Low Cost Research Articles

Effects of Sports Participation on Academic Performance in Adolescents

Purpose: The aim of the study was to assess the effects of sports participation on academic performance in adolescents. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: The study indicate a positive correlation between sports involvement and academic achievement, others highlight potential drawbacks such as time constraints and fatigue. Sports participation has been associated with improved cognitive function, time management skills, and self-discipline, which can positively impact academic performance. However, excessive commitment to sports may lead to neglect of academic responsibilities and increased stress. Furthermore, the influence of sports on academic performance can vary depending on factors such as the type of sport, level of competition, and individual characteristics of the student. Overall, while sports participation can offer various benefits for adolescents, striking a balance between athletic and academic pursuits is crucial for maximizing overall development and success. Implications to Theory, Practice and Policy: Self-determination theory, social learning theory and achievement goal theory may be used to anchor future studies on assessing effects of sports participation on academic performance in adolescents. Educators and school administrators should prioritize the integration of physical activity and sports programs within school curricula to support academic success. Policymakers should recognize the importance of sports participation in promoting holistic youth development and academic success.

Influence of Air Quality on Respiratory Health in Urban Areas in Japan

Purpose: The aim of the study was to analyze the influence of air quality on respiratory health in urban areas in Japan. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: Research in Japan indicates a clear link between urban air quality and respiratory health, with pollutants like PM2.5 and nitrogen dioxide posing significant risks. High pollution levels, stemming from factors like vehicular emissions and industrial activities, are particularly detrimental in densely populated areas. Vulnerable groups, such as children and the elderly, are especially affected, experiencing worsened symptoms and reduced lung function. Urgent implementation of effective air quality management measures is crucial to protect public health in Japanese cities. Unique Contribution to Theory, Practice and Policy: Environmental justice theory, exposure-response theory & place-based theory may be used to anchor future studies on analyze the influence of air quality on respiratory health in urban areas in Japan. Implement community-based interventions that target vulnerable populations, such as children, the elderly, and individuals with pre-existing respiratory conditions, in collaboration with local stakeholders and healthcare providers. Advocate for stricter air quality standards and regulations at the local, national, and international levels to reduce emissions of pollutants from industrial sources, transportation, and residential activities.

Impact of Air Quality on Respiratory Health in Children in Mexico

Purpose: The aim of the study was to analyze the impact of air quality on respiratory health in children in Mexico. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: High air pollution levels in Mexico, largely from traffic and industry, worsen respiratory health in children. This includes higher rates of asthma, respiratory infections, and decreased lung function. Urban areas with limited healthcare access are hit hardest. Urgent action is needed, including stricter regulations and public health initiatives, to protect Mexican children's well-being. Unique Contribution to Theory, Practice and Policy: Environmental determinism theory, bronfenbrenner’s ecological systems theory & health belief model (HBM) may be used to anchor future studies on analyze the impact of air quality on respiratory health in children in Mexico. Encourage pediatricians and healthcare providers to routinely discuss air quality issues during visits and provide guidance on minimizing exposure, especially in areas with known poor air quality. Policy initiatives should aim to reduce the emission of key pollutants identified in the research as harmful to children's respiratory health.

Ru Single Atom Dispersed on MoS2/MXene for Enhanced Sulfur Reduction Reaction in Lithium-Sulfur Batteries.

The high theoretical energy density (2600 Whkg-1) and low cost of lithium-sulfur batteries (LSBs) make them an ideal alternative for the next-generation energy storage system. Nevertheless, severe capacity degradation and low sulfur utilization resulting from shuttle effect hinder their commercialization. Herein, Single-atom Ru-doped 1T/2H MoS2 with enriched defects decorates V2C MXene (Ru-MoS2/MXene) produced by a new phase-engineering strategy employed as sulfur host to promote polysulfide adsorption and conversion reaction kinetics. The Ru single atom-doped adjusts the chemical environment of the MoS2/MXene to anchor polysulfide and acts as an efficient center to motivate the redox reaction. In addition, the rich defects of the MoS2 and ternary boundary among 1T/2H MoS2 and V2C accelerate the charge transfer and ion movements for the reaction. As expected, the Ru-MoS2/MXene/S cathode-based cell exhibits a high-rate capability of 684.3 mAh g-1 at 6 C. After 1000 cycles, the Ru-MoS2/MXene/S cell maintains an excellent cycling stability of 696 mAh g-1 at 2 C with a capacity degradation as low as 0.02% per cycle. Despite a high sulfur loading of 9.5mg cm-2 and a lean electrolyte-to-sulfur ratio of 4.3, the cell achieves a high discharge capacity of 726 mAh g-1.

