bluuebunny/crossref_metadata_2025 huggingface dataset:
Onboard Neuro-Fuzzy Adaptive Helicopter Turboshaft Engine Automatic Control System
Authors: Vladov Serhii , Bulakh Maryna , Vysotska Victoria , Yakovliev Ruslan
Published: August 2024

A modified onboard neuro-fuzzy adaptive (NFA) helicopter turboshaft engine (HTE) automatic control system (ACS) is proposed, which is based on a circuit consisting of a research object, a regulator, an emulator, a compensator, and an observer unit. In this scheme, it is proposed to use the proposed AFNN six-layer hybrid neuro-fuzzy network (NFN) with Sugeno fuzzy inference and a Gaussian membership function for fuzzy variables, which makes it possible to reduce the HTE fuel consumption parameter transient process regulation time by 15.0 times compared with the use of a traditional system automatic control (clear control), 17.5 times compared with the use of a fuzzy ACS (fuzzy control), and 11.25 times compared with the use of a neuro-fuzzy reconfigured ACS based on an ANFIS five-layer hybrid NFN. By applying the Lyapunov method as a criterion, its system stability is proven at any time, with the exception of the initial time, since at the initial time the system is in an equilibrium state. The use of the six-layer ANFF NFN made it possible to reduce the I and II types of error in the HTE fuel consumption controlling task by 1.36…2.06 times compared with the five-layer ANFIS NFN. This work also proposes an AFNN six-layer hybrid NFN training algorithm, which, due to adaptive elements, allows one to change its parameters and settings in real time based on changing conditions or external influences and, as a result, achieve an accuracy of up to 99.98% in the HTE fuel consumption controlling task and reduce losses to 0.2%.
Short-Circuit Fault Diagnosis on the Windings of Three-Phase Induction Motors through Phasor Analysis and Fuzzy Logic
Authors: Reyes-Malanche Josue A. , Ramirez-Velasco Efrain , Villalobos-Pina Francisco J. , Gadi Suresh K.
Published: August 2024

An induction motor is an electric machine widely used in various industrial and commercial applications due to its efficiency and simple design. In this regard, a methodology based on the electric phasor analysis of line currents and the variations in the phase angles among these line currents is proposed. The values in degrees of the angles between every pair of line currents were introduced to a fuzzy logic algorithm based on the Mamdani model, developed using the Matlab toolbox for detection and isolation of the inter-turn short-circuit faults on the windings of an induction motor. To carry out the analysis, the induction motor was modified in its stator windings to artificially induce short-circuit faults of different magnitudes. The current signals are acquired in real time using a digital platform developed in the Delphi 7 high-level language communicating with a float point unit Digital Signal Processor (DSP) TMS320F28335 by Texas Instruments. The proposed method not only detects the short circuit faults but also isolates the faulty winding.
The Response of Denitrification to Increasing Water Temperature and Nitrate Availability: The Case of a Large Lowland River (Po River, Northern Italy) under a Climate Change Scenario
Authors: Gervasio Maria Pia , Castaldelli Giuseppe , Soana Elisa
Published: August 2024

Water warming and nutrient pulses following extreme rainfall events, both consequences of climate change, may have a profound impact on the biogeochemical dynamics of large temperate rivers, such as the Po River (Northern Italy), affecting denitrification capacity and the delivery of N loads to terminal water bodies. Manipulative experiments on denitrification kinetics were carried out using dark laboratory incubations of intact sediment cores collected from the lower Po River. Denitrification was measured along temperature and NO3− concentration gradients using 15N additions, in summer and autumn, the two seasons when climate change-induced warming has been shown to be higher. The combination of increased temperatures and pulsed NO3−-enhanced denitrification, suggesting that electron acceptor availability limits the process. The direct link between climate change-induced effects and the positive response of denitrification may have implications for the improvement of water quality in the coastal zone, as it may help to partially buffer N export, especially in summer, when the risk of eutrophication is higher. Further research is needed to investigate the quality and quantity of sediment organic matter as important drivers regulating river denitrification.
Microplastic and Nanoplastic Particle Isolation from Liquid and Biological Samples via Mini-Extruder Filtration (MEF)
Authors: Hall Abigail , Cardona Polo Luis F. , Helms Kennedy , Christodoulides Alexei , Alves Nathan J.
Published: August 2024

Microplastic pollution poses an increasing environmental and human health risk and additional techniques are needed to facilitate nondestructive, quantitative particle recovery and analysis. Using a mini-extruder filtration (MEF) device, the efficiency of pristine particle capture from solution and digested biological tissue (blood clots) was assessed. Polystyrene particles in both the submicron (100, 300, and 500 nm) and micron range (2, 5, 7, and 10 µm) with aminated, carboxylated, or unmodified surface modifications were explored. The MEF-isolated-particle recovery was analyzed pre- and postseparation isolation and quantified via a Nanosight LM10 particle tracking system (submicron particles) or hemacytometer (micron particles). Particles’ surface chemistry and concentration did not impact recovery compared to unfiltered samples with smaller particle sizes reducing recovery efficiency. Micron particle size recovery averaged 86.8 ± 4.3% across all surface chemistries at the same concentration; however, submicron particle recoveries varied by size and charge with 500 nm exhibiting recoveries of 80.6 ± 16.6%, 300 nm 73.0 ± 10.4%, and 100 nm particles 17.0 ± 10.3%. The mini-extruder device, used as a filtration recovery system, efficiently captures 10 to 0.5 µm particles from environmental and tissue samples making it an effective and low-cost platform facilitating the nondestructive capture of diverse microplastics for subsequent analysis.
The Emerging Role of Environmental Cadmium Exposure in Prostate Cancer Progression
Authors: Saad Rama , Hussein Mohamed Ali , Munirathinam Gnanasekar , Kajdacsy-Balla André
Published: August 2024

