본 연구는 시멘트 산업의 대체연료(폐합성수지 등) 사용량 증대에 따라 이를 활용한 탄소배출 저감 및 시멘트/콘크리트 제조 적용 기술 및 방안에 대해 검토하고자 했으며, 향후 시멘트 산업의 탄소중립 실현을 위한 기초 자료로써 활용하고자 한다. 시멘트 제조 에 있어 폐합성수지 사용은 경제적 장점과 높은 발열량으로 인해 연료로서의 가치가 높은 것으로 나타났으며, 열경화성 수지는 부가가 치가 높은 저탄소 시멘트 복합체의 비반응성 골재로 작용할 수 있는 것으로 확인되었으며, 감마선 조사는 다양한 폐플라스틱의 성능 평가에 적용되는 것으로 확인되었다.

Carbon dots (C-dots) are a developing subclass of nanomaterials which are characterized by a typical diameter of less than 10 nm. C-dots are a type of core–shell composites that feature a surface passivation with various functional groups, including amine, carboxyl, hydroxyl group, and a carbon core. Green C-dots, which have drawn a lot of interest from researchers due to their superior water solubility, excellent biocompatibility, and environmental-friendly behavior when compared to chemically generated C-dots, can be made from a variety of low-cost and renewable materials. Since green C-dots have heteroatoms on their surface in the form of carboxyl, amine, hydroxyl, or other functional groups, which can enhance their physicochemical characteristics, quantum yield (QY), and likelihood of visible light absorption, further surface passivation is not necessary. Green C-dots may find use in the areas of biosensing, catalysis, bioimaging, and gene and drug delivery. In this paper, the creation of C-dots was outlined, and its fluorescence process examined. This review represents the summary of synthesis, mechanism, properties, characterization, and applications of C-dots. This article aims at the green chemistry strategies for C-dot synthesis. Furthermore, a discussion on the applications of C-dots produced with green approaches is presented. The paper may help the researchers in the field to develop new C-dots with potential features to attract the attention of new applications.

초고성능 콘크리트(UHPC)는 높은 압축강도를 위해 일반콘크리트에 비해 높은 시멘트 및 바인더 함량을 가지고 있다. UHPC 의 시멘트량을 줄이기 위한 연구가 지속적으로 수행되었으며, 그중 플라이애시와 고로슬래그는 각각 20%, 50% 수준까지는 강도 저하 없이 적용 가능하다는 연구가 확인되었다. 본 연구에서는 UHPC 배합에서 시멘트를 플라이애시와 고로슬래그로 치환하여 강도변화 및 유동성 변화를 분석하였다. 압축강도는 플라이애시 치환 실험체가 가장 낮으며, 고로슬래그는 치환 전과 유사한 강도를 보였다. 휨강도 는 고로슬래그, 플라이애시 치환 실험체 모두 감소하였다. 그러나 유동성은 플라이애시, 고로슬래그 실험체 모두 향상되면서 고성능감 수제 저감이 가능한 것을 확인하였다.

The electro-Fenton (EF) process was first proposed in 1996 and, since then, considerable development has been achieved for its application in wastewater treatment, especially at lab and pilot scale. After more than 25 years, the high efficiency, versatility and environmental compatibility of EF process has been demonstrated. In this review, bibliometrics has been adopted as a tool that allows quantifying the development of EF as well as introducing some useful correlations. As a result, information is summarized in a more visual manner that can be easily analyzed and interpreted as compared to conventional reviewing. During the recent decades under review, 83 countries have contributed to the dramatic growth of EF publications, with China, Spain and France leading the publication output. The top 12 most cited articles, along with the top 32 most productive authors in the EF field, have been screened. Four stages have been identified as main descriptors of the development of EF throughout these years, being each stage characterized by relevant breakthroughs. To conclude, a general cognitive model for the EF process is proposed, including atomic, microscopic and macroscopic views, and future perspectives are discussed.

