Read by QxMD icon Read

Bulk heating

Lijun Wang, Siyi Chang, Shuqi Zheng, Teng Fang, Wenlin Cui, Pengpeng Bai, Luo Yue, Zhigang Chen
Extensive attention has been focused on thermoelectric performance optimization of SnTe because of its potential in waste heat recovery. Here, we fabricate high thermoelectric performance Se/Cd co-doped SnTe octahedral particles by microwave-stimulated solvothermal method. The SnTe-based octahedral particles have the sizes ranging from several micrometers to hundreds of nanometers, forming dense bulks after spark plasma sintering. Combined with the strong point defect scattering by Se and Cd dopants, a low thermal conductivity of 1...
June 22, 2017: ACS Applied Materials & Interfaces
Samira Shiri, James C Bird
The ability to enhance or limit heat transfer between a surface and impacting drops is important in applications ranging from industrial spray cooling to the thermal regulation of animals in cold rain. When these surfaces are micro/nanotextured and hydrophobic, or superhydrophobic, an impacting drop can spread and recoil over trapped air pockets so quickly that it can completely bounce off the surface. It is expected that this short contact time limits heat transfer; however, the amount of heat exchanged and precise role of various parameters, such as the drop size, are unknown...
June 19, 2017: Proceedings of the National Academy of Sciences of the United States of America
Ulrike Stockert, Ricardo Donizeth Dos Reis, M O Ajeesh, Sarah J Watzman, Marcus Schmidt, Chandra Shekhar, Joseph P Heremans, Claudia Felser, Michael Baenitz, Michael Nicklas
The Weyl semimetal NbP exhibits an extremely large magnetoresistance (MR) and an ultra-high mobility. The large MR originates from a combination of the nearly perfect compensation between electron- and hole-type charge carriers and the high mobility, which is relevant to the topological band structure. In this work we report on temperature- and field-dependent thermopower and thermal conductivity experiments on NbP. Additionally, we carried out complementary heat capacity, magnetization, and electrical resistivity measurements...
June 19, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Margarita Albertí, Anna Amat, Antonio Aguilar, Fernando Pirani
The present paper focuses on the characterization of the properties of methanol and water molecules in gas and liquid environments. A force field for methanol-methanol and methanol-water interactions, useful to be applied in Molecular Dynamics (MD) simulations, is proposed. The electrostatic interaction contributions, arising from permanent charge and/or from anisotropic charge distributions originating from permanent electric multipoles (Vel), different in gas and in liquid phases, are combined with the non electrostatic ones (Vnel), defined by means of Improved Lennard-Jones (ILJ) functions [F...
June 19, 2017: Physical Chemistry Chemical Physics: PCCP
Cheng-Hua Lee, Dmitriy V Soldatov, Chung-Hao Tzeng, Long-Li Lai, Kuang-Lieh Lu
Three dendrimers, (t-Bu-G 2 N) 2 , CC(t-Bu-G 1 N) 3 and (t-Bu-G 1 N) 2 , with 3,5-di-tert-butyl amidobenzene as a common peripheral moiety were prepared in 64-83% yields and characterized. The bulk solids had high BET surface areas of 136-138 m(2)/g, which were similar for the three dendrimers in spite of their different molecular weight (ranging from 1791 to 2890). It was concluded that the peripheral amide groups do not imbed in the interstitial space of neighbouring dendrimer molecules but rather build a supramolecular architecture through strong intermolecular H-bonds...
June 16, 2017: Scientific Reports
Xintian Wu
The two-dimensional Ising model with a slit is studied. The slit free energy is defined, in which the bulk term, edge terms, and corner terms other than that of the slit are canceled. The bond propagation algorithm is used to calculate the free energy, internal energy, and heat capacity numerically. At the critical point, the slit free energy has a logarithmic correction L^{-1}lnL, in addition to the correction lnL, where L is the typical length of the system. The fitted coefficients of these terms agree with the conformal field theory very well...
May 2017: Physical Review. E
T Sergan, I Dozov, V Sergan, R Voss
We measured the Rapini-Papoular polar anchoring strength coefficient W for 4^{'}-pentyl-4-cyanobiphenyl (5CB) on alignment layers formed by the reactive mesogen photopolymers RM 257, RM 82, and RM 84 [4,4^{'}-bis(acryloyl)biphenyl] (by Merck). These materials are commonly used for the photostabilization of the liquid crystal (LC) director in the bulk as well as at the surface of the LC layer via the formation of a loose polymer network that captures the director orientation. We developed a method of fabrication of alignment layers from these polymers, and estimated W from the measurements of the optical retardation as a function of applied voltage in uniformly aligned cells...
