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Vanadium pentoxide nanostructured thin films (NSTs) have been studied to analyze the effect of plasma on nanostructures grown and morphology of films deposited using sublimation process. Nanostructured thin films were deposited on glass substrates, one in presence of oxygen plasma and other in oxygen environment (absence of plasma). Films were characterized using XRD, Raman spectroscopy, SEM and HRTEM. XRD studies revealed α-V2O5 films (orthorhombic phase) with good crystallinity. However, film deposited in presence of plasma have higher peak intensities as compared to those deposited in absence of plasma. Raman studies also support these finding following same trends of considerable increase in intensity in case of film deposited in presence of plasma. SEM micrographs makes the difference more visible, as film deposited in plasma have well defined plate like structures whereas other film have not-clearly-defined petal-like structures. HRTEM results show orthorhombic phase with 0.39 nm interplanar spacing...

In this report, vanadium pentoxide nanostructured thin films (NSTs) with nanoplates (NPs) have synthesized on Ni coated glass substrate employing plasma assisted sublimation process (PASP), as a function of deposition/growth durations. The effect of deposition durations on the morphological, structural, vibrational, and compositional properties have been investigated one by one. The structural and vibrational studies endorsed that the grown NPs have only orthorhombic phase, no other sub oxide phases are recorded in the limit of resolution. The morphological results of all samples using SEM, revealed that the features, coverage density, and alignments of NPs are greatly controlled by deposition duration and the best sample is obtained for 25 min (S2). Further, the more insight information is accomplished by HRTEM/SAED on the best featured sample, which confirmed the single crystalline nature of NPs. The XPS result again confirmed the compositional purity and the nearly stoichiometric nature of NPs.

In the present paper, we reported the role of substrate locations relative to source on the growth of MoO3 films deposited on Ni coated glass substrates using plasma assisted sublimation process (PASP). According to the XRD and SEM results, substrate location is very crucial factor to control the morphology of MoO3 films and the best nanostructure growth (in terms of alignments and features) is obtained in case of Sample B (in which substrate is placed on source). The structural results point out that all films exhibit only orthorhombic phase of molybdenum oxide (i.e. α-MoO3)but the most preferential growth is recorded in Sample B due to the presence of intense peaks crossponding to only (0 k 0) family of crystal planes (k = 2, 4,6..). The Raman analysis again confirms the orthorhombic nature of MoO3 NFs and details of vibrational bondsin Sample B have been given in the present report. The MoO3 NFs show intense PL emission in wavelength range of 300-700 nm with three peaks located at 415, 490, and 523 nm in accordance to the improved crystallinity in Sample B.

In this communication, we synthesizedvanadium pentoxide (α-V2O5) nanostructured thin films (NSTs) using four different methods for obtaining vanadate species namely thermal evaporation (source of vanadate species are V2O5 powder and vanadium metal foil) and plasma assisted sublimation process (source of vanadate species are V2O5 powder and vanadium metal foil). The effect of plasmaon morphological and structural propertieshave been systematicallystudied. XRD revealed thermal evaporation process yielded amorphous films whereassublimation process yielded highly crystalline α-V2O5 films. HRTEM of nanobelts show, the growth is preferred in (001) crystallographic direction with interplanar distance of 0.43 nm. XPS revealed O/V ratio of ~2.4, which nearly agrees with standard V2O5 stoichiometry. SEM revealed deposition process affect morphology of films; thermal evaporation results in smoother film while plasma assisted sublimation process reveals nanoflakes and nanobelts (NBs). All the results are inconcordanc...

In this report, the effect of plasma voltage on plasma assisted sulfurization (PAS) of vertically aligned molybdenum trioxide (α- MoO3) nanoflakes (NFs) on glass substrates has been studied systematically. MoO3 NFs were deposited using plasma assisted sublimation process. These nanoflakes were subjected to H2S/Ar plasma at two different plasma voltages 600 and 1000 volts; to study the effect of plasma ionization on degree of sulfurization of MoO3 into MoS2. XRD and Raman analysis show that film sulfurized at 1000 volts have relatively higher degree of conversion into MoS2, as more intense peaks of MoS2 and MoO2 are obtained than that sulfurized at 600 volts. HRTEM of sulfurized film shows that outer surface of nanoflake has been converted into MoS2 (4-5 monolayers). Meanwhile, MoO3 was reduced into MoO2 as confirmed by XRD and Raman results. All the observed results are well in consonance with each other.

Laser back-scattered radiation from a human forearm is affected by the compositional variation in tissues and was imaged by a reflectance imaging system. The measurement probe consisted of one input fibre and one output fibre, separated by a distance of 0.3 cm. The diffuse reflectance data were collected by placing the probe on the forearm. By interpolation and median filtering of these data, the colour-coded reflectance images of the forearms of ten subjects were reconstructed. For comparative analysis of the mean reflectance, the forearm area was divided into ten regions. The mean normalised back-scattered intensity (NBI) near the ulnar region of the wrist was 4.76 +/- 0.24% and was significantly higher (p0.0005) compared with that at other regions, which varied from 3.49 +/- 0.17% to 4.43 +/- 0.14%. Tissue-equivalent phantoms of these, required for the clinical assessment of optical techniques, were constructed using various combinations of paraffin wax and dyes. The matching of the NBI images of these stable and inexpensive phantoms with those of the forearms of the respective subjects showed the similarity of their optical parameters.

