Photorefractive Polymers With High Speed

1999 ◽  
Vol 561 ◽  
Author(s):  
N. Peyghambarian ◽  
K. B. Ferrio ◽  
J. A. Herlocker ◽  
E. Hendrick ◽  
B. D. Guenther ◽  
...  
Keyword(s):  
Time Constant ◽  
High Speed ◽  
Response Rates ◽  
Rapid Progress ◽  
New Materials ◽  
Photorefractive Polymers ◽  
Recent Developments ◽  
Photorefractive Polymer ◽  
Grating Formation

ABSTRACTRapid progress in photorefractive polymers includes new materials with improved response rates. We briefly review recent developments in this rapidly evolving area and report grating formation with a 2-millisecond time-constant, the fastest reported to date in any photorefractive polymer.

Application of Advanced Electrochemical Methods with Nanomaterial-based Electrodes as Powerful Tools for Trace Analysis of Drugs and Toxic Compounds

2019 ◽  
Vol 15 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Parviz Norouzi ◽  
Bagher Larijani ◽  
Taher Alizadeh ◽  
Eslam Pourbasheer ◽  
Mostafa Aghazadeh ◽  
...  
Keyword(s):  
Trace Analysis ◽  
High Speed ◽  
Portable Devices ◽  
Great Opportunity ◽  
Toxic Compounds ◽  
High Speed Analysis ◽  
Recent Developments ◽  
Sensitivity And Selectivity ◽  
Trace Measurement ◽  
Health Application

Background: The new progress in electronic devices has provided a great opportunity for advancing electrochemical instruments by which we can more easily solve many problems of interest for trace analysis of compounds, with a high degree of accuracy, precision, sensitivity, and selectivity. On the other hand, in recent years, there is a significant growth in the application of nanomaterials for the construction of nanosensors due to enhanced chemical and physical properties arising from discrete modified nanomaterial-based electrodes or microelectrodes. Objective: Combination of the advanced electrochemical system and nanosensors make these devices very suitable for the high-speed analysis, as motioning and portable devices. This review will discuss the recent developments and achievements that have been reported for trace measurement of drugs and toxic compounds for environment, food and health application.

AlGaN/GaN HEMTs: RECENT DEVELOPMENTS AND FUTURE DIRECTIONS

2008 ◽  
Vol 18 (04) ◽  
pp. 913-922 ◽  
Author(s):  
SIDDHARTH RAJAN ◽  
UMESH K. MISHRA ◽  
TOMÁS PALACIOS
Keyword(s):  
Field Effect ◽  
High Speed ◽  
Digital Circuits ◽  
Field Effect Transistors ◽  
Rf Power ◽  
Power Performance ◽  
Future Directions ◽  
Recent Developments ◽  
Gan Hemts ◽  
State Of Art

This paper provides an overview of recent work and future directions in Gallium Nitride transistor research. We discuss the present status of Ga -polar AlGaN / GaN HEMTs and the innovations that have led to record RF power performance. We describe the development of N -polar AlGaN / GaN HEMTs with microwave power performance comparable with state-of-art Ga -polar AlGaN / GaN HEMTs. Finally we will discuss how GaN -based field effect transistors could be promising for a less obvious application: low-power high-speed digital circuits.

scholarly journals Error Performance Estimation of Modulated Retroreflective Transdermal Optical Wireless Links with Diversity under Generalized Pointing Errors

Telecom ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 167-180
Author(s):  
George K. Varotsos ◽  
Hector E. Nistazakis ◽  
Konstantinos Aidinis ◽  
Fadi Jaber ◽  
Mohd Nasor ◽  
...  
Keyword(s):  
High Speed ◽  
Signal To Noise Ratio ◽  
Spatial Diversity ◽  
Performance Estimation ◽  
Optical Wireless ◽  
Wireless Data ◽  
Error Performance ◽  
Pointing Errors ◽  
Implanted Medical Devices ◽  
Recent Developments

