Types Of Impregnation Research Articles

ANALYSIS OF THE FIRE‐PROTECTION IMPREGNATION INFLUENCE ON WOOD STRENGTH

The paper presents the description, results and result analysis for the effect of fire‐protection impregnation with a salt‐containing agent, made by a vacuum‐and‐pressure method, on wood strength. A significant effect of this impregnation type was proven for the strength types as follows: static bending, tension, lengthwise compression (ie along fibres), crosswise compression (ie across fibres), as well as for dynamic bending and impact strength in normal and elevated temperatures.

Impacts of impregnation with Imersol‐Aqua on the modulus of elasticity in bending

AbstractThe aim of this study was to investigate the effects of impregnation with Imersol‐Aqua (I‐AQUA) on the modulus of elasticity in bending of some woods. For our study, Oriental beech (Fagus orientalis Lipsky), oak (Quercus petrea Liebl.), Scotch pine (Pinus sylvestris Lipsky), Uludağ fir (Abies Bornmülleriana Lipsky), Oriental spruce (Picea orientalis Lipsky), and poplar (Populus nigra L.) wood samples were prepared according to TS EN (Turkish Standards; European Norm) 408 and impregnated with I‐AQUA by the method of short‐, medium‐, and long‐term dipping according to ASTM D 1413 and producers' definition. After the impregnation process, modulus of elasticity was measured according to TS EN 408. Consequently, among the nonimpregnated wood samples, modulus of elasticity was found to be the highest in Oriental beech (Fagus orientalis Lipsky), (12,490 N mm−2) and the lowest in poplar (5439 N mm−2). As for the period of dipping, the highest modulus of elasticity was obtained in short‐term dipping and the lowest in long‐term dipping. Considering the interaction of wood type and period of impregnation, the highest modulus of elasticity in bending was obtained in Oriental beech (Fagus orientalis Lipsky) with short‐term dipping (10,720 N mm−2) whereas the lowest was in poplar with long‐term dipping (4597 N mm−2). In consequence, in massive constructions and furniture elements where the modulus of elasticity in bending after impregnation is of great concern, short term impregnation of Oriental beech and Scotch pine materials could be recommended. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3210–3217, 2006

Light propagation and scattering in porous silicon nanocomposite waveguides

AbstractPlanar waveguides have been achieved from oxidised porous silicon layers (OPS) which have been impregnated by solvents, Congo Red (CR) dye and poly(p‐phenylene vinylene) (PPV) polymer. Optical loss has been investigated by a simple technique based on surface optical scattering measurements. Optical loss has been studied as a function of the wavelength, impregnation type and CR concentration. The main sources of attenuation, such as absorption, scattering from interface roughness, scattering from nano‐ crystallites and modification of the refractive indexes after filling are discussed. Optical loss measured at 0.633 µm is about 1.8 dB/cm for the OPS waveguides The optical loss decreases with wavelength. Otherwise, the optical loss increases with the concentration of Congo Red dye which is absorbent at this wavelength. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Influence of surface properties on the mechanism of H2S removal by alkaline activated carbons.

