scholarly journals A Method of Correction for Unresolved Levels in Fissile Nuclei

1967 ◽  
Vol 20 (1) ◽  
pp. 73 ◽  
Author(s):  
AR Musgrove
Keyword(s):  
Total Width ◽  
Neutron Width

A method of correcting for unresolved levels in fissile nuclei is described. The method is based on the distribution of the ratio of the reduced neutron width to the total width of a level. Calculations are carried out on three sets of data for 233U, and it is shown that approximately one-quarter of the resonance levels are undetected.

scholarly journals Top-induced contributions to H → $$ b\overline{b} $$ and H → $$ c\overline{c} $$ at $$ \mathcal{O}\left({\alpha}_s^3\right) $$

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Roberto Mondini ◽  
Ulrich Schubert ◽  
Ciaran Williams
Keyword(s):  
Top Quark ◽  
Clustering Algorithm ◽  
Percent Level ◽  
Effective Field ◽  
Total Width ◽  
Monte Carlo Code ◽  
Final State ◽  
Fully Differential ◽  
State Selection ◽  
The Impact

Abstract In this paper we present a fully-differential calculation for the contributions to the partial widths H →$$ b\overline{b} $$ b b ¯ and H →$$ c\overline{c} $$ c c ¯ that are sensitive to the top quark Yukawa coupling yt to order $$ {\alpha}_s^3 $$ α s 3 . These contributions first enter at order $$ {\alpha}_s^2 $$ α s 2 through terms proportional to ytyq (q = b, c). At order $$ {\alpha}_s^3 $$ α s 3 corrections to the mixed terms are present as well as a new contribution proportional to $$ {y}_t^2 $$ y t 2 . Our results retain the mass of the final-state quarks throughout, while the top quark is integrated out resulting in an effective field theory (EFT). Our results are implemented into a Monte Carlo code allowing for the application of arbitrary final-state selection cuts. As an example we present differential distributions for observables in the Higgs boson rest frame using the Durham jet clustering algorithm. We find that the total impact of the top-induced (i.e. EFT) pieces is sensitive to the nature of the final-state cuts, particularly b-tagging and c-tagging requirements. For bottom quarks, the EFT pieces contribute to the total width (and differential distributions) at around the percent level. The impact is much bigger for the H →$$ c\overline{c} $$ c c ¯ channel, with effects as large as 15%. We show however that their impact can be significantly reduced by the application of jet-tagging selection cuts.

Morphometric characteristics of the metacestode Echinococcus vogeli Rausch & Bernstein, 1972 in human infections from the northern region of Brazil

2014 ◽  
Vol 89 (4) ◽  
pp. 480-486 ◽  
Author(s):  
F. Almeida ◽  
F. Oliveira ◽  
R. Neves ◽  
N. Siqueira ◽  
R. Rodrigues-Silva ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Morphological Changes ◽  
Northern Region ◽  
Laser Scanning Microscopy ◽  
Health Concern ◽  
Confocal Laser ◽  
Total Width ◽  
Morphometric Characteristics ◽  
Blade Area ◽  
Echinococcus Vogeli

AbstractPolycystic echinococcosis, caused by the larval stage (metacestode) of the small-sized tapeworm, Echinococcus vogeli, is an emerging parasitic zoonosis of great public health concern in the humid tropical rainforests of South and Central America. Because morphological and morphometric characteristics of the metacestode are not well known, hydatid cysts from the liver and the mesentery were examined from patients following surgical procedures. Whole mounts of protoscoleces with rostellar hooks were examined under light and confocal laser scanning microscopy. Measurements were made of both large and small hooks, including the total area, total length, total width, blade area, blade length, blade width, handle area, handle length and handle width. The results confirmed the 1:1 arrangement of hooks in the rostellar pad and indicated, for the first time, that the morphometry of large and small rostellar hooks varies depending upon the site of infection. Light and confocal microscopy images displayed clusters of calcareous corpuscles in the protoscoleces. In conclusion, morphological features of large and small rostellar hooks of E. vogeli are adapted to a varied environment within the vertebrate host and such morphological changes in calcareous corpuscles occur at different stages in the maturation of metacestodes.

