73 research outputs found
Tek Yönlü Düşük Yoğunluklu İçi Boş Yerel Eğrilikli Lifler İçreren Kompozitlerin Basınç Altında Kırılmasının Teorik Limiti
Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Bu çalışmada, Üç-boyutlu lineerleştirilmiş stabilite teorisi kapsamında, yerel eğrilikli, içi boş tek lif içeren sonsuz uzunluklu elastik bir malzemenin yapısındaki stabilite kaybı araştırılmıştır. Stabilite kaybı kriteri olarak başlangıçta var olduğu kabul edilen yerel eğilme genliklerinin büyüyüp sonsuza gitmeye başlaması durumu kabul edilmiştir ve yükün bu değeri kritik yük olarak belirlenmiştir. Stabilite kaybı, bahsedilen kompozit malzemeye, lif yönünde sonsuzda p yoğunluklu homojen yayılmış normal basınç kuvvetleri etki gösterdiğinde araştırılmış ve bununla ilgili sayısal veriler elde edilmiştir.In this paper, the investigation of the stability loss in the structure of the infinite elastic media containing a local curved hollow single fiber is made in the framework of the Three- Dimensional Linearized Theory of Stability. It is assumed that this fiber has an initial infinitesimal local imperfection and as a stability loss criterion, the external compressive force is taken, for which the initial infinitesimal local imperfection starts to increase and grow indefinitely. This investigation of the stability loss is studied when the body is loaded at infinity by uniformly distributed normal forces with intensity p acting in the direction of the fibers and the corresponding numerical results are presented
Scintillation Light Detection with MAPD-3NK and MPPC-S12572-010P Readout
The linearity and energy resolution of two different solid-state photomultipliers (SiPMs) has been studied with reading out the LFS-8 scintillator (3x3x10 mm3). First SiPM (MAPD-3NK) from Zecotek Photonics consists of deeply burned pixels (cells) and has an active area of 3.7x3.7 mm2. The second one (MPPC-S12572-010P) from Hamamatsu has a surface cell structure and an active area of 3x3 mm2. Both SiPMs have the same pixel density of 10000 mm−2. Energy resolution and linearity of the SiPMs has been studied in the energy range of 59.6-1275 keV. It is found that both SiPMs demonstrate good linearity of signal amplitude as a function of the gamma ray energy in the studied energy range. The detector based on the MAPD-3NK provides significantly good energy resolution in comparison to the detector based on the MPPC-S12572-010P
A compact and sustainable electronic module for silicon photomultipliers
This article presents the development of a cost-effective and efficient
electronic module for silicon photomultipliers (SiPM). The electronic module
combines essential functionalities, such as a high voltage power supply, a
preamplifier, and a signal comparator, into a compact circuit. A high voltage
power supply with a range of 30 to 140 V provides a stable bias voltage with
0.01 V accuracy for the SiPMs, while a preamplifier with 40 gain and 250 MHz
bandwidth enables signal amplification necessary to extract weak signals. The
comparator converts an analogue signal (higher than 8 mV) into TTL
(transistor-transistor logic), which makes it easy to process and analyze with
digital devices such as microcontrollers or make it possible to send signals
over long distances by a cable. The module has been tested using an LYSO
scintillator and a SiPM called a micropixel avalanche photodiode (MAPD). It
provides a more effective and efficient solution for reading out signals from
SiPMs in a variety of applications, delivering reliable and accurate results in
real-time.Comment: an article, 9 pages, 6 figure
Portable neutron/gamma scintillation detector for status monitoring of accelerator-driven neutron source IREN
Accelerator-driven system (ADS) facilities world-wide opens new opportunities
for nuclear physics investigations, so that a high flux of neutrons through
spallation reactions can be produced at these facilities. It is known that the
measurement, continuous monitoring and optimization of the particle accelerator
beam intensity are among the most important actions in the operation of such
facilities. Considering this point of view, this paper presents a neutron/gamma
counter based on a micropixel avalanche photodiode (MAPD) and a plastic
scintillator that monitors the status of the accelerator-driven intense
resonance neutron source (IREN) facility by measuring the neutron-gamma
intensity in the target hall. The electronics of the modular neutron counter
has been designed and developed, including a bias voltage source (up to 130 V),
a preamplifier (36 gain) and discriminator (>10 mV) circuit. The last product
of MAPD (operation voltage- 55 V, PDE- 33 %, total number of pixels- 136900)
was used as a photon readout from a plastic scintillator. The sensitive area of
MAPD was 3.7*3.7 mm2 and the size of the plastic scintillator 3.7*3.7*30 mm3.
