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The conducted investigation is aimed at providing information on air flow parameters in the cylindrical and spiral shell (devices are designed for separating solid particles from air flow having tangent flow inlet). Experimental research has employed multi-cyclones created by the Department of Environmental Protection at Vilnius Gediminas Technical University. The study is focused on investigating and comparing the distribution of the dynamic pressure of the airflow in six-channel cyclones inside the structures of devices. The paper establishes and estimates the efficiency of air cleaning changing air phase parameters using different particulate matters. The efficiency of the cyclone has been defined applying the weighted method based on LAND 28-98/M-08 methodology. The article presents the results of experimental research on the air cleaning efficiency of cylindrical and spiral shells using 20 µm glass and clay particulate matter under the initial concentration that may vary from 500 mg/m3 to 15 g/m3 using semi-rings with windows at different positions. The obtained results has shown that the maximum efficiency of the cylindrical shell increases up to 87,3 % while the initial concentration of glass makes 15 g/m3.Article in Lithuanian

A cylindrical rolling robot is developed that generates roll torque by changing the shape of its flexible, elliptical outer surface whenever one of four elliptical axes rotates past an inclination called trigger angle. The robot is equipped with a sensing/control system by which it measures angular position and angular velocity, and computes error with respect to a desired step angular velocity profile. When shape change is triggered, the newly assumed shape of the outer surface is determined according to the computed error. A series of trial rolls is conducted using various trigger angles, and energy consumed by the actuation motor per unit roll distance is measured. Results show that, for each of three desired velocity profiles investigated, there exists a range of trigger angles that results in relatively low energy consumption per unit roll distance, and when the robot operates within this optimal trigger angle range, it undergoes minimal actuation burdening and inadvertent braking, both of which are inherent to the mechanics of rolling robots that use shape change to generate roll torque. A mathematical model of motion is developed and applied in a simulation program that can be used to predict and further understand behavior of the robot.

The CARB bearing is a single row bearing with long, slightly crowned symmetrical rollers. It combines the self-aligning capability of the spherical roller bearing with the unconstrained axial displacement ability of the cylindrical roller bearing. The optimal combination of both raceway profiles provides a favorable load distribution in the bearing, as well as low frictional running. This paper emphasizes the functioning characteristics of the SKF CARB toroidal roller bearing by means of a multibody dynamics simulation. Different conditions like load direction, races relative position or angular misalignment, are taken into consideration.

Chiral cylindrical molecular complexes of homo- and hetero-double-helices derived from helicene oligomers self-assemble in solution, providing functional heterogeneous liquid-solid materials. Gels and liotropic liquid crystals are formed by fibril self-assembly in solution; molecular monolayers and fibril films are formed by self-assembly on solid surfaces; gels containing gold nanoparticles emit light; silica nanoparticles aggregate and adsorb double-helices. Notable dynamics appears during self-assembly, including multistep self-assembly, solid surface catalyzed double-helix formation, sigmoidal and stairwise kinetics, molecular recognition of nanoparticles, discontinuous self-assembly, materials clocking, chiral symmetry breaking and homogeneous-heterogeneous transitions. These phenomena are derived from strong intercomplex interactions of chiral cylindrical molecular complexes.

In this work, an investigation for the dynamic analysis of thin composite cylindrical and spherical shells is presented. The analytical solution is based upon the higher order shear deformation theory of elastic shells from which the developed equations are derived to deal with orthotropic layers. This will cover the determination of the fundamental natural frequencies and mode shapes for simply supported composites cylindrical and spherical shells. The analytical results obtained by using the derived equations were confirmed by the finite element technique using the well known Ansys package. The results have shown a good agreement with a maximum percentage of discrepancy, which gives a confidence of using this solution in prediction the dynamic analysis of cylindrical and spherical shells

