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Based on the recordings of 42 permanent seismic stations in Northern Jiangsu Basin (NJB) and its surrounding areas, we obtained both the sediment and crustal thickness in the region, using the nearest-neighbor algorithm and H–κ stacking method of receiver functions. We proposed a solution to use the sediment thickness to correct the depth of actual Moho discontinuity beneath the basin areas. Our results indicate that the sediment thickness in the northwest of the NJB is <1 km. We suggest that the southeastern border of the NJB should extend to the Yangzhou-Rudong area. The results of Moho variations show that the undulations of the Moho beneath the western NJB retains the traces of the sinistral shearing movement of the Tan-Lu Fault since the Miocene. Finally, we suggest the area around the Gaoyou city to be a prospective area for geothermal exploration. [ABSTRACT FROM AUTHOR]

Extreme precipitation events are expected to increase in frequency and intensity in the future climate, but the magnitude of these changes remains uncertain. The relationship between extreme precipitation and the surface temperature has been investigated to more robustly assess projected increases in extreme precipitation considering that projected temperature is more adequately simulated. Relationships between extreme precipitation (daily and sub‐daily) and surface air temperature (SAT) or surface dew‐point temperature (SDPT) are analyzed in this study using the 50‐members ensemble from the fifth version of the Canadian Regional Climate Model covering the Northeastern North America region over the period 1956–2099. Temperature‐precipitation scaling rates (TPSRs) were estimated using local SAT and SDPT seasonal anomalies as covariate over both periods for 2–100‐year extreme precipitation events and durations ranging from 1 to 24 h. Contrasting responses were obtained when using SAT or SDPT, especially in the southern part of the domain. Median scaling rates over the entire domain for SDPT were close to the Clausius‐Clapeyron scaling (≈7%/°C) while they were much smaller for SAT and even negative in southern regions, showing that moisture availability is a key factor for these regions. TPSR based on SDPT is also more robustly constrained and can be used to estimate changes in short‐duration extreme precipitation in a future period from TPSR in the historical period over a large part of the domain. Plain Language Summary: Extreme precipitation events are expected to be more intense and frequent in the future. The magnitude of these changes remains, however, uncertain. It is also possible to relate extreme precipitation changes to changes in surface temperature. The basic idea is that a warmer atmosphere can hold more moisture and therefore trigger more intense precipitation. Such a relationship can estimate future changes in extreme precipitation since simulated temperature from climate models is more reliable than precipitation. The response of extreme precipitation events to changes in surface air temperature and the surface dew‐point temperature was analyzed over the Northeastern North America region using a large ensemble of 50 climate simulations covering the period 1956–2099. It was shown that more robust estimates of the temperature‐precipitation relationship are obtained when using the surface dew‐point temperature, confirming that available moisture can be a limiting factor in increasing extreme precipitation for some regions. Those estimates were consistent between the historical and future climate over a large part of the study region for the more extreme events and confirm that future extreme precipitation changes can be estimated from changes in dew‐point temperature. Key Points: Temperature‐precipitation scaling using surface dew‐point temperature provides more robust estimates compared to surface air temperatureThe link between extreme precipitation and surface dew‐point temperature (SDPT) changes is more robustly constrained for short‐duration events and the future periodThe scaling using SDPT in historical period can be used to estimate changes in rainfall extremes in the future over most of the domain [ABSTRACT FROM AUTHOR]

Electronic archives of data from standard meteorological observations (mean daily/monthly surface air temperatures - SAT) at the meteorological stations at Bukhta Tikhaya (Hooker Island, 1929-1960) and Krenkel Observatory (Hayes Island, 1957-2017) on Franz Josef Land (FJL) are presented. Parallel data series of SAT made in 1958 and 1959 on both meteorological stations were analyzed. Linear regression equations used for extrapolation of observational data representative for Krenkel Observatory for the period 1929-1957 are also presented. The assessment of long-term changes in SAT on FJL was carried out based on the analysis of the obtained series (1929-2017). The main conclusions that follow from our study are: (1) The total warming in the FJL archipelago was 1.6-1.8°C (0.2°C/decade) for the entire available period of instrumental observations (1929-2017); (2) The highest rates of warming were recorded in March-April and amounted to 0.6°C/decade; (3) A particular strong warming has been observed since the 1990s. The annual temperature increased by 6.3°C (2.2°C/decade) for the period 1990-2017 and 5.2°C (2.9°C/decade) for the period 2000-2017; (4) For the period 1990-2017 the maximum rate of warming occurred between October to February with 4.4°C/decade; (5) For the period 2000-2017 the maximum rate of warming occurred between January to April and from November to December with 5.6°C/decade; (6) The dominant seasons of the year are winter (November-April), spring (May), summer (June-September) and autumn (October); (7) Over the entire observation period the largest temperature increase was observed in the winter season. During the period of modern warming (1990-2017), the largest temperature increase was observed in winter and autumn. [ABSTRACT FROM AUTHOR]

