최근 시멘트 콘크리트 포장의 아스팔트 덧씌우기 포장을 유지보수 공법으로 채택할 경우 반사균열이 다수 발생하여 유지보수 비용 증가로 이루어지고 있다. 반사균열 발생일 지연시키기 위하여 다양한 재료 및 공법을 사용하고 있으나 이에 대한 효과를 정확하게 평 가하는 시험방법 및 평가기준이 미비한 상태이다. 미국에서도 반사균열 문제로 인하여 유지보수 비용이 급격히 증가하고 있으며, 아스 팔트 함량을 높게 하고 개질제 및 그리드를 사용하여 반사균열 발생을 지연시키려는 노력을 하고 있다. 미국 및 선진국에서는 반사균열 평가 시험법으로 Texas Overlay Tester를 범용으로 사용하고 있으며, 반사균열 저항성 평가에 유일무 이한 장비로 알려져 있다. 최근 93%에 이르는 하중 감소율에 도달하는 하중 재하횟수 시험에 시간적 노력과 편차가 크다는 논란이 재 기되어 1000회 까지만 수행하여 균열발생(crack initiation)과 균열전파(crack propagation) 특성울 계산하여 보다 역학적인 방법에 의한 반 사균열 저항성 평가가 시도되고 있다. 밀입도, PSMA, 구스, 그리드 보강 아스팔트 혼합물에 대한 Overlay Tester를 이용하여 반사균열 수행을 수행하였으며, 이에 대한 균 열발생과 균열 전파 특서을 정량화 하여 비교 분석을 실시하였다.

The ovicidal effect of plant extract mixture (5% cinnamon extract + 10% citronella oil + 30% citrus oil + 10% derris extract + 20% neem extract + 25% penetrating surfactant) against several major insect pests was tested using the spraying method. In the case of stink bugs, eggs tended to die during hatching. When treated with a plant extract mixture (500-times solution), mortality for Halyomorpha halys, Riptortus clavatus, Eurydema dominulus, Trialeurodes vaprarorium, Bemisia tabaci, Spodoptera exigua, and Agrotis ipsilon reached as high as 100%. Therefore, it is believed that industrialization will be feasible in the future.

몇 종의 주요 농작물 해충에 대한 식물추출물(cinnamon extract 5% + citronella oil 10% + citrus oil 30% + derris extract 10% + neem extract 20% + penetrating surfactant 25%)의 살란 효과를 분무법으로 검정하였다. 노린재류의 경우 알이 부화하는 과정에서 치사하는 경향을 보였다. 식물추출물(500배액) 처리시 썩덩나무노린재(Halyomorpha halys), 톱다리개미허리노린재(Riptortus clavatus), 홍비단노린재(Eurydema dominulus), 온실가루이(Trialeurodes vaprarorium), 담배가루이(Bemisia tabaci), 파밤나방(Spodoptera exigua), 검거세미밤나방(Agrotis ipsilon) 에 대한 최종 살란 효과는 100%로 높게 나타나, 향후 산업화가 가능할 것으로 생각된다.

2022년 기준 국내 폐타이어 발생량은 약 37만톤으로 그 중 88.9%인 약 32만 9천톤이 재활용되는 것으로 조사되었다. 하지만 이 중 약 75%가 시멘트소성로용 등 열이용 분야에 사용되었다. 폐타이어는 대부분 고무와 플라스틱으로 이루어져 있기 때문에, 고온에서 분 해되면서 다양한 유해가스와 오염물질이 발생할 수 있고, 이러한 공해물질은 적극적으로 관리되지 않으면 대기오염, 수질 오염 등 다 양한 환경문제를 발생시킬 수 있다. 때문에 친환경적이고 지속적인 재활용에 대한 필요성이 대두되고 있다. 폐타이어 고무 분말을 아스팔트 혼합물의 골재 일부로 치환하여 재활용하는 접근 방식은 환경에 미치는 영향을 완화할 뿐만 아니라 천연 자원의 고갈 측면에서도 긍정적인 영향을 미치는 것으로 판단된다. 따라서 타이어분말을 아스팔트 혼합물에 적용하는 것은 환경 문제를 해결하고 자원 효율성을 높이는 두 가지 이점을 가지고 있다. 폐타이어 분말을 아스팔트 바인더와 아스팔트 혼합물에 적용할 경우 미치는 영향을 평가하기 위하여 DSR, BBR, MSCR 등의 시험 을 진행하였으며, 아스팔트 혼합물 내 폐타이어 분말의 분포를 조사하기 위해 SEM을 실시하였다. 또한 IDEAL-CT와 IDEAL-Rutting 시 험을 통해 아스팔트 혼합물의 성능을 평가하였다.

