Статті в журналах: "Column unit"

1

Kh Kurbangaleeva, M. "Improving the Safety of the Rectification Unit for the Production of Alkylphenols." IOP Conference Series: Earth and Environmental Science 988, no. 2 (February 1, 2022): 022007. http://dx.doi.org/10.1088/1755-1315/988/2/022007.

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Abstract As a result of the study, the analysis of occurrence of fire hazardous situation during the operation of rectification column of production facility of one of the city’s enterprises was carried out. This installation refers to facilities for which additional safety requirements are imposed. The main danger of the operation of rectification columns and their piping used at the installation is thefear of depressurization and theinitiation of gas contamination and fire situation on the site. As theresult of the fire, the rectification column and supporting metal structures can be in flame or be under the influence of thermal radiation from the flame in adjacent column, which can lead to the collapse of structures or to losses of bearing capacity under the influence of high temperatures. Depending on the height of the column, the water supply system can have different ways of distributing water: at small height of the column, manual water nozzles are used with the use of fire hydrants; at considerable height of the columns, stationary water irrigation systems (irrigation rings) are used.

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2

Gaber, Maryam, Anuar Kasa, Norinah Abdul Rahman, and Jamal Alsharef. "Comparison between unit cell and plane strain models of stone column ground improvement." International Journal of Engineering & Technology 7, no. 2 (March 12, 2018): 263. http://dx.doi.org/10.14419/ijet.v7i2.8797.

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This article presents a comparative study of the behaviour of clayey soil reinforcements using stone column ground improvement by means of numerical analyses. Two-dimensional finite element analyses with commercially available software, PLAXIS, were performed on end-bearing stone columns using 15-noded triangular elements to investigate the impact of the modelling type on the stress concentration ratio and failure mechanism of an improved foundation system. Consolidation analyses were conducted throughout the study using Mohr-Coulomb’s criterion. The computed values of the stress concentration ratios were compared for different key parameters, including the diameters of stone columns, c/c spacing of columns, friction angle of stone column material, and undrained cohesion of soft soil. The major conclusions of this study were that the stone column in the unit cell model shared between 2.5 to 3.14 times more loads than the surrounding soil, whilst in the plane strain model it shared between 1.7 to 2.9 times more loads. The use of plane strain approach to model the stone column gave a more comprehensive representation of the stress distribution and load transfer between the soil and columns, in addition to being a better method than the unit cell concept to evaluate the failure mode in this system.

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3

Yang, Yingxin, Dongdong Song, Kuilin Huang, Haitao Ren, and Jian Zhou. "Unit Experimental Study on Impact Crushing Rock of the Microcoring PDC Bit." Shock and Vibration 2019 (November 3, 2019): 1–10. http://dx.doi.org/10.1155/2019/3173298.

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In light of the situation of sliced or powdery cuttings produced by conventional PDC bit, it is found that they are not convenient for geological logging and stratification. The unit crushing experiment which contains two breaking forms (static-pressure breaking and impact) is conducted on core columns of sandstone, limestone, and granite. This experimental study showed the following: The breaking work ratio of the three core column types is much less than that of the flat rock. The height of the core column has little effect on the bit penetration rate, while core column diameter has greater effect on the bit penetration rate. The experimental results further indicate that a core column has been generated in the central area of the drill bit, which is beneficial to the volume breaking of the rock and can improve the rock-breaking efficiency of the drill bit. The microcoring bit is suitable for raising speed in soft, medium, and hard formations and is helpful for geological logging.

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4

Masia, Mark J., and Nigel G. Shrive. "Carbon fibre reinforced polymer wrapping for the rehabilitation of masonry columns." Canadian Journal of Civil Engineering 30, no. 4 (August 1, 2003): 734–44. http://dx.doi.org/10.1139/l03-015.

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The use of carbon fibre reinforced polymer (CFRP) wrapping to strengthen existing cracked masonry columns was investigated experimentally. The study was aimed at quantifying the increase in strength that can be achieved and assessing the effect of column size on the strength increase. Eighteen columns were tested, with three different square cross-sectional sizes (290 mm × 290 mm, 390 mm × 390 mm, 490 mm × 490 mm) and two different types of clay masonry unit. Six columns were constructed in each size, two columns using unit type 1 and four columns using unit type 2. Strengthening was achieved by wrapping the square section columns directly with a single-layer CFRP laminate or by wrapping the columns after first casting a circular concrete jacket around the column. The latter treatment was applied to two of the small-sized columns and two of the intermediate-sized columns. All other square section columns were wrapped directly. Significant strength increases were achieved, particularly when the columns were provided with the cylindrical concrete jacket. These preliminary tests indicate that the use of CFRP wrapping is an effective technique for rehabilitating damaged masonry columns. Decisive conclusions could not be made regarding the effect of column size (cross-sectional area) on the strength increase achieved. Further tests together with nonlinear finite element modelling aimed at duplicating the experimental observations would greatly enhance the information provided by the current tests.Key words: masonry, columns, rehabilitation, strengthening, fibre reinforced polymer, experimental.

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5

Silva, Pedro F., and Sri Sritharan. "Seismic Performance of a Concrete Bridge Bent Consisting of Three Steel Shell Columns." Earthquake Spectra 27, no. 1 (February 2011): 107–32. http://dx.doi.org/10.1193/1.3525919.

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This paper describes the performance of a full-scale, three-column concrete bridge bent test unit that was designed, constructed, and tested under simulated in- plane seismic loads. Representing a typical bent configuration used by the Alaska Department of Transportation and Public Facilities, the test unit employed 12.7-mm-thick steel shell concrete columns and evaluated adequacy of an improved beam-to-column joint design procedure. The steel shell served as the external reinforcement and formwork for the columns. As intended, plastic hinges were fully developed in the columns adjacent to the interface with the cap beam, with minimal damage occurring to the cap beam and joints due to simulated seismic actions. These observations, along with the recorded force-displacement hysteretic response, confirmed the desirable seismic performance of the test unit. Design details, analytical response, test observations, key experimental results, and design recommendations are presented.

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6

Li, Zhi Miao, Ju Bao Liu, Min Luo, and Qiang Zhang. "Dynamic Finite Element Analysis and Experimental Study of Rotating Column in Cylinder." Applied Mechanics and Materials 229-231 (November 2012): 453–56. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.453.

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Rotary slender column in cylinder is a special structure in oil engineering. It contacts with outer cylinder and interacts with its inner pipe fluid and outer annular fluid. A partitioned coupling model was founded by dispersing slender column into beam element, dividing fluid domain into some sections, dispersing fluid section into hexahedron unit and transfer method of the information of coupling interface was described. Dynamics experimental device of column-liquid interaction was built to do column rotating test with considering the displacement and force boundary conditions of rotating column and testing axial excitation force of bottom column, axial acceleration of head column, transverse displacement of columns and collision and contact forces between inner columns and outer pipeline. The maximum absolute error between experimental results and numerical results is 0.31mm and this research provides the methods of numerical simulation and experimental study.