Drill rock cuttings from different depths of two geothermal wells (Az-26 and Az-49) from the Los Azufres Geothermal Field (LAGF), Mexico, were analyzed for rock magnetic properties (magnetic susceptibility, χ lf ; frequency-dependent susceptibility, χ fd; susceptibility of anhysteretic remanent magnetization, χ ARM ; isothermal remanent magnetization, IRM; saturation isothermal remanent magnetization, SIRM; "hard" isothermal remanent magnetization, HIRM) and their inter-parametric ratios (SIRM/ χ lf , χ ARM /SIRM and S-ratio) to explore the relationship, if any, between these properties and hydrothermal alteration. In both the geothermal wells, the intensity of hydrothermal alteration increases with depth and temperature of the well. The samples exhibit hydrothermal alteration-induced changes in several rock magnetic properties: (1) a decreasing trend in the values of concentration-dependent rock magnetic parameters (χ lf ; χ fd, χ ARM , IRM 300mT , and SIRM); (2) a decrease in S-ratio (relative proportions of ferrimagnetic and anti-ferromagnetic minerals) values and an increase in HIRM ("hard" IRM; concentration of magnetically "hard" minerals, e.g., hematite) values; and (3) increasing SIRM/ χ lf and χ ARM /SIRM ratio values. Most of the rock cuttings in both the wells are characterized by coarse SSD grains and they exhibit χ lf values between 1 × 10−6 m3kg−1 (acid igneous rocks) and 10 × 10−6 m3kg−1 (SSD/MD grain size). Our study also indicates that the initial (primary) mineralogy of reservoir rocks may have an influence on the type of hydrothermal minerals that would form at low reservoir temperatures and/or with low intensity of hydrothermal alteration; however, this may not have any significant influence at high reservoir temperatures and/or high intensity of hydrothermal alteration. Our study suggests that in a homogenous litho-unit (rocks of the same type and age) of a large area, a zone characterized by anomalously low values of concentration-dependent rock magnetic properties (χ lf , χ fd, χ ARM , IRM 300mT and SIRM), high SIRM/ χ lf , χ ARM /SIRM and HIRM values and low S-ratio values may indicate intense hydrothermal alteration. Consequently, rock magnetic properties may be a simple, yet an important tool, to identify hydrothermally altered rocks and zones of hydrothermal alteration, particularly in the initial stages of geothermal exploration. • Application of rock-magnetic properties in identification of hydrothermally altered rocks. • Characteristics of magnetic grain-size and magnetic domains in relation to hydrothermal alteration. • Rock magnetic properties may be useful tools in the initial stages of geothermal exploration. [ABSTRACT FROM AUTHOR]

Solidification during selective laser melting (SLM) needs to be better understood. In this work, track formation and how it affects grain growth during SLM of Co-29Cr-6Mo alloy over the laser power range of 180-360 W with other parameters kept constant have been studied. The track shape observed has suggested a conduction mode during SLM consistent with the calculated normalized enthalpy that indicates no significant vaporisation to form keyholes. Increasing the laser power led to increases in the track size with track boundaries remained largely circular arc-shaped. Grain growth direction and size are shown to be affected by track size. Measured values of track size have enabled the estimation of growth rate and, coupled with the measurement of cell size, the thermal gradient has been calculated. These data will be discussed in relation to modes of solidification. [ABSTRACT FROM AUTHOR]

Abstract The design of the wing leading edge of re-entry vehicles is a very challenging task since severe aerothermal loads are encountered during the re-entry trajectory. Hence, advanced materials and structural concepts need to be adopted to withstand the elevated thermal gradients and stresses. Furthermore, particular attention must be paid to the design of hot areas and connections between hot and cold areas of the structure, where the presence of major thermal gradients associated to significant thermal expansion coefficients variations, can lead to damage onset and failure. In order to face this issues, Ceramic Matrix Composites are generally employed as passive hot structures due of their capability to operate at elevated temperatures retaining acceptable mechanical properties. In the present work a novel thermo-structural concept of an hypersonic wing leading edge is introduced and verified by means of an advanced finite element thermo-structural model. [ABSTRACT FROM AUTHOR]

The Antarctic Peninsula experienced a rapid rise in regional temperature during the second half of the 20th century, but the regional pattern of multi-centennial temperature changes and their dynamical drivers remain poorly understood. Here we use proxies of biological productivity in rare, deep moss banks to infer past surface air temperature changes on the Antarctic Peninsula and identify the drivers of these changes. Late Holocene temperatures are broadly consistent between the low-elevation moss bank records and a high-elevation ice core site, and we conclude that variation in the strength of the westerlies, linked to the Southern Annular Mode, is the most likely driver. Our data do not support a hypothesized persistent temperature dipole over the Antarctic Peninsula related to a strong influence of El Niño-Southern Oscillation. Rates of change in biological productivity on the peninsula over the 20th century are unusual in the context of the late Holocene, and further warming will drive rapid future increases in moss growth and microbial populations. [ABSTRACT FROM AUTHOR]

The overhead transmission lines are considered one of the major sources of electric and magnetic fields, which can induce electrical currents within the human body. In this study, the electric and magnetic fields generated by two recent designs of 400 kV transmission lines used in the Romanian power system are computed and compared to the exposure limits established by the International Commission on Non-Ionizing Radiation Protection for the general public. The computations are carried out with two dedicated software tools, called PowerMag and PowerELT, which have been developed based on a 2D quasi-static analytical approach. This approach, as well as the electric and magnetic field distributions obtained for the considered 400 kV overhead transmission lines, will be discussed in detail. To confirm the validity of the results, some comparisons to finite element computations will also be presented. [ABSTRACT FROM AUTHOR]

This paper reviews the main issues arising from the use of fiber Bragg gratings as temperature sensors in the presence of significant thermal gradients. These conditions occur for example during laser thermal ablation of tumors. In particular, the paper focuses on the identification of the grating position along the fiber, which represents one of the main uncertainty contributions. A novel experimental setup for the grating center localization is proposed and the corresponding characterization procedure has been devised. The setup is built in such a way as to generate reproducible linear temperature distributions. Tests carried out using a sensor prototype have shown that the grating position can be found with a standard uncertainty of 0.3 mm. [ABSTRACT FROM AUTHOR]

Transient hot-wire and laser flash methods are the two commonly used techniques for measuring the thermal conductivity of nanofluids. However, a comparative study of these two techniques considering identical nanofluids has not been carried out. In this regard, the current study aims at comparison of two methods with identical distribution of Al 2 O 3 and Ag nanoparticles in water. The study also accounts quantitatively for the wide difference in the measured thermal conductivities on the basis of the flux of nanoparticles across the thermal boundary layer resulting from the Brownian movement. It has been observed that the collision flux of the nanoparticle increases with increase in the initial perpendicular distance of the nanoparticle from the heat source wall. Such an increase results in higher thermal conductivity in case of transient hot-wire compared to laser flash method. [ABSTRACT FROM AUTHOR]

