Cylindrical Shape Research Articles

Chiral fluid membranes with orientational order and multiple edges.

We carry out Monte Carlo simulations on fluid membranes with orientational order and multiple edges in the presence and absence of external forces. The membrane resists bending and has an edge tension, the orientational order couples with the membrane surface normal through a cost for tilting, and there is a chiral liquid crystalline interaction. In the absence of external forces, a membrane initialized as a vesicle will form a disk at low chirality, with the directors forming a smectic-A phase with alignment perpendicular to the membrane surface except near the edge. At large chirality a catenoid-like shape or a trinoid-like shape is formed, depending on the number of edges in the initial vesicle. This shape change is accompanied by cholesteric ordering of the directors and multiple π walls connecting the membrane edges and wrapping around the membrane neck. If the membrane is initialized instead in a cylindrical shape and stretched by an external force, it maintains a nearly cylindrical shape but additional liquid crystalline phases appear. For large tilt coupling and low chirality, a smectic-A phase forms where the directors are normal to the surface of the membrane. For lower values of the tilt coupling, a nematic phase appears at zero chirality with the average director oriented perpendicular to the long axis of the membrane, while for nonzero chirality a cholesteric phase appears. The π walls are tilt walls at low chirality and transition to twist walls as chirality is increased. We construct a continuum model of the director field to explain this behavior.

Determination of device construction design and parameters for copper wire extending methods

This article analyses the factors that affect the surface layers that occur in the stretching methods used for processing on traction machines on copper materials, and the structures of the technological equipment, the causes of which are studied, and provides recommendations. The essence, technical function, basic elements, attachment sequence and principles of operation of the structure of the device recommended for traditional stretching methods are fully stated in the traction machines. In the process of stretching, in the centre of the working part of the device structure, the formulas for determining the compressions, stretches, elongation coefficients, voltages and tensile forces formed by plastic deformation are presented. In the structure of the device, designed with the aim of theoretical substantiation of research, the compression values in the process of stretching copper wires of the M1 brand are determined by the ratio of stretching, and the dependence of the cone angle of the technological unit on the force of gravity is determined by the parameters for the traditional method of stretching Based on these results, to stretch coloured metal wires in a cylindrical shape using ballots, the device structure is recommended as technological equipment for traction machines used in industry.

Omnidirectional Barometric Tactile Sensor with Cylindrical Shape

Omnidirectional Barometric Tactile Sensor with Cylindrical Shape

A High-Power Sandwiched Omnidirectional Circularly Polarized Antenna for GNSS Systems

This paper presents a small-size, low-profile antenna for anti-attacking systems that work against unmanned GNSS-guided attacking vehicles to protect a vital area. The proposed antenna has the ability to handle, theoretically, a peak power up to 157.7 kW. It has a cylindrical shape with a diameter of 75.4 mm and a height of 12.8 mm on a low-cost FR-4 substrate. This small size allows the integration of the proposed antenna with any portable system that prevents the attacks of GNSS-guided vehicles. The proposed antenna covers the whole GNSS frequency band with a fractional impedance bandwidth of 32.5% (1.16–1.61) GHz and a fractional axial ratio bandwidth of 37.6% (1.1–1.61) GHz utilizing a sandwiched structure. This broadband performance is realized using capacitive feeding. The proposed design maintains circularly polarized radiation over a wide elevation angle of 132° and a 360° azimuth angle which makes the proposed design suitable for GNSS anti-attacking systems.

Influence of in-package microwave treatment and geometry on selected characteristics of Paneer

In this paper, the influence of in-package microwave treatment and geometry (cylinder and cube) of paneer on its colour, texture and sensory characteristics was investigated. The freshly prepared paneer was moulded into cylinder and cube shapes with the help of moulds and packed in polypropylenepack. This packed paneer was exposed to different level of microwave power (270, 360 and 450W) for varying time (10, 20and 30s) and evaluated for colour, texture and sensory attributesof the paneer. It was observed that microwave power and exposure time had significant effect on colour, texture and sensory quality of both cylinder and cube shaped paneer. It was observed that all important quality and properties of paneer viz. whiteness index, hardness, flavour and overall acceptability were higher in cube shaped paneer than that of cylinder shaped paneer. Therefore, it may be recommended that for in-package microwave treatment, a cube shaped paneer may be used over cylindrical shape

