Investigation of magnetic dead layer formation at the interfaces of sputtered Ni80 Fe20 thin films

Thesis (Master)--Izmir Institute of Technology, Physics, Izmir, 2009Includes bibliographical references (leaves: 57-60)Text in English; Abstract:Turkish and Englishxi, 60 leavesIn this thesis, magnetic dead layer formation at the interfaces of the sputtered Ni80Fe20 thin films has been investigated experimentally. Different insulators such as Ta2O5, Al2O3 and metallic Ta thin films have been deposited as seed and cap layers to determine the MDL formation at the interface of Ni80Fe20. The magnetization of samples has been probed by Vibrating sample magnetometry and X-ray reflectivity measurements have been carried out to investigate the thickness and roughness of the interlayers. Ta films cause the most MDL formation when grown as seed as well as cap layer. It has been observed that the thickness of MDL is strongly temperature dependent. MDL thickness decreases for all trilayers deposited except for Ta2O5/Ni80Fe20/Ta2O5 when they are exposed to 300 .C annealing temperature. Further annealing at 500 .C causes an interdiffusion between the layers and the thickness of the MDL increases. According to XRR measurements, the thickness of the inter alloy layers between the Ni80Fe20 and its adjacent layers is consistent with the thickness of magnetic dead layer calculated from Liebermann equation. MDL calculations reveal that SiO2/Ta/Ni80Fe20/Al2O3 multilayer has the lowest MDL thickness therefore might be a possible candidate to be used in spin valve structures

Near Critical Gas Condensate Relative Permeability of Carbonates

Typical gas condensate fields contain a gas/liquid system during depletion. Such systems are difficult to model experimentally because they exhibit near-miscible behavior at high pressure and temperature. One way to simplify laboratory experimentation is to use a binary retrograde condensate fluid and to adjust temperature to control miscibility. A series of relative permeability test were conducted on a moderate-permeability carbonate core using methanol/n-hexane at near miscible conditions in the presence of immobile water. Potassium carbonate was added to the water to prevent miscibility with methanol. The experiments used a pseudo-steady-state technique under conditions similar to the near well region of a carbonate gas-condensate reservoir. The flow of gas and condensate at different force ratios was investigated. Relative permeabilities were obtained by matching historical production and pressure data using a coreflood simulator. It was observed that relative permeability depended on fluid composition and flow rate as well as initial condensate and water saturations. As the wetting phase (condensate) flow rate increased or interfacial tension decreased, relative permeability versus wetting phase saturation curves shifted towards lower wetting phase saturations. It was found that a simple three-parameter mathematical model that depends on a new dimensionless number called condensate number successfully modeled the gas-condensate relative permeability data. The developed model resulted in a good agreement with published gas-condensate relative permeability data as well as end point relative permeabilities and saturations. The relative permeability behavior as a function of IFT highly resembles the one observed in sandstones

LIQUEFACTION OF NIGDE-ULUKISLA OIL SHALE: THE EFFECTS OF PROCESS PARAMETERS ON THE CONVERSION OF LIQUEFACTION PRODUCTS

In this paper, the direct liquefaction of Turkish Nigde-Ulukisla oil shale in noncatalytic and catalytic conditions was studied. The effects of pressure, tetralin/oil shale ratio, catalyst type and concentration, reaction time and temperature and oil shale/waste paper ratio on the process were investigated. It was found that tetralin/oil shale ratio had no considerable effect on the total and liquefaction products conversions under the noncatalytic conditions. Fe2O3, MoO3, Mo(CO)(6), Cr(CO)(6) and zeolite were used as catalysts in catalytic liquefaction. The highest total and liquefaction products conversions were obtained using MoO3 as catalyst at a concentration of 9% by weight. Reaction temperature of 400 degrees C and reaction time of 90 minutes were chosen according to obtained liquefaction results. Co-liquefaction experiments were performed using waste paper. Both the total and oil + gas conversions were increased to a considerable extent by the application of the co-liquefaction process. According to gas chromatographic-mass spectrometric (GC-MS) analysis, the liquid product from the liquefaction process of oil shale under catalytic conditions of experiment 22 consisted mainly of naphthalene and its derivatives and polycyclic hydrocarbon such as indene and its derivatives

