bluuebunny/crossref_metadata_2025 huggingface dataset:
Accelerated gradient-based algorithm combined with progressive Big-Bang to optimize the layout in offshore wind farms
Authors: Gonzalez-Rodriguez Angel Gaspar , Roldan-Fernandez Juan Manuel , Muñoz Díez José Vicente
Published: September 2023

A new layout optimization method for offshore wind farms is proposed to minimize power deficits due to wake effect. The main engine of the algorithm is a gradient-descent method, in which an analogy is established between power deficit and repulsive electrostatic potential energy. To achieve a maximum dispersion in the initial solution, throughout the optimization process, new turbines are included in the centre of the concession area, and quickly expand outward looking for areas with less potential, in turn pushing the previous ones. When the optimization process ends, to avoid local maximums, it enters into a process of suppression of the set of locations that cause the greatest potential (power deficit). Then, a potential map of the entire area is created and a greedy algorithm includes new turbines to complete the layout with the final number of turbines. To speed up the search process and the creation of the potential map, two simplifications have been validated and added: the spatial distribution of velocities has been converted into its equivalent with point symmetry; and, for turbines affected by multiple wakes, the power deficit has been calculated by using a linear aggregation of powers, instead of the usual linear (or quadratic) aggregation of speeds. Owing to this type of aggregation, the process is accelerated in a factor of 90.
Advances in Additive Manufacturing for Polymer Textiles: From 3D to Innovative 4D Printing. A Review
Authors: Franco Urquiza Edgar A
Published: September 2023

Three-dimensional (3D) and four-dimensional (4D) printing emerged as the next generation of manufacturing techniques, spanning several research areas such as engineering, chemistry, biology, computing, and materials science. Three-dimensional printing allows the manufacture of complex shapes with high precision, by adding layer by layer of different materials. The use of smart materials that change shape or color, produce an electrical current, become bioactive, or perform an intended function in response to an external stimulus. Shape memory materials (SMMs) in 3D printing technology have attracted a lot of attention due to their ability to respond to external stimuli, leading this technology towards an emerging area of research, "4D printing technology." The core part of this review summarizes the effect of the main external stimuli on 4D textile materials followed by the main applications 4D printed textiles can change their shape over time due to external stimuli such as temperature.
Changes in Magnitude and Shifts in Timing of Australian Flood Peaks
Authors: Bari Mohammed Abdul , Amirthanathan Gnanathikkam , Woldemeskel Fitsum , Feikema Paul
Published: September 2023

We analysed changes in magnitude and timing of the largest annual observed daily flow (Amax), in each water year, for 596 stations in high-value water resources catchments and flood risk locations across Australia. These stations are either included in the Bureau of Meteorology's Hydrologic Reference Stations, or used in its operational flood forecasting services. Monotonic trend (which are either consistently increasing or decreasing) analyses of the magnitude and timing of flood peaks (estimated using Amax) were performed using Theil-Sen and Mann-Kendell approach and circular statistics to identify strength of seasonality and timing. Regional significance at the drainage division scale was analysed using the Walker test. Monotonic decreasing trends in Amax flood magnitude were detected in the Murray-Darling River basin and in other drainage divisions in Victoria, south-west and mid-west of Western Australia and South Australia. No significant obvious pattern in Amax magnitude was detected in northern Queensland, coastal NSW, central Australia and Tasmania. Only the Tanami-Timor Sea Coast drainage division in northern Australia showed monotonic increasing trends. Monotonic trends in Amax magnitude were regionally significant at the drainage division scale. We found two distinct patterns in flood seasonality and timing. In the northern and southern parts of Australia, flood peaks generally occur during February to March and August to October, respectively. The strength of this seasonality varies across the country. Weaker seasonality was detected for locations in the Murray-Daring River basin, and stronger seasonality was evident in northern Australia, south-west of Western Australia, South Australia, Victoria and Tasmania. The trends of seasonality and timing reveal that in general, flood peaks are occurring later in the water year in recent years. In northern Australia, flood peaks are generally occurring earlier – at a rate of 12 days/decade. In Victoria, New South Wales and Tasmania, trends in timing are generally mixed. However, in the south-west of Western Australia, the largest change in timing was evident – with Amax peaks commencing later at a rate of 15 days/decade. Decadal variability in flood timing was found at the drainage division scale as well. Most stations show a decreasing trend in Amax magnitude, but how that trend is associated with the change in timing is not clear.
A Comprehensive Approach to LNOI Electro-Optic Modulator Design and Performances Optimizing
Authors: Ke Xin , He Yuntao , Wang Hong
Published: September 2023

Thin-film lithium niobate has gained significant attention in photonics due to its broad optical transparency, high refractive index, nonlinear coefficient, and substantial electro-optic coefficient. It holds great promise for developing electro-optic modulators with low loss, a compact size, and wide bandwidth. This study focuses on a meticulous investigation utilizing microwave photonics to establish a high-performance electro-optic modulator. Specifically, we analyze the optical mode field distribution and traveling wave electrode structure of lithium niobate thin-film materials. The proposed modulator achieves an impressive half-wave voltage-length product of 1.69 V·cm, a negligible metal loss of 0.01 dB/cm, and a substantial 3dB electro-optic bandwidth of 50 GHz. This research successfully realizes low-loss, high-efficiency LNOI electro-optical modulators, providing a strong foundation for large-scale integrated optoelectronic systems.
Encephalomalacia in a Young Adult: A Rare Presentation
Authors: Harjpal Pallavi , Qureshi Irshad
Published: September 2023

