814 research outputs found
Structural model calibration of RC structure with two-leaf cavity brick infill wall by deterministic approach
An adaptive solution for updating structural model of a RC structure with two-leaf cavity brick infill wall under flexible boundary problem is presented in this paper. The structure was simulated with Diana 9.4.4 finite element software. Next, an elastic foundation with interface elements was used to overcome this stiffness problem of the foundation. The validation of the structure was made with the optimization based modal updating using MATLAB. Five calibration types were performed and compared with experimental data.info:eu-repo/semantics/publishedVersio
Pushover analysis of historical Elti Hatun Mosque
Historical structures, being an important part of cultural heritage, have shown extreme vulnerability to seismic actions. A clear understanding of the performance of them is thus of critical importance for taking preventive actions. This paper presents a case study related to pushover analysis of a historical masonry structure located in Tunceli, Turkey. The evaluated monument is Elti Hatun Mosque located in the seismic zone 2 according to seismic zone map of Turkey. The mosque is modeled and analyzed with Diana finite element software on the base of real dimensions measured on site. Material properties are obtained from literature on the base of similar studies. The results are presented as pushover curves, crack distribution and failure modes. The results show that the safety level of the structure is acceptable at its current condition
Design and Optimization of High-Speed Resonant Cavity Enhanced Schottky Photodiodes
Cataloged from PDF version of article.Resonant cavity enhanced (RCE) photodiodes (PD’s)
are promising candidates for applications in optical communications
and interconnects where high-speed high-efficiency photodetection
is desirable. In RCE structures, the electrical properties
of the photodetector remain mostly unchanged; however, the
presence of the microcavity causes wavelength selectivity accompanied
by a drastic increase of the optical field at the resonant
wavelengths. The enhanced optical field allows to maintain a high
efficiency for faster transit-time limited PD’s with thinner absorption
regions. The combination of an RCE detection scheme with
Schottky PD’s allows for the fabrication of high-performance
photodetectors with relatively simple material structures and
fabrication processes. In top-illuminated RCE Schottky PD’s,
a semitransparent Schottky contact can also serve as the top
reflector of the resonant cavity. We present theoretical and
experimental results on spectral and high-speed properties of
GaAs–AlAs–InGaAs RCE Schottky PD’s designed for 900-nm
wavelength
100 GHz resonant cavity enhanced Schottky photodiodes
Cataloged from PDF version of article.Resonant cavity enhanced (RCE) photodiodes are promising candidates for applications in optical communications and interconnects where ultrafast high-efficiency detection is desirable. We have designed and fabricated RCE Schottky photodiodes in the (Al, In) GaAs material system for 900-nm wavelength. The observed temporal response with 10-ps pulsewidth was limited
by the measurement setup and a conservative estimation of the bandwidth corresponds to more than 100 GHz. A direct comparison of RCE versus conventional detector performance was performed by high speed measurements under optical excitation at resonant wavelength (895 nm) and at 840 nm where the device functions as a single-pass conventional photodiode. A more than two-fold bandwidth enhancement with the RCE detection scheme was demonstrated
Early postzygotic mutations contribute to de novo variation in a healthy monozygotic twin pair
Cataloged from PDF version of article.Background: Human de novo single-nucleotide variation (SNV) rate is estimated to range between 0.82-1.70×10-8 mutations per base per generation. However, contribution of early postzygotic mutations to the overall human de novo SNV rate is unknown. Methods: We performed deep whole-genome sequencing (more than 30-fold coverage per individual) of the whole-blood-derived DNA samples of a healthy monozygotic twin pair and their parents. We examined the genotypes of each individual simultaneously for each of the SNVs and discovered de novo SNVs regarding the timing of mutagenesis. Putative de novo SNVs were validated using Sanger-based capillary sequencing. Results: We conservatively characterised 23 de novo SNVs shared by the twin pair, 8 de novo SNVs specific to twin I and 1 de novo SNV specific to twin II. Based on the number of de novo SNVs validated by Sanger sequencing and the number of callable bases of each twin, we calculated the overall de novo SNV rate of 1.31×10-8 and 1.01×10-8 for twin I and twin II, respectively. Of these, rates of the early postzygotic de novo SNVs were estimated to be 0.34×10-8 for twin I and 0.04×10-8 for twin II. Conclusions: Early postzygotic mutations constitute a substantial proportion of de novo mutations in humans. Therefore, genome mosaicism resulting from early mitotic events during embryogenesis is common and could substantially contribute to the development of diseases
High bandwidth-efficiency resonant cavity enhanced Schottky photodiodes for 800-850 nm wavelength operation
Cataloged from PDF version of article.High-speed resonant cavity enhanced Schottky photodiodes operating in 800-850 nm wavelength region are demonstrated. The devices are fabricated in the AlGaAs/GaAs material system. The Schottky contact is a semitransparent Au film which also serves as the top reflector of the Fabry-Perot cavity. The detectors exhibit a peak quantum efficiency of eta = 0.5 at lambda = 827 nm wavelength and a 3 dB bandwidth of more than 50 GHz resulting in a bandwidth-efficiency product of more than 25 GHz. (C) 1998 American Institute of Physic
Decreasing trends in cardiovascular mortality in Turkey between 1988 and 2008.
