Silver Nanoclusters And Nanofractals In Natural Rubber Matrix.

Silver nanocrystals were synthesized in natural rubber matrix via UV irradiation technique. A high intensity UV light with a wavelength below 300 nm was used to reduce the silver ions in the natural rubber matrix

Adaptive thresholding in dynamic scene analysis for extraction of fine line

This paper presents an adaptive threshold method whereby a fine thin line of one-pixel width lines could be detected in a gray level images. The proposed method uses the percentage difference between the mean of the pixels within a window and the center pixel. The minimum threshold value however is heuristically set to 32. If the percentage difference is greater than 40% then the threshold value will be set to the difference value. This method has been applied in detecting moving objects with fine lines and the results showed that the method was able to pickup straight thin edges that belong to the moving objec

Ultrasonographic imaging on the progress of wound healing after abdominal surgery in dogs

The present study has been carried out with the aim of evaluating the progress of abdominal wound healing after abdominal surgery and to detect any changes that might occur during the reparative phase using B-mode ultrasound. Five dogs of different breeds, sex and age were used in this study. The dogs had undergone ventral abdominal surgery for various reasons. A real-time B-mode ultrasound machine (Capasee TOSHIBA) connected with a 7.5 MHz linear array transducer was used in this study. The ultrasonographic examination was done transversely across the ventral abdominal midline (wound) from cranial to caudal and longitudinal scan was done along the wound (incision site) from cranial to caudal. Initial scanning was carried out on day one (approximately 24 hours) post-operation. Subsequent scans were carried out on the basis of one day apart while the animal was still in the hospital. The ultrasonographic appearance of wound (surgical site) at the early stage was ill-defined hypoechoic with acoustic shadowing artefact. With time the wound appeared hypoechoic with some degree of an echogenic centre and casting acoustic shadowing artefact. By day 11 post-operation, the wound was found to have a disorganized echogenic structure with acoustic shadowing artefact. By day 13 post-operation, the wound appeared as disorganized hyperechoic with acoustic shadowing artefact due to the presence of fibrous tissue formation. Results from this study also demonstrate that the wound could be evaluated in both transverse and longitudinal scans. However, the transverse scan seems to be easier than the longitudinal scan in evaluation of the surgical wound

Development of PAN (personal area network) for Mobile Robot Using Bluetooth Transceiver

In recent years, wireless applications using radio frequency (RF) have been rapidly evolving in personal computing and communications devices. Bluetooth technology was created to replace the cables used on mobile devices. Bluetooth is an open specification and encompasses a simple low-cost, low power solution for integration into devices. This research work aim was to provide a PAN (personal area network) for computer based mobile robot that supports real-time control of four mobile robots from a host mobile robot. With ad hoc topology, mobile robots may request and establish a connection when it is within the range or terminated the connection when it leaves the area. A system that contains both hardware and software is designed to enable the robots to participate in multi-agent robotics system (MARS). Computer based mobile robot provide operating system that enabled development of wireless connection via IP address

Electrical and Thermal Behavior of Copper-Epoxy Nanocomposites Prepared via Aqueous to Organic Phase Transfer Technique

The preparation, electrical, and thermal behaviors of copper-epoxy nanocomposites are described. Cetyltrimethylammonium bromide- (CTAB-) stabilized copper (Cu) particles were synthesized via phase transfer technique. Isopropanol (IPA), sodium borohydride (NaBH4), and toluene solution of diglycidyl ether of bisphenol A (DGEBA) were used as transferring, reducing agent, and the organic phase, respectively. The UV-Vis absorbance spectra of all the sols prepared indicate that the presence of Cu particles with the particles transfer efficiency is ≥97%. The amount, size, and size distribution of particles in the organosol were dependent on the content of organic solute in the organosol. The composites were obtained upon drying the organosols and these were then subjected to further studies on the curing, thermal, and electrical characteristic. The presence of Cu fillers does not significantly affect the completeness of the composite curing process and only slightly reduce the thermal stability of the composites that is >300◦C. The highest conductivity value of the composites obtained is 3.06 × 10−2 S cm−1

Fractional boundary value problems: Analysis and numerical methods

This is the author's PDF of an article published in Fractional calculus and applied analysis 2011. The original publication is available at www.springerlink.comThis journal article discusses nonlinear boundary value problems.Fundacao para a Ciencia e Tecnologi

Transient pressure analysis of geothermal wells fractured during well testing

Fracturing during injectivity testing can take place in geothermal wells when the reservoir has low permeability or when the well has significant skin damage. The transient behavior (pressure falloff) of these wells cannot be matched using existing well test analysis methods. At the same time, modelling fracturing in geothermal re-servoirs using rock mechanics and commercial finite element software is complicated due to several field un-certainties (e.g. formation height, reservoir permeability and porosity). In addition, rock mechanics data (rock stress, strain and Young’s modulus) are normally unknown in geothermal fields. This makes it difficult to develop an appropriate fracture model that matches the field test data. This study attempts to develop a fracture model without integrating rock mechanics. The model is setup with a simple grid using the TOUGH2 geothermal reservoir simulator and validated using the advanced pressure derivative transient analysis. Multiple subsets of fracture geometries were developed to represent the different stages of fracture closure during pressure falloff. The PyTOUGH code was used to simplify the running of the different fracture stages. The results are very promising and provide a clear justification and explanation for the commonly en-countered fractured well behavior. This model should be of use in matching data from geothermal wells with similar pressure response