The minimum mass designs of state of the art helical circumferential grids are compared to axial helical grids. Analytical models based on the classical laminate theory deliver optimization results in less than one second. Using finite element models the obtained results are validated and adjusted in a second optimization step. Studies on the influence of rib heights and Young’s modulus show potential to create lighter grids in axial helical design than in helical circumferential design. This is shown for medium length cylinders from relatively low up to very high load levels. [ABSTRACT FROM AUTHOR]

Aiming at the static stability of the parabolic single-layer cylindrical reticulated shell, the following research is conducted: the static stability of the parabolic single-layer cylindrical reticulated shell is compared with that of the single-layer cylindrical reticulated shell and the inverted catenary single-layer cylindrical reticulated shell. A large scale parameter analysis is carried out on the parabolic cylindrical reticulated shell. An optimized design for the parabolic single-layer cylindrical reticulated shell is conducted. Research shows that compared with the cylindrical reticulated shell, the ultimate load of the parabolic single-layer reticulated cylindrical shell is greatly enhanced. Rise-span ratio and length-span ratio influence the ultimate load of the shell significantly. The shell is proved to be sensitive to initial geometric imperfection. There exists an optimal oblique rod intersection angle of about 50° under which the static stability is the best. When the grid space layout is arranged according to the geometric series and the value of the ratio α is between 0.85 and 0.95, the static stability of the shell is the best. [ABSTRACT FROM AUTHOR]

Solar energy is used not only at low latitudes, where it is available at large amounts, but also at higher latitudes, where height of sun and irradiance are significantly lower. On the other hand, the length of day at higher latitudes is longer in summer than at low latitudes, and also the path of the sun is longer. The present research deals with seeking for new shapes of solar collectors capable of receiving more solar energy. For designing and evaluating new shapes of solar collectors, it is necessary to have new methods for simple calculations of energy received from the sun by surface of any shape and direction. Such a method is explained in the present paper. Based on calculations by the proposed method, a new form of solar collector - a cylindrical collector - has been worked out. This collector is intended for air heating, but main principles can also be used for water heating, and even for photovoltaics. A cylindrical collector receives more energy in the morning and evening than a flat one, but at midday power of both collectors is equal, if effective areas are equal. Daily energy sum of the cylindrical solar collector is 1.5 times greater than that of the flat one. [ABSTRACT FROM AUTHOR]

Twenty one samples of relatively pure tubular halloysites (HNTs) from localities in Australia, China, New Zealand, Scotland, Turkey and the USA have been investigated by X-ray diffraction (XRD), infrared spectroscopy (IR) and electron microscopy. The halloysites occur in cylindrical tubular forms with circular or elliptical cross sections and curved layers and also as prismatic tubular forms with polygonal cross sections and flat faces. Measurements of particle size indicate a range from 40 to 12,700 nm for tube lengths and from 20 to 600 nm for diameters. Size distributions are positively skewed with mean lengths ranging from 170 to 950 nm and mean diameters from 50 to 160 nm. Cylindrical tubes are systematically smaller than prismatic ones. Features related to order/ disorder in XRD patterns e.g. as measured by a 'cylindrical/prismatic' (CP) index and IR spectra as measured by an 'OH-stretching band ratio' are related to the proportions of cylindrical vs. prismatic tubes and correlated with other physical measurements such as specific surface area and cation exchange capacity. The relationships of size to geometric form, along with evidence for the existence of the prismatic form in the hydrated state and the same 2M1 stacking sequence irrespective of hydration state (i.e. 10 vs. 7 Å) or form, suggests that prismatic halloysites are the result of continued growth of cylindrical forms. [ABSTRACT FROM AUTHOR]

