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Interdiffusion studies in Co-Cr-Fe-Mn-Ni, Co-Fe-Mn-Ni, Co-Cr-Fe-Ni, and Co-Cr-Mn-Ni, as well as a reevaluation of the previous results obtained for Al-Co-Cr-Fe-Ni, were conducted. In the experimental part, diffusion couples were annealed at four different temperatures: 1230, 1270, 1310 and 1350 K for each system. Then, the results were evaluated with use of the optimization-based technique, combined with the Miedema's thermodynamic description, what allowed obtaining of tracer diffusion coefficients for all elements in all considered systems. The correctness of the applied approach was tested on the example of Co-Cr-Fe-Mn-Ni system, showing very good agreement of determined tracer diffusivities with the values obtained by other authors. Obtained values of diffusivities were compared with the available data for a number of conventional binary and ternary systems. No signs of diffusion retardation were observed in the absolute temperature scale. In the case of temperature scale normalized with respect to the melting point, an abnormal behavior, previously attributed to the HEAs' sluggish diffusion effect was observed. However, it occurred only for alloys with prominent manganese content and was completely independent of the number of components, being just as likely to occur in binary systems as in HEAs. Therefore, the alleged sluggishness of diffusion in HEAs should be treated just as a result of specific compositions of the previously studied alloys and cannot be generalized for all high entropy systems.

Upconversion luminescence and optical temperature sensing properties of Yb3+/Er3+/Li+ tri-doped ZnMoO4 phosphors were investigated. It has been demonstrated that Li+ doping affected not only the local symmetry of Yb3+ and Er3+ but also the distribution of them in the host lattice. As a result, the significantly improved green upconversion luminescence was obtained when excited at 980 nm. The pumping power dependent photo-thermal behavior was used to evaluate the reliability of upconversion temperature sensing. An accurate temperature scale was established by eliminating the impact of thermal effect, and the sensing ability was evaluated via a comparison with the results reported in literatures.

Flow rate mal-distribution in parallel pipes has been a common problem in all kinds of heat exchangers, which threatens the performance, even the safety of the applications. Many researches have been focusing on the control methods to achieve a rational flow distribution. However, in order to develop an effective control method, the most sensitive inputs should be located first. In this work, a numerical model of the two-parallel-pipe-system has been developed. The flow and heat transfer are considered. The properties of the hydrocarbon fuel used (RP-3) has been compared and selected. Then the sensitivity analysis on the flow rate and fuel temperature distribution of RP-3 in non-uniformly heated parallel pipes was performed using a local sensitivity analysis method. The target inputs are the thermal properties of RP-3 ( ρ , c p , λ , μ , d ρ / dT f ) and the operating condition: like thermal deviation. The results indicate that the d ρ / dT f is the most sensitive input and c p takes the second place. They are much more sensitive when the temperature exceeds pseudo-critical point. The sensitivities of ρ , λ , μ are relatively low. While the thermal deviation is also very sensitive and shows an obvious impact on temperature distribution in the whole temperature scale studied.

The temperature dependence of the Er3+ green luminescence in Y3Ga5O12 crystal were analysed under ultraviolet and near-infrared laser excitations for optical sensing purposes. Changes in the relative green emission intensities from the 2H11/2 and 4S3/2 thermally-coupled multiplets to the 4I15/2 ground state were measured from room temperature up to 1000 K. The calibrated temperature scale shows a maximum in the absolute thermal sensitivity of ~23.9 × 10−4K−1 at 580 K and a relative thermal sensitivity of ~1.36%K−1 at RT, combining results for both blue and near-infrared laser excitations. The excellent results obtained, compared with other Er3+-based optical temperature sensors, are a consequence of the advantages of garnet crystals as optically efficient hosts that, apart from an impressive capability to be synthesized both as bulk and fiber forms, allow extending the long working temperature range up to 1000 K, and beyond, to the melting point limit close to 2000 K. In addition, the use of green emissions for the temperature calibration, with negligible black-body radiation disturbance, only needs a low-cost, basic setup that uses commercially available lenses, lasers and detectors. All these facts support the Er3+-doped Y3Ga5O12 garnet crystal as a potential candidate as temperature sensor, showing large sensitivity and good temperature resolution for ultra-high temperature industrial applications.

In the last few decades, theoretical and experimental studies of glass-forming liquids have revealed presence of universal regularities in the viscosity-temperature data. In the present work, we propose a viscosity model for scaling description of experimental viscosity data. A feature of this model is presence of only two adjustable parameters and high accuracy of experimental data approximation by this model for a wide temperature range. The basis of the scaling description is an original temperature scale. Within this scaling description we obtain the transformed Angell plot, in which the area separating "fragile" and "strong" glass-formers emerges. The proposed scaling procedure make it possible to reconsider belonging some liquids to the type of "fragile" glass-formers. The obtained results form basis for development of a generalized scaling description of crystallization kinetics in supercooled liquids and glasses., 18 pages, 4 figures, 1 tables

Atomic emission double-spectrum temperature measurement method was developed, and a photoelectric temperature detector based on silicon photomultiplier tube was designed. The structure and principle of the temperature measurement of the photoelectric temperature detector were introduced. The spectral radiation signal of the copper sheet excited by the laser was transmitted to the photoelectric thermometer, and Cu I 510.5 nm and Cu I 521.8 nm were used as the temperature scale spectral lines during the temperature measurement. In different acquisition delays, the ratio of the intensity of the two Cu plasma spectral lines was obtained through the LIBS system. At the same time, the ratio of the maximum voltage value of the two channels was measured using a photoelectric thermometer. At the time of 6us, and the maximum temperature of Cu plasma excited by different laser energy was calculated to be 12745 K. The results show that the atomic emission dual-spectrum temperature measurement method has the characteristics of the higher temperature measurement limit and faster response speed.

