2,302 research outputs found
Bioactive, Physicochemical and Antimicrobial Properties of Koruk (Unripe Grape, Vitis vinefera L.) Products
Get PDFIn the study, the bioactive, physicochemical and antimicrobial properties of koruk juice and dried koruk pomace were investigated. The total phenolic contents of koruk juice and pomace were determined as 1119.670 and 1182.170 mg GAE/L, respectively. Higher DPPH radical scavenging activity found in koruk pomace, which was consistent with total phenolic contents. Organic acid, total sugar and ascorbic acid contents of koruk juice (3.44%, 4.737 g/L and 2.559 mg/100 mL) were higher than koruk pomace (0.19%, 0.866 g/L and 0.242 mg/100 mL). The counts of Total Psychrophilic Aerobic Bacteria and mold-yeast in pomace were determined as 0.694 and 1.016 log CFU/g, respectively, while no growth was observed in koruk juice. Koruk juice and pomace indicated antimicrobial effect on all test microorganisms in the range of 31.3-500.0 µg/mL (Minimum Inhibition Concentration). The most sensitive bacteria to koruk juice were Bacillus cereus, while Pediococcus acidilactici was the most sensitive one to koruk pomace. Koruk juice also showed bactericidal effect on all test cultures at concentration ranging between 250.0 and 500.0 µg/mL (Minimum Bactericidal Concentration), koruk pomace was not showed bactericidal effect on Escherichia coli O157:H7, Salmonella Typhimurium, E. coli and B. cereus. This study demonstrated that the koruk products could be used in food applications as natural antioxidant and antimicrobial substance
Displacement of a bubble by acoustic radiation force into a fluid-tissue interface.
Get PDFMicrobubbles in an ultrasound beam experience a primary Bjerknes force, which pushes the microbubbles against a fluid-tissue interface and deforms the tissue. This interaction has been used to measure tissue elasticity and is a common interaction in many therapeutic and diagnostic applications, but the mechanisms of deformation, and how the deformation dynamic depends on the bubble and ultrasound parameters, remain unknown. In this study, a mathematical model is proposed for the displacement of a bubble onto a fluid-tissue interface and the tissue deformation in response to the primary Bjerknes force. First, a model was derived for static loading and the model's prediction of bubble-mediated tissue displacement and stresses in tissue were explored. Second, the model was updated for dynamic loading. The results showed that the bubble is both displaced by the applied force and changes its shape. The bubble displacement changes nonlinearly with the applied force. The stress values in tissue are quite high for a distance within one radius of the bubble from the bubble surface. The model proposed here is permissible in human tissue and can be used for biomedical ultrasound applications, including material characterization
Hasan Fehmi Tümerkan's life and works
No full textİttihat ve Terakki Cemiyeti, Osmanlı Devleti'nin son zamanlarında ve Cumhuriyet Dönemi'nin ilk zamanlarında siyasi olarak oldukça etkili olmuştur. Bu cemiyetin sarıklı mebuslarından Hasan Fehmi Tümerkan Meclis-i Mebusan'da ve akabinde TBMM'de yapmış olduğu konuşmalarla, önerilerle ve kanun teklifleriyle ön plana çıkan mebuslardan biri idi. Kendisi, dönemin yenilikçi anlayışını benimseyerek reform taraflısı oldu. Hasan Fehmi Bey eğitimini bitirince İlahiyat Fakültesi'nde müderrislik yapmış ve Sinop Müftülüğü görevini icra etmiştir. İstanbul'un işgalinin ardından ise Malta'ya sürgün edilen isimler arasındadır. Esaret hayatı boyunca kendisini Kur'an'ı Türkçe'ye çevirme işine adamıştır. Böylelikle sadece bir siyasetçi değil; aynı zamanda dini ilimlere katkı sunan bir yazar da olmuştur. Şunu da belirtmek gerekir ki Sinop mebusu ve ardından Kastamonu milletvekili olarak görev yaptığı zamanlarda, kaleme aldığı eserleri ile ilmi ve fikri yönünü ortaya koymuştur.The Committee of Union and Progress (İttihat ve Terakki Cemiyeti) played a pivotal role in the political landscape during the final years of the Ottoman Empire and the early period of the Turkish Republic. Among its notable members was Hasan Fehmi Tümerkan, a turbaned deputy who distinguished himself through his speeches, legislative proposals, and policy suggestions in both the Ottoman Chamber of Deputies (Meclis-i Mebusan) and later in the Grand National Assembly of Turkey (TBMM). Tümerkan embraced the progressive ideology of the era and was a staunch advocate of reform. Following his education, Hasan Fehmi served as a professor at the Faculty of Theology and later held the position of Mufti of Sinop. After the occupation of Istanbul, he was among those exiled to Malta. During his time in captivity, he dedicated himself to translating the Qur'an into Turkish. In doing so, he emerged not only as a politician but also as an author contributing to Islamic scholarship. It is also worth noting that during his tenure as a deputy representing Sinop and later Kastamonu, he demonstrated his intellectual and scholarly inclinations through the works he authored
