• Title/Summary/Keyword: Types of M&A

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Influence of Sample Preparation Method and Silver Salt Types on MALDI-TOFMS Analysis of Polybutadiene

  • Choi, Sung-Seen;Ha, Sung-Ho
    • Macromolecular Research
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    • v.16 no.2
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    • pp.108-112
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    • 2008
  • Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis of nonpolar polymeric materials is affected by the sample preparation as well as the matrix and cationizing agent. This study examined the influence of silver salt types on the MALDI analysis of polybutadiene (PB). Silver trifluoroacetate (AgTFA), silver benzoate (AgBz), silver nitrate ($AgNO_3$), and silver p-toluenesulfonate (AgTS) were used as the silver salts to compare the MALDI mass spectra of PB. The mixture solution of PB and 2,5-dihydroxybenzoic acid (DHB), as a matrix dissolved in THF, was spotted on the sample plate and dried. A droplet of the aqueous silver salt solution was placed onto the mixture. The mass spectrum with AgBz showed the clear $[M+Ag]^+$ ion distribution of PB while the mass spectrum with AgTFA did not show $[M+Ag]^+$ ions but only silver cluster ions. The mass spectra with $AgNO_3$ and AgTS did not show a clear $[M+Ag]^+$ ion distribution. The difference in the formation of $[M+Ag]^+$ ions of PB depending on the silver salts was attributed to the silver cation transfer reaction between the silver salt and the matrix (DHB). The mass spectrum showed a clear $[M+Ag]^+$ ion distribution of PB when the conjugate acid of the silver salt was less acidic than the matrix.

An Experimental Study on Reinforcing Efficiency of H-Shaped Steel Beams with a Rectangular Web Opening (유공 H 형강보의 보강효율에 관한 실험적 연구)

  • Kim, Jin-Mu;Cho, Chul-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.3 no.1
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    • pp.171-178
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    • 1999
  • Despite of decrease in shear and moment strengths, most steel structural designers use web openings in beams because of economical benefit and requirement. The purpose of this study is to suggest the method of reinforcement of H-shape steel beams with a rectangular web opening. If shear predominates over bending, it is necessary to consider all possible combinations of shear force and bending moment acting at the opening. In this paper, the ultimate strength and behavior of perforated beams have been investigated according to parameters (ratio of M/V, opening width within opening height ratio D/h, various reinforcing types A/B/C/D/M/N/W). The results of this study are as follows ; 1. Deformation of H-shape steel beams with a rectangular web opening was greatly affected by not only bending but also shear. 2. SB1-2/3 series have little difference in the reinforced efficiency, but SB1-2E/3E series have difference in the reinforced efficiency according to the reinforcement type. 3. Efficiency of SB1-2E/3E series is determined by reinforcing types, which RB1-2E-B/M/C and RB1-3E-M/D/C specimens have good efficient. Reinforcing type of perforated beams chooses efficient method according to ratio of M/V and D/h.

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Fine Structure of Optic Lobes of Cephalopods (Todarodes pacificus and Octopus minor) inhabiting the Korean Waters (한국 연근해산 두족류 (Todarodes pacificus and Octopus minor) 시엽 (Optic lobe)의 미세구조)

  • Han, Jong-Min;Chang, Nam-Sub
    • Applied Microscopy
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    • v.32 no.2
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    • pp.131-147
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    • 2002
  • Optic lobes of Todarodes pacificus and Octopus minor are largely divided into cortex and medulla, the cortex being composed of three layers (an outer granule cell layer, a plexiform layer, and an inner granule cell layer). The cortex of Todarodes pacificus is about $420{\sim}450{\mu}m$ thick, being $170{\sim}200{\mu}m$ thicker than that of Octopus minor of which thickness is about $250{\sim}290{\mu}m$. In the outer granule cell layer of Todarodes pacificus, three types of nerve cells (type-A, type-B and type-C) and neuroglial cells that surround or contact with the neurons are observed, while in the outer granule cell layer of Octopus minor, two types of nerve cells (type-A and type-B) and a single type of neuroglial cells are observed. In a plexiform layer, a presynaptic bag and nerve endings are connected to each other, consequently forming various types of synaptosomes. The synaptosomes of Todarodes pacificus contain electron dense vesicles, electron dense-core vesicles and electron lucent vesicles, either individually or in a mixture. On the other hand, three types of synaptosomes a mixture of electron dense-core vesicles and electron lucent vesicles, electron lucent vesicles only, and electron dense-core vesicles only are observed in Octopus minor. The structures of the inner granule cell layer are almost similar in the two species. It is composed of two types of nerve cells (type-A, type-B) and a single type of neuroglial cells. In the medulla of Todarodes pacificus, the cells of $7{\times}5{\mu}m$ are arranged to a line and form the palisade cell layer, but these are not observed in Octopus minor.

