Photoalpha Reactions in the Region Z = 22 – 30

1972 ◽  
Vol 50 (13) ◽  
pp. 1554-1567 ◽  
Author(s):  
N. A. Keller ◽  
D. B. McConnell
Keyword(s):  
Statistical Model ◽  
Experimental Results ◽  
Angular Distributions ◽  
Model Calculations ◽  
Good Agreement

The yields and angular distributions of photoalphas from seven elements in the region Z = 22–30 were investigated experimentally. Strong anisotropies in the angular distributions from the even–even nuclei were observed. Improved statistical model calculations using the known spins and parities of the low lying levels of the even–even daughters give good agreement with the experimental results.

scholarly journals Isomer ratios for the 88Sr(p,xn) and 88Sr(p,p3n) reactions

1967 ◽  
Vol 45 (22) ◽  
pp. 2711-2721 ◽  
Author(s):  
D. R. Sachdev ◽  
L. Yaffe
Keyword(s):  
Statistical Model ◽  
Spin Density ◽  
Cross Section ◽  
Experimental Results ◽  
Density Parameter ◽  
Model Calculations ◽  
Experimental Values ◽  
Parameter Values ◽  
Good Agreement

Isomeric cross-section ratios for nuclides formed from (p,2n), (p,3n), (p,4n), and (p,p3n) reactions on 88Sr are presented. The experimental results for the 88Sr(p,2n)87Ym,g reaction are compared with statistical-model calculations wherein spin-density parameter values were obtained from various theoretical formalisms. The parameters required to match the calculated and experimental values are in good agreement with those obtained by Vandenbosch et al.

Cross sections and thermonuclear reaction rates for the 24Mg(α,n)27Si, 25Mg(p,n)25Al, 27Al(p,n)27Si, and 28Si(α,n)31S reactions

1980 ◽  
Vol 58 (5) ◽  
pp. 697-702 ◽  
Author(s):  
C. W. Cheng ◽  
J. D. King
Keyword(s):  
Statistical Model ◽  
Cross Sections ◽  
Theoretical Calculations ◽  
Reaction Rates ◽  
Model Calculations ◽  
Model Predictions ◽  
Low Energies ◽  
Positron Decay ◽  
Γ Rays ◽  
Good Agreement

Cross sections for the 24Mg(α,n)27Si, 25Mg(p,n)25Al, 27Al(p,n)27Si, and 28Si(α,n)31S reactions have been measured at energies from near threshold to 3 to 4 MeV above threshold by detection of 0.511 MeV γ-rays in coincidence following positron decay of the product nuclei. Comparison with the theoretical calculations of Woosley, Fowler, Holmes, and Zimmerman shows good agreement between experiment and theory except at low energies where the statistical model calculations tend to overestimate the cross section. Reaction rates have been calculated for temperatures of interest in explosive nucleosynthesis and found to be in good agreement with the statistical model predictions for temperatures above 2 × 109 K.

scholarly journals A Statistical Model Analysis of (p,α)-Reactions on 26Mg, 37Cl and 45Sc

1966 ◽  
Vol 21 (7) ◽  
pp. 1002-1014 ◽  
Author(s):  
A. Richter ◽  
A. Bamberger ◽  
P. von Brentano ◽  
T. Mayer—Kuckuk ◽  
W. von Witsch
Keyword(s):  
Statistical Model ◽  
Correlation Functions ◽  
Direct Interaction ◽  
Angular Distributions ◽  
Final States ◽  
Excitation Functions ◽  
Model Calculations ◽  
Level Width ◽  
The Mean ◽  
Interaction Contribution

The reactions 26Mg (p, α)23Na, 37Cl(p, α)34S, and 45Sc (p, α) 42Ca have been studied. Excitation functions and angular distributions were measured for proton energies 9 to 13.26 MeV, 11 to 11.952 MeV, and 8.5 to 9.412 MeV in steps of 20 keV, 8 keV, and 6 keV, and the transitions into 4, 3, and 5 final states have been resolved, respectively. All the excitation functions exhibit strong fluctuations and were analysed in terms of the various correlation functions, from which the mean level width Γ, the normalised variance, and the amount of direct interaction contribution was derived. Statistical model calculations have been used to fit the averaged angular distributions and an attempt was made to estimate the J-dependence of the mean level width Γ in the compound nuclei excited at about 20 MeV.

