Machining strategy development in 5-axis milling operations using process models

Increased productivity and part quality can be achieved by selecting machining strategies and conditions properly. At one extreme very high speed and feed rate with small depth of cut can be used for high productivity whereas deep cuts accompanied with slow speeds and feeds may also provide increased material removal rates in some cases. In this study, it is shown that process models are useful tools to simulate and compare alternative strategies for machining of a part. 5-axis milling of turbine engine compressors made out of titanium alloys is used as the case study where strategies such as flank milling (deep cuts), point milling (light cuts) and stripe milling (medium depths) are compared in terms of process time by considering chatter stability, surface finish and tool deflections

Preparation Of Acrylate And Sulfonamide Based Polymeric Sorbents For Separation Of Biomolecules

Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2010Thesis (PhD) -- İstanbul Technical University, Institute of Science and Technology, 2010Bu tezde hidrazin, amin, karboksilik asit ve metansülfonik asit içeren reçineler hazırlanmış ve karekterize edilmişlerdir. Hidrazin, amin ve karboksilik asit içeren reçineler çapraz bağlı poli(vinilbenzil klorür)’den başlayarak sentezlenmişlerdir. Poli(glisidil metakrilat) ve poli(etil akrilat) PVBC üzerine ATRP yöntemiyle aşılanmışlardır. Aşılanmış reçineler hidrazin, amin ve karboksilik asit gruplarıyla modifiye edilmişlerdir. Hidrazin grubu aldehidleri hidrazon oluşturmak üzere adsorplayabilir. Bu mekanizma enzimlerin adsorpsiyonu için kullanılmıştır. Adsorpsiyon deneyleri pH, iyonik şiddet ve sıcaklığa bağlı olarak gerçekleştirilmiştir. Reçinelerin adsorpsiyon izotermleri ve kinetik özellikleri çalışılmıştır. Ayrıca hidrazin fonksiyonel reçinenin termodinamik parametreleri bulunmuştur. Poli(etil akrilat) PVBC üzerine ATRP ile aşılanmış ve ester grubu poli(akrilik asit) grubu elde etmek için hidroliz edilmiştir. Reçine bazik boyaların giderilmesinde kullanılmıştır. Boya tutma özellikleri, boya tutma kinetiği ve yüklü reçineden boyanın ger kazanımı incelenmiştir. Metansülfonik asit fonksiyonu çapraz bağlı klorosülfolanmış poli(stiren)’nin metan sülfonik asit ile reaksiyonuyla elde edlmiştir. Sülfonamidler asidik ve bazik ortamda kolaylıkla hidroliz olmazlar. Bu özellik geri kazanım işlemi için önemlidir. Reçine tripsin proteinin adsorpsiyonunda kullanılmış ve adsorpsiyon özellikleri farklı pH, iyonik şiddet, sıcaklıkda incelenmiştir. Adsorpsiyon kinetiği ve desorpsiyon koşulları da bulunmuştur. Reçine ayrıca bazik boyaların giderilmesinde kullanılmıştır.In this thesis hydrazine, amine, carboxylic acid and methanesulfonic acid containing resins were prepared and characterized. Hydrazine, amine, carboxylic acid containing resins were synthesized starting from crosslinked poly(vinylbenzyl chloride). Poly (glycidyl methacrylate) and poly (ethyl acrylate) were grafted onto the PVBC by using ATRP method. Grafted resins were modified hydrazine, amine and carboxylic acid group. Hydrazine group can sorb aldehyde to form hydrazone. This mechanism was used in sorption of enzymes. Sorption experiments were investigated depending on pH, ionic strength and temperatue. The adsorption isotherms and kinetic characteristics of the resins were studied. Also, thermodynamic parameters of the hydrazine functional resin were found. Poly (ethyl acrylate) was grafted onto PVBC by ATRP and was hydrolyzed ester group to obtain poly (acrylic acid) group. The resin was used to remove basic dyes. Dye sorption properties, dye sorption kinetics and desorption of the dye loaded resin was investigated. Methanesulfonic acid function was obtained starting from reaction with crosslinked chlorosulfonated poly (styrene) and methane sulfonic acid. Sulfonamides do not hydrolyse in acidic and basic media easily. This property is important for regeneration process. The resin was used sorption of Trypsin protein and sorption of the protein was studied in different pH, ionic strength and temperature. Sorption kinetics, and desorption conditions were also investigated. The resin was also used to remove basic dyes from water.DoktoraPh

