• Title/Summary/Keyword: true density

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Observation of Elusive CF2Cl…Cl in Matrix Infrared Spectra and Density Functional Calculations

  • Cho, Han-Gook
    • Bulletin of the Korean Chemical Society
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    • v.34 no.11
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    • pp.3274-3278
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    • 2013
  • $CF_2Cl{\cdots}Cl$, an elusive photo-isomer of $CF_2Cl_2$, has been observed in matrix IR spectra from the precursors exposed to radiation from laser ablation of transition-metals. Other plausible products, $CFCl_2{\cdots}F$ and $FClC{\cdots}F-Cl$ are not detected due to their considerably higher energies. Parallel to its previously reported analogues, the C-X bonds are considerably stronger than those of the reactant, and particularly the Cl atom that is weakly bound to the residual Cl atom forms an unusually strong carbon-halogen bond. NBO analysis reveals that the C-Cl bond is a true double bond, and the weak $Cl{\cdots}Cl$ bond is largely ionic, $F_2C=Cl^{\delta+}{\cdots}Cl^{\delta-}$. IRC computation reproduces smooth inter-conversion between the reactant and product, and the transition state is energetically close to the product, consistent with its prompt disappearance in the early stage of photolysis.

Effect of the Ni Content and W Grain Size on the High Temperature Com-pressive Properties of W-Ni Activated Sintered Parts (Ni 함량과 W 결정립 크기에 따른 W-Ni 활성소결체의 고온압축 특성)

  • 박영삼;오승탁;양주환;김영도;문인형
    • Journal of Powder Materials
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    • v.11 no.2
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    • pp.149-157
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    • 2004
  • High temperature deformation behavior of activated sintered W powder compacts was investigated. The compression tests were carried out in the temperature range between 900 and 110$0^{\circ}C$ at the strain rate of $10^{-3}s^{-1}$. The sintered specimens of Ni-doped submicron W powder compacts showed decrease in W grain size with increasing the Ni content. As the result, the flow stress was significantly increased with increasing the Ni content. We obtained Ni-activated sintered W compacts with the relative density of 94 $\pm$ l%and the average grain size of less than 5${\mu}{\textrm}{m}$. A moderate true strain up to 0.60 was obtained without fracture even at 110$0^{\circ}C$ with the strain rate of $10^{-3}s^{-1}$ for the activated W compact despite adding the 1.0 wt%Ni to submicron W powder.

Multilayer thin Film technology as an Enabling technology for System-in-Package (SIP) and "Above-IC" Processing

  • Beyne, Eric
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2003.09a
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    • pp.93-100
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    • 2003
  • The continuing scaling trend in microelectronic circuit technology has a significant impact on the different IC interconnection and packaging technologies. These latter technologies have not kept pace with the IC scaling trends, resulting in a so-called“interconnect technology gap”. Multilayer thin film technology is proposed as a“bridge”- technology between the very high density IC technology and the coarse standard PCB technology. It is also a key enabling technology for the realisation of true“System-in-a-Package”(SIP) solutions, combining multiple“System-on-a-Chip”(SOC) IC's with other components and also integrating passive components in its layers. A further step is to use this technology to realise new functionalities on top of active wafers. These additional“above-IC”processed layers may e.g. be used for low loss, high speed on chip interconnects, clock distribution circuits, efficient power/ground distribution and to realize high Q inductors on chip.

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Ideological Approach to Television Dispositif (텔레비전 장치의 이데올로기적 접근)

  • Shin, Shang Ki
    • Journal of Korea Multimedia Society
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    • v.21 no.12
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    • pp.1513-1525
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    • 2018
  • This study examines the mechanism of how the dispositif, a dispositional concept of television, which is changing in form, Q-Sheet, is expressed as 'ideology' embedded in television. The dispositif implemented in television aims at the realization of mechanical desire through the internal disposition and makes the reality that it dazzles the public by adjusting the density of the gap and depreciates the existence of the aura itself. Instead of gaining new experience through the disposition, the public accepts the manipulated experience and falls into the illusion that it is true. In the television literacy program, the Q-sheet acts in the intervals and gaps that exist in the movement between the stacks, spreading the ideology, and the act of Channel Surfing by using the remote control is also a dispositf form of television viewing. In modern capitalist societies, television disposition are regenerating through proliferation and expansion, showing intent to dominate even art and culture through disposition, and autonomously injecting ideologies by television disposition.