In this report, the sulfurization of vertically aligned molybdenum trioxide (α- MoO3) nanoflakes (NFs) with high aspect ratio (height/thickness >20) on the nickel coated glass substrates in a mixture of H2S and argon gas at atmospheric pressure has been studied. The effect of sulfurization have been investigated to understand the basic reaction mechanism and the morphology, structural properties of grown nanoflakes. XPS and XRD indicate the formation of MoS2 along with the other intermediate phase such as MoO2 at temperature 200 °C. The surface morphology of samples have been studied systematically by using scanning electron microscope (SEM). The results demonstrate partial conversion of MoO3 NFs into MoS2 along with the change in the morphology of nanoflakes. All the observed results are well in consonance with each other.

In this communication, we reported the role of Ni seed layer on the growth of vanadium pentoxide (α-V2O5) nanostructured thin films (NSTs) using plasma assisted sublimation process (PASP). Two different substrates, simple glass substrate and the Ni coated glass substrate (Ni thickness ∼ 100 nm) are employing in the present work. The influence of seed layer on structural, morphological, and vibrational properties have been studied systematically. The structural analysis divulged that both films deposited on simple glass as well as on Ni coated glass shown purely orthorhombic phase, no other phases are detected. The morphological studies of V2O5 film deposited on both substrates are carried out by SEM, revealed that features of V2O5 NSTs is completely modified in presence of Ni seed layer and the film possessing the excellent growth of nanorods (NRs) on Ni coated glass rather than simple glass. The HRTEM analysis of NRs is performed at very high magnification, shows very fine fringe pattern, which confirmed...

In this work, we report the growth of α-V2O5 (orthorhombic) nanoplates on glass substrate using plasma assisted sublimation process (PASP) and Nickel as catalyst. 100 nm thick film of Ni is deposited over glass substrate by thermal evaporation process. Vanadium oxide nanoplates have been deposited treating vanadium metal foil under high vacuum conditions with oxygen plasma. Vanadium foil is kept at fixed temperature growth of nanoplates of V2O5 to take place. Samples grown have been studied using XPS, XRD and HRTEM to confirm the growth of α-phase of V2O5, which revealed pure single crystal of α- V2O5 in orthorhombic crystallographic plane. Surface morphological studies using SEM and TEM show nanostructured thin film in form of plates. Uniform, vertically aligned randomly oriented nanoplates of V2O5 have been deposited.

Aim: To compare non-coplanar 3DCRT planning and partial arc VMAT planning dosimetrically for unilateral brain tumours.Introduction:Intensity modulated radiation therapyhas gainedwide popularity as a radiotherapy treatment of choice for many clinical sites. Volumetric modulated arc therapy is a kind of therapy in which rather than using multiple static fields at different gantry angles, one or multiple full or partial arcs are used for radiotherapy planning and treatment. Its ability to provide superior target coverage and better normal tissue sparing makes it a treatment of choice over conventional and 3DCRT radiotherapy planning techniques. But, on the same time volume of low dose region which can increase probability of secondary malignancy in VMAT planning is reported to be on the higher side. Our study compares various parameters of plan quality along with low dose volumes in the techniques under comparison.Materials and methods:10 anonymized patients with unilateral malignant brain tumours previously treated with nc3DCRT were selected for the study and planned with partial arc VMAT. Conformity Index, Homogeneity Index, Target Coverage, Doses to critical structures and normal brain were compared.Conclusion:In our study by using VMAT technique we were able to reduce doses to critical structures (Brainstem, optic nerves, and optic chiasm) significantly, got better target coverage along with lesser number of MUs per fraction and significant reduction in low dose volume and reduction in doses to contralateral normal structures including lesser amount of low dose volume.

Oxidation of MoO2/MoS2 core–shell nanoflakes (NFs) has been investigated in different oxidation ambients i.e. oxygen (O2) gas and its plasma. Core–shell nanoflakes are oxidized at temperatures varying from 150 °C to 450 °C and the effect of oxidation temperature on the structural and morphological changes of nanoflakes are investigated systematically. High-resolution transmission electron microscopy (TEM) images show that shell of nanoflake is oxidized with varying thicknesses and strongly depending upon the temperature and ambience. X-ray diffraction (XRD) and Raman analysis revealed the formation of MoO3 at low temperature (≤150 °C) in O2 plasma. Whereas, in O2 gas at a relatively higher temperature (≥350 °C). Scanning electron microscopy (SEM) results show noticeable changes in the morphology as deformation of nanoflakes after oxidation. X-ray photoelectron spectroscopy (XPS) revealed, oxidizing in O2-plasma led to multiple oxidation states of Mo (4+, 5+, and 6+) and S (2−, 6+). It is evident that the extent of oxidation of MoS2 shell is higher in plasma due to reactive species of oxygen (O+, , O*, etc), as compared to O2 gas.