Effect of waste rock inclusions on the seismic stability of an upstream raised tailings impoundment: a numerical investigation

2015 ◽  
Vol 52 (12) ◽  
pp. 1930-1944 ◽  
Author(s):  
Behnam Ferdosi ◽  
Michael James ◽  
Michel Aubertin
Keyword(s):  
Ground Motions ◽  
Low Frequency ◽  
Horizontal Displacement ◽  
Waste Rock ◽  
Seismic Stability ◽  
Environmental Damage ◽  
Total Width ◽  
Tailings Impoundment ◽  
Downstream Slope ◽  
Potential Failure

Over the years, seismic activity has been a relatively common cause of tailings impoundment failure. The flow of liquefied tailings from such ruptures can result in very severe consequences, including loss of life and environmental damage. A co-disposal technique consisting of placing waste rock inclusions in tailings impoundments prior to and during tailings deposition was proposed by the authors. The waste rock is placed to create continuous inclusions within the impoundment, which provide a number of environmental and geotechnical benefits, particularly with respect to seismic stability. The results of numerical simulations previously performed have shown that the UBCSAND model can predict the seismic response of tailings. The UBCSAND constitutive model was used to conduct simulations to evaluate of the use of waste rock inclusions to improve the seismic stability of a tailings impoundment. The evaluation consists of numerical analyses of an actual tailings impoundment as constructed (without inclusions), and then assuming that it was constructed with inclusions, subjected to earthquake loads of various energy contents and with different predominant frequencies. The analyses were conducted in static, seismic, and post-shaking phases. The displacement of the surface of downstream slope of the tailings dyke was recorded during the analyses. The results indicate that the presence of waste rock inclusions can significantly improve the seismic behavior of the impoundment by reducing the displacements of the surface of the downstream slope and the extent of potential failure zones. Also, the results show that in most cases, the influence of a low-frequency earthquake on the displacement of the downstream slope of the tailings dyke is more important than that of a high-frequency earthquake. The performances of the tailings impoundment with different configurations of waste rock inclusions (varying width and center-to-center spacing) were classified based on the average normalized horizontal displacement of the downstream slope (ARx) for a range input ground motions. Charts were then developed to show how ARx is influenced by the total width of inclusions, their spacing, and the input ground motions.

Characterization of Melting and Solidification Phenomena in Electromagnetic Punching of Aluminum Tubes

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
De Waele Wim ◽  
Faes Koen ◽  
Van Haver Wim
Keyword(s):  
Plastic Deformation ◽  
Energy Levels ◽  
High Energy ◽  
Effect Of Temperature ◽  
Fracture Mechanisms ◽  
Time Interval ◽  
Short Time Interval ◽  
Total Width ◽  
Premature Failure ◽  
Charging Energy

Electromagnetic punching of tubular products is considered to be a promising innovative perforating process. The required punching energy decreases when using high velocities. Also, less tools are required when compared to conventional mechanical punching. However, the increase in punching speed can involve new strain and fracture mechanisms which are characteristic of the dynamic loading. In high energy rate forming processes the effect of temperature versus time gradient on the material properties becomes important due to the heat accumulated from plastic deformation and friction. The deformation induced heating will promote strain localization in it, possibly degrade its formability and cause premature failure in the regions of high localized strain. The feasibility of the electromagnetic pulse forming process for punching holes in aluminum cylindrical specimens has been investigated on an experimental trial-and-error basis. Experiments were performed using a Pulsar system (model 50/25) with a maximum charging energy of 50 kJ and a discharge circuit frequency of 14 kHz. Microscopic and metallographic inspection of the punched workpieces, together with hardness measurements, was performed to critically evaluate the quality of the cuts. It was observed that damage occurred at part of the edge of the punched hole during some of the perforation experiments. It was evidenced that in most workpieces, especially those performed at higher charging energy levels, a considerably high temperature must have been reached in the regions near the punched hole. The aluminum in this region was assumed to have melted and resolidified. These assumptions were affirmed by the following observations. Microscopic-size precipitates present in the unaffected base metal microstructure, had completely dissolved in that region; shrinkage cavities and dendrite rich regions were clearly visible. Next to this region, a heat affected zone was present where the grain boundaries had partially melted and precipitates partially disappeared. Considerably high temperatures, in the order of 520 to 660 °C, were reached in the regions around the punched holes, leading to melting and resolidification of the material. The total width of the thermally affected regions appeared to be larger at higher energy levels. The combination of heat generated by ohmic heating and by plastic deformation in a very short time interval is the most probable cause of the high peak temperatures that have occurred during the electromagnetic punching process.

scholarly journals Nailfold capillary density is associated with the presence and severity of pulmonary arterial hypertension in systemic sclerosis

2008 ◽  
Vol 68 (2) ◽  
pp. 191-195 ◽  
Author(s):  
H M A Hofstee ◽  
A Vonk Noordegraaf ◽  
A E Voskuyl ◽  
B A C Dijkmans ◽  
P E Postmus ◽  
...  
Keyword(s):  
Systemic Sclerosis ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Capillary Density ◽  
Total Width ◽  
Healthy Controls ◽  
Mean Pulmonary Arterial Pressure ◽  
Microvascular Changes ◽  
Pulmonary Arterial ◽  
Disease Specificity

