Generation Cycle Research Articles

Study on effect of gas-liquid two phase physical feature on slug flow in microchannels

At present, there are relatively few studies on the slug flow generation mode obtained by exchanging gas-liquid two-phase inlets. In this study, an experimental system combining microfluidic devices and high-speed cameras was used to study the effects of gas-liquid two-phase flow rate, liquid physical parameters, etc., On the characteristic length, generation period and other generation characteristics of slug flow, and dimensionless analysis was conducted to investigate the main factors affecting the characteristic length of gas slug. Results show that 1) when the gas flow rate affects the aeroelastic generation characteristics, the aeroelastic characteristic length increases from 443 μm when the gas flow rate increases changes to 657 μm. The generation period decreases rapidly at first and then the change amplitude slows down. The maximum value of aeroelastic generation frequency is 217 s-1; 2) when studying the effect of different liquid flow rates, increasing the liquid flow rate, the characteristic length of the gas bomb gradually decreases, and the generation period of the gas bomb gradually increases. Aeroelastic characteristic length from 770 μm changes to 378 μm. The range of aeroelastic generation cycle is 4–13.4 ms, and the maximum value of aeroelastic generation frequency is 250 s-1; 3) there is a functional relationship between the ratio of aeroelastic characteristic length to channel size L/d and dimensionless gas-liquid flow ratio Q*, Reynolds number Re, Weber number We: L/d=3.677Q*0.58/Re0.11.

A computationally efficient heuristic approach for solving a new sophisticated arrangement of cogeneration combined heat and power cycle

Cogeneration combined heat and power cycle components are continually optimized using new methods and solutions. Due to the interconnection of two different power generation cycles, the design of the cogeneration cycle is extremely complex and any changes in the structure directly affect the power, efficiency, costs, and other variables. To address this issue, a new arrangement of the cogeneration combined heat and power cycle is presented in this study, as well as a suitable fit function for exergy analysis and evolutionary algorithms used for model optimization. Several objectives are considered when optimizing, such as reducing costs, increasing profitability, etc. Optimization algorithms increased energy efficiency by 2.7% and exergy efficiency by 8.6%, indicating substantial long-term energy savings. A significant improvement was made in all desired parameters as well. Therefore, we can conclude that the upgraded algorithm considered in this study is effective in designing power generation cycles due to the particular importance of optimal design in power generation cycles.

Using mathematical modeling, identify the repetition and progression of the human eye's colour pattern

The formation of human eyes is basically a result of genetic mutation process. The colour of eyes is determined by variation of genes which are associated with eye colour to produce transport or storage of a pigment is called melanin. In this research this aspect is confirm with the theory of Jordan algebra which has invented from an associative algebra which is relative to the arrangement, this scheme is called special Jordan algebras. To verifying the eyes colour mutation an appropriate number of datasets are collected from survey and observation, similar result found from the collected datasets which show that, the human eyes colour which is an outcome of genetic mutation of eye genes which appeared in first generation is mostly skip in second generation cycle and same process is repeat in generation to generations. The climate of Pakistan is usually varying in region to region because of temperature its dry and warm near the coastline and low-lying region and gradually cooler in the northern highland’s areas. Mostly in coldest area of Pakistan the colour of eyes are lighter but in some warm areas the lighter eyes colour in eyes colour in eyes causes different types of eyes disease. Lighter eye colour is more sensitive to light because of less amount of melanin. Melanin protects eyes from sun light due to lesser amount of melanin there is chances of macular degeneration (an eye disease that can blur your central vision). The darker coloured eyes practice less visual discomfort in sun light, mean it help in protection from ultraviolet (UV) rays. Lighter coloured of eyes increased the risk of cancer because of less amount of melanin which cannot/less protect eyes from sun light which is very harmful and increase the chance of cancer. Colour vision deficiency, sometime called colour blindness is usually a genetic (hereditary) condition transfer into next generation. Colour blindness is a cause of less melanin ration, the prediction of repetition of eye colour of next generation can be helpful to stop the problem of colour blindness.

