y empleado en la práctica dental para incrementar el volumen óseo en sitios elegidos para la colocación implantes dentales. Las mallas de titanio han sido utilizadas para la reconstrucción de defectos óseos, como un sistema de contención de injertos particulados. Reporte de un caso: Se presenta un paciente con severa reabsorción en zona posterior bilateral mandíbular. Basados en el estudio tomográfico se obtuvo un modelo estereolitográfico sobre el cual se preformarón las mallas de titanio para realizar el aumento de reborde combinando xenoinjerto, aloinjerto, autoinjerto y plasma rico en factores de crecimiento. Se retiran 3 meses y medio después obteniendo aproximadamente 3 mm de ganancia para la posterior colocación de implantes en la zona y rehabilitación de los mismos. Conclusión: Las mallas de titanio son una excelente alternativa para el aumento de reborde en mandíbulas o maxilares atróficos, brindando al paciente la posibilidad de colocación de implantes dentales
Percepción estética de cirujanos dentistas, ortodoncistas y pacientes a diferentes tipos de perfiles modificados por un programa de computadora
Authors: Quiroz María Fernanda , Grageda Enrique
Published: September 2022

INTRODUCCIÓN: Los conceptos de belleza del rostro y armonía del perfil desempeñan una función decisiva en el terreno de las relaciones sociales del hombre, por lo cual es tema de intenso estudio en investigaciones científicas. OBJETIVO: Evaluar la percepción estética que sobre un perfil modificado por computadora tienen los cirujanos dentistas, ortodoncistas y pacientes. MATERIALES: 2 perfiles modificados por el programa Dolphin Imaging and Management®, 30 pacientes, 30 ortodoncistas y 30 cirujanos maxilofaciales de la DEPeI. MÉTODOS: Se utilizaron fotografías y cefalografías de un hombre y una mujer mexicana. La posición de la mandíbula y del maxilar fueron  modificados por el programa Dolphin Imaging and Management® creandose dos secuencias, 90 personas (30 ortodoncistas, 30 cirujanos maxilofaciales, 30 pacientes de la DEPeI) evaluaron los perfiles en la escala analógica visual, todos los análisis estadísticos fueron procesados usando SPSS.Las puntuaciones dadas por cirujanos, ortodoncistas y pacientes para cada perfil fueron comparados con pruebas Kruskal- Wallis. RESULTADOS: la confiabilidad dentro de los evaluadores fue buena y se encontró que las percepciones del atractivo facial entre cirujanos maxilofaciales y ortodoncistas contra pacientes tuvo concordancia en general. Las interacciones de la dimensión vertical y anteroposterior, así como la magnitud de cambio entre cada dimensión influye en la percepción del atractivo facial. CONCLUSIONES: los resultados sugieren que las preferencias del atractivo facial por ortodoncistas y cirujanos dentistas están generalmente en acuerdo. Esta información puede ayudara a los clínicos en la planeación del tratamiento y al hacer recomendaciones.
Análisis macroscópico in Vitro de los tejidos dentales y de algunos materiales dentales de uso en endodoncia sometidos a altas temperaturas con fines forenses
Authors: Vázquez Lucero , Rodríguez Patricia , Moreno Freddy
Published: September 2022

Objetivo: Describir los cambios físicos macroestructurales que ocurren en los tejidos y en los materiales dentales empleados en un tratamiento endodóncico convencional al ser sometidos a altas temperaturas.Materiales y métodos: Se realizó un estudio experimental in Vitro para observar los cambios físicos macroscópicos de los tejidos dentales (esmalte, dentina y cemento) y de los materiales de uso odontológico empleados comúnmente en endodoncia (gutapercha Maillefer Dentsply®, cemento endodóncico a base de óxido de zinc eugenol Eufar®, cemento endodóncico a base de resina epóxica Top Seal® Dentsply®, ionómero de vidrio Fuji® GC América®, amalgama de plata GS80® SDI® y resina Point 4® Kerr®) en 124 dientes humanos, sometidos a cinco rangos de temperatura (200ºC, 400ºC, 600ºC, 800ºC, 1000ºC).Resultados: Los tejidos y los materiales dentales estudiados en esta investigación, presentan gran resistencia a las altas temperaturas sin variar considerablemente su macroestructura, de tal manera que los cambios físicos (estabilidad dimensional, fisuras, grietas, fracturas, textura, color, carbonización e incineración) pueden llegar identificarse y asociarse a cada rango de temperatura específico.Conclusiones: Los tejidos y los materiales dentales presentan gran resistencia a la acción de altas temperaturas. Del mismo modo, presentan cambios específicos (color, textura, fisuras, grietas, fracturas, fragmentación) que pueden contribuir con el proceso de identificación de un cadáver o restos humanos quemados, incinerados o carbonizados.
Distracción vertical caudal de transplante de peroné para reconstrucción de defecto mandibular a consecuencia de herida por proyectil de arma de fuego y rehabilitación con implantes osteointegrados
Authors: Ceseña Medina José Francisco , López Noriega Juan Carlos , Ruiz Rodríguez Rafael , Jiménez Castillo René
Published: September 2022

