Fabrication and characterization of poly(methyl methacrylate)/CaCu3Ti4O12 composites

Composites comprising Poly(Methyl Methacrylate) (PMMA) and CaCu₃Ti₄O₁₂ (CCTO) via melt mixing followed by hot pressing were fabricated. These were characterized using X‐ray diffraction, thermo gravimetric, scanning electron microscopy, and Impedance analyzer for their structural, morphology, and dielectric properties. Composites were found to have better thermal stability than that of pure PMMA. The composite, with 38 Vol % of CCTO (in PMMA), exhibited remarkably low dielectric loss at high frequencies and the low frequency relaxation is attributed to the space charge polarization/MWS effect. Theoretical models were employed to rationalize the dielectric behavior of these composites. At higher temperatures, the relaxation peak shifts to higher frequencies, due to the merging of both β and α relaxations into a single dielectric dispersion peak. The AC conductivity in the high frequency region was attributed to the electronic polarization. POLYM. ENG. SCI., 54:551–558, 2014. © 2013 Society of Plastics Engineers     

Carbon nanotubes/amorphous carbon composites as high-power negative electrodes in lithium ion capacitors

A nitrogen-rich carbon nanotubes/amorphous carbon (CNT/C) composite was prepared by carbonising a CNT/polyaniline (PANI) composite, and characterised. Scanning electron microscopy and X-ray photoelectron spectroscopy confirmed that the composite retained a mesoporous CNT structure as its backbone, whilst the nitrogen-rich PANI-derived carbon formed a thin amorphous coating on the CNT surface. Electrochemical characterisation of the CNT/C composite indicated that it had nearly double the reversible Li⁺ intercalation capacity (390 vs. 219 mAh g^?1) and 39 % less irreversible capacity (622 vs. 1,015 mAh g^?1) than the pristine CNT. The CNT/C composite showed exceptionally high rate capability with a de-intercalation capacity of 81 mAh g^?1 at a very high charge/discharge rate of 60 C (time taken for charge or discharge is 1 min) (1 C = 1 h charge or discharge), whereas the pristine CNT delivered 53 mAh g^?1 at this C-rate. By comparison, the rate capabilities of conventional graphite (N3 and SLP30) were very poor above 5 C (~17 mAh g^?1 at 5 C). Both the pristine CNT and CNT/C composite showed an excellent cyclability at 1 C charge/discharge over 600 cycles. The CNT/C composite maintained a fairly stable capacity of ~200 mAh g^?1 after 600 cycles, whilst the commercial graphite showed a steady and significant decrease in de-intercalation capacity; reaching <70 mAh g^?1 after 600 cycles.     

Mitigation of Soot Deposition in Exhaust Gas Recirculation Coolers Using a Spiral Insert

In diesel engines, the emission of nitrogen oxides can profoundly be controlled by using exhaust gas recirculation (EGR) coolers. Nevertheless, the deposition of unwanted materials, in form of primarily particulate matter and hydrocarbons, causes a major hurdle to the durability of such devices. In this study, a novel technique, i.e., a spiral insert, has been developed to mitigate particulate fouling in tubular EGR coolers. It is made of a helical rotating blade which is inserted inside the tubes of EGR coolers, and it rotates around its axis under the force of entering gas flow. As the blade rotates, it wipes out the deposit. An EGR experimental setup has also been used to examine how effective the spiral insert is in suppressing particulate fouling for two different gas velocities with and without using the insert. With no insert, the deposition was severe, fast, and continuous. For the latter, though, it was first very slow, and second, the fouling resistance was four times lower to that of no insert. No sign of any deposit was also observed on the insert after fouling runs. Despite the promising results, the insert requires further development so it can rotate at the low gas velocities.

Copyright 2014 American Association for Aerosol Research     

Hydrogenated silicon oxycarbonitride films. Part II. Physicochemical and functional properties

The optical, and electrophysical characteristics of hydrogenated silicon oxycarbonitride films synthesized by the plasma enhanced chemical vapor decomposition of the mixtures of 1,1,1,3,3,3-hexamethyldisilazane with oxygen and nitrogen in the temperature range of 373–973 K have been studied. It has been shown that the obtained films are highly transparent (transmittance is ～92–99%) in the UV, visible, and IR ranges of the spectrum; they have refractive indices in the range of 1.43–2.25, a low reflection coefficient of visible light (nearly 3%), and low dielectric permittivity.     

Microenvironment of Tumor-Draining Lymph Nodes: Opportunities for Liposome-Based Targeted Therapy

The World Health Organization (WHO) recently reported that the total number of global cancer cases in 2013 reached 14 million, a 10% rise since 2008, while the total number of cancer deaths reached 8.2 million, a 5.2% increase since 2008. Metastasis is the major cause of death from cancer, accounting for 90% of all cancer related deaths. Tumor-draining lymph nodes (TDLN), the sentinel nodes, are the first organs of metastasis in several types of cancers. The extent of metastasis in the TDLN is often used in disease staging and prognosis evaluation in cancer patients. Here, we describe the microenvironment of the TDLN and review the recent literature on liposome-based therapies directed to immune cells within the TDLN with the intent to target cancer cells.     

Today's Public Outreach for New Projects Must Be Well-Planned,Stay Current

In the not-too-distant past, the standard outreach plan for many entities consisted of little more than advertisements in print media, donations to nonprofits or public fundraisers, a phone number for “customer service” questions, and maybe a monthly newsletter in a customer's energy statement. For projects where outreach was coupled with an “ask” from stakeholders, there would be public meetings, face-to-face before regulatory filings, and interviews with local (or national) media if the need arose. It took a lot of work to get a company message out and many messengers to handle stakeholder communications. Although there has always been opposition to companies and projects, other than a neighborhood phone tree or public meeting, cohesion was a rarity. For some companies, that may seem like nirvana, but that isn't positive or realistic.     

Active Monitoring of Thermal Insulation Protection Status of Pipelines

Refractories and Industrial Ceramics - The article discusses the temperature regimes of transit pipelines for steam and hot water movement. A new device for thermal insulation of high-temperature...     

Phase Behavior of Selected Condensed Double-Decker Shaped Silsesquioxane Compounds

Silicon - Bisfunctional dichlorosilanes were reacted with tetrasilanol of double-decker shaped octaphenylsilsesquioxane (DDSQ) to form fully condensed DDSQ compounds. The crystallographic and...     

Experimental investigation of lift enhancement by suction-assisted delayed separation of the boundary layer on NACA 0012 airfoil

In the aerodynamic industry, one of the major problems of interest is the lift enhancement without any increase in the drag. In this paper, an attempt is made to increase the lift coefficient by delayed boundary layer separation using suction at various points, also the study is carried out to identify the optimum location for suction which provides maximum lift augmentation. The experiment is conducted with selected suction pressures of 60, 70, 80, 90?kN/m² at different locations in the range of 40–75% of the chord length of the airfoil. Among the selected pressures, the lowest one at the 70% length provides maximum performance. The critical Reynolds number occurs at around 95% of the length instead of 45% of the length when the same experiment is conducted without suction. The suction also assists in the heat transfer enhancement over the airfoil surface.