Various research works are being undertaken around the world on the subject of thermal efficiency improvisation and emission reduction from diesel engines. This research work analyzes the performance and emission characteristics of a thermal barrier coated diesel engine which used palm biodiesel. The piston and cylinder liners were coated with equal percentages of alumina (Al₂O₃) and yittria-stabilized zirconia (YSZ) powder using plasma spraying coating method. The piston was coated with 100 μm thickness and the two cylinder liners were coated with 150 and 200 μm thicknesses and were used to analyze the performance and emission characteristics. Test results of the thermal barrier coated engine using palm biodiesel were compared with the results derived from the base engine. The tests revealed an increase of 3.8% specific fuel consumption (SFC) as an average when neat palm biodiesel was used in the base engine. Interestingly, the palm biodiesel used in the 150- and 200-μm thick thermal barrier coated engine was responsible for a significant decrease of the SFC by an average of 4.18% and 8.05% respectively. The brake thermal efficiency was found to decrease on an average of 1.02% when tests were run using the neat palm biodiesel in the base engine. But an average proportionate increase of 0.72% and 2.19% was visible when palm biodiesel was used in the tests conducted on the 150- and 200-μm thick thermal barrier coated engine. There was also an understandable brake specific reduction of 0.991 g/kWh carbon monoxide (CO) emission and 0.025 g/kWh unburned hydrocarbon (HC) levels. The nitrogen oxide (NOₓ) emission was observed as 14.06 g/kWh in the 200-μm thick thermal barrier coated engine which was slightly higher when the results were compared with that of the uncoated engine. The novelty of this research investigation is based on the usage of yttrium-stabilized zirconia and alumina thermal barrier coating on the cylinder liner and piston head of engine. This is justified due to the fact that most of the previous investigations undertaken focused on the thermal barrier coating in the piston, valve, and cylinder head alone. The utility factor of the palm biodiesel (B 100) in the low heat rejection engine has also proved to be another significant and novel factor in the present investigation outlined in this paper. This is mainly due to the fact that the ongoing investigations in this realm concentrated only on blends of 20 to 30% of palm biodiesel with diesel fuel in the low heat rejection diesel engine.

Silver nanoparticles (AgNPs) were prepared by reacting Kyllinga brevifolia extract (KBE) with AgNO₃ aqueous solution at room temperature (22 ± 3 °C). The phytochemical constituents in KBE responsible for the reduction process were identified as carbohydrate, protein, and plant sterols (stigmasterol and campesterol). KBE was also found to function as a capping agent for stabilization of AgNPs. The AgNPs were stable at room temperature and had a quasi-spherical shape with an average particle size 22.3 nm. The use of KBE offers not only eco-friendly and non-pathogenic path for AgNPs formation, it also induced rapid formation of the AgNPs. Methylene blue (MB) removal was then done on the AgNPs in the presence of either KBE or NaBH₄. Ninety-three percent removal of MB was achieved with a rate of reaction 0.2663 min⁻¹ in the solution with KBE+AgNPs (pH 2). However, in NaBH₄+AgNPs system, 100% MB removal was achieved at pH 8–10. The reaction rate was 2.5715 min⁻¹ indicating a fast removal rate of MB dye. The process of reduction occurs via electron relay effect whereas in KBE+AgNPs system, sedimentation occurred along with the reduction process. Nevertheless, the use of KBE+AgNPs system is preferred as the reducing agent is more benign to the environment.

