• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.132-139
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• 1997

This study was carried out to examine the kinetics and reaction mechanism of denitration with formic acid in the simulated radwaste solution containing 6 components such as Nd, Pd, Ru, Zr, Mo and Fe. All experiments were performed with the changes of initial nitric acid concentration, molar ratio of formic acid to nitric acid, and denitration time at $90^{\circ}C$ and a batch system. As results, destruction rate of nitric acid and formic acid was obtained as follows, respectively. $\frac{d[HNO_3]}{dt}=-4.842{\times}10^{-2}[HNO_3][HCOOH],\;\frac{d[HCOOH]}{dt}=-8.911{\times}10^{-2}[HNO_3][HCOOH]$ It was confirmed that denitration with formic acid was controlled by reaction mechanism suggested this study in the range of the initial nitric acid of 2~5M and $[HCOOH]/[HNO_3]$ of 1.5~2.0. In the 1M initial nitric acid, however, it was found that the nitric acid and the formic acid were decomposed by a different reaction mechanism.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.11
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• pp.101-109
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• 2009

Generally, depth cache and pixel cache of 3D graphics are designed by using write-back scheme for efficient use of memory bandwidth. Also, there are write after read operations of same address or only write operations are occurred frequently in 3D graphics cache. If a cache miss is detected, an access to the external memory for write back operation and another access to the memory for handling the cache miss are operated simultaneously. So on frequent cache miss situations, as the memory access bandwidth limited, the access time of the external memory will be increased due to memory bottleneck problem. As a result, the total performance of the processor or the IP will be decreased, also the problem will increase peak power consumption. So in this paper, we proposed a novel early write back cache architecture so as to solve the problems issued above. The proposed architecture controls the point when to access the external memory as to copy the valid data block. And this architecture can improve the cache performance with same hit ratio and same capacity cache. As a result, the proposed architecture can solve the memory bottleneck problem by preventing intensive memory accesses. We have evaluated the new proposed architecture on 3D graphics z cache and pixel cache on a SoC environment where ARM11, 3D graphic accelerator and various IPs are embedded. The simulation results indicated that there were maximum 75% of performance increase when using various simulation vectors.

• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.363-369
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• 2013

In this work, the effects of ozone treatments on mechanical interfacial properties of carbon fibers-reinforced nylon-6 matrix composites were investigated. The surface properties of ozone treated carbon fibers were studied by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). Mechanical interfacial properties of the composites were investigated using critical stress intensity factor ($K_{IC}$). The cross-section morphologies of ozone-treated carbon fiber/nylon-6 composites were observed by scanning electron microscope (SEM). As a result, $K_{IC}$ of the ozone-treated carbon fibers-reinforced composites showed higher values than those of as-received carbon fibers-reinforced composites due the enhanced $O_{1s}/C_{1s}$ ratio of the carbon fiber by the ozone treatments. This result concludes that the mechanical interfacial properties of nylon-6 matrix composites can be controlled by suitable ozone treatments on the carbon fibers.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.8
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• pp.1181-1188
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• 2013

Two experiments were conducted to evaluate the effect of supplementing a corn-soybean meal-based diet with an enzyme complex containing amylase, protease and xylanase on the performance, intestinal health, apparent ileal digestibility of amino acids and nutrient digestibility of weaned pigs. In Exp. 1, 108 piglets weaned at 28 d of age were fed one of three diets containing 0 (control), 100, or 150 ppm enzyme complex for 4 wks, based on a two-phase feeding program namely 1 to 7 d (phase 1) and 8 to 28 d (phase 2). At the end of the experiment, six pigs from the control group and the group supplemented with 150 ppm enzyme complex were chosen to collect digesta samples from intestine to measure viscosity and pH in the stomach, ileum, and cecum, as well as volatile fatty acid concentrations and composition of the microflora in the cecum and colon. There were linear increases (p<0.01) in weight gain, gain: feed ratio and digestibility of gross energy with the increasing dose rate of enzyme supplementation during the whole experiment. Supplementation with enzyme complex increased the digesta viscosity in the stomach (p<0.05) and significantly increased (p<0.01) the concentrations of acetic, propionic and butyric acid in the cecum and colon. Enzyme supplementation also significantly increased the population of Lactobacilli (p<0.01) in the cecum and decreased the population of E. coli (p<0.05) in the colon. In Exp. 2, six crossbred barrows (initial body weight: $18.26{\pm}1.21$ kg), fitted with a simple T-cannula at the distal ileum, were assigned to three dietary treatments according to a replicated $3{\times}3$ Latin Square design. The experimental diets were the same as the diets used in phase 2 in Exp. 1. Apparent ileal digestibility of isoleucine (p<0.01), valine (p<0.05) and aspartic acid (p<0.05) linearly increased with the increasing dose rate of enzyme supplementation. In conclusion, supplementation of the diet with an enzyme complex containing amylase, protease and xylanase improved piglet performance. This is likely a result of improvement in nutrient digestibility, volatile fatty acid concentrations and bacteria ratio in the large intestine.

