Cooling by evaporation of flowing water over a hollow roof

This paper discusses the thermal modelling of the technique for cooling buildings by means of open evaporation of water over the roof. A comparative study of cooling by means of (i) a roof pond, (ii) a water spray and (iii) moving water over the roof is presented. The influences of parameters such as wind speed, relative humidity and water flow velocity on the performance of the system are numerically examined.     

Experimental Investigation of SLS Process for Flexural Strength Improvement of PA-3200GF Parts

The strength of functional parts is of key importance in additive manufacturing, and the selection of proper parameters is essential to improve manufacturing solutions. Therefore, research is currently focused on determining the influence of process parameters (i.e., part bed temperature, laser power, scan speed, and scan spacing) on the flexural strength of laser-sintered glass-filled polyamide specimens. A response surface methodology-based mathematical model was proposed to predict flexural strength, and the adequacy of the developed model was verified thorough the analysis of variance technique. Further, optimized conditions were established to maximize the output parameter through the desirability function approach.     

Tailoring Thickness of Conformal Conducting Polymer Decorated Aligned Carbon Nanotube Electrodes for Energy Storage

Aligned Carbon nanotubes (A‐CNT) based electrodes have emerged as high‐performance elements in electric energy storage and conversion devices. Morphological tailoring of conformal coatings of poly(ethylenedioxythiophene) (PEDOT) conductive polymer (CP) on the A‐CNT scaffold is demonstrated by controlling CP thickness at the nm scale. Results show that the CP nano‐films dominate the electrode capacitance in a supercapacitor application, contributing as much as 10x (pseudo)capacitance over the electric double layer of pristine A‐CNT due to volumetric vs. surface charge storage. Comparison to theoretical ion mobilities shows that the conformal CP films have active sites at ∼30% doping, indicating the CP quality is similar to thin films on flat substrates and that all these sites are accessed at all CP thickness values (up to 10 nm PEDOT thickness) and do not limit the rate of ion transport in and out of the CP film volume. Supercapacitor electrodes fabricated from these novel morphology‐controlled nanostructured composites provide a new route towards high‐performance next generation energy storage devices.     

Fabrication of quaternary composite scaffold from silk fibroin,chitosan, gelatin,and alginate for skin regeneration

Quaternary composite scaffold consisting of chitosan, alginate, gelatin, and silk fibroin, was fabricated by applying foaming method, for tissue engineering applications. The fabricated scaffold was evaluated for its applicability in skin tissue regeneration. The environmental scanning electron microscopy (ESEM) showed the presence of interconnected pores, mostly spread over the entire surface of the scaffold with mean pore size 92±11.8 μm and the porosity 88%. The scaffold showed good mechanical stability under physiological conditions as determined by short term mechanical stability testing. In vitro scaffold‐degradation study showed no degradation at day 1 and from day 3 scaffold starts degrading. The degradation of the composite scaffold after 28 days was 38%. Less degradation rate of the scaffold might be beneficial, as it can provide sufficient time for the formation of neo‐tissue and extracellular matrix (ECM) during tissue regeneration. In vitro cell culture studies by seeding L929 mouse fibroblast cells over composite scaffold showed good cell viability, proliferation, and adhesion as indicated by 3‐(4,5‐dimethylthiazol‐2‐yl‐2,5‐diphenyltetrazolium bromide) (MTT) assay and ESEM of cell‐scaffold construct. Giemsa staining of L929 fibroblast cells over the scaffold showed fibroblastic morphology of L929 cells, having elongated cells with nuclei and faint cytoplasm, and these cells are positive for Oil Red stain and negative for Alizarin Red staining—indicating that they maintained their dermal fibroblastic phenotype and were not differentiated into any other cell types in presence of composite scaffold. Results of histological staining supports growth and viability of L929 fibroblasts over scaffold, thereby proving the great prospective of this scaffold for skin tissue engineering applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42743.     

Present scenario and future scope of food waste to biofuel production

Food waste is the outcome of different food processing practices that have not been reused and are disposed of as waste. Food wastes are rich in a wide variety of organic constituents including starches, proteins, oils, fats, phosphates, nutrients, amino acids, and natural acids. Food waste is a zero-value and nonconsumable resource. In this context, the valorization of food waste to different sorts of biofuels, for example, biodiesel, bioethanol, biohydrogen, bio-oil, biochar, and biomethane by employing well-structured and efficient valorization technologies can be an attractive and viable approach to counter the current global energy crisis and in establishing a sustainable bioeconomy. This type of food waste management not only resolves the serious pollution problem but also helps to reduce the dependency of the energy sector on fossil fuels. This review discusses the characteristics of food waste, common strategies for food waste management, food waste as a feedstock, biofuels as a renewable energy source, valorization of food waste to various types of biofuels, microbes-assisted valorization of food waste, biofuels and bioeconomy, and future scope and challenges in the valorization of food waste to biofuels.     