Effectiveness of Telemedicine Interventions on Mental Health Outcomes during Pandemics in Brazil

Purpose: The aim of the study was to analyze the effectiveness of telemedicine interventions on mental health outcomes during pandemics in Brazil. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: Research in Brazil shows promising results for telemedicine's effectiveness in improving mental health outcomes during pandemics. Telemedicine interventions, like virtual therapy sessions, enhance access to care, especially in remote areas. Patients express satisfaction with remote mental health support, citing convenience. However, challenges such as the digital divide and privacy issues require attention for equitable and confidential service delivery. Unique Contribution to Theory, Practice and Policy: Social cognitive theory (SCT), technology acceptance model (TAM) & health belief model (HBM) may be used to anchor future studies on analyze effectiveness of telemedicine interventions on mental health outcomes during pandemics in Brazil. Telemedicine platforms should be designed to accommodate Brazil's diverse cultural and linguistic landscape. Policy makers should develop clear regulatory guidelines for telemedicine practice in Brazil, particularly concerning licensure, privacy protection, and reimbursement policies.

Effects of Dietary Interventions on Type 2 Diabetes Management in Zambia

Purpose: The aim of the study was to analyze the effects of dietary interventions on type 2 diabetes management in Zambia. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: Dietary interventions in Zambia for managing Type 2 Diabetes showed improved glycemic control, emphasizing fresh foods and reducing processed ones. Participants reported better adherence, leading to weight loss and reduced medication dependency. Additionally, improvements in lipid profiles and blood pressure were noted, highlighting broader cardiovascular benefits. Overall, culturally tailored dietary interventions are crucial for effective Type 2 Diabetes management in Zambia. Unique Contribution to Theory, Practice and Policy: Social cognitive theory (SCT), health belief model (HBM) & trans theoretical model (TTM) may be used to anchor future studies on analyze the effects of dietary interventions on type 2 diabetes management in Zambia. Emphasize the importance of individualized dietary approaches in diabetes management, considering factors such as cultural preferences, socioeconomic status and comorbidities. Promote policies that prioritize nutrition education, access to healthy foods, and community-based interventions aimed at preventing and managing type 2 diabetes.

Effectiveness of Mindfulness-Based Interventions in Enhancing Sports Performance

Purpose: The aim of the study was to assess the effectiveness of mindfulness-based interventions in enhancing sports performance. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: The study found that mindfulness-based interventions (MBIs) hold promise in enhancing sports performance across various disciplines. The study indicate that athletes who engage in mindfulness practices experience improvements in attentional control, emotional regulation, and stress management, all of which are critical for optimal athletic performance. By cultivating present-moment awareness and fostering a non-judgmental attitude toward thoughts and sensations, athletes can better focus on the task at hand, manage competitive pressure, and maintain peak performance under stressful conditions. Furthermore, MBIs have been shown to facilitate skill acquisition and execution, as well as promote recovery and injury rehabilitation. Overall, these findings highlight the potential of incorporating mindfulness training into sports training programs to enhance athletes' mental resilience and overall performance. However, further research is needed to elucidate the specific mechanisms through which mindfulness exerts its effects on sports performance and to optimize the integration of MBIs into athletic training regimens. Implications to Theory, Practice and Policy: Self-determination theory, cognitive-behavioral theory and flow theory may be used to anchor future studies on assessing effectiveness of mindfulness-based interventions in enhancing sports performance. Develop evidence-based mindfulness training programs tailored specifically for athletes across different sports disciplines and performance levels. Advocate for the integration of mindfulness training into athlete development programs at the grassroots, elite, and professional levels.