Se presentan los resultados estéticos y funcionales satisfactorios obtenidos en la corrección de una asimetría facial en un paciente reconstruido con injerto de peroné, a causa de herida por proyectil de arma de fuego, así como la rehabilitación del aparato estomatognático mediante la colocación de implantes ósteointegrados.       El procedimiento se realizo en cuatro fases quirúrgicas. Posterior a un  diagnóstico clínico, imagenológico y apoyado con estudios estereolitográficos. En la primera fase se realiza distracción osteogénica en la región mentoniana en sentido caudal, posteriormente en una segunda fase se lleva a cabo distracción osteogénica en región de cuerpo mandibular en sentido caudal de forma bilateral, en una tercer fase quirúrgica la reconstrucción de labio inferior y en una fase quirúrgica final, la colocación de implantes osteointegrados. Gracias al análisis cuidadoso del caso y a los recursos diagnósticos que pudimos tener a nuestro alcance, se pudo planear la secuencia del tratamiento quirúrgico, logrando ser mejorada la forma, la dimensión anatómica de la región mandibular, corrección de las cicatrices de tejidos blandos, debido a secuelas de reconstrucción mandibular y para finalizar con el rehabilitación de la función masticatoria, mediante la rehabilitación con una prótesis implanto soportada.
Encogimiento por polimerización de cementos duales a través de distintos grosores de cerámica
Authors: Baena Monroy Tania , Guerrero Ibarra Jorge , Alvarez Gayosso Carlos , Celis Rivas Luis
Published: September 2022

Los cementos a base de resina dual utilizados para la cementación de las restauraciones estéticas indirectas presentan encogimiento por polimerización, el cual puede incrementarse al aumentar el grosor de las restauraciones cerámicas; dicho encogimiento genera esfuerzos de contracción que son responsables de los problemas en la interfase diente-restauración. El objetivo de éste estudio fue determinar la influencia del grosor de cerámica en el encogimiento por polimerización de tres cementos duales. Se realizaron discos de cerámica IPS Empress® de 1mm, 1.5mm y 2mm de grosor, se calculó el encogimiento por polimerización de los cementos Variolink II, (Ivoclar Vivadent, Liechtenstein) Maxcem, (Kerr, Orange, EUA) y Duolink, (Bisco, Schaumburg, EUA) mediante el método de Watts y Cash. Se realizaron para cada cemento 10 determinaciones control incidiendo la luz sin usar un disco de cerámica, 10 incidiendo la luz a través de un disco de cerámica de 1mm de grosor, 10 a través de un disco de cerámica de 1.5mm y 10 a través de un disco de 2mm. Los resultados se analizaron con ANOVA y se encontraron diferencias estadísticamente significativas entre los tres cementos del grupo control y los grupos experimentales. El cemento con menor porcentaje de encogimiento en todos los grupos fue Variolink II. El grosor de las restauraciones influye significativamente en el encogimiento por polimerización, lo que debe ser tomado en cuenta por el clínico durante la preparación dental.
Alimentación difícil en el paciente neonato, el enfoque estomatológico. Reporte de un caso.
Authors: Durán Gutiérrez Américo , Castillo Mancilla Erika Berenice , De la Teja Ángeles Eduardo , Ramírez Mayans Jaime A
Published: September 2022

Una de las funciones vitales en los recién nacidos es la alimentación, mecanismo que se lleva a cabo mediante la correcta succión y deglución así  como el de la respiración coordinada que hacen posible que el neonato se alimente de forma adecuada, sin embargo en ocasiones encontramos pacientes que por sus características físicas, síndromes genéticos como Treacher Collins, síndrome de Pierre Robin, fisura labioalveolopalatina o neurológicas, retraso psicomotor, artrogriposis, están condicionados a una alimentación difícil, por lo que es importante establecer un protocolo de atención de estos pacientes para que sean atendidos de forma más eficaz y no terminen en primera instancia con gastrostomías, así como la reintegración de las funciones para la alimentación posterior al uso de sondas, jeringas y otros dispositivos, por lo que el manejo multidisciplinario es fundamental para estos casos.Apoyándonos también en la revisión de la literatura de estos padecimientos, presentamos el seguimiento de un caso de una paciente con síndrome de Treacher Collins con problemas para alimentarse en la etapa neonatal, así como el tratamiento recomendado hasta su completa reincorporación a la fisiología normal de la alimentación. Surge la necesidad de dar a conocer las características de estos pacientes presentan y las indicaciones para una atención estomatológica que no puede considerarse convencional.
The bearing capacity of arch cover structures made of thin-walled cold-formed profiles
Authors: Korgin Andrey V. , Ermakov Valentin A. , Zeyd Kilani Leys Z.
Published: September 2022

