Mg-Y-Zn alloys with long period stacking ordered(LPSO)structure have received much attention recently and exhibit great potential in applications such as automotive,aerospace and in bio-medical fields.This paper aimed...Mg-Y-Zn alloys with long period stacking ordered(LPSO)structure have received much attention recently and exhibit great potential in applications such as automotive,aerospace and in bio-medical fields.This paper aimed to investigate the effect of different phase constitution of LPSO structures on corrosion rate of bio-medical Mg-Y-Zn alloys.The results showed that as-cast Mg98.5Y1Zn0.5 alloys containing only 18R structure exhibited the highest corrosion resistance with the corrosion rate of 2.78 mm/year.The precipitation of 14H lamellas within a-Mg grains during solid solution treatment introduced the crystallographic orientation corrosion by accelerating micro-galvanic corrosion.The increase of 18R/14H interfaces deteriorated the corrosion resistance,and the grain boundaries also suffered from severe electrochemical dissolution.This work suggested that Mg-Y-Zn alloys with single LPSO structure(either 18R or 14H)exhibited better corrosion resistance than alloys with co-existence 18R and I4H LPSO structures.展开更多
Hydroxyapatite (HA) having chemical formula Ca10(PO<sub>4</sub>)<sub>6</sub>(OH)<sub>2</sub>, is the main chemical component of human bone tissue (70%). This is the reason why it ha...Hydroxyapatite (HA) having chemical formula Ca10(PO<sub>4</sub>)<sub>6</sub>(OH)<sub>2</sub>, is the main chemical component of human bone tissue (70%). This is the reason why it has been widely engaged in the dental and non-load bearing implantations, to cope up with the bone response as a bioactive material. In this study HA powder was synthesized by wet chemical method, using phosphoric acid (H3PO4) and eggshells. The synthesized HA powder was characterized by X-ray diffraction analysis, Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and Fourier transform (FT-IR) spectroscopy. The Thermos gravimetric analysis (TGA-DTA) was also carried out to evaluate the stability of the synthesized HA powder at higher temperatures. The results of the study indicate that sintered (at 900°C) HA powder resembles the feature of pure and single apatite phase having favourable Ca/P ratio ranging from 1.7 to 2.4.展开更多
Magnesium and its alloys have gained significant popularity due to their light weight and their potential for use as bioresorbable materials.However,their application is limited in practice due to their relatively poo...Magnesium and its alloys have gained significant popularity due to their light weight and their potential for use as bioresorbable materials.However,their application is limited in practice due to their relatively poor corrosion resistance.Several methods are available for improving the corrosion resistance of Mg alloys for bio-applications such as using different coatings,alloying,and modifying the microstructural parameters such as the grain size and the crystallographic texture.This review provides a comprehensive summary of the effects of crystallographic texture and twinning,as one of the most important deformation mechanisms of Mg and Mg alloys,on the corrosion behavior.Regarding the crystallographic texture,it is shown that theoretically the basal planes should exhibit a lower corrosion rate but in some cases,such as when there is a galvanic effect or when corrosion films control the overall corrosion behavior,different results may take place.Also,there are contradictory results concerning the effect of twinning on the corrosion behavior.Thus,in some cases twinning may provide preferential sites for corrosion due to the higher energies of atoms located in the twin region by comparison with normal atomic positions in the crystalline lattice whereas there are also other examples where experiments show that twins produce more protective films than in the surrounding matrix.展开更多
Natural anisotropic nanostructures occurring in several organisms have gained more and more attention because of their obvious advantages in sensitivity, stability, security, miniaturization, portability, online use, ...Natural anisotropic nanostructures occurring in several organisms have gained more and more attention because of their obvious advantages in sensitivity, stability, security, miniaturization, portability, online use, and remote monitoring. Due to the development of research on nature-inspired bionic structures and the demand for highly efficient, low-cost microfabrication techniques, an understanding of and the ability to replicate the mechanism of structural coloration have become increasingly significant. These sophisticated structures have many unique functions and are used in many applications. Many sensors have been proposed based on their novel structures and unique optical properties. Several of these bio-inspired sensors have been used for infrared radiation/thermal, pH, and vapor techniques, among others, and have been discussed in detail, with an intense focus on several biomedical applications. However, many applications have yet to be discovered. In this review, we will describe these nanostructured materials based on their sources in nature and various structures, such as layered, hierarchical, and helical structures. In addition, we discuss the functions endowed by these structures, such as superhydrophobicity, adhesion, and high strength, enabling them to be employed in a number of applications in biomedical fields, including cell cultivation, biosensors, and tissue engineering.展开更多
