• Asian-Australasian Journal of Animal Sciences
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• v.28 no.6
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• pp.807-815
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• 2015

The present study aimed at evaluating the intensity of Tifton 85 conditioning using a mower conditioner with free-swinging flail fingers and storage times on dehydration curve, fungi presence, nutritional value and in vitro digestibility of Tifton 85 bermudagrass hay dry matter (DM). The dehydration curve was determined in the whole plant for ten times until the baling. The zero time corresponded to the plant before cutting, which occurred at 11:00 and the other collections were carried out at 8:00, 10:00, 14:00, and 16:00. The experimental design was randomised blocks with two intensities of conditioning (high and low) and ten sampling times, with five replications. The high and low intensities related to adjusting the deflector plate of the free iron fingers (8 and 18 cm). In order to determine gas exchanges during Tifton 85 bermudagrass dehydration, there were evaluations of mature leaves, which were placed in the upper middle third of each branch before the cutting, at every hour for 4 hours. A portable gas analyser was used by an infrared IRGA (6400xt). The analysed variables were photosynthesis (A), stomatal conductance (gs), internal $CO_2$ concentration (Ci), transpiration (T), water use efficiency (WUE), and intrinsic water use efficiency (WUEi). In the second part of this study, the nutritional value of Tifton 85 hay was evaluated, so randomised blocks were designed in a split plot through time, with two treatments placed in the following plots: high and low intensity of cutting and five different time points as subplots: cutting (additional treatment), baling and after 30, 60, and 90 days of storage. Subsequently, fungi that were in green plants as well as hay were determined and samples were collected from the grass at the cutting period, during baling, and after 30, 60, and 90 days of storage. It was observed that Tifton 85 bermudagrass dehydration occurred within 49 hours, so this was considered the best time for drying hay. Gas exchanges were more intense before cutting, although after cutting they decreased until ceasing within 4 hours. The lowest values of acid detergent insoluble nitrogen were obtained with low conditioning intensity after 30 days of storage, 64.8 g/kg DM. The in vitro dry matter of Tifton 85 bermudagrass did not differ among the storage times or the conditioning intensities. There was no fungi present in the samples collected during the storage period up to 90 days after dehydration, with less than 30 colony forming units found on plate counting. The use of mower conditioners in different intensities of injury did not speed up the dehydration time of Tifton 85.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.3
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• pp.123-129
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• 2021

Purpose: The purpose of this study was to investigate antifungal activity of shiitake mushroom yeast and hyphal type of Candida albicans. Materials and Methods: The extract from shiitake mushroom was collected by drying the supernatant after soaking shiitake mushrooms in water or ethanol. The antifungal activity of the extracts against yeast type of C. albicans was investigated by the susceptibility assay using microplate. C. albicans biofilm was formed on 12-well plate using Ham's F-12 medium in CO₂ incubator and treated with the ethanol extract. Furthermore, C. albicans biofilm was formed on denture base resin disk and treated with or without the ethanol extract in the presence of denture cleanser. Live C. albicans in biofilm was counted by cultured colony forming unit value after inoculated on agar plate. Results: Ethanol extract from shiitake mushroom showed stronger antifungal activity against yeast type of C. albicans compared to its water extract. The ethanol extract significantly reduced count of C. albicans in hyphal biofilm (P < 0.05). Also, the ethanol extract showed synergistically antifungal effect with denture cleanser on candidal biofilm on denture base resin disk (P < 0.05). Conclusion: The ethanol extract of shiitake mushroom may be a candidate for preventing candidal stomatitis as well as denture-related stomatitis.

• Journal of Environmental Health Sciences
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• v.38 no.3
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• pp.241-250
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• 2012

Objectives: This study was performed to investigate hygienic behavior of food handlers and general population focusing on awareness of hand-washing and the microbial load of their hands. Methods: A questionnaire survey and microbiological analysis were carried out for sixty-four people each. Samples for microbiological analysis were collected through the glove-juice method from the hands, and were analyzed for the presence of aerobic plate counts, total coliform, fecal coliform, Escherichia coli, Staphylococcus aureus, and Salmonella spp. according to the Food Code of Korea. Results: In the survey, significant differences between the food handlers and general population (p < 0.01) were found in hand-washing frequency, duration, use of hand-washing agents, washing parts of hands, hand-drying method, and method of turning off water. In eight different situations among the ten particular situations in their daily life, more food handlers responded to wash their hands than general population (p < 0.05). Bacterial load on hands with general population was consistently higher than with food handlers (p < 0.05), however, percentages of positive hands of S. aureus and Salmonella spp. were not. Conclusions: Poor hand hygiene practices were indicated by the positive results for E. coli, S. aureus, and Salmonella spp. on the hands of some respondents in both groups. This study reveals that there is the need for programs or campaigns to increase hand-washing practices of both groups.

