Performance Test Research Articles

The effect of different vulcanization reagents on the synthesis of NiFeS and the performance test of seawater electrolysis

Hydrogen energy, as the most promising new energy for sustainable development, has aroused wide concern of researcher in the field of energy chemical industry. Among the many hydrogen generation approaches, electric water splitting for producing H2 is considered to be a simple and environmentally friendly method. Transition metal-based catalysts have become an important field in alkaline seawater electrolysis due to their high abundance and superior catalytic performance. Therefore, NiFeS (Ni3S2@FeS) was in-situ generated on nickel foam through a simple two-step hydrothermal approach in this paper. NiFeS/NF catalysts synthesized by three vulcanization reagents (Na2S·9H2O, CH3CSNH2, CH4N2S) were characterized and compared by a series of electrochemical tests. It is worth noting that for the first time, different vulcanization reagents were used to explore the activity of the same catalyst in seawater splitting and urea splitting. It was found that the NiFeS catalyst synthesized by Na2S·9H2O (Ni3S2@FeS-1/NF) had better oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance and good stability in alkaline seawater. The overpotential required for the OER with Ni3S2@FeS-1/NF electrode in alkaline seawater (1 M KOH + seawater electrolyte) is 290 mV at the 10 mA cm-2, and 92 mV for the hydrogen evolution reaction at the 10 mA cm-2. It is found that the NiFeS catalyst obtained by vulcanization of NiFe-LDH not only has high activity and conductivity, but also can effectively inhibit Cl- corrosion. Ni3S2@FeS-1/NF catalyst has a unique cluster rosette nanosheet array structure, which can present more catalytic reaction centres, accelerate the electron transfer rate and promote electrochemistry performance. The work proposes a novel way to explore the effect of different synthesis methods of the same composition on the performance of electrolytic seawater.

Mechanical Performance Tests of Customized CORC Cable

Mechanical Performance Tests of Customized CORC Cable

Oral but Not Topical Sodium Bicarbonate Improves Repeated Sprint Performance During Simulated Soccer Match Play Exercise in Collegiate Athletes.

This study investigated the effect of oral and topical sodium bicarbonate (SB) on soccer-specific performance during simulated soccer exercise. In a block randomized, double-blind, crossover design, 10 collegiate male soccer players (stature: 181.7 ± 3.2cm, body mass: 81.7 ± 10.5kg) performed soccer-specific performance tests (countermovement jumps, Illinois agility, 8 × 25m repeated sprints) throughout a 90-min soccer-specific aerobic field test (SAFT90) following 0.3g/kg body mass SB in capsules (SB-ORAL), 0.9036g/kg body mass PR Lotion (SB-LOTION), or placebo capsules and lotion (PLA). Soccer-specific performance tests were conducted pre-SAFT90, during half-time and post-SAFT90. Blood samples were analyzed for acid-base balance (pH; bicarbonate, HCO3-) and strong ions (sodium, Na+; potassium, K+). Average sprint times were quicker for SB-ORAL than PLA during half-time (3.7%; p = .049; g = .57) and post-SAFT90 (4.9%; p = .041; g = .66). SB-ORAL increased pH and HCO3- prewarm-up and during half-time (p < .05), and lowered K+ during half-time (p = .035) compared with PLA. SB-LOTION increased pH (p = .019) and lowered K+ (p = .012) during half-time compared with PLA. SB-LOTION increased Na+ postexercise compared with PLA (p = .008). Repeated sprint times during simulated soccer exercise improved for SB-ORAL, which might have been mechanistically underpinned by elevated blood buffering capacity and greater regulation of strong ion concentration. Consuming SB in capsules is a more effective strategy than topical SB application for improving blood buffering capacity and repeated sprint performance throughout competitive soccer matches.

