• Title/Summary/Keyword: Carbon dioxide (CO2)

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An Experimental Study on Denitrification Efficiency of Agricultural Byproducts for Prevention of Nitrate Contamination from LID or Groundwater Recharge Facilities (지하수 함양시설 또는 LID시설에서의 질산성질소 오염방지를 위한 농업부산물의 탈질효율 실험연구)

  • Lee, Jinwon;Phung, Thanh Huy;Lee, Byungsun;Kim, Kangjoo;Lee, Gyusang
    • Journal of Soil and Groundwater Environment
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    • v.26 no.6
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    • pp.82-94
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    • 2021
  • Facilities for low impact development (LID) or groundwater recharge have the high potential spreading groundwater nitrate contamination because of the rapid infiltration. This study was initiated to remove nitrate from the waters using agricultural byproducts as organic sources for denitrification during infiltration. As the first step of this purpose, we experimentally tested the denitrifying efficiency of 4 organic materials (pine tree woodchips, cherry leaves, rice straws, and rice hulls) and tried to identify the key factors controlling the efficiency. For this study, we precisely investigated the change of chemical reactions during the experiment by analyzing various geochemical parameters. The result shows that the denitrification efficiency is not simply linked to the availability of the easily decomposable contents in the organic matter. It is found that avoiding the severe pH decrease due to the CO2 generation is the essence to derive the efficient denitrifying conditions when organic matters were used.

Economic Growth, Financial Development, Transportation Capacity, and Environmental Degradation: Empirical Evidence from Vietnam

  • NGUYEN, Van Chien;VU, Duc Binh;NGUYEN, Thi Hoang Yen;PHAM, Cong Do;HUYNH, Tuyet Ngan
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.4
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    • pp.93-104
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    • 2021
  • In recent years, there has been a substantial theoretical and empirical study on the role that financial market development has significantly played in promoting economic growth and development in the world. The development of an economy requires the financial industry to be developed. In the context of rapid economic development, global warming has become a serious problem with issues such as rising average temperatures, climate change, rising sea level, and increasing carbon dioxide emissions. This study aims to examine the influence of economic growth, financial development, transportation capacity, and environmental degradation. Using time-series data from 1986 to 2019 and environmental degradation being measured by CO2 emissions, the study employs a quantity of ample unit root tests, the structural break unit root tests, Autoregressive Distributed Lag (ARDL), and cointegration bounds test. The results show that there is a significant long-term cointegration among study variables. Empirical findings also indicate that an increase in per capita GDP and financial development worsens environmental quality whereas transportation capacity and foreign investment can improve environmental quality.

A Case of Eagle's Syndrome Treated with Carbon Dioxide Laser

  • Byun, Kwang Hyun;Ahn, Jung Hyun;Lee, Sang Joon;Woo, Seung Hoon
    • Medical Lasers
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    • v.9 no.1
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    • pp.71-75
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    • 2020
  • Eagle syndrome is relatively uncommon with an incidence of abnormal stylohyoid length being 4% to 7.3%. A vast majority of individuals with elongation of the styloid process are asymptomatic. It is a syndrome marked by the clinical signs and symptoms of facial pain, ear pain, throat pain, dysphagia and a globus sensation in the throat. The cause of Eagle syndrome is believed to be a congenital or hormonal change and reactive osseus hyperplasia of the styloid process in response to pharyngeal trauma or surgical intervention, such as tonsillectomy. We present here a case of a 37-year-old female with a twelve-month history of both sided oropharyngeal pain and globus sensation which has no trauma or surgical intervention. The patient presented with a long, slender, bony intraoral projection that was found to be an elongated styloid process. We removed this elongated styloid process with a CO2 laser, and her symptoms disappeared.

Comparative Life Cycle Assessment of Reusable and Disposable Distribution Packaging for Fresh Food (신선식품용 재사용 EPE박스와 EPS박스에 대한 전과정 환경영향평가)

  • SY Kim;Charoensri Korakot;YJ Shin;HJ Park
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.29 no.3
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    • pp.181-193
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    • 2023
  • In this study, we conducted a comparative life cycle assessment (LCA) of two different products, considering reusable and single-use packaging for fresh food distribution. For reusable packaging, we utilized expanded polyethylene (EPE), while for comparison, a disposable box made of widely used expanded polystyrene (EPS) was selected. We comprehensively analyzed the environmental impacts of production, transportation, reprocessing (for reused boxes), and disposal across 18 impact categories. Upon analyzing the actual reuse of 300 rounds of fresh food, the cumulative global warming potential (GWP) values for the EPE box were found to be 280.21 kg carbon dioxide (CO2) eq, demonstrating a significant 75% reduction compared to those of the EPS box. Furthermore, it was observed that the GWP values for the EPE boxes became equivalent to those of the EPS boxes after 12 rounds of reuse. In conclusion, reusable packaging shows substantial potential to contribute to the reduction of environmental burdens, aligning well with global environmental requirements for sustainable food distribution and related industries.

