• Journal of Radiation Protection and Research
• /
• v.26 no.4
• /
• pp.425-432
• /
• 2001

A bacteria infection on film cassette contact surface was examined at the diagnostic radiology department. Studies have demonstrated a bactericidal effect of ultraviolet irradiation, and to assess the contamination level on film cassette contact surface as a predictor of patient prevent from nosocomial infection. The study showed that the laboratory result was identified non-pathologic and pathologic bacterial in the five different cassette size of the contact surface. Film cassettes were exposed to ultraviolet light for 1, 2 and 3 minutes. Ultraviolet light disinfection practices suitable for bacteria. The study concludes that presence of a bacterial infection will prevent a using antiseptic technique on film cassette contact surface. In conclusion, ultraviolet irradiate on film cassette over the surface more than 2 minutes. Ultraviolet dose of $1565 {\mu}W{\codt}s/cm^2$ Win in 30 second relative to ultraviolet dose in time.

• Journal of Digital Convergence
• /
• v.19 no.1
• /
• pp.211-216
• /
• 2021

This study was carried out to evaluate the effects of disinfection using environmental disinfectant after having assessed the extent of contamination through microbial culture testing and the Adenosine Triphosphate Bioluminescence method among the environmental management evaluation methods used for the environment in the hospital ward of patients infected by multidrug-resistant organisms. This study was conducted with the patient wards isolated due to multidrug-resistant organisms as the environmental surface. Specimens were collected from five locations including infusion pumps, IV poles, bedside cabinets, bed railings, keyboards, and blood pressure measurement cuffs. ATP and microbial culture testing were executed prior to, immediately after, and five minutes post-disinfection. According to the result contamination of the infusion pumps was statistically significantly reduced after disinfection. In addition, the bacteria before and after disinfection reduced in IV pole, bed railing, and keyboard. That is, regular environmental surface disinfection can provide safer environments to patients against infection. Therefore, it is necessary to establish guidelines including disinfection methods and intervals for environmental surfaces by evaluating the persistence of disinfectants at various institutions in the future.

• Journal of Environmental Health Sciences
• /
• v.48 no.3
• /
• pp.167-175
• /
• 2022

Background: Disinfection is essential to provide drinking water from a water source. The disinfection process mainly consists of the use of chlorine and ozone, but when chlorine is used as a disinfectant, the problem of disinfection by-products arises. In order to resolve the issue of disinfection by-products, electro-chlorination technology that produces chlorine-based disinfectants from salt water through electrochemical principles should be applied. Objectives: This study surveys the possibility of optimally producing active chlorine from synthetic NaCl solutions using an electro-chlorination system through RSM. Methods: Response surface methodology (RSM) has been used for modeling and optimizing a variety of water and wastewater treatment processes. This study surveys the possibility of optimally producing active chlorine from synthetic saline solutions using electrolysis through RSM. Various operating parameters, such as distance of electrodes, sodium chloride concentration, electrical potential, and electrolysis time were evaluated. Results: Various operating parameters, such as distance of electrodes, sodium chloride concentration, electrical potential, and electrolysis time were evaluated. A central composite design (CCD) was applied to determine the optimal experimental factors for chlorine production. Conclusions: The concentration of the synthetic NaCl solution and the distance between electrodes had the greatest influence on the generation of hypochlorite disinfectant. The closer the distance between the electrodes and the higher the concentration of the synthetic NaCl solution, the more hypochlorous acid disinfectant was produced.

• The Journal of Advanced Prosthodontics
• /
• v.4 no.1
• /
• pp.24-29
• /
• 2012

PURPOSE. To compare the effect of sodium hypochlorite and microwave disinfection on the dimensional stability of denture bases without and with relining. MATERIALS AND METHODS. A brass die was prepared by simulating an edentulous maxillary arch. It was used to fabricate 1.5 mm and 3 mm of thickness denture bases (n = 40). The 1.5 mm of thickness-specimens (n = 20) were relined with 1.5 mm of autopolymerizing relining resin. Five holes were prepared over crest of ridge of brass die with intimately fitting stainless steel pins which were transferred to the intaglio surface of specimens during fabrication of denture bases. For calculation of dimensional changes in denture bases, differences between the baseline area before and after disinfection of the specimens were used. The denture bases without and with relining were divided into 2 groups (each n =20). Data were analyzed using student paired 't'and unpaired 't'test. RESULTS. Microwave disinfection produces significant shrinkage in both denture bases without relining (t =17.16; P<.001) and with relining (t = 14.9; P<.001). Denture bases without relining showed more shrinkage when compared with relined denture bases after microwave disinfection (t = 6.09; P<.001). The changes in dimensional stability after sodium hypochlorite disinfection were not significant for both denture bases without relining (t = 2.19; P=.056) and denture bases with relining (t = 2.17; P=.058). CONCLUSION. Microwave disinfection leads to increased shrinkage of denture bases without and with relining. Chemical disinfection with sodium hypochlorite seems to be a safer method of disinfection with regards to physical properties such as changes in dimensional stability.

