The nonstationary thermoelectric elasticity problem for a long piezoceramic cylinder

А new closed-loop solution for the coupled nonstationary problem of thermoelectric elasticity is designed for a long piezoceramic radially polarized cylinder. The case of the nonstationary load acting on its inner cylindrical surface is considered as a function of temperature change at a given law of the convection heat exchange on the outer face wall (boundary conditions of heat conductivity of the 1st and 3rd types). Electrodynamic cylinder surfaces are connected to a measuring device with a high input resistance (electric idling). We investigate the problem where the rate of the temperature load changes does not affect the inertial characteristics of the elastic system. It makes it possible to expand the initial linear computational relations with the equilibrium, electrostatics and heat conductivity equations with respect to the radial component of the displacement vector, electric potential as well as the function of temperature field changes. Hyperbolic LS-theory of the thermal conductivity is used in the computations. The problem is solved with a generalized method of biorthogonal finite integral transformation based on a multicomponent ratio of eigen functions of two homogeneous boundary value problems. The structural algorithm of this approach allows identifying a conjugated operator, without which it is impossible to solve non-self-conjugated linear problems in mathematical physics. The resulted computational relations make it possible to determine the stress-strain state, temperature and electric fields induced in the piezoceramic element under an arbitrary external temperature effect. By connecting the electroelastic system to the measuring tool, we can find voltage. Firstly, the analysis of the numerical results allows identifying the rate of the temperature load changes, at which it is necessary to use the hyperbolic theory of thermal conductivity. Secondly, it allows determining the physical characteristics of the piezoceramic material for the case when the rate of changing the body volume leads to a redistribution of the temperature field. The developed computational algorithm can be used to design non-resonant piezoelectric temperature sensors.

Experimental assessment for the thermal performance of scrap tire blocks as external wall insulators

In this paper, the advantage of reusing scrap tires in Scrap Rubber Block (SRB) to improve thermal insulation in buildings was examined experimentally. By testing the use of SRB in black and white colours as external wall insulators and comparing their performance with walls without insulation. The results indicated that a wall with scrap tire blocks gave the best thermal insulation results when the outer face was painted white. The decrement factor (f) and the rate of heat loss increase, while the rate of heat gain decreases. This was done through the mechanisms of heat transfer by conduction through the layers of the wall and the effect of adding the rubber block on its thermal properties. The results showed that the use of rubber blocks reduces the temperature of the inner surface of the wall by 3-4oC lower than the traditional wall. The thermal diffusion inside the wall was determined effectively in the case of a wall with the rubber block, where the temperature of the inner surface reaches its maximum value by about 0.5-hour difference from the traditional wall in the case of the wall with the rubber block in black colour, and 9.5-hour in the case with the white block.

The Role of Capsid in HIV-1 Nuclear Entry

HIV-1 can infect non-dividing cells. The nuclear envelope therefore represents a barrier that HIV-1 must traverse in order to gain access to the host cell chromatin for integration. Hence, nuclear entry is a critical step in the early stages of HIV-1 replication. Following membrane fusion, the viral capsid (CA) lattice, which forms the outer face of the retroviral core, makes numerous interactions with cellular proteins that orchestrate the progress of HIV-1 through the replication cycle. The ability of CA to interact with nuclear pore proteins and other host factors around the nuclear pore determines whether nuclear entry occurs. Uncoating, the process by which the CA lattice opens and/or disassembles, is another critical step that must occur prior to integration. Both early and delayed uncoating have detrimental effects on viral infectivity. How uncoating relates to nuclear entry is currently hotly debated. Recent technological advances have led to intense discussions about the timing, location, and requirements for uncoating and have prompted the field to consider alternative uncoating scenarios that presently focus on uncoating at the nuclear pore and within the nuclear compartment. This review describes recent advances in the study of HIV-1 nuclear entry, outlines the interactions of the retroviral CA protein, and discusses the challenges of investigating HIV-1 uncoating.