Cadmium (Cd) is a widespread environmental pollutant with several adverse effects on the general population. While Cd is a well-established risk factor for some cancers, such as lung cancer, its impact on prostate cancer (PCa) is not well understood. PCa mortality is associated with its progression to metastatic spread. This underscores the importance of studying the environmental/or molecular factors that govern the progression from organ-confined tumors to widely metastatic disease. To date, most studies addressing the effects of Cd on PCa are focused on the incidence rather than the progression/outcome. Furthermore, most of these epidemiological studies are limited by the small number of samples and the fact that most of these studies measured Cd levels in the air, blood, or urine, which is less applicable for addressing associations in environmental exposure than the measurement of Cd concentrations in the prostate microenvironment. It is still unknown whether Cd is a driver or a consequence of PCa aggressiveness. Addressing the plausibility of causality requires using proper in vitro and in vivo models for sub-micromolar Cd doses that mimic environmental exposure. Most in vitro studies addressing the functional and molecular effects of Cd are limited by the exclusive use of aggressive PCa cell models and very high micromolar unbound Cd concentrations, which are irrelevant for environmental exposure. Significantly, few studies have addressed the effects of sub-micromolar Cd concentrations. Hence, we suggest using nanomolar concentration that resembles real-life exposure, using less aggressive in vitro models such as RWPE-2, employing 3D organoid culture systems, and adopting high throughput-omics techniques, including metallomics, and using transgenic animal models might represent a more effective model. Here, we focus on reports on the impact of Cd on the progression and aggressiveness of already-established PCa instead of on the initial steps of carcinogenesis. We suggest potential future directions for substantiating the plausible link between Cd exposure and PCa aggressiveness.
Efficient Bioethanol Production from Spent Coffee Grounds Using Liquid Hot Water Pretreatment without Detoxification
Authors: Huang Jiale , Li Biying , Xian Xiaoling , Hu Yinan , Lin Xiaoqing
Published: August 2024

Coffee beans, a popular commodity in the world, are processed into coffee, which generates a considerable quantity of spent coffee grounds (SCGs). However, SCGs, a byproduct rich in hemicellulose, poses a challenge due to fermentable sugar loss during conventional pretreatment. This study investigates the efficient production of bioethanol from SCG using an optimized liquid hot water (LHW) pretreatment combined with separate hydrolysis and fermentation (SHF) process. LHW pretreatment at 180 °C for 20 min with a high solid-to-liquid ratio (SLR) of 1:6 (w/v) was optimized to disrupt the lignocellulosic structure and retain high levels of fermentable sugars, which included mannose and glucose. This approach achieved a bioethanol concentration of 15.02 ± 0.05 g/L and a productivity rate of 1.252 g/(L·h), demonstrating the efficiency of this integrated process. Interestingly, the high SLR LHW pretreatment significantly reduces water usage and enhances product concentration, offering a promising, environmentally friendly, and economically viable method for industrial bioethanol production from SCGs without the necessity of detoxification.
Oral Yak Whey Protein Can Alleviate UV-Induced Skin Photoaging and Modulate Gut Microbiota Composition
Authors: Wang Diandian , Zhou Yaxi , Zhao Jian , Ren Chao , Yan Wenjie
Published: August 2024

Excessive UV exposure can lead to skin roughness, wrinkles, pigmentation, and reduced elasticity, with severe cases potentially causing skin cancer. Nowadays, various anti-photoaging strategies have been developed to maintain skin health. Among them, dietary supplements with anti-photoaging properties are gaining increasing attention. Yak whey protein (YWP) possesses multiple benefits, including anti-inflammatory, antioxidant, and immune-boosting properties, effectively protecting the skin. This study used a mixed UVA and UVB light source to irradiate a nude mouse model, exploring the advantages of YWP in anti-photoaging and regulating gut microbiota. The results indicated that YWP alleviated UV-induced skin damage, wrinkles, dryness, and reduced elasticity by inhibiting oxidative stress, inflammatory factors (IL-1α, IL-6, and TNF-α), and matrix metalloproteinases (MMP-1, MMP-3, and MMP-12), thereby increasing the levels of elastin, type I collagen, and type III collagen in the extracellular matrix (ECM). Additionally, YWP significantly improved the abundance of Firmicutes and Bacteroidota in the gut microbiota of mice, promoting the growth of beneficial bacteria such as Lachnospiraceae_NK4A136_group, Ruminococcus_torques_group, and Clostridia_UCG_014, mitigating the dysbiosis caused by photoaging. These findings underscore the potential of YWP in anti-photoaging and gut microbiota improvement, highlighting it as a promising functional food for enhancing skin and gut health.
Organophosphate Detection in Animal-Derived Foods Using a Modified Quick, Easy, Cheap, Effective, Rugged, and Safe Method with Liquid Chromatography–Mass Spectrometry
Authors: Kim Byung-Joon , Yang Seung-Hyun , Choi Hoon
Published: August 2024

