• Transactions of Materials Processing
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• v.6 no.2
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• pp.136-144
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• 1997

(Ag-10%Ni)/Cu clad metals for electric contact switch were fabricated by cold-roll bonding process. 2 or 3 passes of cold-rolling was carried out for each process to investigate the effect of the rolling passes on the bonding property. The effect of the annealing temperature of copper before the cold-roll bonding on the bond strength was also studied. The specimen bonded with copper annealed below 30$0^{\circ}C$ before roll bonding showed good bond strength. This is because high stored energy in copper promoted the short range diffusion and the grain refinement of copper by the static recrystallization increased the degree of the interfacial coherency. The maximum peel strength of clad metals bonded with Cu annealed below 30$0^{\circ}C$ was 120N.

• Journal of Biosystems Engineering
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• v.5 no.1
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• pp.33-42
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• 1980

This study was carried out to investigate the actual environmental paddy storage conditions in conventional Korean farm warehouses. The paddy storage conditions by the locations and sizes of warehouses were figured out. The effectiveness of the small insulated box for storing paddy was also examined. Observations were made at sixteen different warehouses located in Moonsan-Myeon, Jinyandg-gun, Gyungnam Province from July lst to September 28 th, the period which was considered to be the worst for storing grains. The results are as follows ; 1. the average temperatures of rough rice and air inside the warehouse were 0.9 and 0.7$^\circ$ higher than the outside air temperature. 2. The average relative humidity in warehouses was 1.5percent higher than that of the atomosphere. This fact resulted in the increased moisture content of grains. Therefore, the ventilation for equalizing the relative humidity of inside and outside of warehouses was required. 3. The dry matter of stored rough rice was decreased by 1.1 percent in average druing the observation period. In order to reduce the dry matter loss, application of new grain storing method ;hermetic storage or filling inert gas storage, was highly recommended. 4. Environmental conditions for storing rough rice in a warehouse located in a sloping site are, in general , better than those of a warehouse located in a flat site. But as far as the dry matter of rough rice was concerned, above situation is not always satisfactory. Because it is fairly frequent to observe the higher rate of moisture absorption by grains stored in a warehouse located in a sloping site. 5. Environmental conditions for storing rough rice in a large-scale warehouse were better than those in a small size warehouse. Therefore, it is advisible for farmers to store their grins in the large-scale warehouses commonly used by villagers. 6. It was undesirable to store rough in a insulated box.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.12-20
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• 2006

This study was carried out to investigate the relationship between each quality characteristics and changes of grain quality according to storage temperature and moisture contents of rough rice of Dongjin 1 and Siodongjinbyeo. Respiration rate of rough rice and fat acidity of brown rice were increased with moisture contents of rough rice and storage temperature. Germination rate of rough rice was the highest at $17{\sim}18%$ moisture contents of rough rice stored at low temperatures for 12 months. Germiation rate of the stored at low temperature after 16 months was up to 80% however the rate of $13{\sim}14%$ moisture contents of rough rice stored at room temperature was severely decreased to below the 10%. Gloss value of cooked rice was increased with moisture contents of rough rice and the lower storage temperature. Fat acidity of brown rice was lower in Sindongjinbyeo than Dongjin 1 at the lower storage temperature. Sensory score of cooked rice of Sindongjinbyeo which stored at low temperature for 16 months was better than Dongjin 1 and excllent at $17{\sim}18%$ moisture contents of rough rice. Correlations between sensory score of cooked rices and color b value of brown rice, gloss value of cooked rice and color L value of brown rice were significant 0.731**, 0.625*, and 0.615*, resectively, and were also positively significant correlated with break down, peak viscosity, pasting temperature, and fat acidity of brown rice -0.864**, -0.795**, -0.786**, and -0.779**, respectively.

• Korean journal of food and cookery science
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• v.26 no.2
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• pp.220-228
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• 2010

This study was designed to examine the effectiveness of an unused tunnel as a rice storage place. The physicochemical changes of rice grains were investigated during 8-months of storage in the tunnel located at Kyungnam province, Korea. Two kinds of tunnel stored rices, NP(rice grown with no pesticides) and LP(rice grown with less pesticides) were compared with $5^{\circ}C$ stored rice as a control. The peroxidase activities, as an index of freshness of rice grains, gradually decreased and NP appeared to be fresher than LP. Whiteness, grain wholeness, and chalkyness were less desirable for the tunnel stored rice than the control, with no significant difference of physicochemical properties, including the broken, damaged, colored rice, and contents of moisture, protein, and amylose. Palatability dropped below 70 in all three groups at later phase. The sensory evaluation showed that overall preference was slightly higher for the control but not significantly different from the other two groups. From all the evidences shown, unused tunnels may be an effective place for a long-term rice storage, since the average temperature inside the tunnel was maintained very constantly around $14.3^{\circ}C$ and relative humidity was optimal for rice storage, especially during spring and summer seasons.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.3
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• pp.259-264
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• 1990

Improvement in production, post-harvest processing, quality grading, storage and malting process of malting barley is apparantly necessary to upgrade the beer quality and to reduce the losses in malt production. To establish the bases for the improvement, the present study examined the effect of storage conditions on the germinability of malting barley by quality grade of barley at production, and feasibility of mixing different varieties and different quality grades. Germinability of malting barley decreased significantly after 13 months of storage in the off-grade grain storage house, and after 15 months in the 1st grade storage house under the climate of Korea. Malting barley that was off-grade at harvest deteriorated faster than the 1st grade during 5 years storage under ordinary conditions. Mixing of varieites, different grain-quality grades or differently stored barleys seems to increase variability in germinating forces and germinability, resulting in uncontrollable malting processes and poor quality of malts and beer.

