bluuebunny/crossref_metadata_2025 huggingface dataset:
Susceptibility of Ocular Surface Bacteria to Various Antibiotic Agents
Authors: Ghita Aurelian Mihai , Iliescu Daniela Adriana , Ghita Ana Cristina , Ilie Larisa Adriana
Published: October 2023

Periodic assessment of bacterial contamination is necessary as it allows proper guidance in cases of eye infections through the use of appropriate antibiotics. Due to the extensive use of antibiotic treatment, most of the contamination flora is resistant to the usual ophthalmic antibiotics. The present study shows an updated picture of the susceptibility of Gram-positive and Gram-negative bacteria found on the ocular surface to the most commonly used antibiotic agents in patients undergoing cataract surgery. A total of 993 patients were included in the study with ages between 44 and 98 years old. Conjunctival culture was collected 7 days before cataract surgery. The response of Gram-positive and Gram-negative bacteria to various antibiotic classes like glycopeptides, cephalosporins, carbapenems, fluoroquinolones, aminoglycosides, phenicols, tetracyclines, rifamycins, macrolides and penicillins was assessed. From the tested antibiotics, vancomycin had 97.8% efficacy on Gram-positive bacteria. In the cephalosporin category, we observed an increased resistance of the cefuroxime for both Gram-positive and negative bacteria. Antibiotics that have more than 90% efficacy on Gram-positive bacteria are: meropenem, imipenem, netilmicin, amikacin and rifampicin. On Gram-negative bacteria, we found 100% efficacy of all tested fluoroquinolones, aminoglycosides (except for tobramycin), doxycycline, azithromycin, clarithromycin and chloramphenicol. The current study illustrates patterns of increased resistance of certain bacteria present on ocular surface to some of the commonly used antibiotics in ophthalmological clinical practice. One such revealing example is cefuroxime, which has been highly used as an intracameral antibiotic for the prevention of bacterial endophthalmitis after cataract surgery.
HA-Coated PLGA Nanoparticles Loaded with Apigenin for Colon Cancer with High Expression of CD44
Authors: Yang Bo , Mao Yongqing , Zhang Yanjun , Hao Yue , Guo Meitong , Li Bian , Peng Haisheng
Published: October 2023

Apigenin (API) possesses excellent antitumor properties, but its limited water solubility and low bioavailability restrict its therapeutic impact. Thus, a suitable delivery systems is needed to overcome these limitations and improve the therapeutic efficiency. Poly (lactic-co-glycolic acid) (PLGA) is a copolymer extensively utilized in drug delivery. Hyaluronic acid (HA) is a major extracellular matrix and can specifically bind with CD44 on colon cancer cells. Chitosan (CS) can serve as an intermediate binding with HA and PLGA. Herein, we aimed to perpare receptor-selective HA-coated PLGA nanoparticles (NPs) for colon cancer with high expression of CD44. Firstly, API was encapsulated in PLGA to obtain PLGA-API-NPs, which were then sequentially combined with CS and HA to form HA-coated PLGA NPs. HA coated PLGA NPs had a stronger sustained-release capability. Cellular uptake of HA coated PLGA NPs was enhanced in HT-29 cells with high expression of CD44. HA-PLGA-DiR-NPs can target specificity towards the HT-29 ectopic tumor model. Overall, HA coated PLGA NPs was an effectively drug deliver platform for API in treatment of colon cancer with high expression of CD44.
Analisis Persepsi Mahasiswa Terhadap Ketidakjujuran Akademik : Studi Kasus di Fakultas Teknik UNS
Authors: Wicaksono Andrye Sukma , Widiastuti Indah , Pambudi Nugroho Agung
Published: October 2023

Academic dishonesty is a deliberate violation of academic rules for personal gain. Academic dishonesty can reduce the reputation of students and universities, as well as dishonest behavior in the world of work, so research is needed regarding engineering students' perceptions of academic dishonesty. This study aims to determine perceptions, experiences, reasons why engineering students commit academic dishonesty, and to determine the influence between perceptions and experiences of witnessing acts of academic dishonesty. The population used in this study were S1 students from the UNS Faculty of Engineering and the samples taken were 97 respondents. The results of the study show that engineering students' perceptions of academic dishonesty are that students know that academic dishonesty is important, can have an impact on damaging moral character, including actions that violate social and religious norms, so that it becomes the student's responsibility, and must be responsible for caring for the integrity of other students. . The experience of engineering students with academic dishonesty is that students have committed dishonesty but support existing policies, often use unauthorized material during exams, work on papers or articles without including references, and ask for help from seniors who have taken exams but rarely submit assignments properly. pay someone else to complete it and rarely miss out on group assignments. Academic dishonesty policies already exist but sanctions and supervision need to be tightened to reduce academic dishonesty. The reason engineering students commit academic dishonesty is because they don't get sanctioned or punished, the attitude of the lecturer, many friends who do this, will make grades better, difficulty working on questions, easy internet access and fear of failure and lack of study time. Most of the respondents committed academic dishonesty due to internal factors. There is a positive and significant influence between perception and experience of witnessing techniques on the experience of committing academic dishonesty. So that when the perception and experience of witnessing gets higher, they will not commit academic dishonesty.
EFIKASI DAN TANGGUNG JAWAB GURU KEJURUAN SELAMA PANDEMI COVID-19 PADA GURU KEJURUAN BIDANG PEMESINAN DI KOTA SURAKARTA
Authors: Kurniawati Putri Ari , Estriyanto Yuyun , Rohman Ngatou
Published: October 2023

