• Title/Summary/Keyword: Materials science and engineering

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Relationship between Selected Metal Concentrations in Korean Raspberry (Rubus coreanus) Plant and Different Chemical Fractions of the Metals in Soil

  • Ahn, Byung-Koo;Lee, Jang-Choon;Han, Soo-Gon;Lee, Jin-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.4
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    • pp.591-596
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    • 2011
  • The applications of chemical fertilizers and various types of organic materials may cause heavy metal accumulation in soil. In this study, we conducted to investigate the relationship between the different chemical forms of heavy metals such as Cr, Cd, Pb, Cu, Ni, and Zn retained in soil and the metal concentrations in Korean raspberry plant. Forty five soil samples were collected from 2 to 6 years old Korean raspberry cultivation fields (RCFs), Gochang, Korea, to determine total, exchangeable (1.0 M $MgCl_2$-extractable), DTPA-extractable metal contents. The leaves and fruits of raspberry plant were sampled at harvest stage. Total metal contents in soils ranged from $0.87mg\;kg^{-1}$ to $66.82mg\;kg^{-1}$. Exchangeable and DTPA-extractable metals ranged between 0.02 and $0.67mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $7.07mg\;kg^{-1}$, respectively. The metal concentrations in the plant leaf and fruit determined on a dry-basis were between $1.30mg\;kg^{-1}$ and $38.82mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $21.51mg\;kg^{-1}$, respectively, but Cd and Pb were not detected in the leaf. The total, exchangeable, and DTPA-extractable contents of the metal ions in soil were directly correlated one another, but the contents of different metals in the different fractions were inversely correlated in general. Most of total and DTPA-extractable metals in the soil were directly correlated with the contents of the same metals in the plant, whereas exchangeable metals in the soil were not statistically correlated with the same metals in plants. Thus, we concluded that the metal contents in the raspberry field soils were much lower thanthe levels of Soil Contamination Warning Standard (SCWS), and the plant metal concentrations were also less than the maximum permissible limits. The total and DTPA-extractable metals in the soil were closely related to the metal concentrations in the plant.

Design of a Prototype System for Graft-Taking Enhancement of Grafted Seedlings Using Artificial Lighting - Effect of air current speed on the distribution of air temperature and relative humidity in a graft-taking enhancement system (인공광을 이용한 접목표 활착촉진 시스템의 시작품 설계 - 활착촉진 시스템 내의 기온과 상대습도 분포에 미치는 기류속도의 효과)

  • 김용현
    • Journal of Biosystems Engineering
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    • v.25 no.3
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    • pp.213-220
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    • 2000
  • Grafting of fruit-bearing vegetables has been widely used to increase the resistance to soil-borne diseases, to increase the tolerance to low temperature or to soil salinity, to increase the plant vigor, and to extend the duration of economic harvest time. After grafting, it is important to control the environment around grafted seedlings for the robust joining of a scion and rootstock. Usually the shading materials and plastic films are used to keep the high relative humidity and low light intensity in greenhouse or tunnel. It is quite difficult to optimally control the environment for healing and acclimation of grafted seedlings under natural light. So the farmers or growers rely on their experience for the production of grafted seedling with high quality. If artificial light is used as a lighting source for graft-taking of grafted seedlings, the light intensity and photoperiod can be easily controlled. The purpose of this study was to develop a prototype system for the graft-taking enhancement of grafted seedlings using artificial lighting and to investigate the effect of air current speed on the distribution of air temperature and relative humidity in a graft-taking enhancement system. A prototype graft-taking system was consisted by polyurethane panels, air-conditioning unit, system controller and lighting unit. Three band fluorescent lamps (FL20SEX-D/18, Kumho Electric, Inc.) were used as a lighting source. Anemometer (Climomaster 6521, KANOMAX), T-type thermocouples and humidity sensors (CHS-UPS, TDK) were used to measure the air current speed, air temperature and relative humidity in a graft-taking system. In this system, air flow acted as a driving force for the diffusion of heat and water vapor. Air current speed, air temperature and relative humidity controlled by a programmable logic controller (UP750, Yokogawa Electric Co) and an inverter (MOSCON-G3, SAMSUNG) had an even distribution. Distribution of air temperature and relative humidity in a graft-taking enhancement system was fairly affected by air current speed. Air current speed higher than 0.1m/s was required to obtain the even distribution of environmental factors in this system. At low air current speed of 0.1m/s, the evapotranspiration rate of grafted seedlings would be suppressed and thus graft-taking would be enhanced. This system could be used to investigate the effects of air temperature, relative humidity, air current speed and light intensity on the evaportranspiration rate of grafted seedlings.

