• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.7
• /
• pp.884-891
• /
• 2016

A secondary injection system in a diesel engine has benefits: it can be controlled independently without interrupting engine control, it can be adapted to various layouts for exhaust systems, and it pose no reductant dilution problems compared to post injection systems in the combustion chamber or other supplemental reductant injections. In a secondary injection system, the efficiency of the catalyst depends on the method of reducing the supply. The reductant needs to be maintained and optimized with constant pressure, the positions and angles of injector is a very important factor. The concentration and amount of reductant can be changed by adjusting secondary injection conditions. However, secondary injection is highly dependent upon the type of injector, injection pressure, atomization, spray technology, etc. Therefore, it is necessary to establish injection conditions the spray characteristics must be well-understood, such as spray penetration, sauter mean diameter, spray angle, injection quantity, etc. Uniform distribution of the reductant corresponding to the maximum NOx reduction in the DeNOx catalyst system must also assured. With this goal in mind, the spray characteristics and impingement plate types of a secondary injector were analyzed using visualization and digital image processing techniques.

• Journal of Food Hygiene and Safety
• /
• v.39 no.3
• /
• pp.231-238
• /
• 2024

Vibrio parahaemolyticus is a major seafood-borne pathogen commonly detected in marine environments. In Korea, V. parahaemolyticus-induced foodborne illnesses account for 7.5% of bacterial pathogen-related food poisonings. Moreover, the amount of antimicrobial agents used in aquatic cultures is continuously increasing. In this study, we isolated V. parahaemolyticus from seafood samples and performed antimicrobial susceptibility tests using the microbroth dilution method. Furthermore, using whole-genome sequencing, we identified antimicrobial resistance genes, virulence genes, and sequence types (STs). We could isolate V. parahaemolyticus from 47 (59.5%) of the 79 seafood samples we purchased from retail markets in Seoul and Chungcheong provinces. Antimicrobial susceptibility tests revealed that 2 and all of the 47 isolates were ampicillin-resistant (4.3%) and susceptible to all tested antimicrobial agents (100%), respectively. The genotype analysis revealed that all isolates carried beta-lactam-, tetracycline-, and chloramphenicol-associated antimicrobial resistance genes. However, we could detect fosfomycin resistance only in one isolate. Concerning the virulence genes, we detected T3SS1 and T3SS2-associated genes in all and one isolate, respectively. However, we could not detect the tdh and trh genes. Of the 47 isolates, 17 belonged to 15 different STs, including ST 658 with 3 isolates. The rest 30 isolates were identified as 25 new STs. The results of this study support the need for operating a continuous monitoring system to prevent foodborne illnesses and the spread of antimicrobial resistance genes in V. parahaemolyticus.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.14 no.2
• /
• pp.45-49
• /
• 2010

Purpose: Several radiopharmaceuticals were used for cisternography. But recently, due to more short acquisition time, high resolution than other radiopharmaceuticals like In-111 DTPA, we were using Tc-99m DTPA in cisternography. Using of Tc-99m DTPA for intrathecal, was not officially recognised by the FDA. And there are matters of aseptic meningitis, muscular tetany, seizures by inappropriate radiopharmaceuticals handling. So, it is necessary to prevent adverse reactions while handling the radiopharmaceuticals using in cisternography. Therefore, this study aims to evaluation of usefulness and procedures for safety of radiopharmaceuticals in cisternography. Materials and Methods: Subjects were 12radioactive tracer vials using in cisternography in 2008 Dec. 16 - 2009 Dec. 30. (1) Radioactive tracer Vial test - We were measured NaPertechnetate radiation dose and volume, normal saline volume for dilution, source volume and dose activity for patient injection. And then, calculated mass of pure DTPA. (2) Bacterial endotoxin test - We performed pyrogen test using by negative/positive control vials which was added normal saline 0.2 mL and added normal saline 0.1 mL, Tc-99m DTPA 0.1 mL in test control vial. And then, reacted by digital hot plate in $37.5^{\circ}C$ for 1 hour and compared of gel-clot in each control vials. (3) Compliance safety procedure - We were checked safety issues and wrote out a safety procedure exam sheet. Results: (1) Radioactive tracer Vial test - Mass of DTPA per dose for patient injection (mg) was 0.88 (mg) on average, and Mass of DTPA per volume for patient injection (mg) was 0.74 (mg) on average. (2) Bacterial endotoxin test - All control test vials showed negative reactions. (3) Compliance safety procedure - We were checked safety issues and wrote out a safety exam sheet in all the exams. So, there were no adverse reactions. Conclusion: We could examine easier to safety tests using by Techscan - DTPA (Mallinckrodt): CaNa3. Each test results were passed the safety tests and there are no adverse reactions. The use of Tc-99m DTPA for cisternography, always has been become an issue. Since it has occur adverse reaction while examine the cisternography using by Tc-99m DTPA, it needs to set up the 'Standard Operating procedures'.