The mass production of highly crystalline carbon nanotubes (CNTs) is highly demanded, yet achieving it remains challenging due to incomplete understanding of how synthetic parameters, except temperature, affect the crystallinity of CNTs. Notably, the choice of carbon precursor significantly influences CNT synthesis, but its impact on crystallinity remains unclear. Here, we employed a data analytics approach to examine the effect of carbon precursors on CNT crystallinity during their synthesis in a fluidized bed reactor. We compared ethylene, acetylene, and a mixture of these. Using Bayesian optimization (BO), we optimized synthesis conditions to maximize IG/ID of CNTs for each precursor. Key parameters considered were reaction temperature, precursor concentration, and hydrogen concentration. We conducted three separate BO processes to evaluate the effectiveness of each carbon precursor on CNT crystallinity. The results indicated no significant difference in IG/ID of CNTs among the carbon precursors. In addition, multiple linear regression analysis did not support a synergetic effect between acetylene and ethylene. Interestingly, contour plots demonstrated consistent relationships between synthesis parameters and IG/ID across different carbon precursors. This data analytics approach allowed us to successfully assess the impact of carbon precursors on the CNT crystallinity and analyze the relationship between synthesis parameters and CNT crystallinity.

Hyperoxaluria is a disorder associated with an increased risk of renal stones, one of the most common conditions. For people with hyperoxaluria, there are a limited number of effective therapeutic options. The aim of this study was to examine whether an oxalate-degrading enzyme, oxalate decarboxylase (OxdC), can inhibit crystallization of calcium oxalate (CaOx) in vitro, and whether it can prevent nephrolithiasis caused by CaOx induced by ethylene glycol (EG) in rats. When OxdC was applied at various concentrations to CaOx in vitro, there was a significant reduction in the crystallization of CaOx. The OxdC was found to inhibit crystal formation as well as the formation of crystals that had sharp edges. In animal experiments, rats that had been treated with EG showed impaired renal filtration functions, as well as increased deposition of CaOx crystals and the creation of kidney stones. It has been found that oral administration of OxdC to rats with chronic EG-induced nephrolithiasis that is characterized by CaOx intratubular crystal deposits with hyperoxaluria dramatically reduces the severity of the disease. The results of this study point to a potential therapeutic approach for treating human hyperoxaluria as well as CaOx nephrolithiasis that could be achieved by the oral administration of OxdC.

Carbon fibers of polyacrylonitrile (PAN) type were coated with nickel nanoparticles using a chemical reduction method in alkaline hydrazine bath. The carbon fibers were firstly heated at 400 °C and then chemically treated in hydrochloric acid followed by nitric acid to clean, remove any foreign particles and functionalized its graphitic surfaces by introducing some functional groups. The functionalized carbon fibers were coated with nickel to produce 10 wt% Cf/Ni nanocomposites. The uncoated heat treated and the nickel coated carbon fibers were investigated by SEM, EDS, FTIR and XRD to characterize the particle size, morphology, chemical composition and the crystal structure of the investigated materials. The nickel nanoparticles were successfully deposited as homogeneous layer on the surface of the functionalized carbon fibers. Also, the deposited nickel nanoparticles have quazi-spherical shape and 128–225 nm median particle size. The untreated and the heat treated as well as the 10 wt% Cf/Ni nanocomposite particles were further reinforced in ethylene vinyl acetate (EVA) polymer separately by melt blending technique to prepare 0.5 wt% Cf-EVA polymer matrix stretchable conductive composites. The microstructures of the prepared polymer composites were investigated using optical microscope. The carbon fibers as well as the nickel coated one were homogenously distributed in the polymer matrix. The obtained samples were analyzed by TGA. The addition of the nickel coated carbon fibers to the EVA was improved the thermal stability by increasing the thermal decomposition temperature Tmax1 and Tmax2. The electrical and the mechanical properties of the obtained 10 wt% Cf/Ni nanocomposites as well as the 0.5 wt% Cf-EVA stretchable conductive composites were evaluated by measuring its thermal stability by thermogravimetric analysis (TGA), electrical resistivity by four probe method and tensile properties. The electrical resistivity of the fibers was decreased by coating with nickel and the 10 wt% Cf/Ni nanocomposites has lower resistivity than the carbon fibers itself. Also, the electrical resistivity of the neat EVA is decreased from 3.2 × 1010 to 1.4 × 104 Ω cm in case of the reinforced 0.5 wt% Cf/Ni-EVA polymer composite. However, the ultimate elongation and the Young’s modulus of the neat EVA polymer was increased by reinforcing with carbon fibers and its nickel composite.

