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The purpose of this paper is to measure the thermal insulation of protective clothing with multilayer gaps in low-level heat exposures.

Nine different combinations of protective clothing systems with multiple air gaps are used to measure the thermal insulation by a self-designed bench-scale test apparatus in different levels of an external thermal radiation of 2-10 kW/m2. The outside and inside surface temperatures of each fabric layer are also measured to calculate the local thermal insulation of each fabric layer and each air gap.

The results show that the total thermal insulation of protective clothing under thermal radiation is less than that in normal environments, and the exposed thermal radiation will worsen the total thermal insulation of the multilayer fabric systems. Air gap plays a positive role in the total thermal insulation, and thus provides the enhanced thermal protection. It is also suggested that the local resistance of the air gap closer to the external thermal radiation is more easily affected by the thermal radiation, due to the different heat transfer ways in the fabric system and the external thermal radiation.

Effects of air gap on the thermal insulation of protective clothing, and contribution of the local thermal resistance of each fabric layer and each air gap to the total thermal insulation.

An installation has been developed for carrying out thermal cycling experiments on soldered SMT joints. Using this thermal cycle installation (which was developed by the authors) and a simulated chip carrier, study has been made of the influence of various factors on the reliability of soldered SMT joints during thermal cycling. These factors include the position of the soldered joint, the temperature range of the thermal cycle, the dwell time, etc.

Focuses on the development and capabilities of interconnect stress testing (IST), a stress testing method for printed circuit boards (PCBs) that is fast, repeatable and reproducible. IST technology was originally developed in the mid 1980s. Notes that using IST as an electrical test delivers a capability to remove the human factor from the decision making process of product acceptance or rejection and that the technology is emerging as an important test methodology for the assessment of PCB interconnects. IST has the capability to effectively and rapidly quantify the integrity of plated through holes and the unique ability to identify the presence and levels of post separations within a multilayer board.

This review paper aims to provide a better understanding of formulation and processing of anisotropic conductive adhesive film (ACF) material and to summarize the significant research and development work for the mechanical properties of ACF material and joints, which helps to the development and application of ACF joints with better reliability in microelectronic packaging systems.

The ACF material was cured at high temperature of 190°C, and the cured ACF was tested by conducting the tensile experiments with uniaxial and cyclic loads. The ACF joint was obtained with process of pre-bonding and final bonding. The impact tests and shear tests of ACF joints were completed with different aging conditions such as high temperature, thermal cycling and hygrothermal aging.

The cured ACF exhibited unique time-, temperature- and loading rate-dependent behaviors and a strong memory of loading history. Prior stress cycling with higher mean stress or stress amplitude restrained the ratcheting strain in subsequent cycling with lower mean stress or stress amplitude. The impact strength and adhesive strength of ACF joints increased with increase of bonding temperature, but they decreased with increase of environment temperature. The adhesive strength and life of ACF joints decreased with hygrothermal aging, whereas increased firstly and then decreased with thermal cycling.

This study is to review the recent investigations on the mechanical properties of ACF material and joints in microelectronic packaging applications.

One family of defects in soldered electronic assemblies that is almost invariably re‐worked is that due to outgassing, manifested as visible blowholes and solder blow‐out. It is known that re‐working can be very detrimental to the service life of an electronic assembly and should be avoided whenever possible. This paper describes work aimed to determine whether outgassing faults such as blowholes are harmful to service performance or whether more harm will be done by re‐working such faults. Standard test plated‐through‐hole (PTH) assemblies with controlled degrees of outgassing faults have been subjected to mechanical testing, thermal shock testing, mechanical fatigue, low cycle thermal fatigue and corrosion testing. Measurements in all these régimes have been carried out quantitatively with baseline controls. No evidence of significant loss of solder joint performance has been found, even for severe cases of solder loss. On the contrary, in cyclic fatigue testing, solder fillets with outgassing faults exhibit statistically significant performance enhancement. The conspicuous nature of blowholing and solder blow‐out undoubtedly over‐emphasises the problem during visual quality control inspection. Provided the copper barrel has been wet by the solder, outgassing faults should not be re‐worked. These faults should be used as process indicators and to draw attention to processes and the need for process control.

The purpose of this study is to fabricate and compare the mechanical and thermal properties of Sansevieria and Kaans fiber reinforced polyester matrices composites.

Treated Sansevieria and Kaans fiber was used as reinforcement for the fabrication of polymer matrix composites. Kaans fiber, which was available plenty in the delta region, but physical and mechanical properties of Kaans fiber were low when it compared with Sansevieria fiber. To make use of Kaans fiber for the fabrication of composite, the physical and mechanical properties have to be enhanced. So Egg shell powder was selected as a filler material to enhance the Kaans fiber reinforced composite. The selected fibers were properly weaved after alkali treatment. A three-layered (0°/45°/0°) Sansevieria fiber reinforced polymer (S-FRP) and Kaans fiber reinforced polymer (K-FRP) composite plates were fabricated using the compression molding method. As per American Society for Testing and Materials standards, the specimens were cut and mechanical, thermal and absorption properties of Sansevieria and Kaans fiber composites were investigated experimentally.