Tujuan dari penelitian ini yaitu untuk mengetahui tingkat efikasi dan tanggung
jawab guru kejuruan bidang teknik pemesinan di Kota Surakarta dalam
pembelajaran selama pandemi. Jenis penelitian ini berupa penelitian kuantitatif
bersifat deskriptif eksploratif. Peneliti juga mengambil beberapa buku, artikel,
jurnal, dan skripsi lain sebagai penunjang dalam penelitian. Teknik pengumpulan
dalam penelitian ini berupa teknik sampling dan angket/kuisioner. Teknik analisis
data dalam penelitian ini menggunakan teknik statistik descriptive kuantitatif
presentase. Adapun hasil dari penelitian ini yaitu peneliti menemukan: (1) guru
dengan gender laki-laki memiliki tingkat efikasi dan tangung jawab yang
besar dengan rata-rata (85,13%) untuk efikasi dan (88,2%) untuk
presentase tanggung jawab, (2) bahwa guru dengan usia 40-50 tahun
memiliki tingkat efikasi dan tanggung jawab yang tinggi,(3) guru dengan
masa kerja >20 tahun memiliki nilai efikasi dan tanggung jawab tinggi, (4)
guru dengan status kepegawaian PNS mendapatkan nilai efikasi dan
tanggung jawab tinggi dengan prosentase ratarata sebesar (80,28%), (5)
guru yang memiliki tingkat pendidikan terakhir S1 memiliki tingkat efikasi
dan tanggung jawab yang tinggi dengan prosentase sebesar (92,47%).
EFFICIENCY OF SUPPLEMENTARY OUTPUTS IN SIAMESE NEURAL NETWORKS
Authors: Melnychenko Artem , Zdor Kostyantyn
Published: October 2023

In the world of image analysis, effectively handling large image datasets is a complex challenge that requires using deep neural networks. Siamese neural networks, known for their twin-like structure, offer an effective solution to image comparison tasks, especially when data volume is limited. This research explores the possibility of enhancing these models by adding supplementary outputs that improve classification and help find specific data features. The article shows the results of two experiments using the Fashion MNIST and PlantVillage datasets, incorporating additional classification, regression, and combined output strategies with various weight loss configurations.  The results from the experiments show that for simpler datasets, the introduction of supplementary outputs leads to a decrease in model accuracy. Conversely, for more complex datasets, optimal accuracy was achieved through the simultaneous integration of regression and classification supplementary outputs. It should be noted that the observed increase in accuracy is relatively marginal and does not guarantee a substantial impact on the overall accuracy of the model.
EL ESTADO LAICO EN COLOMBIA: UN PRINCIPIO Y UN DERECHO INNOMINADO
Authors:   Universidad Libre, Fajardo Sánchez Luis Alfonso
Published: October 2023

The present article focuses on analyzing the influence of the jurisprudence of the Constitutional Court in Colombia regarding the consolidation of the secular state and the protection of human rights. In this regard, we will examine how the decisions of the Constitutional Court have contributed to guaranteeing the separation between church and state, promoting religious neutrality in public institutions, and ensuring the free exercise of different beliefs and religious practices. Additionally, we will explore how these judicial decisions have strengthened the protection of human rights, ensuring equality, freedom of conscience, and non-discrimination in the religious sphere. From another perspective, and as an integral part of the development of this article, we will analyze how the tax exemption granted to churches has resulted in a contradiction to the principles of equality and neutrality that the state should uphold concerning religion. The research problem that underlies the respective inquiries and the process of theoretical synthesis can be summarized in two questions: What is the impact of the jurisprudence of the Constitutional Court on the consolidation of the secular state and the protection of human rights in Colombia? And how has the tax exemption of churches become a historical debt of the secular state in the country? Finally, it was concluded that thanks to the jurisprudential development of the Constitutional Court, there was a crucial impact on the establishment of the Secular State by expanding the interpretation of its elements, scope, and undeniable relationship with Human Rights.
Development of a Qr Code-Based Student Worksheet in the Course of Media and Learning Resources Development to Improve Digital Literacy
Authors: Nurhasnawati Nurhasnawati , Zarkasih Zarkasih , Putriani Zelly , Berlian Mery , Vebrianto Rian
Published: October 2023

This article is based on the limited number of reading materials and instructions in using a laboratory facility, so the development of media and learning resources is important to be updated using the encyclopedia and videos as the learning resources in the form of QRCode. Therefore, this article aimed to develop media and learning resources by using a QRCode to improve digital literacy. This article used the Plomp model consisting of problem identification and analysis phase, development and prototyping phase, and assessment phase. The data were collected by distributing an online questionnaire and analyzed by using the descriptive-quantitative method. Based on this development study QR Code-based student worksheets fulfilled the practicality of 83.40% in the ‘practical’ category and the effectiveness seen from the score of the students’ literacy skills of 78.89% in the “Good/ Effective” category. The implication of this study is producing a product with a novelty and can be a reference for conducting effective and efficient learning.
A Bibliometric Review of Learning Approaches in Primary Education Level: Examining the Indonesian Contribution to the Field
Authors: Ghufron Syamsul , Rulyansah Afib
Published: October 2023