Alkaline activated carbons are widely used as adsorbents of hydrogen sulfide (H2S), one of the major odorous compounds arising from sewage treatment facilities. Although a number of studies have explored the effects of various parameters, mechanisms of H2S adsorption by alkaline carbons are not yet fully understood. The major difficulty seems to lie in the fact that little is known with certainty about the predominant reactions occurring on the carbon surface. In this study, the surface properties of alkaline activated carbons were systematically investigated to further exploit and better understand the mechanisms of H2S adsorption by alkaline activated carbons. Two commercially available alkaline activated carbons and their representative exhausted samples (8 samples collected at different height of the column after H2S breakthrough tests) were studied. The 8 portions of the exhausted carbon were used to represent the H2S/carbon reaction process. The surface properties of both the original and the exhausted carbons were characterized using the sorption of nitrogen (BET test), surface pH, Boehm titration, thermal and FTIR analysis. Porosity and surface area provide detailed information about the pore structure of the exhausted carbons with respect to the reaction extent facilitating the understanding of potential pore blockages. Results of Boehm titration and FTIR both demonstrate the significant effects of surface functional groups, and identification of oxidation products confirmed the different mechanisms involved with the two carbons. From the DTG curves of thermal analysis, two well-defined peaks representing two products of surface reactions (i.e., sulfur and sulfuric acid) were observed from the 8 exhausted portions with gradually changing patterns coinciding with the extent of the reaction. Surface pH values of the exhausted carbons show a clear trend of pH drop along the reaction extent, while pH around 2 was observed for the bottom of the bed indicating sulfuric acid as the predominant products. Although both carbons are coal-based and of KOH impregnated type, performances of different carbons differ significantly. A correlation is well established to link the reaction extent with various surface properties. In summary, not only the homogeneous alkali impregnation and physical porosity but also the carbon surface chemistry are significant factors influencing the performances of alkaline activated carbons as H2S adsorbents.

Laminated impregnated magnetic wood manufacturing methods and magnetic characteristics from DC to 13.5 GHz band

Summary form only given. Since the introduction of magnetic wood, the authors have proposed various functions such as heating, attraction and electromagnetic wave absorption. The impregnated type magnetic wood, which is manufactured by impregnating magnetic fluid through conduit pipes, has the best woody characteristics among the three types of magnetic woods (impregnated type, powder type and coating type). In spite of the merits, the manufacturing methods up until now have been unsuccessful in producing an impregnated type magnetic wood with good magnetic characteristics, because it is difficult to impregnate a sufficient amount of magnetic fluid into the wood board. The purpose of this paper is to suggest a new impregnating method and report on the experimental results of DC and AC magnetic characteristics. The manufacturing method involves taking a thin layer of film from the wood and impregnating this section with a magnetic fluid. Next, these layers are laminated and adhered to create a board. Comparative measurements were made of the specific gravity of the laminated impregnated type and impregnated type magnetic woods. The experimental results for the proposed laminated impregnated type show that uniform magnetic characteristics are obtained and apparently good characteristics are shown from DC to 13.5 GHz.

Wood construction and magnetic characteristics of impregnated type magnetic wood

The results of experiments involving the AC and DC magnetic characteristics of impregnated type magnetic wood were studied by taking into consideration the wood construction and fiber direction. The experimental results show that the sufficient amount of impregnated magnetic fluid varies depending on the fiber direction and length, and the grain face of the wood material. The impregnated type magnetic wood sample that is fully impregnated by magnetic fluid has a 60% saturation magnetization compared to the saturation magnetization of magnetic fluid. Samples for which the wood fiber direction was the same as the direction of the magnetic path had a higher magnetization intensity and permeability.

Highly selective formation of aldehydes in the hydrogenation of the corresponding acid chlorides with silica-supported palladium catalysts prepared by a complexing agent-assisted sol–gel method

Synthesis of aldehydes from acid chlorides was carried out using four types of supported Pd/SiO 2 catalysts, which were prepared by a complexing agent-assisted sol–gel method and two types of impregnations with organic solvents or water, and a commercial Pd/BaSO 4 catalyst. The performance of the catalysts was much affected by the catalyst preparation and activation conditions. The sol–gel catalysts activated under milder conditions exhibited the highest performance for the formation of aldehydes. The high performance of the sol–gel catalysts was due to the organic residues derived from acetylacetone and ethylene glycol used in the sol–gel catalyst preparation process. The organic residues play a role similar to that of a poison added into the reaction solution for the traditional Rosenmund reduction, while being kept in the silica gel matrices.

