Climate change is a critical yield–limiting factor that has threatened the entire global crop production system in the present scenario. The use of biostimulants in agriculture has shown tremendous ...potential in combating climate change–induced stresses such as drought, salinity, temperature stress, etc. Biostimulants are organic compounds, microbes, or amalgamation of both that could regulate plant growth behavior through molecular alteration and physiological, biochemical, and anatomical modulations. Their nature is diverse due to the varying composition of bioactive compounds, and they function through various modes of action. To generate a successful biostimulatory action on crops under different parameters, a multi–
omics
approach would be beneficial to identify or predict its outcome comprehensively. The ‘
omics’
approach has greatly helped us to understand the mode of action of biostimulants on plants at cellular levels. Biostimulants acting as a messenger in signal transduction resembling phytohormones and other chemical compounds and their cross–talk in various abiotic stresses help us design future crop management under changing climate, thus, sustaining food security with finite natural resources. This review article elucidates the strategic potential and prospects of biostimulants in mitigating the adverse impacts of harsh environmental conditions on plants.
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•Thermal efficiency of solar collector increased using eco-friendly nanofluids with maximum improvement up to 24%.•Exergy efficiency increased with weight concentration of ...eco-friendly nanoparticles.•Maximum increase in friction factor was around 7.9% for 0.1% nanofluid than base fluid.•Relative pumping power slightly increases with increment in nanofluid concentration but is quite close to that of the base fluid.•Pay back period was 5.615% lesser using nanofluids than water.
The conventional method of synthesizing carbon-based nanofluids produces harmful products that are highly toxic and hazardous. The present investigation deals with the effects of using eco-friendly, non-corrosive, covalent functionalized Graphene Nanoplatelets with gallic acid (GGNPs) as heat transfer fluid on energetic and exergetic performance of a Liquid flat-plate solar collector (LFPSC). Long-term dispersible stable GGNP nanofluids with base fluid distilled water are prepared with different weight concentrations of 0.025%, 0.05% & 0.1%. For varying concentrations, fluid flow rates of 0.8, 1.2, and 1.5 L/min, heat flux intensities of 600, 800, and 1000 W/m2, and inlet temperature ranging from 303 to 323 K are considered for the conduction of experiments. Improvement in energy and exergetic efficiency was achieved using GGNP nanofluids. Thermal efficiency surges with increment in flow rate and heat flux intensities, meanwhile it decreases for increment in inlet temperature. The maximum enhancement in LFPSC efficiency is 24.09% for 0.1 wt% GGNPs and flow rate of 1.5 L/min than distilled water. Analysis of exergetic performance revealed that exergy efficiency reduces with a rise in mass flow rate meanwhile enhanced with an increase in nanofluid concentration. Exergy efficiency was maximum for 0.1% GGNP concentration and flow rate of 0.8 L/min. The maximum increase in friction factor values is approximately 1.5, 2.6 and 7.9% for 0.025, 0.05 and 0.1% GGNP nanofluids than distilled water. Relative pumping power slightly increases with the increment of GGNP concentration but is quite close to that of the base fluid. Performance index greater than one is obtained with higher values achieved at an increase in GGNP weight concentration. Economic consideration of GGNP nanofluids in LFPSC showcased a maximum reduction of 26.41% in the size of collector area using 0.1% GGNP nanofluid instead of distilled water. The payback period for LFPSC using GGNPs was 5.615% lesser than that of using water.
A sensing platform with NiFe2O4 nanoparticles integrated into carbon paste for the electrochemical determination of nitrite has been developed. Spinel NiFe2O4 nanoparticles were synthesised via a ...simple solvent deficient method and investigated by X-ray diffraction (XRD), Fourier transfer infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and Scanning electron microscopy (SEM), for their structural and morphological characteristics. The NiFe2O4 integrated carbon paste electrode (NiFe2O4-CPE) displayed enhanced catalytic activity towards oxidation of nitrite than the bare electrode in phosphate buffer solution (PBS) of pH-7 owing to the synergistic effect arising from the mixed metals. The electrochemical response of NiFe2O4-CPE under the influence of several parameters such as effect of scan rate, catalyst-carbon ratio and the concentration of analyte was studied. The oxidation of nitrite was found to be a diffusion controlled process as the oxidation currents varied linearly with scan rate and concentration of the analyte. The diffusion coefficient and rate constant for nitrite oxidation was found to be 3.71 × 10−5 cm2 s−1 and 9 × 108 cm3 mol−1 s−1 respectively. The sensing platform demonstrated a nitrite detection limit of 0.1236 μM (S/N = 3) with a wide linear range between 0.1 and 1000 μM and a sensitivity of 7.9617 μA μM−1 cm−2.
