Search results

From all of these stages, cooling is the most significant stage that affects the productivity and the quality of the moulded parts [3].
Formula (10) shows that the cooling channels configuration does not directly affect the cooling time.
However, it affects the mould surface temperature, thus indirectly affect the cooling time.
Table 1 shows the material properties for coolant, mould inserts (cavity and core inserts) and plastic material.
Material Properties.

In terms of a quality of surface smoothness, profile, sharp blaze edge, surface roughness, peak to valley Ry and optical performance of the replica, the PMMA microstructures replicated under the optimal conditions, were ideally identical with those in the mold in dimension, and it was found that the demolding temperature is the most important factor for replication.
The process of this technology is comparably simple, but the mold inserts used for the manufacturing of microstructures themselves are microstructures and therefore sensible against all mechanical influences such as lateral forces induced by the difference between the thermal expansion coefficients of the mold and the substrate materials [4].
Therefore, in addition to the improvement of the material properties of the mold insert and its design, the molding process has to be performed carefully as possible.
A further condition for a quality of the hot embossed microstructure means that the thermal shrinkage and demolding do not affect any structural deformation compared to the mold structure.
The research on finding optimal molding conditions has been performed [4], but it is not well-introduced how the blazed microstructure and its optical performance are affected by molding error in hot-embossing.

The structure and properties of the prepared samples were studied by X-Ray Diffraction (XRD), Energy Dispersive X-Ray Spectroscopy (EDX), Field Emission-Scanning Electron Microscope (FE-SEM) and Ultraviolet-Visible Spectrophotometer (UV-Vis).
Iron (Fe) and Nitrogen (N) are the effective dopants for modification of the optical and photo-electrochemical properties of TiO2 [11,12].
UV-Vis (Shimadzu, UV-1800) in the wavelength of 300-700 nm was used to measure the optical properties of the samples.
Thus, the influencing factors in the photocatalytic degradation of MO are owed to the TiO2 structure, phase and surface area of the catalyst [7].
Hou, Deposited TiO2 thin films by atomic layer deposition (ALD) for optical properties, ARPN J.

Introduction Shrinkage cracking existing like cancer would affect the durability of cement-based materials and the safety of the building structure.
The authors considered that K value would be affected by some factors in the following aspects, namely material composition parameters (including water-cement ratio, aggregate-cement ratio, fiber content, fiber length, superplasticizer content and fly ash content), environmental parameters (including temperature, humidity, wind velocity and light intensity, characterized by water loss evaporation rate), initial structural parameters (segregation degree), and constraints condition parameters (constraint degree).
Based on these, the seven-element constitutive equation of plain mortar and the nine-element constitutive equation of the mortar with fiber when the factors of four aspects all changed were established in this paper, and were verified outdoors.
The multivariate constitutive equation (1) of K on seven factors is established as follows: K=5.23×0.110Wc×1.77Sc×0.990FA×0.460P×0.370Cd×1.93Sd×0.0740v (1) where Wc = water-cement ratio, Sc = aggregate-cement ratio, FA = fly ash content (%·c, c is the cement content (kg), the same below), P = superplasticizer content (%·c), Cd = constraint degree, Sd = segregation degree (cm), v = water loss evaporation rate (kg·m-2·h-1).
Effects of polypropylene fibres on the physical and mechanical properties of cement-based composites (I)--plastic shrinkage cracking resistance, J.

Nitrogen, as an austenite-forming element instead of Ni, contributes to the improvement of mechanic properties by solid solution strengthening [3, 4].
Degallaix et al. [8] researched the effect of nitrogen additions on the fatigue properties of AISI 316 (0.03-0.25N) and 21Cr-4Mn-9.5Ni-(0.34-0.39N) steels.
In the whole curve, the room temperature fatigue properties of the as-forged alloy are generally higher than that of the solid solution alloy.
The distance between striations varies with the amplitude of stress intensity factor.
Vogt, Fatigue properties of high nitrogen steels.

It has outstanding properties that draw much attention from several researchers.
Thus, in 2016, there was a significant increase in the research trend, besides several factors, including the economic, health, and environmental sectors.
Effects of immersion duration and temperature on mechanical properties of optical fibers aged in CTAC aqueous solution.
Yan, Fabrication and properties of sulfur (S)-doped ZnO nanorods, J.
Poulain, Effects of immersion duration and temperature on mechanical properties of optical fibers aged in CTAC aqueous solution, Eng.