Cadmium (Cd) has long been noted to induce neurodegenerative disorders. Therefore, this study aimed to assess the toxicological impact of Cd on rat brains and evaluate the possible ameliorative impact of omega-3 fatty acids as a protective agent of nervous system. Rats were divided into four groups: group I supplemented orally with saline; group II intoxicated with CdCl₂ (5 mg/kg b.w. orally), and groups III and VI supplemented with omega-3 (100 mg/kg b.w. orally) simultaneously or before CdCl₂ administration, respectively. Cd intoxication induced biochemical and histopathological disturbances in treated rats. Omega-3 fatty acid considerably improved the Cd-associated biochemical changes, reduced the elevation of lipid peroxidation, and normalized the Cd impact on the levels of superoxide dismutase, catalase, glutathione-S-transferases, 8-hydroxydeoxyguanosine, heatshock protein70, nuclear factor-κB, and interferon-γ as well as of neuronal enzymes such as acetylecholinesterase and monoamine oxidase within the brains of treated rats. Additionally, histological findings supported the results that Cd treatment-induced neurodegenerative changes and that polyunsaturated fatty acids act as antioxidants and neuroprotective agents against Cd toxicity. Co-treatment with omega-3 fatty acid was more beneficial than pretreatment. Thus, omega-3 fatty acid should be included in diet to prevent or suppress neurodegenerative disorders caused by continuous exposure to Cd.

To investigate the characteristics and formation mechanisms of haze pollution in the autumn season in the Sichuan Basin, hourly concentrations of water-soluble inorganic ions in PM₂.₅ (Na⁺, K ⁺, NH₄⁺, Mg²⁺, Ca²⁺, Cl⁻, NO₃⁻, and SO₄²⁻) and major gaseous precursors (HCl, NH₃, SO₂, HONO, and HNO₃) were measured by a gas and aerosol collector combined with ion chromatography (GAC-IC) from September to November 2017 at an urban site in Chengdu. The average mass concentration of total water-soluble ions was 36.9 ± 29.4 μg m⁻³, accounting for 62.8% of PM₂.₅ mass. Nitrate was the most abundant ion, comprising 41.2% of the total ions, followed by sulfate (27.1%) and ammonium (18.1%), indicating the important contribution of motor vehicle emissions to PM₂.₅ in Chengdu. Secondary formation of inorganic ions and biomass burning emissions played a vital role in the haze pollution processes. The formation of nitrate aerosol was particularly dominant and exhibited the most substantial increase during haze processes. It was likely to be produced primarily through homogeneous reactions, whereas heterogeneous reactions dominated sulfate formation. Additionally, distinct differences in diurnal patterns of secondary inorganic ions between clean days and polluted days were observed, reflecting different formation characteristics under polluted conditions. Due to a large increase of acidic aerosols, most particles collected on polluted days were acidic, and ammonium in most samples existed mainly as NH₄HSO₄ and NH₄NO₃. Furthermore, backward-trajectory cluster analysis revealed that air masses originating from the northeast of Chengdu prevailed in the autumn season, and haze pollution was dominated mainly by short-distance transport within the Sichuan Basin.

Microplastics (MPs) in natural environments have attracted lots of attention. Although the quantity of MPs present in terrene is much higher than that in aquatic environment, few studies have investigated the chemical behavior of MPs in terrestrial environment. This study investigate the Cu²⁺ (as a model heavy metal) adsorption capacity of six kinds of MPs (polyamide-6 (PA), polyethylene (PE), polystyrene (PS), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polymethyl methacrylate (PMMA)) in batch adsorption experiments and the effects of different soil environmental factors, including pH and the presence of cations and low-molecular-weight organic acids (LMWOAs), as well as ultraviolet (UV) aging. The Cu²⁺ adsorption capacities of PA and PMMA were higher than those of other MPs and their maximum equilibrium adsorption capacities (estimated by the Langmuir adsorption equation) were 323.6 μg/g ± 38.2 and 41.03 ± 1.78 μg/g, respectively. The Cu²⁺ adsorption on MPs was affected by pH, and the greatest amount of Cu²⁺ adsorbed on PA and PMMA was observed at pH = 6 and pH = 7, respectively. The presence of Ca²⁺ or Mg²⁺ inhibited Cu²⁺ adsorption by MPs, due to competition for the adsorption sites. Moreover, Cu²⁺ adsorption by MPs was affected by various types of LMWOAs. The Cu²⁺ adsorption on PA was significantly reduced by citric acid, followed by oxalic acid, and oxalic acid was particularly evident for Cu²⁺ adsorption on PMMA. UV aging (200 h) had different effect on Cu²⁺ adsorption on MPs and it depends on the change of carbonyl index. Results demonstrate that soil environmental factors can change the ability of different MPs to adsorb Cu²⁺ and affect the transport of pollutants as carriers.