Blue Carbon Resources in the East Sea of Korea and Their Values and Potential Applications (동해안 블루카본 자원의 가치와 활용방안)

  • Yoon, Ho-Sung;Do, Jeong-Mi;Jeon, Byung Hee;Yeo, Hee-Tae;Jang, Hyeong Seok;Yang, Hee Wook;Suh, Ho Seong;Hong, Ji Won
    • Journal of Life Science
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    • v.32 no.7
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    • pp.578-587
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    • 2022
  • Korea, as the world's 7th largest emitter of greenhouse gases, has raised the national greenhouse gas reduction target as international regulations have been strengthened. As it is possible to utilize coastal and marine ecosystems as important nature-based solutions (NbS) for implementing climate change mitigation or adaptation plans, the blue carbon ecosystem is now receiving attention. Blue carbon refers to carbon that is deposited and stored for a long period after carbon dioxide (CO2) is absorbed as biomass by coastal ecosystems or oceanic ecosystems through photosynthesis. Currently, there are only three blue carbon ecosystems officially recognized by the Intergovernmental Panel on Climate Change (IPCC): mangroves, salt marshes, and seagrasses. However, the results of new research on the high CO2 sequestration and storage capacity of various new blue carbon sinks, such as seaweeds, microalgae, coral reefs, and non-vegetated tidal flats, have been continuously reported to the academic community recently. The possibility of IPCC international accreditation is gradually increasing through scientific verification related to calculations. In this review, the current status and potential value of seaweeds, seagrass fields, and non-vegetated tidal flats, which are sources of blue carbon on the east coast, are discussed. This paper confirms that seaweed resources are the most effective NbS in the East Sea of Korea. In addition, we would like to suggest the direction of research and development (R&D) and utilization so that new blue carbon sinks can obtain international IPCC certification in the near future.

Development of a Pre-treating Equipment and the Carcass Disposal System for Infected Poultry (감염가금 전처리 및 폐사가축 처리시스템 개발)

  • Hong, J.T.;Kim, H.J.;Yu, B.K.;Lee, S.H.;Hyun, C.S.;Ryu, I.S.;Oh, K.Y.;Kim, S.;Kwon, J.H.;Tack, D.S.
    • Journal of Animal Environmental Science
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    • v.17 no.2
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    • pp.81-92
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    • 2011
  • When we bury the infected poultry into the ground, we have many problems such as the difficulty of making sufficient area for burying, environmental contamination by the leachate, unpleasant ordor. Also, in case of burning the carcass of the infected poultry, there are some problems such as high cost, dust, unpleasant odor, etc. It could cause environmental contamination which many peoples and environmental organization complains about. In this study, we develop a treating system which treats the infected poultry carcass in a environmental method preventing the environment contamination. This system is composed of many processes. The euthanasia system uses rigid vinyl to trap and to do a euthanasia the infected poultry with lethal gas, carbon dioxide. And then, with the tractor attached grappler infected poultry carcass could be put into the carcass treating system. The euthanasia system uses rigid vinyl to trap the infected birds and to confine lethal gas, carbon dioxide. Infected poultry carcass are moved to carcass disposal system by collecting device which is attached at tractor. The carcass treatment system (capacity of disposal : 6.3 $m^3$) is installed on a truck and do one pass work, which is input, crush, stir, sterilize, and discharge treated carcass. 1,000 chickens was killed within 9.7min by $CO_2$ (300L/min) in the tent (10 $m^3$). The collecting device could carry 142 chickens at a time, and the movable carcass treatment system could sterilize 2 tons carcass per hour (at one time). This treatment systems was eco-friendly because it reduced the volume of carcass by 31.9% with no wastewater generation.

Measurement and Analysis of Indoor Thermal Environment in Passenger Car (철도차량 객차내 온열환경 측정 분석)

  • So, Jin-Sub;Yoo, Seong-Yeon
    • Journal of the Korean Society for Railway
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    • v.11 no.2
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    • pp.120-125
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    • 2008
  • The Ministry of Environment established a guide line Indoor Air Quality Management guidelines in Public Facilities in December 2006. As the items of the guideline, $CO_2$ (Carbon dioxide) and PM10 (Particulate matter). Therefore trains and subway need to control air quality. The indoor thermal environment in passenger car is very important for the enhancement of the amenity and health of passengers. Many researchers have studied it not for train but for building. So, in this study, we have performed thermal environment in passenger car (KTX, Mugunghwa, Saemaeul), and verified the relation between the PMV (Predicted Mean Vote) and PPD (Predicted Percent Dissatisfied) from September to October 2007. As a result, the average PMV value for each trains are 0.1, 0.22 for KTX, 0 for Mugunghwa, 0.1 for Saemaeul. So it satisfies the ASHRAE Handbook thermal environmental limit (-0.5 < PMV < +0.5).

