26 research outputs found
Quantum size effects on spin-tunneling time in a magnetic resonant tunneling diode
Full text linkWe study theoretically the quantum size effects of a magnetic resonant
tunneling diode (RTD) with a (Zn,Mn)Se dilute magnetic semiconductor layer on
the spin-tunneling time and the spin polarization of the electrons. The results
show that the spin-tunneling times may oscillate and a great difference between
the tunneling time of the electrons with opposite spin directions can be
obtained depending on the system parameters. We also study the effect of
structural asymmetry which is related to the difference in the thickness of the
nonmagnetic layers. It is found that the structural asymmetry can greatly
affect the traversal time and the spin polarization of the electrons tunneling
through the magnetic RTD. The results indicate that, by choosing suitable
values for the thickness of the layers, one can design a high speed and perfect
spin-filter diode.Comment: 6 pages, 5 figure
The Effects of Socio-Cultural, Economical, Political and Geographical Factors on International Trade (A Case Study on Afghan-India Trade Relations)
Get PDFFrom an early age, human beings have been involved in a number of works and activities for the supply and continuing of life, the most important and main work was to trade. Ever since humans began social life, their business and trade relationships have been more significant due to meeting and needs of their lives alongside other human relationships. Day by day human communities expanded and the world divided into dependent and independent countries, and the countries considering to their needs and other effective factors developed their trade relationships with each other. Afghanistan and India from the early age considering to the Economical, Social, Cultural, Political and Geographical factors have followed the good trade relationships with each other and this trend is expanding and developing day by day. India is the second importer and exporter for Afghanistan and the main motivation behind this trade is some impactful factors (Economical, Social, Cultural, Political and Geographical factors) that based on them the trade relationships between India and Afghanistan is increasing and developing
A new way of valorizing biomaterials: the use of sunflower protein for 1 a-tocopherol microencapsulation
Get PDFBiopolymer based microparticles were efficiently prepared from sunflower protein (SP) wall material and a-tocopherol (T) active core using a spray-drying technique. Protein enzymatic hydrolysis and/or N-acylation were carried out to make some structural modifications to the vegetable protein. Native and hydrolyzed SP were characterized by Asymmetrical Flow Field-Flow Fractionation (AsFlFFF). Results of AsFlFFF confirmed that size of proteinic macromolecules was influenced by degree of hydrolysis. The effect of protein modifications and the influence of wall/core ratio on both emulsions and microparticle properties were evaluated. Concerning emulsion properties, enzymatic hydrolysis involved a decrease in viscosity, whereas acylation did not significantly affect emulsion droplet size and viscosity. Microparticles obtained with hydrolyzed SP wall material showed lower retention efficiency (RE) than native SP microparticles (62-80% and 93% respectively). Conversely, acylation of both hydrolyzed SP and native SP allowed a higher RE to be reached (up to 100%). Increasing T concentration increased emulsion viscosity, emulsion droplet size, microparticle size, and enhanced RE. These results demonstrated the feasibility of high loaded (up to 79.2% T) microparticles
Subtrochanteric fracture location effect on surgical management using intermedullary nail (IMN) versus extramedullary plate (EMP): a finite element method analysis
No full textBackground
Finite Element Method (FEM) analysis of the subtrochanteric fracture (STF) location effect in the subtrochanteric region (STR) fixated with the Intermedullary Nail (IMN) versus Extramedullary Plate (EMP) implant.
Material and methods
A femur computed tomography (CT) scan was used to create a femur FE-model with a straight-line fracture located at the STR. During the analysis, the fracture was stepwise lowered from 0.5 to 4.5 cm below the lesser trochanter (LT) with a total of 9 steps of 0.5 cm. The IMN (using Proximal Femoral Nail Antirotation) and EMP (using Dynamic Hip Screw) implants were modelled and implemented for fracture management.
Results
EMP illustrated lower Von-Mises stress for the proximal fractures (until 3.5 cm below LT); whereas IMN showed lower stress for distal fractures (from 4 cm below LT). The mean Von-Mises stress ratio for IMN versus EMP also decreased from proximal (1.93) to distal (0.47) of STR, with an intersection cross-point at 3.8 cm below LT.
Conclusions
The simulation shows that for the straight-line STF, EMP seems more favourable for proximal and IMN is more likely favourable for distal fractures. However, more FEM studies need to be conducted (e.g., with different fractures or implant types) on this topic
