bluuebunny/crossref_metadata_2025 huggingface dataset:
Altitude, geological substrate, and dynamics of Natura 2000 habitat types in Cretan low-vegetation pastures
Authors: Bendali Frederic , Godron Michel
Published: October 2024

New Greek legislation imposes conservation goals for habitat types (HTs) in sites of (European) community interest (SCI), so the ecological equilibrium status must be checked before impact assessment in these sites. We processed 1,875 vegetation samples (relevés) from the previous Conservation Status Assessment campaign in Crete (2014–2015) concerning low-vegetation pastures in 29 SCI. We conducted a frequency analysis to find vegetation groups (VGs) and relevés groups (RGs) using the same matrix species × relevés. We present a general table where the RG are defined by their habitat code and class values of altitudinal and geological substrates. We also used ecological profiles on these variables to fine-tune the differences within the VG. These methods led to phytosociological and ecological precisions: in the grass habitats (HT code 6220), the class of Lygeo sparti–Stipetea tenacissimae is on tertiary substrate at an altitude below 210 m, the Helianthemetea guttati is below 1,250 m on hard limestone and at a low altitude on noncalcareous substrate, while the Stipo–Trachynietea distachyae is below 800 m and is not substrate-restricted. Concerning phryganas and heaths, the altitude at 1,500 m separates HT 5420-5430 downward, associated with classes Ononido–Rosmarinetea and Cisto–Lavanduletea stoechadis, from HT 4090 upward, associated with the Daphno–Festucetea. The altitude of HT 5420 remains downward of 800 m. HT 4090 and 5430 are also characterized by calcareous geological substrates, namely hard limestone and marble. We suggest that HT 5420 is the most post-cultural vegetation and HT 5430 is a long-term pasture on noncultivable substrates.
Development of Sound Power of Onshore Wind Turbines including its Spectral Distribution
Authors: van den Berg Frits (G.P.) , Koppen Erik , Boon Jaap , Ekelschot-Smink Madelon
Published: October 2024

The sound power LW of wind turbines (WTs) over the past decades has developed in relation to their electric power P as LW ∝ logP. The spectral distribution of the sound did not change significantly over time. This applies to the average performance of wind turbines, with differences between individual WT types. Because of the expected growth of onshore wind energy, a greater number of people will be living close to wind farms. This sustains the need for sound reduction. Sound reduction measures, such as serrations, reduced tip speed and low noise modes, may counteract the development of higher sound power from ever bigger WTs. To investigate this, the sound production of WT types over the last decades is analysed in relation to their size and electric power and the application of sound reduction measures. The analysis includes the broad band A-weighted and low frequency sound power levels as well as more detailed spectral distributions. Results show that the sound power level of wind turbines above 3 MW on average increases less with size than smaller turbines did. This is due to a lower blade tip speed and the use of sound reducing serrations. The spectral content of wind turbine sound, including the lower frequencies, has not changed significantly.
Imprecision in Yield Estimates Using Timber Volume in Forest Management Plans in the Amazon
Authors: Silva Ribeiro Renato Bezerra da , Lisboa Leila Sheila Silva , Dias Carlos Tadeu dos Santos , Oliveira Afonso Henrique Moraes , Araújo Emanuel José Gomes de , Andrade Dárlison Fernandes Carvalho de , Martorano Lucieta Guerreiro
Published: October 2024

The evaluation of logging in a forest management area using only the volume variable is not sufficient to assess the effectiveness of the harvest. The objective was to evaluate harvested volume using different logging variables to point out possible divergences between what was planned and what was actually carried out, in order to indicate adjustments to next annual operating plans (AOPs). The database comes from a community forest management area in the Tapajós National Forest, considering three sources: forest inventory, AOP planning and the post-exploration report. The yield considering the number of trees felled and the effective volume were compared with the AOP planning. The volume estimated by the generic equation was compared with the cubed volume and the commercial height variable was evaluated. Of the 6,267 trees selected, 5,090 trees were harvested (3.2 trees ha-1), indicating a yield of 85% of the estimated volume. Of the 25 commercial species logged, the most representative were: Manilkara huberi, Vochysia maxima, Lecythis lurida, Couratari guianensis and Hymenaea courbaril. It can be concluded that the number of trees, cubed volume and commercial height are post-exploration yield response variables and not just volume, as is currently used in Sustainable Forest Management Plans (SFMPs).
Exploring the Complex Interplay Between Oral Fusobacterium nucleatum Infection, Periodontitis, and Robust microRNA Induction Including Multiple Known Oncogenic miRNAs
Authors: Jeepipalli Syam , Aravindraja Chairmandurai , Duncan William D , Vekariya Krishna Mukesh , Sahay Bikash , Chan Edward K.L. , L Kesavalu
Published: October 2024

