•Used fuels including preheated and unpreheated Jatropha oil, diesel fuel.•Impacts of triple-physical properties of fuel on atomization, breakup, and combustion.•Trilateral correlation of deposits, ...spray characteristics, and engine performance.•Thorough analysis on the relation of accumulated deposits and pollutant emissions.•Dependence of spray penetration and cone angle on formed deposits and fuel properties.
The benefits and advantages of bio-based fuels according to the research results of scientists and researchers related to the stable maintenance and sustainable development for the purpose of harmonizing the environment and life is an indisputable fact. Experimental studies on the use of bio-based fuels for engines in the long term should be thus thoroughly conducted to obtain the fullest results of economic-technical features and emissions, to name just a few. In this paper, a state-of-the-art analysis on the core correlation based on the trilateral relationship of spray characteristics, combustion, and emissions of a high-speed four-stroke diesel engine running on Jatropha oil (JO) in two cases of preheated and unpreheated in comparison to diesel fuel was investigated and carried out. Tests included two phases: (i)-tests of spray characteristics, analysis of combustion and emissions for engine fueled with preheated JO, unpreheated JO, and DF at the first hour and after 300 h of endurance test for engine, (ii)-analysis of formed deposits in the nozzle orifices and piston crown after 300 h of operation. As a result, huge deposits formed in the injector orifices and piston crown based on optical observation by SEM in case of using unpreheated JO as fuel were found, followed by preheated JO and DF. In addition, a sharp increase in spray penetration length and a significant decrease of cone angle for unpreheated JO compared to preheated JO and DF were also indicated, whereas thermal efficiency of the test engine for preheated JO, unpreheated JO, and DF was reduced by respectively 1.68%, 4.38%, and 0.98% after 300 h of operation. For emission data, negative changes such as a more reduction of NOx along with a higher augment of CO, HC, and smoke with unpreheated JO than those of preheated JO and DF were reported. In closing, core correlation as well as trilateral impacts of accumulated deposits, spray characteristics, and combustion were thoroughly demonstrated and deeply analyzed.
Heat activates persulfate (S2O82−) into sulfate radical (SO4−), a powerful oxidant capable of transforming a wide variety of contaminants. Previous studies have shown that an increase in temperature ...accelerates the rates of persulfate activation and contaminant transformation. However, few studies have considered the effect of temperature on contaminant transformation pathway. The objective of this study was to determine how temperature (T = 22–70 °C) influences the activation of persulfate, the transformation of benzoic acid (i.e., a model compound), and the distribution of benzoic acid oxidation products. The time-concentration profiles of the products suggest that benzoic acid was transformed via decarboxylation and hydroxylation mechanisms, with the former becoming increasingly important at elevated temperatures. The pathway through which the products were further oxidized was also influenced by the temperature of persulfate activation. Our findings suggest that the role of temperature in the persulfate-based treatment systems is not limited only to controlling the rates of sulfate and hydroxyl radical generation. The ability of sulfate radical to initiate decarboxylation reactions and, more broadly, fragmentation reactions, as well as the effect of temperature on these transformation pathways could be important to the transformation of a number of organic contaminants.
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•The degradation of benzoic acid by heat-activated persulfate was studied.•Temperature affects the distribution of benzoic acid transformation products.•The mechanism through which benzoic acid is transformed was established.•The roles of temperature in heat-activated persulfate systems are discussed.
The development of spinel ferrite nanomaterial (SFN)-based hybrid architectures has become more popular owing to the fascinating physicochemical properties of SFNs, such as their good electro-optical ...and catalytic properties, high chemothermal stability, ease of functionalization, and superparamagnetic behaviour. Furthermore, achieving the perfect combination of SFNs and different nanomaterials has promised to open up many unique synergistic effects and advantages. Inspired by the above-mentioned noteworthy properties, numerous and varied applications have been recently developed, such as energy storage in lithium-ion batteries, environmental pollutant monitoring, and, especially, biomedical applications. In this review, recent development efforts relating to SFN-based hybrid designs are described in detail and logically, classified according to 4 major hybrid structures: SFNs/carbonaceous nanomaterials; SFNs/metal-metal oxides; SFNs/MS
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; and SFNs/other materials. The underlying advantages of the additional interactions and combinations of effects, compared to the standalone components, and the potential uses have been analyzed and assessed for each hybrid structure in relation to lithium-ion battery, environmental, and biomedical applications.
