• Journal of Korean Society of Forest Science
• /
• v.105 no.1
• /
• pp.93-102
• /
• 2016

This research was conducted for major cultivated chestnut (Castanea spp.) in Korea to compare chestnut quality characteristics according to storage temperatures ($4^{\circ}C$ vs. $-1^{\circ}C$) and cultivars. Color, hardness, soluble solids content (SSC), rate of decay and sensory evaluation were investigated during 16 weeks storage. Cultivars 'Tsukuba' and 'Ishizuchi' showed the least pericarp color change while cultivars 'Riheiguri' and 'Daebo' showed the most pericarp color change during storage. Chestnut fruits stored at $-1^{\circ}C$ showed less pericarp color change than those stored at $4^{\circ}C$. Cultivars 'Arima' and 'Tanzawa' exhibited the decrease tendency of hardness with lowest hardness during storage at $-1^{\circ}C$. Chestnut fruits stored at $4^{\circ}C$ showed high hardness than those stored at $-1^{\circ}C$. Cultivars 'Riheiguri' showed the highest increase of SSC, while cultivar 'Arima' showed the lowest increase of SSC after 16 weeks of storage. The SSC increased in nuts from all cultivars at both temperatures, but nuts stored at $-1^{\circ}C$ showed higher increases in SSC than nuts stored at $4^{\circ}C$. Cultivars 'Ishizuchi' and 'Riheiguri' showed high rates of decayed nuts in contrast to cultivars 'Daebo', 'Okkwang' and 'Tanzawa' that showed low rates of decayed nuts during storage. The chestnut fruit stored at $-1^{\circ}C$ showed less decay than fruit stored at $4^{\circ}C$. Texture and sweetness were tested for sensory evaluation. Among the tested cultivars, 'Riheiguri', 'Daebo' and 'Tsukuba' showed hard texture and very sweetness, while 'Tanzawa' showed relatively soft texture. 'Arima' and 'Okkwang' showed weak sweetness during storage. Nuts stored at $4^{\circ}C$ exhibited harder texture than nuts stored at $-1^{\circ}C$ while $-1^{\circ}C$ exhibited more sweetness than nuts stored at $4^{\circ}C$. Chestnuts for hard texture and short-term storage (less than one month), $4^{\circ}C$ will be a proper storage temperature, while in order to store long-term (more than 4 month), $-1^{\circ}C$ will be a proper storage temperature. Result from this study provide base-line data of postharvest management for Korean cultivated chestnut as well as contributing increased product value and income for chestnut producers.

• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.1
• /
• pp.101-106
• /
• 1992

Secretory patterns of serum tri-iodothyronine, thyroxin and testosterone were analysed by specific radioimmunoassay in Kaghani (n = 42), Rambouilet (n = 42) and Kaghani ${\times}$ Rambouillet (n = 42) male sheep to determine age and breed related changes. Animals were examined at 1-2 wk, 8, 10, 12, 20, 22 and 24 months of age (n = 6/age group). All animals were maintained under standard conditions of feeding and management. $T_3$ and $T_4$ concentrations were maximal (p < 0.01) in 1-2 wk old lambs of all breeds studied ($207.4{\pm}14.9-276.8{\pm}20.4ng/dl$ and $5.76{\pm}0.3-7.23{\pm}0.9{\mu}g/dl$, respectively). For all the breeds, concentrations of $T_3$ declined markedly (p < 0.01) at 8 month of age and then varied in a narrow range ($44.5{\pm}14.0-87.0{\pm}4.8ng/dl$) up to the age of 24 month. While, serum $T_4$ concentrations decreased (p < 0.01) to nadir ($0.97{\pm}0.1-1.43{\pm}0.3{\mu}g/dl$) at 10 months of age in all the 3 breeds. Afterwards, $T_4$ levels increased gradually and attained a small peak at 20 months before declining again at 22 and 24 months of age. Serum $T_3$ and $T_4$ concentrations were correlated significantly (p < 0.05) and their ratio was constant at all ages in the different breeds. Age significantly (p < 0.01) influenced the secretion of testosterone in the breeds examined but the breed differences were comparable. Mean serum concentrations of testosterone were low from 1-2 wk to 10 months of age in the Kaghani, Rambouillet and Kaghani ${\times}$ Rambouillet animals. Peak testosterone levels were noted in the 12 months old Kaghani ($1.75{\pm}0.4ng/ml$), Rambouillet ($1.30{\pm}0.2ng/ml$) and their $T_3$ cross animals ($1.16{\pm}0.08ng/ml$). Mean testosterone levels, thereafter, decreased at 20 months and then at 22 and 24 months remained variable but higher than observed at 1-2 wk -10 months of age. The findings of the present study indicate a significant influence of age but not of breed on the peripheral concentrations of thyroid hormones and testosterone. Serum concentrations of $T_3$ and $T_4$ were not related to testosterone levels. High thyroid secretory activity observed at prenatal phase of development may play an important role in preparing the lambs to extrauterine environments.

