목 적 : 두경부는 해부학적 구조가 복잡하기 때문에 두경부 검사 시 고해상도의 영상을 필요로 하게 된다. 하지만 고해상도의 영상을 얻기 위한 검사 시 상악부에 치과 보철물이 삽입되어 있거나 뇌동맥 coil이 있는 경우 1.5T에 비해 3T는 자화 감수성의 차이가 더욱 더 커지게 되어 metallic susceptibility artifact가 크게 나타나게 된다. 이에 자기 공명 확산강조 검사 시 자장 세기의 증가로 인한 금속물질에 대한 metallic susceptibility artifact의 증가와 기존의 3T에서 Single shot DWI를 이용한 DWI검사에 비해 RESOLVE technique을 이용한 DWI 검사 시 metallic susceptibility artifact의 감소에 대한 유용성을 알아보고자 한다. 대상 및 방법 : 치과보철물(백금78%+metal) 과 임플란트(티타늄+메탈), 두 개내 혈관용 코일(10cm)을 기존의 Single shot DWI를 이용하여 scan을 시행하고 RESOLVE를 이용하여 3T에서 각각 5회씩 Scan하였다. 또한 자장의 강도에 따른 자화 감수성의 변화를 알아보기 위하여 1.5T에서 Single shot DWI를 5회 추가로 scan하였다. 사용된 장비는 SIEMENS사의 Avanto 1.5T와 Skyra 3.0T를 사용하였으며 1.5T에서 진행한 Scan parameter는 FOV 220mm, matrix 190, slice Thickness 5.0mm, slice gap 1.5mm, TR 4000ms, TE 95ms, slice수 24이며 3.0T에서 진행한 single shot DWI scan parameter는 FOV 220mm, matrix 190, slice Thickness 5.0mm, slice gap 1.5mm, TR 5300ms, TE 87ms, slice수 24이며 3.0T에서 진행한 REOLVE DWI scan parameter는 FOV 220mm, matrix 190, slice Thickness 5.0mm, slice gap 1.5mm, TR 4700ms, TE1 68ms, TE2 112ms, slice수 24, readout segment 7 이며 phase encoding 방향은 Anterior-Posterio로 모두 동일하게 하였다. arifact의 측정은 marosis사의 M-view의 length tool을 이용하여 b-value 0은 window width(이하 ww) 1800 window level(이하 wl) 1000, b-value 1000은 ww 1000, wl 500으로 ADC는 ww 3000, wl 1500으로 고정하여 10년 이상의 경력을 가진 방사선사 3인이 5회씩 측정한 후 평균값을 산출하였다. 결 과 : 측정결과 급성뇌경색 진단에 주로 사용하는 b-value 1000에서 백금 78%+metal은 평균 측정치 1.5T single shot DWI 44.76mm, 3.0T single shot DWI 47.96mm, 3.0T RESOLVE 36.13mm이며 임플란트(티타늄)는1.5T single shot DWI 31.26mm, 3.0T single shot DWI 37.44mm, 3.0T RESOLVE 32.48mm이고 두 개 내 코일은 1.5T single shot DWI 19.76mm, 3.0T single shot DWI 31.20mm, 3.0T RESOLVE 16.44mm로 모든 실험에서 3.0 single shot >1.5Tsingle shot> 3.0T RESOLVE순으로 Metallic artifact가 크게 나타났으며 재료별로는 보철물>임플란트>코일 순으로 Metallic artifact가 크게 나타났다 결 론 : 확산 강조 자기공명 검사에서 자장의 세기가 증가할 때 metallic susceptibility artifact는 더욱 크게 나타나며 RESOLVE를 사용한 확산강조 자기공명 검사는 자화율차이에 의한 왜곡에 효과적이며 보철물이나 뇌동맥 coil과 같은 금속물이 삽입되어 있는 두경부 검사에서 metallic susceptibility artifact를 감소시키는데 그 유용성이 매우 큰 것으로 사료된다