• Journal of the Korean GEO-environmental Society
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• v.15 no.1
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• pp.53-62
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• 2014

In Korea, in general, separation distance between existing parallel tunnels was set at two to five times as distant as the diameter of the tunnels according to ground conditions. Recently, however, actual applicability of closely spaced parallel tunnels whose distance between tunnel centers was shorter than the diameter has increased due to environmental damages resulting from massive cutting, restriction in purchase of required land, and maintenance of linear continuity. In particular, when the pillar width of tunnel decreases, the safety of pillars affects behaviors of the tunnel and therefore the need for diverse relevant studies has emerged. However, research so far has been largely confined to analysis of behavior characteristics of pillars, or parameters affecting design, and actually applicable and quantitative data have not been presented. Accordingly, in order to present a stability evaluation method which may maximally reflect construction conditions of spots, this study reflected topographical and stratigraphic characteristics of the portal part with the highest closeness between the tunnels, simulated multi-layer conditions with rock mass and complete weathering, and assessed the degree of effect the stability of pillars had on the entire tunnels through numerical analysis according to changes in pillar width by ground strength. This study also presented composite analysis result on ground surface settlement rates, interference volume rates, and average strength to stress and a formula, which may be applicable to actual work, to evaluate safety rates of closely spaced parallel tunnel pillars and minimum pillar width by ground strength based on failure criteria by Hoek-Brown (1980).

• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.2
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• pp.104-115
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• 1989

In an effort to clarify the wetted patterns of sandy loam soil under trickle irrigation conditions, the distance of wetted zone, infiltration capacity and soil wetted patterns, etc. were measured by gypsum block as soil moisture sensor located every 5 cm vertically and horizontaly in the soil bin under the such conditions as a). irrigation rates set to 2, 4, 6, 8 liters per hour b). total amount of water applied fixed to 14.62 liters per soil bin c) the hearing force of soil measured by plate penetrometer ranging from 1.04 to 1.22kg/cm$_2$ The results can be summarized as follows ; 1. The wetted distance in horizontal direction(H), the wetted distance in vertical direction(D), the horizontal infiltration capacity (iH) and the vertical infiltration capacity(in)could by explained as a function of time t. 2. The horizontal wetted distance (H) is explained by an exponetial function H= a$.$ t where b was found ranging from 021 to 026 under surface trickle irrigation, which was considered a lotlower than the classical value of 0.5 and these measurements were indifferent to the increasing irrigation rates. 3. As for the surface trickle irrigation where horizontal infiltration capacity(iH) is explained as iH = A $.$ t h, the coefficient A increases with respect to irrigation rates within the limits of 0.89~1.34. 4. In terms of surface trickle irrigation of the ratio of Dm Which is maximum vertical wetted distance to Hm, which is maximum horizontal wetted distance, found to be within range of 1.0 to 1.21. It was also noted that the value of Dm decreses when irrigation rates increases while the value of Hm changes the opposite direction. 5. The optimum location of sensors from emitter for surface trickle irrigation should he inside of hemisphere whose lateral radius is 28~30cm long and vertical radius is 10~12cm long. The distance between emitters should be within 60cm long. 6. In the study of vertical wetted distance( D) where D= a $.$ tb, the exponential coefficient b ranged from 0.61 to 0.75 in surface trickle irrigation, and from 0A9 to 0.68 for subsurface trickle irrigation. These measurements showed an increasing tendency to with respect to irrigation rates. 7. In case of vertical infiltration capacity( in), where iD= A $.$ t 1-h, the coefficient A for surface trickle irrigation found to be within range of 0.16 to 0.19 and did not show any relationships with varying degree of irrigation rates. However, the coefficient was varying from 0.09 to 0.22 and showed a tendency to increase vis-a-vis irrigation rates for subsurface trickle irrigation, in contrast. 8. In the observation of subsurface trickle irrigation, it was found that Dm/Hm ratio was within 1.52 to 1.91 and showed a decreasing tendency with respect to increasing rates of irrigation. 9. The location of sensors for subsurface trickle irrigation follows same pattern as above, with vertical distance from emitter being 10~17cm long and horizontal 22~25cm long. The location of emitter should be 50 cm. 10.The relationship between VS which is the volume of wetted soil and Q which is the total amount of water when soil is reached field capacity could be explained as VS= 2.914Q0.91and the irrigation rates showed no impacts on the above relationship.

• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.556-563
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• 2014

The purpose of this study was to evaluate the effects of container types on seedling growth of Chamaecyparis obtusa (2-year-old) in the container nursery culture. We used three container types [20 cavities (400 mL/cavity, $150seedlings/m^2$), 24 cavities (320 mL/cavity, $200seedlings/m^2$), and 35 cavities (240 mL/cavity, $260seedlings/m^2$)] and measured root collar diameter (RCD), height, biomass, root density and seedling quality index (SQI). The RCD, height, biomass, root density and SQI were the highest at 20 cavities/tray because this container has the largest volume and lowest seedling density. However, H/D and T/R ratio at all container types were not significantly different. The total biomass per unit area ($m^2$) were the lowest at 35 cavities/tray and those at both 20 and 24 cavities/tray were not significantly different. Container volume was positively correlated with RCD, height, biomass, root density and SQI except for H/D and T/R ratio, while seedling density negatively affected on them. Based on these results, 20 cavities/tray are optimal for container seedling production of C. obtusa. Usage of optimal container will make us get better quality seedlings and reduction of production costs in the container nursery as well as good field performances with higher survival rate in plantation.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.66-74
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• 2008

