Nitrogen cycle of effluent-irrigated energy crop plantations:from wastewater treatment to thermo-chemical conversion processes

This paper reviews nitrogen (N) cycle of effluent-irrigated energy crop plantations, starting from wastewater treatment to thermo-chemical conversion processes. In wastewater, N compounds contribute to eutrophication and toxicity in water cycle. Removal of N via vegetative filters and specifically in short-rotation energy plantations, is a relatively new approach to managing nitrogenous effluents. Though combustion of energy crops is in principle carbon neutral, in practice, N content may contribute to NOx emissions with significant global warming potential. Intermediate pyrolysis produces advanced fuels while reducing such emissions. By operating at intermediate temperature (500°C), it retains most N in char as pyrrolic-N, pyridinic-N, quaternary-N and amines. In addition, biochar provides long-term sequestration of carbon in soils.

Impedance analysis of Al2O3/H-terminated diamond metal-oxide-semiconductor structures

Impedance spectroscopy (IS) analysis is carried out to investigate the electrical properties of the metal-oxide-semiconductor (MOS) structure fabricated on hydrogen-terminated single crystal diamond. The low-temperature atomic layer deposition Al2O3 is employed as the insulator in the MOS structure. By numerically analysing the impedance of the MOS structure at various biases, the equivalent circuit of the diamond MOS structure is derived, which is composed of two parallel capacitive and resistance pairs, in series connection with both resistance and inductance. The two capacitive components are resulted from the insulator, the hydrogenated-diamond surface, and their interface. The physical parameters such as the insulator capacitance are obtained, circumventing the series resistance and inductance effect. By comparing the IS and capacitance-voltage measurements, the frequency dispersion of the capacitance-voltage characteristic is discussed.

Catalytic systems based on carbon fiber materials for the low-temperature oxidation of carbon monoxide

New heterogenized catalytic systems for the low-temperature oxidation of CO were synthesized by supporting solutions of Pd, Cu, and Fe salts on carbon fibrous materials (carbopon and busofit). The carbon supports were studied by elemental analysis, SEM, TGA, and TPD. The effects of the nature of the support, the concentration and composition of the active component, and the conditions of preparation on the efficiency of the catalytic system were studied. It was ascertained that attenuation of hydrophilic properties of the support led to the decrease in system activity. The investigation of the catalysts by XPS showed that sample treatment in the reaction medium results in redistribution of the components of the active phase in the near-surface layer of the catalyst. The catalytic system based on carbon fibrous material carbopon prepared by supporting active components (Pd, Cu, and Fe salts) in three stages with intermediate activation in the reaction medium ensures 95% conversion of CO under respiratory conditions, and is promising for the design of the main element of breathing masks on its basis.

On-line learning with adaptive back-propagation in two-layer networks

An adaptive back-propagation algorithm parameterized by an inverse temperature 1/T is studied and compared with gradient descent (standard back-propagation) for on-line learning in two-layer neural networks with an arbitrary number of hidden units. Within a statistical mechanics framework, we analyse these learning algorithms in both the symmetric and the convergence phase for finite learning rates in the case of uncorrelated teachers of similar but arbitrary length T. These analyses show that adaptive back-propagation results generally in faster training by breaking the symmetry between hidden units more efficiently and by providing faster convergence to optimal generalization than gradient descent.

Topography of α-internexin-positive neuronal aggregates in 10 patients with neuronal intermediate filament inclusion disease

