Tip Plate Research Articles

Stick, slip... bounce? Influence of violin bow rotational inertia on bouncing strokes

Prior perceptual tests using an experimental bow whose moment of inertia (relative to the pivot around the thumb) could be modified by moving small masses along the stick have indicated that violinists exhibit significant sensitivity to this parameter. This sensitivity was particularly notable when playing bouncing strokes like sautillé: some players reported perceiving a shift in the bouncing point, which refers to where the bow naturally bounces. Using the same experimental bow, we wanted to investigate further this influence of the bow rotational inertia. Through modal analysis, we examined the influence of moment of inertia on the bow's dynamic behavior. Additionally, a playing experiment involving motion capture was conducted on one player to explore how his control parameters were affected by a change of moment of inertia. This is of interest for bow makers as they can easily adjust the moment of inertia without affecting the stick's integrity by just varying the weight of the tip plate.

On the sensitivity of bifurcation-based electrostatic MEMS sensors: cantilever with tip plate

On the sensitivity of bifurcation-based electrostatic MEMS sensors: cantilever with tip plate

Legenda Tokoh Jokotole sebagai Representsi Pendidikan Karakter dalam Pengembangan Media Aplikasi Android pada Pembelajaran Bahasa Indonesia Aspek Kemampuan Membaca Kelas VII Di SMP Negeri se-Kabupaten Bangkalan

These studies are research on the development of research and development (R & D) using the Borg and Gall model. However, this development research takes several stages, namely, problem identification, information gathering, product design, and product testing. The results of the study found that Jokotole figures were legendary figures in the Madura region from Bangkalan, Sampang, Pamekasan, and Sumenep. The legend of Jokotole is found in every legend in the villages of Madura, there are 38 stories that tell the character of Jokotole both in his journey (stop) so as to create his own legend or narrate the battle against his enemies, while in the Bangkalan region there are 12 legends which tell Jokotole namely in the area of talk, keleyen, tip plate, and so forth. In this development research, the Jokotole story was made the main character in its emergence as a learning media based on andorid, because the tendency of the majority of Madurese people to accept Jokotole figures as positive figures starting from Jokotole's birth, journey, chivalry, spirituality, and death. Furthermore, in the development research this took the legend of the villages that gave rise to the character of Jokotole. Andorid media based on learning media applications ranging from stories, places (the area adopted from google map maps, questions, and reading ability tests using the ability formula to read elementary school children, namely junior high school. Jokotole figures in the andorid learning media application created using multimedia unity and design Corel Draw with Story Board Jokotole character journey when visiting the western Madura area until the trip in Bangkalan area, namely in the village of Telang, Socah, Ujung Plate, Bancaran, and Jambu Village.

Failure Analysis and Remedy Procedure for Cracking of Fuel Nozzles in a Gas Turbine

A common failure in a certain type of gas turbine, observed during the first periodic inspection, is radial cracks in the tip plate of gas fuel nozzles. Here, each gas turbine has 18 nozzles. In all nozzles and in all similar units, these cracks of lengths ranging from 1 mm to a maximum of 14.5 mm are observed. As prescribed by the manufacturer, the defective part must be removed and replaced by welding and machining of a new one. But this problem is repeated and observed in the next periodic visits, and in all units. Depending on the number of nozzles in each gas turbine unit and the number of units in total, these repairs are very expensive and time-consuming. In this paper, the failure is analyzed and the causes of the cracks in the nozzles are investigated. Studies show that the main causes of nozzle failure are residual stresses caused by welding and thermal stresses caused by the start-up and shutdown processes. According to results, a solution has been proposed to release these residual and thermal stresses. After the implementation of this method in 1998, no more failure has been reported by the repair team, which proves the effectiveness of this solution. Since this paper has been prepared based on technical reports from the years between 1996 and 1998, the cited references of this paper are these technical reports.

Effect of toughened epoxy resin on partial discharge at solid–solid interface**Supported by China Academy of Engineering Physics (Project 2014B05005).