ON THE DETERMINANTS OF ENTREPRENEURSHIP IN MIDDLE EAST AND NORTH AFRICA

  • Zmami, Mourad;Salha, Ousama Ben
    • International Journal of Computer Science & Network Security
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    • v.21 no.2
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    • pp.181-187
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    • 2021
  • The purpose of this study is to examine empirically the short- and long-run determinants of entrepreneurial activity in a sample of 15 the Middle East and North African economies between 2006 and 2018. More specifically, four groups of determinants are considered in the analysis, namely economic, demographic, business environment, and institutional. Given the autoregressive feature of the entrepreneurial activity process, a dynamic panel data model is estimated using the system GMM estimator. Findings reveal that unemployment, trade openness, population density, and economic freedom are the main drivers of new business creation in the short-run, while the cost and number of procedures to start a new business negatively affect entrepreneurship. In the long-run, the same findings hold true. Moreover, education and political stability and the absence of violence/terrorism positively affect entrepreneurial activity. Policy recommendations are accordingly designed.

Some Physical Properties of 9-Year-Old Xylia xylocarpa Planted in Malaysia

  • Sahd, Mohd. Hamami;Josue, James;Chun, Su-Kyoung
    • Journal of the Korea Furniture Society
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    • v.19 no.6
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    • pp.411-419
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    • 2008
  • Xylia xylocarpa is fast-growing trees that are currently planted on trial basis in Sabah, Malaysia. The wood quality of trees grown in Sabah may differ from those grown in other places due to the environmental factors. Five 9-year-old trees of each species were extracted from their respective plots at Luasong, Tawau. Wood specimens were prepared from three height levels; bottom, middle and top, at the inner and outer radial positions. The within-tree and between-tree variations of physical properties of these species were analyzed. The basic density, oven-dry density and green moisture content(MC) are 0.72g/$cm^3$, 0.78g/$cm^3$ and 49.8% respectively. The shrinkage from green to oven-dry conditions for the radial and tangential directions were 3.35% and 5.76%, respectively. The trends of within-tree variations for most properties were more consistent in radial rather than vertical direction. This suggests diameter growth to be a more important factor contributing to the variations compared to height. Samples from the outer part of the stem were found to have higher density, shrinkage and mechanical strengths. The between-trees variations of some wood properties were found to be significantly different, probably due to genetic and micro-environmental factors. Significant correlation was recorded among the physical properties of the species. The true potential of X. xylocarpa for end-uses would be enhanced by further research such as the study on properties of wood from different sites and other properties like durability, seasoning, processing and machining characteristics. The characteristics of X. xylocarpa are comparable to a number of local popular hardwood species, indicating its suitability for heavy construction uses.

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The Study on Mordant Absorption and Mordanting Treatment Condition of Natural Dyeing (천연염색의 매염제 흡착 및 매염조건에 관한 연구)

