Analytical prediction techniques for axisymmetric flow in gas labyrinth seals

Labyrinth seals are commonly found in turbines and compressors. Their objective is to control gas leakage from high pressure regions to low pressure regions. The correct prediction and control of this leakage is crucial for the efficient and economic operation of turbomachinery. In this paper we present approaches for obtaining the above prediction in a simple analytical and explicit method. Both constant and pressure dependent flow coefficients are incorporated in the present study which extends to the higher inlet/outlet pressure differences. The results obtained with our methods compare favorably with the ones obtained by both numerical and experimental techniques. In many cases there is hardly a distinction between our results and the numerical prediction

Donor lung selection criteria and surgical application at University of Pittsburgh

Lung transplantation is the standard treatment for patients with end-stage lung disease. Unfortunately scarce source of donor organs, particularly in lungs, limits this selected treatment to very few recipients each year. To decrease waiting list deaths and provide organs to more diverse recipient population, widening selection criteria of donor lungs was offered. Besides expanded criteria in organ selection to increase lung transplant surgery, donation after cardiac death and ex-vivo lung perfusion were introduced to current medicine. University of Pittsburgh in last decade doubled its lung transplant volume by extending the acceptance criteria for donor lungs for which many other centers would decline in first line or some selected centers may try ex-vivo perfusion protocols on these lungs. Nonetheless successful transplant surgery requires successful donor procurement surgery. Based on this practice, we wanted to review the Pittsburgh model of expanding lung donor selection criteria and surgery for donor lung procurement

The morphometric measurement of the brain stem in Turkish healthy subjects according to age and sex

Background: This paper determined the morphometric measurements of the brainstem including mesencephalon, pons and medulla using magnetic resonance imaging (MRI) in Turkish healthy population. Materials and methods: Two hundred sixty-three (263; 158 females and 105 males) subjects aged from 18 to 65 years were included in this study. The measurements were taken from subjects having brain MRI in the Radiology Department. Statistical analysis was done by SPSS 21.00 package programme. ANOVA test and χ2 test were used to determine the relation between measurements and age and sex groups. The p < 0.05 value was considered as significant. Results: The overall means and standard deviations of the measurements were: pons anteroposterior diameter, 15.41 ± 1.27 mm; pons vertical diameter, 22.02 ± 2.07 mm; mesencephalon anteroposterior diameter 9.39 ± 1.00 mm; mesencephalon vertical diameter, 15.20 ± 1.53 mm; distance between the interpeduncular fissure and aqueduct, 11.72 ± 1.58 mm; distance from cerebral peduncles to aqueduct, 13.64 ± 1.66 mm; anterior surface of the pons midway between the mesencephalon and medulla to the fourth ventricular floor, 21.62 ± 1.64 mm; the shortest anteroposterior diameter of the medulla at the pontomedullary junction, 13.46 ± 1.28 mm, and the shortest anteroposterior diameter of the medulla at the medullospinal junction, 10.24 ± 1.43 mm in females, respectively, whereas the corresponding values were 15.58 ± 1.53 mm; 22.64 ± 2.35 mm; 9.37 ± 1.66 mm; 15.64 ± 1.52 mm; 11.14 ± 1.31 mm; 13.01 ± 1.30 mm; 21.97 ± 1.65 mm;13.47 ± 1.19 mm; 9.91 ± 1.35 mm in males, respectively. There were significant differences in some parameters such as pons vertical diameter, mesencephalon vertical diameter, distance between the interpeduncular fissure and aqueduct, and distance between cerebral peduncles to aqueduct between sexes. Conclusions: The brainstem dimensions of healthy population provide important and useful knowledge in terms of comparison of abnormalities clinically. These data may be valuable for the representatives of clinical disciplines

Age influence in gender stereotypes related to Internet use in young people

[EN]The existence of gender stereotypes in relation to the use of the Internet led to the need to carry out the present study, which approaches young people perception of the use of the Internet and technologies. Based on knowledge of the existence of gender stereotypes in relation to the use of the Internet, the objective of the study is to detect whether the age of young people, with some previous experience on the Internet, marks differences in relation to the use they make of the Internet; in other words, whether the use made of the world network and the existing stereotypes may or may not have some type of dependent relationship with the age of the subjects. The study was applied in a group of the University of Salamanca (Spain) during the academic year 2018/2019, after the previous realization of activities during four months of sensitization, under the European project WYRED (netWorked Youth Research for Empowerment in the Digital). The final sample was composed by 48 subjects. For this purpose, a questionnaire was applied with 40 final items, which collected different activities that can be carried out on the Internet in order to find out what trend of use they presented in relation to the Internet, in comparison to their age. The two groups consisted of 26 people aged 20 or younger, and 22 people aged 20 or older. By means of a descriptive analysis, and the application of normality tests and non-parametric tests, no dependent relationships were detected between the use of the Internet after carrying out the survey and the age group in which the subject belonged. For the future it would be of special interest to be able to repeat the study comparing the opinion and use of young people on the Interne

The determination of the pituitary gland, optic chiasm, and intercavernous distance measurements in healthy subjects according to age and gender

