Abstract. The surrogate-reactionmethod is an indirect way of determining cross sections for reactions that proceed through a compound nucleus. This technique may enable neutron-induced cross sections to be extracted for short-lived nuclei that otherwise cannot be measured. However, the validity of the surrogate method for extracting capture cross sections has to be investigated. In this work we study the reactions 238 U(d,p) 239 U, 238 U( 3 He,t) 238 Np, 238 U( 3 He, 4 He) 237 U as surrogates for neutron-
Neutron-induced cross sections of short-lived nuclei are crucial for fundamental nuclear physics, astrophysics and also for applications such as reactor physics. In particular, (n, ) cross sections on minor actinides are one of the largest sources of uncertainty in modelling new reactors for nuclear waste transmutation using fast neutrons. However, very often the high radioactivity of the actinide samples makes the direct measurement of these cross sections extremely difficult. The surrogate-reactionmethod is an indirect way of determining cross sections for compound-nuclear reactions. This method was first
Abstract. The surrogate reactionmethod is an indirect way of determining cross sec- tions for nuclear reactions that proceed through a compound nucleus. In this method, the compound nucleus is produced via an alternative (surrogate) reaction and its decay (by fission, gamma or neutron emission) is measured in coincidence with the outgoing ap- propriate charged particle. This technique has enabled neutron-induced cross sections to be extracted for nuclear reactions on short-lived nuclei that otherwise could not be mea- sured. The CENBG collaboration has successfully applied this technique to determine the neutron-induced fission cross sections of several short-lived nuclei such as 233 Pa, 242 , 243 Cm
Introduction: Escherichia coli O157:H7, as a pathogenic agent, can be transmitted through the foods including meat, meat products, dairy products, vegetables and water. The World Health Organization has recommended that all countries in the world, especially developing countries, should consider the investigation of E. coli O157:H7 as a research priority. The aim of this study was to determine the frequency of E. coli O157:H7 in meat of cow, sheep, goat, and camel in Kerman province of Iran using culture and polymerase chain reaction (PCR) methods.
Mathematical model is unavailable, the parameters must be determined experimentally. Controller tuning is the process of determining the controller parameters which produce the desired output . Controller tuning allows for optimization of a process and minimizes the error between the variable of the process and its set point .Types of controller tuning methods include the trial and error method, and process reaction curve methods . The most common classical controller tuning methods are the Ziegler-Nichols and process reaction curve methods. These methods are often used when the mathematical model of the system is not available. The Ziegler-Nichols method can be used for both closed and open loop systems, while process reactionmethod is typically used for open loop systems . A closed-loop control system is a system which uses feedback control.
In this work, the effect of acidity of the working solution on the properties of polyoxyethylene monosorbitan laurate was investigated by a spectroscopic method. Since the substance under study does not absorb light waves in the visible region of the spectrum, the study was conducted in the ultraviolet region. The effect of solution pH on the reaction of the interaction between polysorbate-20 and barium salt to form a cationic particle of polysorbate-barium was also studied by spectrophotometric method. The possibility of reaction between the obtained cationic particle of polysorbate- barium and the anions of 12-molybdophosphate and 12-tungstenphosphate heteropoly acids was investigated and the nature of the bond in the obtained compounds was determined. The composition of the complexes and the ratio of the components were determined by the saturation method at a wavelength of 265 nm. The results of these studies can be used in the development of a new method for the determination of polysorbate-20 in industrial products ionometric method using potentiometric sensors reversible to polysorbate-20.
In this paper, the homotopy analysis method is applied to non-linear reaction diffusion system of Lotka-Volterra type subject of extensive numerical and analytical studies. The comparisons of the other analytical techniques are presented in tables to show the accuracy of this method. The results show that the homotopy analysis method is more reliable than the other available techniques giving the advantage of the choice of some quantities such as initial guess, auxiliary function, auxiliary parameter that play an important role in the convergence of the series solution.
From the Research, it can be concluded that the experts involved in the assessment found that in the criteria related to Technology Maturity, Technology Availability and Initial Investment Cost are more important than any other criteria. The results of this study can be useful to develop a comprehensive sustainable Energy model for a developing country like India. It should be noted that the model’s application is country-specific, since the strategic criteria depend on the country’s specific Biogas energy characteristics. The method used and the results obtained from this study can be used in the further research.
A discrete monotone iterative method is reported here to solve a space-fractional nonlinear diﬀusion–reaction equation. More precisely, we propose a Crank–Nicolson discretization of a reaction–diﬀusion system with fractional spatial derivative of the Riesz type. The ﬁnite-diﬀerence scheme is based on the use of fractional-order centered diﬀerences, and it is solved using a monotone iterative technique. The existence and uniqueness of solutions of the numerical model are analyzed using this approach, along with the technique of upper and lower solutions. This methodology is employed also to prove the main numerical properties of the technique, namely, the consistency, stability, and convergence. As an application, the particular case of the space-fractional Fisher’s equation is theoretically analyzed in full detail. In that case, the monotone iterative method guarantees the preservation of the positivity and the boundedness of the numerical approximations. Various numerical examples are provided to illustrate the validity of the numerical approximations. More precisely, we provide an extensive series of comparisons against other numerical methods available in the literature, we show detailed numerical analyses of convergence in time and in space against fractional and integer-order models, and we provide studies on the robustness and the numerical performance of the discrete monotone method.
