• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.13 no.4
• /
• pp.3-11
• /
• 2003

It is very important to detect and remove original sources of various attacks through networks. One of the effective method to detect the sources is traceback systems. In this paper, we design and implement an agent-based traceback system that does not require the reaction of routers and administrators and does not need numerous log data. In the design, we introduce a traceback server and traceback agents in each network Using sniffing and spoofing, the server transmits a packet with a specific message. The agents detect the packet and provide the information for the server to trace back the original source.

• Journal of the Korean Ceramic Society
• /
• v.43 no.8 s.291
• /
• pp.472-478
• /
• 2006

The effect of compositional and processing variables on a nitriding reaction of silicon powder compact and subsequent post sintering of RBSN (Reaction-Bonded Silicon Nitride) was investigated. The addition of a nitriding agent enhanced nitridation rate substantially at low temperatures, while the formation of a liquid phase between the nitriding agent and the sintering additives at a high temperature caused a negative catalyst effect resulting in a decreased nitridation rate. A liquid phase formed by solely an additive, however, was found to have no effect on nitridation for the additive amount used in this research. The original site of a decomposing pore former was loosely filled by a reaction product ($Si_3N_4$), which provided a specimen with nitriding gas passage. For SRBSN (Sintered RBSN) specimens of high porosity, only a marginal dimensional change was measured after post sintering. Its engineering implication for near-net shaping ability is discussed.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.21 no.3
• /
• pp.397-410
• /
• 2023

This study examined the efficacy of various chlorinating agents in partitioning light water reactor spent fuel, with the aim of optimizing the chlorination process. Through thermodynamic equilibrium calculations, we assessed the outcomes of employing MgCl₂, NH₄Cl, and Cl₂ as chlorinating agents. A comparison was drawn between using a single agent and a sequential approach involving all three agents (MgCl₂, NH₄Cl, and Cl₂). Following heat treatment, the utilization of MgCl₂ as the sole chlorinating agent resulted in a moderate separation. Specifically, this method yielded a solid separation with 96.9% mass retention, 31.7% radioactivity, and 44.2% decay heat, relative to the initial spent fuel. In contrast, the sequential application of the chlorinating agents following heat treatment led to a final solid separation characterized by 93.1% mass retention, 5.1% radioactivity, and 15.4% decay heat, relative to the original spent fuel. The findings underscore the potential effectiveness of a sequential chlorination strategy for partitioning spent fuel. This approach holds promise as a standalone technique or as a complementary process alongside other partitioning processes such as pyroprocessing. Overall, our findings contribute to the advancement of spent fuel management strategies.

• Restorative Dentistry and Endodontics
• /
• v.49 no.3
• /
• pp.23.1-23.10
• /
• 2024

Objectives: Previous in vitro studies determined the whitening effects of bleaching products on stained resin composite surfaces. This in vitro study aimed to verify the effectiveness of a whitening system on composite resin previously subjected to pigmentation, specifically examining the depth of whitening effectiveness within the material structure. Materials and Methods: A commercially available nano-filled composite resin was used. Specimens were stained using a coffee-based solution and a 10% carbamide peroxide-based gel was employed as the whitening agent. The pigment's penetration and the effect of the bleaching gel were evaluated by measuring color (CieLab values) from the outer edge to the inner part of the specimens. Color measurements were taken at 14 points, starting from 0.1 mm from the external perimeter up to 3.0 mm. Results: Analysis of variance tests showed a statistically significant difference between the Control Group (CG), Pigmentation Group, and Whitening Group. The whitening agent was effective up to 1.5 mm in depth, with Whiteness index (W) values not statistically different from those of CG up to 0.5 mm in depth. Conclusions: Whitening agents on nano-filled resin composite previously pigmented appear effective in restoring the W to values similar to the original, particularly in the superficial layers of the sample.

• Food Science and Preservation
• /
• v.17 no.3
• /
• pp.358-364
• /
• 2010

Ginger was dried using maltodextrin or recycled dehydration liquid as dehydrating agents, and the quality of dried ginger was compared with that of freeze-dried and hot-air-dried samples in terms of color, moisture content, water activity, dehydration rate, rehydration rate, and sensory properties. Ginger prepared using molecular press dehydration (MPD) retained its original color. The dehydration rate increased when ginger was dried using a dehydrating agent. The rehydration rate was increased in ginger dried using such an agent. Both dehydration and rehydration rates were elevated with increasing concentrations of soluble solids in the dehydration liquid. The sensory qualities of ginger prepared using the MPD method were better than those of freeze-dried and hot air-dried samples. These results indicate that drying of ginger rhizomes using recycled dehydrating liquid is very efficient.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.2
• /
• pp.517-520
• /
• 2012

Single original gemcitabine is commonly used as salvage treatment in platinum-resistant ovarian cancer, fallopian tube cancer and primary peritoneal adenocarcinoma (PPA) with a satisfactory outcome. However, efficacy data fro this regimen are limited. We therefore conducted a retrospective study to evaluate the outcome of patients who received single-agent generic gemcitabine (GEMITA) after development of clinical platinum resistance. The study period was between May 2008 and December 2010. Gemcitabine was administered intravenously in two different schedules: 1,000 $mg/m^2$ on day 1,8, and 15 every 28 days; and on days 1 and 8 every 21 days with the same dosage. Administration was until disease progression was noted. The response rate was evaluated using the Gynecologic Cancer Intergroup (GCIG) criteria while toxicity was evaluated according to WHO criteria. Sixty-six patients met the inclusion criteria in the study period. Two-thirds of them received gemcitabine as the second and third line regimen. The overall response rate was 12.1%. The median progression free survival and overall survival was 2 and 10 months, respectively. With the total 550 courses of chemotherapy,the patients developed grades 3 and 4 hematologic toxicity as follows: anemia, 1.5%; leukopenia, 13.7%; neutropenia, 27.3%; and thrombocytopenia, 3.0%. In conclusion, single agent generic gemcitabine revealed a modest efficacy in patients with platinum-resistant ovarian cancer, fallopian tube cancer and PPA without serious toxicity.