It is crucial to employ contemporary pedagogical approaches in primary education to cultivate capable and skilled young individuals who are equipped to excel in competitive environments. Despite a significant amount of field research on the use of learning approaches in primary education, there is a lack of studies that consolidate the findings through bibliometric techniques. The main aim of this bibliometric investigation is to identify prevalent research patterns and evaluate Indonesia's scientific contributions to the study of learning approaches in primary education. The study employs bibliometric analysis, which includes four stages: initial search, application of inclusion and exclusion criteria, data extraction, and data cleaning. Data analysis is conducted using Publish or Perish, Ms. Excel, and Chat GPT. This research analyzed 549 papers published over 56 years, which gathered 4552 citations. The citation frequency peaked in 2008 with 690 citations. The 17 most influential authors came mainly from Indonesia and the United States. Most of the most-cited works were published more than ten years ago. The British Journal of Educational Psychology and Switzerland's Sustainability Journal lead in publishing educational research articles. Six out of the top 11 institutions in learning approaches research are Indonesian universities, showcasing Indonesia's dominance in the field. Surpassing other countries like the United States, Turkey, Spain, the UK, Australia, and China, Indonesia has achieved significant success.
Al-Ghazali's Philosophical Theology and Its Relevance to the Polemic of Science and Islamic Theology During Pandemic Covid-19
Authors: Fatkhan Muh , Arif Muhammad
Published: October 2023

This article covers philosophical theology and its relevance to the issues between Islamic theology and science during Pandemic COVID-19. There were numerous scientific discoveries on covid-19 such as its contagion, the importance of physical distancing, the importance of wearing the mask, the importance of avoiding crowds, vaccines, etc. All of them have been public consumption. As a consequence, there was religious dissent in Muslim society. The one group took science on its side and negated any communal worship without health protocol. The other group chose “Islamic theology” and still conducted any communal worship without health protocol. To answer this reality, it is important to see how al-Ghazali handled philosophy and Islamic theology in harmony. Like al-Ghazali, Muslim society should respect scientific discoveries concerning the COVID-19 pandemic. However, not only appreciate the scientific discoveries but Muslim society also should keep in mind that the will and act of God are attached to the efforts of science to handle the COVID-19 pandemic.
Hizbiyyah and Hizbut Tahrir Indonesia's New Member Recruitment Strategy After Disbandment
Authors: Rahman Mohammad Taufiq , Bukhori Bukhori , Setia Paelani
Published: October 2023

This article discusses Hizbut Tahrir Indonesia's new member recruitment strategy after the government disbanded them through Perppu on Community Organization Number 2 of 2017. The research method used is qualitative through data collection, observation, interview, and document review. This research found that Hizbut Tahrir Indonesia changed its strategy from open recruitment to using strategies through informal groups and individuals in recruiting members behind closed doors, especially after they were banned by the government in 2017, namely through the student movement, through the activities of figures in mosques, and women. According to HTI, these three strategies have a safe tendency because they can be done secretly and escape the control of the government and mass organizations that oppose them. According to HTI, the student movement is considered necessary because they are educated citizens who have the potential to become agents of change in society. Meanwhile, the mosque is the center of Muslim activity, where the recruitment of DKM administrators, preachers, and congregants can accelerate the preaching of the Khilafah. Meanwhile, the use of women as another HTI recruitment agent is done because the HTI doctrine believes in the importance of women as pillars of civilization. This article argues that although the government has banned HTI, they are still fighting back, mainly through invisible and covert means.
Literature Analysis of Cash Waqf: Trends and Future Research Agenda
Authors: Nur Azizah Annisa Aprilianti , Bayinah Ai Nur , Handoko Luqman Hakim
Published: October 2023

This research aims to determine the trend of the cash waqf analysis published in Scopus-indexed journals. The data were obtained from Scopus on December 07, 2022, with a bibliometric and SLR analysis used through VOSViewer software and Ms. Excel as the analysis tool. The results showed that the 93 documents on the trend of cash waqf increased in recent years. Meanwhile, the distribution emphasized the type of 80 documents (86%), 6 Book Chapters (7%), 4 Reviews (4%), and 3 Conference Papers (3%) contained, with English (92%) being the language most widely used. The productive journal containing articles with the theme of cash waqf was also the Isra International Journal of Islamic Finance (8), with the most productive author, country, and institution being Gürsoy C. (5) and Malaysia (51), and International Islamic University (Malaysia), respectively. For the most cited, inspiring article, and author in cash waqf research, Mohammed M.O. (33) was observed. Based on the keyword, density, overlay, and recent article SLR investigations, at least 16, 10, 10, and 10 topics were determined, respectively. From these results, many opportunities were still capable of being conducted and highly studied regarding cash waqf.
Распространение вариантов вируса SARS-COV-2, вызывающих интерес (VOI) и субвариантов Omicron, находящихся под наблюдением (VUM), на основе количества их геномов, депонированных в базу данных GISAID за неделю с 30 сентября по 6 октября 2023 г.
Authors: Дмитриева Людмила , Краснов Ярослав , Чумачкова Елена , Осина Наталья , Зимирова Анастасия , Иванова Александра , Карнаухов Игорь , Караваева Татьяна , Щербакова Светлана , Кутырев Владимир
Published: October 2023

