Relationship Between Sports Policy, Policy Satisfaction, and Participation Intention During COVID-19 in Korea

This study aimed to identify the effect of trust in and contents of sports-related policies during COVID-19 on public policy satisfaction and examine the relationship between policy satisfaction and sports participation intention. People living in Korea were selected as the study population using convenience sampling, and 441 responses were collected using an online questionnaire. Data were analyzed using SPSS 23.0. The results indicated that policy trust had a positive effect on policy satisfaction in the order of consistency, expertise, and existing policy performance. In addition, social equity, market responsiveness, and policy effectiveness, which are sub-factors of policy content, had a positive effect on policy satisfaction. Furthermore, sports policy satisfaction had a negative effect on sports participation intention. This study suggests that the government should equally consider policy trust and content when establishing sports-related policies and strive to establish policies based on the positive functions of sports

Step-by-Step Hybrid Conversion of Glucose to 5-acetoxymethyl-2-furfural Using Immobilized Enzymes and Cation Exchange Resin

An alternative to 5-hydroxymethyl-2-furfural (HMF), which is a promising furan derivative that can be used as a starting material for the preparation of non-petroleum-derived polymeric materials from sugars, is 5-acetoxymethyl-2-furfural (AMF). The less-hydrophilic acetyl group of AMF has advantages over the hydroxy group of HMF in terms of thermal stability and isolation. In previous studies, fructose has been used as a starting material along with lipases for the enzymatic synthesis of AMF. In this study, we designed a hybrid synthesis system that includes the isomerization and esterification of glucose into AMF. For the step-by-step conversion of glucose to 1,6-diacetylfructose (DAF), glucose-isomerase and immobilized lipase (Novozym 435) were used as enzymes. Furthermore, for the synthesis of AMF, the direct dehydration of DAF was performed using a cation exchange resin (Amberlyst 15), combined with several industrial solvents, such as dimethylsulfoxide (DMSO), acetonitrile (AN) and dimethylformamide (DMF) for the synthesis of AMF. In order to improve the final yield of AMF, we determined the best solvent conditions. While the AMF yield after the direct dehydration of DAF in a single solvent was maximum 24%, an AMF and HMF yield in the mixed solvent such as dioxane and DMS (9:1) was achieved each 65% and 15%. According to these results, we found that the addition of dioxane in aprotic polar solvents could affect the dehydration reaction and dramatically improve the formation of AMF and HMF

Adsorption Strategy for Removal of Harmful Cyanobacterial Species Microcystis aeruginosa Using Chitosan Fiber

Microcystis aeruginosa is one of the predominant species responsible for cyanobacterial-harmful algal blooms (Cyano-HABs) in water bodies. Cyano-HABs pose a growing number of serious threats to the environment and public health. Therefore, the demand for developing safe and eco-friendly solutions to control Cyano-HABs is increasing. In the present study, the adsorptive strategy using chitosan was applied to remove M. aeruginosa cells from aqueous phases. Using a simple immobilization process, chitosan could be fabricated as a fiber sorbent (chitosan fiber, CF). By application of CF, almost 89% of cyanobacterial cells were eliminated, as compared to those in the control group. Field emission scanning electron microscopy proved that the M. aeruginosa cells were mainly attached to the surface of the sorbent, which was correlated well with the measurement of the surface area of the fiber. We tested the hypothesis that massive applications of the fabricated CF to control Cyano-HABs might cause environmental damage. However, the manufactured CF displayed negligible toxicity. Moreover, we observed that the release of cyanotoxins and microcystins (MCs), during the removal process using CF, could be efficiently prevented by a firm attachment of the M. aeruginosa cells without cell lysis. Our results suggest the possibility of controlling Cyano-HABs using a fabricated CF as a non-toxic and eco-friendly agent for scaled-up applications

Virtual reality and consumer behavior: constraints, negotiation, negotiation-efficacy, and participation in virtual golf