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Dredging Material Application Lightweight Foamed Soil Full Scale Test Bed Verification (준설토 활용 경량기포혼합토 실규모 현장 실증 연구)

  • Kim, Dong-Chule;Yea, Gue-Guwen;Kim, Hong-Yeon;Kim, Sun-Bin;Choi, Han-Lim
    • Journal of Coastal Disaster Prevention
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    • v.5 no.4
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    • pp.163-172
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    • 2018
  • To propose the design technique and the execution manual of the LWFS(Lightweight Foamed Soil) method using dredged soil, the operation system for the test-bed integrated management, and to establish an amendment for the domestic quantity per unit and specifications, and a strategy for its internationalization. In order to utilize the dredged soil from the coastal area as a construction material, we constructed the embankment with LWFS on soft ground and monitored its behavior. As a result, it can be expected that the use of LWFS as an embankment material on the soft ground can improve the economic efficiency by reducing the depth and period of soil improvement as well as the uses of nearby dredged soil. To verify the utilization of the dredged soil as a material for light-weighted roadbed, soft ground and foundation ground, and surface processing, perform an experimental construction for practical structures and analyze the behavior. It is expected to be able to improve the soft ground with dredged soil and develop technique codes and manuals of the dredged soil reclamation by constructing a test-bed in the same size of the fields, and establish the criteria and manual of effective dredged soil reclamation for practical use. The application technology of the dredged soil reclamation during harbor constructions and dredged soil reclamation constructions can be reflected during the working design stage. By using the materials immediately that occur from the reclamation during harbor and background land developments, the development time will decrease and an increase of economic feasibility will happen. It is expected to be able to apply the improved soil at dredged soil reclamation, harbor and shore protection construction, dredged soil purification projects etc. Future-work for develop the design criteria and guideline for the technology of field application of dredged soil reclamation is that review the proposed test-bed sites, consult with the institutions relevant with the test-bed, establish the space planning of the test-bed, licensing from the institutions relevant with the test-bed, select a test-bed for the dredged soil disposal area.

Improvement of the Occupational Safety and Health Act by the Comparison of the Domestic and Foreign Radon-related Policies (국내·외 라돈 관련 제도 비교를 통한 산업안전보건법 개선방안)

  • Lim, Dae Sung;Kim, Ki-Youn;Cho, Yong Min;Seo, Sung Chul
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.31 no.3
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    • pp.226-236
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    • 2021
  • Objectives: Concerns have been raised about the possible health effects of radon on both workers and consumers with the spread of social attention to the impact of radon exposure. Thus, an entire raw material handling workshop was investigated, and standards for radon levels in the workplace were newly established at 600 Bq/m3. However, regulations on the management of workers exposed to radon are still insufficiently developed. Therefore, by comparative analysis of overseas and domestic radon-related regulations for workplaces, this study aims to suggest improvement plans of protection regulations under the Occupational Safety and Health Act (OSH Act) for the prevention of health disorders of radon-exposed workers. Methods: For overseas case studies, we consulted radon-related laws and reports officially published on the websites of the European Union (EU), the United States (U.S.) and the United Kingdom (UK) government agencies. Domestic law studies were conducted mainly on the Act on Protective Action Guidelines against Radiation in the Natural Environment and the OSH Act. Results: In Europe, the basic safety standards for protection against risks arising from radon (Council Directive 2013/59/EURATOM of 5 December 2013) was established by the EU. They recommend that the Member States manage radon level in workplaces based on this criterion. In the U.S., the standards for workplaces are controlled by the Occupational Safety and Health Administration (OSHA) and the Mine Safety and Health Administration (MSHA). Action on radon in the UK is specified in "Radon in the workplace" published by the Health and Safety Executive (HSE). Conclusions: The Act on Protective Action Guidelines against Radiation in the Natural Environment mainly refers to the management of workplaces that use or handle raw materials but does not have any provisions in terms of protecting naturally exposed workers. In the OSH Act, it is necessary to define whether radon is included in radiation for that reason that its current regulations have limitations in ensuring the safety workers who may be exposed to naturally occurring radon. The management standards are needed for workplaces that do not directly deal with radon but are likely to be exposed to radon. We propose that this could be specified in the regulations for the prevention of health damage caused by radiation, not in Article 125 of the OSH Act.

