Recent developments in our understanding of spin effects at high energy

1989 ◽  
Author(s):  
J. Soffer
Keyword(s):  
High Energy ◽  
Spin Effects ◽  
Recent Developments

scholarly journals The Growth of Semiconductor Thin Films Studied by RHEED

1990 ◽  
Vol 43 (5) ◽  
pp. 583
Author(s):  
GL Price
Keyword(s):  
Thin Films ◽  
Surface Science ◽  
High Vacuum ◽  
High Energy ◽  
Ultra High Vacuum ◽  
Large Area ◽  
Growth Modes ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Recent Developments

Recent developments in the growth of semiconductor thin films are reviewed. The emphasis is on growth by molecular beam epitaxy (MBE). Results obtained by reflection high energy electron diffraction (RHEED) are employed to describe the different kinds of growth processes and the types of materials which can be constructed. MBE is routinely capable of heterostructure growth to atomic precision with a wide range of materials including III-V, IV, II-VI semiconductors, metals, ceramics such as high Tc materials and organics. As the growth proceeds in ultra high vacuum, MBE can take advantage of surface science techniques such as Auger, RHEED and SIMS. RHEED is the essential in-situ probe since the final crystal quality is strongly dependent on the surface reconstruction during growth. RHEED can also be used to calibrate the growth rate, monitor growth kinetics, and distinguish between various growth modes. A major new area is lattice mismatched growth where attempts are being made to construct heterostructures between materials of different lattice constants such as GaAs on Si. Also described are the new techniques of migration enhanced epitaxy and tilted superlattice growth. Finally some comments are given On the means of preparing large area, thin samples for analysis by other techniques from MBE grown films using capping, etching and liftoff.

scholarly journals Towards the Hydrogen Economy—A Review of the Parameters That Influence the Efficiency of Alkaline Water Electrolyzers

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3193
Author(s):  
Ana L. Santos ◽  
Maria-João Cebola ◽  
Diogo M. F. Santos
Keyword(s):  
Energy Content ◽  
Water Electrolysis ◽  
High Energy ◽  
Operating Conditions ◽  
Energy Sources ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water ◽  
New Energy ◽  
Recent Developments ◽  
Cell Components

Environmental issues make the quest for better and cleaner energy sources a priority. Worldwide, researchers and companies are continuously working on this matter, taking one of two approaches: either finding new energy sources or improving the efficiency of existing ones. Hydrogen is a well-known energy carrier due to its high energy content, but a somewhat elusive one for being a gas with low molecular weight. This review examines the current electrolysis processes for obtaining hydrogen, with an emphasis on alkaline water electrolysis. This process is far from being new, but research shows that there is still plenty of room for improvement. The efficiency of an electrolyzer mainly relates to the overpotential and resistances in the cell. This work shows that the path to better electrolyzer efficiency is through the optimization of the cell components and operating conditions. Following a brief introduction to the thermodynamics and kinetics of water electrolysis, the most recent developments on several parameters (e.g., electrocatalysts, electrolyte composition, separator, interelectrode distance) are highlighted.

scholarly journals Recent Developments of the Liège Intranuclear Cascade Model in View of its Use into High-energy Transport Codes

2014 ◽  
Vol 118 ◽  
pp. 312-315 ◽  
Author(s):  
S. Leray ◽  
A. Boudard ◽  
B. Braunn ◽  
J. Cugnon ◽  
J.C. David ◽  
...  
Keyword(s):  
Energy Transport ◽  
High Energy ◽  
Cascade Model ◽  
Intranuclear Cascade ◽  
Recent Developments

scholarly journals The Impact of Microelectronics on High Energy Physics Innovation: The Role of 65 nm CMOS Technology on New Generation Particle Detectors

2021 ◽  
Vol 9 ◽  
Author(s):  
N. Demaria
Keyword(s):  
Particle Physics ◽  
High Energy Physics ◽  
Hadron Collider ◽  
Cmos Technology ◽  
High Energy ◽  
Main Role ◽  
Noise Power ◽  
Recent Developments ◽  
The Impact ◽  
Energy Physics

The High Luminosity Large Hadron Collider (HL-LHC) at CERN will constitute a new frontier for the particle physics after the year 2027. Experiments will undertake a major upgrade in order to stand this challenge: the use of innovative sensors and electronics will have a main role in this. This paper describes the recent developments in 65 nm CMOS technology for readout ASIC chips in future High Energy Physics (HEP) experiments. These allow unprecedented performance in terms of speed, noise, power consumption and granularity of the tracking detectors.

scholarly journals Stochastically pumped adaptation and directional motion of molecular machines

2018 ◽  
Vol 115 (38) ◽  
pp. 9405-9413 ◽  
Author(s):  
R. Dean Astumian
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
High Efficiency ◽  
Probability Distributions ◽  
Molecular Machines ◽  
High Energy ◽  
Stochastic Thermodynamics ◽  
Recent Developments ◽  
Directional Motion ◽  
External Fluctuations