Spark Discharge Aerosol-Generated Copper-Based Nanoparticles: Structural & Optical Properties; Application on the Antiviral (SARS-CoV-2) and Antibacterial Improvement of Face Masks.

Nanoparticle formation by Spark Discharge Aerosol Generation offers low-cost fabrication of nanoparticles, without the use of chemicals or vacuum. It produces aerosol particles of a few nanometers in size with high purity. In this work, copper-based -CuO (tenorite) and Cu- nanoparticles are produced, characterized and used to modify face mask air filters, achieving the introduction of antibacterial and antiviral properties. A range of characterization techniques have been employed, down to the atomic level. The majority of the particles are CuO (of a few nanometers in size that agglomerate to form aggregates), the remainder being a small number of larger Cu particles. The particles were deposited on various substrates, mainly fiber filters in order to study them and use them as biocidal agents. On face masks, their antibacterial activity against Escherichia coli (E.coli) results in a 100 % decrease in bacteria cell viability. Their antiviral activity on face masks results in a 90 % reduction of the Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) viability, 15 minutes post the application of the virus stock solution. This highlights the effectiveness of this approach, its simplicity, its low cost and its excellent environmental credentials.

Production and Optimization Study of Biodiesel Produced from Non-edible Seed Oil

The fuel demand is increasing globally. The conventional fuel is toxic and causes global warming and pollution. Therefore, biodiesel is being used as the alternative to petroleum fuel because it is non-toxic and can be renewable. Nowadays, non-edible feedstock is gaining more attention for the production of biodiesel because it can grow anywhere on land, have low cost, and doesn’t cause an imbalance in the food economy. This study deals with the biodiesel production and optimization of biodiesel from Ricinus communis oil using sodium hydroxide (NaOH) and potassium hydroxide (KOH) as solid base catalyst. The free fatty acid content (22.14 % mg KOH/g) of castor oil calculated before transesterification indicated that the pretreatment of raw oil with acid was required for biodiesel synthesis. Therefore, the esterification process was used to reduce the free fatty acid content of castor oil from 22.14% to 0.84%. After that, the transesterification process was used for production of biodiesel using a catalyst (NaOH and KOH). The four different parameter reactions (i.e. Ratio (alcohol to oil), Time, Temperature, and catalyst amount) were used to optimize the yield of biodiesel production. Firstly, NaOH was used as the catalyst and different reactions were done by making changes in all parameters to get maximum yield. The same procedure was done to get maximum yield using KOH as the catalyst. The maximum yield obtained using NaOH and KOH was 94.6 % and 96.2% respectively. In the future, the properties of biodiesel on different parameters can be analyzed and also can be used as a diesel engine to check the working of the engine.

Prediction of Poor Outcome Using the Urea to Albumin Ratio in Thoracic Empyema

Purpose: The prognostic performance of urea-to-albumin ratio (UAR) has been assessed in various pulmonary and nonpulmonary conditions, but never in thoracic empyema. Therefore, our aim was to determine whether this marker has the ability to predict outcome in such patients.Methods: A single-center retrospective study was conducted in a Clinic of Thoracic Surgery at a University Hospital between January 2021 and October 2023. A total of 84 patients who underwent emergency surgery due to thoracic empyema were involved. Serum levels of urea and albumin at admission were used to calculate UAR. We analyzed area under receiver operating characteristics (AUROC) curves of UAR, systemic inflammatory response syndrome (SIRS) and quick-sequential organ failure assessment (qSOFA), and compared their prognostic performance.Results: The identified in-hospital mortality was 10.7%. The UAR showed the best ability to prognosticate mortality compared to qSOFA (AUROC = 0.828 vs 0.747) and SIRS (AUROC = 0.828 vs 0.676). We established a sensitivity of 87.5% and specificity of 74.2% at optimal cut-off value UAR > 51.1 for prediction of adverse outcome.Conclusion: In patients with thoracic empyema urea-to-albumin ratio showed significant prognostic performance and a potential for clinical application as a low cost and widely available predictor of death.

