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This study aims to explore the compressive behavior of hollow triply periodic minimal surface (HTPMS) cellular structures by selective laser melting (SLM).

This study presents a design method for gyroid hollow triply periodic minimal surfaces (G-HTPMS) and primitive hollow triply periodic minimal surfaces (P-HTPMS) cellular structures, and SLM technology was applied to manufacture these cellular structures. Compressive behaviors and energy absorption behaviors of hollow cellular structures were researched in this study.

Compared with normal gyroid triply periodic minimal surfaces (G-TPMS) and normal primitive triply periodic minimal surfaces (P-TPMS), the G-HTPMS and P-HTPMS have higher elastic modulus, plateau stress and effective energy absorption under uniaxial compression. The hollow design in HTPMS can enhance the mechanical properties and energy absorption of the cellular structure. Finite element analysis also demonstrates that the hollow design can reduce stress concentration, which improved the compressive curves from a severely fluctuating state to a relatively flat state and reduces fracture. According to compressive behaviors, G-TPMS and G-HTPMS are the bending-dominated cellular structures with strain hardening characteristics, and P-TPMS and P-HTPMS are the stretching-dominated cellular structures with strain softening characteristics.

This research provided a design method for HTPMS, and it was proved that the mechanical properties increased by hollow design inspired by bamboo.

This paper aims to investigate the water absorption behaviors and mechanical properties, according to water absorption and temperature, of components fabricated by fused deposition modeling (FDM) and injection molding. The mechanical properties of FDM and injection molded parts were studied under several environmental conditions.

FDM components can be used as load-carrying elements under a range of moisture and temperature conditions. FDM parts show anisotropic mechanical properties according to build orientation. Components were fabricated from acrylonitrile-butadiene-styrene in three different orientations. The mechanical properties of parts fabricated by FDM were compared to injection molded components made from the same material. Water absorption tests were conducted in distilled water between 20 and 60°C to identify the maximum water absorption rate. Both moisture and temperature were considered as environmental variables in the tensile tests, which were conducted under various conditions to measure the effects on mechanical properties.

The water absorption behavior of FDM components obeyed Fickian diffusion theory, irrespective of the temperature. High temperatures accelerated the diffusion rate, although the maximum water absorption rate was not affected. The tensile strength of FDM parts under dry, room temperature conditions, was approximately 26-56 per cent that of injection molded parts, depending on build orientation. Increased temperature and water absorption had a more significant effect on FDM parts than injection molded components. The tensile strength was decreased by 67-71 per cent in hot, wet environments compared with dry, room temperature conditions.

The water absorption behavior of FDM components was investigated. The quantitative effects of temperature and moisture on tensile strength, modulus and strain were also measured. These results will contribute to the design of FDM parts for use under various environmental conditions.

The purpose of this study is focused on the mechanical properties of multi-materials porous structures manufactured by selective laser melting (SLM).

The Diamond structure was designed by the triply periodic minimal surface function in MATLAB, and multi-materials porous structures were manufactured by SLM. Compression tests were applied to analyze the anisotropy of mechanical properties of multi-materials porous structures.

Compression results show that the multi-materials porous structure has a strong anisotropy behavior. When the compression force direction is parallel to the material arrangement, multi-materials porous structure was compressed in a layer-by-layer way, which is the traditional deformation of the gradient structure. However, when the compression force direction is perpendicular to the material arrangement, the compression curves show a near-periodic saw-tooth waveform characteristic, and this kind of structure was compressed consistently. It is demonstrated that the combination with high strength brittle material and low strength plastic material improves compression mode, and plastic material plays a role in buffering fracture.

This research provides a new method for the design and manufacturing of multi-materials porous structures and an approach to change the compression behavior of the porous structure.

The aim of this paper is to investigate transverse impact behaviour and energy absorption of 3‐D glass/polyester resin cellular woven composite impacted by flat‐ended rod and to discuss the failure modes of the composite under quasi‐static and dynamic loading.

The quasi‐static compression tests were conducted with MTS 810.23 tester. The impact behaviours of the 3‐D cellular woven composite were tested with a modified split Hopkinson pressure bar (SHPB) apparatus.

Failure loads and energy absorption capacities of the 3‐D cellular woven composite increase as the increase of load speed, i.e. the composite is strain rate sensitive. The failure loads and energy absorptions in warp direction are lower than those in weft direction at the same loading speed because of the lower linear density of warp yarns. The damage morphologies of the 3‐D cellular woven composite manifest the compression failure in the front side and tension failure in rear side.

The influence of different structure parameters on the failure mode should be studied.

The study provided information on the failure mode and energy absorption of the 3‐D cellular woven composite under impulsive loading. This could be used for light weight structure design, such as vehicle and aircraft stringer structures.

Understanding energy absorption of the 3‐D cellular woven composite under transverse impact is much more important than those under quasi‐static loading. This paper provides the results of dynamic mechanical properties of a new kind of 3‐D cellular woven composite under impact loading.

The purpose of this paper is to compare the influence of relative density (RD) and strain rates on failure mechanism and specific energy absorption (SEA) of polyamide lattices ranging from bending to stretch-dominated structures using selective laser sintering (SLS).

Three bending and two stretch-dominated unit cells were selected based on the Maxwell stability criterion. Lattices were designed with three RD and fabricated by SLS technique using PA12 material. Quasi-static compression tests with three strain rates were carried out using Taguchi's L9 experiments. The lattice compressive behaviour was verified with the Gibson–Ashby analytical model.