Background: This paper was undertaken to determine the morphometry of pituitary gland diameter, pituitary gland height, intercavernous distance, optic chiasm diameter and optic chiasm height in skulls of Turkish population aged between 18 and 60 years. Materials and methods: It was a retrospective study in which 292 subjects were included 187 females and 105 males, ranging from 18 up to 60 years. Subjects underwent brain magnetic resonance imaging in the Radiology Department. Statistical analysis was performed with SPSS 21.00 programme. ANOVA test, χ2 test, and Pearson correlation analysis were used to determine the relation and significance between measurements and age group. The p < 0.05 value was considered as significant. Results: The groups were divided into five groups according to age. The overall means and standard deviations of the measurements were: pituitary gland width, 13.09 ± 1.99 mm; pituitary gland height, 4.91 ± 1.10 mm; intercavernous distance, 15.93 ± 3.05 mm; optic chiasm width, 12.82 ± 1.27 mm; and optic chiasm height, 2.80 ± 0.49 mm in females, respectively whereas, the same measurements were 12.96 ± 1.74 mm; 4.79 ± 0.95 mm; 16.08 ± 3.11 mm; 13.13 ± 1.37 mm; 2.86 ± 0.70 mm in males, respectively. Height of the pituitary gland reached a maximum in the age group of 18 to 20 years in both females and males and there was a decrease in the pituitary gland height in the subsequent age groups. Conclusions: Knowledge of the variation in the size of pituitary gland, intercavernous distance and optic chiasm is important to evaluate the dimensions of these structures for clinical and pathological processes

Dumlupınar Üniversitesi Öğrencilerinin İnternet Kullanım Ve Doyum Motivasyonlarının Bazı Parametreler Bakımından İncelenmesi,

İletişim teknolojilerindeki hızlı gelişmeler sonucunda internetin toplumsal yaşamımızdaki önemi hızla artmıştır. İnternet birçok alanda kullanıcısına fayda sağlamaktadır. Bunlar; bilgi edinme, eğlence, sohbet, alışveriş, iletişim gibi farkörler bunların başında gelmektedir. Bu araştirmada, katılımcıların bazı parametrelerinin internet kullanımında etkili olan 6 faktör üzerindeki etkilerinin incelenmesi amaçlanmıştır. Araştırma Kütahya Dumlupınar Üniversitesi “Beden Eğitimi Spor Yüksek Okulu, Mühendislik Fakültesi, İİBF, Eğitim Fakültesi, Fen edebiyat Fakültesinde” okuyan basit tesadüfî örneklem yoluyla seçilen 691 öğrenci üzerinde uygulamalı olarak gerçekleştirilmiştir. Araştırmaya 309 Bayan ve 382 erkek katılım sağlamıştır. Katılımcılara spor aktiviteleri, günlük hayatları, internet kullanım farklıklılıkları, süreleri gibi bazı sorular yöneltilmiştir. Ayrıca katılımcıların demografik özellikleride belirlenmiştir. Ailelerinin ekonomik, eğitim ve yaşadıkları bölgeler hakkında da bilgi toplanmıştır. Elde edilen bu bilgilerle uygulamaya gidilmiştir. Uygulamada SPSS istatistik 15 programı kullanılarak analiz gerçekleştirilmiştir. Analizde farklı teknikler ve yöntemler kullanılmıştır. Uygulama ve analizden elde edilen veriler çalışmanın tartışma ve sonuç kısmında açıklanmıştır. Çalışma sonunda, internet kullanımının motivasyon ve doyum düzeyi üzerinde etkili olduğu sonucuna ulaşılmıştır

Studying the Factors Affecting Osteoporosis in Women with The Logistic Regression Analysis

The purpose of this investigation is to study the factors affecting osteoporosis in women with the logistic regression analysis in order to evaluate the effect of those risk factors. The age of women ranged between 40-70 years. A questionnaire was prepared for this study and the questions were directed to patients. The research was conducted on a total of 250 patients. As the dependent variable is in a categorical data type with two levels, binary logistic regression analysis was applied. According to the analysis results, such factors as age, weight, calcium amount of the individual, duration of the exercise, genetic factors, being in menopause and smoking have significant effect pushing individuals towards being osteoporotic. In order to prevent osteoporosis, a person should lose weight, increase weekly exercises, be careful about the calcium amount in her body and reduce smoking. particularly elder ones

Orbitofrontal and caudate volumes in cannabis users: a multi-site mega-analysis comparing dependent versus non-dependent users.

Cannabis (CB) use and dependence are associated with regionally specific alterations to brain circuitry and substantial psychosocial impairment.The objective of this study was to investigate the association between CB use and dependence, and the volumes of brain regions critically involved in goal-directed learning and behaviour-the orbitofrontal cortex (OFC) and caudate.In the largest multi-site structural imaging study of CB users vs healthy controls (HC), 140 CB users and 121 HC were recruited from four research sites. Group differences in OFC and caudate volumes were investigated between HC and CB users and between 70 dependent (CB-dep) and 50 non-dependent (CB-nondep) users. The relationship between quantity of CB use and age of onset of use and caudate and OFC volumes was explored.CB users (consisting of CB-dep and CB-nondep) did not significantly differ from HC in OFC or caudate volume. CB-dep compared to CB-nondep users exhibited significantly smaller volume in the medial and the lateral OFC. Lateral OFC volume was particularly smaller in CB-dep females, and reduced volume in the CB-dep group was associated with higher monthly cannabis dosage.Smaller medial OFC volume may be driven by CB dependence-related mechanisms, while smaller lateral OFC volume may be due to ongoing exposure to cannabinoid compounds. The results highlight a distinction between cannabis use and dependence and warrant examination of gender-specific effects in studies of CB dependence