• Korean Journal of Food Science and Technology
• /
• v.22 no.7
• /
• pp.799-801
• /
• 1990

Of the several methods proposed for decreasing toxicity of Paralytic shellfish poison(PSP) from intoxicated shellfish, heat treatment has been most popular, although a large percentage of the incidents of PSP illness have been related to the ingestion of cooked shellfish. The purpose of this study was to determine the kinetics of PSP destruction at various temperatures. The homogenate of intoxicated blue mussel(Mytilus edulis) was heated at temperature ranging from $90\;to\;121^{\circ}C$ and toxicities measured in samples heated for various time intervals. The rate constant(k) per second was $3{\times}10^{-4},\;at\;90^{\circ}C,\;4.98{\times}10^{-4},\;at\;100^{\circ}C,\;7.38{\times}10^{-4},\;at\;116^{\circ}C,\;and\;8.38{\times}10^{-4},\;at\;121^{\circ}C,\;$. By the Arrhenius equation, the decimal reduction time(D-value) was $121min.\;at\;90^{\circ}C,\;82min,\;at\;100^{\circ}C,\;58min.\;at\;116^{\circ}C\;and\;53min.\;at\;121^{\circ}C$. The z-value, activation energy($E_a\;and\;Q_{10}$) was $72^{\circ}C,\;3.9{\times}10^7(J/kg\;mol)$ and 1.39, respectively.

• Korean Journal of Food Science and Technology
• /
• v.22 no.3
• /
• pp.343-349
• /
• 1990

The solubility of protein and phytate was measured at various pH's in distilled water and at various concentrations of NaCl, $CaCl_2\;and\;Na_2SO_3$ solutions, and then optimum condition for producing low phytate protein isolate from perilla flour was investigated. The protein solubility in water showed minimum at pH 4.0 and increased at pH higher or lower than 4.0, while phytate solubility was highest at pH 5.0 and decreased at pH higher or lower than 5.0. In NaCl solution, protein solubility was lowest between pH 3.0-4.0, while phytate solubility was high between pH 2.0-5.0 and abruptly decreased above PH 6.0. In $Na_2SO_3$ solution, protein solubility was lowest between pH 2.0-3.0 and phytate solubility showed maximum values between pH $5.0{\sim}6.0$, and it's solubility was low in 3% salt concentration at all pH ranges. In $CaCl_2$ solution, protein solubility in 3% salt concentration was relatively low at all pH ranges, and phytate solubility showed highest values between pH $2.0{\sim}3.0$ and abruptly decreased (1.0%) above pH 4.0. In order to make low phytate protein isolate, defatted perilla flour protein was extracted at pH9.0 and precipitated at pH 4.0 in 3% NaCl solution. The yield of low phytate protein isolate was 61.4% of total protein. This protein was found to contain 0.02% phytate by weight.

• Journal of Environmental Health Sciences
• /
• v.16 no.2
• /
• pp.11-20
• /
• 1990

