1,729 research outputs found

    Tunable Graphene Antennas for Selective Enhancement of THz-Emission

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    In this paper, we will introduce THz graphene antennas that strongly enhance the emission rate of quantum systems at specific frequencies. The tunability of these antennas can be used to selectively enhance individual spectral features. We will show as an example that any weak transition in the spectrum of coronene can become the dominant contribution. This selective and tunable enhancement establishes a new class of graphene-based THz devices, which will find applications in sensors, novel light sources, spectroscopy, and quantum communication devices

    Color: The Mantra for Marketing

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    In the present scenario, color is emphasized as the most required component of the market and marketers. The customers are attracted using different colors for the products by the manufacturers. The competition prevailing in the market has made the organizations use several strategies using color. Now days the customers go to the various retail stores and buy the products by seeing the packaging as it creates an effective image of the product in their minds. The marketers have to understand the knowledge of the consumers to select the right color for product. The impact of the visual aspects helps the organizations to pass the information to the consumers. The color can affect the consumer's perception and their buying decision. The brands are also recognized because of the fixed colors of their products which provide them brand equity. Every color has been accepted in different way by the various cultures and the emotions attached to it is also different. Color is opted differently by the two genders. In this research paper how the color is used by different cultures, the sentiments associated are studied. A glance of the impact of the color on the consumer behavior is also studied. Without appropriate selection of color the marketers will not be able to attract the customers

    Scattering cancellation of the magnetic dipole field from macroscopic spheres

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    Based on the scattering cancellation technique we suggest a cloak that allows to conceal macroscopic objects, i.e. objects with an optical size comparable to wavelengths in the visible and whose scattering response is dominated by a magnetic dipole contribution. The key idea in our approach is to use a shell of polaritonic spheres around the object to be cloaked. These spheres exhibit an artificial magnetism. In a systematic investigation, where we progressively increase the complexity of the considered structure, we devise the requirements imposed on the shell and outline how it can be implemented with natural available materials

    Inadequacies of micronutrient intake in normal weight and overweight young adults aged 18-25 years: a cross-sectional study

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    Objectives: This study aims to assess adequacy in micronutrient intake in comparison with reference nutrient intakes (RNI) and to identify differences in intakes between normal weight and overweight individuals. Study design: A sample of 542 university students (18e25 years), normal weight (N ยผ 369) and overweight (N ยผ 173), was included in a cross-sectional study. Methods: A three-day diet diary was used to assess energy and nutrient intake. BMI and waist circumference were measured. Results: Mean dietary vitamin D intake was lower than RNI in both men (4.44 mg) and women (5.04 mg). Mean intakes of calcium (597.44 mg), iron (8.62 mg) and folate (171.29 mg) were also lower than recommendations in women. Weight status (normal weight versus overweight) was significantly associated with micronutrient intake, and a trend towards a decrease in vitamin and mineral intake with increasing weight was noted. Conclusions: Results suggest the need to increase the intake of some micronutrients to meet the RNI, to ensure optimal health. This study provides a helpful tool to reinforce recommendations and potential health promotion and intervention strategies in university settings and could influence manufacturers involved in new food product development targeted to this young population

    Investigation of techniques for combating malicious objects in unreliable wireless sensor networks

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    Unreliable net\vorks can take many different forms such as in the general case an ad hoc network or more specifical1y as a wireless sensor networks (WSNs). Some of the fields you can [md these types of networks used in would be the telecommunications industry with mobile phones, biological research for monitoring animals in the wild and military applications to monitor soldiers. Networks in these areas are handling an increasing amount of data. This data is very valuable and therefore a source of concern in making sure that none of it is lost or damaged. From a security standpoint there are many ways that an attack on these types of networks can be implemented. Some attacks are rather difficult to execute and would require knowledge of the particular network that is being attacked to be effective. One of the most effective attack methods would be for the attacker to inject its own data into the network either with the simplest goal of consuming network resources or having some other purpose such as capturing or corrupting the data stored in the network. Thinking in terms of biological systems the data that these attackers inject into the network is similar to a virus entering a human body. In the medical field medicine can be used to help cure a person by targeting this virus, in much the same way this chapter considers introducing a special type of anti-virus to the network to remove this data inserted by an attacker. This chapter considers leveraging the properties of unreliable network combined with a recommended approach employing an anti-virus to remove the virus from the network effectivel

    Prospects and problems of cognitive radio network architectures in wireless sensor networks

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    Cognitive radio is a technique proposed by Mitola which provides a way to efficiently use precious radio spectrum resources [1, 2]. A cognitive radio recognizes, analyzes, and learns the situations of the radio spectrum and then employs various strategies to maximize spectrum usage. The concept of cognitive radio is to detect and ascertain \vhich aspect of the spectrum is presently unused, and then perform data transmission at the newly discovered frequency band. An alternative cognitive radio scheme is to transmit signals on top of existing transmissions as long as the interference temperature measure is lower than threshold. Spectrum sharing, spectrum sensing, and spectrum management are the stages of a cognitive radio. Spectrum sensing gathers up-to-date spectrum usage data, spectrum management determines the optimal spectrum access timing and scheme, and spectrum sharing ensures that users are served in a fair and timely mann
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