Recent developments in both optical wireless communication (OWC) systems and implanted medical devices (IMDs) have introduced transdermal optical wireless (TOW) technology as a viable candidate for extremely high-speed in-body to out-of-body wireless data transmissions, which are growing in demand for many vital biomedical applications, including telemetry with medical implants, health monitoring, neural recording and prostheses. Nevertheless, this emerging communication modality is primarily hindered by skin-induced attenuation of the propagating signal bit carrier along with its stochastic misalignment-induced fading. Thus, by considering a typical modulated retroreflective (MRR) TOW system with spatial diversity and optimal combining (OC) for signal reception in this work, we focus, for the first time in the MRR TOW literature, on the stochastic nature of generalized pointing errors with non-zero boresight (NZB). Specifically, under these circumstances, novel analytical mathematical expressions were derived for the total average bit error rate (BER) of various system configurations. Their results revealed significant outage performance enhancements when spatial diversity was utilized. Moreover, taking into consideration the total transdermal pathloss along with the effects of stochastic NZB pointing errors, the critical average signal-to-noise ratio (SNR) metric was evaluated for typical power spectral-density values.

Improving the Efficiency of High-Speed AC Contact Suspension

2021 ◽  
Vol 5 (5) ◽  
pp. 39-43
Author(s):  
Maksim V. SHEVLYUGIN ◽  
◽  
Daria V. SEMENOVA ◽  
Keyword(s):  
Power Supply ◽  
High Speed ◽  
Single Phase ◽  
New Technologies ◽  
Alternating Current ◽  
Rolling Stock ◽  
New Materials ◽  
High Speed Railway ◽  
Electric Rolling Stock ◽  
Electrified Railways

When developing a high-speed contact suspension for railways electrified with alternating current, it is important to ensure that the electric rolling stock passes the neutral insert without turning off the current and without reducing the speed of movement. The article provides an analysis of previously developed devices in the field of power supply of electrified railways of single-phase alternating current, in which an attempt was made to pass an electric rolling stock of a neutral insert without disconnecting the load. The device of isolating coupling of a catenary and a neutral insert for high-speed railway lines electrified on alternating current is described. In this case, the passage of the neutral insert is carried out under current and braking of the electric rolling stock will not occur. Among other things, to improve the efficiency of high-speed contact suspension for railways electrified with alternating current, it is proposed to use new materials and new technologies that can be used in the device of insulating coupling of the catenary

Use of High-Temperature Superconductors in High Speed Electronic Switches with Current Gain

1987 ◽  
Vol 99 ◽  
Author(s):  
Bryan A. Biegel ◽  
R. Singh
Keyword(s):  
High Temperature ◽  
Josephson Junction ◽  
Resonant Tunneling ◽  
High Speed ◽  
High Temperature Superconductors ◽  
Semiconductor Devices ◽  
Proximity Effects ◽  
Current Gain ◽  
Recent Developments ◽  
Electronic Switches

ABSTRACTRecent developments in superconductivity have taken 77 K superconducting electronics from a dream to a likelihood. Rather than following the conventional path by developing Josephson junction-based devices, this paper discusses the unique possibilities of hybrid superconductor/semiconductor devices. The two devices discussed are a true three-terminal hybrid resonant tunneling transistor and the semiconductor-coupled Josephson junction. Also, a list is given of as yet uninvestigated issues concerning the new superconductors and their proximity effects with semiconductors -issues that are critical to the operation of these hybrid superconductor/semiconductor devices.

Recent Developments in Ride Control

2015 ◽  
Author(s):  
Alan J. Haywood ◽  
Benton H. Schaub ◽  
Chris M. Pappas
Keyword(s):  
Control Systems ◽  
High Speed ◽  
New Technologies ◽  
Early Adoption ◽  
Wide Range ◽  
Ride Control ◽  
Recent Developments ◽  
Material Choice ◽  
Maintenance Requirements ◽  
Broad Understanding

The use of ride control systems on high speed vessels has become the norm within many industries, producing better seakeeping that in turn provides a more comfortable and operationally effective vessel. Commercial ferry designers have been at the forefront of adoption of new technologies notably with early adoption of T-foils and interceptors. These devices have been taken up by others, for example offshore crew boats and frontline naval warships. The range of vessel types has also expanded with more industries adopting different hull designs including catamarans and trimarans. Ride control systems have developed alongside innovative designers producing for example combined lifting foil and ride control systems, lifting T-foil systems, retractable T-foils. This paper will review the different ride control devices including fins, trim tabs, interceptors, T-foils (including retractable T-foils) and lifting foils. As well as technical aspects, the discussion will consider costs, ease of installation, operational and maintenance requirements and material choice. Extensive examples from a wide range of industries will be presented. By the end of the talk, delegates will have a broad understanding of the options available to them in improving the seakeeping of their vessels.

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