Larval development of Holothuria tubulosa, a new tractable system for evo-devo

To explore animal diversity, new experimentally tractable organisms must be established. Echinoderms include five groups of marine animals that have been used as developmental models for over a century thanks to their low costs, high fecundity, optically clear larvae and genetic tractability. An additional advantage of echinoderms is that their larval forms display diverse morphologies. This rich diversity enables comparative studies to investigate the evolutionary relationships among cell types, tissues, and organs. However, reproducible protocols to obtain gametes, detailed information on embryogenesis, and genomic tools have been optimized only for selected species of sea urchins and sea stars. To address this gap, we established the abundant Mediterranean sea cucumber Holothuria tubulosa as a new experimental system. Here we describe a method to reliably obtain gametes and make embryonic cultures multiple times from the same animal and characterize unique larval tissues combining immunohistochemistry and high-resolution microscopy. This work represents a step forward in our understanding of holothurian development and establishes H. tubulosa as an emerging experimental system for evo-devo and other biological disciplines.

Advancements in 3D printing materials: A comparative analysis of performance and applications

3D printing has rapidly evolved and matured in recent years, with a key factor being the improvement in printing materials. This paper compares the performance and applications of various 3D printing materials, including plastics, metals, ceramics, and biomaterials. Plastics remain the most widely used material due to their low cost and ease of printing, while metals are gaining popularity due to their superior mechanical properties. However, recent advancements in ceramic and biomaterials have opened up new possibilities for 3D printing in industries such as aerospace, healthcare, and electronics. The comparative analysis provides insights into the strengths and limitations of each material, and how they can be optimized for specific applications. With continuous developments in 3D printing technology and materials, the potential for this technology to revolutionize manufacturing and other industries is promising.

High-Entropy CeNbO4+δ-Based Ceramics with Ultrahigh Comprehensive Thermosensitive Performances.

Next-generation advanced high-temperature sensors rely heavily on negative temperature coefficient thermosensitive ceramics with low cost, small volume, high sensitivity, and fast response. However, thus far, the enormous challenge of achieving ultrahigh stability and accuracy has become a critical bottleneck restricting the development of thermosensitive ceramics in high-temperature sensor applications. Here, we propose a high-entropy strategy to design a "cation valence self-equilibrium" system in CeNbO4+δ-based ceramics introducing redox couple compensation and ultrahigh density dislocations to solve the problem of temperature-dependent oxygen nonstoichiometry that restricts the performances of high-temperature thermosensitive ceramics. Ferroelastic domains are generated by enhancing the configurational entropy at both A and B sites, resulting in a dramatic increase of dislocation density to >1010 mm-2, which ultimately optimizes the thermosensitive performances. Extreme temperature measurement accuracy with R2 as high as 999.98‰ and RSS as low as 0.011 and high-temperature stability with ΔR/R0 as low as 0.23% after aging at 873 K for 1000 h are realized in high-entropy CeNbO4+δ-based ceramics, indicating a breakthrough in the comprehensive performances of thermosensitive ceramics. This work opens up an effective way to design thermosensitive materials with ultrahigh comprehensive performance to meet the requirements of advanced high-temperature sensors.

Trifluoromethoxylation of Arynes using 2,4‐Dinitro‐1‐(trifluoromethoxybenzene) as Trifluoromethoxide Anion Source

The trifluoromethoxy moiety, an emerging fluorinated group, shows interesting properties for pharmaceutical and agrochemical applications. However, only few methods have been reported for the direct introduction of this group on molecules with high efficiency, safety and low cost. Indeed, most of direct trifluoromethoxylation reagents are either expensive, hazardous or require preliminary synthesis before their use. Here we describe the use of 2,4‐dinitro‐1‐(trifluoromethoxy)benzene (DNTFB) as an easy‐to‐handle, safe, commercially available and cheap source of trifluoromethoxide anion for the trifluoromethoxylation of arynes.

