Power Product Research Articles

Extending Non-Perturbative Simulation Techniques for Open-Quantum Systems to Excited-State Proton Transfer and Ultrafast Non-Adiabatic Dynamics.

Excited state proton transfer is an ubiquitous phenomenon in biology and chemistry, spanning from the ultrafast reactions of photobases and acids to light-driven, enzymatic catalysis and photosynthesis. However, the simulation of such dynamics involves multiple challenges, since high-dimensional, out-of-equilibrium vibronic states play a crucial role, while a fully quantum description of the proton's dissipative, real-space dynamics is also required. In this work, we extend the powerful matrix product state approach to open quantum systems (TEDOPA) to study these demanding dynamics, and also more general nonadiabatic processes that can appear in complex photochemistry subject to strong laser driving. As an illustration, we initially consider an open model of a four-level electronic system interacting with hundreds of intramolecular vibrations that drive ultrafast excited state proton transfer, as well as an explicit photonic environment that allows us to directly monitor the resulting dual fluorescence in this system. We then demonstrate how to include a continuous "reaction coordinate" of the proton transfer that allows numerically exact simulations that can be understood, visualized and interpreted in the familiar language of diabatic and adiabatic dynamics on potential surfaces, while also retaining an exact quantum treatment of dissipation and driving effects that could be used to study diverse problems in ultrafast photochemistry.

Remanufacturing Construction and Demolition Waste and Incineration Ashes into Eco-blocks: Quantitative Sustainability Assessment

This study performed a sustainability evaluation of a proposed business for remanufacturing concrete materials from construction and demolition waste (CDW) and ash from the combustion of municipal solid waste (MSW) to produce eco-blocks for construction applications. Six possible industrial remanufacturing alternatives are proposed based on commercially available industrial machinery and their economic sustainability was compared by a cost and profit feasibility study. Furthermore, the technical feasibility was evaluated by considering the maturity of the selected machinery based on the relationships among the cost–productivity, power–productivity, and number of workers–productivity pairs. The proposed remanufacturing business achieves a maximum profit of 17,643 USD/day with a minimum remanufacturing cost of 30.65 USD/t for the production of 529 t of eco-blocks in an 8-h factory shift. A quantitative environmental sustainability assessment was performed using the remanufacturing cost, profit, concrete savings, energy savings, CO2 emission savings, and eco-cost savings as criteria based on demographic statistics from the literature for current and predicted CDW and MSW generation. CDW and incineration ash are widely available, so the proposed process is viable worldwide. Based on the technical, economic, and environmental sustainability results, a final sustainability index of 0.874 was calculated, which exceeds literature thresholds for a sustainable business, indicating that the proposed eco-block remanufacturing process has the potential to generate substantial profits, while positively contributing to reducing waste and energy usage by recovering valuable resources and producing value-added products. The remanufactured eco-blocks are prepared in the same way as typical concrete blocks and can be used for all of the same residential, commercial, and industrial construction and landscaping applications. The remanufactured eco-blocks have several advantages over typical concrete blocks, including a much lower manufacturing cost (∼50% lower), significant environmental and resource savings by avoiding the use of new sand and gravel resources, and improved mechanical properties.

Exploring advanced antimicrobial effects of Pediococcus pentosaceus and Lactococcus lactis derived from Bufo gargarizans: In vitro analysis and in vivo evaluation in mice