Organophosphates are widely used in the livestock industry. In this study, we developed a method for detecting 27 organophosphate insecticides in animal-derived foods, including beef, pork, chicken, milk, and eggs, using liquid chromatography–tandem mass spectrometry. A modified QuEChERS method was optimized for sample pretreatment. A mixture of acetonitrile and acetone was used as the extraction solvent, and MgSO4 and NaCl were used as salts. Among the five different dispersive solid-phase extraction systems, MgSO4, primary secondary amines, and C18 were selected for purification because they had the highest recovery rates and least matrix effects. The matrix-dependent limit of quantitation was 0.0005–0.005 mg/kg, and the correlation coefficient of the matrix-matched calibration curve was >0.99, which was acceptable for quantifying residues below 0.01 mg/kg—the default maximum residue limit in a positive list system. The recovery efficiencies ranged from 71.9 to 110.5%, with standard deviations ranging from 0.2% to 12.5%, satisfying the SANTE guidelines. The established analytical method was used to monitor organophosphates in animal-derived foods obtained from a local market, and no pesticides were detected. With respect to industry standards, our proposed method is recommended for practical organophosphate detection in animal-derived foods.
The Right to Oncological Oblivion: A Legislative Response to Cancer Survivor Discrimination in Italy
Authors: D’Antonio Gianpiero , Bolino Ginevra , Sorace Letizia , Volonnino Gianpietro , Pellegrini Lavinia , Di Fazio Nicola , Frati Paola
Published: August 2024

Despite the increasing efficacy of modern medicine in diagnosing and treating cancer, survivors often face discrimination in employment, economics, insurance, and society. Law no. 193/2023, also known as the “Oncological Oblivion Law”, aims to provide an initial legislative response to discrimination against cancer survivors in Italy. After defining oncological oblivion in Article 1, the Law provides, in Articles 2, 3, and 4, directives to prevent discrimination against cancer survivors in the area of access to banking and insurance services, adoption procedures and access to or retention in employment. The aim of this work is to illustrate the content and the critical aspects of the recent Law 193/2023 in the landscape of European directives. The legislative process at the Chamber of Deputies and the Senate of the Italian Republic has been retraced through the consultation of preparatory works and bills registered on institutional databases. Law 193/2023 represents the first initiative in Italy aimed at the recognition of the right to oncological oblivion, not only in access to banking and insurance services as in other countries, but also in adoption, employment, and re-employment. Our opinion piece highlights the need for further clarification and expansion to prevent discrimination and protect the social–work–relational rights of people who have been affected by oncological diseases.
Frailty Assessment and Its Impact on Loneliness among Older Adults Receiving Home-Based Healthcare during the COVID-19 Pandemic
Authors: Klesiora Maria , Tsaras Konstantinos , Papathanasiou Ioanna V. , Malliarou Maria , Bakalis Nikolaos , Kourkouta Lambrini , Melas Christos , Kleisiaris Christos
Published: August 2024

The purpose of this study was to identify the effect of frailty on loneliness among older adults receiving home care, in correlation to their socioeconomic and homebound statuses. This cross-sectional study recruited 218 individuals aged ≥65 years receiving home-based health services from the “Help at Home” program in the Region of Evrytania, Greece through an open invitation from the municipality authorities from March to June 2022. The Tilburg Frailty Indicator (TFI) was used for the evaluation of frailty, the UCLA Loneliness Scale version 3 was used for loneliness, and social isolation was accessed through five questions (living alone, frequency of interaction with children, relatives, friends, and participation in social organizations). The mean age of the participants was 81.48 ± 9.06, 61.9% were female, 54.1% experienced high levels of loneliness (UCLA-3 mean 45.76 ± 11.10 [range 20–68]), and 46.3% of the participants were found to be socially isolated. Also, 58.3% of the individuals were identified as frail (TFI mean 5.95 ± 3.07) [TFI range 0–13], with 57.3% experiencing physical frailty, 43.6% experiencing psychological frailty, and 27.1% experiencing social frailty. An analysis of covariance (ANCOVA) using UCLA-3 as the dependent variable revealed that loneliness across all domains of TFI was significantly higher in participants with frailty (total frailty [Yes] 49.27 vs. [No] 40,87 p < 0.001) (physical frailty [Yes] = 48.99 vs. [No] = 41.42, p < 0.001, psychological: 48.60 vs. 43.57 p < 0.001, and social: 53.38 vs. 42.94 p < 0.001), particularly compared to non-frail individuals, even after adjusting for potential confounding effects (covariates: gender, age, marital status, family status, living status, educational level, annual income, chronic diseases, homebound status, and social isolation). Our findings indicate that frail older adults experienced higher levels of loneliness, suggesting that frailty and loneliness are independently associated among older adults who receive home-based healthcare.
The Effects of Prolonged Indoor Inhalation of Nature-Derived Odors on Menopausal Women
Authors: Kim Choyun , Lee Gayoung , Song Chorong
Published: August 2024

