bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of Platform E-commerce UGC Mode on the Consumption Willingness of "Generation Z"
Authors: Hu Yingwei
Published: September 2023

With the rapid development of the Internet, the interactive performance of the network has been further developed. Sharing makes the value of goods or services transferred and improved. The Internet community has developed based on this. Especially during the period of epidemic at home, the UGC mode of each major platform has been further developed, which will bring new challenges and opportunities to e-commerce platforms. The Internet community has developed based on this. Especially during the period of epidemic at home, the UGC mode of each major platform has been further developed, which will bring new challenges and opportunities to e-commerce platforms. Xiaohongshu provides a good example for other platforms. "Generation Z", as the main force of UGC's creation and future consumption, should be the focus of e-commerce platforms. This paper will use the methods of questionnaire survey, reliability and validity test, regression analysis, etc. to analyze the development history of Xiaohongshu. This paper will use the methods of questionnaire survey, reliability and validity test, regression analysis, etc. to analyze the development history of Xiaohongshu platform and e-commerce model. Combining the application of UGC model, consumer theory and basic e-commerce Combining the application of UGC model, consumer theory and basic e-commerce theory, this paper will explore the impact mechanism of UGC platform on the consumption behavior of "Generation Z" consumers.
Global Value Chains in the Digital Age: The Impact of Smart Manufacturing and the Internet of Things
Authors: Zhang Dan
Published: September 2023

The rapid development of the digital era is changing the global economic pattern and production mode, and the application of digital technology is profoundly affecting the operation of the global value chain. Smart manufacturing and the Internet of Things, as core technologies in the digital age, are having a profound impact on global value chains. By exploring the application and impact of smart manufacturing and the Internet of Things in global value chains in the digital age, this paper aims to gain a deeper understanding of the driving and transformative impact of these technologies on the global economy.
The Role of Technology Transfer and Intellectual Property Protection in Investment in China and Southeast Asia
Authors: Xu Jing
Published: September 2023

This article aims to explore the relationship and impact of technology transfer and intellectual property protection in Chinese investment within Southeast Asia. Against the backdrop of increasing globalization and cross-border collaboration, technology transfer has gained significant attention as a crucial means to promote innovation and international investment. However, the issue of intellectual property protection in the process of technology transfer has also raised widespread concerns. This study first provides an overview of the relevant theories and concepts related to technology transfer and intellectual property protection. Subsequently, it focuses on analyzing the challenges and opportunities faced by Chinese companies in their investments in Southeast Asia. Factors such as cultural differences, legal environments, and the uncertainty of intellectual property protection pose challenges to technology transfer. Nonetheless, technology transfer also presents opportunities for Chinese companies, including entry into new markets, accelerated innovation cycles, and enhanced competitiveness. In order to address challenges and leverage opportunities, companies need to formulate effective intellectual property protection strategies, underscore the importance of contracts and agreements, and strengthen international collaboration and cooperative innovation. Furthermore, the study points out in its future outlook that intelligent technology transfer and digital platforms will shape future developments. Exploration in emerging technological domains will bring forth new possibilities for technological collaboration. Governments play a pivotal role in this landscape, requiring strengthened establishment and enforcement of laws and regulations, promotion of talent development and exchange, and the advancement of sustainable development and social responsibility. Through the exploration of these issues, this research aims to provide valuable insights for the field of technology transfer and intellectual property protection, fostering the development of cross-border collaboration and innovation.
The Impact of China's Digital Agriculture on Carbon Emissions under the Dual Carbon Target
Authors: Liu Yinghui , Zhou Zejiong
Published: September 2023

This article measures carbon emissions and digital agriculture in 30 provinces and cities in China from 2011 to 2020, and empirically analyzes their influencing factors. The results indicate that the total carbon emissions and the overall level of digital agriculture development in China are showing an increasing trend; Under different quantiles, the impact of population size and digital agriculture development level on inter provincial carbon emissions decreases, the impact of industrial upgrading level first decreases and then increases, and the impact of economic development level and greening level increases; The population size will promote the rise of carbon emissions in the local area and suppress carbon emissions in neighboring areas, the level of economic development will promote the rise of carbon emissions in the local and neighboring areas, the level of digital agriculture development will suppress the rise of carbon emissions in the local area, and the level of industrial upgrading and greening will suppress the rise of carbon emissions in the local and neighboring areas. Therefore, it is recommended to promote China's accelerated progress towards carbon neutrality goals through rational allocation of energy elements, enhancement of ecosystem carbon absorption capacity, and vigorous development of digital agriculture.
Overcoming Fear of Abuse Through Socialization in Samra’s A Good Wife Escaping The Life I Never Chose
Authors: Mary R Priskilla , Priya N. S. Vishnu
Published: September 2023