With the context of increasing global concern about antibiotic resistance, the study presented the antibacterial properties of two novel edible bacterial strains, Pediococcus pentosaceus TE0302 and Lactococcus lactis TE0801, derived from the unique ecosystem of Bufo gargarizans. Significant antibacterial efficacy of these strains, with inhibitory zones of 14.77 mm and 15.26 mm, were confirmed through a multi-omics approach involving agar diffusion assays, mouse models, metabolomics, and genomics. These strains also mitigate pathogen-induced colitis and improve gut microbiota by increasing beneficial bacteria and reducing harmful ones. A crucial investigation is that the bacteria's substantial production of N-butyric acid is linked to antimicrobial effectiveness with a correlation coefficient ≥0.972. Genomic analysis shown that these strains feature diverse biosynthetic pathways similar to established antibiotics like Tetracycline and Vancomycin and contain genes for powerful bacteriocin production, especially Enterolysin_A. Pan-genome analysis indicated the unique gene counts of 124 and 179, greatly enhanced the genomic diversity compared to typical reference strains to emphasize the novelty. This study can facilitate a clear understanding of probiotics' genetic and biochemical properties. It highlighted the pivotal role in providing sustainable solutions to combat antibiotic resistance and improve gastrointestinal health, foreshadowing a new era of food science biotechnology.

Misconceptions and Errors Among Grade 12 Students When Learning Differentiation Rules: A Case Study

t is an established fact that some grade 12 students learning differentiation in calculus are found struggling with the rule of differentiation and these rules include power rule, quotient rule, chain rule and product rule. Because of these, some students came up with some misconceptions which eventually resulted to the students having multiple errors when learning rules of differentiation. The reason associated with these common errors are not far from their failure to model some prerequisite knowledge in the laws of logarithm into their learning of the laws of differentiation. And this has resulted to the poor performance of some students in mathematics (calculus) since calculus carries about 40% in the overall grade in mathematics as a subject at grade 12 level. On this note, this paper presents an analysis of students’ errors and misconceptions in learning differentiation rule. The study was conducted among grade 12 students preparing for NSC examination in a high school in Limpopo province in South Africa. And the data was initially collected using 35 test scripts of grade 12 on the topic of differentiation and differentiation rule. A qualitative approach was considered, and the data collected was analysed, focusing on product rules, quotient rules and chain rules and the errors committed. The result of the study indicated that some grade 12 students make some errors and misconceptions in differentiation rules. And these were because of poor conceptual understanding, poor mathematics language understanding, and some other error. It was confirmed that the results of this study highlight the common mistakes and errors students make when learning differentiation rules, and these errors are; conceptual, systemic, language, and generalization errors.

Analysis of Temperature effect on Power Productivity of Solar Panels in Residence Area

Analysis of Temperature effect on Power Productivity of Solar Panels in Residence Area

Protective effect of propolis in protecting against radiation-induced oxidative stress in the liver as a distant organ

Stresses caused by ionizing radiation can also damage tissues and organs through the circulatory system. In this study, we aimed to determine the radioprotective effect of propolis, a natural and powerful antioxidant product, against oxidative liver damage caused by cranial irradiation. Thirty-two male albino Sprague–Dawley rats, divided into four groups, were designed as sham group, irradiation (IR) group, propolis plus IR, control group of propolis. Biochemical parameters were measured in liver tissue of rats. While Total enzymatic superoxide scavenging activity (TSSA) and non-enzymatic superoxide scavenging activity (NSSA), glutathione peroxidase (GSH-Px) activities of all groups were statistically significantly higher than rats receiving only-irradiation, Glutathione-S-transferase (GST) activity in the IR group was significantly lower than in the sham control group and IR + propolis group. Superoxide dismutase (SOD) activity in the IR group was found to be significantly higher than both the sham control group and the propolis control group, but lower than the IR + propolis group. Malondialdehyde level and xanthine oxidase activity were higher in the IR group than in the other groups. Compared to the sham control group, in the group treated with propolis, a significant elevation in antioxidant parameters, specifically TSSA, NSSA, SOD, and GST activities, was noted, with corresponding increases of 32.3%, 23.2%, 47.6%, and 22.6%, respectively. Our findings show that propolis can be a radioprotective agent against ionized radiation damage by increasing antioxidant activity and reducing oxidant stress in liver tissue.