Characteristics of the Menstrual Cycle According to the Sports Groups of the New Generation of Female Athletes

PURPOSE To examine the characteristics of menstrual cycles in female athletes in different sports, comparison of possible deviations and changes associated with new generations of female athletes in training processes.
 METHODS The research included a total of 143 respondents (average age 17.46 ± 2.61; average training experience 8.67 ± 3.85) who were divided into three groups: sports games (n=59), martial arts (n= 16) and aesthetic sports (n= 68). An anonymous survey specially prepared for the needs of this research was conducted among the respondents. The results were processed in the IBM SPSS program, v.26. Comparisons by sports categories were made using the Chi-square test for categorical variables and Kruskal-Walis analysis of variance for ordinal variables. In the case of significant differences obtained by Kruskal - Wallis analysis, the Dunn-Bonferroni post hoc test was performed to determine between which groups there is a difference. A logistic regression analysis was performed to predict the regularity of the menstrual cycle using age, length and duration of training and sport category.
 RESULTS The groups of sports do not differ from each other with regard to cycle regularity (p=0.088). There are no differences between sports groups (p=0.935) in cycle changes. There is also no difference in duration (p=0.883) and abundance of bleeding (p=0.700). A slightly higher irregularity of menstrual cycles was observed in the martial sports group.
 CONCLUSION The examined characteristics of the menstrual cycle of the new generation of female athletes according to the sports groups in this research did not show significant changes, but they were noticeable in the martial sports group. Although there is a common difference in the training duration of individual sports groups, future research and monitoring of the menstrual cycle in female athletes should be further reduced according to the possible effects on the reproductive and general health of female athletes.

Annual variations of abundance, egg production rate, and community structure of Oithona similis in Jiaozhou Bay, the Yellow Sea

In marine ecosystems, copepods (<2 mm) play an important role in the transfer of carbon and energy to higher tropic levels. Investigations in Jiaozhou Bay were carried out throughout 2017–2018, combined with laboratory experiments. The annual abundance, egg production, female prosome length, female carbon mass, clutch size, population composition, and development time of Oithona similis at different temperatures were analyzed to assess the life strategies and estimate generation cycles of O.similis in typical temperate regions at mid-latitude, represented by Jiaozhou Bay. The results include: 1) O.similis abundance was characterized by bimodal cycles, with the major peak in winter (1471 ± 206 ind/m³) and the minor peak in spring (740 ± 320 ind/m³). O. similis abundance was not subject to food limitations except in January. The lower abundance was mainly affected by temperature (>20°C) and low salinity in August. Predation from large size zooplankton was one of the factors in regulating O. similis abuncance in Jiaozhou Bay. 2) Over the year, the egg production rate, female prosome length, and female carbon mass of O.similis ranged from 0.03 ± 0.02 to 1.21 ± 0.25 eggs female-1d-1, 410 ± 6 to 472 ± 4 μm, and 0.35 ± 0.05 to 0.43 ± 0.03 μg c female-1 respectively. Female prosome length, and female carbon were both significantly negative correlated with temperature(P<0.01). The clutch size of O.similis varied between 4 and 21 and we did’t find it was related with other factors. 3) O. similis appeared at almost all stages, and reproduced continuously throughout the year. According to the sex ratio of O.similis and other factors, we inferred that O. similis produced four generations per year in Jiaozhou Bay.

Design strategy of food residues biorefineries based on multifeedstocks analysis for increasing sustainability of value chains

Food residues (FR) have caused economic, environmental, and social issues. Few studies have integrated the biorefinery and value chain concepts for increasing FR valorization opportunities in a real context. This paper proposes a FR biorefineries design strategy involving limiting factors of the Food Value Chain (FVC). The strategy integrates key points such as links and actors, generation cycles, FR composition, and residues integration. Two case studies were analyzed by applying the proposed design strategy. The first case study valorizes rejected avocado and plantain generated in the producers link. The second case valorizes organic kitchen food waste (OKFW) into added-value products. The proposed design strategy introduces value chain analysis as a tool for designing feasible and reliable biorefineries. A possible integration mass ratio of 22:13:65 was identified considering rejected avocado, rejected plantain, and plantain pseudostem, respectively. The most promising alternative to upgrading the FR generated in the producers link is related to avocado oil and biogas production. The best results obtained for upgrading OKFW is to produce levulinic acid since low capital and operational expenditures are required compared with other bulk products. When involving context variables and a complete value chain analysis the opportunities to enhance sustainability and close open loops are increased.

