Pulse reflection

This book explores both the state-of-the-art and the latest achievements in UWB antennas and propagation. It has taken a theoretical and experimental approach to some extent, which is more useful to the reader. The book highlights the unique design issues which put the reader in good pace to be able to understand more advanced research.

0p cucdai_1 19-10-2012 31 5   Download

Industry in Jepara comprises a complex network of relationships and flexible subcontracting. The first aim of this survey was therefore to investigate how these relationships are structured, and how production is organised and linked to the different market segments, including the sources of the wood. In addition, we sought to record and quantify these relationships to understand the contribution of a unit of raw material to the employment, education, and social wealth of people in the system7 .

59p can_thai 10-12-2012 44 5   Download

Cinema is meant and believed to entertain, to take the viewer to a world that is starkly different from the real one, a world which provides escape from the daily grind of life. Cinema is a popular media of mass consumption which plays a key role in moulding opinions, constructing images and reinforcing dominant cultural values. The paper deals with representations of women characters in mainstream Bollywood movies.

9p khanhchilam 01-04-2013 37 5   Download

Another trend supporting the use of social media for knowledge exchange, information and learning purposes, is reflected in the high usage of Internet sites and services to exchange audiovisual content. In 2008, as Figure 4 illustrates, 61% of European Internet users and 81% of those aged 16 to 24 used the Internet for leisure activities related to obtaining and sharing audiovisual content, ranging from 43% (aged 16 to 24: 65%) in Ireland to 43% in Luxembourg (95% in the Netherlands for 16 to 24 year olds). 33% (aged 16 to 24: 46%) used it for listening to Web...

12p docvachiase 03-05-2013 20 3   Download

The laser has a range of pulse widths from 5 to 100 milliseconds, which is longer than the thermal relaxation time of the epidermis and comparable to that of the follicle. This pulse width range can effectively damage the follicle. However, the epidermis also contains some melanin and must be protected. A sapphire window (ChillTip) with high thermal conductivity is put in direct contact with the skin. It cools the epidermis before, during, and after each laser pulse. Because of index matching, it also reduces internal reflection of back-scattered light.

13p giamdocamnhac 06-04-2013 21 4   Download

Operation of the ultrasonic transducers is based on the echo-sounding principle. Short ultrasonic pulses are sent out by the ultrasonic transducer, reflected from objects in the vicinity and received again by the ultrasonic transducer. The ultrasonic transducer sends the period of time required between sending the ultrasonic pulse and receiving the first echo to the PDC unit which, in turn, calculates the distance to the nearest object from this period of time. Ultrasonic waves propagate at different speeds in gases, liquids and solids.

8p nhacnenzingme 23-03-2013 18 3   Download

The ultrasonic transducer behaves as a ‘speaker’ in send mode (from 40 to 50 kHz). The electronics of the ultrasonic transducer produces electrical pulses to set the piezoceramic element in motion (conversion of electrical energy to mechanical energy). The piezoceramic element is located on the inside of the outer diaphragm. The outer diaphragm vibrates in line with the resonance frequency and produces ultrasonic waves. The short pulse sequences hit an obstacle and are bounced back (reflected).

12p nhacnenzingme 23-03-2013 15 3   Download