Journal articles: 'Conical assembly'

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Pu, Xin Zheng. "Finite Element Analysis of Assembly Body of Conical Pick." Applied Mechanics and Materials 397-400 (September 2013): 573–76. http://dx.doi.org/10.4028/www.scientific.net/amm.397-400.573.

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In order to improve the structure mechanics performance of assembly body of conical pick, the finite element method was taken to analyse assembly body of conical pick based on rock cutting theory, and the distortion law of stress and displacement of carbide tip, pick arbor and pick holder were obtained. The results show that the maximum stress appearing in pick carbide tip and its weld site is 371MPa, maximum stress of pick holder appearing in its weld site is 157MPa. Consequently, the quality of the weld should be ensured in processing and manufacturing or welding installation to reduce the performance of carbide tip and pick holder drop. The maximum displacement of assembly body of conical pick is 1.14mm, which has little influence on the structure mechanics performance of assembly body. The research results could provide some guidance for designing, manufacturing or welding the assembly body of conical pick.

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Woodward, Cora L., Sarah N. Cheng, and Grant J. Jensen. "Electron Cryotomography Studies of Maturing HIV-1 Particles Reveal the Assembly Pathway of the Viral Core." Journal of Virology 89, no. 2 (November 12, 2014): 1267–77. http://dx.doi.org/10.1128/jvi.02997-14.

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ABSTRACTTo better characterize the assembly of the HIV-1 core, we have used electron cryotomography (ECT) to image infected cells and the viral particles cryopreserved next to them. We observed progressive stages of virus assembly and egress, including flower-like flat Gag lattice assemblies, hemispherical budding profiles, and virus buds linked to the plasma membrane via a thin membrane neck. The population of budded viral particles contains immature, maturation-intermediate, and mature core morphologies. Structural characteristics of the maturation intermediates suggest that the core assembly pathway involves the formation of a CA sheet that associates with the condensed ribonucleoprotein (RNP) complex. Our analysis also reveals a correlation between RNP localization within the viral particle and the formation of conical cores, suggesting that the RNP helps drive conical core assembly. Our findings support an assembly pathway for the HIV-1 core that begins with a small CA sheet that associates with the RNP to form the core base, followed by polymerization of the CA sheet along one side of the conical core toward the tip, and then closure around the body of the cone.IMPORTANCEDuring HIV-1 assembly and release, the Gag polyprotein is organized into a signature hexagonal lattice, termed the immature lattice. To become infectious, the newly budded virus must disassemble the immature lattice by proteolyzing Gag and then reassemble the key proteolytic product, the structural protein p24 (CA), into a distinct, mature hexagonal lattice during a process termed maturation. The mature HIV-1 virus contains a conical capsid that encloses the condensed viral genome at its wide base. Mutations or small molecules that interfere with viral maturation also disrupt viral infectivity. Little is known about the assembly pathway that results in the conical core and genome encapsidation. Here, we have used electron cryotomography to structurally characterize HIV-1 particles that are actively maturing. Based on the morphologies of core assembly intermediates, we propose that CA forms a sheet-like structure that associates with the condensed viral genome to produce the mature infectious conical core.

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Renner, Nadine, Donna L. Mallery, K. M. Rifat Faysal, Wang Peng, David A. Jacques, Till Böcking, and Leo C. James. "A lysine ring in HIV capsid pores coordinates IP6 to drive mature capsid assembly." PLOS Pathogens 17, no. 2 (February 1, 2021): e1009164. http://dx.doi.org/10.1371/journal.ppat.1009164.

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The HIV capsid self-assembles a protective conical shell that simultaneously prevents host sensing whilst permitting the import of nucleotides to drive DNA synthesis. This is accomplished through the construction of dynamic, highly charged pores at the centre of each capsid multimer. The clustering of charges required for dNTP import is strongly destabilising and it is proposed that HIV uses the metabolite IP6 to coordinate the pore during assembly. Here we have investigated the role of inositol phosphates in coordinating a ring of positively charged lysine residues (K25) that forms at the base of the capsid pore. We show that whilst IP5, which can functionally replace IP6, engages an arginine ring (R18) at the top of the pore, the lysine ring simultaneously binds a second IP5 molecule. Dose dependent removal of K25 from the pore severely inhibits HIV infection and concomitantly prevents DNA synthesis. Cryo-tomography reveals that K25A virions have a severe assembly defect that inhibits the formation of mature capsid cones. Monitoring both the kinetics and morphology of capsids assembled in vitro reveals that while mutation K25A can still form tubes, the ability of IP6 to drive assembly of capsid cones has been lost. Finally, in single molecule TIRF microscopy experiments, capsid lattices in permeabilised K25 mutant virions are rapidly lost and cannot be stabilised by IP6. These results suggest that the coordination of IP6 by a second charged ring in mature hexamers drives the assembly of conical capsids capable of reverse transcription and infection.

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Vinh, Le Quang, and Nguyen Manh Cuong. "Dynamic analysis of FG stepped truncated conical shells surrounded by Pasternak elastic foundations." Vietnam Journal of Mechanics 42, no. 2 (June 29, 2020): 133–52. http://dx.doi.org/10.15625/0866-7136/14749.

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This research presents a continuous element model for solving vibration problems of FG stepped truncated conical shells having various material properties and surrounded by Pasternak foundations. Based on the First Order Shear Deformation Theory (FSDT) and the equations of the FGM conical shells, the dynamic stiffness matrix is obtained for each segment of the shell having constant thickness. The interesting assembly procedure of continuous element method (CEM) is employed for joining those segments in order to analyze the dynamic behavior of the FG stepped truncated conical shells an assembly procedure of continuous element method (CEM) is employed for joining those segments. Free vibrations of different configurations of FG stepped truncated conical shells on elastic foundations are examined. Effects of structural parameters, stepped thickness and elastic foundations on the free vibration of FG stepped truncated conical shells are also presented.

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Zhang, Yiming, Jiqiang Tang, and Tong Wen. "A Modified Transfer Matrix Method for Modal Analysis of Stepped Rotor Assembly Applied in the Turbomolecular Pump." Shock and Vibration 2022 (February 27, 2022): 1–13. http://dx.doi.org/10.1155/2022/3692081.

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An accurate modal analysis of the stepped rotor assembly is significant in the design process of rotors. The transfer matrix method (TMM) is widely used in the modal analysis of the rotor. However, the influences of the step and the assembling modes are not considered in the traditional TMM. In this paper, a modified transfer matrix method is presented for the modal calculation of the rotor in the turbomolecular pump. The stiffness reduction of stepped segments and the effect of assembled components are considered in this modified method. First of all, the traditional transfer matrix model is built. Then, the stepped segments of the rotor are changed into conical segments and the lumped mass model of conical segments is calculated. Next, the conicities of conical segments are analyzed and relations between conicities and dimensions of the rotor are discovered. Finally, the stiffness factors which can describe the effects of different assembling modes are introduced and optimized. The optimized stiffness factors are analyzed and explained from the perspective of contact stress. The modal of the stepped rotor assembly could be computed with high accuracy by using this method.

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Lázaro, Guillermo R., Bogdan Dragnea, and Michael F. Hagan. "Self-assembly of convex particles on spherocylindrical surfaces." Soft Matter 14, no. 28 (2018): 5728–40. http://dx.doi.org/10.1039/c8sm00129d.