Development of a top-lit-up-draft biomass gasifier as a sustainable heat source for effective drying of plantain slices in a cabinet dryer

This paper explored the development of a top-lit-up-draft biomass gasifier as a sustainable heat energy alternative to the traditional sun drying and the costly, unreliable heat energy sources such as grid-electricity and petrochemical fuels commonly used for cabinet dryers, especially in developing countries like Nigeria. The gasifier utilized the principle of top-lit-updraft biomass gasification system to thermochemically converts agricultural residues into clean heat energy. The designed gasifier has reactor diameter and height of 28cm and 90cm, fuel consumption rate of 55kg/hr, gasification airflow rate of 82.1m3/hr, DC fan motor of 15W, equipped with 30Ah battery power source, and capable of supplying heat energy of 260.16MJ/h. Performance testing using input variables of fuel loading (10kg-20kg), fan speed (4000rpm-6000rpm), and fuel type (palm-kernel shell, coconut shell, coconut husk, and wood shavings) assessed the gasifier responses such as fuel gasification time, flame temperature, thermal and combustion efficiencies, and carbon monoxide (CO) emission of the flame. Results revealed maximum thermal efficiency, peak flame temperature and longest gasification time of 86.02%, 8750C, and 130min respectively, when operated with palm-kernel shell at maximum fan speed and fuel loading, which emitted average CO of 1ppm lower than the least international air pollutant threshold of 9ppm. Highest combustion efficiency of 99.9% was attained using wood shavings at maximum fan speed and fuel loading. The results highlighted the potential of the gasifier as an effective heat source for drying applications, particularly for drying plantain slices in a cabinet dryer.

Formulation and evaluation of herbal shampoo

The main objective of these study is to evaluate and formulate herbal shampoo. Shampoo are one of the cosmetic products used in daily life. Synthetic preservatives and detergents have sometimes been the cause of adverse effects among consumers. A more radical approach in reducing the synthetic ingredients is by incorporating natural ingredients whose functionality is comparable with their synthetic ingredients. The ingredients used in formulation of Herbal Shampoo are Ficus Religiosa leaves (Powder), Hibiscus Leaves (Powder), Reetha (Powder), Shikakai (Powder), Aloevera, then prepared by mixing with each other and evaluated for its organoleptic and physio-chemical characteristics and performance tests in terms of wetting time test, pH, solid contents, surface tension, dirt dispersion, foam Stability, and Viscosity was performed. The combination of several such ingredient of herbal origin has made it possible to secure highly effective dry powder shampoo. The formulation at laboratory scale was done and evaluated for number of parameters to ensure its safety and efficacy The Formulated Herbal Shampoo was clear and good appealing. It demonstrated good froth stability, detergency, good cleansing, small bubble size, low surface strain, and execution of good conditioning property. The physicochemical evaluation of the formulated shampoo showed ideal results. However, to improve its quality, product performance, and safety, further development was required.

