1,729 research outputs found
Tunable Graphene Antennas for Selective Enhancement of THz-Emission
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
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
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
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Cavitation Induction by Projectile Impacting on a Water Jet
Following the work of Field et al. [4], who experimentally visualised cavity formation and shock propagation in impacted liquids at high velocities, the present study focuses on the simulation of the high velocity impact of a solid projectile on a water jet. The undeformable solid projectile is modelled through a direct forcing Immersed Boundary Method. The simulation is carried out using an explicit density based compressible solver, developed by Kyriazis et al. [6], which employs a two-phase flow model and includes phase change. This study gives a better insight on the phenomena following the impact of solids on liquids, including shock propagation and vapour formation, and demonstrates the capabilities of the presented Immersed Boundary Method to handle compressible cavitating flows
Inadequacies of micronutrient intake in normal weight and overweight young adults aged 18-25 years: a cross-sectional study
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
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
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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