Development, exergoeconomic assessment and optimization of a novel municipal solid waste-incineration and solar thermal energy based integrated power plant: An effort to improve the performance of the power plant

Due to the growing population rate and increasing social activities, the content of municipal solid waste (MSW) production is increasing. Energy production from MSW is one of the promising ways to dispose of waste and reduce the limitations of fossil energies. However, this technology has a relatively low efficiency due to the high volume of moisture and inert materials in MSW and the lower heating value of waste. The integration of solar thermal collectors is one of the suggested solutions to increase the temperature of inlet steam to the power generation cycle in order to improve the power plant performance. In this regards, the present study develops a comprehensive thermodynamic-conceptual and exergoeconomic investigation of the performance of a MSW-incineration (MSWI) plant integrated with a parabolic trough collector (PTC)-based solar field. Accordingly, the temperature of the steam elevates by the solar field before entering the electric power generation cycle. Additionally, the solar unit is integrated with a phase change material (PCM)-based storage system. The use of storage tank at the delivery line of PTC can improve the power plant’s reliability. A comprehensive comparison of the developed power plant with the conventional MSWI power plant is presented. In addition, the technical and economic behaviors of the considered power plant have been optimized under two different single and multi-objective optimization scenarios. The outcomes indicated that the developed power plant can provide 15.75% and 15.68% higher energetic and exergetic efficiencies compared to MSWI power plant. In addition, the rate of electric power obtained from S-MSWI power plant is almost 16.1% more compared to MSWI power plant. However, the total cost rate of MSWI plant is almost 24.13% lower compared to the developed power plant. But, the value of LCOE in the developed power plant is approximately 8.93% lower than MSWI power plant. It was also found that, the multi-objective optimization can provide better and optimal results to energy engineers and decision makers compared the single-optimization. The conceptual design of the implementation of the solar field is also developed in a specific geographical condition. Additionally, this research comes from the key technology of the National Key Laboratory of Environmental Protection.

Exergetic evaluation of the effect of nanofluid utilization for performance enhancement of a solar driven hydrogen production plant

Recently, research and development on progressive and efficient hydrogen production methods has been paid lots of attention due to carbon-free feature of hydrogen. Application of nanoparticles to enhance an integrated solar-based hydrogen production unit is suggested and investigated in this work. The integrated plant consists of parabolic trough collectors coupled with a Kalina cycle for electricity generation to be consumed in a polymer electrolyte membrane electrolyzer for hydrogen production. The system performance is apprised for nanofluid as the heat transfer media for solar collectors and is compared with the pure basefluid case. Thermal model for parabolic trough collectors as well as thermodynamic models for Kalina cycle and electrolyzer are developed and validated. Also, thermo physical properties of nanofluid is assessed based on volume fraction of the nanoparticles. Parametric analyses are implemented for system performance assessment in which influence of design variables related to solar collectors, nanoparticels as well as the Kalina cycle are appraised. The effect on the hydrogen rate and solar-to-hydrogen exergy efficiency of design variables are comprehensively examined and discussed. According to the obtained results, the ηex,STH is found to be 9.19% for the case with basefluid (without nanoparticles), whereas it can be improved to 9.63% with employment of 5% volume fraction of CuO nanoparticles. Such an efficiency improvement is due to the increment of hydrogen production from 0.669 kg/h to 0.702 kg/h using CuO-based nanofluid.

