Digital Density Meter Research Articles

Metrological Evaluation of the Compatibility of Two Different Digital Density Meter Adjustment Methods

Brazilian regulation requires the test methods for analysing the shrinkage factor, and the solubility ratio in crude oils must be estimated under the measurement conditions for appropriation. Since these physicochemical parameters depend upon the density, a Brazilian oil company proposed an adapted and more user-friendly methodology for adjusting the digital density meter under high pressure and temperature conditions. This study aimed to evaluate the metrological compatibility of this proposal by comparing it with the fit model presented by a manufacturer of a digital densimeter and with the tabulated reference values of fluid density. Since the density data behaviour presented non-normal distributions, the Wilcoxon signed-rank test showed metrological compatibility between the approaches studied in the pressure range from 0 psi to 1200 psi (8.273709 MPa) and the temperature range from 5 °C to 70 °C.

Thermodynamic Studies of Aqueous Binary and Ternary Solutions Involving Lysozyme and Urea at 298.15 K

Measurements for osmotic pressure and densities for lysozyme in aqueous and aqueous solutions containing urea have been reported at 298.15 K using a vapor pressure osmometer and vibrating tube digital density meter, respectively. The partial molar volumes and activity coefficients of both the components and the osmotic pressure of the solutions have been calculated. The molar mass and second virial coefficient of lysozyme have been obtained using the McMillan–Mayer theory of solutions and are compared with the values obtained in aqueous salt solutions. The Guggenheim–Stokes equation for osmotic coefficient has been used to obtain the protein molecular diameter in an aqueous medium. The estimated diameter of lysozyme is similar in magnitude to that in the pure state, confirming the retaining of the native state of the protein in aqueous solutions over the studied concentration region. These studies have been extended to aqueous–urea (∼2.0 mol·kg–1) solutions at 298.15 K. Data of water activity and activity coefficient of all the three components in ternary solutions as a function of lysozyme concentration have been determined by the methodology developed by us earlier. The data have been further analyzed to obtain Gibbs free energy changes of transfer of lysozyme as well as that urea from corresponding aqueous binary to aqueous ternary solutions through which information about the binding of denaturant to protein can be derived. The analysis further reveals that the binding of urea to the protein molecules occurs through the breakdown of protein–water H–bonds leading to the opening of a coiled structure of lysozyme. All these results are discussed in terms of protein hydration, protein–protein hydrophobic interactions, and protein denaturant binding equilibria for the solutions of lysozyme.

Molecular interactions of glycine and L-alanine + citrate buffer solutions at different temperatures: Volumetric, viscometric, and FTIR approach

Densities,, and viscosities,of glycine/L-alanine in water and in (0.10, 0.50, 1.00) aqueous trisodium citrate buffer (Na 3 CB) solutions of pH 7.40 at T = (298.15 to 318.15) K have been measured by using vibrating tube digital density meter and suspended level Ubbelohde capillary viscometer, respectively, at atmospheric pressure i.e. 101.3 kPa. Thermodynamic parameters, i.e. , , , viscosity B-coefficients, and obtained from density and viscosity measurements have been used to unravel predominant forces among glycine/L-alanine and aqueous Na 3 CB solutions. Activation free energies, for the viscous flow of solutions, have been obtained by applying transition state theory to the viscosity B-coefficients values. The results are further supported by FTIR studies for glycine/L-alanine in water and aqueous Na 3 CB solutions of pH 7.40, revealing the intermolecular hydrogen bonding in these systems. Moreover, the results obtained from volumetric, viscometric, and spectroscopic studies provide valuable information on intermolecular interactions, influencing their efficacy in biological applications.

