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Thermoelectric (TE) material is a class of materials that can convert heat to electrical energy directly in a solid-state-device without any moving parts and that is environmentally friendly. The study and development of TE materials have grown quickly in the past decade. However, their development goes slowly by the lack of cheap TE materials with high Seebeck coefficient and good electrical conductivity. Carbon nanotubes (CNTs) are particularly attractive as TE materials because of at least three reasons: (1) CNTs possess various band gaps depending on their structure, (2) CNTs represent unique one-dimensional carbon materials which naturally satisfies the conditions of quantum confinement effect to enhance the TE efficiency and (3) CNTs provide us with a platform for developing lightweight and flexible TE devices due to their mechanical properties. The TE power factor is reported to reach 700–1000 μ W / m K 2 for both p-type and n-type CNTs when purified to contain only doped semiconducting CNT species. Therefore, CNTs are promising for a variety of TE applications in which the heat source is unlimited, such as waste heat or solar heat although their figure of merit Z T is still modest (0.05 at 300 K). In this paper, we review in detail from the basic concept of TE field to the fundamental TE properties of CNTs, as well as their applications. Furthermore, the strategies are discussed to improve the TE properties of CNTs. Finally, we give our perspectives on the tremendous potential of CNTs-based TE materials and composites.

The combined effect of free and forced convections on mass transfer between two liquids was studied experimentally and theoretically. In the experiments, steady-state dissolution rates into flowing water of an aniline or furfural drop which was sandwiched between a capillary and a rod and had a nearly cylindrical surface were measured, and the continuousphase mass transfer coefficients were obtained. During an experimental run, the amount of the drop phase dissolved into water was supplied continuously through the capillary and the drop volume was kept constant. It was observed that the Sh values depend on the flow direction of water in the range of 5 < Re < 100 and that in the case of upward flow, Sh takes the minimum at some Re number. Numerical simulations of the phenomena were tried, using the finite element method, and the experimental results are explained qualitatively.

Effectively reducing climate change requires marked, global behavior change. However, it is unclear which strategies are most likely to motivate people to change their climate beliefs and behaviors. Here, we tested 11 expert-crowdsourced interventions on four climate mitigation outcomes: beliefs, policy support, information sharing intention, and an effortful tree-planting behavioral task. Across 59,440 participants from 63 countries, the interventions’ effectiveness was small, largely limited to nonclimate skeptics, and differed across outcomes: Beliefs were strengthened mostly by decreasing psychological distance (by 2.3%), policy support by writing a letter to a future-generation member (2.6%), information sharing by negative emotion induction (12.1%), and no intervention increased the more effortful behavior—several interventions even reduced tree planting. Last, the effects of each intervention differed depending on people’s initial climate beliefs. These findings suggest that the impact of behavioral climate interventions varies across audiences and target behaviors.

This data set contains the 100-member ensembles of monthly gross primary production (GPP) estimated using the biosphere model BEAMS and d4PDF data for historical and non-warming climates in 1951-2010/2011, 100-member ensembles of yearly GPP of the historical sensitivity experiment for 7 input variables in 1951-2010, yearly GPP of the extended CO2 sensitivity experiment using four RCP scenarios in 1951-2300. Data is 0.5625-degree (640×320) 4-byte binary (.raw). Undefined value is -9999. For more details, please check the ReadmeGPP.pdf If you questions, please contact Irina Melnikova (irina.melnikova.russia@gmail.com)

Abstract Statistical flame front structure of turbulent premixed flames at high pressure up to 1.0 MPa was measured on a nozzle-type Bunsen burner with OH-PLIF technique. Turbulent burning velocity, flame surface density and flame brush thickness, as well as the local curvature and radius of curvature were derived from the experimental OH-PLIF images. Turbulence–flame interaction was analyzed based on the geometric parameters combined with laminar flame properties and turbulence length scales. Results show that the flame wrinkles at high pressure are dominated by small scale cusps superimposed with large scale flame branches which is a general characteristic of the turbulent premixed flames at high pressure. S T / S L increases remarkably with u ′/ S L and the influence of elevated pressure on S T / S L is significant. This is mainly due to the increase of flame front area caused by the turbulence wrinkling. Flame surface density significantly increases with the increase of pressure indicating that there is a large amount of fine cusps and small wrinkles in the flame front at high pressure. This would be due to the enhancement of the flame instability represented by effective Lewis number Le eff and flame intrinsic instability scale l i . With the increase of turbulence intensity, the Σ at high pressure increases while slightly decreases at normal pressure. The most frequent length scale of the flame front moves to smaller value and the possibility increases with the increase of u ′/ S L for all pressures. The effect of flame intrinsic instability on finer flame front at high pressure is mainly on the formation of a large number of convex structures which enlarge the effective contact surface between flame front and unburned reactants, resulting in the increase of S T / S L .

Abstract Numerical simulations of combined natural convection–conduction in a droplet of n-dodecane suspended from a thermocouple were carried out, taking into consideration evaporation, and the effect of thermocouple diameter on the evaporation characteristics was investigated. The calculated temperature history of the droplet is in good agreement with experimental results; both show that the rate of heating decreases with increasing thermocouple diameter. The maximum error in temperature due to the thermocouple increases linearly with increasing thermocouple diameter. Thus, in investigations involving a droplet suspended from a thermocouple, it is preferable to use a thermocouple with the smallest possible diameter.

The reactivities of 34 coal chars of varying rank with H2O have been determined to examine the effect of coal rank on the gasification rate of coal char. The reactivities of chars derived from caking coals and anthracites (carbon content > 78 wt%, daf) were very small compared with those from non-caking (lower-rank) coals. The reactivities of low-rank chars do not correlate with the carbon content of the parent coals. To clarify which factor is more important in determining the reactivity, the evolution of CO and CO2 from char, the moisture content of char and the amount of exchangeable cations were determined for these low-rank coals or their chars. These values were considered to represent the amount of active carbon sties, the porosity and the catalysis by inherent mineral matters, respectively. It was concluded that the amount of surface active sites and/or the amount of exchangeable Ca and Na control the reactivity of low-rank chars in H2O.