Pycnometer Method Research Articles

Uticaj odabranih faktora na gustinu tečne hrane

The density of materials can be used for assessing their quality. The density of food materials depends on temperature and is caused by thermal expansion during heating. The density of a material is defined as a ratio between the mass of the material and its volume at the same temperature. One of the most exact methods for measuring liquid density is the pycnometric method. Measurements of materials density could also be performed using hydrometers or densimeters, where the exact value of density can be discerned on the hydrometer scale or on the display of measurement devices. During our experiments, we used two methods of density determination: pycnometric method and determination by a densimeter Mettler Toledo DM 40. Measurements were performed in the approximate temperature range (0 - 30) °C. The effect of various parameters (such as temperature, fat content, alcohol content and short storing time) on the density of the material was analysed in this paper. A linear decreasing character was applied for temperature dependencies of the sample density in the measured temperature range. The highest fat content of milk caused the lowest density, whereas lower fat contents (less than 1.5 %) were not consistent with this proportion due to different amounts of proteins in the measured samples of milk. The effect of the alcohol content on density had to be investigated alongside the material composition (wine, whisky and piña colada). The density values obtained were a bit higher after a short storage period due to the water loss during storage.

Properties of recycled ceramic aggregates specified in WT-1 2014 Aggregates - Technical Requirements

The article presents the results of research on primary recycling properties of ceramic aggregates conducted following the procedures outlined in WT-1 2014 Aggregates - Technical Requirements. The material for the tests was obtained from a company producing sanitary ceramic products. Damaged ceramic products, coming from the factory waste heaps, were transported to the laboratory and crushed. This enabled producing aggregate that was later subjected to tests carried out on the aggregates commonly used in the production of mineral-asphalt mixes applied in making road surfaces. The factors that were examined include the following: the flow rate of fine aggregates (angularity of fine aggregate), fine particles content - methylene blue test, light-weight impurities content, frost resistance, bulk density of grains as well as water absorption determined by pycnometric method. The test results showed that the properties of the recycled aggregates are similar to those included in traditional aggregates used for the production of mineral-asphalt mixes. On the basis of the conducted analyses, the waste ceramic aggregate was recommended for use.

Thermophysical and chemical characterization of induction furnace slags for high temperature thermal energy storage in solar tower plants

An induction furnace is an electric furnace in which ferrous metal scrap and fluxes (e.g. silica, limestone) are melted using an electromagnetic field to produce steel or cast iron. This metallurgical process is accompanied by the generation of large amounts of wastes called slags, which are composed mainly of a non-metallic part as well as a small metallic part. At the end of the melting process the slags layer is removed from the furnace top, then it is air-cooled and stored prior to discharge. While blast furnace slags (BFS), electric arc furnace slags (EAFS), and ladle furnace slags (LFS) were characterized in earlier works for thermal energy storage up to 1000°C, the induction furnace slags (IFS) have never been investigated for this application. Thus the aim of this paper is the thermophysical and chemical characterization of IFS to be used as high-temperature thermal energy storage materials (around 1000°C) in packed bed TES system. Chemical investigation of this metallurgical waste was conducted using: Energy dispersive X-ray spectroscopy (EDS) coupled with the Scanning electron microscopy (SEM), and infrared spectroscopy (FTIR). Their thermal heat capacity was measured using Modulated differential scanning calorimetry (MDSC), while their bulk density was determined using the pycnometer method. It was found that they have a good specific heat capacity (Cp ≈ 700J/kg°C) and a good bulk density (ρ≈ 2583kg/m3). The thermal stability of the IFS was assessed using thermogravimetric analysis (TGA) from room temperature up to 1000°C; Three cycles of heating/cooling were applied on the IFS and their thermal stability was proved at the end of the first cycle. The obtained results suggest that IFS are good candidate materials for high-temperature thermal energy storage application (up to 1000°C).

The Determination of Alcohol in Wines by Means of Near Infrared Technology

A rapid method for alcohol determination using Near Infra-red technology was investigated and compared to the standard pycnometric method. The apparatus was tested to show wine colour and sugar content had an influence on the analysis. The reproducibility of the technique was also checked and compared to that of the pycnometric method. It was found that colour, turbidity and sugar have little effect on the analysis and the reproducibility of the Near Infrared apparatus had a standard deviation of~ 0,04% as compared to the~ 0,06% of the pycnometer.

