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This paper presents a durability analysis of two types of copper leadframe, i.e. the un-oxidised leadframe and the oxidised leadframe. Both leadframe types were used in the fabrication process of a Quad Flat No-Lead (QFN) package, which can be said as a recent type of the 3D stacked die semiconductor package. This study involved the durability test and analysis on QFN packages when these packages were subjected under constant cyclic loadings. In order to perform the cyclic test, the procedure of the three-point cyclic bending test has been employed on the packages. In addition, a strain gauge which was connected to the dynamic data acquisition system was used for each tested QFN package for determining the response of the captured cyclic strain signal. It has been found that the variable amplitude pattern of signal response has been obtained during the constant cyclic test. The obtained response signals for both type of leadframe were then analysed using the approaches of signal processing technique, which is relatively new in this field. The collected response signal were analysed using the normal statistical methods, the Power Spectrum Density (PSD) calculation and also the time-frequency localization analysis. From the detail signal analysis, it has been found that the un-oxidised leadframe showed a lower range of strain response compared to the oxidised leadframe, indicating higher lifetime. As a result, this finding lead to the durability conclusion, for which the un-oxidised leadframe has more durability effects and it also has higher lifetime compared to the oxidised leadframe. Finally, a micro-crack phenomenon at the epoxy interface between the die and the leadframe was also observed for the QFN package with the oxidised leadframe.

To avoid the delamination of bimorph actuator and enhance the performance of the room-temperature type functionally graded (RTFG) piezoelectric bending actuator, the high temperature type FG (HTFG) piezoelectric bending actuator was designed and fabricated. The material compositions with different dielectric and piezoelectric constants were selected from the Pb(Ni_1/3N_b2/3)O₃-PbZrO₃-PbTiO₃ (PNN-PZ-PT) family, and used as the five layers in the HTFG piezoelectric actuator. Compared with the FG actuator, the HTFG actuator has advantages for applications at high temperature. The durability of the fabricated HTFG piezoelectric actuators was measured in a vibration test and compared with that of the bimorph actuator to evaluate the improvement of performance. The results show that the durability of the HTFG piezoelectric actuators is much higher than that of the bimorph actuator.

Asymptotic homogenization technique and two-scale convergence is used for analysis of macro-strength, fatigue and creep durability of composites with a periodic structure. The linear damage accumulation rule is employed in the phenomenological micro-durability conditions (for each component of the composite) under varying cyclic or creep loading. Both local and nonlocal strength and durability conditions are analyzed. The strong convergence of the strength and fatigue and creep damage measures as the structure period tends to zero is proved and their limiting values are estimated.

The concept of superhydrophobicity has been widely used after years of theoretical and experimental exploration. Researchers have obtained materials with excellent surface superhydrophobicity for numerous areas (e.g. textiles, paints, and coatings industries), through different design and synthesis methods using low surface energy components (LSECs) and micro/nanohierarchy composite structures. However, the durability of superhydrophobic material surfaces has gradually become a prominent obstacle to restricting applications. In this paper, advances in improving the durability of superhydrophobic surfaces in the past decade are reviewed, covering different schemes for recovering fractal surfaces based on the LSECs and micro/nanocomposite structures. It also presents a balanced review on wet chemical methods, chemical vapor deposition (CVD), layer-by-layer (LbL), microarc oxidation (MAO), and self-healing of the fractal surfaces, with the aim at developing sustainable superhydrophobicity. In addition, it innovatively summarized the research on the synthesis of self-healing superhydrophobic materials by machine learning methods. By the end it discusses perspectives on future development in this emerging research area.

Durability is a key factor to determine the service life of organic coating. The addition of nanomaterials can improve the mechanical properties and compactness of the organic coatings. As a kind of nanomaterial, g-C₃N₄ has lamellar structure and can be excited by visible light. At the same time, its cost is low. So it can be selected as a filler to prepare organic coating. The lamellar structure of g-C₃N₄ is favorable for its dispersion in organic coatings. Stearic acid is an environmentally friendly material with low surface energy. It can improve the hydrophobicity of the coating. In this research, porous g-C₃N₄ nanosheets were used as filler and stearic acid was used as surface modifier to prepare waterborne acrylic resin-based organic composite coating. The chemical reagent durability, electrochemical durability and mechanical properties of the composite coating were tested. At the same time, the photocatalytic degradation performance of the coating surface was also tested. The results showed that g-C₃N₄ as filler and stearic acid could effectively improve the durability of the waterborne acrylic resin coating. Meanwhile, the coating surface has obvious visible light-activated photocatalytic performance due to the addition of g-C₃N₄.

