A software-assisted comparative assessment of the effect of cement type on concrete carbonation and chloride ingress

S. Demis,V.G. Papadakis 사단법인 한국계산역학회 2012 Computers and Concrete, An International Journal Vol.10 No.4

Utilization of supplementary cementing materials (SCM) by the cement industry, as a highly promising solution of sustainable cement development aiming to reduce carbon dioxide emissions, necessitates a more thorough evaluation of these types of materials on concrete durability. In this study a comparative assessment of the effect of SCM on concrete durability, of every cement type as defined in the European Standard EN 197-1 is taking place, using a software tool, based on proven predictive models (according to performance-related methods for assessing durability) developed and wide-validated for the estimation of concrete service life when designing for durability under harsh environments. The effect of Type II additives (fly ash, silica fume) on CEM I type of cement, as well as the effect of every Portland-composite type of cement (and others) are evaluated in terms of their performance in carbonation and chloride exposure, for a service life of 50 years. The main aim is to portray a unified and comprehensive evaluation of the efficiency of SCM in order to create the basis for future consideration of more types of cement to enter the production line in industry.

Sustainable concrete mix design for a target strength and service life

Julia G. Tapali,Sotiris Demis,Vagelis G. Papadakis 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.12 No.6

Considering the well known environmental issues of cement manufacturing (direct and indirect levels of CO2 emissions), clinker replacement by supplementary cementing materials (SCM) can be a very promising first step in reducing considerably the associated emissions. However, such a reduction is possible up to a particular level of SCM utilization, influenced by the rate of its pozzolanic reaction. In this study a (4-step) structured methodology is proposed in order to be able to further adjust the concrete mix design of a particular SCM, in achieving additional reduction of the associated levels of CO2 emissions and being at the same time accepted from a derived concrete strength and service life point of view. On this note, the aim of this study is twofold. To evaluate the environmental contribution of each concrete component and to provide the best possible mix design configuration, balanced between the principles of sustainability (low environmental cost) and durability (accepted concrete strength and service life ). It is shown that such a balance can be achieved, by utilising SCM by-products in the concrete mix, reducing in this way the fixed environmental emissions without compromising the long-term safety and durability of the structure.

Predictive modeling of concrete compressive strength based on cement strength class

V.G. Papadakis,S. Demis 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.11 No.6

In the current study, a method for concrete compressive strength prediction (based on cement strength class), incorporated in a software package developed by the authors for the estimation of concrete service life under harmful environments, is presented and validated. Prediction of concrete compressive strength, prior to real experimentation, can be a very useful tool for a first mix screening. Given the fact that lower limitations in strength have been set in standards, to attain a minimum of service life, a strength approach is a necessity. Furthermore, considering the number of theoretical attempts on strength predictions so far, it can be seen that although they lack widespread accepted validity, certain empirical expressions are still widely used. The method elaborated in this study, it offers a simple and accurate, compressive strength estimation, in very good agreement with experimental results. A modified version of the Feret’s formula is used, since it contains only one adjustable parameter, predicted by knowing the cement strength class. The approach presented in this study can be applied on any cement type, including active additions (fly ash, silica fume) and age.

Performance of Some Introduced Korean Garlic (Allium sativum L.) Cultivars in Ethiopia

Getachew Tabor,Seong Sook Han,Do-Ham Pae,Soonsung Hong,Fekadu Gebretinsay,Demis Fikru 한국국제농업개발학회 2021 韓國國際農業開發學會誌 Vol.33 No.2

