bluuebunny/crossref_metadata_2025 huggingface dataset:
Análisis de las percepciones del profesorado sobre la implementación de la e-evaluación en la universidad: resultado de la formación docente
Authors: Cuervo Montoya Bibiana María , Valencia Posada Katerin Johana , Calvo Betancur Víctor Daniel , Torres Valois Tarcilo
Published: September 2023

La evaluación de los aprendizajes es una parte fundamental de cualquier propuesta formativa, en particular en educación superior. Una metodología atractiva que apunta a este propósito es la e-evaluación, siendo clave las tecnologías de la información y la comunicación (TIC) en la mediación de la enseñanza y del aprendizaje. Este estudio tuvo como objetivo describir las percepciones de los docentes (hombres y mujeres) sobre la relevancia de la implementación de la e-evaluación en sus cursos de formación en la universidad. Para ello, se realizó un estudio observacional descriptivo tipo transversal en docentes de la Universidad de Antioquia que habían participado en los cursos de formación de e-evaluación. La muestra estuvo conformada por 154 docentes que realizaron el curso de e-evaluación entre los periodos 2019 y 2022. Para la recolección de la información, se adaptó y sistematizó un instrumento ad hoc (Alsaadoun, 2022) con la finalidad de identificar las variables observables que conformaron las variables latentes «Enseñanza» y «Aprendizaje». Los resultados mostraron una alta confiabilidad del instrumento, con un coeficiente omega de 0,88 y 0,92 para las dimensiones «Enseñanza» y «Aprendizaje», respectivamente. Este estudio también mostró que los participantes consideraban que la e-evaluación mejora los ambientes de aprendizaje en los cursos de educación superior. Asimismo, se pudo constatar que los encuestados opinaban que tanto la enseñanza como el aprendizaje se mejoran con esta metodología de la e-evaluación.
Evaluación formativa: implementación de una estrategia en el desempeño docente de profesoras de Preescolar con el apoyo de las TIC en el contexto de la pandemia
Authors: López Contreras María del Rayo , Pedroza Zúñiga Luis Horacio , Ruiz Mendoza Karla Karina
Published: September 2023

Durante la pandemia provocada por la COVID-19 fue necesario recurrir a la educación remota de emergencia y a diversas herramientas tecnológicas con la finalidad de continuar con la formación de los docentes y mejorar su práctica a través de la evaluación formativa. Este artículo se propone evaluar los resultados de la implementación de una estrategia de evaluación formativa en el desempeño de docentes (mujeres) de educación Preescolar a partir del uso de herramientas tecnológicas, informáticas y digitales. Se utilizó un diseño cuasiexperimental, de línea base múltiple, a través de cinco participantes. La evidencia de la práctica fue recolectada mediante un portafolio digital y se empleó una rúbrica alineada al programa de Educación Preescolar mexicano para valorar el desempeño docente. Los resultados mostraron una mejora modesta en el desempeño, aunque esta fue consistente. Se discute sobre los hallazgos en comparación con otros estudios, la variación del desempeño, las características y los principios de la evaluación formativa docente, así como la aportación del uso de las tecnologías de la información y la comunicación (TIC). Se concluye que la estrategia de evaluación formativa usada con el apoyo de las TIC promovió una mejora en el desempeño de las docentes, ya que se cumplió con los criterios de consistencia y los patrones de cambio para reflejar el efecto de la intervención.
Experiencias del cuidador familiar con la utilización de las Tecnologías de la Información y la Comunicación: implementación de una intervención educativa
Authors: Olivares-Roldan Ana María , Reyes-Audiffred Virginia
Published: September 2023

Introducción: Las Tecnologías de la Información y Comunicación (TICs) son un recurso a través del cual los profesionales de la salud pueden proporcionar apoyo y asesoría a distancia.
Objetivo: Describir las experiencias de una cuidadora familiar (CF) con el uso de las TICs en la implementación de una intervención educativa como apoyo para su autocuidado y el cuidado del adulto mayor (AM).
Metodología: Estudio de caso con abordaje cualitativo. Una pasante de la licenciatura en Enfermería y Obstetricia implementó una intervención educativa en una CF del 15 diciembre 2020 al 25 junio 2021, periodo de pandemia por COVID-19. La recolección de datos se realizó a partir de entrevistas a profundidad, mensajes de texto y voz de WhatsApp, así como por observación. Se realizó análisis de contenido tipo temático según de Souza Minayo.
Resultados: Se identificó el teléfono celular como el dispositivo más utilizado, las funciones de videollamada y mensaje de voz de WhatsApp como las herramientas más útiles y preferidas por la CF, y las infografías y videos como los materiales educativos más adecuados para esta población.
Limitaciones: Solo se incluyó una CF y un AM, lo cual puede generar un sesgo de respuesta, ya que la CF quizás estuvo más motivada y dispuesta a participar que otros cuidadores hipotéticos.
Valor: Implementar un nuevo canal de comunicación entre el profesional de enfermería, el AM, la CF y otros familiares.
Conclusiones: El uso de las TICs fue aceptado por la CF para recibir capacitación en su autocuidado y cuidado del AM.
Lesiones por presión: la incidencia en el paciente crítico con neumonía por SARS-CoV-2, en respuesta a la estrategia del decúbito prono durante la pandemia COVID-19
Authors: Medrano-Godoy Abraham , Becerra-Pérez Marissa de Lourdes
Published: September 2023

