• Communications of the Korean Mathematical Society
• /
• v.24 no.2
• /
• pp.215-226
• /
• 2009

For a class of Holling type II food chain systems with biological and chemical controls, we give conditions of the local stability of prey-free periodic solutions and of the permanence of the system. Further, we show the system is uniformly bounded.

• Polymer Science and Technology
• /
• v.25 no.3
• /
• pp.232-238
• /
• 2014

• Journal of the Korean Society of Safety
• /
• v.33 no.5
• /
• pp.42-50
• /
• 2018

The Chemical Controls Act strictly regulates for the chemical companies to establish sufficient space between the liquid chemical tank and dike, but facilities already installed suffer from the space shortage between the tank and dike. Installing leakage preventing plates on the dike is considered as one of the economic solutions that can alleviate the space deficiency. However, there is no technical and reasonable criterion for the safety evaluation of the leakage preventing plate on the dike. In order to address this problem, we provide generalized and verified calculating equations that give maximum height and horizontal distance of leakage trajectories. Through the proposed equations, proper heights of the leakage preventing plates on the dike can be easily determined. In this study, new calculating methods are also developed to determine the impact force of the liquid to the leakage preventing plates. In addition, we performed the reactivity experiments between four corrosive liquid chemicals and two stainless steel materials that are candidate substances for the construction of the leakage preventing plate. The results of this study is expected to be applicable as a guideline in the design of safe dike and its leakage preventing plates.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2006.06a
• /
• pp.67-71
• /
• 2006

Strong oxidizing biocides are commonly used to control biofilm formation in alkaline papermaking systems. However, paper streams contain many substances that react with or consume oxidizers (e.g., fiber and starch, Therefore, to achieve effective microbiological control, the oxidizer must be overfed to overcome the effect of these substances. When dosed in this manner, the oxidizer can cause many unwanted reactions and adverse side effects, including the consumption of costly papermaking additives increased corrosion rates, and reduced felt life. Some oxidizers also contribute to the formation of halogenated organic compounds. When used for biofilm control, strong oxidizers can cause more problems than they remedy. A patented biocide that effectively controls biofilm without the adverse side effects associated with strong oxidizing biocides is available from Hercules. $Spectrum^{(R)}$ XD3899 Ammonium Bromide Technology, which can be described as a mild oxidizer, is currently used on more than 300 machines globally and has resulted in numerous production and/or machine efficiency records since its introduction in 2001.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.7
• /
• pp.1837-1838
• /
• 2010

• Elastomers and Composites
• /
• v.54 no.4
• /
• pp.308-312
• /
• 2019

Polyphenylene sulfide (PPS) is a well-known super engineering plastic with a high melting temperature (above 290℃). It is generally insoluble under regular conditions. Therefore, it can be used for replacing metallic materials. Many researchers are looking at the possibility of replacing aluminum in the engine compartment of an automobile. However, studies on PPS are not common as compared to conventional engineering plastics because only a few companies produce super engineering plastics. In this research, the material properties of PPS composites containing two different kinds of glass fibers and produced under different processing temperatures were investigated. The tensile strength of the PPS composites increased as the processing temperature increased. Although glass fibers with similar aspect ratios were compounded under the same processing condition, one of them yielded a higher mechanical strength.

• Journal of Acupuncture Research
• /
• v.40 no.4
• /
• pp.351-355
• /
• 2023

Background: Wet cupping (WC) is an efficient and cost-effective technique for removing metabolic waste from the bloodstream via the skin. The study aimed to examine the effect of WC on cholesterol levels including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in a Sudanese population. Methods: In this prospective cross-sectional study, 30 participants undergoing regular WC therapy were enrolled. Blood samples collected twice: pre-WC therapy (case group) and 10-14 days afterward (controls). Results: Of the participants, 56.67% were male and 43.33% were female, aged 24-69. Pre-WC TC and LDL-C levels were significantly higher than the post-WC control group (p = 0.001). Conversely, HDL-C levels decreased significantly in the pre-WC cases compared to controls (p = 0.001). No significant sex-based difference in mean cholesterol levels (p > 0.05). Conclusions: After WC, males and females experienced significant reductions in TC and LDL-C, and significant increase in HDL-C.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1988.11a
• /
• pp.1-20
• /
• 1988

1. Diesel emission controls becoming more severe 2. Major changes in diesel engine design expected 3. Some meoh may be used 4. Fuel S expected to decrease 5. Less need for high tbn oils 6. Low ash oils have been demonstrated 7. Lower oil consumption expected 8. Emission control timing amy be relaxed to give more time

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.12
• /
• pp.7345-7349
• /
• 2013

Background: Because of the high prevalence of hepatocellular carcinoma (HCC) in Egypt, new markers with better diagnostic performance than alpha-feto protein (AFP) are needed to help in early diagnosis. The aim of this work was to compare the clinical utility of both serum and mRNA glypican3 (GPC3) as probable diagnostic markers for HCC among Egyptian patients. Materials and Methods: A total of 60 subjects, including 40 with HCC, 10 with cirrhosis and 10 normal controls were analyzed for serum GPC3 (sGPC3) by ELISA. GPC-3 mRNA from circulating peripheral blood mononuclear cells was amplified by RT-PCR. Both markers were compared to some prognostic factors of HCC, and sensitivity of both techniques was compared. Results: Serum glypican-3 and AFP were significantly higher in the HCC group compared to cirrhotic and normal controls (p<0.001). Sensitivity and specificity were (95% each) for sGlypican-3, (82.5% and 85%) for AFP, and (100% and 90%) for Glypican3 mRNA, and (80% and 95%) for double combination between sGPC3 and AFP respectively. Conclusion: Both serum GPC-3 and GPC-3mRNA are promising diagnostic markers for early detection of HCC in Egyptian patients. RT- PCR proved to be more sensitive (100%) than ELISA (95%) in detecting glypican3.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.1
• /
• pp.158-164
• /
• 2014

Substance P and neuropeptide Y were discovered as early diagnostic biomarkers of acute myocardial infarction in Korean patients and confirmed using enzyme-linked immunosorbent assay (ELISA). We screened 12 peptides from the sera of Korean acute myocardial infarction (AMI) patients and detected 3 peptides (neuropeptide Y, substance P, and N-terminal pro-B-type natriuretic peptide) to be elevated from patients' sera by liquid chromatography mass/mass spectrometry. The elevated concentration of 3 peptides was confirmed by ELISA. The screening results revealed the substance P, neuropeptide Y, and pro-B-type natriuretic peptide (47-76) concentrations were higher in patients' sera than in healthy controls. The sensitivity and specificity of substance P for AMI diagnostic marker were 80% and 83%, respectively, and those of neuropeptide Y were 87% and 90%, respectively compared to healthy controls. These results suggest that substance P and neuropeptide Y could be used as early diagnostic biomarkers in patients with AMI.