Thermal Stability of \beta -PtO_2 Investigated by Simultaneous Thermal Analysis and Its Influence on Platinum Resistance Thermometry

We present thermogravimetric and differential scanning calorimetric studies of PtO \(_2\) powders measured in different atmospheres. In synthetic air a mass loss of 11.4 % is found at the decomposition temperature \(T_\mathrm {D}\)  = 595  \(^{\circ }\hbox {C}\) which can be attributed to the reduction of PtO \(_2\) . In a helium atmosphere the mass loss is 12.0 % and is found at 490  \(^{\circ }\hbox {C}\) . Subsequent heating in air leads to another oxidation process above \(T_\mathrm {D}\) and a reduction at 800  \(^{\circ }\hbox {C}\) . The second oxidation and reduction process is strongly suppressed when the powder is heated in He. The remaining mass above \(T_\mathrm {D}\) does not comply with a reduction path PtO \(_2 \rightarrow \) PtO \(\rightarrow \) Pt. Differential scanning calorimetry shows an endothermic reaction at \(T_\mathrm {D}\) in synthetic air as well as in helium which corresponds with the mass loss. These measurements imply that the powder can be assigned to be \(\beta \) -PtO \(_2\) . Furthermore, catalytic activity of the PtO \(_2\) powder is evidenced by mass spectrometry to be present below 460  \(^{\circ }\hbox {C}\) . Finally, the impact of these findings on the stability of platinum resistance thermometers is discussed.     

Measurement of the (p, \rho,T) Properties for Pure Hydrocarbons at Temperatures up to 600 K and Pressures up to 200 MPa

The data available for the thermodynamic properties of propane, \(n\) -butane, and isobutane at temperatures above 440 K are outdated and show significant discrepancies with each other. The ambiguity associated with these data could be limiting to the development of any understanding related to the effects of mixing of these substances with other materials such as \(\text{ CO}_{2}\) , ammonia, and non-flammable or lower-flammable HFC refrigerants. In this study, the (p, \(\rho \) , T) properties of propane, \(n\) -butane, and isobutane were measured at temperatures ranging from (360 to 600) K and pressures ranging from (50 to 200) MPa. Precise measurements were carried out using a metal-bellows variable volumometer with a thermostatted air bath. The expanded uncertainties \((k = 2)\) in the temperature, pressure, and density measurements were estimated to be \(<\) 5 mK, 0.02 MPa, and 0.88 kg  \(\cdot \)  m \(^{-3}\) ( \(T\le 423\)  K, \(p<100\)  MPa), 0.76 kg  \(\cdot \)   \(\text{ m}^{-3}\) ( \(T\le 423\)  K, \(p\ge 100\)  MPa), 0.76 kg  \(\cdot \)   \(\text{ m}^{-3}\) ( \(T>423\)  K, \(p < 100\)  MPa), and 2.94 kg  \(\cdot \)   \(\text{ m}^{-3}\) ( \(T>423\)  K, \(p \ge 100\)  MPa), respectively. The data obtained throughout this study were systematically compared with the calculated values derived from the available equations of state. These models agree well with the measured data at higher temperatures up to 600 K, demonstrating their suitability for an effective and precise examination of the mixing effects of potential alternative mixtures.     

Containerless Measurements of Density and Viscosity for a Cu_{48}Zr_{52} Liquid

The densities of solid and liquid Cu \(_{48}\) Zr \(_{52}\) and the viscosity of the liquid were measured in a containerless electrostatic levitation system using optical techniques. The measured density of the liquid at the liquidus temperature (1223 K) is (7.02 \(\pm \) 0.01) g \(\cdot \) cm \(^{-3}\) and the density of the solid extrapolated to that temperature is (7.15 \(\pm \) 0.01) g \(\cdot \) cm \(^{-3}\) . The thermal expansion coefficients measured at 1223 K are (6.4 \(\pm \) 0.1) \(\,\times \,10^{-5}\) K \(^{-1}\) in the liquid phase and (3.5 \(\pm \) 0.3) \(\,\times \,10^{-5}\) K \(^{-1}\) in the solid phase. The viscosity of the liquid, measured with the oscillating drop technique, is of the form \(A\exp \left[ \left( {{E}_{0}}+{{E}_{1}}\left( 1/T-1/{{T}_{0}} \right) \right) \times \left( 1/T-1/{{T}_{0}} \right) \right] \) , where \({{T}_{0}}=1223\) K, \(A= (0.0254 \pm 0.0004)\) Pa \(\cdot \) s, \({{E}_{0}}\) =  (8.43 \(\pm \) 0.26) \(\,\times \,10^3\) K and \({{E}_{1}}\) =  (1.7 \(\pm \) 0.2) \(\,\times 10^7\) K \(^{2}\) .     

