Current Issue : April - June Volume : 2016 Issue Number : 2 Articles : 9 Articles
Stability boots can protect the ankle ligaments from overloading after serious injury and facilitate protected movement in order to\naid healing of the surrounding soft tissue structures. For comparing different stability shoe designs and prototypes, a reliable and\nfast testing method (FTM) is required. The aim of this study was to assess the reliability of a novel custom-built device. Six different\nstability boots were tested in a novel device that allowed body weight to be taken into account using a pneumatic actuator. The\nfixation of the boots was controlled using two air pad pressure sensors. The range of motion (RoM) was then assessed during 5\ntrials at physiological ankle joint torques during flexion/extension and inversion/eversion. Furthermore the intraclass correlation\ncoefficient ICC was determined to assess the repetitive reliability of the testing approach. The measured ankle angles ranged from\n3.4âË?Ë? to 25âË?Ë? and proved to be highly reliable (ICC = 0.99), with standard deviations <9.8%. Comparing single trials to one another\nresulted in a change of 0.01âË?Ë? joint angle, with a mean error of 0.02âË?Ë?.The FTM demonstrates that it is possible to reliably measure\nthe ankle joint RoM in both the sagittal and frontal planes at controlled torque levels, together with the application of body weight\nforce....
Based on the atomistic tight-binding theory (TB) and a configuration interaction (CI) description, the electron-hole exchange\ninteraction in the morphological transformation of CdSe/ZnS core/shell nanodisk to CdSe/ZnS core/shell nanorod is described\nwith the aim of understanding the impact of the structural shapes on the change of the electron-hole exchange interaction.Normally,\nthe ground hole states confined in typical CdSe/ZnS core/shell nanocrystals are of heavy hole-like character.However, the atomistic\ntight-binding theory shows that a transition of the ground hole states from heavy hole-like to light hole-like contribution with the\nincreasing aspect ratios of the CdSe/ZnS core/shell nanostructures is recognized. According to the change in the ground-state hole\ncharacters, the electron-hole exchange interaction is also significantly altered. To do so, optical band gaps, ground-state electron\ncharacter, ground-state hole character, oscillation strengths, ground-state coulomb energies, ground-state exchange energies, and\ndark-bright (DB) excitonic splitting (stoke shift) are numerically demonstrated. These atomistic computations obviously show the\nsensitivity with the aspect ratios. Finally, the alteration in the hole character has a prominent effect on dark-bright (DB) excitonic\nsplitting....
Praying mantis is one of the most efficient predators in insect world, which has a pair of powerful tools, two sharp and strong\nforelegs. Its femur and tibia are both armed with a double row of strong spines along their posterior edges which can firmly grasp\nthe prey, when the femur and tibia fold on each other in capturing. These spines are so sharp that they can easily and quickly cut\ninto the prey. The geometrical characteristic of the praying mantis�s foreleg, especially its tibia, has important reference value for the\ndesign of agricultural soil-cutting tools. Learning from the profile and arrangement of these spines, cutting blades with tooth profile\nwere designed in this work. Two different sizes of tooth structure and arrangement were utilized in the design on the cutting edge.\nA conventional smooth-edge blade was used to compare with the bionic serrate-edge blades. To compare the working efficiency\nof conventional blade and bionic blades, 3D finite element simulation analysis and experimental measurement were operated in\npresent work. Both the simulation and experimental results indicated that the bionic serrate-edge blades showed better performance\nin cutting efficiency....
Furfural is an important chemical solvent and intermediate. Sensitive detection of this compound has attracted great interest in\nvarious fields. Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive method for material detection because of its\noptical enhancement effect of plasmonic nanostructures. This study presents a simple and versatile method to synthesize a SERS\nsubstrate, where poly aminothiophenol (PATP) was used to realize the stable combination of Au nanoparticles (AuNPs) and Au film\nvia self-assembly.The near-field electric field distribution was calculated using the finite difference time domain (FDTD) simulation\nto determine the parameters responsible for electric field enhancement. The simulation results show that SERS enhanced factors\nare sensitive to interparticle spacing and materials for solid support but insensitive to particle size. Moreover, the experimental\nresults show that the optimized substrates with the highest Raman activity were formed by six layers of 60nm AuNPs decorated\non a 30 nm thick Au film, thereby validating the simulation results. The SERS factor of the optimal substrates is approximately 5.57\nÃ?â?? 103, and the in situ detection limit is 4.8 ppm. The 3D Raman spectra, relative standard deviation values for major peaks, and\nchanges in signal intensity with time show the good reproducibility and stability of the substrates....