Public Exposure to Natural Radiation and the Associated Increased Risk of Lung Cancer in the Betare-Oya Gold Mining Areas, Eastern Cameroon

  • Joseph Emmanuel Ndjana Nkoulou II;Louis Ngoa Engola;Guy Blanchard Dallou;Saidou;Daniel Bongue;Masahiro Hosoda;Moise Godefroy Kwato Njock;Shinji Tokonami
    • Journal of Radiation Protection and Research
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    • v.48 no.2
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    • pp.59-67
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    • 2023
  • Background: This study aims to reevaluate natural radiation exposure, following up on our previous study conducted in 2019, and to assess the associated risk of lung cancer to the public residing in the gold mining areas of Betare-Oya, east Cameroon, and its vicinity. Materials and Methods: Gamma-ray spectra collected using a 7.62 cm×7.62 cm in NaI(Tl) scintillation spectrometer during a car-borne survey, in situ measurements and laboratory measurements performed in previous studies were used to determine the outdoor absorbed dose rate in air to evaluate the annual external dose inhaled by the public. For determining internal exposure, radon gas concentrations were measured and used to estimate the inhalation dose while considering the inhalation of radon and its decay products. Results and Discussion: The mean value of the laboratory-measured outdoor gamma dose rate was 47 nGy/hr, which agrees with our previous results (44 nGy/hr) recorded through direct measurements (in situ and car-borne survey). The resulting annual external dose (0.29±0.09 mSv/yr) obtained is similar to that of the previous study (0.33±0.03 mSv/yr). The total inhalation dose resulting from radon isotopes and their decay products ranged between 1.96 and 9.63 mSv/yr with an arithmetic mean of 3.95±1.65 mSv/yr. The resulting excess lung cancer risk was estimated; it ranged from 62 to 216 excess deaths per million persons per year (MPY), 81 to 243 excess deaths per MPY, or 135 excess deaths per MPY, based on whether risk factors reported by the U.S. Environmental Protection Agency, United Nations Scientific Committee on the effects of Atomic Radiation, or International Commission on Radiological Protection were used, respectively. These values are more than double the world average values reported by the same agencies. Conclusion: There is an elevated level of risk of lung cancer from indoor radon in locations close to the Betare-Oya gold mining region in east Cameroon. Therefore, educating the public on the harmful effects of radon exposure and considering some remedial actions for protection against radon and its progenies is necessary.

Radiation Protection Effects of Dendranthema Zawadskii Var. Latilobum (Maxim.) Kitam. Extracts on Blood Cells, Intestine, and Uterus of Female SD Rats Irradiated with Gamma-Ray 10 Gy (구절초 추출물이 감마선 10 Gy에 조사된 암컷 SD Rat의 혈구 및 소장, 자궁에 미치는 방사선 방호효과)