Application of Non-Isothermal Thermogravimetric Method to Interpret the Decomposition Kinetics of \hbox {NaNO}_{3}, \hbox {KNO}_{3}, and \hbox {KClO}_{4}

The non-isothermal thermogravimetric method was used to study the thermal decomposition of \(\hbox {KClO}_{4}, \hbox {KNO}_{3}\) , and \(\hbox {NaNO}_{3}\) at heating rates of (5, 10, 15, and 20)  \(\hbox {K}\cdot \hbox {min}^{-1}\) . The activation energy of thermal decomposition reactions was computed by isoconversional methods of Ozawa–Flynn–Wall, Kissinger–Akahiro–Sunose, and Friedman equations. Also, the kinetic triplet of the thermal decomposition of salts was determined by the model-fitting method of the modified Coats–Redfern equation. The activation energies of \(\hbox {KClO}_{4}, \hbox {KNO}_{3}\) , and \(\hbox {NaNO}_{3}\) of (293 to 307, 160 to 209, and 192 to 245)  \(\hbox {kJ}\cdot \hbox {mol}^{-1}\) , respectively, are obtained by non–isothermal isoconversional methods. The modified Coats and Redfern method showed that the most probable mechanism functions \(g(\alpha )\) of \([-\hbox {ln}(1 - \alpha )]^{1/3}\) (model A3: Arami–Erofeev equation) and \((1 - \alpha )^{-1}- 1\) (model F2: second order) can be used to predict the decomposition mechanisms of \(\hbox {KClO}_{4}\) , \(\hbox {KNO}_{3}\) , and \(\hbox {NaNO}_{3}\) , respectively.     

Effective Thermal-Conductivity Measurement on Germanate Glass–Ceramics Employing the 3\omega Method at High Temperature

It can be noted that the germanate glass–ceramic is a functional material with excellent thermal stability which can be used in optical devices. The temperature-dependent effective thermal conductivities of CaO–BaO–CoO–Al \(_{2}\) O \(_{3}\) –SiO \(_{2}\) –GeO \(_{2}\) glass–ceramics from 295.5 K to 780 K are determined using a \(3\omega \) method. One of the main advantages for the \(3\omega \) method is to diminish radiation errors effectively when the temperature is as high as 1000 K. Thermal conductivities of CaO–BaO–CoO–Al \(_{2}\) O \(_{3}\) –SiO \(_{2}\) –GeO \(_{2}\) increase with a rise in temperature. Effective thermal conductivities of a sample increase from \(1.55~\hbox {W}\cdot \hbox {m}^{-1}\cdot \hbox {K}^{-1}\) at 295.5 K to \(7.64~\hbox {W}\cdot \,\hbox {m}^{-1}\cdot \hbox {K}^{-1}\) at 698.1 K. The effective thermal conductivity of CaO–BaO–CoO–Al \(_{2}\) O \(_{3}\) –SiO \(_{2}\) –GeO \(_{2}\) glass–ceramic increases with a rise of temperature. This investigation can be used as a basis for the measurement of thermal properties of ceramic materials at higher temperature.     

Study on the Difference Between the Triple-Point Temperatures of ^{20}Ne and ^{22}Ne Using Sealed Cells