Türkiye’nin Batı Akdeniz Yöresinde doğal olarak yetişen dağ çayı (Sideritis libanotica Labill. subsp. linearis (Bentham) Bornm) ve bayır kekiği (Origanum sipyleum L.) türlerinin uçucu yağ oranları ve bileşenlerinin belirlenmesi

Bu çalışmada, ülkemiz için endemik türlerden olan ve Lamiaceae familyasına ait Sideritis libanotica Labill. subsp. linearis (Bentham) Bornm ve Origanum sipyleum L.’un uçucu yağ oranları ve bileşenlerinin belirlenmesi amaçlanmıştır. Antalya-Beşkonak ve Isparta-Ayazmana yöresinden 2007 ve 2008 yılında toplanan türler, Süleyman Demirel Üniversitesi Orman Fakültesi Orman Botaniği Laboratuarına getirilmiş, oda şartlarında kurutulmuş ve Clevenger (uçucu yağ analiz aparatı) hidrodistilasyon cihazında 3 saat süreyle distilasyona tabi tutularak uçucu yağ oranları saptanmıştır. Elde edilen uçucu yağların bileşenleri ise GC-MS (Perkin Elmer) cihazında belirlenmiştir. Elde edilen sonuçlara göre uçucu yağ oranları S. libanotica subsp. linearis’de % 0,18 ml ve O. sipyleum’da % 0,16 ml olarak bulunmuştur. Gaz kromatografisi sonuçlarına göre en etkili bileşenler S. libanotica subsp. linearis’de -bisabolol (%30.85), -fellandren (%25.29) ve germakren-D (%8.68); O. sipyleum’da γ-terpinen (%45.46), p-simen (%24.29) ve karyofilen (%9.74) olarak tespit edilmiştir. Sonuçlar ülkemizin değişik yörelerinde aynı türlerde yapılan çalışmalarla karşılaştırılmıştır. Anahtar kelimeler: Sideritis libanotica subsp. linearis, Origanum sipyleum, Endemik, Uçucu yağ, -bisabolol, γ-terpine

Tek taraflı cerrahi destekli hızlı üst çene genişletmesi

İskeletsel tek taraflı posterior çapraz kapanış özellikle yetişkinlerde tedavisi zor bir anomalidir. Genç bireylerde bu problemin çözümünde kolaylıkla uygulanan hızlı maksiler genişletme, yetişkinlerde maksillanın çevre yüz kemikleriyle yaptığı artikülasyonların rijiditesindeki artma nedeniyle maksillada yapılan kortikotomiler yardımıyla uygulanmaktadır. Bu yolla yapılan çift taraflı genişletme darlık olmayan tarafta da genişlemeye sebep olmakta, bu da tedavi süresini uzatmaktadır. Bu olgu sunumunda 16 yaşında, tek taraflı posterior çapraz kapanışı olan bayan hastada, tek taraflı kortikotomi ve hızlı üst çene genişletmesini takiben yapılan ortodontik tedavi sunulmuştur. Ekspansiyon sonrası darlık olmayan tarafta aşırı bir genişlemeye sebep olmadan, iyi bir okluzyon ve estetik bir gülümseme elde edilmiştir

A Rare Etiology of Heart Failure: Traumatic Arteriovenous Fistula Due to Stab Injury 17 Years Ago

Background: Although traumatic fistula is frequently encountered, high-output heart failure due to fistula is a very rare condition. Despite an indefinitive history of trauma, arteriovenous (AV) fistula may develop insidiously, and therefore identification of a shunt is highly important for treatment. Case Report: Here we report a 46-year-old male patient with heart failure due to traumatic femoral arterio- venous fistula developed following a penetrating stab injury 17 years ago. Conclusion: Traumatic AV fistula is a curable cause of heart failure. Also, careful examination of the patient is as significant as radiological imaging methods