The vapour–liquid equilibrium properties of binary mixtures of R1123 and R1234yf, which are key components of the next generation of refrigerant mixtures, were measured using a recirculation-type vapour–liquid equilibrium property measurement apparatus. Two sets of measurements were conducted by two different technicians (co-authors Nishida and Saito) using the same apparatus and sample. The first set of measurements were conducted at temperatures that were close to the integer values in absolute temperature, whereas the second set of measurements was taken at temperatures that were close to the integer values in terms of degrees Celsius. Both sets of measurements were based on the ITS-90 temperature scale and were found to be in good agreement at the measurement temperatures (300 and 330 K). These data were compared with the predictions of a Helmholtz-type equation of state, and a systematic deviation of approximately 8% was observed at low temperatures. A regression analysis using the binary interaction parameter kij of the modified Peng–Robinson equation of state more accurately reproduced the experimental measurements.

The outer part (myzoderma) of carrot was tested using dynamic mechanical analysis (DMA), in air with three different values of humidity (50, 70, and 90%) in temperature scans between 30 and 90 °C. Temperature plots of storage ( SM i.e. elastic) and loss ( LM i.e. inelastic) moduli were obtained. The DMA was combined with Dielectric thermal analysis (DETA). The tissue toughness decreased with increasing temperature; the kinetic analysis of the data led to four characteristic temperatures different for different air humidity; these characteristic temperatures divided temperature scale into temperature ranges A, B1, B2, and B3. The range A, limited for all tested cases with different humidity by 50 °C, is termed low temperature drying. With decreasing air humidity, the characteristic temperatures also decrease. The ranges B1, B2, and B3 represent the different stages of high temperature drying (initial – B1, rapid or main – B2, and final – B3). Part B2 can be understood as the temperature range where drying is most rapid and the role of plasmodesma destruction can play the fundamental role.

We have investigated the influence of substituting P by As and As by Sb on the thermoelectric properties of LaFe 4 X 12 (X = P, As and Sb) compounds. It has been found that substituting P → As → Sb show significant influence on the bands dispersions, bond lengths, effective masses, the carriers mobility and hence the transport properties. Replacing P by As cause significant increases in the carriers concentration with increasing the temperatures, while replacing As by Sb exhibit insignificant increase in the carriers concentration of LaFe 4 Sb 12 with respect to LaFe 4 As 12 . It is clear that LaFe 4 As 12 show the highest electrical conductivity among the other compounds along the temperature range. Calculations show that LaFe 4 Sb 12 exhibit low electronic thermal conductivity in the temperature range between 50 and 600 K, then above 650 K the LaFe 4 P 12 compound show the lower electronic thermal conductivity. The Seebeck coefficient of LaFe 4 X 12 (X = P, As and Sb) compounds increases with increasing the temperature. Moving from P → As → Sb cause significant increases in the Seebeck coefficient and LaFe 4 Sb 12 compound exhibit the highest Seebeck coefficient along whole temperature scale. The power factor of LaFe 4 X 12 (X = P, As and Sb) compounds increases with increasing the temperature and LaFe 4 Sb 12 compound show the highest power factor along the whole temperature range.

The current high temperature part of the international temperature scale of 1990 (ITS-90) is based on extrapolation from a reference fixed point, using Plancks law in ratio form. However in the near future the mise en pratique for the definition of the kelvin will also allow an interpolated thermodynamic scale based on high temperature references whose temperatures are known a priori. Both approaches to dissemination will be considered equally valid. A transfer radiation thermometer specifically designed with the dissemination to industry of a temperature scale based on the mise en pratique-kelvin approach has been constructed. It was calibrated at a national measurement institute and used to compare the two possible realisation schemes (i.e. radiation thermometer calibrated to ITS-90, and the same thermometer calibrated using high temperature references) to the local ITS-90 scale at an accredited industrial calibration laboratory. All the scales agreed within their respective uncertainties. It was found that the interpolation scheme could significantly reduce the uncertainties in a calibration laboratory without the full cost of maintaining ITS-90.

The redefinition of the kelvin, through the Boltzmann constant, is taken as a good opportunity to address the realization and dissemination of the kelvin under the new definition, and the relation with the most successful temperature scale to date, the ITS-90, being the closest approximation to thermodynamic temperature. An overview is given of its evolution, since the definition, in the cryogenic ranges: 14–273 K for the SPRT, 3–25 K for the ICVGT and the 3He/4He vapour pressure scales. Several of the problems encountered and the various solutions so far envisaged are highlighted. Some possible consequences of the new kelvin definition are also illustrated.

