Photonic Materials: Introduction

MRS Bulletin ◽  
1988 ◽  
Vol 13 (8) ◽  
pp. 14-15 ◽  
Author(s):  
Alastair M. Glass
Keyword(s):  
Semiconductor Lasers ◽  
Optical Fibers ◽  
High Performance ◽  
Information Technologies ◽  
Photonic Materials ◽  
Wide Bandwidth ◽  
Photonic Switching ◽  
Optical Amplification ◽  
Fundamental Limitations

Optical technologies have advanced dramatically in recent years. In just two decades the transparency of optical fibers has improved by four orders of magnitude. Semiconductor lasers have evolved from a new invention to highly reliable, high performance commercial devices for wide bandwidth optical communications. New approaches to higher frequency modulation, wider bandwidth transmission, more sensitive detection and optical amplification are constantly being developed. Fundamental limitations are sufficiently far removed from current capabilities that considerable further progress can be anticipated. These advances have provided the stimulus for a much broader investigation of the potential of optics in future information technologies in which optics and electronics play complementary roles. This rapidly developing field is referred to as “photonics.” Increasing attention is now being paid to applying optics to wide bandwidth switching systems and to exploring the potential of optics for image processing and computation.Past progress in optical communication can be traced largely to the dramatic progress in optical fiber and compound semiconductor materials technologies. Likewise, future opportunities in photonic switching and information processing will depend critically on the development of improved photonic materials. The future role of optics in these conventionally electronic technologies, and the extent of that role, depends on whether materials can be designed and fabricated with the required characteristics.

PROSPECTS FOR A MOLECULAR SUPERCOMPUTER 15 YEARS AHEAD

2006 ◽  
Vol 05 (04n05) ◽  
pp. 377-382
Author(s):  
YASUO WADA
Keyword(s):  
High Performance ◽  
Information Technologies ◽  
Semiconductor Devices ◽  
Current Status ◽  
Performance Information ◽  
Current Information ◽  
Fundamental Limitations ◽  
Optical Discs

Current information technologies totally rely on semiconductor devices and magnetic/optical discs, however, they are all foreseen to face fundamental limitations within a decade. Therefore, superseding devices are required for the next paradigm of high performance information technologies. This paper describes prospects for a molecular supercomputer which would be the only possible candidate beyond the silicon limitations. Possible four milestones for realizing the Peta/Exa-floating operations per second (FLOPS) personal molecular supercomputer are proposed. Current status and necessary technologies of the first milestone are described, and necessary technologies for the next three milestones are also discussed.

Trace nanoanalysis

1994 ◽  
Vol 52 ◽  
pp. 940-941
Author(s):  
D. E. Newbury ◽  
R. D. Leapman
Keyword(s):  
High Performance ◽  
Secondary Ion Mass Spectrometry ◽  
Detection Efficiency ◽  
Volume Element ◽  
And Performance ◽  
Trace Constituents ◽  
Secondary Ion ◽  
Concentration Levels ◽  
Structure Properties

Trace constituents, which can be very loosely defined as those present at concentration levels below 1 percent, often exert influence on structure, properties, and performance far greater than what might be estimated from their proportion alone. Defining the role of trace constituents in the microstructure, or indeed even determining their location, makes great demands on the available array of microanalytical tools. These demands become increasingly more challenging as the dimensions of the volume element to be probed become smaller. For example, a cubic volume element of silicon with an edge dimension of 1 micrometer contains approximately 5×1010 atoms. High performance secondary ion mass spectrometry (SIMS) can be used to measure trace constituents to levels of hundreds of parts per billion from such a volume element (e. g., detection of at least 100 atoms to give 10% reproducibility with an overall detection efficiency of 1%, considering ionization, transmission, and counting).

Two Short Tests Fail to Detect Vigilance Decrements

2001 ◽  
Vol 17 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Juan Botella ◽  
María José Contreras ◽  
Pei-Chun Shih ◽  
Víctor Rubio
Keyword(s):  
Individual Differences ◽  
High Performance ◽  
Selection Process ◽  
Vigilance Task ◽  
Air Traffic Controllers ◽  
Job Selection ◽  
Performance Deterioration ◽  
Short Test ◽  
Psychological Dimensions

Summary: Deterioration in performance associated with decreased ability to sustain attention may be found in long and tedious task sessions. The necessity for assessing a number of psychological dimensions in a single session often demands “short” tests capable of assessing individual differences in abilities such as vigilance and maintenance of high performance levels. In the present paper two tasks were selected as candidates for playing this role, the Abbreviated Vigilance Task (AVT) by Temple, Warm, Dember, LaGrange and Matthews (1996) and the Continuous Attention Test (CAT) by Tiplady (1992) . However, when applied to a sample of 829 candidates in a job-selection process for air-traffic controllers, neither of them showed discriminative capacity. In a second study, an extended version of the CAT was applied to a similar sample of 667 subjects, but also proved incapable of properly detecting individual differences. In short, at least in a selection context such as that studied here, neither of the tasks appeared appropriate for playing the role of a “short” test for discriminating individual differences in performance deterioration in sustained attention.

