VLSI implementation of a microprocessor compatible 128-bit programmable correlator

Ankara : The Department of Electrical and Electronics Engineering and the Institute of Engineering and Sciences of Bilkent Univ. , 1989.Thesis (Master's) -- Bilkent University , 1989Includes bibliographical references leaves 55.Ungan, İsmail EnisM.S

Electronic band structure of GaAs/AlxGa1−xAs superlattice in an intense laser field

ABSTRACT: We perform theoretical calculations for the band structure of semiconductor superlattice under intense high-frequency laser field. In the frame of the non-perturbative approach, the laser effects are included via laser-dressed potential. Results reveal that an intense laser field creates an additional geometric confinement on the electronic states. Numerical results show that when tuning the strength of the laser field significant changes come in the electronic energy levels and density of states

The effect of magnetic field on the impurity binding energy of shallow donor impurities in a Ga1−xInxNyAs1−y/GaAs quantum well

ABSTRACT: Using a variational approach, we have investigated the effects of the magnetic field, the impurity position, and the nitrogen and indium concentrations on impurity binding energy in a Ga1−xInxNyAs1−y/GaAs quantum well. Our calculations have revealed the dependence of impurity binding on the applied magnetic field, the impurity position, and the nitrogen and indium concentrations

The association between non-HDL cholesterol and SYNTAX score in premature heart disease

Aim: This study aimed to estimate the association of coronary artery disease complexity with non-HDL-C levels in premature CAD. Background: Primary prevention has utmost importance in terms of minimizing the number of patients who had premature coronary artery disease (CAD). Non-high density lipoprotein cholesterol (non-HDL-C) contains potentially atherogenic lipoprotein fractions. Material and methods: Coronary angiographic recordings of two hundred acute coronary syndrome patients were evaluated by two cardiologists. Clinical, demographic and lipid parameters of the patients were compared with SYNTAX score. Results: Median age of the study group was 41 (18-45) years. One hundred eighty five (90.5%) of them were male, nineteen (9.5%) of them were female. Median SYNTAX score and ejection fraction of the patients were 17 (4.5-39) and 50 (33-68), respectively. SYNTAX score of the male patients was significantly higher compared to females [17 (4.5-39) vs 12 (8-26), p=0.048), similarly, diabetic patients had higher values of syntax score compared to non-diabetic patients [19 (10-39) vs 16 (4.5-37), p=0.005), There were no differences of SYNTAX score with respect to presence of hypertension, smoking status and family history of CAD.  There were very strong positive correlation between SYNTAX score and non-HDL-C, TC and LDL-C levels (r=0.958, r=0.946 and r=0.921, respectively, p<0.001 for all).   HgA1c levels showed positive correlation, whereas HDL-C showed negative correlation with SYNTAX score (r=0.793 and r=-0.620, respectively, p<0.001 for both). Conclusion: non-HDL-C was a valuable tool in assessing the complexity of atherosclerotic cardiovascular disease in young patients

Mean platelet volume is elevated in patients with patent foramen ovale

INTRODUCTION: Platelets play a major role in thromboembolic events. Increased mean platelet volume (MPV) indicates higher platelet reactivity and also a tendency to thrombosis. Patent foramen ovale (PFO), persistence of the fetal anatomic shunt between right and left atria, is strongly associated with cryptogenic stroke. The aim of this study is to determine the relationship between MPV and PFO and if such an association exists, whether higher MPV levels may require antiplatelet therapy before a thromboembolic event happens, together with a literature review. MATERIAL AND METHODS: Thirty patients (15 women, 15 men), free of any cerebrovascular events, were diagnosed with PFO by transesophageal echocardiography (TEE), enrolled as the study group. Thirty consecutive patients (16 women and 14 men), who were diagnosed as normal in TEE, were enrolled as the control group. These two groups were compared according to MPV and anatomical features of the right atrium. RESULTS: There was no significant difference between study and control groups in clinical features and also no difference was observed in platelet counts; however, MPV in the PFO group was significantly higher than the control group (8.38 ±0.93 fl and 7.45 ±0.68 fl respectively). CONCLUSIONS: Our results indicate that elevated MPV may be detected in patients with PFO. This might be one of the explanations for the relationship between PFO and cryptogenic stroke; however, larger cohorts are warranted in order to define further mechanisms

Current-mode wired logic circuit technique in CMOS technology

Ph.D. - Doctoral Progra

The variation of electronic properties with the doping concentration of modulation-doped AlxGa1-xAs-GaAs double quantum wells

In this paper we have calculated the sub-band structure and the confinement potential of modulation-doped Ga1-xAlxAs-GaAs double quantum wells as a function of the doping concentration. The electronic properties of this structure were determined by self-consistent solutions of the Schrodinger and Poisson equations. To understand the effects of doping concentration on band bending, sub-band energies, and sub-band populations, the doping concentration on one right side of the structure is decreased while holding it constant on the left side. We found that at low doping concentrations on the right side, the effects of the doping concentration are more pronounced on band bending and sub-band populations. (c) 2006 Elsevier Ltd. All rights reserved