Introducción: Se suele aplicar en pacientes con SARS-CoV-2 el decúbito prono (DP) prolongadamente, pues ha demostrado beneficios para solventar la falta de equipos de ventilación mecánica; sin embargo, también tiende a producir lesiones por presión (LPP) en regiones anatómicas no experimentadas en otras prácticas.
Objetivo: Calcular la incidencia de LPP en el paciente crítico de COVID-19 en DP, describir características de los pacientes y las lesiones.
Metodología: Estudio observacional, descriptivo, de carácter transversal con enfoque retrospectivo. La recolección de datos se realizó en un hospital de tercer nivel de la Ciudad de México, incluyó 230 pacientes que desarrollaron LPP posterior a su ingreso. Se analizó el expediente electrónico y los registros de la clínica de heridas, la recolección de datos se generó en Excel y el análisis estadístico en el programa SPSS.
Resultados: La incidencia fue de 18.05%, las LPP con esfacelo corresponden al 33.9% y las de necrosis al 40%. La localización anatómica en pabellón auricular, pómulos y tórax fue de 36.1% y 46.5% fueron lesiones de categoría III con afectación de las estructuras musculares. La correlación con el IMC demostró que pacientes con sobrepeso presentaron mayor incidencia de LPP con fibrina y esfacelo en un 60.3%.
Limitación del estudio: No se consideraron variables como la carga de trabajo de enfermería.
Originalidad: Esta investigación no ha sido postulada previamente en ningún órgano editorial.
Conclusiones: La incidencia coincide con estudios en otros países, por lo que es necesario estandarizar las acciones para la prevención de LPP y reducir su incidencia.
Competencia clínica del personal de enfermería para el manejo de la hipotensión arterial intradialítica en el servicio de hemodiálisis del Centro Médico Naval
Authors: Citalán Morales Ángel , Gallardo García Isidora , López Rivera Jesús
Published: September 2023

Introducción: el correcto manejo de la hipotensión arterial durante la hemodiálisis es fundamental en la formación y trabajo del personal de enfermería nefrológica del Centro Médico Naval. El personal debe tener conocimientos suficientes sobre la hipotensión y sus factores asociados que le ayuden a predecirla y actuar de manera preventiva, así como con habilidades instrumentales para llevar a cabo medidas en la práctica.
Objetivo: analizar la competencia clínica del personal de enfermería en el servicio de hemodiálisis del Centro Médico Naval con respecto a su formación académica y experiencia profesional en el manejo de la hipotensión arterial intradialítica.
Metodología: estudio prospectivo, descriptivo y observacional. Se emplearon dos instrumentos: una adaptación del Cuestionario de conocimientos para el manejo de hemodiálisis de Miller y la Guía de observación de habilidades instrumentales en el personal de enfermería de Murillo.
Resultados: se contó con una muestra de doce enfermeros pertenecientes al servicio de hemodiálisis. El 33.3% mostró un nivel regular de competencia clínica y 66.7% un nivel bueno. En promedio, la competencia clínica se ubicó en 78%.
Discusión: los resultados obtenidos difieren de los reportados en otras investigaciones, tanto por el año de aplicación como de los sujetos evaluados.
Limitaciones: se contó con una muestra baja debido a que el personal del servicio no es numeroso.
Conclusiones: es necesario reforzar los conocimientos del personal sobre el tema. Sin embargo, se observó que las habilidades instrumentales fueron excelentes en todos los casos. No se observa relación con el nivel de estudios o la experiencia profesional.
Cuidado humanizado del profesional de enfermería en la atención del paciente oncológico hospitalizado
Authors: Gómez-Lucio María del Carmen
Published: September 2023

Introducción: El cuidado a pacientes oncológicos consiste, más allá de satisfacer necesidades físicas, en una atención holística, pues el cuidado humanizado favorece una interrelación esencial entre ciencia y valores para establecer una asistencia de calidad, que dé solución a las demandas humanas del usuario. Objetivo: Identificar el nivel de cuidado humanizado que proporciona el profesional enfermero a pacientes hospitalizados en un centro de oncología. Material y métodos: Estudio descriptivo, observacional-transversal. Muestreo no probabilístico de oportunidad y secuencial con cuota de 35 pacientes. Medición realizada con el instrumento “Percepción del cuidado humanizado en pacientes hospitalizados”. Análisis de resultados mediante estadística descriptiva. Resultados: El cuidado proporcionado a pacientes oncológicos hospitalizados es humanizado, pues afirman recibir trato amable con efecto positivo en ellos derivado de la actitud de la enfermera en su labor, en la que impera el conocimiento y la experiencia para proveer cuidados individualizados y empáticos a partir de comunicación, expresión de sentimientos y escucha, atendiendo no sólo necesidades físicas, sino también sociales, culturales y espirituales. Discusión: Los pacientes oncológicos mencionan que el profesional de enfermería actúa comprendiendo al usuario integralmente, lo que les permite enfrentar positivamente su proceso de enfermedad. Conclusiones: El cuidado humanizado de calidad es una relación entre el profesional de enfermería y el paciente a cuidar, en la que impera la comunicación, el debido uso de la palabra y la escucha para generar confianza, lo cual se suma a la base científica y las habilidades técnicas, a fin de intervenir de forma humana, eficiente y segura.
Strategi Manajerial Kepala Sekolah dalam Meningkatkan Literasi Digital Guru
Authors: Noor Wachidatur Rochmah Shofia , Hidayati Dian , Rizqon Mubarok Arian
Published: September 2023

