scholarly journals Modelling the effect of vacuum on the morphology for large format detector arrays

2021 ◽  
Vol 2085 (1) ◽  
pp. 012021
Author(s):  
Yue Huang ◽  
Chun Lin
Keyword(s):  
Rapid Growth ◽  
Ex Situ ◽  
Total Deformation ◽  
Large Format ◽  
Detector Arrays ◽  
And Performance ◽  
Physical Phenomena

Abstract Rapid growth in the size and performance of the detector arrays unavoidably faced the morphology concern which was susceptible to peripheral exertions. Ex-situ interferometer characterization was carried out to modelling the effect of vacuum on the morphology whose results, in turn, was used to build the ANSYS model. The modelled total deformation explained the physical phenomena very well.

Nanoindentation Assisted Self-Assembly of Quantum Dots

2006 ◽  
Author(s):  
Curtis Taylor ◽  
Eric Stach ◽  
Gregory Salamo ◽  
Ajay Malshe
Keyword(s):  
Quantum Dots ◽  
Self Assembly ◽  
Surface Strain ◽  
Ex Situ ◽  
Atomic Step ◽  
Uniform Size ◽  
Force Microscopy ◽  
Atomic Force ◽  
And Performance ◽  
Spatial Positioning

The ability to pattern quantum dots with high spatial positioning and uniform size is critical for the realization of future electronic devices with novel properties and performance that surpass present technology. This work discusses the exploration of an innovative nanopatterning technique to direct the self-assembly of nanostructures. The technique focuses on perturbing surface strain energy by nanoindentation in order to mechanically bias quantum dot nucleation. Growth of InAs quantum dots on nanoindent templates is performed using molecular beam epitaxy (MBE). The effect of indent spacing and size on the patterned growth is investigated. The structural analysis of the quantum dots including spatial ordering, size, and shape are characterized by ex-situ atomic force microscopy (AFM). Results reveal that the indent patterns clearly bias nucleation with dot structures selectively growing on top of each indent. It is speculated that the biased nucleation is due to a combination of favorable surface strain attributed to subsurface dislocation strain fields and/or multi-atomic step formation at the indent sites, which leads to increased adatom diffusion on the patterned area.

China's Science and Technology System: Governance, Funding and Performance

2014 ◽  
Vol 06 (03) ◽  
pp. 53-66
Author(s):  
Litao ZHAO
Keyword(s):  
Research And Development ◽  
Rapid Growth ◽  
Science And Technology ◽  
Technology System ◽  
Global Innovation ◽  
Development Expenditure ◽  
And Performance ◽  
Quality Of Research ◽  
T System

As China progresses, its Science and Technology (S&T) system evolves as well, driven by new aspirations, changing needs and surging resources. With the rapid growth of research and development expenditure and a growing supply of talents, China has been reshaping the global research landscape. The quality of research however has been criticised as less impressive than the quantity. To become a global innovation powerhouse, China needs to reform its S&T governance, funding and evaluation.

Test structures and performance analysis for uncooled resistance bolometer detector arrays

1998 ◽  
Author(s):  
Kevin C. Liddiard ◽  
Olaf Reinhold ◽  
Ulf Ringh ◽  
Christer Jansson
Keyword(s):  
Performance Analysis ◽  
Detector Arrays ◽  
And Performance

Indium antimonide large-format detector arrays

2011 ◽  
Vol 50 (6) ◽  
pp. 061016 ◽  
Author(s):  
Mike Davis
Keyword(s):  
Indium Antimonide ◽  
Large Format ◽  
Detector Arrays

scholarly journals A slow-cooling-ratein situcell for long-duration studies of mineral precipitation in cold aqueous environments on Earth and other planetary bodies

2018 ◽  
Vol 51 (4) ◽  
pp. 1197-1210
Author(s):  
Stephen P. Thompson ◽  
Hilary Kennedy ◽  
Sarah J. Day ◽  
Annabelle R. Baker ◽  
Benjamin M. Butler ◽  
...  
Keyword(s):  
Ex Situ ◽  
Mineral Precipitation ◽  
Mars Rover ◽  
Slow Cooling ◽  
Ice Caps ◽  
Outer Planets ◽  
Long Duration ◽  
Solar System Bodies ◽  
Complex Ecosystem ◽  
And Performance