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Simulations and continuum theory of self-assembly of conical subunits around a spherocylindrical template show the tuning the template mean curvature, Gaussian curvature, and curvature anisotropy enables the controlled formation of a rich array of assembly geometries.

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Chen, Yan, and Li Bao An. "Simulation of Electric Field for Carbon Nanotube Assembly by Dielectrophoresis." Advanced Materials Research 941-944 (June 2014): 421–24. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.421.

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In the process of carbon nanotube assembly by dielectrophoresis, the geometry and spacing of electrodes are significantly affecting the assembly precision. In the simulation process, we showed the geometrical shape of conical, round and rectangular electrode and compared the electric field distribution with these electrodes. Compared with single electrode pairs, comb electrodes can achieve high-yield manipulation. Simulation results show that when the distance between adjacent electrode pairs is larger than twice electrode width, it will avoid electric field superimposition. A method of using floating metal posts within the electrode gap can realize precise positioning of assembled carbon nanotubes.

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Belarifi, Farid, and E. Bayraktar. "The Tredgold Method in Reverse Engineering to Check the Assembly of a Conical Spur Gear Using CAD." Advanced Materials Research 264-265 (June 2011): 1598–603. http://dx.doi.org/10.4028/www.scientific.net/amr.264-265.1598.

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Defining and generating a working drawing of a conical spur gear to replace an original piece requires geometrical and dimensional constraints, especially when the cutting module is determined by reverse engineering. We propose an approach using Computer aided design (CAD) to establish the drawing definitions and to verify the assembly of the conical spur gear. We have developed the model drawing according to the standard International Standard Organisation (ISO), in which we introduce a new non-existent coast into the current dimensioning and check the assembly using the Tredgold method, which transforms a conical spur gear into a model cylindrical spur gear, to which the equations for parallel cylindrical gearing can be applied. This method determines a good estimate if the couple of gear verifies the specified geometrical conditions of assemblies. We present the developed algorithms, as well as the results of applications of various programs.

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Lepoitevin, Mathilde, Bastien Jamilloux, Mikhael Bechelany, Emmanuel Balanzat, Jean-Marc Janot, and Sebastien Balme. "Fast and reversible functionalization of a single nanopore based on layer-by-layer polyelectrolyte self-assembly for tuning current rectification and designing sensors." RSC Advances 6, no. 38 (2016): 32228–33. http://dx.doi.org/10.1039/c6ra03698h.

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von Schwedler, Uta K., Kirsten M. Stray, Jennifer E. Garrus, and Wesley I. Sundquist. "Functional Surfaces of the Human Immunodeficiency Virus Type 1 Capsid Protein." Journal of Virology 77, no. 9 (May 1, 2003): 5439–50. http://dx.doi.org/10.1128/jvi.77.9.5439-5450.2003.

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ABSTRACT The human immunodeficiency virus type 1 initially assembles and buds as an immature particle that is organized by the viral Gag polyprotein. Gag is then proteolyzed to produce the smaller capsid protein CA, which forms the central conical capsid that surrounds the RNA genome in the mature, infectious virus. To define CA surfaces that function at different stages of the viral life cycle, a total of 48 different alanine-scanning surface mutations in CA were tested for their effects on Gag protein expression, processing, particle production and morphology, capsid assembly, and infectivity. The 27 detrimental mutations fall into three classes: 13 mutations significantly diminished or altered particle production, 9 mutations failed to assemble normal capsids, and 5 mutations supported normal viral assembly but were nevertheless reduced more than 20-fold in infectivity. The locations of the assembly-defective mutations implicate three different CA surfaces in immature particle assembly: one surface encompasses helices 4 to 6 in the CA N-terminal domain (NTD), a second surrounds the crystallographically defined CA dimer interface in the C-terminal domain (CTD), and a third surrounds the loop preceding helix 8 at the base of the CTD. Mature capsid formation required a distinct surface encompassing helices 1 to 3 in the NTD, in good agreement with a recent structural model for the viral capsid. Finally, the identification of replication-defective mutants with normal viral assembly phenotypes indicates that CA also performs important nonstructural functions at early stages of the viral life cycle.

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Fessler, H., T. H. Hyde, and L. V. Lewis. "Assembly stresses and deflection of conical-faced flanges without gaskets." International Journal of Mechanical Sciences 33, no. 8 (January 1991): 623–35. http://dx.doi.org/10.1016/0020-7403(91)90032-x.

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Dharan, Raviv, Asaf Shemesh, Abigail Millgram, Ran Zalk, Gabriel A. Frank, Yael Levi-Kalisman, Israel Ringel, and Uri Raviv. "Hierarchical Assembly Pathways of Spermine-Induced Tubulin Conical-Spiral Architectures." ACS Nano 15, no. 5 (April 26, 2021): 8836–47. http://dx.doi.org/10.1021/acsnano.1c01374.

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Rodal, Avital A., Lukasz Kozubowski, Bruce L. Goode, David G. Drubin, and John H. Hartwig. "Actin and Septin Ultrastructures at the Budding Yeast Cell Cortex." Molecular Biology of the Cell 16, no. 1 (January 2005): 372–84. http://dx.doi.org/10.1091/mbc.e04-08-0734.

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Budding yeast has been a powerful model organism for studies of the roles of actin in endocytosis and septins in cell division and in signaling. However, the depth of mechanistic understanding that can be obtained from such studies has been severely hindered by a lack of ultrastructural information about how actin and septins are organized at the cell cortex. To address this problem, we developed rapid-freeze and deep-etch techniques to image the yeast cell cortex in spheroplasted cells at high resolution. The cortical actin cytoskeleton assembles into conical or mound-like structures composed of short, cross-linked filaments. The Arp2/3 complex localizes near the apex of these structures, suggesting that actin patch assembly may be initiated from the apex. Mutants in cortical actin patch components with defined defects in endocytosis disrupted different stages of cortical actin patch assembly. Based on these results, we propose a model for actin function during endocytosis. In addition to actin structures, we found that septin-containing filaments assemble into two kinds of higher order structures at the cell cortex: rings and ordered gauzes. These images provide the first high-resolution views of septin organization in cells.

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Ganser-Pornillos, Barbie K., Uta K. von Schwedler, Kirsten M. Stray, Christopher Aiken, and Wesley I. Sundquist. "Assembly Properties of the Human Immunodeficiency Virus Type 1 CA Protein." Journal of Virology 78, no. 5 (March 1, 2004): 2545–52. http://dx.doi.org/10.1128/jvi.78.5.2545-2552.2004.