Effect of packaging on quality attributes of functional cookies during storage

Bamboo shoot is a functional food due to the presence of biochemical components. Therefore, there exists a great opportunity especially, for the preparation of bamboo shoot powder and its utilization in food products as a therapeutic agent. The bamboo shoot powder and extracted bamboo dietary fiber were incorporated in cookies at 0% (Cookies with 100% refined wheat flour), 2%, 4%, 6%, 8%, and 10% level by supplementing refined wheat flour. The prepared cookies with different treatments were evaluated for sensory attributes. The treatment with the highest sensory scores was packed in low-density polyethylene (LDPE) pouches and polyethylene terephthalate (PET) jars. Changes in chemical (moisture, water activity, ash, crude fat, crude protein, total carbohydrate, and total dietary fiber) and sensory scores (appearance, texture, aroma, taste, and overall acceptability) of cookies were monitored during storage (17°C and 54% relative humidity for 90 days). Although, the cookies supplemented with 6% and 8% bamboo shoot powder and dietary fiber, respectively, can be stored in LDPE pouches and PET jars up to 90 days under ambient conditions, the quality retention was better in PET jars with minimal changes in quality.     

Effect of hybrid nanoparticles MgO and Al2O3 added water-in-diesel emulsion fueled diesel engine using hybrid deep neural network-based spotted hyena optimization

The automotive sector is one of the top energy consumers globally compared with any other sector where oil plays the main role. According to statista.com (an online platform that displays the stats on oil consumption and reserves), in 2016, the demand for crude oil was about 85.3 million barrels per day worldwide. In 2019, the demand almost reached 100 barrels per day, and then it was reduced to 91 million per day during the 2020 global COVID-19 crisis. However, it was predicted that the global crude oil requirements will exceed 100 million barrels per day by 2023 and will continue to raise. Also, geographically, not all countries worldwide have the oil reservoirs or the technology to extract oil from the reservoirs. Although the oil demand worldwide is increasing every year, researchers have estimated that there are only 47 years of oil left on the planet earth if the current oil consumption will raise this way. Researchers are looking for finding alternative fuels, such as electrochemical energy (electric vehicles), biodiesel, electricity, ethanol, hydrogen, natural gas, propane, emerging fuels, or the use of such fuels in the existing engines to minimize the use of nonrenewable energy resources. However, researchers are also looking more at fuels based on hybrid nanoparticles added to emulsified fuels. Due to the limitations of utilizing electrochemical energy or biofuels include high charging time, limited millage, harmful exhaust emissions, complicated production process, engine efficiency, the cost of fuel, and the advantages over hybrid nanoparticles added emulsified fuels than biofuels. Hence, after going through numerous researches, in this present experimentation, “hybrid nanoparticles (MgO and Al₂O₃) added water-in-diesel emulsion” are formulated to enhance the quality of emission and improve the performance of the compression ignition engine. The best combination of diesel, MgO, and Al₂O₃, a water-in-diesel (W/D) emulsion blend, is proposed. The results were further validated using deep neural network-based spotted hyena optimization (DNN-SHO) prediction and compared with traditional machine learning approaches artificial neural network (ANN), convolution neural network (CNN), regression-based network (RBN), recurrent neural network (RNN), and DNN. As a result, the best proportions of the proposed nanoparticles added into the W/D bend are identified to be 10% W/D, 50 ppm of MgO, and 50 ppm of Al₂O in terms of engine performance and emission characteristics brake thermal efficiency 30.7%, brake-specific fuel consumption 0.29 kg/kW-h, CO 0.027 vol%, NO_x 855 ppm vol, and HC 12 ppm vol. Besides this, the DNN-SHO-based validated outcomes are in good agreement with the experimental values and outperformed other traditional approaches ANN, CNN, RBN, RNN, and DNN used in this study.     

Modified stability analysis of double-diffusive convection in viscoelastic fluid layer saturating porous media

The present analysis mathematically investigates the thermohaline convection problem in viscoelastic fluid layer saturating porous media by utilizing the modified Boussinesq approximation. By performing linear stability analysis, the Darcy–Rayleigh numbers for stationary and oscillatory modes of convection are derived. The effects of different parameters describing the problem are studied numerically. In nonlinear stability analysis, the heat and mass transfer rates in the form of Nusselt and Sherwood numbers, respectively, are obtained for oscillatory convection using the derived Ginzburg–Landau equation. From the results, it is observed that overstability is the preferred mode of instability in linear stability. It is found that in linear double-diffusive convection problems, the stress relaxation imparts a destabilizing effect whereas the strain retardation time, the coefficient of specific heat variation due to temperature, and the concentration gradient have a stabilizing effect on the system's stability. The numerical values of heat and mass transfer rates varied with the coefficient of specific heat showing that the heat transport decreases while the mass transport increases. Also, the stress relaxation time, the concentration gradient, and the gravity modulation's amplitude increase while the strain retardation time decreases the heat and mass transfer rates. The wavelength of oscillations remains unaltered with the variation of specific heat variation due to temperature. The modulation frequency does not affect the heat/mass transfer rate; though, the wavelength of oscillations decreases with increasing frequency.