• Macromolecular Research
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• v.17 no.5
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• pp.332-338
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• 2009

Rheological behavior of natural hydrogel produced from seeds of three Salvia spp. (S. miltiorrhiza (SM), S. sclarea (SS), S. viridis (SV)) was investigated by using a Rheometer equipped with a cone and plate geometry measuring system under never-dried condition. Different chemical contents of such hydrogels give significant effects on their rheological properties. Because of incomplete penetration of water inside the hydrogels after drying before-dried hydrogels were used for rheological analysis. To know molecular interactions which predominated in the gel formation, some constituents were externally added to the 1.0% (w/w) hydrogel. Addition of urea to disrupt hydrogen bonds reduced 3.4-67% viscosity of the untreated hydrogels and changed viscoelastic properties from gel to liquid-like behavior. Neutral salts added to the hydrogel solution at 0.1 M also lowered the viscosity in a manner related with increase in size of cations and temperature. Changing from gel state to liquid-like state was also easily confirmed by oscillation measurement (storage, G', and loss, G", modulii) typically observed in the cases of potassium sulfate and potassium thiocyanate. Influence of pH variation on the viscosity explained that weak alkaline condition (pH 8-9) creates a higher resistance to flow due to increasingly electrostatic repulsions between negative charges ($COO^-$) Importance of calcium bridges was also demonstrated by recovery of viscosity of the hydrogels by addition of calcium after acidification. The summarized results indicate that electrostatic repulsion is a major contributor for production of hydrogel structure.

• Journal of the Korean Ceramic Society
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• v.50 no.2
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• pp.142-148
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• 2013

Conventional cold isostatic pressing, slip casting, and filter pressing are not completely suitable for fabricating large plates because of disadvantages such as the high cost of equipment and formation of density gradient. These problems could be avoided by employing pressure-vacuum hybrid slip casting (PVHSC). In the PVHSC, the consolidation occurs not only by the compression of the slip in casting room, but also by vacuum sucking of the dispersion medium around the mold. We prepared the alumina bodies by the PVHSC in a static- or stepwise-pressure manner for loading up to 0.5 MPa using an aqueous slip. The green bodies were dried at $30^{\circ}C$ with 40 ~ 80% relative humidity. Under static pressure, casting induced a density gradient in the formed body, resulting in cracking and distortion after the firing. However, the stepwise pressure loading resulted in green bodies with homogeneous density, and the minimization of the appearance of those defects in final products. Desirable drying results were obtained from the cast bodies dried with 80% RH environment humidity. When sintered at $1650^{\circ}C$ for 4 h, the alumina plate made by stepwise-pressure casting reached full density (> 99.7% relative density).

• Journal of Environmental Health Sciences
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• v.36 no.2
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• pp.95-107
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• 2010

Hand-washing is one of the major factors in personal hygiene and public health. This study was undertaken to investigate the hygienic behavior of food-service employees, focusing on awareness of hand washing, hand washing practices, and the load of index microorganisms (aerobic plate count, total and fecal coliforms, Escherichia coli, and Staphylococcus aureus) on the hands of food-service employees. A questionnaire survey completed by direct interview, direct observation of restrooms by the researcher and trained observers, and microbiological examination according to the Food Code of Korea were carried out. In the survey, a positive attitude toward hand washing compliance was reported; however, improper hand washing and poor hand hygiene of the food-service employees were seen under direct observation. Significant differences (p<0.05) were found between the questionnaire survey and the direct observations in hand washing compliance after using the toilet, duration of hand washing, use of hand washing agents, use of hand washing tools, washing of different parts of the hands, hand-drying method, temperature of water, and method of turning off the water. Samples taken from employees' hands before washing showed higher levels of bacteria than those taken during work and/or after washing (p<0.05). Poor hand washing practices were indicated by the positive results for total and fecal coliforms, E. coli, and S. aureus on the hands of some food-service employees. This study showed that there is a marked difference between the food-service employees' awareness of hand-washing and their actual hand-washing practices. The poor hand hygiene of and improper hand washing by the food-service employees should be addressed for improved food safety.