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ABSTRACT During retroviral maturation, the CA protein oligomerizes to form a closed capsid that surrounds the viral genome. We have previously identified a series of deleterious surface mutations within human immunodeficiency virus type 1 (HIV-1) CA that alter infectivity, replication, and assembly in vivo. For this study, 27 recombinant CA proteins harboring 34 different mutations were tested for the ability to assemble into helical cylinders in vitro. These cylinders are composed of CA hexamers and are structural models for the mature viral capsid. Mutations that diminished CA assembly clustered within helices 1 and 2 in the N-terminal domain of CA and within the crystallographically defined dimer interface in the CA C-terminal domain. These mutations demonstrate the importance of these regions for CA cylinder production and, by analogy, mature capsid assembly. One CA mutant (R18A) assembled into cylinders, cones, and spheres. We suggest that these capsid shapes occur because the R18A mutation alters the frequency at which pentamers are incorporated into the hexagonal lattice. The fact that a single CA protein can simultaneously form all three known retroviral capsid morphologies supports the idea that these structures are organized on similar lattices and differ only in the distribution of 12 pentamers that allow them to close. In further support of this model, we demonstrate that the considerable morphological variation seen for conical HIV-1 capsids can be recapitulated in idealized capsid models by altering the distribution of pentamers.

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Zhang, Zhiqing, Maozhou He, Shimeng Bai, Feng Zhang, Jie Jiang, Qingbing Zheng, Shuangquan Gao, et al. "T = 4 Icosahedral HIV-1 Capsid As an Immunogenic Vector for HIV-1 V3 Loop Epitope Display." Viruses 10, no. 12 (November 26, 2018): 667. http://dx.doi.org/10.3390/v10120667.

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The HIV-1 mature capsid (CA) assumes an amorphous, fullerene conical configuration due to its high flexibility. How native CA self-assembles is still unclear despite having well-defined structures of its pentamer and hexamer building blocks. Here we explored the self-assembly of an engineered capsid protein built through artificial disulfide bonding (CA N21C/A22C) and determined the structure of one fraction of the globular particles. CA N21C/A22C was found to self-assemble into particles in relatively high ionic solutions. These particles contained disulfide-bonding hexamers as determined via non-reducing SDS-PAGE, and exhibited two major components of 57.3 S and 80.5 S in the sedimentation velocity assay. Particles had a globular morphology, approximately 40 nm in diameter, in negative-staining TEM. Through cryo-EM 3-D reconstruction, we determined a novel T = 4 icosahedral structure of CA, comprising 12 pentamers and 30 hexamers at 25 Å resolution. We engineered the HIV-1 V3 loop to the CA particles, and found the resultant particles resembled the morphology of their parental particles in TEM, had a positive reaction with V3-specific neutralizing antibodies, and conferred neutralization immunogenicity in mice. Our results shed light on HIV CA assembly and provide a particulate CA for epitope display.

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Ganser, B. K. "Assembly and Analysis of Conical Models for the HIV-1 Core." Science 283, no. 5398 (January 1, 1999): 80–83. http://dx.doi.org/10.1126/science.283.5398.80.

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Turof, Mihaela. "Reconstitution of the geometric elements of a conic gear." Scientific Bulletin of Naval Academy XXIII, no. 1 (July 15, 2020): 55–65. http://dx.doi.org/10.21279/1454-864x-20-i1-008.

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Conical gears are used if the axes of the shafts between which the rotation movement is transmitted are concurrent. The technology of execution of these gears is more demanding, they are more sensitive to the deviations of execution and / or assembly and introduce large axial forces, which complicates, to some extent, the construction of the supports of the wheel support shafts. The straight-toothed conical gears, with relatively simple wheels for technological purposes, are used only at low peripheral speeds (𝑣 < 3 𝑚/𝑠), when step deviations and those of the tooth profiles do not yet produce high dynamic demands and noise. These gears, however, are sensitive to less precise mountings and to deformations, under load, of the support shafts. The calculation of the resistance of the conical gears, in contact and bending, is performed accepting the same calculation assumptions as in the calculation of cylindrical gears with straight teeth. It is, therefore, necessary to make a transition from the conical gear to an imaginary cylindrical gear, called virtual gear, and to find equivalence relations between the two gears - real and virtual.

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Il’inykh, Viktor. "Evaluation of quality parameters of conical profile compounds in nodes of multi-purpose machines." E3S Web of Conferences 140 (2019): 02003. http://dx.doi.org/10.1051/e3sconf/201914002003.

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The article presents a study of the mandrel spindle assembly for accuracy, contact stiffness and strength. The study was made on the basis of conical profile connections with an equiaxed contour. Experiments were carried out for multi-purpose machines of various layouts on the basis of the previously developed program-mathematical complex of evaluating the parameters of the shaft-sleeve coupling. The analysis of the simulation modeling results of the accuracy of the shaft (mandrel) installation in the hole of the sleeve (spindle) is carried out taking into account the error in shape, taper, the magnitude of the assembly force and the external conditional load in the spatial setting. With respect to the three coordinate axes, the possible displacements and rotations of the tool mandrels with a modified shank design are determined when they are based and secured in the spindle. In each design case, the accuracy of the relative position of the parts of the conical profile connections was compared during reusable assembly for the horizontal and vertical machine, respectively, and during the operation of the spindle-mandrel assembly under the condition of an external load. As a result of research, it was found that the layout of the machine does not significantly affect the quality parameters of the profile connection in conditions of reusable assembly. A significant effect of the error in the shape of the mating parts of the connection has been determined, which leads to an increase in maximum contact pressures till 22MPa, a displacement of the mandrel along the Z axis up to 25 µm, and a significant influence on the ultimate external load, which leads to elastic displacements of the mandrel along the Y axis to 2 µm for tapering 1:10.

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Yang, Hsueh-Cheng, and Wen-Jun Liang. "A helical gear with discrete ring-involute teeth." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 234, no. 8 (December 15, 2019): 1554–68. http://dx.doi.org/10.1177/0954406219893392.

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This study produces a skewed-imaginary planar rack cutter with discrete conical teeth that is used to create a helical gear with discrete ring-involute teeth. A mathematical equation for the skewed-imaginary rack cutter with discrete conical teeth is firstly solved. The coordinate system for the rack cutter and gear pair is then established and a family of the rack-cutter surfaces is obtained using homogeneous coordinate transformation. The relative velocity method is used to produce the equation for meshing between the rack cutter and the gear pair. Substituting the equation of meshing into the family of the rack-cutter surfaces gives the mathematical models for the gear pair with discrete ring-involute teeth. The transmission error for the gear pair is calculated using the assembly error and a tooth contact analysis. A computer-aided design software package is used to establish solid model for the gear pair. A software interference function is used to simulate the contact condition for the gear pair for various assembly errors. Finite element analysis software is then used to determine the contact stress for the gear pair. The transmission error and the contact stress for the gear pair are insensitive to any horizontal misalignment in the assembly errors.

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Fontana, Juan, Kellie A. Jurado, Naiqian Cheng, Ngoc L. Ly, James R. Fuchs, Robert J. Gorelick, Alan N. Engelman, and Alasdair C. Steven. "Distribution and Redistribution of HIV-1 Nucleocapsid Protein in Immature, Mature, and Integrase-Inhibited Virions: a Role for Integrase in Maturation." Journal of Virology 89, no. 19 (July 15, 2015): 9765–80. http://dx.doi.org/10.1128/jvi.01522-15.