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7

Popov, S. V., N. Y. Krymkin, O. V. Khabibrakhmanov, and E. N. Papulovskikh. "Reconstruction of the hardware design for isopropylbenzene production for the production of ethylbenzene." Proceedings of the Voronezh State University of Engineering Technologies 83, no. 2 (September 27, 2021): 184–90. http://dx.doi.org/10.20914/2310-1202-2021-2-184-190.

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The hardware design of the rectification unit for the production of isopropylbenzene in the presence of the AlCl3 catalyst is considered, the use of which has a number of problems associated with its corrosiveness, rapid deactivation, the complexity of regeneration, etc. One of the possible solutions to the listed technological disadvantages is the use of heterogeneous zeolite-containing catalysts. In this case, during the reconstruction of the existing production of isopropylbenzene in the technological scheme of separation of alkylate, three rectification columns are released, which are expediently used to separate the alkylate of ethylbenzene production. To study the possibility of using the discharging distillation columns, a computational experiment was carried out using the Honeywell UniSim Design modeling system, in which a model of the alkylate separation unit for ethylbenzene production was formed. The NRTL method was used as a mathematical package for calculating the thermodynamic properties of the mixture components. As a result of modeling the operation of the alkylate separation unit for each distillation column, the optimal operating process parameters were obtained: pressure of the top and bottom of the column, reflux ratio, temperature profile along the height of the column. The calculated material balance of the technological scheme shows that in the first distillation column, complete separation of benzene from the alkylation reaction mass is achieved, the second column ensures the production of commercial ethylbenzene, and in the third column, a fairly clear separation of diethylbenzene from the remaining components of the mixture is obtained. The performed computational experiment showed that for the organization of the stable operation of the technological scheme for the separation of alkylate in the production of ethylbenzene, it is possible to use all the considered distillation columns without changing their design parameters at a load on the reaction mass of alkylation of about 60 t / h.

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8

Bucsa, Sorin, Alexandru Serban, Mugur C. Balan, Claudia Ionita, Gabriel Nastase, Catalina Dobre, and Alexandru Dobrovicescu. "Exergetic Analysis of a Cryogenic Air Separation Unit." Entropy 24, no. 2 (February 13, 2022): 272. http://dx.doi.org/10.3390/e24020272.

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This case study analyzes a cryogenic air separation unit (ASU) with a production of V˙O2=58,300 [m3Nh] of gaseous oxygen with a concentration greater than 98.5%, operating in Romania on a steel plant platform. The goal of the paper is to provide an extensive model of exergetic analysis that could be used in an optimization procedure when decisional parameters are changed or structural design modifications are implemented. For each key part of the Air Separation Unit, an exergetic product and fuel were defined and, based on their definition, the coefficient of performance of each functional zone was calculated. The information about the magnitude of the exergetic losses offers solutions for their future recovery. The analysis of the exergy destructions suggests when it is worth making a larger investment. The exergetic analysis of the compression area of the ASU points out an exergy destruction and loss of 37% from the total plant’s electrical energy input. The exergy loss with the heat transferred to the cooling system of compressors can be recovered; for the exergy destruction portion, the challenge between investment and operating costs should be considered. The exergy destruction of the air separation columns found the High Pressure Column (HPC) to be more destructive than the Low Pressure Column. The share of the exergy destruction in the total plant’s electrical energy input is 8.3% for the HPC. The local COP of the HPC, calculated depending on the total exergy of the local product and fuel, is 62.66%. The calculus of the air separation column is performed with the ChemSep simulator.

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9

Beler-Baykal, B., G. Witte, and I. Sekoulov. "Activated carbon and residual nitrification for higher quality effluents for the coastal areas." Water Science and Technology 46, no. 8 (October 1, 2002): 99–104. http://dx.doi.org/10.2166/wst.2002.0153.

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Efforts for the task of modification of a nitrification/denitrification unit operating in a series of two fixed bed columns are outlined. The problem was elevated dissolved oxygen concentrations at the entrance of the denitrification column, resulting in an excessive consumption of methanol. The possibility of using a column of activated carbon for adsorption alone and in which both adsorption and residual nitrification take place was investigated. The results were observed to be very satisfactory in reducing dissolved oxygen levels to practically zero at the entrance of the denitrification unit especially for the case where both adsorption and residual nitrification were employed.

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10

Khabbazian, Majid, Victor N. Kaliakin, and Christopher L. Meehan. "Column Supported Embankments with Geosynthetic Encased Columns: Validity of the Unit Cell Concept." Geotechnical and Geological Engineering 33, no. 3 (January 18, 2015): 425–42. http://dx.doi.org/10.1007/s10706-014-9826-8.

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11

Lee. "Test Result on Embedded Steel Column-to-Foundation Connection for Modular Unit Structural System." Journal of Korean Society of Steel Construction 26, no. 6 (2014): 537. http://dx.doi.org/10.7781/kjoss.2014.26.6.537.

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12

Kharun, V. R., V. М. Senchishak, V. Ya Popovych, and І. І. Shostakivskyi. "The research beam pumping unit of start-up mode." Oil and Gas Power Engineering, no. 1(35) (June 29, 2021): 48–59. http://dx.doi.org/10.31471/1993-9868-2021-1(35)-48-59.

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In the article, research of the beam-pumping unit start-up mode has been performed in accordance with the existing configurations of the rod column, the diameter of the plunger and the dynamic fluid level in the well. A mathematical model of the pumping unit actuator has been developed, it takes into account the mechanical characteristics of the drive motor, the moments of inertia of the belt drive and gears of the gearbox and the mass of the actuator components. Calculations have been performed for the variant of the pump rod column layout - two-stage, for the diameters of the plunger 55mm and depths of pump suspension of 1456 m. The problem of the beam-pumping units’ startup is defined for two cases. The first case is applied when the mass of the counterweights installed on the cranks of the pumping unit exceeds the mass of the column of rods and liquid, which is located in the tubing column above the plunger of the pump (rebalance of the beam pumping unit). The second - when the mass of counterweights is insufficient to balance the column of rods and the liquid in the tubing column above the pump plunger (imbalance of the beam pumping unit). The cases of rebalancing and imbalancing of the pumping unit occur in wells that are under periodic operative conditions. The first case - rebalancing occurs when the oil rocking pumping unit does not work, and the liquid level behind the tubing gradually increases up to its static level. After switching on the drive motor, the torque created by the crank counterweights exceeds the moment caused by means of the weight of the rod column and the liquid in the tubing column. Therefore, it is recommended to start the pumping unit from the lowest position of the rod suspender. In the second case, the imbalance occurs when the liquid’s dynamic level behind the tubing is lowered before receiving the submersible pump. Then the torque, created by the crank counterweights is insufficient to compensate the moment, caused by means of weight of the rods’ column and the liquid in the tubing column. Therefore, it is recommended to start the beam pumping unit from the top position of the rod suspension. As a result of calculations, the conditions of overload occurrence in wells with periodic operative conditions of the pumping unit are determined

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13

Mokhtar, Saiful Anuar Mohd, and Marina Mosir. "Optimizing for Viability – Revamping Vacuum Distillation Unit in a Brownfield Project." International Journal of Research in Engineering, Science and Management 3, no. 11 (November 25, 2020): 91–94. http://dx.doi.org/10.47607/ijresm.2020.381.

