• 제목/요약/키워드: environmental controls

검색결과 688건 처리시간 0.026초

Output Power Control of Wind Generation System by Machine Loss Minimization

  • Abo-Khalil Ahmed;Lee Dong-Choon
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2005년도 춘계학술대회
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    • pp.51-54
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    • 2005
  • Generator efficiency optimization is important for economic saving and environmental pollution reduction. In general, the machine loss can be reduced by the decreasing the flux level, resulting in the significant reduction of the core loss. This paper proposesan model-based controller is used to decrement the excitation current component on the basis of measured stator current and machine parameters and the q-axis current component controls the generator torque, by which the speed of the induction generator iscontrolled according to the variation of the wind speed in order to produce the maximum output power. The generator reference speed is adjusted according to the optimum tip-speed ratio. The generated power flows into the utility grid through the back-to-back PWM converter. The grid-side converter controls the dc link voltage and the line-side power factor by the q-axis and the d-axis current control, respectively. Experimental results are shown to verify the validity of the proposed scheme.

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열원 및 공조설비의 최적제어시스템 현장 적용성에 관한 연구 (A Study on the Application of the Optimal Control System for Heat Source and HVAC System)

  • 백승재;김진;안병천;송재엽
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.1014-1019
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    • 2009
  • The optimal control system for heat source and HVAC system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor load and outdoor temperatures. The optimal set-points of control parameters are supply air temperature and chilled or hot water temperatures. The optimal control study has been implemented for biosafety laboratory by using TRNSYS simulation program in order to investigate energy performance for heat source and HVAC system.

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THE MICROSOMAL EPOXIDE HYDROLASE(MEPHXS) POLYMORPHISMS AND THE ASSOCIATION OF MICRONUCLEI(MN) IN THE BENZENE-EXPOSED WORKERS

  • Kim, Tae-Yon;Kwon, Seul-A;Kim, Jin-Sik;Kim, Su-Young;Lee, Young-Jun;Chung, Eun-Jung;Paek, Do-Myung;Park, Jung-Keun;Chung, Hai-Won
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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    • pp.134-134
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    • 2002
  • In order to investigate whether genetic polymorphisms in the mEH exon3 (Tyr139His), exon4 (His113Arg) interact with the formation of MN in benzene exposed workers, the PCR-RFLP based genotyping of 76 exposed and 115 controls were performed and cytokinesis-block micronucleus (CBMN) analysis of 56 exposed and 53 controls was employed.(omitted)

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열원 및 공조설비 통합 최적제어기법 구현에 관한 연구 (Real Time Near Optimal Control Application Strategy for Heat Source and HVAC System)

  • 송재엽;안병천;주영덕;김진
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.60-65
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    • 2008
  • The near-optimal control algorithm for central cooling and heating system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor load and outdoor temperatures. The optimal set-points of control parameters with near-optimal control are supply air and chilled or hot water temperatures. The near optimal control algorithm has been implemented by using LabVIEW program in order to analyze energy performance for central cooling and heating control system.

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중앙냉방시스템의 실시간 준최적제어 적용에 따른 실험적 연구 (Real Time Near Optimal Control Application Strategy of Central Cooling System)

  • 안병천;송재엽;주영덕;김진
    • 설비공학논문집
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    • 제20권7호
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    • pp.470-477
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    • 2008
  • The near-optimal control algorithm for central cooling system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor cooling load and outdoor temperatures. The optimal set-points of control parameters with near-optimal control are supply air and chilled water temperatures. The near optimal control algorithm has been implemented by using LabVIEW program in order to analyze energy performance for central cooling control system.

