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This study examined a room with a surface of 1.8 × 1.8 × 2.85 (m) and a well-insulated floor (adiabatic condition) and examined the heat exchange from the side surfaces and ceiling. In this closed room, the heat transfer effects with radiation were investigated while bringing them to comfort conditions ranging from 30 (°C) air temperature to 20–24 (°C). A computer with a power of 25 (W) as a source of heat, a person with an average metabolic activity of 50–70 (W) and a table were found in this closed room. In this study, the cooling of the room from the floor, ceiling and air conditioner was inquired while the computer was running, in a closed area under the specified heat transfer conditions. As a scenario, the air exchange coefficient was modeled via Ansys Fluent, fed with air of 15 (°C) with 1, 3, 5, 10, 15 air. In addition, the comfort values of the human wrist (the distance of 0.1 m) and the shoulder (the distance of 1.1 m) were researched according to ASHRAE-55. The obtained results were analyzed as a comparison of ACH results, and the comfort parameter values were analyzed by reading the sections taken from the ankle shoulder level and velocity, temperature, values according to ANSI/ASHRAE-55. The relative humidity was 50% in the room, while the metabolic activity is 1.2 (met). These parameters corresponded to the sitting position; the clothing effect was found to be 0.67 (clo). The novelty of this study encourages the production of the ideal CFD analysis on the thermal comfort conditions of a cooled room, the task of engineering.

Green energy technologies (GETs) are environmentally friendly in nature, making a promising contribution to attaining net-zero carbon goals. Although the Pakistani government has begun using GETs to minimize the adverse effects of carbon emissions, consumers' adoption rate is quite low. There are few studies examining consumers' desire to adopt GETs in the country. This study attempts to fill this research gap and also contributes by adding three novel factors to the theory of planned behavior (i.e., green energy technology awareness, openness to experience, and green energy technology discomfort) to comprehensively analyze the impact of various factors influencing consumers' desire to adopt GETs. For this purpose, the study establishes a systematic research framework. Data were collected from (n = 330) households in the five major cities (Peshawar, Abbottabad, Mardan, Mingora, and Swabi) of Khyber Pakhtunkhwa Province via an inclusive questionnaire survey. The formulated hypotheses are evaluated and scrutinized using structural equation modeling. The results reveal that environmental concern (β = 0.245), green energy technology awareness (β = 0.362), openness to experience (β = 0.256), and green energy technology benefits (β = 0.225) positively affect consumers' desire to adopt GETs. On the other hand, green energy technology costs (β = 0.325) and green energy technology discomfort (β = 0.395) have a negative effect on consumers' adoption of GETs. The research findings emphasize the importance of increasing recognition of GETs, reforming policy frameworks, and providing budget-friendly and user-friendly technologies. Research limitations and future research perspectives are also addressed.

Abstract The safe decommissioning as well as decontamination of the radioactive waste resulting from the nuclear accident in Fukushima Daiichi represents a huge task for the next decade. At present, research and development on long-term safe storage containers has become an urgent task with international cooperation in Japan. One challenge is the generation of hydrogen and oxygen in significant amounts by means of radiolysis inside the containers, as the nuclear waste contains a large portion of sea water. The generation of radiolysis gases may lead to a significant pressure build-up inside the containers and to the formation of flammable gases with the risk of ignition and the loss of integrity. In the framework of the project “R&D on technology for reducing concentration of flammable gases generated in long-term waste storage containers” funded by the Japanese Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT), the potential application of catalytic recombiner devices inside the storage containers is investigated. In this context, a suitable catalyst based on the so-called intelligent automotive catalyst for use in a recombiner is under consideration. The catalyst is originally developed and mass-produced for automotive exhaust gas purification, and is characterized by having a self-healing function of precious metals (Pd, Pt and Rh) dissolved as a solid solution in the perovskite type oxides. The basic features of this catalyst have been tested in an experimental program. The test series in the REKO-4 facility has revealed the basic characteristics of the catalyst required for designing the recombiner system.

Abstract The heat transfer performance of various thermal devices may be augmented by active and passive techniques. One of the passive techniques is the addition of ultrafine particles (called nanoparticles) to the common heat transfer fluids so that the thermal transport properties of the prepared suspension (called nanofluid) will be enhanced as compared to the base fluid. Nanorefrigerants are a special type of nanofluids which are mixtures of nanoparticles and refrigerants and have a broad range of applications in diverse fields for instance refrigeration, air conditioning systems, and heat pumps. In this paper, a review is performed in order to clarify effect of nanorefrigerant properties (such as nanoparticle type, size and concentration) on heat transfer and pressure drop compared to pure refrigerant. Moreover, studies related to the thermophysical properties, flow and pool boiling, and applications of nanorefrigerants to some specific areas such as domestic refrigerators, heat pipes and air conditioners are also summarized.