PURPOSES: It is theoretically well known all over the world, that porous hot mixed asphalt (HMA) with hydrated Lime improves moisture and rutting resistance, and reduces pothole occurrence frequency, as well as the life cycle cost (LCC). METHODS : Addictive in the two different formations of the liquid anti-stripping Agent and powder Hydrated-Lime was applied in this investigation in order to obtain relatively clear results according to their types and conditions. Firstly, the moisture conditions were set, and applied to the porous HMA mixtures with hydrated lime (anti-stripping agent). Next, it was followed by a non-destructive test with the application of three freeze-thaw cycles, which were individually carried out thrice to compare the results of the dynamic moduli. Lastly, the hydrated lime effect related to moisture sensibility to porous HMA has been verified through the analysis of the modulus results regarding the change rate of dynamic modulus per n-cycle. RESULTS: It is clear from this investigation, that the dynamic modulus is inversely proportional to the change in temperature, as the graph representing the rigidity of the thermorheologically simple (TRS) material showed gradual decline of the dynamic modulus with the increase in temperature. CONCLUSIONS: The porous HMA mixture with the anti-stripping agent (hydrated Lime) has been found to be more moisture resistant to freezing and thawing than the normal porous HMA mixture. It is clear that the hydrated lime helps the HMA mixture to improve its fatigue resistance.

The aim of this paper is to assess the mediating effect of self-congruity on the relationship between susceptibility to interpersonal influence and status consumption. The findings of this paper are based on 222 sample. The paper utilises Baron and Kenny procedure and Sobel test to examine the mediation effects of self-congruity on the relationship between susceptibility to interpersonal influence and status consumption. Results indicate that self-congruity played a mediating role in the effect of susceptibility to interpersonal influence on status consumption. A partial type of mediation was established. Possible areas for further research are indicated at the end of the paper.

The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), has been considered as a major thrips species after its invasion in 1993 in Korea although recently F. intonsa (Trybom) was found as a dominant species locally. To explain their asymmetrical abundance in the field, we hypothesized differential insecticide susceptibility of both thrips species as an underlying mechanism. Laboratory assays were conducted to know their susceptibility to different pesticides including chlorfenapyr, chlorpyrifos, thiamethoxam, spinosad, s-metolachlor, and metalaxyl by direct spray, residue, and oral ingestion. Results showed that both thrips species were highly susceptible to chlorfenapyr and mortality reached 100% within 12 hours in F. occidentalis in all the assays while 9 hours in F. intonsa in direct spray and residual assays. The LT50[h] values of tested insecticides were significantly lower than that of herbicide or fungicide regardless of exposure methods except metalaxyl from direct spray. The insecticides tested here differed considerably in species specific toxicity, and F. intonsa is generally more susceptible to the insecticides irrespective of exposure methods.

The sweetpotato whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is a disastrous pest in horticultural plants worldwide. B. tabaci is a species complex including at least 24 biotypes in the world. In Korea, B-biotype has been invaded in 1998, Q-biotype in 2005 and widely spread into the country. B. tabaci is also a vector of more than 100 plant viruses, especially begomoviruses. Since 2008, Tomato yellow leaf curl virus (TYLCV) has been invaded into Korea and severely damaged tomato cultivar in all over of the country. B. tabaci is the only vector insect of TYLCV. Here we demonstrated whether TYLCV influence on the vector physiology during virus transmission. Pesticide susceptibility of whiteflies on TYLCV acquisition was determined in B. tabaci using the two-layered parafilm feeding chamber which containing 20% sugar solution including different doses of imidacloprid. Our result showed that TYLCV-viruliferous whiteflies were more susceptible to imidacloprid ingestion than non-viruliferous whiteflies. This study suggests that plant virus can manipulate the physiological conditions of vector insects.

목 적: 콘택트렌즈 케이스에서 분리한 균주들을 동정하고, Serratia marcescens 균주들에 대해 항생 제 감수성 검사를 시행하였다. 방 법: 총 65개의 콘택트렌즈 케이스를 수거하여 분리한 균주들을 16s rRNA gene 염기서열을 분석하여 동정하였고, Serratia marcescens 균주들을 Nalidixic acid(30㎍), Ciprofloxacin(5㎍), Ofloxacin(5㎍), Levofloxacin(5㎍) 항생제를 이용하여 디스크 확산법으로 항생제 감수성 검사를 실시하였다. 결 과: 30개의 콘택트렌즈 케이스에서 세균이 검출되었으며, 균주로는 Achromobacter sp. 8균주, Achromobacter xylosoxidans 3균주, Achromobacter spanius 1균주, Pandoraea pnomenusa 1균주, Serratia marcescens 17균주가 동정되었다. Serratia marcescens 균주에 대한 항생제 감수성 검사에서는 Nalidixic acid, Ciprofloxacin, Ofloxacin, Levofloxacin 모두 감수성으로 나타났다. 결 론: 콘택트렌즈 케이스에서 분리한 균주들을 16S rRNA gene 염기서열을 분석하여 동정한 결과 모두 30 균주가 동정되었으며, 콘택트렌즈 케이스에서 많이 분리 동정된 Serratia marcescens 균주에 대한 Quinolone 계 항생제 감수성 검사에서 모두 감수성으로 나타났다. 그러나 항생제의 지속적인 사용으로 내성 균주들이 나타날 것으로 예측되며 Quinolone 항생제의 내성 발생률에 대한 체계적인 연구와 관리가 필요한 것으로 사료된다.

