504 research outputs found

    Nanoparticle Classification in Wide-field Interferometric Microscopy by Supervised Learning from Model

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    Interference enhanced wide-field nanoparticle imaging is a highly sensitive technique that has found numerous applications in labeled and label-free sub-diffraction-limited pathogen detection. It also provides unique opportunities for nanoparticle classification upon detection. More specif- ically, the nanoparticle defocus images result in a particle-specific response that can be of great utility for nanoparticle classification, particularly based on type and size. In this work, we com- bine a model based supervised learning algorithm with a wide-field common-path interferometric microscopy method to achieve accurate nanoparticle classification. We verify our classification schemes experimentally by using gold and polystyrene nanospheres.Comment: 5 pages, 2 figure

    Strictly singular operators and isomorphisms of Cartesian products of power series spaces

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    V. P. Zahariuta, in 1973, used the theory of Fredholm operators to develop a method to classify Cartesian products of locally convex spaces. In this work we modify his method to study the isomorphic classification of Cartesian products of the kind E0p(a)×E¥ q(b) where 1 £ p,q £ ¥, p ¹ q, a = (an)n=1¥ and b = (bn)n=1¥ are sequences of positive numbers and E0p(a), E¥ q (b) are respectively lp-finite and lq-infinite type power series spaces

    High-resolution Imaging of nanoparticles in wide-field interferometric scattering microscopy

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    Single particle interferometric scattering microscopy has demonstrated great capability in label-free imaging of sub-wavelength dielectric nanoparticles (r<25 nm); however, it suffers from diffraction-limited resolution. Here, we demonstrate ~2-fold improvement in lateral resolution upon asymmetric illumination.Published versio

    Kayseri Erciyes Dağı Eteklerinde Bulunan İki Türbe

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    [No Abstract Available

    Interferometric detection and enumeration of viral particles using Si-based microfluidics

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    Single-particle interferometric reflectance imaging sensor enables optical visualization and characterization of individual nanoparticles without any labels. Using this technique, we have shown end-point and real-time detection of viral particles using laminate-based active and passive cartridge configurations. Here, we present a new concept for low-cost microfluidic integration of the sensor chips into compact cartridges through utilization of readily available silicon fabrication technologies. This new cartridge configuration will allow simultaneous detection of individual virus binding events on a 9-spot microarray, and provide the needed simplicity and robustness for routine real-time operation for discrete detection of viral particles in a multiplex format.This work was supported in part by a research contract with the ASELSAN Research Center, Ankara, Turkey, and in part by the European Union's Horizon 2020 FET Open program under Grant 766466-INDEX. (ASELSAN Research Center, Ankara, Turkey; 766466-INDEX - European Union's Horizon 2020 FET Open program)First author draf

    Factorization of unbounded operators on Köthe spaces

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    The main result is that the existence of an unbounded continuous linear operator T between Kothe spaces lambda(A) and lambda(C) which factors through a third Kothe space A(B) causes the existence of an unbounded continuous quasidiagonal operator from lambda(A) into lambda(C) factoring through lambda(B) as a product of two continuous quasidiagonal operators. This fact is a factorized analogue of the Dragilev theorem [3, 6, 7, 2] about the quasidiagonal characterization of the relation (lambda(A), lambda(B)) is an element of B (which means that all continuous linear operators from lambda(A) to lambda(B) are bounded). The proof is based on the results of [9) where the bounded factorization property BF is characterized in the spirit of Vogt's [10] characterization of B. As an application, it is shown that the existence of an unbounded factorized operator for a triple of Kothe spaces, under some additonal asumptions, causes the existence of a common basic subspace at least for two of the spaces (this is a factorized analogue of the results for pairs [8, 2])

    Güney Sapanca Havzası taşkın yayılım haritalarının modellenmesi : Keçi Deresi örneği