마늘은 에티오피아에서 양념으로 쓰이는 가장 중요한 작목 중 하나이다. 그럼에도 생산성은 세계 평균의 절반 수준에 머물고 있는 실정이다. 이렇게 생산성이 낮은 주요 원인으로는 품종의 다양성 부족, 낮은 영농기술 수준과 병해충 등을 들 수 있겠다. 이를 극복하기 위하여 한국의 농촌진흥청 국립원 예특작과학원으로부터 13종류의 마늘 품종이 도입되어 데브라 자이트와 쿨룸사에 위치한 농업연구소(Debre Zeit and Kulumsa agricultural research centers)에서 예비 실험이 진행 되었다. 도입된 13 품종 중에서 Namdo, Daeseo 및 Wangyo 57022 등 3 품종에서만 주아 (bulbil)가 형성이 되었다. 한국에서 도입된 마늘 3 품종의 적응성을 조사한 결과는 아래와 같이 정리할 수 있다. 1. Namdo 품종은 구근의 직경이 38~60 mm였고 무게는 25.1 g부터 92.7까지로 다양하였다. 구근은 8~11 쪽으로 구성 되었다. 2. Namdo와 Daeseo 등 한국 품종들은 Kuriftu라는 지역 품종에 비하여 구근의 크기는 약 2배 정도 컸으며, 마늘 쪽의 무게는 약 5배 정도 무거웠다. 하지만 성숙까지의 기간은 지역 품종(120일)에 비하여 약 60일 이상 길었다 (179일). 3. 쿨룸사 농업연구소에서 진행된 재배결과에서는 지역 품종인 Tesday의 생산량은 12.87 t/ha으로 Namdo (9.53 t/ha) 및 다른 실험군에 비하여 유의적으로 높았다. 하지만 Namdo 품종의 구근 무게는 지역 품종인 G-104/94에 비하여 50% 이상 높은 것으로 확인된 반면, 쪽의 숫자는 9개로 G-94-1/94의 14 개와 Tseday의 23개 보다 유의적으로 적었다. 즉, 상품성 측면에서 한국 품종이 우수하다는 결과로 사료되었다. 4. 파종시기에 따른 Namdo 품종의 발달 차이를 살펴본 결과 높이, 7월 중순에 파종한 경우가 8월이나 9월에 파종한 경우보다 마늘 쪽의 두께, 크기 및 무게가 유의적으로 우수한 것으로 확인되었다. 한국에서 도입된 품종 중에서 특히, Namdo의 경우 성장 기간이 조금 떠 짧아질 수 있다면 에티오피아에서 생산이 가능한 품종으로 판단된다. Garlic is one of the most important crops used as condiments in Ethiopian. However, its productivity of garlic is less than half the world average. Lack of productive varieties and improved agronomic practices, as well as diseases and insect pests are the major causes of low productivity. The objective of the present study was to investigate an adaptive performance of some introduced garlic genotypes of Korean varieties in Ethiopia. The thirteen garlic genotypes were imported from the National Institute of Horticulture and Herbal Sciences (NIHHS), Rural Development Administration, Republic of Korea. The genotypes were tested for adaptation at Debre Zeit and Kulumsa agricultural research centers. Among the thirteen genotypes tested, only three genotypes Namdo, Daeseo, and Wangyo 57022 formed bulbs, while the remaining ten genotypes did not form bulbs despite the long growth period (179 days) taken to mature. The three genotypes had bigger bulbs and fewer but bigger cloves compared to the local varieties such as G-94-1/94, G-104-1/94, and Holeta local. A follow up replicated trial comparing Namdo with three local varieties was undertaken at Kulumsa. The replicated trial also showed that Namdo had better yield than the three local varieties. Moreover, it produced bigger bulbs and cloves than all the local varieties, which eases household and industrial processing of cloves. Therefore, verification of Namdo for production in Ethiopia could provide a better option for processing garlic.

CSR과 ISO26000 : 일본의 대응

Nobuyuki Demise 한국노동연구원 2010 국제노동브리프 Vol.8 No.11

EEG-SSVEP Signals Extraction with Nonlinear Adaptive Filter for Brain-Controlled Wheelchair

Arjon Turnip,Demi Soetraprawata,Tua Agustinus Tamba 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10

In this paper, an application of nonlinear adaptive filter on EEG-SSVEP extraction for brain-controlled wheelchair is proposed. In the experiment, four subjects with age about 25±1 years were tested. The experimental results in this work show that the implementation of the proposed method achieves a very significant statistical improvement in extracting peak amplitude features. After a short time of practice, most participants could learn to extract the EEG-SSVEP wave with greater than 95% accuracy.