Experimental study on magnetic and heating characteristics of magnetic wood

Magnetic wood, wood which demonstrates magnetic characteristics, was introduced by the Oka group in 1991. Based on previous studies, we have proposed that magnetic wood can be used as a heating board by induction heating, applying a high frequency magnetic field. This article covers experimental magnetic and heating characteristics for three types of magnetic wood: an impregnated type (the wood is impregnated with a water-based magnetic fluid), a powder type (Mn–Zn ferrite powder and wood powder are mixed and pressed into boards), and a coating type (Mn–Zn ferrite powder is coated onto a fiber board). Our results showed that the coating-type magnetic wood had the highest surface temperature when using a solenoid excitation coil. In this case the surface temperature rose 50 °C. The heating board we propose can be used in furniture and medical equipment that require a warm and smooth surface.

3-Dimensional Photonic Crystals at Optical Wavelengths

Different experimental strategies towards the 3-dimensional photonic crystals operating at optical wavelength are classified. The detailed discussion is devoted to the recent progress in photonic crystals fabricated by template method — the photonic band gap materials on the base of opal. The control of photonic properties of opal-based gratings is achieved through impregnating the opal with high refractive index semiconductors and dielectrics. Experimental study demonstrated the dependence of the stop band behaviour upon the type of impregnation (complete or partial) and showed a way for approaching complete photonic band gap. The photoluminescence from opal- semiconductor gratings revealed suppression of spontaneous emission in the gap region with following enhancement of the emission efficiency at the low-energy edge of the gap.

Influence of Water on the Sulfidation of Co/NaY and Co/CaY Prepared by Impregnation. A Mössbauer Emission Spectroscopy and EXAFS Study

The influence of physisorbed water on the sulfidation of impregnation type Co/NaY(imp) and Co/CaY(imp) catalysts which contain about 4 wt % Co and are prepared via pore volume impregnation is studied by Mössbauer emission spectroscopy and extended X-ray absorption fine structure. It is found that in the absence as well as in the presence of water, sulfidation of the impregnated samples finally results in the formation of Co9S8-like species at the outer zeolite surface. In the presence of water, this process proceeds via the intermediate formation of a well-ordered “CoS1+x” phase (NiAs structure). Water removal prior to sulfidation retards the formation of Co9S8-like species. This retardation in Co9S8 formation is found to be more effective for CaY−zeolite than for NaY−zeolite, which means that a larger part of the formed “Co−sulfide” is preserved in highly dispersed “Co-sulfide” particles. These findings are clearly different from those obtained earlier with ion exchanged CoNaY(ion ex) samples, for which drying prior to sulfidation resulted in very small “Co−sulfide” species with no resemblance to “Co9S8”.

96/05865 The role of catalyst impregnation and solvent type in improving liquefaction efficiencies

96/05865 The role of catalyst impregnation and solvent type in improving liquefaction efficiencies

Steam explosion pretreatment and enzymatic hydrolysis of eucalyptus wood

Wood from Eucalyptus globulus Labill has been pretreated under various conditions of acid impregnation and steam explosion. The effects of these pretreatment conditions have been assessed by measuring monomer (xylose and glucose) and oligomer solubilization. Samples pretreated under conditions that yielded optimal hemicellulose solubilization for acid impregnated or non-impregnated wood have been further subjected to enzymatic hydrolysis, using a preparation of cellulases, enriched in xylanase activities. Saccharification efficiencies were found to be equivalent for both types of impregnation.

Co-impregnation of rhodium chloride with hydrofluoric acid into dry and pre-wet alumina

This work compares and contrasts wet versus dry co-impregnation of RhCl 3 with hydrofluoric acid into the walls of honeycomb supports made from γ-alumina. The internal distributions of rhodium within the supports were measured by electron probe microanalysis (EPMA) and compared with respect to the transport mechanisms during wet and dry impregnation. The type of rhodium distribution produced was strongly effected by the type of impregnation (wet versus dry) and the impregnation time. With short impregnation times, the wet and dry co-impregnations produced subsurface bands (egg-whites) of rhodium. These subsurface bands were found to diffuse toward the support center with increasing impregnation times. Calculated characteristic times for diffusion during wet and dry impregnation are shown to be capable of accurately predicting the penetration depth of these bands during diffusion. Subsurface cores (egg-yolks) of rhodium were formed for both the wet and dry methods at long impregnation times (>5 min) by diffusion of the subsurface bands. At still longer impregnation times, these subsurface cores were washed out by back-diffusion and produced uniform distributions of rhodium. This back-diffusion process is modelled accurately as the diffusional decay of a square concentration profile.