  • Chu Young-Joo
    • Journal of the Korean Society of Costume
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    • v.55 no.5 s.95
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    • pp.101-107
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    • 2005
  • In this article, mordant absorption rate by the Change of temperature and fabric, discharge level by water washing, mordant density and method in mordant dye are going to be handled. Besides, how treatment method will have an effect on absorption rate and color, is also going to be covered. An atom extinction photometer was used to measure the amount of mordant absorbed in fabric at each temperature and mordant type. It turned out that absorption rate differs according to the type of mordant and sample or temperature. Also it turned out that the mordant input amount has little influence on absorption rate, that is to say, if though you use more mordants, just tiny amount of mordant is going to be absorbed in cloth. It is true that the higher temperature goes up, the better mordant absorption gets. It is found that the type of mordant and sample, treatment period affects the discharge rate. Normally $15{\~}98\%$ mordant comes off the fabric by water washing, to be specific, $17{\~}47\%$ Iron by water washing and it has better performance on cotton and nylon than silk, $1\%{\~}52\%$ Aluminum by water washing and better absorption on silk, $36{\~}89\%$ Chrome by water washing and better absorption on silk, $50{\~}89\%$ copper by water washing and better absorption on silk, poor on cotton. The examination of the K/S values and colors between before and after soaping has been conducted under the circumstance that the test fabrics had been treated at $80^{\circ}C$ for 30 minutes with $0.2\%$ soaping solution. In case of pre-mordanted fabrics, the K/S value nosedived after soaping, meanwhile densely mordanted fabric's K/S value soared but after soaping, it dropped sharply. It turned out that soaping treatment deteriorates absorption much more than water washing. It's considered that $0.1 \%$ (W/V) of mordant density is appropriate.

A Study on Adsorbent Munufacture for Removal of VOC by Recycling of Paper Sludge and Red mud (제지슬러지와 적니를 이용한 VOC 제거를 위한 흡착제 개발 연구)

  • Min, Byong-Hun;Kim, Jeong-Ho;Chung, Chan-Kyo;Suh, Sung-Sup;Kang, Sung-Won
    • Clean Technology
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    • v.8 no.2
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    • pp.61-66
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    • 2002
  • Recycling method of red mud, byproduct from the aluminium manufacturing process, and paper sludge was investigated in order for them to be utilized as the adsorbent for the removal of volatile organic components(VOCs). Either high density polyethylene(HDPE) or low density polyethylene(LDPE) was added to facilitate the manufacture of adsorbents. The utilization of HDPE in the adsorbents increased the adsorption capacity due to the good physical properties, such as, BET and true density, compared with LDPE. BET values of the manufactured adsorbents were much lower than the commercial activated carbon ($10^{-2}-10^{-3}$). It may be due to the fact that the time for decomposition of the paper sludge was not enough during the manufacturing of adsorbents. But the specific adsorption capacity of the manufactured adsorbents (mole adsorbed per unit surface area) had much higher value than the commercial activated carbon (10-100). Therefore, it is important that BET of manufactured adsorbents needs to be increased to obtain the same adsorption capacity as the commercial activated carbon.

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Full Geometry Optimizations of Bond-Stretch Isomers of C202+ Fullerene Dication by the Hybrid Density Functional B3LYP Methods

  • Lee, Ji-Hyun;Lee, Chang-Hoon;Park, Sung-S.;Lee, Kee-Hag
    • Bulletin of the Korean Chemical Society
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    • v.32 no.1
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    • pp.277-280
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    • 2011
  • We studied the relative stability and atomic structure of five $C_{20}^{2+}$ isomers obtained by two-electron ionization of a $C_{20}$ cage (the smallest fullerene). All the isomers are bond-stretch isomers, i.e., they differ in bond length. In particular, in one of the isomers with Ih symmetry, all the bond lengths are equal. Full geometry optimizations of the dipositive ion $C_{20}^{2+}$ were performed using the hybrid density functional (B3LYP/6-31G(d)) methods. All isomers were found to be true minima by frequency analysis at the level of B3LYP/6-31G(d) under the reinforced tight convergence criterion and a pruned (99,590) grid. The zero-point correction energy for the cage bond-stretch isomers was in the increasing order $D_{2h}<C_{2h}<C_2<T_h<I_h$ of $C_{20}^{2+}$. The energy difference among the isomers of cage dipositive ions was less than that among neutral cage isomers. Our results suggest that these isomers show bond-stretch isomerism and that they have an identical spin state and an identical potential energy curve. Although the predominant electronic configurations of the isomers are similar, the frontier orbital characteristics are different, implying that we could anticipate an entirely different set of characteristic chemical reactions for each type of HOMO and LUMO.