The planned lander missions to the surface of Europa will access samples from the subsurface of the ice in a search for signs of life. A small thermal drill (probe) is proposed to meet the sample requirement of the Science Definition Team's (SDT) report for the Europa mission. The probe is 2 cm in diameter and 16 cm in length and is designed to access the subsurface to 10 cm deep and to collect five ice samples of 7 cm 3 each, approximately. The energy required to penetrate the top 10 cm of ice in a vacuum is 26 Wh, approximately, and to melt 7 cm 3 of ice is 1.2 Wh, approximately. The requirement stated in the SDT report of collecting samples from five different sites can be accommodated with repeated use of the same thermal drill. For smaller sample sizes, a smaller probe of 1.0 cm in diameter with the same length of 16 cm could be utilized that would require approximately 6.4 Wh to penetrate the top 10 cm of ice, and 0.02 Wh to collect 0.1 g of sample. The thermal drill has the advantage of simplicity of design and operations and the ability to penetrate ice over a range of densities and hardness while maintaining sample integrity. [ABSTRACT FROM AUTHOR]

In this study, fractal/multifractal modeling methods have been applied for preliminary hydrothermal Ni prospection using a set of stream sediment geochemical data of Ahangaran district, which is an arid terrain in eastern Iran. The study area has a complex geological and morphological setting, which is dominated by the presence of aeolian sands. Cretaceous ophiolitic rocks hosting nickel endowment are influenced by extensive listwanitic alteration. Hydrothermal nickel mineralization occurs as veinlets and disseminated forms within the listwanite units. Among the analyzed elements, Ni, Cr and, Co have been recognized as being associated with listwanitic alteration and Ni mineralization, through robust factor analysis of compositional data. The regional background patterns of these mineralization-related elements were delineated via the concentration – area (C-A) fractal modeling method. Different multifractal characteristics of the selected elements were recognized using the multifractal spectrum f ( α ) curves and different multifractal indices. The enrichment and depletion patterns of the related elements in different parts of the study area were also identified using the local singularity mapping technique. The application of local singularity mapping manifested different geochemical patterns that were not recognized via the C-A fractal modeling method. The superiority of the local singularity mapping technique in delineating geochemical populations over the C-A fractal modeling method, was revealed by quantification of the correlation between geochemical anomalies and geological evidence of the mineralization. [ABSTRACT FROM AUTHOR]

Geothermal exploration relies in large parts on subsurface models derived from seismic reflection profiling. Based on a case study of the Larderello area we discuss the influence of seismic velocity uncertainties in geothermal prospecting and highlight the role of unrecognized seismic anisotropy. For the field study we investigated the anisotropy of typical rock samples under simulated in-situ HP/HT conditions. It turns out that the target horizons may be found up to 300 m shallower and 200 m horizontally displaced compared to the isotropic case due to anisotropic bias. Correspondingly, the uncertainty of temperature extrapolation may increase from 10 to 20%. [ABSTRACT FROM AUTHOR]

We theoretically investigate the behavior of Leidenfrost drops on a flat substrate submitted to a horizontal thermal gradient and highlight that they are able to self-propel in a preferential direction. Namely, they are found to travel towards the colder parts of the substrate, as if they were trying to maximize their lifetime. In particular, a centimetric water drop can reach velocities of the order of cm/s for thermal gradients of the order of a few K/mm. In general, the presented model, based upon the lubrication approximation in the vapor cushion as in the work of Sobac et al. ["Leidenfrost effect: Accurate drop shape modeling and new scaling laws," Phys. Rev. E 90, 053011 (2014)] and here formulated for simplicity for a 2D drop, enables predicting the values of these velocities as a function of the thermal gradient, drop size, superheat, and fluid properties. Surprisingly, the variability of vapor properties with temperature turns out to be instrumental for the drop to move, even if the vapor film profile is always asymmetric anyway. Finally, this asymmetry being typically weak, its effect also proved to be well captured by linearization around the corresponding symmetric Leidenfrost state. [ABSTRACT FROM AUTHOR]

A large temperature gradient is useful for concentrating temperature-sensitive molecules having non-zero Soret coefficients. Aiming at such molecular manipulation as a final goal, this study analyzed the heat transfer equation for two types heat sources, two-dimensional lattice of metal domains and a single-spot metal domain, both being able to undergo plasmon resonance and generate heat. It turned out that the plasmonic heating from the single-spot domain can generate only a monotonic temperature profile with a single maximum associated by a gradual decay of radial gradient of temperature. In contrast, with an adequate choice of the boundary conditions, the lattice of the metal domains was found to give a profile with a large, periodic temperature gradient that is useful for the manipulation of temperature-sensitive molecules, in particular those favoring low temperatures. A preliminary experiment utilizing a lattice of silver domains confirmed creation of a large, roughly periodic temperature gradient of the order of 10 3 K/mm (being in harmony with the heat transfer analysis), which encourages a further study of temperature gradient controlled by the plasmonic heating and of the molecular manipulation utilizing this gradient. [ABSTRACT FROM AUTHOR]

The wintertime Arctic temperature (T; surface-400 hPa) decreased from 1979 to 1997 and increased rapidly from 1998 to 2012, in contrast to the global mean surface air temperature. Here aspects of circulation variability that are associated with these temperature changes are examined using the NCEP-NCAR reanalysis and ERA-Interim products. It is found that the Nordic-Siberia seesaw of meridional winds near 70°N is associated with two-thirds of the variance of the Arctic winter mean T, possibly contributing to the cooling and warming trends. It is suggested here that the seesaw accounts for much of the difference in Arctic amplification between observations and climate models. Growth of sea ice in winter is hindered by southerly winds over the Nordic region (0°-60°E). Through modulation of the wind seesaw, the eastern Atlantic (EA) pattern is found to be significantly associated with Arctic and East Asia winter climate variations. In one phase of the EA pattern, a midlatitude North Atlantic ridge anomaly is associated with a poleward shift of the mean storm track, a weakened eddy-driven jet over Eurasia, and above-normal sea level pressure (SLP) over Siberia, most significantly in the region to the northwest of Lake Baikal. The EA pattern is associated with two-thirds of the variance of winter-average SLP over Siberia. [ABSTRACT FROM AUTHOR]