EPIMORPHISMS, DOMINIONS FOR GAMMA SEMIGROUPS AND PARTIALLY ORDERED GAMMA SEMIGROUPS

PHOOL MIYAN,SELESHI DEMIE,GEZEHEGN TEREFE The Korean Society for Computational and Applied M 2023 Journal of applied mathematics & informatics Vol.41 No.4

The purpose of this paper is to obtain the commutativity of a gamma dominion for a commutative gamma semigroup by using Isbell zigzag theorem for gamma semigroup and we prove some gamma semigroup identities are preserved under epimorphism. Moreover, we extend epimorphism, dominion and Isbell zigzag theorem for partially ordered semigroup to partially ordered gamma semigroup.

Investigation of the Relationship Between Perceived Stress and Sleep Hygiene in High School Students

Haylı Çiğdem Müge,Kösem Dilek Demi̇r,Felek Emrah 대한수면학회 2023 sleep medicine research Vol.14 No.3

Background and Objective This study aimed to conduct a descriptive study to examine the relationship between perceived stress and sleep hygiene in high school students.Methods The data required for the research were collected online between December 16, 2022 and March 10, 2023. The study group of the research consisted of high school students. An online survey method, a socio-demographic data collection form, Perceived Stress Scale (PSS), and Sleep Hygiene Index (SHI) were obtained from 219 high school students living in Hakkari, Turkey, who were selected by the convenience sampling method, one of the nonprobability sampling methods. The independent sample t-test, ANOVA analysis, and Pearson correlation test were used to analyze the data.Results A total of 51.1% of the participating high school students were boys, and 48.9% were girls. A total of 35.6% of the participating high school students were 16 years old, 27.4% were 17 years old, 21.5% were 15 years old, and 15.5% were 18 years old. It was found that there was no significant difference (p > 0.05) between the PSS subdimensions and the SHI scores of high school students according to the variables, such as age, high school type, and class status. It was found that there was a significant relationship among the gender variable, the PSS subdimensions, and the SHI scale (p < 0.05).Conclusions It can be concluded that factors, such as age, high school type, and class status, did not affect the relationship between perceived stress and sleep hygiene in high school students and that the gender variable had an effect on the relationship between perceived stress and sleep hygiene. It is recommended that research to examine the relationship between perceived stress and sleep hygiene should be performed by expanding the samples.

No Effect of Serotoninergic Gene Variants on Response to Interpersonal Counseling and Antidepressants in Major Depression

Alessandro Serretti,Chiara Fabbri,Silvia Pellegrini,Stefano Porcelli,Pierluigi Politi,Silvio Bellino,Marco Menchetti,Veronica Mariotti,Cristina Demi,Valentina Martinelli,Marco Cappucciati,Paola Bozzat 대한신경정신의학회 2013 PSYCHIATRY INVESTIGATION Vol.10 No.2

Objective-Gene variants within the serotonin pathway have been associated with major depressive disorder (MDD) treatment outcomes, however a possible different modulation on pharmacological or psychological treatments has never been investigated. Methods-One hundred sixty MDD patients were partially randomized to either inter-personal counseling (IPC) or antidepressants. The primary outcome was remission at week 8. Five serotonergic polymorphisms were investigated (COMT rs4680, HTR1A rs6295, HTR2A rs2224721, HTR2A rs7997012 and SLC6A4 rs421417). Results-IPC (n=43) and antidepressant (n=117) treated patients did not show any difference in remission rates at week 8 (corrected for baseline severity, age and center). None of the studied gene variants impacted on response and remission rates at week 8 neither in the IPC nor in the antidepressant group. An analysis of the whole sample showed a trend of association between rs7997012 AA genotype and a better treatment outcome. Conclusion-Our study confirms that IPC is an effective psychological intervention comparable to antidepressants in mild-moderate MDD. Polymorphisms related to the serotonin system did not exert a major effect on clinical outcomes in none of the treatment groups.