Background: We hypothesized that a rectangular cross-sectional femoral stem may produce more initial stability of the transverse subtrochanteric femoral shortening osteotomy rather than a circular cross-sectional stem.Methods: Twenty, fourth-generation, synthetic femur models were inserted with either circular or rectangular cross-sectional femoral stems after 3 cm of transverse subtrochanteric shortening. Half of the models were tested with axial bending and the other half with torsional loads. After the femora underwent cyclic loading, they were loaded until failure. Outcome parameters were stiffness values before and after cyclical loading, failure loads/torques, and displacements at the osteotomy sites.Results: In axial bending tests, the results were not significantly different between the groups. Under rotational forces, the mean stiffness value before cyclical loading and failure torque of the cylindrical stems was significantly higher than that of rectangular cross-sectional stems (11.8 ± 1.2 vs 7.1 ± 2.8 Nm/degree; P = .009 and 136.9 ± 60.2 vs 27.1 ± 17.5 Nm; P = .027 Nm, respectively). The mean amounts of displacements at the osteotomy sites were not significantly different between the groups in any direction in both axial and rotational tests.Conclusions: According to the results of the study, using straight, cylindrical femoral stems can increase rotational stability of the transverse osteotomy more than the rectangular cross-sectional stems although the latter one has the advantages of rectangular geometrical design. [ABSTRACT FROM AUTHOR]

The heat equation is a partial differential equation that elegantly describes heat conduction or other diffusive processes. Primary methods for solving this equation require time-independent boundary conditions. In reality this assumption rarely has any validity. Therefore it is necessary to construct an analytical method by which to handle the heat equation with time-variant boundary conditions. This paper analyzes a physical system in which a solid brass cylinder experiences heat flow from the central axis to a heat sink along its outer rim. In particular, the partial differential equation is transformed such that its boundary conditions are zero which creates a forcing function in the transform PDE. This transformation constructs a Green's function, which admits the use of variation of parameters to find the explicit solution. Experimental results verify the success of this analytical method. [ABSTRACT FROM AUTHOR]

In this paper, four types of floating breakwaters (FB) are proposed: cylindrical floating breakwater (CFB), porous floating breakwater (PFB), mesh cage floating breakwater type-I (MCFB-I) and mesh cage floating breakwater type-II (MCFB-II). The hydrodynamic performance of each type has been tested to identify the most effective configuration for wave attenuation. The experiment was conducted in a wave flume in which regular waves were produced. The incident and transmitted waves, the tensions in the mooring lines and the motion responses of all of the four types of floating breakwaters were measured. It is shown that all proposed types of floating breakwaters can effectively reduce transmitted wave amplitude. Among them the MCFB-I is seen to yield the most attenuating effect on incident wave amplitude. [ABSTRACT FROM AUTHOR]

This article describes a new thermophysical characterization method for granular materials. It is based on the creation of a cylindrical probe, fitted with peripheral flux and temperature sensors. These sensors record changes in thermal variables in the case of cylindrically symmetrical heat diffusion. A numerical exchange model integrated into an inversion algorithm identifies the thermal effusivity and diffusivity of the material being tested and the sensor/material contact resistance. In this first study, the method was applied to dry sand. [ABSTRACT FROM AUTHOR]

High power impulse magnetron sputtering (HIPIMS) allows the deposition of thin films from plasmas with high metallic ion content. For several applications, indium tin oxide (ITO) films were successfully deposited by HIPIMS from planar ceramic targets, e.g. for ice-free windshields or shaped glass tubes. These films present good conductivity as well as high wear resistance, derived from their nanocrystalline structure. With respect to industrial implementation, the use of rotatable cylindrical cathodes as a promising alternative due to their many advantages like better material utilization, longer durability, or reduced arcing is studied. In this work, ITO films were produced from a rotating cylindrical cathode by HIPIMS and DC magnetron sputtering. The influence of process parameters (average power, voltage, peak current and pressure) on the resulting film properties was investigated. All depositions were performed at room temperature, followed by annealing steps. Electrical and optical properties were analyzed and the process stability investigated. Highly transparent films were obtained with resistivity between 300 and 400 μΩ cm. [ABSTRACT FROM AUTHOR]

