493 research outputs found

    The mosaic of surface charge in contact electrification

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    When dielectric materials are brought into contact and then separated, they develop static electricity. For centuries, it has been assumed that such contact charging derives from the spatially homogeneous material properties (along the material's surface) and that within a given pair of materials, one charges uniformly positively and the other negatively. We demonstrate that this picture of contact charging is incorrect. Whereas each contact-electrified piece develops a net charge of either positive or negative polarity, each surface supports a random "mosaic" of oppositely charged regions of nanoscopic dimensions. These mosaics of surface charge have the same topological characteristics for different types of electrified dielectrics and accommodate significantly more charge per unit area than previously thought

    Product Placement as a Rising Marketing Communication Activity: An Assessment on Television Serials

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    AbstractProduct placement which has gradually increased in importance especially with globalization and competition, which has intensified in recent years, is a marketing communication activity which has started to be frequently employed in television serials, cinema industry, computer games and books. In this study, the general characteristics of product placement as a marketing communications practice shall be discussed and how such practice is employed in the most watched Turkish television serials shall be scrutinized through examples

    Machine Learning and Kalman Filtering for Nanomechanical Mass Spectrometry

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    Nanomechanical resonant sensors are used in mass spectrometry via detection of resonance frequency jumps. There is a fundamental trade-off between detection speed and accuracy. Temporal and size resolution are limited by the resonator characteristics and noise. A Kalman filtering technique, augmented with maximum-likelihood estimation, was recently proposed as a Pareto optimal solution. We present enhancements and robust realizations for this technique, including a confidence boosted thresholding approach as well as machine learning for event detection. We describe learning techniques that are based on neural networks and boosted decision trees for temporal location and event size estimation. In the pure learning based approach that discards the Kalman filter, the raw data from the sensor are used in training a model for both location and size prediction. In the alternative approach that augments a Kalman filter, the event likelihood history is used in a binary classifier for event occurrence. Locations and sizes are predicted using maximum-likelihood, followed by a Kalman filter that continually improves the size estimate. We present detailed comparisons of the learning based schemes and the confidence boosted thresholding approach, and demonstrate robust performance for a practical realization.Comment: 8 pages, 9 figure

    Primary Small Cell Carcinoma of the Lung Presenting with Breast and Skin Metastases

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    Cutaneous metastases originating from an internal cancer are relatively uncommon in clinical practice, and metastatic lesions to the breast are rarer than those to the skin. Skin metastases of lung cancer, which may be the first sign of the disease, usually indicate progressive disease and a poor prognosis. We describe a 47-year-old male who presented with recurring masses in the lumbar region bilaterally and the right breast. Immunohistochemical findings and radiological imaging suggested lung cancer. This is the first reported case of small cell lung cancer metastasizing to two separate, uncommon sites, the skin and breast

    İs the vertical scarmammaplasty a safe procedure for reduction of heavy sized breasts?

