Support Materials (support + material)

Distribution by Scientific Domains


Selected Abstracts


A Feasibility Study of Wire-Woven Cellular Metal as Catalytic Support Material,

ADVANCED ENGINEERING MATERIALS, Issue 7 2009
Byung-Chul Choi
Wire-woven bulk Kagome (WBK) specimens were fabricated by wires made of Fecralloy, a Fe-Cr-Al alloy, and their feasibility as supports for an oxidation catalyst was investigated. For catalytic reactivity, the catalyst-coated WBK supports perform as well as the corresponding cordierite support, even though the WBK support has much lower flow resistance. Moreover, WBK is advantageous in terms of mass productivity, weight, durability and impact strength. The image shows a close-up view of the WBK support after heat treatment. [source]


The Activity of Covalently Immobilized Grubbs,Hoveyda Type Catalyst Is Highly Dependent on the Nature of the Support Material.

CHEMINFORM, Issue 19 2007
Florian Michalek
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]


Biofilm Growth and Bed Fluidization in a Fluidized Bed Reactor Packed with Support Materials of Low Density,

ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 2 2004
R.A. Saucedo-Terán
Abstract Support materials of low-density for fluidized bed reactors provide several operational advantages, including lower energy requirements and proper biofilm growth balance. The aim of this investigation was to study the extent of biofilm growth and bed fluidization in an experimental reactor, using polyester resin (,pr,=,1220,kg/m3) and vitrified expanded perlite (,vep,=,1710,kg/m3) as alternative support materials to conventional silica sand. A noteworthy amount of biofilm was observed to be attached to both support materials from the very beginning of the bioreactor operation. Nevertheless, there were significant variations in biofilm growth and activity over the course of the experimental trials. For both perlite and polyester beds, the highest biofilm mass and the highest total number of mesophilic bacteria were observed between the 7th and the 10th day, showing a steady state trend at the end of the experimental runs. The chemical oxygen demand (COD) removal levels were concomitant with biofilm mass and total mesophilic bacteria changes, although the polyester bed efficiency was slightly higher than that for the perlite bed. As expected, the polyester bed was fluidized at a lower re-circulation flow compared to the perlite bed. Reactor back-washing was not required for these support materials since biomass excess was adequately separated by means of a special internal device. The efficiencies of removal of organic matter achieved were acceptable (up to 78,%) despite the low volume of the support material (25,%) and the low hydraulic retention time (30,min). [source]


Alkaline neutralization of crude soybean oil by various adsorbents

EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 3 2008
Sukran Kuleasan
Abstract The effect of sodium hydroxide in neutralization was increased by using various adsorbents. NaOH in various concentrations was attached to the particles of Kieselguhr, Celite and Bentonite. The neutralization reaction was performed at ambient temperature, and different reaction times were applied. The soap formed after reaction was removed by centrifugation; thus, washing and drying steps were omitted. The amount of remaining soap, the acidity and color of oils were determined after each treatment. According to the results, free fatty acid neutralization in crude oil was achieved by Kieselguhr application. In this process, 9.5% NaOH was applied for 60,min of reaction time. The free fatty acid content of crude oil was decreased from 0.56 to 0.14%, and the remaining soap was found at 34,mg/kg after centrifugation. The use of adsorbents increased the efficiency of NaOH in the neutralization reaction and in the removal of soap from the neutralized oil. Neutralization with support material is a new and promising approach. The application is energy saving, more practical and in accordance with the strict environmental legislation about waste disposal. [source]


Fe2O3 on Ce-, Ca-, or Mg-stabilized ZrO2 as oxygen carrier for chemical-looping combustion using NiO as additive

AICHE JOURNAL, Issue 8 2010
Magnus Rydén
Abstract Oxygen-carrier particles for chemical-looping combustion have been manufactured by freeze granulation. The particles consisted of 60 wt % Fe2O3 as active phase and 40 wt % stabilized ZrO2 as support material. Ce, Ca, or Mg was used to stabilize the ZrO2. The hardness and porosity of the particles were altered by varying the sintering temperature. The oxygen carriers were examined by redox experiments in a batch fluidized-bed reactor at 800,950°C, using CH4 as fuel. The experiments showed good reactivity between the particles and CH4. NiO was used as an additive and was found to reduce the fraction of unconverted CH4 with up to 80%. The combustion efficiency was 95.9% at best and was achieved using 57 kg oxygen carrier per MW fuel. Most produced oxygen carriers appear to have been decently stable, but using Ca as stabilizer resulting in uneven results. Further, particles sintered at high temperatures had a tendency to defluidize. © 2010 American Institute of Chemical Engineers AIChE J, 2010 [source]


