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Due to increasing environmental concerns, there is growing interest in sustainable natural fiber-based hybrid composites. However, these materials face significant challenges across various fields and applications. This study aims to enhance jute-palmyra fiber-reinforced epoxy hybrid composites by incorporating nano-silica particles. The research investigates the improvement of physical, mechanical, and tribological characteristics of the composites with functionalized silica nanoparticle concentrations ranging from 0 % to 4 wt.%. Results show that increasing SiO2 content enhances the composite's density. Specifically, the composite with 3 wt.% SiO2 exhibits the highest flexural strength (71.20 MPa), while 2 wt.% SiO2 demonstrates superior tensile strength (55.52 MPa), impact resistance (4.02 J), and hardness (36 HV). Dry sliding wear tests using an L16 orthogonal array design reveal that hybrid nanocomposites with 2 wt.% SiO2 display superior wear resistance under specified conditions. These findings underscore the significant performance advantages of SiO2-natural fiber hybrid composites, highlighting their potential in sustainable material applications. [ABSTRACT FROM AUTHOR]

The study characterized the temporal and spatial variability in greenhouse gas (GHG) fluxes (CO2, CH4, and N2O) between December 2020 and November 2021 and their regulating drivers in the subtropical wetland of the Indian Himalayan foothill. Five distinct habitats (M1—sloppy surface at swamp forest, M2—plain surface at swamp forest, M3—swamp surface with small grasses, M4—marshy land with dense macrophytes, and M5—marshy land with sparse macrophytes) were studied. We conducted in situ measurements of GHG fluxes, microclimate (AT, ST, and SMC(v/v)), and soil properties (pH, EC, N, P, K, and SOC) in triplicates in all the habitat types. Across the habitats, CO2, CH4, and N2O fluxes ranged from 125 to 536 mg m−2 h−1, 0.32 to 28.4 mg m−2 h−1, and 0.16 to 3.14 mg m−2 h−1, respectively. The habitats (M3 and M5) exhibited higher GHG fluxes than the others. The CH4 flux followed the summer > autumn > spring > winter hierarchy. However, CO2 and N2O fluxes followed the summer > spring > autumn > winter. CO2 fluxes were primarily governed by ST and SOC. However, CH4 and N2O fluxes were mainly regulated by ST and SMC(v/v) across the habitats. In the case of N2O fluxes, soil P and EC also played a crucial role across the habitats. AT was a universal driver controlling all GHG fluxes across the habitats. The results emphasize that long-term GHG flux monitoring in sub-tropical Himalayan Wetlands has become imperative to accurately predict the near-future GHG fluxes and their changing nature with the ongoing climate change. [ABSTRACT FROM AUTHOR]

Hybrid nanofluids contain two or more nanoparticles mixed with a conventional coolant to enhance the thermophysical properties at the molecular level. The current research investigates the performance of heat exchangers under the influence of hybrid nanofluids. Simulation is performed using Ansys 2020 R2 and RNG k-ϵ model is used to solve the problem because it is the most accurate model suggested for turbulent flow. A single-pass heat exchanger of length 650 mm and diameter 20 mm was investigated and inserted with twisted tapes of twist ratios(y/W) 4 and 3 for volume concentrations ranging from 0.5 to 3%. A hybrid metal matrix nanofluid, a mixture of Al2O3 and CuO in a ratio of 70:30, was used as a working fluid to conduct the study. It is astonishing to find that with the increase in volume concentrations of hybrid nanofluid, there is a significant increase in Nusselt number, which is 370% for twisted tape of twist ratio 3. The study also revealed that there is minimal effect of volume concentration on the friction factor, although inserting twisted tape increases the friction factor 294% more than the plain tube. The thermal performance factor of the heat exchanger with twisted tape of Twist ratio = 3 is 3.52 times more than that of a plain tube. An empirical correlation between the Nusselt number and the friction factor is established for various volume concentrations and twist ratios. We conclude that the use of a hybrid nanofluid with higher thermophysical characteristics is beneficial for obtaining a high thermal performance system. [ABSTRACT FROM AUTHOR]

