• Title/Summary/Keyword: Li reduction

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Effect of relative stiffness on seismic response of subway station buried in layered soft soil foundation

  • Min-Zhe Xu;Zhen-Dong Cui;Li Yuan
    • Geomechanics and Engineering
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    • v.36 no.2
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    • pp.167-181
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    • 2024
  • The soil-structure relative stiffness is a key factor affecting the seismic response of underground structures. It is of great significance to study the soil-structure relative stiffness for the soil-structure interaction and the seismic disaster reduction of subway stations. In this paper, the dynamic shear modulus ratio and damping ratio of an inhomogeneous soft soil site under different buried depths which were obtained by a one-dimensional equivalent linearization site response analysis were used as the input parameters in a 2D finite element model. A visco-elasto-plastic constitutive model based on the Mohr-Coulomb shear failure criterion combined with stiffness degradation was used to describe the plastic behavior of soil. The damage plasticity model was used to simulate the plastic behavior of concrete. The horizontal and vertical relative stiffness ratios of soil and structure were defined to study the influence of relative stiffness on the seismic response of subway stations in inhomogeneous soft soil. It is found that the compression damage to the middle columns of a subway station with a higher relative stiffness ratio is more serious while the tensile damage is slighter under the same earthquake motion. The relative stiffness has a significant influence on ground surface deformation, ground acceleration, and station structure deformation. However, the effect of the relative stiffness on the deformation of the bottom slab of the subway station is small. The research results can provide a reference for seismic fortification of subway stations in the soft soil area.

Clinical Study on Safety and Efficacy of Microwave Ablation for Primary Hyperparathyroidism

  • Ying Wei;Lili Peng;Yan Li;Zhen-long Zhao;Ming-an Yu
    • Korean Journal of Radiology
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    • v.21 no.5
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    • pp.572-581
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    • 2020
  • Objective: To evaluate the safety, feasibility, and efficacy of microwave ablation (MWA) for the treatment of primary hyperparathyroidism (PHPT). Materials and Methods: This study enrolled 67 PHPT patients (22 men, 45 women; mean age, 56.0 ± 16.3 years; range, 18-83 years) from January 2015 to December 2018. The laboratory data, including the serum intact parathyroid hormone (iPTH), calcium, phosphorus, and alkaline phosphatase (ALP) levels, were evaluated before MWA and again 2 hours, 1 day, 7 days, 1 month, 3 months, 6 months, 12 months, 18 months, and 24 months after. Results: Complete ablation was achieved with all 72 hyperplastic parathyroid glands found on the 67 patients enrolled, 64 of whom were treated in one session and 3 were treated over two sessions. The technical success rate was 100%. The median follow-up time was 13.6 months (range, 10.0-31.1 months). The clinical success rate was 89.4%. The volume reduction rate was 79.4% at 6 months. Compared to pre-MWA, the serum iPTH, calcium, phosphorus, and ALP levels had significantly improved 6 months post-MWA (iPTH, 157.3 pg/mL vs. 39.2 pg/mL; calcium, 2.75 ± 0.25 mmol/L vs. 2.34 ± 0.15 mmol/L; phosphorus, 0.86 ± 0.20 mmol/L vs. 1.12 ± 0.22 mmol/L; ALP, 79 U/L vs. 54 U/L, respectively; all, p < 0.01). Hoarseness was a major complication in 4 patients (6.0%), but it improved spontaneously within 2-3 months. Conclusion: MWA is safe, feasible, and effective for the treatment of PHPT.