Radiologists refer to any area of cerebral parenchymal loss with or without surrounding gliosis as encephalomalacia. This archaic phrase, which literally translates to "softening of the brain" due to liquefactive necrosis, was coined by pathologists to describe the macroscopic appearance of the brain following a variety of traumas, such as cerebral infarction. The final outcome of brain parenchymal liquefactive necrosis after insult, which typically happens after cerebral ischemia, cerebral infection, hemorrhage, traumatic brain damage, surgery, or other insults. Gliosis, or the growth of glial cells in reaction to injury, is frequently seen around it. The location, size, and number of the lesions as well as the existence of other issues like seizures, hydrocephalus, or infection affect the symptoms and prognosis of encephalomalacia. While some people might not have any symptoms, others might have neurological abnormalities such hemiparesis, aphasia, cognitive decline, or behavioral changes. Depending on the underlying reason and the severity of the problem, treatment options may include medication, surgery, or rehabilitation. This is a case of a young male who reported for rehabilitation his left upper limb weakness, upon investigations Encephalomalacia was diagnosed.
Recent Advances in Psychotherapeutic Treatment and Understanding of Alexithymia in Patients with Obesity and Diabetes Mellitus Type 2
Authors: Mustač Filip , Galijašević Tin , Podolski Eva , Belančić Andrej , Matovinović Martina , Marčinko Darko
Published: September 2023

Alexithymia as the inability to describe one's own feelings, is being increasingly researched. According to contemporary psychodynamic theories, negative emotions cannot be adequately named and externalized, but remain trapped in the body. Recent research shows the connection of alexithymia with numerous somatic diseases. Diabetes mellitus type 2 and obesity represent a great challenge in treatment, and the psychological profiles in these diseases are being studied more and more often. Therefore, alexithymia enters the focus of some research as one that could play a significant role namely in these diseases as the factor that makes a difference. The aim of this paper is a review of the literature with the purpose of understanding the current knowledge about the interconnection between alexithymia, obesity and type 2 diabetes mellitus.
A New Model of Gravity at Large Distances
Authors: Kumar Naman
Published: September 2023

In this letter, we construct an effective field theory of gravity at large distances. We obtain to the leading order for large distances: a cosmological constant term and a logarithmic term in addition to the usual General Relativistic terms. The novel logarithmic term has important implications in explaining phenomena such as flat galactic rotation curves and stronger gravitational lensing than predicted that are generally attributed to the presence of dark matter.
The Emotional Landscape of Pregnancy and Post-Partum during COVID-19 Pandemic in Italy. A Mixed-Method Analysis Using Artificial Intelligence
Authors: Ravaldi Claudia , Mosconi Laura , Bonaiuti Roberto , Vannacci Alfredo
Published: September 2023

The COVID-19 pandemic affected the perinatal emotional landscape in Italy, a country with high mortality and strict lockdown. This study explored the emotions and challenges of pregnant and post-partum women during the pandemic, using AI-based mixed-methods. The study analyzed 1774 women from the national survey COVID-ASSESS: 1136 pregnant and 638 post-partum. The survey had qualitative questions on emotions and feelings related to birth, communication with healthcare professionals, media, and peers and family. We used natural language processing and machine learning to classify emotions, identify themes, and extract citations from the data. Fear and anxiety replaced joy as dominant emotions during the pandemic: trust and joy decreased by 49.3% and 36.4%, respectively, while sadness and fear increased by 52.3% and 49.3%, respectively. The pandemic also induced loneliness, isolation, frustration, and anger. Women faced challenges related to birth, communication with HCPs, media, and peers and family. They also used coping strategies such as self-care, news limitation, and tried to cultivate gratitude and hope. The study provides a comprehensive exploration of the perinatal emotional landscape of Italian women during the pandemic. The findings underscore the significant psychological impact of the pandemic, and also highlights women’s resilience and coping strategies.
Medical Rehabilitation of Patients with Post-Covid-19 Syn-drome – a Comparison of Aerobic Interval and Continuous Training
Authors: Mooren Johanna Maria , Garbsch René , Schäfer Hendrik , Kotewitsch Mona , Waranski Melina , Teschler Marc , Schmitz Boris , Mooren Frank Christoph
Published: September 2023

