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Результаты 4231-4240 из 7,292
Optimal decisions for green supply chain with a risk-averse retailer under government intervention Полный текст
2022
Tang, Li | Li, Eldon Y. | Wu, Peipei | Jiang, Jiang
This paper investigates the effects of the financial subsidy and product access policies on the performance of green supply chains (GSCs). Based on the game theory and preference theory, we study a green supply chain consisting of a risk-neutral manufacturer and a risk-averse retailer under government interventions from different power structures. The result reveals that green production can be effectively promoted only when product access exceeds a certain threshold. The Nash equilibrium game has the highest greenness and expected utility of GSC. It also shows that regardless of the market structure and government intervention policy, the retailer’s risk aversion is positively correlated with the highest level of product access. Moreover, once effective product access is implemented, the retailer’s risk aversion does not affect the optimal greenness of manufacturer production. Besides, compared with other intervention policies, the highest optimal product greenness exists in the scenario of financial subsidy with effective product access. The study suggests that the government needs to set certain green standards when implementing subsidy policies and promoting the risk aversion of retailers.
Показать больше [+] Меньше [-]Photocatalytic remediation of methylene blue and antibacterial activity study using Schiff base-Cu complexes Полный текст
2022
Fasna, P. H Fathima | Sasi, Sreesha | Sharmila, T. K Bindu | Chandra, C. S Julie | Antony, Jolly V. | Raman, Vidya
This work describes the design of novel Cu(II) complexes and their application in the photocatalytic degradation of methylene blue (MB). The same photocatalyst exhibits antibacterial activity against Escherichia coli (gram-negative) and Bacillus circulans (gram-positive). The characterisation of the photocatalysts has been done by several up-to-date physical methods. The rationale behind the photocatalysts’ beneficial intervention is discussed in this study. Statistical analysis of the degradation of MB is done using a one-way ANOVA, and the significance of means is determined by a multiple comparison test using Turkey HSD. Also, the degradation of MB follows pseudo first-order kinetics with high correlation coefficient values (R² > 0.95), making them useful as simple and low-cost organic dye degradation agents.
Показать больше [+] Меньше [-]Development of an environmental-friendly durable self-compacting concrete Полный текст
2022
Tripathi, Deep | Kumar, Rakesh | Mehta, Pradeep Kumar
In this experimental study on self-compacting concrete (SCC), the Manufactured sand (M-sand) and Fly ash (FA) were utilised for partial replacement of Natural sand (N-sand) and Ordinary Portland Cement (OPC), respectively. N-sand was partially replaced by M-sand at various percentage levels, after the dose of FA in the mix was optimised. In terms of compressive strength, the optimum replacement level of OPC by FA was 20%, whilst for replacement of N-sand by M-sand it was 50%. Two types of mixes were prepared to compare the macro and micro level properties of SCC, i.e., SCC-I (100%OPC + 100%N-sand) and SCC-II (80%OPC + 20%FA + 50%N-sand + 50%M-sand). The characteristics of fresh concrete mixes were determined using Slump flow, T₅₀ time, V-funnel, L-box, U-box, and J-ring tests. After 28 days of curing in tap water, both types of specimens were exposed to a solution of ammonium sulphate [(NH₄)₂SO₄] containing sulphate salt concentration of 2.0 g/l for 360 days to test their durability. Loss in compressive strength, weight change, sorptivity, and micro-structural changes (XRD, SEM, and EDS) all were evaluated for up to 360 days. It was found that the use of FA and M-sand in concrete makes it more environmental-friendly and durable, as well as have better performance in a sulphate environment.