The Design of Digital Liquid Density Meter Based on Arduino

A measure of liquid thickness is needed to make a dough or formula for medicinal syrup. The tools to measure the thickness available in the market are analog that is less accurate and precision. To overcome these problems, digital density measuring devices are needed. The limitation of the digital density meter, especially liquid, urges the author to carry out further research on the digitization of this measuring instrument. This research aims to make a digital density meter for liquid matter with a high level of measurement accuracy, as the reference measurement study for liquid density in digital form. The instrument was designed using the load cell method as the main sensor. It was also equipped with a DS18B20 water-resistant temperature sensor to measure the temperature of the liquid. The data were analyzed to obtain the accuracy and error of the liquid density measurement from the density meter. The liquid samples used for research were Pertamax, solar, and water. Sample accuracy and error measurement results were 99.83 percent and 0.17 percent respectively for Pertamax, 99.63 percent and 0.37 percent for solar and 99.46 percent and 0.54 percent for water. The measured density value was finally shown on the 16x2 LCD.

Density and viscosity of binary mixtures of diethyl oxalate with ethanol, ethyl acetate, tetrahydrofuran, and toluene

ABSTRACT This study presents the densities and viscosities of four binary liquid mixtures containing diethyl oxalate (DEO) with the organic solvents ethanol, ethyl acetate (EA), tetrahydrofuran (THF), and toluene at temperatures ranging from 303.15 to 323.15 K and at atmospheric pressure. DEO is widely used in the pharmaceutical industry as an intermediate or reaction reagent for synthesizing active pharmaceutical ingredients. The measured thermophysical properties are important for pharmaceutical process design and development. A vibrating tube digital density meter and a capillary viscometer were used for density and viscosity measurements, respectively. According to the measurement data, the excess molar volumes (VE ) and viscosity deviations ( ) of the binary mixtures were calculated and satisfactorily correlated with the four-parameter Redlich–Kister equation. Ethanol or THF addition to DEO led to a positive deviation of VE , whereas EA or toluene addition to DEO led to a negative deviation. These results indicated the molecular packing of DEO with EA and toluene was more efficient than that with ethanol and THF. By contrast, the values of the four binary mixtures were negative, indicating that the viscosity was markedly lower than that of an ideal mixture.

Jar-by-Jar: Curation Improvements to the Herpetology Collection at CUMNH

The University of Colorado Museum of Natural History (CUMNH) Herpetology Collection is comprised of over 65,000 fluid-preserved specimens representing over 2,500 taxa from more than 70 countries. Despite its active use, a history of irregular topping up schedules and a decades-long dearth in rehousing projects due to budgetary constraints left the collection in substandard conditions. A 2015 survey of roughly 10% of the collection revealed average ethanol concentrations far below desired levels, with only 15% of specimen jars surveyed containing optimal preservative strengths of 70% (+/- 2.5%). In Fall 2017, CUMNH secured an Institute of Museum and Library Services (IMLS) grant to holistically address shortcomings in the micro- and macro-storage environments within the Herpetology Collection. Program activities include jar-by-jar ethanol remediation using a digital density meter and a topping up algorithm proposed by Notton 2010, collection-wide replacement of faulty jars and lids, and installation of new static and mobile compactor shelving. Updates to nomenclature and a full specimen inventory including condition and location tracking in Arctos also fall within the project scope. This talk will cover progress thus far, our approaches to moving a collection in place, and systematic remedial topping up as a valuable counterpart to routine monitoring in fluid collections.

Interactions of glycine with aqueous solutions of sodium phosphate buffer at T = (288.15, 293.15, 298.15, 303.15, 308.15, 310.15, 313.15, 318.15, 323.15 and 328.15) K: Volumetric and UV absorption studies