To investigate ionic characteristics of acid rain by the succeeding rainfall. bulk precipitation was collected every each 5mm rainfall from march to october 1990 at Dae Jeon area. pH, sulfate nitrate, chloride, ammonium ion was measured and analyzed. The result was as follows: 1. The weighted average pH of rain was 5.1$\pm$ 0.72(4.15~7.6) and rain pH less than 5.5 was appeared 51.3% 2. Average ion concentrations of sulfate, nitrate, chloride and ammonium ion was 125.12 $\mu$eq/l, 62.38 $\mu$eq/l, 31.95 $\mu$eq/l, 66.6 $\mu$eq/l and rates of each anions was 57%, 28.4%, 14.6% and rate of sulfate by nitrate was 2 times. 3. There is no correlations time interval of rainfall and Ion concentration change. 4. From initial to 15mm rainfall, each ion concentrations were decreased. and average concentration of pH, SO$^{-2}_{4}$, Cl ion concentration was increased in the succeeding rainfall 5. Only sulfate ion was correlated by the simple regression analysis with pH except NO$^{-}_{3}$, Cl$^{-}$ and NH$_{4}^{+}$ Cl$^{-}$ correlation coefficient was very high at the multiple regression analysis with pH. 6. Simple & multiple correlation coefficient among anions and NH$^{+}_{4}$ was very high especially N$^{+}_{4}$ and SO$^{2-}_{4}$ at simple regression analysis and SO$^{-2}_{4}$ and NO$_{3}^{-}$, Cl$^{-}$, NH$_{4}^{-}$ at multiple regression analysis.

• Korean Journal of Poultry Science
• /
• v.17 no.2
• /
• pp.79-82
• /
• 1990

An experiment was conducted to evaluate relative biopotency of tri-iodothyronine ($T_3$) and thyroxine ($T_4$) to induce oxygen consumption in young chicks. Four experimental groups of 3 chicks were injected with $T_3$ or $T_4$ at a dose of 500 or 1000mg per kg body weight, and thereafter oxygen consumption was measured by indirect calorimetry using a respiration apparatus. Oxygen consumption was significantly increased at 2 and 4 hour in the $T_3$ or $T_4$ treated chicks at 500mg at 2 hour. From coefficient of a multiple regression equation of oxygen consumption on $T_3$ or $T_4$, it was concluded that $T_3$ was shown to be two to three times as biologically active as $T_4$.

• Journal of the Korean institute of surface engineering
• /
• v.33 no.4
• /
• pp.251-260
• /
• 2000

Ta and Hf added Ti-l5Sn-4Nb alloys without V and Al elements for biomaterial were melted by arc furnace in response to recent concerns about the long term safety of Ti-6Al-4V alloy. All specimens were homogenized at $1000^{\circ}C$ and solution treatment was performed at $812^{\circ}C$ and aging treatment at $500^{\circ}C$. The microstructure and mechanical properties were analysed by optical micrograph, hardness tester and instron. Ti-l5Sn-4Nb system alloys showed widmanstatten microstructure which is typical microstructure in $\alpha$＋$\beta$ type Ti alloys. The Ti-l5Sn-4Nb-2Hf and Ti-l5Sn-4Nb-2Ta alloys showed better hardness and tensile strength compared with Ti-6Al-4V. The result of XPS analysis, Ti-l5Sn-4Nb alloy in air atmosphere consisted of $TiO_2$, SnO and NbO.

• Korean journal of applied entomology
• /
• v.46 no.1 s.145
• /
• pp.27-35
• /
• 2007

Seasonal occurrences of tobacco cutworm, Spodoptera litura and beet armyworm, Spodoptera exigua were observed using sex pheromone traps at different locations and climatic regions in Yeongnam district. In Gyeongnam province, S. litura male adults kept occur from mid or late March to mid or late November Whereas in Gyeongbuk province, S. litura occurred from mid or late April to early or mid November with exception at Uljin where it was late May to late October. According to the climatic regions, the peak occurrence of S. litura was middle September at the southern coast region, late August at the inland and the basin region, middle August at the inland mountainous region, and early September at the eastern middle coast region. The occurrence rate of S. litura was the highest at Jinju with 20.0% and the lowest at Changyeong with 8.6% in Cyeongnam province, while it was the highest at Sungju with 3.3% and the lowest at Uljin with 0.8% in Gyeongbuk province. In accordance with the climatic regions, the occurrence rate of S. litura was the highest at the inland region with 43.7%, and followed by the southern coast region (36.3%), the basin region (8.4%) and the inland mountainous region (7.0%), and was the lowest at the eastern middle coast legion with 4.6%. On the other hand, S. exigua occurred from early March to middle November with the exception of the eastern middle coast region including Pohang, Yeongdeog and U]ien in Cyeongbuk province where it occurred from mfd April to middle November. The peak occurrence of s. exigua was early August at the inland region, the basin region and the inland mountainous region, and was late of August at the southern coast region and the eastern middle coast region. The occurrence of S. exigua was the highest at Changyeong with 1.6% and the lowest at Busan with 0.4% in Gyeongnam province, while it was the highest at Sungju with 37.2% and the lowest at Uljin with 2.7% in Gyeongbuk province. The climatic regional occurrence rate of S. exigua was the highest at the basin region with 54.3%, and followed by the inland mountainous region (29.9%), the eastern middle coast region (9.3%) and the inland (3.9%), and was the lowest at the southern coast region with 2.6%. As a whole, S. litura occurred more in Gyeongnam province than Cyeongbuk province, while S. exigua occurred more in Gyeongbuk province than Gyeongnam province. According to the regions grouped by climatic differences, the occurrence of S. litura and S. exigua was the highest at the inland region in Gyeongnam province and at the basin region in Gyeongbuk province. The total number of S. litura captured by sex pheromone trap was 2.4 times higher than that of S. exigua. However, the first occurring time and the peak occurrence of S. exigua were slightly earlier than those of S. litura.