The sequential changes in shape of left ventricle (LV), which are the result of cellular interactions and their levels of organizational complexity, in its long axis view during one cardiac cycle are obtained. The changes are presented in terms of shape descriptors by processing of images obtained from a normal subject and two patients with dilated left ventricular cardio-myopathy. These images are processed, frame by frame, by a semi-automatic algorithm developed by MATLAB. This is consisting of gray scale conversion, the LV contour extraction by application of median and SRAD filters, and morphological operations. By filling the identified region with pixels and number of pixels along its contour the area and perimeter are calculated, respectively. From these the changes in LV volume and shape index are calculated. Based on these the stroke volume (SV) and ejection fraction (EF) are calculated. The changes in LV area, perimeter, volume and shape index in cardiac patients are less than that of normal subject. The calculated SV and EF of normal subject are within the range as obtained by various imaging procedures.

Analysis of the aggregation of erythrocytes as measured by aggregation index in blood samples obtained from patients with elevated levels of immunoglobulin G (Ig G) and immunoglobulin A (Ig A) is carried out. The aggregation index (AI) and plasma viscosity (PV) are correlated with the total protein, albumin, Ig G, Ig A and Ig M and total globulin concentrations of samples and are compared with that of normal blood. The results show that the AI depends more on the monoclonal globulin concentrations and this dependence is more for Ig A than that for Ig G. There is no correlation between either AI and IgM in both these samples. The present study shows that the aggregation index could further be used as a rapid supplementary test for the initial investigation and therapeutic response of hyperglobulinemic patients. ? 2001 �ditions scientifiques et m�dicales Elsevier SAS.

Based on the principle of backscattering of laser radiation from tissues, a noninvasive PC-AT based reflectance imaging technique is developed. The laser beam from a semiconductor laser operating at 670 nm is guided to the tissue site by an optical fibre. The backscattered radiation is collected by another fibre placed in the same probe, and is detected by a photodiode-amplifier assembly. This probe is moved manually over the organs under observation, and the data after the ADC, interpolation and median filtering are displayed in the form of reflectance image of the organ along with grey scale. By this technique images of the human hands and forearms are obtained, which depend on the variations in their colour, composition and blood flow. A comparison is made with perfusion images, obtained by a Periflux laser Doppler flowmeter. These show that the reflectance images provide greater details of the tissue structure than the perfusion images.Based on the principle of backscattering of laser radiation from tissues, a non-invasive PC-AT based reflectance imaging technique is developed. The laser beam from a semiconductor laser operating at 670 nm is guided to the tissue site by an optical fibre. The backscattered radiation is collected by another fibre placed in the same probe, and is detected by a photodiode-amplifier assembly. This probe is moved manually over the organs under observation, and the data after the ADC, interpolation and median filtering are displayed in the form of reflectance image of the organ along with grey scale. By this technique images of the human hands and forearms are obtained, which depend on the variations in their colour, composition and blood flow. A comparison is made with perfusion images, obtained by a Periflux laser Doppler flowmeter. These show that the reflectance images provide greater details of the tissue structure than the perfusion images.

The measurement of He-Ne laser light reflectance of various internal organs in-situ, to obtain the absorption and scattering parameters, is carried out. The laser reflectometer is consisting of an optical fibre- Y guide probe. Through one arm of this the laser beam is guided to the various internal organs of the anasthetized mongrel dogs. The reflected radiations from the tissue site are collected by another arm of the probe and detected by HAD-1000A photodetector—amplifier assembly. The results show that the reflectance of the internal organs varies over a large range and is the maximum at the arch of aorta and the minimum at the spleen. The optical parameter, the scattering and absorption coefficients, calculated based on the above data show variation related to their tissue compositions.

MANET is wireless mobile network which has no centralized control for the mobile nodes; and nodes are free to move in network without centralized administrator. DSR is manet routing protocol which is used as dynamic. In this paper the throughput is analysed for original DSR and UPDATED DSR in order to compare both. The simulation is carried on 100 mobile nodes using the opnet simulator. Also study have been made on dsr manet routing protocol for analyzing the routing traffic received and routing traffic sent.

Based on the variation in the optical density due to erythrocyte concentration and movement, the axial tomographic and image velocimetry techniques are respectively applied to determine the flow field, i.e., the distribution of erythrocytes and axial and radial velocity components, in steady blood flow through a curved glass capillary with a diameter of 180 microns. The data at four positions (two straight and two curved segments of the capillary) are recorded by a video-microscopic system on a video cassette. The erythrocyte and velocity distribution profiles change from symmetric at the straight position to an asymmetric shape at the curved sections. These profiles become symmetric again at the straight section of the capillary. The increase in the radial velocity component at curved portions is attributed to the secondary flow. The tomograms obtained by concentration profiles show respective changes in the cellular population at various cross-sectional positions. The kinetic energy dissipation, as calculated based on a determination of the flow field, is the minimum for the observed profiles. Any deviation towards parabolic form leads to the dissipation of a higher amount of energy.