Introduction: Post-COVID-19 syndrome (PCS) is a multisystemic disorder marked by impaired physical performance as one lead symptom. Since it has been suggested that endurance training as part of medical rehabilitation may be effective to improve physical performance capacity in PCS, this study aimed to compare different modes of aerobic endurance training.
Methods: Hundred-ten PCS patients (49.3±11.8 years, 38% women, time after infection=260.2±127.5 days) underwent detailed clinical screening including symptom-limited cardiopulmonary exercise testing at admission and after 4-6 weeks of inpatient medical rehabilitation. Questionnaires were used to assess disease perception. Patients performed controlled isocaloric cycle ergometer training (3-5 sessions/week, 18 min) as either continuous training (CT) at 50% of maximal workload or as interval training (IT, load=60%, relief=30%). Outcomes of PCS patients were compared to coronary artery disease patients (CAD, n=96) to evaluate overall training effectiveness.
Results: Training participation was comparable between both groups with no indication of training-specific exercise-induced fatigue. Overall, PCS patients improved significantly by a mean of 6.8±12.1% for W at VT1, 3.1±10.0% for VO2 at VT1, 5.5±14.7% for O2-pulse at VT1, 7.5±15.0% for W at VO2peak, 2.7±11.0% for VO2peak and 4.6±12.4% for O2-pulse at VO2peak (all p<0.05) with no significant differences between groups (p>0.05). Both groups showed reduced levels of fatigue, anxiety and depression as well as improved quality of life and wellbeing (all p<0.05). Compared to guideline-based cardiac rehabilitation, PCS patients showed a similar improvement in workload and oxygen uptake compared to CAD patients.
Conclusion: PCS patients benefit from aerobic endurance training, performed as moderate continuous or interval training as part of a medical rehabilitation program in terms of improved physical exercise capacity and disease perception. Results for PCS patients are comparable to guideline-based rehabilitation of CAD patients.
Clinical Trial: NCT06016192
Silica-Based Stationary Phase with Surface Bound N-Acetyl-Glucosamine for Hydrophilic Interaction Liquid Chromatography
Authors: Rajendiran Vaithilingam , El Rassi Ziad
Published: September 2023

A hydrophilic silica-based stationary phase with surface bound N-acetylglucosamine (GlcNAc-silica) was prepared in house and characterized physically via Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA) and chromatographically over a wide range of mobile phase compositions. While both FTIR and TGA confirmed the attachment of the GlcNAc ligands to the silica surface, the chromatographic evaluation of the GlcNAc-silica with polar and slightly polar standard solutes (e.g., sugars, nucleic acid fragments, phenolic and benzoic acid derivatives) yielded the typical hydrophilic interaction liquid chromatography (HILIC) behaviors in the sense that retention increased with increased solute’s polarity and the organic content (i.e., acetonitrile) of the hydro-organic mobile phase (i.e., ACN-rich mobile phase). Sugars derivatized with 1-naphthylamine (1-NA) and 2-aminoanthrcene (2-AA) such as xylose, glucose and short chains maltooligosaccharides constituted the most polar species for HILIC retention evaluation, and in addition the maltooligosaccharides offered a polar homologous series for gauging the hydrophilicity of the GlcNAc-silica in analogy with alkylbenzene homologous series and other nonpolar homologous for evaluating the hydrophobicity of non-polar stationary phases. On the other hand, the benzoic acid and phenolic acid derivatives were the probe solutes for evaluating the HILIC retention dependence of ionizable solutes on the pH of the mobile phase. Similarly, the nucleobase and nucleoside weak basic solutes as well as some typical cyclic nucleotide acidic solutes allowed the examination of the dependence of solute retention on the pH of the mobile as well as the polarity of the species.
The Extraction of Roof Feature Lines of Traditional Chinese Village Buildings Based on UAV Dense Matching Point Cloud
Authors: Fu Xiangxiang , Deng Yunyuan , Yan JinBiao , Zhou Jialu , Zhou Wenlong , Liu Peilin
Published: September 2023

The extraction of roof feature lines is an important foundation for realizing large-scale and batch 3D modeling. However, the current traditional point cloud segmentation algorithms do not have satisfactory results in extracting roof feature lines of Chinese traditional residential buildings. In this paper, taking Jingping Village in Western Hunan as an example, we propose a method that combines multiple algorithms based on slope segmentation of roof patches to extract feature lines. Firstly, VDVI and CSF algorithms are used to extract the building and roof point cloud based on the MVS point cloud. Secondly, according to roof features, village buildings are classified, and 3D roof point cloud is projected into 2D regular grid data. Finally, the roof slope is segmented via slope direction, and internal and external feature lines are obtained after refinement through Canny edge detection and Hough straight line detection. Results reveal that this method effectively extracts feature lines of low-building roofs in traditional villages, with slope-based roof surface segmentation accuracy surpassing 99.6%. This method significantly outperforms the RANSAC algorithm and region segmentation algorithm.
Approaches to Obtaining Water-Insoluble Fibrous Matrices from Regenerated Fibroin
Authors: Kildeeva Natalya Rustemovna , Sazhnev Nikita Aleksandrovich , Drozdova Maria , Zakharova Vasilina Aleksandrovna , Svidchenko Eugenia , Surin Nikolay , Markvicheva Elena
Published: September 2023

