Natural β-chitin-protein complex film obtained from waste razor shells for transdermal capsaicin carrier

In the literature, the produced β-chitin samples are in powder or flake forms but there is no natural β-chitin based film. Also, the commercially available transdermal patches are produced from synthetic polymers. In this regard,we produced natural β-chitin-protein complex (CPC) film fromthewaste shells of Ensis spp. The obtained natural filmwas characterized by FTIR, TGA and SEM. Additionally, swelling, thickness, contact angle and antioxidant tests were done to learn more about the films. After production and characterization of the film, capsaicin, which is commonly used for pain reliefwas loaded into the film. The loading capacitywas recorded as 5.79%. The kineticmodelswere studied in three different pH, then the resultswere fittedwith Higuchimodelwith high correlation at pH 7.4. After considering all the obtained results, the capsaicin loaded CPC film may be an alternative candidate for transdermal patch instead of the synthetic ones.info:eu-repo/semantics/publishedVersio

Calibration of the CMS hadron calorimeters using proton-proton collision data at root s=13 TeV

Methods are presented for calibrating the hadron calorimeter system of theCMSetector at the LHC. The hadron calorimeters of the CMS experiment are sampling calorimeters of brass and scintillator, and are in the form of one central detector and two endcaps. These calorimeters cover pseudorapidities vertical bar eta vertical bar ee data. The energy scale of the outer calorimeters has been determined with test beam data and is confirmed through data with high transverse momentum jets. In this paper, we present the details of the calibration methods and accuracy.Peer reviewe

Az miktarda azot eklenmiş uzun dalga boylu yarı iletken kuantum kuyu lazerlerin teorik karşılaştırılması

Tez (Yüksek Lisans) -- Kırıkkale Üniversitesi88102

Mikroakışkan sistemlerde empedans bazlı kan hücresi tespiti

Tez (Doktora) -- Kırıkkale Üniversitesi116724

Impedance-based blood cell detection in microfluidic systems

YÖK Tez ID: 476577Bu tez çalışmasında hücrelerin sayımı, tanımlanması ve sınıflandırılması için yaygın bir teknik olan empedans akış sitometrisi tekniği kullanılarak mikroakışkan bir sistem geliştirilmiştir. Bu çalışmada kapasitif-impedimetrik biyosensörler araştırılarak, mikroakışkan sistemin duyarlılık sınırlarının geliştirilmesi ve bunun bir sonucu olarak kan hücresi tespiti yapılabilmesi hedeflenmiştir. Hücreler elde edilmesi ve manipüle edilmesi zor parçacıklar olduğundan mikroakışkan sistemi geliştirmek için hücre ile eşdeğer elektriksel özelliğe sahip olan 6 µm çapındaki polistiren mikro küreler kullanılmıştır. Mikroakışkan sistem içerisinden mikro küre taşıyan 2.5 S/m iletkenliğine sahip bir sıvı geçirilerek, sıvı içerisindeki mikro küreler elektriksel empedans ölçümü yoluyla tespit edilmiştir. Mikroakışkan sistemin hassasiyetini artırmak için sonlu elemanlar metodu ile simülasyonlar yapılarak parçacıkların kanal içerisindeki konum ve boyutlarına bağlı olarak verdiği sinyaller hesaplanmıştır. Empedans değişiminin elektro aktif bölgede yer değiştiren parçacığın hacmi ile orantılı olduğunu göstermek için ise farklı boyutlardaki elektrot ve kanalların performansı teorik ve deneysel olarak incelenmiştir. En uygun kanal ve elektrot geometrisini bulabilmek için öncelikle elektrot boyutu sabit tutularak farklı kanal boyutlarına sahip mikroçiplerde, daha sonra kanal boyutu sabit tutularak farklı elektrot boyutlarına sahip mikroçiplerde deneyler yapılmıştır. Kanal ve elektrot genişliği azaldıkça mikro kürenin empedans değişiminin arttığı ve elde edilen sonuçlarında Maxwell mixture teorisi ile uyumlu olduğu gösterilmiştir. Bu ön çalışmalardan yola çıkarak 4, 6 ve 8 µm çaplarındaki polistiren mikro küreleri yüksek hassasiyet ile ayırt edebilen bir elektrot ve kanal yapısı geliştirilmiştir. Hücre sınıflandırma cihazları saniyede binlerce hücre analizi yapabilir fakat genellikle küçük bir örnek hacminin kullanımı için uygun olmayan komplike makinalardır. Bu çalışmada empedansa dayalı mikroakışkan sistem içerisinde alınan bir damla kan örneği kullanılarak kırmızı kan hücreleri sayılmış ve kan örneğindeki farklı mikro parçacıklar tespit edilmiştir. Bu sayede kan sayım cihazı teknolojisine dair bir altyapı geliştirilmiştir. Bu altyapı ile kan hastalıklarının tespitine yönelik, çok az miktarda kan ile dahi cevap verebilen, portatif sistemlerin geliştirilebilmesinin zemini oluşturulmuştur.In this dissertation, a microfluidic system was developed by using the impedance flow cytometry technique that is in common use for cell counting, identification, and classification. Through investigation of capacitive-impedimetric biosensors, this work aimed to improve the sensitivity levels of the microfluidic system and to identify blood cells as a result of it. Since it is difficult to obtain and manipulate cells, 6 µm polystyrene micro beads having equivalent electrical properties with cells were employed to develop the microfluidic system. By passing a fluid, which has 2.5 S/m conductivity and carriers the micro beads within the microfluidic system, the micro beads were identified impedimetrically. To improve the sensitivity of the microfluidic system, simulations were performed with the Finite Element Method (FEM) to calculate the signals that the particles give depending on their locations and sizes within the channels. In order to show that the impedance change is proportional on the volume of the particle changing its location within the electro-active region, the performances of electrodes and channels with different dimensions were investigated both theoretically and experimentally. To find the optimum channel and electrode geometries, firstly, experiments were performed with microchips with fixed electrode dimensions and varying channel dimensions. This was followed by employing microchips with fixed channel dimensions and varying electrode dimensions. It was shown that the impedance change of the bead increases as the channel and electrode widths decrease and the results match well with the Maxwell mixture theory. With these primary works, an electrode-channel structure was developed which can sort 4, 6, 8 µm diameter polystyrene beads with high sensitivity. Cell classification devices can perform thousands of cell analyses within seconds, but they are not suitable for the use of small volume samples. In this work, impedance based microfluidic system was used to count red blood cells and sense different micro particles from a drop of blood sample. Thanks to that, an infrastructure was developed for the blood counter technology. With this infrastructure, a ground was formed to develop portable systems, even sensitive to very small volume blood samples, for the diagnosis of hematologic diseases

