• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.1
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• pp.39-46
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• 2022

This study compared the effects of cocopeat and perlite growth media on the storability and quality of sweet pepper fruit stored using modified atmosphere packages (MAP) and carton boxes. The fruits were stored at 8℃ for 35 and 30 days, respectively. Perlite-grown fruits had a significantly lower size at harvest due to the medium's inability to hold plenty of water during the growing stage. Contrary to what is expected for small fruits, the result shows box-stored perlite-grown fruits to have lower weight loss and a longer shelf life than cocopeat-grown fruits, while MAP fruits have indifference. Perlite fruits also had a higher quality in terms of dry matter, soluble solids, and vitamin C, while box-stored fruits had a better visual quality. As expected, respiration and ethylene production rates were high, and fruits had similar after-storage firmness values. Based on the findings, perlite-grown sweet pepper fruits may have a better quality and give preference in a box storage condition.

• Advances in concrete construction
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• v.13 no.3
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• pp.233-242
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• 2022

An attempt is made to develop an eco-friendly concrete with ground granulated blast furnace slag (GGBS) and pond ash as partial replacement materials for cement and fine aggregate, respectively without compromising the strength and durability. Sixteen concrete mixes were developed by replacing cement and fine aggregate by GGBS and pond ash, respectively in stages of 10%. The maximum replacement levels of cement and fine aggregates were 50% and 30% respectively. Experimental results revealed that the optimum percentage of GGBS and pond ash replacement levels were 30% and 20% respectively. The optimized mix was used further to study the flexural behavior and durability properties. Reinforced Concrete (RC) beams were cast and tested under a four-point bending configuration. Also, the specimens prepared from the optimized mix were subjected to alternate wet and dry cycles of acid (3.5% HCl and H₂SO₄) and sulphate (10% MgSO₄) solutions. Results show that the optimized concrete mix with GGBS and pond ash had a negligible weight loss and strength reduction.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.4
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• pp.11-23
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• 2023

In Korea, open burning of agricultural residues is prevalent due to inadequate collection systems, which have caused environmental impacts such as GHGs and particulates. This illegal treatment of agricultural residues also results in economic loss, considering that agricultural residues can be utilized as resources such as pellets and energy sources. To understand the effect of avoiding open burning, this study evaluated the economic, environmental, and social effects of two alternative management options for agricultural residues: incineration and pelletizing. The study estimates the potential amount and dry weight by region for 18 items, taking various factors into account. Regarding the economic aspect, pelletizing facilities in all regions in Korea create economic benefits. This study shows that most regions have an environmental advantage by pelletizing residues. However, incineration creates more environmental benefits than pelletizing in metropolitan cities with relatively low density of residues. It is expected that the environmental, economic, and social findings of this study can be used to inform policies for bioenergy as the need for agricultural residue increases.

• Korean Journal of Materials Research
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• v.2 no.2
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• pp.126-132
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• 1992

Experiment has been performed to investigate the thermal and magnetic properties of Mn-ferrite by electrolysis. Using the 0.2%C mild steel as soluble anode and SUS 304 stainless steel as cathode, Mn-ferrite could be made from the sulfuric acid leaching of the wasted manganese dry cell and $MnSO_4$reagent by electrolysis. As the result of X-ray diffraction, thermal analysis and magnetic measurement, Mn-ferrite was the spinel type in $Mn_{x}Fe_{3-x}O_4$ (X=1), the weight loss rate of $Mn_{x}Fe_{3-x}O_4$ were linearly increased up to the $200^{\circ}C$. Ms, Mr and Hc values were decreased with increasing Mn content and heating temperature. When Mn-ferrite was formed by $MnCl_2$reagent electrolysis, Ms values were higher than those formed from the sulfuric acid leaching of the wasted manganese dry cell and $MnSO_4$reagent by electrolysis. In Mn-ferrite, which was formed from the sulfuric acid leaching of the wasted manganese dry cell by electrolysis, Ms and Mr values were higher, Hc values were lower than which was formed by $MnSO_4$ reagent electrolysis at $200^{\circ}C\;and\;300^{\circ}C, while the same values at $100^{\circ}C$. The shape of particles was spherical type, the sizes of them were about $0.1{\mu}m$ sub-micron in $MnSO_4$reagent electrolysis, $0.5{\mu}m$ in the sulfuric acid leaching of the wasted manganese dry cell by electrolysis.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.1
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• pp.58-65
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• 1993