Samra Zafar, a young and inspiring award-winning speaker in Canada, recounts her real-life experiences in her literary work, "A Good Wife: Escaping the Life I Never Chose." This poignant memoir chronicles Samra's journey through the hardships she faced in pursuing her education and her abusive marriage. From her teenage years, she endured turbulent experiences that instilled fear within her. However, she came to realize that her dreams were more significant than succumbing to her fears. By pursuing education and utilizing it as a tool for empowerment, she overcame these fears. Fear is deeply interconnected with human emotions and sentiments, as Friedrich Nietzsche once stated, "Fear is the mother of morality," and this quote resonates with Samra's experiences. Raised in a religiously rooted environment, Samra was influenced by moral and religious beliefs. By utilizing concepts from social psychology and theories of socialization, this paper aims to explore how Samra's experiences with social interactions, support systems, and self-perception contributed to her ability to overcome the fear of abuse and reclaim her autonomy. The analysis provides valuable insights into the transformative power of socialization in the context of overcoming fear and breaking free from abusive relationships.
Inclination of Teachers to Implement Outcome-Based Education in English Courses in Saudi Universities
Authors: Al-Saqqaf Marina Abdullah Bukeir
Published: September 2023

This study examines the inclination of English teachers in different Saudi universities to implement outcome-based education (OBE) in their English courses. OBE represents a nontraditional educational approach that depends on setting clear outcomes at both course and program levels. This approach emphasizes student competency through theoretical and practical demonstration of these outcomes with clear evidence of performance. OBE is a student-centric pedagogy that prioritizes students’ benefits. The present study employed a survey as a data collection method, and the data were subsequently analyzed using IBM SPSS. The survey included three main dimensions: learning, teaching, and measuring students’ performance (assessment), all of which are directly linked to the tenets of OBE. Participants in the survey were exclusively English language academic staff currently employed in different universities across Saudi Arabia. The study included participants from various Saudi institutions located in different regions to ensure broader representation and more comprehensive analysis. The findings of this investigation show that English teachers working in Saudi universities are inclined toward implementing OBE. Also, the findings demonstrate that biodemographic factors, such as gender and age, as well as other professional aspects such as job title, academic rank, or institutional affiliation, do not interfere with teachers’ inclination toward OBE implementation. In conclusion, the study demonstrates a positive attitude among English teachers toward OBE, emphasizing its viability and potential applicability in the Saudi higher education context.
Pengembangan Pop Up Qr Book sebagai Media Belajar Kosa Kata Bahasa Inggris Anak Usia 3-4 Tahun
Authors: Putri Yolanda Anggiana , Kurniawan Mozes
Published: September 2023

Bahasa Inggris adalah bahasa yang universal karena digunakan oleh sebagian besar negara di dunia sebagai bahasa utama. Selain itu, bahasa Inggris merupakan salah satu bahasa internasional yang penting untuk dikuasai atau dipelajari (Maduwu, 2016). Pengumpulan data merupakan Langkah awal dan sangat berperan penting dalam penelitian. Dengan mengumpulkan data peneliti menjadi tahu kebutuhan atau apa yang menjadi issue didalam masyarakat. Dalam penelitian ini Teknik pengumpulan data yang dilakukan adalah dengan observasi, wawancara, dan dokumentasi. Validator ahli media dan bahasa adalah Eunice Widyanti S., S.Pd., M.Pd. Instrumen penilaian yang diserahkan berjumlah 10 butir dengan skor ideal adalah 50. Hasil perolehan skor yang diberikan validator ahli berjumlah 43. Hasil skor kemudian dihitung menggunakan rating scale dengan rumus yang sudah tersedia diatas. Hasil presentasenya adalah 86% dengan kriteria kategori sangat baik. Berdasarkan pembahasan dan hasil penelitian dapat disimpulkan bahwa Pop Up Qr Book “Trip to GrandParents’ House” sangat baik digunakan sebagai media pembelajaran kosa kata Bahasa Inggris anak usia 3-4 Tahun.
Heat And Mass Transfer on MHD flow Past an Exponentially Accelerated Vertical Plate Through Porous Medium
Authors: Balu K
Published: September 2023

In this paper, we analyze the magnetic hydrodynamics of the fluid flow past an exponentially accelerated inclined vertical plate with mass distribution with varying temperature and heat source through a porous medium. Applying a larger number of possible non- dimensional necessary conditions with limitations and starting conditions is a mathematical workout. The plate temperature is extended on an inclined vertical plate alongside at time t, and the focus level is close to the plate. The dimensionless administering conditions in the current examination are tackled utilizing the inverse Laplace transform technique. The velocity outlines are graphically explained for different physical parameters: heat Grashof value, mass Grashof value, Schmidt value, and duration. It has been observed that the velocity increases with an increase in the thermal grashof number Gr and also with an expansion in the time t of the plate, but the velocity increments with an increase in the permeability of the porous medium while decreasing in the presence of magnetic parameters. The impacts of boundaries M, K, t, and Sc on the velocity profiles are demonstrated graphically Keywords: MHD, Porous medium; Exponentially, Accelerated, Vertical plate, Laplace transform.
ANALISA RANCANGAN ANGGARAN BIAYA DAN PENJADWALAN PADA PEMBANGUNAN DINDING PENAHAN TANAH
Authors: Junaidi Filipus Alfriyadi , Sari Sely Novita , Ardian Oggi Heical
Published: September 2023