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Revamping an existing column in an operating plant for a higher throughput is always a challenge especially when the column is already operating at its rated capacity. This is particularly true for a Vacuum Distillation Unit (VDU) column which involves multiple product and pump-around streams and associated auxiliary units like a steam ejector system. Optimizing the design and operation of the column, hence, is inevitable to ensure the viability of a brownfield project as it avoids major modifications required to the column and its associated auxiliary systems. This paper discusses how optimization was done on the design and operation of an existing VDU column in an oil refinery, avoiding major modifications of the associated ejector, steam, cooling water, sour water systems and heat exchanger network, allowing a brownfield project to stay commercially viable.

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14

Liu, A., and R. Park. "Seismic behavior and retrofit of pre-1970's as-built exterior beam-column joints reinforced by plain round bars." Bulletin of the New Zealand Society for Earthquake Engineering 34, no. 1 (March 31, 2001): 68–81. http://dx.doi.org/10.5459/bnzsee.34.1.68-81.

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Four exterior beam-column joints reinforced by plain round bars designed according to pre-1970's codes were subjected to simulated seismic loading. Each of the test units was full size in scale. The main test variables were the manner in which the longitudinal beam bars were hooked in the joint core and the level of the axial load applied to the columns. The amount of transverse reinforcement in the beams, columns and joint cores was very small, as was typical of the pre-1970's. The tests on the units demonstrated that the available stiffness and strength was low when the axial load was zero. The final failure occurred due to opening of the beam bar hooks in tension and column bar buckling, irrespective of the hook details of the beam bars. The presence of axial compressive load of 0.25fc'Ag on the columns delayed the failure initiated by the beam bar hooks, leading to much improved stiffness and strength of the units. In one unit with beam bar hooks bent away from the joint core, the column regions adjacent to the joint core were jacketed with fibre-glass and the unit when tested showed much improved stiffness and strength. When compared with the results of similar units reinforced by deformed bars, the units reinforced by plain round bars showed less joint shear distortion but more opening of beam bar hooks in tension and column bar buckling. As a result, premature concrete tension cracking failure along the outer layer of column bars adjacent to the beam bar hooks was enhanced, and the attained stiffness and the force strength were significantly lower, especially the stiffness.

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15

Shahu, J. T., and Y. R. Reddy. "Estimating long-term settlement of floating stone column groups." Canadian Geotechnical Journal 51, no. 7 (July 2014): 770–81. http://dx.doi.org/10.1139/cgj-2012-0477.

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Design charts for estimating long-term drained settlement of floating stone column group foundations are presented based on three-dimensional, elastoplastic, finite element analyses. In the analyses, the soft soil behavior is represented by the modified Cam-clay model while the stone column and mat are represented by the Mohr–Coulomb model. The finite element predictions are calibrated against model test results. A detailed parametric study of prototype stone column group foundations of various configurations is carried out to evaluate the relative importance of various foundation parameters on the group response. Next, finite element analyses of corresponding unit cells and single columns are performed. Reasonable correlations of load responses are found between single column and group behavior. Group and single column responses are then used to investigate Sg/S1 relationship with different foundation parameters, where Sg and S1 represent the settlement of the group and single column, respectively.

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16

Cimentada, Ana, Almudena Da Costa, Jorge Cañizal, and César Sagaseta. "Laboratory study on radial consolidation and deformation in clay reinforced with stone columns." Canadian Geotechnical Journal 48, no. 1 (January 2011): 36–52. http://dx.doi.org/10.1139/t10-043.

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A series of laboratory tests was performed to study the deformation and radial consolidation around end-bearing (fully penetrating) stone columns. For this purpose, the behaviour of a horizontal slice of a unit cell representative of a column and the surrounding soil was analysed. The tests were carried out in a Rowe–Barden large oedometric cell that was instrumented to measure vertical stresses and pore pressures at several distances from the axis. Two column geometries were tested, with cell-to-column diameter ratios of N = 3 and 4. The most important findings of this work were the rate of pore pressure dissipation, the vertical strain reduction due to the presence of the column of approximately 25% for N = 4 and 35% for N = 3, and the load transfer to the column related to the stiffness ratio between the column and soil resulting in incremental stress concentration factors in the range 2.5 to 9.2. Results were compared with theoretical solutions that are commonly used for the study of stone column behaviour.

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17

Zhou, San Ping, and Xi Man Lu. "A New Type of Packing Apparatus with High Efficiency and the Experimental Research of its Mass-Transfer Performance." Advanced Materials Research 291-294 (July 2011): 3245–49. http://dx.doi.org/10.4028/www.scientific.net/amr.291-294.3245.

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In this paper, a new type of packing apparatus with high efficiency and uniform flow was developed to deal with wall effect and scaling effect of packed column. A desorption experiment was made in a circular cold-model experiment packed column by using air-water-CO2 as working substance, determining the height of mass transfer unit of liquid phase of the cold-model experiment packed column under different gas-liquid loads, with and without the packing apparatus. The experimental results show that under different spray densities, the height of mass transfer unit of liquid phase of the packed column added with the packing apparatus decreased approximately above 19% more than that not added the packing apparatus; the height of mass transfer unit of liquid phase lowers more with the decrease of the spray density, which demonstrated that the mass transfer efficiency of the packed column added with the packing apparatus was much higher than that of the column not added the packing apparatus.

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18

McCarthy, Gregory J. "Laboratory Note. A LOTUS 1-2-3 Spreadsheet to Aid in Data Reduction for Publication of X-Ray Powder Diffraction Data." Powder Diffraction 3, no. 1 (March 1988): 39–40. http://dx.doi.org/10.1017/s0885715600013105.