기후 변화에 따른 위험성은 전 세계적으로 오랜 기간 강조되고 있으며, 이를 극복하기 위한 노력은 해운분야에서도 국제해사 기구를 중심으로 이어지고 있다. 연소과정에서 발생한 매연을 제어하기 위하여 매연 생성 특성에 관한 연구는 필수적이다. 본 연구에서는 에틸렌 가스를 기반으로 한 대향류 확산화염에서 불활성 기체인 질소를 혼합하여 화염온도, 화염형태, 매연 생성 관련된 화학종의 상태변 화를 확인하기 위해 광소멸법과 화학반응 수치해석을 수행하였다. 연구 결과. 질소의 혼합비율이 증가함에 따라 화염온도 감소와 매연체 적분율 감소로 이루어졌다. 매연 입자가 분포하는 구간도 감소하였으며, 30% 이상 혼합비율이 높아지면 체적분율 감소율이 감소하였다. 매연 성장에 관여하는 화학종들의 몰분율도 감소하였다. HACA 반응 관련 화학종은 탄화수소 연료 비율에 따라 영향을 받으나, 홀수탄소 경로 관련 화학종은 탄화수소 연료 비율뿐만 아니라 화염온도 영향을 받는 것을 확인하였다.

Ethylene-mediated premature floral senescence influences the postharvest quality and longevity of rose flowers. In recent years, studies have unveiled the action of ethylene during the development and senescence of rose flowers. However, despite the evidence that ethylene is highly produced in ethylene-sensitive roses, there is not always a direct interrelationship between ethylene sensitivity and rose flower longevity. In addition, ethylene sensitivity and ethylene-related gene expressions in roses are still not clearly understood. In this review, we summarized and discussed ethylene synthesis and sensitivity, role of ethylene-related genes, and impacts of ethylene on the postharvest quality of cut roses. By combining the mechanism of ethylene biosynthesis and signaling with ethylene sensitivity, we also highlighted the potential use of ethylene inhibitors for ethylene control and to improve the postharvest quality of cut rose flowers. We believe that this review will provide sufficient information about ethylene biology in rose flowers and contribute in developing effective methods to extend the postharvest life of roses by preventing ethylene damage.

Numerous studies have reported that good adhesion and fluorination of carbon materials in a fluoropolymer matrix enhance their electrical and mechanical properties. However, a composite reinforced with oxyfluorinated graphite has not been reported for improving mechanical properties. This paper discusses the fabrication of conductive fluorinated ethylene–propylene (FEP)/oxyfluorinated graphite (f-graphite) composite bipolar plates (BPs) via compression molding. To investigate the effects of fluorinating graphite, graphite with a large particle size of 500 μm was mixed with FEP powder with a small particle size of 8 μm through ball milling. The FEP/graphite composites exhibited high anisotropic electrical conductivity with the in-plane conductivity much higher than the through-plane conductivity because of the planar orientation of the graphite sheets. Therefore, the mechanical properties of the composites such as flexural strength tended to deteriorate with increasing graphite content. In particular, the FEP/f-graphite composites exhibited excellent flexural strength of 12 MPa, much higher than that of FEP/graphite composites at 9 MPa with a graphite content of 80 wt%. The interfacial interaction between FEP and f-graphite led to improved physical compatibilization, which contributed to enhance the mechanical properties of these composites. Our results are a step toward developing BPs for use in high-temperature fuel cells and heat-sink components.

현재 도로나 보도의 포장은 콘크리트 포장, 아스콘 포장, 석재 포장, 자갈 포장, 흙 포장, 목재 포장, 우레탄 포장, 고무칩 포장, 블록 포장 등이 시공되고 있으며, 그 중 수지와 합성고무 칩 또는 우레탄 칩 등을 혼합한 다양한 재질의 탄성포장재 가 주로 사용되어지고 있다. 이러한 탄성포장재는 탄성이 좋고 사용성이 좋으나, 2000년대 들어서면서 화학제품에 대한 환경유해성 논란이 대두됨에 따라 탄성 포장재에 대한 환경문제가 제기되었다. 따라서 이 연구에서는 친환경 소재인 알톱밥과 EPDM 칩을 사용하여 친환경 포장재의 개발을 목적으로 하였다. 휨강도 시험, 인장강도 및 신장률 시험, 투수성 시험, 중금속 및 유해 화학물질 총량 시험, 폼 알데하이드 방출량 시험, 경제성 분석을 통해 탄성 포장재에 대한 한국산업규격 KS F 3888-2 및 기존 논문들과 비교 분석하여 이 연구에서 제시한 포장재의 역학적 특성과 환경 유해성 물질 기준을 제시하였다.