Experimental Investigation of the Effect of Temperature on Friction Pressure Loss of Polymeric Drilling Fluid Through Vertical Concentric Annulus

Accurate estimation of annular friction pressure loss is necessary to perform drilling and well completion operations without lostcirculation, pipe sticking or more serious well control problems. Determination of friction pressure loss for Newtonian and non-Newtonianfluids has been investigated in several experimental and theoretical works by considering the effects of eccentricity, pipe rotation or pipegeometry. However, there is a gap in the studies about the temperature effect that is important especially in geothermal wells.This study experimentally investigated the effect of temperature on friction pressure loss through vertical concentric annulus by usingwater and the polymer based drilling fluid including Polyanionic Cellulose and Xanthan Gum. Experiments were conducted in flow loophaving 21-ft smooth and concentric annular test section (2.91 in ID casing x 1.85 in OD pipe).The effect of temperature on rheological model parameters, apparent viscosity, Reynolds number was examined. It was found thatconsistency index and yield point were more sensitive to change in temperature than flow behavior index. Also, apparent viscositydecreased exponentially with increasing temperature and this decrease was more obvious in low shear rate values. Then, according toReynolds number – temperature plot, earlier regime transition was observed with increasing temperature.As a result, increasing temperature caused the decrease in friction pressure loss, and temperature effect should be considered in futureexperimental and theoretical studies in order to estimate friction pressure loss in annuli precisely

Treatment of symptomatic calcaneal lipoma with osseoscopy using a synthetic allograft

Objective: This study evaluated the results of symptomatic calcaneal lipoma patients treated with a recently introduced minimally invasive arthroscopic method. Materials and methods: Seven patients treated with osseoscopy in our clinic for calcaneal lipoma between 2013 and 2018 were evaluated. The median age of the patients was 37.7 years and five were male. The common compliant of the patients was pain that partially disrupted daily life. Surgery was utilized for patients who did not respond to conservative methods (sports restriction, partial weight bearing, and heel support) had persistent pain longer than 3 months and had a risk of impending fracture (>30% loss in trabecular bones). Results: The mean follow-up period after surgery was 21 (12–33) months. In all patients, the location of the ICL was in Ward’s triangle and the mean size was 28.8 (20-43) mm. According to Milgram’s classification, three ICLs were stage I, two were stage II, and two were stage III. The radiological result was evaluated using the classification system of Glutting and Chang. There was no persistent cyst and no recurrence. The radiological success rate was 100%. The mean ankle-hindfoot scale score (max. 100 pts) increased from a preoperative 74.7 ± 5.3 points (range: 69–83) to a postoperative 96.7 ± 2.62 points (range: 93-100). Conclusions: In the treatment of calcaneal lipoma, treatment with osseoscopy is easy and fast, has low complication rates, and is a cosmetically desirable alternative. The use of synthetic allografts to fill the cavity is a safe, inexpensive, and easy alternative

Türk popülasyonunda oligozoospermi ve azospermi hastalarında infertilitenin genetik nedenleri

Objective: Advances in the science of genet- ics and the development of assisted reproductive techniques focus on the genetic causes of infer- tility. The aim of this research is to reveal genetic abnormalities in terms of sex chromosome aneu- ploidy and Y chromosome microdeletions. Material and Methods: A total of 350 patients with azoospermia or severe oligozoospermia were selected. After general examination of the patients and laboratory investigations were performed, cartoypes and Y chromosome microdeletions were examined. Results: A total of 225 infertile men with non-obstructive azoospermia (NOA) and 125 in- fertile men with oligozoospermia were enrolled into the study. The overall cytogenetic anomaly rate was 16%. Chromosomal changes were detected in 32 of 350 (9.1%) cases. The most common genetic anomaly was 47, XXY (Klinefelter syndrome) and the incidence was 11.5% in NOA group. This rate was 3.2% in oligozoospermia group. Y chromosome microdeletions were detected in 24 (6.8%) patients and similarly, it was observed more frequently in the NOA group than in the oligozoospermia group. Conclusion: The incidence of genetic causes have been increasing with the severity of infertil- ity. As a result, genetic screening and appropriate genetic counseling are needed before the use of assisted reproductive techniques.Amaç: Genetik bilimindeki ilerlemeler ve yardımcı üreme tekniklerindeki gelişmeler, infer- tilitenin genetik nedenlerine odaklanmamızı sağ- lamaktadır. Bu çalışmada, sex kromozomu anöplo- idisi ve Y kromozom mikrodelesyonları açısından genetik anormallikleriaraştırmayı amaçladık. Gereç ve Yöntemler: Azospermi veya şiddet- li oligozoospermi (≤ 5 milyon spermatozoa/ml) olan toplam 350 hasta analiz edildi. Hastalar genel muayene ve laboratuvar değerlendirmesi sonrası, karyotip ve Y kromozom mikrodelesyonu açısın- dan değerlendirildi. Bulgular: Non-obstrüktif azospermi (NOA) olan toplam 225 infertil erkek ve oligozoospermi olan 125 infertil erkek çalışmaya dahil edildi. Ge- nel sitogenetik anomali oranı% 16 idi. Üç yüz elli vakanın 32’sinde (% 9,1) kromozom değişiklikleri tespit edildi. En sık görülen genetik anomali 47, XXY (Klinefelter sendromu KS) idi ve insidansı NOA grubunda % 11.5 ve oligozoospermi gru- bunda % 3,2 idi. Y kromozom mikrodelesyonu 24 (% 6.8) hastada tespit edildi ve benzer şekilde NOA grubunda oligozoospermi grubuna göre daha sık görüldü (% 9.3 vs % 2.4, sırasıyla). Sonuç: İnfertilitenin şiddeti ile birlikte gene- tik nedenlerin görülme sıklığı artmaktadır. Sonuç olarak, yardımcı üreme tekniklerinin kullanılma- sından önce genetik tarama ve uygun genetik da- nışmanlığa ihtiyaç duyulmaktadır