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ABSTRACTDuring virion maturation, HIV-1 capsid protein assembles into a conical core containing the viral ribonucleoprotein (vRNP) complex, thought to be composed mainly of the viral RNA and nucleocapsid protein (NC). After infection, the viral RNA is reverse transcribed into double-stranded DNA, which is then incorporated into host chromosomes by integrase (IN) catalysis. Certain IN mutations (class II) and antiviral drugs (allosteric IN inhibitors [ALLINIs]) adversely affect maturation, resulting in virions that contain “eccentric condensates,” electron-dense aggregates located outside seemingly empty capsids. Here we demonstrate that in addition to this mislocalization of electron density, a class II IN mutation and ALLINIs each increase the fraction of virions with malformed capsids (from ∼12% to ∼53%). Eccentric condensates have a high NC content, as demonstrated by “tomo-bubblegram” imaging, a novel labeling technique that exploits the susceptibility of NC to radiation damage. Tomo-bubblegrams also localized NC inside wild-type cores and lining the spherical Gag shell in immature virions. We conclude that eccentric condensates represent nonpackaged vRNPs and that either genetic or pharmacological inhibition of IN can impair vRNP incorporation into mature cores. Supplying IN intransas part of a Vpr-IN fusion protein partially restored the formation of conical cores with internal electron density and the infectivity of a class II IN deletion mutant virus. Moreover, the ability of ALLINIs to induce eccentric condensate formation required both IN and viral RNA. Based on these observations, we propose a role for IN in initiating core morphogenesis and vRNP incorporation into the mature core during HIV-1 maturation.IMPORTANCEMaturation, a process essential for HIV-1 infectivity, involves core assembly, whereby the viral ribonucleoprotein (vRNP, composed of vRNA and nucleocapsid protein [NC]) is packaged into a conical capsid. Allosteric integrase inhibitors (ALLINIs) affect multiple viral processes. We have characterized ALLINIs and integrase mutants that have the same phenotype. First, by comparing the effects of ALLINIs on several steps of the viral cycle, we show that inhibition of maturation accounts for compound potency. Second, by using cryoelectron tomography, we find that ALLINIs impair conical capsid assembly. Third, by developing tomo-bubblegram imaging, which specifically labels NC protein, we find that ALLINIs block vRNP packaging; instead, vRNPs form “eccentric condensates” outside the core. Fourth, malformed cores, typical of integrase-deleted virus, are partially replaced by conical cores when integrase is supplied intrans. Fifth, vRNA is necessary for ALLINI-induced eccentric condensate formation. These observations suggest that integrase is involved in capsid morphogenesis and vRNP packaging.

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Bolotov, M. A., V. A. Pechenin, N. V. Ruzanov, and D. M. Balyakin. "Neural network model in digital prediction of geometric parameters for relative position of the aircraft engine parts." Information Technology and Nanotechnology, no. 2416 (2019): 87–94. http://dx.doi.org/10.18287/1613-0073-2019-2416-87-94.

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The quality of aircraft and rocket engines depends primarily on the geometric accuracy of assembly units and parts. Mathematical models implemented in the form of computer models are used to predict quality indicators (in particular, assembly parameters). Direct modeling of the conjugation process using numerical conjugation and finite-element models of assemblies requires significant computational resources and is often accompanied by problems convergence of solutions. In order to solve the above problems, it is possible to use neural network models describing the main regularities of the pairing process based on the accumulated results. The work presents a neural network model for predicting assembly parameters of the parts based on the use of actual surfaces of the parts obtained as a result of mathematical modeling. Assembly on conical surfaces is considered. A convolutional neural network was used to predict assembly parameters.

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Itoh, S., S. Kubota, S. Nagano, and M. Fujita. "On Generation of Ultra-High Pressure by Converging of Underwater Shock Waves." Journal of Pressure Vessel Technology 120, no. 1 (February 1, 1998): 51–55. http://dx.doi.org/10.1115/1.2841884.

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The characteristics of a new assembly for the shock consolidation of difficult-to-consolidate powders, such as inter-metallic compounds or ceramic materials, were investigated by both the experimental method and numerical simulation method. The assembly consists of an explosive container, a water chamber, and a powder container. Once the explosive is detonated, a detonation wave occurs and propagates, and then impinges on the water surface of the water chamber. After that, there occurs immediately an underwater shock wave in the water chamber. The underwater shock wave interacts with the wall of the chamber during its propagation so that its strength is increased by the converging effect. We used the usual shadow graph system to photograph the interaction process between detonation wave and water. We also used a Manganin piezoresistance gage to measure the converged pressure of the conical water chamber. Finally, we numerically investigated, in detail, the converging effects of the various conical water chambers on the underwater shock waves. The experimental results and the correspondingly numerical results agree quite well with each other.

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Mattei, Simone, Annica Flemming, Maria Anders-Össwein, Hans-Georg Kräusslich, John A. G. Briggs, and Barbara Müller. "RNA and Nucleocapsid Are Dispensable for Mature HIV-1 Capsid Assembly." Journal of Virology 89, no. 19 (July 15, 2015): 9739–47. http://dx.doi.org/10.1128/jvi.00750-15.

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ABSTRACTHuman immunodeficiency virus type 1 (HIV-1) is released from infected cells in an immature, noninfectious form in which the structural polyprotein Gag is arranged in a hexameric lattice, forming an incomplete spherical shell. Maturation to the infectious form is mediated by the viral protease, which cleaves Gag at five sites, releasing the CA (capsid) protein, which forms a conical capsid encasing the condensed RNA genome. The pathway of this structural rearrangement is currently not understood, and it is unclear how cone assembly is initiated. RNA represents an integral structural component of retroviruses, and the viral nucleoprotein core has previously been proposed to nucleate mature capsid assembly. We addressed this hypothesis by replacing the RNA-binding NC (nucleocapsid) domain of HIV-1 Gag and the adjacent spacer peptide 2 (SP2) by a leucine zipper (LZ) protein-protein interaction domain [Gag(LZ)] in the viral context. We found that Gag(LZ)-carrying virus [HIV(LZ)] was efficiently released and viral polyproteins were proteolytically processed, though with reduced efficiency. Cryo-electron tomography revealed that the particles lacked a condensed nucleoprotein and contained an increased proportion of aberrant core morphologies caused either by the absence of RNA or by altered Gag processing. Nevertheless, a significant proportion of HIV(LZ) particles contained mature capsids with the wild-type morphology. These results clearly demonstrate that the nucleoprotein complex is dispensable as a nucleator for mature HIV-1 capsid assembly in the viral context.IMPORTANCEFormation of a closed conical capsid encasing the viral RNA genome is essential for HIV-1 infectivity. It is currently unclear what viral components initiate and regulate the formation of the capsid during virus morphogenesis, but it has been proposed that the ribonucleoprotein complex plays a role. To test this, we prepared virus-like particles lacking the viral nucleocapsid protein and RNA and analyzed their three-dimensional structure by cryo-electron tomography. While most virions displayed an abnormal morphology under these conditions, some particles showed a normal mature morphology with closed conical capsids. These data demonstrate that the presence of RNA and the nucleocapsid protein is not required for the formation of a mature, cone-shaped HIV-1 capsid.

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Santus, Ciro, L. Bertini, and M. Beghini. "Fretting Fatigue Apparatus for Shrink-Fitted Shaft Assembly." Applied Mechanics and Materials 7-8 (August 2007): 43–48. http://dx.doi.org/10.4028/www.scientific.net/amm.7-8.43.

