Pycnometer Method Research Articles

Physical and rheological investigation of vegetable oils and their effect as lubricants in mechanical components

ABSTRACTThe aim of this investigation was to study castor, canola, and sesame vegetable oils in order to evaluate their potential use as lubricants in steel mechanical components. For this purpose, densities of each oil were evaluated using the pycnometer method, as well as their dynamic viscosities through a Brookfield DV-II rotational viscometer. Both properties were evaluated at temperatures of 25, 40 and 100 °C. Additionally, viscosity indexes were determined according to ASTM D 2270. These rheological properties were used to estimate the lubrication regime considering parameters of real contact conditions in mechanical components. Friction and wear analyses were carried out to investigate the behaviour of the vegetable oil as lubricants. Such tests were carried out at room temperature on a CSM tribometer with pin-on-disk configuration by using castor, canola and sesame oils as lubricants. AISI 4140 hardened steel against AISI 100Cr6 steel pin was used as a mechanical component. From the rheological study, it was observed that canola and sesame oils behave as dilatant fluids at the evaluated temperatures, while castor oil behaves like a Newtonian fluid at 25 and 40 °C. Castor oil showed the highest density value among oils studied, but it also exhibited the lowest value of viscosity index (271). Contrarily, sesame oil was the least dense, but it exhibited the highest viscosity index (545). On the other hand, the lubrication regime study showed that by using castor oil as a lubricant in the mechanical component (4140/100Cr6), the system worked in a mixed lubrication regime while by using canola and sesame oils the system operated in boundary lubrication conditions. Finally, the kinetic friction coefficients were different for each lubricant obtaining the lowest value with castor oil while the highest value of friction coefficient was exhibited by the sesame oil lubricant.

Evaluation of the quality of local butters: A new approach based on Raman spectroscopy and supported by the classical pycnometer method.

In this study, the quality of the local Romanian butters was investigated using the classical pycnometer and optic microscopy methods, combined with Raman spectroscopy. We used a pool of 10 samples with different characteristics, and analyzed them by the three aforementioned methods. Pycnometric measurements showed a direct correlation between the fat content and the density values of the samples. Raman spectroscopy validated the results from the pycnometric measurements and the optical microscopy and indicated several other properties, such as protein content, hydration, saturation level of the polycarbonate chains, as well as the total cis isomer content and the type of arrangement preferred by the aliphatic chains (polymorphic transition). The methods employed in the present study have a strong potential to become analytical tools for the food industry and food safety agencies in order to assess the quality of butters and margarines, in a fast and cost-effective manner.

Selection of phase change material for solar thermal storage application: a comparative study

The study of five paraffin waxes and wood resin was carried out to investigate their thermo-physical properties. The investigation aimed at selection of a phase change material (PCM), for its potential use as a thermal energy reservoir (TER) in a fabricated solar dryer. Differential scanning calorimeter was used to determine the melting point, solidification point, latent heat of fusion and solidification of these PCM. The T-history analysis was carried out to determine the effective thermal conductivity and specific heat in liquid and solid states. Bulk density of these PCMs was determined using standard pycnometer method. A comparative analysis was done for the selection, and PW1 was selected among the paraffin waxes, while wood resin was rejected. The selected PCM was used in the flat plate collector of solar dryer to identify the thermal zones and to validate its capability as a TER. Maximum temperature achieved at outlet of flat plate collector was 50 °C. The temperature profile built in different zones was determined with and without using PCM. It was found that after 18:00 IST evening, the average flat plate collector chamber temperature with PCM PW1 was found to be 23.5% higher than that without using PCM.

Разработка многослойного упаковочного материала на основе полиолефиновых смесей, модифицированных сополимером этилена с пропиленом, для хранения пищевых продуктов

The research features a comprehensive study aimed at increasing the technological compatibility of multilayer packaging materials. The paper describes a recycling technology with the prospect of returning the resulting secondary raw materials to the production cycle. The research included the following tasks: to conduct a comprehensive study of polyolefin mixtures modified by ethylene propylene copolymer; to study the effect of the copolymer on the rheological and physicomechanical properties of polymer compositions; to propose a technology for the recycling of secondary polyolefin mixtures. The research involved the following methods: the capillary viscometry method was used to determine the rheological properties of polymer compositions; the tensile test method was employed to define the physicomechanical properties of the compositions; the pycnometric method was used to assess the density of the mixtures. The study featured such polymers as polyethylene, polypropylene, and ethylene-propylene copolymer, which was chosen as a link between the polymers. The authors obtained polymer compositions in various ratios of polyethylene, polypropylene, and ethylene-propylene copolymer: 70:30:0; 68.5:28.5:3; 65:25:10; 30:70:0; 28.5: 68.5: 3; 25:65:10. The article describes the process of modifying polyolefin compositions based on polyethylene and polypropylene by ethylene-propylene copolymer on a single-screw extruder. The authors defined the rheological properties and the deformation-strength characteristics of the polymer mixtures. Repeated processing proved to lead to a decrease in the physicomechanical properties of polyolefin mixtures, with the exception of compositions based on polyethylene and polypropylene in the ratio of 30:70, where the breaking stress increased. The number of processing cycles increased the melt flow rate of the mixtures. The proposed technology is meant for producing multilayer packaging materials using packaging waste in the middle layer for contact with food.