45Sc(p, p')45Sc and the Attainment of a Thermal Distribution of States in an Astrophysical Environment

1981 ◽  
Vol 34 (1) ◽  
pp. 105 ◽  
Author(s):  
MR Anderson ◽  
SR Kennett ◽  
ME Sevior ◽  
DG Sargood
Keyword(s):  
Statistical Model ◽  
Energy Range ◽  
Excited States ◽  
Cross Section ◽  
Cross Sections ◽  
Model Calculations ◽  
Thermal Distribution ◽  
Model Cross Section ◽  
Superelastic Scattering ◽  
Good Agreement

Cross sections for inelastic scattering of protons by 45SC have been measured over the energy range Ep = 1?2-2? 5 MeV for protons leading to the second, third, fourth, sixth and eighth excited states of 45SC. Statistical model calculations are' in good agreement with the data. Further statistical model cross section calculations are used in an investigation of the part played by inelastic and superelastic scattering of protons in bringing about a thermal distribution of states in 45SCin a stellar interior under the conditions of explosive silicon burning. This mechanism is found to be effective for temperatures above 4? ?x 109 K

Enhanced Photoyield with Decreasing Film Thickness on Metal-Semiconductor Structures

1996 ◽  
Vol 448 ◽  
Author(s):  
V. Hoffmann ◽  
M. Brauer ◽  
M. Schmidt
Keyword(s):  
Quantum Yield ◽  
Film Thickness ◽  
Layer Thickness ◽  
Experimental Results ◽  
Experimental Result ◽  
Model Calculations ◽  
Hot Carrier ◽  
Semiconductor Structures ◽  
Carrier Scattering ◽  
Good Agreement

AbstractExperimental results of the internal quantum yield Yi associated with the internal photoemission on Au/n-Si structures are presented. The samples were prepared on Si(100) and Si(111) substrates with photoemitter layer thicknesses ranging from 5 nm to 50 nm. The Yi was measured at temperatures between 165 K and 300 K with the photoexciting energy varying from 0.72 eV to 1.07 eV. It was found that the Yi increases with decreasing Au layer thickness with a strong enhancement (40 times) in regard to the conventional Fowler theory. This experimental result is in good agreement with model calculations taking account of hot carrier scattering in the photoemitter layer. Barrier energies are larger than deduced from the Fowler plot.

Inducing Frictional Force to Enhance the Transient Response in Beams

2019 ◽  
Vol 22 (2) ◽  
pp. 88-93
Author(s):  
Hamed Khanger Mina ◽  
Waleed K. Al-Ashtrai
Keyword(s):  
Numerical Analysis ◽  
Transient Response ◽  
Frictional Force ◽  
Damping Ratio ◽  
Experimental Results ◽  
Damping Capacity ◽  
Tightening Force ◽  
Contact Areas ◽  
Good Agreement ◽  
Ansys Workbench

This paper studies the effect of contact areas on the transient response of mechanical structures. Precisely, it investigates replacing the ordinary beam of a structure by two beams of half the thickness, which are joined by bolts. The response of these beams is controlled by adjusting the tightening of the connecting bolts and hence changing the magnitude of the induced frictional force between the two beams which affect the beams damping capacity. A cantilever of two beams joined together by bolts has been investigated numerically and experimentally. The numerical analysis was performed using ANSYS-Workbench version 17.2. A good agreement between the numerical and experimental results has been obtained. In general, results showed that the two beams vibrate independently when the bolts were loosed and the structure stiffness is about 20 N/m and the damping ratio is about 0.008. With increasing the bolts tightening, the stiffness and the damping ratio of the structure were also increased till they reach their maximum values when the tightening force equals to 8330 N, where the structure now has stiffness equals to 88 N/m and the damping ratio is about 0.062. Beyond this force value, increasing the bolts tightening has no effect on stiffness of the structure while the damping ratio is decreased until it returned to 0.008 when the bolts tightening becomes immense and the beams behave as one beam of double thickness.

PHOTOINDUCED NONLINEAR OCTUPOLAR POLARIZATION: TRANSIENT AND PERMANENT REGIMES

1996 ◽  
Vol 05 (04) ◽  
pp. 653-670 ◽  
Author(s):  
CÉLINE FIORINI ◽  
JEAN-MICHEL NUNZI ◽  
FABRICE CHARRA ◽  
IFOR D.W. SAMUEL ◽  
JOSEPH ZYSS
Keyword(s):  
Theoretical Analysis ◽  
Second Harmonic ◽  
Experimental Results ◽  
Polar Field ◽  
Rotational Spectrum ◽  
Dual Frequency ◽  
One Dimensional ◽  
Ethyl Violet ◽  
Disperse Red 1 ◽  
Good Agreement

An original poling method using purely optical means and based on a dual-frequency interference process is presented. We show that the coherent superposition of two beams at fundamental and second-harmonic frequencies results in a polar field with an irreducible rotational spectrum containing both a vector and an octupolar component. This enables the method to be applied even to molecules without a permanent dipole such as octupolar molecules. After a theoretical analysis of the process, we describe different experiments aiming at light-induced noncentrosymmetry performed respectively on one-dimensional Disperse Red 1 and octupolar Ethyl Violet molecules. Macroscopic octupolar patterning of the induced order is demonstrated in both transient and permanent regimes. Experimental results show good agreement with theory.