The molecular basis of regulation of bacterial capsule assembly by Wzc

Bacterial extracellular polysaccharides (EPSs) play critical roles in virulence. Many bacteria assemble EPSs via a multi-protein “Wzx-Wzy” system, involving glycan polymerization at the outer face of the cytoplasmic/inner membrane. Gram-negative species couple polymerization with translocation across the periplasm and outer membrane and the master regulator of the system is the tyrosine autokinase, Wzc. This near atomic cryo-EM structure of dephosphorylated Wzc from E. coli shows an octameric assembly with a large central cavity formed by transmembrane helices. The tyrosine autokinase domain forms the cytoplasm region, while the periplasmic region contains small folded motifs and helical bundles. The helical bundles are essential for function, most likely through interaction with the outer membrane translocon, Wza. Autophosphorylation of the tyrosine-rich C-terminus of Wzc results in disassembly of the octamer into multiply phosphorylated monomers. We propose that the cycling between phosphorylated monomer and dephosphorylated octamer regulates glycan polymerization and translocation.

The cryo-EM structure of vesivirus 2117 highlights functional variations in entry pathways for viruses in different clades of the Vesivirus genus.

Vesivirus 2117 is an adventitious agent that has been responsible for lost productivity in biopharmaceutical production following contamination of Chinese hamster ovary cell cultures in commercial bioreactors. A member of the Caliciviridae, 2117 is classified within the Vesivirus genus in a clade that includes canine and mink caliciviruses but is distinct from the vesicular exanthema of swine clade, which includes the extensively studied feline calicivirus (FCV). We have used cryogenic electron microscopy (cryo-EM) to determine the structure of the capsid of this small, icosahedral, positive-sense RNA containing virus. We show that the outer face of the dimeric capsomeres, which contains the receptor binding site and major immunodominant epitopes in all caliciviruses studied thus far, is quite different from that of FCV. This is a consequence of a 22 amino-acid insertion in the sequence of the FCV major capsid protein that forms a ‘cantilevered arm’, which plays an important role in both receptor engagement and undergoes structural rearrangements thought to be important for genome delivery to the cytosol. Our data highlight a potentially important difference in the attachment and entry pathways employed by the different clades of the Vesivirus genus. Importance Vesivirus 2117 has caused significant losses in manufacturing of biopharmaceutical products following contamination of cell cultures used in their production. We report the structure of the vesivirus 2117 capsid, the shell which encloses the virus's genome. Comparison of this structure with that of a related Vesivirus - feline calicivirus (FCV), highlighted potentially important differences related to virus attachment and entry. Our findings suggest that these two viruses may bind differently to receptors at the host cell surface. We also show that a region of the capsid protein of FCV that rearranges following receptor engagement, is not present in vesivirus 2117. These structural changes in the FCV capsid have been shown to allow assembly of a portal-like structure, hypothesised to deliver the viral genome to the cell's interior. Our data suggest that the 2117 portal assembly may employ a different means of anchoring to the outer face of the capsid.

SEIMSIC CONDITION ASSESSMENT OF TEMPLE A CASE STUDY ON SHIVA-PARBATI TEMPLE

Shiva Parvati temple is an uncommon shrine built on a four-step brick platform. It stands out particularly due to its three golden pinnacles. It was Bahadur Shah Idea to construct a hybrid temple that incorporated Newar and Rajput style on top of the pavilion built by King Laxmi Narasimha Malla who ruled in the seventeenth century. The temple has been renovated in 1998AD. The golden pinnacle of this temple is quite artistic and one of the best in the Durbar Square. It consists of three tapering spires alternating with four floral stalks on a small platform. It is unique because it departs from the traditional Newar appearance and adopts the Rajput/Mughal style. Shiva-Parvati Temple which is adorned with images of Shiva and his consort Parvati. With its “Shiva-Parvati Temple” historical importance as Monument underlying the UNESCO World Heritage Sites and One which is affected by the Gorkha Earthquake (2015). The main objective of the study is to carry out seismic condition assessment of the temple based on detail damage assessment. A set of Architectural and Structural Drawings has been prepared along with the NonDestructive Tests and Finite Element Modeling by using the Structural Analysis and Design software SAP. The temple is built with the traditional newer construction technology with load bearing walls in surkhi mortar cladding on outer face by Dachi Appa and floor and roof with timber members. This paper focuses on the visual damage assessment and detail study of the cracks in different locations of the temple. The flexible diaphragm, lack of bands and insufficient chukuls (Spikes) leads to the damage on the Temple.