Exergy analyses and optimization of a single flash geothermal power plant combined with a trans-critical CO2 cycle using genetic algorithm and Nelder–Mead simplex method

Compared with conventional fossil fuel sources, geothermal energy has several advantages. The produced geothermal energy is safe for the environment and suitable for meeting heating power needs. Because the hot water used in the geothermal process can be recycled and used to generate more steam, this energy is sustainable. Furthermore, the climate change does not affect geothermal power installations. This study suggests a combined power generation cycle replicating using the EES software that combines a single flash cycle with a trans-critical carbon dioxide cycle. The findings demonstrate that, in comparison to the BASIC single flash cycle, the design characteristics of the proposed system are greatly improved. The proposed strategy is then improved using the Nelder–Mead simplex method and Genetic Algorithm. The target parameter is exergy efficiency, and the three assumed variable parameters are separator pressure, steam turbine outlet pressure, and carbon dioxide turbine inlet pressure. The system’s exergy efficiency was 32.46% in the default operating mode, rising to 39.21% with the Genetic Algorithm and 36.16% with the Nelder–Mead simplex method. In the final step, the exergy destruction of different system components is calculated and analyzed.Graphical

Economic Feasibility of Thermal Energy Storage-Integrated Concentrating Solar Power Plants

Concentrating solar power (CSP) is a high-potential renewable energy source that can leverage various thermal applications. CSP plant development has therefore become a global trend. However, the designing of a CSP plant for a given solar resource condition and financial situation is still a work in progress. This study aims to develop a mathematical model to analyze the levelized cost of electricity (LCOE) of Thermal Energy Storage (TES)-integrated CSP plants in such circumstances. The developed model presents an LCOE variation for 18 different CSP configurations with TES incorporated for Rankine, Brayton, and combined power generation cycles, under regular TES materials and nano-enhanced TES materials. The model then recommends the most economical CSP plant arrangement. Within the scope of this study, it was found that the best configuration for electricity generation is a solar power tower with nano-enhanced phase change materials as the latent heat thermal energy storage medium that runs on the combined cycle. This returns an LCOE of 7.63 ct/kWh with a 22.70% CSP plant efficiency. The most favorable option in 50 MW plants is the combined cycle with a regular TES medium, which has an LCOE of 7.72 ct/kWh with a 22.14% CSP plant efficiency.

Need for speed: a breakthrough speed breeding protocol for hemp

Need for speed: a breakthrough speed breeding protocol for hemp

A solar energy driven thermochemical cycle based integrated system for hydrogen production

In this study, an assessment of a newly developed solar energy-driven thermochemical cycle for hydrogen generation and potentially injection into the natural gas pipeline is performed. The hydrogen, produced by the heavy element halide cycle, is blended with natural gas at particular ratios. A blend of 80% natural gas and 20% hydrogen by volume is supplied to the community for the gas turbine system, gas cooker, and combi boiler. The desalination units are integrated to produce freshwater for a community, which potentially consists of 10,000 houses. The present integrated system is then analyzed through the energy and exergy approaches. The parametric studies are further performed for different volumetric hydrogen ratios, ambient temperature, and the number of houses. Here, 0.005 kg/s of hydrogen and 0.19 kg/s of natural gas are provided to the gas turbine system to generate electricity and heat. A heat recovery steam generator is utilized both for organic Rankine cycle and multi-effect distillation unit. A total of 4.5 MW electricity is generated by the gas turbine and the organic Rankine cycles. Moreover, a total of 34.62 kg/s of freshwater is provided by two specific reverse osmosis and multi-effect distillation units. The overall exergetic and energetic efficiencies of the present integrated system are obtained as 21.3% and 26.1% for the selected operating conditions.

4E analyses of a novel multi-generation system based on methanol-steam reforming integrated with scramjet multi cooling cycle and ammonia synthesis

A state-of-art multi-generation plant integrated with a scramjet multi-cooling cycle for power, hydrogen, ammonia, and freshwater generation was analyzed from an energy, exergy, exergoeconomic as well as environmental (4E) standpoint. The coolant of the cooling cycle was the fuel of the scramjet cycle and in terms of optimizing consumed power, this cycle is benefiting from four-stage compressors. To improve the rate of hydrogen production, a methanol steam reforming procedure was employed. To provide fresh water, a reverse osmosis membrane was employed and integrated into the plant. To consider the powers of input design variables on the implementation criteria of the plant and reduce CO and CO2 emission, an exhaustive parametric investigation was performed. The thermodynamic efficiencies, the sum unit cost of the products, the system emission rate, and the environment penalty cost rate as well as values of the products as the multi-generation plant's performance criteria were computed. Raising the hydrogen mole fraction caused an increase in the emission rate.