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The present paper proposes a new test rig to perform fretting fatigue tests on a shrinkfitted shaft assembly. A shrink-fitted shaft is put under rotating bending by means of an eccentric offset at one end. The shaft is driven near to its first resonance condition to significantly reduce the required force to produce bending. Test parameters are the imposed bending stress amplitude, and the hub radial pressure obtained through conical fitting. The proposed apparatus allows for changing bending stress amplitude and hub pressure to generate fretting fatigue tests at different conditions. In particular, the role of slip amplitude in fretting fatigue can be investigated. At the present stage the proposed apparatus is under construction at the Mechanical Department of the University of Pisa.

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Мещеряков, Sergey Meshcheryakov, Романович, Aleksey Romanovich, Воронов, Vitaliy Voronov, Апухтина, and Inna Apukhtina. "ASSEMBLY FOR GRINDING PRESSURE AND DISAGGREGATION PRESSED MATERIALS." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 2, no. 1 (December 8, 2016): 144–49. http://dx.doi.org/10.12737/24018.

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The article describes the design of a pilot plant PVI includes a feed hopper mounted on the frame of the conical rolls and designersusa device, which consists of additional rolls with a reverse taper rolls the main. allows to combine the processes of comminution and disaggregation of compressed materi-als. We theoretically studied the implementation of directional movement pressed into the plate material from the main to the additional rolls desagglomeration device. Presents an analysis of the graphic curves constructed according to the obtained equations for the linear size of the capture zone dezagregarea rolls plates of pressed material. It is concluded that the intensive change of the angle is on the interval from zero to 0.25 meters, which should be taken into account when designing the press roller cutter device for desagglomeration materials.

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Wu, S. H., and S. J. Tsai. "Geometrical design of skew conical involute gear drives in approximate line contact." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 223, no. 9 (April 24, 2009): 2201–11. http://dx.doi.org/10.1243/09544062jmes1340.

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A novel design for skew conical involute gear drives in approximate line contact is proposed. Such a drive has a contact ellipse with a large major-to-minor-axis ratio, which allows it to overcome the weakness of conical gear drives for application in power transmission. This gearing design approach is characterized by reduced edge contact sensitivity and increased surface durability. The edge contact sensitivity that can arise with this kind of gear drive due to assembly or manufacturing errors is evaluated by analysing the value of the shift of the line of action caused by such errors. The surface durability is evaluated by calculating the Hertz stress. Some guidelines are developed based on the analysis of the influence of the gearing parameters on the edge contact sensitivity and the surface durability made possible using this design approach for conical gear drives in the approximate line contact. The guidelines are summarized and, finally, a practical example is given to demonstrate the feasibility of the approximate line contact design.

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Pawar, Sanjay R., and Vikas M. Phalle. "Effect of wear on the performance of hole entry hybrid conical journal bearing employing constant flow valve compensation." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 233, no. 9 (March 21, 2019): 1277–92. http://dx.doi.org/10.1177/1350650119838078.

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Hybrid bearings gets worn gradually during the start and stop operation. This wearing leads to change in the geometry of bearing and affects the radical clearance as well as fluid film thickness. Therefore, these discontinuities in the radial clearance can influence the performance characteristics. With the purpose of preventing irreparable failure state of bearing assembly, it is essential to concentrate on the actual changes in the performance parameters of hole entry hybrid conical journal bearing due to wear. In this context, the main aim of this analysis is to predict the performance of hole entry hybrid conical journal bearing employing constant flow valve compensation. Modified Reynolds equation in spherical coordinate form is used to govern the flow of lubricant in the narrow region between journal and conical bearing. The solution to this Reynolds equation is obtained by finite element analysis with appropriate boundary conditions. This paper summarizes that for a given bearing with constant flow valve as compensating element, the wear causes variation in lubricant film thickness, which strongly affects load capacity, pressure generated, and dynamic performance parameters.

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Abramov, I. V., F. F. Fattiev, D. M. Gurkov, S. V. Tanygin, and B. I. Korotkov. "Manufacture of conical joints for the assembly of sections of paper-making equipment." Chemical and Petroleum Engineering 22, no. 4 (April 1986): 146–47. http://dx.doi.org/10.1007/bf01149243.

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Dehtiarov, Ivan, Anna Neshta, Mykola Samardak, Vitalii Kononovych, and Yaroslav Klok. "Analysis of geometric parameters and technical requirements for pin conical joints in pump nodes." Bulletin of the National Technical University «KhPI» Series: New solutions in modern technologies, no. 4 (10) (December 30, 2021): 24–35. http://dx.doi.org/10.20998/2413-4295.2021.04.04.

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The article analyzes the causes of the situation with the appearance of manufacturing errors and the lack of the necessary technical requirements to perform a pin conical joint his intended purpose. The analysis was performed based on geometric construction of the assembly dimensional chain of two parts to be connected and a conical pin with a taper 1:50 according to GOST 9465-79, which is used in the pin joints of pumping equipment. The geometric analysis included the separation of deviations into linear dimensions and angular deviations. The values of the angular deviations were reduced to the linear values of their projections along the axis of the pin, to determine the tolerance on the end height protrusion of the pin above the surface of the connecting parts. Also, the unfoundedness of assigning the roughness index of the hole under the pin at the level of Ra 1.6 μm and its inexpediency when it is impossible to ensure the required contact length is theoretically proved and the solution of this contradiction is proposed. A detailed analysis of the technical requirements for drawings of pumping equipment units containing pin conical joints and paragraphs of the relevant standards, which resulted in the inconsistencies, and offer recommendations that will ensure the quality of the joint following its official purpose. Analysis of the geometric parameters of pin conical joints for the first time allowed to determine the dependence of the height of the pin end protrusion above the surface of the connecting parts and the tolerance for this parameter, as well as to propose mathematical dependences for their determination. The presented dependencies can be used in practice for a reasonable calculation during the design of pin conical joints in pump nodes and in machine-building enterprises where such joints are used. For the first time, the determination of the tolerance for hole size for machining conical reamers is presented, and the formula for calculating this parameter is proposed, which is given in the recommendations for their use in machine building enterprises and products containing pin conical joints.

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Arasu, S., and A. Krishnamoorthy. "Design and Manufacturing of Conical Vent Profile Disc Brake." Applied Mechanics and Materials 766-767 (June 2015): 1028–33. http://dx.doi.org/10.4028/www.scientific.net/amm.766-767.1028.

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Braking system is one amongst the foremost vital contact mechanisms in an automobile. The braking potency in automobile depends on the desertion characteristics of the constraint assembly. The heat refusal from the system is proportional to the desertion of brake. This paper aims to bring out producing, testing of conical shape vent profile and studies of existing cooling vent profile heat refusal throughout the braking. This result reduces the thermal and structural stress on the brake plate. The prevailing vehicles brakes has been made from cylindrical vent profiles that in theory has lesser cooling potency because the direction of the air flow .The profile favor to increase the cooling potency by conical shape vent. The vent is reshaped in such some way that the face of the round shape vent is within the direction of air flow throughout vehicle motion that permits a lot of quantity of air to flow across the brake plate. This style changes results to extend the heat convey rate throughout the braking

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Ovejero, César A., Silvia A. González, and José L. Affranchino. "The Conserved Tyr176/Leu177 Motif in the α-Helix 9 of the Feline Immunodeficiency Virus Capsid Protein Is Critical for Gag Particle Assembly." Viruses 11, no. 9 (September 4, 2019): 816. http://dx.doi.org/10.3390/v11090816.