Wastewater collection and treatment, as well as the effective utilization of sewage sludge, are tasks of great importance for growing populations, rapidly developing industry and pollution reduction efforts aimed at curbing the harmful by-products generated by such processes. In this study, the current status and theory behind municipal sewage sludge disposal in Lithuania is presented. Since 2004, the country has rapidly developed its wastewater treatment system by applying contemporary technologies used in other European countries. According to statistical data, the amount of accumulated sewage sludge in the country will reach 82,000 t/year dry weight in 2016. Of that, approximately 60% is stored in storage plants and landfills, 14% is used in agriculture, and 26% is composted. Storing such a large percentage of waste is not viable from an environmental or an economic perspective. Thermal utilization of sewage sludge is considered a promising alternative to storage, and there is strong demand for more reliable data on accruing quantities of sewage sludge and its properties, including heavy metals concentrations, at separate wastewater treatment plants. Sludge samples were collected from seven wastewater treatment plants in the cities of Vilnius, Kaunas, Klaipeda, Siauliai, Panevezys, Alytus and Silute which had populations of 528, 307, 159, 107, 97, 57 and 17 thousand inhabitants, respectively, in 2013. These cities utilized different waste water treatment technologies, and the primary industrial activities in the places selected varied. Heavy metal concentrations and ash melting temperatures were determined based on an analysis of the sludge content, and conclusions for agricultural application and energy production were made. For energy production, co-incineration with municipal waste or wood and gasification are the most reliable ways to utilize sewage sludge. Implementation of such technologies is beginning and further research into these methods is occurring at both the local and international levels. [ABSTRACT FROM AUTHOR]

Field driven nucleation and propagation of transverse domain walls (DWs) in Fe nanowires under thermal gradients were studied using Monte Carlo simulations. Simulations identified that thermal gradients contribute to stabilizing nucleation of multiple DWs. The results also showed that the correct combination of a magnetic field and temperature gradients applied along a wire can provide a high degree of control over the direction, velocity, and acceleration of DW propagation, which is of paramount importance for technological applications. [ABSTRACT FROM AUTHOR]

Binary and/or ternary metallic alloys of uranium (U) and plutonium (Pu) with transition metals are considered to be promising fuels for fast breeder reactors due to their high fissile atom content, high breeding ratio with lower doubling time, dimensional stability at high burn-up and high thermal conductivity, etc. Hence, the development of new and promising analytical methodologies for the characterization of trace impurities in advanced metallic fuels is always appreciated. In the present work, a number of trace impurities viz., B, Ce, Cd, Co, Eu, Dy, Gd, Mn, Nd, Ni, Sm and Tb in U–Ti, U–Zr and U–Mo alloys were determined by inductively coupled plasma mass spectrometry (ICP-MS). Solvent extraction using tributylphosphate (TBP) in carbon tetrachloride (CCl4) was used for the partial removal of matrix elements so as to reduce the matrix effect on these analytes during mass spectrometric analysis. The common analyte internal standard (CAIS) technique was refined and utilized to account for the effect of the remaining matrix elements. The proposed refined CAIS technique was validated by standard addition using synthetic samples and the analyte recoveries were found to be ≥92%. Real samples of U–Ti, U–Zr and U–Mo alloys were analyzed for trace elements and the relative standard deviations (RSDs) were found to be between 5 and 8%. Cross-validation of the proposed method was carried out by isotope dilution mass spectrometry (IDMS) and recovery studies employing gamma spectrometry. The method detection limit (MDL) lies in the range of 3–15 ng mL−1. [ABSTRACT FROM AUTHOR]

This paper aims to decipher the thermal evolution of the Montagne Noire Axial Zone (MNAZ, southern French Massif Central) gneiss core and its metasedimentary cover through determination of P-T paths and temperature gradients. Migmatitic gneiss from the core of the dome record a clockwise evolution culminating at 725 ± 25 °C and 0.8 ± 0.1 GPa with partial melting, followed by a decompression path with only minor cooling to 690 ± 25° C and 0.4 ± 0.1 GPa. Field structural analyses as well as detailed petrological observations indicate that the cover sequence experienced LP- HT metamorphism. Apparent thermal gradients within the cover were determined with garnet-biotite thermometry and Raman Spectroscopy on Carbonaceous Matter. High-temperature apparent gradients (e.g. ∼530 °C km−1 along one transect) are explained by late brittle-ductile extensional shearing evidenced by phyllonites that post-date peak metamorphism. In areas where normal faults are less abundant and closely spaced, gradients of ∼20 to 50 °C km−1 are calculated. These gradients can be accounted for by a combination of dome emplacement and ductile shearing (collapse of isotherms), without additional heat input. Finally, the thermal evolution of the MNAZ is typical for many gneiss domes worldwide as well as with other LP- HT terranes in the Variscides. [ABSTRACT FROM AUTHOR]

A mathematical relation between deformation and vertical vorticity tendency is built by introducing the frontogenesis function and the complete vertical vorticity equation, which is derived by virtue of moist potential vorticity. From the mathematical relation, it is shown that properly configured atmospheric conditions can make deformation exert a positive contribution to vortex development at rates comparable to other favorable factors. The effect of deformation on vortex development is not only related to the deformation itself, but also depends on the current thermodynamic and dynamic structures of the atmosphere, such as the convective stability, moist baroclinicity and vertical wind shear (or horizontal vorticity). A diagnostic study of a heavy-rainfall case that occurred during 20-22 July 2012 shows that deformation has the most remarkable effect on the increase in vertical vorticity during the rapid development stage of the low vortex during its whole life cycle. This feature is mainly due to the existence of an approximate neutral layer (about 700 hPa) in the atmosphere where the convective stability tends to be zero. The neutral layer makes the effect of deformation on the vertical vorticity increase significantly during the vortex development stage, and thus drives the vertical vorticity to increase. [ABSTRACT FROM AUTHOR]