Two experiments were conducted to assess the effect of replacing a conventional concentrate with mixed cassava (Manihot esculenta) foliage and legume (Phaseolus calcaratus) foliage. In Exp. 1, three rumen fistulated crossbred cows were used for in sacco rumen degradability studies. In vitro gas production was also studied. In Exp. 2, 11 crossbred F2 heifers (Red Sindhi$\times$Holstein Friesian), with initial live weight of $129{\pm}6kg$ and aged six months, were allocated in a Completely Randomized Design (CRD) to evaluate a mixture (ratio 3:1) of cassava and legume foliage (CA-LE feed) as a protein source compared to a traditional concentrate feed (Control) in diets based on fresh elephant grass (Pennisetum purpureum) and urea treated rice straw ad libitum. The Control feed was replaced by the CA-LE feed at levels of 0% (Control), 40% (CA-LE40), and 60% (CA-LE60) based on dry matter (DM). The in sacco degradation of CA-LE feed was higher than Control feed (p<0.05). After 48 h incubation the degradation of CA-LE feed and Control feed was 73% vs. 58% of DM and 83% vs. 65% of CP, respectively. The gas production of CA-LE feed was also significantly higher than of Control feed during the first 12 h of incubation. The results of the performance study (Exp. 2) showed that the level of CA-LE feed in the concentrate had no effect on total dry matter intake (p>0.05), but live weight gains (LWG) in CA-LE40 and CA-LE60 were significantly higher (551 and 609 g/d, respectively) than in the Control group (281 g/d). The intake of CP was higher (p<0.05) for the treatments CA-LE40 and CA-LE60 (556 and 590 g/d, respectively) compared to that of Control (458 g/d), while there was no significant difference in ME intake. The feed conversion ratio was 16.8, 9.0 and 7.9 kg DM/kg LWG in Control, CA-LE40 and CA-LE60, respectively. The feed cost of CA-LE40 and CA-LE60 corresponded to 43% and 35%, respectively, of the feed cost of Control feed. The best results were found when CA-LE feed replaced 60% of DM in Control feed and considerably decreased feed cost. It is concluded that feeding cassava foliage in combination with Phaseolus calcaratus legume as a protein supplement could be a potentially valuable strategy which leads to reduced feed costs and a more sustainable system in smallholder dairy production in Vietnam.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.10
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• pp.583-589
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• 2015

This study was performed to evaluate the feasibility of anaerobic pretreatment for the leachate solubilized from thermal hydrolysis of sewage sludge cake. Overall process for the treatment of sludge cake consists of thermal hydrolysis, crystallization of magnesium, ammonium, and phosphate (MAP) for the leachate and anaerobic digestion of supernatant from MAP crystallization. The experimental evidence showed that the optimum ratio of Mg : P for the struvite crystallization of leachate solubilized from thermal hydrolysis of sludge cake was 1.5 to 1.0 as weight basis at the pH of 9.5. With this operational condition, the removal efficiencies of ammonia nitrogen and phosphorous achieved 50% and 97%, respectively. The mesophilic batch test showed that the ultimate biodegradability of the supernatant from MAP crystallization reached 63% at S/I ratio of 0.5. The readily biodegradable fraction of 90% ($S_1$) of the MAP supernatant BVS (Biodegradable Volatile Solids, $S_0$) degraded with $k_1$ of $0.207day^{-1}$ for the initial 17 days where as the rest slowly biodegradable fraction ($S_2$) of 10% of BVS degraded with $k_2$ of $0.02day^{-1}$ for the rest of the operational period. Semi-Continuously Fed and Mixed Reactor (SCFMR) was chosen as one of the best candidates to treat the MAP supernatant because of its total solids content over 6%. Maximum average biogas production rates reached 0.45 v/v-d and TVS removal efficiency of 37~41% was achieved at an hydraulic retention time (HRT) of 20 days and its corresponding organic loading rate (OLR) of 1.43 g VS/L-d.

• Korean journal of applied entomology
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• v.14 no.3 s.24
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• pp.137-140
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• 1975

Field experiments on red-pepper were conducted in Suweon area during 1972-1974 to determine the seasonal fluctuation of Heliothis assulta H. using black light traps and direct counts. Adult moths emerged in late May, and showed three peaks of fluctuation from late June to middle July, from middle August to late August, and in mid-September. Eggs were first discovered in the field in early July, with peak incidence Iron late August to early September. Larval peaks occurred in late July to early August, in late August and mid-September to mid-October Initial hatching in the field occurred in early July. The numbers of the first larval generation were the highest. The parasitization ratio of Trichogramma spp. on eggs averaged 51 percent during mid-July to mid-September. The numbers of Trichogramma spp. emerging from one tobacco bud-worm egg ranged from one to four, but in most cases one or two egg parasitizing wasps emerged.