The backscattered fraction of laser incident beam from the biological tissues depends on their composition, leading to change in their optical properties. The tissue models consist of heart tissue as the base embedded with adipose and spleen tissues at various depths from the tissues surface Monte Carlo simulation is carried out to detect the changes in back-scattered fraction (BSF) at various locations on the tissue surface. The BSF is increased and decreased with the presence of adipose and spleen tissues located at various depths, respectively. The location of these is carried by construction of the BSF images by scanning at various locations. From the variation in images the location and type of abnormality is determined. Thus this study provides the possibility of detection of various changes in tissue composition

Aggregation of erythrocytes at hematocrit 5% in plasma, placed in a glass chamber, is analyzed under dynamic conditions by transmission of He-Ne laser light. The transmitted intensity (TI) signal which contains mean intensity superimposed with fluctuations caused by the movement of erythrocytes and formed aggregates, is detected by photodiode-amplifier assembly mounted on a stepper motor. The alignment of this detector for the maximum TI is achieved by a dedicated software. The TI data after A/D conversion is stored in a PC-AT for further processing. The parameters, aggregate size index, aggregate sedimentation time index, total time taken for completion of the process, process onset time index, total number of fluctuations, and asymmetry index are calculated sequentially for the entire data. A comparison of these parameters in blood samples obtained from healthy and diabetic subjects show the significance of these parameters.

Blood samples of malaria patients (n = 30), selected based on the severity of parasitemia, were divided into low (LP), medium (MP) and high (HP) parasitemia, which represent increasing levels of the disease severity. Healthy subjects (n = 10) without any history of disease were selected as a control group. By processing of erythrocytes images their contours were obtained and from these the shape parameters area, perimeter and form factor were obtained. The gray level intensity was determined by scanning of erythrocyte along its largest diameter. A comparison of these with that of normal cells showed a significant change in shape parameters. The gray level intensity decreases with the increase of severity of the disease. The changes in shape parameters directly and gray level intensity variation inversely are correlated with the increase in parasite density due to the disease.

Laser backscattering from biological tissues depends on their composition and blood flow. The onset of the tissue abnormalities is associated with the change in composition at a specific location which may affect laser backscattering. The objective of the present work is to detect the compositional changes in tissue-equivalent phantom of fat, prepared by mixing paraffin wax with wax colors, and to characterize these in terms of their optical parameters. For this purpose these phantoms are scanned by a multi-probe non-contact automatic laser scanning system and images of the normalized backscattered intensity (NBI) are constructed. By scanning the background subtracted image of the phantom the location of the abnormality and its size from the full width at half maximum (FWHM) are determined. The data obtained by ultrasonic technique for localization of the abnormalities are in agreement with that as obtained by the present method. The optical parameters of the abnormality are obtained by matching the measured surface profiles of the abnormality with that of the profile obtained by Monte Carlo simulation. This analysis shows the possibility of detection of changes at the onset stage in tissues as required for planning of the photodynamic therapy.

The interactions of laser radiation with pathological slide reveal their diverse optical characteristic depending on their compositional variation. Their point to point compositional variation is determined by reconstruction of the reflectance images which carry valuable information. However conventional microscope only deals with giving the image as an enlarged form, and is also light dependent. The system of confocal imaging is very complex and involves large number of lenses. Surface reflected laser radiations from slide are measured by a reflectance imager. Laser radiations (680 nm) are guided by an optical fiber inclined at 45 degree angle and reflected radiations are collected by photo detectors placed at an angle of 45 degree to the source which is also at 45 degree. An array of source and detectors (i.e. 12 source and 12 detectors) are placed in a probe which is stationary. The slide is placed on a platform which moves in steps of 1mm.The platform moves and data representing two-dimensional variation are collected, after amplification, these are digitized, and post processing of the images is done. An advanced algorithm of image processing is used and color coding is done. The probe design is highly refined and first of its kind. The accuracy is high since the source is stationary. The reflected image can be inferred by the processing technique which gives useful parameters. This system is capable of producing output equivalent to C.T-scan or M.R.I in one-fifth of their cost.

To study the effect of maturational geometric changes on flow characteristics in the pulmonary artery trunk, anatomically accurate, acrylic flow-through models were constructed from four flexible silicone rubber casts obtained in situ in lambs weighing 2.4, 7.8, 9.5, and 11.5 kg. A silicone rubber cast of the right heart was fabricated by injecting the superior caval vein in situ with liquid silicone rubber (Dow Corning's HS-II RTV, Midland, MI). Each cast was used as a template for a transparent acrylic mold of the pulmonary artery trunk and primary generation branches. The acrylic block was then fitted with a curved rigid Plexiglass inflow tube (to simulate the curvature of the right ventricle) just proximal to the pulmonary valve sinuses and mounted in a closed loop system driven by a variable speed pulsatile pump (to simulate physiological flow rates between 0.5 and 4.0 lmin−1) A blood analog solution of polystyrene beads (Rohm & Haas Amberlite, Philadelphia, PA) suspended in a 45% by weight glycerine solution was illuminated by a laser source (15 mwatts, Siemens, Germany) to trace the flow patterns. Two flow field planes of the main pulmonary artery trunk—one parallel, and one perpendicular, to the origins of the right and left arterial branches—were visualized and video recorded (Canon H660 8mm, Japan) for subsequent analysis. A prominent vortex, originating in the center of the main pulmonary artery and directed inferiorly toward the inner wall, was noted in the flow field plane perpendicular to the bifurcation in the 9.5 and 11.5 models. These characteristics were less developed in the 7.8 kg model and not present in the 2.4 kg model, possibly because the angle of curvature was less acute than in the larger models. In the flow field plane parallel to the bifurcation, the patterns were more complex, principally influenced by turbulence in the main pulmonary artery (which increased at higher flow rates) and the geometric changes in the branch pulmonary arteries.

