A Verification and Validation Study of the Cyclops I PBX 9502 Experiment

Author(s):  
John W. Grove ◽  
Adam C. Coleman ◽  
Carl E. Johnson ◽  
Ralph Menikoff

Abstract A computational verification and validation study of the Cyclops I experiment [1–7] was conducted using the Los Alamos Eulerian Applications code xRage [8]. The purpose of this study was to validate the Scaled Unified Reactive Front (SURF) plus (SURFplus) model for insensitive high explosives [9–12]. Diagnostics from the experiment included photon doppler velocimetry measurements of the encasing shell for the device and proton radiography photographs of the explosions. This data was compared to the xRage computed data and a convergence study of burn front evolution was conducted. We conclude that the SURFplus high explosive model does an excellent job at predicting the high explosive burn front velocity and shape with results that converge to the experimental data at rates near to or better than first order in most cases. Some companion verification metrics for the solution convergence are also described. These metrics show that the xRage computed solution for the high explosive burn front converges to first order or better, as consistent with the treatment of shock fronts in a higher order Godunov hydrodynamic solver as used in xRage.

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammad Ahmadian ◽  
Sohyla Reshadat ◽  
Nader Yousefi ◽  
Seyed Hamed Mirhossieni ◽  
Mohammad Reza Zare ◽  
...  

Due to complex composition of leachate, the comprehensive leachate treatment methods have been not demonstrated. Moreover, the improper management of leachate can lead to many environmental problems. The aim of this study was application of Fenton process for decreasing the major pollutants of landfill leachate on Kermanshah city. The leachate was collected from Kermanshah landfill site and treated by Fenton process. The effect of various parameters including solution pH, Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time was investigated. The result showed that with increasing Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time, the COD, TOC, TSS, and color removal increased. The maximum COD, TOC, TSS, and color removal were obtained at low pH (pH: 3). The kinetic data were analyzed in term of zero-order, first-order, and second-order expressions. First-order kinetic model described the removal of COD, TOC, TSS, and color from leachate better than two other kinetic models. In spite of extremely difficulty of leachate treatment, the previous results seem rather encouraging on the application of Fenton’s oxidation.


2020 ◽  
Vol 1 (2) ◽  
pp. 54-62
Author(s):  
Naser Al Amery ◽  
Hussein Rasool Abid ◽  
Shaobin Wang ◽  
Shaomin Liu

In this study, two improved versions of UiO-66 were successfully synthesised. Modified UiO-66 and UiO-66-Ce were characterised to confirm the integrity of the structure, the stability of functional groups on the surface and the thermal stability. Activated samples were used for removal harmful anionic dye (methyl orange) (MO) from wastewater. Batch adsorption process was relied to investigate the competition between those MOFs for removing MO from aqueous solution. Based on the results, at a higher initial concentration, the maximum MO uptake was achieved by UiO-66-Ce which was better than modified-UiO-66. They adsorbed 71.5 and 62.5 mg g-1 respectively. Langmuir and Freundlich isotherms were employed to simulate the experimental data. In addition, Pseudo first order and Pseudo second order equations were used to describe the dynamic behaviour of MO through the adsorption process. The high adsorption capacities on these adsorbents can make them promised adsorbents in industrial areas.


2021 ◽  
Author(s):  
Richard Czikhardt ◽  
Juraj Papco ◽  
Peter Ondrejka ◽  
Peter Ondrus ◽  
Pavel Liscak