Aspects of Developing an Innovative, Energy-Efficient, Low-Emission Co-Generator

Purpose. To develop a model and construct an experimental, innovative co-generator with high energy efficiency and low emissions. This involves developing a system that can efficiently generate both electricity and heat simultaneously while minimizing emissions, contributing to sustainability efforts, and addressing energy demands in a more environmentally friendly manner. Methodology. To achieve the goal, a system approach is utilized, enabling the selection of modelling types for the development of an experimental, cutting-edge co-generation system capable of efficiently producing both electricity and heat with superior energy efficiency and minimal emissions. For this purpose, the following steps were completed: processing and summarizing available literature and patent sources, analysing scientific and technical papers on the selection and application of modelling types in co-generation systems, and considering principles and individual approaches to input data formation for mathematical modelling. This process enables the selection of a mechanism and the creation of simulation models for effective energy production at various enterprises. Findings. Assessment is performed of the energy efficiency of the co-generator system under various operating conditions, comparing it with existing conventional methods of electricity and heat generation. Results are presented of performance testing to determine the system’s capability to simultaneously generate electricity and heat efficiently, considering factors such as output stability, load responsiveness, and overall reliability. Identification and evaluation are performed of innovative technologies and methodologies integrated into the co-generator design, highlighting their effectiveness in enhancing energy efficiency and reducing emissions. Insights into any operational challenges encountered during the construction, testing, and optimization phases, along with proposed solutions or improvements to solve these problems. The analysis of the overall environmental impact of deploying the co-generator showed potential benefits in terms of reduced greenhouse gas emissions and local air quality improvement. Originality. Using a combination of scientific approaches encompassing physics and heat transfer engineering, in accordance with the first law of thermodynamics, such as the conservation laws of energy and entropy, and principles of heat exchange employed to transfer heat between different mediums, gas kinetics have yielded values for the energy transformation coefficient, indicating qualitative characteristics of fuel thermolysis and power generation as the final product. Practical value. The results provide for developing a comprehensive model of an advanced co-generation system capable of efficiently producing both electricity and heat with superior energy efficiency and minimal emissions. It also entails determining the types of models for mathematical modelling at all management levels and establishing a new method for input data formation for both technologies and their subsystems, incorporating additional technological implementations.

Developing a battery of physical performance tests to predict functional disability in Japanese older adults: A longitudinal study from the Kasama study.

Preventing functional disability benefits the quality of life of older adults and mitigates the economic burden of an aging society. However, the most effective physical performance tests and optimal cut points for identifying older adults at risk of functional disability remain unclear, and Japan lacks physical function-based assessment tools. We aimed to identify the physical performance tests related to functional disability and to develop a predictive test battery for it. We included 975 older adults (mean 72.8 ± 5.2 years, 55.4% women) in Kasama City, Japan. Functional disability was defined as certification of care level 2 or above based on the long-term care insurance system. Cox proportional hazards analysis examined the association between physical performance tests and incident functional disability. During a mean follow-up of 8.6 years (maximum 14 years), 236 participants (24.2%) developed functional disability. After adjusting for covariates, higher performances in grip strength, single-leg balance with eyes open (SLB), timed up-and-go (TUG), five-repetition sit-to-stand (5-STS), and 5-m habitual walk were significantly associated with a lower risk of functional disability. In a stepwise model, SLB, TUG, and 5-STS were key predictors of functional disability. Receiver operating characteristic analysis determined optimal cut points of 32.6/32.7 s for SLB, 6.5/6.6 s for TUG, and 7.8/7.9 s for 5-STS. We developed a predictive battery combining these cut points (area under the curve = 0.78). The developed battery of physical performance tests predicts future functional disability and is useful for screening older adults at high risk. Geriatr Gerontol Int 2024; ••: ••-••.

Wearable Haptics for Orthotropic Actuation Based on Perpendicularly Nested Auxetic SMA Knotting.

Smart wearable tactile systems, designed to deliver different types of touch feedback on human skin, can significantly improve engagement through diverse actuation patterns in virtual or augmented reality environments. Here, a perpendicularly nested auxetic wearable haptic interface is reported for orthotropically decoupled multimodal actuation (WHOA), capable of producing diverse tactile feedback modes with 3D sensory perception. WHOA incorporates shape memory alloy wires that are intricately knotted into an auxetic structure oriented along orthotropic dual axes. Its perpendicularly nested auxetic structure enables orthotropic actuation, allowing independent expansion and contraction along both x and y-axes, as confirmed by force-strain and displacement-time performance tests. Additionally, the perylene coating provides orthogonal electrical isolation to WHOA, allowing for stripe-specific localized actuation and enabling multiple tactile feedback modes. As an orthotropic wearable haptic interface, WHOA distinguishes between x-axis and y-axis directions and ultimately delivers multi-dimensional information regarding movements in 3D space through tactile feedback. As a result, when worn on the foot or arm, WHOA naturally delivers spatiotemporal tactile information to the user, facilitating navigation and teleoperation with 3D sensory perception.

