A Comparative Overview of Geophysical Methods

This report was prepared with support from the Air Force Research Laboratory, under contract FA8718-07-C-0021.The shallow subsurface structure of the Earth is important to understand for many economic and safety reasons. The problem is usually difficult due to complexity of the earth’s subsurface processes especially near the surface. A number of geophysical methods are used for this purpose using different physical characteristics of the Earth materials. A particular geophysical method illuminates part of the problem, but a reliable solution can only be found by combining results of different methods. In order to synthesize information from different geophysical methods, it is important to understand their similarities and differences. The aim of this study is to correlate the basic principles of geophysical methods side-by-side starting from fundamental equations. This study reveals that many analogies exist among these methods both in their mathematical formulation, and sometimes, in ways they are used in the geophysical applications

Strongly interacting one-dimensional Bose condensates

Ankara : Department of Physics and the Institute of Engineering and Science of Bilkent Univ., 2000.Thesis (Master's) -- Bilkent University, 2000.Includes bibliographical references leaves 39-43Recent observation of Bose-Einstein condensation in dilute alkali gzises led to a great interest in this area both experimentally and theoretically. The most important characteristics of a Bose-Einstein condensate is that it consists of a large number of atoms occupying a single quantum state. This kind of a feature seen in photons led to the production of widely-used photon lasers. Coherent state of atoms may lead to the production of atom lasers in near future. The well-known Bogoliubov model to explain the nature of Bose-Einstein condensates of trapped dilute gases is valid when the interaction between particles is weak. However, as the number of atoms is increased, the interaction effects lead to a significant contribution in the system. Several attempts were made to improve the Bogoliubov model and to explain strongly interacting systems but these treatments are accurate up to a finite strength of the coupling . One-dimensional Bose systems is important because exact solution of the homogenous problem exists. Also it is a good testing ground to study interaction effects since only two-body interactions play role in these systems. Furthermore, experimental realization of one-dimensional systems are attracting a great deal of interest into the present problem. We investigate a somewhat different method to study the properties of strongly coupled Bose condensates in one-dimensional space. It uses the socalled Kohn-Sham theory to solve the problem by considering the exact solution of the homogenous one-dimensional Bose gas. The new approach reveals that interactions are expressed by a ■0^ term in the strongly coupled regime in contrast to a 0^ term in weak coupling regime. The model is applied to several types of trap potentials by performing a numerical minimization. We also improve the model for the case of a finite temperature. We observe that the system has a non-zero critical temperature which suggests a real phase transition in onedimensional space. In the last part, we work on the stability of a two-component condensate in a harmonic trap potential. We find that for a wide range of system parameters either a coexisting or a phase-segregated mixture can be obtained.Erkan, KamilM.S

Gastric outlet obstruction caused by focal nodular hyperplasia of the liver: A case report and literature review

AbstractINTRODUCTIONHere, we present a case of gastric outlet obstruction due to focal nodular hyperplasia of the liver.PRESENTATION OF CASEA 23-year-old female presented to our emergency clinic with nausea, vomiting, and abdominal pain. Endoscopy showed that the prepyloric region of the stomach was externally compressed by a lesion. Computed tomography and magnetic resonance imaging revealed a 70mm solid mass originating from the liver, extending caudally in an exophytic manner, and compressing the stomach. Laparotomy revealed an irregular and exophytic mass originating from the liver, which caused gastric outlet obstruction. The mass was resected with a 10mm safety margin. The histopathology report of the mass returned as focal nodular hyperplasia.DISCUSSIONGastric outlet obstruction is a clinical syndrome characterized by abdominal pain, nausea, and postprandial vomiting. This clinical condition frequently develops as a result of peptic ulcer disease, pyloric stenosis, and obstruction of pylorus by foreign bodies including phytobezoars, congenital duodenal webs, malignant disorders, and various lesions externally compressing the stomach. Gastric outlet obstruction due to hepatic lesions is extremely rare; few cases have been reported.CONCLUSIONThis is the first reported case of gastric outlet obstruction that developed due to focal nodular hyperplasia of the liver

Crustal thermal regime at The Geysers/Clear Lake area

ABSTRACT The Geysers/Clear Lake area in northern California is characterized by extensive volcanism and intrusion of bimodal magmatic products within the last 2 Ma and by the presence of one of the largest (steam dominated) geothermal systems in the world. Based on a compilation of data from over 650 heat flow sites in 100 to 600 m wells, the region is also characterized by a large area of elevated regional heat flow (an area greater than 1,600 km 2 ). The heat flow over this large area averages 150 mW/m 2 , about double the already high Coast Range regional heat flow of 75 mW/m 2 . Temperature-depth data from numerous deep wells (average 3 km) demonstrate characteristics of the thermal regime in this magmatic/volcanic system to depths where the temperatures are 250 to 350 °C. One of the characteristics of vapor dominated systems is their low permeability. Thus the large thermal data set and the very low permeability of the upper crust in this region allow a look at the upper and mid-crustal thermal effects of a large scale intrusive center with limited surface expression. Two dimensional forward and a 3-d inverse thermal models of the intrusions (varying both in size and frequency, based on the present day heat flow pattern and the igneous record of the last 2 M.Y.) that underlay this upper crustal system are described. The heat flow and deep temperature data are powerful constraints on the interesting parameters that are otherwise only known from fossil systems, not currently active, large, cryptic, magmatic systems. The rate of intrusion is on the order of 0.005 km 3 /yr which is slow enough to allow for significant cooling so that most of the upper crust is below magmatic temperatures for most of the time. This region of thermal disturbance is characterized by a negative gravity anomaly and by shallowing of the seismogenic layer. Direct seismic evidence of magma has not been identified, but nonetheless this area represents an active plutonic system in a geologic sense

