Effect of Flank Wear on the Topography of Machined Surfaces

The effect of flank wear on the topography of machined surfaces is investigated by studying its effect on the shape of the tool nose. For this purpose, turning experiments were performed to produce surfaces corresponding to different levels of flank wear. The distribution of flank wear at the tool nose during these experiments caused the nose radius to decrease, which when replicated on the machined surface resulted in narrower and deeper feedmarks. This change in the geometry of feedmarks was represented by the increase in the arithmetic average roughness of the surface profile heights.     

Surgical tool motion during conventional freehand and robot-assisted microsurgery conducted using neuroArm

Surgical tool motion during microsurgery could arguably reflect surgical performance. This paper reports on how the motion of a surgical tool correlates or differs between conventional freehand surgery and robot-assisted surgery. In this pilot study, components of the position and orientation as well as the linear and angular velocities of a surgical tool, over the same period of operation, are compared during the two scenarios. For freehand surgery, a bipolar forceps is retrofitted with a tracking system to measure translational and rotational components of the tool motion. In robot-assisted surgery, the position and orientation components are obtained using kinematics of the neuroArm image-guided robotic system. A cross correlation analysis was used to investigate correlation between each pair of displacement or velocity components from freehand and robot-assisted scenarios to indicate how strongly or weakly two sets of data are linked together. The absolute maximum value of the cross correlation coefficient is calculated for each pair of components to quantitatively investigate the correlation between two sets of data. Results showed that the positional and rotational components, reflecting the surgical workspace, in both scenarios are correlated. However, for the cases studied, surgical tool rate of motion differs between the two scenarios. Results are important as they can be utilized to design robot-assisted neurosurgical systems that reflect characteristics of freehand surgery gained by surgeons through years of training, knowledge, and experience.     

Preparation and evaluation of novel nano-bioglass/gelatin conduit for peripheral nerve regeneration

Peripheral nerves are exposed to physical injuries usually caused by trauma that may lead to a significant loss of sensory or motor functions and is considered as a serious health problem for societies today. This study was designed to develop a novel nano bioglass/gelatin conduit (BGGC) for the peripheral nerve regeneration. The bioglass nanoparticles were prepared by sol–gel technique and characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis. The interfacial bonding interaction between the nano-bioglass and gelatin in the developed conduits was assessed by FTIR. The surface morphology and pore size of the nanocomposite were investigated through scanning electron microscopy with the pore size of the conduits being 10–40 μm. Biocompatibility was assessed by MTT assay which indicated the BGGC to have good cytocompatibility. The guidance channel was examined and used to regenerate a 10 mm gap in the right sciatic nerve of a male Wistar rat. Twenty rats were randomly divided into two experimental groups, one with the BGGC and the other being normal rats. The gastrocnemius muscle contractility was also examined at one, two and three months post-surgery in all groups using electromyography (EMAP). Histological and functional evaluation and the results obtained from electromyography indicated that at three months, nerve regeneration of the BGGC group was statistically equivalent to the normal group (p > 0.05). Our result suggests that the BGGC can be a suitable candidate for peripheral nerve repair.     

An estimation of the penetration rate of rotary drills using the Specific Rock Mass Drillability index

The main purpose of the present study was to provide a practical,convenient drillability prediction model based on rock mass characteristics,geological sampling from blast holes,and drill operational f...     

Acoustic startle response in young and aging C57BL/6J and CBA/J mice.

C57 mice demonstrate progressive age-related hearing loss during the 1st yr, whereas CBA mice lose little sensitivity through 18 mo of age. The acoustic startle response (ASR) was measured to determine behavioral correlates of aging with and without presbycusis. Stimuli were tone pips with frequencies of 4–24 kHz at intensities of 70–200 dB SPL. ASR thresholds increased with age, and startle amplitudes became smaller. Changes in startle parameters were more pronounced in C57 mice, with middle to high frequencies severely affected. Startle latencies at and above ASR threshold increased with age in C57 mice. CBA data indicate that aging has little effect on ASR parameters; the C57 data show that hearing loss is a cogent factor. ASR parameters of C57 mice are altered to a greater extent than expected, on the basis of the elevations of absolute sensory thresholds, particularly for middle frequencies. Both peripheral and central mechanisms may account for the discrepancy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rheology of Glaze Suspensions

Rheological properties of suspensions and ceramic glaze slurries under steady flow conditions have been considered. Colloidal forces play an important role in the rheology of such ceramic slurries. Since the potential function characterizes the rheology of colloidal systems, a new dimensionless group, viz. potential number, is introduced within a dimensional analysis representing the relative significance of the potential to the Brownian energy. In order to relate the relative viscosity to other dimensionless groups, a new model is proposed by the inclusion of an extra term in addition to that of the hard‐sphere theory owing to the fact that the presence of colloidal forces always increases the fluid viscosity with respect to that predicted by the hard‐sphere. Steady viscosity measurements have been carried out on ceramic glaze suspensions at different volume fractions, particle diameters, and shear rates. Experimental results have been used to modify the model relating the relative viscosity to the Péclet number, potential number, volume fraction, and maximum packing fraction.     

Broadband-CDMA overlay

A Broadband Code Division Multiple Access (B-CDMA) technique is presented that will overlay the existing cellular telephone spectrum (825 to 894MHz). The overlay will provide additional capacity to the network while allowing high quality voice and high speed data services to be coexistent with the existing cellular services (AMPS and TDMA). The advantages of using B-CDMA in a fading environment are analyzed. The low level of mutual interference between the existing cellular telephone system and the B-CDMA overlay system is shown.Portions of this paper have been submitted as partial fulfillment of the requirements of the Ph.D. dissertation in electrical engineering at the City College of New York.     

HBMO algorithm for calibrating water distribution network of Langarud city

In this paper a new meta-heuristic approach based on the nature of honey bees mating has been used for the calibration of a real city in the north of Iran named Langarud. This city has a population of nearly 68,000 people and about 43,000 water consumers. Langarud's area is about 900 km(2). The method was used to determine the Hazen-Williams roughness factor of the main pipes of the town and a correction factor for the nodal demands in the main nodes of the network.     

A new restricted boltzmann machine training algorithm for image restoration

Multimedia Tools and Applications - A variety of approaches have been proposed for addressing different image restoration challenges. Recently, deep generative models were one of the mostly used...