Gaseous-liquid fuel combinations of biogas as primary fuel and diesel as pilot fuel were employed to power a compression ignition (CI) engine in this study. The effects of variable input factors such ...as engine load, compression ratio, and pilot fuel injection advance on the dual-fuel engine's combustion, thermal, and emission performance were investigated. The data acquired during this lab-based testing was used to develop a prognostic model using a Bayesian optimization strategy for hyperparameter optimization and a contemporary ensemble Gaussian process regression (GPR) technique. During model testing, the error analysis revealed that the developed model could predict the experimental data rather correctly, with R2 values ranging from 0.9995 to 0.9999 and MSE values ranging from 0.00018 to 0.1334. The mean absolute error was discovered to be between 0.0091 and 0.3065. Consequently, the developed GPR model can effectively simulate the on-board performance, emission, and combustion characteristics of a diesel-biogas dual-fuel setting. As a consequence, the current work established the GPR model in the existing CI engine meta-modeling framework as a consistent, trustworthy, and robust system analytical approach for diesel-biogas dual fuel mode of operation.
•Waste-derived biogas was used to power the diesel engine in dual-fuel mode.•Gaussian process regression was employed to develop a prognostic model.•Bayesian approach was used for hyper parameter optimization for best results.•Used model could predict emission and performance of the engine with 99.9% accuracy.•A precise metamodel framework to simulate the input–output paradigm was developed.
•Diesel engine was powered with ternary blends of biodiesel-diesel-oxyhydrogen.•Third-generation biodiesel was synthesized from biomass of Azolla Pinnata.•A low-cost device-31 plates generator ...generated oxyhydrogen gas.•Oxyhydrogen addition improved engine performance and lowered emissions.•Box-Behnken design coupled with desirability approach used for optimization.
The current study explores and improves the effects of engine load, injection time, and oxyhydrogen fuel flow rate on the combustion and emissions characteristics of a diesel engine. Experiment with the combustion and exhaust characteristics of a medium-sized diesel engine working in tri-fuel mode using microalgae oil methyl ester-diesel blends as injected fuel and an oxyhydrogen gas combination as inducted fuel. The Box-Behnken design (BBD) was used to reduce the number of testing. The parameters and proposed attributes were calculated utilizing response surface techniques and BBD-generated quadratic models. The response surface analysis displayed the patterns of input interactions on the output using surface diagrams. The desirability-based optimization revealed the optimal engine operating parameters as 22.92° crank angles advance, 76% engine load, and 0.92 L per minute oxyhydrogen flow rate. At these optimized operating ranges, the performance and combustion output of the study was 30.8 % brake thermal efficiency (BTE), 0.3 kg/kWh brake specific fuel consumption (BSFC), and 65.6 bar peak cylinder pressure (PCP). On the emission front, the CO emission was 0.0107%, UHC was 26 ppm, and NOx was 853 ppm. The optimized values were validated through experimental testing, and all the results were within 7% of the model-predicted output. The addition of oxyhydrogen significantly improved the combustion of an algal biodiesel-diesel-oxyhydrogen-powered diesel engine in terms of fuel efficiency and fuel consumption and lower carbon-based emission levels except for nitrogen oxide emissions.
Objective: The objective of this study is to investigate the importance and diversity of living values and living value education for preschool children are receiving research attention from many ...scientists around the world. Method: This study uses the quantitative bibliometric method with a Scopus database data source to find the characteristics of published data related to living values and living value education for kindergarten students. Results and Discussion: The findings indicate an increasing number of publications; developed countries dominate the number of publications; and higher education institutions are interested in living values and living value education for kindergarten students. Research Implications: There is a need for research in different directions, both on a large scale at the international level and in depth, on each issue of living values and living value education for today's kindergarten students. Originality/Value: This study contributes to the literature by providing an overview of living values and living value education for preschool children have been researched by researchers all over the world.
Language is a very socially important and basic structure of thought. It allows the child to integrate into society and dealing with abstract concepts. The principle of language education is that ...Montessori language is attached to human life; language is a form of sound or image that represents human perception of objective or subjective life. Thus, Maria's principle of language development is attached to things, from abstract objects to linguistic sounds, and from linguistic sounds to symbolic characters. This article systematizes Maria Montessori's core views on children’s language acquisition as well as the principles affecting this process. Subsequently, it analyzes the development principles of the Montessori method as a basis for lesson and teaching tools development for Vietnamese language education.
This study aims to explore the effects of intimate partner violence during pregnancy (p-IPV) on postpartum depression among women in central Vietnam. p-IPV was defined among 150 women aged 18 years ...and older in the third trimester of their pregnancy. Baseline data was collected between February and May 2019, and then those women were followed up to 3-5 months after childbirth to assess depression using the Patient Health Questionnaire-9 (PHQ-9). Data collection was completed in September 2019. Relative risk was estimated to identify the effect of p-IPV on maternal postpartum depression. Twenty-one women reported IPV during pregnancy. In the follow-up assessment, 8 of 21 mothers exposed to p-IPV and 23 of 127 mothers not exposed to p-IPV developed postpartum depression. p-IPV including emotional and physical violence were increased the risk of postpartum depression. The findings support evidence that p-IPV increases the risk of postpartum depression among women in central Vietnam.
We sought to evaluate the adherence of Vietnamese adults to Coronavirus Disease 2019 (COVID-19) preventive measures, and gain insight into the effects of the epidemic on the daily lives of Vietnamese ...people. An online questionnaire was administered from March 31 to April 6, 2020. The questionnaire assessed personal preventive behavior (such as physical distancing, wearing a face mask, cough etiquette, regular handwashing and using an alcohol hand sanitizer, body temperature check, and disinfecting mobile phones) and community preventive behavior (such as avoiding meetings, large gatherings, going to the market, avoiding travel in a vehicle/bus with more than 10 persons, and not traveling outside of the local area during the lockdown). A total adherence score was calculated by summing the scores of the 9 personal and the 11 community prevention questions. In total, 2175 respondents completed the questionnaire; mean age: 31.4 ± 10.7; (range: 18–69); 66.9% were women; 54.2% were health professionals and 22.8% were medical students. The mean adherence scores for personal and community preventive measures were 7.23 ± 1.63 (range 1–9) and 9.57 ± 1.12 (range 1–11), respectively. Perceived adaptation of the community to lockdown (Beta (β) = 2.64, 95% Confidence Interval (CI) 1.25–4.03), fears/worries concerning one’s health (β = 2.87, 95% CI 0.04–5.70), residing in large cities (β = 19.40, 95% CI 13.78–25.03), access to official COVID-19 information sources (β = 16.45, 95% CI 6.82–26.08), and working in healthcare/medical students (β = 22.53, 95% CI 16.00–29.07) were associated with a higher adherence score to anti-COVID instructions. In conclusion, this study confirmed a high degree of adherence to personal and community preventive behavior among Vietnamese people. Our findings are consistent with the epidemiology of COVID-19 in Vietnam, where there have been few infections and no recorded deaths up to the first week of July 2020.
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