Показать больше [+] Меньше [-]Enhanced removal of mercury and lead by a novel and efficient surface-functionalized imogolite with nanoscale zero-valent iron material Полный текст
2022
A novel hybrid nanomaterial, nanoscale zero-valent iron (nZVI)-grafted imogolite nanotubes (Imo), was synthesized via a fast and straightforward chemical procedure. The as-obtained nanomaterial (Imo-nZVI) was characterized using transmission electron microscopy (TEM), electrophoretic mobility (EM), and vibrating sample magnetometry (VSM). The prepared Imo-nZVI was superparamagnetic at room temperature and could be easily separated by an external magnetic field. Sorption batch experiments were performed for single- and multicomponent systems and demonstrated that Hg²⁺ and Pb²⁺ could be quantitatively adsorbed at pH 3.0. For multicomponent systems, maximum adsorption capacities of 61.6 mg·g⁻¹ and 76.9 mg·g⁻¹ were obtained for Hg²⁺ and Pb²⁺ respectively. It was observed that the functional groups in Imo-nZVI interact preferentially with analytes according to the Misono softness parameter. The higher performance of Imo-nZVI compared with Imo and nZVI is related to the increased number of adsorption sites in the functionalized nanomaterial. The sorption equilibrium data obeyed the Langmuir model, while kinetic studies demonstrated that the sorption processes of Hg²⁺ and Pb²⁺ followed the pseudo-second-order model. This study suggests that the Imo-nZVI composite can be used as a promising sorbent to provide a simple and fast separation method to remove Hg and Pb ions from contaminated water.
Показать больше [+] Меньше [-]Total cholesterol: a potential mediator of the association between exposure to acrylamide and hypertension risk in adolescent females Полный текст
2022
Acrylamide (AA) exposure is associated with a range of adverse health effects. However, whether AA exposure is related to hypertension in adolescents remains unclear. The associations of blood hemoglobin biomarkers of AA (HbAA) and its metabolite glycidamide (HbGA) with hypertension risk, diastolic blood pressure (DBP), and systolic blood pressure (SBP) were evaluated by multivariate logistic regression and linear regression. We identified a potential positive association between blood HbGA and hypertension risk in adolescent females (OR 1.81, 95% CI 1.00–3.30; P for trend = 0.022); however, there was no correlation in the non-linear model (P = 0.831). In the sex-stratified linear models, blood HbGA level had a strong positive association with SBP in adolescent females (beta 0.84, 95% CI 0.13–1.55, P = 0.020). Mechanistically, a one-unit increase in blood HbGA (ln transformed) was associated with a 2.83 mg/dL increase in total cholesterol (TC) among females in the fully adjusted model. Mediation analysis showed that TC mediated 24.15% of the association between blood HbGA level and the prevalence of hypertension in females. The present results provide epidemiological evidence that exposure to AA, mainly its metabolite glycidamide, is positively associated with the prevalence of hypertension or increased SBP in adolescent females.
Показать больше [+] Меньше [-]The pain of breathing: how does haze pollution affect urban innovation? Полный текст
2022
In China, innovation plays an important role in achieving economic development with green growth, but innovation activities are inhibited by the spread of haze pollution (also called smog). Using panel data on 265 cities in China at the prefectural level from 2001 to 2018, this paper investigates the relationship between haze pollution and urban innovation. The conclusions are as follows. First, haze pollution has a significant inhibitory effect on urban innovation. After we consider endogeneity, eliminate extreme values, replace variables, and incorporate spatial correlation, we find that the negative impact of haze pollution on urban innovation still exists. Second, the channels through which haze pollution affects urban innovation are mainly attributed to production efficiency, willingness to consume, and entrepreneurial activity. Third, the inhibitory effect of haze pollution on innovation has a spatial spillover effect. Fourth, among the different regions in China, the most serious inhibitory effect of haze pollution on innovation is in the central region, while that of the eastern and western regions is insignificant. Moreover, across diverse Chinese cities, the significant inhibitory effects of haze pollution on innovation are mainly in cities that are abundant in natural resource. Accordingly, the efficient management of haze pollution is a critical prerequisite and effective guarantee for increasing urban innovation, such as promoting clean energy, strengthening technological innovation, and improving human capital.
Показать больше [+] Меньше [-]Reduction of chemical oxygen demand through electrocoagulation: an exclusive study for hazardous waste landfill leachate Полный текст
2022
Gautam, Pratibha | Kumar, Sunil
Leachate produced from hazardous waste landfills has been observed to exhibit very complex characteristics including the presence of a high amount of refractory organics and toxic elements which make it unfit for conventional treatment. This study is focused on the characterization and treatability of “hazardous waste landfill leachate” through electrocoagulation for the reduction of chemical oxygen demand (COD). Effect of different operating parameters, such as electrode material, interelectrode distance (IED), current density (CD), and electrolysis time (ET), has also been studied. For galvanized iron (GI) electrodes, a significant reduction in phenolic compounds, cadmium, lead, and zinc concentration was observed and more than 80% reduction in COD and color was achieved on a bench-scale reactor for a CD value of 41.64 A/cm² at IED of 1.5 cm and for ET equating to 240 min. Substantiated by experimental results and statistical analysis like ANOVA and post hoc analysis, it appears that electrocoagulation is a proficient technology for the treatment of hazardous waste landfill leachate which has a huge potential for further research.
