Mapping of Velocity Variations to Investigate Seismicity in the Upper Crust of the Central Virginia Seismic Zone, Virginia, USA

Local earthquake tomography is used to investigate three dimensional velocity structure in the aftershock zone of the 2011 Mineral, VA, mainshock. A total of 5125 arrival times for 324 aftershocks recorded by 12 stations were used in the inversion. The inversion volume is small (22 x 20 x 16 km) with a block size of 1 x 1 x 1 km. Most of the aftershocks located at or below 2 km are associated with an NE trending, SE dipping anomalous velocity region with negative P-wave velocity (Vp) anomalies, positive S-wave velocity (Vs) anomalies, and Vp/Vs ratios as low as 1.54. We interpret the anomalous region as a highly quartz-rich sandstone or quartzite that accumulated in Paleozoic time along the passive margin of Laurentia and subsequently incorporated into the Piedmont Chopawamsic terrane during the Taconic orogeny. Two negative Vp and Vs anomalies are interpreted as metagraywacke and typical Chopawamsic rocks

Kinetics of Length Scale Dependent Deformation of Gold Microspheres and Micropillars

In this thesis length and time scale dependence of the operative plastic deformation mechanisms in Au is studied. Uniaxial compression tests were performed at various loading rates on FIB-milled Au micropillars and single-crystalline Au microspheres of diameter ranging from 0.8 to 6.0 µm to investigate the incipient and bulk plasticity events. Constant-load ambient-temperature creep tests were performed on the micropillars to study the time-dependent plasticity at very slow strain rates. Uniaxial compression tests were also performed on coated Au microspheres to study the effect of extrinsic constraint on the deformation mechanisms. During uniaxial compression, both the Au micropillars and microspheres displayed strain jumps, the frequency of which decreased with increasing sample diameter and increasing resolved shear stress. The bulk flow stress, corresponding to 5% – 20% average compressive strain, was dependent upon both the strain rate and the specimen diameter. Analysis of the apparent activation volume, V*, and energy, Q*, of the deformation process indicated that the operative deformation mechanism for the small 0.8 µm diameter pillars and spheres was characteristic of a mechanism limited by surface nucleation of dislocations while larger diameter samples displayed values indicative of the more common dislocation-obstacle interaction limited deformation mechanism. The deformation-rate dependence of incipient plastic deformation of the Au micropillars and microspheres was also dependent upon the strain rate and sample diameter. For the smallest, sub-micrometer size, samples the incipient plasticity was controlled by heterogeneous dislocation nucleation events, while a dislocation-obstacle interaction limited glide process was found to be operative in the larger specimens. In the extrinsic constraint study, Au microspheres that were coated with a 40 – 80 nm thick Ni layer displayed a slightly increased flow stress compared to similar size uncoated microspheres. The estimated V* and Q* values for the coated microspheres suggest that the mechanism responsible for the initiation of first dislocation motion is essentially the same regardless of the presence of a constraining coating

Diagnosis of cervical lesion by colposcopy, VIA, pap smear tests, and their correlation with histopathology in a tertiary level laboratory in Chattogram, Bangladesh

Background: Cervical carcinoma is one of the most common causes of mortality among women. This mortality rate can be reduced by early detection of cervical neoplasm by different screening tests. The main objective of this study was to diagnose cervical diseases by colposcopy, by pap smears for cytological examination as well as correlate these findings as screening tests with histopathological diagnosis. Methods: In this cross-sectional observational study, total 143 cases were included. History was taken and clinical examination was done. Colposcopy and VIA test was done, pap smear sample was collected and reporting was made. Cytological findings were correlated with histopathology. Results: Mean age of the study cases was 41.2±11.5 years. VIA test was positive in 98 study cases (68.5%). On colposcopy, most of the cases show neoplastic proliferation (80 cases, 55.9%). Among them, most cases were diagnosed as cervical intraepithelial neoplasia-I (CIN-I). Sixty-three (63) cases (44.1%) were non-neoplastic. Most of the biopsies was diagnosed histopathologically as cervical intraepithelial neoplasia-I (CIN-I) (20 cases, 14.0%). Association of colposcopy findings with histopathological diagnosis was done which was significant. Sensitivity of diagnosis of cervical malignancy by colposcopy was 33.33% and specificity was 98.57%. Conclusions: The study provides good cyto-histopathology correlation in detecting different cervical lesions and malignancy with colposcopy. Although colposcopy sensitivity was low but it can be increased by adequate training and avoiding technical errors. Bethesda system is strongly recommended for adequacy of sampling to minimize inconsistency. Early and regular screening should be advised for reduction of mortality rates from cervical carcinoma