  • Sung-Hyun, Joo;Hae-Suk, Kim;Sang-Hyun, Jeong;Jae-Gyeong, Choi;Seong-Ok, Jin;Byung-In, Min
    • Journal of radiological science and technology
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    • v.46 no.1
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    • pp.23-28
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    • 2023
  • The purpose of this study is to see the radiation protection effect of the oral injected Dendranthema zawadskii var. latilobum (Maxim.) Kitam. extracts on the small intestine and uterus of female SD Rat as a natural radiation protection agent. The experimental group was divided into four groups: Normal Control group (NC group), Injected Dendranthema zawadskii var. latilobum (Maxim.) Kitam. extracts group (DZ group), irradiated group after injecting Dendranthema zawadskii var. latilobum (Maxim.) Kitam. extracts (DZ+IR group). The whole body of SD Rat was irradiated with gamma-ray 10Gy, and the administration of oral Dendranthema zawadskii var. latilobum (Maxim.) Kitam. Extract was 2 cc (71.56 mg/day/kg) once a day for 2 weeks. For this study, chages in blood cell levels, SOD assay, small intestine and uterus were observed. In the 21st white blood cell level, the DZ+IR group recovered to a normal level, and the IR group didn't. The IR group villus length was lower than other groups on Day 1. IR group was partially recovered, and DZ+IR group was recovered like the NC group on Day 21. In the case of the first-day endometrium, the IR group was thin and the boundary was cloudy, and the DZ+IR group was thicker and the boundary was clearer than the IR group. Day 21 IR group still did not recover, and DZ+IR group recovered like NC group. This is believed to have radiation protection effects in the blood cells and small intestine and uterus of the irradiated female SD Rat, and is expected to be useful for the study of natural radiation protection materials.

Knowledge, Barriers and Attitudes Towards Breast Cancer Mammography Screening in Jordan

  • Abu-Helalah, Munir Ahmad;Alshraideh, Hussam Ahmad;Al-Serhan, Ala-Aldeen Ahmad;Kawaleet, Mariana;Nesheiwat, Adel Issa
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.3981-3990
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    • 2015
  • Background: Breast cancer is the most common type of cancer in Jordan. Current efforts are focused on annual campaigns aimed at increasing awareness about breast cancer and encouraging women to conduct mammogram screening. In the absence of regular systematic screening for breast cancer in Jordan, there is a need to evaluate current mammography screening uptake and its predictors, assess women's knowledge and attitudes towards breast cancer and screening mammograms and to identify barriers to this preventive service. Materials and Methods: This cross-sectional study was conducted in six governorates in Jordan through face-to-face interviews on a random sample of women aged 40 to 69 years. Results: A total of 507 participants with mean age of $46.8{\pm}7.8$ years were interviewed. There was low participation rate in early detection of breast cancer practices. Breast self-examination, doctor examination and periodic mammography screening were reported by 34.9%, 16.8% and 8.6% of study participants, respectively. Additionally 3.8% underwent breast cancer screening at least once but not periodically, while 87.6% had never undergone mammography screening. Reported reasons for conducting the screening were: perceived benefit (50%); family history of breast cancer (23.1%); perceived severity (21.2%); and advice from friend or family member (5.8%). City residents have shown higher probability of undergoing mammogram than those who live in towns or villages. Results revealed negative perceptions and limited knowledge of study participants on breast cancer and breast cancer screening. The most commonly reported barriers for women who never underwent screening were: fear of results (63.8%); no support from surrounding environment (59.7); cost of the test (53.4%); and religious belief, i.e. Qadaa Wa Qadar (51.1%). Conclusions: In the absence of regular systematic screening for breast cancer in Jordan, the uptake of this preventive service is very low. It is essential for the country of Jordan to work on applying regular systematic mammography screening for breast cancer. Additionally, there is a need for improvement in the current health promotion programmes targeting breast cancer screening. Other areas that could be targeted in future initiatives in this field include access to screening in rural areas and removal of current barriers.

User Behavior Classification for Contents Configuration of Life-logging Application (라이프로깅 애플리케이션 콘텐츠 구성을 위한 사용자 행태 분류)

  • Kwon, Jieun;Kwak, Sojung;Lim, Yoon Ah;Whang, Min Cheol
    • Science of Emotion and Sensibility
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    • v.19 no.4
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    • pp.13-20
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    • 2016
  • Recently, life-logging service which has expanded to measure and record the daily life of the users and to share with others are increasing. In particular, as life-logging services based on the application has become popular with the development of wearable-devices and smart-phones, the contents of this service are produced by user behavior and are provided in infographic menu form. The purpose of this paper is to extract user behavior and classify for making contents items of life-logging service. For this paper, the first of all, we discuss the definition and characteristics of life-logging and research the contents based on user behavior related to life-logging by the publications including thesis, articles, and books. Secondly, we extract and classify the user behavior to build the contents for life-logging service. We gather users' action words from publication materials, researches, and contents of existing life-logging service. And then collected words are analyzed by FGI (Focus Group Interview) and survey. As the result, 39 words which suit for contents of life-logging service are extracted by verify suitability. Finally, the extracted 39 words are classified for 19 categories -'Eat', 'Keep house', 'Diet', 'Travel', 'Work out', 'Transit', 'Shoot', 'Meet', 'Feel', 'Talk', 'Care for', 'Drive', 'Listen', 'Go online', 'Sleep', 'Go', 'Work', 'Learn', 'Watch' - which are suggested by the surveys, statistical analysis, and FGI. We will discuss the role and limitations of this results to build contents configuration based on life-logging application in this study.