The measurement was carried out in the IREN target hall, where it was necessary
to monitor not only high neutron fluxes, but also gamma quanta. The
experimental results demonstrated a dependence between the count rate of the
detector and the frequency of the accelerator, which ranges from 2 to 50 Hz.Comment: 8 pages, 7 figure
Assessment of information value of targeted biopsy and endoscopic removal of colorectal polyps
This research is based on histological investigation of targeted biopsy material and resected polyps’ at 354 patients who applied to National Center of Oncology from 2005 to 2010. All patients underwent targeted biopsy at first with subsequent endoscopic polypectomy and 494 polyps were removed and histologically investigated. The most prevalence type was tubular polyp — 212 (43 %) cases. The rest types of polyps were distributed as follow: tubule-villous type — 125 (25.3 %), villous type — 16 (3.2 %), inflammatory type — 28 (5.7 %), hyperplastic type — 40 (8.1 %), hamartoma type — 21 (4.3 %) cases. In 52 (10.4 %) cases malignant polyps were revealed.Sensitivity of targeted biopsy in iagnostics of dysplasia was 65.1 % while in revealing of malignancy was even lower — just 36.5 %. So we consider performing of endoscopic polypectomy and histological evaluation of resected polyps in all case even after previous targeted biopsy
Formulation of a mathematical problem and methods for solving the development of antistatic clothing for protection from elevated temperatures
The article is devoted to the study and development of a mathematical model of the process of electrification of textile materials in the system "man - clothing - environment" in hot climatic conditions. The phenomenon of static electrification, which occurs in the processes of manufacturing textile materials and products from them, as well as during the operation of finished products, leads to a decrease in the quality of products, causes inconvenience in work, and when an electric discharge occurs, it poses a threat to human life. Such interactions of elements in the "person - clothing - environment" system such as friction, compression, tension, shear increase the contact area of two media, and depending on the rate of these processes, they enhance or weaken metabolic processes, which contributes to an increase in the maximum static charge generated on contacting surfaces. temperature values for special clothing of limited length at the nodal points. At the same time, the number of nodal points is 1601, the number of connected elements is 800. In the area of temperature distribution along the length of the garment, in four different versions, it was found that in the I – version , in the II – version , in the III – version , in the IV – version , in the V – version , in the VI - version, the length of the clothes in this area increased by 10% compared to the length of the clothes in the II – version
Performance of a plastic scintillator developed using styrene monomer polymerization
This paper presents a newly developed plastic scintillator produced in
collaboration with Turkiye Energy, Nuclear and Mineral Research Agency
(TENMAK). The scintillator is manufactured using thermal polymerization of
commercially available styrene monomer. The absorption spectrum of the
scintillator exhibited two absorption bands at 225 nm and 340 nm, with an
absorption edge observed at 410 nm. The wavelength of the emitted light was
measured in the range of 400-800 nm, with a maximum intensity at 427 nm.
Monoenergetic electrons from the 137Cs source were used to evaluate the
characteristics of the new scintillator, particularly its light yield. As the
light readout the MAPD-3NM type silicon photomultiplier array (4 x 4) with an
active area of 15 x 15 mm2, assembled using single MAPDs with an active area of
3.7 x 3.7 mm2, was used. The light yield of the scintillator was determined to
be 6134 photons/MeV. In addition, the efficiency of the scintillator for gamma
rays with an energy of 662 keV was found to be approximately 1.8 %. A CmBe
neutron source was employed to evaluate its fast neutron detection performance.