The presence of Mn dispersoids is also a crucial factor in enhancing the mechanical properties of aluminium alloys [4]. 2xxx alloys with Mn and Zr present great potential to enhance its strength with the optimum control of Mn and Zr.
This result implies that not only the fraction recrystallized but the mechanism of microstructural evolution are affected by the presence of Mn.
[3] Staley, J.T., Properties Related to Fracture Toughness, ASTM STP 605, American Society for Testing and Materials, 1976

TiB2-(Ti,W)C Eutectic Composite Ceramics Prepared by Combustion Synthesis under High Gravity Xuegang Huang, Long Zhang, Zhongmin Zhaoa, Chuanzeng Pan and Guanling Su Laboratory of Special Ceramics, Institute of Advanced Materials, Mechanical Engineering College, Shijiazhuang 050003, China a zhaozm2007@Yahoo.cn Keywords: TiB2-(Ti,W)C composite; Combustion synthesis; High gravity; Structure transformation Abstract.
Introduction TiC-TiB2 composite ceramics exhibited superior properties such as high hardness and good chemical stability at high temperature in comparison to the conventional ceramet based on TiC and WC [1].
Currently, TiC-TiB2 composite ceramics have been prepared by hot-pressing or reactive hot-pressing, the two processes both require long exposures at high temperatures due to high degree of covalent bonding and the low self-diffusion coefficients of the constituent elements, hence, the high processing temperature adversely affects the microstructures of the materials due to grain growth and also increases the cost [2].
In terms of the current investigation of TiC-TiB2 quasi-eutectic composites prepared by combustion synthesis under high gravity recently [5], the WO3 was introduced into the combustion synthesis as another oxidants in thermit to avoid macrocracks by increasing the melting temperature of alloy liquid, and large-bulk, full-dense TiB2-(Ti,W)C eutectic composite ceramics were achieved, the correlations of the microstructures, structure formation and properties of these solidified TiB2-(Ti,W)C eutectic composite were discussed.
According to the literature [8], the key factor controlling the densification process of TiB2-(Ti,W)C is the liquid phase formed in the products.

Moreover, Garbacz [5] showed that in most cases acoustic properties of PCC are close to those for concrete substrate and NDT procedures developed for concrete assessment can be used for evaluation of repair efficiency [6].
Taking into account results of investigation of similar concrete slabs placed close to measurements place it can be assumed that carbonation did not affect NDT measurements [7].
Impact-Echo, IE: mechanical impact used to generate the stress waves; high penetration of concrete, frequency analysis of waveform. - evaluation of thickness of concrete slab and thick overlays, - defect detection in concrete, like flaws, delamination, honeycombing, debonding, - estimation of depth of surface-opening cracks. - detection of large defects, relatively deeply located, - needs expert for interpretation of results.
Ground Penetrating Radar, GPR: short electromagnetic pulses are used; variations in the electromagnetic properties are related to the presence of heterogeneities. - detection of delamination, - locating reinforcing bars in structures, - measurement of pavement thickness, - measurements of water content of fresh concrete. - improper estimation of relative dielectric constant resulted in large error, - results depends on in-situ conditions, - needs expert for interpretation of results.
The detection is possible if for D/t > 0,3 (D - steel bar diameter, t - cover thickness) and the fbar can be calculated from the equation: fbar = acp/4t, where cp – wave speed [m/s], t – coating thickness [mm], a - empirical factor depending on D/t ratio.

Their individual nature affects the mechanical, optical, magnetic, thermodynamic, catalytic and chemical properties.
One of the objectives of material scientists is to transpose the specific properties of these divided states of matter to the macroscopic scale.
For the shaping of these objects, the various treatments should not involve their deterioration and/or the loss of the divided state which would imply the disappearance of their specific properties.
In addition to the temperature, one of the factors limiting the traditional sintering of nano-powders, even under pressure, is obviously the duration of the cycle.
Single-wall (SWCNT) or multi-wall (MWCNT) carbon nanotubes have extremely interesting mechanical properties (e.g. low density, – Young's modulus higher than 1.1012Pa).