Abnormal neuronal intermediate filament (IF) inclusions immunopositive for the type IV IF α-internexin have been identified as the pathological hallmark of neuronal intermediate filament inclusion disease (NIFID). We studied the topography of these inclusions in the frontal and temporal lobe in 68 areas from 10 cases of NIFID. In the cerebral cortex, CA sectors of the hippocampus, and dentate gyrus granule cell layer, the inclusions were distributed mainly in regularly distributed clusters, 50-800 μm in diameter. In seven cortical areas, there was a more complex pattern in which the clusters of inclusions were aggregated into larger superclusters. In 11 cortical areas, the size of the clusters approximated to those of the cells of origin of the cortico-cortical pathways but in the majority of the remaining areas, cluster size was smaller than 400 μm. The topography of the lesions suggests that there is degeneration of the cortico-cortical projections in NIFID with the formation of α-internexin-positive aggregates within vertical columns of cells. Initially, only a subset of cells within a vertical column develops inclusions but as the disease progresses, the whole of the column becomes affected. The corticostriate projection appears to have little effect on the cortical topography of the inclusions. © 2006 EFNS.

Kinetic studies of the metathesis of 1-hexene using Re2O7/γ-Al2O3 and the synthesis and metathesis of oxazolines

The kinetics of the metathesis of 1-hexene using Re2O7/-Al_2O_3 as the catalyst were investigated under a variety of conditions. The experiments were carried out under high vacuum conditions. The product solutions were characterised by gas liquid chromatography and mass spectroscopy. The initial kinetics of the metathesis of 1-hexene showed that the reaction was first order in the weight of the catalyst and second order in the concentration of 1-hexene. A kinetic scheme which correlated the experimental data with the metallocarbene chain mechanism postulated by Herisson and Chauvin and the kinetics of the reaction was explained using a model based on the Langmuir-Hinshelwood theory. The low conversion of 1-hexene to its products is due to termination reactions which most likely occur by the decomposition of the metallocyclobutane intermediate to produce a cyclopropane derivative and an inactive centre. The optimum temperature for the metathesis of 1-hexene over Re_2O_7/-Al2O3 is 45oC and above this temperature, the rate of metathesis decreases rapidly. Co-catalysts alter the active sites for metathesis so that the catalyst is more selective to the metathesis of 1-hexene. However, the regeneration of metathesis activity is much worse for promoted catalysts than for the unpromoted. The synthesis and metathesis of 4,4-dimethyl-2-allowbreak (9-decenyl)-1,3-oxazoline and 4,4-dimethyl-2-allowbreak (3-pentenyl)-1,3-oxazoline was attempted and the products were analysed by thin layer chromatography, infra-red, 13C and 1H nmr and mass spectroscopy. Obtaining the oxazolines in a good yield with high purity was difficult and consequently metathesis of the impure products did not occur.

Brush plating of bearing alloys on aluminium alloy shells

The turbocharging of diesel engines has led to increase in temperature, load and corrosive attack of plain bearings. To meet these requirements, overlay plated aluminium alloys are now preferred. Currently, lead-tin alloys are deposited using a zincate layer and nickel strike, as intermediate stages in the process. The nickel has undesirable seizure characteristics and the zincate can given rise to corrosion problems. Consequently, brush plating allows the possible elimination of these stages and a decrease in process together with greater automation. The effect of mode application, on the formation of zincate films, using film growth weight measurements, potential-time studies, peel adhesion testing and Scanning Electron Microscopy was studied, for both SIC and AS15 aluminium alloys. The direct plating of aluminium was also successfully achieved. The results obtained indicate that generally, although lower adhesion resulted when a brush technique was used, satisfactory adhesion for fatigue testing was achieved. Both lead-tin and tin-cobalt overlays were examined and a study of the parameters governing brush plating were carried out using various electrolytes. An experimentally developed small scale rig, was used to produce overlay plated bearings that were fatigue tested until failure. The bearings were then examined and an analysis of the failure mechanisms undertaken. The results indicated that both alloy systems are of the regular codeposition type. Tin-cobalt overlays were superior to conventional lead-tin overlays and remained in good condition, although the lining (substrate) failed. Brush plated lead-tin was unsatisfactory. Sufficient understanding has now been gained, to enable a larger scale automated plant to be produced. This will allow a further study of the technique to be carried out, on equipment that more closely resembles that of a full scale production process.

