• Korean Journal of Soil Science and Fertilizer
• /
• 제46권2호
• /
• pp.73-80
• /
• 2013

Due to the fact that possible risk associated with soil-crop-food chain transfer, metal contamination in croplands has become a major topic of wide concern. Accumulation of toxic metals in edible parts of crops grown in contaminated soils has been reported from number of crops including rice, soybean, wheat, maize, and vegetables. Therefore, in order to ensure food safety, measures are needed to be taken in mitigating metal pollution and subsequent uptake by crop plants. Present paper critically reviewed some of the cost effective remediation techniques used in minimizing metal uptake by crops grown in contaminated soils. Liming with different materials such as limestone ($CaCO_3$), burnt lime (CaO), slaked lime [$Ca(OH)_2$], dolomite [$CaMg(CO_3)_2$], and slag ($CaSiO_3$) has been widely used because they could elevate soil pH rendering metals less-bioavailable for plant uptake. Zn fertilization, use of organic amendments, crop rotation and water management are among the other techniques successfully employed in reducing metal uptake by crop plants. However, irrespectively the mitigating measure used, heterogeneous accumulation of metals in different crop species is often reported. The inconsistency might be attributed to the genetic makeup of the crops for selective uptake, their morphological characteristics, position of edible parts on the plants in respect of their distance from roots, crop management practices, the season and to the soil characteristics. However, a sound conclusion in this regard can only be made when more scientific evidence is available on case-specific researches, in particular from long-term field trials which included risks and benefits analysis also for various remediation practices.

• Korean Journal of Environmental Agriculture
• /
• 제40권2호
• /
• pp.92-98
• /
• 2021

BACKGROUND: Unintentional residual pesticide in soil derived from preceding crops and the transfer to succeeding crops was considered a critical barrier for positive list system (PLS). Thus, an uncertain risk is predicted for ethoprophos applied at cultivation of preceding crop (Korean cabbage) to succeeding crop (spinach). METHODS AND RESULTS: Ethoprophos was treated on soil following the recommended dose and 5 times dose according to the safe use guidelines for Korean cabbage after seeding. On the 4 days after harvesting of preceding crop, spinach was sowed. The initial residual amounts of ethoprophos on soil (7.081-19.493 mg/kg) were decreased to 3.832-7.218 mg/kg until the harvest of Korean cabbage, and then finally decreased to 0.011-0.079 mg/kg after spinach cultivation. The uptake rates of ethoprophos from soil by Korean cabbage were 0.01-0.03% and distributed to root (0.150-0.903 mg/kg) and shoot (0.021-0.151 mg/kg), respectively. The residual amounts of uptake and translocation from preceding crop cultivated soil to spinach edible part were found to be below LOQ. CONCLUSION: The plant back internal (PBI) for ethoprophos is not recommended during sequential cultivation of leafy vegetables, since the residual amounts of ethoprophos in spinach were less than MRL (0.02 mg/kg).

• Journal of Advanced Marine Engineering and Technology
• /
• 제39권10호
• /
• pp.1002-1010
• /
• 2015

Natural gas hydrates are newly emerging as an environment-friendly source of energy to substitute for fossil fuels in the 21stcentury.NGHs are reported to holds much amounts of natural gas (up to 182 standard volumes of gas per volume of hydrate); they are easy to store and safe to carry at about minus 20 degree Celsius under atmospheric pressure because of the self-preservation phenomenon of gas hydrates. The transporting method by gas-ice-hydrate ship carriers has been introduced and developed by a variety of industry and research institutions. Our team has been conducted to develop NGH total systems, including a breakthrough NGH carrier for sea transportation, since 2011. The NGH pellet carrier does not require a separate cooling system for cargo, and the initial temperature is maintained through insulation of the cargo tanks throughout the transport to the final destination. The heat conducted from the exterior and passing through the insulation material of the hull should be cut off as much as possible, but heat inflow inside the cargo tank from an external source is inevitable during transport. In this study, the heat transfer in a cargo tank of a 115K NGH carrier was analyzed through simulation with a commercial CFD code to estimate the boil-off gas/boil-off rate on the developed carrier and understand major hazards that could significantly impact the safety of the vessel.