Silk fibroin (SF) extracted from Bombyx mori cocoons is a biocompatible and biodegradable polymer shows potential as matrices for tissue engineering and regenerative medicine, or con-trolled drug delivery systems. Regenerated fibroin, obtained by removing sericin from natural silk, is water-soluble. Its aqueous solutions can be processed into a variety of materials, for example, fibrous matrices, using the electrospinning method.
In this article, the concentration dependences of the properties of aqueous solutions of regener-ated fibroin, that determine the possibility of obtaining electrospun mats for tissue-engineering applications, are studied. A slowdown in the growth of viscosity after a concentration of fibroin of 30% and a decrease in the transparency of the solution were found; this may be due to the on-set of conformational rearrangements: the transition of fibroin from the random coils, charac-teristic for dilute solutions, to the anisotropic conformation of the helix and the appearance of β-pleated sheets. Fibrous mats from regenerated fibroin were obtained from solutions with a concentration of 10 and 20%.
Two methods were used to prevent solubility of fibroin-based matrices: conversion of fibroin to the β-conformation by treatment with an ethanol solution and chemical cross-linking with gen-ipin (Gp). The structures of the fibrous samples were studied by AFM and confocal laser scan-ning microscopy. The composition of the moulding solution for the electrospinning of regener-ated fibroin fibrous matrices and the conditions for their modification have been optimised. It has been shown that the composition of fibroin with chitosan contributes to a decrease in the solubility of electrospun fibrous matrices by increasing the number of amino groups available for modification by Gp, and also leads to a decrease in the diameter of the fibers.
Electrospun fiber matrices based on regenerated SF, modified by cross-linking with Gp in water-alcohol solutions, promote cell growth and proliferation and may be promising for tissue engineering.
Discrepancies in Adolescent–Parent Perceptions of the Parental Phubbing and Their Relevance to Adolescent Smartphone Dependence: The Mediating Role of Parent-Child Relationship
Authors: Chen Shi , Qiu Dongqing , Li Xing , Zhao Qingbai
Published: September 2023

Parental phubbing behavior is a significant factor in predicting adolescent smartphone dependence, but prior research has predominantly focused on a unidirectional perspective from the child's viewpoint, overlooking potential perceptual differences between parents and their children regarding parental phubbing. Therefore, are there differences in the perceptions of parental phubbing between parents and their children? Based on the "Discrepancy-Maladaptive" hypothesis, the presence of perceptual discrepancies in family factors can lead to adverse developmental outcomes in children. Does the parent-child perceptual discrepancy in parental phubbing influence adolescent smartphone dependence? And what role does parent-child relationship play in this context? This study selected 728 families from a middle school in Wuhan, and surveys were administered to both children and parents. The findings reveal: (1) There exist significant parent-child perceptual discrepancies in parental phubbing. (2) Parent-child perceptual discrepancies in parental phubbing significantly positively predict adolescent smartphone dependence and negatively predict parent-child relationships, while parent-child relationships significantly negatively predict adolescent smartphone dependence. (3) The parent-child relationship plays a mediating role between parent-child perceptual differences in parental phubbing behavior and adolescent smartphone dependence.
Evaluating an Immersive Virtual Classroom as an Augmented Reality Platform in Synchronous Remote Learning
Authors: Florez Marulanda Juan , Collazos César Alberto , Hurtado Alegria Julio Ariel
Published: September 2023

Previous research has explored different models of synchronous remote learning environments supported by videoconferencing and virtual reality platforms. However, few studies have evaluated the preference and acceptance of synchronous remote learning in a course streamed in an immersive or augmented reality platform. This case study uses ANOVA analysis to examine the engineering students´ preferences for receiving instruction during the COVID19 pandemic in three classroom types: face-to-face, conventional virtual (mediated by videoconferencing) and an immersive virtual classroom (IVC). Likewise, structural equation modeling, was used to analyze the acceptance of the IVC perceived by students, this includes four latent factors: ease of receiving a class, perceived usefulness, attitude towards IVC and IVC use. The findings showed that the IVC used in synchronous remote learning has a similar level of preference to the face-to-face classroom, and higher than the conventional virtual one. Despite the high preference for receiving remote instruction in IVC, aspects such as audio delays that affect interaction still need to be resolved. On the other hand, a key aspect for a good performance of these environments is the dynamics associated with the teaching-learning processes and the instructor´ qualities.
Systems Theory and Intercultural Communication:
Methods for Heuristic Model Design
Authors: Genest Sylvie
Published: September 2023

This article focuses on methods for designing heuristic models within the paradigm of systems theory and in the disciplinary context of intercultural communication. The main question arises from the striking observation that the common language is insufficient to develop knowledge about human communication, especially when many factors of complexity (such as ambiguity, paradoxes, or uncertainty) are involved in the composition of an abstract research object. This epistemological, theoretical, and methodological problematic is one of the main challenges to the scientificity of anthropological theories and concepts on culture. Moreover, these questions lie at the heart of research in intercultural communication. Authors and theorists in the complexity sciences have already stressed the need, in such case, to think in terms of models or semiotic representations, since these tools of thought can mediate much more effectively than unformalized language between the heterogeneous set of perceptions arising from the field of experience, on the one hand, and the philosophical principles that organize speculative thought, on the other. This sets the scene for a reflection on the need to master the theory of heuristic models when it comes to developing scientific knowledge in the field of intercultural communication. In this essay, my first aim is to make explicit the conditions likely to ensure the heuristic value of a model, while my second aim is to clarify the operational function and required level of abstraction of certain terms such as concepts, categories, headings, models, systems, or theories that are among the most commonly used by academics in their descriptive accounts or explanatory hypotheses. To achieve this second objective, I propose to create cognitive meta-categories to identify the three (nominal, cardinal or ordinal) roles of words in the reference grids we use to classify our ideas, and to specify how to use these meta-categories in the construction of our heuristic models. Alongside the theoretical presentation, examples of application are provided, almost all of which are drawn from my own research into the increased cultural vigilance of the majority population in Quebec since the reasonable accommodation crisis in this French-speaking province of Canada. The typology I propose will perhaps help to avoid the confusions regularly committed by authors who attribute only cosmetic functions to words that nevertheless have a highly heuristic value, and who forget to consider the logical leaps of their theoretical thinking in the construction of heuristic models.
KARAKTERISTIK ANGKUTAN PENYEBERANGAN SUNGAI DONAN KABUPATEN CILACAP (Studi Kasus Rute Kalipanas-Kutawaru)
Authors: Alamsyah Muhammad Duta , Handayani Dewi , Hartono Widi
Published: September 2023