Interactions of glycine with sodium phosphate buffer have been investigated by volumetric and UV absorption studies. Densities have been measured for glycine in water of pH=(1.00, 7.40 and 13.40) and in 0.1M, 0.5M and 1M aqueous sodium phosphate buffer (NaPB) solutions as a function of concentration at T=(288.15 to 328.15) K and at pH=(1.00, 7.40 and 13.40) by using digital density meter. Apparent molar volumes (V∅) and partial molar volumes (V2o) obtained from these density data have been used to calculate partial molar volumes of transfer (∆trV2o) from water to aqueous sodium phosphate buffer solutions, which are positive for zwitterionic and deprotonated form of glycine. Interaction coefficients have been obtained from McMillan-Mayer's approach. Effect of temperature on these thermodynamic properties have been studied by determining the partial molar expansibilities (∂V2o/∂T)P at infinite dilution and their second order derivative (∂2V2o/∂T2)P at different temperatures and at pH=(1.00, 7.40 and 13.40). Hydration number (nH) of glycine at pH7.40 have been determined from the V2o data. The results have been rationalized in terms of various interactions taking place in these systems. Further, absorption spectra have also been recorded for the present system with the help of UV–visible spectrophotometer at 298.15K which is helpful in interpreting the possible molecular interactions between glycine and NaPB.

鲁道夫密度仪在原油密度测量中的应用

鲁道夫密度仪属于U型振动管数字式密度仪，具有精密度高、操作简单、自动化程度高、无人为读数误差等优点。测量结果与漂浮式密度计一致，而且重复性更好，可以实现大批量、快速检测原油的密度，降低了人员劳动强度，提高了工作效率。 Rudolph density meter belongs to U-Shaped vibrating tube digital density meter, which has the advantages of high precision, simple operation, high degree of automation, no artificial reading error, etc. Measurement results are consistent with floating type density meter and have better repeatability. Rudolph density meter can realize high volume and rapid measurement of crude oil density, reduce the staff labor intensity and improve work efficiency.

Evaluation of Density-Measurement Methods for Construction Slurries

Abstract The density of slurries is an important quality-control parameter for many types of geotechnical works, such as slurry trenching, grouting, and bored piling. Although the working range of this parameter has been refined over the years in many standard specifications, surprisingly almost nothing has been done to improve the accuracy of the density-measurement technique. For density testing, almost all of the current standards specify the use of the conventional mud balance, although it has a measurement range far greater than what is actually needed for civil engineering works. To provide a scientific basis for the possible adoption of other measurement tools, this paper compares the performance of four different tools, namely, mud balance, digital density meter, aerometer, and pycnometer. From the results, it was found that the performance of the pycnometer depends on its measurement volume, and that the one with a nominal volume of 2 liters gives the best overall performance (measurement error ≤0.001 g/cm3). The accuracy of the mud balance and the aerometer has been found to be dependent on how they are read (i.e., to the original scale division or with care to a half a division) and also on the specimen. The digital density meter, although having good overall performance, cannot be used to measure fluids containing coarse soil particles because of the small diameter of the internal vibrating U-tube. The findings of this study will find applications in geotechnical works involving the use of slurries or grouts.

Densities and viscosities of binary liquid mixtures of 1-ethyl-3-methylimidazolium tetrafluoroborate with acetone, methyl ethyl ketone, and N-methyl-2-pyrrolidone

In this study, the densities and viscosities of three binary liquid mixtures of 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim][BF4]) with acetone, methyl ethyl ketone, and N-methyl-2-pyrrolidone were measured at 303.15, 313.15, 323.15, and 333.15K under atmospheric pressure. A vibrating-tube digital density meter and a capillary viscometer were used for density and viscosity measurements, respectively. The trends in densities and viscosities with respect to composition and temperature were compared. In addition, excess molar volumes and viscosity deviations were calculated to investigate the molecular interaction between an ionic liquid and an organic solvent. The ability of hydrogen bonding formation and interstitial accommodation were investigated to clarify the influence of excess molar volumes and viscosity deviations. In addition, the obtained excess molar volumes and viscosity deviations were fitted using a four-parameter Redlich–Kister equation. The optimally fitted parameters are presented. The correlated results were consistent with the experimental data.