Literasi digital perlu dilakukan oleh seorang pendidik, sebab akan mempermudah dalam memperoleh, memahami serta menyebarluaskan informasi proses pembelajaran. Oleh karena itu,
penelitian ini bertujuan untuk mengetahui serta menjelaskan strategi manajerial yang dilakukan oleh kepala sekolah dalam meningkatkan literasi digital guru. Penelitian ini menggunakan pendekatan kualitatif dengan teknik pengumpulan melalui wawancara dan dokumentasi. Partisipan pada penelitian ini yaitu kepala sekolah dan guru SMP Negeri 4 Sekayam. Data yang telah terkumpul kemudian direduksi, dilakukan penyajian data, dan selanjutnya ditarik kesimpulan. Penelitian ini memyimpulkan bahwa strategi manajerial kepala sekolah SMP Negeri 4 Sekayam dalam meningkatkan literasi digital guru adalah: 1) Melakukan perencanaan dengan menganalisis kebutuhan (melihat keadaan guru dalam penggunaan digital, ketersediaan alat, dan juga akses yang diperlukan); 2) Menyediakan fasilitas yang dibutuhkan dalam upaya meningkatkan literasi digital, seperti menyediakan tablet, ChromeBook, dan menyediakan akses internet berupa Wifi; 3) Mengikutsertakan guru-guru dalam pelatihan yang diselenggarakan, seperti pelatihan yang dilakukan melalui forum digital seperti Zoom Meeting; 4) Melakukan evaluasi dan melakukan perbaikan pada masa selanjutnya.
Analisis Yuridis Pelaksanaan Kewenangan Bawaslu sebagai Lembaga Pengawas dan Lembaga Pemutus Sengketa Pemilihan Umum
Authors: Juhardin Juhardin , Ismail Ananda Adhe
Published: September 2023

Penelitian ini bertujuan untuk menganalisis pelaksanaan kewenangan bawaslu sebagai lembaga pengawas pemilu dan penyelesaian sengketa proses pemilu. Penelitian ini merupakan penelitian hukum normatif denganmenelaah semua undang-undang dan regulasi yang berkaitan dengan isu hukum yang sedang diteliti. Pendekatan penelitian menggunakan pendekatan perundang-undangan dan pendekatan konseptual. Sumber bahan hukum yang digunakan adalah bahan hukum primer yakni bahan hukum yang bersifat otoritas, yang terdiri dari peraturan perundang-undangan, catatan resmi, atau risalah dalam pembuatan peraturanperundang-undangan serta bahan hukum sekunder (bahan yang memberikan penjelasan mengenai bahan hukum primer, meliputi, dokumen, buku, majalah, jurnal-jurnal hukum dan laporan penelitian yang terkait dengan penelitian ini). Kesimpulan penelitian ini telah diperoleh hasil bahwa Pertama, Bawaslu sebagai lembaga pengawasan pemilu melakukan fungsi pencegahan pelanggaran. Kedua, Kewenangan Menyelesaikan Sengketa Proses Pemilu Bawaslu merupakan kewenangan atributif  berdasarkan Undang-Undang No. 7 Tahun 2017 tentang Pemilihan Umum pada Pasal 94 ayat (3) poin d dan Anggota Bawaslu telah memenuhi kriteria sebagai hakim pada sidang Adjudikasi Bawaslu karena telah melewati jalur seleksi yang begitu ketat sesuai dengan tahapan-tahapan yang telah mereka laksanakan dan Tim Seleksi telah melakukanpenilaian berdasarkan kriteria yang telah termuat dalam pasal 117 UU Pemilu. Ketiga, Pasal 469 yang menyatakan bahwa Putusan Bawaslu adalah final dan mengikat merupakan kalimat yang memberikan kedudukan atau kekuatan kepada putusan adjudikasi Bawaslu bersifat final. Tetapi, kekuatan tersebut langsung di hapus pada frase selanjutnya yang memberikan pengecualian kepada perihal-perihal tertentu.
RELATO DE CASO: SÍNDROME DE GUILLAIN-BARRÉ APÓS INFECÇÃO POR DENGUE
Authors: Costa Ana Beatriz Nascimento , Costa Gabriela Thamirys Soares , Pereira Jéssica Souza , Bobst Pedro Gadbem , Costa Júnior Renato Pereira da
Published: September 2023

Esse relato busca expor uma das complicações neurológicas da dengue, que é a  arbovirose urbana mais comum em nosso país. O quadro clínico da dengue pode variar de cefaleia, erupções cutâneas, mialgia, diarreia a manifestações neurológicas graves, cuja prevalência varia de 0,5 a 21%² e dentre elas, destaca-se a Síndrome de Guillain-Barré (SGB), uma polirradiculoneuropatia inflamatória desmielinizante aguda de caráter autoimune. Os mecanismos relacionados à SGB e à dengue ainda são pouco conhecidos. No entanto, evidências sugerem que a dengue possui características de doença neurológica imunomediada, uma vez que as mesmas substâncias pró-inflamatórias que participam da resposta imune ao vírus da dengue também possuem papel importante na patogênese da SGB, o que pode, de fato, estabelecer a relação entre estas duas doenças.4 Neste relato de caso, os diagnósticos de dengue e de Síndrome de Guillain Barré foram baseados em achados clínicos, exame do líquido cefalorraquidiano, achados eletrofisiológicos associados a títulos específicos de IgM para dengue.
EDUCAÇÃO DIGITAL POSITIVA: UMA DISCUSSÃO APROFUNDADA SOBRE CYBERBULLYING E EMPATIA ONLINE PARA OS ALUNOS DO ENSINO MÉDIO EM UMA ESCOLA PÚBLICA NO MUNICÍPIO DE LÁBREA, NO AMAZONAS
Authors: Silva Lucivânia Ventura da , Silva Gleice Oliveira da , Queiroz Rosane Gomes , Silva Rosenilde Soares da
Published: September 2023