Proyek pembangunan konstruksi di Indonesia saat ini masih meningkat salah satunya yaitu proyek pembangunan dinding penahan tanah di Jembatan Benyo. Penelitian ini bertujuan untuk menganalisa rancangan anggaran biaya dan penjadwalan proyek pembangunan dinding penahan tanah di Jembatan Benyo. Lokasi penelitian ini terletak di Kabupaten Bantul, DIY dan data yang digunakan yaitu data sekunder seperti gambar rencana, Standar Harga Bahan dan Jasa, dan Analisa Harga Satuan Pekerjaan. Hasil analisis data rancangan anggaran biaya pekerjaan dinding penahan di Jembatan Benyo dengan dimensi panjang 30 meter dan tinggi 4 meter membutuhkan biaya Rp. 248,307,765.00 dan untuk waktu pelaksanaan proyek dilaksanakan selama 72 hari.
Prevalence and bacteriology of tonsillitis among patients attending otorhinolaryngology Department at Muhimbili National Hospital, Dar es Salaam- Tanzania
Authors: Abraham Zephania Saitabau , Bazilio Jane , Kahinga Aveline Aloyce , Manyahi Joel , Ntunaguzi Daudi , Massawe Enica Richard
Published: September 2023

Background: Tonsillitis is a common infectious disease contributing to significant social-economic impact worldwide. Like other infectious diseases, the determination of the pathogenic agents is important in antibiotic selection for the medical treatment of tonsillitis. Data on bacteriology of tonsillitis in Tanzania is scarce. The aim of this study was thus to determine the prevalence and bacteriology of tonsillitis in one of the largest tertiary hospital in Tanzania.

Methods: Descriptive cross-sectional study was conducted involving 485 patients at Muhimbili National Hospital, from June to December 2016. Data was collected using specially designed questionnaires. Laboratory isolation of bacterial pathogens implicated in tonsillitis followed by consequent antimicrobial susceptibility testing was doneat the Country's largest laboratory. Gathered data was then analyzed using the SPSS program version 20.

Results: A total of 485 patients were recruited in the study, where majority were females (55.7%) and the mean age was found to be 27.7 years. Out of 485 patients 100(20.6%) had tonsillitis. Male preponderance was found (51%). The most affected age group was 1-10years (42.6%). Nearly 25% of patients had family history of tonsillitis with siblings being commonly affected. The isolated bacteria were Coagulase negative staphylococcus 41.7%, S. pyogenes 40%, Bacillus species 8.3%,K.pneumoniae 5.8%, E.Coli 2.5% and P.aeruginosa 1.7%. S.pyogeneswas susceptible to Ceftriaxone 95.7%; Azithromycin 93.6%; Doxycline 91.5%; Clindamycin 87.2%; Ampicillin 80.9%; Erythromycin 74.5%; Amoxiclav 59.6% and resistant to penicillin G(38.3%).

Conclusion: Tonsillitis was found to be prevalent in our setting with young individuals being most commonly affected. Male preponderance was found in this study and family history of tonsillitis was depicted in nearly 25% of patients.  Majority had recurrent tonsillitis and S. pyogenes was found to be the commonest isolated pathogenic bacterium and was susceptible to most of the drugs available in our setting though it was found to be resistant to penicillin G.
Challenges of Public Participation in Solid Waste Management at Nkanfoa Landfill Site in the Cape Coast Municipality of Ghana
Authors: Kofi Adanu Selase , Kwame Boakye Maxwell , Kwabena Agbosu Worlanyo , Francis Gbedemah Shine , Christopher Adu-Gyamfi , Richard Asare Kwadzo , Asabre Ampomah Charles
Published: September 2023

Public participation in waste management is considered a sustainable approach to waste management as such it should be embraced. In municipalities of developing countries like Ghana, public outcry over the wrong location of waste dumpsites and poor public interest in waste management has called for this study to understand how public participation contributes to efficiency in solid waste management. For those living close to waste dump sites, conditions including odour and smoke pollution are believed to be avoidable when the public participates in decision making on the location of waste dump sites. This study investigated challenges facing Nkanfoa community regarding their involvement in waste management decision making. A mixed method approach was used to gain an in-depth understanding of the challenges associated with public participation in solid waste management. The findings showed that the community members feel their concerns are not factored into the decision making process of the assembly as such a lack of trust between them and the municipal assembly. Also, there is the perception that political office holders interfere in public meetings and are not accountable to citizens hence the public apathy towards collective waste management decision making and their unwillingness to pay for waste services. The study concludes that for community participation in waste management to be effective, there should be online platforms for verification of the extent to which assemblies engage the public in collective decision making and this should be one criteria for allocating more common funds to district assemblies that perform well on this indicator.
Acercamiento a la Planeación Estratégica de una Clase
Authors: Pérez Nepta Jorge Enrique
Published: September 2023