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    Aim: The vertical scar mammaplasty is one of the most frequently performed operations among reduction mammoplasties. The technique has now been adopted by many surgeons for mastopexies and small reductions, but it has not been commonly used for large reductions because of the frequency of healing problems of the vertical scar. The best candidate for surgery is a patient with elastic skin, moderate hypertrophy (up to 800 g removed per breast), and a breast which is a mixture of fat and glandular tissue. Method: In this study, we present our late term results with vertical scar reduction mammaplasty in heavy sized breast with resection of 1000g or more per breast in eleven patients. Eleven patients with heavy sized 22 breasts in which more than 1000g of tissue was resected are evaluated. Results: Median age of the patients was 32 years (20-46 years) and the average amount of resected specimen was 1322g (1000-1780g) per breast. All patients were operated by the same team and senior surgeon. During the follow up period 2 major complications in the early period were observed: partial nipple-areola necrosis and hematoma. Secondary healing of a partial nipple areola necrosis in a heavy smoker patient resulted in periareolar hypertrophic scar. There were no late term complications. Conclusion: We think that the vertical mammaplasty technique can safely be applied to heavy breasts and large reductions over 1000 gr of tissue.Amaç: Dikey izli (vertikal skar) meme küçültme tekniği mevcut ameliyat teknikleri içinde sıklıkla kullanılan yöntemlerden biridir. Bu teknik, özellikle meme düzeltme ve çok büyük olmayan memelerin küçültülmesinde pekçok cerrah tarafından başarı ile uygulanmaktadır.Ancak aşırı büyük memelerde özellikle dikey izin iyileşme problemleri ile ilgili olarak kullanımı tartışmalıdır. Bu tekniğe en iyi aday hasta elastik derisi olan, orta derecede hipertrofik(800gr.danaz) veyağ vebez karışımından oluşan memelerdir. Yöntem: Bu çalışmada, 1000gr.danfazla miktarda doku rezeksiyonu yaptığımız toplam 11 hastadaki aşırı büyük memelerde uyguladığımız dikeyizli tekniğin erken ve geç dönem sonuçları sunulmuştur. Bulgular: Hastaların yaşları 20 ile 46 arasında değişmekte olup ortancası 32idi. Eksize edilen doku miktarı 1000 ile 1780 gr. arasında olup ortalaması 1322 gr. idi. Tüm hastalar aynı cerrahi ekip tarafından ameliyat edildiler. İzlem süresince olgularda erken dönemde iki komplikasyon gözlendi: parsiyel meme başı - areola nekrozu ve hematom. Aşırı sigara içimi öyküsü olan nekrozlu hasta hipertrofik skar ile iyileşti. Uzun dönem sonuçlarında hastalarda herhangi bir komplikasyon gözlenmedi. Sonuç: Sonuç olarak dikey izli meme küçültme yönteminin, 1000 gr. dan fazla rezeksiyon yapılacak aşırı büyük memelerde güvenli bir şekilde uygulanabileceği görüşündeyiz

    Sample-to-sample torque fluctuations in a system of coaxial randomly charged surfaces

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    Polarizable randomly charged dielectric objects have been recently shown to exhibit long-range lateral and normal interaction forces even when they are effectively net neutral. These forces stem from an interplay between the quenched statistics of random charges and the induced dielectric image charges. This type of interaction has recently been evoked to interpret measurements of Casimir forces in vacuo, where a precise analysis of such disorder-induced effects appears to be necessary. Here we consider the torque acting on a randomly charged dielectric surface (or a sphere) mounted on a central axle next to another randomly charged surface and show that although the resultant mean torque is zero, its sample-to-sample fluctuation exhibits a long-range behavior with the separation distance between the juxtaposed surfaces and that, in particular, its root-mean-square value scales with the total area of the surfaces. Therefore, the disorder-induced torque between two randomly charged surfaces is expected to be much more pronounced than the disorder-induced lateral force and may provide an effective way to determine possible disorder effects in experiments, in a manner that is independent of the usual normal force measurement.Comment: 7 pages, 3 fig

    Boosted output performance of triboelectric nanogenerator via electric double layer effect

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    For existing triboelectric nanogenerators ( TENGs), it is important to explore unique methods to further enhance the output power under realistic environments to speed up their commercialization. We report here a practical TENG composed of three layers, in which the key layer, an electric double layer, is inserted between a top layer, made of Al/polydimethylsiloxane, and a bottom layer, made of Al. The efficient charge separation in the middle layer, based on Volta's electrophorus, results from sequential contact configuration of the TENG and direct electrical connection of the middle layer to the earth. A sustainable and enhanced output performance of 1.22mA and 46.8 mW cm(-2) under low frequency of 3 Hz is produced, giving over 16-fold enhancement in output power and corresponding to energy conversion efficiency of 22.4%. Finally, a portable power-supplying system, which provides enough d.c. power for charging a smart watch or phone battery, is also successfully developed.ope
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