Understanding the behavior of soil under cyclic loading conditions is essential for assessing its response to seismic events and potential liquefaction. This study investigates the effect of non-plastic fines content (FC) on excess pore pressure generation in medium-density sand-silt mixtures subjected to strain-controlled cyclic direct simple shear (CDSS) tests. The investigation is conducted by analyzing excess pore pressure (EPP) ratios and the number of cycles to liquefaction (Ncyc-liq) under varying shear strain levels and FC values. The study uses Jumunjin sand and silica silt with FC values ranging from 0% to 40% and shear strain levels of 0.1%, 0.2%, 0.5%, and 1.0%. The findings indicate that the EPP ratio increases rapidly during loading cycles, with higher shear strain levels generating more EPP and requiring fewer cycles to reach liquefaction. At 1.0% and 0.5% shear strain levels, FC has a limited effect on Ncyc-liq. However, at a lower shear strain level of 0.2%, increasing FC from 0 to 10% reduces Ncyc-liq from 42 to 27, and as FC increases further, Ncyc-liq also increases. In summary, this study provides valuable insights into the behavior of soil under cyclic loading conditions. It highlights the significance of shear strain levels and FC values in excess pore pressure generation and liquefaction susceptibility.

Aralia elata, Chaenomeles sinensis fruit, and Glycyrrhizae radix have been widely used as oriental medicinal plants in Korea, China and Japan and found to possess anti-oxidative and anti-inflammatory activities. The current study was conducted to investigate the neuroprotective effect of an ethanol extract of a mixture of A. elata, C. sinensis fruit, and Glycyrrhizae radix (ACG) against ischemia-induced brain injury in rats and excitotoxic and oxidative neuronal death in primarily cultured rat cortical neurons. Transient focal cerebral ischemia was induced by 2 h middle cerebral artery occlusion followed by 24 h reperfusion (MCAO/R) in rats. Oral administration of ACG (10, 25, and 50 mg/kg) 30 min before MCAO, after 1 h of MCAO, and after 1 h of reperfusion reduced MCAO/R-induced brain infarct and edema formation. ACG also inhibited development of behavioral disabilities in MCAO/R-treated rats. Exposure of cultured cortical neurons to 500 μM glutamate for 12 h resulted in neuronal cell death. ACG (1, 10, and 50 μg/mL) inhibited glutamate-induced neuronal death. Furthermore, ACG inhibited 100 μM hydrogen peroxide (H2O2)- and hypoxia-induced neuronal death. These results suggest that the neuroprotective effect of ACG against ischemia-induced brain damage might be associated with its anti-excitotoxic and anti-oxidative activity and that ACG may have a therapeutic role for prevention of neurodegeneration in stroke.

The present study was conducted to examine the effect of soybean silage as a crude protein supplement for corn silage in the diet of Hanwoo steers. The first experiment was conducted to evaluate the effect of replacing corn silage with soybean silage at different levels on rumen fermentation characteristics in vitro. Commercially-purchased corn silage was replaced with 0, 4, 8, or 12% of soybean silage. Half gram of the substrate was added to 50 mL of buffer and rumen fluid from Hanwoo cows, and then incubated at 39°C for 0, 3, 6, 12, 24, and 48 h. At 24 h, the pH of the control (corn silage only) was lower (p<0.05) than that of soybeansupplemented silages, and the pH numerically increased along with increasing proportions of soybean silage. Other rumen parameters, including gas production, ammonia nitrogen, and total volatile fatty acids, were variable. However, they tended to increase with increasing proportions of soybean silage. In the second experiment, 60 Hanwoo steers were allocated to one of three dietary treatments, namely, CON (concentrate with Italian ryegrass), CS (concentrate with corn silage), CS4% (concentrate with corn silage and 4% of soybean silage). Animals were offered experimental diets for 110 days during the growing period and then finished with typified beef diets that were commercially available to evaluate the effect of soybean silage on animal performance and meat quality. With the soybean silage, the weight gain and feed efficiency of the animal were more significant than those of the other treatments during the growing period (p<0.05). However, the dietary treatments had little effect on meat quality except for meat color. In conclusion, corn silage mixed with soybean silage even at a lower level provided a greater ruminal environment and animal performances, particularly with increased carcass weight and feed efficiency during growing period.

