Aircraft validation of ERS-1 ATSR and NOAA-14 AVHRR sea surface temperature measurements

Infrared brightness temperature (BT) measurements obtained from the UK Meteorological Research Flight C-130 Hercules aircraft, spatially coincident and near contemporaneous with ERS-1 Along Track Scanning Radiometer (ATSR) and NOAA-14 Advanced Very High Resolution Radiometer (AVHRR), are presented. These data have been used to obtain much needed on-going validation of the ERS-1 ATSR prior to the de-commissioning of the ATSR instrument in March 1997. BT comparisons between the ATSR and AVHRR nadir channels show negligible differences of 0.3 deg K, indicating that both radiometers are well calibrated. However, significant differences are found when common sea surface temperature (SST) algorithms are applied to the BT data. The original dual view ERS-1 ATSR skin SST (SSST) algorithm has a 0.6K cool bias relative to the in situ observations, which is consistent with other in situ validation studies. New SSST coefficients derived using the same atmospheric transmission model show that, when the appropriate pixel noise contribution is considered in the algorithm derivation, substantially improved SSST is derived from the ERS-1 ATSR. Comparing the NOAA-14 AVHRR non-linear SST (NLSST) and multi-channel SST (MCSST) algorithms to the aircraft data, the non-linear nature of the NLSST algorithm results in a small bias of 0.3 deg K compared to a substantial cool bias of 1 deg K in the MCSST case. This result highlights deficiencies in the MCSST.     

Characterization of copper layers produced by cold gas-dynamic spraying

The cold gas-dynamic spray method produces coatings or deposits by introducing solid feedstock particles into a supersonic gas stream developed through the use of a converging-diverging (de Laval) nozzle. The particles thus accelerated impact on a substrate surface and develop into a dense deposit through a process believed to be similar to cold compaction. The work reported here explores the internal nature and physical characteristics of copper deposits produced by the cold gas-dynamic spray method using two vastly different starting powders: in one case, a “spongy” copper obtained by a direct-reduction process, and in the second, a denser, more spheroidal particulate produced by gas atomization. Optical and electron microscopies (scanning electron microscopy [SEM] and transmission electron microscopy [TEM]) were used to observe details of microstructure in the feedstock particles and deposits. Young’s modulus and residual stress measurements for the deposits were obtained through mechanical means, and measurements of hardness and electrical conductivity are reported. The internal structure of the cold-spray deposit was influenced by the surface purity of the feedstock material.     

Toxicity of N-substituted aromatics to acetoclastic methanogenic activity in granular sludge

N-substituted aromatics are important priority pollutants entering the environment primarily through anthropogenic activities associated with the industrial production of dyes, explosives, pesticides, and pharmaceuticals. Anaerobic treatment of wastewaters discharged by these industries could potentially be problematical as a result of the high toxicity of N-substituted aromatics. The objective of this study was to examine the structure-toxicity relationships of N-substituted aromatic compounds to acetoclastic methanogenic bacteria. The toxicity was assayed in serum flasks by measuring methane production in granular sludge. Unacclimated cultures were used to minimize the biotransformation of the toxic organic chemicals during the test. The nature and the degree of the aromatic substitution were observed to have a profound effect on the toxicity of the test compound. Nitroaromatic compounds were, on the average, over 500-fold more toxic than their corresponding aromatic amines. Considering the facile reduction of nitro groups by anaerobic microorganisms, a dramatic detoxification of nitroaromatics towards methanogens can be expected to occur during anaerobic wastewater treatment. While the toxicity exerted by the N-substituted aromatic compounds was closely correlated with compound apolarity (log P), it was observed that at any given log P, N-substituted phenols had a toxicity that was 2 orders of magnitude higher than that of chlorophenols and alkylphenols. This indicates that toxicity due to the chemical reactivity of nitroaromatics is much more important than partitioning effects in bacterial membranes.     

Use of anaerobic hybrid reactors for treatment of synthetic pharmaceutical wastewaters containing organic solvents

The performance of anaerobic hybrid reactors treating an organic solvent-containing synthetic pharmaceutical wastewater was evaluated under various wastewater volumetric loading rates and influent compositional changes. The biodegradation, toxicity and treatability of the target C₃ and C₄ solvents, tert-butanol, isopropanol, isobutanol, sec-butanol and ethyl acetate, were examined. At a hydraulic retention time (HRT) of 2 days and volumetric loading rates ranging from 3·5 to 4·5 kg COD m⁻³ day⁻¹, the reactors achieved total and soluble COD removal efficiencies of 97–99% in less than five times the HRT. These removal rates were achieved following the introduction of target solvents not previously supplied to the reactors. However, inadequate removal of tert-butanol resulted in a decrease in the soluble COD removal efficiency to 58%. Bacterial enrichments from the reactor biomass using tert-butanol as the sole substrate proved unsuccessful, confirming that tert-butanol is poorly degradable anaerobically. Inclusion of a trace metal cocktail in the feed did not affect steady-state reactor performance, but was beneficial during changes in the influent composition. After 405 days of operation, the matrix-associated biomass contributed only a minor fraction (2–4%) of the total biomass present in both reactors. On takedown, the retained biomass present in the matrix-free section of both reactors was found to be granular in nature, despite the omission of trace elements from the influent to one of the AHRs. The specific methanogenic activity profile of the granular sludge from the trace element limited AHR was, however, significantly lower (α = 0·05) than that of the reference AHR.     