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•Spinel NiFe2O4 nanoparticles have been synthesised for the first time by mechanochemical solvent deficient method.•The synthesised NiFe2O4 is mesoporous with high surface area.•Electrochemical sensing of nitrite is studied at NiFe2O4 integrated carbon paste electrode.•The nitrite sensor has excellent sensitivity and low detection limit owing to synergistic activity of mixed metal oxides.
Synthesis of carbon-based working fluid involves toxic acids that are hazardous to the human and surrounding environment. In the current experimental investigation, thermal analysis of liquid flat ...plate solar collector was carried out using distilled water and environmentally friendly, covalent functionalized graphene nanoplatelets. Gallic acid was grafted on GNPs using the green free radical technique. Chemical characterization was analyzed using EDX and FESEM. Colloidal stability of GGNP nanofluids was found to be stable for more than 60 days. GGNPs were dispersed in distilled water with varying mass concentrations from 0.025 to 0.1%, and analysis was carried out for flow rate ranging from 0.5 to 1.5 L min
−1
for different heat flux intensities and inlet temperature. The thermal performance of LFP solar collector augments with the surge in GGNP concentration, flow rate and heat flux intensities, whereas declines with the increase in reduced temperature parameter. Maximum thermal efficiency enhancement of 21.48%, 16.06% and 12.36% is achieved using 0.1%, 0.05% and 0.025% GGNP nanofluid than distilled water. A penalty in the form of a slight surge in pressure drop and pumping power was observed with a subsequent increase in GGNP concentration. The maximum increase in pressure drop and pumping power was about 0.85% and 0.567% for 0.1% concentration and mass flow rate 1.5 L min
−1
. A maximum reduction of about 25% in the size of the LFP solar collector area is attained using 0.1% GGNPs than base fluid.
Maize is an important industrial crop where yield and quality enhancement both assume greater importance. Clean production technologies like conservation agriculture and integrated nutrient ...management hold the key to enhance productivity and quality besides improving soil health and environment. Hence, maize productivity and quality were assessed under a maize-wheat cropping system (MWCS) using four crop-establishment and tillage management practices FBCT-FBCT (Flat bed-conventional tillage both in maize and wheat); RBCT-RBZT (Raised bed-CT in maize and raised bed-zero tillage in wheat); FBZT-FBZT (FBZT both in maize and wheat); PRBZT-PRBZT (Permanent raised bed-ZT both in maize and wheat, and five P-fertilization practices P
(100% soil applied-P); P
+ 2FSP (50% soil applied-P + 2 foliar-sprays of P through 2% DAP both in maize and wheat); P
+ PSB + AM-fungi; P
+ PSB + AMF + 2FSP; and P
(100% NK with no-P) in split-plot design replicated-thrice. Double zero-tilled PRBZT-PRBZT system significantly enhanced the maize grain, starch, protein and oil yield by 13.1-19% over conventional FBCT-FBCT. P
+ PSB + AMF + 2FSP, integrating soil applied-P, microbial-inoculants and foliar-P, had significantly higher grain, starch, protein and oil yield by 12.5-17.2% over P
besides saving 34.7% fertilizer-P both in maize and on cropping-system basis. P
+ PSB + AMF + 2FSP again had significantly higher starch, lysine and tryptophan content by 4.6-10.4% over P
due to sustained and synchronized P-bioavailability. Higher amylose content (24.1%) was observed in grains under P
+ PSB + AMF + 2FSP, a beneficial trait due to its lower glycemic-index highly required for diabetic patients, where current COVID-19 pandemic further necessitated the use of such dietary ingredients. Double zero-tilled PRBZT-PRBZT reported greater MUFA (oleic acid, 37.1%), MUFA: PUFA ratio and P/S index with 6.9% higher P/S index in corn-oil (an oil quality parameter highly required for heart-health) over RBCT-RBCT. MUFA, MUFA: PUFA ratio and P/S index were also higher under P
+ PSB + AMF + 2FSP; avowing the obvious role of foliar-P and microbial-inoculants in influencing maize fatty acid composition. Overall, double zero-tilled PRBZT-PRBZT with crop residue retention at 6 t/ha per year along with P
+ PSB + AMF + 2FSP while saving 34.7% fertilizer-P in MWCS, may prove beneficial in enhancing maize productivity and quality so as to reinforce the food and nutritional security besides boosting food, corn-oil and starch industry in south-Asia and collateral arid agro-ecologies across the globe.
