The Influence of Power Mode on Ir-Leds Resistance to the Irradiation with Fast Neutrons

2015 ◽  
Vol 770 ◽  
pp. 518-521 ◽  
Author(s):  
A.V. Gradoboev ◽  
V.V. Sednev
Keyword(s):  
Fast Neutrons ◽  
Radiation Defects ◽  
Emissive Power ◽  
Defective Structure ◽  
Second Stage ◽  
Whole Process ◽  
Forward Current ◽  
Fast Neutron Irradiation ◽  
Power Mode ◽  
Partial Annealing

In this paper we present the results of investigation of the power mode influence on the resistance to fast neutron irradiation of IR-LEDs based on AlGaAs heterostructures. The investigation shows that there are 2 stages of LED emissive power lowering. At the first stage the emissive power decreases due to reorganization of existing defective structure. At the second stage it happens as the result of radiation defects introduction. The rate of defects introduction that influences the emissive power lowering at the first stage in the space charge region of the embedded p-n junction is higher than in the neutral region. The forward current flowing under irradiation results in partial annealing of introduced defects and consequently to resistance growth at the first stage of emissive power lowering. The LED power mode doesn’t contribute essentially to the power lowering at the second stage while observed difference is due to decrease of contribution of the first stage to the whole process of emissive power lowering.

scholarly journals Two-stage air stripping combined with hydrolysis acidification process for coal gasification wastewater pretreatment

2019 ◽  
Vol 79 (11) ◽  
pp. 2185-2194 ◽  
Author(s):  
Xiurong Chen ◽  
Xiaoli Sun ◽  
Xiaoxiao Wang ◽  
Peng Xu ◽  
Chenchen Yang ◽  
...  
Keyword(s):  
Biological Treatment ◽  
Coal Gasification ◽  
Ammonium Ion ◽  
Air Stripping ◽  
Second Stage ◽  
Whole Process ◽  
Volatile Phenol ◽  
Coal Gasification Wastewater ◽  
Gas Washing ◽  
Hydrolysis Acidification

Abstract Coal gasification wastewater is mainly from gas washing, condensation and purification processes in the gas furnace with high NH3-N (nitrogen in water in the form of free ammonia (NH3) and ammonium ion (NH4+)), TN (total nitrogen) and refractory organics content, which will inhibit the subsequent biological treatment. The ‘air stripping – hydrolysis acidification – air stripping’ process was proposed as the pretreatment for coal gasification wastewater to improve the biodegradability and nitrogen removal, which could reduce the subsequent biological treatment load. The first-stage air stripping process before hydrolysis acidification could achieve a significant removal of NH3-N (97.0%) and volatile phenol (70.0%), reducing the corresponding toxicity on hydrolysis acidification. The group with air stripping had more abundant microbial communities and a more effective organic degradation performance in hydrolysis acidification than that without air stripping. The second-stage air stripping removed NH3-N released from hydrolysis acidification, and significantly reduced the TN concentration in effluent. The whole process achieved a TN removal from 2,000 ± 100 mg/L to 160 ± 80 mg/L, and a total phenols removal from 700 ± 50 mg/L to 80 ±20 mg/L.

On Linkage and Revaluation

1980 ◽  
Vol 15 (1) ◽  
pp. 79-105 ◽  
Author(s):  
Israel Gilad
Keyword(s):  
Tort Law ◽  
Breach Of Contract ◽  
The Real ◽  
Second Stage ◽  
Whole Process ◽  
Injured Party ◽  
Compensation For Damage ◽  
Definition Of ◽  
Two Stages

The breach of contract or commission of a civil wrong gives rise to a right of the injured party to compensation for damage caused by the violation of his right. In principle, the amount of money to be received as compensation is determined in two stages: the first stage is the establishment of the real scope of the compensable damage, i.e. the definition of the loss or detriment with respect to which the victim is entitled to compensation; the second stage is the monetary assessment of the compensable damage—translating the loss or detriment into monetary units which will reflect the financial value of such loss or damage. The whole process is governed by the higher principle ofrestitutio in integrum, i.e. restoring the victim to his former position, which in the field of tort law means restoration of the victim to his position prior to the commission of the tort, and, in the field of contracts, means bringing him to the situation in which he would have been had the agreement been honoured.

scholarly journals Combination Estimation of Smoothing Spline and Fourier Series in Nonparametric Regression

