이 논문은 EU의 플라스틱 규제 정책이 글로벌 환경 규제 확산에 미친 영향을 네트워크 분석을 통해 검토하였다. 본 연구는 네트워크 분석 방 법론을 통해 규제 확산 과정을 시각적으로 명확히 제시하고, 규제의 중 심 국가와 확산 경로를 실증적으로 분석하였다. 브뤼셀 효과(Brussels Effect)를 중심으로, EU의 규제가 다른 국가에 어떻게 확산되었는지 규 제 도입 시점과 국가 간 관계를 중심으로 살펴보았다. 주요 분석 도구로 는 Python의 NetworkX 라이브러리를 활용한 네트워크 시각화 및 중심 성 지표 계산을 사용하였다. Degree Centrality(연결 중심성)를 통해 각 국가가 네트워크 내에서 얼마나 중심적인 역할을 했는지 평가하였으며, 이를 통해 플라스틱 규제 확산의 허브 역할을 한 국가들을 식별하였다. 또한 시간에 따른 규제 도입 경로를 분석함으로써 EU의 규제가 단일 지 역에 국한되지 않고 국제적으로 확산된 과정을 확인하였다. 특히 EU와 다른 주요 국가 간 규제의 유사성 및 상호작용이 플라스틱 규제 확산에 중요한 요인으로 작용했음을 밝혔다. 결과적으로 브뤼셀 효과는 규제 도 입과 확산에서 중요한 역할을 하였음을 알 수 있었다.

본 논문에서는 소성 설계를 기반으로 한 프레임 구조 설계 시, 기둥의 종류에 따른 구조 제작 비용과 거동의 차이를 연구하였다. 축 력과 횡력을 모두 받는 구조물에 적합한 기둥 부재를 선택하는 것이 중요하며, 플라스틱 설계 방법을 채택할 경우 기둥의 역할이 더욱 강조된다다. 특히, 횡력은 기둥의 연성을 요구하며, CFT(콘크리트 충전 강관)형 기둥은 RC(철근 콘크리트) 기둥보다 높은 강철 비율 로 연성을 확보하게 된다. 이 논문에서는 CFT 기둥이 RC 기둥보다 더 나은 성능을 보이는지 확인하기 위해 다양한 구조 유형에서 기 둥을 설계하고 분석하였다. CFT 기둥을 소성 설계에 채택함으로써 얻을 수 있는 이점은 다양한 구조 유형에 따른 하중 유형의 분석을 통해 제시한다.

In this study, the strength properties of recycled plastic materials using polypropylene, polyethylene, and high-density polyethylene were evaluated by measuring their compressive and flexural strengths, which are typically measured in cement-concrete pavements, to assess the feasibility of using recycled plastic materials as construction materials for modular pavements that can easily integrate advanced sensors, such as those for future autonomous driving. Two types of recycled plastic (composite resin and high-density polyethylene (HDPE)) and two types of inorganic materials (fly ash and limestone filler) were selected to evaluate the strengths of recycled plastic materials. Specimens for the compressive and flexural strength tests were prepared with four different recycled plastic contents (100%, 80%, 60%, and 40%). The compressive and flexural strengths of the recycled plastic specimens were measured according to the KSL ISO 679 and KSL 5105 methods, and the strength properties were analyzed based on the type and content of the recycled plastic and type of inorganic material used. Distortion and shrinkage problems were observed during specimen preparation using the 100% recycled plastic material. This indicated that inorganic materials must be incorporated to improve the flexural strength and facilitate specimen preparation. The compressive strength of plastic materials was comparable to the 28-day compressive strength of conventional cement-concrete pavements. The compressive strength of the composite resin was approximately twice that of HDPE. The flexural strengths of both the composite and HDPE were in the range of 15–25 MPa, suggesting their suitability as materials for the construction of modular pavement structures. Based on the limited strength test results, we can conclude that the strength properties of recycled plastic materials are similar to those of conventional cement-concrete paving materials. From the strength perspective, we confirmed that recycled plastic materials can be utilized as construction materials for modular pavements. However, further research should be conducted on factors such as molding methods for modular pavement structures based on different types of recycled plastic materials.