Research into the influence OF AL2O3 nanoparticle admixtures on the magnitude of isopropanol molar volume

The results obtained in experimental study of density of solutions of isopropyl alcohol and Al 2 O 3 nanoparticles are given. Studies on nanofluid density were carried out using pycnometric method in a temperature range from 250 K to 315 K at weight concentrations of nanoparticles 0.92 %, 1.81 %, 4.01 % and 6.65 %. The obtained data made it possible to reveal temperature and concentration dependences of the studied nanofluids and calculate magnitude of the excess molar volume as well as hydrodynamic diameter of nanoparticles. The data on the value of hydrodynamic diameter obtained from the information on excess molar volume were in good agreement with the data measured by the method of dynamic light scattering. It was shown that the equivalent diameter of the adsorption layer of isopropanol molecules on nanoparticles decreases with an increase in concentration of Al 2 O 3 nanoparticles. Based on these studies, a new method for predicting molar volume of nanofluids was proposed. This technique takes into account presence of a sorbed layer of base fluid molecules on the nanoparticle surface. As the studies show, density of the sorption phase is higher than density of isopropyl alcohol at the set-up parameters. Presence of a sorption layer of isopropyl alcohol molecules on the nanoparticle surface determines magnitude of the excess molar volume. This fact has to be taken into account when simulating density of nanofluids. A simple method was also proposed for determining equivalent diameter of the adsorbed layer of base fluid molecules on the nanoparticle surface. The essence of the method is an assumption that nanoparticles have a shape close to spherical and the surface layer is a spherical layer of sorbed isopropanol molecules on the nanoparticle. This method allows determination of the equivalent diameter from easily measured data. It is recommended for use in modeling viscosity, thermal conductivity and heat capacity of nanofluids. It is also recommended for use in development of heat exchange models for power equipment.

Effect of sintering temperature and micro structural analysis on sol-gel derived silver bismuth titanate ceramics

The silver bismuth titanate – Ag0.5Bi0.5TiO3 (ABT) ceramics with various grain sizes were synthesized by stearic acid gel method. The density measurement was calculated based on pycnometer method. The relative density of ABT pellet was calculated as 64.91%. The microstructure analysis establishes the relationship between the sintering temperature and grain size. Moreover, the micrographs show the pores and oriented particles of nano meter to micrometer size. The effect of sintering temperature on grain growth behavior of sol-gel derived porous silver bismuth titanate sample was discussed in detail.

Density evolution of the energy-rich compound furazano[3,4-e]tetrazine-4,6-dioxide as stability indicator during prolonged storage

Pycnometric method, powder X-ray diffraction analysis, and IR spectroscopy were used to study the fundamental aspects of how the density of energy-rich compound furazano[3,4-e]tetrazine-4,6-dioxide varies during its prolonged storage. It was shown that the density grows during the first stage with length of up to 14 days due to the recrystallization. In further storage during eight years, the density gradually falls due to the buildup of stresses in the crystal lattice, created by thermal decomposition products. The degree of decomposition at 22°C during 8 years, evaluated by extrapolation of the Arrhenius dependence, is 0.24%. The observed decrease in the density is attributed to the anomalously weak hampering effect of the crystal lattice.

Excess properties and spectroscopic studies of binary system of 1-methoxy-2-propanol + dimethyl sulfoxide at T = (298.15–318.15) K

ABSTRACTThermophysical property data for the binary system of 1-methoxy-2-propanol (PGME) + dimethyl sulfoxide (DMSO), a potential candidate for use as the scrubbing liquid for the absorption of SO2, are lacking in the literature. This paper presents experimental data at 0.1 MPa on the density and viscosity for this binary system measured over the whole composition range at T = (298.15, 303.15, 308.15, 313.15 and 318.15) K. The extended combined uncertainty Uc with a 0.95 level of confidence for the pycnometer method and Ubbelohde viscometer used in this study is 0.002 g·cm−3 and 0.028 cm2·s−1, respectively. The PGME + DMSO system shows negative values of the excess molar volume at all temperatures and compositions. Based on UV-Vis and FTIR, the intermolecular interaction of PGME with DMSO was confirmed as hydrogen bonding between the hydroxyl hydrogen atom in PGME and the oxygen atom in DMSO.