Excess and Absolute Adsorption from Binary Liquid Solution by Microporous Crystalline Adsorbents: Cumene + n-Octane/Zeolite NaX

The excess adsorption isotherms of cumene from solutions in n-octane in zeolite NaX have been measured at 303.15, 338.15 and 363.15 K using the conventional static method. The absolute (limiting) adsorption values of the pure components have been measured by the pycnometric method. The absolute adsorption isotherms for the system have been calculated using a non-fitting three parameter equation, based on the modified Dubinin–Radushkevich one. The detailed derivation of the formulas for these calculations is given. The absolute adsorption data are then used for estimation of average adsorbate density and other characteristics of the adsorbed phase.

Densities and Viscosities of Oleic Acid at Atmospheric Pressure

AbstractThe densities of oleic acid were measured over the temperature range from (293 to 459) K at atmospheric pressure using a densimeter based on the modified hydrostatic weighing method. The dynamic viscosities of the same oleic acid sample were measured using a capillary viscometer (VPZ‐2 m) in the range from (293 to 363) K at atmospheric pressure. The combined expanded uncertainty of the density, atmospheric pressure, viscosity, and temperature measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be 0.15%, 1.0%, 3.5%, and 15 mK, respectively. The values of uncertainty for density and viscosity include the effects of purity and calibration (total expanded uncertainty). These experimental data were used to develop wide‐range correlations for the density and viscosity based on theoretically confirmed Arrhenius–Andrade and Vogel‐Tamman‐Fulcher (VTF) models. The value of the glass temperature ( T g=179.78 K.) for the oleic acid was estimated using the VTF parameters derived from the present viscosity measurements. To additionally validate the reliability of the measured density data, the same oleic acid samples were measured using the pycnometric method. The present study showed that the densities measured using the modified hydrostatic weighing densimeter (HWD) agree with the values obtained using the pycnometric method within 0.09% for Sample 1 and 0.25% for Sample 2.

Excess Molar Volume Calculation and Viscosity Deviation and Excess Gibbs Energy for Binary Solution of 1- Propanol with Butyl Acetate at Temperatures (40,50,60) 0C

In this research, the solubility Process of the binary liquid solution(1-Propanol and butyl acetate) were studied at temperature(40,50.60)0C. Densities ρ by pycnometer method and viscosity ƞ by OSTWALD tube that calibrated with distilled water was measured. Then excess molar volume was calculated of pure component and its mixtures that was prepared over the entire mole fraction range. It has been observed that excess molar volumes values were negative at all temperatures. After that, the deviation in viscosity ∆ ƞ and Excess Gibbs free energy ∆GE was determined and it has been observed that it takes negative values at all temperatures. Excess molar volume, deviation in viscosity, excess Gibbs free energy were correlated with Redlich-Kister equation Type polynomial and the showed an accepted standard deviation between the experimental and calculated values it has been shown the effect of Hydrogen bonds formation and the spherical shape for the molecules and its size on the excess thermodynamic properties.

Biodegradation of biosolids and specific gravity determination

This paper presents a literature review on the geotechnical behaviour/properties of biosolids and sewage sludge materials, including biodegradation effects, and then focuses on the determination of specific gravity (Gs) for these challenging and difficult geomaterials. For water pycnometry, biodegradation occurring during the course of the test procedure results in apparent higher Gsvalues, leading to erroneous determinations for the solid, liquid and gas phases per unit volume. As demonstrated in the paper, this issue can be addressed by using kerosene or white spirits as the density liquid. Since the pycnometer method is tedious and time consuming, specific gravity is often correlated with total volatile solids (STV), as measured by ignition loss, which is a more straightforward test, having arguably greater reliability. Existing correlations are investigated but found unsuitable for biosolids and sewage sludge materials. Hence, a new Gs–STVrelationship is established specifically for these materials, avoiding the necessity for direct Gsdeterminations in practice. Other issues investigated include the effects of intraparticle voids within the test material and the different specimen oven-drying temperatures of 50 and 105°C specified in different codes. It is concluded that oven drying at 105°C should be consistently used for testing of these materials.

