Kalınlığı Hiperbolik Değişen Fonksiyonel Derecelendirilmiş (Fd) Dönen Disklerin Lineer Elastostatik Analizi

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Bu çalışmada mühendislikte çok geniş uygulama alanına sahip olan ve son yıllarda oldukça önem kazanan fonksiyonel derecelendirilmiş (FD) malzemeden yapılmış, değişken kalınlıklı ve sabit açısal hızla dönen disklerin lineer elasto-statik analizi Tamamlayıcı Fonksiyonlar yöntemi ile etkin bir şekilde ele alınmıştır. Metod üç farklı metal-seramik çifti için ve ıraksak/yakınsak hiperbolik disk profileri ile üniform disk profili için uygulanmıştır. Malzeme değişim fonksiyonu olarak üssel değişim seçilmiştir. Söz konusu malzemelerden yapılmış disklerde meydana gelen radyal doğrultudaki yer değiştirme ile radyal ve teğetsel gerilmelerin açısal hız ve disk profillerine göre değişimleri grafikler halinde sunulmuştur.In the present study, elasto-static linear analysis of the rotating variable-thickness disks made of functionally graded (FG) materials, having a wide range of applications in engineering and gaining considerable importance in recent years, is discussed effectively with the Complementary Functions method. This method has been applied for three different ceramic-metal pairs, divergent/convergent hyperbolic disc profiles and uniform disc profiles. An exponential function is chosen as a material grading rule. The variation of the radial displacement, radial and hoop stresses of disks made of such ceramic-metal pairs with the angular velocity and disk profiles are presented graphically

Robust Bayesian Satisficing

Distributional shifts pose a significant challenge to achieving robustness in contemporary machine learning. To overcome this challenge, robust satisficing (RS) seeks a robust solution to an unspecified distributional shift while achieving a utility above a desired threshold. This paper focuses on the problem of RS in contextual Bayesian optimization when there is a discrepancy between the true and reference distributions of the context. We propose a novel robust Bayesian satisficing algorithm called RoBOS for noisy black-box optimization. Our algorithm guarantees sublinear lenient regret under certain assumptions on the amount of distribution shift. In addition, we define a weaker notion of regret called robust satisficing regret, in which our algorithm achieves a sublinear upper bound independent of the amount of distribution shift. To demonstrate the effectiveness of our method, we apply it to various learning problems and compare it to other approaches, such as distributionally robust optimization

Comprehensive investigation of the extremely low lattice thermal conductivity and thermoelectric properties of BaIn2Te4

Recently, an extremely low lattice thermal conductivity value has been reported for the alkali-based telluride material BaIn2Te4. The value is comparable with low-thermal conductivity metal chalcogenides, and the glass limit is highly intriguing. Therefore, to shed light on this issue, we performed first-principles phonon thermal transport calculations. We predicted highly anisotropic lattice thermal conductivity along different directions via the solution of the linearized phonon Boltzmann transport equation. More importantly, we determined several different factors as the main sources of the predicted ultralow lattice thermal conductivity of this crystal, such as the strong interactions between low-frequency optical phonons and acoustic phonons, small phonon group velocities, and lattice anharmonicity indicated by large negative mode Gruneisen parameters. Along with thermal transport calculations, we also investigated the electronic transport properties by accurately calculating the scattering mechanisms, namely the acoustic deformation potential, ionized impurity, and polar optical scatterings. The inclusion of spin-orbit coupling (SOC) for electronic structure is found to strongly affect the p-type Seebeck coefficients. Finally, we calculated the thermoelectric properties accurately, and the optimal ZT value of p-type doping, which originated from high Seebeck coefficients, was predicted to exceed unity after 700 K and have a direction averaged value of 1.63 (1.76 in the y-direction) at 1000 K around 2 x 1020 cm-3 hole concentration. For n-type doping, a ZT around 3.2 x 1019 cm-3 concentration was predicted to be a direction-averaged value of 1.40 (1.76 in the z-direction) at 1000 K, mostly originating from its high electron mobility. With the experimental evidence of high thermal stability, we showed that the BaIn2Te4 compound has the potential to be a promising mid- to high-temperature thermoelectric material for both p-type and n-type systems with appropriate doping.Eskisehir Technical University [ESTU-BAP 22ADP150]C.S. acknowledges the support from the Eskisehir Technical University (ESTU-BAP 22ADP150). The numerical calculations reported in this paper were partially performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA resources)