The cryo-EM structure of vesivirus 2117 highlights functional variations in entry pathways for viruses in different clades of the Vesivirus genus

Vesivirus 2117 is an adventitious agent that has been responsible for lost productivity in biopharmaceutical production following contamination of Chinese hamster ovary cell cultures in commercial bioreactors. A member of the Caliciviridae, 2117 is classified within the Vesivirus genus in a clade that includes canine and mink caliciviruses but is distinct from the vesicular exanthema of swine clade, which includes the extensively studied feline calicivirus (FCV). We have used cryogenic electron microscopy (cryo-EM) to determine the structure of the capsid of this small, icosahedral, positive-sense RNA containing virus. We show that the outer face of the dimeric capsomeres, which contains the receptor binding site and major immunodominant epitopes in all caliciviruses studied thus far, is quite different from that of FCV. This is a consequence of a 22 amino-acid insertion in the sequence of the FCV major capsid protein that forms a ‘cantilevered arm’, which plays an important role in both receptor engagement and undergoes structural rearrangements thought to be important for genome delivery to the cytosol. Our data highlight a potentially important difference in the attachment and entry pathways employed by the different clades of the Vesivirus genus.

Evidence for anaphase pulling forces during C. elegans meiosis

Anaphase chromosome movement is thought to be mediated by pulling forces generated by end-on attachment of microtubules to the outer face of kinetochores. However, it has been suggested that during C. elegans female meiosis, anaphase is mediated by a kinetochore-independent pushing mechanism with microtubules only attached to the inner face of segregating chromosomes. We found that the kinetochore proteins KNL-1 and KNL-3 are required for preanaphase chromosome stretching, suggesting a role in pulling forces. In the absence of KNL-1,3, pairs of homologous chromosomes did not separate and did not move toward a spindle pole. Instead, each homolog pair moved together with the same spindle pole during anaphase B spindle elongation. Two masses of chromatin thus ended up at opposite spindle poles, giving the appearance of successful anaphase.

Nondestructive Determination of Fruit Surface Area Using Archimedean Buoyancy

Estimates of fruit surface area are often required in physiological and technological studies. The objective was to establish a procedure to accurately quantify the fruit surface area based on Archimedean buoyancy measurements. The setup comprised a fixed, linear stepper motor mounted with its spindle vertical and aligned directly above the pan of an electronic balance. A fruit was clamped to the motor spindle and a beaker of water rested on the balance pan. When the motor was activated, the fruit was progressively immersed, stepwise, in the water. Each vertical displacement step increased the buoyant upthrust on the fruit, which was opposed by a corresponding increase in the downthrust on the balance. Pairs of the step displacement length (mm) and corresponding buoyancy increment (g) values were recorded in an MS Excel (Microsoft, Redmond, WA) spreadsheet using Arduino components. Each displacement step immersed another “virtual slice” of the fruit in the water. From each pair of known displacement–buoyancy measurements, the volume (mL) of that slice could be calculated with high precision based on the known density of the liquid (g·mL−1). With the fruit orientated so that its morphological “long” axis was vertical, for most fruitcrop species, the slice can be assumed to have a circular cross-section. Hence, the slice can be analyzed geometrically as a truncated cone of known height (mm) and known volume (mL). Therefore, the surface area of its outer face is calculable. The surface area of the whole fruit was calculated as the cumulative total of the surface areas of all steps (virtual slices). The procedure was evaluated and calibrated using stainless-steel spheres in place of the fruit. However, the measured surface area was slightly greater than that calculated for a sphere. The calculated and measured areas did not differ by more than 1.7%. The surface area determinations were highly reproducible (cv = 0.95%). The magnitude of the displacement steps affected the variability of the surface area measurements. Increasing the step displacements decreased the measurement variability, but there were no significant effects on the surface area measurements of the surface tension of the liquid or of the wettability of the surface of the fruit or the stainless-steel subject. Using stainless-steel spheres (diameter, 5–60 mm) or rubber truncated cones (mean diameter, 8–45 mm) revealed an excellent agreement between the measured and calculated surface areas. Using tomatoes, grapes, blueberries, and strawberries, the measured surface areas were in excellent agreement with those calculated from the fruit dimensions and appropriate geometrical assumptions. The results demonstrate that the surface areas of fruit with approximately circular cross-sections normal to their morphological axes can be determined with high accuracy and reproducibility using Archimedean buoyancy.