Collection of hydrophilic and hydrophobic charged submicron particles by charged water droplets

An experimental system capable of measuring the collection efficiency of charged submicron particles by charged water droplets is described. Collection efficiencies are measured for both hydrophilic and hydrophobic particles to clarify the effect of wettability on collection. Excellent agreement with the theory is obtained for hydrophilic submicron particles when the Coulombic force is dominant. No significant difference in collection efficiencies between hydrophilic and hydrophobic particles is observed. It is concluded that the wettability of submicron particles has no effect on its collection by water drops when Coulombic attraction is the dominant mechanism.     

Factors That Govern the Performance of Thermal Interface Materials

Finite element modeling is conducted to understand the factors that govern the performance of thermal interface pastes of controlled thickness between copper surfaces of controlled roughness. Carbon black paste is lower in thickness than metal particle paste, so it shows better performance. The performance of both pastes is more influenced by the paste-copper interfacial conductance than by the paste thermal conductivity. The effects of pressure, paste thickness, and copper surface roughness on performance are mainly due to the change in fractional filling of the valleys in the copper surface topography. Reasonable agreement is found between modeling and experimental results.     

Ethanol steam reforming over supported ruthenium and ruthenium–platinum catalysts: Comparison of organometallic clusters and inorganic salts as catalyst precursors

Alumina-supported Ru and Ru–Pt catalysts, derived from either organometallic clusters ([HRu₃(CO)₁₁]⁻, Ru₃(CO)₁₂ and [Ru₅PtC(CO)₁₅]²⁻) or inorganic salts, were investigated for their performance in the production of hydrogen via the steam reforming of ethanol. The cluster-derived catalysts were found to be more active and selective than a commercial catalyst as well as their salt-derived counterparts. Although all three cluster-derived catalysts exhibit similar activity and selectivity, it appears that the presence of Pt might help to promote water gas shift reaction at low temperatures, while ethanol C–C bond cleavage also appears to be facilitated over the bimetallic cluster-derived catalyst. With the use of cluster precursors, excellent control of bimetallic composition and smaller particle sizes were achieved. This approach is demonstrated to be useful in the design of efficient ethanol steam reforming catalysts.     

Analysis of ground source heat pumps with horizontal ground heat exchangers for northern Japan

Computer simulation and analysis of a ground source heat pump system with horizontal ground heat exchangers operating in heating (max 5.5 kW) and cooling (max 3.3 kW) mode was carried out for a typical residential house, with 200 m² of living space, located in Sapporo (Japan). In spite of high electricity rate, the ground source heat pump system is more beneficial alternative for space heating than an oil furnace and an electric resistance system. Besides, the heat pump technology offers relatively low thermal degradation of the ground environment, lower cost of heating and cooling, higher operating efficiency than electric resistance heating or air-source heat pump and is environmentally clean, i.e. without greenhouse gas emission, if the electricity is generated from renewable energy resources, such as wind and solar. The use of the cooling mode can provide further benefits like a shorter investment payback and human thermal comfort in summer. As a result, application of horizontal loops for new and retrofit residential and commercial use in northern Japan is feasible particularly in farmland areas.     

Physical analysis of breakdown in high-κ/metal gate stacks using TEM/EELS and STM for reliability enhancement (invited)

In this invited paper, we demonstrate how physical analysis techniques that are commonly used in integrated circuits failure analysis can be applied to detect the failure defects associated with ultrathin gate dielectric wear-out and breakdown in high-κ materials and investigate the associated failure mechanism(s) based on the defect chemistry. The key contributions of this work are perhaps focused on two areas: (1) how to correlate the failure mechanisms in high-κ/metal gate technology during wear-out and breakdown to device processing and materials and (2) how the understanding of these new failure mechanisms can be used in proposing “design for reliability” (DFR) initiatives for complex and expensive future CMOS nanoelectronic technology nodes of 22 nm and 15 nm. Hf-based high-κ materials in conjunction with various gate electrode technologies will be used as main examples while other potential high-κ gate materials such as cerium oxide (CeO₂) will also be demonstrated to further illustrate the concept of DFR.     

Fabrication and characterization of RF nanoantenna on a nanoliter-scale 3D microcontainer

We report the design and fabrication of a nanoantenna structure on the surface of a 3D nanoliter-scale container for the development of communicable nanoliter-scale chemical delivery systems. The porous container was self-assembled, after which the nanoantenna was fabricated on the top of the microcontainer using focused ion beam (FIB) ion-induced metal deposition. The nanoantenna was structured as a rectangular metal coil composed of platinum (Pt) nanowires (70?nm in width). The response of the nanoantenna structure was simulated using finite element software and showed a strong resonant feature at 10.8?GHz, which was confirmed by high frequency measurements.     

