Lignoceric Acid and Hexacosanoic Acid: Major Components of Soldier Frontal Gland Secretions of the Formosan Subterranean Termite (Coptotermes formosanus)

Qualitative and quantitative analyses were performed on trimethylsilyl derivatives of soldier frontal gland secretions of the Formosan subterranean termite, Coptotermes formosanus Shiraki, by using gas chromatography–mass spectrometry. Ranges of 17.23–33.78 mg/g (acid/wet weight of secretion) of lignoceric acid and 5.39–7.67 mg/g of hexacosanoic acid were found in the soldier frontal gland secretion of three different colonies. This is the first report that organic acids occur in the soldier secretions of this species.     

An automated three-dimensional plus time registration framework for dynamic MR renography

Dynamic contrast-enhanced 3D images of the kidneys, or 3D MR renography, has the potential for broad clinical applications, but suffers from respiratory motion that limits analysis and interpretation. Manual registration is prohibitively labor-intensive. In this paper, a fully automated technique, Wavelet Representation and the Fourier Transform (WRFT) method, that corrects for translation and rotation motion in 3D MR renography is presented. The method was composed by anisotropic denoising, wavelet-based feature extraction, and Fourier-based registration. This was first evaluated on a set of simulated MR renography images with defined degrees of kidney motion. The method was then tested on 24 clinical patient MR renography data sets. Results of clinical testing were compared with the results obtained using a mutual information registration method. Based on intrarenal time-intensity curves, our method showed robust and consistent agreement with the results of manually coregistered data sets.     

Flame Spray Pyrolysis of Precursors as a Route to Nano-mullite Powder: Powder Characterization and Sintering Behavior

The flame spray pyrolysis of alcohol-soluble precursors allows the synthesis of mullite-composition nanopowders (average size of ∼60–100 nm) that, when annealed carefully, provide processable nano-mullite powders. The powders have been characterized using several spectroscopic and microscopy methods, including thermal gravimetric analysis, differential thermal analysis, diffuse reflectance infrared Fourier transform spectroscopy, and transmission electron microscopy. Preliminary studies on the pressureless-sintering behavior of these powders are presented. Without additives or any efforts to optimize the process, powder compacts could be sintered to relative densities of >90%, with grain sizes of <500 nm at 1600°C.     

Particle packing simulations based on Newtonian mechanics

A program to simulate the packing of round particles was made in the course of this work. The theoretical packing of the particles was studied in 3-dimensional situations with the program. The effects of friction, elasticity, size and spring co-efficient on packing were examined. It was observed that increased friction caused decreased packing density. Elasticity had a minor effect on the density, while the spring constant defining the interactions between particles had a minimal effect.     

A Transient Behaviour in the Initial Production of Aromatic Compounds from Methane Catalyzed by Mo/HZSM-5

The production of aromatic compounds directly from methane using catalysts based on zeolite HZSM-5 impregnated with molybdenum was investigated using a flow reactor at 750 °C. Main products were benzene and naphthalene as well as toluene and others like azulene in smaller amounts. Naphthalene appeared after benzene following an induction period suggesting a consecutive reaction path. A transient behavior in the production of naphthalene was observed along the time on stream, being benzene practically the only product at the steady state. The transient behavior disappeared when increasing contact time, which produced more naphthalene at the expense of benzene.     

Antarctic ice sheet and sea ice regional albedo and temperature change, 1981-2000, from AVHRR Polar Pathfinder data

Spring-summer (November, December, January) ice sheet and sea ice regional surface albedo, surface temperature, sea ice concentration and sea ice extent averages and trends from 1981 to 2000 have been calculated for the Antarctic area. In this research the AVHRR Polar Pathfinder 5-km EASE-Grid Composites and the combined SMMR and SSMI data sets from the National Snow and Ice Data Center (NSIDC), Boulder, Colorado have been employed. A regional analysis has been made for five longitudinal sectors around Antarctica: the Weddell Sea (WS), the Indian Ocean (IO), the Pacific Ocean (PO), the Ross Sea (RS) and the Bellingshausen-Amundsen Sea (BS). The IO and PO sectors show ice sheet albedos of 0.85 and temperatures of − 25 °C. The corresponding values in the RS and BS sectors are 0.80 and − 16 °C respectively. The sea ice albedo is about 0.60 in the RS, BS and WS sectors and 0.55 in the IO and PO sectors. The average sea ice temperature varies around − 12 °C. All the sectors show slight increasing spring-summer albedo trends and decreasing spring-summer temperature trends and similar interannual variability in albedo and surface temperature. The steepest ice sheet albedo trend of 0.0019 ± 0.0009/yr is found in the RS sector. The steepest sea ice albedo trend of 0.0044 ± 0.0017 /yr occurs in the PO sector. The steepest temperature trends for both the ice sheet and sea ice occur in the BS sector, having values of − 0.075 ± 0.040 °C/yr and − 0.107 ± 0.027 °C/yr respectively. The sea ice concentration shows slight increasing trends, the highest being in the PO sector (0.3 ± 0.12%/yr), whereas the sea ice extent trends are near zero with the exception of the RS sector (14,700 ±8600 km²/yr) and the BS sector (− 13,000 ± 6400 km²/yr).     

The Determination of relative amounts of Phases in Binary Mixtures with Quantitative X-Ray Diffraction

The quantitative x-ray diffraction analysis offers often an exact and practical technique to determine the relative amounts of the phases of the solid in question. The sample may contain only one amorphous phase.

The purpose of this paper is to estimate the suitability of this technique to quantify the phase fractions of pharmaceutical substances. Three different method were used to determine the relative amounts of phases. Methods were compared and the major sources of error were estimated. The measurements and calculations are carried out using selegilin hydrochloride, mannitol and modified starch as an example. The results show that the amount of about 2 % of selegilin hydrochloride can be observed reliably from among the mannitol (crystalline substance) or modified starch (amorphous substance). During the work it became obvious that the accuracy of these calculations can essentially be improved planning the measurements carefully.