Two Polymorphisms of Interleukin-4 Gene in Korean Adult Periodontitis

  • Kang, Byung-Yong;Choi, Young-Kyu;Choi, Wook-Hwan;Kim, Ki-Tae;Choi, Sung-Sook;Kim, Kyungjae;Ha, Nam-Joo
    • Archives of Pharmacal Research
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    • 제26권6호
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    • pp.482-486
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    • 2003
  • Adult periodontitis is a multifactorial disease characterized by multple genetic and environmental factors. In view of the importance of interleukin-4 (IL-4) gene as a genetic factor for adult periodontitis, we investigated the relationship between two polymorphisms (-590 C $\rightarrow$ T polymorphism and 70 bp repeat polymorphism) of the human IL-4 gene and adult periodontitis in the Korean population. Genomic DNA was extracted from white blood cells of 32 adult periodontitis patients and 150 normal controls, respectively. There were no significant differences in the allele, genotype and haplotype distributions of two polymorph isms between normal controls and adult periodontitis group. Therefore, our results suggest that IL-4 gene locus contributes little to the interindividual susceptibility for adult periodontitis in Korean population.

다환성 방향족 탄화수소 노출에 의한 DNA 산화적 손상과 Paraoxonase-1(PON1) 유전자 다형성이 폐암 발생에 미치는 영향 (Effects of Oxidative DNA Damage Induced by Polycyclic Aromatic Hydrocarbons and Genetic Polymorphism of the Paraoxonase-1 (PON1) Gene on Lung Cancer)

  • 이철호;이계영;최강현;홍윤철;김용대;강종원;김헌
    • Journal of Preventive Medicine and Public Health
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    • 제38권3호
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    • pp.345-350
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    • 2005
  • Objectives : Polycyclic aromatic hydrocarbons (PAHs), which are risk factors for lung cancer, have been reported to induce oxidative DNA damage. The paraoxonase (PON) plays a significant role in the detoxification of a variety of organophosphorous compounds, with paraoxonase-1 (PON1) being one of the endogenous free-radical scavenging systems in the human body. The aim of this case-control study was to investigate the effects of PAH exposure, oxidative stress and the Q192R polymorphism of PON1 genes, and their interactions in the carcinogenesis of lung cancer. Methods : One hundred and seventy seven lung cancer patients and 177 age- and sex-matched controls were enrolled in this study. Each subject was asked to complete a questionnaire concerning their smoking habits and environmental exposure to PAHs. The Q192R genotypes of the PON1 gene was examined, and the concentrations of urinary 1-hydroxypyrene (1-OHP), 2-naphthol and 8-hydroxydeoxyguanosine (8-OH-dG) measured. Results : Cigarette smoking was found to be a significant risk factor for lung cancer. The urinary 8-OH-dG level was higher in the patients, whereas the urinary 1-OHP and 2-naphthol levels were higher in the controls. There was a significant correlation between the urinary levels of 8-OHdG and 1-OHP in both the cases and controls. The PON1 polymorphism was associated with an increased risk of lung cancer. Individuals carrying the Q/Q genotype of the PON1 gene were found to be at higher risk of developing lung cancer. There was a significant correlation between the urinary levels of 8-OH-dG and 1-OHP in those with the PON1 Q/Q genotype. Conclusions : These results lead to the conclusion that PAHs would induce oxidative DNA damage, especially in individuals with the PON1 Q/Q genotype. Therefore, people with the PON1 Q/Q genotype would be more susceptible to lung cancer than those with the R/R or Q/R genotypes of the PON1 gene.

임간재배 시 광조절과 부엽토 처리에 따른 삽주의 생육 및 광합성 특성 (Growth and Photosynthetic Characteristics of Atractylodes japonica by Light Controls and Leaf Mold Treatment in Forest Farming)

  • 전권석;송기선;최규성;김창환;박용배;김종진
    • 한국약용작물학회지
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    • 제23권2호
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    • pp.161-167
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    • 2015
  • This study was carried out to determine the effects of light controls and leaf mold on root growth and physiological responses of Atractylodes japonica growing in forest farming. The experiment was performed by light controls (100%, 62.5%, 40.3% and 19.7% of full sunlight) and application of leaf mold to soil. Height, stem diameter, number of flower buds and root collar diameter were the highest in leaf mold within 62.5% of full sunlight (relative light intensity 62.5%). And these were the higher in leaf mold within each light level. As the shading level increased, light saturation point and maximum photosynthesis rate decreased. As the light level decreased, SPAD value increased in control and leaf mold. As a result of surveying the whole experiment, A. japonica was judged worse root growth under the lower light level. It was concluded that the light level was one of the most important factors to produce A. japonica. Also, producing high-quality of A. japonica with the price competitiveness by using leaf mold like the experiment can be an effective way to increase incomes for farmers.