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My students and I have developed a LOTUS 1-2-3 spreadsheet to aid in data reduction tasks associated with preparing powder diffraction data for publication in the Powder Diffraction File (PDF) (1987) and this journal. Portions of a sample spreadsheet and the formulae in each of the computational cells are given in the Table 1. The concept of this spreadsheet should apply to any of the available computer spreadsheet programs, although the specific codes for the mathematical functions may differ.The user enters data only into columns C, D and F-H. All other entries will be calculated from the input data. Observed 2θ angles are entered into column D. The corresponding d-spacing is calculated in column A. The Miller indices of these peaks are entered into column C. Prior to use of the spreadsheet, the observed 2θ angles and hkl's had been used to refine unit cell parameters using the Appleman and Evans (1973) least squares unit cell parameter refinement computer program implemented for the IBM PC by Garvey (1986).

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19

Li, Xuan, Qiaozhu Zhai, and Xiaohong Guan. "Robust transmission constrained unit commitment: a column merging method." IET Generation, Transmission & Distribution 14, no. 15 (August 3, 2020): 2968–75. http://dx.doi.org/10.1049/iet-gtd.2018.6314.

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20

Samolová, Erika, and Jan Fábry. "Caesium propanoate monohydrate." Acta Crystallographica Section E Crystallographic Communications 76, no. 8 (July 17, 2020): 1307–10. http://dx.doi.org/10.1107/s2056989020009639.

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Caesium propanoate monohydrate, Cs+·C3H5O2 −·H2O, is composed of two symmetry-independent Cs+ cations, which are situated on the special position 4e of space group P\overline421 m, one symmetry-independent propanoate molecule in a general position and a pair of water molecules also situated on special position 4e. Two pairs of these symmetry-independent cations, four propanoate molecules and two pairs of symmetry-independent water molecules form a repeat unit. These units form columns that are directed along the c axis and possess symmetry mm2. There are four such columns passing through each unit cell. Each column is interconnected to its neighbours by four bifurcated three-centred Ow—H...Op (w = water, p = propanoate) hydrogen bonds of moderate strength. There are also four intramolecular Ow—H...Op hydrogen bonds of moderate strength within each column. One Cs+ cation is coordinated by six oxygen atoms (two water and four carboxylate) in a trigonal–prismatic geometry, while the other Cs+ cation is coordinated by four water and four carboxylate O atoms in a tetragonal–prismatic arrangement.

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21

Liu, Aizhen, and R. Park. "Seismic load tests on two concrete interior beam-column joints reinforced by plain round bars designed to pre-1970s codes." Bulletin of the New Zealand Society for Earthquake Engineering 31, no. 3 (September 30, 1998): 164–76. http://dx.doi.org/10.5459/bnzsee.31.3.164-176.

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Two identical reinforced concrete interior beam-column joint assemblies were tested under simulated seismic loading as part of an investigation of the behaviour of existing reinforced concrete structures designed to pre-1970s codes when subjected to severe earthquake forces. The test units were full-scale in size, and were replicas of part of the moment resisting frame of an existing building in Christchurch that was constructed in the 1950s. The longitudinal and transverse reinforcement were from plain round bars, the beams and columns had low quantities of transverse reinforcement and the joints had no shear reinforcement at all, as was typical of pre-1970s construction in New Zealand. One unit was tested with zero axial column load, and the other unit with a constant axial column load of 0.12 f’c Ag, where f’c = concrete cylinder compressive strength and Ag = the gross column section area. The units displayed very low structural stiffness, flexural strength less than conventionally calculated, and significant degradation of stiffness and strength during testing. The low structural stiffness and flexural strength could be attributed to the slip of the plain round longitudinal bars through the joint. However, the utilisation of plain round bars although leading to bond slip was found to improve the joint shear strength and to result in reduced shear distortion of the joint. Buckling of longitudinal column bars was found to initiate failure, due to inadequate ties.

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22

Noor, Shabana, Sarvendra Kumar, Suhail Sabir, Rüdiger W. Seidel та Richard Goddard. "Crystal structure of {6,6′-dihydroxy-2,2′-[iminobis(propane-1,3-diylnitrilomethanylylidene)]diphenolato-κ5O1,N,N′,N′′,O1′}copper(II)". Acta Crystallographica Section E Crystallographic Communications 71, № 11 (24 жовтня 2015): m203—m204. http://dx.doi.org/10.1107/s2056989015019684.

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The title compound, [Cu(C20H23N3O4)], crystallizes in the space groupCcwith two independent molecules in the asymmetric unit. The CuIIatoms are each coordinated by the pentadentate Schiff base ligand in a distorted trigonal bipyramidal N3O2geometry. The equatorial plane is formed by the two phenolic O atoms and the amine N atom, while the axial positions are occupied by the two imine N atoms. In the crystal, the two independent molecules are each connected into a column along thebaxis through intermolecular O—H...O hydrogen bonds. The two independent columns are further linked through an N—H...O hydrogen bond, forming a double-column structure.

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23

Mohtasham, Mohammad Reza, and Mahdi Khodaparast. "Investigation of the Effect of Dimensional Characteristics of Stone Column on Load-Bearing Capacity and Consolidation Time." Civil Engineering Journal 4, no. 6 (July 4, 2018): 1437. http://dx.doi.org/10.28991/cej-0309184.

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One of the best methods for rehabilitating loos and soft soils is the application of stone columns. This method enhances the soil properties by increasing its load-bearing capacity, decreasing the soil subsidence, and accelerating the consolidation rate. In the present paper, numerical analysis of a stone column of 10 m in length into a clayey soil using ABAQUS software is presented. The stone column was modelled based on the concept of unit cell, i.e. a single stone column with the surrounding soil. In this respect, material of the stone column was modelled using the elastoplastic behavioural model of Mohr-Coulomb, while Cam Clay behavioural model was used for the surrounding clayey soil. Furthermore, throughout the analyses performed in this study, effects of different parameters (e.g. applied load on rigid foundation, and the stone column length and diameter) on the subsidence and consolidation time of the rigid foundation were examined. The results indicated that, construction of a stone column into clayey soil decreases the subsidence and consolidation time of the soil considerably. In additions, increases in length and diameter of the stone column were found to significantly contribute to reduced subsidence and consolidation time of soil.

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24

Rudnev, Igor, Viktor Zhadanov, and Vladimir Garipov. "Validation of the calculation of a wooden column with a support unit on glued steel plates." E3S Web of Conferences 263 (2021): 02054. http://dx.doi.org/10.1051/e3sconf/202126302054.