We have summarized recent developments in SFN-based hybrid designs. The additional interactions, combination effects, and important changes have been analyzed and assessed for LIB, environmental monitoring, and biomedical applications.
For the short-term use of diesel engines, biodiesel can provide a comparable engine performance to that of using fossil diesel fuel. However, some arising problems including the reduction of the ...engine performance, the increase in lacquer deposits, and excessive carbon blacks in the combustion chamber and in the injectors resulting in an increase in the emissions and the damage to the engine have been indicated. Deposits formed inside or outside the injector may have an adverse influence on the engine performance and the fuel injection system. In this study, a review of the formed deposits in the injector of diesel engines fueled with biodiesel was conducted. The physicochemical mechanism of the deposit formation in the injector including injector nozzles, injector holes, and injector tips was mentioned. Moreover, the test-cycles for determining the deposit formation level in the injector were also introduced. Especially, the effects of the key factors such as biodiesel components, temperature, and injector configurations on the formation level of deposits were reviewed, and the utilization of the cativation mechanism in the controlling strategy of the deposits was presented. Besides, the impacts of deposits in the injector on the spray characteristics, combustion, and diesel engine operation process were also referred.
Magnetic nanoparticles (MNPs) exhibiting certain superparamagnetic properties are optimal for drug delivery because they facilitate imaging and targeting of biological interactions at the cellular ...and molecular levels. In terms of monitoring, magnetic particle imaging (MPI) yields real-time MNPs position and concentration data, and guides MNPs to desired positions if an actuation function is available. Here, we describe a new, user-driven steering scheme for MNPs based on a virtual field free point (FFP). The scheme utilizes a general MPI system, with no need for additional hardware. The scheme facilitates interactive user manipulation with real-time imaging and MNPs actuation within the body. An FFP with four coils is used to model the resultant magnetic force and a virtual FFP to linearize that force with respect to the relative positions of the MNPs and the real FFP. Simulations and experiments confirm that the direction and magnitude of the forces exerted on MNPs via manipulation of the virtual FFP are controllable. An intuitive guidance system featuring real-time MPI at 2 Hz and user-driven virtual FFP manipulation (via a computer mouse) is employed to show that MNPs trajectories can be controlled. Our MPI-based navigation platform allows the user to effectively guide MNPs using real-time visual feedback, facilitating targeted drug delivery.
•Higher geopolitical risk is associated with lower corporate investment.•Greater cash holdings weaken the negative impact of geopolitical risk on investment.•The adverse impact is more pronounced for ...high investment irreversibility firms.
This paper examines the effect of geopolitical risk on corporate investment in emerging Asian countries. Using an extensive sample spanning 1995–2018, we find that geopolitical risk is negatively associated with corporate investment. Geopolitical risks in China and Russia have a greater impact on corporate investment, while a less significant influence is found in India and Turkey. Our findings are robust to using alternative measures of geopolitical risk, using alternative proxies of investment, even after controlling for endogeneity concerns by a two-stage least square estimation, a system generalized method of moments regression, and the incremental effect of geopolitical risk. The adverse impact of geopolitical risk on firm investment is more pronounced for firms with a higher degree of investment irreversibility. However, firms with greater cash holdings can better mitigate this negative impact. Overall, this paper shows that geopolitical risk is a crucial macrolevel shock influencing corporate investment.
Research Question/Issue
This study investigates whether and how board reforms affect labor investment efficiency using a difference‐in‐differences analysis of board reforms in 41 countries worldwide ...as an exogenous shock.
Research Findings/Insights
Board reforms are positively associated with labor investment efficiency because they benefit firms in reducing over‐hiring, under‐firing, under‐hiring, and over‐firing. Further, we show that the positive effect is more pronounced among firms with lower board independence before the reforms, firms with high institutional foreign ownership, firms with higher corporate social responsibility (CSR), and labor‐intensive firms. While countries with rule‐based reforms experience a greater reduction in abnormal net hiring post‐reform, the effects of reforms are similar across civil and common law countries. Further analyses reveal that in countries with higher employment protection legislation, the beneficial relationship between board reforms and labor investment efficiency is weaker.
Theoretical/Academic Implications
Our study suggests that one of the mechanisms linking board reforms and labor investment efficiency is a reduction in frictions, such as moral hazard and adverse selection, which hamper efficient labor investment. To the best of our knowledge, this is the first international study that explores globally the relationship between board reforms and firm labor policies, in particular, labor investment efficiency.
