Lunar resources: a review

There is growing interest in the possibility that the resource base of the Solar System might in future be used to supplement the economic resources of our own planet. As the Earth’s closest celestial neighbour, the Moon is sure to feature prominently in these developments. In this paper I review what is currently known about economically exploitable resources on the Moon, while also stressing the need for continued lunar exploration. I find that, although it is difficult to identify any single lunar resource that will be sufficiently valuable to drive a lunar resource extraction industry on its own (notwithstanding claims sometimes made for the 3He isotope, which are found to be exaggerated), the Moon nevertheless does possess abundant raw materials that are of potential economic interest. These are relevant to a hierarchy of future applications, beginning with the use of lunar materials to facilitate human activities on the Moon itself, and progressing to the use of lunar resources to underpin a future industrial capability within the Earth-Moon system. In this way, gradually increasing access to lunar resources may help ‘bootstrap’ a space-based economy from which the world economy, and possibly also the world’s environment, will ultimately benefit

Lacrimal glands structure components of the laboratory rat

Conclusion: The lacrimal glands of laboratory rats have an individual well-defined connective tissue capsule. The intraepithelial interstitial spaces contain vessels of the hemomicrocirculatory tract, mainly capillaries, precapillary arteries, and postcapillary venules, in the volume of the extraorbital and infraorbital glands. Arterioles and venules are usually visualized for its boundaries

Thermal characterization of polymer composites with nanocrystalline maghemite

Samples of multiblock poly(ether-ester) copolymer doped with magnetic γFe2O3 nanoparticles (at small concentrations of 0.1 wt. % and 0.3 wt. %) have been investigated by DSC method to study the melting and crystallization behavior. Two forms of magnetic γFe2O 3 nanoparticle filler were used: solid-state grains and a suspension of γFe2O3 with palmitic acid in toluene. Application of the solid filler caused formation of agglomerates of size of about 20 μm while in the suspension form separate nanoparticles were in the range 10-20 run. The thermal and thermo-oxidative stability of composites was analyzed by conventional TGA analysis. The DSC results showed that crystallization and, to a smaller extent, melting, were considerably affected by the introduction of magnetic nanoparticles. The main influence is a shift in the crystallisation temperature up to 20 °C and melting/glass transition shift up to 6 °C. Thermogravimetric analysis showed significant enhancement of thermal and thermo-oxidative stability of the composites with respect to pure PEE. The dependence of thermal parameters on the concentration of magnetic filler has shown that the largest agglomerates produced the biggest change in all thermal parameters

Influence of maghemite concentration on magnetic interactions in maghemite/PTT-block-PTMO nanocomposite

Temperature dependence of dc magnetization and ferromagnetic resonance (FMR) of two samples containing γ-Fe2O3 (maghemite) magnetic nanoparticles dispersed at low concentration (0.1 and 0.3 wt%) in a nanocomposite based on a poly(ether-ester) multiblock copolymer (PTT-block-PTMO) matrix was investigated. The polymer filler was in a powder form consisting of small-sized magnetic nanoparticles arranged in agglomerates 2-3 μm long and 100 nm thick. The studied samples were characterized by SEM spectroscopy. The SEM showed that the concentration of magnetic nanoparticles was homogenous in both samples The temperature dependence of the dc magnetization revealed that the blocking was about 100 K and the ZFC (zero-field cooling) mode at low magnetic fields uncovered the presence of magnetic interactions between magnetic nanoparticles depending on the properties of the matrix. FMR measurements were carried out in the temperature range 4.2-300 K. An intense resonance absorption line attributed to γ-Fe2O3 nanoparticles was recorded with a slightly asymmetric lineshape. At room temperature the resonance line was centered at Hr = 3241(2) and 3253(2) G, with linewidths of ΔH = 1069(1) and 1070(1) G for samples with concentrations of 0.1 and 0.3 wt%, respectively. All FMR parameters showed an anomalous behavior at matrix critical temperatures. It was shown that the difference in concentration of magnetic nanoparticles could be responsible for the observed differences in the thermal behavior of the FMR spectra. © 2008 Elsevier B.V. All rights reserved