An improved cultivation device for appendicularians with notes on the biology ofFritillariasp. collected in Sagami Bay, Japan

AbstractTo cultivate zooplankton species with highly fragile mucoid structures, a new type of cultivation device was developed, which uses a novel method to gently circulate the water in the culture vessel. Using this device, a species of the fritillarid appendicularia (Fritillariasp.) collected in Sagami Bay was successfully cultivated. This form resemblesFritillaria haplostomaorFritillaria formica tuberculata, but some taxonomical characteristics differed from those of the latter forms. A novel device comprising a polycarbonate bucket with a motor-driven rotating cylinder inserted into the water in the bucket was developed and maintainedFritillariasp. over ten filial generations in the laboratory. The animals reached trunk lengths of 1026 ± 85μm (mean ± SD) four days after fertilization at 23°C. The instantaneous growth rates were calculated as 1.11–1.72 at 20–26°C, representing a 3.0–5.6-fold daily increase in body weight. The house constructed by this species is extraordinarily fragile, typically has a barrel-like or cylindrical shape, and accommodates its entire body and food-concentrating filter. At 23°C, the species produced houses at a rate of 28 ± 2.8 houses d−1. The new device is useful for the continuous cultivation of the fragile form of fritillarid appendicularia, and even for various other zooplankton. It also shows thatFritillariasp. could be a significant secondary producer and transporter of organic matter in marine ecosystems due to its high growth and house production rates.

Microstructural, Morphological, and Optical Study of Synthesis of ZnO and Pt‑ZnO Nanoparticles by a Simple Method Using Different Precipitating Agents

Due to its multiple applications, zinc oxide (ZnO) is one of the most used materials in science and technology. Therefore, this research carried out the synthesis of ZnO and Pt-ZnO nanoparticles (NPs) by the direct precipitation method, which is characterized by being simple and reproducible, using two different precipitating agents, potassium hydroxide (KOH) and sodium hydroxide (NaOH); for the doping of Pt-ZnO NPs was used platinum acetylacetone. To evaluate the effect of the precipitating agent on the properties of each doped material, they were characterized by Fourier transform infrared spectroscopy, where the Zn-O vibrations were more pronounced using KOH. X-ray diffraction analysis shows a hexagonal structure (wurtzite) formation for ZnO with NaOH, obtaining a smaller crystal size than the other synthesized materials. Scanning electron microscopy analysis showed hexagonal and hemispherical shapes for ZnO (with NaOH and KOH) and Pt-ZnO (with NaOH), respectively; also, cylindrical shapes were obtained for Pt-ZnO (with KOH). The highest band gap obtained was for the Pt-ZnO material synthesized with KOH.

Lightweight aggregate: a sustainable alternative for reuse of sawdust waste in the industrial process

Sawdust generated by wood processing, both in industries processing and in tree felling, is a waste that has several applications for reuse, but, in many cases, it is still discarded irregularly in the environment, contaminating the soil, air, and water. The production of lightweight aggregate (LWA) can be an option for the reuse of this sawdust. The LWA is a gravel solution used in civil construction with the objective of reducing the weight of the structure, improving thermal and acoustic compliance, or as an option for locations where gravel is not available. In Brazil, and in most parts of the world, there are common clays available that can be used in the LWA production. The aim of this research was to produce an LWA for different applications, among them, as aggregate for civil construction, bricks, and as an adornment element. Formulations were tested to produce LWA containing illitic clay and sawdust. In the same way, for comparison, a commercial LWA was purchased, and formulations were made with clay and coal, and clay and fuel oil. The specimens were produced by pressing at 30 MPa in a cylindrical shape with a diameter of 19 mm and a height of 15 mm. After firing, the specimens were characterized by technological tests of water absorption, bulk density, compressive strength, X-ray diffraction analysis, and chemistry by X-ray fluorescence. The results indicated that the incorporation of sawdust in the formulations can be an alternative to produce LWA, once it obtained high strength and low density, compared to commercial LWA and to that produced with unattractive materials. Furthermore, it may contribute to the reduction of environmental impact, resulting from the disposal of sawdust and the generation of natural resources, necessary to produce construction materials.