The emergence of virtual sports shows promises in encouraging participation among those who may be constrained from participating in traditional recreational sports (Choi et al., 2019). To maximize virtual sports’ potential in increasing sports participation, this study aimed to investigate the relationships between constraints, negotiation, negotiation-efficacy, and participation. Results from virtual golf participants found that, as predicted, (a) constraints had a negative direct influence on participation, (b) negotiation-efficacy had a negative direct influence on constraints, (c) negotiation-efficacy had a positive direct influence on negotiation, and negotiation had a positively direct influence on participation. The findings of this study indicated that reduced constraints did not result in increasing virtual golf consumers’ participation because negotiation did not play a significant role in their decision to participate. Thus, the current study provides a comprehensive understanding of interrelationships among leisure participation, constraints, and negotiation, particularly extending to the context of virtual golf

Improving Biosensors by the Use of Different Nanomaterials: Case Study with Microcystins as Target Analytes

The eutrophication of lakes and rivers without adequate rainfall leads to excessive growth of cyanobacterial harmful algal blooms (CyanoHABs) that produce toxicants, green tides, and unpleasant odors. The rapid growth of CyanoHABs owing to global warming, climate change, and the development of rainforests and dams without considering the environmental concern towards lakes and rivers is a serious issue. Humans and livestock consuming the toxicant-contaminated water that originated from CyanoHABs suffer severe health problems. Among the various toxicants produced by CyanoHABs, microcystins (MCs) are the most harmful. Excess accumulation of MC within living organisms can result in liver failure and hepatocirrhosis, eventually leading to death. Therefore, it is essential to precisely detect MCs in water samples. To date, the liquid chromatography–mass spectrometry (LC–MS) and enzyme-linked immunosorbent assay (ELISA) have been the standard methods for the detection of MC and provide precise results with high reliability. However, these methods require heavy instruments and complicated operation steps that could hamper the portability and field-readiness of the detection system. Therefore, in order for this goal to be achieved, the biosensor has been attracted to a powerful alternative for MC detection. Thus far, several types of MC biosensor have been proposed to detect MC in freshwater sample. The introduction of material is a useful option in order to improve the biosensor performance and construct new types of biosensors. Introducing nanomaterials to the biosensor interface provides new phenomena or enhances the sensitivity. In recent times, different types of nanomaterials, such as metallic, carbon-based, and transition metal dichalcogenide-based nanomaterials, have been developed and used to fabricate biosensors for MC detection. This study reviews the recent advancements in different nanomaterial-based MC biosensors

Green and Sustainable Hot Melt Adhesive (HMA) Based on Polyhydroxyalkanoate (PHA) and Silanized Cellulose Nanofibers (SCNFs)

Polyhydroxyalkanoate (PHA), with a long chain length and high poly(4–hydroxybutyric acid) (P4HB) ratio, can be used as a base polymer for eco-friendly and biodegradable adhesives owing to its high elasticity, elongation at break, flexibility, and processability; however, its molecular structures must be adjusted for adhesive applications. In this study, surface-modified cellulose nanofibers (CNFs) were used as a hydrophobic additive for the PHA-based adhesive. For the surface modification of CNFs, double silanization using tetraethyl orthosilicate (TEOS) and methyltrimethoxysilane (MTMS) was performed, and the thermal and structural properties were evaluated. The hydrophobicity of the TEOS- and MTMS-treated CNFs (TMCNFs) was confirmed by FT-IR and water contact angle analysis, with hydrophobic CNFs well dispersed in the PHA. The PHA–CNFs composite was prepared with TMCNFs, and its morphological analysis verified the good dispersion of TMCNFs in the PHA. The tensile strength of the composite was enhanced when 10% TMCNFs were added; however, the viscosity decreased as the TMCNFs acted as a thixotropic agent. Adding TMCNFs to PHA enhanced the flowability and infiltration ability of the PHA–TMCNFs-based adhesive, and an increase in the loss tangent (Tan δ) and adjustment of viscosity without reducing the adhesive strength was also observed. These changes in properties can improve the flowability and dispersibility of the PHA–TMCNFs adhesive on a rough adhesive surface at low stress. Thus, it is expected that double-silanized CNFs effectively improve their interfacial adhesion in PHA and the adhesive properties of the PHA–CNFs composites, which can be utilized for more suitable adhesive applications

