Study on Special Shaped Polyester Fibers and Development of Products

2021 ◽  
Vol 8 (3) ◽  
pp. 17-22
Author(s):  
Yeqian Ge ◽  
Qin Deyan ◽  
Wang Hongfang ◽  
Tu Jianhong ◽  
Wang Xuefei ◽  
...  
Keyword(s):  
Cross Section ◽  
Natural Fibers ◽  
Great Influence ◽  
Circular Cross Section ◽  
Synthetic Fibers ◽  
Pet Fabric ◽  
Knit Fabrics ◽  
Section Shape ◽  
Pet Fibers ◽  
Profiled Fibers

Non-circular profiled fibers are generally synthetic fibers that have a modified cross-section shape, which are created to mimic natural fibers or to obtain special properties. The shape of the cross-section has great influence on the properties of profiled polyester (PET) fibers and their fabrics. The structure and properties of flat-shaped and hexagonal-shaped profiled PET fibers and ordinary PET fibers, as well as the properties of their knit fabrics were characterized. Experimental results showed that air permeability, heat retention, and wrinkle resilience of profiled PET fabrics were better than that of circular a cross-section PET fiber fabric, while the circular cross-section PET fabric was softer than the profiled PET fiber fabrics.

Modeling the Phonon Transport in Nanowire with Different Cross-Section

2013 ◽  
Vol 401-403 ◽  
pp. 852-855
Author(s):  
Gao Hui Su ◽  
Zi Chun Yang ◽  
Feng Rui Sun
Keyword(s):  
Thermal Conductivity ◽  
Cross Section ◽  
Diffuse Reflection ◽  
Silicon Nanowire ◽  
Circular Cross Section ◽  
Phonon Transport ◽  
Reflection Mode ◽  
Section Shape ◽  
Section Size ◽  
The Cross

The phonon transport in silicon nanowire was simulated by Monte Carlo Method (MCM). The effect on the phonon transport of the boundary reflection mode, cross-section size and cross-section shape was studied. Analysis shows that diffuse reflection can result in phonon accumulation at the circumferential boundary. As the cross-section size decrease, the nonuniformity of the temperature distribution within the cross-section becomes more severe. When the area of the square cross-section silicon nanowire (SCSN) is equal to that of the circular cross-section silicon nanowire (CCSN), the thermal conductivity of them is more close to each other.

Effect of standoff distance and area ratio on the performance of circular exhaust ejector using computational fluid dynamics

2017 ◽  
Vol 232 (15) ◽  
pp. 2821-2832 ◽  
Author(s):  
L Singh ◽  
SN Singh ◽  
SS Sinha
Keyword(s):  
Fluid Dynamics ◽  
Reynolds Number ◽  
Cross Section ◽  
Circular Cross Section ◽  
Area Ratio ◽  
Standoff Distance ◽  
Tube Length ◽  
Mass Entrainment ◽  
Section Shape ◽  
Ejector Nozzle

Numerical investigation is carried out to study the effect of standoff distance and area ratio on mass entrainment of an air–air circular exhaust ejector. Nozzle and mixing tube are the two components of an ejector, and for the present study, circular cross section shape has been chosen. Numerical simulations have been carried out at Reynolds number in the range of 6.85 × 104 and 4.11 × 105. Area ratio is varied between 1.25 < area ratio < 4 and standoff distance is varied from 1 Dnz < standoff distance < 4 Dnz, where Dnz represent the nozzle exit diameter. It is observed that for the ejector configuration with area ratio as 2, 2.25, and 2.5, the mass entrainment characteristics are nearly independent of standoff distance between 1 Dnz to 4 Dnz. For ejector configuration with area ratio below 2, mass entrainment decreases with increase in standoff distance. For ejector configuration with area ratio greater than 2.5, mass entrainment increases with increase in standoff distance for the range investigated and has the tendency to taper off beyond 4 Dnz for most of the area ratios. Effect of change in mixing tube length is also studied. It is seen that the mass entrainment improves with increase in length up to 8 Dnz. Further increase in length does not effect mass entrainment. This study provides important guidelines that can aid in arriving at an optimal design of circular exhaust ejectors.

scholarly journals Efficiency of Hysteresis Rods in Small Spacecraft Attitude Stabilization

2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Assal Farrahi ◽  
Ángel Sanz-Andrés
Keyword(s):  
Thin Film ◽  
Cross Section ◽  
Circular Cross Section ◽  
Semiempirical Method ◽  
Spacecraft Attitude ◽  
Flight Data ◽  
Small Satellites ◽  
Attitude Stabilization ◽  
Section Shape ◽  
Good Agreement