본 연구는 들깻잎과 들깻잎 생산환경을 대상으로 31개의 시료를 채취하여 S. aureus 를 분리 하였다. 분리된 S. aureus 31주의 toxicity를 평가하고자 독소유전자와 항생제 내성을 검색하였다. 그 결과 분리된 균주에서 4개의 서로다른 독소유전자 패턴은 확인하였으며 sea와 sed유전자를 동시에 보유하는 균주는 4균주 (12.9%)였고, sed 유전자를 보유하는 균주는 9균주 (29.0%)였으며 see 유전자를 보유 하는 균주는 1균주 (3.2%)였다. 한편 seb와 sec 유전자를 보유하는 균주는 없었다. 항생제 내성평가결과, 12제의 항생제(penicillin, ampicillin, oxacillin, amoxicillin-clavulanic acid, cefazolin, cephalothin, imipenem, gentamicin, tetracycline, ofloxacin, norfloxacin, and erythromycin)에 내성을 보인 균주는 7균주 (22.6%)였다. 또한 분리된 균주의 2균주 (2.6%)는 5제의 항생제(penicillin, ampicillin, amoxicillin- clavulanic acid, gentamycin, and telithromycin)에 내성을 보였고 MRSA (Methicilline Resistant Staphylococcus aureus)는 포장지, 장갑, 들깻잎에서 발견되었다. 따라서 본 연구결과는 들깻잎에 오염된 S. aureus에 의하여 독소형식중독이 발생할 가능성을 시사하며 들깻잎과 생산 환경에서 항생제 저항성 S. aureus가 검출되어 의약계뿐만 아니라 농업현장에서도 항생제내성균주 출현을 예방하는 대책이 요구된다.

PURPOSES : The purpose of this paper is to evaluate the moisture susceptibility of asphalt mixtures containing developed liquid antistripping agents using the boiling water test as a screening test. METHODS: The boiling water test was used to evaluate the moisture susceptibility of asphalt mixtures containing different anti-stripping agents. The tensile strength ratio was calculated to compare the moisture susceptibility of the asphalt mixtures after indirect strength tests were performed. Additionally, image analysis techniques were used to calculate and analyze the quantity of stripped area in the asphalt mixtures. RESULTS: In general, the asphalt mixtures containing anti-stripping agents showed a higher resistance of anti-stripping based on the boiling water test and tensile strength ratio. CONCLUSIONS: The boiling water test can be used to differentiate the resistance of moisture susceptibility of asphalt mixtures, except for asphalt mixtures containing hydrated lime. The boiling water test can be used as a screening test for asphalt mixtures before conducting time consuming and expensive indirect tensile strength tests.