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The capsid domain (CA) of the lentiviral Gag polyproteins has two distinct roles during virion morphogenesis. As a domain of Gag, it mediates the Gag–Gag interactions that drive immature particle assembly, whereas as a mature protein, it self-assembles into the conical core of the mature virion. Lentiviral CA proteins are composed of an N-terminal region with seven α-helices and a C-terminal domain (CA-CTD) formed by four α-helices. Structural studies performed in HIV-1 indicate that the CA-CTD helix 9 establishes homodimeric interactions that contribute to the formation of the hexameric Gag lattice in immature virions. Interestingly, the mature CA core also shows inter-hexameric associations involving helix 9 residues W184 and M185. The CA proteins of feline immunodeficiency virus (FIV) and equine infectious anemia virus (EIAV) exhibit, at equivalent positions in helix 9, the motifs Y176/L177 and L169/F170, respectively. In this paper, we investigated the relevance of the Y176/L177 motif for FIV assembly by introducing a series of amino acid substitutions into this sequence and studying their effect on in vivo and in vitro Gag assembly, CA oligomerization, mature virion production, and viral infectivity. Our results demonstrate that the Y176/L177 motif in FIV CA helix 9 is essential for Gag assembly and CA oligomerization. Notably, mutations converting the FIV CA Y176/L177 motif into the HIV-1 WM and EIAV FL sequences allow substantial particle production and viral replication in feline cells.

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Bołoz, Łukasz. "Directions for increasing conical picks’ durability." New Trends in Production Engineering 2, no. 1 (October 1, 2019): 277–86. http://dx.doi.org/10.2478/ntpe-2019-0029.

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Abstract Conical picks are cutting tools used in many branches, in particular in the mining, road construction and building branch. Contact with the excavated face causes their constant wear, which is an unfavorable but unavoidable process. Milling heads of working machines are equipped with several dozen conical picks, and mining in abrasive or hardly accessible rocks can reduce their life to a few hours. It is in the interest of both users and producers to increase their durability, as tools replacement, apart from purchase and logistic costs, results in machine downtimes. In the article various solutions of conical picks, their construction, dimensions and materials used have been discussed. Technical procedures applied to increase the durability of conical picks and their regeneration as well as methods of extending the life of picks working in difficult conditions have been presented. Two author’s methods of extending the life of picks working in difficult conditions, covered by a patent application, have also been presented. The first solution involves ensuring an uninterrupted rotational movement of the pick in the holder. Patent claims include an innovative method of equipping the additional sleeve integrated with the holder with a rotational bearing, which enables a continuous rotation of the pick. The tool equipped with a bearing generates much lower movement resistance than the standard mounting. The holder is designed to mount classic commercial picks. What is important, the pick replacement does not require interfering with the bearing assembly. The second solution concerns the manner of protecting the working part of the pick by means of a special element made of an abrasion resisting material. This element is the pick tip, the geometry of which varies from the commonly applied posts made of sintered carbide. In this solution, the tip has a shape corresponding to the form of conical pick’s wear, which causes that its steel body does not wear. Moreover, there is a possibility of applying a mobile, rotational mounting of the tip to the body.

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Harvey, James E. "Image degradation due to assembly and alignment errors in conical foil x‐ray telescopes." Optical Engineering 35, no. 10 (October 1, 1996): 3037. http://dx.doi.org/10.1117/1.600954.

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Zhong, Yu-Wu, Yutaka Matsuo, and Eiichi Nakamura. "Lamellar Assembly of Conical Molecules Possessing a Fullerene Apex in Crystals and Liquid Crystals." Journal of the American Chemical Society 129, no. 11 (March 2007): 3052–53. http://dx.doi.org/10.1021/ja068780k.

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Ilyinykh, V. A. "Application of conical profile spindle-mandrel joints in multi-purpose machines." Omsk Scientific Bulletin, no. 175 (2021): 12–16. http://dx.doi.org/10.25206/1813-8225-2021-175-12-16.

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The article deals with the solution of the problem of improving the quality of torque transmission connections of spindle units of multi-purpose machines. The aim of the work is to determine the contact stiffness of the spindle-mandrel joints of various types, based on the conducted simulation experiments of the assembly and disassembly process of auxiliary tools of various structural forms, in conditions of reusable replacements. A comparative analysis of the mathematical expectations of contact stiffness of traditional and non-traditional conical profile split joints based on an equiaxial contour with a number of faces equal to three under external loading conditions is performed. The results obtained allow us to predict the quality indicators of multi-purpose machines in the design of quick-release connections

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Yoon, Joonsik, Minjoo Noh, Jun Bae Lee, and Jun Hyup Lee. "Highly Sustainable and Completely Amorphous Hierarchical Ceramide Microcapsules for Potential Epidermal Barrier." Polymers 12, no. 9 (September 22, 2020): 2166. http://dx.doi.org/10.3390/polym12092166.

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As a main component of the stratum corneum, ceramides can construct protective lamellae to provide an epidermal barrier against dehydration or external microorganisms. However, as ceramide molecules can easily form the isolated crystalline phase through self-assembly due to the amphipathic nature of bioactive lipids, the effective incorporation of ceramides into liquid media is the remaining issue for controlled release. Here, we report an unprecedented effective strategy to fabricate a completely amorphous and highly sustainable hierarchical ceramide polymer microcapsule for promising epidermal barrier by using the interpenetrating and cooperative self-construction of conical amphiphiles with a different critical packing parameter. The self-constructed amorphous architecture of ceramides in polymer microcapsule is achieved by the facile doping of conical amphiphiles and subsequent in situ polymerization of shell polymer in the core-shell geometry. It is experimentally revealed that an irregular cooperative packing structure formed by adaptive hydrophobic–hydrophilic interactions of cylindrical ceramides and conical amphiphiles in the confined microcapsule geometry enables a completely amorphous morphology of ceramides to be realized during the spontaneous encapsulation process. Furthermore, this elegant approach affords a highly dispersible and uniform hierarchical amorphous ceramide microcapsule with a greatly enhanced long-term stability compared to conventional crystalline ceramides.

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Chang, Y. Y., C. R. Chen, P. Chen, J. J. Huang, M. A. Huang, T. C. Liu, J. W. Nam, et al. "Inverted-conical light guide for crosstalk reduction in tightly-packed scintillator matrix and MAPMT assembly." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 771 (January 2015): 55–65. http://dx.doi.org/10.1016/j.nima.2014.10.037.

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38

Yang, Hsueh-Cheng, and Chih-Yao Sun. "Using a planar rack cutter with variable modulus to generate a spherical gear pair." Transactions of the Canadian Society for Mechanical Engineering 44, no. 1 (March 1, 2020): 108–20. http://dx.doi.org/10.1139/tcsme-2018-0265.