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The article proposes a structural solution for the base of a wooden frame column on flat links glued in the support part of the column – steel plates welded to the base plate. The results of numerical studies of the column, taking into account the parameters of the adhesive connection of the plates with wood and the anisotropy of wood, are presented. The column model takes into account the geometric and physico-mechanical characteristics of wood, steel plate bonds and adhesive compound. The main results of numerical studies are verified with the results of the analytical calculation of the column performed by the method of initial parameters. A physical model with the proposed structural solution of the column base was made and tested. The numerical and analytical calculations of the column were validated, and the main conclusions of the experimental and theoretical study were presented.

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25

Voinov, Nikolai A., Anastasiya V. Bogatkova, and Denis A. Zemtsov. "Intensification of Heat and Mass Transfer in a Diabatic Column with Vortex Trays." ChemEngineering 6, no. 2 (April 12, 2022): 29. http://dx.doi.org/10.3390/chemengineering6020029.

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We used vortex contact devices that we developed and investigated to make a new design of an alcohol diabatic distillation column with heat exchange pipes (as the reflux condenser) passing through concentrating section trays. In the column, ascending vapors partially condensed on the surface of vertically installed heat exchange tubes, forming a reflux. The reflux was then mixed with the draining liquid flow in the vortex contact devices placed on the trays. Heat was removed from the column through the boiling of the draining water film along the inner surface of the heat exchange pipes. We compared both diabatic and adiabatic columns fitted with the developed vortex contact devices on the trays. The proposed innovative contact system allows increasing productivity, reducing column dimensions and steam- and heat-transfer medium consumption, and increasing separation efficiency. Dependences for calculating the gas content, hydraulic resistance, and interphase surface required for designing the vortex contact devices of the proposed unit trays are presented.

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26

Klykov, M. V., and T. V. Alushkina. "Development of Technological Schemes for Increasing the Selection of Vacuum Gas Oil." Chemistry and Technology of Fuels and Oils 625, no. 3 (2021): 17–20. http://dx.doi.org/10.32935/0023-1169-2021-625-3-17-20.

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The analysis of the operation of the vacuum columns of the ELOU AVT units showed that in a number of cases the half-gas contains up to 30% of vacuum gas oil with a boiling point of up to 560 ° C. A comparative analysis of three options for deepening the selection of heavy vacuum gas oil during the distillation of fuel oil has been carried out. A traditional scheme with a pressure reduction at the top of the vacuum column, the rectification of a half-sludge without heating it after the main vacuum column in an additional its subsequent rectification in the second column, with the selection of heavy vacuum gas oil. The analysis of the operation of the vacuum column of the vacuum rectification unit ELOU AVT-6 was carried out. The process was simulated in the environment of the software product Aspen HYSYS, the possibility of increasing the selection of heavy vacuum gas oil in the process of deep vacuum rectification of tar was theoretically proved. The advantages and disadvantages of two-column vacuum distillation of fuel oil are considered. Structural design of the rectification column and raw material input device is proposed.

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27

Lee Simons, Sherri. "Nurse Managers: The Ties That Bind." Neonatal Network 22, no. 5 (January 2003): 69–71. http://dx.doi.org/10.1891/0730-0832.22.5.69.

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The job of managing people, whether a team, a unit, or an entire department, is a challenging one at best. Couple that with larger staffs, shrinking budgets and a burgeoning nursing shortage, and the challenge becomes even greater. This new column is intended to offer some insights into the complex world of the nurse manager. Combining humor with years of management experience, our column editor will delve into a variety of issues facing nurse managers. As with all of our columns, your suggestions and questions are welcome. Please feel free to e-mail the journal, and your thoughts will be forwarded to Ms. Simons.

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28

Ratanatamskul, C., C. Chiemchaisri, and K. Yamamoto. "The use of a zeolite-iron column for residual ammonia and phosphorus removal in the effluent from a membrane process as an on-site small-scale domestic wastewater treatment." Water Science and Technology 31, no. 9 (May 1, 1995): 145–52. http://dx.doi.org/10.2166/wst.1995.0354.

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Laboratory-scale experiments were performed to investigate the performance of the on-site small-scale combined system of membrane separation bioreactor (MSB) and zeolite-iron (Z-Fe) column. Average nitrogen removal by the membrane separation bioreactor was varied from 83% at an influent nitrogen concentration of 30 mg/l to 50% at 75 mg/l. Residual ammonia nitrogen in the effluent from the membrane separation bioreactor was further polished by a Z-Fe column to an initially non-detectable concentration and finally to 1.2 mg/l. The average phosphorus removal by this column unit was 70%. Improvement by providing aeration to the bottom part of iron bed in the long column improved phosphorus removal efficiency to as much as 92% until water logging occurred inside the column. Moreover, further improvement was achieved by inserting three short columns in series for 116 day of operation. Average effluent phosphorus concentrations of 1.2, 0.39 and 0.16 mg/l were obtained after the 1st, 2nd and 3rd column respectively with an applied influent phosphorus concentration of 5.3 mg/l on average. Furthermore, batch experiments were carried out to investigate the factors, such as pH and temperature, which affect the performance of the Z-Fe column in phosphorus removal.

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29

Ng, Ronald H., Mani Menon, and Jack H. Ladenson. "Collection and Handling of 24-Hour Urine Specimens for Measurement of Analytes Related to Renal Calculi." Clinical Chemistry 31, no. 2 (February 1, 1985): 308. http://dx.doi.org/10.1093/clinchem/31.2.308.

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Abstract Vol. 30 p 468: In line 7, left column, HCl should be 12 mol/L. p 536: In Figs. 4 and 5, change the unit on the ordinates to "%." Change the ordinate numbers on Fig. 4 from 0, 20, 40, 60, 80, and 100 to 0, 5, 10, 15, 20, 25. On Fig. 5, change the ordinate number from 120 to 30. p 725: In line 8, right column, change "logarithmic probability," to "probit." In Figs. 2 and 3, replace the terms "log 10" and "double log" by "probit" and "simple log," respectively. p 729: Insert "γ" in the empty space on line 23, right-hand column, so the expression reads "100(1 – γ)%." pp 856–7: Exchange the legends for Figures 2 and 3. p 1111: Units in the left-hand Table should be "µg/L," not "g/L." p 1260: In the first column, just under equation 2, delete "β" and insert the words "for a." p 1294: In paragraph three, line 6, for "blunted" read "blunt." p 1353: Transpose Figures 2 and 3 over the (unchanged) legends. 0.53 1.02 2.71 5.0 p 1364: The sixth line of data, columns 2–4 should read "176.4 ± 43," "470 ± 198," and "0.5." The final line of data, columns 2–4, should read "1.95 ± 0.47," "5.05 ± 2.12," and "0.4," and, under "Range" the following should be inserted at the bottom of the column: 0.4–0.7 0.2–0.8 0.1–0.7. p 1365: The data in columns 2 and 4, and some in column 3, of Table 3 should read: See table in the PDF file p 1429: The middle column, next to last paragraph, should read: "Hb 27 g/L" and "leukocytes 186 x 109/L." p 1812: Column 1, fifth line of text: change "decreasing" to "increasing." p 1813: Column 2, x refers to whole blood rather than plasma, y to plasma.