Frequency of nodal metastasis in differentiated thyroid carcinoma

Background: Thyroid cancer is the most common endocrine malignancy. Moreover, within thyroid cancer, differentiated thyroid carcinoma (DTC) is the most common variety, with the incidence rising over the past decade. Often, most of the cases present with multicentric disease and presenting with lymph node metastases at the time of diagnosis. Nodal metastasis has prognostic importance, and it may guide surgeons regarding further management. Considering this scientific fact, the study was performed to see the frequency of lymph node metastasis in DTC among the patients admitted to a tertiary care hospital. Methods: This cross-sectional study was conducted in the department of otolaryngology and head-neck surgery, Sher-E-Bangla Medical College Hospital, for 9 months after the acceptance of the protocol. A total of 50 patients (in all age groups) who attended the relevant department due to thyroid malignancies were approached and interviewed. Thorough history taking, physical examination, and relevant investigation were done and recorded into separate case record forms. Informed written consent was taken from each subject. Following collection, data were coded and inputted into statistical software. Data analysis was done with SPSS 21 according to the objective of the study. Data were presented in the form of tables, and charts. Results: Among the 50 patients, the mean age of the patients was 47.86±15.69 SD (years) with minimum and maximum ages of 14 and 78 years respectively. The male-female ratio was 1:4 (20% male vs 80% female). Papillary carcinoma was the most frequent (88%) followed by follicular (10%). Nodal metastasis was most common in the papillary variety, about 54.55% of cases, whereas 20% were present in the follicular variety. The majority of the patients underwent total thyroidectomy with neck dissection (90%) and the remaining cases were managed by lobectomy (10%). Conclusions: This study concluded that nodal metastasis was present in 54.55% of cases of papillary carcinoma.

Pattern of Pre-Hospital Treatment Received by Cases of Pesticide Poisoning

Background: Prehospital treatment following acute pesticide poisoning is not optimal and mortality following such poisoning is high in Bangladesh. Method: It was a prospective study in which pattern of pre-hospital treatment received and outcome of pesticide poisoned patient were studied at one adult medical unit of Dhaka Medical College Hospital from October 2005 to June 2006. Results: The number of cases of pesticide poisoning were 60 (1.98%) of 3030 admitted patients. The mean age was 24.7±8.8 years. Most of them (40, 66.7%) were male. The incidence of poisoning was high among students (11, 18.3%) and housewives (10, 16.7%). The most common cause of poisoning was intentional (55, 91.7%). Familial disharmony was underlying cause in 27 (45%) patients. More than half of the patients (41, 68.3%) purchased the poison self. 25 (41.7%) patients got first contact with physician within 30 minutes of poisoning. In majority cases (45, 75%) first contact health care provider was government hospital. Only 22 (36.7%) patients received first aid before arrival to present hospital. Among them, 19 (31.7%) patients received induced vomiting by ingestion of tamarind water or lemon water or soap water or putting finger or other substances (cow dung, human excreta etc.) in mouth and 3 (15%) patients received home remedy like milk, raw egg etc. The overall mortality was 16.7%. Conclusion: Measures should be taken to increase the awareness among general population regarding the first aid following pesticide poisoning