Türkçe Rap müziğin tarihi
No full textAnkara : İhsan Doğramacı Bilkent Üniversitesi İktisadi, İdari ve Sosyal Bilimler Fakültesi, Tarih Bölümü, 2013.This work is a student project of the The Department of History, Faculty of Economics, Administrative and Social Sciences, İhsan Doğramacı Bilkent University.by Hasan Çolak.Çolak, Hasan. HIST 200-15ÇOLAK HIST 200-15/10 2012-1
The effects of ultrasound parameters and microbubble concentration on acoustic particle palpation
Get PDFThe elasticity of tissue-an indicator of disease progression-can be imaged by ultrasound elasticity imaging technologies. An acoustic particle palpation (APP) has recently been developed-the use of ultrasonically driven acoustic particles (e.g., microbubbles)-as an alternative method of tissue deformation. APP has the potential to improve the resolution, contrast, and depth of ultrasound elasticity imaging; but the tissue displacement dynamics and its dependence on acoustic pressure, center frequency, and microbubble concentration remains unknown. Here, displacements of at least 1 μm were produced by applying ultrasound onto a microbubble solution (concentration: 10 × 106 microbubbles ml-1) placed within a tunnel surrounded by a 5% gelatin phantom. Displacements of more than 10 μm were produced using a 1, 3.5, or 5 MHz center frequency pulse with peak-rarefactional pressures of 470, 785, and 1210 kPa, respectively. The deformation of the distal wall varied spatially and temporally according to the different parameters investigated. At low pressures, the deformation increased over several milliseconds until it was held at a nearly constant value. At high pressures, a large deformation occurred within a millisecond followed by a sharp decrease and long stabilization. Ultrasound exposure in the presence of microbubbles produced tissue deformation (p < 0.05) while without microbubbles, no deformation was observed
Displacement of a bubble located at a fluid-viscoelastic medium interface
Get PDFA model for estimating the displacement of a bubble located at a fluid-viscoelastic medium interface in response to acoustic radiation force is presented by extending the model for a spherical object embedded in a bulk material. The effects of the stiffness and viscosity of the viscoelastic medium and the amplitude and duration of the excitation force on bubble displacement were investigated using the proposed model. The results show that bubble displacement has a nonlinear relationship with excitation duration and viscosity. The time at which the steady state is reached increases with increasing medium viscosity and decreasing medium stiffness
Detection of air leakage into vacuum packages using acoustic measurements and estimation of defect size
No full textAir leakages in food and ingredient packages which are sealed in vacuum environments may cause a marked deterioration of the product, leading to a loss of functionality. Manufacturers of such products have very stringent but rather costly quality control procedures and there is a pressing need for developing more economical ways of automated quality control techniques to test the vacuum packages reliably. However, due to the fact that the defect size of a typical package with a leakage problem could be micro- or nano-scale, such faults are not detectable using conventional techniques. In this paper, the performance of a proposed acoustic method is assessed for the detection of air leakage in instant dry yeast packages sealed in a vacuum environment, which are typical of food and ingredients packaged under vacuum conditions. The investigation is carried out in both laboratory and in-situ environments. The acoustic pressure created by leaking air into the faulty packages is measured using a low-noise microphone in an acoustic chamber. Faulty packages are then identified using the changes in measured sound pressure levels within a certain frequency band. A mathematical model is also proposed to predict the pressure inside a yeast package with certain defect size as a function of time. The mathematical model is then used to determine the size of a defect causing the leakage, using the time required for the pressure inside a faulty yeast package to reach to a threshold level. The results of this investigation show that, using the state of the art measurement techniques, it is possible to detect packages with leakage problem if the diameter of the defect is greater than a few tens of micrometres.WOS:0004471127000302-s2.0-85047247899Science Citation Index ExpandedArticleUluslararası işbirliği ile yapılmayan - HAYIROcakYÖK - 2018-1