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30

Pennycook, S. J., P. D. Nellist, N. D. Browning, P. A. Langjahr, and M. Rühle. "Quantitative structure determination of interfaces through Z-contrast imaging and electron energy loss spectroscopy." Proceedings, annual meeting, Electron Microscopy Society of America 54 (August 11, 1996): 104–5. http://dx.doi.org/10.1017/s0424820100162983.

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The simultaneous use of Z-contrast imaging with parallel detection EELS in the STEM provides a powerful means for determining the atomic structure of grain boundaries. The incoherent Z-contrast image of the high atomic number columns can be directly inverted to their real space arrangement, without the use of preconceived structure models. Positions and intensities may be accurately quantified through a maximum entropy analysis. Light elements that are not visible in the Z-contrast image can be studied through EELS; their coordination polyhedra determined from the spectral fine structure. It even appears feasible to contemplate 3D structure refinement through multiple scattering calculations.The power of this approach is illustrated by the recent study of a series of SrTiC>3 bicrystals, which has provided significant insight into some of the basic issues of grain boundaries in ceramics. Figure 1 shows the structural units deduced from a set of 24°, 36° and 65° symmetric boundaries, and 24° and 45° asymmetric boundaries. It can be seen that apart from unit cells and fragments from the perfect crystal, only three units are needed to construct any arbitrary tilt boundary. For symmetric boundaries, only two units are required, each having the same Burgers, vector of a<100>. Both units are pentagons, on either the Sr or Ti sublattice, and both contain two columns of the other sublattice, imaging in positions too close for the atoms in each column to be coplanar. Each column was therefore assumed to be half full, with the pair forming a single zig-zag column. For asymmetric boundaries, crystal geometry requires two types of dislocations; the additional unit was found to have a Burgers’ vector of a<110>. Such a unit is a larger source of strain, and is especially important to the transport characteristics of cuprate superconductors. These zig-zag columns avoid the problem of like-ion repulsion; they have also been seen in TiO2 and YBa2Cu3O7-x and may be a general feature of ionic materials.

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31

Odijie, Agbomerie Charles, Facheng Wang, and Jianqiao Ye. "A review of floating semisubmersible hull systems: Column stabilized unit." Ocean Engineering 144 (November 2017): 191–202. http://dx.doi.org/10.1016/j.oceaneng.2017.08.020.

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32

Alexandre, Frédéric, Frédéric Guyot, Jean-Paul Haton, and Yves Burnod. "The cortical column: A new processing unit for multilayered networks." Neural Networks 4, no. 1 (January 1991): 15–25. http://dx.doi.org/10.1016/0893-6080(91)90027-3.

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33

Bulii, Y. V., O. M. Obodovych, and V. V. Sydorenko. "INCREASING THE DEGREE OF EXTRACTION OF ORGANIC IMPURITIES OF RECTIFIED ALCOHOL." Thermophysics and Thermal Power Engineering 43, no. 1 (March 4, 2021): 68–74. http://dx.doi.org/10.31472/ttpe.1.2021.8.

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Obtaining high quality rectified ethyl alcohol is a priority for the further development of the alcohol industry. The solution to this urgent problem is possible under the condition of deeper extraction and concentration of volatile alcohol impurities on the plates of the column equipment of the Distillation/Rectification Unit. In the columns of the Distillation/Rectification Unit simultaneously with the release of volatile alcohol impurities due to the esterification reaction is the formation of organic compounds that degrade its quality and reduce the yield of the final product. Thus, during the interaction of alcohols, acids, and aldehydes, the breakdown products of amino acids, sulfur compounds, and other components of the brew in the fermentation column are the formation of esters, aldehydes, and acetals of organic acids. The aim of the work was to determine the optimal technological modes of distillation of alcohol-containing intermediate products and by-products of the distillation/rectification process in the accelerating column, epuration of wash distillate in the epuration column, the concentration of rectified alcohol in the alcohol column, and its repeated epuration in the column of final clearance, under which the content of organic impurities in rectified ethyl alcohol would be the lowest. Materials and methods. Research methods were analytical, chemical, physico-chemical with the use of instruments and research methods used in the production of rectified ethyl alcohol. The concentration of volatile alcohol impurities was determined on a gas chromatograph with a column of HP FFAP 50 m × 0.32 m. It is determined that to increase the degree of extraction of organic impurities it is necessary to ensure the concentration of ethyl alcohol in the column bottom of the accelerating column, which does not exceed 4% vol.; pasteurization zone in the rectification column increase to 10 plates, reduce the concentration of ethanol in the epurate to 22-29% by hydroselection of impurities; for hydroselection in the epuration column use free of impurities bottom products of the accelerating column. To improve the quality of rectified alcohol and reduce energy consumption by extending the contact time on the plates of steam and liquid, a promising direction is the use of mass transfer equipment of cyclic mode. The proposed measures require constant monitoring of technological parameters and provide for the operation of technological equipment in an automated mode.

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34

Gao, Yong Tao, and Xiao Hu. "Member Stability Calculation and Analysis of the Unit Glass Curtain Wall." Applied Mechanics and Materials 71-78 (July 2011): 109–12. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.109.

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The formula to calculate the stability of the unit glass curtain wall (UGCW) is given on the theory of the structure stability is applied to analyze the whole stability of the frame of the UGCW and the calculation formula is provided. Due to the special structure form of the vertical column of the UGCW the formula is given to calculate the critical moment of the vertical column when torsional and flexural buckling occur, and then, the design basis is provided for reasonable and safe design of the UGCW.

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35

Ingold, Oliver, David Pfister, and Massimo Morbidelli. "A reactive continuous chromatographic process for protein PEGylation." Reaction Chemistry & Engineering 1, no. 2 (2016): 218–28. http://dx.doi.org/10.1039/c5re00055f.

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A multicolumn process in the form of a twin-column MCSGP unit is fitted with an additional column to perform a on-column protein PEGylation reaction. Thanks to this rMCSGP process, the conjugation reaction is obtained simultaneously with the purification of the products at high yield and high conversion of the protein.

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36

Kabra, P. M., J. H. Wall, and P. Dimson. "Automated solid-phase extraction and liquid chromatography for assay of cyclosporine in whole blood." Clinical Chemistry 33, no. 12 (December 1, 1987): 2272–74. http://dx.doi.org/10.1093/clinchem/33.12.2272.