An experimental study of bioheat transfer characteristics induced bypulsed-laser irradiation was presented. The heat transfer characteristics of bio-materials, and theinfluences of pulse duration, power density, speci...An experimental study of bioheat transfer characteristics induced bypulsed-laser irradiation was presented. The heat transfer characteristics of bio-materials, and theinfluences of pulse duration, power density, species of bio-materials, thickness and initialmoisture content of bio-materials on heat transfer were studied in details. The experimental resultsindicate that the penetration and absorption of laser in bio-materials are considerable, the heattransfer inside the bio-materials should include the effects of volumetric absorption, pulseduration, power density, bio-materials thickness, and material species have a significant influenceon the temperature variation.展开更多
The energy consumption of the construction sector and its overall environmental impact has greater potential for improvement than those of many other sectors.Most energy consumed throughout the lifecycle of a building...The energy consumption of the construction sector and its overall environmental impact has greater potential for improvement than those of many other sectors.Most energy consumed throughout the lifecycle of a building is expended during its operation and maintenance,for which the building envelope plays an important role.This study reports on the design,construction,and thermal performance evaluation of a ventilated facade.The facade should be quickly assembled,disassembled,and stored in containers for easy onward transport.Such features comply with the Rules and Buildins Code of the Solar Decathlon Middle East 2018 and the relevant Eurocodes.The facade is constructed using bio-based materials in keeping with the principles of a circular economy.The exterior cladding consists of sanitary paper,grass,reeds,recycled textiles,drinking water treatment waste,bio-based polyester resin,and other materials.Temperature and the air velocity measurements recorded on the facade in Dubai showed that the facade had contributed to cool temperatures within the apartment,particularly during the hottest hours of the day.The facade is a promising option for climates with hot summers and mild winters as it contributes to reducing energy consumption and the environmental impact of building materials.展开更多
基金the National Natural Science Foundation of China(Grant Nos.51774109 and 51979099)the Fundamental Research Funds for the Central Universities(Grant No.2018B48414 and 2018B690X14)+3 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX18_0570)The Key Research and Development Project of Jiangsu Province of China(Grant No.BE2017148)Postgraduate Education Reform Project of Jiangsu Province(JGLX19_027)Natural Science Foundation of China(Grant No.51979099).
文摘Mg-Y-Zn alloys with long period stacking ordered(LPSO)structure have received much attention recently and exhibit great potential in applications such as automotive,aerospace and in bio-medical fields.This paper aimed to investigate the effect of different phase constitution of LPSO structures on corrosion rate of bio-medical Mg-Y-Zn alloys.The results showed that as-cast Mg98.5Y1Zn0.5 alloys containing only 18R structure exhibited the highest corrosion resistance with the corrosion rate of 2.78 mm/year.The precipitation of 14H lamellas within a-Mg grains during solid solution treatment introduced the crystallographic orientation corrosion by accelerating micro-galvanic corrosion.The increase of 18R/14H interfaces deteriorated the corrosion resistance,and the grain boundaries also suffered from severe electrochemical dissolution.This work suggested that Mg-Y-Zn alloys with single LPSO structure(either 18R or 14H)exhibited better corrosion resistance than alloys with co-existence 18R and I4H LPSO structures.
文摘Hydroxyapatite (HA) having chemical formula Ca10(PO<sub>4</sub>)<sub>6</sub>(OH)<sub>2</sub>, is the main chemical component of human bone tissue (70%). This is the reason why it has been widely engaged in the dental and non-load bearing implantations, to cope up with the bone response as a bioactive material. In this study HA powder was synthesized by wet chemical method, using phosphoric acid (H3PO4) and eggshells. The synthesized HA powder was characterized by X-ray diffraction analysis, Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and Fourier transform (FT-IR) spectroscopy. The Thermos gravimetric analysis (TGA-DTA) was also carried out to evaluate the stability of the synthesized HA powder at higher temperatures. The results of the study indicate that sintered (at 900°C) HA powder resembles the feature of pure and single apatite phase having favourable Ca/P ratio ranging from 1.7 to 2.4.