Wilayah Kelurahan Kutawaru, Kecamatan Cilacap Tengah dengan wilayah ibukota kabupaten dipisahkan oleh Sungai Donan. Ditambah rute memutar dan waktu tempuh lebih lama bila menggunakan jalan darat dengan kondisi jalan yang rusak membuat masyarakat sekitar mengadakan angkutan penyeberangan. Kondisi tersebut melatarbelakangi penelitian dalam rangka mengetahui karakteristik angkutan penyeberangan Sungai Donan di Cilacap pada rute Kalipanas-Kutawaru dilihat dari aspek operasional dan teknis. Langkah pengambilan data dilakukan dengan observasi lapangan, wawancara, dan pengisian kuisioner kepada pengguna jasa dan operator kapal motor. Data tersebut dianalisis dengan deskriptif kualitatif dan kuantitatif. Karakteristik pengguna jasa didominasi pria sebesar 54,31%, usia mayoritas pada rentang 21-30 tahun sebesar 25,86%, tingkat pendidikan banyak berakhir pada SMA/SMK/MA sebesar 37,07%, pendapatan per bulan paling banyak pada rentang ≤ Rp2.000.000 sebesar 65,52%, kendaraan sepeda motor dimiliki sebagian besar pengguna sebesar 89,66%, sebagian besar pekerjaan ialah buruh sebesar 21,55%, mayoritas bermaksud melakukan perjalanan dalam rangka kegiatan sosial sebesar 37,07%, frekuensi penggunaan pengguna jasa mayoritas 2 kali dalam satu minggu sebesar 68,10%, dan alasan penggunaan paling banyak adalah cepat sebesar 54,31%. Karakteristik operator didominasi pria, batas bawah usia 30 tahun dan atasnya 64 tahun, tingkat pendidikan sebagian besar berakhir di SD/MI, seluruh operator bertempat tinggal di Kelurahan Kutawaru, dan beberapa sudah mencapai lebih dari 10 tahun menjadi nahkoda kapal.
PENGEMBANGAN BAHAN AJAR DASAR DESAIN GRAFIS SEBAGAI MULTIMEDIA PEMBELAJARAN INTERAKTIF BERBASIS ANDROID DI SMK NEGERI 34 JAKARTA
Authors: Diat Nurhidayat  , Mohamad Ihya Ulumudin  , Yuliatri Sastrawijaya
Published: September 2023

Kegiatan pembelajaran Dasar Desain Grafis di SMK Negeri 34 Jakarta mempunyai permasalahan karena belum mempunyai media pembelajaran yang sesuai dengan standar pembelajaran yang seharusnya, yaitu belum adanya bahan ajar yang terangkum sebagai bahan belajar siswa dan belum adanya jobsheet sebagai pendukung kegiatan praktik Dasar Desain Grafis.

Penelitian menggunakan metode pengembangan (Research and Development) yang diadaptasi dari model pengembangan ADDIE (Analysis, Design, Development, Implementation, and Evaluation), namun penelitian ini dibatasi hanya sampai tahap implementation. Pembuatan aplikasi dasar desain grafis menggunakan software Adobe Flash Professional, validasi dilakukan oleh ahli materi, ahli media, praktisi pembelajaran dasar desain grafis (guru), dan siswa menggunakan kuesioner/angket. Data hasil penelitian kemudian dianalisis dengan menggunakan teknik deskriptif kuantitatif.

Hasil Penelitian menunjukan bahwa tingkat kelayakan bahan ajar dasar desain grafis sebagai multimedia pembelajaran interaktif berbasis android mendapatkan penilaian berdasarkan : 1) ahli materi memberikan nilai persentase 100% ”Ya” yang termasuk kategori sangat baik, 2) ahli media diperoleh rata-rata skor 9.1 yang termasuk kategori sangat baik, 3) praktisi pembelajaran dasar desain grafis (guru) diperoleh rata-rata skor 9.1 yang kategori sangat baik, dan 4) Siswa diperoleh nilai persentase 91.19% yang termasuk kategori sangat baik.
PENGEMBANGAN RESTFUL WEB SERVICE PADA SISTEM KOLABORASI GURU MATA PELAJARAN DI WILAYAH JAKARTA TIMUR DENGAN METODE SCRUM
Authors: Swardiantara Silalahi  , Hamidillah Ajie  , Widodo
Published: September 2023

