The conservation of modern architectural heritage buildings in Turkey: İstanbul Hilton and İstanbul Çınar Hotel as a case study

This article contributes to the conservation of modern architectural heritage buildings by emphasizing the retrofitting of their construction systems. Modern architectural heritage buildings in Turkey are crucial in terms of transferring not only the cultural identity of the nations to further generations but also architectural sustainability of its distinguished period. By time, where these buildings can have constructional problems with its original structural systems, proposing a new system related with new earthquake regulations is inevitable in order to conserve them. Because most of the buildings are under threat of being demolished. The purpose of the research is to evaluate existing modern architectural heritage buildings in terms of its existing structural system and to develop a constructional model for renewal of them. As a case study, two hotel examples in İstanbul as a modern architectural heritage is selected, one is Hilton Hotel and the other is Çınar Hotel respectively. Then, the architectural plans and sections of the buildings as a data has been collected through literature survey by content analysis. At the end, the model proposal has been developed for each hotel buildings according to existing structural systems. The proposed models can be applied to sustain the life of the hotel buildings with a retrofitted structural system. So, the paper tries to conserve/protect the modern architectural heritage buildings by retrofitting its construction via presenting a remarkable study of two hotel buildings. © 2022 THE AUTHOR

The accuracy rate of Alvarado score, ultrasonography, and computerized tomography scan in the diagnosis of acute appendicitis in our center

Objective: In this study, we aim to compare the relationship between the Alvarado score, ultrasonography, and multislice computerized tomography (CT) findings used for the diagnosis of the patients who presented to our emergency unit with clinical features suggestive of acute appendicitis.Materials and Methods: Seventy.four patients operated with the diagnosis of acute appendicitis were included in the study. The demographic  characteristics of the patients, physical findings, blood parameters,  Alvarado scores, the radiological method used for the diagnosis, the  surgical methods (open or laparoscopic) and the pathology results wererecorded on the standard proforma. The collected data were analyzed with Statistical Package for Social Sciences (SPSS 15 for Windows, SPSS Inc., Chicago, Illinois, USA) computer program.Results: During study period, the sensitivity of ultrasonography was found to be as 71.2%, specificity as 46.7%, the positive predictive value (PPV) as 82.2%, the negative predictive value (NPV) as 31.8%, and the accuracy  rate was determined as 65.7%. The sensitivity of tomography was  determined as 97.2%, the specificity as 62.5%, PPV as 92.1%, and NPV as 83.3%, and the accuracy rate was determined as 90%. The sensitivity of  the Alvarado score was calculated as 54%, the specificity as 73.3%, the PPV as 88.2% and the NPV as 29.7%, and the accuracy rate was determined as 57.7%.Conclusion: In conclusion, computerized tomography (CT) was found to have higher specificity and sensitivity than Alvarado score and USG which are not sufficient on their own for taking the decision for surgery. We also found that CT scan had lower negative laparotomy rate when compared with the other two modalities.Key words: Alvarado score, appendicitis, computerized tomography, ultrasonograph

Comparison of hyperpronation and supination‑flexion techniques in children presented to emergency department with painful pronation

Context: Radial head subluxation, also known as ‘pulled elbow’, ‘dislocated elbow’ or ‘nursemaid’s elbow’, is one of the most common upper extremity injuries in young children and a common reason to visit Emergency Department (ED).Aim: To compare supination of the wrist followed by flexion of the elbow (the traditional reduction technique) to hyperpronation of the wrist in the reduction of radial head subluxations (nursemaid’s elbow) maneuvers in children presented to ED with painful pronation and to determine which method is less painful by children.Settings and Design: This prospective randomize study involved a consecutive sampling of children between 1‑5 year old who were presented to the ED with painful pronation.Materials and Methods: The initial procedure was repeated if baseline functioning did not return 20 minutes after the initial reduction attempt. Failure of that technique 30 minutes after the initial reduction attempt resulted in a cross‑over to the alternate method of reduction.Statistical analysis used: Datas were analyzed using SPSS for Windows 16.0. Mean, standard deviation, independent samples t test, Chi‑square test, and paired t test were used in the assessment of pain scores before and after reduction.Results: When pain scores before and after reduction were compared between groups to determine which technique is less painful by children, no significant difference was found between groups.Conclusions: It was found that in the reduction of radial head subluxations, the hyperpronation technique is more effective in children who were presented to ED with painful pronation compared with supination‑flexion. However, there was no significant difference between these techniques in terms of pain.Key words: Child, emergency department, nursemaid’s elbow, pain, pulled elbo