Horner Sendromu Tortikollis İlişkisi; bir Olgu Sunumu

Horner Sendromu, okülosempatik yolaktaki kesinti nedeniyle gözün sempatik innervasyon kaybı sonucu pitozis, miyozis, tek taraflı anhidrozis ve nadiren enoftalmus klinik semptomları ile karakterize nadir görünen bir klinik tablodur. Konjenital musküler tortikollis, sternokleidomastoid kasının fibrozisi ve buna bağlı kısalması ile oluşan bir kas iskelet sistemi malformasyonudur. Bu olgu sunumunda, konjenital musküler tortikollise ikincil gelişen horner sendromu ve bunun rehabilitasyon sürecindeki tanısı ele alınmıştır. Üç aylık bir kız bebek, konjenital musküler tortikollis tanısıyla, çocuk sağlığı ve hastalıkları polikliniği tarafından birimimize yönlendirildi. Öyküsünden, ikiz eşi olarak 34 haftalık gebelik sonrası sezaryen ile doğduğu, doğum sonrası yoğun bakım ihtiyacı olmadığı, ilk kez bir buçuk aylıkken ailesi tarafından boyunda asimetri fark edildiği ve çocuk sağlığı ve hastalıkları polikliniğine başvurduğu öğrenildi. Fizik muayenesinde kraniyofasiyal asimetri, servikal sol lateral fleksiyon, sola rotasyonda kısıtlılık ve olive belirtisi vardı. Rehabilitasyon sırasındaki takiplerinde yüzünün sağ yarısında anhidrozis, daha silik olarak sol tarafta miyozis ve pitozis bulguları da fark edilerek hastaya Horner Sendromu tanısı konuldu. Ayırıcı tanısı yapılarak olası diğer nedenler dışlandı ve etiyoloji hastadaki mevcut tortikollise bağlandı. Sonuç olarak hastalar tortikollis yönünden değerlendirilirken, nadir de olsa, tortikollise Horner Sendromu'nun eşlik edebileceği, klinik bulgular silik seyredebileceğinden tanının kolayca gözden kaçabileceği akılda tutulmalıdırHorner Syndrome is a rare condition characterized with ptosis, miosis, unilateral anhidrosis and rarely enophtalmos resulting from the sympathetic innervation loss by interruption of oculosymathetic pathway. Congenital muscular torticollis is a musculoskeletal system malformation resulting from fibrosis, therefore shortening of sternocleidomastoid muscle. In this report, Horner’s syndrome secondary to congenital muscular torticollis and diagnosis in rehabilitation period are discussed. Three-month-old baby girl was referred to our unit by pediatrics clinic with congenital muscular torticollis diagnosis. Her history comprised of cesarean delivery following a 34-week pregnancy as twin, and no intensive care need; her parents realized asymmetry in neck when she was a-month-anda-half old and they admitted to pediatrics. Craniofacial asymmetry, cervical left lateral flexion, restricted left rotation and olive sign were detected in physical examination. During rehabilitation, anhidrosis in the right side of face, soft left miosis and ptosis were also observed, and patient was diagnosed with Horner’s syndrome. Other possible reasons were ruled out with differential diagnosis and etiology was linked to torticollis. Consequently, while evaluating patients with torticollis, it must be considered that Horner’s syndrome, rarely accompanies, and since clinical findings may be soft, diagnosis may easily be missed ou

Factors affecting outcomes of corneal collagen crosslinking treatment

PurposeTo assess the effects of preoperative patient characteristics on clinical outcomes of corneal crosslinking (CXL) treatment in patients with progressive keratoconus.MethodsThis retrospective study comprised 96 eyes of 96 patients who had unilateral CXL treatment for progressive keratoconus. All patients underwent a complete ophthalmological examination and corneal topography at baseline and 1 year. Subgroup analyses were performed according to the age (0.05).ConclusionsIn patients with progressive keratoconus, age, baseline visual acuity, and baseline thinnest pachymetry seem to affect the success of the CXL treatment. © 2014 Macmillan Publishers Limited All rights reserved

Pelvik organ prolapsusu olan hastalarda el kavrama Gücünün Değerlendirilmesi]