The Hindon River is the main tributary of river Yamuna and it is a significant source of surface water, which flows through the major cities of western Uttar Pradesh, India. The indiscriminate development of industries and urbanization along river basin coupled with rapid population growths contribute various amounts of pollutant in the river. Therefore, the present study was conducted to assess the spatial–temporal variability of river water quality (seventeen physicochemical parameters and eight heavy metals) during pre- and post-monsoon seasons for 5 years data at 19 sampling sites along the river stretch. Indices associated with water quality and heavy metals were computed to scale the accurate state of risk associated to its use for drinking and irrigation. During the pre- and post-monsoon seasons, only four sites were found having safe water quality index (WQI) values. The mean heavy metal concentrations are found in order of Zn > Fe > Pb > Cu > Cr > Cd > Ni > Mn. Considering the spatial and temporal distribution, the study benchmarked the water quality of Hindon River for priority attention. [ABSTRACT FROM AUTHOR]

Irrational use of ofloxacin, a fluoroquinolone-based derivative, imparts harmful effects to the natural habitat and humans; hence, sorption and removal of such compounds can be of high primordial interest. Structural modifications on the edge and basal planes of reduced graphene oxide (rGO) account for its higher adsorption and removal rates for various pharmaceutical and organic contaminants. Thus, herein for the first time, we report the synthesis of reduced graphene oxide–copper oxide nanocomposite (rGO–CuO), decorated with 6-amino-5-nitroso-2-thiouracil (rGO@CuO/6A5N2TU). The heterostructure was fabricated using a combination of "sonochemical" and "hydrothermal" methods, wherein hydrothermally synthesized rGO–CuO nanocomposite was made to react with 6A5N2TU under ultrasonication to produce rGO@CuO/6A5N2TU. The obtained methodology provides sustainability and prevents the use of harsh chemicals during composite formation. Morphological assessment of rGO@CuO/6A5N2TU shows uniform deposition of 6A5N2TU as sharp needles over the rGO sheets at 100 nm scale, while the CuO deposition shows a flower-like arrangement over the surface of rGO, observed at 1 μm scale. The vibrational spectra of rGO@CuO/6A5N2TU confirm the presence of (N–H), (N=O), and (C=O) groups. The low D band and high G band intensities, obtained by Raman scattering, symbolize the restoration of pie network in rGO and a lesser number of surface functional groups. Moreover, XRD analysis shows high crystallinity and the presence of CuO and other oxygenated functional groups over the surface of rGO@CuO/6A5N2TU. Further, the fabricated metal centered heterostructure was explored for efficient removal of ofloxacin from contaminated water specimens. Batch adsorption modeling and modeled isotherm fitting experiments were done to elucidate the behavior of ofloxacin removal. The time-dependent decrease in the λmax value of ofloxacin in the presence of rGO@CuO/6A5N2TU was determined to estimate removal efficiency. Interestingly, we observed complete removal of ofloxacin at concentrations as low as 20 ppm within 120 min, with adsorption capacities ranging up to ~ 85.8 mg/g and a removal efficiency of ~ 86%. Moreover, the kinetic modeling demonstrates that the adsorption follows pseudo-second-order linear kinetics [R2 (~ 0.986)]. The ofloxacin adsorption on rGO@CuO/6A5N2TU fits well with the Langmuir adsorption isotherm, representing monolayer adsorption by the heterogenous substrate, i.e., a surface-oriented chemisorption. Further, the calculation of the thermodynamic parameter shows its spontaneous and exothermic nature, i.e., decreasing the system randomness during adsorption. Upon real sample analysis, the rGO@CuO/6A5N2TU is considered as an ideal adsorbing material with recyclability rates obtained up to seven cycles. Overall, we believe rGO@CuO/6A5N2TU acts as an ideal adsorbent material for the removal of antibiotics from water, limiting its pollution. The present system can be tested for the removal of other water-soluble antibiotic samples. [ABSTRACT FROM AUTHOR]