Multiparametric MRI of rectal cancer—repeatability of quantitative data: a feasibility study

PURPOSEIn this study, we aimed to analyze the repeatability of quantitative multiparametric rectal magnetic resonance imaging (MRI) parameters with different measurement techniques.METHODSAll examinations were performed with 3 T MRI system. In addition to routine sequences for rectal cancer imaging protocol, small field-of-view diffusion-weighted imaging and perfusion sequences were acquired in each patient. Apparent diffusion coefficient (ADC) was used for diffusion analysis and ktrans was used for perfusion analysis. Three different methods were used in measurement of these parameters; measurements were performed twice by one radiologist for intraobserver and separately by three radiologists for interobserver variability analysis. ADC was measured by the lowest value, the value at maximum wall thickness, and freehand techniques. Ktrans was measured at the slice with maximum wall thickness, by freehand drawn region of interest (ROI), and at the dark red spot with maximum value.RESULTSA total of 30 patients with biopsy-proven rectal adenocarcinoma were included in the study. The mean values of the parameters measured by the first radiologist on the first and second measurements were as follows: mean lowest ADC, 721.31±147.18 mm2/s and 718.96±135.71 mm2/s; mean ADC value on the slice with maximum wall thickness, 829.90±144.24 mm2/s and 829.48±149.23 mm2/s; mean ADC value measured by freehand ROI on the slice with maximum wall thickness, 846.56±136.31 mm2/s and 848.23±144.15 mm2/s; mean ktrans value on the slice with maximum wall thickness, 0.219±0.080 and 0.214±0.074; mean ktrans by freehand ROI technique (including as much tumoral tissue as possible), 0.208±0.074 and 0.207±0.069; mean ktrans measured from the dark red foci, 0.308±0.109 and 0.311±0.105. Intraobserver agreement was very good among diffusion and perfusion parameters obtained with all three measurement techniques. Interobserver agreement was very good, except for one of the measurement techniques. As far as interobserver variability is considered, only ADC value measured on the slice with maximum wall thickness differed significantly.ConclusionMultiparametric MRI of rectum, using ADC as the diffusion and ktrans as the perfusion parameter is a repeatable technique. This technique may potentially be used in prediction and evaluation of neoadjuvant treatment response. New studies with larger patient groups are needed to validate the role of multiparametric MRI

Comparison of the Early Results of Preterm Infants who Underwent the Surgical Ligation of Patent Ductus Arteriosus with two Different Surgical Approaches