Tensile and flexural test reveals that K-FRP composite has good ductility and bending property than S-FRP composite plate. But from the other test results, S-FRP possesses high elongation capability than K-FRP. Thermo gravimetric analysis, moisture absorption and swelling test too done which clearly appeared S-FRP composite plate has prevalent execution than K-FRP composite plate.

This original research study enlists the mechanical, thermal properties and absorption properties of fabricated S-FRP and K-FRP composite plates.

The purpose of this paper is to analyze the impact of design solutions used in clothing on the thermal resistance of the material systems from which the clothing is made, design solutions used in clothing on its thermal insulation and clothing size on its thermal insulation properties.

This study involved laboratory tests of clothing protecting against cold and textile systems used in this type of garment using a “skin model” test stand and a thermal manikin.

Analysis of the results obtained from tests carried out showed that the design solutions used in a garment can model its local and overall insulation. It was found that using a bib in trousers has a dominant influence on the thermal properties of clothing. An important parameter is also the use of a hood, as well as the length of the jacket. No significant effect of other structural solutions, such as jacket fastening, pockets and reflective tapes, on the thermal performance of the clothing set was noted.

Although the reports available in the literature pay a lot of attention to the impact of the design of clothing protecting against cold on its thermal performance, most of the presented research results relate to the aspects of fit, whereas the analyses of the effects of other aspects of garment construction on thermal properties are lacking. Therefore, the analysis of the impact of design solutions used in clothing on its thermal insulation properties is a key original factor of this paper.

The aim of this paper is to examine the impact of layer thickness on irreversible thermal expansion, residual stress and mechanical properties of additively manufactured parts.

Samples were printed at several layer thicknesses, and their irreversible thermal expansion, tensile strength and flexural strength were determined.

Irreversible thermal strain increases with decreasing layer thickness, up to 22 per cent strain. Tensile and flexural strengths exhibited a peak at a layer thickness of 200 μm although the maximum was not statistically significant at a 95 per cent confidence interval. Tensile strength was 54 to 97 per cent of reported values for injection molded acrylonitrile butadiene styrene (ABS) and 29 to 73 per cent of those reported for bulk ABS. Flexural strength was 18 to 41 per cent of reported flexural strength for bulk ABS.

The large irreversible thermal strain exhibited that corresponding residual stresses could lead to failure of additively manufactured parts over time. Additionally, the observed irreversible thermal strains could enable thermally responsive shape in additively manufactured parts. Variation in mechanical properties with layer thickness will also affect manufactured parts.

Tailorable irreversible thermal strain of this magnitude has not been previously reported for additively manufactured parts. This strain occurs in parts made with both high-end and consumer grade fused deposition modeling machines. Additionally, the impact of layer thickness on tensile and flexural properties of additively manufactured parts has received limited attention in the literature.

The purpose of this paper is to acquire thermal conductivities of both fresh and preheated polyamide 12 powder under various conditions to provide a basis for effective and accurate control during the laser sintering (LS) process.

A Hot Disk® TPS 500 thermal measurement system using a transient plane source (TPS) technology was employed for thermal conductivity measurements. Polyamide 12 powder was packed at different densities, and different carrier gases were used. Tests were also performed on fully dense laser sintered polyamide 12 to establish a baseline.

Polyamide 12 powder thermal conductivity varies with packing density and temperature, which is approximately one-third bulk form thermal conductivity. Inter-particle bonding is the primary factor influencing polyamide 12 thermal conductivity.

Limited ranges of density were tested, and the carrier gas needed carefully control to prevent powder oxidation. Thermal properties obtained were not tested in the LS process.

This experimental result could be used to enhance thermal control during the LS process.

The purpose of this paper is to measure the thermal and moisture resistance of the knitted upper fabrics with the foot model, which provided basis for designing and producing sports shoes with thermal-moisture comfort.

In this paper, different yarn materials and fabric stitches were selected as the changing factors. The three kinds of yarn materials and the three kinds of fabric stitches were combined to design and weave eight pieces of knitted upper fabrics. Human sweating was simulated by the thermal-moisture comfort foot model, and then tested the thermal and moisture resistance of eight pieces of fabrics in different parts of the foot. Finally, the relationship between yarn material, fabric stitch, and the thermal and moisture resistance in different parts of the foot was analyzed by data.

The composition of the yarn material and fabric stitch has certain effect on the thermal-moisture comfort in different sections of the foot. When the yarn material of the four parts of the lateral arch, medial arch, ankle and heel is composed of 31.1tex moisture wicking polyester/33.3tex spandex coated yarn, the yarn material of the instep and toes is composed of 31.1tex ordinary polyester/33.3tex spandex coated yarn, and all parts of fabric stitch choose single-sided loop transfer stitch, the knitted sports shoes have the best thermal-moisture comfort.

The study used the thermal-moisture comfort foot model to simulate the human body metabolism and sweating system. Through the quantitative analyze of the thermal and moisture resistance of knitted upper fabrics to provide basis for the producers to design and product knitted sports shoes with good thermal-moisture comfort.