基金the European Research Council under Grant Agreement No.267464-SPDMETALS(TGL)。
文摘Magnesium and its alloys have gained significant popularity due to their light weight and their potential for use as bioresorbable materials.However,their application is limited in practice due to their relatively poor corrosion resistance.Several methods are available for improving the corrosion resistance of Mg alloys for bio-applications such as using different coatings,alloying,and modifying the microstructural parameters such as the grain size and the crystallographic texture.This review provides a comprehensive summary of the effects of crystallographic texture and twinning,as one of the most important deformation mechanisms of Mg and Mg alloys,on the corrosion behavior.Regarding the crystallographic texture,it is shown that theoretically the basal planes should exhibit a lower corrosion rate but in some cases,such as when there is a galvanic effect or when corrosion films control the overall corrosion behavior,different results may take place.Also,there are contradictory results concerning the effect of twinning on the corrosion behavior.Thus,in some cases twinning may provide preferential sites for corrosion due to the higher energies of atoms located in the twin region by comparison with normal atomic positions in the crystalline lattice whereas there are also other examples where experiments show that twins produce more protective films than in the surrounding matrix.
基金Acknowledgements We gratefully acknowledge financial support from the Innovative and Entrepreneurial Talent Recruitment Program of Jiangsu Province, the National Natural Science Foundation of China （21405014, 21635001, 21627806 and 21501026）, Key Research and Development Plan of Jiangsu Province BE2016002, the Project of Special Funds of Jiangsu Province for the Transformation of Scientific and Technological Achievements （BA2015067）, the 111 Project （B 17011, Ministry of Education of China）, and the Natural Science Foundation of Jiangsu Province （B K20140626 and B K20140619）. China Postdoctoral Science Foundation funded Project （2017M621597）. The Fundamental Research Funds for the Central Universities （2242018R20011）.
文摘Natural anisotropic nanostructures occurring in several organisms have gained more and more attention because of their obvious advantages in sensitivity, stability, security, miniaturization, portability, online use, and remote monitoring. Due to the development of research on nature-inspired bionic structures and the demand for highly efficient, low-cost microfabrication techniques, an understanding of and the ability to replicate the mechanism of structural coloration have become increasingly significant. These sophisticated structures have many unique functions and are used in many applications. Many sensors have been proposed based on their novel structures and unique optical properties. Several of these bio-inspired sensors have been used for infrared radiation/thermal, pH, and vapor techniques, among others, and have been discussed in detail, with an intense focus on several biomedical applications. However, many applications have yet to be discovered. In this review, we will describe these nanostructured materials based on their sources in nature and various structures, such as layered, hierarchical, and helical structures. In addition, we discuss the functions endowed by these structures, such as superhydrophobicity, adhesion, and high strength, enabling them to be employed in a number of applications in biomedical fields, including cell cultivation, biosensors, and tissue engineering.
基金This research was financially supported by the Chinese National Key Foundation Research Subject (No.G2000026305), National Natural Science Foundation of China (No.50276060), and the director foundation of Institute of Engineering Thermophysics, Chinese A
文摘An experimental study of bioheat transfer characteristics induced bypulsed-laser irradiation was presented. The heat transfer characteristics of bio-materials, and theinfluences of pulse duration, power density, species of bio-materials, thickness and initialmoisture content of bio-materials on heat transfer were studied in details. The experimental resultsindicate that the penetration and absorption of laser in bio-materials are considerable, the heattransfer inside the bio-materials should include the effects of volumetric absorption, pulseduration, power density, bio-materials thickness, and material species have a significant influenceon the temperature variation.
基金This research was supported by the Stimuleringsfonds Metropool Regio Eindhoven(proj.nr.LINQ-5670),Europees Innovatieprogramma Zuid Nederland(proj.nr.Innovationspace-PROJ.01736),and Impulsregeling S mart E nergy R egios Brabant(proj.nr.LINQ)voor innovatie en bedrijvigheid in energie in de gebouwde omgeving voor bedrijven in de provincie Noord-Brabant.
文摘The energy consumption of the construction sector and its overall environmental impact has greater potential for improvement than those of many other sectors.Most energy consumed throughout the lifecycle of a building is expended during its operation and maintenance,for which the building envelope plays an important role.This study reports on the design,construction,and thermal performance evaluation of a ventilated facade.The facade should be quickly assembled,disassembled,and stored in containers for easy onward transport.Such features comply with the Rules and Buildins Code of the Solar Decathlon Middle East 2018 and the relevant Eurocodes.The facade is constructed using bio-based materials in keeping with the principles of a circular economy.The exterior cladding consists of sanitary paper,grass,reeds,recycled textiles,drinking water treatment waste,bio-based polyester resin,and other materials.Temperature and the air velocity measurements recorded on the facade in Dubai showed that the facade had contributed to cool temperatures within the apartment,particularly during the hottest hours of the day.The facade is a promising option for climates with hot summers and mild winters as it contributes to reducing energy consumption and the environmental impact of building materials.
