The dividends of investing in computational software design: A case study

2017 ◽  
Vol 33 (2) ◽  
pp. 322-331 ◽  
Author(s):  
Anshu Dubey ◽  
Petros Tzeferacos ◽  
Don Q Lamb
Keyword(s):  
High Energy ◽  
High Energy Density ◽  
Core Collapse ◽  
Fluid Structure Interactions ◽  
Research Areas ◽  
Type Ia ◽  
Scientific Results ◽  
Ia Supernovae ◽  
The Impact

A significant fraction of computational software for scientific research grows through accretion. In a common scenario, a small group develops a code for a specific purpose. Others find the software useful, so they add to it for their own use. The software grows to the point where its management becomes intractable and scientific results obtained from it become unreliable. This is in stark contrast with a small number of scientific codes that have undergone a design process, be it due to an upfront investment, or when haphazardly grown codes have reset and started again. At a minimum, these codes reduce the time to obtain research results for the communities they serve because individual researchers do not have to develop their own codes. They provide further benefits; the results they produce are more reproducible due to greater scrutiny, leading to better science. One of the more overlooked benefits, which is perhaps of greater significance, is that a well-designed code can expand to serve communities beyond the ones it was designed for. Thus, research communities with similar computational requirements can symbiotically improve computation-based research for each other. In this article, we present a case study of FLASH, a code that was designed and developed for simulating thermonuclear runaways such as novae and type Ia supernovae in astrophysics. Designed to be modular and extensible, users from several diverse research areas have added capabilities to it and adapted it for their own communities. Examples include cosmology, high-energy density physics, core-collapse supernovae, star formation, fluid–structure interactions, and chemical combustion. We give a summary of design features that facilitated the expansion and quantify the effort needed to expand into some of the above-mentioned fields. We also quantify the impact on different communities by mining the database of publications using FLASH, collected by its developers.

scholarly journals Body Mass, Physical Activity and Eating Habits Changes during the First COVID-19 Pandemic Lockdown in Poland

2021 ◽  
Vol 18 (11) ◽  
pp. 5682
Author(s):  
Hubert Dobrowolski ◽  
Dariusz Włodarek
Keyword(s):  
Physical Activity ◽  
Body Weight ◽  
Body Mass ◽  
Social Life ◽  
Eating Habits ◽  
High Energy ◽  
High Energy Density ◽  
Average Weight ◽  
Study Participants ◽  
The Impact

The outbreak of the COVID-19 pandemic caused a number of changes in social life around the world. In response to the growing number of infections, some countries have introduced restrictions that may have resulted in the change of the lifestyle. The aim of our study was to investigate the impact of the lockdown on body weight, physical activity and some eating habits of the society. The survey involving 183 people was conducted using a proprietary questionnaire. The mean age of the study participants was 33 ± 11 and mean height 169 ± 8 cm. An average increase in body weight was observed in 49.18% by 0.63 ± 3.7 kg which was the result of a decrease in physical activity and an increase in food consumption. We also observed a decrease in PAL from 1.64 ± 0.15 to 1.58 ± 0.13 and changes in the amount of food and individual groups of products consumption, including alcohol. Among the study participants who did not lose body mass, there was an average weight gain of 2.25 ± 2.5 kg. In conclusion, an increase of weight was shown in about half of the respondents in the study group which was associated with a decrease in physical activity and an increase in the consumption of total food and high energy density products.

scholarly journals Editorial from the Editor in Chief: Impact factors and open access publishing

2006 ◽  
Vol 24 (4) ◽  
pp. 467-468
Author(s):  
Dieter H.H. Hoffmann
Keyword(s):  
Impact Factor ◽  
Ultrashort Pulses ◽  
Dense Matter ◽  
High Energy ◽  
Research Field ◽  
High Energy Density ◽  
Open Access Publishing ◽  
Impact Factors ◽  
Particle Beams ◽  
The Impact

The primary goal of Laser and Particle Beams as part of the Cambridge University Press is the dissemination of knowledge in our research field. How effective we are in this respect is not easy to determine. But the impact factor published annually in June by Thomson ISI® 2005 Journal Citation Reports (JCR), gives at least an indication and a method to compare other journals in the field. In this respect, Laser and Particle Beams is a journal with a very high ranking in the field of applied physics, but it also compares very well to journals in other field of physics. The impact factor of a journal gives an account of how often an average paper in the journal is referred to, in a two year time span after publication. The current impact factor of 2.59 is based on an evaluation conducted in 2005 of Laser and Particle Beams publications of 2003 and 2004. During the evaluation period (2005), Laser and Particle Beams publications were cited about 1000 times. The topics that attracted most attention were Fast Ignition (Deutsch, 2004; Mulser & Schneider, 2004a; Hora, 2004; Mulser & Bauer, 2004b), Inertial Fusion Targets (Borisenko et al., 2003), and Ion and Electron Acceleration in laser plasma and Ultrashort Pulses (Shorokhov & Pukhov, 2004; Osman et al., 2004; Malka & Fritzler, 2004; Limpouch et al., 2004; Pegoraro et al., 2004). However, the editorial boards of Laser and Particle Beams strongly encourage authors to submit their results in High Energy Density Physics, the emerging field of Warm Dense Matter, Pulsed Power and Accelerator Physics and Technology.