• Journal of Korean Society on Water Environment
• /
• v.23 no.5
• /
• pp.613-619
• /
• 2007

This study has carried out a performance of dimensionally stable anode for the purpose of disinfection of Legionella pneumophila in water. Three kinds of electrode were prepared by plating and thermal deposition, which were coated by the oxides of Pt, Ru and Ir on Ti metal surface, respectively. The order of disinfection performance for Legionella pneumophila was Ru/Ti > Ir/Ti > Pt/Ti. Free Cl and $ClO_2$ generation of Ir/Ti electrode was higher than that of two electrodes. However, the concentrations of generated $H_2O_2$ and $O_3$ of the Ru/Ti electrode were highest among the three electrodes. The higher NaCl concentration was, the more oxidants was generated and disinfection effect was increased. However, optimum NaCl dosage was 0.0125% due to the regulation on the conductivity and $Cl^-$ concentration for the cooling water quality of air conditioning and refrigeration equipment. With the increase of current, oxidants was more generated and following disinfection effect was increased. The increase of electrode distance reduced oxidants generation due to the low electric power, and their disinfection effect was decreased accordingly.

• Journal of Internet Computing and Services
• /
• v.22 no.6
• /
• pp.41-49
• /
• 2021

Due to the COVID-19 pandemic, issues related to quarantine are emerging. There are various infection prevention methods, but among them, it is certain to frequently disinfect the surface or the entire space of an object that has come into contact with the virus. However, the reality is that the number of times such disinfection is legally designated and the required number of personnel are very different depending on the building and facility. For this reason, there are no companies and systems that can professionally receive orders for disinfection work. In order to solve the aforementioned problems, this paper presents a method to design a disinfection service platform based on the MVC pattern, and implements the required functions based on this. Through this, it is possible to build a more systematic system, and it is hoped that it will be of great help to quarantine with an orderly process for disinfection work.

• Journal of Environmental Health Sciences
• /
• v.32 no.3
• /
• pp.215-221
• /
• 2006

This study investigated the inactivation of the total coliform, an indicator organism in chlorine dioxide, in order to assess the optimal disinfection procedure for drinking water treatment and distribution systems. This research focus on a number of factors, including the dosage of disinfectant, contact time, pH, temperature and DOC. Water samples were taken from the outlet of a settling basin at a conventional surface water treatment system. As the pH increased in the range of pH 6-9, the bactericidal effects of disinfectants decreased. Changes in levels of pH did not significantly after the disinfection effect of chlorine dioxide for total coliform. With an increase in temperature, there was a subsequent increase in the bactericidal effects of disinfectants. Thus, it is evident that a decrease in temperature will higher the CT values required to inactivate coliform for during the winter. DOC addition can also reduce total coliform inactivation. DOC is the most significant variable in total coliform inactivation with chlorine dioxide.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.62 no.4
• /
• pp.87-97
• /
• 2020

The livestock infections had been happened seasonally, but they have gradually changed to be irrelevant to seasons and have an aspect to rapidly spread after outbreak. Especially in Korea, proactive disinfection measures are very important because the livestock farms are located densely so high as to accelerate the spread of disease between farms. livestock disease outbreaks like HPAI and FMD occurred with high probability due to vehicles visiting the farms, this study is to evaluate the efficiency of livestock vehicle disinfection systems by investigating the disinfectant coverage according to the type of vehicle disinfection system and the type of vehicle quantitatively. In field experiments, water-sensitive papers (WSPs) were attached to 21 locations on the surface of four vehicles (sedan, SUV, truck, and feed transport), respectively, and exposed to disinfectants while the vehicle was sprayed in two vehicle disinfection systems (tunnel type and simplified type). The WSPs were scanned and image-processed to calculate the disinfectant coverage. The results showed that the tunnel-type vehicle disinfection system had a better disinfection performance with an average coverage of 90.27% for all vehicles compared to 32.62% of the simplified type system. The problem of the simplified system was a wide coefficient of variation (1.05-1.31) of the disinfectant coverage between 21 locations indicating a need for further improvement of nozzle location and arrangement.

• Journal of radiological science and technology
• /
• v.24 no.1
• /
• pp.27-32
• /
• 2001

The bacteria infection on film cassette contact surface was examined at the diagnostic radiology department of the S. hospital. The objective of this study was to assess the contamination level on film cassette contact surface as a predictor of patient prevention from nosocomial infection and for improvement of the hospital environment. The laboratory result was identified non-pathologic bacterial in the five different cassette size of the contact surface. Film cassettes were exposed to ultraviolet light for 1, 2 and 3 minutes. Ultraviolet light disinfection is proven suitable for bacteria. The study concludes that presence of a bacterial infection will prevent a using antiseptic technique on film cassette contact surface. In addition education of nosocomial infection for radiographers will be required. In conclusion, ultraviolet is considered effective to irradate bacteria. Additionally, two minutes are required to sterilize film cassettes.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.767-772
• /
• 2006

The SWTR(Surface Water Treatment Rule) requires achieving removal 99.9% Giardia and 99.99% Virus. To remove Giardia and Virus, disinfection process is essential process. CT is important index for Disinfection performance. CT value is expressed by CXT. C is represented by disinfection concentration and T is represented by $T_{10}$ which means 90% contact time in clearwell. To improve Disinfection performance, it is desirable to increase $T_{10}$. Primary factor affected $T_{10}$ is flow Pattern. Because guide wall change that flow pattern is uniform, we have installed guide wall to increase $T_{10}$. In this paper, we have performed numerical analysis for clearwell installed symmetric guide wall and center divided guide wall using CFD. We have analyzed flow pattern and $T_{10}$ in each clearwell. And. we compare symmetric guide wall with center divided guide wall in flow pattern and $T_{10}$.