Interlayer Zone Research Articles

Potassium fixation in heavy soils of east Croatia

Bioavailability of potassium is strongly affected by present alkaline earth ions Ca and Mg and fixation of potassium into interlayer zones of some clay minerals. Soil fixation ability strongly affects the efficiency of fertilization. The research has been conducted on 6 hydromorphic and gleysoils in eastern Croatia. Soil fertilization with 450-4500 kg ha-1 K2O was simulated in lab-conditions. After one day the samples were extracted with NH4OAc 6 times, shaked, centrifuged and transferred into flasks. Fixation of potassium was calculated according to the formula: Kf = Ka – Ke + Ko, in which Kf is fixated K2O in mg 100g-1 soil ; Ka is K2O added as fertilizer in mg 100g-1 ; Ke is K2O determined in the eluate and Ko is K2O in the sample without fertilization. Fertilizing simulation of heavy soils in eastern Croatia with medium or very high dosages of potassium (450-4500 kg ha-s ; ), deducted in lab-conditions, showed that AL method of potassium extraction gives relatively high values of available potassium (two times higher than extraction in NH4OAc). Also, highest relative amount of potassium is fixated at lower fertilizing dosages (approximately 76%), the increase in fertilization increases absolute, but reduces relative fixation. Some heavy soils have high ability of fixation (above 70-90%) and very low desorption, and require special attention when establishing dosages for fertilization and ameliorative fertilization with potassium. Results obtained by soil analyses show connection between high fixation of potassium added by fertilization and higher amount of clay in the soil as well as lower level of available potassium before fertilization.

Characterization and depth profiles measurements of silicon nitride thin films on silicon and molybdenum substrates by Auger electron spectroscopy

Silicon nitride thin films were deposited on Si or Mo substrates using a technique of plasma enhanced chemical vapor deposition (PECVD). Depth profiles measurements were carried out on these Si 3N 4 layers, as well as on the Si 3N 4/Mo and Si 3N 4/Si interlayer by Auger electron spectroscopy, associated with Argon ion sputtering. For the Si 3N 4 films deposited on Mo substrates a sequence of three distinguishable zones were observed: the Si 3N 4 layer; an interlayer containing Si–N, Mo–N, and presumably Mo–Si bonds, a diffusion zone of nitrogen into the Mo substrate. On the Si substrate a more usual depth profile was evidenced involving the sequence of the Si 3N 4 layer, an interlayer zone with the presence of Si–N and Si–Si bonds, and finally the Si substrate.

The Bulong Gold Deposit—a Quartz‐Barite Vein Type Gold Deposit in Xinjiang: Geological Characteristics and S, He and Ar Isotopic Compositions

Abstract The Bulong gold deposit, located in the southwest Tianshan in China, occurs in the Upper Devonian finegrained clastic rocks. The gold orebodies are controlled by an gently inclined interlayer fractured zone. They are hosted only in quartz‐barite veins though there are barite veins and quartz veins in the ore district. The δ34S values of pyrite in the ores range from 14.6‰ to 19.2‰ and those of barite from 35.0‰ to 39.6‰, indicating that the sulfur was derived from the strata. 3He/4 He ratios of fluid inclusions in pyrite are 0.24–0.82 R/Ra, approximating to that of the crust. The 40Ar/36Ar ratios range from 338 to 471, slightly higher than that of the atmosphere. 40Ar /4He ratios of ore fluids range from 0.015 to 0.412 with a mean of 0.153. Helium and argon isotope compositions of fluid inclusions show that the ore fluids of the Bulong gold deposit were mainly derived from the crust.

Structure alteration of C-S-H (calcium silicate hydrated phases) caused by sorption of caesium

Summary The sorption behavior of Cs onto C-S-H (calcium silicate hydrated phases) was investigated by evaluating the effect of sorption on the C-S-H structure. The C-S-H have a tobermorite-type layer structure. Each layer consists of central calcium and oxygen atoms sandwiched by silicate tetrahedral chains. Additional calcium and water are located in interlayer zones. The XRD spectra showed that the tobermorite-type layer degraded and that the sorption of Cs made the fragments of layer intergrowths much smaller. The fragmentation of the tobermorite-type layer was observed for C-S-H in contact with CsCl solution or with CsOH solution, but not for the C-S-H in contact with Na solution. Furthermore, 29Si NMR spectroscopy revealed that the sorption of Cs onto C-S-H induced cleavages of silicate chains in C-S-H. It was also suggested that the OH− ion contributed to breaking the silicate chains.