Project PROMETHEUS: Design and Construction of a Radio Frequency Quadrupole at TAEK

The PROMETHEUS Project is ongoing for the design and development of a 4-vane radio frequency quadrupole (RFQ) together with its H+ ion source, a low energy beam transport (LEBT) line and diagnostics section. The main goal of the project is to achieve the acceleration of the low energy ions up to 1.5 MeV by an RFQ (352 MHz) shorter than 2 meter. A plasma ion source is being developed to produce a 20 keV, 1 mA H+ beam. Simulation results for ion source, transmission and beam dynamics are presented together with analytical studies performed with newly developed RFQ design code DEMIRCI. Simulation results shows that a beam transmission 99% could be achieved at 1.7 m downstream reaching an energy of 1.5 MeV. As the first phase an Aluminum RFQ prototype, the so-called cold model, will be built for low power RF characterization. In this contribution the status of the project, design considerations, simulation results, the various diagnostics techniques and RFQ manufacturing issues are discussed.Comment: 4 pages, 8 figures, Proceedings of the 2nd International Beam Instrumentation Conference 2013 (IBIC'13), 16-19 Sep 2013, WEPC02, p. 65

АНАЛИЗ КОЭФФИЦИЕНТА ПЕРЕДАЧИ АКУСТИЧЕСКОГО ТРАКТА ДАТЧИКА УГЛОВОЙ СКОРОСТИ

The change in characteristics of ultrasonic waves’ transmittion in solid rotating media is the basis for the operation of acoustic angular velocity sensor. The transmission coefficient of the sensing element (SE) of the acoustic path deter-mines the level of angular velocity sensor informative signal based on detecting changes in characteristics of bulk acoustic waves in solid media. In this regard, the efforts aimed at obtaining maximum transmission coefficient are relevant and represent an important stage in the design of such devices. The sensitive element of the acoustic path consists of radiating and receiving plate piezoelectric transducers, propagation medium (acoustic duct), contact layers and electrical load. The coefficient is identical to the path of ultrasonic delay lines on bulk acoustic waves. Although, many sources present the theoretical analysis of the path of this type, they carry out the analysis in so-called one-dimensional approximation, i.e. they perform the analysis without taking into account the limited transverse dimensions, whereas the path of the sensing element should have limited lateral dimensions, which can affect the value of transmission coefficient. The above-mentioned sources do not present the results of experiments. Thus, it is necessary to conduct a complex of simulation and experiments to analyze the acoustic path transmission coefficient of the angular velocity sensor. Authors of the paper developed a pathmodeling program in Mathcad software to perform simulation. For implementation of the experiment, authors created the installation, as well as a number of proto-types with transducers made of piezoelectric quartz and piezoelectric ceramics. The results demonstrate that fundamental statements developed for one-dimensional approximation one can use to determine the transmission coefficient of the acoustic path with limited dimensions. Besides, the use of the matched electrical load gives the opportunity to increase the transmission coefficient. For example, in case of Y-cut piezoelectric quartz converter prototype the increase reached 20 dB.Изменение характеристик ультразвуковых волн, распространяющихся в твердых вращающихся средах, лежит в основе функционирования акустических датчиков угловой скорости. Уровень информативного сигнала зависит от коэффициента передачи акустического тракта чувствительного элемента (ЧЭ) датчика такого типа, в связи с чем актуальны работы по достижению максимального коэффициента. Акустический тракт ЧЭ на объемных волнах состоит из излучающего и приемного пластинчатых пьезопреобразователей, среды распространения (звукопровода), контактных слоев и электрической нагрузки. Он идентичен тракту ультразвуковых линий задержки. Теоретический анализ характеристик трактов такого типа широко представлен в литературе, однако анализ базируется на решении систем волновых уравнений в одномерном приближении. В этом случае расчеты выполняются без учета ограниченности поперечных размеров. На практике тракт ЧЭ должен иметь ограниченные поперечные размеры, которые могут повлиять на значение коэффициента передачи. Описания экспериментальных исследований в литературе не приводятся. Таким образом, потребовалось провести комплекс теоретических и экспериментальных исследований по анализу коэффициента передачи акустического тракта датчика угловой скорости. Для теоретического анализа разработана моделирующая тракт программа в системе Mathcad. Для экспериментальных исследований создана установка и изготовлен ряд макетов с преобразователями из пьезокварца и пьезокерамики. В результате показано, что теоретические положения, разработанные для одномерного приближения, могут применяться для определения коэффициента передачи акустического тракта ограниченных размеров. Кроме того, использование согласованной электрической нагрузки позволяет увеличить коэффициент передачи. Например, для макета с преобразователями из пьезокварца Y-среза это увеличение составило 20 дБ