Knee injury is a common medical issue. A full understanding of the kinematics and mechanical properties of knees following total\nknee arthroplasty (TKA) repair utilizing patellar replacement (only the base of the patella is replaced) versus patellar retaining\nsurgical techniques is still lacking. In the current paper, we investigated magnetic resonance (MR) imaging data from knees\nrepaired by these two methods and evaluated total knee models created using imaging reconstruction technology that simulated\ngait conditions. Results revealed that patellar replacement had little influence on tibiofemoral kinematics, although the tibia-surface\nequivalent stress increased slightly. By contrast, patellar replacement had a significant influence on the patellofemoral joint; patellar\ninternal rotation, external rotation, and medial-lateral translation were all increased. Moreover, the stress distribution on patellar\nprostheses was altered, resulting in an increased surface maximal equivalent stress on the corresponding area. Moreover, during\nthe gait cycle, we found that the area with maximal equivalent stress shifted its position. Finally, the patellofemoral joint showed\ndecreased motion stability. From the view of kinematics and mechanics, this paper suggests that patella should be retained during\nTKA if it is possible.The present study presented approaches and technologies for evaluating kinematics and mechanical properties\nof total knee joint after TKA under gait loads....
We demonstrate an all-optical modulator based on self-modulation in a one-dimensional slab photonic crystal (PhC) by using\noptical Kerr nonlinearity of graphene and Fano resonance effect. It has been shown that the effect of Fano resonance in a one dimensional\nslab PhC for intensity enhancement can provide low threshold (âË?¼1MW/cm2), high frequency (>1 THz), and wide\ndynamic range (>3 THz) tunability for the all-optical self-modulator. Such a self-modulator can find applications in optical pulse\ngenerations, optical clocks, frequency shifting, and so forth....
Multiwalled carbon nanotube(MWCNT) enhanced MWCNT/TiO2 nanocomposites were synthesized by surface coating of carbon\nnanotube with mixed phase of anatase and rutile TiO2 through a modified sol-gel approach using tetrabutyl titanate as raw material.\nThe morphological structures and physicochemical properties of the nanocomposites were characterized by FT-IR, XRD, DTA-TG,\nTEM, and UV-Vis spectra. The results show that TiO2 nanoparticles with size of around 15nm are closely attached on the sidewall\nof MWCNT.The nanocomposites possess good absorption properties not only in the ultraviolet but also in the visible light region.\nUnder irradiation of ultraviolet lamp, the prepared composites have the highest photodegradation efficiency of 83% within 4 hours\ntowards the degradation of Methyl Orange (MO) aqueous solution. The results indicate that the carbon nanotubes supported TiO2\nnanocomposites exhibit high photocatalytic activity and stability, showing great potentials in the treatment of wastewater....
Formation of optical centers in nanodiamond grains with narrow, near-infrared emission at room temperature is one of the\nmost important challenges nowadays. Our aim was to form a metal-related color center through the CVD growth process of\nnanodiamond. Previously undocumented photoluminescence (PL) system with 865 nm zero-phonon line (ZPL) and 2nm full\nwidth at half maximum (FWHM) was successfully created in nanodiamond grains.According to the detailed analysis of the spectral\nfeatures of the ZPL and quasilocal modes of the vibronic sideband, a complex center containingNi and Si atoms could be accounted\nfor these PL features. The inclusion of Ni and Si impurity atoms in the complex optical center was strengthened by micro-Raman\nspectroscopy performed in the frequency range due to quasilocal vibrations of the vibronic sideband....
Ruminants live in various parts of land. Similar cloven hooves assist ruminants in adapting to different ground environment\nduring locomotion. This paper analyzes the general terrain adaptability of the feet of ruminants using kinematics of the equivalent\nmechanism model based on screw theory. Cloven hooves could adjust attitude by changing relative positions between two digits\nin swing phase. This function helps to choose better landing orientation. ââ?¬Å?Graspingââ?¬Â or ââ?¬Å?holdingââ?¬Â a rock or other object on the\nground passively provides extra adhesion force in stance phase. Ruminants could adjust the position of the metacarpophalangeal\njoint or metatarsophalangeal joint (MTP orMCP) with no relative motion between the tip of feet and the ground, which ensures the\nadhesion and dexterity in stance phase. These functions are derived from an example from chamoisââ?¬â?¢ feet and several assumptions,\nwhich are believed to demonstrate the foundation of adaptation of ruminants and ensure a stable and continuous movement....
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