This paper treats various forms of Roman urn, evidence of cremation as a customary manner of burial in what is now Bosnia and Herzegovina. The Antiquities Department of the National Museum of Bosnia and Herzegovina holds the largest collection of Roman urns of various types and dates: 76 complete or fragmentary specimens. The urns may be classified in terms of material into glass, pottery and stone urns. Several different forms are identified within each group. The most diverse are stone urns, which may be square, rectangular boxshaped and sarcophagus-like, or cylindrical. [ABSTRACT FROM AUTHOR]

Objective: To investigate the relationship between mini-screw implant (MSI) diameter (1.6 vs 2.0 mm) and shape (tapered vs cylindrical) and the amount of microdamage generated during insertion. Materials and Methods: Thirty-six cylindrical and 36 tapered MSIs, 6 mm long, were used in this study. Half of each shape was 1.6 mm in diameter, while the other half was 2.0 mm. After pilot drilling, four and five MSIs were inserted, respectively, into fresh cadaveric maxillae and mandibles of dogs. Bone blocks containing the MSIs were sectioned and ground parallel to the MSI axis. Epifluorescent microscopy was used to measure overall cortical thickness, crack length, and crack number adjacent to the MSI. Crack density and total microdamage burden per surface length were calculated. Three-way analysis of variance (ANOVA) was used to test the effects of jaw, and MSI shape and diameter. Pairwise comparisons were made to control the overall significance level at 5%. Results: The larger (2.0 vs 1.6 mm) cylindrical MSIs increased the numbers, lengths, and densities of microcracks, and the total microdamage burden. The same diameter cylindrical and tapered MSIs generated a similar number of cracks and crack lengths. More total microdamage burden was created by the 2.0-mm cylindrical than the 2.0-mm tapered MSIs. Although higher crack densities were produced by the insertion of 1.6-mm tapered MSIs, there was no difference in total microdamage burden induced by 1.6-mm tapered and 1.6-mm cylindrical MSIs. Conclusions: Pilot drilling is effective in reducing microdamage during insertion of tapered MSIs. To prevent excessive microdamage, large diameter and cylindrical MSIs should be avoided. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the treatment effects of a hybrid hyrax-facemask (FM) combination in growing Class III patients. Material and Methods: A sample of 16 prepubertal patients (mean age, 9.5 ± 1.6 years) was investigated by means of pre- and posttreatment cephalograms. The treatment comprised rapid palatal expansion with a hybrid hyrax, a bone- and toothborne device. Simultaneously, maxillary protraction using an FM was performed. Mean treatment duration was 5.8 ± 1.6 months. The treatment group was compared with a matched control group of 16 untreated Class III subjects. Statistical comparisons were performed with the Mann-Whitney U-test. Results: Significant improvement in skeletal sagittal values could be observed in the treatment group over controls: SNA: 2.4°, SNB: -1.7°, Co-Gn: -2.3 mm, Wits appraisal: 4.5 mm. Regarding vertical changes, maintenance of vertical growth was obtained as shown by a small nonsignificant increase of FMA and a small significant decrease of the Co-Go-Me angle. Conclusions: The hybrid hyrax-FM combination was found to be effective for orthopedic treatment in growing Class III patients in the short term. Favorable skeletal changes were observed both in the maxilla and in the mandible. No dentoalveolar compensations were found. [ABSTRACT FROM AUTHOR]