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In this study, an imaginary planar rack cutter with variable modulus and discrete conical teeth was used to generate a spherical gear pair with double degree of freedom. First, a geometric method was used to design the mathematical model of the imaginary planar rack cutter with variable modulus and discrete conical teeth. Next, the relationship of coordinate systems between the generating and generated surfaces was established. Then, the family of the imaginary planar rack cutter surfaces was obtained by homogeneous coordinate transformation matrix. Further, two equations of meshing between the generating and generated surfaces were determined by the two-parameter envelope theory. The mathematical model of spherical gear pair with variable modulus and discrete ring-involute teeth can be created by using the two equations of meshing and the family of the imaginary planar rack cutter surfaces. The mathematical models of the spherical gear pair with double degree of freedom and tooth contact analysis method were used to investigate the assembly errors of the gear pair in four cases.

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39

Radermacher, M., V. Rao, R. Grassucci, J. Frank, A. P. Timerman, S. Fleischer, and T. Wagenknecht. "Cryo-electron microscopy and three-dimensional reconstruction of the calcium release channel/ryanodine receptor from skeletal muscle." Journal of Cell Biology 127, no. 2 (October 15, 1994): 411–23. http://dx.doi.org/10.1083/jcb.127.2.411.

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The calcium release channel (CRC) from skeletal muscle is an unusually large tetrameric ion channel of the sarcoplasmic reticulum, and it is a major component of the triad junction, the site of excitation contraction coupling. The three-dimensional architecture of the CRC was determined from a random conical tilt series of images extracted from electron micrographs of isolated detergent-solubilized channels prepared in a frozen-hydrated state. Three major classes of fourfold symmetric images were identified, and three-dimensional reconstructions were determined for two of these. The two independent reconstructions were almost identical, being related to each other by a 180 degrees rotation about an axis in the plane of the specimen grid. The CRC consists of a large cytoplasmic assembly (29 x 29 x 12 nm) and a smaller transmembrane assembly that protrudes 7 nm from one of its faces. A cylindrical low-density region, 2-3 nm in apparent diameter, extends down the center of the transmembrane assembly, and possibly corresponds to the transmembrane Ca(2+)-conducting pathway. At its cytoplasmic end this channel-like feature appears to be plugged by a globular mass of density. The cytoplasmic assembly is apparently constructed from 10 or more domains that are loosely packed together such that greater than 50% of the volume enveloped by the assembly is occupied by solvent. The cytoplasmic assembly is suggestive of a scaffolding and seems well adapted to maintain the structural integrity of the triad junction while allowing ions to freely diffuse to and away from the transmembrane assembly.

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Collas, Philippe. "Cytoplasmic control of nuclear assembly." Reproduction, Fertility and Development 10, no. 8 (1998): 581. http://dx.doi.org/10.1071/rd98049.

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The reconstitution of a replication-competent, transcriptionally active nucleus following mitosis, fertilization or nuclear transplantation involves a stepwise series of reactions, most (if not all) of which are controlled by the cytoplasmic environment. This review discusses the nature of cytoplasmic contributions to the development of the male pronucleus at fertilization, and the effect of altering the cytoplasmic environment on nuclear assembly. The system used to investigate these regulations consists of permeabilized sea urchin sperm nuclei incubated under controlled conditions in a cell-free extract of fertilized sea urchin eggs. (1) In egg cytoplasmic extract, male pronuclear formation is initiated by the disassembly of the sperm nuclear lamina as a result of lamin phosphorylation by a cytosolic protein kinase C. (2) Sperm histones are phosphorylated by an as yet unidentified soluble kinase. (3) The conical sperm nucleus decondenses into a spherical pronucleus in an ATP-and cytosolic pH-dependent manner. (4) Chromatin decondensation is associated with the replacement of sperm histones by maternal histones. (5) Nuclear membranes form by ATP-dependent binding of vesicles to chromatin and GTP-dependent fusion of these vesicles to one another. (6) Three cytoplasmic vesicle populations with distinct biochemical, chromatin-binding and fusion properties are required for nuclear envelope assembly. (7) Targeting of the bulk of nuclear membrane vesicles to chromatin is mediated by an integral membrane protein similar to human lamin B receptor. (8) The last step of male pronuclear formation, nuclear swelling, is promoted by the assembly of nuclear pores, nuclear import of soluble lamins and growth of the nuclear membranes. (9) Once inside the nucleus, lamin B associates with lamin B receptors, presumably to tether the inner nuclear membrane with the lamina. Overall, these processes are similar to those characterizing nuclear reconstitution after mitosis in somatic cells or nuclear remodeling following transplantation into oocytes or eggs. The influence of the egg cytoplasmic environment on some aspects of nuclear remodeling after nuclear transplantation is also discussed.

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41

Sofiienko, Andrii, Chad Jarvis, and Ådne Voll. "Monte Carlo Simulations of a Scanning System Based on a Panoramic X-Ray Tube with a Conical Anode." Physics Research International 2014 (August 21, 2014): 1–9. http://dx.doi.org/10.1155/2014/847651.

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Monte Carlo simulations were used to study photon production in a panoramic X-ray tube with a conical tungsten target to determine the optimal characteristics of the target shape and electron beam configuration. Several simulations were performed for accelerating potentials equal to 250 kV, 300 kV, and 500 kV with electron beams of various radii and anode sizes. The angular distribution of the photon intensity was analysed by numerical calculations for an assembly composed of an X-ray tube and an external collimator with a cylindrical hole to simulate a panoramic scanning system with an X-ray pencil beam.

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Kadam, Sanket Shankar, N. M. Virupakshappa, and U. Achutha Kini. "Root cause analysis of rough conical seat grinding problem in fuel pump cylinder head by Shainin methodology." MATEC Web of Conferences 144 (2018): 05009. http://dx.doi.org/10.1051/matecconf/201814405009.

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Problem solving plays a major role in quality engineering and it is popularly adopted by manufacturing industry. This study is aimed to determine root cause for rejection of cylinder head due to rough conical grinding problem by Shainin method. This has two major parts, first is diagnostic part which involves finding out the root cause and second is a remedial action part which consist of actual application of findings to rule out the problem. Wear in tool holder assembly is identified as root cause for rough grinding problem. Converging to root cause and validating the same achieved by successful implementation of Shainin tools.

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Accola, Molly A., Stefan Höglund, and Heinrich G. Göttlinger. "A Putative α-Helical Structure Which Overlaps the Capsid-p2 Boundary in the Human Immunodeficiency Virus Type 1 Gag Precursor Is Crucial for Viral Particle Assembly." Journal of Virology 72, no. 3 (March 1, 1998): 2072–78. http://dx.doi.org/10.1128/jvi.72.3.2072-2078.1998.

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ABSTRACT The capsid (CA) and nucleocapsid domains of the human immunodeficiency virus type 1 Gag polyprotein are separated by the p2 spacer peptide, which is essential for virus replication. Previous studies have revealed that p2 has an important role in virus morphogenesis. In this paper, we show that a crucial assembly determinant maps to the highly conserved N terminus of p2, which is predicted to form part of an α-helix that begins in CA. A mutational analysis indicates that the ability of the N terminus of p2 to adopt an α-helical structure is essential for its function during virus assembly. To prevent CA-p2 processing, it was necessary to mutate both the CA-p2 cleavage site and an internal cleavage site within p2. Virions produced by the double mutant lacked a conical core shell and instead contained a thin electron-dense shell about 10 nm underneath the virion membrane. These results suggest that p2 is transiently required for proper assembly, but needs to be removed from the C terminus of CA to weaken CA-CA interactions and allow the rearrangement of the virion core shell during virus maturation.