Novel and Efficient Synthesis of Phenethyl Formate via Enzymatic Esterification of Formic Acid

Current methods for the production of esters, including chemical synthesis and extraction from natural sources, are hindered by low yields and environmental pollution. The enzymatic synthesis of these compounds could help overcome these problems. In this study, phenethyl formate, a commercially valuable formate ester, was synthesized using commercial immobilized lipases. The effects of specific enzymes, enzyme concentration, formic acid:phenethyl alcohol molar ratio, temperature, and solvent were studied in order to optimize the synthesis conditions, which were identified as 15 g/L of Novozym 435 enzyme, a 1:5 formic acid:phenethyl alcohol molar ratio, a 40 °C reaction temperature, and 1,2-dichloroethane as the solvent. Under these conditions, phenethyl formate was obtained in a conversion yield of 95.92%. In addition, when 1,2-dichloroethane was replaced with toluene as the solvent, the enzyme could be recycled for at least 20 reactions with a steady conversion yield above 92%, testifying to the economic aspects of the process. The enzymatic synthesis of phenethyl formate using the proposed method is more environmentally friendly than methods currently employed in academic and laboratory settings. Moreover, the method has the potential to enhance the value-added properties of formic acid owing to its downstream use in the production of commercially essential esters

Silver Nanowire Networks: Mechano-Electric Properties and Applications

With increasing technological demand for portable electronic and photovoltaic devices, it has become critical to ensure the electrical and mechano-electric reliability of electrodes in such devices. However, the limited flexibility and high processing costs of traditional electrodes based on indium tin oxide undermine their application in flexible devices. Among various alternative materials for flexible electrodes, such as metallic/carbon nanowires or meshes, silver nanowire (Ag NW) networks are regarded as promising candidates owing to their excellent electrical, optical, and mechano-electric properties. In this context, there have been tremendous studies on the physico-chemical and mechano-electric properties of Ag NW networks. At the same time, it has been a crucial job to maximize the device performance (or their mechano-electric performance) by reconciliation of various properties. This review discusses the properties and device applications of Ag NW networks under dynamic motion by focusing on notable findings and cases in the recent literature. Initially, we introduce the fabrication (deposition process) of Ag NW network-based electrodes from solution-based coating processes (drop casting, spray coating, spin coating, etc.) to commercial processes (slot-die and roll-to-roll coating). We also discuss the electrical/optical properties of Ag NW networks, which are governed by percolation, and their electrical contacts. Second, the mechano-electric properties of Ag NW networks are reviewed by describing individual and combined properties of NW networks with dynamic motion under cyclic loading. The improved mechano-electric properties of Ag NW network-based flexible electrodes are also discussed by presenting various approaches, including post-treatment and hybridization. Third, various Ag NW-based flexible devices (electronic and optoelectronic devices) are introduced by discussing their operation principles, performance, and challenges. Finally, we offer remarks on the challenges facing the current studies and discuss the direction of research in this field, as well as forthcoming issues to be overcome to achieve integration into commercial devices

Ethanol production from acid hydrolysates based on the construction and demolition wood waste using Pichia stipitis

The feasibility of ethanol production from the construction and demolition (C&D) wood waste acid hydrolysates was investigated. The chemical compositions of the classified C&D wood waste were analyzed. Concentrated sulfuric acid hydrolysis was used to obtain the saccharide hydrolysates and the inhibitors in the hydrolysates were also analyzed. The C&D wood waste composed of lumber, plywood, particleboard, and medium density fiberboard (MDF) had polysaccharide (cellulose, xylan, and glucomannan) fractions of 60.7-67.9%. The sugar composition (glucose, xylose, and mannose) of the C&D wood wastes varied according to the type of wood. The additives used in the wood processing did not appear to be released into the saccharide solution under acid hydrolysis. Although some fermentation inhibitors were detected in the hydrolysates, they did not affect the ethanol production by Pichia stipitis. The hexose sugar-based ethanol yield and ethanol yield efficiency were 0.42-0.46 g ethanol/g substrate and 84.7-90.7%, respectively. Therefore, the C&D wood wastes dumped in landfill sites could be used as a raw material feedstock for the production of bioethanol.clos