Static Experiment Method Research Articles

Research on strain testing method and accuracy evaluation of spacecraft in heat and force field.

Ground experimentation is an important method to verify the performance and quality of spacecraft structures. How to simulate the force and heat fields that a spacecraft may be subjected to during flight is a challenge for experiment design. In this paper, the static strength experimental method of spacecraft in the combined force and heat fields is studied. Furthermore, the coupling cases of the spacecraft during the flight process are simulated using an airbag and a resistive heater. Finally, it can be concluded that the accuracy of the proposed experimental method as well as the structural strength of the spacecraft can meet technical requirements during flight.

Inhibition of Calcium Carbonate Scale Using an Environmental Friendly Scale Inhibitor

Abstract Calcium carbonate is considered as the most frequent scale commonly occurring in cooling water systems. To reduce calcium carbonate scale in an environment–friendly way, a copolymer consisting of acrylic acid (AA)-acrylamide (AM)-polypropylene glycol and maleic anhydride (PPGAZMA) was developed to inhibit this phenomenon. The structure of the AA-AM-PPGAZMA was characterized by FT-IR method. The performance of AA-AM-PPGAZMA inhibition process was evaluated from static experiment method. Results indicated that excellent ability to control inorganic minerals, with approximately 71.1% calcium carbonate inhibition under the optimum conditions. Also the effect of the copolymer addition on the crystals of calcium carbonate scales morphology was examined through scanning electron microscopy (SEM). SEM illustrated that great changes in the size and morphology of the calcium carbonate scales took place under the influence of AA-AM-PPGAZMA. SEM and XRD results identify that not only the scales shape and size changed but also that the scales forms altered to an extent.

An Eco-Friendly Process for Removal of Lead from Aqueous Solution

The adsorption of lead (Pb II) ion on different types of synthesized zeolite was investigated. The BET surface area, total pore volume & average pore size distribution of these synthesized zeolites were determined by adsorption isotherms for N2, the surface area & total pore volume of their sources were found by adsorption isothermN2.The adsorption equilibrium was measured after 24h at room temperature (RT) & concentration 10mg.L-1 of Pb (II) was used. The adsorption of heavy metal Pb (II) on four different prepared zeolites (LTA from Montmorillonite clay, FAU(Y)-B.H (G2) from Barley husk, Mordenite (G1) from Chert rock, FAU(X)-S.C (G3) from shale clay & modified Shale clay by oxalic acid (N1) & sodium hydroxide (N2)), were compared with the adsorption of their sources by using static batch experimental method. The major factors affecting the heavy metal ion sorption on different synthesized zeolites & their sources were investigated. The adsorption equilibrium capacity (Qm) of Pb (II) ion for different synthesized zeolites ordered from (N1>N2>LTA>G3>G2>G1&for their sources ordered Shale clay >Montmorilonite> Barley husk>Chert rock. The atomic absorption spectrometry was used for analysis of lead heavy metal ion, the obtained results in this study showed that the different synthesized zeolites were efficient ion exchanges for removing heavy metal, in particular, the modified zeolite from shale clay by oxalic acid.

Curcumin–malic acid based green copolymers for control of scale and microbiological growth applications in industrial cooling water treatment

The formation of calcium sulphate (CaSO4) scale and microbiological growth accumulation poses major problems in cooling water treatment plants, thereby affecting the performance of this type of equipment. In order to inhibit or minimize these problems, new types of green copolymers, poly(curcumin–malic acid) was specially designed and developed from malic acid and curcumin. The structural, chemical and thermal properties of the copolymers were analysed using SEM/EDX, FTIR, UV–Vis, X-ray diffraction, TGA and GPC. The scale inhibition efficiency for CaSO4 scale was investigated by using the static experiment method. The copolymer showed moderate to high sulphate scale inhibition activities based on the amount of curcumin used during copolymerization. The results revealed that due to high molecular weight, the efficiency of the poly(curcumin–malic acid)6 was >95% at 10mg/L dosage whereas poly(malic acid) (homopolymer) efficiency was 35.5% at 10mg/L. Hence, it may be reasonably concluded that poly(curcumin–malic acid)6 is a highly effective CaSO4 scale inhibitor for industrial cooling water treatment applications. In addition, the developed copolymers possess a broad antibacterial activity against Escherichia coli and may be useful as antibacterial agents in the industrial cooling water treatment plants.

Kinetic Studies of Adsorption of Heavy Metals on Clays

Kinetic studies of adsorption of heavy metals (Pb (II), Cu(II), Cd(II) and Zn(II)) on local clay soils from four different locations in Ekiti state have been studied using static batch experimental method. The major factors affecting the heavy metal ions sorption on local clays were investigated. The experimental data were correlated with adsorption isotherm and kinetic equations using linear regression analysis. The plots of the amount of adsorbate adsorbed against equilibrium concentration or mass of dosage of clay or time showed two distinct segments. Firstly, nearly a straight line plot at low concentration and secondly a flat or plateau portion at high concentration were observed. The monolayer concentration of the adsorbent was calculated. Langmuir isotherm was found to correlate the adsorption data better than the Freundlich isotherm. The parameters in these isotherms were evaluated and fully discussed. The adsorption kinetic data were correlated with three functions. The Olaofe proposed function (R2= 97.5 - 99.0 %) was found to be the best followed by Simple Elovich function (R2= 84.5 - 95.9 %) and the least was the power function (R2= 84.3 - 93.1%) .The parameters in the functions and statistical data were reported and fully discussed. The present report has shown that local raw Nigerian clays can be used as adsorbents.

Study on Calcium Scales Inhibition Performance in the Presence of Double-Hydrophilic Copolymer

Novel double-hydrophilic block copolymers, acrylic acid (AA)-2-acrylamido-2-methyl-propane sulfonate (AMPS)-oxalic acid-allypolyethoxy carboxylate (APEM) was specially designed and synthesized from allyloxy polyethoxy ether (APEG) to inhibit the precipitation of CaCO3 and CaSO4. The structure of the copolymer was characterized by FT-IR and H1-NMR. Using the static experiment method, the scale inhibition efficiencies for CaCO3 and CaSO4 scale were investigated. It was shown that AA-AMPS-APEM exhibited excellent ability to control inorganic minerals scales, with approximately 97.1% CaSO4 inhibition and displayed significant ability to prevent the formation of CaCO3 scales. The synthesized AA-AMPS-APEM was also compared with that of current commercial inhibitors. The effect of the copolymer addition on the crystals of CaCO3 and CaSO4 scales morphology and structures were examined through scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction studies (XRD). It proved that great changes in the size and morphology of the calcium scales took place under the influence of AA-AMPS-APEM. The proposed inhibition mechanism suggests the formation of complexes between the side-chain carboxyl groups of AA-AMPS-APEM and calcium ions on the surface of inorganic minerals, and the excellent solubility of complexes resulted from a number of hydrophilic polyethylene glycol (PEG) and sulfonic group (-SO3H) group.

Preparation and application of copolymer modified with the palygorskite as inhibitor for calcium carbonate scale

The scale inhibitor copolymer modified with palygorskite was prepared from maleic anhydride, styrene sulfonic sodium and palygorskite. The conditions of preparing scale inhibitor were optimized. The structure and morphology of the copolymer were characterized by FT-IR, SEM and XRD. Using the static experiment method, the influences of copolymer concentration, temperature, time, and Ca2+ concentration of the system on the inhibition efficiency were investigated. The experimental results showed that the scale inhibitor copolymer modified with palygorskite had an excellent efficiency of scale inhibition, and nearly 98.97% of scale inhibition efficiency for CaCO3 was obtained. The prepared scale inhibitor could be used in the system of high temperature and high hardness water.

Experimental and numerical analysis of the static strength and fatigue life reliability of parabolic leaf springs in heavy commercial trucks

The objective of this study is to perform experimental and numerical analysis of the static strength and fatigue life reliability of parabolic leaf springs in heavy commercial trucks. To achieve this objective, stress and displacements under static loading were analytically calculated. A computer-aided design model of a parabolic leaf spring was created. The stress and displacements were calculated by the finite element method. The spring was modelled and analysed using CATIA Part Design and ANSYS Workbench. The stress and displacement distributions on a three-layer parabolic leaf spring were obtained. The high-strength 51CrV4 spring steel was used as sample parabolic leaf springs material, and heat treatments and shoot peening were applied to increase the material strength. Sample parabolic leaf springs were tested to obtain stress and displacement under static loading conditions. By comparing three methods, namely, the static analytical method, static finite elements method and static experimental method, it is observed that results of three methods are close to each other and all three methods are reliable for the design stage of the leaf spring. Similarly, sample parabolic leaf springs were tested to evaluate the fatigue life under working conditions. The reliability analysis of the obtained fatigue life test value was carried out. It was shown that both analytical model and finite element analysis are reliable methods for the evaluation of static strength and fatigue life behaviour in parabolic leaf springs. In addition, it is determined by a reliability analysis based on rig test results of nine springs that the spring achieves its life cycle of 100,000 cycles with a 99% probability rate without breaking. Furthermore, the calculated fatigue life is 2.98% greater than experimentally obtained fatigue life mean and the leaf spring can be used safely and reliably during the service period in heavy trucks.

Poly(ethyleneimine) functionalized organic-inorganic hybrid silica by hydrothermalassisted surface grafting method for removal of nickel(II)

Poly(ethyleneimine)-functionalized organic-inorganic hybrid silica adsorbent was synthesized by hydrothermal-assisted surface grafting technique for the removal of Ni(II) ions from aqueous solution, and was characterized by FT-IR, nitrogen adsorption and the static adsorption-desorption experiment method. The results indicated that the maximum static adsorption capacity of Ni(II) on poly(ethyleneimine)-functionalized hybrid silica adsorbent by hydrothermal heating method was 1.6 times as much as the conventional heating method. The poly(ethyleneimine)-functionalized hybrid silica adsorbent offered a fast kinetics for the adsorption of Ni(II), had a substantial binding capacity in the range of pH 4-8 and could be used repeatedly. The Langmuir adsorption model was more favorable than the Freundlich and Dubinin-Radushkevich adsorption models. The adsorption followed a pseudo-second-order model compared with pseudo-first-order model. Various thermodynamic parameters such as ΔG°, ΔH° and ΔS° indicated that the adsorption process was spontaneous and endothermic. The results showed that poly(ethyleneimine)-functionalized hybrid silica adsorbent could be employed as an effective material for the removal of Ni(II) ions from aqueous solution.

Preparation and Application of Polymers as Inhibitors for Calcium Carbonate and Calcium Phosphate Scales

The scale inhibitor was prepared based on itaconic acid (IA), styrene p-sulfonic sodium (SSS), maleic anhydride (MA), and acrylamide (AM) as monomers, and ammonium persulfate as an initiator by the free-radical polymerization. The structure of the polymer was characterized by FT-IR and UV-Vis spectroscopy. Using the static experiment method, the scale inhibition efficiency to CaCO3, the effects of some factors (concentration of polymer, time, concentration of Ca2+, pH value, concentration of HCO3 −, and temperature) were investigated. Using the malachite green photometric method, the scale inhibition efficiency to Ca3(PO4)2 and the effects of some factors (concentration of polymer, time, Ca2+, pH, temperature, and the concentration of PO4 3−) were also investigated. The experimental results showed that the polymer had an excellent efficiency of scale inhibition and a resistance rate of calcium carbonate scale up to 96.67%, a resistance rate of calcium phosphate scale up to 92.5%, and could be used in the system of high-temperature and high-hardness water. The polymer had good dispersing ability with respect to iron.

Scale Inhibitor Copolymer Modified with Oxidized Starch: Synthesis and Performance on Scale Inhibition

A series of scale inhibitor copolymers modified with oxidized starch have been synthesized. The effects of content of monomer and initiator, reaction time, reaction temperature to inhibit calcium carbonate scale were studied by orthogonal experiment. The structure, thermal property and morphology of the copolymer were characterized by FT-IR, TGA and SEM. Using the static experiment method, the scale inhibition efficiency for CaCO3 scale was investigated. The experimental results showed that the scale inhibitor copolymer modified with oxidized starch had an excellent efficiency of scale inhibition, good tolerance of calcium and could be used in the high hardness water.

Multi-parameter Experimental Adsorption Effect of 239Pu on Phyllitic Slate and Clay

The paper studies the adsorption features of 239Pu in phyllitic slate and clay media through static experiment method. The two different geo-media were collected from a site for disposing very low level waste (VLLW) as experimental samples. Experimental results have shown that an adsorption equilibrium time of 239Pu in phyllitic slate and clay is approximately 10 days, and the adsorption coefficient (Kd) B Bvalues of phyllitic slate and clay are about 6000ml/g and 2700ml/g, respectively. The experimental result of particle size effect indicates when adsorption of plutonium in particle samples increases, the KBdB values of these two geo-media increase while the particles decrease in size. And the experimental impact on aqueous phase pH value reveals that Kd of 239Pu in creases at higher aqueous phase pH value, illustrating stronger adsorption capacity. Experimental data are also measured through the curve fitting, KBdB values are thus obtained theoretically.

Adsorption and desorption of uranium (VI) in aerated zone soil

In this paper, the adsorption and desorption behavior of uranium (VI) in aerated zone soil (from Southwest China) was systematically investigated using a static experimental method in order to provide useful information for safety assessment of the disposal of (ultra-)low uraniferous radioactive waste, as well as a potential remediation method for uranium-contaminated soils. The adsorption behavior of uranium (VI) was firstly studied by batch experiments as functions of contact time, pH, liquid/solid ratio, temperature, colloids, minerals and coexistent ions. The results indicated that the adsorption of uranium (VI) by natural soil was efficient at an initial concentration of 10 mg/L uranium (VI) nitrate solution with 100 mg natural soil at room temperature when pH is about 7.0. The adsorption was strongly influenced by the solution pH, contact time, initial concentration and colloids. The adsorption equilibrium for uranium (VI) in soil was obtained within 24 h and the process could be described by the Langmuir adsorption equation. For uranium (VI) desorption, EDTA, citric acid and HNO3 were evaluated under different conditions of temperature, concentration and proportion of liquid to solid. The adsorbed uranium (VI) on natural soil could be easily extracted by all these agents, especially by HNO3, implying that the uranium-contaminated soils can be remedied by these reagents.

Preparation, characterization and scale performance of scale inhibitor copolymer modification with chitosan

A scale inhibitor copolymer modification with chitosan was prepared from maleic anhydride, styrene sulfonic sodium, acrylic amide and chitosan. The conditions of preparing scale inhibitor were optimized. The chemical structure and thermal property were investigated. Using the static experiment method, the influences of copolymer concentration, temperature time, Ca2+ concentration, HCO3− concentration of the system on the inhibition efficiency were investigated. The experimental results showed that the polymer was excellent calcium carbonate scale inhibition and the resistance rate of calcium carbonate scale up to 95.62%, and could be used in the system of high temperature and high hardness water.

Study and Application on Computational Methods for Ultimate Bearing Capacity of Single Pile

It is difficult and important to accurately calculate single pile ultimate bearing capacity during pile foundation design. Typical computational methods on single pile ultimate bearing capacity are contrastively analyzed in this paper. Contact element method on single pile ultimate bearing capacity is relatively accurate and economical, but it isn’t used in practical projects until now because its computational process is complicated. 343 different single pile ultimate bearing capacities are calculated with the contact element method in order to study a simple computational formula based on the contact element method. All data calculated are analyzed with a linear recursive multi-analysis program which is programmed with Fortran90. A simple computational formula on the contact element method is presented based on the analysis results. The simple computational formula, the experiential formula in the code, the contact element method and the static load experiment method are respectively used to calculate single pile ultimate bearing capacity in two practical projects in order to test the simple computational formula. The results show that the simple computational formula is relatively accurate. Some advice is presented based on the analysis results.

Adsorption and migration of 241Am in aerated zone soil

As an important radioisotope in nuclear industry and other fields, 241 Am is one of the most serious contamination concerns due to its high toxicity and long half-life. In order to supply useful reference for disposal of 241Am waste with low-medium radioactivity, the adsorption and migration behavior of 241Am on aerated zone soil were investigated by the static experimental method and column experiments. The results showed that more than 98% of the total 241Am could be adsorbed from 241Am solution of 0.32·10−7−1.1·10−7 mol/l by the soil at pH 4–9. The adsorption of 241Am on the soil was a pH-dependent process at pH 4, the adsorption rate of 241Am on the soil changed minutely. The adsorption equilibrium was achieved within 24 hours and no significant effect on adsorption of 241Am was observed at liquid-solid ratios of 50:1–500:1. The relationship between concentration of 241Am and adsorption capacities of 241Am can be described by the Freundlich adsorption equation. Adsorption of 241Am on the soil can be inhibited by humic acid, ferric hydroxide colloid, or some anions, such as citric acid anion, saturated EDTA solution, C2O4 2− and CO3 2−. It was also noted that the adsorption rate of 241Am drops in solutions containing Eu3+ or Nd3+, even 0.5 times above the 241Am concentration. A migration distance of 8 mm for 241Am(III) is observed only in the aerated zone soil containing ferric colloid, while a migration distance of less than 2 mm is noted in other soil samples after more than 250 days. All these results indicate that the aerated zone soil is an efficient sorbent for 241Am and can inhibit the migration of 241Am.