This study aimed to investigate the effects of prolonged inhalation of nature-derived odors indoors on humans. Twenty-six women participated in this study. Heart rate variability, heart rate, blood pressure, pulse rate, estradiol, testosterone, and cortisol were used as indicators of autonomic nervous system and endocrine system activities. Profile of mood state, state–trait anxiety inventory, menopause rating scale and general sleep disturbance scale were used as psychological indicators. The order was as follows: After the participants relaxed in a chair for 5 min, their heart rate variability and heart rate were measured for 3 min with their eyes closed. Subsequently, blood pressure and pulse rate were measured, salivary samples were collected for estradiol, testosterone, and cortisol analyses, and a subjective assessment was conducted. The participants received a diffuser containing fir essential oil and were instructed on its usage and precautions. Subsequently, they returned home and inhaled the fir oil for a week. After 7 days, participants revisited the laboratory for posttest measurements, conducted at the same time as the pretest. Prolonged inhalation of the fir essential oil resulted in increased estradiol concentration, decreased systolic and diastolic blood pressure, relief of menopausal symptoms, reduced anxiety levels, improved sleep quality and mood states. Prolonged inhalation of the fir essential oil induced physiological and psychological relaxation on menopausal women.
Outcomes of a Self-Management Program for People with Non-Communicable Diseases in the Context of COVID-19
Authors: Hernández Rodrigo Cesar León , Martínez Jorge Luis Arriaga , Del Angel Martha Arely Hernández , de Córdova Isabel Peñarrieta , Solís Virginia Solís , Salinas María Elena Velásquez
Published: August 2024

Objective: To evaluate the effectiveness of the online version of the Chronic Disease Self-Management Program (CDSMP) on physical activity and depressive symptoms in individuals with non-communicable diseases (NCDs) in Mexico and Peru during the COVID-19 pandemic. Materials and Methods: Quasi-experimental study with a non-probability sample of 114 people with NCDs, recruited by invitation in Mexico and by convenience in Peru. The participants were assigned to intervention (n = 85) and control (n = 29) groups. The Personal Health Questionnaire (PHQ-8) and the Physical Activity Scale were used to assess the outcomes. Measurements were taken before and after the intervention. The CDSMP comprises six sessions that take place once per week and last 2.5 h each. Results: The intervention group showed a significant reduction in depressive symptoms and an increase in physical activity (PA) at the end of the program. In contrast, the control group showed no significant improvement in depression and presented a significant decrease in PA.
Healthcare Outcomes of Patients and Antecedents via Teleophthalmology in Eastern Taiwan during COVID-19
Authors: Chen Hsing-Chu , Chang Ching-Yu , Tsai Chung-Hung , Hsu Wei-Lin , Sung Wen-Fang , Wu Yu-Xuan
Published: August 2024

Objective: The coronavirus disease 2019 (COVID-19) pandemic has caused significant transformations in healthcare. Many countries began the rapid development and adoption of telemedicine to avoid the spread of the pandemic and created an innovative model for healthcare delivery. This study identified the critical antecedents that affected the considered healthcare outcomes via teleophthalmology in Eastern Taiwan during the COVID-19 pandemic. Methods: This study’s participants included residents of five towns in Taitung County who had experience with teleophthalmology. This study analyzed the structured questionnaires completed by the participants to validate the proposed research framework. Statistical methods were used to verify the research models, including descriptive statistical analysis, confirmatory factor analysis, and structural equation modeling. The date of this study was from 1 October 2020 to 31 July 2023. Results: The results of this study reveal that the average monthly use of teleophthalmology by individuals in rural areas increased annually. Females tended to utilize teleophthalmology services more than males. There were no significant differences across any of the constructs with respect to age or educational level. Additionally, the patients’ awareness of healthcare accessibility via and the communication quality of teleophthalmology simultaneously affected teleophthalmology’s adoption and service quality, which in turn jointly affected health outcomes. Both healthcare accessibility and communication quality were the antecedents of the healthcare outcomes. The health outcomes refer to the impact of teleophthalmology on the quality of the patients’ health and well-being. Additionally, teleophthalmology’s adoption and service quality acted as mediators. Conclusions: This study’s findings are expected to increase attention to the healthcare outcomes and antecedents of teleophthalmology to promote better telemedicine practices and services for rural residents.
Healing the Whole: An International Review of the Collaborative Care Model between Primary Care and Psychiatry
Authors: Hernandez Veronica , Nasser Lucy , Do Candice , Lee Wei-Chen
Published: August 2024

The collaborative care model (CCM) was created to improve the delivery of mental health care and is reported to improve access, enhance treatment outcomes, and reduce healthcare costs. To understand the impacts of the CCM on symptom management, diverse populations, and sustainability in healthcare systems, a systematic review was conducted. Several databases were searched for articles assessing the CCM. The inclusion criteria limited the studies to those (1) published between January 2008 and January 2024; (2) written in the English language; (3) analyzing adult patients; (4) analyzing symptom improvement in major depressive disorder, generalized anxiety disorder, or post-traumatic stress disorder; and (5) fitting the given definition of a CCM. We identified 9743 articles. Due to missing information or duplication, 4702 were excluded. The remaining articles were screened, yielding 468 articles for full-text analysis, of which 16 articles met the inclusion criteria. Of these articles, five primarily focused on individual patient outcomes, five focused on specific populations, and six reviewed system impacts; eleven articles studied US populations and five studied international populations. An analysis revealed that in 12 of the final articles, the CCM led to a statistically significant improvement in anxiety and depression symptoms with viable implementation and sustainability strategies. The CCM is an effective method for improving patient symptoms and can be potentially affordable in healthcare systems.
Deviation of the Nail Lamina after Unilateral Partial Matricectomy
Authors: Saura-Sempere Álvaro , Sánchez-Gómez Rubén , Reguera-Medina José Manuel , Márquez-Reina Salvador , Rodríguez-León Rafael , Gómez-Carrión Álvaro
Published: August 2024