A sensitive and reliable analytical method has been developed and validated for the determination of five Alternaria toxins, including tenuazonic acid (TeA), alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT), and tentoxin (TEN), in drinking water using a one-step enrichment and clean-up strategy followed by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Drinking water samples were preprocessed using excess sodium sulfite to remove residual chlorine, and the pH was adjusted by formic acid. Analytes were concentrated and purified from the water samples using hydrophilic-lipophilic balanced (HLB) solid-phase extraction (SPE) cartridges. Chromatographic separation was performed on an Acquity HSS C₁₈ column using 0.1 mM ammonium carbonate and methanol as the mobile phase. The average recoveries at three spiked levels (0.1, 0.5, and 1 ng/L for TeA, AOH, and ALT; 0.01, 0.05, and 0.1 ng/L for TEN and AME) were 76.1–106.5%, with an intra-day precision less than 15.5% and inter-day precision of 11.8–16.5%. The limits of detection (LODs) were 0.05 ng/L for TeA, AOH, and ALT and 0.005 ng/L for TEN and AME. The limits of quantification (LOQs) were 0.1 ng/L for TeA, AOH, and ALT and 0.01 ng/L for TEN and AME. The developed method was applied to monitor 289 drinking water samples collected in Beijing from 2015 to 2017, and TeA and TEN were found in 28 samples, with concentrations ranging from 0.16 to 2.7 ng/L and 0.21 to 2.2 ng/L, respectively.

Because of its low concentration, its unique physico-chemical properties and the analytical difficulties associated with its measurement, the determination of mercury species in solids is not an easy task. Thermal desorption (HgTPD) is an attractive option for the identification of mercury species in solids due to its simplicity and accessibility. However, there are still issues that need to be solved for it to reach its full potential. One such issue is the availability of reference materials that will reproduce real mercury associations. The novelty of this study is the use of six uncommon mercury minerals, taken from around the world, and a sphalerite sample to expand the data base of reference materials for mercury speciation by thermal desorption at programmed temperature. In addition, by using such materials, a number of matrix effects can be ascertained. Different mercury associations were identified depending on the temperature of desorption, thereby validating the thermal desorption as a reliable technique for mercury speciation in solid samples and as a consequence improving the knowledge of the geochemistry of mercury in the environment.

The Batchwa vacha, Eutropiichthys vacha is commercially important, supporting a viable small- and large-scale fishery throughout the Ganges River, NW Bangladesh. This study provides detail information on reproduction of E. vacha including size at sexual maturity, spawning and peak spawning season, and fecundity based on 734 female specimens through regular monthly sampling using cast net, gill net, and square lift net in the Ganges River during January to December 2016. Also, our study estimated the effects of climate change including temperature and rainfall on reproduction of E. vacha in the Ganges River. For each individual, lengths (total length, TL; standard length, SL) and body weight (BW) were measured with slide caliper and digital balance, respectively. Gonads (ovaries) were collected carefully by ventral dissection of each female specimen and weighed to the nearest 0.01 g accuracy. The gonadosomatic index (GSI % = (GW/BW) ×100), modified gonadosomatic index (MGSI % = (GW/BW − GW) × 100), and Dobriyal index (DI = [Formula: see text]) were calculated to estimate the size at sexual maturity (L₅₀) and spawning season. Based on GSI, MGSI, and DI, the L₅₀ was calculated as 12.5 cm TL for female. The TL₅₀, the TL at which 50% of individuals become mature, was calculated by logistic equation as 12.7 cm. Also, on the basis of higher values of GSI, MGSI, and DI, spawning season was ranged from April to August, with the peak in June–July, signifying the peak spawning season for E. vacha in the Ganges River. The total fecundity (FT) ranged from 4800 to 77,976 (mean ± SD, 31384 ± 23,747) and was highly correlated with TL and BW. Water temperature during the spawning period ranged from 28 to 34 °C, with an average of 31 °C and there was significant correlation between temperature and GSI. Also, the spawning season coincides with the peak rainfall and there was significant correlation between rainfall and GSI. Additionally, analysis of long data series indicated that annual average air temperature is increasing by 0.0258 °C/year, while the annual average rainfall is decreasing by 3.107 mm/year. Finally, the findings of this study would be very effective to impose specific management for E. vacha in the Ganges River and surrounding ecosystems.