A novel method for static equation-of state-development: Equation of state of a cross-linked poly(dimethylsiloxane) (PDMS) network to 10 GPa

Pressure-volume-temperature (PVT) equation-of-state (EOS) information for polymers and polymeric composites is valuable for predicting their response to extreme conditions. An obstacle in determining equations of state for polymeric materials is the lack of a simple, static experimental method for acquiring PVT data for solid networks and liquids at pressures greater than several kilobars. Here, we report a novel approach in determining static EOS for polymers using high-pressure diamond-anvil cells coupled with optical microscopy and image analysis. Results are presented for a cross-linked poly(dimethylsiloxane) polymer, Sylgard 184. Static isothermal results were fitted to empirical and semiempirical equations of state, including the Tait, Birch-Murnaghan, and Vinet forms. Static PV data were also converted to pseudoshock velocity-pseudoparticle velocity (U(s)-u(p)) for comparison to dynamic Hugoniot data. A linear Rankine-Hugoniot fit U(s)=s(T)u(p)+c(T) gives c(T)=1.572 km/s and s(T)=1.703. s(T) is related to the pressure derivative of the bulk modulus B(0) (') by s(T)=(B(0) (')+1)/4 and B(0) (')=5.8. A comparison of the static and shock data is given, along with an estimate of the Grüneisen parameter, and a discussion of the free volume content in the polymer network, and limitations of this novel method.

Vapour-liquid equilibrium of (ethers + hydrocarbons or methanol or water) for motor gasoline modelling

Modern environmentally beneficial methods of formulating motor gasoline often use alcohols and/or ethers as octane improvers. Thus, the thermophysical properties of these substances have become important in process engineering design, the simulation of gasoline blending operations, and engine operability. In all of these applications, phase equilibrium properties are represented by thermodynamic models, which are derived from a combination of theory and experimental data. This work seeks to quantify these models from careful measurement of key thermodynamic properties. Vapour-liquid equilibrium measurements on 2-ethoxy-2-methylpropane (ETBE), 2-methoxy-2-methylbutane (TAME) and 2-methoxy-2-methylpropane (MTBE) with various alkanes, aromatics and oxygenates have been made over a temperature range of 293 to 323 K using a static experimental method. These data are utilised in the development of a flexible model for the thermodynamic properties of motor gasolines. The data are well correlated by the UNIQUAC excess Gibbs model for the liquid phase and with the Hayden-O'Connell correlation for the virial equation for the gas phase. Prediction of the vapour phase composition above a gasoline containing MTBE and methanol show maximum differences of 0.0353 in mass fraction.

(Vapour+liquid) equilibria of (alkoxyalkanes+alkanes, oro-xylene, or water, or methanol) for ether mole fractions 0 to 0.5, between temperatures 293 K and 323 K

Modern environmentally beneficial methods of formulating motor gasoline often use ethers and/or alcohols as octane improvers. Thus, the thermophysical properties of these substances have become important in process engineering design, the simulation of gasoline blending operations, and engine operability. In all of these applications phase equilibrium properties are represented by thermodynamic models, which are derived from a combination of theory and experimental phase equilibrium data. This work seeks to quantify these models by careful measurement of key thermodynamic properties. For that purpose (vapour+liquid) equilibrium measurements on 2-methoxy-2-methylpropane, 2-ethoxy-2-methylpropane, and 2-methoxy-2-methylbutane with various alkanes,o-xylene, methanol, and water have been made using a static experimental method, at ether mole fractions ofx=0 tox=0.5 over a temperature range of 293 K to 323 K.