En éste articulo se intenta realizar un acercamiento a la planeación estratégica de una clase real, tal como la implementó el autor, en la Especialización en Mantenimiento Industrial, ofrecida por el Instituto Técnico Central, tomando como pretexto, uno de los temas contemplados en la asignatura de Elementos de Máquinas, como es el tema de Rodamientos para Maquinaria.
Signature Verification System: Using Big Transfer (BiT-M-R50x1) for Accurate Authentication
Authors: Tanvir Kazi
Published: September 2023

In the realm of document security, signature verification stands as a vital pillar for establishing authenticity. This study delves into the utilization of the potent Big Transfer (BiT) BiT-M-R50x1 model for the intricate task of signature validation. This dataset encompasses 2149 signature images sourced from diverse individuals, exhibiting notable fluctuations in writing styles, pen pressures, and signature dimensions. By harnessing the prowess of the pre-trained BiT-M-R50x1 model, renowned for its domaingeneralization capability, we fine-tune it to excel in signature verification. The results of our approach unveil remarkable accomplishments on the dataset, yielding a validation accuracy of 98.60%. The meticulously calibrated BiT-M-R50x1 model adeptly distinguishes between authentic and counterfeit signatures, even when confronted with substantial variation. Through the mechanism of transfer learning, the model captures intrinsic attributes that extrapolate effectively to previously unseen signature specimens. Furthermore, we meticulously assess the model's performance concerning the dataset's distinctive signature idiosyncrasies, scrutinizing its adaptability to diverse styles and dimensions. This experiment underscores the potential of harnessing robust pre-trained models like BiT-M-R50x1 for signature verification undertakings, particularly when grappling with intricate and heterogeneous datasets.
Progress in Legal Methodology – A Methodological Assessment of Six PhD Theses
Authors: Taekema Sanne , van Klink Bart
Published: September 2023

Progress in Legal Methodology – A Methodological Assessment of Six PhD Theses. Special Issue Progress in Legal Scholarship, Marnix Snel, Sanne Taekema & Gijs van Dijck (eds.)

In this article, the question is raised to what extent the methodology debate in legal scholarship has improved the practice by PhD researchers of justifying their methodology. Over the past twenty years, there has been much more consideration and discussion of legal methods, especially in Dutch academia. Taking this Dutch debate as a starting point, Taekema and Van Klink argue that it has led to a normative framework with which the methodology of legal research can be assessed. Formulating a set of topics and questions that form the core of this framework, they apply it to a set of six fairly recent PhD dissertations. Building on these cases, they observe that some progress is made from a methodological point of view, compared with the situation described by Tijssen in his PhD thesis from 2006. Taekema and Van Klink conclude, however, that the methodology debate appears not to have led to a significantly better practice of methodological justification, at least not yet on all assessment criteria. The normative framework of a dissertation, for instance, still deserves attention.
Development of Labyrinth Media to Stimulate Prosocial Behavior Skills of 5-6 years old Children in Purwakarta
Authors: Alsafiah Cut Mutia , Tabroni Imam , Mark Elladdadi , Maharjan Kailie
Published: September 2023

This study aims to produce a valid labyrinth learning media to improve the ability of prosocial behavior in children aged 5-6 years.  This research is a development research with the development model used by Sugiyono.   In this study, researchers only used 7 (seven) stages, namely knowing problems and potential, data collection, product design, design validation, design revision, product trials and product manufacturing.  The next stage was not carried out due to cost and time constraints. The data collection technique used is a questionnaire, where the questionnaire is validated by material experts, media experts and educators. The type of data generated is quantitative and qualitative data. The average percentage result of the pretest conducted on 3 children is 10.6%, proving that the child's condition is still in the undeveloped stage. Then the posttest was carried out, namely the condition after the child was given the labyrinth media, the average percentage result of this posttest was 14.6% which proved that the child experienced a change in condition to develop as expected. So it can be concluded that the Labyrinth media to improve the ability of prosocial behavior of children aged 5-6 years has met the criteria for validity.
Fun Number Recognition Cards as a Learning Media to Count for 4-5 Years Old Children
Authors: Fitriani Ulfa , Tabroni Imam , Guilin Xie , Jiao Deng
Published: September 2023

Mathematics education is a very important education. Early childhood is a golden age, namely the age of 0-6 years in Indonesia and abroad, namely at the age of 0-8 years. According to Jean Piaget, this has been the main reference for the kindergarten curriculum and even education in general. The first step is to design a fun number learning media with the latest literature. The design is tested by experts and validated according to the needs of students. The result of the author's initial observation in the field is that Amira kindergarten students aged 4-5 years do not globally understand the lack of development in the cognitive aspect of knowing numbers and symbolic thinking for effective results. %. Based on the discussion above, it can be concluded that playing while learning using cards recognizes cool numbers in improving six aspects of development in children aged 4-5 years at Amira Plered Purwakarta Kindergarten.
Development of Traffic Maze Media to Stimulate Problem of 4-5 Years Old Children
Authors: Aliyah Nur , Tabroni Imam , Jixiong Cai , Wei Zhang
Published: September 2023