Effect of Lock Operations on Airtightness of Sliding and LS Window Systems (잠금장치 작동에 따른 미서기 및 LS 창호 시스템의 기밀성)

  • Park, Jong Jun;Yun, Yu Ra;Kim, Young Il;Chung, Kwang-Seop
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.9
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    • pp.449-454
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    • 2015
  • In this study, the effects of lock operations on the infiltration rates for the two window types sliding and lift sliding (LS) are investigated through experiment and simulation. The airtightness levels of the two window types-with locks both on and off-were measured according to the KS F 2292 Test method of airtightness that is used for windows and doors. The air-flow rates of both window types with the locks on for a pressure differential of 10 Pa are $1.98m^3/(m^2h)$ and $1.68m^3/(m^2h)$, respectively; with the locks off, the air-flow rates of the sliding and LS windows are $2.64m^3/(m^2h)$ and $5.83m^3/(m^2h)$, respectively, whereby the air-flow rates are 33% higher for sliding and 247% higher for LS. The air change per hour (ACH) was calculated using the ventilation-simulation software CONTAM. For the sliding window, the ACH changed from 0.45 to 0.57 when the lock was operated from on to off, representing an increase of 27%. For the LS window, the ACH changed from 0.29 to 0.81, showing an increase of 179%.

Translocation of Seed Storage Proteins into Microsomes Isoalted from Rice Endosperm Cells

  • Kim, Woo Taek
    • Journal of Plant Biology
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    • v.37 no.3
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    • pp.293-299
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    • 1994
  • Developing rice endosperm cells display two morphologically distinct rough endoplasmic reticulum (ER) membranes, the cisternae ER (C-ER) and theprotein body ER (PB-ER), the latter delimiting the prolamine protein bodies. We (Li et al., 1993) have recently shown that the storage protein mRNAs are not randomly distributed on these ER types; the C-ER is enriched for glutelin mRNAs, whereas the PB-ER harbors predominantly prolamine transcripts. To address whether these ER types have differnet capacities to translate these mRNAs and translocate their proteins into the lumen, a microsomal fraction enriched in C-ER vesicles was prepared from devleoping rice seeds. When present in an in vitro translatin system, the microsomes were able to proteolytically remove the signal peptide and internalize both preproglutelin and preprolamine within the microsomal vesicles. Of the two species, preprolamine was more effectively translocated and processed. These results suggest that the C-ER has the capacity to recognize and bind both storage protein mRNAs during protein synthesis. Moreover, efficient translocation and processing of glutelin requires additional factors that are deficient or absent in the in vitro system.

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Structure and Dynamics of Abies koreana Wilson Community in Mt. Gaya (가야산 구상나무 군락의 구조 및 동태)

  • Lee, Chang-Seok;Hyun-Je Cho
    • The Korean Journal of Ecology
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    • v.16 no.1
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    • pp.75-91
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    • 1993
  • Structure and dynamics of Abies koreana community in Mt. Gaya were studied to provide the basic data for conservation of Abies koreana community, an endemic species in Korea. A. koreana community of this study site was composed of tree layer (4~7m), subtree layer (2~4m), shrub layer (1~2m), and herb layer (below 1m). The heights of tree and subtree layers were low. Floristic composition showed that this study site was subalpine and dry site. In frequency distribution diagram of diameter classes of major species consisting of A. koreana community, those of both A. koreana and other species showed reverse J-shaped types. From these results, it was estimated that A. koreana community of this site might be maintained continuously as a stable climax state like present state. In the spatal distribution diagram of major species, saplings of A. koreana were established under the canopy of A. koreana and Pinus koraiensis and under the dead tree of A. koreana. From these results, it was known that A. koreana saplings were recruited before the community was disturbed and regeneration was accomplished by advance regeneration pattern, in which these saplings established before occurrence of disturbance fill with open site originated from death of mature tree. Growth of annual rings was variable among individuals, it was estimated that such variation was originated in that growth of each individual relates to microclimatic conditions rather than macroclimatic ones. Ecological longevity of A. koreana in this study site estimated by disturbance types and age of dead trees was about 120 years.