Kehidupan pada masa kini hampir tidak dapat dipisahkan dari peran teknologi, salah satunya di bidang Pendidikan. Dominasi peran teknologi dapat dilihat dari banyaknya platform yang menyediakan layanan pendidikan. Jika dilihat, platform-platform yang muncul cenderung berfokus pada siswa. Produk yang berfokus pada guru dapat terbilang masih minim. Saat ini, guru bekerja sama dalam mengembangkan perangkat ajar dan bahan ajar hanya sebatas grup pada media sosial seperti Whatsapp, atau LMS buatan luar negeri. Sehingga dibutuhkan sebuah solusi untuk memberikan ruang kepada para guru agar dapat saling berkolaborasi dalam menjalankan tugasnya sebagai tenaga pendidik. Tujuan dari penelitian ini adalah untuk menghasilkan restful web service yang dapat digunakan untuk mengembangkan sistem kolaborasi guru mata pelajaran serta memiliki sifat adaptif terhadap perubahan yang perlu dilakukan di masa mendatang. Pengembangan dilakukan dengan menggunakan arsitektur Service Oriented Architecture (SOA), metode Scrum, framework ExpressJS dan menghasilkan 77 endpoint. Pengujian dilakukan terhadap seluruh endpoint dengan menggunakan metode unit testing dan bantuan tools Postman. Dari hasil pengujian menunjukkan seluruh endpoint berfungsi dengan baik dan layak digunakan sebagai sisi backend dari sistem kolaborasi guru mata pelajaran.
Green Initiatives in Hydraulic Fracturing Operations
Authors: Sayapov E. , Kurniadi S. D. , Manzano F. , Al-Mahfudhi M. , Guzman R. C.
Published: September 2023

Hydraulic fracturing, a widely adopted stimulation technique in the oil and gas industry, significantly contributes to CO2 emissions. This paper aims to identify the sources of emissions, explore options and methods for reducing the CO2 footprint, and enhance safety measures for personnel involved in hydraulic fracturing operations.

The study examines various factors that collectively contribute to minimizing the environmental impact of hydraulic fracturing. It discusses techniques implemented in Petroleum Development Oman (PDO), as well as other available and potential approaches for reducing CO2 emissions, including customized equipment selection accompanied by emission calculations, spill and pollution prevention measures, adoption of electric fracturing fleets and solar energy, utilization of four-phase separators to eliminate post-fracturing flaring and hydrocarbon waste, among others.

The paper highlights green initiatives already implemented in PDO and quantifies their positive outcomes. Furthermore, it outlines a roadmap for future improvements in the short and long term, assesses the economic and reputational impact resulting from the implementation of such initiatives, and addresses associated requirements and challenges.

The paper presents a diagram evaluating the level of positive economic, environmental, and reputational impacts relative to the costs and efforts involved. Detailed guidelines are provided to assist well engineers in selecting appropriate solutions for different geographical and geological conditions in various fields. By discussing global trends towards environmentally friendly practices in the oil and gas industry and drawing on PDO's experience, this paper unveils strategies for tailoring available solutions to specific conditions and circumstances.
Organic Growth of Hydraulic Fracturingin High Perm Reservoirs – Asset M Case Study
Authors: Kindi O. , Ahmed M. , Al Riyami S. M. , Konwar A. A. , Ghaithi A. , Kindi S.
Published: September 2023

Hydraulic fracturing has proven success to unlock Hydrocarbon production from tight reservoirs in Petroleum development Oman for many years since 1990s. however given the high cost and extensive operation footprint, the Frac was not a favorable option in the South assets where sandstones can vary in permeability between 0.1- 4 Darcy permeability. The objective of this work to is show case Asset M organic growth in Hydraulic fracturing application and the enablers that supported this journey.

Hydraulic fracturing is considered an expensive technology compared to other stimulation techniques and it requires a lot of technical work to screen the right candidates, plan and design the Frac operation. Asset M is a mix of over 20 fields ranging in size, reservoir qualities and Oil properties. This introduces additional challenge in frac candidate selection and design. To overcome these constrains the team have looked at potential techniques that could reduce the cost and accelerate the technical evaluation and frac program maturation. In this paper, the cost saving initiatives will be highlighted along with the frac design and execution simplification done. High level performance compared to baseline of each well will also be shared.

The Organic growth of Hydraulic fracturing in Asset M is truly astonishing. The Asset started with 2 candidates only in 2019 to assure success and based on the outcomes, Hydraulic fracturing has been growing since with 12 wells stimulated with Hydraulic fracturing in 2022. The increase is also linked to the simplified operational approach and the high oil gain associated to these activities where in some of the wells oil gain exceeded 400%.