Identification of the Dynamic Characteristics of Luffa Fiber Reinforced Bio-Composite Plates
No full textLuffa cylindrica plant fiber is a new biodegradable engineering material. However, the dynamic behaviors of these new green materials or their composites should be explored to consider them for practical applications. The dynamic characteristics including modal behavior and the elastic and sound isolation properties of luffa-based bio-composite plates were explored in this study. Structural frequency response function measurements were conducted using a few luffa bio-composite plates to identify their modal behavior. The modal frequencies and loss factors of the luffa bio-composite plates were identified by analyzing the frequency response function measurements using a few modal analysis methods such as half-power, circle-fit, and line-fit. The same luffa bio-composite structures were modelled using a finite element formulation with damping capability, and the elastic moduli of the composite plates were identified. In addition, the transmission loss levels of the same luffa composite samples were measured using the impedance tube method. The results showed that luffa composite structures have considerably high stiffness (elasticity modulus: 2.5 GPa), damping levels (loss factor: 2.6%), and transmission loss level (25 to 30 dB for a 1 cm thickness), and their mechanical properties are promising as an alternative disposable material for noise and vibration control engineering applications.WOS:0004084977000562-s2.0-85026738586Science Citation Index ExpandedArticleUluslararası işbirliği ile yapılmayan - HAYIRHaziranYÖK - 2016-1
Investigation of the acoustic properties of bio luffa fiber and composite materials
No full textConsidering the adverse effects of petroleum-based materials on nature, finding and developing new materials as alternatives to these chemical materials become a necessity in practice. On the other hand, these new materials need characterization to be considered and effectively used in practical applications. The acoustic properties of luffa bio fiber and composite materials are investigated in this study. First, the preparation of various luffa test samples and the method for acoustic characterization of the luffa samples is presented. Then, the acoustic absorption properties of both luffa fiber and composite materials are identified using the impedance tube method. After that, the transmission loss levels of the same luffa samples are determined. All the results are evaluated and the acoustic performances of luffa materials are highlighted. (C) 2015 Elsevier B.V. All rights reserved
Identification of the Dynamic Characteristics of Luffa Fiber Reinforced Bio-Composite Plates
No full textLuffa cylindrica plant fiber is a new biodegradable engineering material. However, the dynamic behaviors of these new green materials or their composites should be explored to consider them for practical applications. The dynamic characteristics including modal behavior and the elastic and sound isolation properties of luffa-based bio-composite plates were explored in this study. Structural frequency response function measurements were conducted using a few luffa bio-composite plates to identify their modal behavior. The modal frequencies and loss factors of the luffa bio-composite plates were identified by analyzing the frequency response function measurements using a few modal analysis methods such as half-power, circle-fit, and line-fit. The same luffa bio-composite structures were modelled using a finite element formulation with damping capability, and the elastic moduli of the composite plates were identified. In addition, the transmission loss levels of the same luffa composite samples were measured using the impedance tube method. The results showed that luffa composite structures have considerably high stiffness (elasticity modulus: 2.5 GPa), damping levels (loss factor: 2.6%), and transmission loss level (25 to 30 dB for a 1 cm thickness), and their mechanical properties are promising as an alternative disposable material for noise and vibration control engineering applications
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