Introduction. The article is focused on evaluating the stress-strain state of nonreinforced arch cover structures made of thin-walled cold-formed profiles and arch cover structures reinforced by arch frames made of triangular trusses and girders. The relevance of the study is backed by the need to reinforce arch covers in the event that the design area of operation of a structure is different from the actual area of operation, which is confirmed by the recent cases of collapse of these structures. To reduce the labour input into simulation, the authors suggest a 3D modelling methodology presented using the case of a hangar reinforced by orthotropic plates and rods. Materials and methods. A 2D analysis of an arch was performed using the parameters of the reduced cross-section and a 3D analysis of the same arch was performed using a combined cross-section of plates and rods to verify the methodology. The 2D arch and 3D models were subjected to snow loading in compliance with the regulatory document document SP 20.13330.2016 “Loads and impacts”. Parameters of reduced straight sections and stresses, arising in the 2D arch, were analyzed on the basis of identified internal forces and the regulatory document SP 260.1325800.2016 “Thin-walled steel structures made of cold-formed galvanized profiles and corrugated sheets”. A reduction in the rigidity of corrugated sections is taken into account by assessing the rigidity subjected to the effect of a single force. Finite element modeling was conducted in SCAD Office software; stresses and displacements were calculated automatically. Results. The 3D calculation method involving orthotropic plates and rods showed satisfactory convergence with the calculation made in the two-dimensional formulation. Maximum stresses arising in a 3D model are 2 % lower than in a 2D arch, and maximum displacements are 21 % lower thanks to a more accurate FEM analysis of the 3D behaviour of the whole hangar. Conclusions. The proposed modeling technique reduces the labor intensity of structural modeling and is suitable for evaluating the joint behaviour of basic and reinforced structures of any type.
Theoretical aspects of innovative development of unified heat supply organizations in the conditions of transition to a new energy system
Authors: Glazkova Valeria V.
Published: September 2022

Introduction. Heat supply, which is one of the most important areas of housing and communal services in our country, is in critical condition, as evidenced by the increase in the number of accidents on heating networks and an increase in heat loss over the past 25 years. The current situation necessitates the modernization of the sphere under consideration, which should be associated with the introduction of modern technologies and innovations in the activities of heat supply. In addition, a number of researchers note that currently there is a change in the energy system based on the partial replacement of existing energy sources towards energy-efficient devices, which, on the one hand, allow meeting growing energy needs, and, on the other hand, reduce the negative impact on the environment. Therefore, it is proposed to consider the modernization and innovative development of heat supply, including in the context of compliance with environmental safety properties. It is determined that the subject of heat supply, which should take responsibility for the implementation of the vector of its innovative development in a certain territory, should be unified heat supply organizations, fixed by legislation as a single center of responsibility, modernization and technological development of heat supply. In this regard, the purpose of the study is to consider the theoretical aspects of the innovative development of unified heat supply organizations in the conditions of transition to a new energy system.

Materials and methods. The theoretical and methodological basis of the study was the works of Russian and foreign authors on the issues of innovative development of economic systems, as well as the work of researchers proving the relationship of cyclical economic growth with innovative development. The study used methods of analysis and synthesis, as well as the method of comparative estimates.

Results. The study of approaches to the innovative development of economic systems allowed us to conclude that, despite the crisis phenomena that are natural in their cyclicity, the decline in the development of these systems is overcome with greater speed in cases of innovation in the system, which, according to the author, should be reflected in practice in the mo­dernization of heat supply, in particular, through the innovative development of unified heat supply organizations.

Conclusions. In the conditions of changing energy structure, the innovative development of unified heat supply organizations should be considered not only from the standpoint of increasing the efficiency of heat supply in Russia, but also from the standpoint of increasing its energy efficiency and minimizing the negative impact on the environment.
Indonesian Legal Protection for Song Commercialization and Music Copyrights in Digital Platforms
Authors: Silfiani Diana
Published: September 2022

The Covid-19 pandemic has accelerated the digital influence on the Indonesian music industry. Music concerts, which are usually held offline with crowds of people, are no longer possible because crowds can make new clusters of Covid-19. The Indonesian music industry needs alternatives to survive the pandemic, and the advance in technology has the solution. Virtual concerts that are broadcasted via digital platforms have started to thrive. They use copyrighted songs and/or music so that royalty payments are made in accordance with the type of use and needs. Unfortunately, the Law Number 28 of 2014 on Copyright and the Government Regulation Number 56 of 2021 on the Management of Song and/or Music Copyright Royalties do not regulate the use in detail and specific manners. Therefore, the industry actors have not found the right payment formula for the economic rights royalties. The absence of regulations certainly does not reduce the user’s primary obligation to obtain a songwriter's permission and pay royalties for song and/or music copyrights. The fulfillment of the obligation to pay royalties must still be accomplished with due regard to applicable provisions. This study examined the problems with a normative juridical method. It considered the practices and customs that apply in Indonesia. It also generated some perspectives from relevant stakeholders.
The Nationalist Critique of Female Double Suicide in Colonial Korea
Authors: Yuh Leighanne , Soddu Claudia
Published: September 2022