Aim: Pelvic organ prolapse(POP) is a common condition that is observed in 50% of parous women. Weakness of pelvic floor muscles is an important factor that leads to POP. The hand grip strength is related to total muscle strength and it could be used to evaluate one's general muscle strength. The Jamar hand dynamometer is a portable dynamometer that uses a strain gauge to measure hand grip strength. We hypothesized that general muscle strength would be impaired in patients with POP. Material and Method: Twenty patients with pelvic organ prolapse and twenty-one controls were recruited from the gynecology clinic of Namik Kemal University School of Medicine. The POP-Q classification was used to quantify the clinical severity of the prolapse. Hand grip strength was measured using a JAMAR hydraulic hand dynamometer. Results: The median pelvic organ prolapse score was 3 (1-4) in prolapse group. The mean Jamar scores of both groups were similar for the right hand, the left hand and the dominant hand (p=0.774, p=0.575 and p=0.707, respectively). The mean body fat percentage was 33.9 +/- 5.7 % in prolapses group and it was 38.9 +/- 7.4% in control group (p=0.021). Discussion: We found no difference in terms of general muscle strength between POP group and healthy controls. Our results showed that Jamar scores, which represented general muscle strength of body, did not related to pelvic organ muscle strength

Decreased ocular pulse amplitude and retinal nerve fibre layer in multiple sclerosis

This study was conducted to assess ocular pulse amplitude and retinal nerve fibre layer in patients with multiple sclerosis and their correlation with disease duration and with severity. Retinal nerve fibre layer thickness was measured by Heidelberg Retinal Tomography II (HRT-II; Heidelberg Engineering, Dossenheim, Germany) and ocular pulse amplitude was measured by dynamic contour tonometry (Ziemer Ophthalmic Systems, Port, Switzerland) in 37 multiple sclerosis patients and 72 age- and gender-matched controls. Ocular pulse amplitude was significantly reduced and retinal nerve fibre layer was significantly thinner in temporal, superotemporal, and nasal sectors in patients with multiple sclerosis regardless of having an optic neuritis attack. The retinal nerve fibre layer was thinner in eyes with a previous optic neuritis attack compared with the eyes without an attack, but the difference was not significant. Ocular pulse amplitude showed a positive correlation with visual evoked potential amplitude and a negative correlation with visual evoked potential latency. Retinal nerve fibre layer thickness showed a significant negative correlation with the disease duration but not with visually evoked potential, disease severity, nor previous optic neuritis. These findings indicate that the process of degeneration starts in the early period of the disease, as our study group is composed of early-middle-stage multiple sclerosis patients, and is independent of relapses. © Informa Healthcare USA, Inc

Are Heimlich maneuver videos on YouTube accurate and reliable?

Introductıon. First aid for airway obstruction is a life-saving maneuver that can be implemented by anyone. In this study, we determined the accuracy of Heimlich maneuver videos posted on the Internet. Materials and methods. Heimlich maneuver videos uploaded on to YouTube were evaluated. We recorded by whom the video was uploaded, upload time, the number of viewers, and to whom it was intended. Scores from 0 to 7 were used to evaluate video suitability. Data were analyzed using SPSS 20.0 for Windows software. A p-value < 0.05 was considered to indicate significance. Results. A total of 640 videos were evaluated; 466 (72.8%) videos were excluded because their content was primarily for entertainment purposes. In total, 174 videos met the inclusion criteria and were subjected to analysis. Of the 174 videos analyzed, 54(31%) were uploaded anonymously, the mean number of viewers was 26,814 ± 4,860, and the median video duration was 4.19 min (range, 0.06–114 min). The mean video score was 2.7 ± 1.6. Using this value as a cut-off, a significant relationship between reliability and uploading institution was detected (p ≤ 0.05), but not between the number of views and reliability (p = 0.428). Conclusion. Our results suggest that Heimlich maneuver videos uploaded to YouTube were not particularly educational because only 13% of the videos received an above-average score

Small gaps between almost primes, the parity problem, and some conjectures of Erdős on consecutive integers II

We show that for any positive integer n, there is some fixed A such that d(x) = d(x +n) = A infinitely often where d(x) denotes the number of divisors of x. In fact, we establish the stronger result that both x and x +n have the same fixed exponent pattern for infinitely many x. Here the exponent pattern of an integer x \u3e 1is the multiset of nonzero exponents which appear in the prime factorization of x