For early detection of abnormalities growing within the healthy tissues a laser based multi-slice reflectance measurement technique is developed. The laser light is guided at the center of the probe. Around this the photo-detectors are arranged symmetrically at various distances from the beam entry point. The optical radiations after scattering within the tissue emerge at various locations which are detected by the detectors. After conversion from current to voltage these signals are digitized and fed to computer. After pre-processing of the backscattered signals from 36 photo-detectors arriving from various locations the reflectance images are reconstructed. As the detectors are placed at various distances from the beam entry point in the form of rings, their respective images are obtained. These multi-slices images provide variation in composition at various depths ranging from 2 - 7.5mm. Thus by placing the probe just once the required data for images reconstruction is obtained. This is in contrast to earlier developments as this does not involve the movement of the probe for image reconstruction. Based on the sequence of images from various depths a three - D image of the tissue structure could also be obtained.

Diabetes mellitus (DM) is a metabolic disorder characterized by varying or persistent hyperglycemia either due to insufficient production of insulin by pancreas or improper utilization of the glucose. Erythrocytes remain in hyperglycemic environment throughout their life span and thus are subjected to series of compositional changes, which in turn affect their flow properties through alteration of deformation at individual level and aggregation at collective level. This brief review summarizes the changes in biochemical parameters primarily contributing to the erythrocyte deformability and aggregation as measured by various techniques, of blood samples obtained from diabetic subjects. The significant changes in erythrocyte aggregation and deformability, in comparison with that of control subjects show the relevance of these measurements. These changes are further supported by in vivo observations of blood flow through microvessels. Finally the relevance of these in combination with other clinical parameters is suggested.

The optical parameters of tissue-equivalent phantoms are determined by matching the normalized backscattering intensity (NBI) profiles iteratively with that obtained by Monte Carlo simulation procedure. Tissue equivalent optical phantoms (control and with abnormality) were prepared by mixing measured quantities of paraffin wax with wax colors. Abnormalities to be placed in the phantoms were prepared by controlling the absorption and scattering coefficients. The NBI profiles of the phantoms are obtained by an automatic non-contact scanning multi-probe laser reflectometer and are displayed as gray level images after processing. The NBI variations from the abnormality phantoms have distinct variations based on the optical characteristics of the abnormality embedded at various locations and depths. There is a considerable decrease or increase in the NBI variations for different detector probes based on the increase or decrease in absorption and scattering coefficients of abnormalities, respectively. From the profile of subtracted image the peak corresponds to the location of the abnormality and from the full width at half maximum the size of the abnormality is obtained. By further scanning of the image of the phantom with abnormality the depth of the embedded abnormality is obtained.

The erythrocyte deformability of blood samples, of diabetes mellitus (DM) patients with and without microangiopathic complications such as nephropathy and retinopathy, is determined and is compared with that of healthy control. The erythrocyte deformability is measured in terms of elongation index (EI) with microfluidic ektacytometer, which is very sensitive to detect changes in EI of erythrocytes due to hyperglycemic process. Each measurement of diffraction pattern of erythrocyte suspension in a highly viscous polyvinyl pyrroridone (PVP) solution in a disposable microchannel is carried out. The results show that EI is well correlated with the levels of glycated hemoglobin and creatinine, as determined from the blood samples of patients. A significant decrease in the EI in DM patients compared with that in normal control is observed. In patients with complications of chronic renal failure, end stage renal disease, retinopathy and with combination of retinopathy and nephropathy, the EI is significantly decreased in comparison with that of diabetes patients without these complications. Further reduction in EI is corresponded to the changes induced by the microangiopathy process despite the maintenance of blood glucose and glycated hemoglobin by drug therapy.

The normalized back-scattered intensity (NBI) profiles at various locations on the human thorax of a subject were obtained by multi-probe laser reflectometer. The laser radiations are guided by an optical fiber onto the human thorax tissues and the backscattered radiations are collected by three optical fibers placed at distance of 2 mm, 4 mm and 6 mm from the input fiber. The data collection of the human thorax tissue is carried out using an automatic non-contact scanning system controlled by the personal computer. The data after digitization, interpolation and filtering, are color-coded and displayed on the outline of the human thorax. These NBI pattern vary depending on the muscular, anatomical and vascular compositions and also on percentage of fat composition at various locations. For optical characterization the optical parameters, scattering (mus) and absorption (mua) coefficients and the anisotropy parameter (g) at each location on the human thorax, by matching of reflectance profiles with that as simulated by a Monte Carlo simulation (MCS) procedure were determined. The point-to-point variations of the optical parameters and NBI variations at various regions of the human thorax tissues are studied