During the colonial period, the double love suicides of young “new women” were sensationalized by media outlets and became the object of discussion at a national level, triggering discourse over the role and value of women in Colonial Korea. This sense of involvement in the life and death of women was even more prominent when these suicides involved young women of child-bearing age, whose deaths could be collectively perceived as a loss of an important human resource for the country. This article will examine why the media focus was on young, educated upper-class women and how the discourse about their suicides expanded beyond a moral cautionary tale and was coopted by the Korean nationalist movement. We analyze the discourse that followed two representative female double suicides, the Yun/Kim suicide of 1926, and the Hong/Kim homosexual double suicide of 1931, focusing on the critique published mainly in the Tonga Ilbo newspaper. We also examine the response of the feminist movements, or lack thereof, and the development of the ideological conflict between feminist and nationalist movements. Female suicide was one of the many battlefields between the nationalist and the feminist movements during the colonial period. As an issue involving women at every level of society, it had the potential to challenge the Confucian patriarchal system and bring to light the new needs of Korean women. However, as this analysis has shown, it was dismissed as a personal and trivial matter compared with the urgent public issue of national liberation. The rise of women's movements in Korea, fueled by a small clique of educated women, was ultimately subsumed by the nationalist movement and relegated to the realm of the private and inconsequential.
The Genealogy in the Koguryŏ Diaspora’s Epitaph
Authors: Ueda Kiheinarichika
Published: September 2022

This study investigates the genealogies in Koguryŏ epitaphs, patterns them, and analyzes their changes over time. The Koguryŏ diaspora occurred during the Unification War under Silla. This study focuses on the Koguryŏ diaspora among the Tang who migrated to China. First, this study summarizes the research on genealogies of the Koguryŏ diaspora's epitaphs and indicates their problems. Second, it confirms the definition of the Koguryŏ diaspora and reviews the number of epitaphs. Third, it categorizes genealogies and analyzes their changes. Finally, this study clarifies the causes of the changes in the genealogies.
Integrating Quality Improvement and Community Engagement Education: Curricular Evaluation of Resident Population Health Training
Authors: Sell Jarrett , Riley Timothy D. , Miller Erin L.
Published: September 2022

Background and Objectives: The Accreditation Council for Graduate Medical Education requires all residents be trained in population health, but the most effective training strategies to impact care of patients and populations are not well established. The purpose of this study is to assess resident self-efficacy and expected application of population management skills through iterative experiential, longitudinal, team-based training in the office and community settings.
Methods: Using a prospective longitudinal curricular evaluation, we surveyed residents at a single institution from 2014-2020, evaluating self-efficacy in population health skills as well as perceived impact on patient care and future practice. We collected surveys before and after participating in a 3-year, longitudinal, team-based, experiential population health curriculum that integrates clinic-based quality improvement and community engagement projects.
Results: Fifty-nine of 68 residents (87%) responded to the presurvey, and 42/56 (75%) responded to the postsurvey. We observed significant increases in resident self-efficacy in all population health skills. All respondents reported finding common population health skills that were applicable in both office and community settings; 81% reported care of their continuity clinic patients changed because of taking part in the curriculum. Finally, 94% of respondents reported the intention to use population health skills and incorporate quality improvement (75%) and community engagement (100%) in future practice.
Conclusions: Teaching population health management skills in both office and community settings allows residents to integrate and apply these skills across settings and may enhance their use in patient care and future practice.
Vienen los insectos: guía de artrópodos de la Universidad Tecnológica de Pereira
Authors: Bustamante Sanint Santiago , García Sierra Jorge Hugo
Published: September 2022

Uno de los grandes problemas actuales de la humanidad es el deterioro de los ecosistemas y la pérdida de biodiversidad, ocasionados principalmente por nuestras actividades. Al punto que los científicos concuerdan en que estamos en una época en donde la velocidad a la que se están extinguiendo las especies permite hablar de la sexta extinción masiva. La pérdida de biodiversidad y con ella los servicios ecosistemicos, como la polinización y el control de plagas de cultivos, es un problema que nos atañe a todos. En ese sentido, son fundamentales todas las acciones humanas encaminadas a lograr que los ciudadanos se apropien, conozcan y se esfuercen por participar en la conservación de las especies y los ecosistemas. Es por ello que, gratamente, encuentro en esta guía un material que permitirá acercarse un poco más y conocer la diversidad de un grupo tan importante en el mantenimiento de las funciones ecosistémicas y en la diversidad del planeta: los artrópodos. Entre ellos, arañas e insectos. Organismos que en ocasiones han sufrido poca aceptación. Sin embargo, las hermosas fotografías de esta guía dan cuenta de una bella, compleja y muy diversa fauna.
The Isthmus of the Cervix: Its Anatomical, and Functional Existence Should be Reconsidered: A Hypothesis I
Authors: Hegazy Ali
Published: September 2022