This paper reports speed of sound experimental measurements in liquid methane ( CH 4 ) along five isotherms, in the temperature range of (130 and 162) K, and for pressures up to 10 MPa. A dedicated experimental apparatus, custom-designed for accurate speed of sound measurement at cryogenic temperatures and high pressures, has been developed and the double pulse-echo technique has been adopted. In order to characterize this new apparatus and its performance, experimental results have been compared with speed of sound values of liquid methane available in literature. A further comparison has been made between the experimental measurements and the speed of sound values obtained using the reference equation of state of methane of Setzmann and Wagner, as well as the GERG-2008 model. The ultrasonic path-length has been calibrated using pure water as a reference fluid, with a relative uncertainty of 0.026%. The temperature was measured with two platinum resistance thermometers with an absolute uncertainty of 0.02 K. Thermometers have been calibrated using the ITS-90 temperature scale between the triple point of argon and the triple point of water. Finally, the relative expanded uncertainty (k = 2) associated to the obtained results is of 0.4%, mainly influenced by the repeatability of the measurements.

Pressure-density-temperature (PρT) properties, vapor pressures, and saturated liquid and vapor densities for refrigerants R 1234ze(Z) (cis-1,3,3,3-tetrafluoroprop-1-ene; CF3CH CHF) and R 245fa (1,1,1,3,3-pentafluoropropane; C3H3F5) were measured with two types of isochoric methods. Pressure was measured with a digital quartz pressure transducer. Temperature was measured with 25 Ω standard platinum resistance thermometer on the ITS-90 temperature scale. Density was calculated from the mass of sample and the inner volume of pressure vessel. By using the present vapor pressure data, new vapor pressure correlations for R 1234ze(Z) and R 245fa have been formulated. In addition, the critical temperature Tc, critical density ρc, and critical pressure Pc were directly determined on the basis of direct observation of the meniscus disappearance.

In this study, effects of Mo and V substitution for Fe on a direct aim of synchronously optimizing glass forming ability (GFA) and soft magnetic properties of Fe-based amorphous/nanocrystalline alloys fabricated by melt-spinning technology are investigated. The introduces of Mo and V had an effective impedance of atoms migration and contributed to the improvement of GFA of Fe73.5-xSi15.5B7Cu1Nb3Mx (M = Mo, V) soft magnetic alloys. The formation of α-Fe phase was kept in a stable temperature scale, while the residual amorphous precipitation showed a better thermal stability against precipitating Fe B compounds. After a suitable annealing process at Ta = 560 °C for 60 min, the α-Fe grains with introducing V had a smaller average size than that of introducing Mo. For the crystallized ribbons, the introduce of V revealed not only a slower decrease of Bs but also a more sluggish increase of Hc. The Bs and Hc were in the range of 0.91 T - 1.07 T and 2.0–3.5 A/m, respectively. These alloys with V = 1 at.% and Mo = 0.5 at.% exhibited higher effective permeability (μe) in the frequency range of 1–200 kHz and 60–200 kHz, respectively. Therefore, the balance between Fe, V and Mo is a key factor to keep Bs in a moderate field and relatively lower Hc, meanwhile it can also improve μe in testing frequency scale. V additions are more beneficial to restrain grain growth, reduce Bs and increase Hc rather than those of Mo. Therefore, V-doped Finemet-type soft magnetic alloy and its nanocrystalline derivations become a potential candidate as transformer core material in wide frequency scale of 1–200 kHz.

Near infrared-to-green upconverted emissions of Er3+-doped Y2O2SO4 yttrium oxysulfate nanophosphor have been studied exciting the sample with a 975 nm laser radiation. Temporal dynamics of the green emission indicates that the main mechanism responsible for the upconversion processes is energy transfer between Er3+ ions. The relative intensities of the near infrared-to-green upconverted emissions from the 2H11/2 and 4S3/2 thermalized levels to the 4I15/2 ground state have been calibrated as a function of temperature in order to develop an optical temperature sensor both in the biological range, from 295 up to 330 K, and in the industrial application range up to 475 K. The temperature scale obtained shows a relative sensitivity with temperature of 1.1 %K−1 at 300 K, and an absolute temperature sensitivity of 73 × 10−4 K−1 at 467 K. These results suggest that the Er3+-doped yttrium oxysulfate can be used as an optical temperature sensor by exciting in the infrared range for biomedicine and industrial applications.

In this work, we report the magnetocaloric properties of a hexagonal intermetallic compound Pr2Ni0.95Si2.95 that exhibits spin cluster glass behaviour below 3.3 K. At lower temperature, the compound undergoes magnetic field induced metamagnetic transition beyond 5 kOe applied field value as inferred from the temperature dependence of magnetization at various fields as well as isothermal magnetization measurements. The temperature dependence of magnetic entropy change ( − Δ SM) has been calculated from the magnetization data and the maximum value is found to be 7.9 J/kg-K for a magnetic field change of 70 kOe. Interestingly, although the compound does not undergo any long range magnetic ordering, it exhibits considerable magnetocaloric effect in a temperature region much above the spin freezing due to the presence of short range magnetic correlation that persists up to much higher temperature. The suppression of short range interaction with the application of magnetic field has been argued to be responsible for such magnetic entropy change and adiabatic temperature change over a large temperature scale.