Development and performance assessment of a calcium-iron bromide cycle-based hydrogen production integrated system

In this study, a novel renewable energy-based trigeneration system integrated with a thermochemical cycle is newly developed, analyzed, and evaluated to determine its performance for residential applications. Both solar radiation and wind kinetic energy are harnessed for electricity production. A newly developed biomass-driven thermochemical cycle for hydrogen generation and potential blending with natural gas is analyzed and evaluated accordingly. The blend is then potentially supplied to the gas engine and some residential appliances, such as combi boilers and gas stoves to provide necessary electricity and heat. The heat obtained from the subsystems is employed for residential heating and cooking, as well as for a distillation unit. The reverse osmosis and multi-effect distillation units are both considered in an integrated fashion to produce fresh water for a community considered which consists of 10,000 houses. A total amount of 14.2 million m3 of the blend (with a ratio of 20% of hydrogen and 80% of natural gas) is annually available to potentially utilize for household appliances and gas engines. Furthermore, the present integrated system is analyzed through both energy and exergy approaches. Some parametric studies are then performed for different hydrogen fractions, hydrogen production rates, solar PV areas, wind turbine swept areas, and the number of houses. Moreover, the overall exergetic and energetic efficiencies are determined as 21.02% and 62.61% for the presently developed system.

Hard ferromagnets as a new perspective on materials for thermomagnetic power generation cycles

We consider the ways in which magnetically hard materials can be used as the working materials in thermomagnetic power generation (TMG) cycles in order to expand the area in the magnetisation vs. applied field (M−H) plane available for energy conversion. There are 3 parts to this Perspective. First, experiments on commercially available hard ferrites reveal that, while these materials are not yet good TMG candidates, hard ferromagnets with higher thermal conductivity and a greater change of magnetization with temperature could outperform existing TMG materials. Second, computational results indicate that biasing a soft magnet with a hard ferromagnet is essentially equivalent to shifting the M−H loop by an amount proportional to the field of the biasing magnet. Work outputs under biased conditions show a substantial improvement over unbiased cycles, but experimental verification is needed. Third, we discuss the rationale for exploring artificial spin reorientation materials as novel TMG working materials.

Shortening generation times for winter cereals by vernalizing seedlings from young embryos at 10 degree Celsius

AbstractMethods allowing quick generation cycles are available for various crop species but are limited to spring genotypes. However, winter types predominate in many crops including wheat and barley. Different from spring ones, winter genotypes need to be treated in low temperature for extended periods to accelerate flowering. Combined with known factors that reduce generation cycles for spring wheat and barley, the generation cycle effects of vernalizing seedlings from young embryos of winter types at 10°C of several crop species were studied. Here, we described how to obtain up to seven generations of winter barley, six generations for winter wheat or five generations for both winter oat and triticale genotypes per annum. This procedure should find wide applications in breeding and other biological studies.

DESIGN AND MODELING OF AN 80 BAR OXY-COMBUSTOR FOR DIRECT FIRED SUPERCRITICAL CO2 APPLICATIONS

As supercritical CO<sub>2</sub> power cycles for fossil energy power generation continue to generate interest, there are significant issues and unanswered questions regarding injector design, flame stabilization, wall heat transfer, CO emissions, combustion dynamics, and other combustion phenomenon. For natural gas, direct-fired cycles with carbon capture it is believed that computational fluid dynamics (CFD) modeling will play an essential role in the combustor design process. To accurately model turbulent reacting flows at these unique conditions, experimental data are needed to validate CFD codes and sub-models and are currently lacking at conditions relevant for these cycles. This paper presents the conceptual design and CFD simulations of an experimental 80 bar oxy-combustion facility and test article currently under construction at National Energy Technology Laboratory (NETL). The facility is targeted towards the testing of a single-injector, direct-fired sCO<sub>2</sub> combustor at the 100 kW thermal output level. While these conditions do not reflect the actual Allam cycle operating conditions (300 bar) they are viewed as a stepping stone in the model validation process at supercritical conditions. Reynolds Averaged Navier-Stokes as well as Large-Eddy Simulation are used to model the turbulent combustion process and aid in the design of the combustor and injector. Process parameters including oxidizer preheat temperature and combustor flowrate are investigated.