Machine Learning Approach to Injury Monitoring in Children and Adolescents

Abstract Pediatric injuries are common and associated with individual suffering and costs for the healthcare systems and society. The incidence of injuries among children in Switzerland has so far been insufficiently monitored. Emergency department patient records can be a valuable database to assess medically relevant injuries and gain information for monitoring and evidence-based prevention. The talk will outline our stepwise development of a machine-learning program for a pediatric injury monitoring system and lessons learnt. In this feasibility study we draw on electronic case histories of children treated for injuries between 2018 and 2022 at the University Children’s Hospital Zürich emergency department (N= to 30’884). The ML- approach follows different steps: step 1. utility evaluation of electronic pediatric patient records regarding ML and injury monitoring and prevention requirements in a test-sample of 100 electronic pediatric case histories; step 2. choice/adaptation of coding tree; step 3. coder training and inter-coder reliability testing; step 4. manual annotation of a sub-sample (n 1000) of the electronic pediatric patient records, step 5. design and testing of the ML program in an iterative process, and step 6. performance testing in a random sample of pediatric patient records. First lessons learnt indicate that electronic case history data contain relevant data and fulfill requirements for monitoring and prevention purposes. The IDB coding system proved too complex and detailed for the pediatric data base, providing too few examples for the ML-learning process, and needed to be adapted. Initial data analyses indicate the majority of cases are classified as less severe (73%) and only few (&amp;lt;1%) as very severe but the later provide the most detailed data. ML is a promising approach and makes use of hospital data for a national monitoring of pediatric injuries in Switzerland.

Serum metabolomics improve risk stratification for incident heart failure

Abstract Background The prediction and early detection of heart failure (HF) is vital to reduce its substantial impact on quality of life, survival and healthcare expenditure. Current incident HF risk stratification strategies achieve only modest performance. Moreover, state-of-the-art risk scores focus on commonly acknowledged clinical risk factors, thus necessitating the integration of heterogenous data sources and prioritizing individuals with obvious risk constellations. Purpose Here, we explored the predictive value of serum metabolomics (168 metabolites detected by proton nuclear magnetic resonance (1H-NMR) spectroscopy) for incident HF. Methods Leveraging data of n = 68,311 individuals and &amp;gt; 0.8 million person-years of follow-up from the UK Biobank (UKB) cohort, we (I) evaluated the association of individual metabolites with incident HF via fitting of per-metabolite COX proportional hazards models and (II) trained and validated elastic net (EN) models to predict incident HF using the serum metabolome. Discriminative performance was benchmarked against a comprehensive, well-validated clinical risk score (Pooled Cohort Equations to Prevent HF, PCP-HF). External validation was conducted in the independent FINRISK study. Results Several metabolites were independently associated with incident HF (90/168 adjusting for age and sex, 48/168 adjusting for PCP-HF). Performance-optimized risk models effectively retained key predictors representing highly correlated clusters (≈ 80 % feature reduction). The addition of metabolomics to PCP-HF improved predictive performance (Harrel’s C: 0.768 vs. 0.755, ΔC = 0.013 (95% confidence interval (CI) 0.004 – 0.022), continuous net reclassification improvement (NRI) = 0.287 (95% CI 0.200 – 0.367), relative integrated discrimination improvement (IDI): 17.47 % (95% CI 9.463 - 27.825)). Simplified models only including age, sex and metabolomics performed almost as well as the PCP-HF model (Harrel’s C: 0.745 vs. 0.755, ΔC = 0.010 (95% CI -0.004 - 0.027), continuous NRI: 0.097 (95% CI -0.025 - 0.217), relative IDI: 13.445 % (95% CI -10.608 - 41.454)). Risk and survival stratification was improved by integrating metabolomics. External validation within FINRISK revealed similar patterns using the original model coefficients. Conclusions Serum metabolomics improve the prediction of incident HF risk. Scores obtained from the combination of age, sex and metabolomics exhibit similar predictive power as clinical risk models. Offering serum metabolomics to a middle-aged cohort might significantly improve HF risk stratification, thus facilitating preventive efforts. Via a single blood draw, serum metabolomics displays a highly cost- and time-effective, standardizable, and scalable alternative to clinical risk scores involving physical measurements and history taking in addition to clinical chemistry.Relative performance (test split)ROC &amp; DCA plots (test split)