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Abstract In this rapid, precise, accurate, cost-effective, automated liquid-chromatographic procedure for determining cyclosporine in whole blood, the cyclosporine is extracted from 0.5 mL of whole blood together with 300 micrograms of cyclosporin D per liter, added as internal standard, by using an Advanced Automated Sample Processing unit. The on-line solid-phase extraction is performed on an octasilane sorbent cartridge, which is interfaced with a RP-8 guard column and an octyl analytical column, packed with 5-microns packing material. Both columns are eluted with a mobile phase containing acetonitrile/methanol/water (53/20/27 by vol) at a flow rate of 1.5 mL/min and column temperature of 70 degrees C. Absolute recovery of cyclosporine exceeded 85% and the standard curve was linear to 5000 micrograms/L. Within-run and day-to-day CVs were less than 8%. Correlation between automated and manual Bond-Elut extraction methods was excellent (r = 0.987). None of 18 drugs and four steroids tested interfered.

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37

Natig Abbasov, Natig Abbasov, and Rufet Ezizli Rufet Ezizli. "IMPROVING THE EFFICIENCY OF THE STABILIZATION COLUMNS IN OIL AND GAS PROCESSING." ETM - Equipment, Technologies, Materials 10, no. 02 (April 2, 2022): 81–89. http://dx.doi.org/10.36962/etm10022022-81.

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Rectification process is widely used in oil and gas processing and petrochemistry. The composition of the bottom product of the rectification column usually differs from the equilibrium composition due to significantly higher content of light components or fractions. This stipulates a necessity to include into the technological schemes of several oil refining processes a stabilization unit that are meant to ensure separation of gases and liquid products. A highly relevant task is to explore new possibilities for improving the stabilization process. The aim of the present work was to improve the stabilization process by changing the operating pressure. It was found that increasing the pressure in the stabilization column enhanced the sharpness of separation of butanes from pentanes, which resulted in improving the quality of the products. The experimental-industrial runs confirmed the possibility of increasing the efficiency of stabilization columns in various processes by increasing the pressure within acceptable limits. Keywords: rectification process, sharpness of separation, stabilization column, pressure.

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38

Xu, Ya Feng, Jian Song, and Peng Ju Sun. "Study on Seismic Behavior of T-Shaped Concrete-Filled Steel Tube Compound Column under Different Axial Compression Ratios." Advanced Materials Research 368-373 (October 2011): 1539–42. http://dx.doi.org/10.4028/www.scientific.net/amr.368-373.1539.

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In this paper, the large-scale finite element software ABAQUS is used to study seismic behavior of T-shaped concrete-filled steel tube compound columns with different axial compression ratios. We determine the appropriate type of unit, measure off rational mesh, choose rational algorithm, through this simulation analysis. And we can get the hysteresis curves and skeleton curves of the columns with dies and management. The destruction and the deformation pattern of the whole columns can be seen different axial compression rations. The results show that the difference of axial compression rations has great impact on seismic behavior of T-shaped concrete-filled steel tube compound column.

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39

Ghrairi, Firas, Arash Alimardani Lavasan, and Torsten Wichtmann. "Evaluation of the Installation Effect on the Performance of a Granular Column." Geosciences 12, no. 5 (May 18, 2022): 216. http://dx.doi.org/10.3390/geosciences12050216.

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The procedure of granular column installation impacts soil properties such as stress state, stiffness, and permeability in the near-field of the column. For an accurate and efficient design of relatively costly geostructures on improved subsoil with granular columns, a reliable estimation of the column installation effects on the properties of natural subsoil deposits is necessary. To achieve this goal, two phases are adopted in numerical simulations: (1) the installation phase based on the cavity expansion method using a 2D model, and (2) the construction phase in conjunction with the improved soil properties after column installation using a 3D model. The latter phase includes the construction of an embankment and the column is considered as an independent unit. The soil profile, i.e., stress and stiffness, is spatially updated from the first simulation (i.e., installation phase). In this frame, the stiffness was calculated according to a procedure suggested by the authors to determine the final stiffness based on the formulation of the Hardening Soil constitutive model. The numerical models were validated through a comparison with the recorded data of a field test obtained from the Klagenfurt site. Results of numerical analyses for the case study indicated that application of proposed methodology led to a more accurate estimate of the settlement, demonstrating that the installation effects have be taken into consideration to assure reliable evaluation of granular-column performance.

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40

Osipov, Eduard, Eduard Telyakov, and Sergey Ponikarov. "Coupled Simulation of a Vacuum Creation System and a Rectification Column Block." Processes 8, no. 11 (October 22, 2020): 1333. http://dx.doi.org/10.3390/pr8111333.

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The purpose of this study was the coupling simulation of the vacuum block of the ethanolamine mixture separation unit to determine the optimal layout of the vacuum creation system. For this, a computational model of the vacuum unit, which was identified by comparing the computational data with the data of an industrial study of vacuum rectification columns, was synthesized in the Unisim Design R461 software package. To determine the required load on the vacuum system, a numerical experiment was carried out, during which it was discovered that the load on the system would be 9600 m3/h. It was proposed to replace individual column vacuum pumps with a single vacuum-generating system (VGS) based on a liquid ring vacuum pump (LRVP). When defining the layout, two possible schemes were considered, the models of which were created in Unisim Design R461. The system layout was determined by matching the characteristics of the system elements with the characteristics of the vacuum columns. A technical and economic comparison of the proposed solutions was carried out and the payback period for capital costs was calculated, which for Scheme 1 was 4.14 years, and for Scheme 2–3.59 years.

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41

Hüttemann, T., and Z. Zhang. "An elementary description of K1(R) without elementary matrices." Algebra and Discrete Mathematics 30, no. 1 (2020): 79–82. http://dx.doi.org/10.12958/adm1568.

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Let R be a ring with unit. Passing to the colimit with respect to the standard inclusions GL(n,R)→GL(n+1,R) (which add a unit vector as new last row and column) yields, by definition, the stable linear group GL(R); the same result is obtained, up to isomorphism, when using the `opposite' inclusions (which add a unit vector as new first row and column). In this note it is shown that passing to the colimit along both these families of inclusions simultaneously recovers the algebraic K-group K1(R)=GL(R)/E(R) of R, giving an elementary description that does not involve elementary matrices explicitly.

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42

Choi, Kyung-Suk, and Hyung-Joon Kim. "Analytical Models of Beam-Column joints in a Unit Modular Frame." Journal of the Computational Structural Engineering Institute of Korea 27, no. 6 (December 31, 2014): 663–72. http://dx.doi.org/10.7734/coseik.2014.27.6.663.

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43

Yu, Yan, Richard J. Bathurst, and Ivan P. Damians. "Modified unit cell approach for modelling geosynthetic-reinforced column-supported embankments." Geotextiles and Geomembranes 44, no. 3 (June 2016): 332–43. http://dx.doi.org/10.1016/j.geotexmem.2016.01.003.