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    06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Akarsularda su seviyesi ve debi zaman içinde değişir. Debinin ve dolayısıyla seviyenin yüksek olduğu dönemlerde akarsu yatağının dışına taşabilir. Hidrolojik ekstrem olaylar olarak bilinen taşkınların sonucunda insanları etkileyen önemli ekonomik, ekolojik ve çevresel zararlar ve hatta can kayıpları meydana gelmektedir. Taşkınların çevreye verdiği zararların öngörülebilmesi ve zararların minimum düzeye indirgenmesi için hidrolojik verilerin toplanması, çeşitli metotlar ile analiz edilmesi ve değerlendirilmesi gerekmektedir. Bu amaçla yapılan tez çalışması ile Sakarya ili güney Sapanca havzasında yer alan Keçi deresi örneği ele alınarak, elde edilen yağış verileri istatistik yöntemler ile 5, 10, 50, 100 ve 500 yıllık taşkın tekerrür debileri hesaplanarak hidrolik analiz yapan paket programlar vasıtasıyla taşkın yayılım haritaları çıkarılmıştır. Elde edilen bu haritalar yardımı ile risk altında bulunan meskûn mahaller ve olası taşkın durumunda yaşanabilecek zararlar tespit edilmiş ve bu zararların önlenebilmesi için önerilerde bulunulmuştur.Flow and stream level change in time at rivers. When flow and water stream at high quantity/level, stream may flow outside of riverbed. Floods known as hydrological extreme incidents may occur grave economic, ecologic and environmental losses and even loss of life. It's a necessity that hydrological datas to be collected, analyzed with various methods estimated in order to reduce damages to minimum and calculation of environmental losses. For this purpose, flood inundation maps have been calculated with computer modelling of precipitation-flow simulation by using statistical methods for 5, 10, 50, 100 and 500 years of flood repetition flows at Keçi stream sample, south Sapanca basin. In this study, damages and built-in spaces affected by flood detected and some solutions presented in order to reduction/prevention

    Measurement Invariance of the Digital Natives Assessment Scale Across Gender in a Sample of Turkish University Students

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    With reference to the digital natives’ debate, there is a gap on digital natives’ characteristics. To fill this gap, the Digital Natives Assessment Scale was developed to measure students’ assessment of the degree to which they perceived themselves to possess the attributes of digital natives. The scale was developed within the Turkish language and requires further validation in cross-cultural adaptation processes. Moreover, to ensure scale validity, empirical investigation to test for invariance across different subgroups is required to engender confidence in the generalizability of the measure. This study aimed to provide initial validation of the Turkish Digital Natives Assessment Scale as a current measure for preservice teachers and to examine scale invariance across gender given that gender has been identified as an important contextual factor when studying digital natives’ characteristics and use of digital technology. Confirmatory factor analyses and measurement invariance analyses across gender for cross-validation were performed. The confirmatory factor analysis results showed that a four-factor structure was confirmed for female and male preservice teachers together and female and male preservice teachers separately. In relation to measurement invariance, the results of the current study indicated support for configural invariance, metric invariance, and scalar invariance by gender

    Bond-selective interferometric scattering microscopy

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    Interferometric scattering microscopy has been a very promising technology for highly sensitive label-free imaging of a broad spectrum of biological nanoparticles from proteins to viruses in a high-throughput manner. Although it can reveal the specimen's size and shape information, the chemical composition is inaccessible in interferometric measurements. Infrared spectroscopic imaging provides chemical specificity based on inherent chemical bond vibrations of specimens but lacks the ability to image and resolve individual nanoparticles due to long infrared wavelengths. Here, we describe a bond-selective interferometric scattering microscope where the mid-infrared induced photothermal signal is detected by a visible beam in a wide-field common-path interferometry configuration. A thin film layered substrate is utilized to reduce the reflected light and provide a reference field for the interferometric detection of the weakly scattered field. A pulsed mid-IR laser is employed to modulate the interferometric signal. Subsequent demodulation via a virtual lock-in camera offers simultaneous chemical information about tens of micro- or nano-particles. The chemical contrast arises from a minute change in the particle's scattered field in consequence of the vibrational absorption at the target molecule. We characterize the system with sub-wavelength polymer beads and highlight biological applications by chemically imaging several microorganisms including Staphylococcus aureus, Escherichia coli, and Candida albicans. A theoretical framework is established to extend bond-selective interferometric scattering microscopy to a broad range of biological micro- and nano-particles.First author draf

    Computational nanosensing from defocus in single particle interferometric reflectance microscopy

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    Single particle interferometric reflectance (SPIR) microscopy has been studied as a powerful imaging platform for label-free and highly sensitive biological nanoparticle detection and characterization. SPIR's interferometric nature yields a unique 3D defocus intensity profile of the nanoparticles over a large field of view. Here, we utilize this defocus information to recover high signal-to-noise ratio nanoparticle images with a computationally and memory efficient reconstruction framework. Our direct inversion approach recovers this image from a 3D defocus intensity stack using the vectorial-optics-based forward model developed for sub-diffraction-limited dielectric nanoparticles captured on a layered substrate. We demonstrate proof-of-concept experiments on silica beads with a 50 nm nominal diameter.Accepted manuscript2021-12-0
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