THERMO-MECHANICAL DESIGN STUDY OF FIBER OPTIC PRESSURE SENSOR DIAPHRAGMS

This thesis parametrically explores the nonlinear design sensitivity of a fiber optic pressure sensor (FOPS), based on selected thermo-mechanical failure mechanisms expected in the sensor diaphragm. The product under study is a miniature FOPS that can be embedded in, or installed on, a structure for pressure monitoring applications. The field operating conditions considered in this study are defined in terms of temperature and pressure The FOPS probe has a Fabry-Perot cavity, with the fiber tip and a miniature diaphragm acting as the two mirrors. The cavity length changes when the diaphragm deflects under pressure. However, due to field operating conditions, several failure mechanisms may affect the structural and optical characteristics of the sensor, such as nonlinear displacement of the diaphragm, cracks in the diaphragm, buckling of the diaphragm, high residual stresses in the optical fiber and deformations and failure in the epoxy sealant between the optical fiber and the steel casing. With the aid of nonlinear thermomechanical finite element analysis, this article investigates conflicting design constraints due to sensitivity and selected failure mechanisms in the sensor, e.g. nonlinear diaphragm deformation, diaphragm fracture and diaphragm buckling. The study is divided into three parts. The first part of this study considers the mechanical loading due to external pressure which the FOPS will experience and gives design guidelines based on the nonlinear diaphragm deflection and stress predictions. The second part accounts for the thermo-mechanical loading in which the FOPS is placed in a temperature drop and the resulting nonlinear in-plane compressive stresses and diaphragm deflections are analyzed. In the third part of this study the combined effects of pressure and thermal loadings are examined for more realistic application conditions. Design guidelines for both simultaneous and sequential changes in temperature and pressure are examined, to represent different working environments

Hierarchy-in-flux: Co-evolving a distributed user interface for orbiting robots

The role of context has been an important focus for Human-Computer Interaction research since the beginning of the Second Wave of HCI. While different theoretical frameworks within the HCI community have different approaches to analysing context, they do so always with the object of understanding its effects on human-machine interaction, often with the larger goal of generating insights into future designs. The forces that shape context itself are typically ignored in these analyses because they are not considered relevant to the interaction itself, which is the focus of HCI. Yet if these forces were to create different contexts for interaction those changes would be relevant to HCI research. This suggests that HCI might benefit from techniques that analyse and design for the creation of the institutional structures that constrain human-machine interactions. We present the notions of multi-scale analysis and multi-scale design as terms which describe approaches that seek to engage the different disciplinary proficiencies that create the context for interaction. In doing so we make the case for a new kind of design education that strives to create multidisciplinary designers capable of harnessing the dynamics of systems at different levels of abstraction to achieve outcomes that exceed what we might expect from HCI alone

Correlation of sinonasal polyposis with chronic suppurative otitis media

Background: Aim of the study was to assess correlation of sinonasal polyposis with CSOM. To see the role of lignocaine nebulisation and to compare its role with use of steroids and bronchodilators alone in post bronchoscopy patients. Methods: In the present study, 50 patients of sinonasalpolyposis were subjected to otoscopic, microscopic examination of tympanic membrane findings and tuning fork tests were performed. Pure tone audiometry (PTA) was also done in all patients. High resolution computed tomography (HRCT) of temporal bones and computed tomography (CT) of paranasal sinuses were used to assess otological and sinonasal pathology. Results: Out of 50 patients, males were 26 and females were 24. Age group 11-20 years had 8 males and 8 females, 21-30 years had 5 males and 7 females, 31-40 years had 11 males and 8 females and 41-50 years had 2 males and 1 female. Left side was involved in 6, right in 9 and both sides in 10 patients. Swab cultures revealed pure aerobic isolates in 16, mixed aerobic and anaerobic isolates in 10. Micro-organisms were staphylococcus aureus in 10, Pseudomonas aeruginosa in 6, Streptococcus spp. in 5, Peptostreptococcus in 3 and Bacteroides in 2 cases. The difference was significant (p<0.05). Out of 50 Sinonasal polyp patients, 26 (52%) had CSOM. Type identified was tubotympanic in 12 and atticoantral in 14. There was positive pearsoncorrelation of CSOM with sinonasal polyp (r value of 0.92, p value 0.021). Conclusions: In the present study there was positive correlation of sinonasal polyposis with CSOM. The prevalence rate was 26%. Micro-organisms were Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus spp., Peptostreptococcus and Bacteroides

SENTINEL LYMPH NODE SCINTIGRAPHY IN BREAST CARCINOMA- COMPARISON OF TWO VERSUS FOUR INJECTION SITE TECHNIQUE

Purpose: Sentinel lymph node (SLN) is the first regional node that drains lymph from the primary tumour and receives seeding of metastatic cells. Axillary node dissection remains the most reliable predictor of disease outcome. Controversies still exist about several aspects of lymphatic mapping and SLN biopsy for breast cancer, including number of radioisotope injection. The purpose of this study is to evaluate the success rate of different number of injection sites in the detection of SLN in breast cancer.Materials and Methods: A total of 120 consecutive breast cancer patients were divided into two groups. Group A (60 patients) received four intradermal periareolar (ID-PA) injections. Group B (60 patients) received two ID-PA injections.Imaging was carried out at 45 min post-injection. A gamma probe was used to explore the SLNs during surgery.Results: In Group A, 60 females with the mean age of 50.77 years were included in the study. 34 (56%) patients had single SLN. 25 (41.7%) had SLN with the second tier. 1 (1.7%) was negative. Group B included 60 patients (59 females and 1 male) with the mean age of 51.9 years. In 30 (50%) patients, single SLN was detected. 29 (48.3%) had SLN with the second tier. 1 (1.7%) was negative.Conclusion: SLN mapping with two periareolar ID injections carries less radiation dose and less pain as compared to the four injections with equal sensitivity for the visualization of SLNs.Key words: Breast cancer, intradermal injection, sentinel lymph node, Tc99 human serum albumi