A multiscale approach to growth and recession is adopted that is compatible with the theory of mixtures. The growth may result from chemical reactions or infiltrations, or combinations thereof. The emphasis of the work is on the construction of approximate constituent elastic deformation gradients, associated with an arbitrary overall deformation, that reflect an initially circularly cylindrical geometry relative to which growth occurs. A decomposition of the deformation into cylindrical and non-cylindrical parts is employed. A cylindrically symmetric reference configuration for a given constituent is adopted in which chemical growth, chemothermal (and/or equivalently moisture) expansion, and appearance or disappearance of the constituent may occur; the reference configuration of a constituent thus possesses evolving spatial dimensions but fixed geometric and material symmetries. The traditional composite micromechanics assumption of common radial stress is adopted, in combination with the assumptions of either common axial deformation rate or common axial deformation, for the cylindrical component of deformation. Elastic deformations of constituents are obtained through comparison, of the actual deformation, to the assumed stress-free deposition configurations and subsequent chemothermal stress-free expansions. The requirement that the local and homogenized cylindrical deformations (or rates) match in the axial and outermost radial directions is used to define a homogenized non-cylindrical component that is applied across the local constituents to couple the cylindrical deformation to the overall deformation. The general objective of the study may be stated as incorporating ordered microstructure-based stresses incorporating growth, chemothermal expansion, inhomogeneous natural states, and applied deformations into a mixture theory-compatible framework to provide an important refinement to the assessments of constituent states. The model is intended to enable a new efficiency of multiscale representation in the modeling of composite materials with evolving microstructures, considering both manufacturing processes and environmental influences. [ABSTRACT FROM PUBLISHER]

An analysis of cylindrical sandwich structures with weak orthotropic core subjected to patch loading is presented. A high order theory model combined with a novel formulation technique is used to predict the static response of the structure. The face-sheets are considered as thin shells that follow the first order shear deformation theory, whereas the core is considered as a linear elastic medium. The effects of core elastic and shear stiffness, curvature to length ratio, and stacking sequence and orientation on the core’s stresses and displacements are presented. The case of a moving load is explored and performance charts are generated to design and optimize the structure in response to the patch loads. In particular, considering an orthotropic core with quasi-isotropic lay-up in the face-sheets, limit the variation of the transverse core shear stress and provide an efficient structural design configuration. [ABSTRACT FROM AUTHOR]

There are many applications for problems involving thermal conduction in twodimensional (2D) cylindrical objects. Experiments involving thermal parameter estimation are a prime example, including cylindrical objects suddenly placed in hot or cold environments. In a parameter estimation application, the direct solution must be run iteratively in order to obtain convergence with the measured temperature histoiy by changing the thermal parameters. For this reason, commercial conduction codes are often inconvenient to use. It is often practical to generate numerical solutions for such a test, but verification of custom-made numerical solutions is important in order to assure accuracy. The present work involves the generation of an exact solution using Green's functions where the principle of superposition is employed in combining a one-dimensional (ID) cylindrical case with a ID Cartesian case to provide a temperature solution for a 2D cylindrical. Green's functions are employed in this solution in order to simplify the process, taking advantage of the modular nature of these superimposed components. The exact solutions involve infinite series of Bessel functions and trigonometric functions but these series sometimes converge using only a few terms. Eigenvalues must be determined using Bessel functions and trigonometric functions. The accuracy of the solutions generated using these series is extremely high, being verifiable to eight or ten significant digits. Two examples of the solutions are shown as part of this work for a family of thermal parameters. The first case involves a uniform initial condition and homogeneous convective boundary conditions on all of the surfaces of the cylinder. The second case involves a nonhomogeneous convective boundary condition on a part of one of the planar faces of the cylinder and homogeneous convective boundary conditions elsewhere with zero initial conditions. [ABSTRACT FROM AUTHOR]

ABSTRACT The study presents computational fluid dynamics (CFD) simulations for evaluation of basic geometrical shapes as headers for equal liquid flow distribution. The headers that have been evaluated are conical header, cylindrical header, pyramidal header, rectangular header and spherical header. The computational approach used in the study has been validated by comparing predictions of numerical simulations with experimental results for a cylindrical header. The effects of volume of header, flow rate, diameter of outlets and pressure imbalance at outlets on flow distribution have been studied. At low flow rates, there is no significant difference in the performance of the headers of different geometrical shapes. At higher flow rates, spherical header is found to be better. The possibility of ensuring equal flow distribution by having outlets of varying cross-sectional area is discussed. The results reported in the study provide useful insights relevant for header design problems. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mechanical Engineering the National Technical University of Ukraine 'Kyiv Polytechnic Institute' is the property of National Technical University of Ukraine KPI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The vector structure of evanescent and propagating wave components of a cylindrical vector optical field with different states of polarization in the cross-section of the field is demonstrated using the vector angular spectrum. The physical pictures of transverse electric (TE) and transverse magnetic (TM) terms of the evanescent and propagating wave components of the cylindrical vector field in the near field are clearly illustrated in detail. The work provides a new approach to manipulate laser beams by choosing proper polarization states in the cross-section of the field. [ABSTRACT FROM AUTHOR]