Density and Viscosity Measurements for Binary Mixtures of 1-Ethyl-3-methylimidazolium Tetrafluoroborate ([Emim][BF4]) with Dimethylacetamide, Dimethylformamide, and Dimethyl Sulfoxide

The density and viscosity data of three binary liquid mixtures containing the ionic liquid (IL) 1-ethyl-3-methylimidazolium tetrafluoroborate and organic solvents, dimethylacetamide (DMAC), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO) were obtained under atmospheric pressure, at temperatures of 303.15 to 333.15 K over the entire composition range. A vibrating-tube digital density meter and a capillary viscometer were used for density and viscosity measurements, respectively. Excess molar volumes (VE) and viscosity deviations (Δη) for the binary mixture system were calculated from the experimental data and were satisfactorily fitted with the Redlich–Kister equation. Adding DMAC, DMF, and DMSO led to negative values of VE and Δη. This finding revealed that the packing of the constituents was more efficient, and the anion–cation interaction of IL was decreased in the binary liquid mixtures. The sequences of VE and Δη for the three binary liquid mixtures in this study are also discussed using interm...

An Active Learning-Based Integrated Project between High Schools and the University: Analysis of Bioethanol Fuel and Its Blends with Synthetic Gasoline

In order to increase the interest of high-school students in chemistry, and initiate their contact with the Institute of Chemistry of the University of São Paulo (Chem-USP), we introduced a project of socio-economic relevance, analysis of bioethanol fuel (hereafter called “ethanol”) and its blends with synthetic gasoline. We used concepts that these students are familiar with, and techniques that can be employed in high schools. Due to historical reasons, Brazilian students are familiar with the use of ethanol as fuel, either hydrous, or as a blend with gasoline in “flex-fuel” cars and motorcycles. They may lack, however, knowledge about industrial production of ethanol and possible adulteration of fuels. We carried out this project in three stages; I and III at the schools and II at Chem-USP. In stage I, the students conducted a literature survey, answered a quiz that their teachers corrected and discussed in class, and then prepared ethanol-water mixtures. In stage II, they came to Chem-USP to determine the densities and refractive indices of their aqueous ethanol mixtures, and the refractive indices of ethanol-synthetic gasoline mixtures using digital density meter and refractometer. They recorded the Uv-Vis spectra of the natural dye β-carotene dissolved in ethanol-water mixtures. All students constructed calibration curves (physical property versus mixture composition) and determined the composition of commercial unknowns (household cleaning ethanol and hydrous ethanol fuel). In stage III, the students discussed with their teachers the results of their experiments, and the concepts involved (e.g., hydrogen-bonding) and then answered an evaluation sheet of the project. They liked the active learning approach; their working in groups with modern equipment. The experimental part of this project can be carried out using less sophisticated infrastructure, namely, volumetric glassware, analytical balance, Abbe refractometer, and a low-cost spectrophotometer.

Effect of potassium phosphate buffer on volumetric behavior of glycine in aqueous solutions at different temperatures

The apparent molar volume (V∅) of glycine in water and in 100, 500 and 1000mM aqueous potassium phosphate buffer (KPB) solutions have been obtained from density measurements at different temperatures (288.15 to 328.15K, including physiological temperature) and at different pH values (1.00, 7.40 and 14.00) by using vibrating-tube digital density meter. The estimated partial molar volumes at infinite dilution (V2o) have been used to obtain the corresponding transfer volume (∆trV2o) from water to aqueous potassium phosphate buffer solutions. Interaction parameters have been calculated from ∆trV2o data. The partial molar expansibilities (∂V2o|∂T)P at infinite dilution and (∂2V2o|∂T2)P values have also been determined from the V2o data at different temperatures. The hydration numbers (nH) of glycine at pH7.4 have been determined from the V2o data in the presence of KPB at different temperatures. The results have been discussed in terms of various interactions operating in these systems.

