scholarly journals Modified expression for calculating refractive index of ANB8-N type binary semiconductors

2016 ◽  
Vol 4 (2) ◽  
pp. 48
Author(s):  
Abdelhakim Latreche ◽  
Salah Daoud
Keyword(s):  
Refractive Index ◽  
Recent Work ◽  
High Frequency ◽  
Simple Formula ◽  
Correction Term ◽  
Present Approach ◽  
Average Percentage ◽  
Average Percentage Deviation

In their recent work, Bahadur and Mishra proposed a new simple formula between the high-frequency refractive index and optical elec-tronegativity difference, which has been established for large number of ANB8-N type binary semiconductors (groups: I-VII, II-VI, III-V and IV-VI.). In the present work, we have improved their expression by addition a correction term in their proposed formula. The minimum average percentage deviation in the present approach reveals that the modified Bahadur relation proves its identity and soundness compared to that of Bahadur’s and others authors' relations.

scholarly journals Comparison of Factors Affecting Crash Severities in Hit-and-Run and Non-Hit-and-Run Crashes

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Bei Zhou ◽  
Zongzhi Li ◽  
Shengrui Zhang
Keyword(s):  
Comparison Group ◽  
Reference Group ◽  
Multinomial Logistic Regression ◽  
Crash Severity ◽  
Property Damage ◽  
Average Percentage ◽  
Crash Data ◽  
Hit And Run ◽  
The Impact ◽  
Average Percentage Deviation

A hit-and-run (HR) crash occurs when the driver of the offending vehicle flees the crash scene without reporting it or aiding the victims. The current study aimed at contributing to existing literatures by comparing factors which might affect the crash severity in HR and non-hit-and-run (NHR) crashes. The data was extracted from the police-reported crash data from September 2017 to August 2018 within the City of Chicago. Two multinomial logistic regression models were established for the HR and NHR crash data, respectively. The odds ratio (OR) of each variable was used to quantify the impact of this variable on the crash severity. In both models, the property damage only (PDO) crash was selected as the reference group, and the injury and fatal crash were chosen as the comparison group. When the injury crash was taken as the comparison group, it was found that 12 variables contributed to the crash severities in both HR and NHR model. The average percentage deviation of OR for these 12 variables was 34%, indicating that compared with property damage, HR crashes were 34% more likely to result in injuries than NHR crashes on average. When fatal crashes were chosen as the comparison group, 2 variables were found to be statistically significant in both the HR and the NHR model. The average percentage deviation of OR for these 2 variables was 127%, indicating that compared with property damage, HR crashes were 127% more likely to result in fatalities than NHR crashes on average.

scholarly journals Determination of the Iodine Content of Some Commonly Consumed Foods in Zaria Metropolis, Nigeria, Using PCNAA and Sandell-Kolthoff Reaction

2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
T. Muhammad ◽  
A. Uzairu ◽  
M. S. Sallau ◽  
M. O. A. Oladipo
Keyword(s):  
Neutron Activation Analysis ◽  
Standard Deviation ◽  
Test Score ◽  
Research Reactor ◽  
Iodine Content ◽  
Food Samples ◽  
Average Percentage ◽  
Average Percentage Deviation ◽  
Percentage Standard Deviation

The Nigerian Research Reactor-1 was employed in the analysis of iodine in local food samples at an operating flux of 5.0×1011 ncm−2 s−1. Preconcentration neutron activation analysis (PCNAA) was compared against the most common spectroscopic (Sandell-Kolthoff reaction) technique, giving a concentration range of 0.295 to 2.960 mg/Kg and 0.264 to 2.725 mg/Kg, respectively, with an average percentage deviation of 11.34% and a positive correlation between the methods at 0.89. PCNAA and Sandell-Kolthoff spectroscopy of NIST 1548a reported values of 0.759±0.06 mg/Kg and 0.751±0.05 with Student’s t-test score of 1 and 0.95 and percentage standard deviation of 0 and 1.12%, respectively.

An approximate method in high-frequency scattering

1962 ◽  
Vol 58 (4) ◽  
pp. 662-670
Author(s):  
A. Sharples
Keyword(s):  
Boundary Condition ◽  
Circular Cylinder ◽  
Integral Representation ◽  
Sound Wave ◽  
High Frequency ◽  
Correction Term ◽  
Scattering Coefficient ◽  
Extended Form ◽  
Geometrical Acoustics ◽  
Plane Sound

ABSTRACTThe diffraction of a high-frequency plane sound wave by a circular cylinder is investigated when the boundary condition on the cylinder is expressed by means of an equation of the form The special feature of this investigation is that an extended form of the Kirchhoff-Fresnel theory of diffraction is used to find an integral representation for the scattering coefficient. In order to avoid the complicated analysis which would be necessary to evaluate the integrals concerned, the more natural geometrical acoustics approach is used to find the first correction term in the scattering coefficient. Numerical results are given for large and small values of the impedance Z.

scholarly journals A New Method of De-Aliasing Large-Scale High-Frequency Barotropic Signals in the Mediterranean Sea

2020 ◽  
Vol 12 (13) ◽  
pp. 2157
Author(s):  
Denghui Hu ◽  
Yongsheng Xu
Keyword(s):  
Mediterranean Sea ◽  
High Frequency ◽  
Average Method ◽  
Tide Gauge ◽  
Spatial Average ◽  
Eof Analysis ◽  
Analysis Method ◽  
The West ◽  
Satellite Altimeter ◽  
Average Percentage