A computer-controlled laser test rig (using a CO laser) offers an interesting alternative to traditional flame-based thermal gradient rigs in evaluating thermal barrier coatings (TBCs). The temperature gradient between the top and back surfaces of a TBC system can be controlled based on the laser power and a forced air back-face cooling system, enabling the temperature history of complete aircraft missions to be simulated. An air plasma spray-deposited TBC was tested and, based on experimental data available in the literature, the temperature gradients across the TBC system (ZrO-YO YSZ top coat/CoNiCrAlY bond coat/Inconel 625 substrate) and their respective frequencies during air-to-air combat missions of fighter jets were replicated. The missions included (i) idle/taxi on the runway, (ii) take-off and climbing, (iii) cruise trajectory to rendezvous zone, (iv) air-to-air combat maneuvering, (v) cruise trajectory back to runway, and (vi) idle/taxi after landing. The results show that the TBC thermal gradient experimental data in turbine engines can be replicated in the laser gradient rig, leading to an important tool to better engineer TBCs. [ABSTRACT FROM AUTHOR]

We predict a thermodynamic magnon recoil effect for domain wall motions in the presence of temperature gradients. All current thermodynamic theories assert that a magnetic domain wall must move toward the hotter side, based on equilibrium thermodynamic arguments. Microscopic calculations, on the other hand, show that a domain wall can move either along or against the direction of heat currents, depending on how strong the magnonic heat currents are reflected by the domain wall. We have resolved the inconsistency between these two approaches by augmenting the theory in the presence of thermal gradients by incorporating in the free energy of domain walls a heat current term present in nonequilibrium steady states. The condition to observe a domain wall propagation toward the colder regime is derived analytically and can be tested by future experiments. [ABSTRACT FROM AUTHOR]

A mathematical model is developed to describe the steady state creep in a rotating Al-SiCp disc having a non-linear thickness profile and distribution of SiC particles along the radial direction. The model is used to investigate the effect of imposing three different kinds of radial temperature profiles viz. linear, parabolic and exponential with fixed values of inner and outer surface temperatures, on the creep stresses and strain rates. It is noticed that by increasing the temperature exponent (nT ), the radial stress (over the entire radius) and tangential stress (near the inner radius) increase in the disc. However, the tangential stress decreases near the outer radius. The radial and tangential strain rates in the functionally graded (FG) disc reduce significantly with the increase in exponent nT . Besides reduction in the magnitude, the distribution of strain rates also become relatively more uniform throughout with the increase in nT . It is concluded that FG disc operating under exponential temperature profile performs better. It is also revealed that amongst several FG discs operating under radial thermal gradients, with different values of temperature exponent (nT ) but having the same average and fixed outer surface temperature, the FGM disc with lower value of nT exhibits the maximum creep life. [ABSTRACT FROM AUTHOR]

In typical drillstem testing (DST), transient pressures are gathered downhole while rate measurements occur at the surface. Effects of heat transfer on pressure, particularly during a buildup test in a gas well, necessitate the close proximity of pressure measurements to the point of fluid entry. While pressure measurements are reliable with sufficient resolution in most settings, rate measurements often lack synergy with pressure because of the sensor resolution and the frequency of monitoring. The reduced-rate sensor resolution and rate-monitoring frequency may precipitate significant uncertainty in transient-test interpretations. This paper presents a case study for a deepwater asset in Western Australia, where, in addition to the traditional downhole-pressure and surface-rate measurements, temperatures were recorded at various depth stations in four wells, each in a different reservoir, before, during, and after transient testing. These temperature data allowed estimation of gas-flow rates. The computational accuracy of flow rates increased at shallower depths because increased heat transfer, leading to larger temperature difference, enhanced the fidelity of measurements. Overall, the distributedtemperature data allowed the estimation of temperature gradients, including their nonlinear trends, for both the static geothermal and dynamic flows. [ABSTRACT FROM AUTHOR]

A number of simplified design methods have been developed to predict composite slab capacities in fire. Most of these extend ambient-temperature large-deflection slab behavior to the elevated-temperature phase by reducing the strengths of fire-exposed concrete and reinforcement while neglecting the effects of thermal expansion and thermal bowing of the slab. Experiments have shown that there are significant differences between the predictions from these methods and the actual behavior and failure modes of ambient- and elevated-temperature concrete slabs in tensile membrane action. Therefore, this paper describes the development of a new analytical method that incorporates both thermal and mechanical effects into the prediction of slab behavior in fire conditions. It uses the variational Rayleigh-Ritz approach to classical large-deflection plate theory. The method is found to produce accurate predictions of deflections and membrane tractions; however, it requires further refinement for accuracy of stresses. The results are compared with numerical modeling using VULCAN, a specialist finite-element (FE) program for structural fire engineering. [ABSTRACT FROM AUTHOR]

Particle diffusion in condensed matters driven by thermal gradient, the so-called Ludwig-Soret effect, has been investigated for about 160 years, but up to the present, seldom do theories on atomic level understand a series of puzzles in relevant experiments. In this work, we derived an expression of Soret coefficient for atomic diffusion in condensed matter from a single atom statistic model with relevant parameters expressed in terms of atomic mass and the potential profile felt by the guest atom without empirical parameters. The reality of the model was strictly tested by molecular dynamics simulations, especially the result for He atom diffusing on graphene sheet, which suggests the Soret effect may be used to separate ³He from 4He. [ABSTRACT FROM AUTHOR]