Influence of Recycled Aggregate Quality on Recycled Concrete

This article deals with the influence of recycled aggregate quality on recycled concrete. Replacement of natural aggregate by recycling aggregate has a negative influence on the properties of concrete. Three types of recycled aggregate were used for the production of concrete. The samples of recycled aggregate were obtained from two recycling plants in the Czech Republic. The samples of recycled aggregate were tested by pycnometric method. From the test results, a different quality of recycled aggregate was discovered. For the testing of concrete, a total of eight concrete mixtures were made, one of which was a reference mixture and the natural aggregate was replaced by recycled aggregate of varying ratio in the other mixtures. Finally, it is possible to say that use of recycled aggregate in concrete influences the properties of concrete. This influence depends on the quality and amount of recycled aggregate in the concrete.

A Simple Method to Determine Bioethanol Production from Coffee Mucilage, Verified by HPLC

This paper proposes a method to determine bioethanol concentration that uses a pycnometer verified with a high performance liquid chromatography (HPLC) technique; it is a simple tool to determine the density of liquids for getting information about the ethanol concentration. The results showed that the sugar concentration affected the bioethanol concentration. A lower initial sugar concentration of 26.5 g/L generated higher yield of 45.3% sugar to bioethanol and a fractional or relative yield of 88.74%. Significance tests were used to compare the two experimental means, revealing that the pycnometer method and HPLC provide the same bioethanol concentration with joint variances of 2.269, 0.242, and 0.112 for 3 different tests with initial sugar concentrations of 26.486 g/L, 49.043 g/L, and 68.535 g/L, respectively. This study established and developed a methodology to determine bioethanol concentration from coffee mucilage by the proposed method.

Index and Strength Characteristics of Residual Lateritic Soils from South-Western Nigeria

Aim: To test consistency and strength of residual lateritic soil of Migmatite Gneiss of the Gneiss C omplex from Abeokuta and Ibadan of South - western Nigeria for utilisation as sustainable road construction materials. Study Design: A rec onnaissance survey was carried out for location and identification of major outcrops around the area. The test pit investigative method was adopted by profiling the subsoil 3 m below the ground surface. Disturbed soil samples were used for the determinati on of the index properties, while shear strength parameters were determined on undisturbed soil specimens. Place and Duration: The study was undertaken in Ibadan and Abeokuta, Southwest, Nigeria between Dec 2011 and March 2012. Methodology: All the proced ures adopted for the tests were in accordance with the British Standard 1377.The specific gravity of the samples was determined using the pycnometer method. The sieve analysis and hydrometer methods were employed to study the particle size distribution of coarse and fine soils respectively, while the Atterberg tests were performed to investigate the

Measurement of the specific and the apparent molar volumes of some even chain length fatty acids in ethanol

The specific and the apparent molar volumes of some fatty acids of even chain length from decanoic to octadecanoic acid were determined in ethanol. The objective was to understand the extent to which the acids can disturb the structure of the solvent as well as affect the micellar characteristics. The specific volumes were obtained by fitting the measured viscosity data to the Einstein equation while the apparent molar volumes were obtained using the pycnometric method. The specific volumes of the acids increased with the increase in the carbon chain length of the acids but were fairly constant within a narrow concentration and temperature ranges. Both the apparent molar volumes and apparent molar volumes at infinite dilution were temperature and carbon chain length dependent. The activation enthalpies for the viscous flows were independent of the carbon chain length suggesting little dissociation/association. The dissolution enthalpies were positive in conformity with the endothermicity of the process. The negative expansivity values were interpreted to originate from the dominant hydrophobic characters of the fatty acids. The combined analysis of (energy contribution of the solute to the free energy of Δµ 2 o the solution) and the Hepler constant dictated the classification of the acids as anomalous structure makers. Keywords : Viscosity, Specific Volume, Apparent Molar Volume, Activation Energy, Expansivity, Hepler Constant

Influence of Mixing Parameters on Homogeneity of Al/Sic Composites/ Wpływ Parametrów Mieszania Na Jednorodność Kompozytów Al/Sic

Abstract The main aim of this work was to study the effect of time and method of Al, SiC powders mixing on the microstructure and mechanical properties of composites. Moreover, the influence of applicating direct extrusion with a reversibly rotating die on the homogeneity of the composites was examined. Microstructure observations with the use of an optical microscope and scanning electron microscope were applied. A quantitative analysis of composite microstructure was conducted. The density (helium pycnometer method), Vickers hardness and the Young’s Modulus of the composites were also determined. The results show that the homogeneity of Al/SiC composites rises with an increase of mixing time. However, better results were obtained by application of high energy ball milling process.