Comparison of quantum well lasers with long wavelenght dilute nitrogen semiconductor

YÖK Tez ID: 344019Günümüzde nano teknolojik uygulamalarda birçok araştırmacının dikkatlerini üzerine çeken, deneysel ve teorik çalışmalarla hızla trendi yükselen, az miktarda azot eklenen kuantum kuyu lazer sistemleri araştırıldı. Bu çalışmada, uzun dalga boylarında ve özellikle fiber optik kabloların dağılım ve kayıplarının en az olduğu bölgelerden biri olan 1.3 µm dalga boylu ışıma yapan az miktarda azot (N) eklenmiş GaInAs alaşımının materyal parametreleri hesaplandı. Uzun dalga boylu InGaNAs/GaAs kuantum kuyu lazer sistemlerinin dalga boyuna bağlı olarak kendiliğinden ışıma ve kazanç hesaplamaları yapıldı. Dörtlü yarıiletken alaşım (InGaNAs) için Indiyum (In) ve Azot (N) konsantrasyonlarının, sıcaklığın, taşıyıcı konsantrasyonların etkisi gibi parametrelerin kazanç üzerindeki etkileri incelendi. Bu sistemler için yapılan hesaplamalar ve sıcaklığa bağlı tepe (pik) kazanç hesaplamaları kullanılarak yüksek hız uygulamaları için gerekli N ve In oranları belirlendi. Seçilen kuantum kuyu lazer yapılar için Güç-Akım-Voltaj (L-I-V) grafikleri çizildi.The quantum well laser systems that were added dilute nitrogen which attracted many researchers studying on nanotechnological applications and whose popularity is increasing due to both theoretical and experimental researches have been investigated. In this study, material parameters of GalnAs alloy which was added a little amount of nitrogen that radiates 1.3 µm was calculated in the long wave length and particularly at a point where the network and the loss of fiber optic cables is the least. The calculations of spontaneous emission and gain of GalnNAs/GaAs quantum well laser systems with long wave were done depending on wave length. For the semiconduction alloy with four parts (GalnNAs), the Nitrogen (N) concentration and Indiyum (In), the effect of heat, and the effects of the parameters of the carrier concentrations on the gain were examined. N and In rates for these systems that are necessary for high speed applications were determined with the help of the calculations of peak gains. Also, the power, current, and voltage (L-I-V) calculations of the selected laser units were done