The purpose of this study is to determine the evolution of carbon and nitrogen concentrations in relation to dry matter and crude protein accumulation in the leaves of forage rape(Brassica napus Subsp. oleifera, CV. Swiss) during the growth period. Field-grown plants were sampled at intervals throughout fall, winter, early and late spring. During over-wintering period(from Nov. 7 1991 to Feb. 4 1992), the carbon concentration in the leaves increased from 382 mg to 435 mg g DM$^{-1}$ , while the concentrations of nitrogen and crude protein significantly decreased. There was little accumulation of fresh and dry matter in the leaves. On early spring growth from 4 Feb. to 30 Mar. marked carbon loss 37 mg. day$^{-1}$ and slight nitrogen accumulation occurred with the increase of fresh weight in the leaves. From spring growth to bolting stage(from 31 Mar. to 16 Apr.) the greatest accumulation of fresh and dry matter was observed and carbon and crude protein concentrations increased with a linear manner. After bolting stage the concentrations of carbon, nitrogen, hydrogen and crude protein in the leaves significantly decreased until late blooming stage, and the decreasing rate was prominent in nitrogen (45.7%) and crude protein(46%). From the results above it is recommended that fertilizer will be applied before early spring growth, and that optimal utilization period is a bolting stage. For the serious modification of the internal C/N balance during the overwintering period.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.116-121
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• 1998

Field experiment were carried out to elucidate the changes of weed occurrence according to the sowing time and to establish the efficient weed control system in dry seeded rice cultivation. E crus-galli and D. sanguinalis are tow major weeds at the earlier sowings, but C. difformis was dominating at the later sowing. In the case of E. crus-galli, there was a tendency of gaining its dominance values as the rice growth stage advances. The later the sowing time was, the more weeds occurred at the early rice growth stages: However, when measured at heading, total dry weight was greater at the earlier sowings. Yield loss due to weeds were also greater at the earlier sowings. Community diversity of weeds was greater at the later sowings, while specific weed was gradually dominating as rice growth stage advances, regardless of sowing time. When herbicides were applied before 15 DAS, weeds were effectively controlled only upto 35 DAS. So systemic herbicide application, one on 0 to 10 DAS and the other on just after flooding, appeared to be recommendable in direct seeded rice cultivation.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.273-283
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• 2019

This study was conducted to evaluate the effect of dietary supplementation of anise flavor on the performance of lactating sows and suckling pigs at different weaning ages. A total of 120 sows (Landrace ${\times}$ Yorkshire) were used in this experiment. Sows were fed with a commercial lactation diet (60 sows) or diet with flavor (60 sows) during days 100 to 114 of gestation period and the whole lactation period. Piglets were allotted to 2 dietary treatments based on their initial body weight (BW) using a $2{\times}2$ factorial arrangement of treatments with 2 levels of anise flavor (0 or 0.5 g/kg) and weaning periods (weaned at 21 day or 28 day after birth). Sows fed with flavor supplemented diets had higher (p < 0.05) back fat and average daily feed intake (ADFI) at weaning, lower (p < 0.05) back fat loss than those fed with non-flavor diets. Sows weaned at 28 day had higher (p < 0.05) weaning back fat and lower (p < 0.05) back fat loss than those weaned on 21 day. During weaning, piglet average daily gain (ADG), ADFI, digestibility of dry matter (DM), nitrogen (N), and gross energy (GE) and fecal score were affected by anise flavor, respectively. In conclusion, dietary flavor supplementation could increase feed intake of lactating sows, improve growth performance and reduce weaning stress of piglets, especially effective in the early weanling piglets. Meanwhile, interactive effects were observed about the piglet performance between weaning ages and anise flavor supplementation after weaning.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.4
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• pp.372-376
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• 1992