Surprising Visitor at Emergency Operating Table: Taenia saginata

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The effect of distension pressure on endothelial injury and vasodilatation response in saphenous vein grafts: conversion of a bypass graft to a dead pipe

Introduction: Endothelial damage caused by high pressure applied for spasm relaxation during graft preparation is one of the most plausible theories explaining early graft failure. Aim of the study: We aimed to demonstrate the extent of endothelial damage in saphenous vein grafts distended to different pressure levels by using immunohistochemical methods and in vitro tissue baths. Material and methods: Saphenous vein grafts (SVGs) of 25 patients who underwent isolated elective CABG surgery were used in this study. By using a specific mechanism, SVGs were distended to five different pressure levels for two minutes: 0 mmHg, 50 mmHg, 100 mmHg, 200 mmHg, 300 mmHg. In vitro tissue baths and immunohistochemical examinations were performed. Results: None of the grafts distended to 300 mmHg pressure were functional in the tissue bath system. The relaxation response to carbachol of SVGs distended to 0, 50, 100 and 200 mmHg was 97.87 +/- 4.47%, 98.52 +/- 3.95%, 93.78 +/- 3.64%, and 30.87 +/- 4.11%, respectively. There were no statistically significant differences in terms of relaxation responses between samples distended to 0, 50, and 100 mmHg (p = 0.490). The relaxation response of samples distended to 200 mmHg was significantly decreased (p = 0.021). The endothelia of samples distended to 0 mmHg were almost intact in CD31 staining. Endothelial cell loss occurred at all tested distension pressures at different degrees. Conclusion: In vitro and immunohistochemical studies revealed that distending an SVG used for coronary artery bypass grafting with pressures of 100 mmHg or less results in less endothelial damage and increases graft patency

Delirium in patients with acute ischemic stroke admitted to the non-intensive stroke unit: Incidence and association between clinical features and inflammatory markers

Background Stroke patients with development of delirium have unfavorable outcomes, higher mortality, longer hospitalizations, and a greater degree of dependence after discharge. Studies suggest that delirium is associated with abnormal immunological responses and a resultant increase in inflammatory markers. Objective Our aim was to determine whether there is an entity relationship between delirium, inflammation and acute ischemic stroke (AIS). Methods Sixty AIS patients admitted to the hospital were consecutively recruited. Delirium was diagnosed with the clinical assessment according to the Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) criteria. Enzyme-linked immunosorbent assay (ELISA) was used to measure serum levels of Interleukin-1 beta (IL-1 beta), Interleukin 18 (IL-18), Tumor Necrosis Factor-alpha (TNF-alpha), Brain-Derived Neurotrophic Factor (BDNF), and Neuron Specific Enolase (NSE) at admission. Results Eleven (18.3%) of 60 patients were diagnosed with delirium, and the majority (n=8, 72.7%) was the hypoactive type. Delirious and non-delirious patients had similar demographic and clinical features. Delirious patients had significantly higher lengths of hospital stay, National Institutes of Health Stroke Scale (NIHSS) at admission and discharge compared to non-delirious patients. In addition, there was no significant statistical difference between delirious and non-delirious patients with AIS in respect of levels of TNF-alpha, IL-1 beta, IL-18, BDNF and NSE. This study suggests that delirium is not scarce in patients with AIS admitted to the non-intensive stroke unit, and that delirium developing after AIS seems not to be associated with serum TNF-alpha, IL-1 beta, IL-18, BDNF and NSE but is associated with length of hospital stay and stroke severity

Orta Anadolu’daki Parkinson Hastalarında Homosistein ve MTHFR Polimorfizmleri Arasındaki İlişkinin Araştırılması ve Tedavi Seçenekleri