Показать больше [+] Меньше [-]Distribution and health-ecological risk assessment of heavy metals: an endemic disease case study in southwestern China Полный текст
2022
This research focuses on the health risks caused by heavy metal (HM) environmental pollution. Soil, water, corn, rice, and patients’ hair samples from Daping Village, Yunnan Province, China, were analyzed for seven selected HMs. Geoaccumulation index (Igₑₒ), pollution indexes (PI), and the Nemerow integrated pollution index (PN) were used to evaluate pollution levels. We employed principal component analysis (PCA), correlation analysis (CA), and spatial distribution to identify the source and distribution characteristics of HMs in soil. Health risks of HMs and exposure pathways were accessed by calculating the hazard quotient (HQ) and hazard index (HI). The Igₑₒ, PI, and PN results show that cadmium (Cd) and arsenic (As) pollution is severe in soil, while other pollution is relatively little. PCA, CA, and spatial distribution show that HMs may be derived from black shale weathering and enrichment. Residents’ drinking water is relatively safe. Arsenic is the element most threatening to local residents (HI = 3.8). Soil (HI = 3.55) ingestion and plant (HI = 1.67) ingestion are the primary exposure pathways to HMs. This unusual disease may be caused by children’s relatively low immunity and long-term exposure to As. We must enhance the protection of children and encourage avoiding soil contact as much as possible. Our results highlight the importance of investigating HM pollution from geological sources and blocking potential exposure pathways.
Показать больше [+] Меньше [-]Ecological risk assessment of heavy metal chromium in a contaminated pastureland area in the Central Punjab, Pakistan: soils vs plants vs ruminants Полный текст
2022
Grazing animals act as a bioindicator to study the heavy metal status in the pasture lands because excessive amount of toxic metals in the animal diet either disturb their normal activity or deposit the contaminants into their tissues. The aim of this study was to appraise the chromium status in soil and pasture crops with respect to the nutritional requirement of grazing animals. Three different sites were selected to collect soil, forages, and animal samples from District Jhang. All the samples were processed through atomic absorption spectrophotometer to analyze the chromium concentration in them. Chromium concentration was varied as 0.703–4.20 mg/kg in soil, 0.45–2.85 mg/kg in forages, and 0.588–2.37 mg/kg in all collected animal samples. Both the soil and forage samples displayed the maximum chromium concentration in the Capparis decidua, whereas animal samples revealed maximum concentration in animal blood. Results of pollution load index (0.078 to 0.463 mg/kg) exhibited that all the sample values are less than unity while enrichment factor (1.57–8.25mg/kg) showed that significant level of chromium is enriched in these sites. The maximum value of daily intake (0.0007–0.0055mg/kg/day) and health risk index (0.0004–0.00370055mg/kg/day) was observed in the buffalo that feed on the Capparis decidua. Bio-concentration factor (0.398–2.09mg/kg) value was the maximum in the Medicago sativa. It is concluded that all the animal samples showed chromium concentration beyond their standards. Thus, proper measures should be taken to reduce the metal contamination in these areas that ultimately lessen the availability of toxic metals to grazing animals.
Показать больше [+] Меньше [-]Assessing the impact of green fiscal policies and energy poverty on energy efficiency Полный текст
2022
This article estimates the ties between green fiscal policies and energy efficiency in COVID-19 era. For this purpose, data envelopment analysis (DEA) approach is considered and applied. The study findings show that green fiscal policies, such as public supports and tax rebates, have significant role in reducing energy poverty of different international countries by advancing energy efficiency. Therefore, a panel data ranging from 2010 to 2020 is used. Our findings indicate that the aggregate degree of green fiscal policies help to decline energy poverty. Renewable energy companies had larger series of net fiscal competence and size efficiency, and their levels of energy efficiency were greater than 0.457%, with the 16% effect of current public supports and 11% effect of taxation rebates supported to diminish energy poverty with 29.7% in different international economies. This is a positive effect by green fiscal policies. The study also presented policy implications suggesting effectively implementing green fiscal policies for more efficient carbon reduction and making climate change supportive for peoples in post COVID-19 period.
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