목 적 : 3.0T 자기 공명 영상에서 강자성 임플란트로 인해 발생한 자화감수성 인공음영에 대한 시퀀스별 WARP기법의 적정한 VAT(view angle tilting)값을 알아보았다. 대상 및 방법 : 자화감수성 인공음영(susceptibility artifact image)이 head용 워터 팬텀영상의 왜곡정도를 평가하기 위하여 head용 워터 팬텀에 강자성 임플란트(ferromagnetic implant)인 금속 와이어를 부착하여 영상을 획득하였다. 진행하였고(VAT(view angle tilting)) Warp를 사용하였다. 사용된 장비는 3.0T MRI system(MAGNETOM Skyra, Siemens, Munich, Germany)이었으며 20ch head/neck coil을 사용하여 TSE T2, TSE T1, FLAIR, Turbo IR T1 시퀀스에 WARP를 적용하여 VAT를 0~100% 범위내에서 10%씩 변화하여 각각 24개의 axial 영상을 얻었다. TSE T2 영상변수는 TR/TE 4410ms/79ms, Matrix 512×291이었으며, TSE T1 영상변수는 TR/TE 693ms/10ms, Matrix 512×291이었으며, Turbo IR T1 영상변수는 TR/TE 2000ms/9.5ms, Matrix 384×307이었으며, FLAIR 영상변수는 TR/TE 9000ms/96ms, Matrix 384×180이었다. 시퀀스별로 slice thickness 4mm, slice gap 0.4mm, NEX 1, bandwidth는 500Hz 였다. 정량평가는 팬텀영상의 대부분을 ROI로 설정 하여 표준편차를 구하였다. 정성 평가는 팬텀 영상 내에 dark area크기, image blurring 정도를 5점 척도로 하여 영상의 변화가 없는 경우 1점, 영상의 질이 약간 우수한 경우 2점, 보통 3점, 우수한 경우 4점, 매우 우수한 경우 5점으로 숙련된 방사선사 3명이 관찰 후 평가하였다. 결 과 : 정량분석으로 TSE T2와 TSE T1의 표준편차(SD)는 VAT 10%에서 VAT 적용전보다 많은 감소를 보였으며, VAT가 증가 할수록 감소하는 경향을 나타냈다. 그러나 IR 계열의 FLAIR와 Turbo IR T1은 WARP의 적용에 따른 영상차이가 없었다. 변동계수는 모든 시퀀스에서 30%이하였다. 또한 VAT 변화에 따라 영상의 위치변화도 나타났다. 정성분석으로 TSE T2는 VAT가 30~60%일 때 우수한 것으로 나타났고, TSE T1은 VAT가 10~70%일 때 우수한 것으로 나타났다. FLAIR와 Turbo IR T1은 WARP사용에 따른 영상의 변화가 없었다 결 론 : WARP는 TSE T2와 TSE T1의 자화감수성 인공음영을 줄이는데는 매우 효과적인 영상기법이었다. 그러나 WARP는 VAT를 증가시키면 image blurring도 증가함으로 VAT값을 최소화해서 사용 되어져야 할 것으로 사료된다.

PURPOSES: The purpose of this study is to evaluate moisture susceptibility of a dense graded and an open graded asphalt mixtures by the method of AASHTO T-283. METHODS: To simulate moisture damage of asphalt pavements with continuously rainfall during summer rainy season, the dense graded and the open graded asphalt mixtures were immersed in water for 15 days and were measured the weight and the change of strength. Also, the mixtures were performed five freeze-thaw cycles to simulate moisture damage of the mixtures by freeze-thaw during winter and were measured the change of strength. The degradation characteristics model was used to analyze the relationship between strength and moisture damage. RESULTS: According to the results, the dense graded and the open graded asphalt mixtures were shown in the similar trends of the strength changes by immersion time and freeze-thaw cycle. However, the moisture damage reduction of open graded asphalt mixture was more sensitive in early phase than that of dense graded asphalt mixture.

Riptortus pedestris possesses Burkholderia as gut symbiont in a symbiotic organ M4 midgut. To answer why Burkholderia symbionts are not eliminated by Riptortu s immune responses, we developed two hypotheses: (i) Burkholderia symbionts do not activate host innate immunity, or (ii) Burkholderia symbionts are resistant to th e host immune responses. For the first hypothesis, we compared the antimicrobial activities of the cultured Burkholderia-injected hemolymph and symbiotic Burkhol deria-injected hemolymphs. As a result, the symbiotic Burkholderia induced antim icrobial activity like the cultured Burkholderia, indicating the symbiotic cells are st ill immunogentic to host. However, when the activated hemolymph was treated to the Burkholderia cells, the symbiotic Burkholderia showed much higher susceptibi lity than the cultured Burkholderia. To understand molecular basis of these results, we purified antimicrobial peptides (AMPs) from Riptortus hemolymph. Similarly, the symbiotic Burkholderia exhibited the high susceptibility to the purified AMPs, riptocin and rip-defensin. To understand how symbiotic Burkholderia can survive in host in spite of their immuno-susceptibility, we examined the AMP expression i n the M4 midgut. Interestingly, the expression of AMPs is suppressed in the M4 mi dgut in comparison to that of the fat body. Finally, we proposed that the immuno-su sceptibility of Burkholderia symbiont helps them to retain in the symbiotic organ. Our in vivo data showing the rapid clearance of the symbiotic Burkholderia after inj ection to host Riptortus supports our proposal.