Precipitation of aluminum in the silicon phase contained in W319 and 356 aluminum alloys

Solidification of Al-Si alloys typically yields regions of a eutectic mixture of aluminum and silicon phases. In 319-type and 356 aluminum alloys, we have determined that a small percentage (10 to 25 pct) of the silicon phase contains small (10 to 15 nm) equiaxed precipitates of aluminum as identified by electron diffraction with an orientation relation to the silicon matrix:

The human lysyl oxidase-related gene (LOXL2) maps between markers D8S280 and D8S278 on chromosome 8p21.2-p21.3

OBJECTIVE: bcl-2 is a protein which prohibits programmed cell death. The purpose of this study was to determine whether bcl-2 staining was related to traditional prognostic factors and/or recurrence in patients with endometrial carcinoma. METHODS: One hundred twenty consecutively surgically treated patients with endometrial carcinoma had their tumors studied immunohistochemically for bcl-2 staining. RESULTS: The mean follow-up of the patients was 53 months with a median of 56 months (range 30 to 68 months). bcl-2 staining was positive in 44.0% of patients with endometrioid carcinomas and in 23. 1% of patients with nonendometrioid carcinomas (P < 0.001). Increasing depth of invasion (P = 0.014), grade (P = 0.011), and FIGO stage (P = 0.018) were each correlated with decreasing bcl-2 staining. bcl-2 staining was positive in 44.1% of patients whose tumors showed no lymphovascular space invasion and in 11.1% of patients with lymphovascular space invasion (P < 0.001). Only 1 of 26 patients with recurrent disease had persistence of bcl-2 staining. Multivariate analysis revealed FIGO stage (P = 0.0051), histologic grade (P = 0.050), and lack of staining for bcl-2 (P = 0.012) to be independent predictors of recurrence. CONCLUSION: bcl-2 persistence is more common in endometrioid than in nonendometrioid adenocarcinomas of the endometrium. It appears to be inversely correlated with the universally recognized prognostic factors of depth of invasion, histologic grade, and FIGO stage. Lack of bcl-2 persistence was an independent predictor of recurrence of disease. This group of patients continues to be followed to determine the role of bcl-2 persistence or lack of persistence as a predictor of 5-year survival of patients with endometrial carcinoma.     

The nature of sialon joints between silicon nitride based bodies

Quite strong joints between silicon nitride based bodies have been made by incorporating a layer of aluminium and oxides between the bodies and heating in a nitriding atmosphere. The joints are resistant to thermal shock and maintain their strength at 1200° C. Microscopic, DTA and X-ray diffraction studies indicated that sialon phases are present in the joints, and that the bonding reaction involves the reduction of Si₃N₄ by aluminium and the subsequent renitriding of the resultant silicon, as well as the simultaneous nitriding of a portion of the aluminium. Transmission electron microscopy of a joint between hot pressed and reaction bonded silicon nitrides showed that 15R aluminium nitride polytype sialon was present on the reaction bonded side of the joint and ß-sialon on the hot pressed side.     

Power modules for appliance motor control

The use of inverters in appliance applications is increasing rapidly. This paper describes hybrid power modules that utilize a unique injection-molded lead-frame design and provide the cost-effective integration of power devices, gate drive and protection for such applications     

Effect of atmospheric radiance errors in radiometric sea-surface skin temperature measurements

Errors in measurements of sea-surface skin temperature (SSST) caused by inappropriate measurements of sky radiance are discussed; both model simulations and in situ data obtained in the Atlantic Ocean are used. These errors are typically caused by incorrect radiometer view geometry (pointing), temporal mismatches between the sea surface and atmospheric views, and the effect of wind on the sea surface. For clear-sky, overcast, or high-humidity atmospheric conditions, SSST is relatively insensitive (<0.1 K) to sky-pointing errors of ?10 degrees and to temporal mismatches between the sea and sky views. In mixed-cloud conditions, SSST errors greater than ?0.25 K are possible as a result either of poor radiometer pointing or of a temporal mismatch between the sea and sky views. Sea-surface emissivity also changes with sea view pointing angle. Sea view pointing errors should remain below 5 degrees for SSST errors of <0.1 K. We conclude that the clear-sky requirement of satellite infrared SSST observations means that sky-pointing errors are small when one is obtaining in situ SSST validation data at zenith angles of <40 degrees . At zenith angles greater than this, large errors are possible in high-wind-speed conditions. We recommend that high-resolution inclinometer measurements always be used, together with regular alternating sea and sky views, and that the temporal mismatch between sea and sky views be as small as possible. These results have important implications for the development of operational autonomous instruments for determining SSST for the long-term validation of satellite SSST.     

Peat Biofiltration as an Odour Control Technology for Sulphur-Based Odours

Due to their low odour thresholds and common occurrence in sewage-treatment operations, volatile sulphur compounds are generally considered to be the most significant malodorants at sewage-treatment works. Biofiltration is an odour-control technology which has proven success in industrial and agricultural applications, and in more recent years has been applied in the water industry.
Experiments were carried out using a test rig to measure the removal efficiencies of hydrogen sulphide and methyl mercaptan, when passed through peat-based materials, under a range of environmental conditions. Temperature, gas loading rate and inoculation with sulphur oxidizing bacteria were all found to significantly affect performance. Removal rates of over 99% of hydrogen sulphide, and 95% methyl mercaptan were achieved. Investigations of full-scale installations at sewage-treatment works supported the experimental results.