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Model-based predictions for nuclear excitation functions of neutron-induced reactions on 64,66-68Zn targets

  • Yigit, M.;Kara, A.
    • Nuclear Engineering and Technology
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    • v.49 no.5
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    • pp.996-1005
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    • 2017
  • In this paper, nuclear data for cross sections of the $^{64}Zn(n,2n)^{63}Zn$, $^{64}Zn(n,3n)^{62}Zn$, $^{64}Zn(n,p)^{64}Cu$, $^{66}Zn(n,2n)^{65}Zn$, $^{66}Zn(n,p)^{66}Cu$, $^{67}Zn(n,p)^{67}Cu$, $^{68}Zn(n,p)^{68}Cu$, and $^{68}Zn(n,{\alpha})^{65}Ni$ reactions were studied for neutron energies up to 40 MeV. In the nuclear model calculations, TALYS 1.6, ALICE/ASH, and EMPIRE 3.2 codes were used. Furthermore, the nuclear data for the (n,2n) and (n,p) reaction channels were also calculated using various cross-section systematics at energies around 14-15 MeV. The code calculations were analyzed and obtained using the different level densities in the exciton model and the geometry-dependent hybrid model. The results obtained from the excitation function calculations are discussed and compared with literature experimental data, ENDF/B-VII.1, and the TENDL-2015 evaluated data.

Prediction of compressive strength of bacteria incorporated geopolymer concrete by using ANN and MARS

  • X., John Britto;Muthuraj, M.P.
    • Structural Engineering and Mechanics
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    • v.70 no.6
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    • pp.671-681
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    • 2019
  • This paper examines the applicability of artificial neural network (ANN) and multivariate adaptive regression splines (MARS) to predict the compressive strength of bacteria incorporated geopolymer concrete (GPC). The mix is composed of new bacterial strain, manufactured sand, ground granulated blast furnace slag, silica fume, metakaolin and fly ash. The concentration of sodium hydroxide (NaOH) is maintained at 8 Molar, sodium silicate ($Na_2SiO_3$) to NaOH weight ratio is 2.33 and the alkaline liquid to binder ratio of 0.35 and ambient curing temperature ($28^{\circ}C$) is maintained for all the mixtures. In ANN, back-propagation training technique was employed for updating the weights of each layer based on the error in the network output. Levenberg-Marquardt algorithm was used for feed-forward back-propagation. MARS model was developed by establishing a relationship between a set of predictors and dependent variables. MARS is based on a divide and conquers strategy partitioning the training data sets into separate regions; each gets its own regression line. Six models based on ANN and MARS were developed to predict the compressive strength of bacteria incorporated GPC for 1, 3, 7, 28, 56 and 90 days. About 70% of the total 84 data sets obtained from experiments were used for development of the models and remaining 30% data was utilized for testing. From the study, it is observed that the predicted values from the models are found to be in good agreement with the corresponding experimental values and the developed models are robust and reliable.

The Sensitivity of the Indonesian Islamic Stock Prices to Macroeconomic Variables: An Asymmetric Approach

  • WIDARJONO, Agus;SHIDIQIE, Jannahar Saddam Ash;El HASANAH, Lak Lak Nazhat
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.3
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    • pp.181-190
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    • 2021
  • This paper empirically examines the asymmetric response of the Indonesian Islamic stock market to macroeconomic variables encompassing money supply, domestic output, exchange rate, and Federal Reserve rate. Our study employs the Jakarta Islamic Index (JII) after the financial crisis in the Southeast Asian country using monthly data from January 2000 to December 2019. Non-linear Autoregressive Distributed lag (NARDL) is applied. Our study considers two models consisting of the model without the Federal Reserve rate and the model with it. Our findings confirm the long-run link between Jakarta Islamic Index and macroeconomic factors being studied. Furthermore, the Jakarta Islamic Index asymmetrically responds to broad money supply and exchange rate, but not to domestic output and Federal Reserve rate. A reduction in the money supply has a worse effect on Islamic stock prices as compared to an increase in the money supply. The Jakarta Islamic Index responds differently to depreciation and appreciation. The transmission of the exchange rate to Islamic stock prices occurs only for appreciation. Our study finds an absence of transmission mechanism from the domestic output and the interest rate to Islamic stock prices. Our results imply that the easy money policy and stabilizing currency are key to supporting Indonesian Islamic stock prices.