Circular economy: Extending end-of-life strategies

The transition from linear economy to circular economy (CE) has gained mainstream status in recent times, not only at product and process levels, but also at component level. In order to adopt the CE as common practice, there is a need to reimagine the product end-of-life (EoL) phase to include assessment of individual component health status. Implementation of EoL strategies on products designed based on wear and tear, robustness, and safety concerns is, however, complex. The purpose of this study is to explore the potential of designing for CE by applying a visual health-based analysis (VHA) at the component level at the EoL stage. The application of this diagnostic tool is exemplified in a case at a large Swedish outdoor power product manufacturer by analyzing components for reuse, remanufacture, refurbishment, recycling, and recovery strategies. The VHA results in the calculation of a CE potential at the component-product level based on individual component's cost, complexity, health, and diagnostic approach. This study presents a diagnostic tool for practitioners to understand circularity at the component-level in the effort to identify EoL strategies. Furthermore, in supporting the CE principle of maximizing resource recovery, the study potentially contributes to the EU's CE action plan and the UN-SDGs 8, 9, 12, and 13.

Enhanced formula-based method to estimate burnup, initial enrichment, and cooling time using limited gamma-ray source data of reference PWR spent nuclear fuel assemblies

This study proposes a framework to develop a model for estimating burnup (BU), initial enrichment (IE), and cooling time (CT) of spent nuclear fuel (SNF) overcoming the limitations of existing models in determining IE. Database (DB) of gamma-ray sources for PWR SNF was generated using ORIGAMI. Target gamma radionuclides were selected based on the ease and credibility of measurement. The concept of Product of Powers of Radioactivity (PPR) was suggested, and PPRs for modeling were selected through evaluation of all possible PPRs. Functions established for PPRs were applied to estimate BU, IE, and CT (BIC) of PWR SNF assemblies. Optimized PPR combinations for estimating BU, IE, and CT respectively, as well as three variables simultaneously with the highest accuracy, were suggested. The estimation model proposed in this study enhanced IE estimations, maintaining the reliability of BU and CT estimations. The above framework enables construction of intuitive BIC estimation models using only a small amount of data. This can help hasten the development of estimation models for SNF from various reactor types. Consequently, it is expected to contribute to the safety and safeguards of SNF management by improving the verification that SNF meets acceptance criteria and conforms to the declared information.

Automated Feedback on Student Attempts to Produce a Set of Dimensionless Power Products from a Set of Physical Quantities that Describe a Physical Problem

Formative feedback is important in learning. Automating the provision of specific, objective, constructive feedback to large cohorts requires complex algorithms that most teachers do not have time to develop, suggesting that a community effort is needed to create a library of specialised algorithms. We present an exemplar algorithm for a class of tasks in ‘dimensional analysis’ relating to the Buckingham Pi theorem. The challenge arises because there are infinitely many valid and invalid answers, but any valid answer is sufficient to complete a task. We present an algorithm that, given one valid reference answer, can evaluate any response to a task. The algorithm uses a vector-space formulation of the Pi theorem. Deployment across seven tasks for 380 students provided feedback 3,090 times, including stating why a response is invalid. The most common reason was that a student-proposed set was not dimensionless, but other educationally relevant reasons were also identified.

Experimental Comparison of Glazed and Unglazed Hybrid Solar Modules Considering Power Productivity and Cell Temperature

AbstractThis study presents the effect of cell temperature on the hybrid solar collectors PV/T for modules with and without using a front glass cover. A numerical model of thermal behaviour was carried out for glazed (PV/Tg ) and unglazed (PV/Tun) modules. As a result of this experimental investigation conducted for presented PV/T modules, a sufficient decrease in the cell temperature of PV/Tun compared to the PV/Tg, PV/Tun module exceeded the PV/Tg by 19%. Thus, the electrical productivity of the PV/Tun module was higher; it was 3.44% higher than the PV/Tg value. The outlet liquid temperature of the un-covered module was 6.34% higher than the outlet liquid temperature of the glass-covered module. Besides, the total efficiency of the PV/Tg was higher during the periods of study. In this sense, the glass-covered module is preferable for applications that deal with overall efficiency as a desirable factor. The un-covered module is much beneficial for applications that need high electrical productivity.

