There has been a large amount of work on smart classrooms spanning over a wide range of research areas including information communication technology, machine learning, sensor networks, mobile ...computing, and hardware. Consequently, there have been several disparate reviews on various aspects of smart classrooms. Such piecemeal development is not sufficient for a pragmatic smart classroom solution. This article complements the literature by providing a consolidated review of interdisciplinary works under a common nomenclature and taxonomy. This multi-field review has exposed new research opportunities and challenges that need to be addressed for the synergistic integration of interdisciplinary works.
The present study explored the deposition of amorphous silicon carbide (a-SiC) thin films on Si (100) and glass substrates using RF-magnetron sputtering. The sputtering power is changed from 100 to ...250 W to study its influence on the characteristics of a-SiC thin films. Raman spectroscopy reveals the formation of a-SiC as well as carbon clusters. The film deposited at 100 W clearly shows the presence of both transverse optical (TO) and longitudinal optical (LO) phonon modes. The average roughness of the a-SiC films found to follow an increasing trend with increase in the sputtering power. The optical band gap of the a-SiC films measured by UV-Visible spectrophotometer was found to increase up to 2.45 eV with decrease in sputtering power. All a-SiC thin films were highly transparent. The Photoluminescence (PL) spectroscopy results were in agreement with the data observed by UV-Visible spectroscopy
•Reviewed resource recovery from organic solid waste towards bio-circular economy.•Aerobic and anaerobic digestion technology: a sustainable approach for biorefinery.•Organic solid waste: a potential ...biorefinery and bio-economy option.
With the inevitable rise in human population, resource recovery from waste stream is becoming important for a sustainable economy, conservation of the ecosystem as well as for reducing the dependence on the finite natural resources. In this regard, a bio-based circular economy considers organic wastes and residues as potential resources that can be utilized to supply chemicals, nutrients, and fuels needed by mankind. This review explored the role of aerobic and anaerobic digestion technologies for the advancement of a bio-based circular society. The developed routes within the anaerobic digestion domain, such as the production of biogas and other high-value chemicals (volatile fatty acids) were discussed. The potential to recover important nutrients, such as nitrogen through composting, was also addressed. An emphasis was made on the innovative models for improved economics and process performance, which include co-digestion of various organic solid wastes, recovery of multiple bio-products, and integrated bioprocesses.
MSMEs (Micro-small and Medium Enterprises) can alter the economic scenario of any developing nation owing to their inherent ability to transform new ideas into innovations and thus successful ...business enterprises. However transforming the socio-economic status of a developing country is not an easy task. Manufacturing organizations especially MSMEs need to focus on important enablers of innovation to sustain global competition. This study aims at identifying important enablers of technological innovation in the context of Indian MSMEs. Extant literature review and expert judgment are used to identify enablers of technological innovation. A novel multi-criteria decision making technique called best–worst method is applied to find out most important enablers among these. Research results indicate project resources and capabilities; technical know-how of entrepreneurs and government policies as most important enablers contributing significantly towards technological development of MSMEs.
•Thirteen enablers of technological innovation in MSMEs have been identified.•Best–worst multi-criteria technique has been used to rank enablers.•Project resources are most important for carrying out technological innovations in MSMEs.
Anaerobic digestion (AD) is a well-established technology used for producing biogas or biomethane alongside the slurry used as biofertilizer. However, using a variety of wastes and residuals as ...substrate and mixed cultures in the bioreactor makes AD as one of the most complicated biochemical processes employing hydrolytic, acidogenic, hydrogen-producing, acetate-forming bacteria as well as acetoclastic and hydrogenoclastic methanogens. Hydrogen and volatile fatty acids (VFAs) including acetic, propionic, isobutyric, butyric, isovaleric, valeric and caproic acid and other carboxylic acids such as succinic and lactic acids are formed as intermediate products. As these acids are important precursors for various industries as mixed or purified chemicals, the AD process can be bioengineered to produce VFAs alongside hydrogen and therefore biogas plants can become biorefineries. The current review paper provides the theory and means to produce and accumulate VFAs and hydrogen, inhibit their conversion to methane and to extract them as the final products. The effects of pretreatment, pH, temperature, hydraulic retention time (HRT), organic loading rate (OLR), chemical methane inhibitions, and heat shocking of the inoculum on VFAs accumulation, hydrogen production, VFAs composition, and the microbial community were discussed. Furthermore, this paper highlights the possible techniques for recovery of VFAs from the fermentation media in order to minimize product inhibition as well as to supply the carboxylates for downstream procedures.
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•Effectiveness of bamboo biochar on nutrient conservation was studied in composting.•Bamboo biochar (BB) notably elevated enzymes activities during co-composting.•Biochar amendment ...has positive and significant influence of C and N preservation.•Gaseous and environmental factors had intensively correlation with intersection of 68.81%.•10% BB addition has lowest C and N losses with 148.89% and 12.59%.
The effectiveness of specific concentrations of bamboo biochar (BB) on nutrient conservation based on gaseous emissions during poultry manure composting was investigated. The results indicate that the total carbon and nitrogen losses were significantly reduced with elevated of biochar from 542.8 to 148.9% and 53.5 to 12.6% (correspondingly with an additive of 0%, 2%, 4%, 6% and 8% to 10% BB dry weight based). The primary contributor was CO2 and NH3 losses (542.3–148.8% and 47.8–10.81%). The enzyme activities related to carbon and nitrogen metabolism indicated a positive and significantly enhanced with high concentration biochar amended composting. Simultaneously, the alteration of total organic carbon and total Kjeldahl nitrogen as well as maturity indexes during ultimate compost also confirmed a high quality product under higher content biochar amended composting. Carbon and nitrogen were best preserved with 10%BB and produced a superior final product. The analysis of a network and heat map illustrated the correlation of gaseous and physicochemical elements as well as enzyme activities, with an intersection of 68.81%.
