Read by QxMD icon Read

Bulk heating

Xing Huang, Shuai Zhang, Liyao Liu, Lei Yu, Genfu Chen, Wei Xu, Daoben Zhu
Highly crystalline material of Copper (II) benzenehexathiolate coordination polymer (Cu-BHT) has been prepared. Its two dimensional kagomè structure has been confirmed by powder x-ray diffraction (PXRD), high-resolution transmission electron microscope (HRTEM) and high-resolution scanning transmission electron microscope (STEM). The as-prepared sample exhibits bulk superconductivity at ~ 0.25 K which is confirmed by the zero resistivity, AC magnetic susceptibility and specific heat measurements. Another diamagnetic transition at ~ 3K suggests that there is a second superconducting phase which may be associated to the single layer or few-layer of Cu-BHT...
November 21, 2017: Angewandte Chemie
C Riekel, M Burghammer, I Snigirev, M Rosenthal
We determined stress-induced deformations and the thermal stability of nanorod-shaped tobacco mosaic virus (TMV) capsids in coffee-ring structures by X-ray nanodiffraction. The hexagonal capsids lattice transforms under compression in the outer boundary zone of the coffee-ring into a tetragonal lattice. The helical pitch of the nanorods increases by about 2.5% across the outer boundary zone while the lateral distance between nanorods decreases continuously across the whole coffee-ring structure by about 2% due to compressive forces...
November 15, 2017: Soft Matter
Anan Yaghmur, Sabah Al-Hosayni, Heinz Amenitsch, Stefan Salentinig
Recent studies demonstrated the potential therapeutic use of newly synthesized omega-3 (ω-3) polyunsaturated fatty acid (PUFA) monoglycerides owing to their beneficial health effects in various disorders including cancer and inflammation diseases. To date, the research was mainly focused on exploring the biological effects of these functional lipids. However, to the best of our knowledge, there is no report on the hydration-mediated self assembly of these lipids that leads to the formation of nanostructures, which are attractive for use as vehicles for the delivery of drugs and functional foods...
November 14, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Sidra Waheed, Joan M Cabot, Niall P Macdonald, Umme Kalsoom, Syamak Farajikhah, Peter C Innis, Pavel N Nesterenko, Trevor W Lewis, Michael C Breadmore, Brett Paull
Synthetic micro-diamond-polydimethylsiloxane (PDMS) composite microfluidic chips and thin films were produced using indirect 3D printing and spin coating fabrication techniques. Microfluidic chips containing up to 60 wt% micro-diamond were successfully cast and bonded. Physicochemical properties, including the dispersion pattern, hydrophobicity, chemical structure, elasticity and thermal characteristics of both chip and films were investigated. Scanning electron microscopy indicated that the micro-diamond particles were embedded and interconnected within the bulk material of the cast microfluidic chip, whereas in the case of thin films their increased presence at the polymer surface resulted in a reduced hydrophobicity of the composite...
November 8, 2017: Scientific Reports
Kai Sotthewes, Pantelis Bampoulis, Harold J W Zandvliet, Detlef Lohse, Bene Poelsema
The classic regelation experiment of Thomson in the 1850s deals with cutting an ice cube, followed by refreezing. The cutting was attributed to pressure-induced melting but has been challenged continuously, and only lately consensus emerged by understanding that compression shortens the O:H nonbond and lengthens the H-O bond simultaneously. This H-O elongation leads to energy loss and lowers the melting point. The hot debate survived well over 150 years, mainly due to a poorly defined heat exchange with the environment in the experiment...
November 10, 2017: ACS Nano
Xiaojue Zhu, Richard J A M Stevens, Roberto Verzicco, Detlef Lohse
In thermal convection, roughness is often used as a means to enhance heat transport, expressed in Nusselt number. Yet there is no consensus on whether the Nusselt vs Rayleigh number scaling exponent (Nu∼Ra^{β}) increases or remains unchanged. Here we numerically investigate turbulent Rayleigh-Bénard convection over rough plates in two dimensions, up to Ra≈10^{12}. Varying the height and wavelength of the roughness elements with over 200 combinations, we reveal the existence of two universal regimes. In the first regime, the local effective scaling exponent can reach up to 1/2...
October 13, 2017: Physical Review Letters
Usmangani K Chhalotiya, Dharmendra J Prajapati, Minesh D Prajapati, Jalpa U Patel, Jaineel Desai
Objective A impressionable, discriminatory and precise stability indicating high performance thin layer chromatographic method has been developed and validated for the estimation of of Enzalutamide in bulk and synthetic mixture. Method The method engaged HPTLC aluminium plates pre-coated with silica gel 60F-254 as the stationary phase while the solvent system was ethyl acetate: toluene (4.5:5.5, v/v). The Rf value of enzalutamide was detected to be 0. 39 ± 0. 005 and the densitometric analysis were carried out in absorbance mode at 246 nm...
October 27, 2017: Current Drug Discovery Technologies
Vikas S Padalkar, Yusuke Tsutsui, Tsuneaki Sakurai, Daisuke Sakamaki, Norimitsu Tohnai, Kenichi Kato, Masaki Takata, Tomoyuki Akutagawa, Ken-Ichi Sakai, Shu Seki
In bulk materials, positional isomers not only help in understanding how slight difference in molecular structure alters the crystal packing and optical properties, but also play a key role in developing new type of materials for functional applications. A detailed study on the photophysical properties of fluorene-HBT positional isomers in solution and in the solid state providing a molecular level understanding of the factors which influence fluorescence behavior is reported. Two molecules Ia and IIa were synthesized by Suzuki coupling reaction and their photophysical properties were compared to positional isomers Ib and IIb...
November 8, 2017: Journal of Physical Chemistry. B
Vikram Reddy Ardham, Frédéric Leroy
Coarse-grained models have increasingly been used in large-scale particle-based simulations. However, due to their lack of degrees of freedom, it is a priori unlikely that they straightforwardly represent thermal properties with the same accuracy as their atomistic counterparts. We take a first step in addressing the impact of liquid coarse-graining on interfacial heat conduction by showing that an atomistic and a coarse-grained model of water may yield similar values of the Kapitza conductance on few-layer graphene with interactions ranging from hydrophobic to mildly hydrophilic...
October 21, 2017: Journal of Chemical Physics
William E Vargas
Three parametric models of Drude-Lorentz (DL) are used to describe the spectral variation of the dielectric function of bulk palladium. An improved version of the acceptance-probability-controlled simulated annealing method is applied to optimize the values of the parameters involved in the models: high-frequency dielectric constant, free-electron collision frequency and corresponding relaxation time, oscillation strengths, nominal resonance frequencies, and Lorentzian widths. Normalization of the oscillation strengths allows the introduction of a new parameter in the context of the original DL model: the number density ratio, which is the ratio between the number density of conduction electrons and the number density of metal atoms...
August 10, 2017: Applied Optics
Peng Zhang, Maohua Jiang, Renjiang Zhue, Dingke Zhang, Yanrong Song
GaAs/AlAs distributed Bragg reflectors (DBRs) are widely used in the gain chips of 1 μm wave band semiconductor disk lasers (SDLs) as an end/folded cavity mirror. Because the generated redundant heat in the active region of a gain chip mainly dissipates through the DBR, thermal conductivities of DBRs are crucial for the output performance of SDLs. For the purpose of more reasonable semiconductor wafer design, to improve the thermal management of SDLs, accurate thermal conductivities of DBRs with various layer thicknesses are under considerable requirement...
May 20, 2017: Applied Optics
Qingyu Lin, Zhimei Wei, Hongli Guo, Shuai Wang, Guangmeng Guo, Zhi Zhang, Yixiang Duan
A highly concentrated, ring-shaped phase conversion (RSPC) method was developed for liquid sample analysis using the laser-induced breakdown spectroscopy (LIBS) technique. In this work, test samples were prepared by mixing the metal particles with polyvinyl alcohol (PVA) supporter in liquid phase. With heat, the PVA solution solidified inside a modified glass petri dish, forming a metal-enriched polymer ring film. Distinguished from other traditional liquid-to-solid conversing methods, the proposed new method takes advantage of enhanced homogeneity for the target elements inside the ring film...
June 10, 2017: Applied Optics
Chinmay Khandekar, Alejandro W Rodriguez
We present an approach for achieving large Kerr χ((3))-mediated thermal energy transfer at the nanoscale that exploits a general coupled-mode description of triply resonant, four-wave mixing processes. We analyze the efficiency of thermal upconversion and energy transfer from mid- to near-infrared wavelengths in planar geometries involving two slabs supporting far-apart surface plasmon polaritons and separated by a nonlinear χ((3)) medium that is irradiated by externally incident light. We study multiple geometric and material configurations and different classes of intervening mediums-either bulk or nanostructured lattices of nanoparticles embedded in nonlinear materials-designed to resonantly enhance the interaction of the incident light with thermal slab resonances...
September 18, 2017: Optics Express
Jae-Hyuck Yoo, Manyalibo Matthews, Phil Ramsey, Antonio Correa Barrios, Austin Carter, Andrew Lange, Jeff Bude, Selim Elhadj
We present two strategies to minimize laser damage in transparent conductive films. The first consists of improving heat dissipation by selection of substrates with high thermal diffusivity or by addition of capping layer heatsinks. The second is reduction of bulk energy absorption by lowering free carrier density and increasing mobility, while maintaining film conductance with thicker films. Multi-pulse laser damage tests were performed on tin-doped indium oxide (ITO) films configured to improve optical lifetime damage performance...
October 16, 2017: Optics Express
Rachael Muschalek, Landon Nash, Ryan Jones, Sayyeda M Hasan, Brandis K Keller, Mary Beth B Monroe, Duncan J Maitland
Polyurethane shape memory polymer (SMP) foams have been developed for various embolic medical devices due to their unique properties in minimally invasive biomedical applications. These polyurethane materials can be stored in a secondary shape, from which they can recover their primary shape after exposure to an external stimulus, such as heat and water exposure. Tailored actuation temperatures of SMPs provide benefits for minimally invasive biomedical applications, but incur significant challenges for SMP-based medical device sterilization...
September 2017: Journal of Medical Devices
Li Tang, Arpita Iddya, Xiaobo Zhu, Alexander V Dudchenko, Wenyan Duan, Craig Turchi, Johann Vanneste, Tzahi Y Cath, David Jassby
The desalination of inland brackish groundwater offers the opportunity to provide potable drinking water to residents and industrial cooling water to industries located in arid regions. Geothermal brines are used to generate electricity, but often contain high concentrations of dissolved salt. Here, we demonstrate how the residual heat left in spent geothermal brines can be used to drive a membrane distillation (MD) process and recover desalinated water. Porous polypropylene membranes were coated with a carbon nanotube (CNT)/poly(vinyl alcohol) layer, resulting in composite membranes having a binary structure that combines the hydrophobic properties critical for MD with the hydrophilic and conductive properties of the CNTs...
November 8, 2017: ACS Applied Materials & Interfaces
Anna-Karin Hellström, Hans Oskarsson, Romain Bordes
Carbon dioxide is commonly used as pH regulator in switchable surfactant systems and in the formation of alkyl ammonium-alkyl carbamate ion-pair. Its use to form a meta-stable anionic surfactant has been less explored and can impart a cleavable character to the amphiphile. The reaction between CO2 and an alkylamine, N,N-di(propylamino)dodecylamine (Y12-amine), under alkaline pH conditions, produced a stable anionic carbamate-based surfactant (Y12-carbamate). By heating and exposure to N2, anionic Y12-carbamate could slowly be reverted into Y12-amine...
September 28, 2017: Journal of Colloid and Interface Science
Francesco Testa, Giuseppe Marano, Federico Ambrogi, Patrizia Boracchi, Antonio Casula, Elia Biganzoli, Paolo Moroni
Elevated bulk tank milk somatic cell count (BMSCC) has a negative impact on milk production, milk quality, and animal health. Seasonal increases in herd level somatic cell count (SCC) are commonly associated with elevated environmental temperature and humidity. The Temperature Humidity Index (THI) has been developed to measure general environmental stress in dairy cattle; however, additional work is needed to determine a specific effect of the heat stress index on herd-level SCC. Generalized Additive Model methods were used for a flexible exploration of the relationships between daily temperature, relative humidity, and bulk milk somatic cell count...
September 28, 2017: Research in Veterinary Science
Hirohito Yamazaki, Rui Hu, Robert Y Henley, Justin Halman, Kirill A Afonin, Dapeng Yu, Qing Zhao, Meni Wanunu
When light is used to excite electronic transitions in a material, nonradiative energy during relaxation is often released in the form of heat. In this work, we show that photoexcitation of a silicon nitride nanopore using a focused visible laser results in efficient localized photothermal heating, which reduces the nearby electrolyte viscosity and increases the ionic conductance. In addition, a strong localized thermal gradient in the pore vicinity is produced, evidenced by finite-element simulations and experimental observation of both ion and DNA thermophoresis...
October 10, 2017: Nano Letters
Kunpeng Zhao, Haozhi Duan, Nunna Raghavendra, Pengfei Qiu, Yi Zeng, Wenqing Zhang, Jihui Yang, Xun Shi, Lidong Chen
High-performance thermoelectric materials require ultralow lattice thermal conductivity typically through either shortening the phonon mean free path or reducing the specific heat. Beyond these two approaches, a new unique, simple, yet ultrafast solid-state explosive reaction is proposed to fabricate nanoporous bulk thermoelectric materials with well-controlled pore sizes and distributions to suppress thermal conductivity. By investigating a wide variety of functional materials, general criteria for solid-state explosive reactions are built upon both thermodynamics and kinetics, and then successfully used to tailor material's microstructures and porosity...
September 29, 2017: Advanced Materials
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"