Surface Modification Induces Oriented Zn(002) Deposition for Highly Stable Zinc Anode

Aqueous zinc metal batteries (AZMBs) are considered a promising candidate for grid-scale energy storage systems owing to their high capacity, high safety and low cost. However, Zn anodes suffer from notorious dendrite growth and undesirable surface corrosion, severely hindering the commercialization of AZMBs. Herein, a strategy for engineering a dense ZnO coating layer on Zn anodes using the atomic layer deposition (ALD) technique is developed, aiming to improve its long-term cycling stability with fewer Zn dendrites. The surface-modified Zn anode (ZnO@Zn) exhibits an excellent long-cycling life (680 h) and stable coulombic efficiency when being used in a symmetric cell. Moreover, the ZnO@Zn electrode shows a high stability with almost no capacity decay after 1100 cycles at 2C in a full cell using MnO2 as the cathode. The ZnO coating is conducive to reducing corrosion and the generation of by-products, thus increasing the reversibility of Zn2+/Zn stripping/plating. Particularly, density functional theory (DFT) calculation results reveal that the ZnO coating layer could effectively lower the adsorption energy of the Zn(002) plane in ZnO@Zn, inducing the preferential deposition of Zn2+ towards the (002) crystal plane with fewer Zn dendrites. The surface ZnO coating protocol provides a promising approach to achieve a dendrite-free Zn anode for stable AZMBs.

Long-term time-course of atrial sensing and incidence of atrial fibrillation in patients with VDD versus DDD pacemakers

Abstract Introduction VDD pacemakers (PM) theoretically have the same advantages with respect to maintaining atrioventricular (AV) synchrony as dual-chamber (DDD) pacemakers, with lower costs and simpler implantation procedure. However, their use is often limited by concerns about the maintenance of atrial sensing (AS) and the occurrence of atrial fibrillation (AF). Purpose We aimed to compare long-term atrial sensing stability, the incidence of AF and complications in VDD and DDD systems. Methods We retrospectively enrolled patients who underwent VDD or DDD PM implantation for AV block between 2014 and 2021 from 2 centers. Clinical, analytical and electrical variables at implantation, their evolution and events at follow-up (25.2±16.2 months) were collected, comparing the groups by Kaplan-Meier and Cox multivariate analysis. Results 487 patients who underwent PM implantation were included, 189 (38,8%) received a VDD PM and 298 (61,2%) a DDD PM. Patients with VDD were older and had a higher prevalence of risk factors and lower atrial voltage at implantation (Table). Complications at implantation and early complications were scarce and without significant differences in both groups. During follow-up, there was a reduction in atrial voltage in the VDD group (implant 1.4+0.8 mV; follow-up 1.2+0.9 mV; p<0.01), with stability in the DDD group (3.8+2.1 vs 3.9+2.2 mV). Total percentages of AS loss were 23.2% (VDD) vs 2.3% (DDD); p<0.01) (Figure 1). In the Cox multivariate analysis the risk of late AS loss was higher in the VDD group (HR=7.6; 95% CI 2.86-20.3; p<0.001) together with the AS values at implant (HR=0.72; 95% CI 0.52-1.00; p=0.052). AS loss was corrected with reprogramming in 23 patients, reintervention was needed in 1 (2%) and VVI was abandoned in 27 (53%). The risk of AF occurrence was lower in the VDD group (HR=0.39 CI 95% 0.18-0.87; p=0.021) (Figure 2). Conclusions In the long term, AS is significantly reduced in VDD MPs, leading to its loss in a quarter of VDD patients. It is usually correctable with reprogramming, rarely requiring abandonment to VVI. AS at implantation is crucial as it is directed related to the AS during follow-up. DDD PMs were independently associated with a higher incidence of AF, with no differences in the remaining complications.TableFigure