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•Biodiesel is a renewable and ecofriendly biofuel.•It can be produced using transesterification, emulsification and pyrolysis process etc.•Enzyme catalyzed and biomass derived ...catalysts reactions are economic and ecofriendly.•Process intensification technology results in higher yield with lower wastes.
Biodiesel is a non-toxic renewable energy source that is gaining attention globally owing to its direct applicability in preexisting engines without any modification. Various technologies from laboratory scale to industrial scale have been developed, and many plants have been established for biodiesel production using various feedstocks. Using biobased technology in biodiesel production is advantageous as these methods generate less waste and are considered ecofriendly. This article mainly discusses the availability of various oil resources (edible, non-edible, waste cooking oils (WCO)) and the advancements in technology related to oil extraction. Specifically, biobased methods, such as immobilized enzymes (matrix) and heterogeneous catalysts (derived from biomass), reported to catalyze the transesterification reaction for biodiesel production are discussed in detail. Biodiesel production using conventional technologies results in low yield and purity and is time-consuming. Newly introduced process intensification technologies (microreactor, membrane reactor, microwave, reactive distillation, and centrifugal contractor) to overcome these issues are also discussed. The need to develop integrated process technologies for biodiesel production to make the process more economical is emphasized.
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•This review explores the potential of using a wide range of apple orchard waste (AOW).•Thermochemical and biological processes were assess towards to circular bioeconomy.•This review ...explores the potential for the use of AOW to produce multi bio-products.•The nature of AOW role in achieving successful circular bio economy is also highlighted.•Sustainable interventions with biorefineries approaches still need look for AOW.
In this review investigate the apple orchard waste (AOW) is potential organic resources to produce multi-product and there sustainable interventions with biorefineries approaches to assesses the apple farm industrial bioeconomy. The thermochemical and biological processes like anaerobic digestion, composting and , etc., that generate distinctive products like bio-chemicals, biofuels, biofertilizers, animal feed and biomaterial, etc can be employed for AOW valorization. Integrating these processes can enhanced the yield and resource recovery sustainably. Thus, employing biorefinery approaches with allied different methods can link to the progression of circular bioeconomy. This review article mainly focused on the different biological processes and thermochemical that can be occupied for the production of waste to-energy and multi-bio-product in a series of reaction based on sustainability. Therefore, the biorefinery for AOW move towards identification of the serious of the reaction with each individual thermochemical and biological processes for the conversion of one-dimensional providences to circular bioeconomy.
•Relative abundance of bacterial was richer in 6% pig manure biochar composting.•Phylogenetic tree and krona have confirmed the bacterial diversity variation.•Bacterial community had distinctive ...distribution among all five composts.•Biochar additive affected bacterial metabolism related to organic waste degradation.
The influence of pig manure biochar amendment (PMBA) during the pig manure (PM) and wheat straw (WS) composting was evaluated. Five concentration of PMBA (0%, 2%, 4%, 6% and10%) were applied to explore the bacterial distributions in PM compost by 16SDNA amplicons sequencing. The results showed that the addition of 6% PMBA could significantly enhanced the bacterial community abundance compared with other composts, while control has relative less bacterial population (332 OTU). The visualization of phylogenetic tree and krona demonstrated the distinctive distribution of each composts, suggested that biochar dosages have an influence on bacterial communities’ variation during co-composting. Beta-diversity of distance matrix heat-map and principal component analysis confirmed that bacterial communities were considerably correlated with increasing PMBA. Redundancy also confirmed the similarity and discrepancy among all treatments and environmental factors. This work considered as the potential of PMBA as a booster in composting, where T4 has most plentiful bacterial community and diversity.
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•Influence of biochar and bacterial inoculum amendment on cow dung composting was studied.•12% WSB and bacterial consortium (BC) has lowest carbon and nitrogen loss.•12% WSB and BC ...has highest bacterial population and degraded efficiency.•12%WSB + BC amendment is superior option for cow manure composting.•12%WSB + BC showed strong interrelation between bacterial community and physicochemical factors.
The present study evaluates the effectiveness of different types of biochar additives and bacterial inoculation on gaseous emission, nutrient preservation, and relevant functional bacterial community during cow manure composting. The result revealed that biochar and bacterial consortium inoculation effectively inhibited gaseous emission and improved carbon and nitrogen sequestration, remarkably enriching the abundance of the functional bacteria community. Notably, superior efficacy was found in 12% wheat straw biochar and bacterial consortium amendment composting of T6 with the lowest cumulative CO2-C and NH3-N (308.02 g and 12.71 g, respectively), minimal total C and N losses, and the highest bacterial population. Additionally, gaseous emission exhibited a strong correlation between physicochemical properties with intersection of 66.78% and a unique substrate utilizing bacterial communities. Consequently, the integrated application of biochar and bacterial consortium inoculation was suggested as an efficient method to adjust microbial activity and facilitate cellulose-rich waste degradation, enabling efficient management of organic waste from cow manure and wheat straw by composting.
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