Deviation of the nail plate in the transverse plane has traditionally been regarded as a postoperative complication following the definitive surgical treatment of ingrown toenails, particularly when only a single nail fold is addressed. The quantification and longitudinal comparison of the operated versus non-operated nail folds could elucidate potential transverse deviations of the nail plate. The objective of this study was to assess the presence or absence of transverse nail plate deviation following ingrown toenail surgery on a single nail fold. Methods: A cohort of 11 patients (three males, eight females) with recurrent ingrown toenails undergoing unilateral partial matricectomy were included in this study. Preoperative measurements were compared to those taken at 7, 14, 21, 28, and 35 days postoperatively. Results: The analysis revealed no statistically significant differences in measurements between the operated and non-operated nail folds, nor were there significant changes in the measurements over time within each group (p > 0.05). Conclusions: Despite the absence of visible deviations in the orientation of the nail plate, the angular measurements post-surgery at 35 days showed no statistically significant alterations. The angular values observed across all time points appeared to be influenced by the intrinsic morphological characteristics of each nail plate.
Application of Deep Learning for the Analysis of the Spatiotemporal Prediction of Monthly Total Precipitation in the Boyacá Department, Colombia
Authors: Niño Medina Johann Santiago , Suarez Barón Marcó Javier , Reyes Suarez José Antonio
Published: August 2024

Global climate change primarily affects the spatiotemporal variation in physical quantities, such as relative humidity, atmospheric pressure, ambient temperature, and, notably, precipitation levels. Accurate precipitation predictions remain elusive, necessitating tools for detailed spatiotemporal analysis to better understand climate impacts on the environment, agriculture, and society. This study compared three learning models, the autoregressive integrated moving average (ARIMA), random forest regression (RF-R), and the long short-term memory neural network (LSTM-NN), using monthly precipitation data (in millimeters) from 757 locations in Boyacá, Colombia. The inputs for these models were based on satellite images obtained from the Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) data. The LSTM-NN model outperformed others, precisely replicating precipitation observations in both training and testing datasets, significantly reducing the root mean square error (RMSE), with average monthly deviations of approximately 19 mm per location. Evaluation metrics (RMSE, MAE, R2, MSE) underscored the LSTM model’s robustness and accuracy in capturing precipitation patterns. Consequently, the LSTM model was chosen to predict precipitation over a 16-month period starting from August 2023, offering a reliable tool for future meteorological forecasting and planning in the region.
Estimation of Incoming Sediments and Useful Life of Haditha Reservoir with Limited Measurements Using Hydrological Modeling
Authors: Ajaaj Aws , Khan Abdul , Mishra Ashok , Alhathloul Saleh
Published: August 2024

Many dammed reservoirs in dry climate conditions witness high sediment inflow rates due to higher soil erodibility, yet there are limited actual sediment influx measurements. Therefore, this study first applies the Soil and Water Assessment Tool (SWAT) hydrologic model to simulate reservoir sedimentation inflow to the Haditha Reservoir. Next, utilizing sediment inflows estimated by the SWAT model, the Trap Efficiency Function (TEF) is employed to estimate its remaining storage capacity and its useful life at multiple reservoir water levels. Calibration (1986–1997) and validation (1998–2007) of the SWAT model were conducted at three streamflow gaging stations and one sediment station located upstream of the reservoir. Results show that the SWAT model performed better during calibration than during the validation period for all streamflow and sediment gaging stations. In addition, modeled streamflow and sediment predictions were relatively more accurate on a monthly scale than on a daily scale. Simulated daily sediment inflow to the reservoir demonstrates slightly lower accuracy than daily streamflow, where the Coefficient of Determination (R2) and Nash-Sutcliffe Efficiency values are 0.34 and 0.32 in the case of sediment load, compared to 0.39 and 0.33 for streamflow, respectively. Reservoir storage capacity for the period (1986–2005) shows a continuous decrease with time at all reservoir water levels, which indicates an increase in sediment accumulation. According to measurements taken between 1986 and 2005, sediment accumulation has reduced the reservoir’s capacity by approximately 15% at a water level of 112 m (the lowest water level in the reservoir). During the same period, the storage capacity loss at 147 m (the design working water level in the reservoir) was calculated to be 35%. Over 19 years of operation (1986–2005) at the 147-m water level, the total sediment buildup in the reservoir is estimated at 3.2 million tons. Notably, about one-third of this sediment was deposited in the five-year span from 2000 to 2005.
Unveiling the Benefits of Artificial Ecological Measures: Water Conveyance Improves the Water Quality of the Taitema Lake, Northwestern China
Authors: Aili Aishajiang , Xu Hailiang , Waheed Abdul , Zhao Xinfeng , Zhang Peng
Published: August 2024

