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31.
When the electromagnetic wave propagates through a slab superconducting material in microwave ranges,tunneling properties of the electromagnetic wave at critical temperature are investigated theoretically.The transmittance and the reflectance of the slab superconducting material vary with the thickness of material as well as the refractive index of substrates.The high transmittance is found for thin superconductor at low wavelength region.However,optical properties are strongly dependent upon temperature and incidence wavelength.The electromagnetic wave is totally transmitted without loss for incidence wavelength(l = 5000 nm) due to the zero refractive index and infinite penetration depth of the superconductor at the critical temperature. 相似文献
32.
Nico Vieweg Mehmet Ali Celik Sabine Zakel Vineet Gupta Gernot Frenking Martin Koch 《Journal of Infrared, Millimeter and Terahertz Waves》2014,35(5):478-485
We present the first systematic study of cyanobiphenyls (CBs) and the phenylcyclohexanes in the range between 50 cm-1 (1.5 THz) and 500 cm-1 (15 THz). The impact of the alkyl chain length and of variations in the core structure on the spectrum is investigated using liquid crystals from the cyanobiphenyl and phenylcyclohexane families. Our measurements are supported by calculations based on density functional theory. This enables us to shine light on the vibrational dynamics of liquid crystal molecules in the terahertz frequency range. 相似文献
33.
Vineet RakeshAshim K. Datta 《Journal of food engineering》2011,107(2):152-163
Increased interest in microwave puffing is due to its ability to obtain low-fat and ready-to-eat healthy products. Determination of optimal conditions for this complex process has been difficult and although several patents exist on the concept, we are yet to see any large scale commercial use. A fundamental physics based modeling approach integrated with relevant experimentation, developed in this work, is an ideal framework to understand and optimize microwave puffing. The results showed that puffing may not be successful unless carried out using an intensive heating source such as microwaves. Addition of infrared and hot air leads to better quality product whereas using forced air convection is not desirable. There is an optimum initial moisture content depending on the puffing conditions. The study provides critical guidelines to food product/process developers for successful development, control and automation of microwave puffing, thereby leading to value-added nutritious products. 相似文献
34.
Chao Peng Tian Zhang Deliris N Ortiz‐Ortiz Apoorva Vishwakarma Hazel A Barton Abraham Joy 《Polymer International》2019,68(7):1255-1262
Each year, thousands of patients die from antimicrobial‐resistant bacterial infections that fail to respond to conventional antibiotic treatment. Antimicrobial polymers are a promising new method of combating antibiotic‐resistant bacterial infections. We have previously reported the synthesis of a series of narrow‐spectrum peptidomimetic antimicrobial polyurethanes that are effective against Gram‐negative bacteria, such as Escherichia coli; however, these polymers are not effective against Gram‐positive bacteria, such as Staphylococcus aureus. With the aim of understanding the correlation between chemical structure and antibacterial activity, we have subsequently developed three structural variants of these antimicrobial polyurethanes using post‐polymerization modification with decanoic acid and oleic acid. Our results show that such modifications converted the narrow‐spectrum antibacterial activity of these polymers into broad‐spectrum activity against Gram‐positive species such as S. aureus, however, also increasing their toxicity to mammalian cells. Mechanistic studies of bacterial membrane disruption illustrate the differences in antibacterial action between the various polymers. The results demonstrate the challenge of balancing antimicrobial activity and mammalian cell compatibility in the design of antimicrobial polymer compositions. © 2019 Society of Chemical Industry 相似文献
35.
Ahmet Sarı Mohammed Ouikhalfan Hassan Chehouani Gökhan Hekimoğlu Alper Bicer Amir Al-Ahmed Fahad A. Al-Sulaiman Vineet Veer Tyagi 《Polymer Engineering and Science》2020,60(5):909-916
In this work, polyethylene glycol (PEG) as a phase change material (PCM) was incorporated with palygorskite (Pal) clay to develop a novel form-stable composite PCM (F-SCPCM). The Pal/PEG(40 wt%) composite was defined as F-SCPCM and characterized using SEM/EDS, FT-IR, XRD, DSC, and TGA techniques. The DSC results revealed that the F-SCPCM has a melting temperature of 32.5°C and latent heat capacity of 64.3 J/g for thermal energy storage (TES) applications. Thermal cycling test showed that the F-SCPCM had good cycling thermal/chemical stability after 500 cycles. The TGA data proved that that both cycled and non-cycled F-SCPCMs had considerable high thermal durability. Consequently, the created F-SCPCM could be considered as an additive material for production of green construction components with TES capability. POLYM. ENG. SCI., 60:909–916, 2020. © 2020 Society of Plastics Engineers 相似文献
36.
Schuessler Benjamin J. Field David P. Overman Nicole R. Joshi Vineet V. 《Metallurgical and Materials Transactions A》2021,52(9):3871-3879
Metallurgical and Materials Transactions A - Uranium alloyed with 10 wt pct Mo (U-10Mo) undergoes discontinuous precipitation (DP) when subjected to sub-eutectoid heat treatment. It is hypothesized... 相似文献
37.
AI & SOCIETY - The advent of the intelligent robot has occupied a significant position in society over the past decades and has given rise to new issues in society. As we know, the primary aim... 相似文献
38.
We present a novel approach to optimally retarget videos for varied displays with differing aspect ratios by preserving salient scene content discovered via eye tracking. Our algorithm performs editing with cut, pan and zoom operations by optimizing the path of a cropping window within the original video while seeking to (i) preserve salient regions, and (ii) adhere to the principles of cinematography. Our approach is (a) content agnostic as the same methodology is employed to re‐edit a wide‐angle video recording or a close‐up movie sequence captured with a static or moving camera, and (b) independent of video length and can in principle re‐edit an entire movie in one shot. Our algorithm consists of two steps. The first step employs gaze transition cues to detect time stamps where new cuts are to be introduced in the original video via dynamic programming. A subsequent step optimizes the cropping window path (to create pan and zoom effects), while accounting for the original and new cuts. The cropping window path is designed to include maximum gaze information, and is composed of piecewise constant, linear and parabolic segments. It is obtained via L(1) regularized convex optimization which ensures a smooth viewing experience. We test our approach on a wide variety of videos and demonstrate significant improvement over the state‐of‐the‐art, both in terms of computational complexity and qualitative aspects. A study performed with 16 users confirms that our approach results in a superior viewing experience as compared to gaze driven re‐editing [ JSSH15 ] and letterboxing methods, especially for wide‐angle static camera recordings. 相似文献
39.
Multimedia Tools and Applications - The transform-based multi-sensor image denoising methods are inefficient in restoring fine details and texture information of noisy images. The fixed and... 相似文献
40.
In the present work, a numerical study has been carried out to predict transient gas flow and pressure behaviour in a gas manifold system. The start‐up and shutdown of the system, varying demands at the consumer ends, malfunctioning of compressors and valves are a few examples of common causes of transience in a gas delivery system. In particular, the sensitivity of oscillations in pressure and mass flux to variation in pipe dimensions, supply pressure and gas flow rate are ascertained under the aforementioned conditions of transience. The present results show that large pipe dimensions, high gas flow rate and high upstream pressure in the branch in which the disturbance is introduced, all cause greater amplitude in mass flux and pressure oscillations in the neighboring branches. The duration of oscillations is also found to be longer. The present study has practical importance in designing as well as in operating, a gas delivery system. 相似文献