The benefits of applied research: 37 years of discoveries, adaptations and solutions

The authors’ work started in fermentation in 1977 and in the 1980’s into sugar production and cane quality. Statistical analysis was a key factor for the success of improving yield in ethanol and sugar production as well as cane quality. Adaption of methods for industrial laboratories also was very important in relation to yield and in reduction of sugar losses in the factory. Methodologies to measure sugar losses occurring through degradation in the factory (evaporation) using ion chromatography and dry substance content with a digital density meter were adapted. The fermentation yield improved from 75% in 1977 to 92% in 2014, which was possible by adapting methods for live bacterial counting within 20 min, and by controlling contamination using antimicrobial products through research in the laboratory and the industry. Since 1990 yeasts for industrial fermentation were selected by karyotyping analysis of the nuclear chromosomes and in the last seven years based on mitochondrial DNA. The last technique made the “Process Driven Selection” possible, i.e. one or several yeast strains which fit each distillery. Floc formation in carbonated beverages is not only due to the Indicator Value (discovery by SPRI research group) but also to aconitic acid and calcium under Brazilian conditions.

Density and Viscosity of Ionic Liquid Binary Mixtures of 1-n-Butyl-3-methylimidazolium Tetrafluoroborate with Acetonitrile, N,N-Dimethylacetamide, Methanol, and N-Methyl-2-pyrrolidone

In this study, thermodynamic properties of the binary mixtures of ionic liquid with an organic compound, as potential solvent systems in pharmaceutical industry applications, are studied. The densities and viscosities of the binary mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) with acetonitrile, N,N-dimethylacetamide, methanol, and N-methyl-2-pyrrolidone were measured at atmospheric pressure over the [C4mim][BF4] mole fraction range from 0.1 to 0.9 and at temperatures from 303.15 to 333.15 K at intervals of 10 K. The densities were measured using a vibrating-tube digital density meter and the viscosities were measured using a capillary viscometer. The excess molar volumes (VE) and viscosity deviations (Δη) were calculated from densities and viscosities of mixture, respectively, and fitted to the Redlich–Kister polynomial. The optimally fitted parameters are also determined and the correlation results are in satisfactory agreement with the experimental data. In addition, the excess molar volumes of binary mixtures of ionic liquid with different organic compounds are compared and discussed using the Hansen solubility parameter.

The densities and viscosities of a binary liquid mixture of 1-n-butyl-3-methylimidazolium tetrafluoroborate, ([Bmim][BF4]) with acetone, methyl ethyl ketone and N,N-dimethylformamide, at 303.15 to 333.15 K

In this study, thermodynamic properties of a binary mixture of ionic liquid and organic solvent as a potential solvent system in pharmaceutical industry are studied. The densities and viscosities of the binary liquid mixture of ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]), with acetone, methyl ethyl ketone (MEK) and N,N-dimethylformamide (DMF), are measured at different temperatures (303.15, 313.15, 323.15 and 333.15K) and atmospheric pressure, over the entire range of compositions. The densities are measured using a vibrating-tube digital density meter and the viscosities are measured using a capillary viscometer. The changing trends of densities and viscosities with temperature and composition are discussed. In addition, the excess molar volumes and viscosity deviations for the binary liquid mixture are calculated and then fitted to the Redlich–Kister polynomials. The optimally fitted parameters are presented and the correlation results show satisfactory agreement with the experimental data. Furthermore, the excess molar volumes of the binary mixtures are also compared and discussed by the viewpoint of molecular interaction.

Effect of chain length of alcohol on thermodynamic properties of their binary mixtures with benzylalcohol

a b s t r a c t Densities (� ) of pure liquids and their mixtures have been measured over the entire composition range for the binary mixtures of benzylalcohol with 1-heptanol, 1-octanol, 1-nonanol and 1-decanol at 298.15 K to 313.15 K and at atmospheric pressure by using Rudolph Research Analytical Digital Density Meter (DDM-2911 model). Further, the speed of sound (u) for the above said mixtures were also measured at 303.15 K and 313.15 K. The experimental density data were used to compute excess molar volumes (V E ) and compared with predictive expression proposed by Redlich-Kister equation. Excess speed of sound (uE), isentropic compressibility (� S) and excess isentropic compressibilities (� E ) were evaluated from experimental sound velocity and density data. Moreover, the experimental speed of sound data was compared in terms of theoretical models proposed by Schaaff's collision factor theory (CFT) and Jacobson's free length theory (FLT). The experimental results were discussed in terms of intermolecular interactions between component molecules. © 2014 Elsevier B.V. All rights reserved.