A semiempirical method for predicting the damping efficiency of hysteresis rods on-board small satellites is presented. It is based on the evaluation of dissipating energy variation of different ferromagnetic materials for two different rod shapes: thin film and circular cross-section rods, as a function of their elongation. Based on this formulation, an optimum design considering the size of hysteresis rods, their cross section shape, and layout has been proposed. Finally, the formulation developed was applied to the case of four existing small satellites, whose corresponding in-flight data are published. A good agreement between the estimated rotational speed decay time and the in-flight data has been observed.

Preparation of Optical Reflective Fiber with Transparent Nylon

2013 ◽  
Vol 821-822 ◽  
pp. 7-13 ◽  
Author(s):  
Hui Yao Li ◽  
Sheng Lin Yang ◽  
Guang Li ◽  
Jun Hong Jin
Keyword(s):  
Cross Section ◽  
Protective Clothing ◽  
Cross Section Shape ◽  
Section Shape ◽  
Profiled Fibers

Optical reflective fiber has been widely used in protective clothing for road workers because of high-reflective effect which promised a strengthened visibility at night or in poor visibility. In this paper, four fibers with different cross section shape, i.e., round, triangle, rectangle and hollow pentagon, were melting spun from the transparent nylon which was analyzed and characterized previously. The spinning conditions were discussed in detail, and the hetercliteness of profiled fibers were also calculated. Both the reflectivity and brightness testing indicated that all profiled fibers showed the better reflective ability than the round one. Moreover, the mechanical, thermal and crystalline properties of round and triangle fibers after drawing were characterized.

scholarly journals Calculation of eigen frequency splitting of a cylindrical resonator of a solid-state wave gyroscope based on numerical integration of high accuracy

2019 ◽  
Author(s):  
O.S. Narajkin ◽  
F.D. Sorokin ◽  
A.M. Guskov ◽  
S.A. Kozubnyak ◽  
D.S. Vahlyarskiy
Keyword(s):  
Solid State ◽  
Angular Velocity ◽  
Cross Section ◽  
Circular Cross Section ◽  
High Accuracy ◽  
Cylindrical Resonator ◽  
Frequency Splitting ◽  
State Wave ◽  
Cross Section Shape ◽  
Section Shape

Solid-state wave gyroscopes are widely used in various fields of technology. The principle of their operation is based on the phenomenon of precession of the elastic wave, which rotates at an angular velocity proportional to the angular velocity of device body rotation. The accuracy of the device is significantly affected by splitting the gyroscope resonator frequency. The article considers splitting caused by the distortion of the cylindrical resonator cross-section shape. Since the splitting is very small, the perturbation method is usually used to determine it. The article proposes a new method for calculating the splitting based on the numerical high accuracy integration of equations of dynamics of a cylindrical shell with a non-circular cross section. To search for two very close frequencies, through the difference of which the splitting was found, a linear boundary eigenvalue problem was solved with retention of a large number of decimal places. Examples of determining the natural frequency splitting are presented for various laws of the distribution of the radial deviation of the cavity cross-section shape along the circumferential coordinate. Verification of the results was performed by the finite element method. When using the method each of the two close frequencies was calculated with high accuracy

Test of Cross-Section Shape of Air-Liquid Interface in Microgrooves With Micro-PIV Method

2011 ◽  
Author(s):  
Xuelei Nie ◽  
Xuegong Hu ◽  
Tao Wang ◽  
Dawei Tang
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Great Influence ◽  
Liquid Interface ◽  
Polynomial Curves ◽  
Micro Piv ◽  
Cross Section Shape ◽  
Section Shape ◽  
The Cross ◽  
Air Liquid Interface

Evaporation of liquid meniscus formed in microgrooves is associated with very high heat transfer rates, but the cross-section shape of air-liquid interface has a great influence to the heat transfer in microgrooves. But the real cross-section shape of interface in microgrooves is still unknown for us. In this work, the micro-PIV (Particle Image Velocimetry) method is used to test the cross-section shape of air-liquid interface in microgrooves. In the experiment, the camera is focus on different planes from top of the microgrooves to the bottom of the microgrooves. In each plane, we can see the boundary between the air and liquid through small particles added into the liquid. The positions of boundary in each plane for a given cross section are drawn in two-dimension coordinate. Then the cross-section shape of interface in microgrooves can be seen from the fitting curve. The results show that the cross-section shapes of the interface in microgrooves are not round, but polynomial curves. The curvature of interface in microgrooves changes along a single curve. Besides, the polynomial curves also vary along axial direction of the microgrooves. The variations are more obvious in vertical microgrooves than in horizontal microgrooves.