Comprehensive study and design optimization of a hybrid solar-biomass system for enhanced hydrogen production and carbon dioxide reduction

This study introduces an innovative multi-generation system powered by biomass, which aims to tackle the urgent problem of climate change by reducing CO2 emissions and increasing sustainability. The main problem being tackled is the ineffectiveness and environmental consequences of conventional biomass systems, which do not have methods for generating and injecting hydrogen. The proposed method combines solar panels with proton exchange membrane electrolyzers to generate green hydrogen, hence improving the quality of combustion byproducts. The methods utilized consist of integrating a supercritical carbon dioxide cycle with a thermoelectric generator to enhance the efficiency and cost-effectiveness of power generation. Additionally, flue gas condensation, a multi-effect desalination unit, and efficient waste heat recovery are employed to maximize the utilization of passive energy. The study concludes that under the optimal design, the proposed system outperforms the standard model that exclusively depends on biomass. The key results demonstrates that these characteristics are clearly demonstrated by its superior net power productivity of 3927 kW, exergy efficiency of 32.9 %, and drinkable water production rate of 9.4 kg/s. In addition, the suggested system has a lower levelized energy cost of 17.6 dollars per megawatt-hour and an emission index of 75.5 kg per MWh. However, upon comparing the rates at which exergy is being destroyed, it becomes evident that the majority of the components in the proposed model, such as photovoltaic panels and the electrolyzer unit, have a higher rate of exergy destruction. Ultimately, it can be noted that the fluctuations in combustion and turbine inlet temperature are crucial design parameters that substantially influence the power cycle and the system’s overall performance.

A hybrid shape functions based temporal finite element method to solve transient heat conduction problems

A novel temporal finite element method is presented to solve Fourier and non-Fourier heat conduction problems. Two kinds of temporal finite element models are developed using Gurtin variational principle and weighted residual technique, respectively. A kind of hybrid shape function with polynomial and trigonometric basis is stressed to give more flexible and appropriate description of temporal behavior of temperature. A recursive algorithm is developed by which the temperature solution at a specific time can be obtained only via a matrix power product with the initial condition, and a criterion of stability analysis is derived, which is can numerically be conducted when the constitution of shape function and time step size are prescribed. The proposed approach is available for Fourier and non-Fourier heat transfer problems, and can conveniently be combined with well-developed numerical algorithms for the boundary value problem, such as FE, SBFEM, etc. Various numerical examples, including those with the nonlinear thermal conductivity, radiative boundary condition, etc. are provided to illustrate the efficiency of proposed approaches, and impacts of the temporal FE model, constitution of shape functions, and step size, etc. are taken into account. Satisfactory results are achieved in comparison with the analytical and the ABAQUS based numerical solutions.

Creation of a roller bench for motorcycle and power product fatigue strength testing

Creation of a roller bench for motorcycle and power product fatigue strength testing

Analysis of the Oxidation Behavior and Formation of an Extremely Thin Oxide Layer with a Novel Hot-Stamped Steel

This study investigates enhancing the high-temperature oxidation resistance of hot-stamped steels by adding the Cr/Mn/Si elements to form an extremely thin oxide layer. Under low oxygen partial pressure conditions and high Cr content in the matrix, the oxide layer of a 38Cr3MnNbVMo hot-rolled plate containing the Mo element and high Si content was further thinned to 0.6 μm after cooling at 900 °C for 5 min. The structure of the ultra-thin oxide layer consists of Fe3O4, Mn oxides, FeCr2O4, Cr2O3, and Fe2SiO4 oxides. Compared to other antioxidant elements, under low oxygen partial pressure conditions, Si is more prone to oxidation, forming ultra-thin (22 nm) Fe2SiO4 oxides at the matrix interface. Combined with Cr2O3, FeCr2O4, and Mn oxides, it collectively inhibits the mutual diffusion of external O ions and matrix Fe ions. Furthermore, the addition of the Mo element improves the oxidation resistance. The synergistic effect of multiple powerful oxidation-resistant elements and oxide products effectively inhibits the growth of the iron oxide scale, enhancing the oxidation resistance of hot-rolled, hot-stamped steel.