May 2017: Physical Review. E
Zhejun Liu, Haomin Song, Dengxin Ji, Chenyu Li, Alec Cheney, Youhai Liu, Nan Zhang, Xie Zeng, Borui Chen, Jun Gao, Yuesheng Li, Xiang Liu, Diana Aga, Suhua Jiang, Zongfu Yu, Qiaoqiang Gan
Passive solar vapor generation represents a promising and environmentally benign method of water purification/desalination. However, conventional solar steam generation techniques usually rely on costly and cumbersome optical concentration systems and have relatively low efficiency due to bulk heating of the entire liquid volume. Here, an efficient strategy using extremely low-cost materials, i.e., carbon black (powder), hydrophilic porous paper, and expanded polystyrene foam is reported. Due to the excellent thermal insulation between the surface liquid and the bulk volume of the water and the suppressed radiative and convective losses from the absorber surface to the adjacent heated vapor, a record thermal efficiency of ≈88% is obtained under 1 sun without concentration, corresponding to the evaporation rate of 1...
February 27, 2017: Global Chall
Elif Eren Gültekin
The scope of the present study is to investigate the change of elastic modulus with the physical and mechanical properties of porcelain tiles. In the study, porcelain tiles were sintered at different temperatures and at different heating rates to obtain minimum water absorption (%). After this, the time of flight of longitudinal and shear ultrasonic waves was measured through the tile. The time of flight of ultrasonic waves was measured using contact ultrasonic transducers operating on a pulse-echo mode. Using the time of flight of the ultrasonic waves and the thickness of the tiles, the velocity of the waves was determined...
June 3, 2017: Ultrasonics
T Schablitzki, J Rogal, R Drautz
Atomistic simulations of thermal desorption spectra for effusion from bulk materials to characterize binding or trapping sites are a challenging task as large system sizes as well as extended time scales are required. Here, we introduce an approach where we combine kinetic Monte Carlo with an analytic approximation of the superbasins within the framework of absorbing Markov chains. We apply our approach to the effusion of hydrogen from BCC iron, where the diffusion within bulk grains is coarse grained using absorbing Markov chains, which provide an exact solution of the dynamics within a superbasin...
July 28, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
N P Brandon, Z Kurban
In recent years, new-found interest in the hydrogen economy from both industry and academia has helped to shed light on its potential. Hydrogen can enable an energy revolution by providing much needed flexibility in renewable energy systems. As a clean energy carrier, hydrogen offers a range of benefits for simultaneously decarbonizing the transport, residential, commercial and industrial sectors. Hydrogen is shown here to have synergies with other low-carbon alternatives, and can enable a more cost-effective transition to de-carbonized and cleaner energy systems...
July 28, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
Nicholas Allen, Michael L Machesky, David J Wesolowski, Nadine Kabengi
Cations in natural solutions significantly impact interfacial processes, particularly dissolution and surface charge measurements for quartz and silica, which are amongst the most naturally abundant and technologically important solids. Thermodynamic parameters for cation-specific interfacial reactions have heretofore been mostly derived instead of directly measured experimentally. This work investigates the energetics of adsorption and exchange reactions of alkali metal (M(+)) and alkaline earth (M(2+)) cations with the quartz surface by flow adsorption microcalorimetry, in tandem with in-situ pH measurements...
June 9, 2017: Journal of Colloid and Interface Science
Anuradha R Pallipurath, Francesco Civati, Juraj Sibik, Clare Crowley, J Axel Zeitler, Patrick McArdle, Andrea Erxleben
Understanding phase transitions in pharmaceutical materials is of vital importance for drug manufacturing, processing and storage. In this paper we have carried out comprehensive high-resolution spectroscopic studies on the polymorphs of the non-steroidal anti-inflammatory drug diflunisal that has four known polymorphs, forms I-IV (FI-FIV), three of which have known crystal structures. Phase transformations during milling, heating, melt-quenching and exposure to high relative humidity were investigated using Raman and terahertz spectroscopy in combination with differential scanning calorimetry and X-ray powder diffraction...
June 8, 2017: International Journal of Pharmaceutics
Ibrahim Zarkesh, Mohammad Hossein Ghanian, Mahmoud Azami, Fatemeh Bagheri, Hossein Baharvand, Javad Mohammadi, Mohamadreza Baghaban Eslaminejad
Biphasic calcium phosphate (BCP) microspheres are of great interest due to their high stability and osteoinductive properties at specific compositions. However, the need for optimal performance at a unique composition limits their flexibility for tuning drug release by modulation of bulk properties and presents the question of engineering surface topography as an alternative. It is necessary to have a facile method to control surface topography at a defined bulk composition. Here, we have produced BCP microspheres with different surface topographies that have the capability to be used as tunable drug release systems...