This experiment was conducted to determine hay making time on the drying period, hay moisture content, hay loss content, yield and forage quality of Italian ryegrass in paddy field. Plant height increased rapidly from middle of April, and leaf weight rate were 55.6% at April 20 and 18.9% at May 30. Moisture content and loss content of hay were 17.1-20.5% and 10.2-15.0%, respectively, at drying for 4 days from May 10 to May 30. As the growth stage later, crude protein, fat and ash contents reduced, but crude fiber and NFE contents increased. Dry matter and TDN yield at the cutting of May 20 and May 30 increased to 17-18% and 5-11%, respectively, than those of April 20＋May 30.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.289-296
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• 2006

Various drying conditions, temperatures (40 to $80^{\circ}C$) and durations (overnight to 72 hrs), for the particulate organic matter (POM) fraction after wet-sieving size fractionation have been applied for determination of POM contents in the weight loss-on-ignition method. In this study, we investigated the optimum drying condition for POM fraction in quantification of POM and/or mineral-associated organic matter (MOM; usually indirectly estimated). The influence of the drying conditions on quantifying POM was dependent upon soil properties, especially the amount of soil organic components. In relatively high organic soils (total carbon > 40 g/kg in this study), the POM values were significantly higher (overestimated) with drying at $55^{\circ}C$ than those values at $105^{\circ}C$, which were, for example, 173.2 and 137.3 mg/kg, respectively, in a soil studied. However, drying at $55^{\circ}C$ for longer than 48 hrs of periods produced consistent POM values even though the values were much higher than those at $105^{\circ}C$. Thus, indirect estimates of MOM (MOM = SOM-POM) also tended to be significantly impacted by the dry conditions. Therefore, we suggest POM fractions should be dried at $105^{\circ}C$ for 24 hrs as determining POM and MOM contents. If the POM traction is needed to be dried at a lower temperature (e.g. $55^{\circ}C$) with a specific reason, at least 48 hrs of drying period is necessary to obtain consistent POM values, and a moisture correction factor should be determined to adjust the values back to a $105^{\circ}C$ weight basis.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.4
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• pp.522-528
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• 2018

Objective: This study evaluated inclusion of buckwheat silage to the diet of growing lambs in terms of meat quality as compared to maize silage. Methods: Buckwheat, rich in total phenols (TP, 33 g/kg dry matter [DM]), was harvested at the end of the milk stage and ensiled in 40 kg plastic bags after wilting (294 g/kg silage DM). A total of 18 growing lambs ($21.6{\pm}1.2$) were individually fed isonitrogenous and isoenergetic total mixed rations (TMR) for 75 d that either contained buckwheat or maize silage at DM proportions of 0.50. At the end of feeding trail all lambs were slaughtered to assess carcass characteristics and meat quality. Results: Buckwheat silage increased (p<0.01) the DM intake of lambs as compared to maize silage, but had no effects (p>0.05) on live weight gain and feed efficiency. Carcass weight, dressing percentage, meat pH, water holding capacity, cooking loss, shear force ($kg/cm^2$), and total viable bacteria count of meat did not differ (p>0.05) between the treatments. However, TP content of meat increased (p<0.001) by feeding buckwheat TMR. Feeding buckwheat TMR also decreased (p<0.05) the b* values of meat. Conclusion: The results provide that buckwheat silage is palatable and could successfully include TMR of growing lambs with no adverse effects on performance, carcass and meat quality. Additionally, feeding buckwheat silage to lambs offers increased TP in meat.