Ethylene Gas Adsorption of Clay-Woodceramics from 3 layers-clay-woodparticleboard

  • Lee, Hwa Hyoung;Kang, Seog-Goo
    • Journal of the Korean Wood Science and Technology
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    • v.31 no.6
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    • pp.83-88
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    • 2003
  • The woodceramics are porous amorphous carbon and glassy carbon composite materials. Woodceramics attracted a lot of attention in recent years because they are environmentally friendly and because of their unique functional characteristics such as catalysis, moisture absorption, deodorization, purification, carrier for microbial activity, specific stiffness, corrosion and friction resistance, and their electromagnetic shielding capacity. In this paper, we made new products of clay-woodceramics to investigate the industrial analysis and ethylene gas adsorption for basic data of building- and packging- materials keeping fruit fresh for a long time. Clay-woodceramics were carbonized for 3 h of heating in a special furnace under a gas flow of nitrogen(15 ml/min.) from 3 layers-clay-woodparticleboard made from pallet waste wood, phenol- formaldehyde resin(hereafter PF, Non volatile content:52%, resin content 30%), and clay(10%, 20% and 30%). Carbonization temperature was 400℃, 600℃ and 800℃. Experimental results shows that the higher the carbonization temperature, the higher the fixed carbon and the lower the volatile contents. The higher the clay content, the more the ash content. The higher the carbonization temperature, the more the ethylene gas adsorption. Carbonization temperature of 800℃ gave the best reslts as same as that of white charcoal and activated carbon.(800℃-clay-woodceramic: 5.36 ppm, white charcoal: 5.66 ppm, activated carbon: 5.79 ppm) The clay contents did not make difference of ethylene gas adsoption.

Eco-friendly ductile cementitious composites (EDCC) technique for seismic upgrading of unreinforced masonry (URM) infill walls: A review of literature

  • Haider Ali, Abbas;Naida, Ademovic;Husain K., Jarallah
    • Earthquakes and Structures
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    • v.23 no.6
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    • pp.527-534
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    • 2022
  • EDCC (Eco-Friendly Ductile Cementitious Composites) is a recently created class of engineered cementitious composites that exhibit extremely high ductility and elastoplastic behavior under pure tension. EDCC contains reduced amounts of cement and very large volumes of fly ash. Due to these properties, EDCC has become one of the solutions to use in seismic upgrading. This paper discloses previous studies and research that discussed the seismic upgrading of unreinforced, non-grouted, unconfined, and non-load bearing masonry walls which are called URM infill walls using the EDCC technique. URM infill wall is one of the weak links in the building structure to withstand the earthquake waves, as the brittle behavior of the URM infill walls behaves poorly during seismic events. The purpose of this study is to fill a knowledge gap about the theoretical and experimental ways to use the EDCC in URM infill walls. The findings reflect the ability of the EDCC to change the behavior from brittle to ductile to a certain percentage behavior, increasing the overall drift before collapse as it increases the energy dissipation, and resists significant shaking under extensive levels with various types and intensities.

A Sustainable Concrete for Airfield Rigid Pavements (공항 활주로 포장용 친환경 콘크리트의 활용 방법)

  • Salas-Montoya, Andres;Chung, Chul-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.23-24
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    • 2021
  • The use of recycled concrete aggregates (RCA) as a substitute for natural aggregates in new concrete produces both economic and environmental advantages. Most of the RCA applications for pavements have been primarily applied to support layers for roads and airfields. This paper summarizes a work completed at the University of Illinois in partnership with the O'Hare Modernization Program to examine the effect of coarse and fine RCA on the concrete's fresh and hardened properties for airfield rigid pavement applications. Ten different RCA concrete mixtures were prepared with the incorporation of different percentages of RCA fines as well as replacement of cement with high volume percentages of supplementary cementitious materials such as Class C fly ash and ground granulated blast furnace slag to improve the workability and long-term properties of RCA concrete. All the mixes on this stage included 100% recycled coarse aggregates and the Two-Stage Mixing Approach was used as a mixing procedure. Based on the results obtained in the research, mixes with high percentages of recycled fine and coarse aggregates could be used for construction of airfield concrete pavements in conjunction with supplementary cementitious materials

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Unconfined Compressive Stress-Strain Behavior of Cemented Granular Geomaterials (강화된 입상지반재료의 일축압축 응력-변형거동)

  • Park, Seong-Wan;Cho, Chung Yeon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5C
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    • pp.183-190
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    • 2009
  • It is necessary to predict the deformation and stresses on soils to establish the nonlinear stress-strain relationship of geomaterials at various strain levels. Especially, a need exists to establish the pre-failure nonlinear characteristic of cemented granular geomaterials used in road constructions. In this paper, therefore, conventional granular soils were mixed with various cementing materials, such as cement and fly ash from coal combustion by-products. Then, the normalized nonlinear behavior of cemented geomaterials was assessed using unconfined compression test. In addition, various constitutive models of soils were evaluated for estimating pre-failure non-linear behavior of cemented geomaterials from the test results.