D.2 Cost-effectiveness analysis of efgartigimod vs chronic IVIg for treatment of patients with generalized myasthenia gravis in Canada

Background: Efgartigimod is a human IgG1 antibody Fc fragment recently approved by Health Canada for patients with acetylcholine receptor antibody positive (AChR-Ab+) generalized myasthenia gravis (gMG). We assessed cost-effectiveness of efgartigimod vs chronic IVIg for adult patients with AChR-Ab+ gMG. Methods: A Markov model estimated costs (treatment and administration, disease monitoring, complications from chronic corticosteroid use, exacerbation and crisis management, adverse events, end-of-life care) and benefits (quality-adjusted life-years [QALYs]). The analysis was conducted from the Canadian healthcare system perspective. Health state transition probabilities were estimated using data from ADAPT, ADAPT+, and a network meta-analysis comparing efgartigimod with chronic IVIg. Utility values were obtained from MyRealWorld MG. Patients with MG-ADL ≥5 who did not die/discontinue were assumed to receive treatment every 4 weeks or every 3 weeks over the lifetime horizon. Results: Over the lifetime horizon, efgartigimod and chronic IVIg were predicted to have total discounted QALYs of 16.80 and 13.35, and total discounted costs of $1,913,294 and $2,170,315, respectively. Efgartigimod dominated chronic IVIg with incremental QALYs of 3.45 and cost savings of $257,020 over the lifetime horizon. Conclusions: Efgartigimod may provide greater benefit at lower costs than chronic IVIg for Canadian patients with AChR-Ab+ gMG, with substantial healthcare system savings over the lifetime horizon.

Evaluating a New Digital App-Based Program for Heart Health: Feasibility and Acceptability Pilot Study.

Cardiovascular disease (CVD) is the leading cause of death in the United States, affecting a significant proportion of adults. Digital health lifestyle change programs have emerged as a promising method of CVD prevention, offering benefits such as on-demand support, lower cost, and increased scalability. Prior research has shown the effectiveness of digital health interventions in reducing negative CVD outcomes. This pilot study focuses on the Lark Heart Health program, a fully digital artificial intelligence (AI)-powered smartphone app, providing synchronous CVD risk counseling, educational content, and personalized coaching. This pilot study evaluated the feasibility and acceptability of a fully digital AI-powered lifestyle change program called Lark Heart Health. Primary analyses assessed (1) participant satisfaction, (2) engagement with the program, and (3) the submission of health screeners. Secondary analyses were conducted to evaluate weight loss outcomes, given that a major focus of the Heart Health program is weight management. This study enrolled 509 participants in the 90-day real-world single-arm pilot study of the Heart Health app. Participants engaged with the app by participating in coaching conversations, logging meals, tracking weight, and completing educational lessons. The study outcomes included participant satisfaction, app engagement, the completion of screeners, and weight loss. On average, Heart Health study participants were aged 60.9 (SD 10.3; range 40-75) years, with average BMI indicating class I obesity. Of the 509 participants, 489 (96.1%) stayed enrolled until the end of the study (dropout rate: 3.9%). Study retention, based on providing a weight measurement during month 3, was 80% (407/509; 95% CI 76.2%-83.4%). Participant satisfaction scores indicated high satisfaction with the overall app experience, with an average score of ≥4 out of 5 for all satisfaction indicators. Participants also showed high engagement with the app, with 83.4% (408/489; 95% CI 80.1%-86.7%) of the sample engaging in ≥5 coaching conversations in month 3. The results indicated that participants were successfully able to submit health screeners within the app, with 90% (440/489; 95% CI 87%-92.5%) submitting all 3 screeners measured in the study. Finally, secondary analyses showed that participants lost weight during the program, with analyses showing an average weight nadir of 3.8% (SD 2.9%; 95% CI 3.5%-4.1%). The study results indicate that participants in this study were satisfied with their experience using the Heart Health app, highly engaged with the app features, and willing and able to complete health screening surveys in the app. These acceptability and feasibility results provide a key first step in the process of evidence generation for a new AI-powered digital program for heart health. Future work can expand these results to test outcomes with a commercial version of the Heart Health app in a diverse real-world sample.