This paper presents an experimental investigation of the performances of concrete-filled glass fiber-reinforced polymer (GFRP) and GFRP externally wound steel circular tubes, subjected to freeze-thaw cycles ranging from -18°C to 18°C. The variation in hoop strains of the tubes during the freeze-thaw cycles was monitored by embedded fiber Bragg Grating (FBG) strain sensors in GFRP layers or between GFRP and steel tube. The residual hoop strain after each freeze-thaw cycle indicates the possible degradation of GFRP materials, such as cracks, debonding of GFRP-concrete or GFRP-steel due to mismatch of the coefficient of thermal expansion, as well as water immersion. A synergistic effect of FRP and steel tubes on the confinement of inside concrete was revealed, resulting in well-improved ductility. After 56 freeze-thaw cycles, remarkable degradation were found in the axial strength, modulus, and strain for concrete-filled GFRP tubes. However, the GFRP-steel tube system showed a negligible reduction in the ultimate axial strain by the freeze-thaw cycles with less degradation in the axial strength and modulus.

Durable superhydrophobic aluminum alloy surfaces were prepared through a facile method: combining high-speed wire electrical discharge machining and chemical modification. Three types of pulse width were selected to machine the aluminum alloy surfaces with different levels of surface roughness. The effect of immersion time in perfluorooctanoic acid on the wettability of the aluminum alloy surfaces was examined. The contact angle of the superhydrophobic aluminum alloy surfaces was $159.7\pm 3^{\circ }$, and the sliding angle was $1\pm 0.5^{\circ }$. After sanding with coarse sandpaper, the aluminum alloy surfaces still exhibited superhydrophobicity with a stroke of 450cm, indicating good mechanical durability. The prepared superhydrophobic aluminum alloy surface heated for 2h within the 190–240^∘C temperature range showed favorable thermal stability. In addition, the superhydrophobic aluminum alloy surface exhibited self-cleaning property. Therefore, the superhydrophobic aluminum alloy surface prepared by using the simple mass production method showed good mechanical stability, thermal stability, and self-cleaning property, as well as broad application potential.

In this paper, the durability of steel fiber reinforced concrete/SFRC is tested under the combined effects of carbonization and acid rain erosion. Mass loss rate, splitting tensile strength loss rate, eroded thickness and neutralization depth were taken as evaluation index. Test results indicated that the concrete mass loss rate, splitting tensile strength loss rate, and eroded thickness of SFRC under the multi-combined effects of acid rain and carbonization are greater than that of SFRC affected by the acid rain; the neutralization depth of SFRC are larger under the multi-factor effects of acid rain and carbonization compared to the superposition of them. According to the analysis of combined effects, the carbonization and acid rain has almost equal contribution to the neutralization of concrete. Proper mixture of steel fiber can effectively inhibit the erosion of original concrete under the effect of acid rain and reduce the neutralization depth. According to the varied mixing proportions in the test, the SFRC with the steel fiber mixing proportions of 1.5% has the best durability.

Developing photosensitizers with high durability is desirable to boost the practical application of photocatalytic hydrogen evolution. Herein, referring to the successful strategy in the field of light-emitting electrochemical cells, the reported Ir(III) complex with intramolecular $\pi –\pi$ interaction, Ir2, is used as a photosensitizer to explore its durability. Photocatalytic hydrogen evolution experiment exhibits that the durability of Ir2 is significantly improved with the duration of 39 h, which is three times longer than that of the classical Ir(III) complex Ir1 (ca. 13 h) under the same condition. As revealed by theoretical calculation, the incorporation of intramolecular $\pi –\pi$ interaction inhibits the rupture of metal–ligand bond in the excited state, thereby reducing the possibility of complex degradation. This is a novel approach to achieve a durable Ir(III) photosensitizer, which stimulates new molecular engineering endeavors. The finding proves the applicability of molecular design strategy in the field of light-emitting electrochemical cells to the photocatalytic hydrogen evolution system, thus boosting the cross integration of different disciplines.

With the growth of the construction industry, the role and importance of sustainable construction practices are also increasing. This study reviews the various advancements in the field of bio-based construction materials, including bio-aggregates, bio-binders, and bio-bricks. The origins of our centuries-old construction methods can be found in bio-based concrete materials, which have been revived and modernized to meet the needs of present-day construction. The integration of recovered construction and agricultural wastes plays a significant role in bringing these materials into the competitive building sector, aligning with sustainability goals. This study provides an in-depth examination of the processes and compositions required to achieve the desired strength and durability of bio-based materials. By comprehensively analyzing global research data, this study offers insights into the successful incorporation of biomaterials, emphasizing their potential to reduce carbon emissions and promote the responsible utilization of natural raw materials. This pathway moving toward more sustainable construction practices underscores the environmental benefits of bio-based concrete materials.