Microstrip patch antennas are very popular due to their numerous advantages. This paper presents the design of a log periodic toothed planer trapezoid microstrip antenna. In this structure the dimensions of the successive sections were increased in geometric progression. A bandwidth of 18.18 percentage for voltage standing wave ratio less than two (VSWR

Erythrocyte deformability improves blood flow in the microvessels and in large arteries at high shear rate. The major determinants of RBC deformability include cell geometry, cell shape and internal viscosity (i.e., mean cell hemoglobin concentration and components of the erythrocyte membrane). The deformability is measured by several techniques but filtration of erythrocytes through micro-pore membranes and ektacytometry are two sensitive techniques to detect changes in erythrocytes under varied experimental and diseased conditions. Diabetes mellitus (DM) is a metabolic disorder, characterized by varying or persistent hyperglycemia, which induces several changes in the erythrocyte membrane and its cytoplasm, leading to alteration in the deformability. A decreasing trend of deformability in these patients is observed. The shape descriptor form factor, as determined by processing of erythrocyte images, increases with the increase of blood glucose levels and shows a pattern similar to filtration time of erythrocyte suspensions through cellulose membranes. Fluidity of the membrane as measured in erythrocytes of these patients is decreased. With prolonged diabetic conditions the deformability of erythrocytes is further decreased, which may complicate the flow of these cells in microvessels.

In this report, the role of oxygen plasma on oxidation of vanadium (V) metal and the volatilization of its oxides has been studied as a function of source (V metal strip) temperature (Tss) and oxygen partial pressure (PO2). The presence of O2-plasma not only enhances the oxidation rate but also ficilitates in transport of oxide molecules from metal to substrate, as confirmed by the simultanous deposition of oxide film onto substrate. Both the oxidized metal strips and oxide films deposited on substrates are characterized separately. The structural and vibrational results evidence the presence of two different oxide phases (i.e. orthorhombic V2O5 and monocilinic V O2) in oxide layers formed on V metal strips, whereas the oxide films deposited on substrates exhibit only orthorhombic phase (i.e. V2O5). The decrease in peak intensities recorded from heated V metal strips on increasing Tss points out the increment in the rate of oxide volatilization, which also confirms by the oxide layer thickness measurements. The SEM results show the noticeable surface changes on V-strips as the function of Tss and PO2 and their optimum values are recorded to be 500 ˚ C and 7.5 × 10−2 Torr, respectively to deposit maximum thick oxide film on substrate. The formation of microcracks on oxidized V-strips, those responsible to countinue oxidation is also confirmed by SEM results. The compositional study of oxide layers formed on V-strips, corroborates their pureness and further assures about the existence of mixed oxide phases. The effect of oxygen partial pressure on oxidation of V-metal has also been discussed in the present report. All the results are well in agreement to each other.

The displacements on the c hest w all due to cardiac action have been measured by an electronic distance measurement technique which is based on the v ariation of the capacitance between the probe and moving surface. The displacements were measured at 36 locations over the entire cardiac region along with ECG and were directly fed to an IBM PC/AT computer after a/d conversion. From this data, the displacement profile during any desired phase of ECG could be reconstructed in perspective view. These plots show the variation in the mechanical activity of the different regions of the heart during various phases of the cardiac c ycle and could be used for the diagnosis of the onset of cardiac disorders.

Malaria due to Plasmodium vivax affects blood flow in cardiovascular system. The present work is aimed to determine the variability of erythrocyte deformability and aggregation in malaria patients in comparison with that of normal subjects. Blood samples of malaria patients (n=16), selected based on occurrence of parasitaemia, are categorized into low (LP), medium (MP) and high parasitaemia (HP), which represent increasing levels of the disease severity. For measurement of aggregation and deformability, by laser aggregometer and optical hemorheometer, the erythrocyte suspensions are prepared in plasma and physiological saline at hematocrit 5%. The results show that the erythrocyte deformability is significantly reduced (p0.001) with the increasing level of parasitaemia. Despite this decrease in deformability, the aggregation parameters are significantly increased, indicating the occurrence of hyper-aggregation, particularly in MP and HP, due to involvement of various factors. These changes may partly be contributing in the observed changes in blood flow in the microcirculation.

Malaria due to P. vivax (PV) is prevalent in many countries. The present work is aimed to determine the cell-cell interaction through formation of aggregates under dynamic conditions. Blood samples are obtained from patients (n=11) suffering from PV malaria, and the normal subjects (n=10) in test tubes containing citrate phosphate dextrose (10:1.4), as an anticoagulant. The signature analysis of infected erythrocytes shows significant alterations in their shape and membrane. For aggregation analysis, erythrocyte suspension in plasma at hematocrit 5%, was placed in a glass chamber and mounted vertically on the stage of the video-microscope system. The aggregate images thus acquired show erythrocytes adhering with each other to form mash-like structures. With increase in parasitaemia, the erythrocytes show hyper-aggregation compared to that of normal cells. By processing of the sequence of recorded images during sedimentation, the various aggregation parameters are obtained. These parameters show that the formed aggregates are compact which produce distinct changes in sedimentation pattern with significantly higher sedimentation velocity compared to that in healthy blood samples. These changes in malaria could partly be responsible for alteration in blood flow through microcirculatory system.