Aim In this study, we aimed to investigate the effects of MTHFR C677T and A1298C polymorphisms to homocysteine levels in patients with Parkinson's disease who were treated with levodopa and entekapone. Materials and Methods Plasma homocysteine (hcy), folic acid and vitamin B12 levels and MTHFR (C677T, A1298C) polymorphisms and treatment options were compared in 70 Parkinson's Disease (PD) patients who taking levodopa (n=26), dopamine agonist (n=11) and levodopa and entacapone treatment together (n=33) with 100 controls. Results Although no statistically significant difference was detected, hcy level of the patients was found higher compared to control group (patient 18.29 ± 9.22 µmol /l vs control 15.77 ± 7.58 µmol / l) and hcy level was highest in the patients receiving only levodopa (19.56 ± 10.77 µmol / l). The frequency of TT genotype in the patients was higher compared to the control group (11.4%, 6%). Especially, hcy level for levodopa-receiving patients with 677TT genotype became significantly higher level when compared with other genotypes of levodopareceiving patients (respectively 677TT 36.28 ± 16.17, 677CT 13.5 ± 1.71, 677CC 17.2 ± 6.59). No statistically significant difference was detected between patients and controls regarding their folic acid and vitamin B12 levels and A1298C polymorphism. Conclusion Finally, both 677TT genotype and levodopa treatment might be jointly contributed to the increasing of the plasma hcy levels in PD patients and entacapone limitedly decreased hcy levels during levodopa treatment. It can be said that results need to be supported with larger sample sized comprehensive studies.Amaç Çalışmamızda levodopa ve entekapon kullanan Parkinson hastalarında MTHFR genindeki C677T ve A1298C polimorfizmlerinin homosistein düzeyine etkilerini araştırmayı amaçladık. Materyal ve Metot 70 Parkinson (PD) hastasında; plazma homosisteini (hcy), folik asit, B12 vitamini seviyeleri, MTHFR (C677T, A1298C) polimorfizmleri ve tedavi seçenekleri karşılaştırıldı. 100 kişilik bir kontrol grubunun yer aldığı çalışmada, 70 hastanın 26’sı levodopa (n=26), 11’i dopamin agonisti (n=11) kullanırken, 33 hasta da levodopa ve entakapon tedavisini birliktealmaktaydı. Bulgular İstatistiki olarak anlamlı bir fark gözlenmese de, hastalardaki homosistein seviyesinin kontrol grubunda yer alanlara göre daha fazla olduğu tespit edildi (hasta 18.29 ± 9.22 µmol /l vs kontrol 15.77 ± 7.58 µmol/ l). Ayrıca homosistein seviyesinin en yüksek olduğu hasta grubunun sadece levodopa kullanan hastalar olduğu görüldü (19.56 ± 10.77 µmol / l). Hastalardaki TT genotipinin sıklığının da kontrol grubunda yer alanlara göre daha fazla olduğu görüldü (%11.4, %6). Özellikle, levodopa kullanan ve 677TT genotipine sahip olan hastalardaki homosistein seviyesi, levodopa kullanan ve diğer genotiplere sahip olan hastalardaki homosistein seviyesine göre anlamlı bir şekilde yüksek (sırasıyla 677TT 36.28 ± 16.17, 677CT 13.5 ± 1.71, 677CC 17.2 ± 6.59). Hastalar ve kontrol grubu arasında folik asit ve B12 vitamini seviyeleri ile A1298C polimorfizmi açısından anlamlı bir farka rastlanmadı. Sonuç Sonuç olarak; Parkinson hastalarında 677TT genotipinin ve levodopa kullanımının bir arada olmasının plazma homosistein seviyesini artırdığı, ayrıca entakaponun levodopa tedavisi esnasında sınırlı da olsa homosistein seviyesini düşürdüğü gözlemlenmiştir. Ancak sonuçların daha fazla örnek sayısı içeren kapsamlı çalışmalarla desteklenmesinin gerekli olduğu söylenebilir