The results of research into regularly fiber-reinforced bodies under large deformations, obtained by using a single-level applied and two-level carcass theories, are presented. Uni-, two-, and three-directionally reinforced bodies of revolution and prismatic ones, with high and low content of reinforcing fibers, subjected to butt-end torsion under the action of compression and rotation-caused centrifugal forces are investigated. Problems on the butt-end torsion of a thick-wall cylinder with axially arranged fibers and of a thick-wall toroidal shell with meridionally located fibers are considered. [ABSTRACT FROM AUTHOR]

Objectives The implant design and surface modification are independent conditions that can alter the implant bone response. The objective of this study is to compare the bone response to roughened tapered and cylindrical screw-type implants with and without hydroxyapatite ( HA) surface coating in the femoral trabecular bone of rabbits. Material and method Thirty-two implants (8 × 3.5 mm) consisting of four different types (eight implants in each group), that is, tapered implants, cylindrical implants, HA-coated tapered implants, and HA-coated cylindrical implants were installed in the femoral condyle of 16 rabbits. After 8 weeks of healing, the femoral condyles were retrieved and studied histologically. The bone-to-implant contact percentage was assessed and analyzed statistically. Results The histomorphometric analysis revealed that the bone-to-implant contact ( BIC) values seemed to be higher for HA-coated tapered implants (65.62 ± 13.02) followed by cylindrical non-coated implants. All four types of implants showed wide distribution of BIC with no statistical significance between different types of implants. Conclusion It can be concluded that under the current experimental conditions, implant design and surface composition had little effect on the bone-to-implant interface. [ABSTRACT FROM AUTHOR]

Some of the famous cylindrical projections are defined by a geometric process that is based on the perspective. This process can be imagined as a semitransparent sphere wrapped by a tube, secant, or tangent, with the same center; then all features of the sphere surface are projected onto the tube surface by light rays from a source in the equatorial plane. Just by changing the light source's position and tube's diameter, different maps can result. In every cylindrical perspective projections, distortions are functions of latitude only, thus, the value of distortion is fixed along a parallel (or a small circle). Therefore, distortion isograms are parallels (or small circles), symmetrical in relation of the equator. Consequently, it is suitable for territories having narrow band shape, extended by the equator (or an oblique equator). The proposed projection in this paper introduces another possible adjustment in cylindrical projections, in which axis of cylinder does not pass through the center of the sphere. This may satisfy case, where territories have a closed curve shape. By comparing the distribution of distortions in other famous perspective cylindrical projections (Lambert, stereographic, and central), with that in the proposed modified perspective cylindrical projection, it was found that distribution of area distortion in the proposed projection can be considered better than others. Therefore, in relation to area representation, the modified perspective cylindrical projection can be considered suitable for mapping regions, having shape close to an ellipse. [ABSTRACT FROM AUTHOR]

An exact series solution for scattering and transmitting of two concentric thick conducting cylindrical cavity-backed apertures is formulated by using radial mode matching technique. The scattered and penetrated fields are represented in terms of an infinite series of radial modes. By applying the appropriate boundary conditions, the coefficients of scattered and transmitted fields are obtained. The behavior of resonance features is characterized for variation of structures with another slotted cylinder inside. [ABSTRACT FROM PUBLISHER]

A structural system for segmented barrel-vaulted glass roofs has been developed, aiming at maximum transparency due to structural optimization. This has led to a structural system with small connections, integrated into the glass, as well as clear, transparent joints. Finite element analysis and a full-scale test has been performed, showing PVB-laminated glass, 101010.4, could be sufficient to create spans up to 20 meters with slightly prestressed cables measuring just 3 mm in diameter.