Wetlands are emitters of greenhouse gases. However, many of the wetlands remain understudied (like temperate, boreal, and high-altitude wetlands), which constrains the global budgets. Himalayan foothill is one such data-deficient area. The present study reported (for the first time) the greenhouse gas fluxes (CO2, CH4, N2O, and H2O vapor) from the soils of the Nakraunda wetland of Uttarakhand in India during the post-monsoon season (October 2020 to January 2021). The sampling points covered six different types of soil within the wetlands. CO2, CH4, N2O, and H2O vapor emissions ranged from 82.89 to 1052.13 mg m−2 h−1, 0.56 to 2.25 mg m−2 h−1, 0.18 to 0.40 mg m−2 h−1, and 557.96 to 29,397.18 mg m−2 h−1, respectively, during the study period. Except for CO2, the other three greenhouse gas effluxes did not show any spatial variability. Soils close to "swamp proper" emitted substantially higher CO2 than the vegetated soils. Soil temperature exhibited exponential relationships with all the greenhouse gas fluxes, except for H2O vapor. The Q10 values for CO2, CH4, and N2O varied from 3.42 to 4.90, 1.66 to 2.20, and 1.20 to 1.30, respectively. Soil moisture showed positive relationships with all the greenhouse gas fluxes, except for N2O. The fluxes observed from Nakraunda were in parity with global observations. However, this study showed that wetlands experiencing lower temperature regime are also capable of emitting a substantial amount of greenhouse gases and thus, requires more study. Considering the seasonality of greenhouse gas fluxes should improve global wetland emission budgets. [ABSTRACT FROM AUTHOR]

Rutin (3, 3′, 4′ 5 and 7-pentahydroxyflavone-3-rhamnoglucoside) is a flavonoid glycoside, found in many edible plants such as buckwheat and berries. Severe malaria is an inflammatory response triggered by oxidative stress that results in multi-organ pathologies and a high mortality rate in children and pregnant women worldwide. Rutin is recommended as a food supplement for the treatment of various diseases due to its anti-oxidative and anti-inflammatory properties, which prompted us to investigate its ameliorative effects in severe malaria pathogenesis against oxidative stress and inflammatory response using in vitro and in vivo bioassays. Rutin was examined in this work for its anti-plasmodial activity against chloroquine-sensitive and resistant Plasmodium falciparum strains, as well as its anti-oxidative and anti-inflammatory activity against LPS-stimulated macrophage cells. The in vitro data were subsequently verified in mice fed orally with rutin alone or in combination with chloroquine in Plasmodium berghei-induced malaria pathogenesis. The anti-plasmodial and anti-inflammatory properties of rutin were demonstrated in in vitro results. Apart from its anti-inflammatory and anti-oxidant effects in malaria pathogenesis, in vivo efficacy studies indicated that oral treatment with rutin reduced parasitaemia, increased mean survival time, and restored haemoglobin and glucose levels in mice at lower dose. Interestingly, both rutin and chloroquine demonstrated synergy in in vitro and in vivo experiments. The findings of the present study thus highlighted the suitability of rutin for further study in the management of drug resistant malaria in combination with standard anti-malarial drugs. [ABSTRACT FROM AUTHOR]

Aim: We estimated how seasonality in conjunction with key climatic variables affects morphological and physiological plant functional traits (PFTs) and soil essential (micro and macro) nutrients in oak, pine, and mixed forests. Method: The different PFTs were tested using several laboratory methods and using the portable photosynthesis system Li-COR 6400 XT, Lincoln NE, USA. Likewise, some chemical traits and soil nutrients were analyzed by using CHNS analyzer. Results: In this study, physiological traits such as CO2 assimilation rate, stomatal conductance and transpiration rate were significantly higher in the rainy season followed by summer and winter seasons. Among the different forest land uses, physiological traits and resource use efficiency have been significantly higher in oak forest (OF) compared to the mixed forest (MF) and pine forest (PF). Likewise, the concentration of macro–micro nutrients was also recorded higher during the rainy season. The concentration of macro–micro nutrients was higher in OF than in MF and PF in different forest land uses. Conclusion: Changes in PFTs ultimately affect the ecosystem services imparted by the different forests. Such changes lead to the local adaptation of these forests through the interaction between PFTs and soil nutrients. [ABSTRACT FROM AUTHOR]