The purpose of this study was to isolate and identify bacteria from the 4 patients with non-odontogenic infectious lesions (mucormycosis, chronic inflammation from wound infection, and two actinomycosis) and determine their antimicrobial susceptibility against eight antibiotics. Bacterial culture was performed under three culture conditions (anaerobic, CO2, and aerobic incubator). The bacterial strains were identified by 16S rRNA gene (16S rDNA) sequence comparison analysis method. For investigating the antimicrobial susceptibility of the bacteria against eight antibiotics, penicillin G, amoxicillin, tetracycline, cefuroxime, erythromycin, clindamycin, vancomycin, and Augmentin® (amoxicillin + clavulanic acid), minimum inhibitory concentration (MIC) measurement was performed using broth microdilution assay. Nosocomial pathogens such as Enterococcus faecalis, Klebsiella pneumoniae, Bacillus subtilis, and Neisseria flavescens were isolated from mucormycosis. Veillonella parvula, Enterobacter hormaechei, and Acinetobacter calcoaceticus were isolated from chronic inflammatory lesion. Actinomyces massiliensis was isolated from actinomycosis in parotid gland. Capnocytophaga ochracea was isolated from actinomycosis in buccal region in anaerobic condition. There was no susceptible antibiotic to all bacteria in mucormycosis. Tetracycline was susceptible to all bacteria in chronic inflammation. C. ochracea was resistant to vancomycin and penicillin G; and other antibiotics showed susceptibility to all bacteria in actinomycosis. The results indicated that the combined treatment of two or more antibiotics is better than single antibiotic treatment in mucormycosis, and penicillin is the first recommended antibiotic to treat actinomycosis.

The purpose of this study is to identify the determinants of the susceptibility of global consumer culture. As determinants, materialism and self monitoring as psychological variables and fashion clothing product knowledge as clothing-related variable were included. It was hypothesized that both psychological variables and clothing-related variable influence susceptibility of global consumer culture. Data were gathered by surveying university students in Seoul metropolitan area, using convenience sampling, and 311 questionnaires were used in the statistical analysis. In analyzing data, exploratory factor analysis using SPSS and confirmatory factor analysis and path analysis using AMOS were conducted. Factor analysis of susceptibility of global consumer culture revealed four dimensions, 'social prestige' factor, 'quality perception' factor, 'conformity to others' factor, and 'conformity to consumption trend' factor. In addition, factor analysis of self monitoring revealed three dimensions, 'center-oriented attention' factor, 'situation-appropriate self-presentation' factor, and 'strategic displays of self-presentation' factor. The results showed that all the fit indices for the variable measures were quite acceptable. In addition, the overall fit of the model suggests that the model fits the data well. Tests of the hypothesized path show that all variables except for the one factor of self monitoring, 'center-oriented attention', and materialism influence all the factors of susceptibility of global consumer culture. The implications of these findings and suggestions for future study are also discussed.

적리를 동반하는 돼지 분변에서 용혈성 균주를 분리 동정한 후, 장 독소 생성 유 무 및 항생제 감수성 시험을 수행하였다. 분리된 용혈성 균주 B. cereus BY06의 gyrB 유전자 염기서열을 분석한 결과, B. cereus와 99% 유사성을 나타내었다. PCR법에 의한 장 독소 유전자 검출 시험에서 B. cereus BY06는 장 독소 분비 양성으로 판정됨에 따라 설사형 식중독 균임이 확인되었다. B. cereus BY06를 이용한 항균제의 감수성 시험 결과, penicillin G에는 내성을 나타낸 반면 cephalothin, vancomycin, clindamycin, fusidic acid, gentamicin, ciprofloxacin, tetracycline 및 rifampin에 대하여 감수성을 나타냈다. 본 연구를 통해 돼지 분변에서 분리된 B. cereus 균주는 설사를 유발하는 장 독소를 분비하며, penicillin G에 대한 내성을 확인하였다.

멀미는 구토 증상뿐만 아니라 현기증, 두통, 졸음, 피로감, 무기력증 등을 동반하여 선박운항자의 신체리듬과 판단능력을 저하시켜 해양사고로 이어질 수 있다. 이 연구는 승선경험이 없는 조타실 근무자(실습항해사)와 기관실 근무자(실습기관사)를 대상으로 뱃멀미 민감성에 대하여 조사하였다. 선박의 X, Y, Z축 방향에 대한 선체운동을 측정할 수 있는 선체운동계측장비(motion sensor)를 이용하여 선체의 운동을 계측하였고, 설문을 통해 조타실과 기관실 근무자의 멀미에 대한 증상 정도(VIR, VSR)를 산출하였다. 이 연구를 통해 동일한 상황에서 조타실 근무자와 기관실 근무자간에 느끼는 멀미 정도에 차이가 있다는 것을 알 수 있었으며, 멀미는 선체 움직임의 크기뿐만 아니라 움직임의 주기와도 높은 연관성이 있다는 것을 확인할 수 있었다. 또한 X축과 Y축 방향 선체운동보다 Z축 방향의 선체운동이 멀미와 상관관계가 높았다. Z축 이외 X축과 Y축에 대한 연구가 진행된다면 조타실과 기관실 근무자의 안전과 선박의 거주성 및 승선감 향상에 크게 기여할 수 있을 것으로 기대된다.

