Utility of electron microscopy in the assessment of transthoracic needle lung biopsy specimens

The soluble form of the leukocyte membrane antigen CD14 is known to increase the sensitivity of endothelial and epithelial cell lines to bacterial lipopolysaccharide (LPS). This molecule also directly induces cytokine production in monocytes. Here, the effect of sCD14 and LPS on the release of IL-6 and IL-8 by human bronchial epithelial cells (HBECs) was studied. Soluble CD14 induced cytokine production both in the presence and absence of LPS. In addition, neither sCD14 nor anti-CD14 monoclonal antibody which blocks the interaction of LPS with CD14 had any effect on the binding of LPS to HBECs. These data suggest that sCD14 may induce the release of IL-6 and IL-8 from HBECs. However, the binding of LPS to bronchial epithelium appears to be mediated by CD14-independent mechanisms.     

Outage and BER analysis of cellular CDMA for integrated services with correlated signal and interference

In this letter, we evaluate the outage and "minimum duration outage" probabilities for integrated services in cellular code-division multiple-acess systems considering correlation among signal and interferers. Correlation is found to lower the outage probability. The effect of correlation and power control error on bit error rate is also studied.     

Sol-gel preparation of silica glass

This paper is a preliminary report on the preparation of silica glass containing very low amount of hydroxyl by the sol-gel processing technique. Gels were prepared from optimized amounts of tetraethyl orthosilicate, fumed silica and water. Acids and bases in small quantities were added for catalysing hydrolysis and adjusting the pH. Dried gels were heated up to 1400°C in various atmospheres to obtain transparent silica glass of the required density and very low (<5 ppm) hydroxyl content.     

Off-line handwritten word recognition using a hidden Markov modeltype stochastic network

Because of large variations involved in handwritten words, the recognition problem is very difficult. Hidden Markov models (HMM) have been widely and successfully used in speech processing and recognition. Recently HMM has also been used with some success in recognizing handwritten words with presegmented letters. In this paper, a complete scheme for totally unconstrained handwritten word recognition based on a single contextual hidden Markov model type stochastic network is presented. Our scheme includes a morphology and heuristics based segmentation algorithm, a training algorithm that can adapt itself with the changing dictionary, and a modified Viterbi algorithm which searches for the (l+1)th globally best path based on the previous l best paths. Detailed experiments are carried out and successful recognition results are reported     

Structure and physical properties of grafted jute fiber

Jute fiber was grafted by acrylonitrile and methylmethacrylate monomers in raw and bleached condition. It was also noted that optimum grafting takes place after about 4 h of grafting. It was also noted that in bleached jute fiber, the grafting percentage is higher at all stages of grafting but the tenacity value at the highest add-on is practically the same as that of raw fiber with much less add-on. The crystalline orientation of the grafted jute fiber was correlated with the fiber tenacity. The moisture regain (%) of the fiber after grafting showed a decreasing trend with an increase in grafting percentage. No structural change of the fiber occurred due to grafting. © 1995 John Wiley & Sons, Inc.     

Condensation polymers from natural oils

Innovative technologies and competitive industrial products are reducing the dependence on petrochemicals for the production of polymers. Increasing concerns about the deteriorating environment caused by conventional polymers have directed worldwide research toward renewable resources. Vegetable oils are one of the most readily available alternative renewable resources. The functional groups present in natural oils can be activated for condensation polymerization. Accordingly, various types of useful condensation polymers, such as polyurethanes, polyesters and polyethers, are being produced by this route. The incorporation of natural oils into the polymer chain allows tailoring the properties of polyurethane products, for their widespread applications.     

Unsupervised texture segmentation using multichannel decompositionand hidden Markov models

In this paper, we describe an automatic unsupervised texture segmentation scheme using hidden Markov models (HMMs). First, the feature map of the image is formed using Laws' micromasks and directional macromasks. Each pixel in the feature map is represented by a sequence of 4-D feature vectors. The feature sequences belonging to the same texture are modeled as an HMM. Thus, if there are M different textures present in an image, there are M distinct HMMs to be found and trained. Consequently, the unsupervised texture segmentation problem becomes an HMM-based problem, where the appropriate number of HMMs, the associated model parameters, and the discrimination among the HMMs become the foci of our scheme. A two-stage segmentation procedure is used. First, coarse segmentation is used to obtain the approximate number of HMMs and their associated model parameters. Then, fine segmentation is used to accurately estimate the number of HMMs and the model parameters. In these two stages, the critical task of merging the similar HMMs is accomplished by comparing the discrimination information (DI) between the two HMMs against a threshold computed from the distribution of all DI's. A postprocessing stage of multiscale majority filtering is used to further enhance the segmented result. The proposed scheme is highly suitable for pipeline/parallel implementation. Detailed experimental results are reported. These results indicate that the present scheme compares favorably with respect to other successful schemes reported in the literature.     

A simple method of photomask yield optimization by defect inspection

The quality of the photomask set decides to a large extent the quality and quantity of the device that will be produced. In order to ensure the quality of the photomasks, several sophisticated instruments are commercially available. However, in a research type of environment, the cost of such equipment can be prohibitive. In this paper, we propose a simple method of multiple master mask preparation with subsequent matching of defective die locations to optimize the master mask set. The advantage here is that a very good master mask set can be chosen so that minimum number of dies on the photomask set itself contribute to low wafer yield. The method is based on manual inspection of individual dies on photomasks and can be practically used for a complexity of up to 500 components.     

Role of the stimulated-emission rate in the photostability of solid-state dye lasers

The lasing and photostability characteristics of Rhodamine 6G and Pyrromethene 567 dyes dispersed in polymeric host materials have been investigated as a function of the intensities of incident pump and signal beams in a longitudinally pumped dye laser in an oscillator-amplifier configuration. A substantial reduction in the rate of photodegradation was observed under lasing conditions and with increasing signal intensity in a dye amplifier, establishing that the service lives of these materials improve with an increase in the rate of stimulated emission. We observed approximately 62% amplifier efficiency at 2 Hz operation and 10% reduction in amplifier efficiency at 10 Hz operation after exposure of 72,000 pulses by use of a Pyrromethene disk.