Effect of Groove Conditions on the Mechanical Properties of Welds Produced by the Combined Welding Process of Flux Cored Arc and Electro Gas in EH36 TMCP Steel Plate for Hull Structures (선체구조용 EH36 TMCP 후판의 FCAW 및 EGW 조합 용접부 기계적 성질에 미치는 개선조건의 영향)

  • Kim, Kihyuk;Kim, Kiwon;Sim, Hoseop;Bae, Kangho;Hong, Hyunuk;Park, Byunggyu
    • Journal of Welding and Joining
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    • v.33 no.5
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    • pp.35-40
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    • 2015
  • Characterization of microstructures and mechanical properties of 83mm thickness EH36-TM welds produced by the combined flux cored arc (FCA) and electro gas (EG) welding processes has been studied with the two different groove conditions, single-V (SV) and double-V (DV) bevels. The welding consumables used for FCA and EG welding processes were ASME/AWS A5.29 (E81T1-K2) and A5.26 (EG72T), respectively. Experimental results showed that all the mechanical properties of welds such as tensile property, CVN toughness and Vickers hardness met IACS requirements. The tensile strength of EG welded plates were reduced by approximately 4% (DV: 3.8%, SV: 4.2%) compared to the base metal. The hardness value of SV-beveled weld metal was slightly lower than that of DV-beveled one. There were no significant differences as per welding groove conditions except for the weld metal. In addition, at the fusion line, the toughness of SV condition was 20J lower and the weld metal was 40J lower than DV condition, respectively. On the basis of microstructural analysis, grain boundary ferrite (GBF) structures for SV condition were 2 times higher volume fraction than for DV condition and their packet sizes were coarsened to almost double. It was thus suggested that the GBF volume fractions and packet sizes in the weld metal of EH36-TM steel plates are the most important factors affecting the mechanical properties of the combined FCA and EG welded joint. Nevertheless, all the results of welds with both DV and SV conditions were found to be excellent.

Characteristics of Landslide Occurrence and Change in the Matric Suction and Volumetric Water Content due to Rainfall Infiltration (강우침투에 의한 산사태 발생 및 모관흡수력과 체적함수비의 변화 특성에 관한 연구)

  • Seo, Won-Gyo;Choi, Junghae;Chae, Byung-Gon;Song, Young-Suk
    • The Journal of Engineering Geology
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    • v.27 no.4
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    • pp.475-487
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    • 2017
  • We performed landslide flume tests to analyze characteristics of landslide occurrence and change in the ground materials due to rainfall infiltration. The test apparatus is composed of flume, rainfall simulator, and measurement sensors and landslides were triggered by heavy rainfall (Intensity=200 mm/hr) sprinkled at the above of an artificial slope. The measurement sensors for matric suction and volumetric water content were installed with 3 sets at shallow (GL-0.2 m), middle (GL-0.4 m), and deep depth (GL-0.6 m) in the slope and the tests were performed with in-situ, loose, and dense condition of each weathered soils of granite, gneiss, and mudstone. The analyses show that surface erosion was dominant in initial time of the test due to heavy rainfall and then landslides occur following locally happened transverse tension cracks. The characteristics of landslide were both shallow failure because of a spread of wetting front induced by the rainfall infiltration and retrogressive failure. While the matric suction was decreased rapidly without any precursor in the soil saturation, the volumetric water content was increased gradually, reached its maximum value, and then decreased rapidly with landslide.