Hydrogeochemical and Environmental Isotope Study of Groundwaters in the Pungki Area (풍기 지역 지하수의 수리지구화학 및 환경동위원소 특성 연구)

  • 윤성택;채기탁;고용권;김상렬;최병영;이병호;김성용
    • Journal of the Korean Society of Groundwater Environment
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    • v.5 no.4
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    • pp.177-191
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    • 1998
  • For various kinds of waters including surface water, shallow groundwater (<70 m deep) and deep groundwater (500∼810 m deep) from the Pungki area, an integrated study based on hydrochemical, multivariate statistical, thermodynamic, environmental isotopic (tritium, oxygen-hydrogen, carbon and sulfur), and mass-balance approaches was attempted to elucidate the hydrogeochemical and hydrologic characteristics of the groundwater system in the gneiss area. Shallow groundwaters are typified as the 'Ca-HCO$_3$'type with higher concentrations of Ca, Mg, SO$_4$and NO$_3$, whereas deep groundwaters are the 'Na-HCO$_3$'type with elevated concentrations of Na, Ba, Li, H$_2$S, F and Cl and are supersaturated with respect to calcite. The waters in the area are largely classified into two groups: 1) surface waters and most of shallow groundwaters, and 2) deep groundwaters and one sample of shallow groundwater. Seasonal compositional variations are recognized for the former. Multivariate statistical analysis indicates that three factors may explain about 86% of the compositional variations observed in deep groundwaters. These are: 1) plagioclase dissolution and calcite precipitation, 2) sulfate reduction, and 3) acid hydrolysis of hydroxyl-bearing minerals(mainly mica). By combining with results of thermodynamic calculation, four appropriate models of water/ rock interaction, each showing the dissolution of plagioclase, kaolinite and micas and the precipitation of calcite, illite, laumontite, chlorite and smectite, are proposed by mass balance modelling in order to explain the water quality of deep groundwaters. Oxygen-hydrogen isotope data indicate that deep groundwaters were originated from a local meteoric water recharged from distant, topograpically high mountainous region and underwent larger degrees of water/rock interaction during the regional deep circulation, whereas the shallow groundwaters were recharged from nearby, topograpically low region. Tritium data show that the recharge time was the pre-thermonuclear age for deep groundwaters (<0.2 TU) but the post-thermonuclear age for shallow groundwaters (5.66∼7.79 TU). The $\delta$$\^$34/S values of dissolved sulfate indicate that high amounts of dissolved H$_2$S (up to 3.9 mg/1), a characteristic of deep groundwaters in this area, might be derived from the reduction of sulfate. The $\delta$$\^$13/C values of dissolved carbonates are controlled by not only the dissolution of carbonate minerals by dissolved soil CO$_2$(for shallow groundwaters) but also the reprecipitation of calcite (for deep groundwaters). An integrated model of the origin, flow and chemical evolution for the groundwaters in this area is proposed in this study.

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The Historical Study of Headache in Chinese Ming Dynasty (명대의가(明代醫家)들의 두통(頭痛)에 대한 인식변화에 관한 연구)