Kinematic Analysis of Selected Rock Slopes along Choa Saidan Shah-Kallar Kahar Road Section

The present study deals with the kinematic analysis of joint orientation data gathered from three selected slope sites situated along the Choa Saiden Shah-Kallar Kahar road section by using Dips (5.1) software suite for Microsoft Windows. The stability analyses indicate that slope faces 1, 2 and 3 are not critical to instability for planar and wedge failure modes; however they carry toppling failure risk of 68%, 50% and 81% respectively. Further it is recommended that the selected slope sites may be stabilized by using rock anchors/bolts, proper drainage of water and the erection of rock catch fences etc. &nbsp

CORRELATION BETWEEN STANDARDIZED UPTAKE VALUE AND HISTOPATHOLOGY OF OESOPHAGEAL CARCINOMA: A SINGLE CENTER ANALYSIS

Aim: This study aims to evaluate the correlation between oesophageal cancer histopathology and the standardised uptake value (SUV) of the primary lesion on positron emission tomography/computed tomography (PET/CT) scan.Methods: We reviewed clinical data of consecutive newly diagnosed oesophageal cancer patients who underwent positron emission tomography with 2-deoxy-2-[ uorine-18] uoro-D glucose integrated with CT (18F-FDG PET/CT) between September 2009 and July 2014. Results: A total of 289 baseline scans were performed in this 55-month period. Of these, 171 (59%) were male. The mean age was 52.6 years (standard deviation ± 12.4 years). On histological review, 214 were squamous cell carcinomas (SCCa) and 75 were adenocarcinomas. Of the SCCa, 15.9% were poorly differentiated, 70.6% were moderately differentiated and 13.5% were well differentiated. Of the adenocarcinomas, 20% were poorly differentiated, 45% were moderately differentiated, 28% were well differentiated and signet ring cell was 7%. Mean maximum SUV (SUVmax) for SCCa was 12.6 ± 5.14 and 10.5 ± 6.2 for adenocarcinomas. In bivariate analysis, being a female was associated with a higher SUV in the primary lesion by 1.66 units (P = 0.011) compared to males. Adenocarcinomas were associated with a lower SUV by 2.14 units (P = 0.004) compared to SCCa. In bivariate analysis, no signi cant correlation was found between the T-stage of the tumour and the SUVmax of the primary tumour (P = 0.339). Multivariate analyses showed no association of the SUV of the primary oesophageal tumour with the degree of differentiation of either SCCa or adenocarcinoma. There was no correlation between the SUVmax of the primary lesion and the presence or activity level of a metastatic focus, whether visceral or nodal. Conclusion: At our centre, three-fourths of patients with oesophageal carcinoma had squamous cell carcinoma on histology. Adenocarcinoma is associated with a lower SUV compared to SCCa. There is no association between the SUVmax and degree of differentiation of the primary oesophageal cancer. Key words: Fluorodeoxyglucose, oesophageal adenocarcinoma, oesophageal squamous cell carcinoma, positron emission tomography/computed tomography, standardised uptake value

Assessment of Cerchar Abrasiveness Index by LCPC Abrasivity Coefficient and Strength Properties of Selected Rocks from Western Salt Range Punjab

Ten sedimentary rock samples including sandstones,limestones and an iron ore were collected from various locations of District Khushab, Mianwali and Trans Indus area        (Punjab, Pakistan). The samples weresubjected to Cerchar and LCPC Abrasivity tests for determination of their abrasivity potential. The Cerchar Abrasivity testswere performed over both sawn and rough rock surfaces.Simple linear regression analysis was performed to establish possible correlations between Cerchar Abrasivity Index (CAI), LCPC Abrasivity Coefficient (ABR) and other physical properties of rocks including UCS and BTS. The validation of developed equations was done by using 95 % confidence interval limits. The work done shows that selected sedimentary rocks from Western Salt Range have low to medium abrasivenes

PSO Based PID Controller Design for a Precise Tracking of Two-Axis Piezoelectric Micro positioning Stage

In this paper the design of an optimal PID controller for single and double axis piezoelectric micropositioning stage system is presented. The Particle Swarm Optimization (PSO) method is used to tune the parameters of the PID controller subject to specific objective function. The proposed controller provides a high performance trajectory tracking responses of the piezoelectric micropositioner stage.A simulation results are presented to show the effectiveness of the proposed control algorithm

Indexing Virus and Virus-Like Diseases of Citrus

Citrus is a highly nutritive and prized fruit crop around the world. It contributes a substantial share in local consumption and exports of a nation to earn a handsome foreign exchange. The production of citrus is under the threat of citrus decline. Different factors are responsible for the citrus decline but virus and virus-like diseases have the major role in this decline. Virus and virus-like diseases alone or in association with other biotic and abiotic factors exist in the citrus orchards. Therefore, indexing of diseases caused by virus and virus-like pathogens is the key factor to manage these citrus diseases. Proper facilities and skilled personnel are the pre-requisite for the diseases indexing procedures. Biological, serological and molecular indexing is sensitive, reliable and durable strategy for managing different citrus virus and virus-like diseases under different conditions. Moreover, indexing of viruses and virus-like pathogens are very important for the production of disease free citrus nurseries. This chapter gives a brief review for the commonly used biological, serological and molecular assays for the detection of citrus virus and virus-like pathogens