Liquid oceans and ice caps, along with ice crusts, have long been considered defining features of the Earth, but space missions and observations have shown that they are in fact common features among many of the solar system's outer planets and their satellites. Interactions with rock-forming materials have produced saline oceans not dissimilar in many respects to those on Earth, where mineral precipitation within frozen seawater plays a significant role in both determining global properties and regulating the environment in which a complex ecosystem of extremophiles exists. Since water is considered an essential ingredient for life, the presence of oceans and ice on other solar system bodies is of great astrobiological interest. However, the details surrounding mineral precipitation in freezing environments are still poorly constrained, owing to the difficulties of sampling andex situpreservation for laboratory analysis, meaning that predictive models have limited empirical underpinnings. To address this, the design and performance characterization of a transmission-geometry sample cell for use in long-duration synchrotron X-ray powder diffraction studies ofin situmineral precipitation from aqueous ice–brine systems are presented. The cell is capable of very slow cooling rates (e.g.0.3°C per day or less), and its performance is demonstrated with the results from a year-long study of the precipitation of the hydrated magnesium sulfate phase meridianiite (MgSO4·11H2O) from the MgSO4–H2O system. Evidence from the Mars Rover mission suggests that this hydrated phase is widespread on the present-day surface of Mars. However, as well as the predicted hexagonal ice and meridianiite phases, an additional hydrated sulfate phase and a disordered phase are observed.

scholarly journals Compared EC-AFM Analysis of Laser-Induced Graphene and Graphite Electrodes in Sulfuric Acid Electrolyte

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7333
Author(s):  
Claudia Filoni ◽  
Bahram Shirzadi ◽  
Marco Menegazzo ◽  
Eugenio Martinelli ◽  
Corrado Di Natale ◽  
...  
Keyword(s):  
Ex Situ ◽  
Oxidation Reactions ◽  
Acid Electrolyte ◽  
Spectroscopy Analysis ◽  
Graphite Electrodes ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis ◽  
And Performance

Flexible and economic sensor devices are the focus of increasing interest for their potential and wide applications in medicine, food analysis, pollution, water quality, etc. In these areas, the possibility of using stable, reproducible, and pocket devices can simplify the acquisition of data. Among recent prototypes, sensors based on laser-induced graphene (LIGE) on Kapton represent a feasible choice. In particular, LIGE devices are also exploited as electrodes for sensing in liquids. Despite a characterization with electrochemical (EC) methods in the literature, a closer comparison with traditional graphite electrodes is still missing. In this study, we combine atomic force microscopy with an EC cell (EC-AFM) to study, in situ, electrode oxidation reactions when LIGE or other graphite samples are used as anodes inside an acid electrolyte. This investigation shows the quality and performance of the LIGE electrode with respect to other samples. Finally, an ex situ Raman spectroscopy analysis allows a detailed chemical analysis of the employed electrodes.

scholarly journals Cellular Simulation for Distributed Sensing over Complex Terrains

2018 ◽  
Author(s):  
Tuyen Truong ◽  
Bernard Pottier ◽  
Hiep Huynh
Keyword(s):  
Long Range ◽  
Graphics Processing Units ◽  
High Performance ◽  
Physical Phenomenon ◽  
Cellular Systems ◽  
Large Area ◽  
Simulation Techniques ◽  
And Performance ◽  
Application Fields ◽  
Physical Phenomena

Long-range radio transmissions open new sensor application fields, in particular for environment monitoring. As an example, the {\sl LoRa} radio protocol enables to connect remote sensors at distance as long as ten kilometers in line-of-sight. However, the large area covered also bring several difficulties, such as the placement of sensing devices in regard to geography topology, or the variability of communication latency. Sensing the environment also carries constraints related to the interest of sensing points in relation with a physical phenomenon. Criteria for designs are thus evolving a lot from the existing methods, especially in complex terrains. This article describes simulation techniques based on geography analysis to compute long-range radio coverages and radio characteristics in these situations. As radio propagation is just a particular case of physical phenomena, it is shown how a unified approach also allows to characterize the behavior of potential physical risks. The case of heavy rainfall and flooding is investigated. Geography analysis is achieved using segmentation tools to produce cellular systems which are in turn translated into code for high-performance computations. The paper provides results from practical complex terrain experiments using LoRa, that confirm the accuracy of the simulation, scheduling characteristics for sample networks, and performance tables for simulations on middle range Graphics Processing Units (GPUs).

scholarly journals Direct Aulacaspis yasumatsui Infestation of Pre-Harvest Cycas Seeds Reduces Germination and Performance of Seedlings

Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 562
Author(s):  
Thomas E. Marler
Keyword(s):  
Germination Percentage ◽  
Ex Situ ◽  
Controlled Study ◽  
Seed Selection ◽  
Stem Height ◽  
Seedling Mortality ◽  
Armored Scale ◽  
Experimental Infestation ◽  
And Performance