  • Chun, Duk-Bong;Maeng, Woong-Jae;Kim, Nam-Il
    • The Journal of Korean Medical History
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    • v.24 no.1
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    • pp.43-56
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    • 2011
  • Everyone once in a life experience headaches as symptoms are very common. According to a study in a country of more than a week and as many as those who have experienced a headache amounts to 69.4%. In addition, the high reported prevalence of migraine in 30s for 80% of all migraine sufferers daily life interfere with work or was affected. In Western medicine, the cause of headaches is traction or deformation of pain induced tissue like scalp, subcutaneous tissue, muscle, fascia, extracranial arteriovenous, nerves, periosteum. But it turns out there are not cause why pain induced tissue is being tracted or deformated. Therefore, most of the western-therapy is mainly conducted with regimen for a temporary symptom reduction. Therefore, I examined how it has been developed in Chinese Ming Dynasty, the perception of headache, change in disease stage and an etiological cause. Oriental medicine in the treatment of headache is a more fundamental way to have an excellent treatment. The recognition of head in "素問($s{\grave{u}}$ $w{\grave{e}}n$)" and "靈樞($l{\acute{i}}ng$ $sh{\bar{u}}$)" began to appear in 'Soul-神($sh{\acute{e}}n$) dwelling place' and 'where to gather all the Yang-'諸陽之會($zh{\bar{u}}$ $y{\acute{a}}ng$ $zh{\bar{i}}$ $hu{\grave{i}}$)'. Also, head was recognized as '六腑($li{\grave{u}}f{\check{u}}$) 淸陽之氣($q{\bar{i}}ng$ $y{\acute{a}}ng$ $zh{\bar{i}}$ $q{\grave{i}}$) and 五臟($w{\check{u}}$ $z{\grave{a}}ng$) 精血($j{\bar{i}}ng$ $xu{\grave{e}}$) gathering place'. More specific structures such as the brain is considered a sea of marrow(髓海-$su{\check{i}}$ $h{\check{a}}i$) in "內經($n{\grave{e}}i$ $j{\bar{i}}ng$)" and came to recognized place where a stroke occurs. Accompanying development of the recognition about head, there had been changed about the perception of headache and the recognition of the cause and mechanism of headache. And the recognition of headache began to be completed in Ming Dynasty through Jin, Yuan Dynasty. Chinese Ming Dynasty, specially 樓英($l{\acute{o}}u$ $y{\bar{i}}ng$), in "醫學綱目($y{\bar{i}}xu{\acute{e}}$ $g{\bar{a}}ngm{\grave{u}}$)", first enumerated prescription in detail by separating postpartum headache. and proposed treatment of headache especially due to postpartum sepsis(敗血-$b{\grave{a}}i$ $xu{\grave{e}}$). 許浚($x{\check{u}}$ $j{\grave{u}}n$) accepted a variety of views without impartial opinion in explaining one kind of headache in "東醫寶鑑($d{\bar{o}}ng-y{\bar{i}}$ $b{\check{a}}oji{\grave{a}}n)$" 張景岳($zh{\bar{a}}ng$ $j{\check{i}}ng$ $yu{\grave{e}}$), in "景岳全書($j{\check{i}}ng$ $yu{\grave{e}}$ $qu{\acute{a}}nsh{\bar{u}}$)", established his own unique classification system-新舊表裏($x{\bar{i}}nji{\grave{u}}$ $bi{\check{a}}ol{\check{i}}$)-, and offered a clear way even in treatment. Acupuncture treatment of headache in the choice of meridian has been developed as a single acupuncture point. Using the classification of headache to come for future generation as a way of locating acupoints were developed. Chinese Ming Dynasty, there are special treatments like 導引按蹻法($d{\check{a}}o$ y ${\check{i}}n$ ${\grave{a}}n$ $ji{\check{a}}o$ $f{\check{a}}$), 搐鼻法($ch{\grave{u}}$ $b{\acute{i}}$ $f{\check{a}})$, 吐法($t{\check{u}}$ $f{\check{a}}$), 外貼法($w{\grave{a}}i$ $ti{\bar{e}}$ $f{\check{a}}$), 熨法($y{\grave{u}}n$ $f{\check{a}}$), 點眼法($di{\check{a}}n$ $y{\check{a}}n$ $f{\check{a}}$), 熏蒸法($x{\bar{u}}nzh{\bar{e}}ng$ $f{\check{a}}$), 香氣療法($xi{\bar{a}}ngq{\grave{i}}$ $li{\acute{a}}of{\check{a}}$). Most of this therapy in the treatment of headache, it is not used here, but if you use a good fit for today's environment can make a difference.

Melting Characteristics for Radioactive Aluminum Wastes in Electric Arc Furnace (아크 용융로에서 방사성 알루미늄 폐기물의 용융특성)