INTRODUCTION: Patent ductus arteriosus (PDA) is the most common congenital heart disease in preterm infants. Surgical ligation is still the gold standard technique, especially in low birth weight patients. To reduce surgical trauma and possible complications, the anterior mini-thoracotomy (AMT) technique has been defined. However, conventional lateral thoracotomy (LT) is still the method preferred by many centers today. In our study, we aimed to compare the early results of preterm infants who underwent PDA ligation with two different surgical techniques in a newly established center. METHODS: A total of 26 patients (12 males, 14 females; median gestational age at surgery 32 weeks [IQR: 29-37]) who underwent surgical PDA ligation in preterm infants between January 2018 and February 2020 were retrospectively analyzed. PDA closure was performed through the left anterior mini-thoracotomy approach in 15 of the patients and left lateral thoracotomy in 11 patients. The early outcomes of the two groups were compared. RESULTS: The median weight at operation was 1000 gr. (IQR: 720-1200) in AMT group and 1200 gr. (IQR: 1000 – 2800) in the LT group. The difference between weights at operation was found statistically significant (p: 0.03). The operation time of the AMT group was found to be statistically significantly shorter. (p: 0.03) DISCUSSION AND CONCLUSION: Anterior mini-thoracotomy technique provides an effective surgical closure in the low-weight preterm infant at least lateral thoracotomy technique. Based on the results of our series and our opinion, it should be considered the first choice surgical method, especially in very low and extremely low-weight preterm infants

Alleviating Effect of Alpha-Pinene on Testicular Torsion and Detorsion Injury in Rats

Objective:It was aimed to evaluate whether alpha-pinene (AP) had a beneficial effect in the testicular ischemia/reperfusion injury (IRI) model for the first time.Materials and Methods:Testicular malondialdehyde, total oxidant status, and total antioxidant status levels were determined using spectrophotometric methods. The superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), myeloperoxidase (MPO), 78-kDa glucose-regulated protein (GRP78), activating transcription factor 6 (ATF6), and C/EBP homologous protein (CHOP) levels were determined using the commercial enzyme-linked immunosorbent assay kits. Hematoxylin-eosin staining method was used in the histopathological evaluation.Results:In the IRI group, testicular MDA, MPO, GRP78, ATF6, and CHOP levels were significantly increased, while GSH and GPx levels were decreased compared with the control group (p<0.01). AP application restored these levels significantly (p<0.05). Johnsen scores were also significantly lower in the IRI group compared the control group (p<0.001), and AP treatment increased these scores significantly (p<0.001).Conclusion:These results suggest that AP can protect the testicular tissue against IRI by inhibiting oxidative stress, inflammation, and endoplasmic reticulum stress with its antioxidant properties, thus providing a molecular basis for a novel medical treatment of testicular IRI. Future studies are needed on other mechanisms of the protective effect of AP on the pathogenesis of testicular torsion

Nodule Detection in a Lung Region that's Segmented with Using Genetic Cellular Neural Networks and 3D Template Matching with Fuzzy Rule Based Thresholding

Objective: The purpose of this study was to develop a new method for automated lung nodule detection in serial section CT images with using the characteristics of the 3D appearance of the nodules that distinguish themselves from the vessels

In-chip microstructures and photonic devices fabricated by nonlinear laser lithography deep inside silicon

Silicon is an excellent material for microelectronics and integrated photonics1–3 with untapped potential for mid-IR optics4. Despite broad recognition of the importance of the third dimension5,6, current lithography methods do not allow fabrication of photonic devices and functional microelements directly inside silicon chips. Even relatively simple curved geometries cannot be realised with techniques like reactive ion etching. Embedded optical elements, like in glass7, electronic devices, and better electronic-photonic integration are lacking8. Here, we demonstrate laser-based fabrication of complex 3D structures deep inside silicon using 1 µm-sized dots and rod-like structures of adjustable length as basic building blocks. The laser-modified Si has a different optical index than unmodified parts, which enables numerous photonic devices. Optionally, these parts are chemically etched to produce desired 3D shapes. We exemplify a plethora of subsurface, i.e., “in-chip” microstructures for microfluidic cooling of chips, vias, MEMS, photovoltaic applications and photonic devices that match or surpass the corresponding state-of-the-art device performances

Çok taneli plastisite ile çift fazlı çeliklerde lokalizasyon ve boyun verme modellenmesi.

In this thesis, the effect of ferrite crystallographic orientation distribution and other microstructural parameters such as martensite morphology, martensite volume fraction, and ferrite grain size on the plastic deformation, localization, and the necking behavior of dual-phase steels are investigated. Two different type of finite element models, i.e. full size micron-scale polycrystalline samples and polycrystalline Representative Volume Element (RVEs) are built through Voronoi tessellation. Local crystal plasticity and J2 plasticity with isotropic hardening frameworks are used to model ferrite and martensite phases, respectively. This work demonstrated that the martensite morphology and the ferrite orientation distribution affect highly the formation of the shear bands and the necking location in the samples. In addition, they significantly affect stress-strain partitioning, location of the plastic localization, tensile strength and hot spots for void formation in the RVEs.Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Aerospace Engineering