Evaluation of the silanol-suppressing potency of ionic liquids

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 8 2006
Micha, Piotr Marsza
Abstract Recently, increasing attention has been paid to the use of ionic liquids for high-performance liquid chromatography (HPLC) and capillary electrophoresis. In the present study, the silanol-suppressing potency of ionic liquids was evaluated by HPLC using the two-retention site model proposed previously by Nahum and Horváth (J. Chromatogr. 1981, 203, 53,63). The binding constant, KA, in that approach has been demonstrated to reliably reflect the ability of the ionic liquids to block the silanols of the silica support material of the stationary phase. The determinations were carried out for ionic liquids of the 1-alkyl-3-methylimidazolium group with the use of a series of basic drugs as the test analytes. Comparison of ionic liquids with standard mobile phase additives such as triethylamine showed the former to possess advantages as silanol suppressors in HPLC. The main advantage of the method is that it provides a simple and fast determination of the silanol complex stability, which allowed comparison of the suppressing efficiency of several ionic liquids. [source]


Degradation of the main components of cellulose-paint thinner by the mould Scopulariopsis brevicaulis cultured on rice hulls

LETTERS IN APPLIED MICROBIOLOGY, Issue 1 2003
J. Alba
Abstract Aims: Biodegradation of the main components of the cellulose-paint thinner (toluene, acetone, isopropanol and xylenes) by Scopulariopsis brevicaulis, isolated from a thinner biodegradation microbial consortium was investigated. Methods and Results: Our results showed that 90% of S. brevicaulis conidia survived after 4 weeks in a cellulose-paint thinner saturated atmosphere. The mould was able to grow under these environmental conditions with a low development of conidia. The biodegradation potential of S. brevicaulis was established with and without support material (rice hulls). Biodegradation without support was very limited, <10% for all the components quantified. There was notable thinner biodegradation when the fungus was grown on rice hulls. Conclusions: Our results suggest the potential use of fungi in biofiltration systems employed in biodegradation of the main components of the cellulose-paint thinner. Sigificance and Impact of the Study: This is the first report of volatile organic compounds biodegradation by this fungal species. [source]


Characterisation and cleaning of oxide support materials for cavity ring-down spectroscopy

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 5 2010
Aras Kartouzian
Abstract Cavity ring-down spectroscopy (CRDS) has been applied to characterise different oxide materials (amorphous silica, borosilicate and yttria stabilised zirconia YSZ) which are suitable to be used as support material for size-selected metal clusters. The sensitivity of the spectroscopic method was improved by means of transversal mode matching and spatial filtering of the laser beam profile, reducing the relative error by 50%. The high sensitivity of CRDS allows the detection of trace amounts of impurities and defect sites in the samples, based on their absorption properties. In YSZ, traces of Nd have been detected. The optical quality of the substrates was determined qualitatively according to the measured optical losses. CRDS surface maps have been used to monitor the homogeneity of the support materials, and the influence of ion bombardment on the surface has been studied. It is shown that in the case of BK7® substrates, sputtering with low energy Ar+ ions could remove deposited gold clusters almost completely causing very low damage to the surface. These results were confirmed analytically. [source]


Role of the support material on laser desorption/ionization mass spectra

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 7 2008
A. Gruszecka
We report the results of experimental studies on the effects of sample supports in laser desorption/ionization mass spectrometry (LDI-MS). LDI time-of-flight (TOF) mass spectra obtained for C60 and insulin samples deposited onto standard stainless steel substrate and/or onto some non-metallic materials (glass, scotch tape, floppy disc foil, Teflon foil, photocopy film), all recorded under identical, typical experimental conditions, have been compared with regard to their intensity and quality. The LDI investigations show that compared with stainless steel, glass and floppy disc foil sample supports boost (2,3.5 times) ion yields for C and C ions, respectively. The stainless steel and scotch tape sample supports are the best for the mass resolution of positive ions and the formation of (C60) (n,,,4) cluster ions, respectively. In the case of detection of insulin by matrix-assisted laser desorption/ionization (MALDI) we did not observe significant differences in sensitivity for the support materials tested. A mechanism of ion formation in the desorption plume is suggested. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Microwave-Assisted Cross-Coupling and Hydrogenation Chemistry by Using Heterogeneous Transition-Metal Catalysts: An Evaluation of the Role of Selective Catalyst Heating