이상의 결과를 종합하면, 혼합유산균 2종(Bifidobacterium animalis ssp. Lactis Bf141와 Lactobacillus rhamnosus Lb102)의 섭취는 고지방식이 유도 비만 마우스에서 체중, 체지방, 제지방, 골밀도 등 주요 체성분에 영향을 주지 않았다. 혼합유산균은 식욕 조절 효과를 위해 측정한 사료 섭취량에도 영향을 주지 않았으며, 간 조직 무게에도 영향을 미치지 않았다. 인슐린저항성과 포도당신생합성의 주요 지표인 공복혈당량 또한 혼합유산균 급여에 의해 변화 하지 않았다. 또한 혼합유산균은 심혈관질환의 지표로 사용되는 혈중 중성지방 및 총 콜레스테롤에 영향을 주지 않았으며, 체내 지방의 소화 및 흡수율에서도 영향을 미치지 않았다. 결론적으로, 고지방식이유도 비만 마우스를 이용하여 혼합유산균(Bf141 + Lb102)의 항비만 생리활성 을 검증한 결과, 유의미한 물리적, 대사적 표현형 개선은 검증되지 않았다. 따라서, 추후 개별 보다 다양한 혼합 조건 및 농도로 연구를 설계하여 혼합유산균의 항비만 효과를 검증할 필요성이 있다.

The young shoots of Aralia elata, Chaenomeles sinensis fruit and Glycyrrhizae radix are edible and traditionally used as anti-inflammatory and antioxidant agents. The present study was performed to investigate the protective effect of an ethanol extract mixture of these three medicinal plants (ACG) against amyloid β protein (Aβ) (25– 35)-induced memory impairment in an ICR mouse model. Memory impairment was induced by intracerebroventricular microinjection of 15 nmol Aβ (25–35) and assessed using the passive avoidance test and the Morris water maze test. The step-through latency in the passive avoidance test was decreased and the latency to reach the hidden platform in the Morris water maze test was increased in mice treated with Aβ (25–35), indicating memory impairment. This memory impairment induced by Aβ (25–35) was significantly prevented by chronic treatment with ACG (10, 25, and 50 mg/kg, p.o., 8 days). In memory impaired mice brain, cholinesterase activity and concentration of thiobarbituric acid reactive substance, a lipid peroxidation marker, were increased and glutathione level was decreased. These biochemical changes in Aβ (25–35)-treated mice were reversed by chronic administration of ACG. The present results suggest that antioxidant and anti-cholinesterase activities of ACG might be responsible for the inhibition of Aβ (25– 35)-induced memory impairment and that ACG preparation may have a therapeutic role in preventing the progression of Alzheimer’s disease.

This study was conducted to find out the effects of seed mixture using new domestic grass varieties orchardgrass ‘Onnuri’ and tall fescue ‘Greenmaster’ on botanical composition and dry matter productivity from 2015 to 2018 in oversown hilly pasture, the central northern area of Korea. This experiment was consisted of 4 mixed grasses (Treatment 1 : tall fescue oriented mixture with imported varieties; Treatment 2 : orchardgrass oriented mixture with imported varieties; Treatment 3 : orchardgrass oriented mixture with domestic varieties, Treatment 4 : tall fescue oriented mixture with domestic varieties). Evaluation of seasonal changes in botanical composition of pasture showed that orchardgrass was the highest in all treatments, ranging from 46 to 89% and Kentucky bluegrass was the second highest in all treatments. Treatment 3 (7,633 kg ha-1) and Treatment 4 (7,570 kg ha-1), mixed grasses using domestic varieties, were showed the highest dry matter yield than Treatment 1(6,950 kg ha-1) and Treatment 2 (6,934 kg ha-1), which were mixed grasses using introduced varieties. Therefore, these results showed that the orchard grass oriented grasses mixture with domestic varieties was good for grassland vegetation and productivity in oversown hilly pasture, the central northern area of Korea.

미국선녀벌레에 방제효과가 높은 3종 (데리스, 시트로넬라, 계피)의 식물추출물과 보조제 (잔탄검과 실리콘 계열 화합물)를 함유하는 조성물을 개발하였다. 이 조성물은 인삼 재배지에서 미국선녀벌레 방제효과가 90% 이상으로 높았다. 또한 다른 흡즙성 해충에도 살충률이 높아 PLS (positive list system) 전면 시행에 따른 대응방안으로 활용이 가능할 것으로 생각된다.