In the past 20 years, the green economy has increasingly attracted the attention of governments and policy makers. However, most studies have only focused on the relationship between the green economy and innovation, and little attention has been given to the relationship between the different innovation stages and the green economy. This study draws on eco-innovation and institutional theories and proposes a model to empirically investigate the effects between the different innovation stages and green economy. Furthermore, it explores how these effects are mediated by knowledge spillover and moderated by absorptive capacity and environment regulations. We use data from the last 5 years (2012–2016) obtained from different China regions to empirically test the model. Results show that knowledge innovation, research and development (R&D) innovation, and product innovation have the same significant positive impact on knowledge spillovers. R&D and product innovation have a significant positive impact on green economy, whereas knowledge innovation has no significant effect on the development of the green economy. Knowledge spillover partially mediates the relationship between the innovation stage and the green economy. Meanwhile, absorptive capacity positively moderates the relationship between knowledge spillover and the green economy. However, environmental regulation negatively moderates the relationship between knowledge spillover and the green economy. In addition, corresponding measures are proposed based on the conclusions.

Rice fallow, a rainfed lowland agro-ecology, is presently gaining particular attention for sustainable cropping intensification in the South Asia. Nevertheless, cropping intensification of rice-fallow areas is largely challenged by non-availability of irrigation, the poor financial status of farmers and soil constraints. Indeed, fast depletion of the soil residual moisture remains the primary obstacle for growing a crop in succession in rice fallows. A field investigation was carried out to identify the most adaptable rice-winter crop rotation and to customize appropriate crop establishment practice for a winter crop that could conserve the soil moisture. Treatments comprised of three crop establishment practices for winter crops [utera (relay cropping, i.e. broadcasting of seeds in standing rice crop 15 days before harvesting), zero tillage (ZT) and ZT with mulching (ZTM)], and five post-rainy-season crops (lentil, chickpea, lathyrus, mustard and linseed). Results showed that lathyrus and lentil could be the potential winter crop in the rice-fallow condition of Eastern India. Except for mustard crop, the productivity of all the winter crops was higher in utera cropping, which was primarily attributed to early crop growth and higher soil moisture content over ZT and ZTM treatments. The higher water use efficiency was recorded under utera cropping over ZT and ZTM treatments. Higher system productivity (system rice equivalent yield) in rice–utera lathyrus (9.3 t ha⁻¹) and rice–utera lentil (8.1 t ha⁻¹) led to higher net returns and production efficiency over other treatments (winter crop × crop establishment practice). Benefits of rice residue mulching were prominent in lentil, mustard and linseed crop productivity. Energy use efficiency of different crop establishment practices follows the trend of utera > ZT > ZTM (p < 0.05), being highest in rice–utera lathyrus (5.3) followed by rice–utera lentil (4.8) crop rotations. The simulated data shows that winter crops grown under utera led to less emission of greenhouse gas (GHG) and low global warming potential (GWP) as compared to ZT and ZTM treatments. Rice–lathyrus, rice–lentil and rice–chickpea systems had lower N₂O emission than rice–mustard and rice–linseed rotations. Hence, lathyrus and lentil could be included in rice fallows ideally with utera for sustainable cropping intensification and improving the farmers’ income in Eastern India.