• Journal of Korean Society on Water Environment
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• v.27 no.1
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• pp.1-8
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• 2011

Although Nepal is naturally bestowed with ample water resources, not all of the population has access to safe and clean drinking water. Waste water treatment is almost nonexistent. In the recent days the flow of population in the urban areas has increased the existing challenges of providing safe water and promoting sanitation. The prevalence of water borne diseases is high. This paper presents overview of issues like water pollution, arsenic contamination of drinking water, waste water treatment and effects of water contamination on public health. Comparison between waste water treatment regulations in South Korea and Nepal has also been made. Implementation strategies to tackle the existing water related problem for promoting public health is also recommended.

• Journal of Korean Society on Water Environment
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• v.27 no.1
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• pp.120-128
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• 2011

Korea Groundwater Quality Monitoring Network is a database of annual groundwater quality survey results to prevent groundwater pollution. We estimated contamination index (CI) values for each type of land use, and analyzed temporal trends of pollutant concentration data in the Groundwater Quality Monitoring Network from 2001 to 2009. Among the pollutants considered in the database, the concentrations of nitrate and chloride were higher than their standards. In the case of nitrate, recreation parks, golf courses and general waste dumping regions showed increasing trends according to linear regression analysis, whereas industrial complexes and residential regions of urgan and recreation parks showed increasing trends in the chloride concentration data. According to multiple variable linear regression analysis, EC, pH and topography were major factors influencing CI values. These results suggest that groundwater with a high CI value and increasing trend is vulnerable for potential contamination, which requires more careful groundwater pollution control.

• Journal of Soil and Groundwater Environment
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• v.27 no.3
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• pp.1-10
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• 2022

Most wells developed in Jeju island before the enactment of the Groundwater Management Ordinance in 2002 are vulnerable to aquifer contamination due to inflow of upper groundwater having the high concentration of nitrate nitrogen, likely due to incomplete grouting in upper section of the wells. Although these wells require entire reinstallation, it is often necessary to rehabilitate the existing wells due to various constraints. Therefore, to identified the inflow section of contaminants, the thermal level sensor (TLS) technique was firstly applied for three wells, which enables to monitor temperature variations in every 50 cm depth. Then, the grouting material was injected to the upper section to prevent the inflow of upper contaminated groundwater into the entire aquifer. By applying TLS technique, it was found that the temperature deviations in the upper groundwater inflow section decreased sharply. Moreover, both the change in the concentration of nitrate nitrogen in the rainy/dry seasons and the average concentrations were found to decrease rapidly after grouting material injection. Consequently, the application of TLS proposed in the study turned out to be appropriate to prevent aquifer contamination.

• Animal Bioscience
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• v.34 no.9
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• pp.1532-1543
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• 2021

Objective: This study was aimed to establish a quantitative detection method for meat contamination based on specific polypeptides. Methods: Thermally stable peptides with good responses were screened by high resolution liquid chromatography tandem mass spectrometry. Standard curves of specific polypeptide were established by triple quadrupole mass spectrometry. Finally, the adulteration of commercial samples was detected according to the standard curve. Results: Fifteen thermally stable peptides with good responses were screened. The selected specific peptides can be detected stably in raw meat and deep processed meat with the detection limit up to 1% and have a good linear relationship with the corresponding muscle composition. Conclusion: This method can be effectively used for quantitative analysis of commercial samples.

• Journal of Korea Trade
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• v.23 no.8
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• pp.132-144
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• 2019

Purpose - The purpose of this paper is to suggest countermeasures to reduce the damage of manufacturers in halal industries and to increase the transparency of the halal market along with raising some problems of halal supply chain management (HSCM). Design/methodology/approach - To achieve to the aim of this research, halal supply chain is categorized as a green zone or a red zone according to the possibility of cross-contamination, and the study introduces 2 examples in Malaysia and Indonesia regarding cross-contamination. Findings - More than 70% of the companies producing halal-certified products are, ironically, non-Muslim suppliers under the halal certificate system and by using halal supply chain. Most Muslim countries do not exercise control over the completed halal supply chain. In most Muslim countries which do not exercise control over halal supply chain properly, there is always a possibility of cross-contamination of products during the processes of distribution. Research limitations/implications - This research has been conducted by accessing cases in halal supply chain. These cases are found in some Muslim countries, not all Muslim countries. Nevertheless, the authors found the possibility of these cross-contaminations in all Muslim countries, and it will damage the halal market. Originality/value - While existing studies have focused on protecting Muslim consumers by ensuring the integrity of halal products in halal supply chain, there is no research on how to protect halal product manufacturers as another important axis of halal SCM.