• Archives of Reconstructive Microsurgery
• /
• 제24권1호
• /
• pp.1-6
• /
• 2015

Purpose: The main cause of flap loss in microsurgical tissue transfer is venous insufficiency. Whether or not multiple venous anastomoses prevents vascular thrombosis and reduces the risk of flap failure remains controversial. Some researchers are in favor of performing dual venous anastomoses, but the counterargument holds that performing a single venous anastomosis does provide advantages. Materials and Methods: We carried out a retrospective analysis of 15 cases of anterolateral thigh free flap for extremity reconstruction performed between January 2011 and December 2013. The patients were categorized into two groups: group A that received a single venous anastomosis and group B that received dual venous anastomoses. The time of the anastomosis, size of the flap, complications of the flap, and survival rate of each group were analyzed. Results: The total microsurgical time in the single venous anastomosis group ranged from 28 to 43 minutes (mean 35.9 minutes). The total time in the dual anastomoses group ranged from 50 to 64 minutes (mean 55.7 minutes). No statistically significant difference was found between the two groups with regards to postoperative complications and flap failure. Conclusion: Our study suggests that the use of a single venous anastomosis in the venous drainage of anterolateral thigh free flaps is a safe and feasible option for extremity reconstruction and provides shorter operative time and easy flap dissection.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 한국지하수토양환경학회 1999년도 정기총회 및 춘계 공동 학술발표회
• /
• pp.149-156
• /
• 1999

In the United States (U.S.), the monitored natural attenuation (MNA) approach has been used as an alternative remedial option for organic and inorganic compounds retained in soil and dissolved in groundwater. The U.S. Environmental Protection Agency (EPA) defines the MNA as“in-situ naturally-occurring processes include biodegradation, diffusion, dilution, sorption, volatilization, and/or chemical and biochemical stabilization of contaminants and reduce contaminant toxicity, mobility or volume to the levels that are protective of human health and the environment”. The Department of Soil Environment. National Institute Environmental Research (NIER) is in the process for demonstrating the MNA approach as a potential remedial option for the BTEX contaminated site in Uiwang City. The project is charactering the research site in terms of the nature and extend of contamination, biological degradation rate, and geochemical and hydrological properties. The microbial-degradation rate and effectiveness of nutrient and redox supplements will be determined through laboratory batch and column tests. The geochemical process will be monitored for determining the concentration changes of chemical species involved in the electron transfer processes that include methanogenesis, sulfate and iron reduction, denitrification, and aerobic respiration. Through field works, critical soil and hydrogeologic parameters will be acquired to simulate the effects of dispersion, advection, sorption, and biodegradation on the fate and transport of the dissolved-phase BTEX plume using Bioplume III model. The objectives of this multi-years research project are (1) to evaluate the MNA approach using the BTEX contaminated site in Uiwang City, (2) to establish a standard protocol for future application of the approach, (3) to investigate applicability of the passive approach as a secondary treatment remedy after active treatments. In this presentation, the overall picture and philosophy behind the MNA approach will be reviewed. Detailed discussions of the site characterization/monitoring plans and risk-based decision-making processes for the demonstration site will be included.

• The Korean Journal of Food & Health Convergence
• /
• 제5권3호
• /
• pp.35-40
• /
• 2019

In this study, general bacterial counts and coliform counts, which are hygienic indicator microorganisms, were tested for candy, chocolate, and jelly which are easily available and enjoyed around. After dropping each sample on the desk, indoors, and outdoors, it is immediately collected, or washed and collected to confirm the myth of the 3-second rule. Immediately after removing the wrapping paper, each sample was dropped on the desk, indoors, and outdoors, and after 3 seconds from the moment of contact with the surface, and then collected in a sample bag using sterilized sanitary gloves. After the same operation, each sample was rinsed for 5 seconds using sterilized sanitary gloves and sterilized distilled water, and then collected in a sample bag. The number of bacteria detected in non-washing candies was 41 CFU/g at outdoor and the number of bacteria detected in non-washing chocolate was 76 CFU/g at outdoor. The number of bacteria detected in non-washing jellies was 79 CFU/g at outdoor. Coliform group was not detected in all samples. This showed good results at the level of m = 10,000 or less, which is an allowable value suggested in the Food Code. Also, effect of washing on contaminated food was confirmed. This result is remarkably low compared with the microorganism specimens shown in Food Code, and it is confirmed that contamination occurs but not high value. Therefore, the myth of the 3-second rule is true compared to the figures based on Food Code. However, it showed the characteristics of bacteria that could survive and cross-contaminate on dry food surfaces and emphasized the importance of hygiene through food contact to unsanitary surfaces to minimize the risk of food poisoning.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• 제14권4호
• /
• pp.127-132
• /
• 2014

In this paper, we propose a digital signage method that can control the contents of the screen and download the desired files to individual smart terminal with no touch of digital signage screen by using Kinect. The main features and contributions of the proposed method are as follows. First, can solve the problems such as the risk of bacterial infection, not cleanliness on the screen as well as maximize advertising effectiveness. Second, can support bi-directional communications with computer while we touch only wanted advertisements. The performance evaluation shows the effectiveness of the proposed method. Especially, we can see that the proposed system operates through the recognition of user's actions when the cursor is within the scope of a certain coordinate and the file transfer time to download information is different depending on the PC performance and the version of personal smart device.