Este artigo descreve uma abordagem educativa e envolvente para lidar com o problema ocasionado pelo cyberbullying, procurando esclarecer aos alunos sobre os efeitos danosos dessa forma de violência virtual, com o intuito de promover a empatia, o respeito mútuo e, ainda, desenvolver habilidades digitais saudáveis. Contudo, a educação sobre o cyberbullying envolve também ações práticas para criar uma cultura escolar inclusiva e segura, utilizando as aulas como metodologia para desmistificar o cyberbullying, desempenhando um papel crucial na promoção de um ambiente online saudável e na capacitação dos alunos, com o objetivo de lidar com os desafios e as responsabilidades da era digital. Estas aulas foram realizadas no Centro de Educação de Tempo Integral “Agostinho Ernesto de Almeida”, na disciplina de projetos Integradores. Ao adotar o cyberbullying como uma educação engajadora, contribuímos para a formação de jovens conscientes e capacitados para utilizar a tecnologia de informação e comunicação de forma responsável, visando criar um ambiente escolar seguro e inclusivo, onde cada aluno possa se expressar livremente e ser respeitado.
SOCIAL RESPONSIBILITY AS A STRATEGY IN BUSINESS MANAGEMENT
Authors: Silva Ana Paula Teixeira da , Coutinho Diogenes José Gusmão
Published: September 2023

This paper addresses aspects of corporate social business responsibility their historical processes and theories that explain this strategy. It addresses the environmental preservation and other theories to improve the quality of life society. Likewise is discussed in the disclosure of the social enterprises and their benefits. The tools for business management ethics are essential to contemporary management. Seeking the welfare of customers, suppliers and society, thus becoming socially responsible. The new way to consume has changed the strategic vision of the companies, seeking to establish itself in the market today. Social responsibility accepts the role of an important management tool that can also result in numerous benefits to society.
Atmospheric CO2 inversion reveals the Amazon as a minor carbon source caused by fire emissions, with forest uptake offsetting about half of these emissions
Authors: Basso Luana S. , Wilson Chris , Chipperfield Martyn P. , Tejada Graciela , Cassol Henrique L. G. , Arai Egídio , Williams Mathew , Smallman T. Luke , Peters Wouter , Naus Stijn , Miller John B. , Gloor Manuel
Published: September 2023

Abstract. Tropical forests such as the Amazonian rainforests play an important role for climate, are large carbon stores and are a treasure of biodiversity. Amazonian forests have been exposed to large-scale deforestation and degradation for many decades. Deforestation declined between 2005 and 2012 but more recently has again increased with similar rates as in 2007–2008. The resulting forest fragments are exposed to substantially elevated temperatures in an already warming world. These temperature and land cover changes are expected to affect the forests, and an important diagnostic of their health and sensitivity to climate variation is
their carbon balance. In a recent study based on CO2 atmospheric
vertical profile observations between 2010 and 2018, and an air column
budgeting technique used to estimate fluxes, we reported the Amazon region
as a carbon source to the atmosphere, mainly due to fire emissions. Instead
of an air column budgeting technique, we use an inverse of the global
atmospheric transport model, TOMCAT, to assimilate CO2 observations
from Amazon vertical profiles and global flask measurements. We thus
estimate inter- and intra-annual variability in the carbon fluxes, trends
over time and controls for the period of 2010–2018. This is the longest period covered by a Bayesian inversion of these atmospheric CO2 profile observations to date. Our analyses indicate that the Amazon is a small net source of carbon to the atmosphere (mean
2010–2018 = 0.13 ± 0.17 Pg C yr−1, where 0.17 is the 1σ uncertainty), with the majority of
the emissions coming from the eastern region (77 % of total Amazon
emissions). Fire is the primary driver of the Amazonian source (0.26 ± 0.13 Pg C yr−1), while forest carbon uptake removes around half of the fire emissions to the atmosphere (−0.13 ± 0.20 Pg C yr−1). The largest net carbon sink was observed in the western-central Amazon region (72 % of the fire emissions). We find larger carbon emissions during the
extreme drought years (such as 2010, 2015 and 2016), correlated with
increases in temperature, cumulative water deficit and burned area. Despite
the increase in total carbon emissions during drought years, we do not
observe a significant trend over time in our carbon total, fire and net
biome exchange estimates between 2010 and 2018. Our analysis thus cannot
provide clear evidence for a weakening of the carbon uptake by Amazonian
tropical forests.
Stratospheric aerosol size reduction after volcanic eruptions
Authors: Wrana Felix , Niemeier Ulrike , Thomason Larry W. , Wallis Sandra , von Savigny Christian
Published: September 2023

Abstract. The stratospheric aerosol layer plays an important role in the radiative balance of Earth primarily through scattering of solar radiation. The magnitude of this effect depends critically on the size distribution of the aerosol. The aerosol layer is in large part fed by volcanic eruptions strong enough to inject gaseous sulfur species into the stratosphere. The evolution of the stratospheric aerosol size after volcanic eruptions is currently one of the biggest uncertainties in stratospheric aerosol science. We retrieved aerosol particle size information from satellite solar occultation measurements from the Stratospheric Aerosol and Gas Experiment III mounted on the International Space Station (SAGE III/ISS) using a robust spectral method. We show that, surprisingly, some volcanic eruptions can lead to a decrease in average aerosol size, like the 2018 Ambae and the 2021 La Soufrière eruptions. In 2019 an intriguing contrast is observed, where the Raikoke eruption (48∘ N, 153∘ E) in 2019 led to the more expected stratospheric aerosol size increase, while the Ulawun eruptions (5∘ S, 151∘ E), which followed shortly after, again resulted in a reduction in the values of the median radius and absolute distribution width in the lowermost stratosphere. In addition, the Raikoke and Ulawun eruptions were simulated with the aerosol climate model MAECHAM5-HAM. In these model runs, the evolution of the extinction coefficient as well as of the effective radius could be reproduced well for the first 3 months of volcanic activity. However, the long lifetime of the very small aerosol sizes of many months observed in the satellite retrieval data could not be reproduced.
Investigation of meteorological conditions and BrO during ozone depletion events in Ny-Ålesund between 2010 and 2021
Authors: Zilker Bianca , Richter Andreas , Blechschmidt Anne-Marlene , von der Gathen Peter , Bougoudis Ilias , Seo Sora , Bösch Tim , Burrows John Philip
Published: September 2023