FISCAL SPACE APPROACH TO ELIMINATE ECONOMIC CRISIS

Ulusal boyutta vuku bulan bir ekonomik krizin, çeşitli önlemlerle kısa sürede giderilmesi mümkündür. Ancak piyasa sisteminin yaygınlaşması, sermaye hareketlerinin serbest bırakılması ve küreselleşmeninhızlanmasıyla beraber,ulusal krizler hızlabölgesel vehattaküresel çaplıekonomik krizlere dönüşebilmektedir. Buna istinaden krizden çıkış süresi uzayabilmektedir. Krizlere karşı bağışıklık kazanılabilmesi için ekonominin güçlendirilmesi gerekmektedir. Bu amaca yönelik olarak mali alanın en önemli katkısı maliye politikasına esneklik kazandırmaktır. Güçlü bir kamu maliyesi, olası durgunluk dönemlerinde maliye politikasının etkin kullanımını mümkün kılabilmektedir. Ani şokların giderilmesine yönelik mali alan oluşturmanın yanı sıra uzun süreli sorunların çözümüne ilişkin bir perspektif belirlemek yapısal dönüşümü sağlayabilmektedir. Böylece ekonomik büyümenin sağlam temellere oturtulması ve mali alan-iyi yönetim bağlamında, mali alanın kendiliğinden genişlemesi mümkün hale gelebilecektir. Mali alan oluşturma yöntemleri arasında; kamu gelirlerinin artırılması, kamu harcamalarının öncelik sırasına göre düzenlenmesi, kamu-özel işbirliği, etkin borç yönetimi, senyoraj geliri elde edilmesi ve potansiyel büyüme hızının artırılması yer almaktadır.An economic crisis, which occurs at national level, can be overcome in a short period of time. Due to the globalization, national crisis can be turned into regional and even global-scale crisis quickly. Therefore the exit from the crisis period may extend. The economy needs to be strengthen to immune for trying to end crisis. Fiscal space affords flexibility to the public budget against extraordinary risks. It provides the ability for the economy managemant to eliminate the cyclical instabilities. In addition, the fiscal space creates some budget rooms for the fiscal sustainability. Fiscal space will expand inherently by an effective government and the perform of structured transformation. There are different ways in which a government can create such fiscal space. These are; to raise of public sector revenues, to redefine of priorities for public sector spending, to profit of public-private partnerships, to gain effectiveness public debt management, to create seigniorage incomes and to provide sustainable economic development

What Do Teachers Think About Finger-Counting?

The aim of this study is to determine preschool, special education, classroom and mathematics teachers’ views of finger-counting in mathematics teaching. The study was conducted with case study design. The sample of the study consisted of 34 teachers. Data were collected using an 8-item written form, and content analysis was performed. The findings of the study indicate that most participants use fingers as manipulatives in the teaching of numbers and counting but use them very little when teaching the four operations. Most participants state that finger-counting should be used at ages 4-8 / 4-11 while some state that there should not be any age limit. According to the participants, the advantages of finger-counting are that it is practical and accessible, facilitates retention and internalization, and makes the arithmetic more concrete while its disadvantages are that it restricts and slows down the execution of the four operations, prevents the development of mental arithmetic skills and turns into a habit. They state that students who insist on finger-counting have high anxiety, poor memory, and low self-confidence and achievement. Some participants encourage their students to perform mathematical calculations without using pen and paper to help them break the habit of finger-counting and also receive parental support during the process. The fact that students have different characteristics should be taken into account when addressing the use of finger-counting in mathematics teaching because the use of fingers in counting and calculation may be a necessity rather than a choice for some students

Meme Kanseri Teşhisi İçin Yeni Bir Skor Füzyon Yaklaşımı

Meme kanseri tüm dünyada yaygın bir hastalık olması sebebiyle hastalığın erken teşhisi, hastaların bu hastalıktan tamamen kurtulabilmeleri açısından kritik öneme sahiptir. Hastalığın teşhisini kolaylaştırmak için tıp doktorları bilgisayar destekli uzman sistemlerden yararlanabilmektedir. Bu çalışmada meme kanseri veri örneklerini iyi huylu veya kötü huylu sınıflarına ayırmak için genel regresyon sinir ağı (Generalized Regression Neural Network-GRNN) ve ileri beslemeli sinir ağı (Feed Forward Neural Network-FFNN) temelli bir skor füzyon yöntemi önerilmiştir. Önerilen yöntem Wisconsin Teşhis Meme Kanseri (Wisconsin Diagnostic Breast Cancer-WDBC) veri seti üzerinde test edilmiştir. Bu iki temel ağın ve önerilen yöntemin kullanışlılığı incelenmiş ve performans sonuçları karşılaştırmalı olarak sunulmuştur. Önerilen yöntem sınıflandırma doğruluğu bakımından literatürde WDBC veri setini kullanarak yapılan mevcut çalışmalar ile kıyaslanmıştır. Elde edilen deneysel sonuçlar önerilen yöntemin, meme kanseri teşhisi için umut vadettiğini ve tıp uzmanlarının hastalığa ilişkin karar vermelerinde yardımcı bir araç olarak kullanılabileceğini göstermektedir

Should Ultrasonographic Giant-Cell Arteritis Signs be Detected in Patients with Polymyalgia Rheumatica?