전 세계적으로 배출되는 폐플라스틱을 석유화학제품으로 재활용하는 순환경제가 본격화되고 있다. 따라서, 화학적 재활용 중 하나인 폐플라스틱 열분해유 생산을 위한 파일럿 규모의 시설도 건설되 고 상업적 생산이 시작되고 있다. 본 연구에서는 파일럿 플랜트에서 조건별로 생산된 총 4종의 폐플라 스틱 열분해유를 활용하기 위해 분리된 각각의 유분의 물성 및 구성성분 분석을 통해 나프타, 선박유 및 보일러유 등 다양한 원료‧연료 등으로 사용이 가능한지 확인해보고자 한다. 폐플라스틱 열분해유의 넓은 비점으로 인하여 경질유분은 상압 및 감압증류를 통해 분리하였고, 중질유분은 감압증류를 통해 분 리하였다. 경질유분(fraction 1)은 나프타를 목적으로 물리적 특성, 탄소분포 및 구성성분을 분석하였는 데, 탄소분포, 비점 등은 적합하지만, 초기 폐플라스틱 열분해유에 비해 염소 함량, 올레핀 및 방향족이 높아 전처리공정이 필요하다, 또한 중질유분(fraction 2)은 보일러유 등을 목적으로 할 때, 적합한 밀도, 동점도, 발열량 및 윤활성 등 물리적 특성을 가졌지만, Si 및 전산가 등이 높았다. 분리하고 남은 잔류물 (residue)은 높은 발열량, 낮은 황 함량, 산소 함량 등은 C중유급 연료로서의 사용이 가능할 것으로 판단되었다. 결론적으로, 분리된 폐플라스틱 열분해유에서 분리되는 모든 유분은 전처리만 가능하다면 나프 타 원료뿐만 아니라 저급 연료로도 활용이 가능하리라 판단된다.

전통적인 도로건설 재료인 시멘트 콘크리트 및 아스팔트 콘크리트는 생산과정에서 이산화탄소 등 대기 유해물질을 발생시키고, 자율 주행관점에서 자율주행 및 전기차 운행을 위한 디지털 센서 기반의 첨단기술 적용이 어려워 이를 대체하기 위한 미래 지향적 도로건설 소재 및 완전자율주행을 지향하는 기술 개발이 필요한 실정이다. 세계적으로 친환경 기술 개발 수요와 동반하여 전기, 수소차 등 친환경 모빌리티 기술과 자율주행 기술에 대한 기술적 진보가 지속적으로 이루어지고 있다. 국내의 경우, 첨단 모빌리티 분야를 국가전략기술로 지정하고 단기적으로 Lv4/4+, 장기적으로 완전자율주행 개발을 목표로 많은 연구와 정책들이 추진되고 있다. 자율주행 레벨이란 미국 자 동차공학회(SAE : Society od Automotive Engineers)가 제시한 자율주행 기술 수준 단계로, Lv.1 비자동화, Lv.2 운전자 보조, Lv.3 부분 자 동화, Lv.4 조건부 자율주행, Lv.5 고등 자율주행, Lv.6 완전 자율주행의 총 6단계로 구성된다. Lv 3.의 경우 주행 중 다양한 돌발 상황 및 주변 사물들을 모두 인식하고 이에 대응할 수 있지만, 부득이한 경우 운전자가 운전할 필요가 있다고 자동차가 판단할 경우 운전자 가 개입하여 운전하는 수준이며, Lv 4.의 경우 특정 환경(구역, 날씨 등)에서는 자동차가 모든 자율주행 기능을 지원, 어떠한 상황에서도 운전자가 개입할 필요가 없는 수준을 말한다. 현재는 조건부 자율주행, Lv 3.에서 자율주행 Lv 4, 즉 고등 자율주행 단계로 넘어가는 시 점이나 영상기반의 현 자율주행 시스템은 악천후 시 자율주행차가 안전하게 주행할 수 있도록 지원하는데 어려운 한계를 가지고 있다. 이와 더불어 자율주행과 관련된 기술과 주행 안전성을 담보하기 위한 도로 인프라, 즉 도로의 재료, 기하구조 문제(노면상태, 차로상태, 도로안내표지 등을 인식하는 문제)에 대한 대안 제시 필요성도 대두되고 있다. 본 연구에서는 현 자율주행 문제의 한계 극복 및 탄소배출 저감이 가능하도록 자율주행 센서 등 다양한 첨단 센서의 적용이 용이한 재활용 플라스틱 소재에 대한 도로 인프라 적용 가능성을 검토하고 기초 실험을 통해 강도측면에서의 재활용 플라스틱의 도로인프라 적 용 가능성을 확인하였다.