BACKGROUND: Cardiovascular disease (CVD) mortality increased in developed countries until the 1970s then started to decline. Turkey is about to complete its demographic transition, which may also influence mortality trends. This study evaluated trends in coronary heart disease (CHD) and stroke mortality between 1988 and 2008.
METHODS: The number of deaths by cause (ICD-8), age and sex were obtained from the Turkish Statistical Institute (TurkStat) annually between 1988 and 2008. Population statistics were based on census data (1990 and 2000) and Turkstat projections. European population standardised mortality rates for CHD and stroke were calculated for men and women over 35 years old. Joinpoint Regression was used to identify the points at which a statistically significant (p < 0.05) change of the trend occurred.
RESULTS: The CHD mortality rate increased by 2.9% in men and 2.0% in women annually from 1988 to 1994, then started to decline. The annual rate of decline for men was 1.7% between 1994-2008, whilst in women it was 2.8% between 1994-2000 and 6.7% between 2005-2008 (p < 0.05 for all periods).Stroke mortality declined between 1990-1994 (annual fall of 3.8% in both sexes), followed by a slight increase between 1994-2004 (0.6% in men, 1.1% in women), then a further decline until 2008 (annual reduction of 4.4% in men, 7.9% in women) (p < 0.05 for all periods).
CONCLUSIONS: A decrease in CVD mortality was observed from 1995 onwards in Turkey. The causes need to be explored in detail to inform future policy priorities in noncommunicable disease control
A review of Morgagni and Bochdalek hernias in adults
The incidence of Bochdalek and Morgagni hernias among adults is very rare.
The purpose of this study was to determine retrospectively the prevalence and
characteristics of adult Bochdalek and Morgagni hernias in a decade. Consequently,
we demonstrated 12 patients with Bochdalek and 8 patients with
Morgagni hernias. We presented plain radiography, operation images, and
computed tomography findings of an adult patient with symptoms due to Bochdalek
and Morgagni hernias. In surgical repair, the Morgagni hernia is best
approached via laparotomy, and the Bochdalek hernia can be treated through
thoracotomy or laparotomy. (Folia Morphol 2011; 70, 1: 5-12
Ethnic differences in total and HDL cholesterol among Turkish, Moroccan and Dutch ethnic groups living in Amsterdam, the Netherlands.
<p>Abstract</p> <p>Background</p> <p>High total cholesterol and low HDL (high-density lipoprotein) cholesterol are important determinants of cardiovascular disease. Little is known about dyslipidemia among Turkish and Moroccan migrants, two of the largest ethnic minority groups in several European countries. This study examines ethnic differences in total and HDL cholesterol levels between Dutch, Turkish and Moroccan ethnic groups.</p> <p>Methods</p> <p>Data were collected in the setting of a general health survey, in Amsterdam, the Netherlands, in 2004. Total response rate was 45% (Dutch: 46%, Turks: 50%, Moroccans: 39%). From 1,220 adults information on history of hypercholesterolemia, lifestyle and demographic background was obtained via health interviews. In a physical examination measurements of anthropometry and blood pressure were performed and blood was collected. Total and HDL cholesterol were determined in serum.</p> <p>Results</p> <p>Total cholesterol levels were lower and hypercholesterolemia was less prevalent among the Moroccan and Turkish than the Dutch ethnic population. HDL cholesterol was also relatively low among these migrant groups. The resulting total/HDL cholesterol ratio was particularly unfavourable among the Turkish ethnic group. Controlling for Body Mass Index and alcohol abstinence substantially attenuated ethnic differences in HDL cholesterol levels and total/HDL cholesterol ratio.</p> <p>Conclusions</p> <p>Total cholesterol levels are relatively low in Turkish and Moroccan migrants. However part of this advantage is off-set by their relatively low levels of HDL cholesterol, resulting in an unfavourable total/HDL cholesterol ratio, particularly in the Turkish population. Important factors in explaining ethnic differences are the relatively high Body Mass Index and level of alcohol abstinence in these migrant groups.</p
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