Investigating the effect of bridge pier material type and related parameters on local scour

Scouring endangers the stability of the hydraulic structures. Studies have considered varied parameters affecting scour around an obstacle. But no substantial work has been done on the impact of obstacle material type on local scouring. The present study analysed the impact of material type of the bridge pier and related parameters on local scour. Cylindrical pier shape was used to simulate the field conditions in the laboratory. Obstacles were made of brick, concrete, wood and steel. Results show noticeable effect of obstacle material on local scour. It was observed that the scour depth and surface roughness of obstacles were inversely correlated and similar was the relation of scour with water absorption. An empirical model was developed to ascertain the maximum scour depth incorporating obstacle parameters. The study will help in better accuracy of scour depth estimation and help in reducing local scour at certain critical junctions of the flow path.

Tvárnenie skla v jednoduchom tvárniacom nástroji

The contribution presents the analysis and issues of glass forming in a forming tool with external heating. The necessary theoretical knowledge and properties of glass, which are necessary for solving the design of the forming tool, are listed. technological methods of glass forming are mainly press-blowing and forming with a double-blowing system. With the help of the described tool, glass can be relatively successfully shaped, which is inserted into the tool in the shape of a plate. The glass plate, which is bent into a cylindrical or hemispherical shape, is placed on the press and heated with a flame until the glass is sufficiently soft to work with.

Spallation target optimization for ADS by Monte Carlo codes

Accelerator Driven System are advanced system for the use of Thorium as fuel, aiming to reduce nuclear waste through transmutation. The spallation target, which is responsible for producing neutrons, is one of the main parts of the ADS system. In this research, neutronic parameters of spallation targets consisting of several materials LBE, Mercury, and Lead, on the cylindrical and conic shapes using Monte Carlo codes (FLUKA, PHITS, MCNPX) were investigated. Energy deposition and spallation neutron yield of spallation target with different shapes and dimensions have been calculated to optimization of the target. According to the results, the neutron yield values from MCNPX and PHITS are similar and it’s close to the experimental result. On the other hand, the error rate of the values in FLUKA is higher.

Ways of Intensification of Grass Seed Production

The main reason that restrains the development of seed production of perennial grasses is losses during harvesting, which depend on the agrotechnical properties of plants and the imperfection of existing means. There are no special grass seeds yet. Therefore, serial equipment with special devices is recommended for their collection. There are enough options for technologies for collecting grass seeds. In the article, six main options of technologies used in production were analyzed and compared according to the main indicators. The best results of a comprehensive comparison are those technologies that process the collected seed mass into a stationary one. The design of a device for wiping the seed mass was proposed to develop this direction of grass seed collection technologies. The article presents theoretical and experimental research results that allowed improving these devices based on rational design and operating parameters. Another way to intensify the production process of leguminous grass seeds is to combine the technological processes of wiping and separation in one machine. The analysis of various separating devices showed that machines with a rotating screen of cylindrical or conical shape are best suited for this purpose. The conducted theoretical studies confirmed the hypothesis that extending the time the material stays on the sieve by using a conical surface increases the yield of clean seeds and contributes to uniform loading of the sieve surface, improving the quality of the initial material. According to the research results, the design of the grating-separating block was proposed for the implementation of this scientific hypothesis. The theoretical and experimental studies presented in the article will allow for significantly intensifying the process of collecting grass seeds and outlining the further development of scientific research in this field.

Validation of a Characteristics Dimensions for Transfers during Convective Drying of Sweet Potato Cubic, Cylindrical and Spherical Shapes

Validation of a Characteristics Dimensions for Transfers during Convective Drying of Sweet Potato Cubic, Cylindrical and Spherical Shapes

Janus nanoplates, -bowls, and -cups: controlling size and curvature via terpolymer/homopolymer blending in 3D confinement.