A series of solid–solid interfaces, consisting of ceramic–epoxy resin interface samples with a tip–plate electrode, were investigated by performing partial discharge tests and real-time electrical tree observations. A toughening agent was added to the epoxy resin at different ratios for comparison. The impact strength, differential scanning calorimetry (DSC) and dielectric properties of the cured compositions and ceramic were tested. The electric field strength at the tip was calculated based on Maxwell’s theory. The test results show that the addition of a toughener can improve the impact strength of epoxy resin but it decreases the partial discharge inception voltage (PDIV) of the interface sample. At the same time, toughening leads to complex branches of the electrical tree. The simulation result suggests that this reduction of the PDIV cannot be explained by a change of permittivity due to the addition of a toughening agent. The microstructural change caused by toughening was considered to be the key factor for lower PDIV and complex electrical tree branches.

Improvement of wind turbine performance using a novel tip plate structure

In this study, the improvement of a horizontal-axis wind turbine performance is numerically studied using different configurations of tip plates. To do so, we independently develop a 3-D numerical code based on the finite volume method to solve the governing equations including the continuity and Reynolds Averaged Navier-Stokes equations using SST k-ω turbulence model. The NREL Phase VI blade is used as a target blade to suppress the induced drag of the blade tip vortices by the plates attached to the blade tips. The numerical results obtained indicate sixteen percent of power improvement in the two-blade horizontal axis wind turbine for the best tip plate configuration.

Oxidative coupling of methane in a corona discharge plasma reactor using HY zeolite as a catalyst

Oxidative coupling of methane in the presence of corona discharge plasma has been studied for the production of higher hydrocarbons under the conditions of ambient temperature and atmospheric pressure. The corona discharge was created by applying 3 kV (DC) between a tip and a plate electrode, 1.5 and 2.5 mm apart, in a tubular reactor. The effects of variables such as methane to oxygen ratio, total flow rate, electric current and more importantly, electrode gap distance were investigated. The electrode gap distance affected the electric field strength and subsequent plasma reactions. Five electrodes shaped like needles in the tip plate were applied to create more discharge intensity. At CH4/O2 ratio = 4, total flow rate = 4 mL/min, electric current = 10 mA and electrode gap distance = 1.5 mm, 31.9, 58 and 55 % of C2 yield, C2 selectivity and methane conversion, respectively were achieved. The main products were ethane, ethylene, acetylene, while CO and CO2 were also observed. The corona discharge interaction with HY-zeolite catalyst has led to low temperature methane conversion. Thus, the effect of surface modified zeolite catalyst was also examined. At a CH4/O2 ratio of 4 and total flow rate of 4 mL/min, 59.4, 69.7 and 85.3 %, of C2 yield, C2 selectivity and methane conversion, respectively were achieved. Experimental results revealed that corona discharge techniques, in the presence of HY-zeolite catalyst, has potentials for improving methane conversion, C2 selectivity and C2 yield.

Comparison of Experimental results with CFD for NREL Phase VI Rotor with Tip Plate

This article presents the results of 3D CFD rotor computations of a NREL Phase VI rotor with tip plate, a stall-regulated turbine with full-span pitch control, has a power rating of 20 kW. In this paper, A full three dimensional CFD–RANS approach by modeling the whole rotor of a wind turbine by means of periodicity was used. All the simulations were performed using the commercial multi-purpose CFD solver ANSYS CFX 12.1 with the transition model of Langtry and Menter is applied to a rotor at stationary wind conditions without wind shear. The comparisons were done for the blade with 0° yaw angle and 3° tip pitch angle on a single rotor blade without tower and nacelle. Reasonably good agreement is obtained when comparing modeled mechanical effects like power and thrust with findings from measurements. Similarly the spanwise force distributions are compared with experimental results for two wind speeds along with pressure distributions at five different spanwise locations. It is shown capability of 3D CFD computations that can be used to extract information about three-dimensional aerodynamic effects.

