We have measured the cross-plane Seebeck coefficient of short period InGaAs/InAlAs superlattices with 5nm wells and 3nm barriers with different doping concentrations. Contrary to the behavior of conventional bulk III-V materials, the Seebeck coefficient did not decrease monotonically with increasing doping concentration. A detailed numerical calculation based on semi-classical Boltzmann transpo...

background & aim: increasing economic role of medicinal herbs in recent society and complexity of modern technologies in production (planting and harvesting), transportation, storage, processing, quality evaluation, distribution, marketing and consumption of these products require a thorough understanding of their physical properties. coefficient of friction of plant on the various surfaces...

by means of first principles calculations we show that both rutile and anatase phases of bulk tio2 doped by s, se or pb can display substantial decreasing in the band gap (up to 50%), while doping by zr does not sizably affect the band-gap value. moreover, the absorption edge is shifted (up to 1 ev) to the lower energy range in the case of tio2 doped by s or pb that opens a way to enhancing of ...

please cite this article as : tavakoli-darestani r, kazemian gh, emami m, kamrani-rad a. poly (lactide-co-glycolide) nanofibers coated with collagen and nano-hydroxyapatite for bone tissue engineering. novel biomed 2013;1:8-15. background: a combination of polymeric nanofibrous scaffold and bioactive materials is potentially useful in bone regeneration applications. materials and methods: in th...

nowadays cmm machines are widely used in surface measurement and inspection. as inspection results from cmm machine are obtained by the means of measuring surfaces with direct contact, they are more precise than non-contact method (like optical measurement). however, cmm machines give more reliable and accurate results rather than non-contact methods but also these results come with error when ...

traditional training which also is called (foreman-peupite) is the eldest training systems in the world. although this system, can not be used as a modern engineering education but it has several factors which could be modified for engineering education and training factor such as occupational goals, on job training and how a turnyman to be come a foman. the paper is dealt with districts and ad...

cartilage is an avascular, aneural, and alymphatic connective tissue with a limited capacity caused by low mitotic activity of its resident cells, chondrocytes. natural repair of full thickness cartilage defects usually leads to the formation of fibrocartilage with lower function and mechanical force compared with the original hyaline cartilage and further deterioration can occur. tissue engine...

background: engineering new bone tissue with cells and a synthetic extracellular matrix represents a new approach for the regeneration of mineralized tissues compared with the transplantation of bone (autografts or allografts). methods: in this study, to mimic the mineral and organic component of natural bone, hydroxapatite (ha) and gelatin (gel) composite scaffolds were prepared. the raw mater...