The synthesis and properties of Janus nanoparticles with spherical, cylindrical, and disk-like shapes are nowadays rather well understood. Other topologies such as nanorings and bowl-shaped Janus nanoparticles are believed to show distinctly different solution behavior and interaction with interfaces, but limitations in their synthesis currently prevents a proper investigation of these properties. Especially the combination of shape- and surface-anisotropy of bowl-shaped Janus nanoparticles could result in enhanced selectivity in uptake of cargo and enhanced directional diffusion. We here produce bowl-shaped Janus nanoparticles without noticeable side products through evaporation-induced confinement assembly (EICA) of triblock terpolymers blended with high molecular weight homopolymer. The triblock terpolymer phase separates from the homopolymer into spherical domes, where the terpolymer adopts a hemispherical lamella-lamella morphology (ll). Selective cross-linking, removal of the homopolymer, and disassembly of the microparticles releases the bowl-shaped Janus nanoparticles. The amount of blended homopolymer determines the size of the spherical dome, allowing to control particle curvature into flat Janus nanoplates, hemispherical Janus nanobowls, and deep Janus nanocups. The use of Shirasu Porous Glass (SPG) membranes with pore sizes in the range of dpore = 0.2-2.0 μm further provides control of particle diameter. Size and shape were analyzed with electron microscopy and the Janus character through selective surface decoration. The diffusion behavior of bowl-shaped Janus nanoparticles was investigated depending on particle curvature and anisotropy using angle-dependent dynamic light scattering.

The Effects of Tree Canopy Structure and Tree Coverage Ratios on Urban Air Temperature Based on ENVI-Met

Vegetation configuration in residential districts improves human comfort by effectively moderating the thermal environment. Herein, the reliability of ENVI-met is verified by comparing the field measured with simulated data, including air temperature and relative humidity. The cooling effect of trees gradually increased with increasing tree coverage. Under the same coverage, trees with a tree crown diameter (TCD) of 3 m have the strongest cooling capacity, followed by trees with a TCD of 7 m, and trees with a TCD of 5 m have the weakest cooling capacity. The cooling capacity of a TCD of 3 m is considerably higher than that a TCD of 5 m and a TCD of 7 m. When the tree coverage ratio is 50%, the difference among the three TCDs is the largest. When the tree coverage is 50% or 70%, the cooling effect of TCD at 7 m is considerably higher than that at 5 m. For different canopy sizes and shapes under the same degree of tree coverage, only when the tree coverage is more than 50% and TCD is 3 m, the cooling capacity of a cylindrical shape is 0.2 to 0.3 °C higher than that of conical and ellipsoidal shapes. However, the difference between conical and ellipsoidal shapes when TCD is 5 or 7 m is not significant (∆Ta < 0.1 °C). Our results suggest that small canopy trees have a better cooling effect than large canopy trees for the same level of coverage.

Buried Object Characterization Using Ground Penetrating Radar Assisted by Data-Driven Surrogate-Models

This work addresses artificial-intelligence-based buried object characterization using 3-D full-wave electromagnetic simulations of a ground penetrating radar (GPR). The task is to characterize cylindrical shape, perfectly electric conductor (PEC) object buried in various dispersive soil media, and in different positions. The main contributions of this work are (i) development of a fast and accurate data driven surrogate modeling approach for buried objects characterization, (ii) construction of the surrogate model in a computationally efficient manner using small training datasets, (iii) development of a novel deep learning method, time-frequency regression model (TFRM), that employes raw signal (with no pre-processing) to achieve competitive estimation performance. The presented approach is favourably benchmarked against the state-of-the-art regression techniques, including multilayer perceptron (MLP), Gaussian process (GP) regression, support vector regression machine (SVRM), and convolutional neural network (CNN).

MODELING THE EFFECT OF PHYSICAL AND CHEMICAL HETEROGENEITY OF GRAIN SURFACE ON NANOPARTICLE TRANSPORT IN A SINGLE PORE IN SOIL

