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AbstractIn recent years, adhesive bonding has increasingly been used in many applications as it has many advantages over traditional joining techniques. More uniform stress distribution, absence of damage in the adhesive-bonded parts, high fatigue resistance, ease of manufacture, capability of fluid sealing, and the possibility of joining dissimilar materials are the advantages of adhesive bonding. This paper reviews the current research, advancements in adhesively bonded single lap joints (SLJs) and the related issues for joining different materials. The influence of various factors such as loading direction joint geometry, type of adhesive, type of adherend, joining technique, surface preparation technique, and environmental conditions on the bond properties of the adhesively bonded joints are also discussed. Different failure mechanisms associated with adhesive bonding are also highlighted. The geometry and method of manufacturing, surface preparation, and curing conditions significantly influence the strength of adhesively bonded joints. The combined surface treatment substantially affects the mode of failure in the adhesive joints. Among the different numerical methods, the cohesive zone modelling (CZM) approach can forecast the adhesive strength of joints for a wide range of designs with minimal error. Advanced numerical methodologies, such as the eXtended finite element method (XFEM) or meshless methods, have been utilized for adhesive joint analysis; however, further enhancements are requisite for their broader adoption. [ABSTRACT FROM AUTHOR]

Abstract Nanoporous green materials like nanozeolite has been in focus for their superb efficiency to treat industrial wastewater. The study reports ultrasound assisted hydrothermal method as a very fast method to convert industrial fly ash from different sources of eastern India to nanozeolite X for efficient removal of toxic dyes and metals from industrial effluent. The pure nanosized zeolite X was synthesized rapidly at 20 min of ultrasound treatment after alkali fusion. The efficiency of nanozeolite X was determined in terms of the adsorption capacity towards various divalent ions such as Zn2+, Cu2+, Cd2+, Pb2+, Ni2+, Ca2+, and Mg2+ as well as various dyes such as methylene blue, crystal violet, indigo carmine, and Congo red. In comparison to commercially available microporous Zeolite X (a maximum of 120.43 mg g−1 for Pb2+ and 134.62 mg g−1 by for methylene blue), all synthesized nanozeolite X shows high adsorption capacity for metals (a maximum of 196.24 mg g−1 for Pb2+) as well as dyes (193.45 mg g−1 for methylene blue). Highly pure nanozeolite X has shown immense potential for treatment of real time industrial wastewater. Graphical abstract Image 1 Highlights • Highly pure nanozeolite X synthesized by hybrid ultrasonic method from flyash. • Differently sourced power-plant fly-ash converted to zeolite X in 20 min. • High adsorption capacity of Nanozeolite X for divalent metals and dyes. [ABSTRACT FROM AUTHOR]

ABSTRACT Selective reduction of one of the nitro group present in dinitro aromatic compounds by a novel Zinin reagent, H2S-laden N-methyldiethanolamine (MDEA) solution, has been explored in the presence of tetra- n-butyl phosphonium bromide as a phase transfer catalyst under the liquid-liquid mode of reaction. Under the room temperature reaction condition, reduction of 2,4-dinitrotoluene (2,4-DNT) with H2S-laden MDEA leads to the selective reduction of one nitro group present either at the fourth position to obtain 4-amino-2-nitrotoluene (4A2NT) or at the second position to get 2-amino-4-nitrotoluene (2A4NT). The reaction was very fast to achieve 100% conversion, and the selectivity of 4A2NT is much higher than the 2A4NT. A detailed parametric study was performed to analyze the effect of parameters on 2,4-DNT conversion and selectivity of both the isomers. The apparent activation energy was found to be as high as 46.25 kJ/mol, and the reaction was found to be kinetically controlled. An empirical kinetic model has been developed to correlate with the conversion version time data obtained experimentally. The present system dealt with an industrial problem in dealing with H2S, present in by-product gaseous streams of many petroleum and natural gas industries. Novelties in the selective monoreduction lie in that fact that the reaction was done at room temperature (303 K), with a novel reagent, H2S-laden MDEA solution. Therefore waste-minimization was effected to yield value-added fine chemicals, that is, amines. [ABSTRACT FROM AUTHOR]