Characteristics and Sampling of Dioxins/Furans from Emission Gas and Fly Ash Produced in Municipal Waste Incinerator (도시 소각로 쓰레기 소각후 생성된 폐가스 및 비산재중에 포함된 다이옥신류의 측정 및 특성고찰)

  • Lim, Chae-Hyun;Kim, Hee-Taik;Sohn, Jung-Hyun;Chang, Yoon-Seok
    • Applied Chemistry for Engineering
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    • v.8 no.5
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    • pp.790-795
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    • 1997
  • Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuransfurans are the archetype of toxic chemicals. So it has absorbed public attention. The majors primary sources of PCDDS and PCDFs are chemical, thermal and photochemical reactions. Municipal solid waste incinerator facilities has been reported as the major contributors of dioxins to the environment. In this paper, Dioxins and furans were examined emission gas and fly ash produced during combustion in municipal solid waste incinerator. More effective method for sampling, extraction was described. The sample was extracted using a soxhlet method and purified using silicagel, alumina and carbon fibre HPLC to remove interfering compound. The extract was then analyzed by HRGC/HRMS. The result of this study showed recovery standard was good and the data resembled those of thermal processes. Total dioxins and furans were $1076.20pg/Nm^3$ and $1452.34pg/Nm^3$ respectively. The amount of highly chlorinated compound was more than that of lowly chlorinated compound. The 2,3,7,8-substituted TCDD was Just 0.34% of the total dioxins/furans amount.

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Studies on Free Amino Acids Composition of Salted Internal Organs of Several Fishes (어류내장(魚類內臟) 숙성(熟成)젓의 Free Amino Acids 조성(組成)에 관(關)한 연구(硏究))

  • Shin, Dong-Wha;Kim, Hyong-Soo
    • Applied Biological Chemistry
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    • v.9
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    • pp.83-90
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    • 1968
  • In order to elucidate the differences among the parts of internal organs of salted fishes (Chang Zut), five parts of the organs were examined for their chemical constituents including amino acids. The moisture content varied from 59.8% to 72.8% Crude protein; 7.13% to 11.19%, Crude ash; to 16.1%, 24.8%, Sodium chloride; 15.3% to 22.4% and ash; 0.8% to 2.2%. Seven essential amino acids including leucine, isoleucine, phenylalanine, tryptophan, threonine, lysine and methionine except valine were existed in the every part of the organ. The contents of tyrosine and hydroxyproline were relatively high, on the other hand, tryptophan was trace amount in the every parts.

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The Strength Characteristics of Activated Multi-Component Cement with Kaolinite (카올린을 혼합한 활성화된 다성분계 시멘트의 강도 특성)

  • Kim, Tae-Wan;Kim, Im-Gon
    • Journal of the Korea Concrete Institute
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    • v.28 no.5
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    • pp.593-600
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    • 2016
  • The paper presented investigates the effects of kaolinite on strength properties of alkali-activated multi-component cement. The binders of this study was blended of ground granulated blast furnace slag (GGBFS), fly ash (FA), silica fume (SF) and kaolinite (KA). In this study, the specimens of combination of 20%~70% GGBFS, 10%~60% FA, 10% SF (constant ratio) and 10%~50% KA binder were used for strength properties tests. The water/binder ratio was 0.5. The binders (GGBFS + FA + SF + KA) was activated by sodium hydroxide (NaOH) and sodium silicate ($Na_2SiO_3$) was 10% by total binder weight (10% NaOH + 10% $Na_2SiO_3$). The research carried out is on the compressive strength, water absorption, ultrasonic pulse velocity (UPV) and X-ray diffraction (XRD). The compressive strength decreased as the contents of KA increase. One of the major reason for this is the low reactivity of KA compared with other raw materials used as precursors such as GGBFS or FA. The presence of remaining KA indicates that the initially used quantity has not fully reacted during hydration. Moreover, the results have indicated that increased of KA contents decreased UPV under all experimental conditions. The drying shrinkage and water absorption increased as the content of KA increase. Test result clearly showed that the strength development of multi-component blended cement were significantly dependent on the content of KA and GGBFS.