The intermediate pyrolysis and catalytic steam reforming of brewers spent grain

Brewers spent grain (BSG) is a widely available feedstock representing approximately 85% of the total by-products generated in the brewing industry. This is currently either disposed of to landfill or used as cattle feed due to its high protein content. BSG has received little or no attention as a potential energy resource, but increasing disposal costs and environmental constraints are now prompting the consideration of this. One possibility for the utilisation of BSG for energy is via intermediate pyrolysis to produce gases, vapours and chars. Intermediate pyrolysis is characterised by indirect heating in the absence of oxygen for short solids residence times of a few minutes, at temperatures of 350-450 °C. In the present work BSG has been characterised by chemical, proximate, ultimate and thermo-gravimetric analysis. Intermediate pyrolysis of BSG at 450 °C was carried out using a twin coaxial screw reactor known as Pyroformer to give yields of char 29%, 51% of bio-oil and 19% of permanent gases. The bio-oil liquid was found to separate in to an aqueous phase and organic phase. The organic phase contained viscous compounds that could age over time leading to solid tars that can present problems in CHP application. The quality of the pyrolysis vapour products before quenching can be upgraded to achieve much improved suitability as a fuel by downstream catalytic reforming. A Bench Scale batch pyrolysis reactor has then been used to pyrolyse small samples of BSG under a range of conditions of heating rate and temperature simulating the Pyroformer. A small catalytic reformer has been added downstream of the reactor in which the pyrolysis vapours can be further cracked and reformed. A commercial reforming nickel catalyst was used at 500, 750 and 850 °C at a space velocity about 10,000 L/h with and without the addition of steam. Results are presented for the properties of BSG, and the products of the pyrolysis process both with and without catalytic post-processing. Results indicate that catalytic reforming produced a significant increase in permanent gases mainly (H2 and CO) with H2 content exceeding 50 vol% at higher reforming temperatures. Bio-oil yield decreased significantly as reforming temperature increased with char remaining the same as pyrolysis condition remained unchanged. The process shows an increase in heating value for the product gas ranging between 10.8-25.2 MJ/m as reforming temperature increased. © 2012 Elsevier B.V. All rights reserved.

Decentralised off-grid electricity generation in India using intermediate pyrolysis of residue straws

Use of agricultural residues, like wheat or rice straw for energy generation, is the most effective measure in terms of costs and availability. The present paper focuses the need of such measure, its impact on the environment as practiced today (open burning). The application of intermediate pyrolysis technology for straw conversion in India is discussed herein. A 20 kg/h Pyroformer has been coupled to a direct quenching system without filtration. The process temperature was around 360 ?C and the yields for the product fractions, char pyrolysis oil, and non-condensable gas fractions were, 32%, 35%, and 33% respectively. The pyrolysis oil was condensed in a quenching unit using bio-diesel or diesel. The blend produced was 30 % pyrolysis liquid and 70 % bio-diesel. The engine has been tested with the pyro-oil/biooil mixture over a long term (75 hours). An overall economic analysis of the process has been carried out.

Effect of preparation conditions on the formation of the active phase of carbon fiber catalytic systems for the low-temperature oxidation of carbon monoxide

We studied the effects of the composition of impregnating solution and heat treatment conditions on the activity of catalytic systems for the low-temperature oxidation of CO obtained by the impregnation of Busofit carbon-fiber cloth with aqueous solutions of palladium, copper, and iron salts. The formation of an active phase in the synthesized catalysts at different stages of their preparation was examined with the use of differential thermal and thermogravimetric analyses, X-ray diffraction analysis, X-ray photoelectron spectroscopy, and elemental spectral analysis. The catalytic system prepared by the impregnation of electrochemically treated Busofit with the solutions of PdCl, FeCl, CuBr, and Cu(NO ) and activated under optimum conditions ensured 100% CO conversion under a respiratory regime at both low (0.03%) and high (0.5%) carbon monoxide contents of air. It was found that the activation of a catalytic system at elevated temperatures (170-180°C) leads to the conversion of Pd(II) into Pd(I), which was predominantly localized in a near-surface layer. The promoting action of copper nitrate consists in the formation of a crystalline phase of the rhombic atacamite CuCl(OH). The catalyst surface is finally formed under the conditions of a catalytic reaction, when a joint Pd(I)-Cu(I) active site is formed. © 2014 Pleiades Publishing, Ltd.