Distinguishing high-harmonic generation from surface and bulk states in topological insulator Bi2Se3

We demonstrated a scheme to differentiate the high-harmonic generation (HHG) originating from the surface states and bulk states of the topological insulator Bi2Se3. By adopting two-color mid-infrared laser fields on Bi2Se3, we found that the nonlinear response sensitively depends on the relative phase of the driving fields. The even harmonics arise from the surface states with a clear signature, whose modulation period equals the cycle of the second-harmonic generation (SHG) field. We reveal that the weak SHG perturbs the nontrivial dipole phase of the electron-hole pair in surface states, and thus leads to the modulation of HHG. It provides a means to manipulate the ultrafast dynamics in surface states through adopting a weak perturbing laser field.

Development of a video-based evidence synthesis knowledge translation resource: Drawing on a user-centred design approach.

We aimed to develop a video animation knowledge translation (KT) resource to explain the purpose, use and importance of evidence synthesis to the public regarding healthcare decision-making. We drew on a user-centred design approach to develop a spoken animated video (SAV) by conducting two cycles of idea generation, prototyping, user testing, analysis, and refinement. Six researchers identified the initial key messages of the SAV and informed the first draft of the storyboard and script. Seven members of the public provided input on this draft and the key messages through think-aloud interviews, which we used to develop an SAV prototype. Seven additional members of the public participated in think-aloud interviews while watching the video prototype. All members of the public also completed a questionnaire on perceived usefulness, desirability, clarity and credibility. We subsequently synthesised all data to develop the final SAV. Researchers identified the initial key messages as 1) the importance of evidence synthesis, 2) what an evidence synthesis is and 3) how evidence synthesis can impact healthcare decision-making. Members of the public rated the initial video prototype as 9/10 for usefulness, 8/10 for desirability, 8/10 for clarity and 9/10 for credibility. Using their guidance and feedback, we produced a three-and-a-half-minute video animation. The video was uploaded on YouTube, has since been translated into two languages, and viewed over 12,000 times to date. Drawing on user-centred design methods provided a structured and transparent approach to the development of our SAV. Involving members of the public enhanced the credibility and usefulness of the resource. Future work could explore involving the public from the outset to identify key messages in developing KT resources explaining methodological topics. This study describes the systematic development of a KT resource with limited resources and provides transferrable learnings for others wishing to do similar.

Immunogenic radiation therapy for enhanced anti-tumor immunity via core-shell nanocomposite-mediated multiple strategies.

Background: Due to the immunosuppressive tumor microenvironment (TME), radiation therapy (RT)-mediated immune response is far from satisfactory. How to improve the efficacy of immunogenic RT by priming strong immunogenic cell death (ICD) is an interesting and urgent challenge. Methods: A polyacrylic acid-coated core-shell UiO@Mn3O4 (denoted as UMP) nanocomposite is constructed for immunogenic RT via multiple strategies. Results: Reshaping the TME via Mn3O4-mediated integration of O2 production, GSH depletion, ROS generation and cell cycle arrest, accompanied by Hf-based UiO-mediated radiation absorption, eventually amplifies UMP-mediated RT to induce intense ICD. With the potent ICD induction and reprogrammed tumor-associated macrophages, this synergetic strategy can promote dendritic cells maturation and CD8+ T cells infiltration, and potentiate anti-tumor immunity against primary, distant, and metastatic tumors. Conclusion: This work is expected to shed light on the immunosuppressive TME-reshaping via multiple strategies to reinforce the immunogenic RT outcome and facilitate the development of effective cancer nanomedicine.