The need for remote monitoring of almost every place in the world is still growing, while many new technical solutions are extensively developed by research community. The knowledge of the environment and the weather conditions of human environment is, in certain cases of polluted places in heavy industrial areas, necessary to allow real-time warnings about deteriorating conditions to living community in these desired places. While huge money investments were used for real-time monitoring of every possible quantity of human body, people's living environment became increasingly poorer. In this paper we present a modern and relatively cheap solution for powering some types of intelligent sensors in which traditional battery power source is insufficient and other powering options are not applicable. Obtaining the energy to supply sensors is possible even from immediate sensors' environment. Sources (which are utilizing thermal gradient) are supplying energy from the surrounding environment and without the need for high-intensity incident light (solar energy based). In order to achieve the full working mode, only a small thermal gradient is needed in order of degrees. The developed test application is using sophisticated electronic circuit provided by Linear Technology Company, which is able to use even small energy bursts for discontinuous intelligent sensors operations. The heat energy is converted into electric energy which is stored in very high-capacity capacitor (about 1F). This power supply type is suitable for any environment, where some permanent thermal gradient is presented. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with geothermal prospecting carried out in the Quaternary volcanic field of Dhamar, which is located almost in the centre of the main Oligo-Miocene basaltic trap plateau of Yemen. By applying geochemical and thermometric techniques in domestic wells producing water from the shallow unconfined aquifer in the area, which is prevalently hosted inside the Quaternary volcano-clastic material, a closed thermal anomaly associated with the Quaternary volcanic activity was well delineated. Although the aquifer(s) has a Ca–Na–HCO3 composition, that is typical of shallow groundwater, there are several chemical anomalies in the hotter central area compared to typical aquifers: i) the pH is lower and, consequently, the calculated partial pressure of CO2 in solution is higher, ii) the electrical conductivity is higher, iii) the total salinity is higher and iv) the fluoride ion concentration is higher. Such chemical anomalies in the hotter part of the aquifer do not seem to be generated by the rising and/or mixing of deep hydrothermal components rising into the shallow aquifer, but rather produced by enhanced water–rock interaction processes resulting from the higher temperature of the aquifer and its greater acidity. By applying some speculative calculations, based on the likely temperature of rainfall in the area and the depth and temperature of individual wells, the local thermal gradients in the area have been calculated. The thermal gradient varies from less than the average Earth gradient at the periphery of the delimitated thermal anomaly, to more than 250°C/km, within an extensive area (exceeding 200km2) where the gradient is greater than 100/120°C/km. [Copyright &y& Elsevier]

In a sandwich-type metallic thermal protection system (MTPS), the contact between the skin and the corrugated core is an important parameter that determines the heat transfer across it. Thermal contact conductance (TCC) between the skin and core is considered in the present transient heat transfer analysis following three-dimensional heat transfer equations for a simplified MTPS filled with insulation for a period of 1000 s. Experimental results on a thermal profile across the MTPS are obtained for two time-varying heat flux histories; for a selected heat flux history, the value of TCC is varied in the analysis. The value that shows close agreement with the test data is then taken for further analysis for the second heat-flux history. A comparison of the surface temperatures and associated duration on the top skin, below the skin, below the horizontal flange connecting the two adjacent webs of the corrugated core, and at the back wall obtained by analysis and testing shows good agreement for the top skin, whereas a qualitative agreement is seen for the back wall with the temperature-dependent properties considered. The study indicates that a higher value of TCC leads to a conservative estimation of the back-wall temperature. [ABSTRACT FROM AUTHOR]

The article presents a study which compares a full three-dimensional (3-D) Cartesian model with oblique subduction and selected two-dimensional (2-D) cross-sections to evaluate the impact of subduction zone geometry on thermal structure. The study uses a dynamic slab and wedge, separated by a kinematic boundary. Results show that the slab surface temperature is more realistic in the 3-D model.

Abstract: Human thermal comfort in urban outdoor places was generally not an issue in Dutch urban design. This neglect shows problematic effects of discomfort, but also missed chances in urban life quality. The existing problems are alleviated due to the expected effects of climate change with even higher temperatures. This altogether requires adaptations in the setup of the urban environment. But there still is a lack of usable urban design guidelines. Therefore, a “research for design” and a “research by design” project was conducted, generating design guidelines for thermally comfortable Dutch urban squares. The “research for design” entailed a survey on people''s microclimate perceptions resulting in a range of design guidelines. These guidelines and additional new design hypotheses were applied in a design process - a “research by design” and tested further through microclimate simulations. These lead to improved design guidelines in the form of spatial patterns for optimized thermal comfort conditions in Dutch urban squares. The results of this project, being a range of design recommendations, facilitate the easy implementation of measures to improve thermal comfort in Dutch public squares and make cities more climate-proof. [Copyright &y& Elsevier]

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In view of the cost and complexity of climate-observing systems, it is a matter of concern to know which measurements, by satellite or in situ, can best improve the accuracy and precision of long-term ensembles of climate projections. We follow a statistical procedure to evaluate the relative capabilities of a wide variety of observable data types for improving the accuracy and precision of an ensemble of Intergovernmental Panel on Climate Change (IPCC) models. Thirty-two data types are evaluated for their potential for improving a 50-y surface air temperature trend prediction with data from earlier periods, with an emphasis on 20 y. Data types can be ordered in terms of their ability to increase the precision of a forecast. Results show that important conclusions can follow from this ordering. The small size of the IPCC model ensemble (20 members) creates uncertainties in these conclusions, which need to be substantiated with the larger ensembles expected in the future. But the larger issue of whether the methodology can provide useful answers is demonstrated. [ABSTRACT FROM AUTHOR]