Combined experimental methods to assess absorption rate of natural and recycled aggregates

The assessment of maximum water absorption and absorption rate are necessary in order to design concrete mixtures from relatively porous aggregates, such as recycled aggregates. The experimental research presented in this paper investigates and improves the existing procedures for determining water absorption rates. New equations and experimental procedures are proposed to correct the existing procedures. Three types of aggregates were studied. Natural aggregates with two gradations 4–10 and 6.3–20 mm, natural limestone aggregates with gradation 4–20 mm and recycled aggregates with two gradations 4–10 and 10–20 mm. For each granular type, two tests were conducted, the first with oven-dried aggregates and the second with aggregates having initial moisture. Effects of initial moisture state were deduced from the first part of the experimental program. Then existing procedures were combined in order to design new procedures. Finally a method was developed for testing the volume variation of aggregates by hydrostatic weighing; the detailed testing procedure and equations of the new method are illustrated using the natural and recycled aggregates. Results from pycnometer method and hydrostatic weighing showed very good correlation.

The effects of mechanical activation on the sintering and microstructural properties of cordierite produced from natural zeolite

In this study, natural zeolite was used as a precursor for cordierite manufacturing. MgO and Al2O3 were added to zeolite to obtain the cordierite stoichiometry. A mixture of MgO/Al2O3/SiO2 in the ratio 2:2:5, which was adjusted according to the cordierite stoichiometry for these raw materials, was mechanically activated using a planetary high-energy ball mill for different mechanical activation durations (0.5, 1 and 2h). The activated powder mixtures were sintered at 1250°C for 1h. Both the activated powders and the sintered samples were examined by various analysis techniques. The globular morphology, agglomeration, amorphisation and particle size reduction were observed for powders characterised using scanning electron microscopy (SEM), X-ray diffractometry (XRD) and particle size analysis. The densities of the powders processed for 0.5, 1 and 2h were measured by the pycnometer method to be 2.655g/cm3, 2.647g/cm3 and 2.637g/cm3, respectively. The sintering behaviour of the samples was determined by measuring the linear shrinkage, water absorption, density and apparent porosity. The sintering and microstructural properties of the samples changed with an increase in the mechanical activation time. The densities of the sintered samples were measured using the Archimedes principle. The densities of the samples processed for 0.5, 1 and 2h were 2.583g/cm3, 2.554g/cm3 and 2.525g/cm3, respectively. The XRD analyses of the sintered samples revealed that spinel and a glassy phase accompanied the cordierite main phase. The average grain sizes of the samples produced from the powders processed for 0.5, 1 and 2h were 2.29μm, 1.91μm and 1.02μm, respectively. The hardness values of the samples processed for 0.5, 1 and 2h were 8.26GPa, 8.63GPa and 9.03GPa, respectively.

Thermophysical properties of HgTe and Hg0.9Cd0.1Te melts

Thermophysical properties, namely, density, viscosity, and electrical conductivity of HgTe and Hg0.9Cd0.1Te melts were measured as a function of temperature. A pycnometric method was used to measure the melt density in the temperature range of 948 to 1073K for the HgTe melt and 1011 to 1131K for the Hg0.9Cd0.1Te melt. The density results show a maximum at 1023 and 1020K, respectively, for the HgTe and Hg0.9Cd0.1Te melts. The viscosity and electrical conductivity were simultaneously determined using a transient torque method from 944 to 1098K for the HgTe melt and from 1016 to 1127K for the Hg0.9Cd0.1Te melt. The measured electrical conductivity decreases as the mole fraction of CdTe, x, increases at a specific temperature, and increases as a function of temperature, which shows a semiconductor-like behavior. The measured viscosity decreases as the mole fraction of CdTe, x, increases at a specific temperature and decreases as the temperature increased. The analysis of the electrical conductivity of the melts and the relationship between the kinematic viscosity and density implied a structural transition in these melts. No relaxation phenomena were observed in the density, electrical conductivity, and viscosity of the HgTe and Hg0.9Cd0.1Te melts.