This study aims to produce a valid Traffic Maze learning media to improve the fine motor skills of children aged 4-5 years.  This research is a development research with the development model used by Sugiyono.   In this study, researchers only used 7 (seven) stages, namely knowing problems and potential, data collection, product design, design validation, design revision, product trials and product manufacturing.  The next stage was not carried out due to cost and time constraints. The data collection technique used is a questionnaire, where the questionnaire is validated by material experts, media experts and educators. The type of data generated is quantitative and qualitative data. The average percentage result of the pretest conducted on 3 children is 12.3%, proving that the child's condition is still in the stage of starting to develop. Then the posttest is carried out, namely the condition after the child is given the Traffic Maze media, the average percentage result of this posttest is 31% which proves that the child has changed the condition to develop as expected. So it can be concluded that Traffic Maze media to improve the problem solving ability of children aged 4-5 years has met the criteria for validity.
Number Board Media to Stimulate the Symbolic Thinking Ability of Children Aged 5-6 Years
Authors: Saripah Ipah , Tabroni Imam , Wang Yuanyuan , Zou Guijiao
Published: September 2023

Children will experience a golden period that is very important and should not be missed until they are 3 years old. Because during these times, children's cognitive abilities are still growing and developing rapidly. In fact, about 80% of children's cognitive skills are optimized in the first 3 years of life, and up to 90% of their abilities will continue to develop until they reach the age of 5. Media is a tool that can be used as an intermediary in stimulating all aspects of development in early childhood both aspects of moral and religious values, physical motor aspects, language aspects, social emotional aspects and cognitive aspects. To stimulate all aspects of early childhood development cannot be separated from learning media because for early childhood learning is done through play using learning media both real media, audio media, visual media, environmental media and audio-visual media, so that learning activities in early childhood run effectively. This article will discuss how the influence of number board media in stimulating the symbolic thinking ability of children aged 5-6 years in Sumurugul Village.
Manipulative Learning Media as an Effort to Improve Understanding of Tajweed Learning
Authors: Sa’adah Nur , Tabroni Imam , Wang Yuanyuan , Zou Guijiao
Published: September 2023

This class action research aims to improve students' understanding of tajweed learning through the application of manaipulative media in class IV MDTA Al-Mubarokah. The data needed in this study using Cycle I and II techniques. The results showed that the level of understanding of students towards learning tajweed through the application of manipulative media had reached 80% in cycle I and 90% in Cycle II.  With the application of manipulative learning media, of course, to make it easier for students to be able to think in understanding the concept of tajweed learning conveyed by the teacher.  Thus, teachers must be creative and innovative in learning, how teachers can create interesting and fun learning methods and media to motivate students to learn tajweed.
Representações sociais e condições de saúde em pessoas com deficiência física
Authors: Gurgel Henrique Samuel Oliveira , De Matos Tallys Newton Fernandes , Da Silva Maria Rocineide Ferreira
Published: September 2023

O objetivo geral foi investigar as representações sociais e condições de saúde em pessoas com deficiência física. O Presente estudo é qualitativo cujo método é a revisão integrativa, através de 6 etapas: (1ª) Elaboração da pergunta norteadora; (2ª) Busca ou amostragem na literatura; (3ª) Coleta de dados; (4ª) Análise crítica dos estudos incluídos; (5ª) Discussão dos resultados; E, por fim, (6ª) Apresentação da revisão integrativa. Os resultados apontaram 6 estudos selecionados em quatro base de dados. Os estudos selecionados proporcionaram a compreensão de que as representações sociais e condições de saúde para com as pessoas com deficiência física envolvia: limitação de vida, problemas de interação social, problemas de saúde, problemas de atividades práticas diárias, preconceito, buscar novas alternativas de vida, incapacidade, dependência, dificuldade de superação, dificuldade de adaptação e as unidades básicas de saúde não apresentam acessibilidade para as Pessoas com Deficiência Física. Por fim, é importante a elaboração de políticas públicas para reverter este cenário em prol da inclusão em inserção.
Guía metodológica para mejorar el desarrollo del lenguaje en los niños del subnivel 2 de inicial.
Authors: Farfán-Polanco Trissia Yurisan , Meza-Intriago Hipatia Alexandra
Published: September 2023