CHEMISTRY - A EUROPEAN JOURNAL, Issue 43 2009
Muhammed Irfan
Abstract The concept of specific microwave effects in solid/liquid catalytic processes resulting from the selective heating of a microwave-absorbing heterogeneous transition-metal catalyst by using 2.45,GHz microwave irradiation was evaluated. As model transformations Ni/C-, Cu/C-, Pd/C-, and Pd/Al2O3 -catalyzed carbon,carbon/carbon,heteroatom cross-couplings and hydrogenation reactions were investigated. To probe the existence of specific microwave effects by means of selective catalyst heating in these transformations, control experiments comparing microwave dielectric heating and conventional thermal heating at the same reaction temperature were performed. Although the supported metal catalysts were experimentally found to be strongly microwave absorbing, for all chemistry examples investigated herein no differences in reaction rate or selectivity between microwave and conventional heating experiments under carefully controlled conditions were observed. This was true also for reactions that use low-absorbing or microwave transparent solvents, and was independent of the microwave absorbtivity of the catalyst support material. In the case of hydrogenation reactions, the stirring speed was found to be a critical factor on the mass transfer between gas and liquid phase, influencing the rate of the hydrogenation in both microwave and conventionally heated experiments. [source]


Biofilm Growth and Bed Fluidization in a Fluidized Bed Reactor Packed with Support Materials of Low Density,

ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 2 2004
R.A. Saucedo-Terán
Abstract Support materials of low-density for fluidized bed reactors provide several operational advantages, including lower energy requirements and proper biofilm growth balance. The aim of this investigation was to study the extent of biofilm growth and bed fluidization in an experimental reactor, using polyester resin (,pr,=,1220,kg/m3) and vitrified expanded perlite (,vep,=,1710,kg/m3) as alternative support materials to conventional silica sand. A noteworthy amount of biofilm was observed to be attached to both support materials from the very beginning of the bioreactor operation. Nevertheless, there were significant variations in biofilm growth and activity over the course of the experimental trials. For both perlite and polyester beds, the highest biofilm mass and the highest total number of mesophilic bacteria were observed between the 7th and the 10th day, showing a steady state trend at the end of the experimental runs. The chemical oxygen demand (COD) removal levels were concomitant with biofilm mass and total mesophilic bacteria changes, although the polyester bed efficiency was slightly higher than that for the perlite bed. As expected, the polyester bed was fluidized at a lower re-circulation flow compared to the perlite bed. Reactor back-washing was not required for these support materials since biomass excess was adequately separated by means of a special internal device. The efficiencies of removal of organic matter achieved were acceptable (up to 78,%) despite the low volume of the support material (25,%) and the low hydraulic retention time (30,min). [source]


Metal-Free Air Oxidation of Thiols in Recyclable Ionic Liquid: A Simple and Efficient Method for the Synthesis of Disulfides

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 14 2010
Devender Singh
Abstract An efficient procedure for the oxidative coupling of alkyl, aryl and heteroaryl thiols with atmospheric oxygen is reported. The methodology utilizes BMIM-BF4 as a recyclable solvent and does not require support materials or metal salts. Symmetric disulfides are obtained in excellent yields. [source]


Biodiesel fuel production via transesterification of oils using lipase biocatalyst

GCB BIOENERGY, Issue 2 2009
MAN XIAO
Abstract Biodiesel has gained widespread importance in recent years as an alternative, renewable liquid transportation fuel. It is derived from natural triglycerides in the presence of an alcohol and an alkali catalyst via a transesterification reaction. To date, transesterification based on the use of chemical catalysts has been predominant for biodiesel production at the industrial scale due to its high conversion efficiency at reasonable cost. Recently, biocatalytic transesterification has received considerable attention due to its favorable conversion rate and relatively simple downstream processing demands for the recovery of by-products and purification of biodiesel. Biocatalysis of the transesterification reaction using commercially purified lipase represents a major cost constraint. However, more cost-effective techniques based on the immobilization of both extracellular and intracellular lipases on support materials facilitate the reusability of the catalyst. Other variables, including the presence of alcohol, glycerol and the activity of water can profoundly affect lipase activity and stability during the reaction. This review evaluates the current status for lipase biocatalyst-mediated production of biodiesel, and identifies the key parameters affecting lipase activity and stability. Pioneer studies on reactor-based lipase conversion of triglycerides are presented. [source]