The purpose of the study was to investigate an effect of water temperature on a non-specific immune response and mortality of tilapia, Oreochromis niloticus, following a bacterial infection. Seventy five tilapia acclimated to 25℃ were then transferred at 16 and 36℃, and examined for non-specific immune responses over 12-96 h. Respiratory burst activity was reduced significantly in the group of fish cultured at 16 and 36℃ over 24-96 h, whereas phagocytic activity decreased significantly in the group of fish reared at a low temperature (16℃) over 12 and 24 h and high temperatures (36℃) over 12-96 h. Lysozyme activity diminished significantly in the group of fish transferred to 16℃ over 12-48 h, but increased significantly in the group of fish at 36℃ over 48 and 96 h. Alternative complement pathway (ACH50) decreased significantly when transferred to 16℃ after 12 h, but increased significantly when transferred to 36℃ after 24 h. In a challenging test, 30 tilapia reared at 25℃ were injected intraperitoneally with Streptococcus iniae at a dose of 2x107 cfu/fish, and then reared onward at water temperatures of 15, 25 (control), and 36℃. Over 12-96 h, the cumulative mortality of S. iniae-injected fish held in 16 and 36℃ was significantly higher than that of injected-fish held in 25℃ In conclusion, transfer of tilapia from 25℃ to low temperature (16℃) after 12 h, and transfer of fish from 25℃ to high temperature (35℃) reduced their immune capability. Furthermore, tilapia under temperature stress at 16 and 36℃ from 25℃ decreased its resistance against S. iniae

신선편의 샐러드와 유기농 채소에 오염되어 있는 식중독균인 B. cereus, S. aureus 그리고 E. coli를 대상으로 살균 소독제와 유기산에 대한 감수성을 평가하여 신선편의 식품의 미생물학적 안전성의 확보를 위한 올바른 세척제와 사용량을 제시하고자 하였다. S. aureus는 2% acetic acid, malic acid, tartaric acid와 1% CaO에 대하여 고농도의 염소계, 과산화수소계 보다 높은 살균 효과를 보였고 E. coli의 경우에는 1% acetic acid 와 CaO처리에 의해 80%의 분리주가 감소하여 50%에탄올과 400 ppm 차아염소산나트륨과 대등한 감소율을 보였다. B. cereus 분리주에 대한 1% CaO, 0.5% acetic acid, 2% malic acid와 tartaric acid 처리는 200 ppm의 차아염소산나트륨보다 높은 감소율을 나타내었고, 1%의 과산화수소와 대등한 감소율을 나타내었다. 본 연구에 따라 천연 물질 유래 살균 소독제인 CaO와 유기산은 기존의 화학적 살균제를 대체할 수 있는 천연 살균 소독제로 활용 될 수 있을 것이고 특히 환경 친화적이고 안전한 유기산은 고품질의 신선편의 채소를 안전성으로 공급하는데 효과적인 것으로 판단되었다.

PURPOSES : This study is to evaluate moisture susceptibility of asphalt mixtures by using non-destructive impact wave and to determine durability so as to decrease the gap between before and after freezing in the future. METHODS : Using non-destructive impact wave, this study is to determine the dynamic modulus of asphalt specimen. Furthermore, the results obtained from two experiment accelerometers are used for the dynamic modulus determination. The dynamic moduli of specimens are compared with those of the freezing-thawing specimens. RESULTS : Test results showed that the dynamic modulus before freezing and thawing environment loads at each temperature dropped about 3.7% after the environmental loads. Furthermore, correlation analysis indicates that transition of dynamic modulus at each point is about 89.59%. CONCLUSIONS: Evaluation of asphalt mixtures using non-destructive impact wave has excellent repeatability and simple equipment for the test. Consequently, the method in the study will be useful for evaluating the characteristics of a various asphalt mixtures.