Aqueous polymerization of protonated 4-vinylpyridine in montmorillonite

The polymerization of protonated 4-vinylpyridine (4-VPH +X −) in the interlayer zone of montmorillonite was studied. Polymerization is critically affected by the degree of surface coverage with a threshold value twice the cation exchange capacity of the mineral. Montmorillonite surfaces show selectivity for protonated 4-vinylpyridine favoring the formation of the quaternized form of the polyvinylpyridine polyelectrolyte. In situ polymerization of 4-VPH +X − in the presence of 10 wt.% or lower sodium montmorillonite in aqueous solution yields exfoliated montmorillonite–polyelectrolyte heterostructures. The rate of polymerization in the presence of delaminated montmorillonite is much faster than in the absence. Mechanisms for intergallery and exogallery polymerization of 4-VPH +X − are described.

Improving the fatigue resistance of carbon/ epoxy laminates with dispersed-particle interlayers

The effect of dispersed-particle interlayers on the fatigue behavior of quasi-isotropic carbon/ epoxy laminates was studied. Two kinds of laminates, with and without the dispersed-particle interlayers, were compared in this study. Tension-tension, compression-compression, and fully reversed (tension-compression) fatigue tests were performed on both laminates. Introducing the dispersed-particle layers remarkably improved the tension fatigue resistance of the laminate by toughening the interlayer zone. The dispersed-particle interlayers delayed the onset of interlaminar delamination from the free edge and impeded the progression of interlaminar delamination until final failure. The compressive and the fully reversed fatigue behaviors were shown to be improved as well by the existence of the dispersed-particle layers. Finally, the vibration damping capability of laminates with and without the dispersed-particle interlayers is compared.

Transmission coefficient calculation using the derived inelastic transport analogy of the transmission matrix method; application to tunnelling into a marginal Fermi liquid

An expression for the probability of transmission of an electron from an ordinary metal into a medium with a finite quasiparticle lifetime is derived. The derivation is based on using a certain matrix, analogous to the transmission matrix for the elastic transport case, assigned to each region of the sample being investigated. This matrix is determined by the functional shapes of the electronic reciprocal-effective-mass tensor, the one-particle potential energy and the retarded self-energy in a given sample region, as well as by the energy and direction of motion of the incident electron. As an example of an application, the differential conductance is calculated for a tunnelling contact between an ordinary metal and an anisotropic marginal-Fermi-liquid metal for various characters of the contact interlayer zone.

Polycarbonate/ABS blends: Processability, thermal properties, and mechanical and impact behavior

AbstractPC/ABS blends, encompassing the whole composition range between PC and ABS, were prepared by a Brabender‐like apparatus and compression molded in sheets. The analysis of processability, confirming the improved PC processability by ABS additions, was accomplished by the same apparatus used for the blend preparation. A DSC investigation confirmed the inward Tg shift found by other authors. Two very different mechanical tests were performed: (a) tensile stress–strain on unnotched specimens at a very low deformation rate, showing a decreased PC ductility in blends with ABS additions; and (b) flexural impact tests (Charpy mode) on sharply notched specimens at a very high deformation rate, where a strong synergistic effect was detected in a restricted composition range (20–30% ABS). A comparison of the experimental data of the Young's modulus versus blend composition with the Kerner's model predictions confirmed the good adhesion existing between PC and ABS domains. The results were interpreted on the hypothesis of interlayer zones existing at the PC/ABS boundary. © 1994 John Wiley & Sons, Inc.

The effect of spruce (Picea abies Karst.) on soil development: an analytical and experimental approach

SummaryChanges in soil and biogeochemical processes following the replacement, 60 years ago, of part of a deciduous forest by a coniferous stand were evaluated by (i) a balance‐sheet approach using soil and biomass element content analyses and the mineral flux, and (ii) the inclusion of test‐mineral and resin bags in an integrative experimental approach.The comparison of soils under different stands shows that the change to spruce is inducing physical, chemical and biological modifications in soil properties. Changes in the humus layers lead to a reduction in mineralization and the mobilization of active organic acids in the system. Under spruce, the soil structural stability is reduced as fine clay is dispersed. Soil acidification is increased, linked to a decrease in soil pH and desaturation of the soil exchange complex. Soil mineralogy also indicates this tendency, particularly with an increase in the stability of Al intergrades. The biogeochemical cycle is modified especially for N, S and Al. with large changes in the internal fluxes between the ecosystem components, but the modification of the input‐output balance due to spruce introduction is large only for S.The acidification is partly due to a change in litter quality, which inhibits biological activity, and partly because, during the dormant season, evergreen species intercept ‘dry and occult’ depositions from the atmosphere containing acidic or potentially acidic components.Use of test‐mineral bags improves understanding and interpretation of the current soil mechanisms. The test mineral, a vermiculite, introduced into the soil or placed in the lysimeter flux very quickly undergoes measurable transformation characterized by desaturation and fixation of non‐exchangeable Al in the interlayer zone, easily identified by Al speciation. The acidifying effect of spruce is clearly demonstrated by the experimental approach used, including the characterization of soil solutions by resin bags.All the techniques are complementary and could be used together or individually, depending on the aim of the study.