scholarly journals Exploring the Human Capital Development Dimensions of Chinese Investments in Africa: Opportunities, Implications and Directions for Further Research

2018 ◽  
Vol 54 (2) ◽  
pp. 189-210 ◽  
Author(s):  
Motolani Agbebi
Keyword(s):  
Human Capital ◽  
Three Dimensions ◽  
Human Capital Development ◽  
Study Approach ◽  
Working Hypothesis ◽  
Research Areas ◽  
Economic Engagement ◽  
Capital Development ◽  
The Impact

This article uses a case-study approach to discuss the effects of Chinese economic engagement on three dimensions of human capital development: local employment, training and skill building, and knowledge and technology transfer. The study findings suggests that Chinese economic engagement can and does contribute to human capital development in Africa; however, this is dependent on certain sectoral factors and contextual conditions. This study advances a working hypothesis that the human capital development impact of Chinese economic engagement will vary across countries and sectors of the African economy. This working hypothesis seeks to guide further research towards developing a theoretical framework for the study of Chinese economic engagement in Africa and its effects on human capital development. The article also identifies research areas that should be further explored in order to gain a deeper understanding of the impact of Chinese economic engagement in Africa.

Thermal Model of a Thin Film Pulsed Pyroelectric Generator

2016 ◽  
Author(s):  
Nicholas R. Jankowski ◽  
Andrew N. Smith ◽  
Brendan M. Hanrahan
Keyword(s):  
Thin Film ◽  
Power Generation ◽  
Energy Conversion ◽  
High Speed ◽  
High Energy ◽  
High Energy Density ◽  
Working Fluid ◽  
Film Material ◽  
Thermodynamic Cycles ◽  
The Impact

Recent high energy density thin film material development has led to an increased interest in pyroelectric energy conversion. Using state-of-the-art lead-zirconate-titanate piezoelectric films capable of withstanding high electric fields we previously demonstrated single cycle energy conversion densities of 4.28 J/cm3. While material improvement is ongoing, an equally challenging task involves developing the thermal and thermodynamic process though which we can harness this thermal-to-electric energy conversion capability. By coupling high speed thermal transients from pulsed heating with rapid charge and discharge cycles, there is potential for achieving high energy conversion efficiency. We briefly present thermodynamic equivalent models for pyroelectric power generation based on the traditional Brayton and Ericsson cycles, where temperature-pressure states in a working fluid are replaced by temperature-field states in a solid pyroelectric material. Net electrical work is then determined by integrating the path taken along the temperature dependent polarization curves for the material. From the thermodynamic cycles we identify the necessary cyclical thermal conditions to realize net power generation, including a figure of merit, rEC, or the electrocaloric ratio, to aid in guiding generator design. Additionally, lumped transient analytical heat transfer models of the pyroelectric system with pulsed thermal input have been developed to evaluate the impact of reservoir temperatures, cycle frequency, and heating power on cycle output. These models are used to compare the two thermodynamic cycles. This comparison shows that as with traditional thermal cycles the Ericsson cycle provides the potential for higher cycle work while the Brayton cycle can produce a higher output power at higher thermal efficiency. Additionally, limitations to implementation of a high-speed Ericsson cycle were identified, primarily tied to conflicts between the available temperature margin and the requirement for isothermal electrical charging and discharging.

scholarly journals From Bench-Scale to Prototype: Case Study on a Nickel Hydroxide—Activated Carbon Hybrid Energy Storage Device

Batteries ◽  
2019 ◽  
Vol 5 (4) ◽  
pp. 65
Author(s):  
Alberto Adan-Mas ◽  
Pablo Arévalo-Cid ◽  
Teresa Moura e Silva ◽  
João Crespo ◽  
Maria de Fatima Montemor
Keyword(s):  
Activated Carbon ◽  
High Energy ◽  
High Energy Density ◽  
Storage Device ◽  
Cobalt Hydroxide ◽  
Bench Scale ◽  
Geometrical Constraints ◽  
Co Precipitation ◽  
Hybrid Devices

Hybrid capacitors have been developed to bridge the gap between batteries and ultracapacitors. These devices combine a capacitive electrode and a battery-like material to achieve high energy-density high power-density devices with good cycling stability. In the quest of improved electrochemical responses, several hybrid devices have been proposed. However, they are usually limited to bench-scale prototypes that would likely face severe challenges during a scaling up process. The present case study reports the production of a hybrid prototype consisting of commercial activated carbon and nickel-cobalt hydroxide, obtained by chemical co-precipitation, separated by means of polyolefin-based paper. Developed to power a 12 W LED light, these materials were assembled and characterized in a coin-cell configuration and stacked to increase device voltage. All the processes have been adapted and constrained to scalable conditions to ensure reliable production of a pre-commercial device. Important challenges and limitations of this process, from geometrical constraints to increased resistance, are reported alongside their impact and optimization on the final performance, stability, and metrics of the assembled prototype.