Taitema Lake, situated at the terminus of the Tarim River Basin in Northwest China, represents a crucial ecological resource impacted by climate variability and anthropogenic interventions. In this study, we investigate the dynamic changes in Taitema Lake’s area and water quality resulting from the implementation of an ecological water transfer project in 2000. Leveraging Landsat remote sensing data and comprehensive water quality monitoring, we analyzed the relationship between lake area variations and shifts in water quality parameters. Notably, our findings reveal a significant increase in Taitema Lake’s area from 9.4 km2 in 2000 to 320 km2 in 2013. Concurrently, water quality indicators exhibited marked fluctuations, with total salt content ranging from 45,323.6 mg/L in 2000 to 970.4 mg/L in 2010 before increasing to 14,586.3 mg/L by 2014. Furthermore, a linear regression analysis highlights the moderate positive correlation between lake area and mineralization (R2 = 0.506) and sodium levels (R2 = 0.4907). Additionally, chloride (R2 = 0.5681) and sulfate (R2 = 0.6213) concentrations demonstrated a strong negative correlation with the lake area, indicative of a dilution effect. Furthermore, a comparison of water quality indicators between the years of minimum (2008) and maximum (2013) lake area underscores improvements in pH, chemical oxygen demand, and anionic surfactant concentrations as the lake area increased. Our study provides valuable insights into the effectiveness of ecological water management strategies in restoring and maintaining the ecological health of Taitema Lake, thereby informing evidence-based decision-making for the sustainable management of freshwater resources in arid environments.
Preparation of Non-Noble Metal Catalyst FeCo2O4/MoS2 for Production of Hydrogen and Oxygen by Electrochemical Decomposition of Water
Authors: Chen Zhouqian , Li Zongmei , Zhang Manyi , Wang Yujia , Zhang Siang , Cheng Yuanyuan
Published: August 2024

FeCo2O4/MoS2 binary composite catalysts were prepared by the hydrothermal method and calcination method. In this paper, the morphology and structure of the materials were characterized by means of SEM, EDS, XRD, and XPS. It was found that MoS2 has high activity and good stability in HER, and and it has more prospect than noble metal catalysts. In oxygen evolution chemical kinetics, its rich redox potential allowed it to adsorb OH− on (Co2+/Co3+, Fe2+/Fe3+) and enhanced the activity of OER. The cross-nanosheet structure of the FeCo2O4/MoS2 composite catalyst exposed more catalytic sites and accelerated charge transfer to achieve more efficient mass transfer. FeCo2O4/MoS2 as an anode and cathode was assembled into a two-electrode system in overall water splitting, which showed good catalytic activity. When the composite ratio of FeCo2O4 to MoS2 was 1:0.3, the composite catalyst had the best catalytic activity. The results show that when FeCo2O4/MoS2 is used as a cathode and anode to assemble an alkaline cell, respectively, the voltage for total water electrolysis is 1.59 V at a current density of 10 mA cm−2 in a 1 M KOH electrolyte, it can keep good stability in a 10 h test with electrolyzed water, and its current retention rate is 98.5%.
On Statistical Features of Ice Loads on Fixed and Floating Offshore Structures
Authors: Sinsabvarodom Chana , Leira Bernt J. , Høyland Knut V. , Næss Arvid , Samardžija Ilija , Chai Wei , Komonjinda Siramas , Chaichana Chatchawan , Xu Sheng
Published: August 2024

Apart from the mechanisms of ice structure interactions under various scenarios of sea ice conditions and structural configurations, the selection of probabilistic models is crucial in order to cope with the loading uncertainty. Sea ice is the primary contributor to design loads in cold regions. In many cases, ice loads present the highest magnitude. In recent years, the probabilistic study of ice thickness, ice strength coefficient, flexural strength, ice drift speed, etc., has significantly increased, corresponding to the increasing activity of offshore operations in cold regions as well as the development of instrument technology for sea ice observation. This paper reviews existing probabilistic modes of sea ice, which are used to estimate the uncertainty of ice loading with various types of offshore structures, including vertical structures, sloping structures, and stations with floating vessels. The ISO 19906 standard is employed for the probabilistic assessment of vertical and sloping structures. The interactions between ice and structures on sloping structures are considered in both the upward and downward directions. The ice resistance method is applied for station-keeping floating vessels in ice. The key parameters of sea ice properties to estimate the design loads are studied. The effect of correlation between the key parameters of ice loads is investigated. This review shows that most existing probabilistic models are proposed for the estimation of ice loading on the various types of offshore structures.
Diagenetic Evolution of Syngenetic Volcanogenic Sediment and Their Influence on Sandstone Reservoir: A Case Study in the Southern Huizhou Sag, Pearl River Mouth Basin, Northern South China Sea
Authors: Chen Jiahao , Zhu Hongtao , Peng Guangrong , Ding Lin , Zeng Zhiwei , Wang Wei , Tao Wenfang , Zhou Fengjuan
Published: August 2024