At the National Metrology Institute of Japan (NMIJ), the triple points of \(^{20}\) Ne and \(^{22}\) Ne were realized using modular sealed cells, manufactured by the Istituto Nazionale di Ricerca Metrologica (INRiM) in Italy to measure the difference of the triple-point temperatures of \(^{20}\) Ne and \(^{22}\) Ne. Standard platinum resistance thermometers (SPRTs) were used that were calibrated by NMIJ on the International Temperature Scale of 1990 (ITS-90). In previous reports, sealed cells of \(^{20}\) Ne and \(^{22}\) Ne were mounted one at a time in a cryostat and their triple points were realized in separate cool-downs (the single-cell measurement). In this study, first, the triple point was realized using the single-cell measurement for \(^{20}\) Ne and \(^{22}\) Ne cells. Second, the \(^{20}\) Ne and \(^{22}\) Ne cells were mounted together on the same copper block and their triple points were realized subsequently one after the other in the same cool-down of the cryostat (the double-cell measurement). The melting curves observed by the single-cell and the double-cell measurements were almost identical for each cell. The difference of the triple-point temperatures between the two cells, \(^{22}T -^{20}\!T\) , was estimated, not only using the subrange of SPRTs defined in the ITS-90 from 13.8033 K to 273.16 K (subrange 1) but also that defined from 24.5561 K to 273.16 K (subrange 2). The difference in \((^{22}T-^{20}\!\!T)\) between the subranges 1 and 2 is within 0.06 mK, which is caused by the subrange inconsistency in the ITS-90. The standard uncertainty in \((^{22}T-^{20}\!T)\) due to the subrange inconsistency is estimated to be 0.017 mK. After correction for the effects of impurities and other isotopes in the \(^{20}\) Ne and \(^{22}\) Ne cells, the difference in the triple-point temperatures between pure \(^{20}\) Ne and pure \(^{22}\) Ne is estimated to be 0.146 64 (5) K on subrange 1, which is consistent within the uncertainty with the former studies. When \(^{22}T-^{20}\!T\) for pure \(^{20}\) Ne and pure \(^{22}\) Ne is estimated on subrange 2, \(^{22}T-^{20}\!\!T\) becomes 0.146 60 (5), which agrees very well with the former reports of INRiM evaluating \(^{22}T-^{20}\!T\) on subrange 2.     

Fabrication of Nb/Al Superconducting Tunnel Junction Using Ozone Gas

An ozone (O \(_{3})\) oxidation process was introduced for Nb/Al-based superconducting tunnel junctions (STJs) in order to form defect-free tunnel barriers at high critical current and to improve the energy resolution ( \(\Delta E\) ) for X-rays. The dependence of critical current ( \(J_\mathrm{C})\) and leak current ( \(I_\mathrm{leak})\) on the O \(_{3}\) exposure was measured to optimize the oxidation condition. The 50-square- \(\upmu \) m STJs produced by the O \(_{3}\) oxidation process exhibited an extremely small \(I_\mathrm{leak}\) of less than 50 pA. As expected, the lower or shorter the O \(_{3}\) exposure, the higher \(J_\mathrm{C}\) and the smaller the normal resistance ( \(R_\mathrm{N})\) . However, the maximum \(J_\mathrm{C}\) was 8 A/cm \(^{2}\) at an O \(_{3}\) exposure of 0.72 Pa min, which is much smaller than those of STJs with the conventional O \(_{2}\) oxidation process. It is expected that the high \(J_\mathrm{C}\) of 1,000 A/cm \(^{2}\) , at which a 9-eV-energy resolution for 277 eV photons is predicted, can be reached by an O \(_{3}\) exposure of 3.5 \(\times \) 10 \(^{-4}\) Pa min.     

Primitive elements with prescribed trace

Let \(q\) be a power of a prime number \(p\) . Let \(n\) be a positive integer. Let \(\mathbb {F}_{q^n}\) denote a finite field with \(q^n\) elements. In this paper, we consider the existence of the some specific elements in the finite field \(\mathbb {F}_{q^n}\) . We get that when \(n\ge 29\) , there are elements \(\xi \in \mathbb {F}_{q^n}\) such that \(\xi +\xi ^{-1}\) is a primitive element of \(\mathbb {F}_{q^n}\) , and \(\mathrm{Tr}(\xi ) = a, \mathrm{Tr}(\xi ^{-1}) = b\) for any pair of prescribed \(a, b \in \mathbb {F}_q^*\) .     

Effect of Grain Size of BaTiO_{3}Ceramics on Thermal Expansion and Electrical Properties

The thermal expansion behavior and electrical resistivity of BaTiO \(_{3}\) ceramics with different grain sizes were investigated. When they were heated and subsequently cooled in the range from 25  \(^{\circ }\) C to 200  \(^{\circ }\) C, the expansion and contraction curves of BaTiO \(_{3}\) ceramics with grain sizes of 600 nm and 1500 nm were not matched well to each other, and abnormal contraction and expansion behaviors were observed. For 30 nm and 150 nm BaTiO \(_{3}\) ceramics, the expansion and contraction curves basically are straight lines during heating. The linear thermal expansion coefficients ( \(\alpha _\mathrm{L}\) ) and the electrical resistivity of BaTiO \(_{3}\) ceramics were also measured. Experimental results showed that the value of \(\alpha _\mathrm{L}\) increases and the electrical resistivity decreases gradually with reducing grain size. This phenomenon can be attributed to the combination effect of the grain boundary and oxygen vacancies.     

