• Journal of Environmental Science International
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• v.31 no.11
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• pp.993-997
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• 2022

This study was conducted to evaluate the structure and composition (i.e., pH, moisture, total-N, pathogens, and volatile fatty acids) of broiler and duck manure treated with larvae of three insect larvae, namely, Tenebrio molitor, Protaetia brevitarsis seulensis, and Ptecticus tenebrifer. Hatched Tenebrio molitor (n=300), Protaetia brevitarsis seulensis (n=60), and Ptecticus tenebrifer (n=300) were used in this study; specially, the larvae were divided into six treatments with three replicates. The treatments were as follows: T1: 110 g broiler manure + Tenebrio molitor larvae (n=50), T2: 110 g duck manure + Tenebrio molitor larvae (n=50), T3: 125 g broiler manure + Protaetia brevitarsis seulensis larvae (n=10), T4: 125 g duck manure + Protaetia brevitarsis seulensis larvae (n=10), T5: 105 g broiler manure + Ptecticus tenebrifer larvae (n=50), and T6: 105 g duck manure + Ptecticus tenebrifer larvae (n=50). For all the larval treatments, the following results were observed: The moisture content of the duck manure treat with three insect larvae was higher than that of the broiler manure (p<0.05), whereas broiler manure had a higher pH (p<0.05). In addition, the total nitrogen content of broiler manure was higher than that of duck manure (p<0.05). However, the insect larvae did not significantly affect pathogens (E.coli and Salmonella) and the volatile fatty acids (p>0.05). In conclusion, the use of the three insect larvae to create organic nitrogen compost using poultry manure is feasible.

• Journal of the Korean Geotechnical Society
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• v.22 no.9
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• pp.5-14
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• 2006

Generally, the sediments contain significant water, clay, colloidal fraction and contaminants, and can result in soft strata with high initial void, and its potential hazards in subsurface environments exist. Electrokinetic technique has been used in sedimentation for volume reduction of slurry tailing wastes and in remediation for extraction of contaminants from contaminated soils. In this research, the coupled effects of sedimentation and remediation of contaminated sediments are focused using electrokinetic sedimentation and remediation techniques from experimental aspects. A series of laboratory experiments including variable conditions such as initial solid content of the specimen, concentration level of the contaminant, and magnitude of applied voltage are performed with the contaminated sediment specimens mixed with ethylene glycol. Commercially available high specification Kaolin was used to simulate slurried sediment. From the test results, the settlement of specimen increases with increasing of applied voltage and decreasing of solid content and contamination level. The density of specimen increases due to settlement of specimen in the process of electrokinetic sedimentation and decreases due to extraction of organic contaminant in the process of electrokinetic remediation.

• Journal of Ecology and Environment
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• v.46 no.1
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• pp.31-40
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• 2022

Background: Plant vegetation appears in heterogeneous and patchy forms in arid and semi-arid regions. In these regions, underneath the plant patches and the empty spaces between them are covered by biological soil crusts (moss, lichen, cyanobacteria, and fungi). Biological soil crusts lead to the formation and development of fertile islands in between vegetation patches via nitrogen and carbon fixation and the permeation of runoff water and nutrients in the soil. Results: The present study has investigated the association of biological soil crusts, the development of fertile islands, and the formation of plant patches in part of the Takht-e Soltan protected area, located in Khorasan Razavi Province, Iran. Three sites were randomly selected as the working units and differentiated based on their geomorphological characteristics to the alluvial fan, hillslope, and fluvial terrace landforms. Two-step systematic random sampling was conducted along a 100-meter transect using a 5 m² plot at a 0-5 cm depth in three repetitions. Fifteen samplings were carried out at each site with a total of 45 samples taken. The results showed that the difference in altitude has a significant relationship with species diversity and decreases with decreasing altitude. Results have revealed that the moisture content of the site, with biocrust has had a considerable increase compared to the other sites, helping to form vegetation patterns and fertile islands. Conclusions: The findings indicated that biological crusts had impacted the allocation of soil parameters. They affect the formation of plant patches by increasing the soil's organic carbon, nitrogen, moisture and nutrient content provide a suitable space for plant growth by increasing the soil fertility in the inter-patch space.

