• Title/Summary/Keyword: A4WP

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Synthesis and Sintering Behavior of Zr2WP2O12 Ceramics (Zr2WP2O12 세라믹스의 합성과 소결거동 연구)

  • Kim, Yong-Hyeon;Kim, Nam-Ok;Lee, Sang-Jin
    • Journal of the Korean Ceramic Society
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    • v.49 no.6
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    • pp.586-591
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    • 2012
  • $Zr_2WP_2O_{12}$ powder, which has a negative thermal expansion coefficient, was synthesized by a solid-state reaction with $ZrO_2$, $WO_3$ and $NH_4H_2PO_4$ as the starting materials. The synthesis behavior was dependent on the solvent media used in the wet mixing process. The $Zr_2WP_2O_{12}$ powder prepared with a solvent consisting of D. I. water was fully crystallized at $1200^{\circ}C$, showing a sub-micron particle size. According to the results obtained from a thermal analysis, a $ZrP_2O_7$ was synthesized at a low temperature of $310^{\circ}C$, after which it was reacted with $WO_3$ at $1200^{\circ}C$. A new sintering additive, $Al(OH)_3$, was applied for the densification of the $Zr_2WP_2O_{12}$ powders. The cold isostatically pressed samples were densified with 1 wt% $Al(OH)_3$ additive or more at $1200^{\circ}C$ for 4 h. The main densification mechanism was liquid-phase sintering due to the liquid which resulted from the reaction with amorphous or unstable $Al_2O_3$ and $WO_3$. The densified $Zr_2WP_2O_{12}$ ceramics showed a relative density of 90% and a negative thermal expansion coefficient of $-3.4{\times}10^{-6}/^{\circ}C$. When using ${\alpha}-Al_2O_3$ as the sintering agent, densification was not observed at $1200^{\circ}C$.

CERTAIN NEW WP-BAILEY PAIRS AND BASIC HYPERGEOMETRIC SERIES IDENTITIES

  • Ali, S. Ahmad;Rizvi, Sayyad Nadeem Hasan
    • Communications of the Korean Mathematical Society
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    • v.32 no.4
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    • pp.885-898
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    • 2017
  • The Bailey lemma has been a powerful tool in the discovery of identities of Rogers-Ramanujan type and also ordinary and basic hyper-geometric series identities. The mechanism of Bailey lemma has also led to the concepts of Bailey pair and Bailey chain. In the present work certain new WP-Bailey pairs have been established. We also have deduced a number of basic hypergeometric series identities as an application of new WP-Bailey pairs.

Assessment of Water Productivity & Potential Water Consumption of Rice by Each Province (벼에 대한 지역별 물 생산성 및 잠재 물 소비량 평가)

  • Hur, Seung-Oh;Choi, Soonkun;Yeop, Sojin;Hong, Seong-Chang;Choi, Dong-Ho
    • Journal of Korean Society of Rural Planning
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    • v.25 no.4
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    • pp.27-33
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    • 2019
  • Agricultural water for crops are faced with the need to improve the use efficiency due to the impact of climate change. Water productivity (WP) is known as a good indicator for assessing resources efficiency. This study was conducted to assess WP of rice and potential water consumption (PWC) as new indicator for water use efficiency assessment. The average of WP was 0.7 kg/㎥, and Jeonbuk had the highest WP as 0.83 kg/㎥. Kangwon and Kyungbuk had the lowest WP as 0.59 kg/㎥. PWC showed the same trend because of rice consumption per capita, but Total PWC considering population living in each province showed the different trend with PWC. Every year, the changing patterns of WP was increasing little by little, and the patterns of PWC was decreasing greatly than WP. These results mean that WP has been slowly improved through breed development and irrigation techniques, and PWC was affected by reduced rice consumption and WP increasing. PWC could also be useful as an indicator to compare the water use efficiency between provinces or nations.

Quality Characteristics of Fish Cake Made with Silver Pomfret (Pampus argenteus) with Added Wasabi Powder (고추냉이 분말을 첨가한 병어 어묵의 품질 특성)

  • Jang, Jin-A;Kim, Hyun-Ah;Choi, Su-Keun
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.1
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    • pp.103-112
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    • 2010
  • This study was preformed to make high quality fish cake made with silver pomfret, which is one of the savory, soft and delicious fishes by adding wasabi powder (WP). WP as natural additives was added to the ratio of 0.6%, 1.2%, 1.8%, 2.4%, 3%, a color values, texture, folding test, sensory evaluation, peroxide value, TBA value, and viable cell count were analyzed. L and a value were decreased significantly by the increase of the ratio of WP. However, b value was increased. In the folding test to show the flexibility of fish cake, it was measured AA in the all samples. As the result of measuring texture, hardness was increased significantly by the addition of WP, cohesiveness was the highest in 1.8 WP and 0.6 WP, Springiness showed no significant difference among samples. However gumminess and chewiness of fish cake adding wasabi powder were significantly higher comparing with control group. In sensory evaluation, 1.8 WP had the best score in overall acceptability. Fish cakes had lower peroxide value, TBA value and viable cell count after frying compared to the one without WP. These results indicate that fish cake could be prepared by adding the WP for high quality and functionality. Consequently, wasabi can be applied as a food preservative or additive in fish cake.