Color Performance and Cost Effectiveness Evaluation of Acid and Basic Dyed Silk Fabric

Silk, the natural protein fiber has a great importance in textile clothing, apparel and home decoration due to its definite lustrous appearance, peach like softness and draping qualities. Fine fibrillar structure and orientation of fiber molecules control its dyeing nature covering almost the entire spectrum of colors and hues. Silk is mainly used for value added premium quality products, so this research work is carried out to find out the economical dyestuff for silk along with required end customer performance. Shade strength measurement using data color is also another technical aspect of this research

Urothelial carcinoma of urinary bladder with histologic grading: a study in a tertiary care hospital, Bangladesh

Background: Urinary bladder cancer is one of the most common forms of all cancers in the world.  It is the ninth leading cause of death from cancer among men. The incidence of urinary bladder cancer in Bangladesh is increasing day by day. The aim of the study was to evaluate different clinic-pathological parameters of urothelial carcinoma of urinary bladder with the grade of the tumor. Methods: This study was a cross sectional study done over a period of two years, from March 2018 to February 2020 at the department of pathology, Dhaka medical college, Dhaka. Total 73 samples were collected, fixed overnight in 10% buffered formalin and stained with hematoxylin and eosin staining. Pathological grading was confirmed and different clinic-pathological parameters were evaluated. Results: Most of the cases (22 cases, 30.1%) were found in the fifth decade (51-60). Mean age of the patients was found to be 60.85 (±12.72) years, 58 (79.5%) cases were male and 15 (20.5%) cases were female with male to female ratio of 3.9:1. Most of the cases (49 cases, 67.1%) were smokers. Most common clinical presentation was hematuria (91.8% cases), most frequent tumor location was the lateral wall of the urinary bladder and 75.3% cases were reported as high-grade urothelial carcinoma. Conclusions: Different clinic-pathological parameters with histologic grading were evaluated in this study which may have a significant impact in epidemiology, diagnosis and assessment of biological behavior of urothelial carcinoma

Characterization Analysis of Textured and Diffused Monocrystalline Silicon Wafer

This paper focuses on examining the characteristic analysis of the textured and diffused silicon wafer. Characterization performance of the textured and diffused wafer using surface reflection method, sheet resistance method, SEM, and surface photovoltage method is examined. From the SRM result, it is observed that the reflection of the textured wafer is lower than the raw wafer. This means that the textured wafer forms the pyramid structure, which was measured by SEM. Sheet resistance measures the resistivity of the raw wafer and after phosphorous diffusion into the p-type silicon, the wafer are 2.3 Ω-cm and 0.80 Ω-cm respectively. From the sheet resistance results, it is observed that the phosphorus doping is properly done. The Surface Photovoltage (SPV) result shows that minority carrier diffusion length and lifetime for a solar cell is 86.4μm and 2.8 μsec respectively

Investigation of Electrical and Optical Transport Properties of Annealed InOx Thin Films

Indium oxide (InOx) films with a thickness of 50–150 nm were deposited onto glass substrate by electron beam evaporation technique. As-deposited InOx films were annealed in air at 575K for 3 hours and characterized by Scanning Electron Microscopy (SEM), electrical and optical measurements. SEM study of the film of thickness 50 nm revealed that the surfaces are distributed uniformly throughout the film with the uniform small grains. Temperature dependence of electrical resistivity was measured in the temperature range 300-475K. The decrease in resistivity with the increase of temperature indicates that InOx films are semiconducting in nature. The reduction in the resistivity with temperature might be associated with thermally activated conduction mechanism. The behavior of resistivity and so also the activation energy of annealed InOx thin films depend on thickness. From Hall study, it is observed that the films exhibit n-type electrical conductivity with carrier concentration of about 1025 m-3. The absorption coefficient was calculated from the transmittance measurements. The direct optical band gap is found to vary from 3.60 to 3.72 eV as the thickness increased from 50 to 150 nm