  • Min, Byung-Youn;Song, Pyung-Seob;Ahn, Jun-Hyung;Choi, Wang-Kyu;Jung, Chong-Hun;Oh, Won-Zin;Kang, Yong
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.4 no.1
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    • pp.33-40
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    • 2006
  • The characteristics of the aluminum waste melting and the distribution of the radioactive nuclides have been investigated for the estimation on the volume reduction and the decontamination of the aluminum wastes from the decommissioning of the TRIGA MARK it and III research reactors at the Korea Atomic Energy Research Institute(KAERI). The aluminum wastes were melted with the use of the fluxes such as flux $A:NaCl-KCl-Na_3AlF_6$, flux B:NaCl-NaF-KF, flux $C:CaF_2$, and flux $D:LiF-KCl-BaCl_2$ in the DC graphite arc furnace. For the assessment of the distribution of the radioactive nuclides during the melting of the aluminum, the aluminum materials were contaminated by the surrogate nuclides such as cobalt(Co), cesium(Cs) and strontium(Sr). The fluidity of aluminum melt was increased with the addition of the fluxes, which has slight difference according to the type of fluxes. The formation of the slag during the aluminum melting added the flux type C and D was larger than that with the flux A and B. The rate of the slag formation linearly increased with increasing the flux concentration. The results of the XRD analysis showed that the surrogate nuclide was transferred to the slag, which can be easily separated from the melt and then they combined with aluminum oxide to form a more stable compound. The distribution ratio of cobalt in ingot to that in slag was more than 40% at all types of fluxes. Since vapor pressures of cesium and strontium were higher than those that of the host metals at the melting temperature, their removal efficiency from the ingot phase to the slag and the dust phase was by up to 98%.

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The Calcium Release from Cardiac Mitochondria by Sodium and Potassium ($Na^+$$K^+$에 의한 심장근 Mitochondria에서의 $Ca^{++}$ 유리작용)

  • Kim, Myung-Suk
    • The Korean Journal of Pharmacology
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    • v.14 no.1_2
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    • pp.1-11
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    • 1978
  • The $Na^+$-and $K^+$-induced $Ca^{++}$ release was measured isotopically by Milipore filter technique in mitochondria isolated from rabbit ventricles. The release of $Ca^{++}$ from mitochondria could be induced by 1-3 mM of $Na^+$ added in incubating medium under the presence of 0.5mM EGTA to prevent the released $Ca^{++}$ from rebinding with mitochondrial membrane. The amount of $Ca^{++}$ released was increased by increasing the concentration of $Na^+$ added. 100mM $K^+$, in itself, did not induce the $Ca^{++}$ release from cardiac mitochondria, the $Na^+$-induced $Ca^{++}$ release, however, was potentiated by the presence of $K^+$. The potentiation of $Na^+$-induced $Ca^{++}$ release by $K^+$ was proportional to the $Na^+/K^+$ ratio presented in the incubating medium. Among the monovalent cations other than $Na^+$, the release of $Ca^{++}$ from cardiac mitochondria was shared only by $Li^+$. The $Na^+$-induced $Ca^{++}$ release could be also observed in the mitochondria isolated from liver and kidney. However, the $Na^+$ sensitivity was somewhat lower in liver and kidney mitochondria than in heart mitochondria. The release of $Ca^{++}$ induced by $Na^+$ in the mitochondria isolated from the experimentally produced failured heart was not different from that in the normal heart mitochondria, and was not directly modified by $10^{-6}{\sim}10^{-5}$ M of Ouabain. From the experiments, it was suggested that the $Ca^{++}$ released from mitochondria by $Na^+$ could be used in excitation-contraction coupling process to initiate the contraction of the cardiac myofibrils. Futhermore, it appeared that the phenomenon of $Ca^{++}$ release from cardiac mitochondria by $Na^+$ and $K^+$ might be related to the inotropic effect of digitalis glycoside which could bring about the increase of $Na^+$ or the reduction of $K^+$ intracellulary through the inhibition of $Na^+$, $K^+$-ATPase.

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Sulfur Dioxide, Mineral Contents and Physicochemical Properties Generated during Manufacture of Bamboo Salt (죽염 제조공정에 따른 이산화황, 미네랄 함량 및 이화학적 특성)