A feasible, portable and convenient density measurement method for minerals via magnetic levitation

This work proposes an improved magnetic levitation (IML) method for measuring the density of minerals in outdoor exploration by horizontally setting the magnetic levitation device. The measuring characteristic of the method is analyzed and verified by a series of beads with known densities. Combined with the usage of different paramagnetic media, the method obtained a measuring range from 1.094 g cm−3 to 9.949 g cm−3, which could cover all common minerals. The method was then applied for measuring different minerals with densities from 1.828 g cm−3 to 6.742 g cm−3. The densities of the minerals were also measured using the pycnometer method and the densitometer method for comparison. The results showed that the IML method is more applicable for measuring single mineral particle with high accuracy (with a maximum of 1.08% relative error), while the other two commonly used methods have a significantly larger mean square error (0.076 g cm−3–0.331 g cm−3, 3–10 times larger approximately) and required samples of a much larger volume to achieve the same accuracy. Compared with the two common methods, the IML method consumes the least time of 22 min for 3 trials, which may save at least 55.1% in terms of time consumed in the measuring process. To our best knowledge, this is the first time that magnetic levitation has been employed in the characterization of minerals in outdoor exploration. Compared with the common methods, the IML method was found to be portable, convenient, and low-cost for outdoor exploration.

Estimating Soil Particle Density using Visible Near‐infrared Spectroscopy and a Simple, Two‐compartment Pedotransfer Function

Core Ideas The two‐compartment pedotransfer function successfully predicted soil particle density. Vis–NIR showed slightly poorer performance than the two‐compartment function for predicting soil ρd. Spectroscopy or OM based pedotransfer models gave better estimates of ρd when a wide range in soil OM data was used. The average particle density (ρd) is a fundamental soil property, used for calculating the total porosity. Traditional ρd measurement by pycnometer method is tedious and time‐consuming. In this study, visible–near‐infrared (vis–NIR) spectroscopy and a simple two‐compartment linear and curvilinear pedotransfer function only requiring knowledge of soil organic matter content (OM) were tested and compared as alternative, indirect, rapid, and cost‐effective methods. Soil ρd was measured by water pycnometer on 179 soils representing a wide range of OM (0.002–0.767 kg kg−1), whereas soil spectra were measured on air‐dry samples by vis–NIR spectroscopy. The ρd models were developed using partial least squares regression with leave‐one‐out‐cross‐validation using vis–NIR spectral data, and a simple two‐compartment pedotransfer function, ρd = A(OM) + B(1 − OM) using the OM content. Predictive abilities of these two methods were tested using three different datasets: (i) minerals soils (OM < 0.1 kg kg−1), (ii) organic soils (OM > 0.1 kg kg−1), and (iii) all soils. Calibrating the two‐compartment pedotransfer function for the entire dataset gave expected values for the individual particle densities of OM (A = 1.244 g cm−3) and mineral particles (B = 2.615 g cm−3). The vis–NIR spectroscopy model successfully predicted soil ρd for the entire dataset (R2 = 0.87, RMSECV = 0.10 g cm−3), with a poorer performance than the two‐compartment linear model (R2 = 0.96, RMSE = 0.06 g cm−3). Using only the mineral soils data did not suffice to obtain realistic and accurate vis–NIR spectroscopy (R2 = 0.62, RMSECV = 0.02 g cm−3) or OM based (R2 = 0.80, RMSE = 0.02 g cm−3) models for ρd, illustrating the importance of the wide range of OM content considered in the present study.

Zeolite usage as source of silica to produce cordierite in MgO\u2013Al2O3\u2013SiO2 system

In this study, natural zeolite was used as source of silica to produce cordierite. MgO and Al2O3 were added to zeolite to obtain the cordierite stoichiometry. Mixture of these raw materials was mechanically activated for different durations. The mechanically activated powder mixture was characterized using XRD, DSC, SEM, specific surface area, and particle size analyzer. The pycnometer method was used to measure the densities of mechanically activated powder mixtures. Mechanically activated for 60 min powder mixture was sintered at 1150–1350 °C for 1 h. The sintering behavior of the samples was determined by measuring the linear shrinkage, density, and apparent porosity. The phases in the sintered samples were identified by XRD. Cordierite and spinel phases were detected for sintered at a temperature higher than 1150 °C but corundum accompanied to cordierite and spinel at 1150 °C. The microstructure of the samples was examined using both SEM and AFM. The sintering behavior and microstructural properties of the samples changed with an increase in the sintering temperature. As the apparent porosity increased with increasing sintering temperature, linear shrinkage and density values decreased. Density values were determined as 2.31–2.69 g/cm3 depending on the temperature. The grains coarsened at higher temperature and the average grain size depending on the temperature was 1.34–1.96 μm. From the results optimum sintering temperature was determined as 1250 °C. Dense material was produced at a temperature as low as 1250 °C using zeolite as raw material.