May 31, 2017: Colloids and Surfaces. B, Biointerfaces
Yoon-Jun Kim, Li-Dong Zhao, Mercouri G Kanatzidis, David N Seidman
The dimensionless figure of merit, ZT, of bulk thermoelectric materials depends mainly on the transport properties of charge carriers and heat carrying phonons. PbTe-4 mol.% SrTe doped with 2 mol.% Na (Pb0.94Na0.02Sr0.04Te) is a nanostructured material system, which exhibits a ZT higher than 2. A precipitate size distribution (PSD) of SrTe precipitates is believed to play a key role. This raises the question of whether its performance is limited by precipitate coarsening (Ostwald ripening) at elevated temperatures...
June 7, 2017: ACS Applied Materials & Interfaces
Seo Yeong Gim, Seungmi Hong, Mi-Ja Kim, JaeHwan Lee
Gallic acid (GA) was grafted in chitosan and the effects of GA grafted chitosan (GA-g-CS) on the oxidative stability in bulk oil was tested at 60 and 140 °C. To text oxidative stability in oils, headspace oxygen content, conjugated dienoic acid (CDA) value, p-anisidine value (p-AV), and acid value were determined. Chitosan itself did not show antioxidative or prooxidative effects in oils at 60 °C. However, GA-g-CS and GA acted as antioxidants at 60 °C. At 140 °C heating with moisture supplied condition, different results were observed...
June 6, 2017: Journal of Food Science
Jason D Forster, Jared J Lynch, Nelson E Coates, Jun Liu, Hyejin Jang, Edmond Zaia, Madeleine P Gordon, Maxime Szybowski, Ayaskanta Sahu, David G Cahill, Jeffrey J Urban
Thermoelectric power generation can play a key role in a sustainable energy future by converting waste heat from power plants and other industrial processes into usable electrical power. Current thermoelectric devices, however, require energy intensive manufacturing processes such as alloying and spark plasma sintering. Here, we describe the fabrication of a p-type thermoelectric material, copper selenide (Cu2Se), utilizing solution-processing and thermal annealing to produce a thin film that achieves a figure of merit, ZT, which is as high as its traditionally processed counterpart, a value of 0...
June 5, 2017: Scientific Reports
Craig V Vinall, Tales C Garcia-Silva, Jennifer S B Lou, Martha H Wells, Daranee Tantbirojn, Antheunis Versluis
PURPOSE: To investigate intrapulpal temperature rise in a primary molar during light activation of a composite restoration to determine if clinically significant pulpal temperatures (greater than 5.5 degrees Celsius) were reached. METHODS: Restorative composites (EsthetX HD, Filtek Supreme Ultra, Filtek Bulk Fill) were placed into a primary molar with occlusal preparation (1.5 mm depth; remaining pulpal floor thickness one mm). The pulp was extirpated through a root access to place a thermocouple against the pulpal roof...
May 15, 2017: Pediatric Dentistry
Yu-Dong Fu, Baochang Wang, Yue Teng, Xiao-Shuo Zhu, Xiao-Xue Feng, Mu-Fu Yan, Pavel Korzhavyi, Weiwei Sun
Niobium based Nb4AlC3, Nb4SiC3, Nb4GeC3 and Nb4GaC3 were investigated by means of density functional theory. Together with the known Nb4AlC3, the role of group III, IV elements in various properties of Nb4AC3 (A = Al, Si, Ga, Ge) was systematically investigated, and particularly the bulk moduli, shear moduli, and Young's moduli helped us to approach the ductility. All the studied compounds were found to be mechanically stable, and they also exhibit the metallic nature that results from the Nb-4d states being dominant at the Fermi level...
June 14, 2017: Physical Chemistry Chemical Physics: PCCP
Olexandr Isayev, Corey Oses, Cormac Toher, Eric Gossett, Stefano Curtarolo, Alexander Tropsha
Although historically materials discovery has been driven by a laborious trial-and-error process, knowledge-driven materials design can now be enabled by the rational combination of Machine Learning methods and materials databases. Here, data from the AFLOW repository for ab initio calculations is combined with Quantitative Materials Structure-Property Relationship models to predict important properties: metal/insulator classification, band gap energy, bulk/shear moduli, Debye temperature and heat capacities...
June 5, 2017: Nature Communications
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"