First- and Second-Order Phase Transition in Parallel Triple Quantum Dots: The Roles of Symmetric and Asymmetric Hopping

By means of the numerical renormalization group method, I study the quantum phase transition (QPT) and the electronic transport in parallel triple quantum dot system with symmetric and/or asymmetric hopping. For symmetric hopping \(t_{1} = t_{2}\) and zero magnetic field \(B = 0\) , I find a first order transition between spin quadruplet and doublet as \(t_{1}\) ( \(t_{2}\) ) increases. With increasing \(B\) , a second order QPT between \(S_{z} = 1/2\) of the doublet and \(S_{z} = 3/2\) of the quadruplet is observed. For asymmetric hopping \(t_{1} \ne t_{2}\) , the QPT depends closely on the other hopping. For fixed \(t_{1} < \varGamma \) , where \(\varGamma \) is the hybridization function between the dots and the leads, a first order transition is observed as \(t_{2}\) increases, while for \(t_{1} \ge \varGamma \) , a crossover occurs. In the presence of \(B\) , the transition between \(S_{z} = 1/2\) and \(S_{z} = 3/2\) is a first order QPT for \(t_{1} < \varGamma \) , while a second order for \(t_{1} \ge \varGamma \) .     

Toward a Detector/Readout Architecture for the Background-Limited Far-IR/Submm Spectrograph (BLISS)

We have built and tested 32-element linear arrays of absorber-coupled transition-edge sensors (TESs) read out with a time-division SQUID multiplexer. This detector/readout architecture is designed for the background-limited far-IR/submm spectrograph (BLISS) which is a broadband (35–433  \(\upmu \) m), grating spectrometer consisting of six wavebands each with a modest resolution of R \(\sim \) 700. Since BLISS requires the effective noise equivalent power (NEP) of the TESs to equal 1  \(\times \)  10 \(^{-19}\)  W/Hz \(^{1/2}\) , our detectors consist of very long (1–2 mm), narrow (0.4 \(\upmu \) m), and thin (0.25 \(\upmu \) m) Si \(_{x}\) N \(_{y}\) support beams that reduce the thermal conductance G between the substrate and the optical absorber. The thermistors of our lowest noise TESs consist of iridium with \(T_{c}=130\) mK. We have measured the electrical properties of arrays of these Ir TESs with various meander and straight support beams and absorber shapes and found that G is \(\sim \) 30 fW/K (meander) and \(\sim \) 110 fW/K (straight), the electrical NEP is 2–3  \(\times \)  10 \(^{-19}\) W/Hz \(^{1/2}\) (meander and straight), and the response time \(\tau \) is 10–30 ms (meander) and 2–5 ms (straight). To reduce spurious or “dark” power from heating the arrays, we mounted the arrays into light-tight niobium boxes and added custom L/R and L/C low-pass chip filters into these boxes to intercept dark power from the bias and readout circuit. We found the average dark power equals 1.3 and 4.6 fW for the boxes with L/R and L/C chip filters, respectively. We have built arrays with \(T_{c}= 70\)  mK using molybdenum/copper bilayers and are working to lower the dark power by an order of magnitude so we can demonstrate NEP \(~=~1~\times \)  10 \(^{-19}\)  W/Hz \(^{1/2}\) with these arrays. PACS numbers: 85.25.Pb; 95.85.Gn; 95.85.Fm; 63.22. \(+\) m     

An algorithm for computing the error sequence of p^{n}-periodic binary sequences

For binary sequences with period \(p^{n}\) , where \(p\) is an odd prime and 2 is a primitive root modulo \(p^{2}\) , we present an algorithm which computes the minimum number \(k\) so that the \(k\) -error linear complexity is not greater than a given constant \(c\) . An associated error sequence which gives the \(k\) -error linear complexity is also obtained.     

An extension of the (strong) primitive normal basis theorem

An extension of the primitive normal basis theorem and its strong version is proved. Namely, we show that for nearly all \(A = {\small \left( \begin{array}{cc} a&{}b \\ c&{}d \end{array} \right) } \in \mathrm{GL}_2(\mathbb {F}_{q})\) , there exists some \(x\in \mathbb {F}_{q^m}\) such that both \(x\) and \((-dx+b)/(cx-a)\) are simultaneously primitive elements of \(\mathbb {F}_{q^m}\) and produce a normal basis of \(\mathbb {F}_{q^m}\) over \(\mathbb {F}_q\) , granted that \(q\) and \(m\) are large enough.     