• Journal of Korean Neurosurgical Society
• /
• 제66권3호
• /
• pp.228-238
• /
• 2023

Intraventricular hemorrhage (IVH) is a serious concern for preterm infants and can predispose such infants to brain injury and poor neurodevelopmental outcomes. IVH is particularly common in preterm infants. Although advances in obstetric management and neonatal care have led to a lower mortality rate for preterm infants with IVH, the IVH-related morbidity rate in this population remains high. Therefore, the present review investigated the pathophysiology of IVH and the evidence related to interventions for prevention. The analysis of the pathophysiology of IVH was conducted with a focus on the factors associated with cerebral hemodynamics, vulnerabilities in the structure of cerebral vessels, and host or genetic predisposing factors. The findings presented in the literature indicate that fluctuations in cerebral blood flow, the presence of hemodynamic significant patent ductus arteriosus, arterial carbon dioxide tension, and impaired cerebral venous drainage; a vulnerable or fragile capillary network; and a genetic variant associated with a mechanism underlying IVH development may lead to preterm infants developing IVH. Therefore, strategies focused on antenatal management, such as routine corticosteroid administration and magnesium sulfate use; perinatal management, such as maternal transfer to a specialized center; and postnatal management, including pharmacological agent administration and circulatory management involving prevention of extreme blood pressure, hemodynamic significant patent ductus arteriosus management, and optimization of cardiac function, can lower the likelihood of IVH development in preterm infants. Incorporating neuroprotective care bundles into routine care for such infants may also reduce the likelihood of IVH development. The findings regarding the pathogenesis of IVH further indicate that cerebrovascular status and systemic hemodynamic changes must be analyzed and monitored in preterm infants and that individualized management strategies must be developed with consideration of the risk factors for and physiological status of each preterm infant.

• International conference on construction engineering and project management
• /
• The 3th International Conference on Construction Engineering and Project Management
• /
• pp.962-969
• /
• 2009

The market of building construction has been competitive in Hong Kong, perhaps as anywhere else in the world. The barrier to entry is low because there are relatively low requirements on the three factors of production - technology, manpower and finance. The prevailing building technology is traditional and labour-intensive. There is also not much need of capital because clients' periodic payments have been the main source of project finance. Further, capitalizing on trade sub-contracting, contractors have been able to keep their direct labour-force small and to transfer much of their business risk to the sub-contractors. Based on interviews to solicit the perception of a sample of building contractors on the particular issues of construction finance, we present the findings in this paper and discuss the various implications. We believe that the current practice of construction financing is both the cause and effect of the competition within, and the competitiveness of, the building construction sector in Hong Kong. We conclude that the building construction sector is "locked or stuck" in this "equilibrium" of traditional technology, reliance on clients' finance and exploitation of sub-contracting. In this "equilibrium" state, there is hardly any motivation for contractors to engage themselves in product or process innovation. Consequently, any talk of industry reform or innovation could only remain just that. We believe that this problem is not unique in Hong Kong. The building construction sector in many other developed and developing economies is posed with similar if not the same problems and constraints. We conclude that there has to be some "external forces" to bring this "equilibrium" state to a higher level "equilibrium" one where higher value-added building construction services are supplied and demanded. This is a state where building contractors possessing innovative technology, better financial and manpower resources could thrive to build better buildings with innovative building methods and processes.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• 제33권1호
• /
• pp.19-33
• /
• 2023

Objectives: The purpose of this study is to systematically identify situations where exposure levels are expected to be high by structuring domestic lead measurement data according to exposure processes and activities. Methods: Occupational exposure data on lead was collected from the results of the Evaluation of Reliability of Working Environment Measurement conducted by the government from 2019 to 2020. Lead exposure characteristics were analyzed by PROC (process category) and activity. The Risk Characterization Ratios (RCRs) of five PROCs according to ventilation type and lead content were evaluated using the MEASE (Metal's EASE) model. Results: The exposure data on lead (n=250) was classified into 12 PROCs and 12 activities, with an average concentration of 0.040 mg/m³ and about 14% exceeding the occupational exposure limit of 0.05 mg/m³. Processes with high exposure levels were PROC 7 (industrial spraying), 23 (open processing and transfer operations of molten metal), 24 (mechanical treatment), 25 (welding), and 26 (handling of powder containing lead). The results of evaluating RCR for the five PROCs were greater than 1 or close to 1 even if local exhaust ventilation was used. Conclusions: There is a possibility that the concentration of exposure is high in the casting and tapping of molten metal containing lead, mechanical treatment such as fracturing and abrasion, handling of powder, spraying, battery manufacturing, and waste battery recycling processes. It is necessary to implement chemical management policies for workplaces with such processes.