Genetic type and metallogenic mechanism of Bankuan gold deposit in special reference to the studies of fluid inclusions and isotopes in minerals

Auriferous quartz veins in the Bankuan gold deposit occur in the interlayer broken zone of the basal conglomerate of the Tietonggou Formation or at the unconformity between the Tietonggou Formation and the crystalline basement. The composition of fluid inclusions in the minerals indicates that the nature and composition of ore-forming hydrothermal solutions show a drastical change soon after the solutions reached the Tietonggou Formation from the crystalline basement, resulting in gold precipitation. So the Bankuan gold deposit can be assigned to the conglomerate strata-bound-type deposits. 137 thermometric data are concentrated in the three ranges 400–340 °C, 330–220 °C and 180–160 °C, representing three episodes of metallogenesis. Oxygen isotope studies demonstrate the evolution of ore-forming hydrothermal solutions from early metamorphic to late meteoric. Diversity of ore-forming materials dominated by deep-source material is supported by sulphur and lead isotope data. From the above discussions it may be concluded that the deposit formed by metamorphism induced as a result of Mesozoic northward intracontinental subduction along the Machaoying fault.

Fibre reinforced composite materials having resin practice inter-layer zones: (Odagiri, N. (Shiga); Suzue, S. (Aichi); Kishi, H. (Kyoto); Nakae, T. (Otsu); and Matsusaki, A. (Shiga); all of Japan) US Pat 5 028 478 (2 July 1991)

Fibre reinforced composite materials having resin practice inter-layer zones: (Odagiri, N. (Shiga); Suzue, S. (Aichi); Kishi, H. (Kyoto); Nakae, T. (Otsu); and Matsusaki, A. (Shiga); all of Japan) US Pat 5 028 478 (2 July 1991)

Use of track autoradiography in crystal and the physical study of synthetic diamond monocrystals

Abstract The track radiography method was used to study the boron impurity distribution throughout the bulk of synthetic diamond crystals. It was found that in most of the crystals the boron concentration in growth pyramids of {100] faces is several times as high as that in the pyramids of {111} faces. The boron impurity in growth pyramids of {100} and {111} faces is placed zonally. The higher boron concentration was observed in the diagonal interlayer zones. The distinction in electrophysical properties of the {100} and {111} growth pyramids is caused not only by the different degree of boron absorption by the growing faces but also by the amount of its compensation with nitrogen.

Study of ion exchange and intercalation of organic bases in layered substrates by vibrational spectroscopy. Inelastic neutron scattering, infrared and Raman spectroscopies of aniline-inserted α-and γ-zirconium hydrogen phosphates

The intercalation of aniline into layered zirconium phosphate of both α and γ structural modifications has been studied using powder X-ray diffraction and vibrational spectroscopy. The intercalate stoichiometries differ (two molecules aniline per atom Zr in α; one molecule aniline per atom Zr in γ) because of inherent structural differences in the internal surfaces of the phosphate layers. X-Ray diffraction indicates the α and γ-type zirconium phosphate layers to be retained in the respective compounds, with expanded interlayer distances. Infrared and Raman spectroscopies show that the anilinium ion is formed in the interlayer zone, but that proton transfer in the α-structured intercalate is incomplete. Incoherent inelastic neutron scattering has allowed the identification of all vibrations of the phenyl ring and, in particular, of the torsional mode of occluded anilinium. The relative frequencies of this mode in intercalates derived from α- and γ-zirconium phosphate suggest that the N—H⋯O hydrogen bond is stronger in the former, for reasons probably related to the lower basicity of the ‘half-exchanged’γ-ZrPO4·HPO4·C6H5NH3, compared with α-Zr(PO4)2·2C6H5NH3.

Cation exchange in synthetic manganates: I. Alkylammonium exchange in a synthetic phyllomanganate

AbstractOn treatment with dodecylammonium chloride, a synthetic Na-saturated phyllomanganate undergoes a cation-exchange reaction in which the structure expands from a collapsed basal spacing of 7 Å or a hydrated one of 10 Å to ∼ 25·5 Å. The exchange reaction is strongly influenced by the saturating cation in the original manganate and by the degree of hydration of the interlayer zone in which the exchangeable cations are located. Of the 12 cations tested, from Groups IA, IIA and IIB of the Periodic Table, only Co-manganate undergoes alkylammonium exchange when fully-dehydrated by evacuation. The results are discussed in the context of existing knowledge of the synthetic phyllomanganate and, by extrapolation, the potential value of the technique in the characterization of natural manganates has been assessed.