In this study, the relationship between the color of the pigment added to the plastic resin and the size of the fractured part of the specimen was confirmed when processing ABS plastic tensile specimens using a sealed 3D printer. Through the test, it was confirmed that the fracture dimension existed in the range of 13.104 to 13.138 ㎜ and there was no significant difference in dimension according to the color of the additive, and the null hypothesis was adopted. In addition, it was confirmed that a significant difference occurred in the order of red, black, white, and green colors.

This study was conducted to prepare a plan for the controlling indoor microclimate environment using natural ventilation for the single-span plastic greenhouses, which account for about 83.8% of the total area of horticultural greenhouses in South Korea. The changes of indoor air temperature and relative humidity according to the side opening height were experimentally compared and analyzed in the experimental greenhouse. As the side opening height was changed to 30, 70, and 110cm, the indoor and outdoor temperature differences were found to be 14.0, 10.1, and 7.7℃, respectively. The indoor and outdoor relative humidity differences were found to be -15.7, -12.5, and -11.1%, respectively. These results were verified for statistical significance by ANOVA. When the variable breadth of the outdoor temperature was 6.9℃, the indoor temperature breadths were 14.5, 12.3, and 9.0℃, and when the outdoor relative humidity breadth was 24%, the indoor relative humidity breadths were 31.2, 28.0, and 23.8%, respectively. It was analyzed that as the side opening height is increased, the indoor temperature and relative humidity become similar to the outdoor environment. This is because the air is mixed by active indoor-outdoor air movement of greenhouses with natural ventilation. The results indicated that the proper opening and closing of side openings is necessary for the stable indoor microclimate environment control of plastic greenhouses.

Over the last decade, there has been growing interest in the plastic degradation capabilities of insect because herbivorous insects may be a valuable resource for microorganisms that can break down synthetic plastics. Insects that can digest plastics using their gut microbiota are gaining interest for use in bioremediation, although their environmental benefits remain unknown. However, most plastics biodegraded by insect gut microbes are polyethylene, polystyrene with little knowledge available on the gut microbiome of insects capable of degrading other synthetic plastics. Therefore, there is an urgent need to secure microbial resources based on insect-microbiome interactions and promote end-of-life solutions for synthetic plastics.

Plastics are widely used in industries in human society and because of their structural stability, degradation is a serious global issue. To estimate the degradation of plastic, 31 edible mushrooms were cultured with the selected plastic films (polyethylene [PE], polystyrene [PS], and poly(ethylene terephthalate) [PET]) for 3 months at 25 °C. Measuring the weight of the films showed that four species of mushrooms, namely Porostereum spadiceum, Ganoderma lucidum, Coprinellus micaceus, and Pleurotus ostreatus, exhibited the highest degrees of plastic degradation. In addition, the mushrooms and fungi that exhibited the most significant plastic degradation were cross-cultured to promote this degradation. As a result, cross-cultivation of G. lucidum and Aspergillus niger showed a weight loss of 2.49% for the PET film. For the PS film, Aspergillus nidulans showed a weight loss of 4.06%. Cross-cultivation of A. nidulans and C. micaceus, which showed a weight loss of 2.95%, was noted as an alternative for PS biodegradation, but is harmful to humans. These bio-degradation effects of edible mushroom will contribute to the development of alternatives for eco-friendly plastic degradation.

The purpose of this study is to review the available literature on the effectiveness of fibers in preventing early-age shrinkage cracking on cementitious concrete. The overview describes the widely used ASTM C1579 (Standard Test Method for Evaluating Plastic Shrinkage Cracking of Restrained Fiber Reinforced Concrete (Using a Steel Form Insert) for plastic shrinkage cracking. The past literature used crack length, width, or area to describe and quantify cracks on concrete specimens. To keep things simple, this review expresses the length, width or area as a percentage of the control specimen. Finally, the study establishes a relationship between fiber volume and aspect ratio on plastic shrinkage and compressive strength of concrete. It was concluded that fiber is sufficient enough to mitigate plastic shrinkage cracking. An increase in fiber volume and aspect ratio reduces the early-age cracking of concrete but harm its compressive strength.