El desarrollo del lenguaje en los niños es determinado como un proceso complejo que se inicia en el nacimiento y abarca principalmente durante los 6 primeros años de vida, el mismo que se vincula de forma directa al entorno que lo rodea y a su familia. El objetivo de este estudio es diseñar una guía metodológica para mejorar el desarrollo del lenguaje en los niños del subnivel 2 de inicial de la Escuela Simón Bolívar de la ciudad de Guayaquil. Siendo una investigación descriptiva, con enfoque cualitativo de tipo no experimental. La muestra estuvo conformada por 5 docentes de educación inicial y 31 estudiantes de la institución, como instrumento se aplicó la encuesta, la misma que fue efectuada a los docentes en Google form y a los estudiantes se les realizó una ficha de observación. Donde los resultados evidenciaron que es necesario el diseño de una guía metodológica que ayude a los docentes en la actualización de conocimientos sobre el uso de estrategias y actividades que mejoren el desarrollo del lenguaje en los niños del subnivel de inicial 2.
Ciencia, tecnología e innovación en salud para pos-COVID-19
Authors: Patiño Pablo J.
Published: September 2023

Las presiones sociales, económicas y sobre el sistema de salud que ha producido la pandemia de la COVID-19 desencadenaron situaciones de diversa índole que pusieron en evidencia las capacidades y limitaciones de los sistemas de CTI y de salud en todo el mundo. La mayor parte de los países tuvieron una respuesta errática que se concentró en la aplicación de medidas de aislamiento, distanciamiento social y uso de dispositivos de protección individual y solo fue hasta la aparición de las vacunas y su aplicación masiva que se cambiaron de forma radical las condiciones. El principal aprendizaje puede ser que para responder a los efectos globales de una enfermedad infecciosa se requiere conocimiento científico y desarrollo experimental que permitan crear e implementar iniciativas que ofrezcan las mejores alternativas para abordar los desafíos que se producirán como consecuencia de epidemias futuras. Colombia tiene la oportunidad de consolidar un sistema de CTI en salud que, además de ayudar a resolver muchas de las dificultades que se evidenciaron en el contexto de la COVID-19, podría robustecer el aparato científico para generar procesos de innovación que preparen a la sociedad para situaciones que afecten la salud de manera significativa.
3DEC Simulations of Dynamic Direct Shear Tests Considering Joint Roughness Coefficient (JRC)
Authors: Kim B. H. , Larson M. K.
Published: September 2023

In general, the dynamic properties, e.g., dynamic rock modulus and dynamic rock (shear or tensile) strength are two to three times greater than static moduli and strengths. Thus, understanding the dynamic rock characteristics is necessary to improve the design of support systems in underground mines, nearly all of which are subject to dynamic loading. In this paper, we report the baseline results of an ongoing study. Experimental direct shear tests were conducted on jointed specimens that were created by 3D printer to represent 3D joint roughness coefficients (JRCs) of 12 and 17. These JRC values are relatively close, but they represent the roughness of a large proportion of joints found in underground mines. We also report the results of numerical direct shear tests using 3DEC modeling code that were conducted for the purpose of learning more about dynamic shear failure mechanisms. We performed static direct shear tests for the purpose of calibrating our models with the empirical solution. Results of these tests compared well with the empirical results. Subsequent dynamic numerical direct shear tests were performed using 3DEC, simulating the dynamic direct shear tests performed in the laboratory. The numerical direct shear stresses compared well with those of the laboratory tests. Furthermore, the results confirm that the ratio of dynamic to static shear strengths vary between approximately 2 and 3 in the range of normal stresses used in the tests.

INTRODUCTION

Dynamic failure in coal mines, known as "bursts" or "bumps," is one of the most challenging and persistent engineering problems associated with coal mining in highly stressed conditions. These events occur when stresses in a coal pillar, used for support in underground workings, exceed the critical strength of the pillar, causing the pillar to rupture without warning. These events can be exceptionally violent, ejecting coal and rock with explosive force [1, 2].

These events occur suddenly and often without warning. As such, miners often do not have the opportunity to move to safety before an event. Although relatively rare, dynamic failure events resulted in worker injury up to and including fatality in 52% of the reported cases occurring from 2000–2019. Moreover, the fatality rate is roughly ten times greater than that associated with roof falls, a leading cause of ground-control-related injuries in underground coal mines [3]. The risk associated with faults/fault zones and coal bumps has been acknowledged by several researchers in the literature. Mauck [4] and Peperakis [5] mention the risk of bumps with regard to the proximity of mining operations to faults. Some describe the role of faults in stress concentration [5-9], thus causing conditions with increased bursts/bumps risk. Others specifically mention fault slip and the resulting release of energy associated with bursts/bumps [5, 7-10].
Experimental and Numerical Investigation on Rock Breakage Mechanisms of a Conical Diamond Element
Authors: Xiong Chao , Li Xinlong , Huang Zhongwei , Shi Huaizhong , He Wenhao , Chen Zhenliang
Published: September 2023

The conical diamond element (CDE) is an innovative conical-shaped 3D cutter, which exhibits high rock-breaking efficiency in hard formation. But there are few researches on the rock breakage mechanism of CDE cutters. In this paper, a series of single cutter tests were conducted on granite. The rock breakage process, the initiation and propagation of micro-cracks, the surface topography and fracture morphology of the cutting groove and large-size debris were analyzed. A three-dimensional rock cutting model with a CDE cutter was established using the finite element method to study the stress distribution and rock damage evolution during the cutting process. The results show that the cutting process can be divided into two parts: crushing and chipping. There is a spherical stress concentration area formed at the tip of the CDE cutter. The rock breakage mechanism of the CDE cutter can be summarized as follows: the rock at the CDE cutter tip occurs shear-compression failure; the rock in front of the CDE is broken under the tensile action; tensile micro-cracks propagating to the rock inside can deteriorate rock strength. The key findings of this work will help to reveal the rock breakage mechanisms and provide guidelines for CDE bits design.