Abstract. During polar spring, ozone depletion events (ODEs) are often observed in combination with bromine explosion events (BEEs) in Ny-Ålesund. In this study, two long-term ozone data sets (2010–2021) from ozonesonde launches and in situ ozone measurements have been evaluated between March and May of each year to study ODEs in Ny-Ålesund. Ozone concentrations below 15 ppb were marked as ODEs. We applied a composite analysis to evaluate tropospheric BrO retrieved from satellite data and the prevailing meteorological conditions during these events. During ODEs, both data sets show a blocking situation with a low-pressure anomaly over the Barents Sea and anomalously high pressure in the Icelandic Low area, leading to transport of cold polar air from the north to Ny-Ålesund with negative temperature and positive BrO anomalies found around Svalbard. In addition, a higher wind speed and a higher, less stable boundary layer are noticed, supporting the assumption that ODEs often occur in combination with polar cyclones. Applying a 20 ppb ozone threshold value to tag ODEs resulted in only a slight attenuation of the BrO and meteorological anomalies compared to the 15 ppb threshold. Monthly analysis showed that BrO and meteorological anomalies are weakening from March to May. Therefore, ODEs associated with low-pressure systems, high wind speeds, and blowing snow more likely occur in early spring, while ODEs associated with low wind speed and stable boundary layer meteorological conditions seem to occur more often in late spring. Annual evaluations showed similar weather patterns for several years, matching the overall result of the composite analysis. However, some years show different meteorological patterns deviating from the results of the mean analysis. Finally, an ODE case study from the beginning of April 2020 in Ny-Ålesund is presented, where ozone was depleted for 2 consecutive days in combination with increased BrO values. The meteorological conditions are representative of the results of the composite analysis. A low-pressure system arrived from the northeast to Svalbard, resulting in high wind speeds with blowing snow and transport of cold polar air from the north.
Negative Social Tipping Dynamics Resulting from and Reinforcing Earth System Destabilisation
Authors: Spaiser Viktoria , Juhola Sirkku , Constantino Sara M. , Guo Weisi , Watson Tabitha , Sillmann Jana , Craparo Alessandro , Basel Ashleigh , Bruun John T. , Krishnamurthy Krishna , Scheffran Jürgen , Pinho Patricia , Okpara Uche T. , Donges Jonathan F. , Bhowmik Avit , Yasseri Taha , Safra de Campos Ricardo , Cumming Graeme S. , Chenet Hugues , Krampe Florian , Abrams Jesse F.
Published: September 2023

Abstract. In recent years research on positive social tipping dynamics in response to the climate crisis has produced invaluable insights. In contrast, relatively little attention has been given to the potentially negative social dynamics that might arise due to an increasingly destabilised Earth system, and how they might in turn reinforce social destabilisation dynamics and/or impede positive social change. In this paper, we identify potential negative tipping elements linked to Earth System destabilisation and draw on related research to understand the drivers and likelihood of these negative tipping dynamics, their potential effects on human societies and the Earth system, and the potential for cascading interactions and contribution to systemic risks. This first attempt to provide a first explorative conceptualisation of negative social tipping dynamics is intended to motivate further research into an under-researched area that is nonetheless crucial for our ability to respond to the climate crisis and for ensuring that positive social tipping dynamics are not averted by negative ones.
Driving sustainability transitions through financial tipping points
Authors: Ameli Nadia , Chenet Hugues , Falkenberg Max , Kothari Sumit , Rickman Jamie , Lamperti Francesco
Published: September 2023

Abstract. Achieving a net-zero carbon economy requires significant structural changes in the financial system, including a substantial shift in investment towards low-carbon assets. Through the alignment of expectations, promotion of herding behavior, utilization of public finance, reduction of capital costs and attainment of low-carbon investment thresholds in developing nations, and implementation of robust financial regulations and policies, the financial system can assume a central role in re-orienting economies onto a net-zero course. Taken together, such mechanisms highlight the positive tipping points that can be triggered within sustainable finance and emphasize the necessity of policy interventions to activate and capitalize on these dynamics. The identification and activation of critical and positive tipping points can lead to the amplification of sustainable investments and foster transformative changes in the practices of the financial sector.
Response of PM2.5 chemical composition to variations in anthropogenic emissions and meteorological conditions during COVID-19 lockdown
Authors: Gong Yitian , Zhou Haijun , Chun Xi , Wan Zhiqiang , Wang Jingwen , Liu Chun
Published: September 2023