Influence of automobile sealing rib structure on sound insulation performance and optimization of section parameters

2021 ◽  
Vol 263 (1) ◽  
pp. 5769-5779
Author(s):  
Xian Wu ◽  
TengLong Jiang ◽  
JianWang Shao ◽  
GuoMing Deng ◽  
Meng Zhao
Keyword(s):  
Cross Section ◽  
Great Influence ◽  
Sound Quality ◽  
Optimal Combination ◽  
Sound Insulation ◽  
Section Shape ◽  
Rib Structure ◽  
The Difference ◽  
Orthogonal Optimization ◽  
Insulation Performance

The door sealing strip plays an important role in the sound insulation of the car, and its sound insulation performance has a great influence on the sound quality and comfort of the vehicle. The sound insulation performance of the seal can be analyzed by Finite Element-Statistic Energy Analysismodel. There are great differences in the cross-section of the door sealing strip system at different positions, which leads to the difference of sound insulation. Therefore, it is very important to study the sound insulation performance of the sealing strip by studying the parameters of different sections. This paper explores the influence of the structure of automobile sealing rib on the sound insulation performance. Taking the sound power of the receiving end of the sealing strip as the index, the orthogonal optimization test is carried out for the simplified section shape of the door seal strip: the wall thickness of the sealing strip, the height of the sealing strip and the rib length. The optimal combination of a set of sealing strip sections is established, and the sound insulation performance of the sealing strip is improved.

scholarly journals Study on Crush Tube Geometric Cross sections and Topology for Axial Crashworthiness

2020 ◽  
Vol 70 (3) ◽  
pp. 249-259
Author(s):  
T.J. Reddy ◽  
V. Narayanamurthy ◽  
Y.V.D. Rao
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Circular Cross Section ◽  
Road Vehicles ◽  
Element Analysis ◽  
Impact Forces ◽  
Axial Crush ◽  
Section Shape ◽  
Energy Absorbing ◽  
Initial Peak

Crush tubes are used as crash impact energy absorbing structure (EAS) and are located in the frontal compartment of road vehicles. Ideal crashworthiness of an EAS mandates that the equivalent decelerations due to impact forces should to be ≤ 20g; and crush force and stroke efficiencies should tend to unity. It is understood from the literature that no single geometric cross-section shape exhibits a near-ideal crashworthiness; and most EAS members exhibit a high initial peak crush force which is detrimental to the occupant safety, and moderate stroke and crush force efficiencies leading to a compromise in the total energy absorbed. In this paper, finite element analysis (FEA) methodology is formulated and experimentally validated for axial crush of a crush tube of SS304 material with circular cross section.  Subsequently, plastic deformation phenomenon and folding patterns in relation to crush force behaviour of crush tubes with various basic cross-sections of polygonal geometric shapes from triangle to octagon and circle are extensively studied through FEA. Further, two new geometric cross-section profiles with combination of basic shapes are proposed to combine the merits of different basic shapes. The crashworthiness of all basic cross-sections including the two proposed cross-section profiles is assessed based on standard parameters. The proposed new geometries may form a basis for the development of new EAS configurations for enhanced crashworthiness.

SAF file: It's really three dimensional file

2018 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Prof. Dr. Jamal Aziz Mehdi
Keyword(s):  
Cross Section ◽  
Root Canal ◽  
Three Dimensional ◽  
Circular Cross Section ◽  
Circular Motion ◽  
Root Canal Treatment ◽  
Metal Core ◽  
Rotating Blade

The biological objectives of root canal treatment have not changed over the recentdecades, but the methods to attain these goals have been greatly modified. Theintroduction of NiTi rotary files represents a major leap in the development ofendodontic instruments, with a wide variety of sophisticated instruments presentlyavailable (1, 2).Whatever their modification or improvement, all of these instruments have onething in common: they consist of a metal core with some type of rotating blade thatmachines the canal with a circular motion using flutes to carry the dentin chips anddebris coronally. Consequently, all rotary NiTi files will machine the root canal to acylindrical bore with a circular cross-section if the clinician applies them in a strictboring manner

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