Physical fitness in youth: a systematic review of changes during and after the COVID-19 pandemic

Abstract Background Restrictions during the COVID-19 pandemic induced changes in the fitness behavior of children and adolescents, which may be associated with long-term public health challenges. This systematic review analyses how physical fitness has changed during the pandemic and to what extent the changes remain in the aftermath of the pandemic. Methods We conducted a systematic search in seven databases with a peer-reviewed search string for studies until Dec 2023. Our inclusion criteria encompassed studies with children and adolescents ≤19 years living in the WHO European Region and in which validated measurements were used (single measurements or test batteries). Eligibility screening, data extraction and risk of bias assessment (using ROBINS-E instrument) were all carried out independently by two reviewers. We published an a priori protocol in a peer-review journal and conducted reporting in accordance with the PRISMA 2020 statement. Trial registration: PROSPERO: CRD42023395871. Results Our search retrieved 28 studies from 15 WHO European Region countries with an age range from 5 to 19 years. Physical fitness was reported in 21 validated single measurements (e.g. 20 m shuttle run, handgrip strength, standing long jump) and 9 validated test batteries (e.g. Alpha-Fitness Battery, German Motor Test, International Physical Performance Test Profile). The preliminary analyses pointed to a sharp decline in youth physical fitness during the COVID-19 pandemic. After restrictions were eased, physical fitness improved, but remained under pre-pandemic levels, particularly in boys. Conclusions The findings indicate a potential suboptimal behavioral adaptation of children and adolescents after the COVID-19 pandemic. Medium and long-term programs to change passive behavior and improve physical fitness are urgently needed. In addition to individual prevention programs, stronger consideration should also be given to schools and sport clubs regarding activities promoting physical fitness. Key messages • Physical fitness in children and adolescents remains below pre-pandemic levels after restrictions removal. • Initiating immediate public health action to increase physical fitness is urgently needed.

Using Media (Video) to Improve Students’ Speaking Skill in Study Case: Junior High School

Learning media in the digital era must be aligned with technological developments. The learning media chosen must be interesting and attached to students. The video is currently popular with many people, including the students of Junior High School, MTsN 1 Kolpajung Pamekasan. Departing from these reasons, the researchers took the initiative to implement the video as a media for interesting and fun learning in delivering material in English for Junior High School. This study aims to find out how effective the video as media is in improving the speaking skills of students majoring at the MTsN 1 Kolpajung Pamekasan. Qualitative method is used for analyzing the data on performance test, observation and discussion on the implementation that were produced by the students as well as processing on student views regarding the use of video media in learning in English subject especially speaking skill. The result indicated that the use of video media is considered quite effective in developing students' speaking skills. From the results of observations, it shows that there has been an increase in student activity, from an average of 74.7% in cycle one and 82.2% in cycle two, to 86.3 in cycle III, as well as teacher activity in the learning process increasing from 85.7 % in cycle I, 90.3% in cycle II increased to 92.03% in cycle III which stated that video media was an innovation in learning English, which made students more relaxed and enjoyed the teaching and learning process and eliminated the mindset that learning English is difficult.

Assessment of the effect of solid herbal extract of primula veris l on the physical performance of rats after chronic alcohol intoxication

The aim of this study was to evaluate the effect of solid herbal extract of Primula Veris L. and comparison drugs phenotropil and mildronate on the physical performance of female rats after chronic alcohol intoxication (CAI). CAI was modeled by replacing drinking water for 6 months with a 10 % solution of ethyl alcohol with sucrose (50 g/l). At the age of 16 months, the “Rotarod performance test”, “The horizontal rope walking test” and “Forced swim test with weight load” were performed. After CAI, rats show a deterioration in coordination and motor activity, a decrease in muscle strength and aerobic-anaerobic endurance. Solid herbal extract of Primula Veris L., phenotropil and mildronate contributed to an increase in the physical performance of animals after CAI.