Abstract. PM2.5 is a primary atmospheric pollutant with various sources and complicated chemical compositions that are influenced by various factors, such as anthropogenic emissions (AE) and meteorological conditions (MC). MC have significant impacts on variations of the atmospheric pollutant; therefore, emission reduction policies and ambient air quality are non-linearly correlated, which hinders accurate assessments of the effectiveness of control measures. The online observations of PM2.5 and its chemical composition were conducted in Hohhot, China, from December 1, 2019, to February 29, 2020, to investigate PM2.5 chemical compositions respond to the variation of AE and MC. Moreover, the random forest (RF) model was used to quantify the AE and MC contributions of PM2.5 and its chemical composition during severe hazes and the COVID-19 pandemic lockdown period. During the clean period, MC contributed -124 % to PM2.5 concentrations, indicating that MC promoted PM2.5 dispersion. During severe pollution episodes, MC contributed 49 % to PM2.5 concentrations, indicating that MC promoted PM2.5 accumulation. The inorganic aerosols (SO42-, NO3-, and NH4+) showed the strongest response to MC. MC had significant contributions to the PM2.5 (36 %), SO42- (32 %), NO3- (29 %), NH4+ (28 %), OC (22 %), and SOC (17 %). From the pre-lockdown to lockdown period, AE (MC) contributed 52 % (48 %), 81 % (19 %), 48 % (52 %), 68 % (32 %), 59 % (41 %), and 288 % (-188 %) to the PM2.5, SO42-, NO3-, NH4+, OC, and SOC variations, respectively. The variations of MC (especially the increase in relative humidity) rapidly generated meteorologically sensitive species (SO42-, NO3-, and NH4+), which led to severe winter pollution. This study provides reference for assessing the net benefits of emission reduction measures for PM2.5 and its chemical compositions.
Impacts of ice-nucleating particles on cirrus clouds and radiation derived from global model simulations with MADE3 in EMAC
Authors: Beer Christof Gerhard , Hendricks Johannes , Righi Mattia
Published: September 2023

Abstract. Atmospheric aerosols can act as ice-nucleating particles (INPs) and influence the formation and the microphysical properties of cirrus clouds, resulting in distinct climate effects. We employ a global aerosol–climate model, including a two-moment cloud microphysical scheme and a parametrization for aerosol-induced ice formation in cirrus clouds, to quantify the climate impact of INPs on cirrus clouds. The model considers mineral dust, (aviation) soot, crystalline ammonium sulfate, and glassy organics as INPs in the cirrus regime. A number of sensitivity experiments are performed to analyse various aspects of the simulated INP-cirrus effect regarding (i) the ice-nucleating potential of the INPs, (ii) the inclusion of ammonium sulfate and organic particles as INPs in the model, and (iii) the model representations of vertical updrafts. The resulting global radiative forcing of the total INP-cirrus effect, considering all different INP-types, assuming a smaller and a larger ice nucleating potential of INPs, is simulated as −28 and −55 mW m−2, respectively. While the simulated impact of glassy organic INPs is mostly small and not statistically significant, ammonium sulfate INPs contribute a considerable radiative forcing, which is nearly as large as the combined effect of mineral dust and soot INPs. Additionally, the anthropogenic INP-cirrus effect is analysed considering the difference between present-day (2014) and pre-industrial conditions (1750) and amounts to −29 mW m−2. In an additional sensitivity experiment we analyse the effect of highly efficient INPs proposed for cirrus cloud seeding as a means to reduce global warming by climate engineering. However, the results indicate that this approach risks an overseeding of cirrus clouds and often results in positive radiative forcings. Idealized experiments with prescribed vertical velocities highlight the crucial role of the model dynamics for the simulated INP-cirrus effects, e.g. resulting forcings increase about one order of magnitude when increasing the prescribed vertical velocity. The large discrepancy in the magnitude of the simulated INP-cirrus effect between different model studies emphasizes the need for future detailed analyses and efforts to reduce this uncertainty and constrain the resulting climate impact of INPs.
The effect of chemical variability and weathering on Raman spectra of enargite and fahlore
Authors: Berkh Khulan , Majzlan Juraj , Meima Jeannet A. , Plášil Jakub , Rammlmair Dieter
Published: September 2023

Abstract. Enargite (Cu3AsS4) and tennantite (Cu12As4S13) are typical As-bearing sulfides in intermediate- and high-sulfidation epithermal deposits. Trace and major element variations in enargite and tennantite and their substitution mechanisms are widely described. However, Raman spectra of the minerals with correlative quantitative chemical information are rarely documented, especially for enargite. Therefore, comparative electron and μ-Raman microprobe analyses were performed on enargite and fahlore grains. These spectra can be used in the industrial detection and subsequent removal of As-bearing sulfides prior to ore beneficiation in order to diminish the environmental impact of the metallurgical technologies. A simple Sb5+–As5+ substitution in enargite was confirmed by Raman analyses. Similarly, a complete solid solution series from tetrahedrite to tennantite (i.e., Sb3+–As3+ substitution) can be correlated with a gradual evolution in their Raman spectra. In turn, Te4+ occupies the As3+ and Sb3+ sites in fahlore by the coupled substitution Te4+ + Cu+ → (As, Sb)3+ + (Cu, Fe, Zn)2+. Accordingly, Raman bands of goldfieldite (Te-rich member) are strongly broadened compared with those of tetrahedrite and tennantite. A secondary phase with high porosity and a fibrous or wormlike texture was found in enargite in a weathered sample. The chemical composition, Raman spectrum, and X-ray diffraction signature of the secondary phase resemble tennantite. A gradual transformation of the primary enargite into this secondary phase was visualized by comparative electron and Raman microprobe mapping.
Quantifying exchangeable base cations in permafrost: a reserve of nutrients about to thaw
Authors: Mauclet Elisabeth , Villani Maëlle , Monhonval Arthur , Hirst Catherine , Schuur Edward A. G. , Opfergelt Sophie
Published: September 2023