Study on WP-IBE compliant Mobile IPSec (WP-IBE 적용 Mobile IPSec 연구)

  • Choi, Cheong Hyeon
    • Journal of Internet Computing and Services
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    • v.14 no.5
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    • pp.11-26
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    • 2013
  • In the wireless Internet, it is so restrictive to use the IPSec. The MIPv4 IPSec's path cannot include wireless links. That is, the IPSec of the wireless Internet cannot protect an entire path of Host-to-Host connection. Also wireless circumstance keeps a path static during the shorter time, nevertheless, the IKE for IPSec SA agreement requires relatively long delay. The certificate management of IPSec PKI security needs too much burden. This means that IPSec of the wireless Internet is so disadvantageous. Our paper is to construct the Mobile IPSec proper to the wireless Internet which provides the host-to-host transport mode service to protect even wireless links as applying excellent WP-IBE scheme. For this, Mobile IPSec requires a dynamic routing over a path with wireless links. FA Forwarding is a routing method for FA to extend the path to a newly formed wireless link. The FA IPSec SA for FA Forwarding is updated to comply the dynamically extended path using Source Routing based Bind Update. To improve the performance of IPSec, we apply efficient and strong future Identity based Weil Pairing Bilinear Elliptic Curve Cryptography called as WP-IBE scheme. Our paper proposes the modified protocols to apply 6 security-related algorithms of WP-IBE into the Mobile IPSec. Particularly we focus on the protocols to be applied to construct ESP Datagram.

Damage of broad mite, Polyphagotarsonemus latus (Banks), on pepper growth and yield and its chemical control (차먼지응애(Polyphagotarsonemus latus)가 고추의 생육과 수확에 미치는 피해 및 화학적 방제)

  • 조명래;전흥영;라승영;김동순;임명순
    • Korean journal of applied entomology
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    • v.35 no.4
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    • pp.326-331
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    • 1996
  • To evaluate the damage of broad mite, Polyphagotarsonemus latus (Banks), on pepper growth and yield, broad mite females were infested on pepper seedlings. In plots infested with 1, 2, and 5 females/plant, pepper growth was significantly reduced after 10 weeks with growth rates of 264, 256, and 177%, respectively, while that of control plot was 337%. Total pepper yields in the plots infested with 1, 2, and 5 females/plant were 443.9, 230. 5, and 103.4 kg/lOa, respectively, which were significantly lower than 1, 197.5 kg/lOa of the control plot. Dicofol EC, Chinomethionat WP, Pyridaben WP, and Pyraclofos WP were effective in controlling the broad mite on pepper showing over 90% mortality by 17 days after application. Although the updated reports on the nationwide occurrence of the broad mite damage on pepper showed that most damages were occurring in greenhouses between October and March, damages were observed in late May in certain locality.

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Depth-dependent Variations in Elemental and Mineral Distribution in the Deep Oceanic Floor Sediments (WP21GPC04) near the Mariana Trench in the Western Pacific Ocean (마리아나 해구에 인접한 서태평양 심해평원의 정점 WP21GPC04에서 수집된 해양 퇴적물의 깊이에 따른 원소 및 광물 분포 변화)

  • Junte Heo;Seohee Yun;Jonguk Kim;Young Tak Ko;Yongjae Lee
    • Economic and Environmental Geology
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    • v.56 no.5
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    • pp.581-588
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    • 2023
  • This study reports depth-dependent elemental distribution and mineral abundance of the oceanic sediment sample (WP21GPC04) near the Mariana Trench collected during the WP21 expedition in 2021. The elemental distribution determined by μ-XRF shows no significant differences with varying depth, with an average SiO2 53.91 wt%, FeO 4.48 wt%, Al2O3 16.56 wt%, MgO 2.56 wt%, CaO 4.79 wt%, Na2O 3.52 wt%, K2O 5.48 wt%, similar to the average chemical composition of global subducting sediments (GLOSS). The mineral abundances analyzed using synchrotron XRD, however, vary with depth. While quartz, mica, and plagioclase were identified at all depths, chlorite was found at shallow depths, and zeolite group minerals, phillipsite and heulandite, showed a gradual change in phase fraction with depth. This suggests a change in sedimentation and alteration environments in the region, or the potential for coexistence emerges due to similar sediment stability. Overall, this study will provide a basis for the future investigations on the evolution of sedimentary environment near the Mariana Trench in the western Pacific Ocean and the phase distribution and the behavior of subducting oceanic sediments, which will affect the lithological and geochemical characteristics of the Mariana susduction system.