Lignocellulosic biomass has low energy content and is high in oxygen content. The proximate and ultimate composition of lignocellulosic biomass is inferior compared to coal. The grinding properties of biomass are completely different compared to coal. Biomass is fibrous, whereas coal is brittle. One way to make biomass look like coal is through torrefaction. The biomass is roasted in an oxygen-free environment at temperatures of 200–300°C for different residence times. During torrefaction, the biomass loses the low energy content of volatiles and produces a solid product that is high in energy content. The solid fraction rich in carbon is torrefied biomass or ‘biocoal’. Biocoal represents a renewable energy commodity that can substitute coal. The torrefied biomass has superior biomass in terms of proximate and ultimate composition and physical properties such as grinding and particle size, but the challenge is low in bulk density. The low bulk density is primarily due to the loss of low energy content volatiles during the torrefaction process. One way to increase the density of the torrefied biomass is through densification. The densification systems commonly used today are pellet mills and briquette presses. Densification helps improve the transportation and handling of low-density torrefied biomass. The challenge is in making a durable pellet using torrefied biomass as the biomass loses its binding ability. Typically, binders are used for making torrefied and densified biomass. The challenge of adding binders is introducing foreign material to the biomass and changing the composition. In addition, adding binders can change the torrefied material properties, such as hydrophobicity. The other option to overcome this limitation is to torrefy the densified biomass. This chapter looks at the production of torrefied and densified biomass and its physical properties.

Recycled Aggregate Concrete (RAC) was prepared with different recycled aggregate replacement ratio, 0, 30%, 70% and 100% respectively. The performances of RAC were examined by the freeze-thaw cycle, carbonization and sulfate attack to assess the durability. Results show that test sequence has different effects on the durability of RAC; the durability is poorer when carbonation experiment was carried out firstly, and then other experiment was carried out again; the durability is better when recycled aggregate replacement ratio is 70%.

An equivalent amount of metallurgical slag, water-quenched slag powder and activator was substituted for a part of the cement to prepare concretes at strength grades of C25, C30 and C40. Due to the filling effect, pozzolanic effect, micro-aggregate effect, and improvement of pore structure, the prepared concretes not only had greater strength compared with reference concrete, but also had greater impermeability and frostresistance. Moreover, the expansion reactions between alkali and aggregates were effectively inhibited. The slag and activator can serve as the raw materials for green concretes.

ADAMS software was used to analyze the kinematics of the crank link mechanism of the compressor. The ADMAMS/Durability module of ADAMS was used to analyze the durability of the crank link mechanism of the compressor. Through the analysis of the durability of the crank connecting rod mechanism, the service life of the mechanism was predicted, which has a good reference value for the improvement of the mechanism.

Bioactive Glass S53P4 (BG) is an osteoconductive allograft material used in obliterating larger bone cavities e.g. frontal sinuses. In vitro model was used to investigate the behaviour of a massive frontal sinus obliteration with BG to estimate the resorption of BG at the obliterated cavities. Two sizes of granules in sixteen separate BG amounts, weight 25 g, were tested both in simulated body fluid (SBF) and a buffer containing trishydroxymethyl aminomethane citric acid (TRIS-c.a) in standard conditions. The dissolution of silicon (Si) and phosphate was detected with current plasma atom emission spectroscopy (DCP-AES) monthly up to 6 months. The calcium phosphate (CaP)- and silica (Si)-gel -layers were studied by scanning electron microscopy (SEM) at 1,3 and 6 months. The cumulative loss of Si and P was stronger in TRIS-c.a than in SBF (p<0.0001) and it was higher with smaller than larger granules in both solutions (p<0.0001). In SBF soaked BG amounts, the CaP-layer occurred in the upper part of BG amount on the uppermost granules. In TRIS-c.a, at 3 to 6 months, CaP- layer occured on the granules in the centre and lower parts of BG amount. BG seems to be a durable filling material for frontal sinuses.

Carbon nanotubes have become hotspots in recent several years in the fields of nanomaterials. In construction engineering, the durability of the cement-based materials become salient. The characteristics and performances of carbon nanotubes (CNTs) and the durability of cement-based materials are introduced individually. With these understanding, the possibility of durability improved by multiwalled carbon nanotubes (MWNTs) is also analyzed. It is concluded that the key of the problem are the uniform dispersion of CNTs in the matrix, the compatibility between MWNTs and the matrix, the characteristics and the mechanism of the durability, lay the foundation for the engineering application.

With the growth of the construction industry, the role and importance of sustainable construction practices are also increasing. This study reviews the various advancements in the field of bio-based construction materials, including bio-aggregates, bio-binders, and bio-bricks. The origins of our centuries-old construction methods can be found in bio-based concrete materials, which have been revived and modernized to meet the needs of present-day construction. The integration of recovered construction and agricultural wastes plays a significant role in bringing these materials into the competitive building sector, aligning with sustainability goals. This study provides an in-depth examination of the processes and compositions required to achieve the desired strength and durability of bio-based materials. By comprehensively analyzing global research data, this study offers insights into the successful incorporation of biomaterials, emphasizing their potential to reduce carbon emissions and promote the responsible utilization of natural raw materials. This pathway moving toward more sustainable construction practices underscores the environmental benefits of bio-based concrete materials.