The invasion of numerous countries by the armored scale Aulacaspis yasumatsui Takagi has caused widespread mortality of host Cycas species. Few studies have looked at reproductive biology responses of host plants to the herbivore. This study was conducted to determine the influence of direct Cycas seed integument infestation of A. yasumatsui on germination and seedling performance. An observational study in a Tinian ex situ Cycas micronesica K.D. Hill garden revealed that germination percentage was reduced two-thirds by heavy pre-harvest integument infestation, and more than half of the seedlings from infested seeds died in the nursery. Multi-year mortality of plants was six times greater for plants from habitats with infested seeds than for plants from minimally infested habitats. Stem height of nine-year-old plants from habitats with infested seeds was 64% of that of plants from habitats with un-infested seeds. A controlled study in a Philippine ex situ C. micronesica and Cycas edentata de Laub. garden corroborated these findings. Germination of infested seeds was about 30% of that for un-infested seeds. Seedling mortality in the nursery following experimental infestation of seed integuments with A. yasumatsui during seed maturation was about 50%, but was minimal for seedlings from un-infested seeds. These results indicate that limitations in regeneration and recruitment of host Cycas plants following A. yasumatsui herbivory may be partly due to the influence of direct seed infestations. Conservationists may use this new knowledge to improve in situ seed selection criteria and use prophylactic treatments to ensure lack of integument infestations for ex situ gardens.

How Do Pre-Alliance Motives and Strategies Affect Post-Alliance Performance in the Airline Industry?

2015 ◽  
pp. 332-358
Author(s):  
Raphaël K. Akamavi ◽  
Yue Xu ◽  
Hrisa Mitreva
Keyword(s):  
Literature Review ◽  
Systematic Literature Review ◽  
Rapid Growth ◽  
Airline Industry ◽  
Research Topic ◽  
Competitive Advantages ◽  
Alliance Performance ◽  
Main Factors ◽  
And Performance ◽  
Terrorist Events

The global airline industry has currently experienced major changes toward cooperation, where competitive advantages can be built via alliance memberships. The pressure of forming an appropriate alliance strategy is increasing because the airline industry has currently experienced uppermost shifts: intensive rivalry, rapid growth of technological explosion, environmental and terrorist events, etc. Despite positive pre-alliance motivations as recognized in most cases, after certain alliances strategies are formed and implemented, the post-alliance performance is not always satisfactory. Thus, the question of: how do pre-alliance motives and strategies affect post-alliance performance in the airline industry seems under explored. This study therefore looks into the triple relationships among: motives, strategy and performance. This study employs a systematic literature review method for this research topic. The review explores the main factors consisting of each triple dimension and then the linkages between them. Subsequently, it identifies theoretical gaps which indicate areas of further investigations.

Assessment of Post-CHF Heat Transfer Models for the SPACE Code

2009 ◽  
Author(s):  
K. Y. Choi ◽  
B. J. Yun ◽  
H. S. Park ◽  
S. K. Moon ◽  
K. D. Kim
Keyword(s):  
Heat Transfer ◽  
Mode Selection ◽  
Film Boiling ◽  
Model Assessment ◽  
Field Equations ◽  
Pressurized Water ◽  
Water Reactors ◽  
And Performance ◽  
Physical Phenomena ◽  
Transfer Models

The SPACE (Safety and Performance Analysis Code) which is based on a multi-dimensional two-fluid, three-field model is under development for a licensing purpose of pressurized water reactors in Korea. A total of 12 wall-to-fluid heat transfer modes were defined and a heat transfer mode selection logic was developed according to the noncondensable gas quality, the void fraction, the degree of subcooling and the wall temperature. Among the constitutive equations of the SPACE code, post-CHF heat transfer models are considered to have the most significant uncertainties because their physical phenomena are not fully understood yet. Though a variety of models and correlations for the post-CHF heat transfer are available, there is no reliable model to reproduce the heat transfer rate as realistically as possible. Several post-CHF heat transfer models are implemented into the SPACE code; critical heat, transition and film boiling models. The present paper describes the model assessment progress which was done for the transition and film boiling models of the SPACE code. A heat flux partition into the continuous liquid, entrained droplet and vapor fields should be taken into account in order to be in line with physical phenomena as the SPACE code has three-field equations in its hydraulic solver. Existing energy partitioning methods were peer-reviewed in order to determine the best model which can be applicable to the SPACE code. The present work will help to consolidate the developed wall-to-fluid heat transfer package of the SPACE code.

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