Based on the presence of ultrasonographic findings of Giant-Cell Arteritis in Polymyalgia Rheumatica patients using Ultrasonography on the temporal artery, the study contributes to the literature evaluating the unclear relationship between Polymyalgia Rheumatica and Giant-Cell Arteritis. It raises awareness that Ultrasonography can be used instead of biopsy in patients with suspected Giant-Cell Arteritis. Twenty patients were newly diagnosed with Polymyalgia Rheumatica and included 20 participants as a control group in the study. The Polymyalgia Rheumatica group was evaluated at baseline and sixth month, while the control group was only assessed at baseline. Laboratory, clinical, and ultrasonographic findings of all participants were assessed. Gray-scale Ultrasonography and colored Doppler Ultrasonography were used to present halo and compression, occlusion, and stenosis in addition to intima-media complex thickness in bilateral temporal arteries and frontal-parietal branches by an experienced radiologist blinded to the subject. No significant difference was found between Polymyalgia Rheumatica and control groups based on demographic features, clinical and ultrasonographic results at baseline and sixth month. Erythrocyte sedimentation rate of Polymyalgia Rheumatica at baseline was statistically higher than the control group. Erythrocyte sedimentation rate values have declined significantly in Polymyalgia Rheumatica patients, but no significant changes were found for clinical or ultrasonographic features during the sixth month. Ultrasonographic findings of Giant-Cell Arteritis are not present in newly diagnosed and six months followed up Polymyalgia Rheumatica patients. Further studies are needed

Adnexal Torsion: Difficulty in Diagnosis and Management

Aim:To investigate both the diagnostic value of Doppler-ultrasonography and factors influencing surgical intervention in patients with adnexal torsion (AT).Methods:We retrospectively examined medical records of 66 women with AT in a single center between January 2007 and December 2016.Results:Forty-three out of 66 patients (65.1%) with AT were correctly diagnosed preoperatively. On Doppler examination, reduced ovarian arterial blood velocity was observed in 39 patients (59.1%); and the sensitivity was 0.67. AT was diagnosed in 49 patients (74.2%) via laparotomy, and the number of patients who were subjected to radical treatment was higher than that of patients managed with conservative treatment (54.6% vs 45.4%). Although there was no difference in the surgical approaches (laparoscopy vs laparotomy) between the groups, age, gravidity, parity, body mass index, and ovarian cyst size were significantly lower in patients who were treated conservatively (p<0.05).Conclusion:The diagnostic value of Doppler examination for AT is limited and the decision for surgical management should not be delayed based on Doppler results. Early age, low gravidity, parity and body mass index, and small size of ovarian cyst on ultrasonography were indication for conservative treatment, whereas black-bluish macroscopic appearance had no influence on the preference towards the selection of treatment

Female Urethral Malignant Melanoma With Vesical Invasion: A Case Report

We report a 75-year-old female with a primary urethral malignant melanoma. A mass protruding from inside the urethra was detected on physical examination. Abdominopelvic magnetic resonance imaging revealed a mass extending from the urethra with dimensions of 4 × 2 cm, and periurethral heterogenous fatty planes consistent with infiltration. The histopathologic examination was consistent with HMB45(+) malignant melanoma. We performed cystourethrectomy and bilateral inguinal and pelvic lymphadenectomy in one session. The pathology report revealed primary malignant melanoma of the urethra invading the inferior bladder wall. The patient received no adjuvant therapy because of cardiopulmonary morbidities and the presence of multiple pulmonary metastases. The patient eventually died 13 months after surgery

A Rare Renal Epithelial Tumor: Mucinous Cystadenocarcinoma Case Report and Review of the Literature

Primary renal mucinous cystadenocarcinoma is a very rare lesion of kidney which originates from the metaplasia of the renal pelvic uroepithelium. Only one case with primary mucinous cystadenocarcinoma has been reported in the English literature. We report second case of mucinous cystadenocarcinoma which was radiologically classified as type-IIF Bosniak cyst in peripheral localization. We aimed to present this extreme and unusual entity with its radiological, surgical, and pathologic aspects under the light of literature