Influence of Grain Size on the Propagation of L_\mathrm{CR} Waves in Low Carbon Steel

The acoustoelastic theory states that mechanical stress relates to the wave speed. The microstructure of the materials influences the propagation of any ultrasonic wave, which is a major drawback in employing critically refracted longitudinal waves (L \(_\mathrm{CR}\) ) in field measurements. The present study investigates the effect of mean austenitic grain size (MAGS) on propagation speed of L \(_\mathrm{CR}\) waves in ASTM A36 low carbon hot-rolled steel plates subjected to different heat treatment temperatures. The samples were heated at 900, 1000, 1050, 1100, 1200  \(^{\circ }\) C for 30 min to obtain different grain sizes. They were measured as received and after the heat treatment, employing the ultrasonic method. The MAGS were compared to the grain size obtained from optical microscopy. The results confirmed the influence of the MAGS on the L \(_\mathrm{CR}\) speed, which can be represented by a second order polynomial curve. From the experimental results, we show that it is necessary to correct the effect of the MAGS on the L \(_\mathrm{CR}\) speed; otherwise we cannot measure the stresses without previous calibration using a stress reference.     

Temperature Coefficients of the Refractive Index for Complex Hydrocarbon Mixtures

Temperature coefficients of the refractive index ( \(\mathrm{d}n/\mathrm{d}T\) ) in the \(25\,^{\circ }\mathrm{C}\) to \(35\,^{\circ }\mathrm{C}\) temperature interval for hydrocarbon mixtures containing as many as 14 compounds were investigated in this work. The measured \(-\mathrm{d}n/\mathrm{d}T\) of the mixtures were compared with calculations based on the values for each compound and their concentrations. Differences of about 1 % between measured and calculated values were observed for all mixtures. The additivity of \(-\mathrm{d}n/\mathrm{d}T\) for these hydrocarbons enables preparation of surrogate fuels that are formulated to have properties like those of specific diesel fuels.     

Comparing Transition-Edge Sensor Response Times in a Modified Contact Scheme with Different Support Beams

We present measurements of the thermal conductance, G, and effective time constants, \(\tau \) , of three transition-edge sensors (TESs) populated in arrays operated from 80–87 mK with T \(_\mathrm{C}\)   \(\sim \)  120 mK. Our TES arrays include several variations of thermal architecture enabling determination of the architecture that demonstrates the minimum noise equivalent power, the lowest \(\tau \) , and the trade-offs among designs. The three TESs we report here have identical Mo/Cu bilayer thermistors and wiring structures, while the thermal architectures are: (1) a TES with straight support beams of 1 mm length, (2) a TES with meander support beams of total length 2 mm and with two phonon-filter blocks per beam, and (3) a TES with meander support beams of total length 2 mm and with six phonon-filter blocks per beam. Our wiring scheme aims to lower the thermistor normal state resistance R \(_{N}\) and increase the sharpness of the transition \(\alpha =\)  dlogR/dlogT at the transition temperature T \(_\mathrm{C}\) . We find an upper limit of \(\alpha \) given by ( \(25\pm 10\) ), and G values of 200 fW/K for (1), 15 fW/K for (2), and 10 fW/K for (3). The value of \(\alpha \) can be improved by slightly increasing the length of our thermistors.     

High-Frequency Shear Viscosity of Low-Viscosity Liquids

A thickness shear quartz resonator technique is described to measure the shear viscosity of low-viscosity liquids in the frequency range from 6 MHz to 130 MHz. Examples of shear-viscosity spectra in that frequency range are presented to show that various molecular processes are accompanied by shear-viscosity relaxation. Among these processes are conformational variations of alkyl chains, with relaxation times \(\tau _{\eta }\) of about 0.3 ns for \(n\) -pentadecane and \(n\) -hexadecane at 25  \(^{\circ }\) C. These variations can be well represented in terms of a torsional oscillator model. Also featured briefly are shear-viscosity relaxations associated with fluctuations of hydrogen-bonded clusters in alcohols, for which \(\tau _{\eta }\) values between 0.3 ns ( \(n\) -hexanol) and 1.5 ns ( \(n\) -dodecanol) have been found at 25  \(^{\circ }\) C. In addition, the special suitability of high-frequency shear-viscosity spectroscopy to the study of critically demixing mixtures is demonstrated by some illustrative examples. Due to slowing, critical fluctuations do not contribute to the shear viscosity at sufficiently high frequencies of measurements so that the non-critical background viscosity \(\eta _\mathrm{bg}\) of critical systems can be directly determined from high-frequency shear-viscosity spectroscopy. Relaxations in \(\eta _\mathrm{bg}\) appear also in the shear-viscosity spectra with, for example, \(\tau _{\eta }\,\approx \) 2 ns for the critical triethylamine–water binary mixture at temperatures between 10  \(^{\circ }\) C and 18  \(^{\circ }\) C. Such relaxations noticeably influence the relaxation rate of order parameter fluctuations. They may be also the reason for the need of a special mesoscopic viscosity when mutual diffusion coefficients of critical polymer solutions are discussed in terms of mode-coupling theory.     