Characterization of Density of Biodiesel from Soybean, Sunflower, Canola, and Beef Tallow in Relation to Temperature, Using a Digital Density Meter with a Metrological Point of View

Abstract In this article we study the behavior of biodiesel density from soybean oil, sunflower oil, canola oil, and beef tallow, the last one transesterified with ethanol and the others with methanol in relation to temperature with a metrological point of view. These quantities were measured with a digital density meter, one of the Brazilian density standards, in a temperature range between 15 and 40°C. Measurement uncertainty was calculated. The behavior of density is analyzed considering the estimated uncertainty. The density from all the samples investigated shows a linear behavior with respect to temperature.

Survey and analysis on abnormal of bone mineral density in healthy people and nursing measures

Objective To know the influence of ages of male and female on the bone mineral density.Methods 614 cases who took the physical examination in the Physical Examination Center of Peking Union Medical College Hospital were selected, including 275 male objects and 339 female objects. These objects were divided into four groups according to the ages, group A (less than 40 years), group B (40 to 49 years), group C (50 to 59 years) and group D (equal or greater than 60 years). Two regions in the upper segment of the lumbar vertebra and femur were measured using the digital dual energy X-ray density meter. Results The abnormal rate of bone mineral density in female obviously increased with age. There were obvious differences among the other groups except that there was no difference between group A and group B. The abnormal rate of bone mineral density in male had an increase tendency with age, with no statistical meaning through Chi-square test. Compared in the same range of age, there was significantly statistical difference in bone mineral density of male and female only in group D. Conclusions The abnormal rates of bone mineral density increase with age both in female and in male, especially in female. There is no difference in the abnormal rate of bone mineral density in male and female before 60 years, while the abnormal rate in female is much higher than that in male after 60 years. Key words: Osteoporosis; Bone mineral density; Body

Thermodynamic studies on the interactions of diglycine with magnesium chloride in aqueous medium at different temperatures

Apparent molar heat capacities ( C P2, ϕ ), apparent molar volumes ( V 2, ϕ ), and viscosities ( η) of diglycine in water and in aqueous magnesium chloride (MgCl 2) solutions of molality m S ≈ (0.05 to 0.70) mol · kg −1 over the temperature range T = (288.15 to 328.15) K have been determined using high sensitivity micro-differential scanning calorimeter, vibrating-tube digital density meter, and automatic viscosity measuring unit (AVS 350), respectively. The data have been used to calculate the partial molar heat capacities ( C P 2 ∞ ) and partial molar volumes ( V 2 ∞ ) at infinite dilution. The viscosity B-coefficients have also been obtained from viscosity data using Jones–Dole equation. The C P 2 ∞ and V 2 ∞ values of diglycine in aqueous MgCl 2 solutions are higher than those in water and thus exhibit positive transfer functions ( Δ tr C P 2 ∞ and Δ tr V 2 ∞ ), which are indicative of strong interactions between diglycine and MgCl 2. Corresponding viscosity B-coefficients of transfer are also generally positive. The transfer functions decrease with increase in temperature and increase with the concentration of MgCl 2. The free energies, enthalpies and entropies of activation for viscous flow of diglycine in aqueous MgCl 2 solutions have been obtained by using the Feakins transition-state theory. Partial molar expansibilities ( ∂ V 2 ∞ / ∂ T ) P and ( ∂ 2 V 2 ∞ / ∂ T 2 ) P at infinite dilution along with their temperature dependence, the interaction coefficients from the volume, heat capacity, and viscosity B-coefficients have been used to divulge the various kinds of plausible interactions between solute (diglycine) and cosolute (MgCl 2) in solutions.