Uranium dioxide (UO 2 ), which is used in light water reactors, exhibits a large range of non-stoichiometry over a wide temperature scale up to 2000 K. Understanding diffusion behavior of uranium oxides under such conditions is essential to ensure safe reactor operation. The current understanding of diffusion properties is largely limited by the stoichiometric deviations inherent to the fuel. The present DICTRA-based model considers diffusion across non-stoichiometric ranges described by experimentally available data. A vacancy and interstitial model of diffusion is applied to the U–O system as a function of its defect structure derived from CALPHAD-type thermodynamic descriptions. Oxygen and uranium self and tracer diffusion coefficients are assessed for the construction of a mobility database. Chemical diffusion coefficients of oxygen are derived with respect to the Darken relation and migration energies of defects are evaluated as a function of stoichiometric deviation.

To clarify recent discussions on the precursor superconducting state in high- T c cuprates, we performed a temperature dependent c - axis optical study on YBa2(Cu1-xZnx)Oy single crystals in the pseudogap region for several different Zn-contents ( x = 0, 0.007, 0.012, and 0.04) and doping levels. The superfluid density calculation revealed a third temperature scale ( T p) for a precursor superconducting state in between the superconducting transition temperature, T c, and the pseudogap opening temperature, T *. We observed the suppression and the disappearance of T p with increasing Zn-content, which is further evidence of the close relation between the origin of T c and T p.

The Curie temperature, TC, is the temperature above which a material loses its long-range ferromagnetic order. Considering the equation of state of a ferromagnet in the mean-field approximation it has been shown theoretically that the value of the demagnetization factor N has a significant influence on the perceived location of TC on the temperature scale. A series of precise measurements of magnetization using two differently shaped single crystals of high-purity gadolinium was carried out to prove this result experimentally and develop a procedure leading to the ‘true’ value of TC.

The area under the glow curve (no thermal quenching and same dose) is conserved only in TL–time plots and is not conserved (scales by a factor by which heating rate is increased) in TL–temperature plots. This increase in area under TL–temperature glow curves with increase in heating rate at a constant dose should not be interpreted as increase in sensitivity of the dosimeter and is the consequence of transformation of time to temperature scale (temperature scale obtained from time scale by multiplying with β , T = T 0 + βt ). This is further supported by the fact that the light output or integrated counts seen by the PMT do not change (ignoring statistical fluctuations) with increase in heating rate at a constant dose. Further for a given heating rate, the glow peak height is similar in time and temperature plots and the glow peak height increases with increase in heating rate. However to conserve area in TL–temperature plots, the TL intensity should be divided by the respective heating rate, which will lead to the decrease of glow peak height in I / β –temperature plots and is the artifact of the normalization process. However for normalized glow curves ( I / β –temperature), the glow peak height decreases with increase in heating rate, which is actually true for I / β or TL/ β versus temperature plots. Hence it is recommended that in such cases where normalized glow curves ( I / β versus temperature) are presented, the obtained peak height must be multiplied by β . By doing so, glow peak height increases with increase in heating rate. In addition to the above, studies are also carried out by considering thermal quenching effect and it is found that a logical way to measure thermal quenching quantitatively is to record the decrease of integrated counts (PMT current) with increase in heating rate at a constant dose, i.e . the integrated peak area (PMT current or TL–time or TL/ β –temperature) must be plotted against the heating rate and the same should be used for interpretation of thermal quenching effect. Only this proves the fact whether the decrease of TL intensity (TL/ β –temperature) is due to thermal quenching or not.

We report lattice computations in SU(N_c) pure gauge theory, where N_c is increased beyond the physical value of 3. We demonstrate two-loop scaling of T_c, thus obtaining the variation of T_c/Lambda_MSbar with N_c, and fixing the temperature scale. We study the equation of state of the gluoN_c plasma, the conformal anomaly, and the approach to the weak coupling theory. We find that the weak-coupling prediction is always closer to the lattice data than the conformal field theory is., 4 pages, 4 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee

The paper analyses the dynamic aspects of the temperature field in a fluidised bed of solids particles (e.g., sand) in which a gaseous fuel is being burned. Such a hot bed emits electromagnetic radiation within the visible range and this can be recorded using a digital video camera. This fact has been used to develop a method for measuring the bed’s temperature in the line of sight, through the quartz sides of the reactor. A solid probe is only used for calibration. Video recordings were obtained covering different regions of the bed over three wavelength bands, red, green and blue. In the course of an experiment, the mean temperature of the bed, measured with thermocouples, was raised from ambient to 1300 K, at a rate of ∼ 1 K/s. The data collected were used for calibration, with the brightness of individual pixels converted to a temperature scale. The calibration can then be used to investigate the dynamic temperature distribution within the field of view, in individual elements of the bed. This can also help the study of heat transfer in the bed, its distribution and dissipation. Using this method, it is possible to make direct observations of the intermittent combustion of gaseous fuels in a bubbling fluidised bed. The results provide direct proof that the temperature gradients observed within such beds are associated with exothermic processes within fast moving bubbles. The method could be adapted to studying, e.g., the combustion of solid fuels.

