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Photographic films and glass plates are widely used as phototools for PCB production. In this two‐part paper photographic and physical characteristics of the products are discussed as well as their differences and specific features. Terms such as contrast, density, speed, processing, etc. are explained and dimensional stability is discussed in depth. Suggestions are made for proper handling of the photographic materials.

To solve the instability problem of Zhangjiayao landslide caused by rainfall, the internal mechanism of slope instability and the supporting effect of anti-slide piles are studied. The research results can provide theoretical basis for the prevention and control of loess landslides.

A three-dimensional finite element model of Zhangjiayao landslide is established by field geological survey, laboratory test and numerical simulation.

The results show that Zhangjiayao landslide is a loess-mudstone contact surface landslide, and rainfall leads to slope instability and traction landslide. The greater the rainfall intensity, the faster the pore water pressure of the slope increases and the faster the matrix suction decreases. The longer the rainfall duration, the greater the pore water pressure of the slope and the smaller the matrix suction. Anti-slide pile treatment can significantly improve slope stability. The slope safety factor increases with the increase of embedded depth of anti-slide pile and decreases with the increase of pile spacing.

Based on the unsaturated soil seepage theory and finite element strength reduction method, the failure mechanism of Zhangjiayao landslide was revealed, and the anti-slide pile structure was optimized and designed based on the pile-soil interaction principle. The research results can provide theoretical basis for the treatment of loess landslides.

1. A three-dimensional finite element model of Zhangjiayao landslide is established.

2. Zhangjiayao landslide is a loess-mudstone contact surface landslide.

3. The toe of Zhangjiayao slope is first damaged by heavy rainfall, resulting in traction landslide.

4. The deformation of Zhangjiayao slope is highly dependent on rainfall intensity and duration.

5. The anti-slide pile can effectively control the continuous sliding of Zhangjiayao slope.

A three-dimensional finite element model of Zhangjiayao landslide is established.

Zhangjiayao landslide is a loess-mudstone contact surface landslide.

The toe of Zhangjiayao slope is first damaged by heavy rainfall, resulting in traction landslide.

The deformation of Zhangjiayao slope is highly dependent on rainfall intensity and duration.

The anti-slide pile can effectively control the continuous sliding of Zhangjiayao slope.

The purpose of this paper is to evaluate the mechanical properties of photopolymer/CB (carbon black) nanocomposite when applied in a visible-light rapid prototyping (RP) machine.

The mechanical properties of the samples such as hardness and tensile strength along with thermal stability were analyzed. The curing time behavior of the photopolymer/CB nanocomposites was tested by using a rigid-body pendulum rheometer. The shrinkage property and dimensional stability were also analyzed using the technique according to ASTM D2566 and ASTM D1204, respectively.

The results showed that the prototype fabricated from pristine photopolymer tended to exhibit poor mechanical properties and low thermal stability. However, after adding the photopolymer with various concentrations of nano-CB and dispersant in appropriate composition, the photopolymer/CB nanocomposite prototype not only reduced its curing time but also enhanced its mechanical properties, thermal stability and dimensional stability.

The presented results can be used in a visible-light RP machine.

The mechanical and thermal properties of photopolymer are improved with nano-CB additives for a RP system.

High demands are placed on base materials for present‐day printed circuits. The requirements for multilayer materials are examined including satisfying criteria regarding low dielectric constant, high glass transition temperature and dimensional stability. Comparisons are made involving different resin systems and reinforcement materials. Improvements in material characteristics are often accompanied by disadvantages in terms of processability, copper peel strength and price. The properties of a number of paper‐based laminates and their requirements are discussed. It is concluded that no ‘ideal’ base material is available which simultaneously fulfills all demands including price.

The printed circuit industry is on the verge of witnessing a change in structure, brought about by the advent of Moulded Thermoplastic PCBs and accompanying electroless plating technology. Currently all fabricators use essentially similar technology and pressed laminates, except a few innovative companies who are exploring the new technology for moulded thermoplastic printed circuit boards. The new moulded PCBs (MPCBs) have many claimed advantages over traditional boards, such as: lower production costs through faster moulding fabrication; more precise drilled holes and board dimensions; custom designed hole shape and board shape; integral moulding of board and device enclosure; higher thermal stability and dimensional stability; better dielectric properties for reduced cross‐talk; and adaptable integration of circuit design and components. Certainly the industry will not change overnight, but, as changes take place, the traditional materials will be replaced by new polymers, chemicals and equipment, as MPCBs are introduced into relevant fields of application. Some firms believe that MPCBs are only a small specialised market, while others feel that they will eventually replace many of the traditional PCB constructions of today. Chem Systems has analysed these views and prepared a study which will help to discover the real impact of MPCBs on designers, fabricators and suppliers on a worldwide basis.

The purpose of the study was to develop the forming methodology for FML laminates with complex shapes, based on aluminium and epoxy-glass composite.

The subject of research encompassed Al/GFRP fibre metal laminates. Autoclave process has been selected for FML profiles production. The manufacturing process was followed by quality analysis for laminates produced.

The achievement of high stability and dimensional tolerance of thin-walled FML laminates is ensured by developed technology. The values of selected sections angles are significantly limited as a result of forming of FML laminates through the components performing. Failure to adhere to technological recommendations and to high regime of developer technology may lead to the occurrence of defects in FML.

Thin-walled composite structures could be applied in light-weight constructions, such as aircraft structures, which must meet rigorous requirements with regard to operation under complex load. The development of this type of technology may contribute to increased importance of FML sections in research area and finally to increased scope of their applications.