Auger studies comparing the surface concentration of barium on tungsten impregnated and M-cathodes

A study comparing the surface concentration of barium on both an impregnated tungsten cathode surface and M-type cathode surface was made to determine whether the higher electron emission capability of the latter can be attributed to a higher average surface barium concentration. Relative quantitative data was obtained by the use of a computerized Auger microprobe spectrometer on the surface of the cathode, half of whose area was M-type, the other half being the tungsten impregnated type. The results indicate that both cathode surfaces have equivalent barium concentrations and that they are approximately equal to a barium monolayer after 3000 h of cathode life.

A comparative investigation of the operation of sintered impregnated and reservoir type journal bearings

A comparative investigation of the operation of sintered impregnated and reservoir type journal bearings

An Aluminum Solid Electrolytic Capacitor

A new aluminum solid foil type capacitor, based on the use of semiconductor material (manganese dioxide) instead of the use of a liquid electrolyte, is described. This capacitor compares favorably with the high reliability liquid-impregnated aluminum types (the so-called extended life types). This new capacitor occupies an intermediate position, as regards capacitance-voltage product per unit of volume, between the above mentioned high reliability type and the solid slug tantalum type. Outstanding properties of this aluminum capacitor are its behavior at low temperature and the stability of the various electrical parameters during life tests. Because of its estimated lower cost as compared with the solid slug tantalum capacitor, this new type will be especially suited for applications where neither the utmost miniaturization nor the better electrical properties of the solid slug tantalum capacitor are needed, but where a conventional liquid impregnated type has inadequate low temperature characteristics and has too short a stable life. Pilot plant production has been started, the output of which is being used for evaluation purposes.

The deactivation of impregnated type cathodes due to metal vapors: J. Vaughn, K. Dudley and L. Lesensky, Vacuum, 11 (2), March 1961, 77–79. (Conference Issue)

A two-dimensional, non-isothermal, two-phase model is developed to investigate the non-isothermal and thermo-osmotic behavior within a flowing electrolyte direct methanol fuel cell (FE-DMFC). The physics of this fuel cell are examined and discussed for varied anode and cathode inlet temperatures, with particular emphasis being placed on the non-isothermal behavior of this fuel cell. The results show that the cathode's thermal entrance length is much larger than that of the anode's, and that the cathode's inlet temperature influences the overall cell temperature more significantly than that of the anode's. This was found to be primarily due to the cathode's high velocity and molecular diffusivity, which allowed for a high degree of convective cooling. This effect was found to cause the mid-plane temperature to be ∼10 °C lower than that of the set point temperature for the coldest air inlet temperature of 40 °C. Furthermore, it was also found that possible flooding conditions could occur within the cathode air channel, if either the anode's or cathode's inlet temperature is too low, relative to the fuel cell's set point temperature.

Some Physical Properties of Glassy Carbon

As is well known, carbons are, in general, porous and gas-permeable materials. However, a gas-impermeable carbon has been recently made by Davidson1, named ‘Cellulose-carbon’, which is not an impregnated type and is formed by centrifuging a water suspension of cellulose, followed by calcination.

The deactivation of impregnated type cathodes due to metal vapors

Introduction Thermionic cathodes used in microwave tubes are frequently affected by their environment. The use of metallic brazes and base metals in the construction of a microwave tube device, warrants a study of the poisoning effect of metal vapors on the emission properties of thermionic cathodes. An investigation was therefore undertaken to determine the influence of various metal vapors on the impregnatedtype cathode. Results are presented that indicate the influence of various metal vapors on the emission properties of thermionic cathodes as a function of metal vapor temperatures.