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Construction of a Bioluminescent Reporter Using the luc Gene and meta-Cleavage Dioxygenase Promoter for Detection of Catecholic Compounds

  • Park, Sang-Ho;Lee, Dong-Hun;Oh, Kye-Heon;Kim, Chi-Kyung
    • Journal of Microbiology
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    • v.38 no.3
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    • pp.183-186
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    • 2000
  • Several types of bioluminescent reporter strains have been developed for the detection and monitoring of pollutant aromatics contaminating the environment. In this study, a bioluminescent reporter strain, E. coli SHP3, was constructed by fusing the luc gene of firefly luciferase with the promoter of pcbC responsible for the meta-cleavage of aromatic hydrocarbons. the bioluminescence expressed by the luc gene in the reporter was well triggered by the promoter when it was exposed to 2,3-dihydroxybiphenyI (2,3-DHBP) at 0.5 to 1 mM concentrations. The bioluminescent response was more extensive when the reporter strain was exposed to 5 mM catechol and 2 mM 4-chlorocatechol. These different types of bioluminescent responses by E. coli SHP3 appeared to be characterized by the nature of the aromatics to stress. Since E. coli SHP3 responded to 2,3-DHBP quite sensitively, this reporter strain could be applied for detecting some catecholic pollutants.

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Growth Characteristics of Pinus thunbergii Parl. after Replanting in Reclaimed from the Sea( I ) - On the Spatial Distribution of Fine Root Phytomass - (바다 매립지 곰솔 이식후 생장특성(I) - 세근 공간적 분포를 중심으로 -)

  • 김도균;곽영세
    • Journal of the Korean Institute of Landscape Architecture
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    • v.31 no.6
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    • pp.77-84
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    • 2004
  • This study was carried out to analyze the vertical and horizontal distribution of fine root biomass of Pinus thunbergii transplanted in reclaimed land from the sea near Gwangyang Bay. The fine-root biomass according to 6 planting ground types were as follows: 98.5 g DM/$m^2$ for P2, 51.1 g DM/$m^2$ for P6, 47.8 g DM$m^2$ for P5, 44.6 g DM/$m^2$ for P3, 38.2 g DM/$m^2$ for P4, 31.8 g DM/$m^2$ for Pl, respectively. The vertical distribution of fine root biomass decreased at descending soil depths of the 6 mounding types. Fine root biomass was 31∼55% in the topsoil of 20cm depth. Fine root biomass that were related to the Spatial distance from the nearest tree were unevenly distributed horizontally in 6 stands. distribution patterns of fine root biomass were closely related to soil hardness and alkalic cation (Ca++, Mg++, Na+, K+) concentrations. Therefore, in order to have good condition for the growth of landscaping plants, we suggest that there is a need for the construction of planting grounds as well as a need for soil improvement in bad soil environments.

A Survey on Furniture Usage in Living room (거실내 가구사용 실태연구$^{\circled{a}}$)

  • 이명옥
    • Journal of the Korean housing association
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    • v.3 no.1
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    • pp.57-67
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    • 1992
  • Field survey were made. and the numbers of samples are 294 houses(3-ways;66-95.7m2, 99-128.7m2) and more than 132m')in Daegu.The major findings are as follows:1) The space evaluation of the living room is changed by the furniture occupancy rate and is different of the arrangement types.2) The space evaluation of the living room is much affected by the type of furniture which lie in near wall arrangement in 66-95.7m2, the proportion of the wall occupancy in 99-128.7m2, the proportion of the space occupancy in more of 132m2.3) In the living room an appropriate quantity of furniture is classified into 3 types of the occupying proportion.As the floor occupancy proportion supporting furniture is 13-22%, wall furniture is 10-l7f% and total furniture which combined both the supporting furniture and the wall furniture is 23-36%. Second. The proportion occupying the wall is 6-11% for the supporting furniture, 14-27% for the wall furniture, and 24-32% for the total furniture. Finally the proportion occupying the space is 12-9% for the supporting, 6-llftfer the wall furniture, and 12-l9ft for the total furniture.

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