The Influence of Thermal Expansion and Mass Loss on the Young’s Modulus of Ceramics During Firing

During the heating stage of the firing of a ceramic material, the mass \(m\) , length \(l\) , and diameter \(d\) of the sample alter their values depending on the temperature \(t\) . Young’s modulus \(E(f,m,l,d)\) measured by a sonic resonance method is also a function of the resonance frequency \(f\) . Therefore, three thermal analyses (TGA, TDA, modulated force TMA) must be performed to obtain correct values of Young’s modulus. The calculation of Young’s modulus can be simplified if TGA and/or TDA are omitted. This necessarily leads to partly incorrect results. If TGA is not performed, we have \(E[f(t),m_0 ,l(t),d(t)]\) and the relative difference \((\{E[f(t),m(t),l(t),d(t)]-E[f(t),m_0 ,l(t),d(t)]\}/E[f(t),m(t),l(t),d(t)])\) reaches 7 % for \(t> 650\,^\circ \text{ C}\) and less than 2 % for \(t< 500\,^\circ \text{ C}\) . If TDA is not performed, we have \(E[f(t),m(t),l_0 ,d_0 ]\) and the relative difference ( \(\{E[f(t),m(t),l(t),d(t)]-E[f(t),m(t),l_0 ,d_0 ]\}/E[f(t),m(t),l(t),d(t)])\) is less than 0.6 % for \(t < 1000\,^\circ \text{ C}\) . For the simplest case, we have \(E[f(t),m_0 ,l_0 ,d_0 ]\) and the relative difference ( \(\{E[f(t),m(t),l(t),d(t)]-E[f(t),m_0 ,l_0 ,d_0 ]\}/E[f(t),m(t),l(t),d(t)])\) is 7.5 % for \(t > 600\,^\circ \text{ C}\) and less than 2 % for \(t<500\,^\circ \text{ C}\) .     

Impact of Associated Gases on Equilibrium and Transport Properties of a \mathrm{CO}_{2} Stream: Molecular Simulation and Experimental Studies

During the various carbon dioxide capture and storage (CCS) stages, an accurate knowledge of thermodynamic properties of \(\mathrm{CO}_{2}\) streams is required for the correct sizing of plant units. The injected \(\mathrm{CO}_{2}\) streams are not pure and often contain small amounts of associated gaseous components such as \(\mathrm{O}_{2}, \mathrm{N}_{2}\) , \(\mathrm{SO}_{x}, \mathrm{NO}_{x}\) , noble gases, etc. In this work, the thermodynamic behavior and transport properties of some \(\mathrm{CO}_{2}\) -rich mixtures have been investigated using both experimental approaches and molecular simulation techniques such as Monte Carlo and molecular dynamics simulations. Using force fields available in the literature, we have validated the capability of molecular simulation techniques in predicting properties for pure compounds, binary mixtures, as well as multicomponent mixtures. These validations were performed on the basis of experimental data taken from the literature and the acquisition of new experimental data. As experimental data and simulation results were in good agreement, we proposed the use of simulation techniques to generate new pseudo-experimental data and to study the impact of associated gases on the properties of \(\mathrm{CO}_{2}\) streams. For instance, for a mixture containing 92.0 mol% of \(\mathrm{CO}_{2}\) , 4.0 mol% of \(\mathrm{O}_{2}\) , 3.7 mol% of Ar, and 0.3 mol% of \(\mathrm{N}_{2}\) , we have shown that the presence of associated gases leads to a decrease of 14 % and 21 % of the dense phase density and viscosity, respectively, as compared to pure \(\mathrm{CO}_{2}\) properties.