• The Plant Pathology Journal
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• v.26 no.2
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• pp.121-129
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• 2010

We evaluated microbial populations and aflatoxin production in unhulled and white rice from rice processing complexes of the National Agricultural Cooperative Federation in five regions in Korea and identified three predominant Aspergillus species. Fungal and bacterial populations in rice samples were significantly different between regions in 2007. Aflatoxins were also detected and varied at the levels of 2.45 - 3.43 ng per g unhulled rice grain and 1.29 - 2.09 ng per g white rice grain. Unhulled rice generally detected higher level of aflatoxins than white rice regardless of sampling regions; however, no significant differences were found in Anseong and Cheonan in 2005 and Cheonan and Gimpo in 2007. Aflatoxin production between sampling regions was not different regardless of rice type and sampling year. Although the fungal diversity was highly distinct from region to region, three Aspergillus isolates were predominant in the rice samples; thus, representative isolates AC317, AF57, and AF8 were selected and identified based on their morphological and molecular characteristics. Consequently, isolates AC317, AF57, and AF8 were identified as A. candidus, A. flavus, and A. fumigatus, respectively. These fungi can produce mycotoxins that are harmful for consumers and thus it is important to detect and reduce the population of storage fungi in rice.

• Journal of Biosystems Engineering
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• v.37 no.3
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• pp.184-191
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• 2012

Purpose: This study was conducted to investigate the storage and quality characteristics of brown rice under the low temperature warehouse conditions using ambient cold air in the winter. Methods: This new technique maintains rough rice warehouse temperature below $15^{\circ}C$ without cooling operation until the end of May. Four hundred tons of rough rice were stored in the low temperature grain warehouse, and were aerated from the top to the bottom using ambient cold air in February. The quality of rough rice was evaluated from February through October. Results: The results were as followings. Moisture contents of rough rice in the low temperature storage had decreased less than the ordinary temperature storage. Cracked rate of brown rice in the ordinary temperature storage and low temperature storage increased by 4~10.8% and 1.6~7.2%, respectively. The germination rate of rough rice under the ordinary and the low temperature warehouse decreased by 15.0~25.0% and 1.7~8.0%, respectively. The acid value of brown rice under the ordinary and the low temperature warehouse increased by 3.67~6.72 KOH mg/100g and 3.08~4.08 KOH mg/100g, respectively. Conclusions: The result indicates that low temperature storage using ambient winter air showed better maintaining germination of rice, less change of physiological activities and cracked kernel, and better maintaining of rice quality, comparing the ordinary temperature storage.

• Applied Biological Chemistry
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• v.33 no.1
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• pp.24-33
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• 1990

The changes in water uptake rate, cooking properties, color of rice grains and gelatinization properties of brown and milled rices during storage were studied. The brown and milled rices were stored at $4^{\circ}$ and $25^{\circ}C$ for 5 and 3 months, respectively. The water uptake rate constants of rices during hydration at $30^{\circ}$ were linearly decreased during storage. The volume increase rate also showed similar trend to the water uptake rate. The terminal point of cooking of milled rice at $100^{\circ}$ in a sealed brass vessel was about a half of that of brown rice. The cooking rate of milled rice was 1.8 times faster than that of brown rice. The cooking rate constant of both brown and milled rices linearly decreased with the increase of storage time. The L(lightness) value increased for brown rice grain and remained unchanged for milled rice grain during storage. The peak viscosity of rice flours by amylograph increased during storage, but enthalpy for gelatinization decreased, as measured by differential scanning calorimetry.

• Applied Biological Chemistry
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• v.31 no.2
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• pp.143-146
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• 1988

The effect of gamma irradiation on controlling infestation of insects on rice grain were investigated. The egg and larva stages of rice weevil (Sitophilus oryzae) were more radiosensitive than the pupal and adult stages. The complete mortal dose of the first two stages was 0.05kGy, while it was 0.5kGy in the second two stages. In indian-meal moth (plodia interpuctella Hubner), sterile doses of egg, larva, pupa and adult were 0.04 to 0.05, 0.05 to 0.06 and 0.2 to 0.25kGy, respectively. Therefore, the irradiation dose within 1.0kGy was considered to be effective for rice storage so far as reinfestation was prevented. Attractiveness of indian-meal moth toward the rice irradiated at 1.0 to 5.0kGy was non-significant in F-test.

• Korea-Australia Rheology Journal
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• v.12 no.1
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• pp.55-67
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• 2000

In this paper, an experimental study of the rheological behavior of granular flow in a new type of storage silo is presented. The main characteristic of the new design is a hexagonal shape chosen with the objective of minimizing the stresses applied to the stored grains, and to reduce grain damage during the filling and emptying processes. Measurements of stress distribution and flow patterns are shown for a variety of granular materials. Because of the design of the silo, the granular material adopts its natural rest angle at all times eliminating collisional stresses and impacts between grains. A homogeneous, low friction flow is naturally achieved which provides a controlled stress distribution throughout the silo during filling and emptying. Secondary dynamic stresses, which are responsible for wall failure in conventional silos of the vertical type, are completely eliminated. A comparison between the two geometries is presented with data obtained for these silos and a number of granular materials. The discharge pattern inhibits powder formation in the silo and the filling system virtually eliminates unwanted material packing. Finally, notwithstanding the rheological advantages of this new design, the hexagonal cells that constitute the silo have many other advantages, such as the possible use of solar energy to control the humidity inside them. The cell type design allows for versatile storage capabilities and the elevation above the ground provides unlimited transportation facilities during emptying.