Electrospun Proficient Polymer Based Nano Fibers with Ceramic Particles

Cobaltite of magnesium, embedded in polyvinylpyrrolidone (PVP) polymeric fibers forming nanocomposite were synthesized by combining conventional sol-gel method with electrospinning method. Ultrathin diameter polymer fibers containing nanoregime ceramic particles were obtained by varying various process parameters like voltage, concentration, feed rate, distance between nozzle tip and base plate on an indigenously assembled electrospinning unit. Polyvinylpyrrolidone (PVP) and polyvinylalcohol (PVA) polymeric fibers in nanoregime were also synthesized separately and the effect of the process parameters was observed on the fiber thickness and continuity. Characterization was done to verify the synthesis parameter effect on structural morphology of polymer based nanofiber composite. Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) were used as tools for study of structural morphology and its correlation with process parameters.

Development of a three-dimensional scroll compressor

Scroll compressor has been employed in various appliances due to its advantages such as high efficiency and low vibration. For the purpose of further performance improvement in scroll compressor, the authors have developed a new conceptual three-dimensional compression mechanism (three-dimensional scroll) by adding an axial compression to the conventional radial compression. By realizing three-dimensional compression, which has been impossible for the conventional scroll, higher efficiency, higher reliability, and smaller size are achieved. Since the three-dimensional scroll has steps in scroll tip and end plate, the key point of efficiency improvement in the three-dimensional scroll is to minimize the gas leakage in the steps. Through cylinder pressure measurements and visualization tests, characteristics of the leakage in the steps are obtained and the optimum clearance ranges are determined. Based on this, the authors have developed high efficiency, small size, and lightweight three-dimensional scroll compressor for commercial air-conditioner. The developed three-dimensional scroll compressor archived 35 per cent smaller size, 26 per cent lighter weight, and 5.5 per cent improvement of efficiency compared with the conventional one.

Analysis acoustic emission and sound during the paperboard of cutting process

Abstract In industry a die cutting system is one of the important technologies for manufacturing paper packages. The cutting productivity or quality is maintained by operators’ experience. Various kinds of automatic techniques for the cutting condition have been evaluated. It was been confirmed that the acoustic estimation methods are useful for detecting the variation of the blade tip shape. From before reports, the relation of the variation of blade tip shape and applied load on the cutting edge has been clarified experimentally. The generation of acoustical signals also changes with the blade tip thickness. To investigate the origin of acoustic phenomena during the cutting process, some trials are carried out with the private designed machine. The acoustic phenomena are due to the collision behavior between the blade tip and counter plate. The cutting behavior of paperboard can be related to the acoustical differential of the displacement and vibration energy.

MODELLING, IDENTIFICATION AND PERFORMANCE ANALYSIS OF A GLASS FIBRE BUSHING

This paper is devoted to the identification and control of a glass fibre bushing. First a mathematical model, based on physical equations (electric, hydraulic and thermal balances), allows to predict the throughput, the electric power consumed and the temperature of the tip plate of the bushing. Then controls oriented linear models are obtained via experimental identification on the industrial process. Performance analysis of the existing control system is then provided by identifying the usual sensitivity functions on real data.

C1q and C4b Bind Simultaneously to CR1 and Additively Support Erythrocyte Adhesion

Previously, we showed that soluble C1q bound specifically to CR1 on transfected cells. If the CR1-C1q interaction were to participate in immune complex clearance, then this interaction should support E adhesion. Using a tip plate adhesion assay, we found that immobilized C1q mediated adhesion of human E. E binding to C1q was specifically inhibited by polyclonal anti-CR1 Fab fragments. Intact C1 was not efficient as an adherence ligand until it was treated with EDTA or the C1 inhibitor to remove the C1r2C1s2 complex from C1, leaving C1q. Titration of C1q alone, C4b alone, and C1q + C4b indicated that the two complement ligands were additive in their ability to support CR1-mediated adhesion of E. Analysis of binding to immobilized CR1 using a BIAcore instrument documented that C1q, C4b, and C3b binding were independent events. Additionally, C1q-dependent binding of immune complexes and heat-aggregated IgG to E was documented. These experiments confirm that the immune adherence receptor in humans, CR1, is the single receptor for all of the opsonic ligands of complement, provide evidence for a single C1q binding site on LHR-D of CR1, and suggest that C1q may participate in immune clearance.