Fusobacterium nucleatum (F. nucleatum, Fn), an oral commensal that can become pathogenic, is associated with periodontitis (PD), adverse pregnancy outcomes, and colorectal cancer (CRC). MicroRNAs (miRNAs) are conserved, non-coding RNAs that play a regulatory role in gene expression and are detected in microbial infections. The aim of this study was to characterize the global microRNA expression kinetics in the mandibles of C57BL/6J mice infected with F. nucleatum for 8 and 16 weeks, and to identify miRNAs as biomarkers of the PD process using high-throughput NanoString nCounter® miRNA panels. Mice were divided into four groups: 8 weeks of Fn infection, 16 weeks of Fn infection, and their respective sham infection. Fn-infected mice at both 8- and 16 weeks showed 100% bacterial colonization on the gingival surface, along with a significant increase in alveolar bone resorption (p<0.0001) and intravascular dissemination to heart, indicating its invasive potential. Out of 577 miRNAs analyzed, seven miRNAs (miR-361-5p, miR-99b-5p) were upregulated, and two miRNAs (miR-362-3p and miR-720) were downregulated in the 8-week Fn infection group. In the 16-week Fn infection group, seven miRNAs (miR-361-5p, miR-99b-5p) were upregulated miRNAs and 13 miRNAs (miR-323-3p, miR-488) were downregulated. Notably, miRNAs such as miR-205, miR-210, miR-199a-3p which were differentially expressed (DE) in the Fn-infected mice at 8 weeks and miR-28 at 16 weeks, have been previously reported in human periodontitis. The 13 miRNAs induced by F. nucleatum (miR-361-5p) are linked to multiple malignancies, including esophageal, gastric, pancreatic, and colorectal cancers. Additionally, the DE miR-126-5p in the 8-week infection group has been identified as a potential biomarker for patients with PD and cardiovascular disease. The results indicate that F. nucleatum acts as a potent oncomicrobe, inducing several miRNAs associated with PD and linking it to systemic comorbidities. Furthermore, the study revealed similar expressions between PD-associated miRNAs and nine CRC tumor-expressed miRNAs.
Predicting Mutual Fund Stress Levels Utilizing Sebi’s Stress Test Parameters in MidCap and SmallCap Funds Using Deep Learning Models
Authors: Maheshwari Suneel , Naik Deepak
Published: October 2024

The Association of Mutual Funds of India (AMFI) under the direction of the Securities and Exchange Board of India (SEBI) provided open access to various risk parameters with respect to MidCap and SmallCap funds on its website in February, 2024. This disclosure of month wise cross-sectional data depicting stress-test and liquidity analysis was hailed as a milestone as it provided a glimpse into inherent risk of mutual funds. The AMFI dataset consisted of 14 variables including stress test results, ownership concentration on both liability & asset sides, standard deviation on portfolio’s returns, portfolio beta, trailing 12-month PE ratio, portfolio turnover etc. Among these, the primary variable identified in grading mutual fund is the stress test parameter, expressed as number of days required to liquidate 50% and 25% of the portfolio respectively on a pro-rata basis under stress condition. A higher number of days to liquidate the portfolio under stress conditions represented higher risk for the investor. The objective of our paper is to test various neural network models which can help in predicting stress levels with the highest accuracy and specificity in MidCap and SmallCap mutual funds based on AMFI’s 14 parameters as predictors.Our study utilizes AMFI datasets available for MidCap and SmallCap mutual funds from February 2024 (inception period) to May 2024. To operationalize the analysis, the derived response variable was binned to represent high and low risk based on the time required for pro-rata liquidation of the portfolio. The study employed feed-forward neural networks, with the logistic regression as the step function, to model the relationships. Results suggest that the simpler neural network models with one hidden layer and two to three nodes show higher accuracy and specificity. Analysis also shows that more complex architectures do not always guarantee better performance as these models might suffer from higher bias. By leveraging advanced computational techniques, this study contributes to the ongoing discourse surrounding risk management and decision-making in the realm of mutual fund investments.
Sociodemographic Determinants of Malnutrition in Rural and Urban Areas of Abia State, Nigeria: A Cross-Sectional Study
Authors: Salisu Abdullateef , Osoteku Demilade , Aina Muyi , Ibrahim Raihanah , Ata Itoro , Ezinne-Raphael Caroline Charles , Uahomo Precious , Njemanze Ihunnaya , Oliseh Ruth , Otono Precious , Adaramati Tobiloba , Amasiatu Valentine , Olufadi-Ahmed Haishat , Fadeyi Oluwaseun , Adetunde Oluwasegun , Aigbogun Jr. Eric , Igbokwe Uchenna
Published: October 2024

Malnutrition in children aged 0-5 years is a significant public health concern in many societies, and is influenced by various sociodemographic factors which when understood may improve intervention planning and results. Background. This study aimed to identify the sociodemographic determinants of malnutrition in rural and urban areas of Abia State, Nigeria. Methods. A cross-sectional observational study involving 842 children (aged 6-59 months) and their caregivers was conducted across selected rural and urban areas in Abia State area of Nigeria. Data collected through semi-structured questionnaires focused on sociodemographic information as well as anthropometric measurements such as weight, height, and mid-upper arm circumference (MUAC). The dietary diversity scores (DDS) were also calculated for each child using a questionnaire that recorded the consumption of various food groups over a 7-day period. Chi-Square tests was adopted for categorical variables, while binomial logistic regression was used to identify determinants of malnutrition and weight classification. Results. Marked sociodemographic differences were found between rural and urban caregivers, with urban caregivers being more likely to have higher knowledge of nutrition (p < 0.01) and education (p < 0.01). Malnutrition, indicated by global acute malnutrition (GAM), was significantly higher in rural areas (53.5%) compared to urban areas (46.5%) (χ2 = 5.353, p = 0.021). Logistic regression showed that children of caregivers in rural areas had higher odds of abnormal BMI-for-age (AOR: 1.407, 95% CI: 1.001–1.978, p = 0.049), while children of caregivers in urban areas were less likely to be malnourished (COR: 0.565, 95% CI: 0.347–0.921, p = 0.022). Conclusion. Implementation scientists should focus on enhancing caregiver education, particularly in rural areas, to promote awareness on diets thereby reducing malnutrition.
Decadal Morphological Evolution and Governance Measures of the South Branch, Changjiang Estuary
Authors: Luan Hualong , Zhou Jianyin , Li Mengyu , Qu Geng , Yao Shiming , Lin Musong , Wang Min , Yuan Yuan
Published: October 2024