Recent developments in synthetic molecular motors and pumps have sprung from a remarkable confluence of experiment and theory. Synthetic accomplishments have facilitated the ability to design and create molecules, many of them featuring mechanically bonded components, to carry out specific functions in their environment—walking along a polymeric track, unidirectional circling of one ring about another, synthesizing stereoisomers according to an external protocol, or pumping rings onto a long rod-like molecule to form and maintain high-energy, complex, nonequilibrium structures from simpler antecedents. Progress in the theory of nanoscale stochastic thermodynamics, specifically the generalization and extension of the principle of microscopic reversibility to the single-molecule regime, has enhanced the understanding of the design requirements for achieving strong unidirectional motion and high efficiency of these synthetic molecular machines for harnessing energy from external fluctuations to carry out mechanical and/or chemical functions in their environment. A key insight is that the interaction between the fluctuations and the transition state energies plays a central role in determining the steady-state concentrations. Kinetic asymmetry, a requirement for stochastic adaptation, occurs when there is an imbalance in the effect of the fluctuations on the forward and reverse rate constants. Because of strong viscosity, the motions of the machine can be viewed as mechanical equilibrium processes where mechanical resonances are simply impossible but where the probability distributions for the state occupancies and trajectories are very different from those that would be expected at thermodynamic equilibrium.

Recent developments of Co3O4-based materials as the catalysts for oxygen evolution reaction

2021 ◽  
Author(s):  
Zhenyu Hu ◽  
Liping Hao ◽  
Fan Quan ◽  
Rui Guo
Keyword(s):  
Energy Density ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Fossil Fuels ◽  
High Energy ◽  
High Energy Density ◽  
Environmental Concerns ◽  
Efficient Energy ◽  
Recent Developments

The demand for the development of clean and efficient energy is becoming more and more pressing due to depleting fossil fuels and environmental concerns. Hydrogen is a high energy density...

scholarly journals Towards a serverless CernVM-FS

2019 ◽  
Vol 214 ◽  
pp. 09007
Author(s):  
Jakob Blomer ◽  
Gerardo Ganis ◽  
Simone Mosciatti ◽  
Radu Popescu
Keyword(s):  
High Energy Physics ◽  
Virtual Machines ◽  
Content Distribution ◽  
High Energy ◽  
Content Delivery Network ◽  
Resource Limited ◽  
Recent Developments ◽  
Software Distribution ◽  
Data Distribution Service ◽  
Dedicated Servers

The CernVM File System (CernVM-FS) provides a scalable and reliable software distribution and—to some extent—a data distribution service. It gives POSIX access to more than a billion binary files of experiment application software stacks and operating system containers to end user devices, grids, clouds, and supercomputers. Increasingly, CernVM-FSalso provides access to certain classes of data, such as detector conditions data, genomics reference sets, or gravitational wave detector experiment data. For most of the high- energy physics experiments, an underlying HTTP content distribution infrastructure is jointly provided by universities and research institutes around the world. In this contribution, we will present recent developments and future plans. For future developments, we put a focus on evolving the content distribution infrastructure and at lowering the barrier for publishing into CernVM-FS. Through so-called serverless computing, we envision cloud hosted CernVM-FS repositories without the need to operate dedicated servers or virtual machines. An S3 compatible service in conjunction with a content delivery network takes on data provisioning, replication, and caching. A chainof time-limited and resource-limited functions (so called “lambda function” or “function-as- a-service”) operate on the repository and stage the updates. As a result, any CernVM-FS client should be able to turn intoawriter, possession of suitable keys provided. For repository owners, we aim at providing cost transparency and seamless scalability from very small to very large CernVM-FS installations.

scholarly journals The oxidation of phosphine at low pressures

1929 ◽  
Vol 125 (797) ◽  
pp. 294-308 ◽  
Keyword(s):  
Energy Content ◽  
Stable Condition ◽  
High Energy ◽  
Gaseous Reaction ◽  
Molecular Collision ◽  
Active Chemical ◽  
Recent Developments ◽  
Collision Processes ◽  
A Chain ◽  
Low Pressures

In the recent developments of chemical kinetics there have been many indications of a type of reaction known as a chain reaction, in which each act of transformation gives rise to a product which, on account of its active chemical nature or high energy content, causes further molecules to be transformed without special activation. Under certain conditions the chain may "branch," and the number of centers from which reaction proceeds increases indefinitely unless the chains are broken. In a gaseous reaction there may be a definite concentration at which the rate of initiation of chains just begins to exceed the rate at which they are broken. At this point a stable condition ceases to be possible. However slow the reaction may be on one side of the limiting concentration, on the other side its rate increases continuously with time till explosion results. The acceleration may require an imperceptible fraction of a second only, since the time scale on which molecular collision processes occur is a very minute one. The remarkable phenomenon to which this gives rise, namely an abrupt transition from negligibly slow reaction to explosion, is exemplified in the union of oxygen with phosphorus vapour and with sulphur vapour at low pressure, and in the combination of hydrogen and oxygen under certain conditions. The present paper deals with a similar phenomenon in the oxidation of phosphine.

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