An experimental study on aerodynamic improvements for edge girder bridges

This study aimed to develop simple, economical and effective aerodynamic attachments for edge girder bridges. In the study, wind tunnel tests and computational flow analyses were combined in order to more efficiently explore the effects of different attachments. As basic cross sections of edge girders, B′=4D type and B′=8D type (B': length between two I-beams, D:deck depth) were used in wind tunnel tests.As a result of the studies, we successfully developed a simple, economical and effective aerodynamic attachment called a “Tip Plate”. The tip plate makes remarkable aerodynamic improvements for edge girders. Especially, this aerodynamic attachment stabilizes torsional flutter and vortex-induced vibration by suppressing flow separation from the leading edge of the deck.

Solution of plate bending problems in fracture mechanics using a specialized finite element technique

This paper deals with the development and application of a special crack-tip finite element to obtain the bending and shear intensity factors for thin elastic plates containing cracks. The bending and shear intensity factors are then used to compute the Strain Energy Density Factor and the direction of crack initiation. The solution procedure is illustrated through several numerical examples. The problem of an axial flow compressor blade containing a crack is solved using a combination of special crack tip plate bending and plane stress elements.

Explanation of the anomalous spin behavior of satellites with long, flexible antennae.

Two satellites, Alouette I and Explorer XX (S-48), have exhibited anomalous spin behavior—• i.e., rapid spin decay—'that could not be explained on the basis of structural, mechanical, aerodynamic, or electrodynami c actions. The common feature of these satellites is the presence of long, extensible, tubular metal antennae (STEM's). The spin behavior is shown herein to be mainly a consequence of the joint action of solar-heating -induced bending of the antennae and solar radiation pressure. A theory of this phenomenon is derived, and the available test data confirm it. The theory pointed the way to a means of preventing the spin changes—i.e., tip plates perpendicular to the antennae—which was applied to Alouette II. The spin data on the latter satellite verify the theory. Both spin-up, and large-amplitude resonant behavior are predicted as possible modes of behavior for this class of vehicles. Nomenclature J diameter of boom deflection f unction [Eq.( 11)] flexural stiffness of boom total moment of inertia about spin axis thermal bending constant length of boom mass of tip plate radiation pressure local heat flux, per unit length of boom area of tip plate

Some exact solutions of the problem of super- and hypersonic gas flow about a yawed wing with fence

Individual examples are known of bodies of three-dimensional form for which it is possible to construct the solution of the flow problem, for example, bodies of star-shaped (polygonal) cross section [1, 2], or bodies of revolution (cone, ellipsoid) at an angle of attack, and so on. The role of such individual solutions is important in clarifying the characteristic features of the three-dimensional flow about bodies. The application of the hypersonic method of small perturbations [3], which reduces the problem of three-dimensional flow to the problem of the unsteady motion of a gas in two dimensions, and also the use of one of the known families of exact solutions of the two-dimensional problem on unsteady motion [4] make it possible to study the flow about a yawed wing with a tip plate in a hypersonic flow in certain particular cases. In the present paper, we construct a more general class of threedimensional bodies of thi s type (combinations of a yawed or triangular wing with tip plate directed parallel to the free stream) for which it is possible to construct simple exact solutions of the supersonic and hypersonic flow problem without use of the method of small perturbations. In a particular case, these solutions describe the flow about two mutually intersecting yawed wings. The example of flow about these bodies reveals an interesting phenomenon of strong interference at high velocities, when, as a result of the interference, local pressures are developed which far exceed the pressures on the isolated wing. w 1. Let us consider a supersonic gas flow about a portion of a triangular (or sweptback) wing similar to that shown in Fig. 1, with thefreestream directed opposite to the x coordinate axis.