Time-dependent Changes of Cadmium and Metallothionein after Short-term Exposure to Cadmium in Rats

  • Cho, Mi-Ran;Kang, Hwan-Goo;Jeong, Sang-Hee;Cho, Myung-Haing
    • Toxicological Research
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    • 제26권2호
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    • pp.131-136
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    • 2010
  • The time-dependent changes in cadmium (Cd) concentration were studied in Female Sprague-Dawley (SD) rats during and after Cd exposure via drinking water (10 and 50 ppm) for 30 days. The cadmium concentration in muscle, liver, kidney, blood plasma, and urine, and the metallothionein concentration in blood plasma were determined every 10 days during exposure and every 7 days after exposure for 3 weeks. The muscle Cd concentration did not change during, and neither after, exposure. The liver Cd concentration increased from 1.4 to 3.3 (at 10 ppm) and from 6.1 to 10.1 folds (at 50 ppm) during exposure and remained higher than those of controls in both groups even during post-exposure period. The kidney Cd concentrations were 2.3 to 5.1 (at 10 ppm) and 4.9-14.0 folds (at 50 ppm) higher than those of controls during exposure and also remained elevated during the post-exposure period. Plasma Cd concentrations were not significantly different from those of controls in both groups. Urine Cd concentrations were more than 2 folds (at 10 ppm) and 6.5 to 12.6 folds (at 50 ppm) higher than those of controls but rapidly decreased over the 7 days of withdrawal. Blood plasma metallothionein concentrations were more than 2.4 folds (at 10 ppm) and 3.1 to 7.4 folds (at 50 ppm), and they remained elevated till 7 days (10 ppm) and 14 days (at 50 ppm) after exposure. Our data support that Cd in urine could be a useful biomarker during Cd exposure period and metallothionein in blood plasma could be as a supportive biological marker for during and post Cd exposure.

Associations between single-nucleotide polymorphisms of the interleukin-18 gene and breast cancer in Iraqi women

  • Zakariya, Bilal Fadil;Almohaidi, Asmaa M. Salih;Simsek, Secil Akilli;Kamal, Areege Mustafa;Al-Dabbagh, Wijdan H.;Al-Waysi, Safaa A.
    • Genomics & Informatics
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    • 제20권2호
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    • pp.18.1-18.7
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    • 2022
  • According to long-term projections, by 2030, the world's population is predicted to reach 7.5 billion individuals, and there will be roughly 27 million new cancer cases diagnosed. The global burden of breast cancer (BC) is expected to rise. According to the Ministry of Health-Iraqi Cancer Registry, cancer is the second largest cause of death after cardiovascular disease. This study investigated the interleukin-18 (IL18) single-nucleotide polymorphisms (SNPs) -607C/A rs1946518 and -137G/C rs187238 using the sequence-specific amplification-polymerase chain reaction approach. Regarding the position -607C/A, there was a highly significant difference between the observed and expected frequencies in patients and controls (χ2 = 3.16 and χ2 = 16.5), respectively. The AA and CA genotypes were associated with significantly increased BC risk (odds ratio [OR], 3.68; p = 0.004 and OR, 2.83; p = 0.04, respectively). Women with the A allele had a 5.03-fold increased susceptibility to BC. The C allele may be a protective allele against BC (OR, 0.19). Although position -137G/C showed no significant differences in the CC genotype distribution (p = 0.18), the frequency of the CC genotype was significantly higher in patients than in controls. In contrast, patients had a significantly higher frequency of GC genotypes than controls (p = 0.04), which was associated with an increased risk of developing BC (OR, 2.63). The G allele frequency was significantly lower in patients than in controls (55.0% vs. 76.2%, respectively). This SNP may be considered a common genotype in the Iraqi population, with the wild-type G allele having a protective function (OR, 0.19) and the mutant C allele having an environmental effect (OR, 2.63).