scholarly journals Enhancing Qualities of Consciousness during Online Learning via Multisensory Interactions

2021 ◽  
Vol 11 (5) ◽  
pp. 57
Author(s):  
Valentina Cesari ◽  
Benedetta Galgani ◽  
Angelo Gemignani ◽  
Danilo Menicucci
Keyword(s):  
Online Learning ◽  
Virtual Environments ◽  
Information Technologies ◽  
Physical Distance ◽  
Traditional Learning ◽  
Sense Of Presence ◽  
Lack Of Control ◽  
Multisensory Interactions ◽  
Feasible Alternative

Online-learning is a feasible alternative to in-person attendance during COVID-19 pandemic. In this period, information technologies have allowed sharing experiences, but have also highlighted some limitations compared to traditional learning. Learning is strongly supported by some qualities of consciousness such as flow (intended as the optimal state of absorption and engagement activity) and sense of presence (feeling of exerting control, interacting with and getting immersed into real/virtual environments), behavioral, emotional, and cognitive engagement, together with the need for social interaction. During online learning, feelings of disconnection, social isolation, distractions, boredom, and lack of control exert a detrimental effect on the ability to reach the state of flow, the feeling of presence, the feeling of social involvement. Since online environments could prevent the rising of these learning–supporting variables, this article aims at describing the role of flow, presence, engagement, and social interactions during online sessions and at characterizing multisensory stimulations as a driver to cope with these issues. We argue that the use of augmented, mixed, or virtual reality can support the above-mentioned domains, and thus counteract the detrimental effects of physical distance. Such support could be further increased by enhancing multisensory stimulation modalities within augmented and virtual environments.

scholarly journals Functional response of Harmonia axyridis preying on Acyrthosiphon pisum nymphs: the effect of temperature

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yasir Islam ◽  
Farhan Mahmood Shah ◽  
Xu Rubing ◽  
Muhammad Razaq ◽  
Miao Yabo ◽  
...  
Keyword(s):  
Functional Response ◽  
High Performance ◽  
Acyrthosiphon Pisum ◽  
Harmonia Axyridis ◽  
Effect Of Temperature ◽  
Functional Responses ◽  
Aphid Control ◽  
Host Aphid ◽  
Predator Foraging

AbstractIn the current study, we investigated the functional response of Harmonia axyridis adults and larvae foraging on Acyrthosiphon pisum nymphs at temperatures between 15 and 35 °C. Logistic regression and Roger’s random predator models were employed to determine the type and parameters of the functional response. Harmonia axyridis larvae and adults exhibited Type II functional responses to A. pisum, and warming increased both the predation activity and host aphid control mortality. Female and 4th instar H. axyridis consumed the most aphids. For fourth instar larvae and female H. axyridis adults, the successful attack rates were 0.23 ± 0.014 h−1 and 0.25 ± 0.015 h−1; the handling times were 0.13 ± 0.005 h and 0.16 ± 0.004 h; and the estimated maximum predation rates were 181.28 ± 14.54 and 153.85 ± 4.06, respectively. These findings accentuate the high performance of 4th instar and female H. axyridis and the role of temperature in their efficiency. Further, we discussed such temperature-driven shifts in predation and prey mortality concerning prey-predator foraging interactions towards biological control.

Revealing the role of dopants in mitigating degradation phenomena in sodium-ion layered cathodes

2021 ◽  
Vol 23 (3) ◽  
pp. 2038-2045
Author(s):  
Kyoungmin Min ◽  
Young-Han Shin
Keyword(s):  
Cathode Materials ◽  
High Performance ◽  
High Stability ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Layered Cathode Materials ◽  
Layered Cathodes

Prevention of the degradation of sodium-based layered cathode materials is the key to developing high-performance and high-stability sodium-ion batteries.

scholarly journals Towards a Glass New World: The Role of Ion-Exchange in Modern Technology

2021 ◽  
Vol 11 (10) ◽  
pp. 4610
Author(s):  
Simone Berneschi ◽  
Giancarlo C. Righini ◽  
Stefano Pelli
Keyword(s):  
Ion Exchange ◽  
Communication Networks ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Modern Technology ◽  
Historical Background ◽  
Wide Range ◽  
Happy Marriage

Glasses, in their different forms and compositions, have special properties that are not found in other materials. The combination of transparency and hardness at room temperature, combined with a suitable mechanical strength and excellent chemical durability, makes this material indispensable for many applications in different technological fields (as, for instance, the optical fibres which constitute the physical carrier for high-speed communication networks as well as the transducer for a wide range of high-performance sensors). For its part, ion-exchange from molten salts is a well-established, low-cost technology capable of modifying the chemical-physical properties of glass. The synergy between ion-exchange and glass has always been a happy marriage, from its ancient historical background for the realisation of wonderful artefacts, to the discovery of novel and fascinating solutions for modern technology (e.g., integrated optics). Getting inspiration from some hot topics related to the application context of this technique, the goal of this critical review is to show how ion-exchange in glass, far from being an obsolete process, can still have an important impact in everyday life, both at a merely commercial level as well as at that of frontier research.

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