• Journal of Korean Society on Water Environment
• /
• v.26 no.2
• /
• pp.200-207
• /
• 2010

The sewage treatment plants to be built to improve the water quality of the Mankyung River will total 11, of which combined capacity will reach $39,850m^3/day$, and saying in detail, 5 at Gunsan city, 2 at Iksan city, 1 at Kimje city and 3 at Wanju gun, The scenario for water quality improvement was developed, considering the conditions of plant operation ratio and the accomplishment of the water quality target (BOD 4.4 mg/L, T-P 0.356 mg/L) at the end of the watershed of Mankyung B was predicted, making use of QUAL2E model. As a result of prediction using QUAL2E model based on scenarios with 70% and 100% of operation ratio, respectively, at 11 plants in 2010, the water quality at the watershed of Mankyung B was estimated at 4.322 mg/L which was lower than the target of BOD 4.4 mg/L, indicating the target water quality was achieved, when it comes to 70% of operation ratio, But in case of T-P, it was estimated at 0.565 mg/L, which was higher than the target. When it comes to 100% of operation ratio, T-P also was 0.563 mg/L which exceeded the target, 0.356 mg/L. As indicated above, the effect of water quality improvement appeared very insignificant, which was attributable to the limit of small scale sewage treatment plant in total reduction capacity. Hence, the measures for additional reduction in a bid to achieve the target water quality of T-P at the designated location need to be taken, and the measures to build the Sewage treatment facilities at the place where the pollution is significantly caused by T-P appeared to be required as well.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.22 no.2
• /
• pp.133-141
• /
• 2000

Purpose : The purpose of this study is to estabilish clinical guidance of microvascular anastomosis in diabetic patients. This study was performed with experimental microvascular anastomosis in streptozotocin induced diabetic rats and observed histopathologic change and endohelial healing process. Materials and Methods : 70 Sprague-Dawley rats, weighting 200 to 250grams, were used for the experiment. 35 induced diabetic rats with streptozotocin and 35 control group were selected. After end-to-end carotid artery microvascular anastomosis was done, the experimental rats were sacrificed at different time interval (1st day, 3rd day, 1st week, 2nd, 4th, 6th and 8th week) for histologic examination. Light microscope observation was used in this study. Results : 1. Histopathologic changes are nearly the same healing process in two groups. But period of tissue reaction was faster in the control than diabetic group. 2. In endotheliall healing, control group started at 1 week after and completed at 4 weeks after, but diabetic group was observed partially at 4 weeks after and complete healing was not observed still at 8 weeks after. 3. In subintimal hyperplasia, control group was observed at 6 weeks after but diabetic group was observed at 6 weeks after and partially at 8 weeks after. 4. All groups showed severe inflammatory response in the early period. This respond is decreased at 2 weeks after in control group but still remained at 8 weeks after in the diabetic group. 5. In media, inflammatory response and degeneration were observed in early period. Regeneration of smooth muscle cell was observed at 1 week after in control group but 4 weeks after in the diabetic group. Conclusions : As the results of study, it could be thought that vascular regeneration process was not failured but delayed in the diabetes. It was considered that diabetes mellitus was not absolute contraindication of microvascular anastomosis.