The work presented here will be the first time to show case Asset M frac journey both from technical and commercial impact. It is a very good case study for replication across other E&P operators which are looking for more oil production beyond the easy oil gain portfolio.
Cyclic Injection Scheme to Reduce Breakdown Pressure in Hydraulic Fracturing Wells: Case Study
Authors: Salah Mohamed , Al Hammadi Mohamed Thani , Al Marzooqi Afnan , Alshehhi Hajer Mohamed Ali J.
Published: September 2023

Globally, the development of unconventional resources has drastically played a pivotal role in the energy supply. The economic production from the unconventional reservoirs is a great challenge where these tight producing zones often exhibit extremely high in-situ stress with low permeability conditions, necessitating the hydraulic fracturing stimulation of each horizon to define fluid and assess productivity. This extreme in-situ stress condition poses a considerable high breakdown pressure, making the hydraulic fracturing techniques challenging when implemented to these types of reservoirs and often treatment parameters approach the equipment capabilities and operational limits without breaking down the formation or creating any fractures. Consequently, conventional techniques have yielded unsatisfactory outcomes, rendering the wells economically unviable. In this paper, a new approach has been developed to help reduce the formation breakdown pressure during the hydraulic fracturing treatment. The new approach encounters injection of hydraulic fracturing fluid in a series of hydraulic pulses schemes to induce fatigue failure damage and weaken rock tensile strength. This paper discusses the fatigue damage mechanism and constitutive relationship for rock subjected to cyclic stress. The mechanical response of rock under both monotonic and cyclic stress loading will be examined. The rate of fatigue damage evolution is influenced by the number of load cycles, stress amplitude and accumulated plastic deformation. This case study presents hydraulic fracturing technique, to reduce rock tensile strength, and induce fatigue damage to one of extremely in-situ stressed reservoirs which could not be broken-down by conventional hydraulic fracturing technique. The results of cyclic fracturing technique are summarized. The cyclic injection scheme fatigue response of rock reduces formation breakdown pressure by 16% compared to the results obtained in conventional hydraulic fracturing.
Integrated Pressure Transient Analysis of Hydraulically Fractured Wells in Tight Gas Condensate Reservoirs in the Sultanate of Oman
Authors: Zhan Lang , Al-Sulaimi Saleh , Liu Mankit , Abdulkadir Ramzi
Published: September 2023

We present an integrated approach that combines pressure transient analysis (PTA) of multiple hydraulically fractured wells and additional measurements from other disciplines to deliver consistent results of formation and fracture properties. PTA for Multi-Fractured Horizontal Wells (MFHW) has greater uncertainty than that of their vertical counterparts. Utilizing complementary characteristics and information from multiple wells reduces the non-uniqueness in parameter estimations of tight gas condensate fields. This paper features a methodology to sequentially estimate fracture conductivity, fracture height, fracture length and formation permeability for MFHWs. First, this new method separates fracture conductivity from fracture geometry using Fracture Radial formation linear (FRFL) flow regime, resulting in a significant reduction of uncertainty in fracture conductivity estimations. Then, fracture height can be estimated by analyzing the end time of FRFL flow because fracture height dictates the termination time of the FRFL flow. Using the end time of the FRFL flow to estimate fracture height is a novel technique in the industry and has significant value because a MFHW can rarely drain hydrocarbon resources beyond fracture height in tight and shale reservoirs while the fracture height is almost always an unknown. After both fracture conductivity and fracture height are determined for MFHWs, formation permeability can be estimated from bilinear flow and/or pseudo-radial flow regimes, if existing. Finally, fracture length can be estimated using the conventional approaches with much less uncertainty because the other three key parameters are known. The proposed sequential interpretation workflow and fracture height estimation will be demonstrated using field examples. The estimated results provide valuable insights into formation features, reservoir quality and completion effectiveness, which help hydraulic fracturing design, reservoir modeling and forecast, and field development optimization.
First Implementation of Nano-Proppant Technology in Middle East
Authors: Buijs H. , Nuriakhmetov R. , Bulekbay A. , Alam A. , Ao Taliwati , Singh Anil , Vazquez Alejandro , Basioni M. , Alloghani J. A. , Al Hammadi A. E. , Al Kindi R. K. , Al Aryani F. M. , Bregar U. B. , Hassan A. M. , Saldungaray P. , Annovi Enrico
Published: September 2023

This paper describes the first application of nano-proppant technology in Middle East that was additionally combined with tailored-made smart-proppant to unlock hard to recover reserves in the first successful hydraulic fracture treatment pumped offshore Abu Dhabi. The primary target reservoir is the Pre-Khuff Clastics Fm., a deep tight gas sandstone that can be found at depths exciding 16,000 ft with temperatures above 350º F.

Given the reservoir characteristics, primarily its low permeability, hydraulic fracturing is required to achieve commercial production rates. The design of the fracture stimulation treatment presented several challenging conditions including high formation temperature, high closure stress, poroelastic effects and, among others, the potential for post treatment proppant flowback in an offshore environment. The implementation of tailored-made proppant technologies provided the means to overcome such challenges while providing key information to optimize fracture treatments as wells were completed.

The primary objectives of nano-proppants were centered on sustaining production performance by propping the formation natural fracture network, mitigation of near wellbore entry friction pressures and fissure leakoff control to assure the successful placement of the frac treatment. In turn, smart-proppant technology was utilized to obtain an accurate fracture height measurement to reduce the uncertainty and non-uniqueness of pressure matching, better determining the placed frac length and width by properly understanding containment. Resin coated proppant was engineered to lock-in conductivity in a high stress and temperature environment based on expected temperature heat-back profiles required to achieve a targeted proppant pack unconfined compressive strength.