Exergy-water nexus of a multi-energy complementary trigeneration system with different fuel mixture ratios

Complex coupling relationships of energy, exergy and water streams in multi-energy complementary systems due to different characteristics of energy flows are necessarily revealed to determine the intensities of downstream products. This paper proposes a multi-energy complementary trigeneration system driven by biomass, solar energy, and natural gas to generate cooling, heating, and power products. An exergy-water analysis approach, considering energy levels of streams, is adopted to determine the exergy and water footprint intensities per unit energy products. A life cycle assessment method is used to calculate the water footprint of biomass and natural gas as the primary energy sources. The relationship between the exergy and water footprint intensity of the system equipment and output products is presented and discussed with the mixture ratios of natural gas and biomass product gas. Furthermore, the cumulative exergy and water footprint intensity of products are analyzed under different system working conditions, such as mixture ratio of biomass and natural gas and the solar irradiance. When the same mixture volume gas fuels drive the trigeneration system, the overall exergy efficiency is 25.38 % while the efficiency including the upstream cumulative exergy destruction is only 21.93 %. The unit water footprint intensities of power and cooling products based on exergy measurement are 7.12 kg/kWh and 36.32 kg/kWh, respectively. The exergy-water footprint sensitivity of biomass and natural gas on system product intensities are implemented to consider the uncertain variables. When the mixture ratio increases from 0 to 1, the cumulative exergy destruction of system power is declined by 35.62 % under the uncertain ranges of ±50 %. Also, its water footprint is declined by 91.62 %. The proposed model provides an effective tool to reveal the exergy-water nexus and determine the intensities of multi-energy products.

Energy, exergy, thermoeconomic analysis of a novel multi-generation system based on geothermal, kalina, double effect absorption chiller, and LNG regasification

The current work proposes a novel CCHP system based on geothermal energy, which can generate hot water, chilled water, and power. Kalina is considered for power generation, double-effect absorption chiller cycle for cooling production, and LNG regasification cycle for thermal integration of absorption chiller and electric power generation. The hot water is generated using the heat recovery exchanger. Energy, exergy, economic, and environmental assessments are made on the proposed system to see how it can improve energy and exergy efficiency compared to the single state. Also, an environmental assessment is carried out to analyze the reduction of CO2 emission rate compared to other studies that used biomass and fossil energy sources. The findings were confirmed considering the outcomes of the previous works, and the proposed system showed remarkable performance in terms of exergy and energy efficiency, which were 85.22 % and 52.79 %, respectively. Also, the highest irreversibility exists in the LNG Regasification sector, with a ratio of 81 %. The economic estimation determined that the two parameters, total cost rate and cost per exergy, are 186.74 $/h and 8.3 $/GJ, respectively. Therefore, the innovation of the work lies in the heart of heating, cooling, and power products compared to the previous works.

Article Socio Economic Impacts of Insufficient Cow Milk Production in Mauritius

Aims: Due to the increase in purchasing power, milk and dairy products have increased steadily in recent years. However, milk production remains insufficient to satisfy the high local demand for milk and dairy products in Mauritius. Adding to the problem of the sector's extinction is the lack of information on the socio-economic impact of dairy production. This study aimed to assess the socio-economic impact of milk production on dairy cattle farms in Mauritius. Methodology: A survey was carried out among 11 respondents in Mauritius, using a validated two-part questionnaire to collect data from dairy farmers and processors. Results: The survey showed that the majority of dairy farmers were ethnic Hindus with secondary (77.8%) or university (22.2%) education. The breeds of cattle raised are generally Creole (56%) and Friesian (44%) with extensive livestock farming being practised. For the majority (77.8%) of respondents, family members are the primary source of labour. The main purpose of raising cattle is to produce milk (55.5%). The price of a litre of milk varies between dairy farmers, ranging from Rs 45 to Rs 70 per litre, with an average of Rs 58 per litre, and the revenue per cow per day averages Rs 1.036. About cheese production, the source of acquisition of cheese production technology is apprenticeship. From an economic point of view, with regard to yield, cost of production and profit margin for cheese production, we were faced with a total refusal of response from the producers. However, the quantity of milk used per day, the quantity of cheese obtained and the unit price per kg of cheese vary from one producer to another. Conclusion: This study has led to the realization that milk is the source of livelihood for the farmer and his family but also for other consumers. The income from the sale of milk contributes to the purchase of food for the farmer’s household and livestock supplements. However, the size of the herd and the low production of milk are an obstacle to the development of this sector.