The early growth process of helium blistering in tungsten and molybdenum: First-principles and statistical model calculations

2021 ◽  
Vol 550 ◽  
pp. 152938
Author(s):  
Kun Jie Yang ◽  
Yue-Lin Liu ◽  
Hai-Hong Li ◽  
Peng Shao ◽  
Xu Zhang ◽  
...  
Keyword(s):  
Statistical Model ◽  
First Principles ◽  
Growth Process ◽  
Early Growth ◽  
Model Calculations

scholarly journals Ensemble Prediction Approach Based on Learning to Statistical Model for Efficient Building Energy Consumption Management

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 405
Author(s):  
Anam Nawaz Khan ◽  
Naeem Iqbal ◽  
Rashid Ahmad ◽  
Do-Hyeun Kim
Keyword(s):  
Energy Consumption ◽  
Statistical Model ◽  
Residential Buildings ◽  
Residential Building ◽  
Experimental Results ◽  
Consumption Patterns ◽  
Ensemble Prediction ◽  
Short Term ◽  
Term Energy ◽  
Prediction Approach

With the development of modern power systems (smart grid), energy consumption prediction becomes an essential aspect of resource planning and operations. In the last few decades, industrial and commercial buildings have thoroughly been investigated for consumption patterns. However, due to the unavailability of data, the residential buildings could not get much attention. During the last few years, many solutions have been devised for predicting electric consumption; however, it remains a challenging task due to the dynamic nature of residential consumption patterns. Therefore, a more robust solution is required to improve the model performance and achieve a better prediction accuracy. This paper presents an ensemble approach based on learning to a statistical model to predict the short-term energy consumption of a multifamily residential building. Our proposed approach utilizes Long Short-Term Memory (LSTM) and Kalman Filter (KF) to build an ensemble prediction model to predict short term energy demands of multifamily residential buildings. The proposed approach uses real energy data acquired from the multifamily residential building, South Korea. Different statistical measures are used, such as mean absolute error (MAE), root mean square error (RMSE), mean absolute percentage error (MAPE), and R2 score, to evaluate the performance of the proposed approach and compare it with existing models. The experimental results reveal that the proposed approach predicts accurately and outperforms the existing models. Furthermore, a comparative analysis is performed to evaluate and compare the proposed model with conventional machine learning models. The experimental results show the effectiveness and significance of the proposed approach compared to existing energy prediction models. The proposed approach will support energy management to effectively plan and manage the energy supply and demands of multifamily residential buildings.

scholarly journals Comparison of Experimental and Numerical Transient Drop Deformation during Transition through Orifices in High-Pressure Homogenizers

2021 ◽  
Vol 5 (3) ◽  
pp. 32
Author(s):  
Benedikt Mutsch ◽  
Peter Walzel ◽  
Christian J. Kähler
Keyword(s):  
High Pressure ◽  
Visual Analysis ◽  
Imaging Technique ◽  
Extensional Flow ◽  
Droplet Breakup ◽  
Experimental Results ◽  
Drop Deformation ◽  
Droplet Deformation ◽  
Shadow Imaging ◽  
Good Agreement

The droplet deformation in dispersing units of high-pressure homogenizers (HPH) is examined experimentally and numerically. Due to the small size of common homogenizer nozzles, the visual analysis of the transient droplet generation is usually not possible. Therefore, a scaled setup was used. The droplet deformation was determined quantitatively by using a shadow imaging technique. It is shown that the influence of transient stresses on the droplets caused by laminar extensional flow upstream the orifice is highly relevant for the droplet breakup behind the nozzle. Classical approaches based on an equilibrium assumption on the other side are not adequate to explain the observed droplet distributions. Based on the experimental results, a relationship from the literature with numerical simulations adopting different models are used to determine the transient droplet deformation during transition through orifices. It is shown that numerical and experimental results are in fairly good agreement at limited settings. It can be concluded that a scaled apparatus is well suited to estimate the transient droplet formation up to the outlet of the orifice.

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