Estuaries and deltas possess significant socioeconomic importance and exhibit high ecological value because of their dynamic geomorphic processes and unique geographical advantages. However, delta recession and the instability of river regimes have become worldwide issues due to intensive human interventions in upstream river basins and local areas in recent decades. This study focuses on a typical example, the South Branch of the Changjiang Estuary, to explore its morphological evolution in the past decades and near future and propose suitable solutions to enhance the stability of the river regimes. Based on bathymetric data analysis, we find significant channel-shoal adjustment within the South Branch from 1958 to 2016, characterized by substantial erosion and deposition on decadal timescales. After 1997, the South Branch experienced overall erosion due to the reduced fluvial sediment supply. Disturbances on the Baimao Shoal and Biandan Shoal further aggravated the river regime’s stability. Numerical predictions for future evolution trends indicate continuous erosion in the South Branch over the next 20 years, with further adjustments to the channel-shoal pattern. Hydrodynamic modeling of the proposed measures demonstrates an increased ratio for the North Baimao Shoal Channel, leading to enhanced stability of the channel-shoal system. These integrated governance measures have been incorporated in the new round of renovation planning for the Changjiang Estuary. The findings provide valuable scientific guidance for the comprehensive management of the Changjiang Estuary and offer insights applicable to other large estuaries.
Exploring the Nexus of Feeding and Processing: Implications for Meat Quality and Sensory Perception
Authors: Rodrigues Sandra S. Q. , Leite Ana , Vasconcelos Lia , Teixeira Alfredo
Published: October 2024

The intrinsic quality of meat is directly related to muscle and fat tissues. Factors such as the rate and extent of anaerobic glycolysis affect muscle pH, influencing the meat's color, water retention, and texture. Postmortem anomalies can result in deviations from this intrinsic quality. The ani-mals' diet plays a crucial role in meat quality. Specific nutrients, such as proteins, vitamins, and minerals, affect meat's texture, flavor, and juiciness. Feeding rich in omega-3 fatty acids can im-prove the sensorial quality of meat. Meat processing and methods such as aging, marinating, and cooking affect texture, flavor, and juiciness, which can be evaluated by specific equipment or trained or untrained consumers. This comprehensive review investigates the relationship be-tween animal feeding practices and meat processing techniques and their combined impact on meat quality and sensory perception. By synthesizing recent research, we explore how various feeding protocols (including diet composition and feed additives) and processing methods shape meat products' nutritional value, texture, flavor profile, and overall consumer appeal. Under-standing this nexus is crucial for optimizing meat quality while ensuring sustainability and safety in the food supply chain.
Optimum Level of Essential Amino Acids-to-True Protein and Energy in Reduced Protein Diets Has the Potential to Enhance Broiler Performance
Authors: Musigwa Sosthene , Cozannet Pierre , Asiamah Collins A. , Wu and Shu-Biao
Published: October 2024

Supplementing essential amino acids (EAA), without considering non-EAA (NEAA) and energy contents in reduced crude protein (CP) diets may alter essential-to-total AA or true protein (E:T) and energy-to-protein ratios, potentially compromising growth. This study aimed to evaluate the effects of CP, E:T and net energy (NE) on broiler performance. Treatments were: T1— reduced CP (16%, RP), low NE (9.9 MJ/kg, LNE), low E:T (0.56, LE:T); T2—RP, LNE, high E:T (0.60, HE:T), with imbalanced EAA (excess Met and deficient Thr); T3—RP, high NE (10.4 MJ/kg, HNE), LE:T; T4—RP, HNE, HE:T; T5— normal CP (18%, NP), LNE, LE:T; T6—NP, LNE, HE:T; T7—NP, HNE, LE:T; and T8—NP, HNE, HE:T. The study employed as-hatched Cobb 500 broilers in two experiments. Exp.1 studied performance from d19 to 35, with 8 replicates per treatment and 16 birds per replicate (n=1024). Exp.2 measured NE values in respiration chambers from d25 to 28, with 6 replicates per treatment, and 2 birds (a male and a female) per replicate (n=96). The measured NE values were used to calculate NE intake (NEi) in Exp.1. The results showed that T4 improved (P < 0.001) weight gain (WG), feed conversion ratio (FCR), and NEi relative to T1, T2 and T3, and protein efficiency (WG/CP intake) relative to all treatments. The live performance (feed intake, WG, FCR) and NEi of birds fed T4 reached a level equal to those of birds fed NP-diets (T5 to T8). These results suggest that a dietary E:T ratio of 0.60 is necessary to maximize nutrient utilization and to restore growth rate in broilers fed RP-diets.
Crouch Gait Recognition in the Anatomical Space using Synthetic Gait Data
Authors: Gonzalez-Islas Juan-Carlos , Dominguez-Ramirez Omar-Arturo , Lopez-Ortega Omar , Pena Ramirez Jonatan
Published: October 2024