  • Kim, Hag-Lyeol;Lee, Seong-Jae;Lee, Jung-Hee;Kim, In-Cheol
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.8
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    • pp.1248-1256
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    • 2014
  • The purpose of this study was to investigate the mechanisms of behind $SO_2$ formation and elevated cause of reducing power in purple bamboo salt (PBS) along with an analysis of physicochemical properties, content of sulfur compounds, oxidation reduction potential (ORP), mineral contents of salt type (MSS, mudflat solar salt; BS, bamboo salt), and addition of raw bamboo (RB). $SO_2$ content of 630 ppm was detected in PBS. $SO_2$ was not detected in MSS, BS, or RB, whereas $SO_2$ (782 ppm) from $K_2SO_4$ was detected after heating a NaCl, KCl, $MgCl_2$, $MgSO_4$, MgO, $CaCl_2$, $K_2SO_4$, and $FeSO_4$ with RB. $SO_2$ content of BS increased with baking time, and it originated from BSRB1 (13.88 ppm) to BSRB4 (109.13 ppm). $SO_3{^{2-}}$ originated only from MSSRB4 and BSRB2~BSRB4. Sulfate ion content decreased along with increasing $SO_2$ and sulfite ion contents. ORP increased with baking time of MSS and BS, and it was present at higher levels in BSRB4 (-211.40 mV) of BS than MSS. Insoluble content was higher in BS than MSS. Further, Ca, K, and Mg ion contents decreased in MSS and increased in BS with baking time. BSRB4 had 1.4 fold higher levels of Ca, 1.5 fold higher levels of Mg, and 1.8 fold higher levels of K than BS. Li, Al, Mn, Fe, and Sr in MSS as well as Al, Fe, and Ni in BS increased with baking time. Anions (Cl, $NO_3$, and Br) and heavy metals (Pb, Cd, Hg, and As) between MSS and BS were not significantly different. These results suggest that the reducing power of BS was due to $SO_2$ and sulfite ion. To increase the amounts of these compounds and reducing power, higher melting temperature and longer baking time are necessary along with BS, which is created by the addition of RB to roasted salt.

Magnetic Tunnel Junctions with AlN and AlO Barriers

  • Yoon, Tae-Sick;Yoshimura, Satoru;Tsunoda, Masakiyo;Takahashi, Migaku;Park, Bum-Chan;Lee, Young-Woo;Li, Ying;Kim, Chong-Oh
    • Journal of Magnetics
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    • v.9 no.1
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    • pp.17-22
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    • 2004
  • We studied the magnetotransport properties of tunnel junctions with AlO and AlN barriers fabricated using microwave-excited plasma. The plasma nitridation process provided wider controllability than the plasma oxidization for the formation of MTJs with ultra-thin insulating layer, because of the slow nitriding rate of metal Al layers, comparing with the oxidizing rate of them. High tunnel magnetoresistance (TMR) ratios of 49 and 44% with respective resistance-area product $(R{\times}A) of 3 {\times} 10^4 and 6 {\times} 10^3 {\Omega}{\mu}m^2$ were obtained in the Co-Fe/Al-N/Co-Fe MTJs. We conclude that AlN is a hopeful barrier material to realize MTJs with high TMR ratio and low $R{\times}A$ for high performance MRAM cells. In addition, in order to clarify the annealing temperature dependence of TMR, the local transport properties were measured for Ta $50{\AA} /Cu 200 {\AA}/Ta 50 {\AA}/Ni_{76}Fe_{24} 20 {\AA}/Cu 50 {\AA}/Mn_{75}Ir_{25} 100 {\AA}/Co_{71}Fe_{29} 40 {\AA}/Al-O$ junction with $d_{Al}= 8 {\AA} and P_{O2}{\times}t_{0X}/ = 8.4 {\times} 10^4$ at various temperatures. The current histogram statistically calculated from the electrical current image was well in accord with the fitting result considering the Gaussian distribution and Fowler-Nordheim equation. After annealing at $340^{\circ}C$, where the TMR ratio of the corresponding MTJ had the maximum value of 44%, the average barrier height increased to 1.12 eV and its standard deviation decreased to 0.1 eV. The increase of TMR ratio after annealing could be well explained by the enhancement of the average barrier height and the reduction of its fluctuation.