Accurate and timely detection of infectious disease outbreaks provides valuable information which can enable public health officials to respond to major public health threats in a timely fashion. However, disease outbreaks are often not directly observable. For surveillance systems used to detect outbreaks, noises caused by routine behavioral patterns and by special events can further complicate the detection task. Most existing detection methods combine a time series filtering procedure followed by a statistical surveillance method. The performance of this "two-step" detection method is hampered by the unrealistic assumption that the training data are outbreak-free. Moreover, existing approaches are sensitive to extreme values, which are common in real-world data sets. We considered the problem of identifying outbreak patterns in a syndrome count time series using Markov switching models. The disease outbreak states are modeled as hidden state variables which control the observed time series. A jump component is introduced to absorb sporadic extreme values that may otherwise weaken the ability to detect slow-moving disease outbreaks. Our approach outperformed several state-of-the-art detection methods in terms of detection sensitivity using both simulated and real-world data. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study is to estimate the stability of unprotected embankment in the warm and ice-rich permafrost (WIRP) region along the Qinghai–Tibet Railway. The estimation was based on field observations of the varying thermal regime under the unprotected embankments and of the ongoing settlement of this type of embankment. The observed data shows that on the one hand, the unprotected embankment could mitigate the frost heave of the subgrade by homogenizing the geothermal gradient and by decreasing the temperature fluctuation of the WIRP layers. On the other hand, leaving the embankment unprotected has led to the warming of the underlying WIRP layer. This layer releases a considerable amount of unfrozen water. However, the released water undergoes untimely drainage, leading to the ongoing settlement of the embankment. To stabilize the settlement, two recommendations are provided. For those existing unprotected embankments, using shading boards to cool down the underlying permafrost is recommended. For the future embankments constructed in WIRP regions, the inset trenches which are drilled perpendicularly to traffic are recommended to aid the drainage of the released water. [Copyright &y& Elsevier]

The skill of state-of-the-art operational seasonal forecast models in extratropical latitudes is assessed using a multimodel ensemble from the Development of a European Multimodel Ensemble System for Seasonal-to-Interannual Prediction (DEMETER) project. In particular, probabilistic forecasts of surface precipitation and maximum temperature in Spain are analyzed using a high-resolution observation gridded dataset (Spain02). To this aim, a simple statistical test based on the observed and predicted tercile anomalies is used. First, the whole period 1960–2000 is considered and it is shown that the only significant skill is found for dry events in autumn. Then, the influence of ENSO events as a potential source of conditional predictability is studied and the validation to strong La Niña or El Niño periods is restricted. Skillful seasonal predictions are found in partial agreement with the observed teleconnections derived from the historical records. On the one hand, predictability is found in spring related to El Niño events for dry events over the south and the Mediterranean coast and for hot events in the southeast areas. In contrast, La Niña drives predictability in winter for dry events over the western part and for hot events in summer over the south and the Mediterranean coast. This study considers both the direct model outputs and the postprocessed predictions obtained using a statistical downscaling method based on analogs. In general, the use of the downscaling method outperforms the direct output for precipitation, whereas in the case of the temperature no improvement is obtained. [ABSTRACT FROM AUTHOR]

3-D gravity models that consider the highly complex density structure of the Norwegian passive volcanic continental margin require a significantly lower density in the mantle below the ocean than below the continent. This is especially pronounced on the crust-free residual gravity anomalies obtained by 3-D gravity stripping. This density contrast in the mantle indicates different physical properties either related to thermal or compositional conditions beneath the two domains. We assess the gravity response of thermal differences and find that a hotter oceanic mantle compared to a colder continental mantle could cause the density contrast. Accordingly, 3-D lithospheric-scale gravity models considering temperature-dependent mantle densities indicate that the transition between continental and oceanic lithosphere is rather sharp with a steep gradient in thickness beneath the continent–ocean transition zone. Furthermore, a mantle wedge of reduced density extends from the oceanic Jan Mayen Fracture Zone to the continental Jan Mayen Lineament and points to increased mantle temperatures and/or compositional changes beneath the lineament. The models further indicate the presence of high-density bodies within the lower crust at the continent–ocean transition that are continuous with the lowermost oceanic layer 3B in terms of geometry and density. This supports the concept of underplated lower crust beneath the western Norwegian margin. Finally, NE–SW trending linear zones of increased density are required in the lower crust beneath the eastern Vøring and Møre Basins to fit the short-wavelength gravity signal. [ABSTRACT FROM AUTHOR]

Abstract: Ganymede has an intrinsic magnetic field which is generally considered to originate from a self-excited dynamo in the metallic core. Driving of the dynamo depends critically on the satellite''s thermal state and internal structure. However, the inferred structure based on gravity data alone has a large uncertainty, and this makes the possibility of dynamo activity unclear; variations in core size and composition significantly change the heat capacity and alter the cooling history of the core. The main objectives of this study is to explore the structural conditions for a currently active dynamo in Ganymede using numerical simulations of the thermal history, and to evaluate under which conditions Ganymede can maintain the dynamo activity at present. We have investigated the satellite''s thermal history using various core sizes and compositions satisfying the mean density and moment of inertia of Ganymede, and evaluate the temperature and heat flux at the core–mantle boundary (CMB). Based on the following two conditions, we evaluate the possibility of dynamo activity, thereby reducing the uncertainty of the previously inferred interior structure. The first condition is that the temperature at the CMB must exceed the melting point of a metallic core, and the second is that the heat flux through the CMB must exceed the adiabatic temperature gradient. The mantle temperature starts to increase because of the decay of long-lived radiogenic elements in the rocky mantle. After a few Gyr, radiogenic elements are exhausted and temperature starts to decrease. As the rocky mantle cools, the heat flux at the CMB steadily increases. If the temperature and heat flux at the CMB satisfy these conditions simultaneously, we consider the case as capable of driving a dynamo. Finally, we identify the Dynamo Regime, which is the specific range of internal structures capable of driving the dynamo, based on the results of simulations with various structures. If Ganymede''s self-sustained magnetic field were maintained by thermal convection, the satellite''s metallic core would be relatively large and, in comparison to other terrestrial-type planetary cores, strongly enriched in sulfur. The dynamo activity and the generation of the magnetic field of Ganymede should start from a much later stage, possibly close to the present. [Copyright &y& Elsevier]