Stężenia adropiny i albuminy modyfikowanej niedokrwieniem w surowicy w zależności od występowania zespołu policystycznych jajników i wartości BMI

Introduction: The aim of this study was to evaluate the effects of polycystic ovary syndrome (PCOS) and body mass index (BMI) on serum adropin and ischemia modified albumin (IMA) levels. Materials and methods: This prospective cross-sectional study was performed with a total of 120 women [group1; non-PCOS = 60 (BMI < 25 = 30, BMI ≥25 = 30) and group 2; PCOS = 60 (BMI < 25 = 30, BMI ≥25 = 30)]. Blood samples were collected between the third and fifth days of the women’s menstrual cycles after a night of fasting. Results: There were no differences between the groups in relation to age, basal follicle stimulating hormone, estradiol, thyroid stimulating hormone, prolactin, high-density lipoprotein cholesterol, total testosterone, dehydroepiandrosterone sulfate levels, systolic and diastolic blood pressures. A significant difference was found in basal luteinizing hormone, fasting glucose, insulin, homeostatic model assessment of insulin resistance, total cholesterol, low-density lipoprotein cholesterol, triglycerides, free testosterone levels, waist-to-hip ratios and the Ferriman-Gallwey scores between the PCOS and non-PCOS patients in the lean and overweight groups (p < 0.05). The serum adropin levels in the lean PCOS group were lower than in the lean non-PCOS group (p < 0.05) and were lower in the overweight PCOS group than in the overweight non-PCOS group (p < 0.05). There was also a statistically significant difference in serum IMA levels in the PCOS group than in the non-PCOS group in both the lean and overweight groups (p < 0.05). Conclusions: Although serum adropin levels were significantly decreased in the PCOS group, IMA levels increased. Further studies are needed to determine the effects of adropin and IMA in women with PCOS and to use a new marker to monitorize treatment outcomes. Wstęp: Badanie przeprowadzono w celu oceny wpływu zespołu policystycznych jajników (polycystic ovary syndrome, PCOS) i wskaźnika masy ciała (body mass index, BMI) na surowicze stężenia adropiny i albumin modyfikowanej niedokrwieniem (ischemia modified albumin, IMA). Materiał i metody: To prospektywne badanie przekrojowe obejmowało 120 kobiet [grupa 1: osoby bez PCOS — n= 60 (BMI &lt; 25 — n= 30; BMI ≥ 25 — n = 30) oraz grupa 2: osoby z PCOS — n= 60 (BMI &lt; 25 — n= 30, BMI ≥ 25 —n = 30)]. Próbki krwi pobierano między trzecim a piątym dniem cyklu menstruacyjnego badanych kobiet, rano na czczo. Wyniki: Grupy nie różniły się pod względem wieku, podstawowego stężenia hormonu folikulotropowego, stężeń estradiolu, tyreotropiny, prolaktyny, cholesterol frakcji HDL, testosteronu całkowitego i siarczanu dehydroepiandrosteronu ani skurczowego i rozkurczowego ciśnienia tętniczego. Stwierdzono natomiast istotne różnice między grupą z PCOS i bez PCOS w podgrupach osób szczupłych i otyłych w zakresie podstawowego stężenia hormonu luteinizującego, glikemii na czczo, wskaźnika insulinooporności w modelu homeostazy, stężeń cholesterolu całkowitego, cholesterolu frakcji LDL, triglicerydów i wolnego testosteronu, a także wskaźnika talia-biodra oraz oceny w skali Ferrimana-Gallweya (P &lt; 0,05). Stężenia adropiny w osoczu były niższe w grupie szczupłych kobiet z PCOS niż u szczupłych osób niechorujących na PCOS (P &lt; 0,05) oraz były niższe u otyłych osób z PCOS niż u otyłych osób z grupy bez PCOS (P &lt; 0,05). Stwierdzono również statystycznie istotną różnice w stężeniach IMA w surowicy między kobietami z PCOS i bez PCOS, zarówno w podgrupie osób szczupłych, jak i otyłych (P &lt; 0,05). Wnioski: Mimo że surowicze stężenia adropiny były istotnie niższe w grupie z PCOS, stężenia IMA były podwyższone w tej grupie badanych. Konieczne są dalsze badania w celu określenia wpływu adropiny i IMA u kobiet z PCOS i stosowanie nowych wskaźników do monitorowania efektów leczenia