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Ni Putu Ayu Mirah Mariati ◽  
I. Nyoman Budiantara ◽  
Vita Ratnasari
Keyword(s):  
Fourier Series ◽  
Least Squares ◽  
Nonparametric Regression ◽  
Simulated Data ◽  
Smoothing Spline ◽  
Penalized Least Squares ◽  
Second Stage ◽  
Whole Process ◽  
Mixed Estimator ◽  
The Mean

So far, most of the researchers developed one type of estimator in nonparametric regression. But in reality, in daily life, data with mixed patterns were often encountered, especially data patterns which partly changed at certain subintervals, and some others followed a recurring pattern in a certain trend. The estimator method used for the data pattern was a mixed estimator method of smoothing spline and Fourier series. This regression model was approached by the component smoothing spline and Fourier series. From this process, the mixed estimator was completed using two estimation stages. The first stage was the estimation with penalized least squares (PLS), and the second stage was the estimation with least squares (LS). Those estimators were then implemented using simulated data. The simulated data were gained by generating two different functions, namely, polynomial and trigonometric functions with the size of the sample being 100. The whole process was then repeated 50 times. The experiment of the two functions was modeled using a mixture of the smoothing spline and Fourier series estimators with various smoothing and oscillation parameters. The generalized cross validation (GCV) minimum was selected as the best model. The simulation results showed that the mixed estimators gave a minimum (GCV) value of 11.98. From the minimum GCV results, it was obtained that the mean square error (MSE) was 0.71 and R2 was 99.48%. So, the results obtained indicated that the model was good for a mixture estimator of smoothing spline and Fourier series.

scholarly journals Computer Modeling of Displacement Cascades in Beryllium Irradiated with Intensive Neutron Flux

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
T. Troev ◽  
N. Nankov ◽  
L. Petrov ◽  
E. Popov
Keyword(s):  
Neutron Flux ◽  
Fast Neutron ◽  
Computer Modeling ◽  
Computer Simulations ◽  
Neutron Fluence ◽  
Fast Neutrons ◽  
Radiation Defects ◽  
Helium Concentration ◽  
Vacancy Clusters ◽  
Displacement Cascades

Computer simulations of the radiation defects created in beryllium irradiated by fast neutrons (E>0.1 MeV) using the Geant4 and SRIM packages were carried out. The atom cascade displacements in Be at a neutron fluence of 1.6×1020 n/cm2 were determined to be 0.06 dpa and the helium concentration was calculated to be 168 appm. The concentration of 6Li has been estimated to be 5% in comparison to the He concentration. Nanoscale calculations were done in 30×30×30 nm cube of fast neutron-irradiated Be. A correlation between the Be primary knock-on atom (PKA) energies and the damage cascades has been established. The final defect distributions of single vacancies, divacancies, and small vacancy clusters were examined. Our results indicate that the damages caused by He atoms are about 3 times less than damages caused by Be primary knock-on atoms (PKAs).

scholarly journals The Evolution of Intumescent Char in Flame-Retardant Coatings Based on Amino Resin

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 709
Author(s):  
Wei Song ◽  
Muting Wu ◽  
Yanrong He ◽  
Yuzhang Wu ◽  
Wei Qu
Keyword(s):  
Flame Retardant ◽  
Urea Formaldehyde ◽  
Formaldehyde Resin ◽  
Chemical Structures ◽  
Second Stage ◽  
Whole Process ◽  
Amino Resin ◽  
Three Stages ◽  
Flame Retardant Properties ◽  
Modified Urea

Intumescent flame-retardant (IFR) coatings have been gaining more attention. The behaviors of intumescent char in IFR coatings play the most important role in its flame-retardant properties. However, the evolution of intumescent char throughout the whole process of protection is still unclear. In this study, both the formation and shrinkage of char were studied. The formulation of IFR includes melamine modified urea-formaldehyde resin (MUF), ammonium polyphosphate (APP) and pentaerythritol (PER). The flame-retardant properties of the coating were measured by the cone calorimeter (CONE). The evolution of the volume and the pore size distribution of char were monitored. The morphological and chemical structures were characterized by the scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results show that the evolution of intumescent char could be divided into three stages. More than 50% shrinkage of char occurs in the second stage. There are obvious transformations of the morphological and chemical structures of char between the different stages.

scholarly journals On models for estimating the post-radiation defect state of the -phase