The Paleogene sandstone reservoir of Huizhou Sag is an important target for deep exploration in the Pearl River Mouth Basin, South China Sea. Because of the intense volcanic activity, it had a significant impact on the development of reservoirs, making it hard to predict. The diagenetic process of volcanogenic sediment and their influence of the reservoir have been studied by petrographic analysis, X-ray diffraction and scanning electron microscopy (SEM). Four types of volcanogenic sediment were identified: volcanic dust (<0.05 mm), volcanic rock fragments, crystal fragments (quartz and feldspar) and vitric fragments. The strong tectonic and volcanic activity of the Wenchang Formation resulted in a high content of volcanic materials, which led to significant reservoir compaction. The main sedimentary facies types are fan delta facies and lacustrine facies; the thick lacustrine mudstone can be used as high-quality source rock. After the source rock of the Wenchang Formation matured and discharged acids, feldspar and rock fragments dissolved to form dissolution pores, which effectively increases the porosity of the reservoir, but the argillaceous matrix and clay minerals produced by the volcanic dust alteration would reduce the permeability of the reservoir. With the weaker tectonic activity of the Enping Formation, the sedimentary facies changed into braided river delta, resulting in the greater componential maturity of the reservoir. Due to the relatively small impact of acidic fluids on the reservoir, the pore types of the reservoir are mainly primary pores with good physical properties.
Effect of La on the Microstructures and Mechanical Properties of Al-5.4Cu-0.7Mg-0.6Ag Alloys
Authors: Li Xiang , Li Anmin , Qin Xiangdu , Yang Hailong , Cheng Peng
Published: August 2024

The effects of the rare earth element La on the microstructure and mechanical properties of cast Al-5.4Cu-0.7Mg-0.6Ag alloys have been investigated through metallographic observation, scanning electron microscopy analysis, transmission electron microscopy, X-ray diffraction, and tensile testing. The present form and action mechanism of La have been analyzed. The findings indicate that the inclusion of trace amounts of La markedly diminishes the grain size in the Al-Cu-Mg-Ag alloy. Furthermore, as the La content increases, the alloy’s strength is significantly improved. When the La concentration reaches 0.4 wt.%, the mechanical properties of the alloy, both at room temperature and at 350 °C, surpass those of the alloy lacking rare earth elements. When the added rare earth La content exceeds 0.2 wt.%, the emergence of the Al6Cu6La phase causes the alloy structure to exhibit a skeletal morphology, altering the morphology and distribution of excess second phases along grain boundaries, thereby impacting the alloy’s overall performance. Incorporating La leads to a reduction in the size of the strengthening precipitate phase Ω while also enhancing its precipitation density, but an excess of La leads to the emergence of Al6Cu6La, depleting the available Cu and suppressing the precipitation of the Ω phase, ultimately affecting the mechanical properties of the alloy.
The Tribological Properties of Novel Sulfoximine Derivatives as Lubricant Additives
Authors: Zhang Jianbin , Zhang Chaoyang , Liu Yanhua , Feng Libang , Yang Wufang , Pei Xiaowei , Yu Qiangliang
Published: August 2024

Introducing an additive is a practical approach to improve the lubrication performance of base oil in the field of tribology. Herein, a series of sulfoximine derivatives was synthesized and incorporated into base oil A51 as additives. The tribological properties of these lubricants were evaluated at both room and high temperatures, and the result demonstrated that they displayed excellent friction reduction and wear resistance in the friction process under both test conditions. Moreover, the chemical composition of the worn scar surface was inspected using EDS, XPS and TOF-SIMS to explore the lubricating mechanism. It is reasonable to conclude that the synergistic interaction between the aromatic ring scaffolds and elements like N, F, and S facilitated the adsorption of lubricant on the steel block surfaces and forming a tribofilm during the friction process. This tribofilm has a dominant impact on the system’s lubrication performance. This research provides novel oil-soluble lubricant additives, offering a facile approach to formulating high-quality lubricants.
Marginal Aggregates: The Role of Clays
Authors: Bentur Arnon , Larianovsky Pavel
Published: August 2024

Clays are components in the fine portion of aggregates, less than 75 microns in size (micro-fines), which are usually washed away when producing coarse or fine (manufactured sand) aggregates in quarries. When marginal sources of aggregates are being used, the content of this washed portion can be quite high, and there is an incentive to keep as much of it in the aggregate, including the clays. The present paper presents a comprehensive treatment of the role of clays in terms of the characterization of their composition and quantification of their effects on the rheological and mechanical properties of cementitious systems, as well as the means to mitigate deleterious influences. It is shown that the strategy for neutralizing the effect of micro-fines containing clays on increased water demand in concrete can be quantified in terms of the combination of their content in concrete and their nature as characterized by the methylene blue value (MBV); this is a more rational approach to considering their influence than their content in specific aggregates as specified in standards. The effect of low and medium MBV aggregates on the water requirement can be neutralized by lignosulfonates when their content in the concrete is below a threshold value of about 150 kg/m3; polycarboxylates (PC) are required at higher contents; for high MBV aggregates, a combination of PC and clay mitigating admixture (CMA) is required. It is also demonstrated that with proper treatment, such micro-fines can be turned into useful fillers, enhancing the strength of concrete and thus also serving as a means for reducing cement content.
Post-Tensioned Hollow-Core Concrete Slabs with Unbonded Tendons for Truck Scale Platforms: Design Assumptions and Tests
Authors: Szydłowski Rafał Stanisław , Łabuzek Barbara , Bednarski Łukasz
Published: August 2024