The impact of Hall physics on magnetized high energy density plasma jets

2014 ◽  
Vol 21 (5) ◽  
pp. 056307 ◽  
Author(s):  
P.-A. Gourdain ◽  
C. E. Seyler ◽  
L. Atoyan ◽  
J. B. Greenly ◽  
D. A. Hammer ◽  
...  
Keyword(s):  
Energy Density ◽  
High Energy ◽  
Plasma Jets ◽  
High Energy Density ◽  
The Impact ◽  
Density Plasma

scholarly journals Type Ia supernovae from dark matter core collapse

2019 ◽  
Vol 100 (3) ◽  
Author(s):  
Ryan Janish ◽  
Vijay Narayan ◽  
Paul Riggins
Keyword(s):  
Dark Matter ◽  
Type Ia Supernovae ◽  
Core Collapse ◽  
Type Ia ◽  
Ia Supernovae

scholarly journals Sensitivity of Type Ia supernovae to electron capture rates

2019 ◽  
Vol 624 ◽  
pp. A139 ◽  
Author(s):  
E. Bravo
Keyword(s):  
Weak Interactions ◽  
Dynamical Evolution ◽  
Sensitivity Study ◽  
Decay Rates ◽  
Type Ia Supernovae ◽  
Thermonuclear Explosion ◽  
Type Ia ◽  
Long Time ◽  
Ia Supernovae ◽  
The Impact

The thermonuclear explosion of massive white dwarfs is believed to explain at least a fraction of Type Ia supernovae (SNIa). After thermal runaway, electron captures on the ashes left behind by the burning front determine a loss of pressure, which impacts the dynamics of the explosion and the neutron excess of matter. Indeed, overproduction of neutron-rich species such as 54Cr has been deemed a problem of Chandrasekhar-mass models of SNIa for a long time. I present the results of a sensitivity study of SNIa models to the rates of weak interactions, which have been incorporated directly into the hydrodynamic explosion code. The weak rates have been scaled up or down by a factor ten, either globally for a common bibliographical source, or individually for selected isotopes. In line with previous works, the impact of weak rates uncertainties on sub-Chandrasekhar models of SNIa is almost negligible. The impact on the dynamics of Chandrasekhar-mass models and on the yield of 56Ni is also scarce. The strongest effect is found on the nucleosynthesis of neutron-rich nuclei, such as 48Ca, 54Cr, 58Fe, and 64Ni. The species with the highest influence on nucleosynthesis do not coincide with the isotopes that contribute most to the neutronization of matter. Among the latter, there are protons, 54, 55Fe, 55Co, and 56Ni, while the main influencers are 54, 55Mn and 55 − 57Fe, in disagreement with Parikh et al (2013, A&A, 557, A3), who found that SNIa nucleosynthesis is most sensitive to the β+-decay rates of 28Si, 32S, and 36Ar. An increase in all weak rates on pf-shell nuclei would affect the dynamical evolution of burning bubbles at the beginning of the explosion and the yields of SNIa.

Computational Study of the Decomposition of Cyclotetramethylenetetranitramine under Impact, Friction, and Electric Fields

2015 ◽  
Vol 1096 ◽  
pp. 407-412
Author(s):  
Hui Hu ◽  
Miao Miao Li ◽  
Bao Shan Wang
Keyword(s):  
Electric Fields ◽  
Energetic Materials ◽  
Density Functional ◽  
Computational Study ◽  
Minimum Energy ◽  
High Energy ◽  
High Energy Density ◽  
Basis Sets ◽  
Gas Phases ◽  
The Impact

Organic CHNO-containing high energy density materials have been widely used for storing large amounts of the chemical energies which can be rapidly transformed into heat upon various external perturbations during detonation. The sensitivity of the energetic materials is subjected to considerable concern for safety and maintenance. Periodic density functional theory with the all-electron basis sets were employed in this work to unravel the impact, friction, and electric-fields induced decomposition of HMX. The minimum energy paths for the N−NO2homolysis reactions of HMX in the bulk and gas phases were obtained. The surface-enhanced effect on the decomposition of HMX were calculated for both (010) and (100) surfaces. A general theoretical scheme has been proposed to assess the intrinsic mechanic and electrostatic sensitivities of the pure energetic materials.

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