Split-window and multi-angle methods of sea surface temperature determination: An analysis

A physical model of split-window and multi-angle algorithms for the retrieval of sea surface temperature has been obtained. It is shown that optical thickness in the thermal infrared window region is approximately represented by a separable function of wavelength and atmospheric variables which greatly simplify the radiative transfer model. In modelling the temperature retrieval algorithms we exploit the correlation that exists between the sea surface temperature and the average temperature of the atmosphere. It is shown that, to the extent this correlation is maintained, there is a simple relationship between surface temperature and the brightness temperatures measured in two split-window or multi-angle channels. The different atmospheric conditions which cause spread in this relationship are briefly discussed. It is shown that measurements at three optical thicknesses instead of two as in the case of the split-window method improve the SST retrieval accuracy since it can take care of non-equilibrium conditions such as inversions, surface instabilities, etc., prevailing in the atmosphere.     

Insect borers of commercially important stored timber in the state of Kerala, India

About 100 commercially important timber species are being extracted from the natural forests and plantations in Kerala State (India), and stored in depots. The stored timber is often attacked by boring Coleoptera. In the present study, 68 species of borers were recorded as pests of 50 species of stored timber. Fourteen new host records are included. The timbers most susceptible to borer infestation were Anacardium occidentale, Bombax ceiba, Hevea brasiliensis, Mangifera indica, and Polyalthia fragrans susceptible to infestation by cerambycid, platypodid, scolytid, or bostrychid borers; and Artocarpus heterophyllus, Canarium strictum, Erythrina indica, Lophopetalum wightianum, Tetrameles nudiflora, and Vateria indica susceptible to infestation by scolytid, platypodid, or bostrychid borers. The nature and extent of damage by these borers warrants adoption of effective prophylactic treatments to timber stored in depots and storage yards.     

The effects of temperature on the partial wet oxidation of peat

The effects of three reaction temperatues, 180, 200 and 220°C, on the partial wet oxidation of peat were investigated. A stirred reactor with a five litre working volume and continuous feed of peat slurry and air was used for the experiments. The effluent was separated into liquid and solid fractions and analyzed to quantify the effects of temperature. The carbon content and heating value of the recovered solids increased with temperature but yields were lower. The composition of the wastewater was only slightly dependent on the reaction temperature, and in all cases contained high concentrations of organics.     

Economic and energy efficiency of salvaging biomass from wildfire burnt areas for bioenergy production in northwestern Ontario: A case study

Wildfire burnt forest biomass can be salvaged as feedstock for bioenergy power generating stations. Despite availability of such forest biomass in northwestern Ontario, its procurement has generally been considered uneconomic and no studies have looked into the cost of harvesting, processing, and transporting the burnt material for bioenergy production. In order to meet the demand of biomass for proposed and existing power generating stations using renewable fuels, a standard costing model is used to determine the feasibility of procuring biomass from burnt areas using a full-tree to roadside, roadside grinder to mill system. The case-study was conducted at the Hogarth Plantations near Thunder Bay, Ontario, Canada. The total cost incurred for processing and delivery of biomass from wildfire burnt area with a hauling distance of 7 km and total trip cycle time of 2.55 h was found to be $29.65 gt^?1, with net energy content of 11.4 GJ gt^?1. The total procurement cost depends on the hauling distance and a linear relationship between the two was established. The energy analysis found a net energy output to input ratio of 35:1 for the operation.     

Dielectric behavior of natural rubber composites in microwave fields

In this article, we report the preparation of conducting natural rubber (NR) with polyaniline (Pani). NR was made into a conductive material by the compounding of NR with Pani in powder form. NR latex was made into a conductive material by the in situ polymerization of aniline in the presence of NR latex. Different compositions of Pani–NR semi‐interpenetrating networks were prepared, and the dielectric properties of all of the samples were determined in microwave frequencies. The cavity perturbation technique was used for this study. A HP8510 vector network analyzer with a rectangular cavity resonator was used for this study. S bands 2–4 GHz in frequency were used. Thermal studies were also carried out with thermogravimetric analysis and differential scanning calorimetry. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2682–2686, 2007     

Rotating machinery prognostics: State of the art,challenges and opportunities

Machinery prognosis is the forecast of the remaining operational life, future condition, or probability of reliable operation of an equipment based on the acquired condition monitoring data. This approach to modern maintenance practice promises to reduce downtime, spares inventory, maintenance costs, and safety hazards. Given the significance of prognostics capabilities and the maturity of condition monitoring technology, there have been an increasing number of publications on rotating machinery prognostics in the past few years. These publications covered a wide spectrum of prognostics techniques. This review article first synthesises and places these individual pieces of information in context, while identifying their merits and weaknesses. It then discusses the identified challenges, and in doing so, alerts researchers to opportunities for conducting advanced research in the field. Current methods for predicting rotating machinery failures are summarised and classified as conventional reliability models, condition-based prognostics models and models integrating reliability and prognostics. Areas in need of development or improvement include the integration of condition monitoring and reliability, utilisation of incomplete trending data, consideration of effects from maintenance actions and variable operating conditions, derivation of the non-linear relationship between measured data and actual asset health, consideration of failure interactions, practicability of requirements and assumptions, as well as development of performance evaluation frameworks.     

Temperature dependence of the optical transitions in CdTe thin film – Investigation with photoresponse spectra

The CdTe thin films have been prepared by electrochemical method from a bath solution containing cadmium sulfate and tellurium dioxide. Schottky devices of the type Au/CdTe were prepared and the spectral response of the device has been investigated. The direct and indirect transitions in the 1.3–1.6 eV region were calculated from the normalized spectral response data. The temperature dependence of the band gap have been investigated and correlated with the theory. The band gap of CdTe at absolute zero temperature is estimated as 1.61 eV and that the rate of change of E_g with temperature is calculated as −0.4 meV/K. The 1.407 eV indirect transition involves a trap level near the conduction band edge. The indirect transition also exhibits temperature dependence.     

Leiterrüstung an der Siegessäule Berlin

Ohne Zusammenfassung     

Volatile aroma compounds of raw and roasted palm kernel

The volatile aroma compounds of raw and roasted palm kernel, isolated by hydrodistillation, were analysed by g.l.c. and g.c.-m.s. A number of compounds have been identified for the first time in this commodity. It was found that δ-lactones and ethyl esters were predominant in the flavour profile. In roasted palm kernels, flavour analysis showed the presence of a number of pyrazines formed during heating. Most of the lactones and esters identified in raw palm kernel were present in the roasted samples also. The flavour concentrate included a number of fatty acids in both the raw and roasted samples, in small amounts.     

Dynamic mechanical analysis of novel composites from commingled polypropylene fiber and banana fiber

Polypropylene (PP)/banana fiber (BF) composites were fabricated from PP fiber and short BF by novel commingling method. The dynamic mechanical analysis (DMA) of the composites was performed with reference to BF loading and fiber surface treatments. By the incorporation of BF into the PP matrix, the storage modulus and loss modulus have been found to increase, whereas damping factor has been found to decrease. Glass transition temperature was found to increase with increase in BF loading. The viscoelastic properties of the composites were also found to depend on fiber surface treatments. The activation energy of the composites for the glass transition has been found to be increased by the increase in BF loading. Surface treatment of the BF further increased the activation energy of the composites, indicating a stronger interface for treated fiber composites. Scanning electron microscopy (SEM) photographs of the BF showed the physical changes induced by the surface treatments. Fourier transform infrared spectroscopy (FTIR) was used to ascertain the existence of the type of interfacial bonds. The use of theoretical equations to predict the storage modulus has also been discussed. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers