Empirical Formula For Calculation Research Articles

Numerical Investigation on Aero-Thermodynamic Characteristics of Wedge Shaped Nose Cone of Near Space Supersonic Flight

A numerical investigation on the space (0-46km) aero-thermodynamic characteristics of a nose cone model was performed using commercial software STAR-CCM++. Turbulence model and numerical calculation strategy was validated by the experimental phenomenon captured in a ground high-enthalpy wind tunnel and empirical formula calculation. The purpose of this paper is to discuss the distinctions between the experiment performed in ground high-enthalpy wind tunnel environment and real space flight using the validated numerical strategy, as well as the aero-thermodynamic characteristics of the nose cone model in different flight altitudes and Mach numbers, which will give a guidance to active cooling of spacecraft in real supersonic flight.

Assembly Blast Walls and Concrete Blast Walls Comparative Analysis of Protective Effectiveness

To reduce the terrorist bombings and the occasional blast damage to people and buildings, a style of steel-sandstone-steel assembly blast walls was designed. To analysis the protective effectiveness of blast walls against the blast wave, The concept of overpressure Protective effects coefficient was proposed. The computational model of assembly blast walls was Established and three-dimensional numerical simulation for the assembly blast walls by using ALE and JWL state equation for the product of explosive detonation was Carried out. Empirical formula calculation results and the test results in the Ref are in good agreement. Using this model the protective effects for blast walls of steel plate with sand, blast walls of steel plate with concrete,concrete blast walls and was studied by 3D numerical simulation. The analyses indicate that protective effectiveness of steel-sandstone-steel blast walls was better than the concrete blast walls and the steel-concrete-steel blast walls.

A Study on the Heat Penetrating Coupling Unsteady State Model of Heavy Oil During Steam Flooding

An unsteady model of temperature field coupled with seepage field during thermal recovery process was derived and the solution method was given. Considering the effects of pressure and temperature during the derivation, the variation laws, with different types of constraints, of temperature and pressure changing with time and space were summarized in the model. The deduced governing equations are applied to oil fields with practical data and the comparison of the results with the numerical results and empirical formula calculation results is basically the same. Examples show that the heat penetrating coupling method can analyze dynamic variation of the formation temperature and pore fluid pressure data near borehole wall quantitatively during thermal production in heavy oil reservoir.

Situ Testing Study on Jacking Force of Manual Pipe-Jacking with Engineering

Manual rectangle pipe-jacking technology is adopted to jack the pre-fabricated hollow box girder slowly and evenly into the load bearing wall of masonry structure, and then core beam is poured to form a whole, therefore, the constructions will be gradually located at a “tray” with enough rigidity, which solves the structural damage caused by inadequate bearing capacity of foundation soil or unsymmetrical support. In actual masonry structure protection, there have been successful examples where such technology is used, however, till now its related fundamental problems have not been researched yet. In this paper, based on study of on-site actual measurement, its fundamental is introduced, such items as action mechanism of box girder and soil body, calculation of jacking force and its influencing factors, and more, are discussed and empirical formula for calculation of jacking force is presented.

Empirical Formula for the Electric Field Calculation in Rectangular Slots on Leaky Coaxial Cable

An empirical formula for calculating the electric field distribution in rectangular slots on leaky coaxial cable (LCX) is derived. With the assistance of the formula, the complicated electromagnetic simulation can be avoided, and people who have little knowledge about the electromagnetic field are also possible to design the LCX. The coefficients in the formula are determined by curve-fitting of a large amount of data obtained from numerical method for various structural parameters of the LCX. The empirical formula is valid for LCXs with characteristic impedances of 50 Ω. Results obtained from the empirical formula are compared with those given by numerical method and experiments, and good agreement between them can be seen. The proposed formula provides a simple and effective means to calculate the electric field in rectangular slots on the LCX, which is very useful to the investigation of the radiation characteristics and to the design of the LCX.

Mathematical Relationship between Solar Radiation Intensity and Exterior Wall Temperature

Explore the mathematic relationship between solar radiation intensity and exterior wall temperature according to empirical formula calculation, the measured data and software fitting. Propose a preliminary function between the intensity and the temperature, and analyze the research direction in the future. Attain the conclusion of using exterior wall temperature instead of the current sol-air temperature to calculate the building heat load could save more energy

An empirical formula for calculation of range of charged particles with Z from 2 to 103 and energy from 2.5 MeV/nucleon to 500 MeV/nucleon in beryllium

A new empirical formula for quick estimation of range in beryllium material of charged particles with the charge number from 2 to 103 and with energy in the range from 2.5 to 500 MeV/nucleon has been given. This formula was found based on a table of ranges measured experimentally and calculated up to 1990. It is shown that the differences between the values calculated by our formula and the values tabulated in the table is less than about 2% for all ions in the whole energy range.

SEMI‐empirical and empirical formulas for calculation of K‐shell ionization cross sections by proton impact: a comparison

AbstractAccording to the plane wave Born approximation (PWBA) and the binary encounter approximation (BEA) models, it is possible to fit the cross sections obtained with any atomic element at any particle energy using a scaling law for a K‐shell. The semi‐empirical K‐shell ionization cross sections are then deduced by fitting the available experimental data normalized to their corresponding theoretical values. For the empirical K‐shell ionization cross sections, a third‐order polynomial was used to fit the same experimental data for protons. Our results are compared with the predictions of the ECPSSR theory and with other earlier works. Good agreement is obtained, but it is emphasized that the ultimate solution is to deduce the cross sections by fitting the available experimental data for each element separately. Copyright © 2008 John Wiley & Sons, Ltd.

Separation and Determination of Iron-Containing Proteins via Liquid Chromatography−Particle Beam/Hollow Cathode−Optical Emission Spectroscopy

Presented here is a method for the quantitative determination of iron-containing metalloproteins. Four iron-containing metalloproteins (transferrin, myoglobin, hemoglobin, and cytochrome c) were separated by high-performance liquid chromatography (HPLC) and determined through particle beam/hollow cathode-optical emission spectroscopy (PB/HC-OES) by the Fe (I) 371.9 nm optical emission. Parametric optimization of sample introduction, nebulization, and hollow cathode source conditions is performed for the suite of Fe-metalloproteins. Response curves for the Fe (I) emission were obtained under optimized conditions with detection limits for triplicate injections occurring on the nanogram level for iron ( approximately 24 ng) with variability of <7% RSD over the concentration range of 0.1-100 microg/mL iron in the metalloproteins. Response curves for S (I) emission yielded similar analytical characteristics. Optical emission detection of the liquid chromatography separations of the iron-containing metalloproteins demonstrates the feasibility of the PB/HC-OES system as a simple element-specific detector for liquid chromatography. The retention times of the four analytes are similar to those determined by UV absorbance (216 nm), demonstrating the ability of the PB interface to preserve the chromatographic integrity of the separation. Additionally, empirical formula calculations based on Fe (I) and S (I) emission response ratios provide a much higher level of specificity than single-element protein determination.

THE CALCULATION OF THE SURFACE ENERGY OF HIGH-INDEX SURFACES OF SILICON AT ZERO TEMPERATURE

We used the molecular dynamics simulation based on the Stillinger–Weber (SW) interatomic potential to calculate the high-index surface energies of surfaces containing any of the stereographic surfaces of silicon at zero temperature. An empirical formula based on the structural unit model was generalized for high-index surfaces. Our simulated results show that the generalized formula can give a good estimation of the surface energy and structural feature of the high-index surfaces not only on the edge of stereographic but also within it. Our simulation and empirical formula results reveal that the closest surface has the lowest energy, so the closest (101) surface has the lowest surface energy and the (101), (111) and (001) surfaces are the extremum on the curve of surface energy versus orientation angle. Both the theoretical simulation results and the empirical formula calculation results are consistent with the available first-principles theoretical data.

Non-metal element detection by radio-frequency glow-discharge optical-emission spectrometry (rf-GD-OES) for determination of sol–gel-immobilized nucleotides

A new method is presented for qualitative and quantitative determination of non-metal elements present in organic analyte species immobilized in a sol-gel matrix. Nucleic acids were chosen as well-defined relevant biomolecules for which element ratios could be used for detection and identification. Solid, lyophilized powders of ribose-form nucleotides (AMP, ADP, and ATP) were immobilized/entrapped in a methlytrimethoxysilane (mTMOS) sol-gel matrix and monitored for P (I) 214.9 nm, C (I) 193.0 nm, O (I) 130.2, and N (I) 149.3 nm emission by radio-frequency glow-discharge optical-emission spectroscopy (rf-GD-OES). Using the sol-gel method, analytical blanks were obtained by use of un-doped sol-gels. Empirical formula calculations by use of P (I) and C (I), P (I) and N (I), and P (I) and O (I) emission response ratios demonstrate the versatility of the technique as an element and species-specific detector. Results show there is high correlation between phosphorus and oxygen emission responses and the extent of phosphorylation, demonstrating the capacity of the method to produce vital qualitative and quantitative information for the specific nucleotide. Absolute sub-nanogram detection limits were achieved for all the elements studied.

Structure Elucidation of Degradation Products of the Antibiotic Amoxicillin with Ion Trap MS n and Accurate Mass Determination by ESI TOF

Today, it is necessary to identify relevant compounds appearing in discovery and development of new drug substances in the pharmaceutical industry. For that purpose, the measurement of accurate molecular mass and empirical formula calculation is very important for structure elucidation in addition to other available analytical methods. In this work, the identification and confirmation of degradation products in a finished dosage form of the antibiotic drug amoxicillin obtained under stress conditions will be demonstrated. Structure elucidation is performed utilizing liquid chromatography (LC) ion trap MS/MS and MS3 together with accurate mass measurement of the molecular ions and of the collision induced dissociation (CID) fragments by liquid chromatography electro spray ionization time-of-flight mass spectrometry (LC/ESI-TOF).

Determination of phosphorus and carbon in phosphorylated deoxynucleotides via particle beam/hollow cathode glow discharge optical emission spectroscopy (PB/HC-OES)

A new approach to the qualitative and quantitative determination of nucleic acids is presented. Particle beam hollow cathode optical emission spectroscopy (PB/HC-OES) has been applied to determinations of five nucleotides (AMP, ADP, dATP, dCTP, and dGTP) by monitoring P I 219.9 nm and C I 193.0 nm optical emission. A high level of correlation exists between the phosphorus emission response and the degree of phosphorylation, demonstrating the technique’s ability to produce vital qualitative and quantitative information for specific nucleotides, with detection limits on the single-nanogram level for phosphorus (9 ng) and picogram level for carbon (20 pg), respectively, with RSD <12% for triplicate injections over a concentration range of 10−4–101 μg mL−1. The stoichiometric response suggests that it is possible to identify the various nucleotides by the amount of phosphate present within the nucleotide. Empirical formula calculations on P I and C I emission response ratios demonstrate the potential of the technique as an element specific detector for liquid chromatography (LC).

The Strange Case of Mole Airlines Flight 1023

Practicing computational skills in an introductory chemistry class can often become tedious and repetitive. The scenario presented was developed to provide an opportunity to practice mole conversions, empirical formula calculations, use of significant figures, and logical cause and effect thinking skills as a team or as an individual, and to capture student interest. The practice is easily evaluated by reviewing the solution of the mystery. Over a period of ten or more years of classroom use, the students have always been intrigured by the scenario and been successful in deciphering the mystery and in mastery of the targeted skills.

CHEMiCALC (4000161) and CHEMiCALC Personal Tutor (4001108), Version 4.0 (Ramsay, O. Bertrand)

CHEMiCALC is a thoughtfully designed software package developed for use by high school and general chemistry students, who will benefit from the personal tutor mode that helps to guide them through unit conversion, empirical formula, molecular weight, reaction stoichiometry, and solution stoichiometry calculations.

Thermal degradation and melt viscosity of ultra-high-molecular-weight poly(ethylene terephthalate)

Abstract The thermal degradation and melt viscosity of ultra-high-molecular-weight poly(ethylene terephthalate) (UHMW-PET) with an intrinsic viscosity exceeding 2 dl g −1 were studied in the melt phase under a nitrogen atmosphere. The degradation rate increased with the molecular weight of the polymer. The high degradation rate of UHMW-PET could be interpreted by the differences in the terminal-end-group concentrations. The activation energy for the degradation of UHMW-PET with an intrinsic viscosity ( IV ) of 2.3 dl g −1 was 41 kcal mol −1 . The effect of molecular-weight change on the thermal degradation of UHMW-PET could be simulated by an empirical formula. The melt viscosity of UHMW-PET with M w = 2.3 × 10 5 at 300°C under zero shear was 8 × 10 5 P and the empirical formula for calculation of the melt viscosity was η 0 = 1.45 × 10 −17 M w 4.23 .

K-Shell Ionization of Molybdenum and Iron by Electron Bombardment

K-ionization cross sections of Mo and Fe by electron impact were measured by detecting characteristic x-ray emitted by thin solid film targets of known mass thickness with a Si (Li) detector. Reflection correction of a substrate was done by bipartition model of electron transport. The experimental results are compared with theoretical calculation and empirical formula calculation.

An empirical formula for the calculation of (n, α) reaction cross sections at 14.5 MeV neutron energy

An empirical formula for quick calculation of (n, α) reaction cross sections at 14.5 MeV neutron energy is presented. Obtained results are in good agreement with the experimental data recently published.

95/00022 Empirical formulae for calculation of real density and total pore volume of hard coals

95/00022 Empirical formulae for calculation of real density and total pore volume of hard coals

Empirical formulae for calculation of real density and total pore volume of hard coals

Equations are derived for calculation of real density and total pore volume of hard coals from their ultimate and proximate analyses. Generalized solutions are obtained for organic matter and mineral matter contents in coals. In the case of organic matter a simplified structural model of coal is utilized. Coefficients and final mathematical expressions are determined by application of statistical methods.