Abstract. Permafrost ecosystems are limited in nutrients for
vegetation development and constrain the biological activity to the active
layer. Upon Arctic warming, permafrost thaw exposes large amounts of soil
organic carbon (SOC) to decomposition and minerals to weathering but also
releases organic and mineral soil material that may directly influence the
soil exchange properties (cation exchange capacity, CEC, and base saturation,
BS). The soil exchange properties are key for nutrient base cation supply
(Ca2+, K+, Mg2+, and Na+) for vegetation growth and
development. In this study, we investigate the distributions of soil exchange
properties within Arctic tundra permafrost soils at Eight Mile Lake
(Interior Alaska, USA) because they will dictate the potential reservoir of
newly thawed nutrients and thereby influence soil biological activity and
vegetation nutrient sources. Our results highlight much lower CEC density in
surface horizons (∼9400 cmolc m−3) than in the mineral
horizons of the active layer (∼16 000 cmolc m−3)
or in permafrost soil horizons (∼12 000 cmolc m−3). Together, with the overall increase in CEC density with depth and
the overall increase in BS (percentage of CEC occupied by exchangeable base
cations Ca2+, K+, Mg2+, and Na+) with depth (from
∼19 % in organic surface horizons to 62 % in permafrost soil
horizons), the total exchangeable base cation density (Ca2+, K+,
Mg2+, and Na+ in g m−3) is up to 5 times higher in the
permafrost than in the active layer. More specifically, the exchangeable
base cation density in the 20 cm upper part of permafrost about to thaw is
∼850 g m−3 for Caexch, 45 g m−3 for
Kexch, 200 g m−3 for Mgexch, and 150 g m−3 for
Naexch. This estimate is needed for future ecosystem prediction models
to provide constraints on the size of the reservoir in exchangeable
nutrients (Ca, K, Mg, and Na) about to thaw. All data described in this paper are stored in Dataverse, the online repository of Université catholique de Louvain, and are accessible through the following DOI: https://doi.org/10.14428/DVN/FQVMEP (Mauclet et al., 2022b).
A new 2010 permafrost distribution map over the Qinghai–Tibet Plateau based on subregion survey maps: a benchmark for regional permafrost modeling
Authors: Cao Zetao , Nan Zhuotong , Hu Jianan , Chen Yuhong , Zhang Yaonan
Published: September 2023

Abstract. Permafrost over the Qinghai–Tibet Plateau (QTP) has
received increasing attention due to its high sensitivity to climate change.
Numerous spatial modeling studies have been conducted on the QTP to assess
the status of permafrost, project future changes in permafrost, and diagnose
contributors to permafrost degradation. Due to the scarcity of ground
stations on the QTP, these modeling studies are often hampered by the lack
of validation references, calibration targets, and model constraints; however,
a high-quality permafrost distribution map would be a good option as a
benchmark for spatial simulations. Existing permafrost distribution maps for
the QTP can poorly serve this purpose. An ideal benchmark map for spatial
modeling should be methodologically sound, of sufficient accuracy, and based
on observations from mapping years rather than all historical data spanning
several decades. Therefore, in this study, we created a new permafrost
distribution map for the QTP in 2010 using a novel permafrost mapping
approach with satellite-derived ground surface thawing and freezing indices as
inputs and survey-based subregion permafrost maps as constraints. This
approach accounted for the effects of local factors by incorporating (into
the model) an empirical soil parameter whose values were optimally estimated
through spatial clustering and parameter optimization constrained by
survey-based subregion permafrost maps, and the approach was also improved to reduce parametric equifinality. This new map showed a total permafrost area
of about 1.086×106 km2 (41.2 % of the QTP area) and
seasonally frozen ground of about 1.447×106 km2
(54.9 %) in 2010, excluding glaciers and lakes. Validations using
survey-based subregion permafrost maps (κ=0.74) and borehole records
(overall accuracy =0.85 and κ=0.43) showed a higher accuracy of
this map compared with two other recent maps. Inspection of regions with obvious
distinctions between the maps affirms that the permafrost distribution on
this map is more realistic than that on the Zou et al. (2017) map. Given the
demonstrated excellent accuracy, this map can serve as a benchmark map for
constraining/validating land surface simulations on the QTP and as a
historical reference for projecting future permafrost changes on the QTP in
the context of global warming. The dataset is available from the repository hosted on Figshare (Cao et al., 2022): https://doi.org/10.6084/m9.figshare.19642362.
Rapid hydration and weakening of anhydrite under stress: implications for natural hydration in the Earth's crust and mantle
Authors: Heeb Johanna , Healy David , Timms Nicholas E. , Gomez-Rivas Enrique
Published: September 2023

Abstract. Mineral hydration is an important geological process that
influences the rheology and geochemistry of rocks and the fluid budget of
the Earth's crust and mantle. Constant-stress differential compaction
(CSDC) tests, dry and “wet” tests under confining pressure, and axial-stress tests were
conducted for the first time to investigate the influence of triaxial
stress on hydration in anhydrite–gypsum aggregates. Characterization of the
samples before and after triaxial experiments was performed with optical
and scanning electron microscopy, including energy-dispersive spectroscopy
and electron backscatter diffraction mapping. Stress–strain data reveal that
samples that underwent constant-stress differential compaction in the
presence of fluids are ∼ 14 % to ∼ 41 % weaker
than samples deformed under wet conditions. The microstructural analysis
shows that there is a strong temporal and spatial connection between the
geometry, distribution, and evolution of fractures and hydration products.
The increasing reaction surface area in combination with pre-existing gypsum
in a gypsum-bearing anhydrite rock led to rapid gypsification. The
crystallographic orientations of newly formed vein gypsum have a systematic
preferred orientation for long distances along veins, beyond the grain
boundaries of wall-rock anhydrite. Gypsum crystallographic orientations in
{100} and {010} are
systematically and preferentially aligned parallel to the direction of
maximum shear stress (45∘ to σ1). Gypsum is also not
always topotactically linked to the wall-rock anhydrite in the immediate
vicinity. This study proposes that the selective inheritance of crystal
orientations from favourably oriented wall-rock anhydrite grains for the
minimization of free energy for nucleation under stress leads to the
systematic preferred orientation of large, new gypsum grains. A sequence is
suggested for hydration under stress that requires the development of
fractures accompanied by localized hydration. Hydration along fractures with
a range of apertures up to 120 µm occurred in under 6 h. Once
formed, gypsum-filled veins represent weak surfaces and are the locations of
further shear fracturing, brecciation, and eventual brittle failure. These
findings imply that non-hydrostatic stress has a significant influence on
hydration rates and subsequent mechanical strength of rocks. This phenomenon
is applicable across a wide range of geological environments in the Earth's
crust and upper mantle.
A Framework for Developing a Hybrid Investment Casting Process
Authors: Parlad Kumar  , Rupinder Singh  , IPS Ahuja
Published: September 2023