• Microalgal growth and nutrient depletion kinetics were simulated in bubble column PBR. • CFD simulations highlight the dependence of microalgal growth on PBR hydrodynamics. • Microalgal productivity of 0.14 g L−1 d-1 achieved with 5.5 % human urine and 4% CO 2. • Phosphate and ammonium removal of 90 % and 84 % was attained in PBR respectively. • Contours of water velocity and turbulent energy gave insights on PBR hydrodynamics. Optimization of microalgae cultivation to reduce the associated costs is one of the major objectives in a biorefinery model. The present study optimized the microalgal cultivation using 4.5–8.5 % v/v of DHU (diluted human urine) as a cost-effective resource, in a bubble column photobioreactor (BCPBR) under real-time conditions. Media with 5.5 % DHU and 4% CO 2 showed maximal biomass productivity of 0.14 g L−1 day−1 with a final concentration of 1.06 g L−1. Phosphate and ammonium removal of 90.70 % and 84.10 % respectively was achieved. The biofixation of CO 2 obtained for 6 days, during the cultivation in 5.5 % DHU, by supplying 4% of CO 2 enriched air was 0.29 g L-1 d-1. Computational fluid dynamics (CFD) simulations were used to study the effects of velocity magnitude, shear stress, turbulent kinetic energy, and irradiance on the microalgal growth inside the BCPBR. The developed kinetic model predicted the biomass concentration and phosphate removal up to 98 % and 82 % accuracy respectively. Such studies would aid in comprehending the large scale commercial cultivation and thereby facilitate the application of microalgae in the future. [ABSTRACT FROM AUTHOR]

Abstract Sono-assisted adsorptive elimination of dyes from industrial effluent is proved to be a fast, efficient and clean technique. Highly pure nanozeolite X (nFAZX) was synthesized from waste coal post-combustion fly ash (CFA) by pre-fusion hydrothermal method. Rapid sono-assisted adsorptive elimination of methylene blue (MB) dye from water solution was studied in presence nFAZX, CFA and commercial zeolite X (CZX). As-synthesized nFAZX, raw CFA, and CZX have been characterized by means of X-ray fluorescence (XRF), X-ray diffraction (XRD), fourier transform infrared (FTIR), transmission electron microscopy (TEM), field emission Scanning electron microscopy (FESEM), and Brunauer Emmett Teller (BET) adsorption/desorption isotherms for surface area analysis. The influence of adsorption variables, for example solution pH (3-11), adsorbent dose (0.05–0.25 g/100 ml), sonication time (2.50–12.50 min), and initial dye concentration (12.50–62.50 mg/L), on the % elimination of MB was explored by response surface methodology (RSM). Maximum MB removal (64.52% by CFA, 99.30% by nFAZX, and 96.57% by CZX) was obtained at pH 8.25, 0.164 g/100 ml of adsorbent, 9.92 min sonication time, and 25 mg/L MB concentration. The adsorption isotherms and kinetic models were best fitted with Langmuir isotherm and pseudo 2nd order model respectively for all three adsorbents. Also, the maximum Langmuir adsorption capacity of CFA, nFAZX and CZX for MB were 78.22 mg/g, 345.36 mg/g, and 250.41 mg/g respectively for 0.160 g/100 ml adsorbents. The experimentation demonstrated a route of development of a cheap, eco-friendly sorbent nFAZX as well as a green, rapid and highly efficient protocol of treating synthetic dyes which are often present in real textile wastewater. Graphical abstract Image 1 Highlights • Highly pure nanozeolite X (nFAZX) was synthesized from Indian coal fly ash (CFA). • CFA and nFAZX were characterized and compared with commercial 13X zeolite (CZX). • Rapid sono-assisted adsorptive removal of methylene blue (MB) dye using nFAZX. • The adsorption of MB on nFAZX given better than CFA and CZX. • The maximum adsorption capacity of MB on nFAZX was found 250.41 mg g-1 [ABSTRACT FROM AUTHOR]