Hybrid modeling is a term that has recently been used to describe the mixture of liquids. Hybrid models are important in a variety of systems, including medical treatments, manufacturing, experimental instrument design, aerosol particle processing, and naval academies, among others. With the presence of the Buoyancy force and Boussinesq second-order thermal variation, the nonlinear, linear, and quadratic Roseland approximations on three-dimensional flow characteristics were considered. In addition, ternary solid nanoparticles of various shapes and densities were included. With appropriate transformation, the resulting ruling partial differential system is changed into a governing ordinary differential system, and a solution with three mixture compositions is supplied (Case-I, Case-II and Case-III). CNTs (Spherical), GNT (Cylindrical), and Al 2 O 3 (Platelet) with water as a base fluid at 0 °C, Case-II mixture of CNT (Spherical), GNT (Cylindrical), and Al 2 O 3 (Platelet) with water as a base fluid at 10 °C, and Case-III mixture of CNTs (Spherical), GNP (Cylindrical) and Al 2 O 3 (Platelet) with water as a base fluid at 50 °C, there are numerous variations in three mixing compositions as follows as well as the flow's linear, quadratic, and nonlinear thermal radiation situations. In comparison to Case-I and Case-III ternary combinations, the temperature distribution in Case-II ternary mixtures is wider. Case-2 CNTs (Spherical), GNP (Cylindrical), and Al 2 O 3 (Platelet) with water as a base fluid at 10 °C has a higher conductivity than Case-1 CNTs (Spherical), GNP (Cylindrical), and Al 2 O 3 (Platelet) with water at 0 °C, and Case-3 CNTs (Spherical), GNP (Cylindrical), and Al 2 O 3 (Platelet) With water as a base fluid at 50 °C. The skin friction coefficient is more in case-1 compared to case-2 and case-3. [ABSTRACT FROM AUTHOR]

The cylindrical shape is one of the most common shapes in geometry. The preparation of cylindrical polystyrene (PS) particles by magnetic stirring has been previously reported (Angew. Chem. Int. Ed. 2018 , 57 , 9936–9940) via two steps: spherical PS particles were synthesized by dispersion polymerization of styrene with polyvinylpyrrolidone (PVP) as the stabilizer, followed by stirring the spherical PS particles in a water medium in the presence of PVP. However, the effects of various parameters on the deformation were not fully investigated. Herein we report full details of the preparation of cylindrical PS particles by stirring at room temperature. The influence of PVP molecular weight in the polymerization process, and various stirring parameters such as the molecular weight of PVP for stirring, concentration of PVP for stirring, stirring time, stirring rate, size of stirrer and amount of the mixture for stirring on the morphology of the resulting particles was investigated systematically. Moreover, a larger glass vial and correspondingly a larger magnetic stirrer were used in this work, which could produce cylindrical polymer particles at a five-fold larger scale. However, the production of cylindrical polymer particles at a even (fifty-fold) larger scale was less successful and might lead to a substantial part of peanut-shaped particles. This work is expected to be useful for improved understanding of the formation of these cylindrical polymer particles. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Radially polarized piezoelectric fibers are now considered to be used in smart composites. The piezoelectric layers in these fibers are generally anisotropic in the transverse direction and therefore difficult to analyze when dynamic loads are involved. The present paper presents a theoretical study of the dynamic behavior of radially polarized cylindrical piezoelectric layers between isotropic elastic media. A new interphase model is developed to provide simple yet accurate evaluation of the dynamic response of such anisotropic elastic layers. Unlike the traditional interface-spring model, the current interphase model satisfies the equations of motion of the layers and can provide reliable prediction of the stress and displacement. A comparison between the developed model, the interface-spring model and the finite element analysis is conducted. The results clearly show the advantages of the current model over the traditional interface-spring model in simulating anisotropic layers. Numerical examples based on this interphase model for different interphase thicknesses, loading frequencies and material combinations are presented to evaluate the dynamic behavior of multilayered elastic media. [Copyright &y& Elsevier]