Hydride-based silica stationary phases for HPLC: Fundamental properties and applications

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 15 2005
Joseph J. Pesek
Abstract Silica hydride is a recent development in chromatographic support materials for HPLC where hydride groups replace 95% of the silanols on the surface. This conversion changes many of the fundamental properties of the material as well as the bonded stationary phases that are the result of further chemical modification of the hydride surface. The general approach for fabricating the silica hydride and subsequent bonded phases is reviewed. Properties of the silica hydride surface are compared to those of the standard material obtained in the preparation of most commercial HPLC stationary phases. Some unique chromatographic properties of hydride-based phases are described as well as some general application areas where these bonded materials may be used in preference to or have advantages not available from typical stationary phases. [source]


Crosslinked Polyacrolein Microspheres with High Loading of Aldehyde Groups for Use as Scavenger Resins in Organic Synthesis,

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 19 2004
Chao Lin
Abstract Summary: Suspension polymerization yielded microspheres (40,50 ,m) of polyacrolein. Smooth and rugged surfaces can be created by varying the polymerization procedure. We have shown that the polyacrolein resins with a high loading of aldehyde groups serve as effective scavengers for primary amines and may be used to remove compounds bearing amino groups in the combinatorial synthesis of compound libraries. Copolymerization with styrene can help to separate the adjacent aldehyde groups, thus making the functional groups more available in organic reactions. The polyacrolein resins in the aldehyde form or after appropriate chemical modifications may also be useful as support materials in solid-phase synthesis. The SEM image of macroporous polyacrolein microspheres with toluene as porogen prepared by free radical polymerization. [source]


Object-Oriented Performance Improvement

PERFORMANCE IMPROVEMENT QUARTERLY, Issue 3 2002
Ian Douglas
ABSTRACT In this paper, a framework to support an object-oriented approach to performance analysis is described. The framework includes the use of collaboration, automation, visual modeling, and reusable repositories of analysis knowledge. The need for a new framework is related to the increasing concern with the cost effectiveness of student and employee development. Efforts to improve the return-on-investment in such development have been hindered by a craft orientation to the design and construction of learning and performance support materials. One solution to this problem has been to enhance the reuse of such materials. Rather than build every new system from scratch in a craft-oriented manner, it is envisioned that systems will be constructed largely of standardized, reusable objects shared through Web-based repositories. Currently, the main focus is on the technological framework necessary for an object-based approach to learning system development. There appears to be little consideration of the changes in analysis and design thinking required for the move towards object-based systems. Such systems should still be required to be directly linked to performance problems and opportunities at both the organizational and individual system levels. [source]


Characterisation and cleaning of oxide support materials for cavity ring-down spectroscopy

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 5 2010
Aras Kartouzian
Abstract Cavity ring-down spectroscopy (CRDS) has been applied to characterise different oxide materials (amorphous silica, borosilicate and yttria stabilised zirconia YSZ) which are suitable to be used as support material for size-selected metal clusters. The sensitivity of the spectroscopic method was improved by means of transversal mode matching and spatial filtering of the laser beam profile, reducing the relative error by 50%. The high sensitivity of CRDS allows the detection of trace amounts of impurities and defect sites in the samples, based on their absorption properties. In YSZ, traces of Nd have been detected. The optical quality of the substrates was determined qualitatively according to the measured optical losses. CRDS surface maps have been used to monitor the homogeneity of the support materials, and the influence of ion bombardment on the surface has been studied. It is shown that in the case of BK7® substrates, sputtering with low energy Ar+ ions could remove deposited gold clusters almost completely causing very low damage to the surface. These results were confirmed analytically. [source]


