• Title/Summary/Keyword: reduction ratio

Search Result 4,659, Processing Time 0.038 seconds

Skin Radioprotector (Diethone) Modifying Dermal Response of Radiation on Rats (방사선 보호제(Diethone)의 랫드 피부반응에 대한 수식작용)

  • Hong, Seong-Eon;Urahashi, Shingo;Kamata, Rikisaburo
    • Radiation Oncology Journal
    • /
    • v.7 no.1
    • /
    • pp.15-22
    • /
    • 1989
  • Investigations were carried out into the time-and dose-related changes in acute skin reaction following graded single dose (20,30 and 40 Gy) of x-ray irradiation in Wistar rats, in order to evaluate the radioprotective effect of Diethon on skin. For the duration of skin response over 1. 5 score in dose of 40 Gy, the Diethone group of 24.7 days was significantly different (p<0.02) from that of control (29.8 days) and vaseline (29.2 days) groups, it was $17.1\%$ diminution of skin response period compared with that of control group. By the averaging daily scores for 10 days during peak skin reaction the mean scores were obtained. Mean score of Diethone group $(2.43\pm0.22)$ was significantly different (p<0.01) from that of control $(2.91\pm0.23)$ and vaseline $(2.81\pm0.18)$ groups of 40Gy dose. By iso-effect dose obtained at level of 2.5 score the dose reduction factor (DRF) was 1.41 which reduced radiation dose of $41\%$ by radioprotective effect of Diethone. From this experimental data, it may be possible to give higer radiation dose to large and/or radioresistant tumor mass rather than conventional treatment doses for improving therapeutic ratio by using topical application of skin radioprotector.

  • PDF

Stabilization of Heavy Metals-contaminated Soils Around the Abandoned Mine area Using Phosphate (인산염을 이용한 휴.폐광산 주변 중금속 오염토양의 안정화처리에 관한 연구)

  • Lee, Eun-Gi;Choi, Sang-Il
    • Journal of Soil and Groundwater Environment
    • /
    • v.12 no.6
    • /
    • pp.100-106
    • /
    • 2007
  • The objective of this study was to evaluate the efficiency of $(NH_4)_2HPO_4$, $Na_2HPO_4{\cdot}12H_2O$, $CaHPO_4{\cdot}2H_2O$, $Ca(H_2PO_4)_2{\cdot}H_2O$ and $H_3PO_4$ for the stabilization of soils contaminated with multi-metals containing Pb, Cd and As. The application rate of stabilizers to soils was determined based on $PO_4/Pb_{total}$ molar ratio of 0.5, 1, 2, 4. The results of Korea Standard Test and TCLP (EPA Method 1311) showed the reduction of metal leachabilities below the regulatory limits for Pb and Cd when $H_3PO_4$ and $Ca(H_2PO_4)_2{\cdot}H_2O$ were applied. However, stabilization efficiency for Cd was low and in case of As leaching concentration increased rather. It is considered that $PO_4$ reacted effectively $Pb^{2+}$ due to leaching Pb under low pH condition created by adding $H_3PO_4$. Accordingly Pb was stabilized by dissolution and precipitation of hydroxypyromorphite. From the change of metals fraction using sequential extraction procedure when $H_3PO_4$ applied as a stabilizer, we confirmed that residual fraction increased more than 60% and this result was accorded with XRD analysis that detected only hydroxypyromorphite peak in $H_3PO_4$.

PEMOCVD of Ti(C,N) Thin Films on D2 Steel and Si(100) Substrates at Low Growth Temperatures