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•Different techniques involved in the green nanoparticle preparation are reviewed.•Factors affecting the preparation, properties of green nanoparticles are presented.•Green nanofluids ...as an alternative working fluid in thermal system are reviewed.•Toxicity, Economic and environmental impact of green nanofluids is discussed.•Key Challenges and future perspectives of green nanofluids are discussed.
An increase in energy demand is leading to the continuous rise in global temperature above pre-industrial levels with the discharges of toxic gases and radiations leading to severe climatical circumstances. Thus, it is mandatory to develop ever-lasting, highly efficient thermal systems to overcome this issue. Scientific works on different nanofluids for enhancing performance in thermal applications have gained attention significantly over the last few years owing to their superior qualities. However, it increases safety and health concerns as they are generally more reactive in solvents. Also, other undesired effects such as corrosion of the equipment, non-biodegradable byproducts occur due to the presence of strong chemicals. Therefore, developing cost-effective, and eco-friendly nanofluids has emerged as an alternate research area that is rapidly growing with a great deal of interest. The current review gives a comprehensive view of the different techniques utilized in the preparation of green nanofluids using several natural extracts. Unique morphology, optical properties, stability, high surface area, less toxicity, and enhanced thermo-physical properties of green nanoparticles makes them a favorable candidate in enhancing the performance of thermal systems. Further, various factors affecting the preparation of green nanofluids are highlighted in addition to the evaluation and enhancement techniques concerning the stability and thermophysical properties. Recent experimental and numerical works on the effect of green nanofluids in thermal systems are critically analyzed and provide an overview from economic and environmental perspectives. The challenges and future developments are highlighted to ensure safer health and environment using nanofluids.
Conventionally tilled maize–wheat cropping system (MWCS) is an emerging cereal production system in semi-arid region of south-Asia. This system involves excessive tillage operations that result in ...numerous resource- and production-vulnerabilities besides impeding environmental-stresses. Likewise, phosphorus is a vital nutrient that limits crop growth and development. It’s a matter of great concern when ∼80% of Indian soils are low to medium in available-P due to its sparing solubility, resulting in crop stress and low yields. Hence, crop productivity, photosynthetic parameters and resilience to nutritional and environmental stresses were assessed in a MWCS using four crop-establishment and tillage management (CETM) practices FBCT-FBCT (Flat bed-conventional tillage both in maize and wheat); RBCT-RBZT (Raised bed-CT in maize and raised bed-zero tillage in wheat); FBZT-FBZT (FBZT both in maize and wheat); PRBZT-PRBZT (Permanent raised bed-ZT both in maize and wheat), and five P-fertilization practices P
100
(100% soil applied-P); P
50
+2FSP (50% soil applied-P + 2 foliar-sprays of P through 2% DAP both in maize and wheat); P
50
+PSB+AM-fungi; P
50
+PSB+AMF+2FSP; and P
0
(100% NK with no-P) in split-plot design replicated-thrice. The results indicated that double zero-tilled PRBZT–PRBZT system significantly enhanced the grain yield (6.1; 5.4 t ha
–1
), net photosynthetic rate (Pn) (41.68; 23.33 μ mol CO
2
m
–2
s
–1
), stomatal conductance (SC) (0.44; 0.26 mol H
2
O m
–2
s
–1
), relative water content (RWC) (83.3; 77.8%), and radiation-use efficiency (RUE) (2.9; 2.36 g MJ
–1
) by 12.8–15.8 and 8.5–44.4% in maize and wheat crops, respectively over conventional tilled FBCT–FBCT. P
50
+PSB+AMF+2FSP conjugating soil applied-P, microbial-inoculants and foliar-P, had significantly higher Pn, SC, RUE and RWC over P
100
besides saving ∼34.7% fertilizer-P under MWCS. P
50
+PSB+AMF+2FSP practice also had higher NDVI, PAR, transpiration efficiency and PHI over P
100
. Whereas lower stomatal limitation index (Ls) was observed under PRBZT–PRBZT system as compared to the conventional FBCT–FBCT system indicating that P is the limiting factor but not stomata. Hence, optimum P supply through foliar P-fertilization along with other sources resulted in higher grain yield by 21.4% over control. Overall, double zero-tilled PRBZT–PRBZT with crop residue retention at 6 t/ha per year, as well as P
50
+PSB+AMF+2FSP in MWCS, may prove beneficial in enhancing the crop productivity and, thereby, bolstering food security in semi-arid south-Asia region.