Experimental and Numerical Investigation of Single-Phase Liquid Cooling for Heterogeneous Integration Multichip Module

Abstract The variety of new electronic packaging technologies has grown significantly over the last 20 years as a result of market demands for higher device performance at lower costs and in less space. Those demands have pushed for heterogeneous packaging, where computer chips with different stack heights are closely packed, creating nonuniform heat flux and temperature and additional challenges for thermal management. Without implementing an appropriate thermal management strategy for heterogeneous packages, large temperature gradients can be observed within the package, which would increase the thermal stresses on the chip and raise reliability issues. To mimic this real-life scenario of such packaging, an experimental setup was designed and built. The design of the new experimental setup consists of four identical 1.2 cm × 1.2 cm ceramic heaters, each of which is connected to a separate power supply and can reach a heat flux of 140 W/cm2. Accordingly, this mock package is capable of delivering different power levels to mimic different multicore microprocessor conditions. To give the heater the ability to move precisely in the x-, y-, and z-directions, each heater is mounted to an XYZ linear stage. Deionized water (DI) was used as the working fluid, and a pin-fin heat sink was used to run the initial steady-state tests on the experimental rig. The tests showed how different flow rates at a constant fluid temperature and input power affect the temperatures of the heaters and the thermohydraulic performance of the heat sink. In addition, a three-dimensional numerical model has been developed and validated with experimental data in terms of heat sink pressure drop and the temperatures of the heaters.

ОБОСНОВАНИЕ ПРИМЕНЕНИЯ ДИФФЕРЕНЦИРОВАННОГО СОЦИАЛЬНОГО ТАРИФА НА ЭЛЕКТРИЧЕСКУЮ ЭНЕРГИЮ ПРИ РЕАЛИЗАЦИИ ПРОЕКТА ЭЛЕКТРОСНАБЖЕНИЯ ОТ АВТОНОМНОЙ ГИБРИДНОЙ ЭНЕРГЕТИЧЕСКОЙ УСТАНОВКИ

The issue of uninterrupted power supply to remote settlements is relevant in many countries of the world, but especially in Russia. Modern autonomous hybrid power plants (AHPP), namely solar power plants (SPP), wind power plants (WPP) and other power plants using renewable energy sources (RES), combined with diesel electric power plants (DES), provide not only an increase in the amount of electricity generated, but, most importantly, they ensure uninterrupted power supply to consumers through a combination of renewable energy sources and covering the missing energy from diesel power plants. In the conditions of the northern areas of the Krasnoyarsk Region, this is especially important. ASPPs make it possible to reduce the cost of electrical energy by saving fuel consumption and budgetary subsidies for its supply to remote areas of the region. The purpose of the study was to substantiate the areas of application of autonomous hybrid power plants for the regions of the Far North with the possibility of establishing a differentiated social tariff for household consumers. To achieve the goal, load coverage graphs were constructed for Vanavara settlement; the parameters of the ASPP were studied for the conditions of Vanavara settlement; simulation of the operating modes of the ASPP was carried out; calculation of the main technical and economic indicators of the use of ASPP for power supply to Vanavara settlement was carried out; recommendations were given on rational areas of application of ASPPs with the possibility of applying special tariffs for the electricity they produce. The authors of the paper carried out a technical and economic assessment of ASUE in the Vanavara settlement with a capacity of 10 MW, including a solar power plant with a capacity of 2,5 MW. It was established that the cost of electrical energy in the first option when powered by diesel power plants is 36,75 rubles/kW.h. In the second option, the cost depends on the time of year and is 32,7 rubles/kW.h in winter, 11.6 in spring, 6.05 in summer, and 12,2 rubles/kW.h in autumn, which makes it possible to establish a differential social tariff for household consumers based on a lower cost in the summer in the amount of 7–9 rubles/kW.h.