DEPENDENCE OF DENSITY OF JOINT AQUEOUS SOLUTIONS OF AMMONIA, AMMONIUM CHLORIDE, AMMINES OF ZINC AND COPPER ON THEIR COMPOSITION

The dependence of the pressure of joint aqueous solutions of ammonia, ammonium chloride, ammines of zinc and copper on their component concentrations was studied by pycnometric method. The equation wich allow calculating the density of solutions mentioned above using known molar concentrations of components was obtained. The error of calculation on equation is not more than 3%. The data obtained can be used at the design of pilot devices for the extraction of zinc and copper by ammonia-ammonium solutions from industrial waste.

Investigation of new volumetric non-destructive techniques to characterise additive manufacturing parts

The assessment of the potential of various non-destructive methods to characterise additive manufactured dense and lattice parts was investigated. The Archimedes’ and gas pycnometric methods for density measurements of both types of structures are presented as well as the percentage of cells in lattice structures. A multi-frequency eddy current method for electrical conductivity measurements of lattice structures is also presented. Finally, C-scan ultrasound method for the characterisation of dense parts was investigated. The advantages and limitations of each method are underlined.

Preparation of anhydrite from eggshell via pyrolysis

AbstractCalcium sulfate dihydrate (CaSO4·2H2O) was prepared from the chemical reaction between calcium carbonate from duck eggshell and sulfuric acid at 25°C. The CaSO4·2H2O was dried in an oven at 110°C and transformed into calcium sulfate hemihydrate or plaster of Paris (CaSO4·0.5H2O). The CaSO4·0.5H2O was calcined at 700, 800 and 900°C and transformed into anhydrite or anhydrous calcium sulfate (CaSO4). The raw material used in this research was the duck eggshell, the waste eggshell generated from food processing industries. The obtained anhydrous calcium sulfate or anhydrite has true density, color, specific surface area, pore diameter and particle size equal to 2.95 g/cm3, white powder, 3.57 m2/g, 96.98 Å and 3.983 μm, respectively. In addition, other characteristics, microstructures, phase transformation and physical properties of raw materials and calcium sulfates were investigated and reported here using X-ray fluorescencemeter, Fourier transform infrared spectrometer, differential thermal analyzer, thermogravimetric analysis, scanning electron microscope, X-ray diffractometer, pycnometer method and Brunauer-Emmett-Teller.

Dried cell wall nanopore configuration of Douglas-fir, western red cedar and aspen heartwoods

Wood cell wall pores are essential for understanding nanostructure and subsequent application to wood processing and new product design. CO2 and N2 sorption isotherms were used to explore nanopores in dried cell walls of Douglas-fir, aspen and western red cedar heartwood specimens. The total cell wall pore volume was estimated as sum of detected micropore volume from the CO2 isotherm and the volume of pores that are less than 10 nm from the N2 isotherm. The estimated pore volumes from the gas sorption method were statistically lower than those obtained from the classical pycnometer method using water and white mineral oil as replacing liquids. Large open hysteresis was observed in CO2 sorption isotherms. Further pore distribution analysis assigned the detected 10–36 nm pores to those in pit membranes. Extraction of western red cedar heartwoods largely affected the detected 0.4–0.6 nm pores, which strongly suggests penetration of extractives into cell walls. Despite the exploratory nature of this study on western red cedar, CO2 sorption analysis shows great potential in exploring micro-distribution of extractives.

Density studies of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-glycerol and CO2-DBU-glycerol solutions at temperatures between 288.15 K and 328.15 K

The binary system of glycerol and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) possesses promising potential for CO2 absorption, and critical physical properties, especially density, analysis are important for its application. In this work, density of DBU-glycerol system before and after CO2 absorption at temperatures between 288.15 K and 328.15 K was studied by the pycnometer method. In DBU-glycerol system, the density decreases with increases in both temperature and DBU concentration. Excess molar volumes (VE) of DBU-glycerol system are negative in the entire composition range and are well correlated with Redlich-Kister equation. Four different models are successfully adopted for correlating and predicting the densities of DBU-glycerol binary solutions. In CO2-DBU-glycerol system, densities are 0–6% higher than that in the DBU-glycerol system when the mass content of CO2 (ωCO2) based on the total mass of DBU and glycerol is less than 8%. Two different models were set up to correlate the densities with the mole fraction of DBU, temperatures, and CO2-loadings. The Jouyban-Acree method and the proposed modified proportionality method are preferred respectively for calculating the densities of the CO2-unloaded and CO2-loaded DBU-glycerol mixtures due to their simplicity and precision. The density data are useful in the engineering design for CO2 capture using DBU-glycerol solvent.