The production of thin-walled FML profiles with complex geometry, which would be characterized by dimensional stability and repeatable structural quality free of defects, is associated with many problems. No studies have been published so far on an effective forming process for FML laminates with complex shapes. Developed methodology has been verified through quality evaluation of produced profiles by means of non-destructive and destructive methods. The development of this type of technology may contribute to increased importance of FML, e.g. in aerospace technology.

Face masks are the most recommended precautionary measure since the emergence of SARS-CoV-2 since 2020 and the most useful PPE against this virus and its variants so far. This study aims to develop reusable and biodegradable mask from 100% regenerated bamboo or/and its blend. Selection of natural and regenerated textile materials is to minimize generation of solid waste. This attempt will eventually protect our earth by minimizing or better discontinuing the production of the disposable nonbiodegradable face masks available worldwide.

Hundred percent regenerated bamboo and 50:50 bamboo:cotton were selected to knit plain and interlock fabrics for manufacturing of reusable sustainable face masks. A 2³ 3²-mixed-level factorial design was applied to study the effect of liquor ratio and temperatures, fabric structure, blend ratios and finishes at three different levels. Model 2³ 3² has two factors (liquor ratio and temperatures) at three levels and three factors (fabric structure, blend ratios and type of finish) at two levels. Knitted fabrics were then applied with antibacterial finishes; sanitized T99-19 and sanitized T27-22, separately at three different liquor ratios (1:10, 1:12 and 1:15) and temperatures (45, 55 and 65 °C) via exhaust method. After completing processing, fabric thickness, pilling resistance, dimensional stability, bursting strength, Berger whiteness index, air permeability and antibacterial properties of each trial were evaluated using standard test procedures.

Selected fabrics treated either by sanitized T27 or sanitized T99 in a liquor ratio of 1:15 against 65 °C, showed excellent bacteriostatic/bactericidal activity. However, 100% regenerated bamboo interlock knitted fabric treated with sanitized T99 in a liquor ratio of 1:15 at 65 °C has the most desired values of dimensional stability, pilling resistance, Berger whiteness, fabric thickness, air permeability and bursting strength which made it the best for the manufacturing of the masks. Reusable mask is comprised of three layers in which the first and the third layers were of selected 100% regenerated bamboo fabric while a PM2.5 filter was inserted in between. Bacterial filtration efficiency, particle filtration efficiency, biocompatibility and microbial cleanliness will be evaluated in future, to compare the performance of proposed reusable and biodegradable face mask with N95 masks and other fabric masks available commercially.

This study resulted in a development of reusable eco-friendly facemask which was not attempted by the preceding investigations. Outcomes of this work pave the way for a greener and safer earth by using easily obtainable regenerated bamboo fabrics, antibacterial finishes and knitted structures.

The influence of buoyancy forces on oscillatory Marangoni flow in liquid bridges of different aspect ratio is investigated by three‐dimensional, time‐dependent numerical solutions and by laboratory experiments using a microscale apparatus and a thermographic visualisation system. Liquid bridges heated from above and from below are investigated. The numerical and experimental results show that for each aspect ratio and for both the heating conditions the onset of the Marangoni oscillatory flow is characterized by the appearance of a standing wave regime; after a certain time, a second transition to a travelling wave regime occurs. The three‐dimensional flow organization at the onset of instability is different according to whether the bridge is heated from above or from below. When the liquid bridge is heated from below, the critical Marangoni number is larger, the critical wave number (m) is smaller and the standing wave regime is more stable, compared with the case of the bridge heated from above. For the critical azimuthal wave number, two correlation laws are found as a function of the geometrical aspect ratio A.

A new aramid base material for use in laminates to be applied to advanced surface mount technology was developed. A new fibre based on PPDETA (Poly‐p‐phenylene/3,4'‐diphenylether terephthalamide) was found to have negative thermal and hygroscopic expansion coefficients, low ionic impurities and high affinity to epoxy and polyimide resins. The fibre was processed into fabrics and papers to be used as a base material for printed circuit boards for advanced surface mount technology. Impregnation with a new epoxy resin with high purity and high temperature resistance implemented the development of a new laminate with minimal electromigration and high dimensional stability. Thus, a new laminate was developed to be used for LCCC, PGA, COB, TAB, Flip‐Chips and other advanced surface mount technologies. Reliability of the laminate to electromigration between surface conductors, between plated‐through barrels, and between opposed conductors was found to be one of the highest available today. These types of behaviour were related to the high purity and high temperature resistance of both the reinforcement material and the resin. The short life of through‐hole plating in thermal shock was improved by the application of a new plating technology. Application to multilayer boards and laminates with a low dielectric constant is also being investigated.

A developmental project has been initiated to create a new type of glass fabric, whose fibers are to be uniformly distributed in the laminate so as to comply with the requirement of homogeneity. As a result, various types of glass fiber fabrics have successfully woven through the uniquely developed “MS process”, and it has been verified that each of the glass fabrics possesses the most suitable structure to attain uniform distribution in the laminates. The laminates, using the newly developed glass fabrics, have proved that the micro‐diameter drilling, that is laser drilling and mechanical drilling with 0.1mm diameter, can be performed very easily with less drill bit breakage, and produces uniform drill holes. It has also been proved that the laminates with the new glass fabrics reveal improved mechanical properties such as lower CTE, decreased warp and twist and better dimensional stability compared with conventional laminates of glass epoxy. Various styles of new glass fabric cover the wide range of thickness from 100 microns down to 27 microns.