Objective Failures in understanding uterine functions during pregnancy
are a major shortcoming of healthcare and can be attributed to many
possible causes. Importantly, there might be flaws in the current
concept of human parturition, which creates a genuine barrier to a
greater understanding of the process. The objective of the study is to
challenge the existence of the isthmus in view of the current
evidence-based studies. Design: Research Study Setting: Portiuncula
University Hospital, Ireland Population: N/A Methods: This study
investigated the current evidence-based literature that may support our
proposed hypothesis. Main Outcome Measures: N/A Results The isthmus of
the cervix, both anatomically and functionally, does not seem to exist.
There has been no convincing evidence to support its existence since
Aschoff first proposed it in 1905. In fact, the embryological,
anatomical, and histological characteristics of the cervix and the
radiological evidence for cervical changes during pregnancy challenge
its existence. The study makes it clear that there are two opposing and
contradicting views about the isthmus. In the first view, the isthmus
and its nebulous character must be accepted, and no evidence
contradicting this concept in the human being could be found. The other
view is that the isthmus, geographically and functionally, does not
exist, and we have provided abundant evidence to support this view.
Conclusion The anatomical and functional division of the cervix into
isthmus and non-isthmus portions may be the main obstacle to
understanding cervical function and parturition and they should be
revised in light of this hypothesis.
Cognitive and psychiatric signs revealing Sneddon syndrome a Case Report.
Authors: Karoui Mehdi , Riahi Hend , MOHAMED DINA BEN , Baklouti emna , Chelli-Bouaziz Mouna
Published: September 2022

Sneddon syndrome (SS) is a clinical entity corresponding to a
non-inflammatory thrombotic vasculopathy that includes livedo
reticularis (typical skin lesions) and cerebrovascular lesions. We
present here a case of autoimmune SS with dementia and psychosis as the
main features that revealed the disease, in a 45-year-old Tunisian man
Can Left Bundle Branch Area Pacing Be a Panacea for Cardiac Resynchronization?: A Case That Puts This Theory in Question
Authors: Zhang Yimin , Ge Xiaozhen , Chen Mengna , Liu Hai , Guo Zhiqin , Zhang Junmeng
Published: September 2022

Studies have shown that left bundle branch area pacing (LBBaP) is not
inferior to biventricular-cardiac resynchronization therapy (BIV-CRT) in
the treatment of heart failure with cardiac electromechanical activity
asynchrony. The patient in this report was a 72-year-old heart failure
patient needing cardiac resynchronization therapy (CRT). The LBBaP
approach was attempted firstly, but it failed to achieve cardiac
electromechanical activity synchronization. Then, the BIV-CRT strategy
was selected and performed successfully. The patient’s heart function
has greatly improved at the postoperative follow-up. Therefore, BIV-CRT
remains an irreplaceable treatment for certain patients.
Study on thermal-mechanical coupling of the ceramic layer in diesel engine piston with thermal barrier coating
Authors: Lin Xu , Yifei Li
Published: September 2022

Piston performance has an important on vehicle reliability, efficiency, and exhaust emissions. Application of the thermal barrier coating is an effective method for preventing heat transfer from combustion chamber to the substrate. The numerical model of thermal barrier coating piston is established by using finite element method, and a comprehensive thermal-mechanical result is given to determine the influence of ceramic thickness on ceramic layer and substrate. Compared with uncoated piston, the maximum temperature of substrate decreased by 3.34%, 4.09%, 5.19%, 5.95%, and 6.69%, corresponding to ceramic thicknesses of 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, and 0.35 mm. The maximum thermal stress decreases from 78 MPa to 73 MPa. For ceramic layer of the thermal barrier coating piston, the maximum temperature appears at the top surface of the ceramic layer, while the maximum thermal stress occurs at the bottom of the ceramic layer. As the ceramics thickness increases from 0.15 mm to 0.35 mm, the maximum temperature of the ceramic layer increases from 322 ?C to 377 ?C, while the maximum thermal stress decreases from 95 MPa to 89 MPa. Thermal-mechanical coupled stress analysis shows that the maximum coupling stress occurs at the pinhole and its value does not change significantly. The thickness of the ceramic layer has little effect on the pinhole, but has a great influence on the ceramic layer.
Study on the thermal response of spiral energy piles based on field test
Authors: Chang Hong , Wang Haoquan , Shen Fengquan , Zhu Wanli
Published: September 2022