Crouch gait is one of the most common gait abnormalities. In the literature, there are few works related to the crouch gait recognition. In this work, we aim at the integration of a framework for multiclass crouch gait recognition using synthetic eight-DoF model gait data in anatomical space. The main contribution of our study is the joint function generator algorithm, which could be used to generate other physiological signals; and the gait data validation stage. In addition, we use a feature selection method and a body region segmentation approach to improve classification performance. We generated a gait dataset containing 25 join functions of each DoF for each gait class (4 crouched and normal). The algorithms that we evaluated for classification were: K-nearest neighbors (kNN), Naive Bayes (NB), discriminant analysis (DA), decision trees (DT), and an artificial neural network (ANN). We calculated the metrics: accuracy (Acc), recall (R), specificity (SP), precision (P) and the F-measure (FM) to asses the classification performance. In general, for this work, the best algorithms were discriminant analysis and artificial neural networks. The main results of the proposed recognition framework provide evidence that can be used in real clinical settings to diagnose and make decisions about treatments related to crouch gait diseases.
Unraveling the Immune Web: Advances in SMI Capsular Fibrosis from Molecular Insights to Preclinical Breakthroughs
Authors: Schoberleitner Ines , Faserl Klaus , Lackner Michaela , Coraca-Huber Debora C. , Augustin Angela , Imsirovic Anja , Sigl Stephan , Wolfram Dolores
Published: October 2024

Breast implant surgery has evolved significantly, yet challenges such as capsular contracture remain a persistent concern. This review presents an in-depth analysis of recent advancements in understanding the immune mechanisms and clinical implications associated with breast implants. The article systematically examines the complex interplay between immune responses and capsular fibrosis, emphasizing the pathophysiological mechanisms of inflammation in the etiology of this fibrotic response. It discusses innovations in biomaterial science, including the development of novel anti-biofilm coatings and immunomodulatory surfaces designed to enhance implant integration and minimize complications. Emphasis is placed on personalized risk assessment strategies, leveraging molecular insights to tailor interventions and improve patient outcomes. Emerging therapeutic targets, advancements in surgical techniques, and the refinement of post-operative care are also explored. Despite notable progress, challenges such as variability in immune responses, long-term efficacy of new interventions, and ethical considerations remain. Future research directions are identified, focusing on personalized medicine, advanced biomaterials, and bridging preclinical findings with clinical applications. As we advance from bench to bedside, this review illuminates the path forward, where interdisciplinary collaboration and continued inquiry weave together to enhance the art and science of breast implant surgery, transforming patient care into a realm of precision and excellence.
Opinion of Flemish Poultry Farmers on How Birds Fit for Transport to the Slaughterhouse Are Selected, Caught, and Crated
Authors: Delanglez Femke , Watteyn Anneleen , Ampe Bart , Garmyn An , Delezie Evelyne , Sleeckx Nathalie , Kempen Ine , Demaître Niels , Van Meirhaeghe Hilde , Antonissen Gunther , Tuyttens Frank André Maurice
Published: October 2024

Pre-transport management activities can cause stress, injuries, and mortality in poultry. This study aimed to gather information about the current pre-transport practices (selection of unfit chickens, catching preparations, catching, and crating) for spent hens and broilers by questioning Flemish poultry farmers. The results showed that catching preparations such as an extra selection of chickens unfit for transport was performed by a minority of the poultry farmers, and that layer farmers were less in line with the EU-legislation for water and feed withdrawal than broiler farmers. All birds were caught inverted except for one broiler farmer who used mechanical catching (not yet common in Flanders). Additionally, mechanical catching may involve extra costs, increased biosecurity risks, and specific recommendations for the stable (height and width). The broiler farmers preferred mechanical catching for broiler catchers' well-being, while upright catching was considered better for animal welfare than catching more than three chickens by one/two legs, mechanically, or by wings. Awareness of the need to perform an extra selection by the poultry farmers before catching is required. Preparations like closing areas under the aviary system and removing litter (layers) can further streamline the process and reduce animal suffering.
Metal Contamination and Human Health Risk Assessment of Soils from Parks and Playgrounds of an Industrialized Town (Galati, Romania)
Authors: Ene Antoaneta , Sion Alina , Stihi Claudia , Gheboianu Anca Irina , Basliu Vasile , Ceoromila Alina Mihaela Cantaragiu , Gosav Steluta
Published: October 2024

