169 research outputs found
THE SUSTAINABLE MANAGEMENT PERSPECTIVE OF DAIRY COMMITTEE AND FARMERS: CASE STUDY OF THE THAI-DANISH (MITTRAPHAP) DAIRY CO-OPERATIVE LIMITED
This study aims to discover factors, indicators, and framework for the sustainable management of the dairy businesses under the daily co-operative. Purposive sampling technique was operated to select samples from the Thai-Danish (Mittraphap) Dairy Co-operative Limited, Muak Lek district, Saraburi province. Primary data were collected with focus group technique together with the secondary data of the past three yearâs meeting minutes. There were 15 people in the focus group which could be divided into two groups: six co-operative commissions and nine daily farmers. The results revealed four factors of sustainable management of daily businesses. They are (1) the role of co-operative commission, including good governance and teamwork which is the most important factor, (2) the role of the co-operative which includes negotiation power, production factor acquisition, training and development, risk management, and adjustment with the competition, (3) the role of member which includes concise mind and teamwork, (4) the role of government which includes promotion and supporting from the government. There are four successful indicators for daily business management, (1) the growth in operating results which includes the amount of raw milk and the quality of raw milk, (2) the ability to make a profit which includes net profit, return on shareholder ratio, cost of improving the quality of raw milk, and interest rate, (3) co-operative reputation which is reward received by the co-operative, and (4) the strengthening of members. The factors and indicators were used to create a framework for managing sustainable dairy business
Formation of artificial pores in nano-TiO2 photo-electrode films using acetylene-black for high-efficiency, dye-sensitized solar cells
Acetylene-black paste without a light scattering layer was applied to meso-porous TiO2 photo-electrode films with a crystalline framework, a low residual carbon, and a tunable morphological pore size. The thermal-treated TiO2 photo-electrode films had an increased acetylene-black concentration with an increase in artificial pores and a decrease in residual carbon. The performance of dye-sensitized solar cells (DSSCs) was enhanced by the use of the TiO2 photo-anode pastes at various acetylene-black concentrations. The photo-conversion efficiency of the DSSCs using TiO2 photo-electrode films with 1.5 wt% acetylene-black was enhanced from 7.98 (no acetylene-black) to 9.75% without the integration of a light-scattering layer.open5
CFD Investigation of the Impacts of Variation in Geometry of Twisted Tape on Heat Transfer and Flow Characteristics of Water in Tubes
An International Study on Psychological Coping During COVID-19: Towards a Meaning-Centered Coping Style
Background/Objective
This study examined the role of different psychological coping mechanisms in mental and physical health during the initial phases of the COVID-19 crisis with an emphasis on meaning-centered coping.
Method
A total of 11,227 people from 30 countries across all continents participated in the study and completed measures of psychological distress (depression, stress, and anxiety), loneliness, well-being, and physical health, together with measures of problem-focused and emotion-focused coping, and a measure called the Meaning-centered Coping Scale (MCCS) that was developed in the present study. Validation analyses of the MCCS were performed in all countries, and data were assessed by multilevel modeling (MLM).
Results
The MCCS showed a robust one-factor structure in 30 countries with good test-retest, concurrent and divergent validity results. MLM analyses showed mixed results regarding emotion and problem-focused coping strategies. However, the MCCS was the strongest positive predictor of physical and mental health among all coping strategies, independently of demographic characteristics and country-level variables.