Introduction: The treatment of dental tissues before adhesive restorative procedures is an important step in the bonding protocol and determines the clinical success of restorations. Aim: The aim of ...this study is to evaluate in vitro the influence of diode laser on the shear bond strength of one- and two-step self-etch (SE) adhesives to dentin when the laser is applied over the adhesives before photopolymerization. Methodology: About 20 freshly extracted noncarious intact maxillary premolars were collected, and the buccal and lingual surfaces of the tooth were ground with the help of diamond disk under water coolant till dentin was exposed. The specimens were divided into two groups of 10 each. Buccal surfaces of all the specimens were exposed to diode laser before light curing (test/experimental group) act as control group. In Group I, Clearfil SE with laser was used on the buccal surface, whereas in Group II, G-bond SE adhesive with laser was used on the buccal surface. Shear bond test was measured using an universal testing machine and the values were obtained in megapascals (MPa). Results: P < 0.05 was considered statistically significant. According to the results, it was found that the mean bond strength values of the laser-treated groups were significantly higher than groups not treated with laser. Conclusion: Within the limitations of this study, it can be concluded that mean bond strength Clearfil SE with and without laser was significantly higher than G-bond with and without laser values.
The concomitant quandaries of pedospheric health deterioration and diminishing factor productivity constitute the preeminent apprehensions within the realms of crop cultivation, particularly in the ...densely populated South Asian region. Conventional tillage practices, coupled with indiscriminate fertilizer application in wheat-based rotations, precipitate the degradation of natural resource bases, thereby posing an ominous threat to the rice-wheat cropping system (RWCS) prevalent in the Indo-Gangetic plains (IGP). Nonetheless, the adoption of zero-tillage (ZT) techniques, co-implemented with the judicious dispensation of nutrients through precision nutrient management (PNM), holds the potential to mitigate nutrient losses, curtail environmental ramifications, and augment the overall sustainability of wheat cultivation within the RWCS paradigm. Hence, efforts were made to investigate the impact of PNM on productivity, use efficiency of nutrients (NtUE), root morphology, soil enzymatic activities, and the N2O fluxes in ZT-wheat (ZT-W). The treatments were soil test-based NPK (STB-NPK), Nutrients Expert (NE)-based NPK NE-(LCCN) NPK, recommended doses of fertilizer (RDF), state recommendation-based NPK, and their nutrients omission treatments, together with consisted of twelve treatments. The result revealed that the PNM practices, like Nutrient Expert + Leaf colour chart (LCC)based NPKNE-(LCCN) NPK co-implemented with ZT significantly (p<0.05) improved the grain yield by (8.05 %), and nutrient use efficiency (NUE) by 58.1 %) but STB-NPK produce ∼ 17.1 % higher grain yield than the RDF. The application of balanced nutrients in ZT-wheat using NE-(LCCN) NPK reduced the cumulative seasonal N2O emission by 19.5 % over RDF, whereas, STB-NPK increased the N2O emission by 26.2 % over RDF, due to the substantial application of N-fertilizer. Similarly, the root length density (RLD), root surface area density (RSAD) and root volume density (RVD) of wheat were found greater under STB-NPK and NE-(LCCN) NPK than the RDF. Furthermore, the soil enzymatic activity was considerably enhanced due to PNM in the ZT-wheat system compared to the remaining treatments. The STB-NPK, and NE-(LCCN) NPK, also improved the crop yield, and photo-synthetically active radiation (PAR) through greater leaf area index (LAI) besides other soil-based parameters of wheat. The NE-(LCCN) NPK notably improves NtUE, and minimises the GHGs emission than the others. Hence, the nutrient applied through NE-(LCCN) NPK could enhance the yields, soil properties, and nutrient use efficiencies besides reducing GHGs emissions, thereby, sustaining cereal-based system in the long run.
•Conjugation of ZT and PNM enhances nutrient use efficiency and yield of wheat.•Improved nutrient use efficiency leads to reduce N2O fluxes.•ZT coupled with nutrients (i.e. P) helped to develop root morphology.•PNM in ZT-system improved crop foliage and harness more solar radiation.•Improved SOC helped to improve soil enzymatic activity in ZT-system.
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