• Journal of Powder Materials
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• v.10 no.6
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• pp.422-429
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• 2003

The reduction mechanism of the composite powders mixed with $WO_3$ and CuO has been studied by using thermogravimetry (TG), X-ray diffraction, and microstructure analyses. The composite powders were made by simple Turbula mixing, spray drying, and ball-milling in a stainless steel jar with the ball to powder ratio of 32 to 1 at 80 rpm for 1 h without process controlling agents. It is observed that all the oxide composite powders are converted to W-coated Cu composite powder after reducing treatment under hydrogen atmosphere. For the formation mechanism of W-coated Cu composite powder, the sequential reduction steps are proposed as follows: CuO contained in the ball-milled composite powder is initially reduced to Cu at the temperature range from 20$0^{\circ}C$ to 30$0^{\circ}C$. Then, $WO_3$ powder is reduced to W $O_2$ via W $O_{2.9}$ and W $O_{2.72}$ at higher temperature region. Finally, the gaseous phase of $WO_3(OH)_2$ formed by reaction of $WO_2$ with water vapour migrates to previously reduced Cu and deposits on it as W reduced by hydrogen. The proposed mechanism has been proved through the model experiment which was performed by using Cu plate and $WO_3$ powder.

• Journal of the Korean Wood Science and Technology
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• v.34 no.5
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• pp.11-18
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• 2006

This study was carried out to evaluate the mechano-sorptive deflection of shear creep of drift pin jointed solid wood. Specimens were the solid wood of Pinus densiflora. The joint was composed with steel plate and drift pin, 85mm in length and 10mm in diameter. The creep tests were conducted under the constant loads in an variable environment. Five different shearing loads were applied parallel to the grain of specimens. The shearing loads applied were 170, 340, 510, 680 and 850 kgf. The stress levels were 10, 20, and 30, 40 and 50% of the bearing strength obtained from the tension-type lateral strength test. The creep tests for specimens were carried out for 10300 hours. A few general conclusions could be drawn from this study: The mechano-sorptive deflection (${\delta}$ ms) is defined as ${\delta}\;ms={\delta}\;t-({\delta}\;c+{\delta}\;sh)-{\delta}\;o$, where ${\delta}$ t is the total deflection, ${\delta}$ c is the pure creep, ${\delta}$ sh is shrinkage-swelling behavior, and ${\delta}$ o is the initial deflection. Changes of relative humidity may cause more severe creep deflection than those of constant humidity, especially during the drying process. The mechano-sorptive behaviors of specimens, except the effects of shrinkage and swelling, gradually increased with increasing time. The deflection is increased in desorption process and recovered in adsorption process. The deflections of drift pin jointed solid wood under different loads showed almost same tendency in all specimens. Although the creep deflection tendencies of each series are very similar, the specimens subjected to a large shearing load exhibit large creep deflections in the desorption process than do those to the small shearing load specimens.

• Membrane Journal
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• v.26 no.1
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• pp.26-31
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• 2016

Polycaprolactone (PCL) has been fabricated into the membrane type scaffolds of 3 dimensional pore network for the tissue engineering applications by the blade method of salt (NaCl) leaching and solution casting. In this study, the experimental designs have each conditions of drying temperature, salt particle size, salt content. The modified dispensing pump connected up to homogenizing mixer system is used for mixing the $PCL/CHCl_3$ solution and NaCl particles. The membrane fabricated use by the film applicator to poured mixed solution on the glass plate. The great pore by NaCl particles and the small pore by the evaporated $CHCl_3$ in the frame wall of great pores are multiply formed in membrane scaffolds.

• Journal of the Korean Ceramic Society
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• v.42 no.3 s.274
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• pp.198-204
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• 2005

Fluosilicate salts based hydration heat reducer(SWP-HR), used in this study, is composed of fluosilicate salts, soluble silica, aromatic polymer condensate and nitrate salt based inorganic compound with latent heat property. Effects of SWP-HR addition on the hydration heat and anti-crack property of cement mortar were investigated. Adiabatic hydration temperature and drying shrinkage length of SWP-HR added cement mortar had a tendency to decrease compared to those of cement mortar without SWP-HR addition. Also, it was confirmed through crack pattern experiment of plate-form specimen for elucidating crack-reducing characteristic that anti-crack property of SWP-HR added cement mortar was improved.