Herbal medicine has been the basis for medical treatments through much of human history, and such traditional medicine is still widely practiced today. Modern medicine makes use of many plant-derived compounds as the basis for pharmaceutical drugs. In traditionally, Achyranthes aspera, Safflower (Carthamus tinctorius) seed and Acanthopanax senticosus have been used for the treatment and prevention of bone-related diseases. In this study, we investigated the pharmacological effect of mixture of Achyranthes aspera, Safflower (Carthamus tinctorius) seed and Acanthopanax senticosus and the other herbs. Two types of enzymes were used to enhance the extraction components of amino acid, mineral content, free sugar, and flavor recovery in extracting natural herbal mixtures(NME). We evaluated regulation of osteogenic differentiation in human bone marrow mesenchymal stem cells using alkaline phosphatase staining, alizarin red S staining and RT-PCR. The CCK-8 assay indicated that NME had no cytotoxicity but increased cell survival. In addition, NME promoted the mineralization and expression of osteogenic differention marker genes in human bone marrow mesenchymal stem cells. Therefore, NME has an effect of promoting proliferation and osteogenic differentiation of human mesenchymal stem cell.

브로일러의 생산성과 닭고기의 품질에 미치는 Bacillus. subtillus, Streptomyces galilaeus 및 Sphingobacteriaceae로 구성된 사료용 복합생균제(PFM, probiotic feed mixture)의 효과를 조사하였다. 병아리 (Ross 308) 240마리를 4개의 처리구로 나누어 35일간 사육하였다. 처리구는 사료용 복합 생균제를 함유하지 않은 대조구(CON, control), 일반생균제(CP3, commercial probiotics 0.3%), 사료용 복합 생균제 3(PFM3, 사료용 복합 생균제 0.3%), 사료용 복합 생균제 5(PFM5, 사료용 복합 생균제 0.5%)로 구분하였다. 체중은 CON과 비교할 때 CP3, PFM3, PFM5가 높았고 PFM3, PFM5는 CP3에 비해 우수하였다(p<0.05). F낭, 흉선, 비장의 무게 및 IgG 수준은 CON과 비교할 때 PFM3, PFM5 및 CP3에서 증가하였으며 PFM3, PFM5는 CP3에 비해 높았다(p<0.05). 맹장의 Lactobacillus 균수는 PFM3, PFM5 및 CP3를 섭취한 브로일러가 CON에 비해서 높았으나 E.coli, Salmonella, coliforms, 총 호기성 균수는 감소하였다(p<0.05). PFM3 및 PFM5를 섭취한 닭가슴살의 보수력은 CON 및 CP3와 비교할 때 증가하였다(p<0.05). 결론적으로 Bacillus subtillus, Streptomyces galilaeus 및 Sphingobacteriaceae를 포함하는 사료용 복합생균제 0.3%가 브로일러의 생산성과 닭고기 품질향상에 기여할 수 있음을 나타낸다.

본 연구는 계란 생산성, 계란품질 및 악취저감에 관한 Bacillus subtillus, Streptomyces galilaeus 및 Sphingobacteriaceae로 구성된 복합생균제(PM, probiotic mixture)의 효과를 조사하였다. 산란계 Hy-Line Brown 240수를 4처리구로 구분하여 6주 동안 사육하였다. 처리구는 복합생균제를 함유하지 않은 대조구(CON, control), 일반생균제(CP3, commercial probiotics 0.3%), 복합생균제 3(PM3, 복합생균제 0.3%), 복합생균제 5(PM5, 복합생균제 0.5%)로 구분하였다. 산란율, 계란 호우유니트, 난각두께, 난각강도, 난황색 및 농후난백 높이는 PM3, PM5가 CON 및 CP3에 비해서 높았다. 계분으로부터 암모니아, E. coli, 총호기성균, Coliform, Salmonella 균수는 CON>CP3>PM3>PM5 순서로 증가하였다. 본 결과는 B. subtillus, S. galilaeus 및 Sphingobacteriaceae로 구성된 복합생균제 0.3%가 산란율, 계란품질 개선 및 분에서 암모니아 발생을 낮추어 양계장 악취저감 효과를 갖는다는 점을 보여 준다.