Effect of a commercially available warm compress on eyelid temperature and tear film in healthy eyes

Purpose: To evaluate eyelid temperature change and short-term effects on tear film stability and lipid layer thickness in healthy patients using a commercially available warm compress (MGDRx EyeBag) for ophthalmic use. Methods: Eyelid temperature, noninvasive tear film breakup time (NITBUT), and tear film lipid layer thickness (TFLLT) of 22 healthy subjects were measured at baseline, immediately after, and 10 minutes after application of a heated eyebag for 5 minutes to one eye selected at random. A nonheated eyebag was applied to the contralateral eye as a control. Results: Eyelid temperatures, NITBUT, and TFLLT increased significantly from baseline in test eyes immediately after removal of the heated eyebag compared with those in control eyes (maximum temperature change, 2.3 +/- 1.2[degrees]C vs. 0.3 +/- 0.5[degrees]C, F = 20.533, p < 0.001; NITBUT change, 4.0 +/- 2.3 seconds vs. 0.4 +/- 1.7 seconds, p < 0.001; TFLLT change, 2.0 +/- 0.9 grades vs. 0.1 +/- 0.4 grades, Z = -4.035, p < 0.001). After 10 minutes, measurements remained significantly higher than those in controls (maximum temperature change, 1.0 +/- 0.7[degrees]C vs. 0.1 +/- 0.3[degrees]C, F = 14.247, p < 0.001; NITBUT change, 3.6 +/- 2.1 seconds vs. 0.1 +/- 1.9 seconds, p < 0.001; TFLLT change, 1.5 +/- 0.9 vs. 0.2 +/- 0.5 grades, Z = -3.835, p < 0.001). No adverse events occurred during the study. Conclusions: The MGDRx EyeBag is a simple device for heating the eyelids, resulting in increased NITBUT and TFLLT in subjects without meibomian gland dysfunction that seem to be clinically significant. Future studies are required to determine clinical efficacy and evaluate safety after long-term therapy in meibomian gland dysfunction patients. © 2013 American Academy of Optometry

Catalytic intermediate pyrolysis of Brunei rice husk for bio-oil production

Rice husks from Brunei were subjected via intermediate pyrolysis for bio-oil production. Two main objectives were set out for this study. The application of intermediate pyrolysis on Brunei rice husk for the production of bio-oil is the main objective of this experiment. Characterisation of the rice husks was inclusive as a pre-requisite step to assess the suitability as feedstock for production of liquid fuels. Following on from the characterisation results, a temperature of 450°C was established as the optimum temperature for the production of bio-oil. A homogenous bio-oil was obtained from the pyrolysis of dry rice husk, and the physicochemical properties and chemical compositions were analysed. The second objective is the introduction of catalysts into the pyrolysis process which aims to improve the bio-oil quality, and maximise the desired liquid bio-oil properties. The incorporation of the catalysts was done via a fixed tube reactor into the pyrolysis system. Ceramic monoliths were used as the catalyst support, with montmorillonite clay as a binder to attach the catalysts onto the catalyst support. ZSM-5, Al-MCM-41, Al-MSU-F and Brunei rice husk ash (BRHA) together with its combination were adopted as catalysts. Proposed criterions dictated the selection of the best catalysts, subsequently leading to the optimisation process for bio-oil production. ZSM-5/Al-MCM-41 proved the most desirable catalyst, which increases the production of aromatics and phenols, decreased the organic acids and improved the physicochemical properties such as the pH, viscosity, density and H:C molar ratios. Variation in the ratio and positioning of both catalysts were the significant key factor for the catalyst optimisation study.