A procedure for non-invasive imaging of the optical attenuation coefficient variation of in vivo thick organs/tissues is developed. The laser back-scattered surface profiles at various locations of human forearm, by multi-probe reflectometer, are measured. These profiles are matched by iterative procedure, with that as obtained by Monte Carlo simulation and the corresponding values of attenuation coefficient (equal to the sum of absorption and reduced scattering coefficients) are determined. By interpolation of this data a 100 x 100 grid is constructed and after median filtering of this data a color-coded image of the variability of the optical attenuation coefficient of the forearm is obtained. These images in different subjects show variation due to change in overall tissue composition and blood pooling. This non-invasive imaging procedure may help in identifying the diseased affected regions in healthy tissues and in application of photodynamic therapy.

The erythrocyte aggregation and deformability of blood samples obtained from normal subjects and malaria patients are determined by microscopic imaging and laser aggregometry techniques, and optical hemorheometer, respectively. By these techniques several parameters are determined but four parameters, aggregate sedimentation velocity (ASV), effective number of cells (ENC), process completion time (PCT) and mean filtration time (MFT), show significant variation in malaria patients compared to that of healthy subjects. For malaria severity analysis artificial neural network (ANN), based on feedforward-error back-propagation algorithm in a supervisory training mode is proposed. This network is first trained for different number of epochs ranging from 20 to 50 by set of patterns and at 30 epochs training session the minimum mean square error (MSE) between desired and actual output is obtained. By applying the same procedure the test patterns belonging to normal, non-severe, severe, and highly severe malaria (NSM, SM and HSM) are identified. The results show that malaria with high severity is classified accurately (100%). The success of classification for non-severe and mildly-severe malaria ranges from 60% to 80%.

The erythrocytes form chain-like aggregates during sedimentation under gravitational field. The dynamic images of these are obtained by video-microscopic system by placing the erythrocyte suspension in plasma at hematocrit 5%, in a glass chamber of thickness 100 ?m. The images at intervals of 2 min for 30 s duration are recorded. As the images are associated with high background noise, after digitization they are preprocessed for illumination correction, video de-interlacing, background subtraction, and deblurring, followed by post-processing involving edge enhancement, thresholding, median filtering and edge detection. By processing these images, to quantify the aggregation process, the morphometric parameters - projected aggregate area (PAA), projected aggregate perimeter (PAP) and form factor (FF), and sedimentation completion time (SCT) are obtained. To determine the variability of erythrocyte aggregation during human aging by this technique, blood samples from subjects of various age groups (from 20 to 60 years) are analyzed. The data obtained show the variability in the formation of aggregates in different age groups. The comparison in subjects of different age groups shows that the PAA, PAP and FF, and SCT are decreased significantly compared to that of subjects of age group 20-30 years. In subjects of 51-60 years, the formed aggregates are compact, which sediment faster compared to that of other age groups. ? 2004 Elsevier SAS. All rights reserved.

The diffuse surface reflectance profiles of the goat's isolated heart, spleen, and adipose tissues by multiprobe laser reflectometer are measured. The normalized backscattered intensity values for adipose, heart, and spleen tissues at source-detector separation 0.2 cm, are 0.060, 0.021, and 0.003, respectively. The optical parameters of these tissues are determined by the best fit (/spl chi//sub 0.99//sup 2/) of their spatial profiles with that as obtained by Monte Carlo simulation by iterative procedure. As the optical parameters of these vary over a wide range, adipose and spleen tissues are treated as inhomogeneity of diameter 0.1, 0.2, or 0.3 cm, and placed inside the control (heart) tissue at different depths. Anisotropic simulation of light backscattering or photon depth distribution is significantly different for various tissues. The surface intensity profiles vary depending on the changes in tissue composition. From the horizontal scans of the subtracted images, the photon backscattering simulated images of control and combination of tissues are obtained. By analysis of peak intensity and full-width at half maximum, the type, location, and size of the tissue compositional variation are determined.

An imaging technique for erythrocyte aggregation analysis under dynamic conditions is developed. A well-mixed erythrocyte suspension in plasma (hematocrit 5%) is placed in a glass micro-chamber (100 /spl mu/m thick) wherein the erythrocytes form three-dimensional aggregate structures, which sediment under gravitational field. During this process a sequence of images of aggregates at various time intervals are recorded. By computerized analysis of these images the aggregation process is quantified in terms of area, perimeter and size distribution. The results obtained by this method are not only in agreement with optical techniques but also provide the visual details of the aggregation process in health and diseases.

