Advances of nanotechnologies for hydraulic fracturing of coal seam gas reservoirs: potential applications and some limitations in Australia

Some of the most promising potential applications of nanotechnology to hydraulic fracturing of coal seam gas (CSG) are reviewed with a focus on Australian CSG wells. Three propitious applications were identified: (1) Nanoparticle enhanced viscoelastic surfactants (VES) fracturing fluids to prevent fluid loss by up to 30%, made possible by the formation of pseudo-filter cakes and reducing the viscosity of the VES fluids. Besides, there is no requirement of clay control additives or biocides. (2) Nano-proppants to extend fracture networks and reduce proppant embedment by introducing them prior to the emplacement of larger proppants. Fly Ash nanoparticles can be particularly effective because of their high sphericity and mechanical strength. (3) Nanoparticle-coated proppants, to mitigate the migration of particle fines by restricting them close to their source by adsorption, with MgO being the most effective. The use of nanotechnology in hydraulic fracturing applications is currently hindered due to a discordant regulatory environment compounded by the cost of the nanoparticles themselves, as well as, a lack of field data to validate the technology under real downhole conditions. Although the necessary field tests are unlikely to be conducted for as long as abundant natural gas is available, exploratory studies could pave the way for future applications

Physical factors affecting longevity and germination of seed of Western dwarfmistletoe (Arceuthobium campylopodum Engelm. f. campylopodum)

Longevity and germination of seed of western dwarfmistletoe (Arceuthobium campylopodum Engelm. f. campylopodum) of ponderosa pine (Pinus ponderosa Laws.) was investigated to determine: 1) the influence of humidity and temperature on seed viability and deterioration during storage; 2) the physiology of seed dormancy; 3) the composition of seed reserve food at intervals during dormancy, and 4) the influence of temperature, moisture and light on seed germination. Standard procedures were used for chemical analyses and paper chromatography; moisture conditions during germination were controlled over gradients of sulfuric acid, while light intensities and temperatures were maintained in standard growth chambers. Seed were collected in paper bags and stored both in shelters in the field and in the laboratory refrigerator. Viability determinations were made with one percent triphenyltetrazolium chloride or three percent hydrogen peroxide whereas the criterion for seed germination was radicle emergence. Western dwarfmistletoe seed, after expulsion in the fall, remain dormant for approximately six months. Preliminary investigations suggested dormancy is regulated by a chemical inhibitor associated with the endocarp. Initial seed viability varied from one infected stand to another, whereas retention of viability was correlated with temperature. Seed stored at 1.5°C retained initial viability levels for 10 months; after 10 months seed began to significantly deteriorate. In some cases, however, viability was observed after a prolonged storage period of 48 months. Western dwarfmistletoe seed germinate over a temperature range from 1.5 to 31°C. The optimum constant temperature lies between 15 and 20°C, whereas various combinations of alternating night-day temperatures revealed a combination of 5 to 15°C to be most favorable for germination. Absorption of liquid moisture is essential for germination and germination readily occurs at reduced levels of aeralion. Germination also occurs in total darkness; however, light intensities between 200 and 1000 foot candles in conjunction with favorable temperatures significantly enhance germination. Increases in photoperiod up to 24 hours progressively increased germination percentages. Red light was slightly more effective in seed germination than far-red light. Black light (near ultraviolet) was injurious to seed when levels were greater than 120 foot candles and exposures exceeded 12 hours. Unfavorable temperatures, moisture, and light during the 30 days following seed discharge appeared to be the most contributory factors toward low seed viability and accompanying low infection potentials

A gauge theory of the hamiltonian reduction for the rational Calogero - Moser system

A gauge theory equivalent to the hamiltonian reduction scheme for rational Calogero - Moser model is presented.Comment: LaTeX, 2 figures. To appear in Phys.Lett.

The Atacama Cosmology Telescope: ACT-CL J0102-4215 "El Gordo," a Massive Merging Cluster at Redshift 0.87

We present a detailed analysis from new multi-wavelength observations of the exceptional galaxy cluster ACT-CL J0102-4915, likely the most massive, hottest, most X-ray luminous and brightest Sunyaev-Zel'dovich (SZ) effect cluster known at redshifts greater than 0.6. The Atacama Cosmology Telescope (ACT) collaboration discovered ACT-CL J0102-4915 as the most significant Sunyaev-Zeldovich (SZ) decrement in a sky survey area of 755 square degrees. Our VLT/FORS2 spectra of 89 member galaxies yield a cluster redshift, z = 0.870, and velocity dispersion, sigma(gal) +/- 1321 106 km s-1. Our Chandra observations reveal a hot and X-ray luminous system with an integrated temperature of T(X) = 14:5 +/- 0:1 keV and 0.5 2.0 keV band luminosity of L(X) = (2:19 0:11) 1045 h(exp -2)70erg s-1. We obtain several statistically consistent cluster mass estimates; using empirical mass scaling relations with velocity dispersion, X-ray Y(X) , and integrated SZ distortion, we estimate a cluster mass of M(200) = (2:16 +/- 0:32) 10(exp 15) h(exp-1) 70M compared to the Sun. We constrain the stellar content of the cluster to be less than 1% of the total mass, using Spitzer IRAC and optical imaging. The Chandra and VLT/FORS2 optical data also reveal that ACT-CL J0102-4915 is undergoing a major merger between components with a mass ratio of approximately 2 to 1. The X-ray data show significant temperature variations from a low of 6:6 +/- 0:7 keV at the merging low-entropy, high-metallicity, cool core to a high of 22 +/- 6 keV. We also see a wake in the X-ray surface brightness and deprojected gas density caused by the passage of one cluster through the other from which we estimate a merger speed of around 1300 km s(exp -1) for an assumed merger timescale of 1 Gyr. ACTCL J0102-4915 is possibly a high-redshift analog of the famous Bullet Cluster. Such a massive cluster at this redshift is rare, although consistent with the standard CDM cosmology in the lower part of its allowed mass range. Massive, high-redshift mergers like ACT-CL J0102-4915 are unlikely to be reproduced in the current generation of numerical N-body cosmological simulations