Examination of the temperature related structural defects of InGaN/GaN solar cells

In this study the effects of the annealing temperature on the InGaN/GaN solar cells with different In-contents grown on sapphire substrate by the Metal Organic Chemical Vapor Deposition (MOCVD) are analyzed by High Resolution X-ray Diffraction (HRXRD) and an Atomic Force Microscope (AFM). The plane angles, mosaic crystal sizes, mixed stress, dislocation intensities of the structure of the GaN and InGaN layers are determined. According to the test results, there are no general characteristic trends observed due to temperature at both structures. There are fluctuating failures determined at both structures as of 350 °C. The defect density increased on the GaN layer starting from 350 °C and reaching above 400 °C. A similar trend is observed on the InGaN layer, too. © 2015 Elsevier Ltd. All rights reserved

Preconditioning-induced ischemic tolerance: a window into endogenous gearing for cerebroprotection

Ischemic tolerance defines transient resistance to lethal ischemia gained by a prior sublethal noxious stimulus (i.e., preconditioning). This adaptive response is thought to be an evolutionarily conserved defense mechanism, observed in a wide variety of species. Preconditioning confers ischemic tolerance if not in all, in most organ systems, including the heart, kidney, liver, and small intestine. Since the first landmark experimental demonstration of ischemic tolerance in the gerbil brain in early 1990's, basic scientific knowledge on the mechanisms of cerebral ischemic tolerance increased substantially. Various noxious stimuli can precondition the brain, presumably through a common mechanism, genomic reprogramming. Ischemic tolerance occurs in two temporally distinct windows. Early tolerance can be achieved within minutes, but wanes also rapidly, within hours. Delayed tolerance develops in hours and lasts for days. The main mechanism involved in early tolerance is adaptation of membrane receptors, whereas gene activation with subsequent de novo protein synthesis dominates delayed tolerance. Ischemic preconditioning is associated with robust cerebroprotection in animals. In humans, transient ischemic attacks may be the clinical correlate of preconditioning leading to ischemic tolerance. Mimicking the mechanisms of this unique endogenous protection process is therefore a potential strategy for stroke prevention. Perhaps new remedies for stroke are very close, right in our cells

In Vivo Near-Infrared Imaging of Fibrin Deposition in Thromboembolic Stroke in Mice

imaging of activated factor XIII (FXIIIa), an important mediator of thrombosis or fibrinolytic resistance. The present study was to investigate the fibrin deposition in a thromboembolic stroke mice model by FXIIIa–targeted near-infrared fluorescence (NIRF) imaging., which were correlated with histology after animal euthanasia. NIRF images and lesion volume.Non-invasive detection of fibrin deposition in ischemic mouse brain using NIRF imaging is feasible and this technique may provide an in vivo experimental tool in studying the role of fibrin in stroke

Magnetic resonance imaging of brain angiogenesis after stroke

Stroke is a major cause of mortality and long-term disability worldwide. The initial changes in local perfusion and tissue status underlying loss of brain function are increasingly investigated with noninvasive imaging methods. In addition, there is a growing interest in imaging of processes that contribute to post-stroke recovery. In this review, we discuss the application of magnetic resonance imaging (MRI) to assess the formation of new vessels by angiogenesis, which is hypothesized to participate in brain plasticity and functional recovery after stroke. The excellent soft tissue contrast, high spatial and temporal resolution, and versatility render MRI particularly suitable to monitor the dynamic processes involved in vascular remodeling after stroke. Here we review recent advances in the field of MR imaging that are aimed at assessment of tissue perfusion and microvascular characteristics, including cerebral blood flow and volume, vascular density, size and integrity. The potential of MRI to noninvasively monitor the evolution of post-ischemic angiogenic processes is demonstrated from a variety of in vivo studies in experimental stroke models. Finally, we discuss some pitfalls and limitations that may critically affect the accuracy and interpretation of MRI-based measures of (neo)vascularization after stroke