Effect of fermented blueberry on the oxidative stability and volatile molecule profiles of emulsion-type sausage during refrigerated storage

  • Zhou, Hengyue;Zhuang, Xinbo;Zhou, Changyu;Ding, Daming;Li, Chunbao;Bai, Yun;Zhou, Guanghong
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.5
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    • pp.812-824
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    • 2020
  • Objective: The aim of this work was to assess the effect of fermented blueberry (FB; 2%, 4%, and 6%) on the oxidative stability and volatile molecule profiles of emulsion-type sausage stored at 4℃ for 28 days. Methods: The antioxidant activity of FB was determined through radical-scavenging activity against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals. Four formulations of sausage treatments with different FB levels (0%, 2%, 4%, 6%) were prepared, then peroxide value (POVs), thiobarbituric acid-reactive substances (TBARS) values, protein carbonyls and thiol groups were measured. The aroma profiles of sausages for each treatment was also determined. Results: The half maximal inhibitory concentration indicated that FB had greater scavenging ability than ascorbic acid against DPPH and hydroxyl radicals. Sausages with FB significantly retarded increases in POVs and TBARS, as well as in the content of protein carbonyls during all storage days (p<0.05). Particularly, 4% and 6% FB-treated sausages had better oxidation inhibition effects. However, FB accelerated the reduction in thiol groups (p<0.05). Additionally, FB inhibits the excessive formation of aldehyde compounds; for example, hexanal, which may cause rancid flavors, decreased from 58.25% to 19.41%. FB also created 6 alcohols (i.e., 2-methyl-1-propanol, 3-methyl-1-butanol, and phenylethyl alcohol), 5 ester compounds (i.e., ethyl acetate, ethyl lactate, and ethyl hexanoate) and 3-hydroxy-2-butanone in the sausages that contribute to sausage flavors. The principal component analysis showed that the aroma profiles of sausages with and without FB are easily identified. Conclusion: The addition of FB could significantly reduce the lipid and protein oxidation and improve oxidative stability for storage. Also, adding FB could inhibit rancid flavors and contribute to sausage flavors.

Agriculture Pollution and its Countermeasures with Special Consideration of Pesticides (작물생산과 농업공해 및 그 대책)

  • Li, Gwo-Chen
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.27 no.4
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    • pp.340-360
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    • 1982
  • Because of the continuing rapid increase in pesticide usage in Taiwan, much attention has been focus on pesticide contamination of food and effect of pesticides on human and environmental health. The Plant Protection Center (PPC) conducts safety evaluation of pesticides usee! in Taiwan. The pesticides are classified into different groups based on their acute toxicities. Pesticides which are classified into extremely toxic group are not allow to used on short term crops or the continuously harvest crops. The acute toxicity of pesticides to the beneficial insects are also studied, special attention has been paid to the two predators of rice brown planthopper. 60% of cultivated land in Taiwan are paddy field; therefore, acute fish toxicity was taken into consideration when a pesticide was applied for registration to be used in the paddy. Fish toxicities were evaluated by the dangerous rating value which is the amount of pesticide residue in the field water over the TLM value. Mutagenicity of pesticides was continuously evaluated by using Arne's microbial testing method. Island wide survey of residual levels of pesticides of known pollutants such as chlorinated hydrocarbon . insecticides, mercurial compounds in soil, water and biological samples were carried out constantly. The potential of a new1y Imported esticides to pollute the environment were studied by using model ecosystem. Ecological magnification (EM) of a chemical was calculated from model ecosystem. A chemical was considered as a pollutant when its EM value over 5000. In order to ensure the levels of pesticides residue of the crop within the safety limit. The 'tolerance' of pesticides on different crop groupings were established base on 1) acceptable daily intake value of individual pesticides, 2) average daily consumption of each crop groupings by Chinese person, 3) Actual residues of pesticides. on different crops obtained from supervised trials. Total about 79 pesticides for which the tolerances have been established on different crop groupings. Because the intensive agricultural system was adopted in Taiwan. The phytotoxicity of pesticides to the non-target crops was therefore become one of the important factor in the safety evaluation of pesticide usage. These will include 1) direct injury, 2) injury caused by pesticide polluted irrigation water, 3) injury caused by the pesticide polluted soil, 4) reduction of growth caused by the effect of pesticide on the soil microorganisms. This paper will reviewed all the aspects mentioned in the previous .paragraphs. Most the works have done in Taiwan by the PPC.y the PPC.

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