A New Objective Diagnostic Tool for Attention-Deficit Hyper-Activity Disorder (ADHD): Development of the Distractor-Embedded Auditory Continuous Performance Test

Background/Objectives: Attention-Deficit Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity. Traditional diagnostic methods, which depend on subjective assessments, often lack precision. This study evaluates the validity and reliability of a newly developed diagnostic tool, the Distractor-Embedded Auditory Continuous Performance Test (da-CPT), which integrates auditory stimuli with distractors to enhance the clinical utility of ADHD diagnosis. Methods: The study included 160 children aged 6–12 years, comprising 80 with a confirmed ADHD diagnosis and 80 controls. All participants completed the da-CPT, a web-based tool designed to assess inattention, hyperactivity, impulsivity, and timing via an auditory-based task. To validate the da-CPT, participants also completed the Conners’ Parent Rating Scale—Revised Short Form (CPRS-R) and either the MOXO or IVA-2 tests. Data were analyzed using ROC curves and statistical correlations to assess sensitivity, specificity, and overall diagnostic accuracy. Results: The da-CPT demonstrated high diagnostic accuracy, with a sensitivity of 91.25% and specificity of 83.75%. ROC analysis indicated that the inattention index had the highest discriminatory power (AUC = 0.881), followed by timing, impulsivity, and hyperactivity (all p &lt; 0.01). Furthermore, the da-CPT scores were strongly correlated with ADHD severity (p &lt; 0.01). Conclusions: This study confirms that the da-CPT is a valid and reliable tool for diagnosing ADHD in children aged 6–12. By incorporating auditory stimuli and distractors, the tool offers a more ecologically valid assessment of ADHD symptoms in clinical settings, improving diagnostic precision and utility.

Surface modification of high-speed steel (HSS) drills by plasma nitriding and cathodic cage tin deposition

Cutting tools made of high-speed steel have significant economic and technological importance. To enhance their productivity, thermochemical treatments are sought to improve both surface mechanical and tribological properties. Plasma nitriding and thin film deposition are widely employed for this purpose. In this study, modifications were made to M2 high-speed steel drills through plasma nitriding at temperatures of 400°C and 450°C. Cathodic cage TiN plasma deposition was also performed, varying the dwell time at a fixed temperature of 450°C. Characterization techniques included optical microscopy, X-ray diffraction (XRD), Vickers microhardness testing, and scanning electron microscopy (SEM). Performance tests were carried out to evaluate the behavior of the drills in relation to wear when machining AISI 1020 steel. It was observed that longer deposition times promote more uniform and thicker layers, and higher nitriding temperatures result in thicker nitride layers. An increase in hardness was noticeable in all deposition and nitriding treatments, with the nitrided samples exhibiting the highest hardness. During performance tests, the cathodic cage plasma TiN deposition demonstrated greater potential for application in HSS drills, with a treatment lasting 4 h providing the best results.

Validity of specific CPT indices in differentiating school-aged children previously diagnosed with attention deficit/hyperactivity disorder from school-aged children with non-attention deficit/hyperactivity disorder in general education classrooms: a case control study