The specific Gibbs energy of seawater is determined from experimental data of heat capacities, freezing points, vapour pressures and mixing heats at atmospheric pressure in the range � 6t o 801C in temperature and 0–120 g kg –1 in absolute salinity. Combined with the pure-water properties available from the 1996 Release of the International Association for the Properties of Water and Steam (IAPWS-95), and the densities from the 2003 Gibbs function of seawater, a new saline part of the Gibbs function is developed for seawater that has an extended range of validity including elevated temperatures and salinities. In conjunction with the IAPWS 2006 Release on ice, the correct description of concentrated brines by the new formulations permits an accurate evaluation of sea ice properties down to salinity saturation temperatures. The new Gibbs function is expressed in terms of the temperature scale ITS-90. Its input variable for the concentration is absolute salinity, available from the new Reference-Composition Salinity Scale of 2008.

We study the thermopower and thermal conductivity of a gate-defined quantum dot, with a very strong Coulomb repulsion inside the dot, employing the X-boson approach for the impurity Anderson model. Our results show a change in the sign of the thermopower as function of the energy level of the quantum dot (gate voltage), which is associated with an oscillatory behavior and a suppression of the thermopower magnitude at low temperatures. We identify two relevant energy scales: a low temperature scale dominated by the Kondo effect and a T ∼ Δ temperature scale characterized by charge fluctuations. We also discuss the Wiedemann–Franz relation and the thermoelectric figure of merit. Our results are in qualitative agreement with recent experimental reports and other theoretical treatments.

VHF wind-profiling radars often measure a decrease of echo power with zenith angle, which can be explained from in situ measurements of horizontal layering or anisotropy of metre-scale temperature structure in the atmosphere. There can also be an azimuthal variation of echo power, which is increased in an azimuth opposite to the vertical shear vector of horizontal wind. This paper checks if the azimuth variation can also be linked to in situ observations of temperature structure, using aircraft flights in the tropopause region near a VHF radar. At heights where VHF radar measures wind shear and aspect sensitivity, there can be an asymmetry in the probability distribution of horizontal gradient of potential temperature, for horizontal scale of e.g. hundreds of metres. The asymmetry is often of opposite sign for up-shear and down-shear flights, and less when VHF echoes are isotropic instead of aspect sensitive. The range of horizontal scales with asymmetry can be used to distinguish e.g. sheared anisotropic turbulence and Kelvin–Helmholtz instability as causes of azimuthal VHF echo power variations.

The sublimation of water in the region of extremely low pressures and temperatures meets increasing interest for the exploration of icy cosmic bodies. At temperatures below 130 K, the shape of the sublimation curve of H2O is not known; neither experimental data nor theoretical treatments exist for this region. Based upon theoretical upper and lower bounds for the heat capacity of water vapor in this range, a narrow region in the pressure–temperature diagram is identified which must necessarily enclose the sublimation curve down to virtually any lower pressures and temperatures. Within this region, an approximate sublimation curve is computed from the 2006 Gibbs potential of ice Ih, using available heat capacity data points of water vapor between 10 and 130 K. The theoretical zero-point limiting law of the sublimation pressure is derived. Valid between 20 and 273.16 K, correlation equations for the sublimation enthalpy and the sublimation pressure are fitted to the computed data. All quantities are expressed in the 1990 temperature scale ITS-90. Under cosmic conditions, our results suggest that the sublimation of ice is unlikely below 50 K and impossible below 23 K.

A saturation vapor pressure equation, p(T), is an essential component in the 3He state equation currently under development. The state equation is valid over the range 0.01–20 K with pressures from 0 to the melting pressure or 15 MPa. The vapor pressure equation consequently must be valid from 0.01 K to the critical temperature. This paper surveys available 3He critical temperature and pressure measurements, leading to new recommended critical values of 3.3157 K and 114603.91 Pa. The ITS-90 temperature scale is defined by the 3He vapor pressure from 0.65 to 3.2 K. A new vapor pressure equation is developed for the interval from the upper end of the T90 scale to this newly defined critical point, employing a mathematical form in which the second derivative d2p/dT2 diverges in agreement with scaling laws at the critical point. Below 0.65 K, an empirical vapor pressure expression is adopted, consistent with a theoretical expression valid in the limit T → 0. These two new components are fitted to be piecewise continuous with the EPT-76 p(T) scale rather than the ITS-90 T(p) scale between 0.65 and 3.2 K. Probable deviations between this vapor pressure scale and PLTS-2000 melting pressure–temperature scale are recognized, but not reconciled.