PurposeFirst, the current study contributes to the available debate by reinvestigating the impact of economic growth (EG), foreign direct investment (FDI), technological innovation (TI) and inflation (INF) on trade openness (TO). Second, the study tests the moderating role of institutional quality (INS) on the relationship among EG, FDI, TI and TO. Third, the study tests how TO contributes to EG efficiency.Design/methodology/approachThe study collects the data from the group of twenty (G20) economies for the period of 1998–2020. The study applied the Kao (1999), Pedroni (2001), and Palamuleni (2017) cointegration tests to test the long-run association between variables. The study applied fully modified least square (FMOLS) and dynamic least square (DOLS) models to test the hypotheses.FindingsFindings of the study showed the positive impact of EG, FDI and TI on TO, which becomes more positive in the presence of institutional quality. Results indicate that INS plays an enhancing role in the relationship between FDI and TO, EG and TO and TI and TO. The study showed a negative relationship between INF and TO, and institutional quality plays a buffering role in the relationship between INF and TO.Originality/valueFirst, the study reinvestigates the empirical association among EG, FDI, TI, INF and TO. Second, the study tests the moderating role of INS on the relationship between the proposed variables by developing an index of all the indicators of INS. Third, the study tests the contributions of TO in economic efficiency (ECE). The contributions of the present study will increase the available literature of TO and help the policy makers of G20 nations to suggest important policies to promote TO and ECE.

Due to its higher oxygen content, biodiesel fuel could play a vital role in the achievement of emission control in the heavy-duty transportation sector. Waste cooking oil (WCO) obtained from various sources such as the food industry, restaurants, and sewers could provide sustainable means of producing low-carbon fuel such as biodiesel. In this research, WCO biodiesel and conventional diesel fuels were characterized fundamentally in terms of their spray and gas entrainment qualities under diesel-like engine conditions using laser-induced fluorescence and particle image velocimetry (LIF-PIV). The impact of fuel injection parameters such as injection pressure and nozzle diameter on the fuel's spray and gas entrainment characteristics were investigated. Furthermore, an empirical equation was used to determine the droplet sizes of the sprays at different injection conditions. For both fuels, spray breakup and atomization were enhanced with the droplet size decreasing as injection pressure increased from 100 to 300 MPa and as nozzle size decreased from 0.16 to 0.08 mm. As a result of higher viscosity and surface tension, it was observed that WCO biodiesel produced longer spray penetration and narrower spray angle than diesel fuel. Furthermore, the quantity of gas entrained by WCO biodiesel spray was lower. As a result of an increase in the surface area, the percentage of gas entrained at the side periphery of the spray increased as time proceeded while the percentage of gas entrained via the spray tip decreased. The combined effect of ultra-high injection pressure of 300 MPa with a smaller nozzle hole diameter of 0.08 mm was observed to enhance gas entrainment processes.

Abstract For passenger cars, various powertrains compete in terms of reducing environmentally-harmful emissions, smooth integration into future energy systems and economic performance. Developing a sound long-term projection of the total cost of ownership (TCO), however, remains challenging. Highlights of our present assessment, include a detailed, component-based manufacturing and operating cost analysis, as well as simulation-based component scaling and fuel consumption analysis. We apply this methodology to eight passenger car concepts based on batteries, fuel cells and combustion engines , spanning four passenger car segments and five different market development scenarios through 2050. With respect to the TCO, our analysis reveals that fully-electric powertrains utilizing batteries (BEVs) and fuel cells (FCEVs) offer the lowest-cost solutions. FCEVs exhibit small but robust benefits compared to BEVs. BEVs will undergo the earliest break-even point with internal combustion engine vehicles (ICEVs), already before 2030. Different market development scenarios would not significantly affect the long-term results.

Purpose The purpose of this paper is to advance the dialogue between the disaster risk reduction (DRR) and adaptation community by investigating their differences, similarities and potential synergies. The paper examines how DRR and adaptation can inform development to tackle the underlying drivers of disaster risk. Design/methodology/approach Based on a risk-based approach to the management of climate variability and change, the paper draws from a critical review of the literature on DRR and adaptation. The study finds that known and emerging risk from disasters continues to increase dramatically in many parts of the world, and that climate change is a key driver behind it. The authors also find that underlying causes of social vulnerability are still not adequately addressed in policy or practice. Linking DRR and adaptation is also complicated by different purposes and perspectives, fragmented knowledge, institutions and policy and poor stakeholder coordination. Findings The author’s analysis suggests that future work in DRR and adaptation should put a much greater emphasis on reducing vulnerability to environmental hazards, if there is truly a desire to tackle the underlying drivers of disaster and climate risks. Originality/value This will require coherent political action on DRR and adaptation aimed at addressing faulty development processes that are the main causes of growing vulnerability. The study concludes with a first look on the new Sendai Framework for Disaster Risk Reduction and how it aims to connect with adaptation and development.