The aim of the present study was to evaluate the contamination state of the surface soil from 10 parks and playgrounds from Galati, Romania, and the health hazard. The soil samples, collected in each site from the playing ground and from the edge of the park, were analyzed by using com-bined Wavelength- (WDXRF) and Energy-Dispersive (EDXRF) X-ray fluorescence techniques. A total number of 27 chemical elements (Ag, Al, As, Ba, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sb, Sc, Sn, Sr, Ti, V, Zn and Zr) were quantified in the urban soils, and the results were compared to the normal and alert values from Romanian legislation for toxic trace elements, as well as with European and world average values of element concentrations. The mineralogical analyses were performed by Scanning Electron Microscopy with Energy Dispersive X-ray Analysis (SEM-EDX) and Attenuated Total Reflectance-Fourier Transform Infrared technique (ATR-FTIR). To assess the soil contamination and the impact on human health of the presence of potential toxic elements and heavy metals in the soil, a series of pollution and health risk indices were used. All the results indicated an unpolluted to moderate polluted soil. The soil samples collected from the edge of the parks presented higher values for the specific pollutants that originated from heavy traffic, such as Cu, Cr, Zn and Pb. The non-carcinogenic risk to children was assessed using the estimate daily intakes (EDI), afferent to the pathways that pollutants can enter the human body, such as ingestion, dermal contact and inhalation. Using the obtained values for EDI, the hazard quotient and hazard index were determined, which strengthen the formerly issued presumption that soil pollution is moderate and, by itself, does not present any threat to the children’s health.
Importance Of Cbct In Implantology In The Pre - And Post-surgical Phase
Authors: Sofia Rita , Abecasis Pedro , Jaureguy Santiago , Miravé Araceli Martinez
Published: October 2024

Cone-beam computed tomography (CBCT) has become a vital tool in implantology, playing a key role in both pre- and post-surgical phases. Preoperatively, CBCT provides detailed three-dimensional evaluation of anatomical structures, offering precise information on bone quality and quantity, as well as the location of critical structure. This accuracy enhances surgical planning, reducing intra- and postoperative risks and ensuring more precise implant placement. Post-surgically, CBCT is equally important for monitoring osseointegration and detecting potential complications, such as failed integration, infections, or implant misalignment. Its high-resolution imaging capabilities enable clinicians to make accurate therapeutic adjustments, improving treatment outcomes. Overall, CBCT improves decision-making in implantology, offering greater predictability and safety compared to traditional two-dimensional radiography, significantly enhancing the success rates of implant-based oral rehabilitation procedures.
Focal Fibrocartilaginous Dysplasia and Growth Arrest
Authors: Adhiyaman Akshitha , Tracey Olivia C. , Nagra Kiranpreet , Zucker Colson P. , Wisch Jenna L. , Jones Ruth H. , Fabricant Peter D. , Heyer Jessica H. , Widmann Roger F. , Doyle Shevaun M.
Published: October 2024

Case:

A pediatric patient with focal fibrocartilaginous dysplasia (FFCD) developed angular deformity and growth arrest despite standard guided growth management. The patient underwent implant-mediated guided growth for proximal tibia varus deformity which recurred; subsequently, a physeal bar of the medial proximal tibia was diagnosed, which progressed to physeal arrest.

Conclusion:

Treatment options for FFCD-associated angular deformity include observation and guided growth. This case highlights the risk of complete physeal arrest in FFCD.
Comparative microbiological, chemical, and sensory traits of aron fermentation in Tengger and laboratory scales
Authors: Krisbianto Oki , Putra Andre Yusuf Trisna , Padaga Masdiana Chendrakasih , Minantyo Hari
Published: October 2024

Aron, a traditional fermented food of the Tengger community, is made from white corn grown in Bromo and has received limited microbiological, chemical, and sensory research attention to date. The research objective was to compare microbiological, chemical, and sensory traits between in situ-produced aron on the slopes of Mount Bromo and ex situ-produced aron in a laboratory in Surabaya. A specific strain of lactic acid bacteria was isolated using de Man, Rogosa, and Sharpe (MRS) Agar from samples of sun-dried white corn. This strain was identified as Gram-positive cocci. In contrast, a different strain of Gram-positive bacilli was found in corn-soaking water, both in situ and in laboratory-fermented aron, on days 0, 7, and 16. Chemical analysis revealed no significant differences in protein, fat, and ash content between the two variables. However, laboratory-fermented aron exhibited higher moisture content. This discrepancy significantly influenced the hedonic texture data for aron, with in situ aron being perceived as drier and more mouth-soluble, while laboratory-fermented aron had a softer texture. Furthermore, the high microbial growth during the fermentation process resulted in aron with a distinct and relatively strong aroma that was less favored by the panelists. The difference in the fermentation location of white corn did not affect the types of lactic acid bacteria that thrived, the nutritional compound content, and the appearance of aron. The variation in the aroma of aron is believed to be primarily influenced by the number of bacteria rather than their specific strains.
Capacity Factor Forecasting for Generation Facilities Based on Renewable Energy Sources in Decentralized Power Systems
Authors: Bramm A. M. , Matrenin P. V. , Papkova N. A. , Sekatski D. A.
Published: October 2024