ZnO thin-films are grown on a p-Si(111) substrate by RF sputtering. The effects of growth temperature and O2 mixture ratio on the ZnO films are investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and roomtemperature photoluminescence (PL) measurements. All the grown ZnO thin films show a strong preferred orientation along the c-axis, with an intense ultraviolet emission centered at 377 nm. However, when O2 is mixed with the sputtering gas, the half width at half maximum (FWHM) of the XRD peak increases and the deep-level defect-related emission PL band becomes pronounced. In addition, an n-ZnO/p-Si heterojunction diode is fabricated by photolithographic processes and characterized using its current-voltage (I-V) characteristic curve and photoresponsivity. The fabricated n-ZnO/p-Si heterojunction diode exhibits typical rectifying I-V characteristics, with turn-on voltage of about 1.1 V and ideality factor of 1.7. The ratio of current density at ± 3 V of the reverse and forward bias voltage is about 5.8 × 103, which demonstrates the switching performance of the fabricated diode. The photoresponse of the diode under illumination of chopped with 40 Hz white light source shows fast response time and recovery time of 0.5 msec and 0.4 msec, respectively.

본 연구의 목적은 온탕침지와 pH교정석회유황합제 처리에 의한 상추 유기종자의 곰팡이와 세균의 소독효과 및 발아율에 미치는 영향을 검정하고자 하였다. 상추종자에 Alternaria sp.가 53.3% 감염되어 있었고 Aspergillus sp.와 Cladosporium sp.은 각각 14.5%와 5.4% 감염되어 있었다. 세균은 형태적으로 Pseudomonas sp., 한 종만 분리되었으며 16.5%가 감염되어 있었다. 상추종자 소독에 효과적인 온탕침지조건을 탐색하고자 온탕의 온도조건(45℃, 50℃, 55℃, 60℃)에 따른 소독효과를 조사하였다. 온탕침지 온도와 처리시간이 증가함에 따라 곰팡이와 세균에 대한 살균효과는 증가하였으나 종자의 발아율은 급격히 감소하였다. 온탕침지 단독처리는 50℃ 온탕에서 20분간 처리할 경우 상추종자의 살균효과와 발아율이 각각 91.1%로 가장 우수하였다. 상추종자 소독을 위한 온탕침지와 pH교정석회유황합제 교호처리는 50℃의 온탕침지 조건에서는 10분간 처리하는 것이 상추종자의 살균효과와 발아율이 각각 100%와 97.6%로 가장 높았다. 본 연구결과는 종자 표면뿐만 아니라 종자내의 곰팡이나 세균을 살균할 수 있는 기술개발에 기여할 수 있을 것으로 생각한다.

PURPOSES: Using recyclable materials in asphalt pavement industry is one of the essential tasks not only for saving construction budgets but also for mitigating environmental pollutions. Over the past decades, several efforts have been made by road maintenance agencies to incorporate various recyclable materials into virgin asphalt paving mixtures. As a result, reclaimed asphalt pavement (RAP), which consists of old pavement material was selected as one of most widely used recyclable materials. In this paper, the effects of using different amounts of single-recycled RAP (SRRAP) and double-recycled RAP (DRRAP) on the low-temperature characteristics of asphalt mixtures were investigated. METHODS: To evaluate the low-temperature characteristics of SRRAP and DRRAP mixtures, two experiments, the bending beam mixture creep test and semicircular bending fracture test were performed. The experimental parameters: creep stiffness, m-value, thermal stress, critical cracking temperature, fracture energy, and fracture toughness were computed then compared. RESULTS : RAP mixtures (SRRAP or DRRAP) showed lower mechanical performance compared with conventional asphalt mixtures. The differences became distinct with increased RAP addition. However, the performance differences between SRRAP and DRRAP mixtures were not significant in all cases, which indicate the possible application of re-recycling technology (DRRAP) in the asphalt pavement industry. CONCLUSIONS : The addition of RAP to virgin asphalt can mitigate low-temperature performance despite the improvement in fracture performance observed in some cases. Therefore, using RAP (SRRAP or DRRAP) mixtures on inter or sublayer construction, but not on the surface layer, is recommended. Moreover, the possibility of applying double-recycling technology in asphalt pavement industry can be introduced in this study because not significant performance differences were found between SRRAP and DRRAP mixtures especially at low temperature.