  • Kim, Myung-Chan;Heo, Cheol-Ho;Boo, Jin-Hyo;Cho,Yong-Ki;Han, Jeon-Geon
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 1999.07a
    • /
    • pp.211-211
    • /
    • 1999
  • Titanium nitride (TiN) thin films have useful properties including high hardness, good electrical conductivity, high melting point, and chemical inertness. The applications have included wear-resistant hard coatings on machine tools and bearings, decorative coating making use of the golden color, thermal control coatings for widows, and erosion resistant coatings for spacecraft plasma probes. For all these applications as feature sizes shrink and aspect ratios grow, the issue of good step coverage becomes increasingly important. It is therefore essential to manufacture conformal coatings of TiN. The growth of TiN thin films by chemical vapor deposition (CVD) is of great interest for achieving conformal deposition. The most widely used precursor for TiN is TiCl4 and NH3. However, chlorine impurity in the as-grown films and relatively high deposition temperature (>$600^{\circ}C$) are considered major drawbacks from actual device fabrication. To overcome these problems, recently, MOCVD processes including plasma assisted have been suggested. In this study, therefore, we have doposited Ti(C, N) thin films on Si(100) and D2 steel substrates in the temperature range of 150-30$0^{\circ}C$ using tetrakis diethylamido titanium (TDEAT) and titanium isopropoxide (TIP) by pulsed DC plamsa enhanced metal-organic chemical vapor deposition (PEMOCVD) method. Polycrystalline Ti(C, N) thin films were successfully grown on either D2 steel or Si(100) surfaces at temperature as low as 15$0^{\circ}C$. Compositions of the as-grown films were determined with XPS and RBS. From XPS analysis, thin films of Ti(C, N) with low oxygen concentration were obtained. RBS data were also confirmed the changes of stoichiometry and microhardness of our films. Radical formation and ionization behaviors in plasma are analyzed by optical emission spectroscopy (OES) at various pulsed bias and gases conditions. H2 and He+H2 gases are used as carrier gases to compare plasma parameter and the effect of N2 and NH3 gases as reactive gas is also evaluated in reduction of C content of the films. In this study, we fond that He and H2 mixture gas is very effective in enhancing ionization of radicals, especially N resulting is high hardness. The higher hardness of film is obtained to be ca. 1700 HK 0.01 but it depends on gas species and bias voltage. The proper process is evident for H and N2 gas atmosphere and bias voltage of 600V. However, NH3 gas highly reduces formation of CN radical, thereby decreasing C content of Ti(C, N) thin films in a great deal. Compared to PVD TiN films, the Ti(C, N) film grown by PEMOCVD has very good conformability; the step coverage exceeds 85% with an aspect ratio of more than 3.

  • PDF

A Study on the Maneuverabilities of the M . S . Pusan 404-Tests by a Series of Turning Circles , New Course Keeping and Spiral (부산 404호의 조종성능에 관한 연구)

  • 김민석
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.28 no.1
    • /
    • pp.21-26
    • /
    • 1992
  • Generally a navigator evaluated the maneuverability of his ship by the scale of turning circle which was described only by the largest rudder angle of the port and starboard sides. But to have the sufficient knowledge of his ship's maneuvering characteristics he should consider the data about the new course keeping test, the spiral test, and the turning circle tests in accordance with the rudder angles together. In this paper the author performed the above tests to study the maneuverability of the stern trawler M.S. Pusan 404 which is a training ship of the National Fisheries University of Pusan. The obtained results are summarized as follows: 1. When the rudder angles being 5。, 10。, 20。, 30。, 35。 the advances of the starboard side turning circles were 12.8, 8.2, 4.8, 2.9, 2.7 times as large as the length of the ship, and of the port side turning circles were 13.3, 8.7, 5.4, 3.5, 2.9, time as large as the large as it. Under the same conditions the tactical diameters were 15.1, 9.7, 5.2, 3.1, 2.8 times as large as the length of the ship, for starboard side, and 17.2, 12.4, 6.4, 3.7, 3.2 times as large as it for port side. 2. As the rudder angle being increased the ratio of the advance to the tactical diameter was nearly 1 and her obeying ability was better than that of the small angle. 3. The mean values of the rates of speed reduction during the steady turning motion were 0.96, 0.92, 0.82, 0.71, 0.65 in accordance with the rudder angles. 4. The relative formulas between the distance to the new course y and the altering course x were as follows: When rudder angles being 10。, 20。, 30。, y=52.2222+1.6133x, y=48.750+0.9383x, y=39.250+0.655x respectively. 5. There was little difference of the distance to the new course between rudder angle 20。and 30。, and so it is desirable for a navigator to a navigator to use the small rudder angles unless sudden emergencies. 6. Though her rudder angle being small her course stability was good according to the spiral tests.

  • PDF

Influence of red mud additive on lightening of artificial aggregates containing coal bottom ash (석탄바닥재가 포함된 인공골재의 경량화에 미치는 적니 영향)

  • Kang, Min-A;Kang, Seung-Gu
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.21 no.1
    • /
    • pp.41-46
    • /
    • 2011
  • The artificial aggregates (AAs) composing of 2 wastes, coal bottom ash and dredged soil (7 : 3, weight ratio) were fabricated as a function of red mud contents,0~30 wt% using direct sintering method at $1050{\sim}1250^{\circ}C$ for 10 min, and those physical properties were evaluated. Especially, in order to analyze the red mud addition effect on the bloating phenomenon of AAs manufactured, the specific gravity and water absorption were measured and studied linked with the microstructural observation results. The lightening of AAs was enhanced due to increased bloating with increasing temperature and red mud contents. The AAS sintered at $1050{\sim}1150^{\circ}C$ showed well-developed black-coring structure, but for the specimens containing red mud sintered over $1200^{\circ}C$ generated excessive liquid and gas caused by reduction of $Fe_2O_3$, thus the black-coring part was gradually burst open out of shell of AAs. Particularly, all specimens containing 30 wt% red mud was burst up when sintered over $1100^{\circ}C$. The AAs containing no red mud sintered at $1200^{\circ}C$ had a specific gravity of about 1.2 and those containing 20 wt% had below 1.0 which are characters of lightweight aggregate.