Conclusions
The findings suggest that the MCCS is a valid measure to assess meaning-centered coping. The results also call for policies promoting effective coping to mitigate collective suffering during the pandemic
Application of mesoporous magnetic nanosorbent developed from macadamia nut shell residues for the removal of recalcitrant melanoidin and its fractions
A novel mesoporous magnetic nanosorbent developed from macadamia nut shell residues was applied as an adsorbent for the removal of dissolved organic carbon (DOC) associated with melanoidin and its fractions in a batch system. The most favored molecular fraction of the melanoidin for adsorption onto the nanosorbent was 1â5 kDa with adsorption capacity of 10.26 mg DOC gâ1 achieving 68.4% removal efficiency. The sorption behaviors were all well fitted to a pseudo-second-order kinetic model and Langmuir isotherm. Optimum operating conditions needed for the maximum uptake of 14.7 mg DOC gâ1 were found to be pH of 6.3, temperature of 41.7°C at the dosage of the magnetic nanosorbent of 877.7 ppm
Mesoporous activated carbon-zeolite composite prepared from waste macadamia nut shell and synthetic faujasite
Novel activated carbon-zeolite composite adsorbent was prepared from macadamia shell bio-waste and synthetic zeolite X using hydrothermal treatment. Characterization studies revealed mainly mesoporous structure with 418 m2 g-1 BET surface area with faujasite clusters on the carbon carrier. Sorption capacity for methylene blue model pollutant increased from 85 to 97 mg g-1 with the temperature increase from 25 to 45 oC, and improved with increasing pH. Nonlinear regression analyses found accurate fit to the pseudo-first-order kinetics model and intra-particle diffusion rate controlling mechanism. Excellent fits to the Jovanovic isotherm model indicated monolayer coverage on chiefly homotattic surfaces with variable potential. The thermodynamic analysis confirmed spontaneous and endothermic physisorption process. The spent adsorbent was regenerated with 20% capacity loss over five reuse cycles.Although the adsorbent was developed for ammonia, heavy metal and organic matter removal from water sources, the results also indicate good performance in cationic dye removal from wastewaters
Removal of natural organic matter and ammonia from dam water by enhanced coagulation combined with adsorption on powdered composite nano-adsorbent
Enhanced coagulation and adsorption were investigated in separate and combined processes to alleviate problems created by high levels of NOM (15 mg L-1) and ammonia (2.5 mg L-1 NH4-N) in dam water. Raw water acidification to pH 6.2 with optimised enhanced coagulation in jar tests achieved effective (68%) DOC reduction and satisfactory residual turbidity, aluminium, and colour, however removed only 5% ammonia. Adsorption on the nano-adsorbent (termed ACZ) led to 45% DOC reduction and excellent 58% ammonia removal in 30 minutes. Concurrent enhanced coagulation and complementary adsorption using only 80 mg L-1 alum and 150 mg L-1 ACZ doses showed high performance with 76% ammonia, 90% DOC, and 95% trihalomethanes formation potential (THMFP) reduction in 20 minutes time. Concurrent treatment can be simply implemented utilising readily available rapid mixers and flocculators, and operated on demand. Pre-adsorption and consecutive enhanced coagulation using the same alum and ACZ doses resulted in slightly better DOC but reduced (61%) ammonia removal. The results showed that concurrent treatment could safely resolve a challenging operational problem. ACZ combines the distinct advantages of zeolite and activated carbon in a single product, and may find additional uses in removing taste and odour, heavy metals, and synthetic organic matter from ground and surface waters
Pre-treatment of Acetic Acid from Food Processing Wastewater Using Response Surface Methodology via Fenton Oxidation Process for Sustainable Water Reuse
This study designed to optimize the operating parameters of the Fenton process in removing acetic acid from food processing using Response Surface Methodology module in the Design of Expert for sustainable water reuse. Optimum operating conditions needed for the highest removal efficiency of 95.2% and 84.7% for color and chemical oxygen demand respectively were found to be at hydrogen peroxide concentration of 0.004 mol/L, ferrous iron concentration of 0.02 mol/L, initial pH of 3.45, and reaction time of 149.08 min for color. While, chemical oxygen demand had a maximum of around 84.7% removal efficiency that could be obtained at a hydrogen peroxide concentration of 0.014 mol/L, ferrous iron concentration of 0.051 mol/L, initial pH of 2.04, and reaction time of 144.58 min. The results showed that the Fenton process via Response Surface Methodology, at a certain level, may be used as a useful technology for pre- and post-treatment of wastewater from food processing for water scarcity as reclaimed water
Use of macadamia nut shell residues as magnetic nanosorbents
Nanosorbents have been increasingly used for targeted contaminant removal; however, handling and separation of spent sorbents from treated water remains a challenge. To address these drawbacks, a hybrid magnetic nanosorbent was prepared from waste macadamia nut shell and magnetite nanoparticles. The novel nanosorbent had primarily meso- and macroporous structure with 70 m2 gâ1 specific surface area. Batch sorption tests using methylene blue model pollutant found sorption capacities increasing from 33 to 42 mg gâ1 with temperature in the 25â45 °C range. Nonlinear regression analyses found that process kinetics was accurately described by a fractal-like pseudo first order model. The isotherms showed excellent fits to the Langmuir model and implied monolayer adsorption mechanism. The thermodynamic parameters confirmed that the process was spontaneous, endothermic, and involved physisorption. The point of zero charge was 7.4, which is advantageous in the removal of anionic aquatic pollutants. The ferrimagnetic sorbent had 48 emu gâ1 saturation and 0.65 emu gâ1 remanence that allowed easy handling and rapid separation by magnetic field. Spent sorbents were effectively regenerated by acidic wash for subsequent reuse over four cycles. The intrinsic characteristics of the magnetite/carbon nanosorbent befit tailored water and wastewater treatment applications
Numerical Investigation of Flow Friction and Heat Transfer in a Channel with Various Shaped Ribs Mounted on Two Opposite Ribbed Walls
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