The influence of a homogeneous external field on a three-dimensional uniaxial magnet behaviour near the critical point is investigated on the microscopic level by the nonperturbative collective variable (CV) method using the ρ 4 model. The research is carried out in the high-temperature region. The critical exponents related with external field are calculated. The analytic explicit expressions for the free energy, average spin moment and susceptibility are obtained without using any phenomenological assumptions and adjusting parameters. The field dependences of the order parameter are plotted for the field region including the neighbourhood of the pseudocritical line. It is established that long-wave fluctuations of the order parameter are responsible for main features of the crossover between the temperature-dependence and field-dependence critical behaviour of the system. The maximum locations on the temperature scale for the long-wave part of the susceptibility are determined for different values of the field.

The 133Cs spin–lattice relaxation rates in Cs2PdCl4 single crystals were measured as functions of temperature and frequency. An abrupt change was observed in the curve of the 133Cs spin–lattice relaxation rate, T 1 - 1 , versus inverse temperature near 341 K which coincides with the phase transition. The phase transition is due to the critical slowing down of the soft mode, as is typically observed in phase transitions from the orthorhombic to the tetragonal phase in Cs2PdCl4 single crystals. When the soft mode slows down, the relaxation rate increases in the fast-motion region. The system is in the fast-motion region both above and below 341 K because there is no frequency dependence of the relaxation rate except possibly at very low temperature. The relaxation rate at 341 K increases from either direction of the temperature scale. The observed anomaly can be related to the decrease in the frequency of the soft mode and to the accompanying increase in atomic displacements.

Thermodynamic properties of chlorine condensed phases have been assessed to 240 K. Correction of the original experimental values for temperature scale, units and atomic weight now give values of similar quality to those already available for bromine and iodine.

The molar heat capacity of copper has been measured between T = (6 and 400) K using an adiabatic calorimeter and thermometry calibrated on ITS-90. Our results are in good agreement with the measurements of Martin [Rev. Sci. Instrum. 58 (1987) 639] and Robie et al. [J. Res. US Geol. Survery 4 (1976) 631], made on the IPTS-68 temperature scale. The agreement is generally within 0.1% between 100 ⩽ (T/K) ⩽ 300 and increases to 0.5% below T = 100 K. However, when our results are compared to compilations of older data (taken before 1966), including the molar heat capacity values recommended by the CODATA Task Group on Thermophysical Properties, there are differences of up to 1% in the range 20 ⩽ (T/K) ⩽ 400. We concur with the conclusion of Martin that the CODATA results are in error below T = 300 K, and we conclude that the error extends to 400 K. The paper also includes a description of the instrumentation and procedures used to obtain the measurements in the Boerio-Goates laboratory.

Large-scale temperature oscillations are observed in 7 years (1995–2001) of night-time hydroxyl (6-2) band rotational temperatures, measured with a scanning spectrometer over Davis station, Antarctica (68.6°S,78.0°E). Variations of up to 30 K are evident in the 1439 nightly averages calculated, in quasi-periodic 10–60 day intervals with no apparent seasonal consistency year-to-year. We investigate the impact of this seasonal variability in large-scale temperature oscillations on long-term trend assessments. Lomb–Scargle periodogram analysis reveals that large-scale (quasi-periods 50–60 day) oscillations dominate March–April and July–October but activity generally decreases around midwinter (mid-May to late-June) when shorter-period smaller-magnitude oscillations are more characteristic. This is consistent with reduced stationary wave penetration into the upper mesosphere due to strong middle atmosphere eastward winds in the southern midwinter. A sliding-window multivariate fit with solar cycle and long-term linear trend terms shows most consistent coefficients of 0.06– 0.07 K/solar flux unit ( ∼8 K per solar cycle) and −0.5– −1.5 K/year for the 70 day windows centred between days 160 and 220 (across midwinter) each year when large-scale oscillations are minimal. Large uncertainties in the trend coefficients over the equinox intervals are obtained and we cannot determine if trends at these times are significantly different from zero. Enhanced cooling in the southern hemisphere upper-mesosphere may be linked with a trend toward stronger eastward flow in the southern high latitude polar vortex (due largely to the trend in photochemical ozone losses), reducing the penetration of waves into the southern winter mesosphere.

Steady natural convection induced by multiple discrete heat sources (DHSs) in two-dimensional horizontal enclosures is numerically investigated. A general combined temperature scale method is first implemented to identify the DHSs of both external and internal types. An associated concept of thermal strength is then introduced in terms of the unified heat transfer characteristics of DHSs to analyze the interaction among them. Four different calculation cases are detailed analyzed, and main attention has been focused on the effects of the Rayleigh number (Ra), the thermal strength (Π), and the separation distance (W*) on the interaction between DHSs. Computational results demonstrated that the combined temperature scale method and the unified heat transfer characteristics analysis are convenient and efficient to evaluate the complex interaction between DHSs and its effects on the fluid flow and heat transfer structures in horizontal natural convection enclosures.