At Cracow University of Technology, attempts were made to develop national truck scale platforms with a capacity of 60 tons, made from prestressed concrete. For this work, we designed slabs partially prestressed with unbonded tendons featuring a cross-section of 1.00 × 0.28 m and a span of 5.94 m. To reduce the weight of the slabs, four channels made from commonly used ø110 × 2.2 mm PVC pipes were used. In this way, we created post-tensioned hollow-core slabs. Due to the unpredictable behavior of slabs operating in a cracked state under a repetitive load, two slabs were subjected to cyclic loads amounting to 1,000,000 cycles with different load values. This paper presents the basic design principles and design details of the slabs, as well as the methodology and results of the research conducted. Lastly, we provide appropriate conclusions directed at further optimizing the slabs.
Microstructure and Mechanical Properties of the Powder Metallurgy Nb-16Si-24Ti-2Al-2Cr Alloy
Authors: Wen Feng , Liu Wentao , Fu Ao , Huang Qianli , Wang Jian , Cao Yuankui , Qiu Jingwen , Liu Bin
Published: August 2024

The Nb-16Si-24Ti-2Al-2Cr alloy was prepared by plasma rotating electrode process (PREP) technology and the hot-pressing (HP) method, and the effects of sintering temperature on the microstructure, mechanical properties and fracture behavior were investigated. The HP alloys sintered at temperatures below 1400 °C are composed of Nbss (Nb solid solution), Nb3Si and Nb5Si3 phases. When the sintering temperature reaches 1450 °C, the Nb3Si phase is completely decomposed into Nbss and Nb5Si3 phases. Meanwhile, the microstructure coarsens significantly. Compared with the cast alloy, the HP alloy shows better mechanical properties. The fracture toughness of the alloy sintered at 1400 °C reaches 20.2 MPa·m1/2, which exceeds the application threshold. The main reason for the highest fracture toughness is attributed to the decomposition of large-sized brittle Nb3Si phase and the formation of a fine microstructure, which greatly increases the number of phase interfaces and improves the chance of crack deflection. In addition, the reduction in the size and content of silicides also reduces their plastic constraints on the ductile Nbss phase.
Elastomeric Compositions of Ethylene–Norbornene Copolymer Containing Biofillers Based on Coffee and Tea Waste
Authors: Malicka Aneta , Rułka Kamila , Latos-Brozio Malgorzata , Masek Anna
Published: August 2024

The development of eco-friendly elastomeric materials has become an important issue in recent years. In this work, thermoplastic elastomer samples of an ethylene–norbornene copolymer (EN) with coffee and tea biofillers mixed with typical fillers such as montmorillonite (MMT), silica (SiO2), and cellulose were investigated. The aim of this research was to determine the effect of fillers on the properties of the materials and to assess their degradability after two ultraviolet (UV) aging cycles (200, 400 h). The scientific novelty of this work is the assessment of the anti-aging effect of simultaneous biofillers–stabilizers based on coffee and tea waste. The surfaces of the obtained polymer compositions were examined using infrared spectroscopy (FTIR-ATR). Contact angles were determined, and surface energy was calculated. The mechanical properties were tested, and the influence of plant fillers and aging on the color change in the materials was analyzed. The combination of coffee with silica, MMT, and cellulose fillers limited the migration of fatty acids and other compounds from the biofiller to the EN surface (FTIR analysis). Based on the aging coefficients K, it was shown that all coffee- and tea-based fillers stabilized the polymer compositions during UV aging (400 h). The results allowed the authors to determine the importance and impact of waste plant fillers on the degradability of the synthetic EN.
Semi-Discretized Approximation of Stability of Sine-Gordon System with Average-Central Finite Difference Scheme
Authors: Wang Xudong , Wang Sizhe , Qiao Xing , Zheng Fu
Published: August 2024

In this study, the energy control and asymptotic stability of the 1D sine-Gordon equation were investigated from the viewpoint of numerical approximation. An order reduction method was employed to transform the closed-loop system into an equivalent system, and an average-central finite difference scheme was constructed. This scheme is not only energy-preserving but also possesses uniform stability. The discrete multiplier method was utilized to obtain the uniformly asymptotic stability of the discrete systems. Moreover, to cope with the nonlinear term of the model, a discrete Wirtinger inequality suitable for our approximating scheme was established. Finally, several numerical experiments based on the eigenvalue distribution of the linearized approximation systems were conducted to demonstrate the effectiveness of the numerical approximating algorithm.
Generalized Bertrand Curves of Non-Light-like Framed Curves in Lorentz–Minkowski 3-Space
Authors: Wu Linlin , Zhou Anjie , Yao Kaixin , Pei Donghe
Published: August 2024

In this paper, we define the generalized Bertrand curves of non-light-like framed curves in Lorentz–Minkowski 3-space; their study is essential for understanding many classical and modern physics problems. Here, we consider two non-light-like framed curves as generalized Bertrand pairs. Our generalized Bertrand pairs can include Bertrand pairs with either singularities or not, and also include Mannheim pairs with singularities. In addition, we discuss their properties and prove the necessary and sufficient conditions for two non-light-like framed curves to be generalized Bertrand pairs.
Superconvergence of Modified Nonconforming Cut Finite Element Method for Elliptic Problems
Authors: He Xiaoxiao , Song Fei
Published: August 2024

In this work, we aim to explore the superconvergence of a modified nonconforming cut finite element method with rectangular meshes for elliptic problems. Boundary conditions are imposed via the Nitsche’s method. The superclose property is proven for rectangular meshes. Moreover, a postprocessing interpolation operator is introduced, and it is proven that the postprocessed discrete solution converges to the exact solution, with a superconvergence rate O(h3/2). Finally, numerical examples are provided to support the theoretical analysis.