В обзоре представлена информация по циркулирующим в настоящее время вариантам вируса SARS-COV-2 вызывающих интерес (VOI) и субвариантов Omicron, находящихся под наблюдением (VUM), геномные последовательности которых размещены в международной базе данных GISAID за неделю с 30 сентября по 6 октября 2023 г.
Patient Preferences and Perceptions of Provider Diversity in Orthopaedic Surgery
Authors: Chen Mingda , Strony John T. , Kroneberger Elizabeth A. , Karns Michael R. , Salata Michael J. , Voos James E. , Gillespie Robert J. , Brown Marsalis C.
Published: October 2023

Background:

Orthopaedic surgery in the U.S. historically has been among the least demographically diverse specialties in medicine. Currently, limited data exist on how patients perceive diversity within the field and what patients look for when choosing an orthopaedic surgeon. The purpose of this study was to identify specific patient preferences for surgeon demographics and understand patient perceptions of racial and gender diversity in orthopaedic surgery.

Methods:

Nonconsecutive patients from orthopaedic clinics affiliated with a U.S. academic health system voluntarily completed a 39-item questionnaire that surveyed basic demographic information, perception of diversity, racial and gender preferences during surgeon selection, and perception of health-care inequalities. Bivariate analyses were used to test the association between patient-surgeon demographic variables and ratings of diversity. Multiple regression models were used to identify independent predictors of overall perceived diversity ratings.

Results:

A total of 349 patients (80.6% White, 17.9% Black, and 1.5% other) were analyzed. Black patients were more likely to experience difficulty relating to their surgeon than White patients (11.48% versus 2.29%; odds ratio [OR], 5.62; 95% confidence interval [CI], 1.55 to 21.1; p = 0.004). Moreover, Black patients were more likely to perceive racial bias from their surgeon than White patients (5.17% versus 0.37%; OR, 14.44; 95% CI, 1.14 to 766.29; p = 0.02). While the level of racial diversity perceived by White patients (2.57 of 10) was significantly higher than that perceived by Black patients (2.10 of 10) (p = 0.001), the absolute difference between these 2 figures was small, suggesting that both groups perceived racial diversity in orthopaedics to be low. White and Black patients differed in their importance ranking of a surgeon’s race (p < 0.0001): Black patients ranked a surgeon’s race with higher importance (mean, 3.49 of 10) when selecting a surgeon compared with White patients (1.45 of 10). Both male and female patients gave relatively low importance rankings for a surgeon’s gender (mean, 1.58 of 10 and 2.15 of 10, respectively, p = 0.02).

Conclusions:

Patients in this study did not perceive orthopaedic surgery as a diverse field (overall diversity rating, <3 of 10). There were significant racial and gender differences in patients’ preferences for specific physician characteristics when choosing an orthopaedic surgeon, which may help explain some instances of perceived racial bias and difficulty relating to their orthopaedic surgeon.
An Unusal Case of Acute Uterine Inversion
Authors:   Senior Consultant, Department of Obstetrics and Gynecology, District Hospital, Dharwad 580001, Karnataka, India., Shetty Satish , Mungase Rupali Vaijunath ,   Resident, Department of Obstetrics and Gynecology, District Hospital, Dharwad 580001, Karnataka, India.
Published: October 2023

Abstract Uterine inversion is a rare case in obstetrics and gynecology field ,but the incident can be life threatening event. In the present case, a 19 year old women presented with total and acute uterine inversion after the delivery in peripheral hospital. She presented with fourth degree uterine inversion with the severe degree of hypovolemic shock with active vaginal bleeding. Immediate resuscitation along with simultaneous successful manual repositioning of uterus was done in the labour room. Medical management for atonic uterus was done. Despite of medical management uterus was atonic so uterine packing done. In view of persistent atonicity of uterus decision for emergency laporotomy were taken and patient was reffered to higher centre were she underwent subtotal hysterectomy with right internal iliac artery ligation. Postoperatively broad spectrum antibiotic and blood and blood product transfusion were done according to investigations. These findings suggest that proper management of 3rd stage of labour and early diagnosis and proper management will save the life of patient. Keywords: Uterine inversion; Atony; Hypovolemic shock; Manual uterine repostion. Abstract Uterine inversion is a rare case in obstetrics and gynecology field ,but the incident can be life threatening event. In the present case, a 19 year old women presented with total and acute uterine inversion after the delivery in peripheral hospital. She presented with fourth degree uterine inversion with the severe degree of hypovolemic shock with active vaginal bleeding. Immediate resuscitation along with simultaneous successful manual repositioning of uterus was done in the labour room. Medical management for atonic uterus was done. Despite of medical management uterus was atonic so uterine packing done. In view of persistent atonicity of uterus decision for emergency laporotomy were taken and patient was reffered to higher centre were she underwent subtotal hysterectomy with right internal iliac artery ligation. Postoperatively broad spectrum antibiotic and blood and blood product transfusion were done according to investigations. These findings suggest that proper management of 3rd stage of labour and early diagnosis and proper management will save the life of patient. Keywords: Uterine inversion; Atony; Hypovolemic shock; Manual uterine repostion.
Feasibility Study and LCoE Analysis of Geothermal Energy Production from Depleted Oil Fields and Gas Prospects Onshore Sarawak, Malaysia
Authors: Bataee Mahmood , Carter Rick , Hamdi Zakaria , Ridha Syahrir
Published: October 2023