• Journal of Animal Science and Technology
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• v.65 no.5
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• pp.895-911
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• 2023

Processed meat products play a vital role in our daily dietary intake due to their rich protein content and the inherent convenience they offer. However, they often contain synthetic additives and ingredients that may pose health risks when taken excessively. This review explores strategies to improve meat product quality, focusing on three key approaches: substituting synthetic additives, reducing the ingredients potentially harmful when overconsumed like salt and animal fat, and boosting nutritional value. To replace synthetic additives, natural sources like celery and beet powders, as well as atmospheric cold plasma treatment, have been considered. However, for phosphates, the use of organic alternatives is limited due to the low phosphate content in natural substances. Thus, dietary fiber has been used to replicate phosphate functions by enhancing water retention and emulsion stability in meat products. Reducing the excessive salt and animal fat has garnered attention. Plant polysaccharides interact with water, fat, and proteins, improving gel formation and water retention, and enabling the development of low-salt and low-fat products. Replacing saturated fats with vegetable oils is also an option, but it requires techniques like Pickering emulsion or encapsulation to maintain product quality. These strategies aim to reduce or replace synthetic additives and ingredients that can potentially harm health. Dietary fiber offers numerous health benefits, including gut health improvement, calorie reduction, and blood glucose and lipid level regulation. Natural plant extracts not only enhance oxidative stability but also reduce potential carcinogens as antioxidants. Controlling protein and lipid bioavailability is also considered, especially for specific consumer groups like infants, the elderly, and individuals engaged in physical training with dietary management. Future research should explore the full potential of dietary fiber, encompassing synthetic additive substitution, salt and animal fat reduction, and nutritional enhancement. Additionally, optimal sources and dosages of polysaccharides should be determined, considering their distinct properties in interactions with water, proteins, and fats. This holistic approach holds promise for improving meat product quality with minimal processing.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.457-464
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• 2023

The rendering residue generated by rendering disposal, an eco-friendly livestock carcass disposal method, is a useful agricultural resource. Methods for recycling this are being actively researched, and this study investigated the impact of applying rendered residue directly to soil on crop productivity and the agricultural environment. The chemical properties of the rendering residue were examined. The pH, OM, T-N, T-P, CaO, K₂O, and MgO content values were 5.47%, 59.8%, 9.22%, 2.96%, 2.16%, 0.51% and 0.10%, respectively. Treatment conditions were divided into control, inorganic fertilizer, and rendering residue, and rendering residue corresponding to 50, 100, and 200% nitrogen content was applied based on the amount of inorganic fertilizer nitrogen input. Greenhouse gases and ammonia were collected during the cultivation period. Rendering residue increased both the yield and growth of peppers and was effective in improving nutrients such as pH and OM of the soil after harvest. However, compared to inorganic fertilizer treatment, it increased emissions of nitrous oxide and methane as well as ammonia. It is judged that the direct agricultural use of rendering residue is difficult, and a utilization method is needed.

• Food Science and Preservation
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• v.30 no.4
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• pp.549-561
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• 2023

Recently, consumers have gained an interest in natural and minimally processed foods, inciting the food industry to consider using of natural products as preservatives. Strawberries are a widely consumed fruit but are also highly perishable. Therefore, in this study, the physicochemical properties of strawberries (Fragaria×ananassa) were evaluated after a 12-h treatment with lemon essential oil (Citrus×limon) or cinnamon essential oil (Cinnamomum cassia) vapor during storage at 22℃ for 4 days in an accelerated shelf-life study and 4℃ for 18 days in a validation study. Weight loss was blunted in fruit treated with oil vapor during the first days of storage (p<0.05). Lemon essential oil delayed fruit darkening (p<0.05) but reduced the firmness of strawberries (p<0.05). Strawberries treated with cinnamon essential oil had a higher concentration of reducing sugars (p<0.05), and a decrease of 16.7% visible decay, although the difference was insignificant. Oil vapor treatment did not alter the pH, organic acid content, or soluble solid content during storage compared to the control. Since lemon and cinnamon essential oils have well-documented antimicrobial properties, they may be suitable for the natural preservation of fruit. This study provides new information on using essential oil vapor treatment to preserve fruits, and potentially decrease fruit loss and waste.