One of the directions of development of the electric power industry is decentralization, aimed at improving the reliability of energy supply, reducing losses during transmission of electric energy and ensuring energy independence of consumers. It is possible to simulate decentralized power systems, including distributed generation facilities, by implementation of multi-agent systems that allow solving design and control problems taking into account the needs of each participant in the process of production, transmission, distribution and consumption of electricity. The development of distributed generation using a multi-agent approach requires the creation of models for assessing the technical and economic efficiency of decisions made by each agent, both at the strategic and tactical levels. The strategic decisions of agents related to distributed generation include, among other things, the creation of power facilities and power plants based on renewable energy sources. An important factor for making such decisions is the estimation of the capacity factor. However, currently there are no models for its estimation with high reliability. The present paper proposes a new algorithm for estimating the capacity factor for the entire territory of a certain administrative unit and a model for its forecasting based on climatic and geographical parameters. The study was conducted on a data sample of 221 generation facilities (solar and wind power plants) in four oblasts (regions) of the Russian Federation. It has been determined that the capacity factor can be forecasted with a mean error within 4 % for photovoltaic power plants and 9 % for wind power plants. Therefore, it is possible to use the developed algorithm and model both in decision support systems when choosing the location of this types of power plants, and in systems that model the development of power systems using a multi-agent approach.
Self-Granulating Thermoplastic Elastic Particles for Fracture Conformance Control in Ultraharsh Reservoirs: Laboratory Investigation and Field Application
Authors: Xue Yan , Yin Qiulu , Zhang Chunquan , Wei Bing , Lu Jun , Wang Yiwen
Published: October 2024

To address the challenges in fracture conformance control using polymer particles in ultraharsh reservoirs, we developed novel self-granulating thermoplastic elastic particles (SGTEPs). The innovation was driven by the complexity of the traditional polymer particle preparation process and the difficulties in balancing injectivity and conformance control performance. Polyvinyl alcohol (PVA) served as the particle skeleton, and millimeter-scale SGTEPs were prepared in situ by incorporating a hydrophobic modifier (HM) and a cross-linking agent (glutaraldehyde, GA) into an aqueous phase. The morphology, mechanical properties, and high-salinity thermal stability of SGTEPs were investigated using scanning electron microscopy (SEM), texture profile analysis (TPA), and thermal aging tests at 130°C. Particle size adjustability was demonstrated through the modulation of HM content and stirring speed. TPA highlighted SGTEPs’ superior elasticity and resilience. SGTEPs underwent thermal plasticization in ultrahigh-salinity brines (22.0 × 104 mg/L, Ca2+ + Mg2+ = 1.2 × 104 mg/L) and crude oil at temperatures up to 130°C, retaining exceptional mechanical properties even after 60 days of aging. Open fracture models were designed to investigate the effect of particle size, injection rate, and particle concentration on SGTEPs’ migration performance. Coreflooding experiments indicated effective migration and conformance control performance of SGTEPs, with appropriate matching coefficients of 1.45 and 1.50. The particles exhibited an “aggregation → accumulation → deformation migration” effect, with particle concentration linearly affecting differential pressures. After high-temperature aging, SGTEPs could efficiently plug the open fracture, achieving breakthrough pressures up to 1860 kPa. Field application results showed significant improvements in oil production and water-cut reduction. Specifically, the daily oil production of Well TK466 increased from 4.6 tons to 15.5 tons, with an incremental oil production of 252.5 tons per well and a reduction in average water cut from 90% to 82.7%. The newly developed SGTEPs offer a fresh perspective on material design for enhancing conformance control in ultraharsh condition reservoirs with large fractures and void spaces. The novel particles demonstrated excellent thermal stability, elasticity, and migration and plugging performance, making them a promising solution for improved oil recovery in challenging reservoir conditions.
Coating System Selection on Offshore Flare Bridge Structure Using Maximum Temperature Estimation from Flare Radiation Simulation
Authors: Hardiananto N. , Harmantoro A. , Anfasa F. , Hartono E.
Published: October 2024

Offshore structures are highly susceptible to general corrosion which can lead to damage and lower the mechanical strength of the structure. Flare bridge structure are more susceptible to corrosion, due to experience combined effects of the corrosive marine environment and thermal radiation from flare. It is important to select a suitable coating system by considering the affected temperature. This paper will discuss about a brief case that describes how coating system selection is implemented in PHE ONWJ using a flare radiation simulation to estimate a maximum temperature.

This study was started by reviewing previous Flare Heat Radiation and Dispersion Study in ‘U’ flow station to focus on flaring scenario, flare design data, and flare heat radiation contour. The next step is calculating the flare bridge temperature due to flare heat radiation exposure. This work combines four steps: (1) Collect flare bridge data, (2) Define maximum heat radiation based on flare contour, (3) Calculate the heat radiation received by flare bridge, (4) Calculate the flare bridge temperature. Lastly, select the coating system which considers the estimate of the flare bridge surface temperature and corrosion resistance to marine environment.

The flare bridge temperature is estimated to be 136°C based on conservative calculation as affected by emergency flaring scenario that last(s) approximately 15 minutes of maximum flare relief duration. After the emergency flaring is over, the fluid service temperature slowly drops to the ambient temperature (approximately 28 to 30°C). This scenario is considered as the conservative approach due to the highest flow rate and maximum thermal radiation applied.