It has been observed that RD and strain rates played a vital role in lattice compressive properties by controlling failure mechanisms, resulting in distinct post-yielding responses as fluctuating and stable hardening in the plateau region. Analysis of variance (ANOVA) displayed the significant impact of RD and emphasised dissimilar influences of strain rate that vary to cell topology. Bending-dominated lattices showed better compressive properties than stretch-dominated lattices. The interesting observation is that stretch-dominated lattices with over-stiff topology exhibited less compressive properties contrary to the Maxwell stability criterion, whereas strain rate has less influence on the SEA of face-centered and body-centered cubic unit cells with vertical and horizontal struts (FBCCXYZ).

This comparative study is expected to provide new prospects for designing end-user parts that undergo various impact conditions like automotive bumpers and evolving techniques like hybrid and functionally graded lattices.

To the best of the authors' knowledge, this is the first work that relates the strain rate with compressive properties and also highlights the lattice behaviour transformation from ductile to brittle while the increase of RD and strain rate analytically using the Gibson–Ashby analytical model.

In the past decades, the desire to use natural source foods has increased because of environmental compatibility, safety and appropriate costs. Sonication is used in food industry owing to its short duration of process and saving energy. The purpose of this study is to investigate the effect of various maize starches in the batter on the oil absorption and quality assessment (moisture content) of chicken nuggets by using five mathematical models.

To determine the effects of different maize starches on oil absorption parameters, 5 per cent starches native, sonicated starch were substituted in batter instead of wheat flour. Suspensions contained native starch were treated with sonication (70 kHz, 5 min) using an ultrasound probe set. Samples were fried in a fryer at 150, 170 and 190°C for 1, 3and 5 min, respectively. Models were compared with R² and Arrhenius equation for estimating model prediction sufficiency.

Obtained results represented that between different formulated samples, maize starch with high temperature had main significant effect (p < 0.05) on moisture content of nuggets. During frying, the amount of oil loses significantly (p < 0.05) depended on temperature and time and sonication treatment.

Incorporation of sonication with maize starch at higher temperature on quality assessment has not been found.

This paper aims to prepare third-order nonlinear optical (NLO) organic materials with large nonlinear optimization value, high damage threshold and ultrafast response time.

A series of novel symmetric and asymmetric compounds possessing third-order NLO properties were synthesized using 1,3,5-tribromobenzene as the basis. The photophysical and electrochemical properties, as well as the click reactions, were characterized by means of UV–VIS–NIR absorption spectroscopy and cyclic voltammetry.

The donor–acceptor chromophores were inserted into compound, making the molecule to have a broader absorption in the near-infrared regions and a narrower optical and electrochemical band gap. It also formed an electron-delocalized organic system, which has larger effects on achieving a third-order NLO response. The third-order NLO phenomenon of benzene ring complexes was experimentally studied at 532 nm using Z-scan technology, and some compounds showed the expected NLO properties.

The click products exhibit more NLO phenomena by performing different click combinations to the side groups, opening new perspectives on using the system in a variety of photoelectric applications.

The purpose of this study was to reuse cement kiln dust (CKD) in cement products and report the results of determining the long-term compression and flexural tensile strengths of mortars containing CKD as a partial replacement of sulfate-resistant cement (SRC). During the manufacturing of Portland cement, voluminous quantities of the byproduct dust are produced, which is commonly known as CKD. In the past decade, according to environmental requirements, many researchers have attempted to reuse CKD in cement products.

The long-term compression and flexural tensile strengths of mortars containing CKD as a partial replacement of SRC were tested. The replacement ratios in this study were 0, 5, 10, 15 and 20 per cent. The specimens were exposed to a highly saline environment after normal curing in water for a 28-day period.

The results indicated a slight increase in the strength of CKD–SRC mortar containing 10 per cent CKD and moderate sulfate resistance when the CKD ratio reached 20 per cent, as compared to the reference mortar. In addition, CKD did not adversely affect the properties of SRC mortar subjected to sulfate exposure, even after one year.

The tests were inducted for the first time on SRC, and the new results can be used to produce an environmental-friendly concrete.

The authors aimed to develop environmentally stable NIR‐absorbing windows by blending a near‐infrared (NIR)‐absorbing dye and a photo‐crosslinkable polymer.

To prepare an environmentally stable NIR‐absorbing window, a NIR‐absorbing dye was mixed with crosslinkable poly(vinyl cinnamate) (PVCn). The crosslinking of PVCn was carried out by photo‐dimerisation reaction of cinnamate with UV‐exposure at a wavelength of 254 nm for 4 min.

The resistance of the photo‐crosslinked hybrid films against humidity, heat, and ultraviolet radiation damage was improved dramatically relative to the pristine NIR‐absorbing dye. These improvements result from the protection of NIR‐absorbing dye to moisture exposure in the presence of the polymer network.

The simple and practical method resulted in a dramatic improvement in the environmental stability of NIR‐absorbing window.

Engagement, motivation, and persistence are usually associated with positive outcomes. However, too much of it can overtax our psychophysiological system and put it at risk. On the basis of a neuro-dynamic personality and self-regulation model, we explain the neurobehavioral mechanisms presumably underlying engagement and how engagement, when overtaxing the individual, becomes automatically inhibited for reasons of protection. We explain how different intensities and patterns of engagement may relate to personality traits such as Self-directedness, Conscientiousness, Drive for Reward, and Absorption, which we conceive of as functions or strategies of adaptive neurobehavioral systems. We describe how protective inhibitions and personality traits contribute to phenomena such as disengagement and increased effort-sense in chronic fatigue conditions, which often affect professions involving high socio-emotional interactions. By doing so we adduce evidence on hemispheric asymmetry of motivation, neuromodulation by dopamine, self-determination, task engagement, and physiological disengagement. Not least, we discuss educational implications of our model.