Due to regulators’ determination to address climate change concerns and the necessity for a global CO2 emissions reduction, renewable energy sources are now seen as preferable options. Geothermal energy has a long history of successful deployment and is a proven, dependable, ongoing, sustainable, and adaptable source of renewable energy that has very low CO2 emissions over its project lifetime. However, there are always uncertainties associated with determining realistic ranges for values of the critical subsurface parameters such as geothermal gradients, aquifer size, transmissivity and geochemistry, when choosing an optimal location for geothermal energy extraction. This project focused on the Baram Basin located in the northern part of the state of Sarawak, Malaysia. Reservoir modelling was used to examine the viability of geothermal energy extraction utilizing publicly available analogue data. For both surface and downhole parameters, published data from existing active fields and recent exploration and appraisal efforts are used. In order to explore the economic feasibility for generating electricity from geothermal heat in this basin, various geothermal development scenarios were investigated both with and without injection wells using the reservoir simulation to determine net heat flow to the surface. The study’s findings compare the production’s enthalpy output estimations from simulations and examine how the LCoE is impacted by heat loss of produced fluids to surface. To investigate commercial competitiveness, different economic tools were run and sensitivity analysis was used to examine the major risk factors and indicate the expected thermal energy recovery ranges for profitable projects. The findings indicate that whilst there is significant geothermal potential in this basin, the challenges are to deploy reliable and cost-effective enabling technologies to deliver an economic return for investors.
A Novel and Cost-Effective Dry Friction Reducer Based Slickwater for Unconventional Reservoir Stimulation
Authors: Qi Ziyuan , Huang Tianping , Kalgaonkar Rajendra , AlGhunaimi Fahd
Published: October 2023

Slickwater has been the most widely used fracturing fluid in stimulation of unconventional reservoirs. Friction reducers (FRs) are one of the key components in a slickwater formulation, while dry FRs (DFRs) are gaining more attention because of logistical and operational benefits. This study aims to develop a cost-effective DFR based slickwater that dissolves quickly with low chemical dosage for slickwater fracturing.

Hydration time of the DFRs in synthetic brine was measured by viscosity monitoring. The rheological properties were measured using rheometer. Friction reduction performances of the DFR samples were characterized by an industry standard flow loop apparatus. The breakability experiments were conducted at 82°C by mixing breakers with DFR solution, and broken fluid was tested on rheometer and gel permeation chromatography (GPC). Flow-back performance of slickwater was estimated using proppant packed chromatographic column. Formation damage evaluation was characterized by measuring core permeability before and after slickwater injection at high temperature.

DFR powder usually contains two times more effective content than liquid friction reducer with same weight, which significantly reduces logistical costs in operation. To tackle the possible lumping of DFR during hydration, a comprehensive evaluation on polymer hydration time was conducted. Viscosity measurements were used to quantitatively compare the hydration time of different DFR samples. An optimum DFR candidate was able to totally dissolve in synthetic brine in less than 2 minutes. The friction reduction can reach up to 75% in 2 minutes for the DFR solutions, and even at a concentration as low as one pound per thousand gallons (pptg). With the addition of flow-back enhancer and polymer breaker, the formation damage of slickwater to core plug is reduced to less than 12%. In the end, one slickwater formulation was developed, with excellent performance in compatibility, viscosity, flow-back percentage, formation damage restoration and friction reduction, which was recommended for field operation.

A novel DFR based slickwater was developed to overcome DFR's hydration and compatibility issues. Analysis on the performance of DFR based chemicals makes this cost-effective slickwater fracturing technology available for field operations.
Evaluation of Polyamidoamine-Assisted Scale Inhibitors to Mitigate Silicate Scale Formation in Near Wellbore Region
Authors: Tan Bee Chea , Saaid Ismail Mohd , Mahat Siti Qurratu'Aini , Zainal Suzalina , Bhaskoro Petrus Tri , Anuar Astriyana
Published: October 2023