2020 ◽  
pp. 47-60
Author(s):  
V. I. Bobrovskii ◽  
Keyword(s):  
Neutron Diffraction ◽  
Fast Neutrons ◽  
Defect State ◽  
Radiation Defects ◽  
Structural Effects ◽  
X Ray ◽  
Reactor Steels ◽  
Post Radiation ◽  
Antisite Defects ◽  
Initial Crystal

Processes that take place in the precipitates of -phase under irradiation with fast neutrons are topical and draw attention when one searches for ways of improving radiation resistance of structural reactor steels. A special feature of these processes is that the formation of vacancies and interstices proceeds at the background of a disordering of the initial crystal lattice, which mani-fests itself in the formation of antisite defects. X-ray and neutron diffraction techniques are efficient tools of studying changes that occur in the post-radiation structural state of such systems. However, interpretation of the experimental results calls for more complicated models for the description of structural effects exerted by accumulation of radiation defects in the material than those developed before for elementary metals. Several models are proposed in this paper.

scholarly journals Изучение микроструктуры кристаллов Si, подвергнутых облучению быстрыми Н-=SUP=-+-=/SUP=--ионами и термообработке, методами высокоразрешающей трехкристальной рентгеновской дифрактометрии и электронной просвечивающей микроскопии

2019 ◽  
Vol 61 (10) ◽  
pp. 1754
Author(s):  
В.Е. Асадчиков ◽  
И.Г. Дьячкова ◽  
Д.А. Золотов ◽  
Ф.Н. Чуховский ◽  
Л.М. Сорокин
Keyword(s):  
Electron Microscopy ◽  
Higher Education ◽  
Heat Treatment ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Structural Features ◽  
Radiation Defects ◽  
Defective Structure ◽  
X Ray ◽  
Transmission Electron

The structural features of the formation of radiation defects in proton-implanted layers of silicon wafers during their heat treatment are studied. New data on the nature, characteristics and concentration of microdefects in Si crystals irradiated with protons with energies of 100+200+300 Kev, with a total dose of 2·1016 ion/cm2, and the evolution of the defective structure during heat treatment in a wide temperature range from 200 to 1100°C were obtained from the analysis of the results of studies by high-resolution three-crystal X-ray diffractometry and transmission electron microscopy. This work was supported by the Ministry of Science and Higher Education within the State assignment FSRC «Crystallography and Photonics» RAS.

scholarly journals Power mode of axisymmetric high-speed combined extrusion of bimetallic road milling picks

2021 ◽  
Vol 66 (4) ◽  
pp. 411-419
Author(s):  
K. Yu. Bykov ◽  
I. V. Kachanov ◽  
I. M. Shatalov
Keyword(s):  
High Speed ◽  
Axisymmetric Deformation ◽  
Stage Model ◽  
Equal Area ◽  
Second Stage ◽  
Industrial Implementation ◽  
Third Stage ◽  
Power Mode ◽  
High Degree ◽  
Special Case

The article presents a simplified three-stage model of the transition from a flat to axisymmetric deformation during high-speed, combined extrusion of bimetallic road milling picks. The transition is based on the principle of equality of areas, according to which the area of a figure during a flat deformation is replaced by an equal area of a circle. In this case, it is assumed that the kinematically possible field of the slip lines remains unchanged. This approach makes it possible to reduce the number of necessary calculations and at the same time maintain a high degree of correctness of the obtained equations. The first stage shows the transition to a special case of a flat problem, in which a stepped rectangular part is extruded from the original square blank, in which one of the sides is equal to the square side of the original blank. At the second stage of the transition, a flat-step part having square sections along its entire length is extruded from the original square-section blank. Directly at the third stage, the final transition to the axisymmetric deformation of the cutter is formed, in which the area of the square is replaced by the equal area of the circle. The dependences obtained because of solving the axisymmetric problem can be recommended for calculations in the industrial implementation of the technology of high-speed combined extrusion of bimetallic milling picks.

Peculiarities of influence of radiation defects on photoconductivity of silicon irradiated by fast neutrons

2010 ◽  
Vol 46 (4) ◽  
pp. 298-300
Author(s):  
M. Karimov ◽  
Sh. Makhkamov ◽  
Sh. A. Makhmudov ◽  
R. A. Muminov ◽  
A. Z. Rakhmatov ◽  
...  
Keyword(s):  
Fast Neutrons ◽  
Radiation Defects
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