The normalised back-scattered intensity (NBI) profiles at various locations on the forearms of ten human subjects were obtained by moving the multi-probe of a laser reflectometer. The statistical analysis of the NBI data showed that the variation in the NBI was significantly higher at the ulnar region compared with that at other regions. For determination of the scattering (mus) and absorption (mus) coefficients and the anisotropy parameter g at each location on the forearm, these profiles were matched with the NBI profiles simulated by a Monte Carlo procedure (chi(2)0.99). For the reconstruction of images of variation of these parameters, the averaged values of mua, mus, and g at all locations on the forearms of the subjects were determined. The absorption coefficient had a minimum (1.92 cm(-1)) and maximum (2.21cm(-1)) at the wrist and the lateral region of the forearm, respectively. The scattering coefficient had a maximum (194 cm(-1)) at the medial side and near the elbow, and a minimum (186 cm(-1)) at the lateral side of the forearm. Similar changes in the anisotropy parameter were also observed. By interpolation of the data of each parameter on a 100 x 100 image matrix and after median filtering, colour-coded images of the variation in the optical parameters were constructed. These images could be useful for diagnostic and therapeutic applications of lasers.

Optical characteristics of freshly isolated tissues depend on their color and composition. The surface backscattered profile, which account for the tissue compositional variation in fresh excised sheep's heart, lungs, bone and muscle, were measured by multi-probe reflectometer. Optical phantoms were prepared from paraffin wax by mixing a specific combination of wax color materials till the surface backscattered profile of these matched with that of the biological tissues. The optical parameters absorption coefficient (micro(a)), reduced scattering coefficient (micro(s)) and anisotropy factor (g) of these phantoms, are the same as that of biological tissues and are obtained by matching their surface backscattered profiles with that as simulated by Monte Carlo procedure. The maximum and minimum values of absorption coefficient are for the phantoms of lungs (1.0 cm(-1)) and muscle (0.02 cm(-1)), whereas, for scattering coefficient these values are for muscle (21.2 cm(-1)) and bone (13.08 cm(-1)).

The optical characterization of various goat organs/tissues, by measurement of the spatial variation of the diffuse reflectance from the surface by laser multi-probe reflectometer, is carried out. For determination of the optical parameters, these profiles are matched by iterative procedures with that obtained by Monte Carlo simulation by best-fit procedure with chi value 0.99. The first set of measurements is carried out with milk phantom. Thereafter, the absorption and scattering coefficients and anisotropy parameter of goat's heart, lungs, kidney, liver, spleen, skeletal muscle, brain and adipose tissues are measured. These parameters vary over a wide range, which is in agreement with results reported by others. Based on these data, their laser scattering profiles along the depth in terms of depth of penetration (DP) and maximum scattered beam width (MSBW) are determined. These are maximum (0.030 and 0.038 m) for kidney and minimum (0.007 and 0.006 m) for spleen, respectively. The backscattered intensity measured 0.002, 0.004 and 0.006 m away from the beam entry point shows the maximum contribution from the respective depths, irrespective of the nature of the organs/tissues. ? 2004 IPEM. Published by Elsevier Ltd. All rights reserved.

Blood flow through a frog mesenteric microvessel, consisting of one loop and two successive bends, was recorded by a video-microscopic system and analysed by a PC-based image processing system. After preprocessing, these images were analysed by the image velocimetry, axial tomography and image processing procedures. The blood flow in the microvessel had a Reynolds number of 0.033, and the Dean number varied from 0.004 in the loop to 0.007 in the bend, showing an increase in secondary flow in the bend region. These changes led to outward shifts in the peaks of velocity and concentration profiles, with an increase in the thickness of the outer walls (of about three times) compared with that of the inner walls. The mean velocity and mean cellular concentration showed a similar pattern. The variation in the cellular concentration in the microvessel was visualised by concentration contours and grey-scale images of the cellular distribution. At the inner wall of the complex geometry, the velocity reduced to zero, whereas the cellular concentration varied from 2 to 5%. In the high shear stress regions in the complex geometry, the vessel wall thickness was two-three times more than that in low shear stress regions.

[No abstract available]

Blood flow through frog mesenteric microvessel with multiple branching, at Reynolds number 0.022, is analyzed. After pre-processing the images the velocity and erythrocyte distribution profiles by image velocimetry and axial tomography are obtained, respectively. The vascular parameters and shape descriptors are obtained by image processing techniques. The axial velocity shows the variation around branching areas associated with an increase in radial velocity, which is up to 10% of axial velocity. From the erythrocyte distribution profiles at various locations in the microvessel the tomograms are reconstructed. Based on these the contours of equal concentration are reconstructed. From these contours the point-to-point variation in cell concentration throughout the microvessel is observed and regions where the cellular concentration varies from 3 to 5%, at zero axial velocity, are identified. The change in erythrocyte shape, determined by the shape descriptors, while passing through the capillary is significant. This passage of cells, depending on their orientation, also displaces the capillary walls by 1.5 to 2.5 microm.

Erythrocyte aggregation and elongation index (EI) (deformability) are measured at temperatures ranging from 5 degrees C to 37 degrees C by aggregometer MA1, and diffractometer Rheodyne SSD and the LORCA, respectively. The test samples are prepared from blood obtained from healthy subjects in test tubes containing EDTA as an anticoagulant and prior to measurement are placed in a water bath for 30 min, maintained at respective temperatures. The aggregation process is given in terms of primary aggregation time and indices of aggregation. These show significant to highly significant changes with the increase of temperature compared to that at 5 degrees C. The EI increases with the increase of shear stress but shows significant decrease with the decrease of temperature.