BackgroundContinuous performance tests (CPTs) are a popular tool for evaluating the symptoms of attention-deficit/hyperactivity disorder (ADHD). Performance measurements are typically linked to the biological features and cognitive functions of individuals. To determine the validity of specific CPT indices in differentiating between school-aged children with ADHD from with non-ADHD, each student’s sex, chronological age, and cognitive abilities should be considered.MethodsIn this prospective case–control study, a total of 30 non-ADHD students and 26 with ADHD who were aged 6 to 12 years were from general education classrooms. All students completed the Continuous Performance Tests (CPTs) and the Peabody Picture Vocabulary Test-revised (Mandarin-Chinese version). Demographic data were collected from the students’ parents.ResultsDetectability, Omissions, Commissions, and Hit Reaction Time Standard Deviation (HRT SD) yielded higher T-scores in children with ADHD than those without. Compared with non-ADHD students, those with ADHD had higher classification scores for Detectability, Omissions, Perseverations, and HRT SD. For each CPT index, after individual factors were controlled for, logistic regression revealed that only students with positive scores for Detectability, Omission, and HRT SD (adjusted odds ratios = 4.627, 9.977, and 3.908, Ps < 0.05) were likely to receive a diagnosis of ADHD. Furthermore, after individual characteristics were controlled for, Logistic regression also revealed that the cumulative positive scores of the Detectability, Omission, or and HRT SD remained associated with an increased risk of ADHD (adjusted odds ratio = 3.116, P < 0.01).ConclusionsCompared with school-aged children with non-ADHD in general education classrooms, those with ADHD exhibited significantly lower performance in inattention-related CPT indices. To reach an accurate diagnosis through CPTs, clinicians should pay attention to Detectability, Omission, and HRT SD. Compared with other CPT indices, Detectability, Omission, and HRT SD may function as more suitable indicators for distinguishing between school-aged children with and non-ADHD in general education classrooms. These indicators are robust and unobscured by individual characteristics.

Improving the Cycle Stability of LiNiO2 through Al3+ Doping and LiAlO2 Coating.

In this study, we addressed the poor cycling and rate performance of LiNiO2, a material with ultrahigh nickel content considered a strong contender for high-energy-density lithium-ion battery cathodes. We introduced nano-Al2O3 during the lithiation process to achieve dual modified material through bulk phase element doping and in situ LiAlO2 coating. Comparison revealed notable improvements in the modified materials. In particular, LiNi0.99Al0.01O2 maintained a capacity retention rate of 73.1% after 300 cycles in a long-cycle test at 0.5C current density, outperforming the undoped material. In rate performance tests, the doped samples consistently exhibited higher discharge-specific capacities than that of the undoped counterpart. Notably, at a high current density of 5C, LiNi0.99Al0.01O2 exhibited a discharge-specific capacity of 101.75 mAh g-1. The results indicate that an appropriate amount of Al doping can effectively stabilize the layered structure of the cathode material and delay the irreversible phase transition from H2 to H3. Further, Al doping facilitates the formation of a LiAlO2 coating on the surface of the particles. This coating acts as a fast-ion conductor, enhancing the transport of lithium ions and reducing the erosion of the active material by the electrolyte.

Characterization of Interface Transition Zone in Asphalt Mixture Using Mechanical and Microscopic Methods

An enormous surge in the pavement sector requires the evaluation of interface bonding in asphalt composite, since the assessment of bonding brings considerable cost savings. Microscopic and mechanical analyses were performed to study the status of the interface transition zone of four groups of asphalt mixtures, using thin-slice preparation to obtain asphalt mixture slices with a flat surface for microscopic analysis. The interface transition zones were characterized using good knowledge of blending or diffusion phenomena by conducting tests both at the micro and macro levels to determine mixture quality. Asphalt mixture components were observed using fluorescence microscopy imaging and evaluated by the gray value change law. Asphalt mixture groups, (virgin, recycled of 30% aged and 70% unaged, 6%, and 4% rejuvenator dosage mixtures) under the same process parameters, which are a mixing time of 270 s and a mixing temperature of 150 °C, been considered optimum for component fusion in a hot asphalt mixture were used. This study relied on the influence of morphology law, assessed through rutting tests for high temperature performance, semi-circular bending tests for low temperature performance, and pull-off tests for interface bonding strength. The relationship between interface transition zones and macro performance was studied. The self-developed pull-off method was a research innovation which can be used as an alternative to study interface transition zones in asphalt mixtures, and provides the necessary data needed with 3D surface failure mode calculations. The device measured the bonding strength of a single aggregate in distinct positions using the bitumen penetration test method. The main goals were to determine a correction factor, identify the appropriate alteration, and compute the actual fracture surface area. Using scanning electron microscopy for interface characterization and micro-morphologies of mortar transition zone, our analysis provides adequate knowledge about interface position and the components present. The applied approaches to characterize asphalt mixture interfaces proved workable and reliable, as all methods have similar trends with useful information to determine asphalt pavement quality.