Study on Preparation Technology of Novel Fluorosilicone Rubber Composite Insulator

Abstract Currently, commonly used external insulation materials for power products lack operational stability compared to high-temperature vulcanized silicone rubber. The excellent hydrophobicity of PTFE provides a direction for further enhancing high-temperature vulcanized silicone rubber. By utilizing fluorinated occupation directional design technology and improving the dispersion degree of the dispersed phase, we have successfully prepared high-temperature vulcanized fluorine silicone rubber. After testing its flammability and other aspects, the prepared material achieved HC1-level hydrophobicity, surpassing conventional silicone rubber insulators in terms of self-cleaning performance.

Investigation on critical erosion of gas production channel for sand carrying during injection and production process in gas storage

Gas wells on underground gas storage typically are operated in high-load mode, with a large working displacement injection and high-strength production. Erosion-corrosion caused by solid particles could cause serious damage to the gas well, leading to tubing column failure and security risks. The influence factors on the tubing column geometry, the fluid properties and particle properties were investigated by the indoor erosion experiments and numerical simulation respectively. Five different erosion models were applied to predict the erosion rate. The Generic model was selected to calculate the influencing value by a range of parameters after comparing the predicted results with the experimental data. The results indicated that the sand production rate, the gas production rate and the production pressure played a crucial role on the tubing column erosion. The error of Generic model is less than 20%. The product of the quadratic power of daily gas production, the negative quadratic power of production pressure and the first power of sand production rate was directly proportional to the erosion rate of tubing column. The sequence of the maximum erosion rate on different sites from high to low was obtained: No-Go Landing Nipple, Safety Valve, integral Y-type wellhead. The erosion effect on Y-type wellhead should be considered emphatically considering the long-term operation. The chart of Critical Erosion Coefficient (C value) was established according to the design criterion of API RP 14E, which is suitable for gas storage production channel. The reasonable C value should be set as 180.0 to ensure the gas storage to meet the service life. Meanwhile, the recommendatory C value range was set between 175.0 and 200.0 for considering the maximum productivity of gas storage. The research results provided a key guidance for judging the service safety of injection-production channel in gas storage.

Measuring heterogeneous preferences for the preservation of prime farmland with and without agrivoltaics

This study addresses a gap in cultural ecosystem service (CES) assessment of prime farmland located in peri-urban areas by presenting results from a choice experiment recently conducted in Utah’s Wasatch Front region. The choice experiment was designed to account for heterogeneous effects associated with a wide array of socio-demographic and attitudinal characteristics on household preferences for farmland preservation, including farmland used for the joint production of solar power and agricultural products. We apply a mixed-logit model to our data that controls for preference heterogeneity among Wasatch Front households along two dimensions – at the individual household level and according to different household types. We find that the typical household is willing to pay a non-trivial annual fee to preserve the region’s existing peri-urban farmland, and to a lesser extent is willing to pay for agrivoltaics on that land. We also find some evidence of preference heterogeneity among different types of households for farmland preservation and agrivoltaics; heterogeneity based upon traditional socio-demographic characteristics such as household income and location, as well as unique attitudinal differences related to how households view themselves in relation to agriculture, farmland preservation, and the extent to which taxation is an appropriate mechanism to fund local public goods. These findings can serve as crucial components of broader land-use studies designed to account for the full range of agri-environmental ecosystem services.