Role of the support material on laser desorption/ionization mass spectra

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 7 2008
A. Gruszecka
We report the results of experimental studies on the effects of sample supports in laser desorption/ionization mass spectrometry (LDI-MS). LDI time-of-flight (TOF) mass spectra obtained for C60 and insulin samples deposited onto standard stainless steel substrate and/or onto some non-metallic materials (glass, scotch tape, floppy disc foil, Teflon foil, photocopy film), all recorded under identical, typical experimental conditions, have been compared with regard to their intensity and quality. The LDI investigations show that compared with stainless steel, glass and floppy disc foil sample supports boost (2,3.5 times) ion yields for C and C ions, respectively. The stainless steel and scotch tape sample supports are the best for the mass resolution of positive ions and the formation of (C60) (n,,,4) cluster ions, respectively. In the case of detection of insulin by matrix-assisted laser desorption/ionization (MALDI) we did not observe significant differences in sensitivity for the support materials tested. A mechanism of ion formation in the desorption plume is suggested. Copyright © 2008 John Wiley & Sons, Ltd. [source]


How New Product Introductions Affect Sales Management Strategy: The Impact of Type of "Newness" of the New Product

THE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 4 2003
Kamel Micheal
How do firms adjust sales management strategy for new product launch? Does sales management strategy change more radically for different types of new products such as new-to-the-world products versus product revisions? Because firms introducing a new product rely considerably on their sales force in the product launch effort, the types and degree of changes made in managing the selling effort are important issues. Past studies have demonstrated that firms make substantial adjustments in their sales management strategy when they introduce a new product. This study expands on previous investigations by examining whether sales management strategy changes are conditioned by the type of newness of the new product to the market and to the firm. Australian sales managers were asked to respond to a mail questionnaire concerning pre- and post-new product launch sales management activities. Three groups of firms were compared: (1) those with new-to-the-market and new-to-the-firm products (i.e., new-to-the-world products); (2) those with products new to the firm but not new to the market; and (3) those with products that are revisions to the firm and not new to the market. The study finds that firms do not make the most adjustments for products with the greatest degree of market newness,the new-to-the-world types of products,except in the sales management strategy categories of compensation and supervision. In the other sales management strategy categories defined for study,organization, training, quotas and goals, and sales support as well as for all categories in the aggregate,sales management strategy changes were greatest in incidence, as measured both by the percent of firms making changes and the average number of changes per firm, when the new product was new to the firm but not new to the market. These results suggest that, because different types of new products face different competitive environments, there may be greater incentive for a not-new-to-the-market new-to-the-firm product to make changes in sales strategy. Uncertainties about market size and customer location with new-to-the-world products may limit the understanding of what changes to make in the strategy categories of quotas and territories. Similarly, uncertainties about product use and customer acceptance of new-to-the-world products may limit the development of training and sales support materials by these firms. Instead, these firms may rely more on compensation and supervision to direct sales efforts for new-to-the-world products. However, observing the market experience and performance of the first-to-market product can benefit firms launching a not-new-to-market and new-to-the-firm product, allowing them to rely more on strategy changes in training, sales support materials, organizational adjustments such as redeployments, and quotas. [source]


A General Approach to Fabricate Diverse Noble-Metal (Au, Pt, Ag, Pt/Au)/Fe2O3 Hybrid Nanomaterials

CHEMISTRY - A EUROPEAN JOURNAL, Issue 27 2010
Jun Zhang Dr.
Abstract A novel, facile, and general one-pot strategy is explored for the synthesis of diverse noble-metal (Au, Pt, Ag, or Pt/Au)/Fe2O3 hybrid nanoparticles with the assistance of lysine (which is a nontoxic, user friendly amino acid that is compatible with organisms) and without using any other functionalization reagents. Control experiments show that lysine, which contains both amino and carboxylic groups, plays dual and crucial roles as both linker and capping agents in attaching noble metals with a small size and uniform distribution onto an Fe2O3 support. Considering the perfect compatibility of lysine with organism, this approach may find potentials in biochemistry and biological applications. Furthermore, this novel route is also an attractive alternative and supplement to the current methods using a silane coupling agent or polyelectrolyte for preparing hybrid nanomaterials. To demonstrate the usage of such hybrid nanomaterials, a chemical gas sensor has been fabricated from the as-synthesized Au/Fe2O3 nanoparticles and investigated for ethanol detection. Results show that the hybrid sensor exhibits significantly improved sensor performances in terms of high sensitivity, low detection limit, better selectivity, and good reproducibility in comparison with pristine Fe2O3. Most importantly, this general approach can be further employed to fabricate other hybrid nanomaterials based on different support materials. [source]