With the development of satellite observation technology, higher resolution and shorter return cycle have also placed higher demands on satellite data processing. The non-tide high-frequency barotropic oscillation in the marginal sea produces large aliasing errors in satellite altimeter observations. In previous studies, the satellite altimeter aliasing correction generally relied on a few bottom pressure data or the model data. Here, we employed the high-frequency tide gauge data to extract the altimeter non-tide aliasing correction in the west Mediterranean Sea. The spatial average method and EOF analysis method were adopted to track the high-frequency oscillation signals from 15 tide gauge records (TGs), and then were used to correct the aliasing errors in the Jason-1 and Envisat observations. The results showed that the EOF analysis method is better than the spatial average method in the altimeter data correction. After EOF correction, 90% of correlation (COR) between TG and sea level of Jason-1 has increased ~5%, and ~3% increase for the Envisat sea level; for the spatial average correction method, only ~70% of Jason-1 and Envisat data at the TGs location has about 2% increase in correlation. The EOF correction reduced the average percentage of error variance (PEL) by ~30%, while the spatial average correction increased the average percentage of PEL by ~20%. After correction by the EOF method, the altimeter observations are more consistent with the distribution of strong currents and eddies in the west Mediterranean Sea. The results prove that the proposed EOF method is more effective and accurate for the non-tide aliasing correction.

An improved solution to the fourth moment equation for intensity fluctuations

1983 ◽  
Vol 386 (1791) ◽  
pp. 461-474 ◽  
Keyword(s):  
High Frequency ◽  
Correction Term ◽  
Approximate Solutions ◽  
Moment Equation ◽  
Solution Procedure ◽  
Fourth Moment ◽  
Basic Solution ◽  
Numerical Work ◽  
First Order ◽  
First Order Correction

An approximate solution is presented for the fourth moment equation that describes fluctuations of intensity in a wave propagating through a randomly fluctuating medium. The solution is valid for high frequency or relatively strong fluctuations in the medium. The solution procedure is straightforward and at zero order agrees with previously derived approximate solutions. However, the present method is much more direct and more easily extended to complicated problems. Indeed, the first order correction to this basic solution is also determined and it is found that significantly better agreement with previous numerical work is obtained. In addition, knowledge of the correction term allows approximate estimates to be made for the error involved in using the basic solution.

scholarly journals Investigating Quick Speech-in-Noise Comprehension in Adult Bimodal Users

2021 ◽  
Author(s):  
Javad Fakhri ◽  
Nematollah Rouhbakhsh ◽  
Reza Hoseinabadi ◽  
Farzaneh Fatahi ◽  
Mahsa Sepehernejad ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
High Frequency ◽  
Speech Comprehension ◽  
Signal To Noise ◽  
Average Percentage ◽  
Speech In Noise ◽  
Adult Participants ◽  
Frequency Components ◽  
The Right ◽  
Technological Limitations

Introduction: The use of cochlear implants, due to technological limitations, causes problems in speech comprehension in the presence of noise. This study aimed to evaluate the speech-in- noise (SIN) comprehension with emphasis on high-frequency components between users of different bimodal adult. Materials and Methods: This study was conducted on 33 adult participants with a mean age of 36 years using bimodal (cochlear implant in one ear and hearing aid in another ear: CI/HA) style of different companies. Quick SIN with emphasis on high-frequency components was performed on the participants using an audiometer, an amplifier, and one speaker. Results: Comparing the average percentage of correct answers from the word recognition test in the presence of noise in bimodal users showed that the Cochlear brand provides a better signal-to-noise (SNR) compare to other brands. Our result shows that bimodal users of Advance bionic and Med-El groups have better performance in speech recognition than other brands. Conclusion: Bimodal users of Advance bionic and Med-El have better SNR loss than other brands. Besides, further studies on different ages can be helpful to make the right decision in this regard.

Optical properties of Al-doped ZnO thin films obtained by the method of high-frequency magnetron sputtering

2021 ◽  
pp. 2150189
Author(s):  
A. Kashuba ◽  
H. Ilchuk ◽  
R. Petrus ◽  
I. Semkiv ◽  
O. Bovgyra ◽  
...  
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
High Frequency ◽  
Optical Constants ◽  
Zno Thin Films ◽  
Optical Parameters ◽  
Single Oscillator ◽  
Doped Zno

The optical constants and thickness of Al-doped ZnO (ZnO:Al(2.5 wt.%)) thin films prepared by high-frequency magnetron sputtering method are determined. ZnO:Al thin films are crystallized in the hexagonal structure from XRD studies. The optical constants and the bandgap of the films under study have been determined. Optical properties (refractive index [Formula: see text], absorption coefficient [Formula: see text], extinction coefficient [Formula: see text], dielectric functions [Formula: see text] and optical conductivity [Formula: see text]) of thin films and thickness [Formula: see text] can be determined from the transmission spectrum. The dispersion of the refractive index was explained using a single oscillator model. Single oscillator energy and dispersion energy are obtained from fitting. Optical parameters of the films were determined using the Cauchy, Sellmeier and Wemple models. The increasing value of dispersion parameter for polycrystalline thin films than for single crystals is observed. The fundamental absorption edge position (3.26 eV) in the transmittance spectrum of studied thin films corresponds to the values that are typical for ZnO:Al compound. No significant increase of the bandgap width was revealed by comparing ZnO:Al thin films with the known results of the optical studies of ZnO thin films. Possible reasons of such behavior were analyzed and the influence of bandgap increase on spectral behavior of optical functions are investigated. The material optical parameters such as normalized integrated transmission, zero and high-frequency dielectric constant, density of state effective mass ratio were also calculated.

Sign in / Sign up

Export Citation Format

Share Document