Silicate scaling is a concern that could result in formation damage and flow assurance issue. Phosphonates and phosphino-polyacrylates are widely used to treat many types of scale but they are not intended to treat silicate scale. Besides that, these inhibitors may have been considered as harmful substances due to their reported inherent biodegradability. Synergistic silicate scale inhibitors are current trends since cationic or anionic polymers alone is found not effective for silicate scale inhibition. The objective of this work is to assess the performance of polyamidoamine-assisted scale inhibitors for silicates. The experiment settings are simulating the environment in near wellbore region, such that higher temperatures and brine that is mostly pH neutral. The effectiveness of scale inhibitors is investigated through static bottle test and dynamic scale loop (DSL) test. The scale inhibitors are also characterized to determine their functional groups in aqueous state. The tendency of scale inhibitors to impede silicate polymerization process is also determined through the remaining concentration of monomeric silica in water after 72 hours. FTIR revealed that all scale inhibitors exhibit amine characteristic in water. Experimental results show that the polyamidoamine-assisted scale inhibitor, PAMAM G-2/PteGlu, is the most effective in mitigating silicate scale formation. It reduces scaling brine's turbidity as much as 94.8% after 72 hours at 90°C. In addition, it also minimizes silicate polymerization process by retaining almost half of the initial monomeric silica concentration. This also implies that PAMAM G-2/PteGlu inhibitor could reduce the tendency of silicate scale formation to 46% as compared to 97% of silicate scale formation without any inhibition at 95°C. From DSL test, PAMAM G-2/PteGlu inhibitor is also the most effective inhibitor. It prolongs the scaling time from 7 minutes to 339 minutes at 0.01 g/L inhibitor concentration. It is also 7% more effective than PAMAM G-1/PteGlu inhibitor in DSL test. In general, the performance of scale inhibitors for silicates can be arranged as: PAMAM G-2/PteGlu > PAMAM G-1/PteGlu > PteGlu > PAMAM G-2 > PAMAM G-1 from top to bottom. In this work, these environment-friendly products had demonstrated good silicate scale inhibition as well as synergistic effect. They could offer as alternatives to commercial scale inhibitors.
Risk and Economical Assessment LNG Fuel System Design in Dual-Fuel Engine Conversion on Crude Oil Tanker
Authors: Wisnu Alhakim Agung Pradenta , Bagus Dinariyana Anak Agung , Pratiwi Emmy , Valentia Maria
Published: October 2023

The shipping industry, both international and domestic, is one of the largest emitters in the world. IMO has made various efforts to reduce the number of emissions the shipping industry generates. MARPOL Annex VI IMO issued a new regulation to reduce the number of emissions from ships. Replacing ship fuel oil with natural gas is one alternative that can substantially reduce the emission produced by ships. Natural gas can reduce CO2 limits by 25-30%, reduce SOx and solid particulate matter (PM) by 100%, and NOx can be reduced by up to 90%. Some have questioned the safety and economic prospects of using natural gas as fuel on ships. Therefore, risk and economic analyses were carried out in this study on converting 63000 GT crude oil tankers into dual-fuel LNG. Converting ship fuel from HFO to LNG means a new design for the fuel system, the P&ID of the LNG fuel system will be designed and analyzed for the fire explosion risks and the economics of the conversion project. The ship's LNG fuel system P&ID design will be carried out using software engineering drawings. The risks will be analyzed using Hazard Operability (HAZOP) from the design. After determining the potential hazard, a quantitative risk analysis using frequency and consequence analysis was conducted. Fault Tree Analysis and Event Tree Analysis methods analyze the frequency of hazards that may arise. The potential hazard will be mapped using modeling software (ALOHA) to determine the impact and consequences that arise from the hazard. The results of this risk analysis will be mapped on the F-N Curve to see each system's risk level. Economic analysis was carried out to determine the length of time the initial investment cost for converting the ship. In the analysis stage, the risk of the fuel system is divided into six nodes. After a frequency analysis, it found that the largest fires in the system are LNG regasification pump with a failure frequency of 4.08.E-03 per year with a Jet Fire, Explosion, and Flash Fire frequency of 8.15.E-04 each, 1.30.E-04; 9.78.E-05. All risks are mapped on the F-N curve, showing that all risk levels are acceptable. For economic analysis calculations on LNG conversion projects, the Capital Recovery Factor (CRF) method determines the return on investment from crude oil tanker conversion projects with ROI obtained for four years with an inflation assumption of 10%.
A Mathematical Model and Numerical Simulation of Waterflood Induced Dynamic Fractures of Low Permeability Reservoirs
Authors: Du Kai , Rui Zhenhua , Dindoruk Birol , Yang Tao , Patil Shirish
Published: October 2023

As a powerful technique for reservoir simulation, the embedded discrete fracture model (EDFM) has been widely used for unconventional fracture reservoirs. However, the appearance of dynamic fractures caused by fracture extension during well stimulation brings significant challenge to reservoir simulation. We presented a new numerical method to model the dynamic fracture performance for horizontal wells in unconventional reservoirs by using EDFM in this study. The proposed method includes a numerical model and a workflow to simulate water-oil flow in an unconventional fracture reservoir. The fracture dynamics are not only considered into the pressure-dependent properties of fractures (such as fracture permeability, porosity), but also incorporated into EDFM by activating or deactivating grid blocks of fractures at each time step. Fracturing treatment data during stimulation and microseismic data after hydraulic fracturing provide a quantitative understanding of the dynamic fracture behaviors, including fracture location and geometries with time. We conducted a comparative analysis with respect to static fracture properties and dynamic fracture properties. In comparison to static fractures, dynamic fractures have a substantially higher bottomhole pressure. We also analyzed how production was impacted by shut-in time and water injection rate. Different production systems have varying cumulative oil and water production, and an optimal production system was identified. The quantitative understanding of fracture dynamics for field application examples helps to achieve more accurate production estimation.
Novel Retarded Acid System Improves Acid Fracturing in High-Temperature Gas Wells
Authors: Al Jama Majid A. , Sahu Qasim A. , Ali Eyad A. , AlMajed Mohammed S. , Cairns Amy J. , Sayed Mohammed
Published: October 2023

The oil and gas industry continue to rely on chemical methods for well stimulation of carbonate-rich formations, particularly hydrochloric acid (HCl). The selection is primarily driven by the fact that it is cost-effective and readily reacts with calcium and magnesium-based carbonates to yield soluble products. However, enhancing the fracture half-length using conventional HCl treatments in acid fracturing operations in high-temperature reservoirs remains a challenge. This is because the fast reaction rate between HCl and the rock matrix causes the acid to be rapidly spent and thus hinders deeper placement into the formation. These limitations were tackled through the development of a novel retarded acid system, referred to as LVAS-1 (Low Viscosity Acid System-1).