• Mycobiology
• /
• v.46 no.2
• /
• pp.92-100
• /
• 2018

The filamentous Ascomycota Colletotrichum gloeosporioides sensu lato is a fungus that has been reported worldwide as a causal agent of anthracnose disease in avocado and other crops. In Mexico, this species affects fruits from an early stage of development in the orchard until the post-harvest stage. Although fungicides are continuously applied to control Colletotrichum species, pericarp cankers and soft rot mesocarp in fruits are still frequently observed. Considering the lack of a precise description of the causative agent, the aim of the current study was to determine the pathogens involved in this symptomatology. Twenty-four isolates were consistently obtained from the pericarp of avocado fruits cv. "Hass" collected in the central avocado-producing area of Mexico. Morphological features such as colony growth, conidia size, and mycelial appressorium were assessed. Bayesian multilocus phylogenetic analyses were performed using amplified sequences of the internal transcribed spacer region of the nuclear ribosomal DNA; actin, chitin synthase, glyceraldehyde-3-phosphate dehydrogenase partial genes; and APn2-Mat1-2 intergenic spacer and mating type Mat1-2 partial gene from the nine selected isolates. In addition, fruits were inoculated with a conidial suspension and reproducible symptoms confirmed the presence of Colletotrichum fructicola in this area. This pathogenic species can now be added to those previously reported in the country, such as C. acutatum, C. boninense, C. godetiae, C. gloeosporioides, and C. karstii. Disease management programs to reduce the incidence of anthracnose should include C. fructicola to determine its response to fungicides that are routinely applied, considering that the appearance of new species is affecting the commercial quality of the fruits and shifting the original population structure.

• Korean Journal of Microbiology
• /
• v.20 no.1
• /
• pp.11-20
• /
• 1982

A study was undertaken to examine the effect of curing agents on the stability, curing and segregation of R plasmid pSL100. And also the stability, transfer frequency, and recombination of its segregants obtained from curing agent treatment were studied. Ethidium bromide, acridine orange, and mitomycin-C were used as curing agent. The results obtained were as follows ; 1. The curing agent ethidium bromide, acridine orange, and mitomycin-C were not effective for curing the multiple antibiotic resistant determinant of pSL100 in Salmonella typhimurium and Escherichia coli. However, they induced plasmid segregation with high frequency in S.typhimuruim LT-2strains. TcApSmCm, TcSmCmKm, TcApCm, TcAp, TcKm, Tc segregants were obtained. 2. The resistant markers of the segregents were transferred to S.typhimurium LT-2 strains with high frequencies whereas they were transferred to E.coli K-12 only with low frequencies. 3. The transconjugants obtained from conjugation between two different S.typhimurium segregants were similar to the phenotype of the original R factor pSL100 and the resistant markers were transferred to the S.typhimurium LT-2 or E.coli strain with equal frequencies, indicating that they are recombinants. 4. The transconjugants obtained from conjugation between pSL100 segrgants and pKM101, or pBR322 possessed the resistant markers of the two parental plasmids and they were transferred to both S.typhimurium and E.coli K-12 strains with the same frequencies and maintained stably, suggesting that they are also recombinants. 5. The recombinant pSL100 could be also obtained in rec A-strains of E.coli, suggesting that the gene function of rec A is required for the recombination of pSL100 segregants in E.coli.

• Applied Chemistry for Engineering
• /
• v.17 no.6
• /
• pp.633-637
• /
• 2006

In this study, the efficient large-scale synthetic route for itraconazole, triazole antifungal agent, was developed. The original synthetic route for medicinal chemistry reported by Janssen Pharmaceutica was linear (14 linear steps) starting from 2,4-dichloroacetophenone with the total yield of 1.4%, and potential hazardous materials such as methanesulfonyl chloride ($CH_{3}SO_{2}Cl$), hydrogen gas, and sodium hydride (NaH) were used. Furthermore, the expensive 1-acetyl-4-(4-hydroxyphenyl)piperazine and palladium were used in this medicinal chemistry route, thus the manufacturing cost would be practically high. In order to improve the commercial route, we developed the process of 12 step convergent synthesis combining two intermediates which are roughly halves of itraconazole with the total yield of 12.0%, and hazardous materials and expensive reagents were excluded in this process, thus the manufacturing cost could be cut down to a great extent.

• Elastomers and Composites
• /
• v.48 no.3
• /
• pp.232-240
• /
• 2013

Microcapsules having healing agent were prepared in which 2,6-dimethylphenol (DMP) as a healing agent forms the core and melamine/formaldehyde resin forms the shell. Microcapsule-contained asphalts showed better mechanical properties than non-contained ones. And as the rest time passed the impact strength of microcapsule-contained asphalt was getting higher than that of asphalt without the microcapsule. As the rest time of 15 days passed, the original strength was restored. This tells that microcapsule-contained asphalt had the ability of self-healing. X-ray photos proved that DMP on asphalt fracture surface, which were burst out of the microcapsules when cracks occurred on asphalt, were polymerized to polyphenyleneoxide and this PPO covered the crack and healed the damage.