Effect of a commercially available warm compress on eyelid temperature and tear film in healthy eyes

PURPOSE: To evaluate eyelid temperature change and short-term effects on tear film stability and lipid layer thickness in healthy patients using a commercially available warm compress (MGDRx EyeBag) for ophthalmic use. METHODS: Eyelid temperature, noninvasive tear film breakup time (NITBUT), and tear film lipid layer thickness (TFLLT) of 22 healthy subjects were measured at baseline, immediately after, and 10 minutes after application of a heated eyebag for 5 minutes to one eye selected at random. A nonheated eyebag was applied to the contralateral eye as a control. RESULTS: Eyelid temperatures, NITBUT, and TFLLT increased significantly from baseline in test eyes immediately after removal of the heated eyebag compared with those in control eyes (maximum temperature change, 2.3 ± 1.2 °C vs. 0.3 ± 0.5 °C, F = 20.533, p <0.001; NITBUT change, 4.0 ± 2.3 seconds vs. 0.4 ± 1.7 seconds, p <0.001; TFLLT change, 2.0 ± 0.9 grades vs. 0.1 ± 0.4 grades, Z = -4.035, p <0.001). After 10 minutes, measurements remained significantly higher than those in controls (maximum temperature change, 1.0 ± 0.7 °C vs. 0.1 ± 0.3 °C, F = 14.247, p <0.001; NITBUT change, 3.6 ± 2.1 seconds vs. 0.1 ± 1.9 seconds, p <0.001; TFLLT change, 1.5 ± 0.9 vs. 0.2 ± 0.5 grades, Z = -3.835, p <0.001). No adverse events occurred during the study. CONCLUSIONS: The MGDRx EyeBag is a simple device for heating the eyelids, resulting in increased NITBUT and TFLLT in subjects without meibomian gland dysfunction that seem to be clinically significant. Future studies are required to determine clinical efficacy and evaluate safety after long-term therapy in meibomian gland dysfunction patients. Copyright © 2014 American Academy of Optometry.

Direct observation of extremely low temperature catalytic dehydrochlorination of 1,1,1-trichloroethane over platinum

Fast X-ray photoelectron spectroscopy reveals that the efficient catalytic destruction of 1,1,1-trichloroethane occurs over Pt{111} surfaces at temperatures as low as 150 K. Decomposition occurs via rapid, sequential C-Cl bond scission to form an alkylidyne surface intermediate that in turn dehydrogenates above room temperature. Atomic chlorine liberated during dehydrochlorination undergoes efficient reaction with surface hydrogen, resulting in the evolution of gaseous HCl and small amounts of ethane, presumably via ethylidyne hydrogenation. Irreversible dehydrogenation of residual hydrocarbon fragments results in significant surface coking above 500 K.

Assembly of a high-dielectric constant thin TiOX layer directly on H-terminated semiconductor diamond

A high-dielectric constant (high-k) TiOx thin layer was fabricated on hydrogen-terminated diamond (H-diamond) surface by low temperature oxidation of a thin titanium layer in ambient air. The metallic titanium layer was deposited by sputter deposition. The dielectric constant of the resultant TiOx was calculated to be around 12. The capacitance density of the metal-oxide-semiconductor (MOS) based on the TiOx/H-diamond was as high as 0.75 µF/cm2 contributed from the high-k value and the very thin thickness of the TiOx layer. The leakage current was lower than 10-13 A at reverse biases and 10-7A at the forward bias of -2 V. The MOS field-effect transistor based on the high-k TiOx/H-diamond was demonstrated. The utilization of the high-k TiOx with a very thin thickness brought forward the features of an ideally low subthreshold swing slope of 65 mV per decade and improved drain current at low gate voltages. The advantages of the utilization high-k dielectric for diamond MOSFETs are anticipated.