The new acid system is prepared by blending a strong mineral acid with a suitable strong organic acid while minimizing the amount of free water in the formulation as a mechanism to control dissociation of the acid and afford the desired retardation properties. This new single-phase low-viscosity acid system has proven its effectiveness in acid fracturing applications. The technology was trial tested in high temperature/high pressure conditions to fracture a conventional gas well in the Middle East. The motivation for field testing this system was to significantly increase the etched fracture half-length and maximum attainable pump rates over the current standard emulsified acid system. This was achieved by controlling both the engineering parameters during the treatment and the acid retardation properties. A rigorous post-treatment analysis was conducted to evaluate the performance of this acid system and benchmark it to previously tested acid systems. This includes pressure transient analysis, post–frac flow back, and friction pressure calculations. Pressure measurements relied on installing downhole gauges for friction calculations and Pressure Build-up (PBU) analysis.

We report here the successful development and deployment of a novel engineered hybrid acid system that overcomes the limitations associated with using emulsified acids. Specifically, the technology exhibits superior retardation properties, the ability to pump at higher rates due to lower friction pressure, and the formulation preparation method reduces operational complexity at the wellsite. Acid fracturing operations using the new acid system have proven successful, as evidenced by the prolonged gas production rate. Results of the PBU analysis show finite-conductive fractures in the reservoir with half-lengths higher than conventional acid systems and negative skin factor.

This paper presents a success story, i.e., from laboratory-to-field scale, in the development and utilization a new retarded acid system for acid fracturing applications. It highlights essential design parameters specific to the new system and lists the advantages and limitations over conventional emulsified acid systems.
Accelerating the Permanent CO2 Storage Process – A Safer and Faster Route to Net Zero
Authors: Mishra Shubham
Published: October 2023

Carbon dioxide (CO2) storage is a key element of the Carbon Capture Utilization and Storage (CCUS) process. While there can be several ways of storing CO2, it's underground storage is the most feasible method perceived today. However, underground CO2 storage is fraught with serious safety and environmental concerns beyond economic viability of the CCUS value chain. These concerns can be largely prevented if the CO2is converted into solid state in the subsurface. This phase change of CO2in subsurface condition is a very time-taking process and can take up to more than 100 years in most cases.

This paper proposes two new methods of accelerating the solidification (or mineralization) of CO2 in subsurface conditions, and thus accelerating the time-cycle of a CO2storage process. It also reviews some of the industry and academic works in accelerating the solidification of CO2.
Successful Hydraulic Fracturing Breakthrough in New Low Quality Reservoir Target from Paku Field, Rokan Block, Central Sumatra Basin
Authors: Kurniawan Hendri , Pradana Aulia , Safarina Aulia Sherly , Prasetio Mario Hadinata , Kristanto Irwan , Tjahjono Hendro
Published: October 2023

Paku Field is a relatively small oil field that is located in Rokan block, Central Sumatra Basin. Paku field had a long production history since 1988 with current recovery factor 24%. The field is still under primary depletion with ESP as its major artificial. Currently, Paku field has two active producers with total oil production of around 100 BOPD. Paku field mostly conducted regular well intervention & well service (add perforation and pump recondition) to maintain/improve production, while special well stimulation like hydraulic fracturing was last conducted in 2016 on Paku #04. Paku #04 fracturing job targeting MGL1 sd with reservoir properties average resistivity 20 ohmm, average porosity 13%, average permeability 44 mD and reservoir pressure 1600 psi. Hydraulic fracturing stimulation in this reservoir successfully conducted resulted in 311 BOPD oil gain and 24% water cut from commingle several reservoirs. Until now Paku #04 is still a good oil producer from the same reservoirs with oil average 60 BOPD and water cut 77%.

Looking at the historical success story of Paku #04 as an analog, Paku #05 also has similar low-quality reservoir sand but from the different geological formations that is BK1 sd. The BK1 sd has reservoir properties of 32 ft net pay, 18 Ohmm resistivity, 11% average porosity, 25 mD average permeability and 1534 psi reservoir pressure. The fracturing job in Paku #05 was successfully executed in October 2022 targeting BK1 sd. The job was conducted with several improvements from the previous job of Paku #04 such as conducted with three times more proppant volume (63 k vs 21 k previously), full sand body perforation, and produced from single zone. Hydraulic fracturing stimulation in Paku #5 resulted in initial production of 242 BOPD and water cut 60%.