Field tests of spiral energy piles under the combined effect of temperature and loading are relatively few. Based on the field test, the heat transfer efficiency, pile strain, axial force and shaft friction of two spiral energy piles were studied. The major findings of the experimental studies were: First, when the double spiral energy pile was heated, the temperature distribution was more uniform; the total heat transfer and the heat transfer rate were higher than those of the single spiral energy pile. Second, the pile strain distribution was such that smaller values were noticed at both pile ends while larger values were in the middle part of the pile. The additional tensile stresses of the two piles generated during cooling reached 4.06 MPa and 4.75 MPa, which exceeded the tensile strength of concrete. Finally, during heating, the shaft friction was negative in the middle and upper pile and positive in the middle and lower pile. The single spiral energy pile showed two neutral points. The downward load generated by the single spiral energy pile was about 885 kN higher than that generated by the double one. The aforementioned changes should be focused on in the actual project.
Effect of protrusion shape on film cooling performance for the cylindrical hole embedded in a contoured crater
Authors: Wang Wenzhuang , Zhang Chao , Tong Zhiting
Published: September 2022

The cratered film-cooling hole is regarded as one of the potential applications with high cooling performance and low cost. This study focuses on the influence of the protrusion shape for the contoured crater embedded in the cylindrical hole. Four protrusion shapes, i.e., arc, rectangle, trapezoid, and triangle, are considered. The cooling effectiveness, flow structure, and aerodynamic loss for the cratered holes at blowing ratios of 0.5-2.5 are obtained using the numerical method with the shear stress turbulence model. The numerical results indicate that the arc and triangle protrusion models provide better lateral coolant coverage and higher area-averaged cooling effectiveness at higher blowing ratios, attributed to the ascendant anti-kidney-shaped vortex pair. The rectangle protrusion model provides the lowest area-averaged cooling effectiveness because the kidney-shaped vortex pair dominates the downstream flow field. For the aerodynamic loss, the largest total pressure loss coefficient occurs for the rectangle protrusion model and nearly equivalent values for the other three protrusion models. The contoured cratered holes with arc and triangle protrusions are generally recommended.
Experimental and numerical investigation on temperature uniformity of LPG cylinder in incineration test
Authors: Zhou Chilou , Lin Haojun , Chen Guohua , Yang Peng , Zheng Yiran , Qiu Xingquan , Li Xiangyue , Yang Yuhang
Published: September 2022

The liquefied petroleum gas (LPG) cylinder incineration test is an important part of the cylinder periodic inspection to clean up the residual gas and ensure the safety of subsequent inspection items. However, the cylinder needs to be incinerated several times due to the uneven temperature distribution of the cylinder, leading to low incineration efficiency and waste of energy. In this study, a cylinder incineration test is experimentally investigated and a CFD model is established to analyze the influence of incinerator structure parameters and cylinder types on the temperature uniformity of the cylinder. The results show that the temperature distribution of the middle surface of the cylinder is most uneven. With the increase of the burner nozzle diameter and the incinerator diameter, the standard deviation of temperature decreases at first and then increases, and the minimum is reached at 150 mm and 530 mm, respectively. The optimized design is found to have a better temperature uniformity of the cylinder with the burner nozzle angle of 0?. The optimal incinerator diameter for different types of LPG cylinders is different and decreases as the cylinder diameter decreases.
Experimental and numerical transient thermal analysis of the idler bearing housing made of steel or polymer material
Authors: Tasic Marko , Mitrovic Radivoje , Miskovic Zarko
Published: September 2022

The research of the influence of housing material on operation temperature of the idler bearing assembly is presented in this paper. Several radial loads and rotary speeds were applied to the test bench to determine the transient temperature field. The results were monitored and recorded for the whole period until the temperature of the assembly reached stationary stage. The FEM model was created where the rolling elements were replaced with the especially designed artificial body, having the shape of irregular ring. It generates heat and connects only those points of the inner and outer ring which are in operating conditions connected with the rolling elements. The experimental results are compared with FEM results. The conclusion is given on suitability of polymer material for this purpose.
Development and validation of a reduced MF/biodiesel mechanism for diesel engine application
Authors: Wei Mingrui , Gao Ji , Liu Jinping , Li Song
Published: September 2022

The 2-methylfuran (MF) is widely used as a surrogate fuel for internal combustion engines. However, the chemical kinetics model of MF for engine combustion simulations remains scarce. In this paper, a reduced MF/biodiesel mechanism consisting of 82 species and 226 reactions was proposed and used to simulate the combustion process of MF and biodiesel dual-fuel diesel engine. First, a detailed chemical reaction mechanism of MF was selected and then mechanism reduction methods were used to reduce the detailed mechanism under engine conditions. Second, the reduced MF mechanism was coupled with a biodiesel mechanism to form a four-component chemistry mechanism, consisting of MD, MD9D, n-heptane, and MF. Third, the combined mechanism was optimized by using rate of production analysis and sensitivity analysis. Finally, the proposed four-component mechanism was verified by comparing the calculated values of ignition delay and species concentrations with the experimental values. Meanwhile, a new dual-fuel diesel engine test was carried out, and the experiments were used to evaluate the reliability of the combination mechanism. Overall, the simulated results of the proposed four-component mechanism in this paper are basically consistent with the experimental results.
Enhanced heat transfer performance of a new horizontal buried tube heat exchanger
Authors: Ma Peifa , Mo Li , Zhang Jie , Wang Pengtao
Published: September 2022