A Burkitt's Lymphoma Case Mimicking Crohn's Disease: A Case Report

Lymphomas are solid tumors that arise from lymphoid tissue and present themselves as Hodgkin's or non-Hodgkin's lymphoma. Particularly gastrointestinal lymphomas can be clinically confused with other gastrointestinal tumors as well as with diffuse and inflammatory bowel disease. Early diagnosis and treatment bear vital importance in the management of lymphomas due to their high proliferation rates. In this report, we are presenting a case which initially displayed clinical and radiological signs of Crohn's disease, but was eventually diagnosed as Burkitt's lymphoma by laparotomy, and also we aim to underscore the importance of differential diagnosis

Generation and characterization of human induced pluripotent stem cell line METUi001-A from a 25-year-old male patient with relapsing-remitting multiple sclerosis

© 2021Multiple sclerosis is a chronic disease characterized by inflammation, demyelination, and axonal damage in the central nervous system. Here, we established an induced pluripotent stem cell (iPSC) line METUi001-A from the peripheral blood mononuclear cells of a 25-year-old male individual with clinically diagnosed Relapsing-Remitting Multiple Sclerosis (RRMS) using the integration-free Sendai reprogramming method. We demonstrated that the iPSCs are free of exogenous Sendai reprogramming vectors, have a normal male karyotype, express pluripotency markers, and differentiate into the three germ layers. The iPSC line can serve as a valuable resource to generate cellular model systems to investigate molecular mechanisms underlying RRMS

New Resistorless and Electronically Tunable Realization of Dual-Output VM All-Pass Filter Using VDIBA

In this paper, a new active element called voltage differencing inverting buffered amplifier (VDIBA) is presented. Using single VDIBA and a capacitor, a new resistorless voltage-mode (VM) first-order all-pass filter (APF) is proposed, which provides both inverting and non-inverting outputs at the same configuration simultaneously. The pole frequency of the filter can be electronically controlled by means of bias current of the internal transconductance. No component-matching conditions are required and it has low sensitivity. In addition, the parasitic and loading effects are also investigated. By connecting two newly introduced APFs in open loop a novel second-order APF is proposed. As another application, the proposed VM APF is connected in cascade to a lossy integrator in a closed loop to design a four-phase quadrature oscillator. The theoretical results are verified by SPICE simulations using TSMC 0.18 um level-7 CMOS process parameters with +-0.9 V supply voltages. Moreover, the behavior of the proposed VM APF was also experimentally measured using commercially available integrated circuit OPA860 by Texas Instruments.In this paper, a new active element called voltage differencing inverting buffered amplifier (VDIBA) is presented. Using single VDIBA and a capacitor, a new resistorless voltage-mode (VM) first-order all-pass filter (APF) is proposed, which provides both inverting and non-inverting outputs at the same configuration simultaneously. The pole frequency of the filter can be electronically controlled by means of bias current of the internal transconductance. No component-matching conditions are required and it has low sensitivity. In addition, the parasitic and loading effects are also investigated. By connecting two newly introduced APFs in open loop a novel second-order APF is proposed. As another application, the proposed VM APF is connected in cascade to a lossy integrator in a closed loop to design a four-phase quadrature oscillator. The theoretical results are verified by SPICE simulations using TSMC 0.18 um level-7 CMOS process parameters with +-0.9 V supply voltages. Moreover, the behavior of the proposed VM APF was also experimentally measured using commercially available integrated circuit OPA860 by Texas Instruments

Original Article Long-term effects of forgotten biliary stents: a case series and literature review

Abstract: There are many studies about the biliary stents, however there is a little information about the long-term stayed forgotten biliary stents except a few case reports. We have reported the results of a number of cases with biliary stents that were forgotten or omitted by the patient and the endoscopist. During February 2010 to May 2013, five patients were referred to the general surgery clinic of Haydarpasa Numune Training and Research Hospital, Istanbul Turkey. Past history and medical documents submitted by the patient did not indicate a replacement of the biliary stent in 3 patients. Two patients knew that they had biliary stents. We also conducted a literature review via the PubMed and Google Scholar databases of English language studies published until March 2014 on forgotten biliary stent. There were 3 men and 2 women ranging in age from 22 to 68 years (mean age 41.6 years). Patients presented with pain in the upper abdomen, jaundice, fever, abnormal liver function tests or dilatation of the biliary tract alone or in combination. Patients' demographic findings are presented i

Comparison of Anastomosis Safety in Colonic Dissections Using Scalpel, Scissors and Cautery in Rats: Experimental Study

Objective:Postoperative anastomotic leakage is still an issue in modern surgery. Re-hospitalization due to postoperative anastomosis leakage prolongs hospital stay and re-operations increase the cost. There is still no consent on how to dissect the intestines. The objective of the present study is to analyze the safety of colonic anastomoses after dissections using scalpel, scissors and cautery in rats.Method:There were 4 groups of 32 Wistar Hannover adult rodents. Each group consisted of 8 animals: group 1: sham, group 2: scalpel, group 3: scissors, group 4: cautery. Anastomosis was done over a single layer. Bursting pressure (BP) was measured at day 7. Tissue and blood samples were taken for the evaluation of biochemical and histopathological parameters.Results:Statistically significant disparity was seen among the sham, scalpel, scissors and cautery groups regarding the mean BP average, mean hydroxyproline levels and fibrosis distributions.Conclusion:Cautery is the best choice for hemostasis; however, when considering tissue healing, scalpel and the scissors were found to be safest alternatives