• Advances in nano research
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• v.15 no.6
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• pp.541-550
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• 2023

The escalating growth of industrial sectors has led to a pervasive global problem—oil pollution, particularly in industrial areas. The release of substantial volumes of oil and its by-products into the environment has resulted in extensive contamination. Multiple factors contribute to the entry of these substances into water bodies and soils, thereby inflicting irreparable consequences on ecosystems, natural resources, and human health. Consequently, it becomes imperative to comprehend the characteristics and behavior of oil pollution, anticipate its impacts, and develop effective mitigation strategies. Understanding this intricate issue requires considering the physicochemical properties of the environment, the interactions between oil and sediments, and biological factors such as evaporation and dissolution. Although the oil industry has brought about remarkable advancements, its activities have raised significant concerns regarding pollution from extraction and production processes. Oil-rich nations face a particularly challenging predicament of soil pollution caused by petroleum compounds. The areas surrounding oil exploration mines and refineries often endure contamination due to oil leakages from storage tanks and transmission lines resulting from deterioration and damage. Investigating the dispersion of such pollutants and devising methods to remediate petroleum-contaminated soil represent crucial and intricate issues within the realm of environmental geotechnics.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.53-58
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• 2023

The storage capacity of 3D-NAND flash memory has been enhanced by the multi-layer dielectrics. The deposition process has become more challenging due to the tight process margin and the demand for accurate process control. To reduce product costs and ensure successful processes, process diagnosis techniques incorporating artificial intelligence (AI) have been adopted in semiconductor manufacturing. Recently there is a growing interest in process diagnosis, and numerous studies have been conducted in this field. For higher model accuracy, various process and sensor data are required, such as optical emission spectroscopy (OES), quadrupole mass spectrometer (QMS), and equipment control state. Among them, OES is usually used for plasma diagnostic. However, OES data can be distorted by viewport contamination, leading to misunderstandings in plasma diagnosis. This issue is particularly emphasized in multi-dielectric deposition processes, such as oxide and nitride (ON) stack. Thus, it is crucial to understand the potential misunderstandings related to OES data distortion due to viewport contamination. This paper explores the potential for misunderstanding OES data due to data distortion in the ON stack process. It suggests the possibility of excessively evaluating process drift through comparisons with a QMS. This understanding can be utilized to develop diagnostic models and identify the effects of viewport contamination in ON stack processes.

• Journal of the korean academy of Pediatric Dentistry
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• v.51 no.2
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• pp.165-175
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• 2024

This study aimed to investigate the effects of blood contamination on the Vickers hardness and the surface morphology of premixed MTA and compare them with the effects on conventional MTA. The Vickers microhardness of Endocem MTA Premixed Regular (EP) and ProRoot MTA (PM) was assessed after immersion in fetal bovine serum (FBS) and saline. Stem cells from human exfoliated deciduous teeth (SHED) were seeded on MTA after immersion in FBS, saline, and deionized water (DW). Cell adhesion patterns and surface morphology were visualized via scanning electron microscopy (SEM). The surface microhardness of EP and PM in FBS was lower than in saline. However, short-term exposure of PM to FBS did not reduce the microhardness compared to saline. Angular crystals formed in water, while rounded crystals with more air voids appeared in FBS. Favorable SHED attachment occurred in all groups. Overall, the surface hardness of EP and PM decreased after FBS exposure, although PM was less influenced. We suggest minimizing the amount of bleeding when using MTA clinically; nevertheless, PM remains an option with more expected blood contamination than EP. In summary, exposure to FBS decreased mechanical performance but allowed cell adhesion for both MTAs, with PM being more resistant to these changes.

• Economic and Environmental Geology
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• v.57 no.3
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• pp.329-342
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• 2024

The exponential increase in nitrate pollution of river water poses an immediate threat to public health and the environment. This contamination is primarily due to various human activities, which include the overuse of nitrogenous fertilizers in agriculture and the discharge of nitrate-rich industrial effluents into rivers. As a result, the accurate prediction and identification of contaminated areas has become a crucial and challenging task for researchers. To solve these problems, this work leads to the prediction of nitrate contamination using machine learning approaches. This paper presents a novel approach known as Grey Wolf Optimizer (GWO) based on the Stacked Ensemble approach for predicting nitrate pollution in the Cauvery Delta region of Tamilnadu, India. The proposed method is evaluated using a Cauvery River dataset from the Tamilnadu Pollution Control Board. The proposed method shows excellent performance, achieving an accuracy of 93.31%, a precision of 93%, a sensitivity of 97.53%, a specificity of 94.28%, an F1-score of 95.23%, and an ROC score of 95%. These impressive results underline the demonstration of the proposed method in accurately predicting nitrate pollution in river water and ultimately help to make informed decisions to tackle these critical environmental problems.

• Geomechanics and Engineering
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• v.38 no.6
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• pp.541-551
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• 2024

Bottom ash classifies as a hazardous industrial-waste material that adversely affects human health. This study proposes its mixing with controlled low strength materials (CLSM) as a probable recycling approach. To this end, experiments have been performed to investigate the applicability of bottom-ash-based CLSM that comprises eco-friendly soil binders, water, fly ash, and a combination of bottom ash and weathered granite soil. The physical and chemical properties of the weathered granite soil, bottom ash, fly ash, and soil binders are analyzed via laboratory tests, including X-ray diffraction and scanning electron microscopy. To determine an appropriate CLSM mixing proportion, the flowability test is first performed on three mixture types having three replacement ratios of fly ash each. Subsequently, compressive-strength tests are performed. Based on the results of these tests, four mixtures are selected for the freeze-and-thaw test to determine the appropriate mixing proportion. Finally, the ground model and soil-contamination tests are performed to examine the field applicability of the mixture. This study confirms that bottom-ash-based CLSM causes negligible soil contamination, and it satisfies the prescribed performance requirements and contamination standards in Korea.