Objective:The aim of this study was to investigate whether there are differences in capillary nailfold changes in patients with systemic sclerosis (SSc) with and without pulmonary arterial hypertension (PAH), and whether these changes are associated with PAH severity and disease specificity.Methods:Capillary density and loop dimensions were studied in 21 healthy controls, 20 patients with idiopathic PAH (IPAH) and 40 patients with SSc. Of the 40 patients with SSc, 19 had no PAH (SSc–nonPAH) and 21 had PAH (SSc–PAH), of whom eight had PAH during exercise.Results:Capillary density was lower in SSc–PAH compared with patients who had SSc–nonPAH (4.33/mm vs 6.56/mm respectively, p = 0.001), but loop dimensions were equal. In comparison with IPAH, patients with SSc–PAH had reduced capillary density (4.33/mm vs 7.86/mm, p<0.001) and larger loop dimensions (total width 101.05 µm vs 44.43 µm, p<0.001). Capillary density in healthy controls (9.87/mm) was significantly higher when compared with SSc–nonPAH (6.56/mm), SSc–PAH (4.33/mm) and with IPAH (7.86/mm). No differences in capillary dimensions were present between healthy controls and IPAH.Capillary density correlated with mean pulmonary arterial pressure (PAP) at rest in SSc–PAH at rest (r = −0.58, p = 0.039) and IPAH (r = −0.67, p = 0.001).Conclusions:Reduction of nailfold capillary density, but not capillary loop dimensions is associated with PAH, and correlates with the severity of PAH in both SSc and IPAH. This suggests that either systemic microvascular changes play a part in the development of PAH, or that PAH itself contributes to systemic microvascular changes.

Experimental Study of the High Cycle Fatigue of Thin Film Metal on Polyethylene Terephthalate for Flexible Electronics Applications

2009 ◽  
Author(s):  
Khalid Alzoubi ◽  
Susan Lu ◽  
Bahgat Sammakia ◽  
Mark Poliks
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Polyethylene Terephthalate ◽  
Flexible Electronics ◽  
Electrical Resistance ◽  
Thermal Stresses ◽  
Electronic Systems ◽  
Total Width ◽  
Flexible Substrates ◽  
Polyethylene Naphthalate

Flexible electronics represent an emerging area in the electronics packaging and systems integration industry with the potential for new product development and commercialization in the near future. Manufacturing electronics on flexible substrates will produce low cost devices that are rugged, light, and flexible. However, electronic systems are vulnerable to failures caused by mechanical and thermal stresses. For electronic systems on flexible substrates repeated stresses below the ultimate tensile strength or even below the yield strength will cause failures in the thin films. It is known that mechanical properties of thin films are different from those of bulk materials; so, it is difficult to extrapolate bulk material properties on thin film materials. The objective of this work is to study the behavior of thin-film metal coated flexible substrates under high cyclic bending fatigue loading. Polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are widely used substrates in the fabrication of microelectronic devices. Factors affecting the fatigue life of thin-film coated flexible substrates were studied, including thin film thickness, temperature, and humidity. A series of experiments for sputter-deposited copper on PET substrates were performed. Electrical resistance and crack growth rate were monitored during the experiments at specified time intervals. High magnification images were obtained to observe the crack initiation and propagation in the metal film. Statistical analysis based on design of experiments concepts was performed to identify the main factors and factor’s interaction that affect the life of a thin-film coated substrate. The results of the experiments showed that the crack starts in the middle of the sample and slowly grows toward the edges. Electrical resistance increases slightly during the test until the crack length covers about 90% of the total width of the sample where a dramatic increase in the resistance takes place.

scholarly journals VIRTUAL SUPERSYMMETRIC CORRECTIONS IN e+e- ANNIHILATION

1998 ◽  
Vol 13 (24) ◽  
pp. 1987-1996 ◽  
Author(s):  
L. CLAVELLI ◽  
P. W. COULTER ◽  
LEVAN R. SURGULADZE
Keyword(s):  
Total Width ◽  
Leading Order ◽  
Squark Mass ◽  
Supersymmetric Particles

Depending on their masses, supersymmetric particles can affect various measurements in Z decay. Among these are the total width (or consequent extracted value of αs), enhancement or suppression of various flavors, and left–right and forward–backward asymmetries. The latter depend on squark mass splittings and are, therefore, a possible test of the supergravity related predictions. We calculate leading order corrections for these quantities considering in particular the case of light photino and gluino where the SUSY effects are enhanced. In this limit the effect on αs is appreciable, the effect on Rb is small, and the effect on the asymmetries is extremely small.

scholarly journals Neutron width statistics in a realistic resonance-reaction model

2018 ◽  
Vol 98 (1) ◽  
Author(s):  
P. Fanto ◽  
G. F. Bertsch ◽  
Y. Alhassid
Keyword(s):  
Reaction Model ◽  
Neutron Width
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