Risk Assessment of Pesticide for Earthworms (농약의 지렁이에 대한 위해성 평가)

  • Park, Kyung-Hun;Park, Yeon-Ki;Joo, Jin-Bok;Kyung, Kee-Sung;Shin, Jin-Sup;Kim, Chan-Sub;Park, Byung-Jun;Uhm, Jae-Youl
    • The Korean Journal of Pesticide Science
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    • v.7 no.4
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    • pp.280-287
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    • 2003
  • To assess the risk of pesticides on earthworm, the acute toxicities of 10 pesticides were investigated and their toxicity exposure ratios(TERs) were calculated. As the TERs of paraquat dichloride and pendimethalin were more than 100, their risks were rated negligible. Risk of benfuracarb, cadusafos, chlorpyrifos-methyl, endosulfan, isazofos and parathion which have TERs of $10\sim100$ were rated low. However, risk of imidacloprid and phorate which have TER of less than 10 were estimated highly to need a reproduction study. Earthworms were exposed to twenty two pesticides including dazomet 98% GR having PECs of more than $5mg{\cdot}kg^{-1}$ in artificial soil at standard and double dose for 14 days. All the earthworms exposed to dazomet 98% GR and metam-sodium 25% SL were died to show their high risk, while no serious adverse effects were observed in the soil treated with 15 pesticides, calcite 95% WP, calcium polysulfide 36% CF, chlorothalonil 75% WP, daminozide 85% WP, dichlonil 6.7% GR, etridiazole 25% EC, fosetyl-Al 80% WP, glyphosate 41 % SL, hymexazol 30% SL, iprodione 50% WP, machine oil 95% EC, mancozeb 75% WP, propineb 70% WP, terbuthylazine 80% WP and triazophos 40% EC. In case of thiophanate-methyl 70% WP, copper hydroxide 77% WP, dimethoate 46% EC, tolclofos-methyl 50% WP and propamocarb hydrochloride 67% SL, any effect did not show clearly, suggesting an additional subchronic toxicity study. The risk of thiophanate-methyl 70% WP to earthworm was estimated high, considering its subchronic effect, while effects of copper hydroxide 77% WP, dimethoate 46% EC, tolclofos-methyl 50% WP and propamocarb hydrochloride 67% SL to earthworms were negligible, considering no adverse effects in subchronic tests.

A new formulation method of small amount wettable powders for pesticide screening (농약스크리닝을 위한 미량 수화제의 간편한 제제방법)

  • Yu, Ju-Hyun;Lee, Byung-Hoi;Cho, Kwang-Yun
    • Applied Biological Chemistry
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    • v.33 no.4
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    • pp.315-318
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    • 1990
  • After technical pesticides and dispersants were dissolved in a volatile organic solvent, the wettable powders(WP's) were formulated by adsorbing the pesticide-dispersant solution to finely powdered porous synthetic silica without milling process. The median sizes of 11 WP'S were smaller than $8{\mu}m$, 9 of which had more than 80% suspensibility after 2 hours. It was possible In formulate 50% WP for liquid of fly technical pesticides. The pesticidal efficacies of WP's tested were comparable In commercial formulations regardless of suspensibilities of WP's.

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Evaluation of Susceptibility of Spoladea recurvalis (Lepidoptera: Crambidae) to Five Insecticides in Spinach (시금치 해충 흰띠명나방(Spoladea recurvalis)의 살충제 감수성)

  • Young Su, Lee;Hee-A, Lee;So-Hee, Kim;Jong Yoon, Choi;Hyun Ju, Lee;Sang-Woo, Lee;Jung-Soo, Park
    • Korean journal of applied entomology
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    • v.61 no.4
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    • pp.529-537
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    • 2022
  • The susceptibilities of five insecticides to the larvae of Spoladea recurvalis, a major pest of spinach, were evaluated. Lufenuron EC, chromafenozide EC, chlorantraniliprole WP, tebufenozide WP, and pyridalyl EW showed 90% or more insecticidal activity at dilution concentrations of 2 (12.5 ppm), 4 (12.5 ppm), 8 (2.5 ppm), 4 (20.0 ppm), and 8 (12.5 ppm), respectively. At their recommended concentrations, Chromafenozide EC, chlorantraniliprole WP, tebufenozide WP, and pyridalyl EW showed very high insecticidal activity of 98.3%, 100%, 95.0%, and 100%, respectively, after 72 h on S. recurvalis larvae exposed after 7 days of treatment. Field tests at two spinach greenhouses in Hwaseong and Yeoncheon showed a high control effect of over 90% after 7 days of treatment in both areas. In addition, the insecticides can be used as exclusive agents for S. recurvalis that occurs in spinach, as there is no phytotoxicity even at double doses.