To reduce the land area of horizontal buried tube heat exchanger, a finned strengthened heat exchanger was designed, and shallow geothermal utilization system model was established. The effects of fin shape and arrangement, soil type, ambient temperature and intermittent operation on the system?s heat transfer performance were investigated. The soil utilization area of the heat exchanger is increased, and the heat exchange performance of the system is enhanced by adding fins on the smooth tube. The optimal shape of the fins is rectangular, and the optimal fin lay-out is horizontal. When the soil property is clay, the heat transfer is the smallest, and the heat transfer performance is improved compared with the smooth tube. Intermittent operation not only improves the heat exchange, but also enhances the effect of adding fins to improve the heat exchange performance of the system. Compared with the original smooth tube, the soil utilization range is increased by 20%, and the heat exchange is increased by 42%.
Cooling enhancement of cubical shapes electronic components array including dummy elements inside a rectangular duct
Authors: Refaey Hassanein , Almohammadi Bandar , Abdelmohimen Mostafa , Abdelrahman Hany , Karali Mohamed
Published: September 2022

In this work, numerical simulation has been done to study the cooling enhancement of electronic components of cubical shapes including dummy elements inside a rectangular duct. The 12 electronic chips (3 ? 4 array) of dimensions (50 mm ? 50 mm ? 10 mm) are tested in an air duct of dimensions (350 mm ? 3500 mm ? 60 mm). The aim of the simulation is to study the influence of changing positions of the hot components on the overall cooling performance at different Reynolds numbers. Moreover, the effect of spacing between electronic components is studied. This is achieved by changing the position of the heat sources while keeping other elements as dummies to keep the flow characteristics. The Reynolds number is in the range (500-19000). The standard k-?, model is used and validated with experimental work showing good agreement. The 37 cases per Reynolds are considered, resulting in an overall 259 studied cases. It is concluded in terms of the large resulting data from this study that, increasing the spacing between elements in the cooling fluid-flow direction influences the cooling rate. Moreover, designers should be interested to operate such systems at optimized higher Reynolds values.
Numerical simulation of the effect of diaphragm orifice diameter in a flameproof enclosure with an interconnected structure during pressure piling
Authors: Li Dong , Dai Shijie
Published: September 2022

Combustible gas explosions are typically triggered at high temperatures by the generation of electric sparks on starting, stopping, or short circuiting of electrical equipment. Flameproof enclosures are widely installed in the petrochemical industry as safety equipment for eliminating ignition sources. Such enclosures are designed with a double-cavity structure, and a hole plate is used to connect the two cavities. However, pressure piling occurs in such double-cavity-connected structures, resulting in flameproof enclosures requiring to bear higher pressure than designed, which is a safety hazard. However, few studies have focused on the effect of the diaphragm orifice diameter of flameproof enclosures. Because the explosion of combustible gas in a flameproof enclosure is a complex process, numerical simulation was performed to study the process. Fluent was used for numerically simulating the ethylene/air premixed gas explosion characteristics of double-cavity-connected structure flameproof enclosures. The effects of an orifice hole diameter from 10 mm to 45 mm on flameproof characteristics, including the maximum explosion pressure, maximum explosion pressure rise rate, and maximum explosion index, were examined. The results are critical for the effective design of a double-cavity flameproof shell and provide theoretical support for fire suppression in a flameproof enclosure.
WE43 Magnezyum Alaşımının Soğuk Sprey Kaplama Yöntemi ile Al/Zn/Al2O3 ve Zn/Al2O3 Kaplanması ve Aşınma Davranışlarının İncelenmesi
Authors: GÜL Canser , ALBAYRAK Sevda , ÇÖMEZ Nilay , DURMUŞ Hülya
Published: September 2022

Mg alaşımları otomotiv, uçak, uzay ve haberleşme sektörlerinde düşük özgül ağırlıkları ve yüksek mukavemetli olması nedenleriyle tercih edilmektedir. WE serisi, Mg, Y, Nd, nadir toprak elementlerini içeren Mg alaşımları serisidir. Bu alaşım serisi için sürünme dayanımı iyi olsa da aşınma dayanımı gelişmeye açıktır. Bu çalışmada amaç, özgül ağırlıkları nedeni ile kullanım potansiyeli yüksek olan WE43 Mg alaşımlarının aşınma dayanımını arttırabilecek kaplamaların, endüstride de kolaylıkla uygulanabilecek bir yöntem kullanarak geliştirilmesidir. Bu amaçla soğuk sprey kaplama yöntemi kullanılarak aynı zamanda yüzeyleri fazlasıyla aktif olan magnezyum alaşımlarının oksitlenmeden kaplanması sağlanmış ve aşınma dayanımı geliştirilmiştir. Yüzeyleri ince kumlama işlemiyle pürüzlendiren WE43 Mg alaşımları soğuk sprey yöntemi kullanılarak Al/Zn/Al2O3 ve Zn/Al2O3 içerikli ve ticari isimleri sırasıyla DYMET K-20-11 ve DYMET K-00-11 olan tozlar kullanılarak 500ºC sıcaklıkta N2 koruyucu gaz atmosferi altında süpersonik hızlardaki tozlar için 6 g/dak. toz besleme hızıyla altlıklar üzerine püskürtülmüştür. Farklı içerikli tozlarla kaplanmış ve kaplanmamış numunelerin morfolojik analizleri SEM ve XRD yöntemleri ile incelenmiş, kaplama kalınlıkları kesitten alınan SEM görüntülerinden ölçülmüş, EDS analizleri ile elementlerin yüzde oranları tespit edilmiştir. Ayrıca aşınma performansının incelenmesi için ball-on disk aşınma testlerinden hacim kayıpları değerlendirilmiştir. Sonuç olarak, soğuk sprey kaplamalarla, kaplamasız duruma göre WE43 alaşımlarının aşınma kaybı yaklaşık %40 oranında azalmıştır.
Seniors and Their Quality of Life
Authors: A Hudáková
Published: September 2022