Bailesti Depression, positioned in the western side or Moesian Platform,is not very well explored until now concerning its hydrocarbons potential due to its specific geological conditions. It consists of a diping zone descending from north-north west to south soth east with a stratigraphical column specific to Moesian Platform, presenting all its main sedimentation cycles with cummulative thickness exceeding 6000-7000 m in the most subsided areas. Depression deposits suffered during their evolution an important termal methamorfism that enables a great part of them to generate hydrocarbons. This feature correlated with the specific structural arrangement provide the necessary conditions for the existence of exploitable petroleum accumulations. Taking into account the characteristics of the already known productive structures from Moesian Platform we may estimate the petroleum prognosis potential for each promising formation/interval of Bailesti Depression deposits. [ABSTRACT FROM AUTHOR]

This study investigates the use of a previously published algorithm for estimating ground heat flux (GHF) at the global scale. The method is based on an analytical solution of the diffusion equation for heat transfer in a soil layer and has been shown to be effective at the point scale. The algorithm has several advantageous properties: 1) it only needs a single-level input of surface (skin) temperature, 2) the time-mean GHF can be derived directly from time-mean skin temperature, 3) it has reduced sensitivity to the variability in soil thermal properties and moisture, 4) it does not requires snow depth, and 5) it is computationally effective. A global map of the necessary thermal inertia parameter is derived using reanalysis data as a function of soil type. These parameter estimates are comparable to values obtained from in situ observations. The new global GHF estimates are generally consistent with the reanalysis GHF output simulated using two-layer soil hydrology models. The authors argue that the new algorithm is more robust and trustworthy in regions where they differ. The proposed algorithm offers potential benefits for direct assimilation of observations of surface temperature as well as GHF into the reanalysis models at various time scales. [ABSTRACT FROM AUTHOR]

Global land surface runoff and sea surface temperatures (SST) are analyzed to identify the primary modes of variability of these hydroclimatic data for the period 1905–2002. A monthly water-balance model first is used with global monthly temperature and precipitation data to compute time series of annual gridded runoff for the analysis period. The annual runoff time series data are combined with gridded annual sea surface temperature data, and the combined dataset is subjected to a principal components analysis (PCA) to identify the primary modes of variability. The first three components from the PCA explain 29% of the total variability in the combined runoff/SST dataset. The first component explains 15% of the total variance and primarily represents long-term trends in the data. The long-term trends in SSTs are evident as warming in all of the oceans. The associated long-term trends in runoff suggest increasing flows for parts of North America, South America, Eurasia, and Australia; decreasing runoff is most notable in western Africa. The second principal component explains 9% of the total variance and reflects variability of the El Niño–Southern Oscillation (ENSO) and its associated influence on global annual runoff patterns. The third component explains 5% of the total variance and indicates a response of global annual runoff to variability in North Atlantic SSTs. The association between runoff and North Atlantic SSTs may explain an apparent steplike change in runoff that occurred around 1970 for a number of continental regions. [ABSTRACT FROM AUTHOR]

Anomalous atmospheric conditions can lead to surface temperature anomalies, which in turn can lead to temperature anomalies in the subsurface soil. The subsurface soil temperature (and the associated ground heat content) has significant memory—the dissipation of a temperature anomaly may take weeks to months—and thus subsurface soil temperature may contribute to the low-frequency variability of energy and water variables elsewhere in the system. The memory may even provide some skill to subseasonal and seasonal forecasts. This study uses three long-term AGCM experiments to isolate the contribution of subsurface soil temperature variability to variability elsewhere in the climate system. The first experiment consists of a standard ensemble of Atmospheric Model Intercomparison Project (AMIP)-type simulations in which the subsurface soil temperature variable is allowed to interact with the rest of the system. In the second experiment, the coupling of the subsurface soil temperature to the rest of the climate system is disabled; that is, at each grid cell, the local climatological seasonal cycle of subsurface soil temperature (as determined from the first experiment) is prescribed. Finally, a climatological seasonal cycle of sea surface temperature (SST) is prescribed in the third experiment. Together, the three experiments allow the isolation of the contributions of variable SSTs, interactive subsurface soil temperature, and chaotic atmospheric dynamics to meteorological variability. The results show that allowing an interactive subsurface soil temperature does, indeed, significantly increase surface air temperature variability and memory in most regions. In many regions, however, the impact is negligible, particularly during boreal summer. [ABSTRACT FROM AUTHOR]

The increasing demand for electrical power as well as energy for heating and cooling of residences and small commercial buildings is a growing worldwide concern. Micro-cooling, heating, and power (micro-CHP), typically designated as less than 30 kW electric, is decentralized electricity generation coupled with thermally activated components for residential and small commercial applications. The number of combinations of components and parameters in a micro-CHP system is too many to be designed through experimental work alone. Therefore, theoretical models for different micro-CHP components and complete micro-CHP systems are needed to facilitate the design of these systems and to study their performance. This paper presents a model for micro-CHP systems for residential and small commercial applications. Some of the results that can be obtained using the developed model include the cost per month of operation of using micro-CHP versus conventional technologies, the amount of fuel per month required to run micro-CHP systems, the overall efficiency of micro-CHP systems, etc. A case study is used to demonstrate differences in the system performances of micro-CHP systems driven by a natural gas internal combustion engine and a diesel engine. Some of the results show that both systems have similar performance and that system total efficiencies in cooler months of up to 80% could be obtained. Also, modeling results show that there is a limit in fuel price that economically prevents the use of CHP systems, which is $11 MBTU-1 for this specific case. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper describes the growth conditions and the structural characterization of thin films PbTiO3 elaborated by a mixed reactive thermal co-evaporation. In a same chamber, in oxygen atmosphere, the titanium source is deposited by electron beam evaporation of TiO2 and the lead source is brought by thermal evaporation of PbO. Crystallographic properties are presented using X-ray diffractometry, morphological and optical characterization aspects are shown by means of electronic, atomic force microscopes (MEB and AFM) and Raman spectroscopy. The effect of post-annealing on morphology is presented. [ABSTRACT FROM AUTHOR]