Vibration Based Technique For Monitoring The Postbuckling Deformation

Structural health monitoring (SHM) is a technology whose objective is to detect damage growth in metallic and composite structural elements long before they reach critical dimensions. Most structural health monitoring approaches that have been developed in the past have confined their attention to material degradation such as cracks in metals and delaminations in composite materials. Buckling instability is another cause of catastrophic failure commonly seen in engineering structures

Comparative Study Of Congestion Control Techniques In High Speed Networks

Congestion in network occurs due to exceed in aggregate demand as compared to the accessible capacity of the resources. Network congestion will increase as network speed increases and new effective congestion control methods are needed, especially to handle bursty traffic of todays very high speed networks. Since late 90s numerous schemes i.e. [1]...[10] etc. have been proposed. This paper concentrates on comparative study of the different congestion control schemes based on some key performance metrics. An effort has been made to judge the performance of Maximum Entropy (ME) based solution for a steady state GE/GE/1/N censored queues with partial buffer sharing scheme against these key performance metrics.Comment: 10 pages IEEE format, International Journal of Computer Science and Information Security, IJCSIS November 2009, ISSN 1947 5500, http://sites.google.com/site/ijcsis

Assessment of the myelination of cerebral tissue using MRI

The aim of this study was to assess the myelination process of cerebral tissue in vivo using different Magnetic Resonance Imaging (MRI) techniques at high field strength and to suggest the optimum MRI technique for the correlation of myelination with the gestational age in the rat brain. Several different techniques have been implemented in order to assess brain maturation. The first approach has been to quantitatively measure the Nuclear Magnetic Resonance (NMR) Ti and T2 relaxation times of brain gray and white matter which is shown to provide a certain degree of tissue characterization (Davis et al 1981). The second approach has been to measure the Apparent Diffusion Coefficient (ADC) which has proven to be of value in cerebral white matter which has been shown to demonstrate anisotropy of water diffusion (Chevert et al 1990). Sprague Dawley (S/D) rats with different age groups ranging from 7 days to adult were used for this study. Studies were carried out in a 7T, 20 cm clear bore magnet (Bruker Biospec). Data were acquired using two different diameter inductively coupled saddle coils. Imaging pulse sequences used were the Spin Echo (SE) and the Stimulated Echo (STEAM). Images were obtained with sufficient resolution to permit clear delineation of selected regions of interest in both gray and white matter. T1 values did not show any significant difference with age in the selected regions of interest whereas T2 and ADC values showed a marked change in signal intensity as the animals age increase. The results obtained have demonstrated the feasibility of accurate high resolution quantitative MRI measurements in S/D rat brain. These techniques may be applied in the assessment of myelin related or white matter pathologies

Production of bio-ethanol from sulfuric acid pre-treated rice husk using co-culture of Saccharomyces cerevisae and Aspergillus niger

This study investigates the potential of bioethanol production from agro wastes. Agro waste from rice husk was subjected to a pretreatment process using acid hydrolysis. 20g of rice husk was soaked in 2 %, 6 % and 10 % H2SO4 acid concentration for 2 hours, followed by filtration using 1 Whatman filter paper. The pH of the filtrate sample was adjusted to pH of 4.5 using 10 % NaOH, and co-culture of Saccharomyces cerevisiae and A. Niger was introduced into the filtrate and stored for 5 days. Distillation was carried out at 78 °C. The ethanol yield, sugar content and ethanol content of all the samples obtained was analysed. The results obtained shows that 10 % H2SO4 pretreated sample resulted into maximum ethanol yield (32.13 g/ml) and sugar content (13.4 %). The colour change to green colour, indicates that ethanol is present in the samples

Bio-ethanol production from cassava (manihot esculenta) waste peels using acid hydrolysis and fermentation process

In this research study, cassava peel waste was used as a sole carbon source for ethanol production using the process of fermentation and co-culture techniques. Production of Bio-ethanol from cassava peels was examined using co-culture of Aspergillus niger and Saccharomyces cerevisiae. Sulfuric acid solution with concentration of 2 %, 6 % and 10 %, was used to hydrolyze the substrates. Aspergillus niger and Saccharomyces cerevisiae were further used to ferment the substrates at 28 oC for 4 days. The fermented liquid was distilled at 78 oC and quantity of ethanol produced was determined. These findings proved that 10 % H2SO4 concentrated acid pretreated sample resulted into maximum ethanol yield (37.35 g/ml), pH 4.55, sugar content (15.5 %) and alcohol content (8.5 %) after 4 days. This study further revealed that bio-ethanol can be produced from cassava peels with maximum yield obtained using 10 % H2S04 acid for hydrolysis and Aspergillus niger and Saccharomyces cerevisiae for fermentation

A Family of 6-Point n-Ary Interpolating Subdivision Schemes

We derive three-step algorithm based on divided difference to generate a class of 6-point n-ary interpolating sub-division schemes. In this technique second order divided differences have been calculated at specific position and used to insert new vertices. Interpolating sub-division schemes are more attractive than approximating schemes in computer aided geometric designs because of their interpolation property. Polynomial generation and polynomial reproduction are attractive properties of sub-division schemes. Shape preserving properties are also significant tool in sub-division schemes. Further, some significant properties of ternary and quaternary sub-division schemes have been elaborated such as continuity, degree of polynomial generation, polynomial reproduction and approximation order. Furthermore, shape preserving property that is monotonicity is also derived. Moreover, the visual performance of proposed schemes has also been demonstrated through several examples

The Outcome of Minimally Invasive Percutaneous Transpedicular Screw Fixation (TPSF) in Thoracolumbar Spine Fractures

Background & Objective:  This study aimed to determine the outcome of percutaneous transpedicular screw fixation (TPSF) in patients with thoracolumbar fractures. Material & Methods:  A total of 157 patients with thoracolumbar fractures were included from the Department of Neurosurgery, LGH, PINS, Lahore. Patients were evaluated with plain X-rays, CT, and MRI scans. Neurological status was documented preoperatively and postoperatively. All patients were treated with Minimally Invasive Percutaneous Transpedicular screw fixation. Data for operative time and per-operative blood loss was obtained through the operative notes. The severity of postoperative pain and length of hospital stay were also documented. Results:  Out of 157 patients, 69.4% were male and 30.6% were female. The 141 (89.8%) were traumatic from road traffic accidents/falls, and 16 (10.2%) were pathologic. The 128 (81%) patients were discharged on the first day, 23(15%) were discharged on the second day, and 6(3.8%) on the third day. 79% of patients had a single level of spine fracture whereas, 20% had 2 spinal fracture levels. The average operative time for MIS percutaneous TPSF was 55 minutes. Postoperative pain was markedly reduced as compared to traditional open surgery and no patient had any new neurological deficit. The mean blood loss was 25 ml and none of the patients needed a postoperative blood transfusion. Conclusion:  Percutaneous transpedicular instrumentation is an ideal surgical approach for thoracolumbar spinal stabilization. Keywords:  Thoracolumbar Fractures, Percutaneous Transpedicular Screw Fixation, Minimally Invasive Spine Surgery, Road Traffic Accidents (RTA)