<p>SAR interferometry (InSAR) is inherently a relative geodetic technique requiring one temporal and one spatial reference to obtain the datum-free estimates on millimetre-level displacements within the network of radar scatterers. To correct the systematic errors, such as the varying atmospheric delay, and solve the phase ambiguities, it relies on the first-order estimation network of coherent point scatterers (PS).</p><p>For vegetated and sparsely urbanized areas, commonly affected by landslides in Slovakia, it is often difficult to construct a reliable first-order estimation network, as they lack the PS. Purposedly deploying corner reflectors (CR) at such areas strengthens the estimation network and, if these CR are collocated with a Global Navigation Satellite Systems (GNSS), they provide an absolute geodetic reference to a well-defined terrestrial reference frame (TRF), as well as independent quality control.</p><p>For landslides, line-of-sight (LOS) InSAR displacements can be difficult to interpret. Using double CR, i.e. two reflectors for ascending/descending geometries within a single instrument, enables the assumption-less decomposition of the observed cross-track LOS displacements into the vertical and the horizontal displacement components.</p><p>In this study, we perform InSAR analysis on the one-year of Sentinel-1 time series of five areas in Slovakia, affected by landslides. 24 double back-flipped trihedral CR were carefully deployed at these sites to form a reference network, guaranteeing reliable displacement information over the critical landslide zones. To confirm the measurement quality, we show that the temporal average Signal-to-Clutter Ratio (SCR) of the CR is better than 20 dB. The observed CR motions in vertical and east-west directions vary from several millimetres up to 3 centimetres, with average standard deviation better than 0.5 mm.<br>Repeated GNSS measurements of the CR confirm the displacement observed by the InSAR, improve the positioning precision of the nearby PS, and attain the transformation into the national TRF.</p>


1996 ◽  
Vol 22 (3) ◽  
Author(s):  
T. L. Nell ◽  
L. Kamfer ◽  
R. P. Van Der Merwe ◽  
D. J. L. Venter

The personality profile of successful prison warders. In an attempt to develop a personality profile for successful prison warders, scores on CattelFs 16-PF (SA92-form) were obtained from 361 warders employed by the South African Department of Correctional Services. Independent criterion information (tempo of promotion) was also obtained and used as indicator of job success. Using Hotelling's T2, it was found that the first order factor profiles of successful and unsuccessful warders differed significantly. There was no difference in their second order profiles. By means of stepwise discriminant analysis with personality as independent and success (expressed as a dichotomy) as the dependant variable, four first order factors were identified and formulae derived which predicted 14,8 better than chance whether a warder would be correctly classified as successful or not on the dichotomous success criterion. Opsomming In 'n poging om 'n persoonlikheidsprofiel vir suksesvolle bewakingsdienspersoneel saam te stel, is response op Cattell se 16-PF (SA92-vorm) vanaf 361 bewakingsdienspersoneellede werksaam by die Suid-Afrikaanse Departement van Korrektiewe Dienste, verkry. Inligting in terme van onafhanklike kriterium (tempo van bevordering) is ook verkry en gebruik as aanduiding van werksukses. Deur die gebruik van Hotelling se T2 is bepaal dat die ecrsteorde profiele van suksesvolle en onsuksesvolle bewakingsdienslede beduidend van mekaar verskil. Daar is geen beduidende verskil ten opsigte van die tweedeorde profiele gevind nie. Deur middel van stapsgewyse diskriminantontleding, met persoonlikheid as onafhanklike en sukses (uitgedruk as 'n digotomie) as afhanklike veranderlike, is vier eersteorde faktore geidentifiseer en formules saamgestel wat 14,8 beter as toeval kan voorspel of "n persoon suksesvol of onsuksesvol volgens die digotomiese sukseskriterium sal wees.


Mathematics ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 179
Author(s):  
Ramandeep Behl ◽  
Ioannis K. Argyros

Our aim in this article is to suggest an extended local convergence study for a class of multi-step solvers for nonlinear equations valued in a Banach space. In comparison to previous studies, where they adopt hypotheses up to 7th Fŕechet-derivative, we restrict the hypotheses to only first-order derivative of considered operators and Lipschitz constants. Hence, we enlarge the suitability region of these solvers along with computable radii of convergence. In the end of this study, we choose a variety of numerical problems which illustrate that our works are applicable but not earlier to solve nonlinear problems.


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