This paper will provide insights on the results and lessons learned from the application of state-of-the-art proppant technologies that paved the way to reach stable commercial rates after the first fracture treatment by improving production performance by over 500%.
Fracturing and Production Characteristics of Tight Gas Reservoir: A Case Study from Thrace Basin, Turkey
Authors: Kilicaslan U. , Mengen A. E. , Ozcan O. , Sevinc S. , Belhoucine S. , Boudissa R. , Mironov V. S. , Khlopkov A. V.
Published: September 2023

During the last three years, Turkish Petroleum Corporation, state owned oil company of Turkish Republic, has put significant efforts to develop its shaly sandstone reservoirs located in the Thrace Basin by-utilizing hydraulic fracturing technology. In this paper, a comprehensive review of operational and modelling aspects in the development of tight gas reservoirs were presented as a real field case study.

Fracturing an over-pressured tight gas reservoir deeper than 3,000 meters (true vertical depth), in a tectonically active area, was the main challenge of the project. The initial priority was performing fracturing operations in a safe, proper, environmentally friendly way. In the post-frac phase, substantial difference observed in the individual well performances and post-frac assessment of estimated ultimate recovery (EUR) have become the main criteria in evaluation of the success of the current stimulation campaign as well as the identification of possible potential infill opportunities.

Diagnostic fracture injection tests showed high closure stresses (up to 1 psi/ft gradient), which resulted in high treating pressures. To prevent screen-out, proppant concentration was increased by 0.25 ppg at each step and considerable sweeps between main stages were carried out. Different type of proppants were employed during the treatments in order to ensure having better fracture initiation and conductivity. The created fracture properties estimated from stimulation software as well as the values from rate-transient analysis were not well aligned. EUR predictions from the decline curve analysis and history matched simulation model only agreed for the first well, after having 2 years of production history, but not for other more recent wells. Image logs were also very helpful to explain different initial flow rates seen in the wells, due to the inferred presence of natural fractures.

This case study summarises the efforts to overcome challenging hydraulic fracturing conditions and to analyse varying production behaviours between the hydraulically fractured wells by means of different methods; to assist the efficient development of the company's tight gas reservoirs in the Thrace Basin, Turkey. It was observed that natural fracture intensity increases as the well locations approach major faults, at which point the complex stress regime may then begin to expose the fracturing operations to a risk of early screen-out. Therefore, any proposed infill wells should be located in those areas at a safe proximity from faults for enhanced production.
Reproductive biology of Acer caesium Wall. ex Brandis (Sapindaceae): a dioecious tree species from Northwestern Himalayas
Authors: Roy Sudip Kumar , Khanduri Priyanka , Bhatnagar Ashok Kumar , Pandey Arun Kumar
Published: September 2023

Acer caesium, commonly known as Himalayan maple, is a tree species endemic to Central and Western Himalaya. This multipurpose tree species has undergone a decline in its natural population number due to overexploitation over the years. Any attempts for conservation of this species will require understanding its reproductive behaviour in natural ecosystems. However, there is hardly any information on pollination ecology of this species. To bridge this gap, we studied the floral biology and pollination ecology in natural populations growing at Kedarnath Wildlife Sanctuary, Uttarakhand, India. In addition, whether the species is experiencing any pollen limitation was examined using hand-pollination experiments. A. caesium is a dioecious tree species with male biased sex ratio in the studied populations. Both male and female flowers exhibit typical characters of a wind pollinated plant. Interestingly, pollination experiments revealed ambophily in the species, with wind as the primary means of pollination and a small percentage of fruit set through insects. Pollen limitation experiments showed that natural fruit set in A. ceasium is pollen limited as pollen supplementation augmented the fruit set. The probable reason for low fruit set in natural pollination conditions seems to be sparse distribution of the male plants around female plants in the population. Thus, for optimal conservation efforts, it is recommended that spatial structure of male and female individuals in the population must be considered for better outcrossing opportunities.
Robust Training of Machine Learning Interatomic Potentials with Dimensionality Reduction and Stratified Sampling
Authors: Ong Shyue Ping , Qi Ji , Ko Tsz Wai , Wood Brandon , Pham Tuan Anh
Published: September 2023

Machine learning interatomic potentials (MLIPs) that enable accurate simulations of materials at scales beyond conventional first-principles approaches have played increasingly important roles in understanding and design of materials. However, MLIPs are only as accurate and robust as the data they are trained on. In this work, we present DImensionality-Reduced Encoded Clusters with sTratified (DIRECT) sampling as an approach to select a robust training set of structures from a large and complex configuration space. By applying DIRECT sampling on the Materials Project relaxation trajectories dataset with over one million structures and 89 elements, we develop an improved materials 3-body graph network (M3GNet) universal potential that extrapolate more reliably to unseen structures. We further show that molecular dynamics (MD) simulations with universal potentials such as M3GNet can be used in place of expensive ab initio MD to rapidly create a large configuration space for target materials systems. For demonstration, we combined this scheme with DIRECT sampling to develop a reliable moment tensor potential for titanium hydrides without the need for iterative optimization. This work paves the way towards robust high throughput development of MLIPs across any compositional complexity.