Traditionally, the process of investment casting is used for making complex components. But, investment casting is considered economical only when the production volume is high enough. If only limited numbers of pieces are promptly required such as in making prototypes, design iterations and design optimisations the investment casting process proves to be very costly due to time and tooling cost for making dies for producing wax patterns. In such situations, the rapid prototyping technologies are considered very useful as these can produce the patterns with good accuracy and without the necessity of costly hard tooling. The fused deposition modeling (FDM) is one of the rapid prototyping technology that can use plastic material, which can be effectively used for making patterns for investment casting. This combination of the traditional investment casting process with the modern rapid prototyping technologies to obtain a new process may be termed as hybrid investment casting. This study is intended to develop a framework for developing a hybrid investment casting process for industrial applications. For this newly developed process, various process parameters, their control and effects have been represented to obtain the desirable mechanical and metallurgical properties of the castings.
Experimental Investigations for Use of ABS Replicas in Investment Casting Applications
Authors: Singh Rupinder , Gupta Munish K.
Published: September 2023

In the present research work effort has been made to study the use of acrylonitrile butadiene styrene (ABS) replicas in investment casting (IC) applications. The study starts with selection of the component for industrial application with an idea of improvement in dimensional accuracy (Δd) of the component. The input parameters are part orientation in fused deposition modeling (FDM), number of layers, layer combination and type of materials in IC. The study highlights the percentage contribution of different input parameters on Δd for ABS replicas in IC.
Study on Porosity of Plasma Sprayed Carbon Nano Tube Reinforced Composite Coatings
Authors: Goyal Rakesh , Chawla Vikas , Sidhu Buta Singh
Published: September 2023

Oxidation of metals and alloys took place when they are heated to elevated temperatures in air or highly oxidising environments. Further, for elevated-temperature service the effect of incorporation of Carbon Nano Tubes (CNTs) into various alloy powder coatings on the morphology of the coating surface and corrosion properties has been a topic of technology concern. The present piece of work describes the effect of CNT inclusion in Al2O3 coatings deposited on various boiler steels. In many cases it is found that porosity is an important factor on the coating surface. Knowledge about the extent of these porosity imperfections is critical since they influence a wide range of spray coated properties and behaviors.The aim of this investigation is to find out the range of porosity of the coatings after CNT is added in the alloy powder.
Corrosion Studies of Thermal Sprayed HA and HA+Al2O3-TiO2 Coatings on 316L Stainless Steel
Authors: Walia Bhupesh , Singh Sarao T. P. , Grewal J. S.
Published: September 2023

This study was performed to evaluate corrosion behavior of thermal sprayed hydroxyapatite (HA) and hydroxyapatite+Alumina-titania (HA+Al2O3-TiO2) coatings on 316L stainless steel (316L SS) implant material. HA powder was mixed with Al2O3-TiO2 in 60:40 wt. % for depositing HA+Al2O3-TiO2 composite coatings. The coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) analyses. Tafel and Potentiodynamic techniques were used to access the in-vitro corrosion behavior of two coatings and un-coated 316L SS in Hank’s solution. The corrosion resistance of 316L SS showed a significant improvement after the deposition of coatings.
Evaluation of Structural and Mechanical Properties of TIG Welded Aluminium Alloy AA-5083 Subjected to Post Cryogenic Treatment
Authors: Sachin. L.S  , Mayur. S  , Pavan. K.M  , Chandrashekar. A  , B.S. Ajaykumar
Published: September 2023

Cryogenic treatment is a low temperature treatment process widely used in recent years to enhance the material properties without considerable sacrifice of other properties at the same time. Cryogenic engineering is a branch of material handling process which has significant commercial applications. AA-5083 is very commonly used in the manufacture of welded pressure vessels, marine, auto aircraft cryogenics, transportation equipment such as building of railroad cars, tip truck bodies, in missile components. In this study, TIG welded Aluminium alloy AA- 5083 plates were subjected to cryogenic treatment after welding and their structural and mechanical properties were evaluated. This is done in order to reveal the weld strength, hardness of welded joints by using weld current as varying parameter. After cryo processing these welded specimens were subjected to tensile test and optical microscopy (which reveals the microstructure and macrostructure of specimens). Microscopic analysis was done inorder to determine the homogeneity of the welding, the joint efficiency of welded plates and to analyze the changes in grain structure after cryogenic treatment in welded region and HAZ. Finally after observing the outcomes of the above mentioned tests higher ultimate tensile strength is obtained for higher welding current in comparison with rest of the currents. The coarse fine structure and entrapment of residual stress was improved. Hence cryogenic treatment was successful on TIG welded joints of aluminium alloy AA- 5083