An indirect determination of the specific gravity of soil solids

The specific gravity of soil solids, Gs, is a significant material property in geomechanics. It is determined in the laboratory by water, gas or kerosene pycnometer, following a rather complex procedure. This Note suggests an original, simple and quick – albeit not empirical –method, which only requires knowledge of the soil unit weight γsat and the water content w in fully saturated conditions and allows one to obtain the soil solids specific gravity Gs as a derived quantity. The method can be also used for unsaturated soils, provided that they (or a paste made of the soil itself) are previously fully saturated. Gs values obtained applying this method to a variety of soils ranging from pure clays to fine-medium sands are in very close agreement with those determined using the pycnometer standard method. As a by-product, the method is a applicable also for assessing the in-situ unit weight of a saturated soil sample γsat, even of cohesionless fine-medium sandy soil, however disturbed it may be.The proposed method is not intended as a substitute for the standard pycnometer method, but as a simple and useful addition to the tool-bag for the characterization of ordinary soils.

ACCOUNTING THERMOBARIC CONDITIONS WHEN DETERMINING THE COUNTING PARAMETERS OF ZEOLITE-CONTAINING ROCKS OF PRODUCTIVE RESERVOIRS OF THE BOLSHEKHETSKAYA DEPRESSION FIELDS

The authors of the article have studied structural features of the reservoirs by using microsections descriptions, XRF, SEM photos, particle size distribution, determination of the mass fraction of carbo-nates by thermo gravimetric method, refinement of mineral density by pycnometric method, study of reservoir properties in the temperature and pressure conditions at saturation as kerosene and water and etc. It has been found that due to its physical and chemical characteristics zeolites have significant impacts on the increase in the degree of hydration and the presence of zeolite water; low density and a large fractional free volume of the dehydrated samples; the existence of similar channels with diameters of molecular dimensions in dehydrated crystals. It is shown that for zeolite-containing rocks the most reliable result can be obtained by using in the calculation of the reduced density of the skeleton and transition to thermobaric conditions in the evaluation of reservoir properties and resistivity.

Specific Features of the Growth, Structure, and Main Physicochemical Properties of FeGa2Se4 Single Crystals

FeGa2Se4 single crystals belonging to the promising class of diluted magnetic semiconductors of the AB2X4 type (A is Mn, Fе, Co, or Ni; B is Ga or In; and X is S, Sе, or Te) are investigated; this compound is currently used for designing solid-state magnetically controlled devices. Optically homogeneous bulk FeGa2Se4 single crystals ~14 mm in diameter and ~50 mm long are obtained for the first time from melt by the modified Bridgman method. The elemental composition of the crystals is determined by X-ray spectral microprobe analysis; it corresponds to the specified composition in the initial charge. It is established by X-ray diffraction analysis that this compound is crystallized into a cubic sphalerite-type structure with unitcell parameter a = 5.498 ± 0.005 A. The melting and crystallization temperatures of the grown FeGa2Se4 single crystals are determined by differential thermal analysis. The melting temperature is 1283 K. The microhardness of the single crystals is measured for the first time, the density is determined by the pycnometric method, and the parameters of hyperfine interaction of iron ions are found on the basis of the Mossbauer spectra.

Densities and surface tensions of ionic liquids/sulfuric acid binary mixtures

Abstract The densities and surface tensions of [Bmim][TFO]/H2SO4, [Hmim][TFO]/H2SO4 and [Omim][TFO]/H2SO4 binary mixtures were measured by pycnometer and Wilhelmy plate method respectively. The results show that densities and surface tensions of the mixtures decreased monotonously with increasing temperatures and increasing ionic liquid (IL) molar fraction. IL with longer alkyl side-chain length brings a lower density and a smaller surface tension to the ILs/H2SO4 binary mixtures. The densities and surface tensions of the mixtures are fitted well by Jouyban–Acree (JAM) model and LWW model respectively. Redlich−Kister (R–K) equation and modified Redlich−Kister (R–K) equation describe the excess molar volumes and excess surface tensions of the mixtures well respectively. Adding a small amount of ILs (xIL