Hence, apart from considerations to select an appropriate coating system such as: Minimum area average roughness, Sa 3; Prime coat functions as corrosion resistance in cyclic temperature; it should be considered that the coating temperature resistance > 136°C. Referring to the company's coating specification, we select BM 4-1 for coating the flare bridge structure.

This practical approach aims to achieve as low as reasonably practicable coating system on the offshore flare bridge structure. Coating refurbishment using the selected coating system is expected to be highly suitable and can stand last for a long time.
An Advanced Workflow and Tool to Map New Sweet Spot and Enhanced Well Placement Strategy using Machine Learning in Unconventional Reservoir
Authors: Wan Sagar S. F. S. , Trianto A. , Musa I. H , Hendraningrat L. , Mazeli A.
Published: October 2024

Unlike conventional reservoirs where the reservoir rock formations are recipient of hydrocarbons from the source rock, unconventional formations constitute both the source and the hydrocarbon containing reservoir units. For the field development, horizontal wells are drilled and later hydraulically fractured in order to produce the gas. The placement of horizontal wells is crucial for the economic viability of the field. This paper describes developing an advanced workflow of new sweet spot mapping and a standalone tool to enhance horizontal well placement and completion optimization using machine learning.

The tool, called Sweet Spots Machine Learning (SS-ML) is developed to integrate petrophysics, geomechanics, seismic, completions attributes and production data in order to map out high productivity zone that will help optimize well placement strategy. This study focused on a case study in Unconventional reservoirs in Canada. The procedure integrates all data from multiple domains such as Petrophysics-Geomechanics-Seismic-Completions attributes with the field production data and establishes a machine learning model (ML) in order to predict and map-out production sweet spots. The output 3D predicted production volume can then be employed to help optimize well placement and completions strategy.

In general, unconventional reservoirs are difficult to produce as they are made up of very tight rocks containing hydrocarbons that cannot be produced without stimulation. Twelve key factors influencing subsurface parameters were identified for controlling production performance in this unconventional reservoir. High productivity sweet spots were identified to be zones with high organic content, high rock stiffness, and low horizontal stress condition. The machine learning model was developed and validated against production wells for sweet spot prediction. Then, 6 new wells were drilled and successfully identified sweet spots with success ratio above 83%. According to the findings, most current production levels fall within an acceptable range that exceeds predictions.

The advanced workflow and new developed tool ML model allow future well placement optimization for this unconventional reservoir in Canada. Zone-based splitting of training and testing wells is recommended for unconventional reservoirs ML modelling to improve accuracy.
Experimental Characterization of H2-Brine-Cement Interactions on Wellbore Integrity During Underground Hydrogen Storage in Depleted Gas Reservoirs
Authors: Zeng Lingping , Lupton Nicholas , Wong Sherman , Heryanto Deasy , Arjomand Elahel , Sander Regina
Published: October 2024

The transition to renewable energy sources has increased the need for efficient and sustainable energy storage solutions, with Underground Hydrogen Storage (UHS) in depleted gas reservoirs emerging as a promising option. Maintaining wellbore integrity in such environments is critical, yet the interactions between hydrogen, brine, and cement, particularly with chemical additives, remain insufficiently understood. This study addresses this gap by investigating the effects of hydrogen and brine on the mineralogy and microstructure of cement with and without chemical additives. We conducted a series of experiments, including X-ray diffract (XRD), scanning electron microscopy (SEM), micro-computed tomography (micro-CT), and water chemistry measurements, to evaluate changes in cement composition and integrity over time.

Key findings reveal that while the primary mineral compositions of cement, such as Portlandite and Calcium-Silicate-Hydrate (C-S-H) compound, transform under hydrogen and brine exposure, chemical additives such as fluid loss, dispersants and retarder show minimal impact on these changes. The average size of the interconnected pore networks increased significantly, but the increase was much lower in cement with additives (38.3%) compared to without (324.6%), indicating that additives help inhibit pore network expansion. Despite this, the overall porosity remained stable. Micro-fractures were more uniformly distributed in cement with additives, whereas in cement without additives, cracks connected existing pores, forming larger void networks. However, the generation and propagation of micro-fractures are more likely due to the changes of temperature and pressure during the samples loading rather than the impact of H2. Ion concentrations, including Na+, K+, Ca2+, and Cl-, remained largely stable, with only a slight increase in SO42- due to gypsum dissolution.

These results suggest that the impact of hydrogen on Class G cement is generally negligible, with minimal changes observed in overall mineral composition. While chemical additives offer some resistance to structural changes induced by hydrogen and brine, their overall effectiveness is limited. The study underscores the need for developing more robust solutions to enhance the durability and strength of cement in UHS applications, which is crucial for the long-term stability and safety of subsurface hydrogen storage systems.
Dual Simultaneous Production and Injection Completion in the Same Well: A Successful Pilot in the Greater Burgan Field
Authors: Ahmad Fajer , Yaser Mohammad , Prakash Roshan
Published: October 2024

With over 75+ years of production from the world's biggest clastic reservoirs of Greater Burgan (GB), Kuwait Oil Company (KOC) Asset team is taking lot of efforts in managing the new well delivery by optimizing drilling targets, both surface and sub-surface. In coming months/year the drilling campaign will be enhanced to drill ∼150-200 wells/year to meet the aggressive production target of ∼1.5 MMBOPD. One of the biggest challenge the asset is facing is to Drilling-Complete-Connect all these upcoming wells in the multi-layered reservoirs of GB, having surface limitations due to existing production and injection infrastructure in the field. Combining injector completion in shallower reservoir and producer completion in the deeper reservoir using a type of dual completion called Simultaneous Injection and Production (SIP) technology is the way to go to achieve the aggressive production targets.