However, neutron/gamma discrimination using pulse shape discrimination (charge
integration) method was not observed. The results demonstrate the potential of
a newly produced plastic scintillator for various applications, particularly in
radiation monitoring and detection systems.Comment: 7 pages, 7 figure
Оценка информативности получаемого материала при прицельной биопсии и эндоскопическом удалении колоректальных полипов
This research is based on histological investigation of targeted biopsy material and resected polyps’ at 354 patients who applied to National Center of Oncology from 2005 to 2010. All patients underwent targeted biopsy at first with subsequent endoscopic polypectomy and 494 polyps were removed and histologically investigated. The most prevalence type was tubular polyp — 212 (43 %) cases. The rest types of polyps were distributed as follow: tubule-villous type — 125 (25.3 %), villous type — 16 (3.2 %), inflammatory type — 28 (5.7 %), hyperplastic type — 40 (8.1 %), hamartoma type — 21 (4.3 %) cases. In 52 (10.4 %) cases malignant polyps were revealed.Sensitivity of targeted biopsy in iagnostics of dysplasia was 65.1 % while in revealing of malignancy was even lower — just 36.5 %. So we consider performing of endoscopic polypectomy and histological evaluation of resected polyps in all case even after previous targeted biopsy.Данное исследование основано на результатах сравнительного гистологического изучения биопсийного материала и удаленных колоректальных полипов у 354 пациентов в отделении эндоскопии Национального центра онкологии в период с 2005 по 2010 г. Всем больным была выполнена предварительная прицельная биопсия из колоректальных полипов и последующая эндоскопическая полипэктомия (удалено 494 полипа). Наиболее распространенным гистологическим типом оказался тубулярный полип — 212 (43 %) случая. Остальные типы полипов распределялись следующим образом: тубуло-виллезный тип — 125 (25,3 %) случаев, виллезный тип — 16 (3,2 %), воспалительный тип — 28 (5,7 %), гиперпластический тип — 40 (8,1 %) и гамартомный тип полипа — 21 (4,3 %) случай. В 52 (10,4 %) случаях были выявлены малигнизированные полипы. Чувствительность прицельной биопсии в определении дисплазии составила 65,1 %, а в выявлении малигнизации — лишь 36,5 %. Таким образом, мы считаем необходимым гистологическое исследование удаленных полипов после эндоскопической полипэктомии во всех случаях, даже при наличии результатов предварительной прицельной биопсии
Primary care medication safety surveillance with integrated primary and secondary care electronic health records: a cross-sectional study
Introduction: The extent of preventable medication-related hospital admissions and medication-related issues in primary care is significant enough to justify developing decision support systems for medication safety surveillance. The prerequisite for such systems is defining a relevant set of medication safety-related indicators and understanding the influence of both patient and general practice characteristics on medication prescribing and monitoring.
Objective: The aim of the study was to investigate the feasibility of linked primary and secondary care electronic health record data for surveillance of medication safety, examining not only prescribing but also monitoring, and associations with patient- and general practice-level characteristics.
Methods: A cross-sectional study was conducted using linked records of patients served by one hospital and over 50 general practices in Salford, UK. Statistical analysis consisted of mixed-effects logistic models, relating prescribing safety indicators to potential determinants.
Results: The overall prevalence (proportion of patients with at least one medication safety hazard) was 5.45 % for prescribing indicators and 7.65 % for monitoring indicators. Older patients and those on multiple medications were at higher risk of prescribing hazards, but at lower risk of missed monitoring. The odds of missed monitoring among all patients were 25 % less for males, 50 % less for patients in practices that provide general practitioner training, and threefold higher in practices serving the most deprived compared with the least deprived areas. Practices with more prescribing hazards did not tend to show more monitoring issues.
Conclusions:Systematic collection, collation, and analysis of linked primary and secondary care records produce plausible and useful information about medication safety for a health system. Medication safety surveillance systems should pay close attention to patient age and polypharmacy with respect to both prescribing and monitoring failures; treat prescribing and monitoring as different statistical processes, rather than a combined measure of prescribing safety; and audit the socio-economic equity of missed monitoring
Publisher Correction:Discovery of rare variants associated with blood pressure regulation through meta-analysis of 1.3 million individuals (Nature Genetics, (2020), 52, 12, (1314-1332), 10.1038/s41588-020-00713-x)
In the version of this article originally published, the e-mail address of corresponding author Patricia B. Munroe was incorrect. The error has been corrected in the HTML and PDF versions of the article
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