scholarly journals SpaceHub: A high-performance gravity integration toolkit for few-body problems in astrophysics

2021 ◽  
Author(s):  
Yi-Han Wang ◽  
Nathan W C Leigh ◽  
Bin Liu ◽  
Rosalba Perna
Keyword(s):  
Open Source ◽  
High Performance ◽  
Error Control ◽  
Performance Accuracy ◽  
Eccentric Orbits ◽  
Planetary Dynamics ◽  
Arbitrary Precision ◽  
Accurate Computations ◽  
New Algorithms

Abstract We present the open source few-body gravity integration toolkit SpaceHub. SpaceHub offers a variety of algorithmic methods, including the unique algorithms AR-Radau, AR-Sym6, AR-ABITS and AR-chain+ which we show out-perform other methods in the literature and allow for fast, precise and accurate computations to deal with few-body problems ranging from interacting black holes to planetary dynamics. We show that AR-Sym6 and AR-chain+, with algorithmic regularization, chain algorithm, active round-off error compensation and a symplectic kernel implementation, are the fastest and most accurate algorithms to treat black hole dynamics with extreme mass ratios, extreme eccentricities and very close encounters. AR-Radau, the first regularized Radau integrator with round off error control down to 64 bits floating point machine precision, has the ability to handle extremely eccentric orbits and close approaches in long-term integrations. AR-ABITS, a bit efficient arbitrary precision method, achieves any precision with the least CPU cost compared to other open source arbitrary precision few-body codes. With the implementation of deep numerical and code optimization, these new algorithms in SpaceHub prove superior to other popular high precision few-body codes in terms of performance, accuracy and speed.

ONAMA: A Quantum Leap in High Performance Computing

2011 ◽  
Vol 328-330 ◽  
pp. 2337-2342 ◽  
Author(s):  
Goldi Misra ◽  
Sandeep Agrawal ◽  
Nisha Kurkure ◽  
Shweta Das ◽  
Kapil Mathur ◽  
...  
Keyword(s):  
Open Source ◽  
High Performance Computing ◽  
High Performance ◽  
Science And Engineering ◽  
New Beginning ◽  
Quantum Leap ◽  
Execution Model ◽  
Key Issues ◽  
Performance Computing

The growth of serial and High Performance Computing (HPC) applications presents the challenge of porting of scientific and engineering applications. A number of key issues and trends in High Performance Computing will impact the delivery of breakthrough science and engineering in the future. ONAMA was developed to cope with increasing demands for HPC. ONAMA, which means a new beginning, is a desktop based Graphical User Interface which is developed using C and GTK. It aims to satisfy the research needs of academic institutions. ONAMA is a comprehensive package, comprising of applications covering many engineering branches. ONAMA provides tools that have a close affinity with practical simulation, thus making the learning process for students more applied. Most of the software tools and libraries are open source and supported on Linux, thereby promoting the use of open source software. It also provides tools to the researchers to solve their day-to-day as well as long term problems accurately in lesser time. The Execution Model of ONAMA serves to execute engineering and scientific applications either in sequential or in parallel on Linux computing clusters.

mmpdb: An Open Source Matched Molecular Pair Platform for Large Multi-Property Datasets

2018 ◽  
Author(s):  
Andrew Dalke ◽  
Jerome Hert ◽  
Christian Kramer
Keyword(s):  
Open Source ◽  
Large Datasets ◽  
Molecular Pair ◽  
New Algorithms

We present mmpdb, an open source Matched Molecular Pair (MMP) platform to create, compile, store, retrieve, and use MMP rules. mmpdb is suitable for the large datasets typically found in pharmaceutical and agrochemical companies and provides new algorithms for fragment canonicalization and stereochemistry handling. The platform is written in Python and based on the RDKit toolkit. mmpdb is freely available.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Use Of Tai Chi Elements To Increase Respiratory Amplitude

2019 ◽  
pp. 11-20
Author(s):  
Mihai-Alexandru Citea ◽  
Marius Neculaes
Keyword(s):  
High Performance ◽  
Tai Chi ◽  
Sports Club ◽  
Optimal Functioning ◽  
Physiological Adaptations ◽  
Competitive Activity ◽  
Abdominal Breathing ◽  
Study Participants ◽  
Different Levels