• Food Science and Preservation
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• v.30 no.2
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• pp.205-223
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• 2023

Fresh mushrooms are vulnerable to browning and tissue changes after harvest. This study monitored the external appearance, physicochemical quality indicators, and nutritional and functional components of a white beech mushroom (Hypsizygus marmoreus) variety (EG2020) newly developed in Korea during cold storage for up to 42 days. Two existing varieties of white H. marmoreus, namely H6 from Korea and HKT from Japan, were used for comparison. The mechanical texture of EG2020 was superior to H6 and HKT due to the increasing hardness of the pileus with time. Browning, in terms of the total color difference during storage, was found to be the most severe in HKT. In terms of composition, EG2020 had the highest total free sugar content, a large amount of organic acids, and higher sugar content than H6 and HKT. EG2020 also contained the largest amount of 𝛽-glucan, and its amount increased during storage. In sensory evaluation, EG2020 received higher scores than HKT in flavor, taste, appearance, and texture. Therefore, the EG2020 variety is more stable than HKT during storage and distribution.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.1
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• pp.29-37
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• 1977

The mineralization of soil nitrogen, amino acid composition of acid hydrolizable organic nitrogen of four Korean soils were investigated in comparison with four Japanese (Hokuriku district) soils which is similar in nitrogen content but different in characteristics of clay minerals. The mineralization rate and pattern were quite different between Korean and Japanese soils; Korean soils were low in amount of mineralized nitrogen but porduced much ammonium nitrogen during the later stage of incubation. In Korean soils the ratio of acid hydrolizable nitrogen to total; especially ${\alpha}$-amino nitrogen and hydrolizable ammonium nitrogen were low while hexosamine content was considerablly high (greater than 10%) In all soils the amount of mineralized nitrogen showed significant positive correlation with ammonium nitrogen and ${\alpha}$-amino nitrogen in acid hydrolizate. The amino acid composition of acid hydrolizate of paddy soils showed higher in basic amino acids and lower in acidic amino acids than those of up land soils (humic volcanic ash soil) from both countries. Alanine content was low in Korean soils. Proline showed increasing trend with nitrogen content but aspartic acid decreasing.

• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.689-697
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• 2005

Mineralogical composition, $^{137}Cs$ activity, total organic carbon (TOC), and particle size of marine sediments near Wuljin Nuclear Powerplant were analyzed and the relationships among those components were investigated. The particle sizes of sediments were equivalent to sand size and in the range of $-0.48\~3.6\;Md\phi$. TOC contents and $^{137}Cs$ activities were in the range of $0.06\~1.75\%$ and minimum detectable activity (MDA) $\~4.0Bq/kg-dry$ with the average value of $1.15{\pm}0.62$ Bq/kg-dry, respectively. The sediments in study area were characterized by large particle size and small TOC contents, and $^{137}Cs$ activity compared with other marine sediments. The main mineral components were quartz and feldspar (albite, microcline, and small amount of orthoclase) with small amount of pyroxene, calcite, hornblende. Minerals with $10{\AA}$ XRD peak (mainly biotite) and chlorite were also identified. Among those minerals, biotite shows the linear relationship with $^{137}Cs$ content probably due to the frayed edge site (FES) on biotite or small amount of mixed illite. However, TOC content shows most linear relationship with $^{137}Cs$ content because no significant amount of clay minerals, which can adsorb significant amount of Cs, were observed in the study area, indicating that the distribution of $^{137}Cs$ in this study area was more significantly affected by the TOC content than mineral composition.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.1
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• pp.73-78
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• 1985

The purpose of this study is to examine the effect of maturity stages and particle length on quality of silage made from Sorghum-sudan hybrid (Pioneer 988). The silage was made at heading, milky, dough and yellow ripe stage and cut 1.0, 2.5, 4.0cm at each stage. The quality of the silage was evaluated on the bases of the chemical compositions, content of organic acids, pH and $NH_3-N$ of the silage, and also the correlation between main compositions of the silage. The results were summarized as follows; 1. The moisture content was decreased with advancing maturity, but dry matter content was increased. Crude protein was decreased with advancing maturity at the level of 12.55 percentageat heading stage. Crude fiber was tended to increase. 2. The moisture content of silage was markedly decreased with advancing maturity (p<0.01). 3. The pH value of silage was the lowest when particle length was 2.5cm, and there was no significant difference between particle lengths. At the yellow ripe stage, the pH value was the lowest (3.53) and at the dough stage, the pH value was the highest (4.59) (p<0.01). 4. The rate of $NH_3-N$ to total-N was the highest (16.3%) at heading stage, the lowest (9.2%) at the dough stage. 5. The organic acid contents was not uniformly fixed at the particle length, but the highest quality silage was produced at yellow ripe stage as was not produced butyric acid and plenty of lactic acid was contented. 6. The correlations between pH and lactic acid (r=0.719), pH and total acid (r=-0.716), butyric acid and Flieg's score (r=0.872) were negative, respectively (p<0.01). And those between lactic acid and total acid (r=0.990), moisture and $NH_3-N$ (r=0.767) were positive, respectively (p<0.01).