The influence of a film geometry on the glass transition is investigated via molecular dynamics (MD) simulations of a (non-entangled) polymer melt. The confinement is realized by two identical potential barriers of the form U wall = z -9 , where z denotes the distance of a particle from the wall. Despite the geometric confinement, basic qualitative features of the system dynamics can be well described in the framework of the mode-coupling theory (MCT). Examples are the two-step relaxation of the incoherent intermediate scattering function, the time-temperature superposition property of the late time α-process and the space-time factorization of the scattering function on the intermediate time scale of the MCT β-process. A comparison of the dynamics in the film and in the bulk shows an acceleration of the relaxation processes due to the presence of the walls. This leads to a reduction of the critical temperature, T c , of MCT with decreasing film thickness. A comparison of the quantities like the static structure factor and the mean-square displacements for the bulk and for the film suggests that T - T c (D) is a relevant temperature scale for the dynamics at intermediate times. Furthermore, we also analyze the sharp rise of the relaxation times at low temperatures by the Vogel-Fulcher-Tammann (VFT) equation and thus estimate the VFT-temperature T 0 (D). We observe that, similar to T c (D), also T 0 (D) decreases for smaller D. As T 0 ≤ T g ≤ T c , these results suggest that also the glass transition temperature should decrease for stronger confinement.

The melting curve of 3 He is used as the new extension of the International Temperature Scale of 1990, the PLTS-2000. A thermodynamic inspection of this scale is described. It has been carried out by application of the Clausius–Clapeyron equation to the available thermal and pVT data of the liquid and solid phases. The overall agreement is found to be very good. The remaining small discrepancies are within experimental error. Nevertheless, the present thermodynamic inspection does not allow a further narrowing of the uncertainty margin at the lowest temperatures of the new scale.

The interdiffusion in amorphous Nb/Si multilayers has been studied using X-ray optical reflection and TEM in a temperature range from 150°C to 350°C. In the whole temperature scale, the experimental data show that annealing causes interface shift without any other detectable change of multilayer parameters, namely period and interface roughness. The model based on diffusion of Si into Nb has been proposed, which fits very well to the Arrhenius relation for diffusion coefficient and provides values comparable with previously published ones.

The recent results in low-temperature relaxations of organic polymers and glasses, obtained in joint research of Bayreuth University and Institute of Spectroscopy RAS groups are reviewed. The comprehensive investigations of equilibrium and nonequilibrium spectral di!usion (SD) via optical hole-burning spectroscopy on a broad time (10~5}106 s) and temperature (0.1}4.2 K) scale are carried out on a few polymer and organic glass samples. Some new e!ects are discovered and interpreted, such as the nonlogarithmic long-time SD asymptotic; nonequilibrium SD, induced by an external electric "eld; light-induced SD, etc. The results of the investigations show that optical hole-burning spectroscopy is a very e$cient technique for investigation of low- and intermediate-temperature organic glass dynamics. ( 2000 Published by Elsevier Science B.V. All rights reserved.

The temperature gradients affecting the temperature scale of a dynamic heat capacity spectrometer based on the 3 ω -method are investigated using the SmecticA-Nematic (SmA/N) transition in the liquid crystal octyloxycyanobiphenyl (8OCB). The heater (sample) temperature was obtained from a thermocouple by superimposing the temperature increase of the heater, where the increase was calculated from the heater power. The calibration using the SmA/N transition yields a linear relation between the temperature rise of the heater Δ T h and the heater power P : Δ T h =55.2 P . An estimation of the maximum temperature gradient in the 8OCB sample shows that the correction of the sample temperature due to the gradient is small compared to Δ T h ( ω =3.98. 2 π rads −1 and −0.14 K for ω =0.01. 2 π rads −1 ). For high heating powers there is a significant temperature gradient in the heater, which causes a broadening of the SmA/N peakwidth from 0.5 K for P =7.7 mW to 2 K for P =29.4 mW.

The influence of temperature (293 308 K 1:1 IDA:Ni2+ complex is dominating. The Cu2+-Ni2+ exchange equilibrium from sulfate medium is characterized by the formation of nickel complexes of both stoichiometries within the whole temperature range studied. The dependence of alpha on T in Zn2+-Co2+ exchange system has been shown to be weaker than that in the Cu2+-Ni2+ system. This result is in a good agreement with the predictions made in the first communication of this series. The results of thermostripping experiments carried out for Cu2+-Co2+ exchange have shown that the efficiency of the thermostripping process depends on both the interval of working temperatures (deltaT) and its position on the temperature scale. The efficiency of thermostripping rises with an absolute deltaT value and also increases following the shift of temperature interval to the lower temperature range.

We present the design, properties of a very simple and very easy to make fix-point device (FPD) for temperature scale definition below 1 K. The FPD consists of five superconductors Mo, Zn, Zr, Ti and AuIn 2 allowing thus to fix the temperature scale from 0.915 K down to 200 mK.

We present μ SR data recorded on a newly prepared sample of the geometrically frustrated magnetic material Gd 2 Sn 2 O 7 . These data confirm previously published results and clearly show that there is a dynamical component in the ground state. This seems in contrast to the result of the linear spin-wave calculation of A.G. Del Maestro and M.J.P. Gingras which predicts the spin-waves to be gapped over the whole first Brillouin zone with a gap larger than about 1.0 K in temperature scale. The measured high-temperature paramagnetic spin dynamics is understood with a simple model. The conditions for observing a spontaneous magnetic field and a finite relaxation rate at low temperature are discussed in terms of the properties of a function which measures the density of fluctuation modes.