Hydraulic fracturing jobs have been proven as one of the solutions to significantly improved production in primary fields such as Paku Field. Especially to improve production from reservoirs that are identified to have oil in low-quality reservoirs in other well or in another reservoir in Paku Field and from other fields that has the same reservoir properties characteristic.
A Pumping Well Wireless Communication Technology Based on Load Pulse of Sucker Rod
Authors: Yang Qinghai , Liao Chenglong , Hao Zhongxian , Shen Qiaochu , Xu Jilei , Zhao Hongyu , Li Yuan , Du Shuming
Published: October 2023

Pumping wells are characterized by fluid discontinuity, complex media, and periodic pump inspection. The data transmission technology, such as preset cable and pressure wave, which are widely used in injection wells, suffers from many problems when applied in pumping wells, such as high cost, complicated technique, and not suitable for pump inspection operation. As a result, there is an urgent need to develop low-cost wireless transmission technologies suitable for pumping well.

This paper proposes an innovative wireless communication technology for pumping well based on the load pulse of sucker rod. Its main components include a downhole load pulse generator (DLPG) and a ground communication controller (GCC). The DLPG is installed between the tubing pump barrel and the stationary valve and is equipped with an 8.5 mm diameter stepless adjusting valve that provides access between the pump chamber and annulus. During the operation of the pumping unit, adjusting the opening or closing state of the adjusting valve can change the working state of the tubing pump and thus change the normal lifting load of the pumping unit. Therefore, wireless uploading of downhole data can be realized by modulating downhole data into lifting load pulse and demodulating of load pulse by the GCC.

The principle and transmission characteristics of the technology have been tested in Jilin Oilfield. The results show that the opening or closing of the adjusting valve of the DLPG generate controllable and identifiable lifting load pulses at the wellhead. Moreover, with the increasing opening of the adjusting valve, the lifting load increases significantly. The average load when the adjusting valve is fully opened is 33.65kN, an increase of 64.7% compared with the normal lifting load. When the adjusting valve is completely closed, the lifting load quickly drops to normal. In addition, at 980 m pump setting depth, the response delay of lifting load dynamic change is very small. The pressure sensor of the DLPG can recognize the pressure changes of the pump chamber and accurately judge the up and down stroke. Using stroke recognition and load pulse automatic control, the downhole data uploading is successfully realized, and the technical principle and feasibility are verified.

This technology realizes wireless uploading of downhole data without changing the structure and working mode of the existing pumping well. It has the advantages of simple structure, easy installation, low cost, and no influence of pump inspection operation. It can be adapted to the current situation of the large number and wide distribution of pumping wells in China, and is expected to provide a new means of communication for improving the downhole understanding of pumping wells.
A detailed procedure to maximize IgM-induced Leishmania major mating in vitro
Authors: Serafim Tiago D. , Valenzuela Jesus G.
Published: October 2023

The steps presented here were developed to maximize the production of Leishmania hybrids in vitro. Our protocol was developed by mimicking as closely as possible the environment inside the gut of the sand fly where we successfully and consistently produced hybrids in vivo. It is important to note that producing hybrids in vitro is less optimal than producing them in vivo. Following this step-by-step protocol faithfully and carefully will significantly improve the success of producing hybrids in vitro.
Risk factors of chemotherapy-induced thrombocytopenia after oxaliplatin-containing chemotherapy for gastrointestinal malignancies
Authors: Li Ju , Wang Wanqing , Jiang Kaipeng , Cui Jiuwei , Wang Chang , Liang Tingting , Wang Yizhuo , Liu Shuhan , Zhou Wenshuo
Published: October 2023

Purpose
Thrombocytopenia is among the most common chemotherapy-related hematologic toxicities. We aim to determine the predictors of oxaliplatin chemotherapy-induced thrombocytopenia (CIT) in patients with gastrointestinal tumors to guide the clinic.
Methods
Clinical data of 750 patients with a malignant gastrointestinal tumor were included as the primary cohort. Basic clinical data, serological indices, and anthropometric indices of these patients were collected. Grouped based on the presence or absence of CIT, univariate analysis was performed to identify significant factors related to chemotherapy-induced thrombocytopenia. Based on the results of multi-factor analysis, a nomogram was constructed using R language programing and its fitness was evaluated using the calibration curve and ROC curve.
Results
Univariate analysis identified 20 factors as closely related to CIT occurrence. The binary logistic multivariate regression analysis revealed five independent risk factors for developing CIT (P < 0.05): the M stage, total dose of oxaliplatin, albumin, baseline thrombocyte count, and natural killer (NK) cell count. The calibration curve of the monogram shows that the combined predictors had good consistency. A better prediction efficiency was observed with the ROC curve of 0.877 with the cut-off value of 0.3579613 (with sensitivity of 78.9% and specificity, 81.8%).
Conclusion
The total dose of oxaliplatin, M stage, albumin, baseline platelet count, and NK cell count were independent risk factors for CIT.
Influence of tool speed movement during cutting honeycomb block on its vibration resistance and cutting accuracy
Authors: Saramud Mikhail V. , Brungardt Maksim , Tololo Alexandr , Talay Evgeniy , Peteckaya Angelina
Published: October 2023

The state of cutting blanks from honeycomb fabric methods is associated with difficulties of rectilinear cutting of cell walls, which leads to a non-straight edge after cutting with a cutting tool. Such a form of curvilinear trajectory of the cutting tool movement is a consequence of the cutting-edge vibration in the process of moving towards cutting. In order to eliminate this effect, it is necessary to determine optimal cutting speed at which the blade and the honeycomb wall will not be in the resonance.