Response Analysis of RC Bridge Pier with Various Superstructure Mass under Near-Fault Ground Motion (근단층지반운동에 대한 상부구조 질량 변화에 따른 RC 교각의 응답분석)

  • Park, Chang-Kyu;Chung, Young-Soo;Lee, Dae-Hyung
    • Journal of the Korea Concrete Institute
    • /
    • v.22 no.5
    • /
    • pp.667-673
    • /
    • 2010
  • The near fault ground motion (NFGM) is characterized by a single long period velocity pulse with large magnitude. NFGMs have been observed in recent strong earthquakes, Northridge (1994), Japan Kobe (1995), Turkey Izmit (1999), China Sichuan (2008), Haiti (2010) etc. These strong earthquakes have caused considerable damage to infrastructures because the epicenter was close to the urban area, called as NFGM. Extensive research for the far field ground motion (FFGM) have been carried out in strong seismic region, but limited research have been done for NFGM in low or moderate seismic regions because of very few records. The purpose of this research is to investigate and analyze the seismic response of reinforced concrete bridge piers subjected to near-fault ground motions. The seismic performance of six RC bridge piers depending on three confinement steel ratios and three superstructure mass was investigated on the shaking table. From these experimental results, it was confirmed that the reduction of seismic performance was observed for test specimens with lower confinement steel ratio or more deck weight. The displacement ductility of RC bridge piers in terms of the stiffness degradation is proposed based on test results the shaking table.

Model Testing on the Behavior of Laterally Loaded Pile in NC Clay Soils (정규압밀 점토 지반에서 매입말뚝의 수평거동에 관한 모형 실험 연구)

  • Kim, Byeong-Tak;Lee, Sang-Ung;Kim, Yeong-Su
    • Geotechnical Engineering
    • /
    • v.14 no.5
    • /
    • pp.39-52
    • /
    • 1998
  • The pupose of the present paper is to estimate the effects of constraint condition of pile head, ground condition(dry unit weight. $\gamma_4$) and embedded pile lengths on the behavior of single pile which is embedded in normally consolidated clay. BBperiment functions can be quantified to these effects obtained from the results of model teats. The ground of model tests is normally consolidated( NC ) clay under three kinds of effective vertical stress. The results of the model tests using the steel pile of two different embedded pile length and of free-head and fired-head show that the lateral load-deflection relationship is to be elasto plastic behavior below $\gamma_d/\gamma_{dmax}$: 0.84 and that the reduction of lateral load of beyond maximum lateral load($Q_{max}$) at each model test is significantly time-dependent. In this study, it is shown that the displacement relationship can be fitted to exponential function of time by model best results. The effect of ground conditions on the ultimate and yield lateral load is fitted to exponential function including the ratio of dry unit weight to maximum dry unit weight. When tests by results are compared with those from Broms and Budhu et at., the predicted results are over-estimated about 27-87 ayo. In effectivity of constraint condition of pile head on the lateral load-deflection response, the $Q_{fixed}/Q_{gree}-y/D$ relationship is highly non-linear and fitted to parabolic function.

  • PDF

Effects of Chestnut Inner Shell Powder on Antioxidant Activities and Quality Characteristics of Pork Patties (율피분말 첨가가 돈육 패티의 항산화 활성과 품질특성에 미치는 영향)