Using the technique of small angle neutron scattering (SANS) the vortex lattice of ultra-pure niobium has been investigated on an extremely fine temperature scale. As the temperature is increased towards T c 2 the longitudinal correlations of the vortices along their length improve, up to the resolution limited value of 100 μ m .

Measurements of the ab -plane complex microwave conductivity of high quality YBa 2 Cu 3 O 6.95 single crystals indicate the presence of a pairing temperature scale around 65 K in addition to the bulk T c of 93.4 K. Qualitatively similar behavior is seen for the case when microwave current flow in both ab -plane and along the c -axis. Influence of c -axis currents tends to broaden the feature in the superfluid density around 65 K. The extracted c -axis low temperature penetration depth, λ c ( T ), shows a linear dependence with a slope nearly 10 times larger than that of λ ab ( T ).

A procedure for simulating temperature programmed desorption (TPD) peaks is discussed with the aim of determining the shape of a TPD peak and the temperature range, where it is placed, when starting from the knowledge of the peak area (corresponding to the volume of gas adsorbed), of the values of the kinetic parameters (related to the energetic interactions adsorbate-adsorbent), and of some important experimental parameters. Finally the goodness of the method is checked by simulating a peak at different heating rate and comparing the value of the activation energy, taken as a starting point, with the one that is calculated from the variation of the peak maximum in the temperature scale with the heating rate.

We present experimental results on YBCO thin film bi-crystal junctions in which additional metallic shunt resistors are added by in-situ evaporation of gold or silver. These junctions are intended for use in the development of an HTS Josephson noise thermometer for primary temperature scale use. The temperature dependence of the critical current and effective shunt resistance are reported and the noise arising from the shunted junctions when biased into the finite voltage regime has been assessed as a function of frequency. This is compared with the predictions of a simple model and the implications for the potential accuracy of the proposed thermometer are considered.

The heat capacity of synthetic sapphire is determined by adiabatic shield calorimetry at temperatures from 298.15 K to 1000 K. The calorimetric procedures are discussed in detail. Special attention is given to temperature calibration, and to transformation of temperatures measured on IPTS-48 and IPTS-68 to ITS-90. The accuracy of the present temperature determination is considered to be within 0.02 K toT= 903 K and within 0.10 K up toT= 1000 K. The effect of the temperature scale changes on the measured heat capacities is within ± 0.03 per cent up toT= 800 K. Above this temperature, adjustment of the heat capacities might be warranted, but it depends on the thermometer used. The present directly determined heat capacities for synthetic sapphire are presumably the most accurate so far covering the range fromT= 300 K toT= 1000 K. The standard deviation of fit of the experimental heat capacity determinations with a smoothed curve is 0.09 per cent. The resulting heat capacity values for synthetic sapphire deviate from those recommended by Archer by less than 0.05 per cent. They thereby confirm the recommended values, which were based on drop-calorimetric results only atT> 700 K.

Rhenium exists in a close-packed hexagonal structure with lattice parameters at 293 K of a = 0.27610 nm c = 0.44583 nm and a density of 21.01 g cm−3 (Donohue [1] corrected for conversion factors recommended in the 1986 revision of the fundamental constants [2]). Wherever possible values have been corrected to the currently accepted atomic weight of 186.207 [3] and to the revision of the ITS-90 temperature scale [4,5]. The melting point determined by Sims, Craighead and Jaffee [6] corrects to 3458 ± 20 K on this scale. A superconducting transition temperature (Tc) of 1.700 K takes in to account the recommended values of both Roberls [7] and Hultgren et al [8]. The previous review of the thermodynamic properties was by the latter authors.

The basis and application of the Douglas equations for the adjustment and calculation of differences in thermodynamic properties due to a change in the temperature scale are reviewed. When higher-order terms in the general Douglas equations are discarded, the simplified Douglas equations are obtained. These simplified equations together with the recently revised set of differences between values of temperatures on the International Temperature Scale of 1990 (ITS-90) and the corresponding values on the International Practical Temperature Scale of 1968 (IPTS-68) for 903.765 K

The Janis line of ultra-low-temperature research refrigerators is presented. Cryogen-containing and cryogen-free 3 He, 3 He– 4 He dilution and adiabatic demagnetization refrigerators for the mK temperature range are described in detail and their possible use for cooling low-temperature sensors and detectors is discussed. A special emphasis is made on the Janis temperature scale down to 10 mK, maintained with a newly designed compact CMN thermometer and superconducting fixed point device.

An understanding of calorimeter design as applied at low temperatures (50–70°C) was used to construct a heat balance calorimeter that is also suitable for high-temperature applications (90–120°C). The broad temperature scale means that a wide range of polyreactions can be studied. An accurate model for the thermal effects of the reaction calorimeter is needed to ensure good estimates of basic parameters and to guarantee an accurate characterization of its operation. The time constants of the temperature measurement devices and the heat capacities of the system parts were carefully determined in simulated reactions. The dynamic behaviour of the calorimeter is well described by the five differential equations presented.