Cascaded contraction-expansion channels for bacteria separation from RBCs using viscoelastic microfluidics

Implementation of viscoelasticity-based particle migration techniques has attracted significant interest thanks to its simplicity to achieve particle separation and enrichment at high sensitivity and accuracy for the last decade. Many methods have previously been developed for particle focusing and separation, but they all require long fluidic channels to enable the desired elastic force on particles. Here, a cascade contraction-expansion microfluidic system with a much shorter channel length is presented. Experimental results show that this system achieved continuous, sheathless particle separation in a viscoelastic fluid, and Enterococcus faecalis was successfully separated from red blood cells (RBCs). Thanks to its small size, the system provides extra advantage for its integration into small chips. (c) 2021 Elsevier B.V. All rights reserved

Preparation and Properties of Novel Mucilage Composite Films Reinforced with Polydimethylsiloxane

Abstract Recently, there is an increasing interest in research on biodegradable, non‐toxic, and high‐strength biomaterials that can replace plastics, especially in the food industry. In this study, mucilage obtained from Linum usitatissimum seeds is used to develop a natural biodegradable biomaterial by reinforcing it with different concentrations of polydimethylsiloxane (PDMS). The biomaterials produced in the form of films are thoroughly investigated in terms of physicochemical (Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy (SEM), energy dispersive X‐ray spectrum (EDX), atomic force microscopy (AFM), contact angle, and mechanical), biodegradable (in soil and water), and antibacterial properties. SEM‐EDX and AFM demonstrate the homogeneous distribution of PDMS throughout the mucilage matrix. The incorporation of PDMS improves the water solubility of the mucilage composite films, thereby enhancing their strength. It also imparts hydrophobic characteristics to the composite films. Thus, PDMS ensures the high barrier property of the composite films against water vapor. Furthermore, the addition of PDMS increases the antimicrobial properties of the mucilage composite films. The obtained results indicate that the first‐time produced mucilage‐PDMS composite films can serve as an alternative product for food packaging applications

Mikroakışkan çip ile kapasitif çözücü tespiti

Solvents are widely used in daily life as well as in almost all laboratories. Identification and detection of these solvents used in many areas have great importance in terms of health, toxicology and environment. For this reason, the main purpose of our study is to be able to identify the solvents in practical ways. In this study, gold microelectrodes were used to define the capacitance detection of various solvents in the frequency range of 20 kHz - 2 MHz. Moreover, the electrical noise and signal output of the solvents at different frequencies were investigated. Measurements were made by micro-channels integrated on microelectrodes for reducing noises and detection with high sensibility.Çözücüler, hem günlük hayatta hem de hemen hemen tüm laboratuvarlarda yaygın olarak kullanılmaktadır. Birçok alanda kullanılan bu çözücülerin tespiti ve tanımlanması, sağlık, toksikoloji ve çevre açısından büyük önem taşımaktadır. Bu nedenle, çalışmamızın temel amacı, çözücülerin pratik yollarla tespit edilebilmesidir. Bu çalışmada, altın mikro elektrotlar kullanılarak 20 kHz – 2 MHz frekans aralığındaki çeşitli çözeltilerin kapasitans ölçümü ile tanımlamaları yapılmıştır. Ayrıca, farklı frekanslardaki çözücülerin elektriksel gürültü ve sinyal çıktıları incelenmiştir. Ölçümler, gürültüyü azaltmak ve yüksek hassasiyette algılama yapabilmek için mikro elektrotlar üzerine entegre edilen mikro kanallarla yapılmıştır

Capacitive detection of single bacterium from drinking water with a detailed investigation of electrical flow cytometry

WOS: 000423887500050Pathogenic contamination of drinking water is critical in regard to human health. In this study, we investigated the electrical detection of single bacterium from drinking water. A microfluidics chip consisting of polydimethylsiloxane (PDMS) microchannel and gold microelectrodes was fabricated with conventional microfabrication techniques. Electrical characterizations were done with an LCR meter and the measurements were in good agreement with simulation results. The impact of channel and electrode dimensions was studied for the different type and size of particles, using both experimental and simulation techniques. In addition, the effect of excitation signal frequency and solution conductivity was analyzed employing both simulation and experimental methods. Finally, capacitive detection of a single Escherichia coli (E. coli) from drinking water was successfully carried out under optimum parameters and design geometries.Scientific and Technological Research Council of Turkey (TUBITAK) [112M944]This project was supported by The Scientific and Technological Research Council of Turkey (TUBITAK project no. 112M944). Authors also thank to Amir Ghobadi for his critical reading the manuscript