A lot of new technologies is being implemented in the GB field to optimize the production, SIP is considered to be very effective as it will reduce the capex of drilling less wells, take less surface foot-print and have simpler well operation.

The biggest limitation for the SIP technology is the wellbore accessibility for surveillance, which can be overcome by installing the permanent Distributed Temperature Sensors (DTS) which can help in the production/injection flow profiling and help in optimizing the rates. To increase the life of the well, Rigless ESP will be required in the future when the well will cease to flow naturally due to increase in the water-cut of the producer string.

Dual completion technology is not new to the Greater Burgan fields, several dual completions have been implemented as dual producers for the last 30 years however special care must be taken in the SIP completion design where simultaneously cold fluid will be injected in one zone and hot reservoir fluid will produce from other zone using parallel tubings. The paper presents the detailed study done in the SIP design and successful implementation of the initial candidates.
Deploying Can Installed Pumping System in an Existing Well Slot for Multiple Reservoir Support
Authors: Nasharudin N. , Siew C. , Ibrahim M. , Holmes A. , Bakar H. , Fadzil N. A'akif
Published: October 2024

Surface water injection method remains the most widely method used method to provide pressure support in the Petroleum Industry, either through treated seawater injection (SWI), produced water re-injection (PWRI) or an existing Aquifer Water Re-Injection (AWRI). Either method or system will need sufficient footprint on the producing platform with maintenance intensive procedures due to pipework integrity monitoring, chemical injection and rotating equipment checking or preventive maintenance.

SWI is a complex method as compared to PWRI as the asset will need to lift water from the sea through high volume pumps passing a series of course and fine filters to remove marine debris. Given the live nature of seawater, bacterial growth tendency is higher thus biocide treatment is often considered to prevent reservoir souring over time. Seawater contains organic material which often reacts with formation water that may increase the scaling tendency therefore requires scale inhibitor treatment. This reaction and exposure may introduce oxygen within the water which requires de-oxygenation using a vacuum tower preventing corrosion downhole especially for the carbon steel tubulars range. These comprehensive treatment facilities will require suitable monitoring systems to ensure the water specification introduced into the reservoir is being in specification, avoiding formation damage and reservoir souring and potential reduction in reservoir permeability affecting production.
Longest Slim Hole ERD Wells Campaign with Limited Entry Liner Using Water-Based Mud in the Region
Authors: Varma Esha Narendra , Ditzler Theodore Jay , Sumaida Ali Ben , Mwansa Peter Levison , Husien Mohammad , Bahrom Abdul Raman Bin , Saragi Raymond
Published: October 2024

Extended reach drilling (ERD) can facilitate the development of untapped resources, reduce greenhouse gas emissions, surface congestion, and drilling costs. This ERD project with lower completion was started with an aim to lower well cost indicators including $/ft and $/bbl. Therefore, the challenge was to drill Slimhole ERD (6-1/8" lateral) wells with water-based mud (WBM). WBM is more cost-effective, environmentally friendly, and less damaging to the reservoir than OBM (oil-based mud). The use of WBM instead of OBM can save 20% per well. The major challenges in drilling Slimhole (6-1/8" size) ERD well with lateral leg include higher torque and failure to deploy lower completion due to high friction factors.

The first pilot well was planned with a liner-less design considering the low friction factors required to drill 15,000’ of 6-1/8" lateral hole and run the lower completion. The second pilot well was targeting a deeper and tighter reservoir zone with higher downhole temperatures. This involved drilling 12-1/4" intermediate hole to the landing point with larger 5-1/2" drill pipe. It enabled a push-pipe technique for drilling the lateral hole with improved weight transfer through the curved profile. The 6-1/8" lateral hole was drilled with 4" high-torque drill pipe, tandem high-flow circulating subs, and specially formulated drilling fluid lubricant. A conventional OBM system provides sufficient lubricity to reduce friction factors as low as 0.10. In this application, a low cost WBM system was made feasible by introducing stable high-temperature lubricant and unique hole cleaning practices.

Following this successful achievement, the 5-year business plan has been revised to include 63 similar wells with a projected total savings of ∼ 30-40% per project.

The Slimhole ERD project has demonstrated substantial value with a 35% reduction in CAPEX. The delivery of these two Slimhole ERD wells overturned conventional drilling and completion practices.

The implemented project resulted in saving up to 35% of the well cost and saved 20 days per well compared to a conventional ERD well with 8-1/2" hole and OBM. These two Slimhole ERD (15,000’ lateral) wells were drilled with a challenging Directional Difficulty Index (DDI) of 7.2. The wells were both completed successfully by running the 4-1/2" lower completion to reach the total depth.