We have developed an improved method for the quan- tification of DNA damage caused by apoptosis and/or necrosis. Linde et al. also reported a new TUNEL assay using a scintillating microplate . However as a radio isotope is used in their method, and the procedure is time consuming, it is not convenient. Compared with their method, our improved method is a simple and repro- ducible technique for quantitatively evaluating DNA da- mages caused by not only apoptosis but also chemicals. Many researchers are currently examining the relation- ship between apoptosis and numerous biologic funct- ions in various organisms. We expect that our improved method will contribute to the progress in this field.
as a catalyst was added to a mixture of water and EtOH (5:1) (6 ml) as solvent and the reaction mixture was sonicated in ultrasonic apparatus with 40 Watt power. The progress of the reaction was monitored by TLC. The reaction mixture was filtered and the precipitate was washed with ethanol. The crude solid product was recrystallized from ethanol to give pure spiroacridine as a target product. Then, all of the products were identified by IR, 1 H NMR,
composite promoted oximation of various carbonyl compounds by hydroxylamine hydrochloride in oil bath (70- 80 °C) under solvent-free conditions. aldoximes and ketoximes were obtained in high yields within 10 to 15 min. This method offers some advantages in term of clean reaction conditions, easy work-up procedure, short reaction time, and suppression of any side product. So we think that NH 2 OH•HCl/SiO 2 @FeSO 4 Nano composite system could
room temperature. The reaction mixture was allowed to stir for 8 h. After completion, the solvent was removed under reduced pressure and the obtained precipitate was washed with a mixture of n-Hexane and EtOAC to give compounds 3.
The proposed method is simple, accurate, precise, sensitive, very rapid, low cost and relatively selective compared to the official method. Furthermore, the proposed method does not require elaboration of procedures, which is usually associated with chromatography methods. The proposed method could be applied successfully for screening the antibacterial activity of penicillamine: ruthenium complex in different concentrations.
reaction time lasted for 1 hour. Solvothermal synthesis experiment was conducted three times, with SLS surfactant amounts of: 1 ml, 3 ml and 5 ml, for determination of sur- factant amount effect on the surface modification of graphene sheets. Graphene sheets with modified surface by SLS surfactant were characterized by high resolution trans- mission electron microscope (HRTEM) Technai F-20 S-Twin equipped with an Energy dispersive X-ray spectroscopy (EDX) detector for elemental analysis at 200 keV. The HRTEM samples were prepared by placing a drop of surface modified by SLS graphene sheets solution (in ethanol) on a holey carbon-coated copper grid. The excess solvent was evaporated and the specimen was dried in a vacuum overnight. X-ray photoelec- tron analysis was carried out on Thermo Scientific XPS spectrometer. Raman spectrum was collected on HORIBA Jobin Yvon HR800 spectrometer, with He-Ne laser at 516 nm. ATR-FTIR spectra were recorded using the JASCO FT/IR-6300 spectrometer. Atomic force microscopy analyses were conducted on 5500 AFM (N9410S) Keysight Technologies, Inc., with measurement mode: AAC (acoustic ac mode in air).
In order to develop a general, practicable and an environmentally benign method for the synthesis of spiro azaheterocycles, the reaction between acenaphthenequinone (1), sarcosine (2) and Knoevenagel adduct (3) was investigated (Scheme 1) in different solvents and the results are listed in Table 1. It is noteworthy to mention that the polar solvents afforded better yield than the nonpolar ones and the best result was obtained in TFE.
The method of images is used to study the charge distribution for cases where Coulomb’s law de- viates from the inverse square law. This method shows that in these cases some of the charge goes to the surface, while the remainder charge distributed over the volume of the conductor. In accord with the experimental work, we show that the charge distribution will depend on the photon rest mass and is very sensitive to it; a very small value of the rest of mass of the photon will create deviation from Coulomb’s law.
Out of two standard methods i.e.; insertion method and replacement method, here in this work the dithiocarbamate complexes were prepared by replacement reaction in which amines first allowed to react with CS2 in presence of sodium hydroxide than the sodium salt of dithiocarbamate reformed allowed to react with metal salts in appropriate ratio.
zyme-substrate complex v and enzyme E. The dimen- sionless technique applies to reduce the non-linear sys- tem of ODE. The HPM was used for a simple enzyme reaction (Eq.1) [1,3]. We have used this method for our case study, and have obtained an analytical approximate solution. Furthermore, a simple approach technique (SIM) was applied. This consisted of three iterations (steps). The approximate solution of the second step is similar to the classical method (HPM) (see Figures 6-10 and Fig- ures 16-20). We have also used the idea of the second norm to determine the best iteration for the problem. So, it is clear that the second iteration method is quite similar to the HPM. Consequently, Figure 21 shows that the second iteration is the appropriate one (see Figure 21 for the H-S2 values). Thus, the SIM technique could be ap- plied to some other complex chemical reactions to find appropriate solutions, and to describe the behaviour of their parameters. For example, it could be applied to many open path ways in terms of biochemical reactions . In addition, we highly recommend applying the simple approach (SIM) to describe the approximate solu- tions of complex enzyme reactions , the reaction mechanism of competitive inhibitions, and the reaction scheme of allosteric inhibitions .