Static analysis of skew composite shells is presented by developing a C0 finite element (FE) model based on higher order shear deformation theory (HSDT). In this theory the transverse shear stresses are taken as zero at the shell top and bottom. A realistic parabolic variation of transverse shear strains through the shell thickness is assumed and the use of shear correction factor is avoided. Sander's approximations are considered to include the effect of three curvature terms in the strain components of composite shells. The C0 finite element formulation has been done quite efficiently to overcome the problem of C1 continuity associated with the HSDT. The isoparametric FE used in the present model consists of nine nodes with seven nodal unknowns per node. Since there is no result available in the literature on the problem of skew composite shell based on HSDT, present results are validated with few results available on composite plates/shells. Many new results are presented on the static response of laminated composite skew shells considering different geometry, boundary conditions, ply orientation, loadings and skew angles. Shell forms considered in this study include spherical, conical, cylindrical and hypar shells. [ABSTRACT FROM AUTHOR]

Abstract: The Texas A&M University Penning trap facility is an ion trap system currently under construction, and will be used for precision nuclear physics experiments with radioactive beams provided by the Cyclotron Institute. Its primary focus is to carry out experiments to search for possible scalar currents in T=2 superallowed proton decays, which, if found, would be an indication of physics beyond the standard model. In addition, TAMUTRAP will provide a low-energy, spatially localized source of ions for various other applications. The experiment is centered around a unique, compensated cylindrical Penning trap that employs a specially optimized ratio in the electrode structure that is not used by any other facility. This allows the electrode structure to exhibit an unprecedented 90mm inner radius, which is larger than in any existing trap, while at the same time remaining a tractable overall length. The trap geometry was designed from first principles to be suitable for a wide range of nuclear physics experiments. In particular, the electrode structure allows for a near quadrupole electric field at the trap center, a feature necessary for performing precision mass measurements. [Copyright &y& Elsevier]

Abstract: In today''s sputtering solutions in the field of precision optics, usually planar targets are used which suffer from inhomogeneous surface erosion. This leads to a drift in uniformity over time, higher material costs and in the case of reactive sputtering an increased tendency to form arcs which cause particle generation. In this paper an approach is presented that overcomes the disadvantages planar magnetrons present to sputtering. A rotating turntable coater was equipped with two dual cylindrical magnetrons in a sputter-up configuration. Thin films prepared by metallic mode reactive sputtering as well as reactive mid-frequency sputtering were investigated. Properties of Ta2O5 and SiO2 such as film stress, optical density and surface roughness are discussed. It is sown that the coatings are suitable for applications in precision optics. [Copyright &y& Elsevier]

Abstract: Self-shielding in spatially distributed samples can be very significant when detecting photons below 100keV. A correction method has been developed for cylindrical samples, typically used in measurements of natural radioactivity with well-type detectors, as is the example of sediment dating. The method calculates the probability of photons to escape the sample, using Monte Carlo techniques with a program written in C. The effects of self-shielding on the angular distribution of photons have been indirectly analyzed as a function of sample geometry, given a fixed detector geometry. The results given by the program have also been used to provide a straightforward way of calculating the self-shielding factors, with uncertainties. Required inputs are the attenuation coefficient of the sample, its radius, and its height. A procedure has also been specified in order to make good use of all the information. To check on the method, measurements of reference material of known activity have been compared with calculated values, obtaining very satisfactory results. [Copyright &y& Elsevier]