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44

Jackson, Scott C., and Dorothy W. Skaf. "Implementing a KARR® extraction column in the unit operations lab." Education for Chemical Engineers 32 (July 2020): 95–101. http://dx.doi.org/10.1016/j.ece.2020.05.006.

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45

Lebedev, Yu N., I. A. Zil'berberg, G. V. Mamontov, and T. M. Zaitseva. "Commercial testing of a combined vacuum column and catalytic cracking unit." Chemistry and Technology of Fuels and Oils 26, no. 12 (December 1990): 624–27. http://dx.doi.org/10.1007/bf00727754.

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46

Abdel-Aal, El-Sayed M., Kaddus Miah, J. Christopher Young, and Iwona Rabalski. "Comparison of Four C18 Columns for the Liquid Chromatographic Determination of Deoxynivalenol in Naturally Contaminated Wheat." Journal of AOAC INTERNATIONAL 90, no. 4 (July 1, 2007): 995–99. http://dx.doi.org/10.1093/jaoac/90.4.995.

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Abstract Three long and 1 short reversed-phase C18 columns were compared for separation of deoxynivalenol (DON) in extracts of naturally contaminated wheat samples using liquid chromatography with ultraviolet detection and liquid chromatography/mass spectrometry (LC/MS). Among the 3 long columns used, a Symmetry C18 column with an isocratic solvent mixture of wateracetonitrilemethanol (90 + 5 + 5, v/v/v) gave the best separation for DON without interferences from other compounds in the wheat extracts. The Symmetry short (75 mm) column was comparable with the long column (250 mm) in resolving DON but significantly reduced retention time (i.e., 5.8 versus 16.3 min). Increasing the column temperature from 25 to 45C resulted in a further reduction in retention time. Identity of DON in the wheat extracts and standard solutions was confirmed by LC/MS in the positive ion mode, whereby DON appeared with an (M+1)+ ion at a mass-to-charge ratio of 297 plus fragment ions associated with loss of water and/or a 30 atomic mass unit (amu) CH2O fragment. The Symmetry short column was also capable of separating a mixture of the mycotoxins DON, 15-acetyl-DON, nivalenol, and zearalenone by use of a combination of an isocratic and gradient solvent system. The overall method showed high precision, exhibiting a relative standard deviation of 4.8%, limit of detection of 50 ng/g, and limit of quantitation of 165 ng/g. It was significantly correlated with enzyme-linked immunosorbent assay analysis, indicating its appropriateness for safety and quality assurance of wheat and related grains.

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47

Wiśniewski, Łukasz, Monika Antošová, and Milan Polakovič. "Simulated moving bed chromatography separation of galacto-oligosaccharides." Acta Chimica Slovaca 6, no. 2 (October 1, 2013): 206–10. http://dx.doi.org/10.2478/acs-2013-0033.

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Abstract A mixture of galacto-oligosaccharides and non-prebiotic sugars was separated using a simulated moving bed unit equipped with eight packed-bed columns of a cation exchanger. In order to determine operating conditions using triangle theory, equilibrium adsorption isotherms of galactose, glucose, lactose, tri- and tetragalacto-oligosaccharide were measured. It was found that each column of the SMB unit had a maximum separation efficiency of more than 3000 theoretical plates. The achieved purity of galacto-oligosaccharides in the raffinate stream was 99.9 %, similarly 99.9 % of extract was formed by non-prebiotic sugars lactose, glucose and galactose. The productivities in the raffinate and extract, were 0.6 g/(L h) and 2.4 g/(L h), respectively.

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48

Isobe, Hiroyuki, Taisuke Matsuno, Shunpei Hitosugi, and Waka Nakanishi. "2,11-Dibromo-5,8-dibutyl[4]helicene." Acta Crystallographica Section E Structure Reports Online 68, no. 4 (March 31, 2012): o1239. http://dx.doi.org/10.1107/s1600536812013141.

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A racemic mixture of the title compound, C26H26Br2, a brominated [4]helicene, crystallizes, forming columns of stacked molecules. There are two crystallographically unique molecules in the asymmetric unit, both with the same helical handedness. As is typical with helicene congeners, the unique molecules show short interatomic contacts between H atoms at the fjord region, with H...H distances of 1.87 and 1.94 Å. Molecules with the same helical handedness segregate in the crystal packing, forming homochiral columns. The stacked molecules are piled in a column with alternate orientations. The shortest C...C distance in the stacked molecules is 3.306 (4) Å.

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49

HONG, Won-Kee, Gyeongju KIM, Chaeyeon LIM, and Sunkuk KIM. "DEVELOPMENT OF A STEEL-GUIDE CONNECTION METHOD FOR COMPOSITE PRECAST CONCRETE COMPONENTS." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 23, no. 1 (July 1, 2016): 59–66. http://dx.doi.org/10.3846/13923730.2014.975740.

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Green Frame is a column-beam structure formed by connecting a composite precast concrete beam with a steel connection on the column side. Similar to steel frame construction, the green columns cover 3 stories per unit, and generate vertical and horizontal eccentricities due to construction errors and the gravitational loads of beams. Such eccentricities make it difficult to install the upper floor beams and adjacent frames. This problem not only results in decreased productivity, but also in time delays and cost overrun. The objective of this study is to develop a new steel-guide connection method for composite precast concrete (CPC) components after analysing the erection process and structural mechanism to resolve eccentricity issues. The connection mechanism developed in this study resolves these eccentricities and promotes efficient, accurate, and safe construction.

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50

Vančura, P., J. Gečnuk, J. Jakovenko, Z. Janoška, J. Jirsa, V. Kafka, O. Korchak, et al. "A low power asynchronous column-parallel 10-bit analog to digital converter with a high input impedance." Journal of Instrumentation 17, no. 05 (May 1, 2022): T05016. http://dx.doi.org/10.1088/1748-0221/17/05/t05016.

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Abstract This paper proposes a low power 10-bit asynchronous fully-differential column analog to digital converter (ADC) with successive approximation (SAR) and charge redistribution in a 180 nm SoI technology. The ADC is designed for use in Spacepix-2 monolithic active pixel sensor. A novel folded architecture of internal capacitive digital to analog converter (CDAC) is proposed. The total capacitance of CDAC is 512 fF, with a single unit capacitor capacitance only 0.5 fF and a size of 2.5 × 1.4 μm2. The total input capacitance of the proposed column ADC is only 220 fF. Two columns of a pixel matrix share a single ADC to double layout width. The layout area is 120 × 923 μm2. The sample rate is 4 MSps with power consumption of 225 μW from 1.8 V power supply.

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