High performance sport has a major impact on the physiological adaptations of the respiratory system. The importance of the optimal functioning of this system is essential to achieve top results in high performance sport but also in maintaining a long term health status. Science journals present numerous studies that highlight the benefits of practicing Tai Chi on the general population, with effects ranging from improving cardiac function, to influencing the immune system. The purpose of this study is to identify whether by practicing Tai Chi forms a athlete can change their breathing pattern and develop their respiratory amplitude. The subjects of the study were 22 fencing practitioners, accredited at the Iași Municipal Sports Club (C.S.M. Iași), aged between 14 and 18 years, with over 3 years of competitive activity. Materials and method: The study participants were evaluated initially and at the end of 7 months of practice. The frequency was 3 sessions per week, and the duration of each session was 20-30 minutes. The evaluation consisted in measuring the circumference of the thorax at 3 different levels: subaxillary, medial thorax (T6-T7) and lower rib (diaphragmatic) in maximal inspiration and expiration. Conclusions: A constant evolution is observed in most of the exposed cases. In cases where this evolution is not visible, a change in the breathing mode can be noticed, transforming from an upper rib breathing into a thoracic or abdominal breathing. With the exception of one case, all subjects had an improvement of the value in the lower rib level.

Application of High Performance Electro-Hydraulic Synchronous Servo System on NC Broaching Machine

2013 ◽  
Vol 721 ◽  
pp. 497-500
Author(s):  
Guo Jin Chen ◽  
Jing Ni ◽  
Ting Ting Liu ◽  
Ming Xu
Keyword(s):  
High Performance ◽  
Control Process ◽  
Servo System ◽  
Numerical Control ◽  
Servo Drive ◽  
Loop Control ◽  
Performance Accuracy ◽  
Drive Control ◽  
Hydraulic Servo ◽  
Output Quantity

Aiming at the lower performance, accuracy and efficiency of the existing motion control process for the traditional broaching machine, the paper studies the high-performance dual-hydraulic synchronous servo drive control technology. The synchronous electro-hydraulic servo system forms the closed loop control by the detection and feedback of the output quantity. It eliminates and restrains largely the influence of the adverse factors to obtain the high-precision synchronous driving performance. The numerical control system based on the real-time error compensation and the intelligent control to the auxiliary machinery is developed. It is used for the CNC broaching machine to make the steady-state synchronous displacement error of the double cylinders be ≤ 0.5mm.

scholarly journals Review on Development and Dental Applications of Polyetheretherketone-Based Biomaterials and Restorations

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 408 ◽  
Author(s):  
Ludan Qin ◽  
Shuo Yao ◽  
Jiaxin Zhao ◽  
Chuanjian Zhou ◽  
Thomas W. Oates ◽  
...  
Keyword(s):  
High Performance ◽  
Dental Resin ◽  
Oral Environment ◽  
Inert Surface ◽  
Oral Implant ◽  
Long Term Performance ◽  
Dental Applications ◽  
Term Performance ◽  
Orthopedic Applications

Polyetheretherketone (PEEK) is an important high-performance thermoplastic. Its excellent strength, stiffness, toughness, fatigue resistance, biocompatibility, chemical stability and radiolucency have made PEEK attractive in dental and orthopedic applications. However, PEEK has an inherently hydrophobic and chemically inert surface, which has restricted its widespread use in clinical applications, especially in bonding with dental resin composites. Cutting edge research on novel methods to improve PEEK applications in dentistry, including oral implant, prosthodontics and orthodontics, is reviewed in this article. In addition, this article also discusses innovative surface modifications of PEEK, which are a focus area of active investigations. Furthermore, this article also discusses the necessary future studies and clinical trials for the use of PEEK in the human oral environment to investigate its feasibility and long-term performance.

Interpenetrating Gels as Conducting/Adhering Matrices Enabling High-Performance Silicon Anodes

2021 ◽  
Author(s):  
Tingting Xia ◽  
Chengfei Xu ◽  
Pengfei Dai ◽  
Xiaoyun Li ◽  
Riming Lin ◽  
...  
Keyword(s):  
Energy Storage ◽  
High Performance ◽  
Electrode Materials ◽  
Three Dimensional ◽  
Electrochemical Energy Storage ◽  
Active Materials ◽  
Silicon Anodes ◽  
Weak Binding ◽  
Binding Forces

Three-dimensional (3D) conductive polymers are promising conductive matrices for electrode materials toward electrochemical energy storage. However, their fragile nature and weak binding forces with active materials could not guarantee long-term...

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