Practitioner/Policy Implications
Given the importance of identifying and confirming the role of corporate governance in human capital investment efficiency, our empirical investigation provides useful insights and policy implications for managers in building efficient labor policies.
This study aimed to measure the exposure of residents to health education messages about non-communicable diseases (NCD)-related risk factors, and activities of village health workers (VHWs) in NCDs ...prevention and control in the mountainous setting of Vietnam. A cross-sectional study was performed in Dap Thanh commune (Ba Che, Quang Ninh province, Vietnam), a mountainous area. There were 151 residents aged 18 years or above recruited for this study. Information regarding exposure to messages about risk factors of NCDs, and activities of VHWs was collected via face-to-face interviews using a structured questionnaire. Multivariate logistic regression was employed to identify associated factors with exposing messages about NCD-related risk factors. The majority of participants heard about messages related to risk factors of NCDs in the last 30 days, from 56.3% (physical inactivity message), 59.6% (diet message), 75.5% (alcohol use message) to 79.5% (smoking message). Radio/television was the most common source of the messages (from 91.8% to 95.8%) and the majority of participants heard these messages from one source (from 77.1% to 80.9%). Most of sample reported the unavailability of VHWs in their locals (53.6%). Among locals having VHWs, health communication and education was the most common service provided (54.3%); however, only 30% received NCD management services. Participants who had other jobs were less likely to hear about diet-related messages (OR = 0.32; 95%CI = 0.11-0.92), and those ever smoking were more likely to hear these messages in the last 30 days (OR = 6.86; 95%CI = 1.06-44.51). People who had diabetes mellitus were more likely to hear physical activity-related messages in the last 30 days (OR = 2.55; 95%CI = 1.20-5.41). Our findings indicated that health communication regarding risk factors of NCDs in mountainous areas in Vietnam was insufficient, and the role of health workers as formal information source was not recognized. Efforts should be made to increase the capacity and involvement of VHWs in health education and NCD prevention in mountainous regions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Considered as the alternative and less polluting fuel, biodiesel deriving from vegetable, animal or waste oils, potentially decreases atmospheric pollutants and greenhouse gases. This study ...contributes to the nuanced understanding of the effects of fish oil biodiesel fuel blends on spray, combustion, performance and emission characteristics. The purpose of this study is testing the effects of various concentrations of fish-oil biodiesel blends (B10, B20, B30) and standard diesel fuel (B0) on single cylinder common rail diesel engine at maximum brake torque speed of 1400 rpm and minimum brake fuel consumption speed of 2200 with different engine loads of 25%, 50% and 75% conditions. The results show that running engines with B30 at 75% load condition, the average values of engine powers, carbon monoxide (CO), unburned hydrocarbons (HC) and soot emissions decreased by 3.00%, 14.3%, 26.2% and 17.5%, respectively, while BSFC and NOx emissions increased by 3.4%, 5.1%, respectively compared to using B0. The result implies that despite testing with varying concentrations of fish oil, the performance and emission engine are not credibly different. Therefore, fish oil biodiesel-diesel fuel blends can be used efficiently as fuels for diesel engine without any major modification in the engines.
In recent years the outbreak of re-emerging and emerging infectious diseases has been a significant burden on global economies and public health. The growth of population and urbanization along with ...poor water supply and environmental hygiene are the main reasons for the increase in outbreak of infectious pathogens. Transmission of infectious pathogens to the community has caused outbreaks of diseases such as influenza (A H5N1), diarrhea (Escherichia coli), cholera (Vibrio cholera), etc throughout the world. The comprehensive treatments of environments containing infectious pathogens using advanced disinfectant nanomaterials have been proposed for prevention of the outbreaks. Among these nanomaterials, silver nanoparticles (Ag-NPs) with unique properties of high antimicrobial activity have attracted much interest from scientists and technologists to develop nanosilver-based disinfectant products. This article aims to review the synthesis routes and antimicrobial effects of Ag-NPs against various pathogens including bacteria, fungi and virus. Toxicology considerations of Ag-NPs to humans and ecology are discussed in detail. Some current applications of Ag-NPs in water-, air- and surface- disinfection are described. Finally, future prospects of Ag-NPs for treatment and prevention of currently emerging infections are discussed.
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