INTRODUCTION

Polycrystalline Diamond Compact (PDC) drill bits have been widely used for drilling wells in the exploitation of hydrocarbon and geothermal resources (Bellin et al. 2010) due to the high rock-breaking efficiency and long duration life. However, for deep and ultra-deep drilling, the conventional PDC cutter is facing the challenges of serious impact and wear damage (Brett et al. 2012). In order to improve the drilling performance of PDC drill bits in hard formation, Durrand et al. (2010) invented Conical Diamond Element (CDE), which has nearly twice as thick as polycrystalline diamond layer than the conventional PDC cutter, so the wear resistance and impact resistance is improved approximately 25% and 100% respectively (Azar et al. 2013). Since CDE was invented, the hybrid PDC drill bit, on which the CDE is strategically positioned at the bit center or behind the primary conventional PDC cutter, has drilled more than 26 million feet in hard and interbed formation. Based on the records, the hybrid PDC bits increased footage up to 77% with corresponding Rate of Penetration (ROP) increases up to 29% in the Permian Basin (Radhakrishnan et al. 2016).
Quantitative Analysis of the Effect of CO2 Adsorption on the Permeable Characteristics of Coal Under True Triaxial Stress Conditions
Authors: Liu Zhiyuan , Zhao Haifeng , Sun Yanqi , Xiao Lu
Published: September 2023

As a heterogeneous porous medium, the anisotropy of the coal body increases the difficulty of retesting and studying the mechanism of internal gas migration. Therefore, in this paper, we analyzed the mechanism of carbon dioxide adsorption properties in the evolution of coal body deformation and permeability. The results of this study are as follows: (1) The adsorption pressure of the coal body was divided into slow increase zone, stable increase zone, and rapid increase zone. (2) With the increasing pressure of the gas, there are two distinct turning points in the changing trend of coal permeability, which is divided into the slow increase zone and the rapid increase zone. (3) the effect of gas adsorption on the permeability of coal consisted of sensitive and insensitive areas. When the gas pressure was less than 1MPa, the impact of gas adsorption on the coal sample permeability was insignificant, while the effect was significant when the gas pressure was in the range of 1-2 MPa.

INTRODUCTION

Carbon dioxide (CO2) and methane (CH4) are the main components of greenhouse gases, which are mainly derived from the burning of non-coal fuels and exhaust from coal mines, respectively. The rapid increases in these two types of gases will trigger global warming issues. Implementation of CO2 capture and sequestration technology (CO2 capture and sequestration, CCS) can reduce CO2 emissions from the energy industry by 20% (Haszeldine, 2010; Oschatz & Antonietti, 2017). CO2 can be sealed in depleted oil and gas layers, and uneconomical coal seams(Konstantinovskaya et al., 2014; Rutqvist et al., 2008; Yamamoto et al., 2013). In particular, when sealed in coal seams, CBM can be replaced. Therefore, the intensive extraction of coal seam gas (CH4) and the realization of CO2 sequestration technology (CO2 sequestration in coals with enhanced coal-bed methane recovery, CO2-ECBM) have attracted extensive research attention from researchers in China and abroad (Li et al., 2011; P. Liu et al., 2019; Onoja et al., 2019; Raziperchikolaee & Mishra, 2019; Vilarrasa et al., 2010)
A New CFD Numerical Simulation Method for Mud-Positive Pulse Signal Generation and Propagation
Authors: Han Hu , Xue Liang , Fan Honghai
Published: September 2023

Based on the theory of computational fluid dynamics (CFD), an integrated numerical model of the positive pulse generator with the upstream and downstream pipeline was established. Compared with the previous numerical simulation, this model can simulate the generation and transmission process of positive pulse signals efficiently and accurately for the first time. Based on the mechanical structure of the common positive pulse generator, the simplified two-dimensional axisymmetric geometric model of the flow region was established considering its flow symmetry characteristics. Combined with dynamic mesh and sliding mesh technology, the reciprocating motion of the valve is simulated, and a custom function controls the motion to generate low-frequency pulse signals. Comparing the new CFD model with the previous numerical model, it is found that with the periodic change of flow area, compression wave, and expansion wave are generated simultaneously in the upstream and downstream of the positive pulse, with the same frequency and opposite phase, which satisfies the transient hydrodynamics theory. Meanwhile, as the pressure wave propagates, the irregular pulse waveform becomes sinusoidal, and its amplitude decreases gradually. This paper presents a new CFD numerical model and simulation scheme, which can provide an efficient and accurate method for designing and simulating a mud pulse telemetry system.