The physical and chemical heterogeneity of soil grains significantly affects nanoparticle transport. However, no quantitative relationships exist for particle deposition rates accounting for grain-surface heterogeneity. This study quantifies the effect of various physicochemical parameters on the nanoparticle deposition rate coefficients in a single heterogeneous pore in soil. A mathematical model is developed to simulate the transport of nanoparticles through an idealized pore of cylindrical shape with rings of the same height on the wall representing roughness. Chemical heterogeneity is considered by assigning positive and negative charges to the top of the ring elements and the remaining area of the pore wall, respectively. Particle transport is simulated by solving the advection-diffusion equation with first-order sorption at the pore wall. Nanoparticle breakthrough curves obtained from simulations are fitted with a 1D advection-dispersion-sorption equation. The pore-averaged deposition rate coefficients obtained thus are satisfactorily described using a power-law relationship vis-a-vis pore-scale parameters. The Damkohler number for nanoparticle attachment to the pore wall is significantly affected by parameters representing pore and particle radii, flow velocity, surface potentials of nanoparticles, and regions of the pore wall having positive and negative charges, and Hamaker constant. However, the Damkohler number for nanoparticle detachment from the pore wall is predominantly influenced by parameters representing particle size, roughness height, surface potentials of nanoparticles, and regions of the pore wall having positive and negative charges, Hamaker constant, and ionic strength. Chemical heterogeneity plays a dominant role in nanoparticle retention than wall roughness. The above relations can be incorporated into a pore-network model to quantify the effect of grain-surface heterogeneity on nanoparticle deposition at the continuum scale.

Heat exchange between the heating element and its shell under the boundary condition of the fourth kind

In this article, the question of finding the temperature field of a heating element made in the form of a cylinder enclosed in a shell of cylindrical shape is considered. It is assumed that the thermal contact between the solid–coating systems is ideal. In this case, heat exchange occurs under boundary conditions of the third and fourth kind. In this paper, based on the methods of differentiation and integration, a solution was obtained to the problem of the distribution of the temperature field in both bodies. The resulting solution has an analytical form containing quadratic and logarithmic functions.

Assessment of Wear Properties on Treated AISI 410 Martensitic Stainless Steel by Annealing Process

Martensitic stainless steels find less application in commercial products as they have high hardness, strength, and wear resistance. It lacks in ductility and exhibits moderate corrosion resistance compared to other stainless steels. As a result, annealing process were been used to strengthen the ductility and maintain stability in hardness of martensitic stainless steel material. AISI 410 was chosen for this research work and the samples were made to cylindrical shape for the following dimensions: 50 mm length and 08 mm diameter. The specimens were annealed at temperatures of 730°C, 830°C, and 930°C. The untreated material is kept aside for results comparison. All specimens were subjected to wear test using a pin on disc wear test apparatus. All the specimens were examined using a scanning electron microscope for the surface morphological changes. The outcomes were compared and the best specimen for the required application was chosen. It was discovered that there was a phase change from the martensite stage to the residual austenite stage.**

Development and Characterization ofAgro-AlliedRice Husks andGroundnut ShellWaste Briquettes

Briquetting of agro-residues can alleviate some of the problems of energy shortage being encountered world-wide. The briquettes are essentially manufactured to provide cheap energy to the various sectors. Most importantly, to the domestic households that are finding it difficult to purchase the other sources of energy because of their cost. In this research the briquettes wereproduced in a briquetting screw press –BSP, using a manually operated piston and cylindrical shape Mould. The individual materials weremixed thoroughly in a ratio of rice husk: groundnut shell (RH:GS) as follows: 100:00; 70:30; 50:50;30:70; and 00:100.A fixed quantity of each mixture wereseparately hand-fed into a manually operated closed-end piston press to compact the briquettes. Thereafter, the briquettes wereejected and placed on drying racks and left in the sun for drying. The moisture content, ash content, volatile matter, fixed carbon, ignition time,flame propagation time, calorificvalue and water boiling test were investigated to determine the physical and thermal properties of the briquettes produced. The results of the investigation showedthat moisture content of the briquettes ranged from 3.96 –5.65%, the calorific value ranges from 130, 63.56–141, 62.87kJ/kg, the range of ash content is 6.10 -9.32 %, for fixed carbon is 7.67 -20.20 %, the ignition time ranges from 238-270sec and the rangesfor water boiling test time is 10.57m, –13.37m. These values satisfactorily comparewell with values obtained by other researchers in the literature. Therefore, the rice husk -groundnut shell briquettes are good alternative source of thermal energy for cooking. It is an economical and also an environmental friendly source of energy and waste disposal.