Effect of surface morphology on the optical properties in metal-dielectric-metal thin film systems

The effect of surface morphology on the optical properties in a metal-dielectric-metal (MDM) thin film was investigated. Ag films were thermally evaporated at different rates to obtain different surface roughnesses and grain sizes. The reflectance spectra of the Ag/MgF(2)/Ag films show a dip due to surface-roughness-induced excitation of surface plasmon polaritons. The dip position varies from 650 to 800 nm, depending on the surface morphology of the multilayered film. An empirical relationship was found between the optical properties (i.e., the dip position and its linewidth) and the Ag film structural properties (i.e., surface roughness, grain size, and filling factor). The causes of and contributions to the shift of the dip position and the linewidth of the dip were discussed. The study is important to metal-dielectric-based structures, and the unique feature of such a MDM film could be used for color filters.     

Thermal Conductivity of Pyroclastic Soil (<Emphasis Type="BoldItalic">Pozzolana</Emphasis>) from the Environs of Rome

The paper reveals the experimental procedure and thermo-physical characteristics of a coarse pyroclastic soil (Pozzolana), from the neighborhoods of Rome, Italy. The tested samples are comprised of 70.7 % sand, 25.9 % silt, and 3.4 % clay. Their mineral composition contained 38 % pyroxene, 33 % analcime, 20 % leucite, 6 % illite/muscovite, 3 % magnetite, and no quartz content was noted. The effective thermal conductivity of minerals was assessed to be about \(2.14\,\hbox {W}{\cdot } \hbox {m}^{-1}{\cdot } \hbox {K}^{-1}\). A transient thermal probe method was applied to measure the thermal conductivity (\(\lambda \)) over a full range of the degree of saturation \((S_{\mathrm{r}})\), at two porosities (n) of 0.44 and 0.50, and at room temperature of about \(25\,^{\circ }\hbox {C}\). The \(\lambda \) data obtained were consistent between tests and showed an increasing trend with increasing \(S_{\mathrm{r}}\) and decreasing n. At full saturation (\(S_{\mathrm{r}}=1\)), a nearly quintuple \(\lambda \) increase was observed with respect to full dryness (\(S_{\mathrm{r}}=0\)). In general, the measured data closely followed the natural trend of \(\lambda \) versus \(S_{\mathrm{r}}\) exhibited by published data at room temperature for other unsaturated soils and sands. The measured \(\lambda \) data had an average root-mean-squared error (RMSE) of \(0.007\,\hbox {W}{\cdot } \hbox {m}^{-1}{\cdot } \hbox {K}^{-1}\) and \(0.008\,\hbox {W}{\cdot } \hbox {m}^{-1}{\cdot } \hbox {K}^{-1}\) for n of 0.50 and 0.44, respectively, as well as an average relative standard deviation of the mean at the 95 % confidence level \((\hbox {RSDM}_{0.95})\) of 2.21 % and 2.72  % for n of 0.50 and 0.44, respectively.     

Preparation and characterisation of polyamide–polyimide organoclay nanocomposites

BACKGROUND: Ternary nanocomposites containing an organomodified layered silicate polyimide additive within a polyamide matrix have been investigated to gain greater insight into structure–property relationships and potential high‐temperature automotive applications. RESULTS: Polyamide nanocomposite blends, containing 3 wt% of organoclay, were prepared and compared with organoclay‐reinforced polyamide and neat polyamide. Nanoclay addition significantly increased heat distortion temperature, as well as both the tensile and flexural moduli and strength. The addition of polyimide demonstrated further increases in heat distortion temperature, glass transition temperature and the flexural and tensile moduli by about 17, 21 and 40%, respectively. The tensile and flexural strengths were either unaffected or decreased modestly, although the strain‐to‐failure decreased substantially. Morphological studies using transmission electron microscopy (TEM) and X‐ray diffraction showed that the nanoclay was dispersed within the ternary blends forming highly intercalated nanocomposites, regardless of the presence and level of polyimide. However, TEM revealed clay agglomeration at the polyamide–polyimide interface which degraded the mechanical properties. CONCLUSIONS: A range of improvements in mechanical properties have been achieved through the addition of a polyimide additive to a polyamide nanocomposite. The decrease in ductility, arising from the poor polyamide–polyimide interface and nanoclay clustering, clearly requires improving for this deficiency to be overcome. Copyright © 2008 Society of Chemical Industry     

Selected bibliography on diversity consulting: Supplement to the special issue on culture, race, and ethnicity in organizational consulting psychology.

This bibliography was created as a resource and supplement for the Special Issue on Culture, Race, and Ethnicity Challenges in Organizational Consulting Psychology. It was intended to be neither exhaustive nor comprehensive but instead a collection of consultation references that have been found helpful in a multicultural consultation practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)