INTRODUCTION

With the development of the global oil and gas exploration and development objects in the direction of "ultra-deep formation, unconventional formation, old development formation," the scale of horizontal wells has increased significantly, and there are many complex underground conditions (Antunes et al., 2015; Mwachaka et al., 2018). We need to integrate logging and measuring while drilling (LWD and MWD), downhole control, and big data analysis in real-time to solve the problems encountered during drilling and completion. As a wireless data transmission mode, mud pulse telemetry (MPT) has a long transmission distance, good economy, and wide application range (Jia et al., 2018; Chin et al., 2014). Among them, a positive pulse is developed earliest, with stable transmission and strong anti-interference ability.
Drawing the Frame of the Shale Barrier Window
Authors: Fjær E. , Larsen I. , Raaen A. M.
Published: September 2023

Well completion usually implies that long sections of the hole are left with an open annulus between rock and casing. In soft shale formations, the in-situ stresses may be sufficiently large to squeeze the rock up against the casing and seal off the annulus, thus forming a so-called shale barrier. While the shale pressure against the casing enables the shale barrier, it may also result in casing failure if the pressure is too high or uneven. A functional shale barrier may therefore exist within a window, framed by non-barrier on one side and casing failure on the other. This paper describes the principles of a semi-analytical model designed to draw the frame of the shale barrier window. Through a set of examples, the model is used to illustrate qualitatively how the shale barrier window is affected by various parameters such as well path, rock strength and stiffness, in-situ pore pressure and stress anisotropy, and casing quality. It is also shown how the shale barrier window may evolve with time.

INTRODUCTION

In numerous wells penetrating shale formations, it has been observed that the shale may creep in and close the initially open annulus between rock and casing, thus forming a sealing shale barrier (Williams et al., 2009; Kristiansen et al., 2018). This reduces the risk of leakage along the well and may represent huge cost savings for the operator during P&A operations. A shale barrier may form if the in-situ stresses, which are pushing the shale towards the casing, are able to overcome the fluid pressure in the annulus, which is pushing the shale away from the casing, and the stress arch formed by the hoop stress within the shale around the hole. The strength of this stress arch depends on the shear stiffness and shear strength of the shale.

In stronger shales, the stress arch is able to resist the in-situ stresses, thus preventing the forming of a shale barrier. In very soft, weak shales on the other hand, the stress arch provides very little resistance against the in-situ stresses, thus leaving the heavy burden on the casing. This may result in casing failure unless the casing has the proper strength and dimensions.
A Synthetical Fracability Evaluation Method for Continental Shale Oil Reservoir
Authors: Xiaobing Bian , Qiuping Qin , Xudong Zhang , Yuan Gao , Liang Fu
Published: September 2023

In China, jurassic continental shale oil resources are rich in Sichuan Basin. Jurassic continental shale oil resources has high clay mineral content, multiple limestone interbeds and variable longitudinal stress, which is barely considered in existing evaluation method. A synthetical fracability evaluation method was established considering six geological characteristic parameters including clay content, quartz content, interlayer thickness proportion, gas content, natural fracture, pressure coefficient, and five engineering characteristic parameters including Poisson's ratio, Young's modulus, brittleness index, horizontal principal stress difference coefficient, interlayer and layer average stress difference. The grey system theory method was selected to calcualte the weight of each parameter considering the correlation degree between multiple parameters and production capacity. Case study demonstrats that the synthetical fracability index has a good positive correlation with the test oil and gas equivalent in the target region, providing guidance for the evaluation of jurassic continental shale oil reservoir.

JURASSIC CONTINENTAL SHALE OIL CHARACTERISTIC

In China, jurassic continental shale oil resources are rich in Sichuan Basin, which is a high clay shale with inorganic pores and extremely low porosity and permeability. The longitudinal lithology of jurassic reservoir varies greatly, the layer heterogeneity is strong and the fluid property is complex. The crude oil is rich in light components and is a high pressure near-saturated condensate gas reservoir (Jia et al, 2012; Zou et al, 2015; Li et al, 2022; Cai et al, 2022).

Compared with marine shales, jurassic continental shales have higher clay content ranging from 48% to 61% and strong plasticity, with mechanical brittleness index 0.383. The shale is also rich in limestone interlayers and dense laminated structure less than 3cm. Based on the mechanical study of the shale, shell limestone has the characteristics of high stress, i.e., 3.8∼4.5 MPa higher than shale, high compressive resistance from 191∼358 MPa, high elastic modulus 44.88∼55.99 GPa, leading to difficult initiation and extension. As the jurassic continental shale is generally characterized by multiple interbeds in layers and variable longitudinal stress (Fig. 1), the results of physical simulation experiments show that longitudinal penetration for fractures to propagate through limestone interlayers is more difficult (Fig. 2).