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Carrascosa, J. L., G. Abella, S. Marco, M. Muyal, and J. M. Carazo. "Three-Dimensional Reconstruction of Two Forms of the Chaperonin GRO EL." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 1 (August 12, 1990): 258–59. http://dx.doi.org/10.1017/s0424820100180045.

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Chaperonins are a class of proteins characterized by their role as morphogenetic factors. They trantsiently interact with the structural components of certain biological aggregates (viruses, enzymes etc), promoting their correct folding, assembly and, eventually transport. The groEL factor from E. coli is a conspicuous member of the chaperonins, as it promotes the assembly and morphogenesis of bacterial oligomers and/viral structures.We have studied groEL-like factors from two different bacteria:E. coli and B.subtilis. These factors share common morphological features , showing two different views: one is 6-fold, while the other shows 7 morphological units. There is also a correlation between the presence of a dominant 6-fold view and the fact of both bacteria been grown at low temperature (32°C), while the 7-fold is the main view at higher temperatures (42°C). As the two-dimensional projections of groEL were difficult to interprete, we studied their three-dimensional reconstruction by the random conical tilt series method from negatively stained particles.

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Yang, S.-C. "A study of an elbow mechanism generated by a conical cutter." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 221, no. 6 (June 1, 2007): 727–38. http://dx.doi.org/10.1243/0954406jmes193.

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This paper presents a method for determining the mathematical model of an elbow mechanism with a convex tooth and a concave tooth. Based on this method, the mathematical model presents the meshing principles of a conical cutter meshed with a tooth that is either convex or concave. Using the developed mathematical models and the tooth contact analysis, kinematic errors are investigated according to the obtained geometric modelling of the designed gear meshing when assembly errors are present. The influence of misalignment on kinematic errors has been investigated. The goal of the current study is to investigate von-Mises stress for three teeth contact pairs. A structural load is assumed to act on a gear of the proposed mechanism. The von-Mises of the proposed gear is determined. The conical cutter used in the design and manufacture of the convex and concave gear is shown. For example, the proposed mechanism with a transmission ratio of 3:2 was determined with the aid of the proposed mathematical model. Using rapid prototyping and manufacturing technology, an elbow mechanism with a convex gear, a concave gear and a frame was designed. The RP primitives provide an actual full-size physical model that can be analysed and used for further development. Results from these mathematical models are applicable to the design of an elbow mechanism.

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Ruan, Bo. "A Semi-Analytical Solution to the Dynamic Tracking of Non-contacting Gas Face Seals." Journal of Tribology 124, no. 1 (June 13, 2001): 196–202. http://dx.doi.org/10.1115/1.1398292.

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The gas film stiffness and damping coefficients for a non-contacting gas face seal are obtained from the unsteady nonlinear Reynolds equation using the perturbation method. The seal assembly is converted to an equivalent spring-damper-mass system. The stator tracking motion is treated as a forced vibration caused by the rotor motion due to its runout and misalignment. The seal steady-state dynamic responses are solved semianalytically. Results for a typical spiral groove gas face seal agree well with that from a full numerical simulation. Stability of the seal axial pulsating and conical whirl are examined using the frequency dependent dynamic force and moment coefficients.

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47

Geints, Yu E., A. A. Zemlyanov, and E. K. Panina. "Peculiarities of the formation of an ensemble of photonic nanojets by a micro-assembly of conical particles." Quantum Electronics 49, no. 3 (March 15, 2019): 210–15. http://dx.doi.org/10.1070/qel16868.

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KUMAKURA, Susumu, Kumiko SAITO, and Goro FUKUOKA. "509 On the self-loosening characteristics of nut assembly with conical spring washer under repeated tensile loads." Proceedings of Yamanashi District Conference 2004 (2004): 141–42. http://dx.doi.org/10.1299/jsmeyamanashi.2004.141.

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Rojas-Sola, José Ignacio, and Eduardo De la Morena-De la Fuente. "The Conical Stones Olive Oil Mill: Analysis through Computer-Aided Engineering." Agriculture 10, no. 7 (July 1, 2020): 255. http://dx.doi.org/10.3390/agriculture10070255.

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This article analyzes an olive oil mill formed of four conical stones used in the milling of the olive. To this end, a study of computer-aided engineering (CAE) was carried out using the parametric software Autodesk Inventor Professional, consisting of a static analysis using the finite-element method (FEM) of the three-dimensional (3D) model of the mill under real operating conditions. The results obtained revealed that the conical stones mill was a very robust machine. When studying the assembly in the most unfavorable situation (blockage of one of its millstones), we observed that the element with the highest von Mises stress was the bearing nut, reaching a value of 263.9 MPa, which was far from the elastic limit of cast iron (758 MPa). On the other hand, the machine hardly presented any equivalent deformations or displacements that could jeopardize the operation as a whole. The maximum displacement obtained was 2.494 mm in the inertia flywheel, and the equivalent deformations did not reach 0.1% of the part dimension. Similarly, the element with the lowest safety coefficient (2.87) was the same bearing nut with the highest von Mises stress, although the next element with the second lowest safety coefficient had a value of 8.69, which showed that the set was clearly oversized. These results demonstrate the convenience of redesigning the set in order to resize some of its elements, and that they could have lower safety coefficients of between 2 and 4. After an initial analysis, the resizable elements would fundamentally be those related to the movement transmission system and the frame structure.

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Wang, Chun'e, and Jiqiang Tang. "Design and Mathematical Analysis of a Novel Reluctance Force-Type Hybrid Magnetic Bearing for Flywheel with Gimballing Capability." Mathematical Problems in Engineering 2013 (2013): 1–17. http://dx.doi.org/10.1155/2013/836058.

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Magnetically suspended flywheel (MSFW) with gimballing capability fulfills requirements of precision and maneuvers for space applications. A novel reluctance force-type hybrid magnetic bearing (RFHMB) is presented based on analysis of demerits of Lorentz force-type magnetic bearing and common RFHMB. It features that radial and axial magnetic bearing units are integrated into a compact assembly with four separate biased permanent magnets and two conical stators; four radial poles with shoes and rotor made of iron-based amorphousness can reduce eddy loss. Equivalent magnetic circuits of permanent magnets and their control currents are presented. Simulation results indicate flux density fluctuates from 0.272 T to 0.41 T; rotor tilting does not affect the suspension force when rotor only tilts aroundX-axis orY-axis. When rotor drifts inX,Y, orZdirection and tilts aroundX-axis orY-axis simultaneously, force in corresponding directions slightly increases with tilting angle’s enlargement, but the maximum change does not exceed 14%. Additional tilting torque mainly determined by uniformity of flux density in conical air gaps is 0.05 Nm which is far smaller than 11 Nm in common RFHMB; magnetic suspension force is effectively decoupled amongX,Y, andZdirections; results prove that MSFW with gimballing capability theoretically meets maneuvering requirement of spacecraft.

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Journal articles on the topic 'Conical assembly'

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