Traditional piles used for deep foundation, such as steel, concrete, and timber, are susceptible to corrosion and a reduction in structural capacity over time. This has led to the development of new materials like concrete-filled FRP piles (CFFP). CFFP is a composite pile filled with concrete and covered with a fiber-reinforced plastic (FRP) shell, providing non-corrosive reinforcement and protection to the concrete. As a result, CFFP is a highly promising candidate for implementation in various fields due to its structural advantages and necessity. Compared to traditional concrete piles, CFFP can be installed with less damage and a lower blow range due to its elastic modulus, damping ratio, and specific weight. The bearing capacity of a pile is influenced by various factors, including its stiffness, residual stress, and axial load resistance. Due to competitive pricing, glass fiber has been widely utilized, and there is a growing interest regarding carbon-fiber-reinforced concrete piles due to the excellent mechanical properties of carbon fiber. The remarkable stiffness and strength attributes of carbon fibers are evident in CFRP-confined piles, which present a notably wide range of load-bearing capacities, boasting an ultimate axial load capacity ranging from 500 to 4000 kN. Furthermore, CFFPs have been confirmed to have superior lateral load resistance compared to conventional piles, attributed to the reinforcement provided by FRP materials. Conventional piles face a challenge in that their structural characteristics deteriorate in the corrosive marine environment, with a projected lifespan of less than 20 years. In contrast, the service life of CFFPs is estimated to range from 50 to 75 years.

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.

In 2006, Cambodian Agriculture Research and Development Institute (CARDI) bred a high-quality tomato ‘Neang Pich’ variety. Since ‘Neang Pich’ is susceptible to Sclerotium rolfsii (S. rolfsii), it is severely affected the production major tomato growing regions. This study was conducted to evaluate the effect of seven S. rolfsii tolerant rootstocks on growth and yield in graft cultivation of ‘Neang Pich’ tomato. ‘Neang Pich’ seedlings were used as scion and non-grafted control. Six eggplant genotypes (‘2017053’, ‘2017062’, ‘17CJVC2’, ‘No. 80’, ‘VI041979A’, ‘VI041996’) and a commercial tomato variety (‘Hulk’) were used as rootstock. The grafted and non-grafted tomatoes were grown in a plastic greenhouse and open field. The survival rate of plants did not differ between plastic greenhouse (80.2%) and open field (79.5%). The top and root fresh weight of plants grown in a plastic greenhouse increased by 77% and 11% compared to the open field and the dry weight increased by 48% and 10%, respectively. The top (309 g) and root (18.9 g) fresh weight, and the top (90.5 g) and root (6.39 g) dry weight depending on rootstock were the highest in plants grafted onto ‘2017062’. The yield of tomatoes in a plastic greenhouse (19.5 MT/ha) was 65% higher than that of open field (11.8 MT/ha). The yield of tomatoes depending on rootstock were the highest in ‘2017062’ (17.8 MT/ha). The effect of cultivation practice and grafting on pH and sugar content (oBrix) of the fruit was non-significant difference (p0.05). The scion diameter, top fresh weight, fruit weight and yield (MT/ha) were significant difference (p0.05) in the interaction effect between tomato cultivation practices (plastic greenhouse and open field) and rootstock.

The tribology characteristics of the graphene coated PA6 were evaluated with scratch experiments. As a result, the following conclusions were obtained. The PA6 of the graphene coating shows a 0.1 improvement in friction coefficient and a lower abrasion depth than PA6 in the variable pressure-type scratch experiments. PA6 of the graphene coating showed a lower friction coefficient of 0.2 or more than PA6 in the friction coefficient in the static pressure scratch experiments, indicating that wear resistance was improved. In both the variable and the static pressure type scratch experiments, the tip depth of graphene-coated PA6 shows a thinner wear depth than PA6, showing the effect of graphene. The graphene content showed excellent tribology characteristics at 3%, and there was no difference in tribology characteristics at higher contents.

The need for lightweight yet strong materials is being demanded in all industries. Carbon fiber-reinforced plastic is a material with increased strength by attaching carbon fiber to plastic, and is widely used in the aerospace industry, ships, automobiles, and civil engineering based on its low density. Carbon-reinforced fiber plastic is a material widely used in parts and manufactured products, and structural analysis simulation is required during design, and application of actual material properties is necessary for accurate structural analysis simulation. In the case of carbon-reinforced fiber plastics, it is reported that there is a porosity of around 0.5% to 6%, and it is necessary to check the change in material properties according to the porosity and pore shape. It was confirmed by applying the method. It was confirmed that the change in elastic modulus according to the porosity was 10.7% different from the base material when the porosity was 6.0%, and the Poisson's ratio was confirmed to be less than 3.0%. It was confirmed that the elliptical spherical pore derived different material properties from the spherical pore depending on the pore shape, and it was confirmed that the shape of the pore had to be confirmed to derive equivalent material properties.