Experimental investigation on the electrical and hydrogen-production performance of a novel PEM electrolyzer driven by CdTe PV with a tracking system

Addressing the challenges of intermittent and variable energy supply, solar hydrogen production via electrolysis has garnered significant attention due to its unique advantages, emerging as a hot topic in the scientific research domain. However, the application of this technology is currently mainly related to the non-tracking system, which undergoes a rapid change in solar irradiation during the day. To expand the matching relationship of solar irradiation, PV characteristics, and electrolyzer, this paper proposes the development of a Proton Exchange Membrane (PEM) electrolyzer driven by Cadmium Telluride (CdTe) photovoltaic (PV) modules with a tracking system for hydrogen production. An experimental platform was set up in Chengdu and the performance tests were carried out for different operating modes during summer. The experimental results demonstrate that the average electrical and hydrogen production efficiencies of the system are 13.11% and 7.88%, respectively, on a sunny day, with a total of 566.7 L of hydrogen produced within 7 h of operation. Furthermore, the solar irradiation received by the tracking surface of the system is significantly enhanced by 10.29% in comparison to the horizontal surface. On a cloudy day with an electrolyzer inlet water temperature of 45 °C, the system has the potential to achieve a hydrogen production efficiency of 11.15 %. At a constant current density of 1.0 A/cm2, the efficiency of the electrolysis process increased by 2.07% and 1.25% for each 10 °C increase in the temperature of the electrolyzer, having an inlet temperature of 35 °C. This study offers a novel approach for a PV-PEM system with a higher hydrogen production efficiency while also establishing a robust foundation for technology optimization and broader implementation.

Preparation of high strength and rigidity carbon layer on SiO material surface by dynamic CVD method using gas carbon source C2H2

The main issue in the application of silicon-based negative electrode materials is the inevitable volume expansion, leading to negative electrode material fracture, which severely impacts the performance of batteries. This study employed Chemical Vapor Deposition (CVD) (C2H2@SiO), solid-phase coating method (Pitch@SiO), and liquid-phase coating method (RGFQ@SiO) to coat the surface of SiO materials with a dense amorphous carbon structure. Material property analysis revealed that C2H2@SiO has a relatively small specific surface area (1.8 m2 g−1) and surface carbon increment (2.4 %). It exhibited high reversible specific capacity (1563.4 mAh g−1), high initial Coulombic efficiency (81.45 %), and low volume expansion rate (9.3 %). Mechanical performance testing indicated that the surface carbon layer Young's modulus of C2H2@SiO was the highest (35 GPa), suggesting that using the CVD method to obtain a dense carbon layer can enhance the structural strength of the material. Based on the electrochemical-mechanical coupling theory simulation analysis of the stress during the charge-discharge process of electrode materials, the evolution of concentration and stress field during lithium insertion process was obtained, showing that the coating can further improve the electrochemical and mechanical performance of the negative electrode materials effectively. Additionally, the negative electrode sheets fabricated using sample C2H2@SiO were assembled into 18650 cylindrical batteries, exhibiting excellent cycling performance in 1000 cycles at 25 °C with a capacity retention rate of 85.7 %, along with good rate capability and high/low-temperature performance. The conclusions of this study provide certain guidance for the design and optimization of negative electrode materials for battery electrodes.