위성신호 반사계측(GNSS-Reflectometry) 기술은 위성으로부터 전송되는 신호의 지표면 혹은 해수면에 반사되는 신호를 측정하여 분석하는 기법으로서, 해수면 높이측정, 태풍 및 기상이변, 그리고 토양의 수분 및 적설량 측정 등에 활용되고 있다. 본 논문에서는 GNSS-R 기술의 해양 활용확대와 그 가능성을 살펴보기 위하여, 위성신호의 신호대잡음비를 이용하는 GNSS-R 기술의 개념과 측정원리에 대해 설명하고, 국제적인 활용 사례를 조사하여 제시하였다. 특히 GNSS-R 기술을 기존 DGNSS 기준국 및 상시관측소 인프라를 이용하여 해양안전 및 환경 모니터링에 활용 가능할 뿐만 아니라, 지상 및 해양기준국, 위성기반, 해상선박 탑재 측면에서의 해양 응용 가능분야를 조사하여 제안하였다.

Artificial intelligence (AI) is rapidly transforming customer service. This paper aims to paint a state-of-the-art of AI and its impact in customer service organizations by conducting a literature review as well as exploring current AI solutions used by practitioners. We will also identify gaps in the research that need to be addressed to better understand the impact of AI in customer service

Paraffin kinds of organic PCM has generally been used concerning for instability of phase change and corrosion of materials in concrete containing PCM. Even though paraffin kinds of organic PCM have various kinds and rule considering mix proportions. This study shows a review of paraffin kinds of organic PCM about mechanical properties according to PCM materials and mix proportions. The paper will help to get the basis of information considering compressive reduction ratio.

This study aims to give a brief summary of the development in the series of studies that have been made regarding the lateral-torsional buckling (LTB) capacity of beam spans with increased cross section at one end, also known as singly stepped beam (SSB), and at both ends, also known as doubly stepped beam (DSB). A three-dimensional program ABAQUS was used to analyze buckling through finite element method, while a statistical regression program MINITAB was used in developing and proposing simple design equations. The following topics discussed in this study include: (1) proposed design equation that account for change in cross section of stepped beams under uniform moment; (2) proposed design equation, with a corresponding moment gradient factor equation, of stepped beams under general loading conditions; (3) proposed design equation for stepped beam with continuous top flange lateral bracing; (4) proposed design equation for monosymmetric stepped beam subjected to uniform moment and to general loading conditions; (5) effect of inelastic buckling of stepped beams subjected to pure bending and general loading conditions considering combined effects of residual stress and geometrical imperfection; and (6) determination of LTB strength of monosymmetric stepped beam by conducting destructive test of subjecting a beam to concentrated load. The summary presented provides researchers information in understanding the subject matter; moreover, this provides a meaningful contribution to futures researches.

Carbon nanotubes, consisting of rolled graphene layer built from sp2 units, have attracted the imagination of scientists as ideal macromolecules and their unusual physical and chemical properties make them useful in the fabrication of nanocomposites, nano-electronic devices and sensors etc. In this account, the current status and prospect of carbon nanotubes is described with a special emphasis on the safety issue of carbon nanotubes. Even though many challenges to be solved remain, extensive and intensive efforts in both academy and industry will clear out those problems soon and finally enable carbon nanotubes to play a key innovative material of 21st century in numerous industrial processes.

This paper aims at designing an accelerated life test sampling plan for bulk material and showing its application for an arc-welded gas pipe. It is an integrated model of the accelerated life test procedure and bulk sampling procedure. The accelerated life tests were performed by the regulation, RSD 0005 of ATS at KITECH and bulk sampling was used for acceptance. Design parameters might be total sample size(segments and increments), stress level and so on. We focus on deciding the sample size by minimizing the asymptotic variance of test statistic as well as satisfying consumer's risk under Weibull life time distribution with primary information on shape parameter.