Hard porous chromium containing macrospheres as new catalysts for the esterification reaction of acetic acid with epichlorohydrin

Abstract This paper reports a systematic study on the preparation, characterization and testing of metallosilicate macrobeads that contain chromium ions as active catalytic centers. In order to obtain hard macrospheres, four metals (Cr, Al, Zr and Zn) were incorporated into the silica matrix using chitosan as a template and shape generator. Metallosilicate macrospheres were synthesized at room temperature using tetraethylorthosilicate as silicon source and chlorohydric acid as catalyst. The size of metallosilicate macrospheres was in the range 0.9 — 1.1 mm. The catalyst was characterised by means of water sorption technique, FTIR spectroscopy and SEM/EDX analyses. FTIR spectra put into evidence the presence of metallic ions within the silica framework. EDX analyses confirmed the efficient incorporation of metals within the silica matrix (the content of metals from the calcined catalyst is almost the same as that from the initial gel mixture). Porous structure of catalyst investigated by water sorption technique and by pycnometric methods (with n-heptan and mercury respectively) proved that the synthesized catalyst had micro, meso and macropores. Catalyst was tested in the esterification reaction of acetic acid with epichlorohydrin. The temperature and the amount of catalyst exerted a marked influence on reaction rate. This work opens new perspectives for heterogeneous catalysis encouraging the replacement of powder catalysts with macrospherical catalysts that are easy to recover and to reuse.

Density Measurement of Coal Slime Powder by Pycnometric Method

Coal slime is solid waste with high solid content, viscosity, fine particles, which is generated in the production process of the coal industry. The density of its powder is an important factor to affect the resistance characteristics of pipeline transportation. Tests show that when the density changes 0.1g/cm3,the corresponding relative error of pipeline transportation resistance is up to 42%.Therefore, accurate density measurement of coal slime powder is the premise to calculate resistance loss, and has significance to study resistance characteristics of pipeline transportation and guide production practices. Based on pycnometric method, this paper improved the measurement, and adopted self-designed exhaust system, which is simple and easy to operate, and can effectively excludes the air in the pycnometer, thus improving measurement accuracy. Practices show that it is an effective method to measure powder density, with easy operation and high accuracy as well as good repeatability.

The polymer free volume as a controlling factor for drug release from poly(lactide‐co‐glycolide) microspheres

ABSTRACTDrug release from poly(lactide‐co‐glycolide) (PLGA) microspheres is strongly determined by the pore structure of the particles. This study examines how swelling‐induced pore constriction delays the drug release and by which factors this process is controlled. Combination of different porosimetric and pycnometric methods enabled insight into the submicroscopic range of the pore structure and revealed that remarkably the polymer free volume plays a crucial role in drug release from PLGA microspheres. Surprisingly, the latter was shown to be inversely correlated to the degree of diffusional drug release. This can be explained by a swelling‐induced constriction of the macroporous channel system in the microspheres which is related to the availability of free volume. The hole free volume was shown to be well controllable by the manufacturing conditions. Thus, the study deepens comprehension of the mechanism of drug release from biodegradable microparticles and offers an effective approach for controlling the release behavior. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39740.

Vplyv skladovania a teploty na reologické a termofyzikálne vlastnosti vzoriek whisky

Temperature and storing time can be included between the most significant parameters that influence physical properties of food. This article deals with selected rheologic and thermophysical properties of alcohol drink whisky. Our research was oriented on measuring of rheologic and thermophysical characteristics of whisky. There were measured two types of whisky – Grant’s and Jim Beam from two different producers, both samples had 40 % of alcohol content. During the experiments were analyzed rheologic parameters as: dynamic viscosity, kinematic viscosity and fluidity and thermophysical parameters as: thermal conductivity, thermal diffusivity and volume specific heat. Selected parameters were measured in temperature range (-5 – 27) °C. Measurements were done on whisky samples in different days during the storage. Measuring of dynamic viscosity was performed by digital rotational viscometer Anton Paar (DV-3P). Principle of measuring is based on dependency of sample resistance against the probe rotation. Density of whisky samples was determined by pycnometric method. Average density at given temperature along with dynamic viscosity value was used at calculation of kinematic viscosity and fluidity was also determined. Measuring of thermophysical parameters was performed by instrument Isomet 2104. Measurement by Isomet is based on analysis of the temperature response of the measured sample to heat flow impulses. Relations of rheologic and thermophysical parameters to the temperature were made and influence of storing time was discussed. From obtained results is clear that dynamic and kinematic viscosity is decreasing exponentially with temperature and fluidity has increasing exponential progress. We found out that both whisky samples had at the beginning and after one week of storage very similar values of rheologic parameters. Very small difference in rheologic parameters of whisky samples was found after two weeks of storing. Values of dynamic and kinematic viscosity were a bit higher and values of fluidity were a bit smaller after storing, that can be caused by loosening of the water during storage. Thermophysical parameters are increasing linearly with temperature for both whisky samples. Higher values of thermophysical parameters were in all cases obtained for whisky Grant’s.