Life Cycle Assessment of Biogas Production in Small-scale Household Digesters in Vietnam

  • Vu, T.K.V.;Vu, D.Q.;Jensen, L.S.;Sommer, S.G.;Bruun, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.5
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    • pp.716-729
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    • 2015
  • Small-scale household digesters have been promoted across Asia as a sustainable way of handling manure. The major advantages are that they produce biogas and reduce odor. However their disadvantages include the low recycling of nutrients, because digestate is dilute and therefore difficult to transport, and the loss of biogas as a result of cracks and the intentional release of excess biogas. In this study, life cycle assessment (LCA) methodology was used to assess the environmental impacts associated with biogas digesters in Vietnam. Handling 1,000 kg of liquid manure and 100 kg of solid manure in a system with a biogas digester reduced the impact potential from 4.4 kg carbon dioxide ($CO_2$) equivalents to 3.2 kg $CO_2$ equivalents compared with traditional manure management. However, this advantage could easily be compromised if digester construction is considered in the LCA or in situations where there is an excess of biogas which is intentionally released. A sensitivity analysis showed that biogas digesters could be a means of reducing global warming if methane emissions can be kept low. In terms of eutrophication, farms with biogas digesters had 3 to 4 times greater impacts. In order to make biogas digesters sustainable, methods for recycling digestates are urgently required.

Effects of a tunnel ventilation system within the tie-stall barn environment upon the productivity of dairy cattle during the winter season

  • Sarentonglaga, Borjigin;Sugiyama, Tatsuhiro;Fukumori, Rika;Nagao, Yoshikazu
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.5
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    • pp.748-756
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    • 2019
  • Objective: The objective of this study was to examine the effect of using a tunnel ventilation system within the dairy barn environment upon the productivity of dairy cows during the winter season. Methods: The study was performed at the University Farm, Faculty of Agriculture, Utsunomiya University. Twenty-one Holstein dairy cows (5 heifers and 16 multiparous) were enclosed in a stall barn. Unventilated (UV) and tunnel-ventilated (TV) was operated by turns every other week, and a number of key parameters were measured in the barn, including tunnel ventilation output, temperature, relative humidity, gas concentrations (oxygen [$O_2$], carbon dioxide [$CO_2$], and ammonia [$NH_3$]). Also, skin and rectal temperature, respiratory rate, blood gas concentrations, and bacterial count were measured from nipple attachments on ten cows. The amount of fodder left uneaten, and general components and somatic cell count of the milk were measured. Results: As for our dairy barn environment, air temperature dropped significantly with the passage of time with TV. Humidity was significantly higher with TV at 0600 h compared to UV, while $CO_2$ and $NH_3$ concentrations with UV were significantly higher than with TV at 0000 h and 0600 h. Skin temperature was significantly lower with TV compared to UV at 0000 h and 0600 h. Respiratory rate was also significantly lower at 0600 h with TV than with UV. Bacterial count for the nipple attachments was significantly lower with TV than with UV at 0600 h. The amount of leftover fodder was significantly less with TV in comparison with UV. Conclusion: Our results suggest that a TV system in the winter barn results in environmental improvements, such as reductions in unfavorable gas concentrations and bacterial growth. Consequently, it is expected that barns utilizing a TV system will be beneficial for both animal health and production.

Improvement of Quality in Treated Water by the pH Adjustment of Raw Water (원수 pH 조정에 의한 정수 수질 개선)

  • Jeong, Gwan-Jo;Lee, Kyeong-Woo;Kim, Hyun-Hee;Jeong, Eui-Sun;Park, Hyeon;Han, Sun-Hee
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.5
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    • pp.469-476
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    • 2010
  • The purpose of the study is to find ways to decrease turbidity and residual aluminum by improving the efficiency of coagulation process through controlling the pH of the source water with $CO_2$ when the pH increases by algal bloom or by the characteristics of the source water. Water quality parameters were monitored before and after $CO_2$ addition in February, March, April, and December, when the pH of the source water is over 8.0 and constant regardless of day and night. Water quality parameters closely related with evaluation of treated drinking water quality were monitored in detail, e.g. aluminum, turbidity, particle counts, TOC, THMs, 2-MIB, and geosmin. According to the results, inorganic water quality parameters such as turbidity, particle counts, and aluminum were decreased due to improved efficiency of the coagulation process. It was concluded that the pH of the water in the arrival basin must be controlled below 7.4 by adding $CO_2$ when the pH of the source water increasing. By controlling pH with $CO_2$, the water quality could be maintained within the drinking water quality goal of Seoul City (<30 particle/mL of particle count, <0.05 NTU of turbidity and <0.02 mg/L of aluminum). The change of the pH could not affect the concentrations of DBP's (e.g., THMs, CH, and HAAs) and taste/odor causing compounds (e.g., 2-MIB and geosmin). 2-MIB and geosmin were affected more by their initial concentrations in the source water.