Aim: We aimed to find out whether the quality of life of seniors is higher in either home or institutional environment. Methods: We ́d realized the on the sample of 128 seniors living in institutional and home environment. We studied their quality of life via structured questionnaire WHOQL - BREF. Results: The achieved results show correlation between satisfaction with the health and perception of quality of life. We found that in the domain of physical health (presence of pain, degree of mobility, fatigue, loss of energy, the ability to do work, self-reliance, the need for frequent medical attention) the final domain score was 16.63 at home and 16.37 in the institutional environment (on a scale of 4-20). The scores found in our research are lowered compared with population norms. Quality of life of elderly living in their homes was 14.8 ± 10 and in the institutional environment it was 12.8 ± 11.09. The respondents from home environment reported better quality of life than respondents in the institutional environment. Conclusion: The support of quality of life should be one of the basic aims of nursing care. Nurses should make early identification of negative factors affecting quality of life and eliminate them by suitable nursing interventions.
First and Preliminary Data about Sars-CoV-2 Serology among Asymptomatic Workers in Central African Republic
Authors: CD Mossoro Kpinde
Published: September 2022

Context and Objectives: The pandemic induced by Sars-CoV-2 has disrupted the organization of work while its extent is not known in CAR. The objective of this study was to estimate the Sars-CoV-2 seroprevalence in the workplace in the Central African Republic. Methods: This is a cross-sectional study that took place at the Department of Occupational Medicine in Bangui. Asymptomatic workers who request to the Occupational Physician a medical certificate and consented were included in the study. A standard sheet was used to collect socio-demographic, professional and biological data. The serology of Sars-CoV-2 was based on 2 rapid immunochromatographic tests for detection of IgM and IgG separately: Covid-19 IgM / IgG Rapid Test (Cypress Diagnostics, Belgium) and Standard Q Covid-19 IgM / IgG Duo (SD Biosensor, Korea). Results: The seroprevalence of Sars-CoV-2 was 18.6% (CI [14.7-22.6]) including 1% positivity of IgM only, 1.0% of positivity of both IgM and IgG and 16.6% of positivity IgG only. Women (p = 0.001), young workers (<40 years; p = 0.01) and residents of Bangui (p = 0.05) were predominantly Sars-CoV-2 serological positive. Paradoxically, compliance with barrier measures was associated with a high Sars-CoV-2 seroprevalence (0.005). The group of health care workers, teachers and traders was more Sars-CoV-2 serological positive (0.0003) than other professions. Conclusion: The seroprevalence of Sars-CoV-2 remains low in CAR despite the progressive generalization of vaccination. The group of occupations with more Sars-CoV-2 seropositive people needs close monitoring and priority vaccination. Understanding the acceptability of vaccination, the kinetics of antibodies following vaccination and continue immunological surveillance in CAR require further studies.
Structural Insight into Antibody Evasion of SARS-Cov-2 Omicron Variant
Authors: N Subbarao
Published: September 2022

The SARS-CoV-2 continues to mutate and evolve with the emergence of omicron as the new variant of concern. The omicron variant has a large set of mutations occurring in the gene encoding spike protein. About half of these mutations are specifically located in the receptor binding domain (RBD), reflecting their significance in ACE2 interaction and antibody recognition. We have carried out the present study to understand how these mutations structurally impact the binding of the antibodies to their target epitope. We have computationally evaluated the binding of different RBD targeted antibodies, namely, CB6 (etesevimab), REGN10933 (casirivimab), S309 (sotrovimab), and S2X259 to the omicron mutation-induced RBD. All the four antibodies show reduced binding affinity towards the omicron RBD. The therapeutic antibody CB6 aka etesevimab was substantially affected due to numerous omicron mutations occurring in its target epitope. This study provides a structural insight into the reduced efficacy of RBD targeting antibodies against the SARS-CoV-2 omicron variant.