  • Joo, Shin Youn;Choi, Hae Yeon
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.43 no.5
    • /
    • pp.698-704
    • /
    • 2014
  • This study was conducted to investigate the effects of chestnut inner shell powder on antioxidant activities and quality characteristics of pork patties. Patties were prepared with different amounts of chestnut inner shell powder (0, 1, 3, and 5% of pork quantity). The total phenol contents and DPPH free radical scavenging activities of the patties significantly increased with increasing amount of chestnut inner shell powder. The moisture content and pH of row patties were not significantly different between the control group and treatment groups. The cooking loss rate significantly decreased with increasing chestnut inner shell powder amount. Reduction ratio of the diameter of experimental patties was lower than that of the control patties, although it was not significant. As the content of chestnut inner shell powder increased, L-value decreased while a-value increased in both row patties and cooked patties. However, b-value changed upon heating. The b-value of row patties also increased with increasing chestnut inner shell powder content, whereas the b-value of cooked patties decreased. The hardness, chewiness, gumminess, and cohesiveness of the control group were lower than those of the treatment group. The consumer acceptability score for patties with 1% chestnut inner shell powder was higher than that for patties in terms of overall preference, appearance, color, and texture. Further, overall preference, appearance, and color for patties with chestnut inner shell powder 3% were higher than those of the control group. We suggest that chestnut inner shell can be improve the quality characteristics and consumer acceptability of pork patties, as well as the development of health-oriented meat products.

Head and Neck Squamous Cell Carcinoma in Iranian Patients and Risk Factors in Young Adults: a Fifteen-Year Study

  • Mafi, Negar;Kadivar, Maryam;Hosseini, Niloufar;Ahmadi, Sara;Zare-Mirzaie, Ali
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.7
    • /
    • pp.3373-3378
    • /
    • 2012
  • Background: Head and neck squamous cell carcinoma (HNSCC) is the 8th most common cancer worldwide. Although older age, male gender, smoking and alcohol consumption are known risk factors, an increasing number of HNSCC patients are without typical risk factors. Our aim was to define demographics of HNSCC in Iran and the potential risk factors related to Iranian ethnicity and lifestyle. Methods: We conducted a cross-sectional analytical study on 262 patients with primary SCC of the larynx, hypopharynx or tongue referred to our pathology department during 1995-2010. Patients' demographics, tumor characteristics and risk factors such as smoking, alcohol consumption and anemia were analyzed and compared in two groups of patients: over 40 years (older group) and 40 years or less (young group); Chi-square and Mann-Whitney analytical tests were employed. Results: 5.7% of patients were young adults. The male to female ratio was 1.5 in the younger group and 5.6 in the older group. In young adults, 40% of tumors were located in larynx and 40% in the tongue. Age >40 was significantly associated with laryngeal location (P<0.001). History of smoking and drinking was significantly associated with age >40 and SCC of larynx in both age groups. Cervical lymph node involvement was significantly correlated with SCC of tongue (P<0.001), however, considering young adults only, SCC of hypopharynx was most frequently accompanied by lymph node involvement (60%). The most prevalent tumor among men was SCC of larynx whereas SCC of hypopharynx was the most prevalent tumor among women (61%), of whom 18.2% were ${\leq}40$. Conclusions: The incidence of HNSCC among young adults seems to be higher in Iran compared to other countries. Reduction in exposure to known risk factors, especially tobacco smoking in forms of cigarettes and bubble pipes, and search for other causative agents of HNSCC in young population is recommended.

Matrine Reduces Proliferation of Human Lung Cancer Cells by Inducing Apoptosis and Changing miRNA Expression Profiles

  • Liu, Yong-Qi;Li, Yi;Qin, Jie;Wang, Qian;She, Ya-Li;Luo, Ya-Li;He, Jian-Xin;Li, Jing-Ya;Xie, Xiao-Dong
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.5
    • /
    • pp.2169-2177
    • /
    • 2014
  • Matrine, a main active component extracted from dry roots of Sophora flavecens, has been reported to exert antitumor effects on A549 human non-small lung cancer cells, but its mechanisms of action remain unclear. To determine effects of matrine on proliferation of A549 cells and assess possible mechanisms, MTT assays were employed to detect cytotoxicity, along with o flow cytometric analysis of DNA content of nuclei of cells following staining with propidium iodide to analyze cell cycle distribution. Western blotting was performed to determined expression levels of Bax, Bcl-2, VEGF and HDAC1, while a microarray was used to assessed changes of miRNA profiles. In the MTT assay, matrine suppressed growth of human lung cancer cell A549 in a dose- and timedependent manner at doses of 0.25-2.5 mg/ml for 24h, 48h or 72h. Matrine induced cell cycle arrest in G0/G1 phase and decreased the G2/M phase, while down-regulating the expression of Bcl2 protein, leading to a reduction in the Bcl-2/Bax ratio. In addition, matrine down regulated the expression level of VEGF and HDAC1 of A549 cells. Microarray analysis demonstrated that matrine altered the expression level of miRNAs compared with untreated control A549 cells. In conclusion, matrine could inhibit proliferation of A549 cells, providing useful information for understanding anticancer mechanisms.