System for plotting subsoil structure and method therefor

Data for use in producing a tomograph of subsoil structure between boreholes is derived by pacing spaced geophones in one borehole, on the Earth surface if desired, and by producing a sequence of shots at spaced apart locations in the other borehole. The signals, detected by each of the geophones from the various shots, are processed either on a time of arrival basis, or on the basis of signal amplitude, to provide information of the characteristics of a large number of incremental areas between the boreholes. Such information is useable to produce a tomograph of the subsoil structure between the boreholes. By processing signals of relatively high frequencies, e.g., up to 100 Hz, and by closely spacing the geophones, a high resolution tomograph can be produced

Spectroscopy of the post-AGB star HD 101584(IRAS 11385-5517)

From an analysis of the spectrum (4000\AA to 8800\AA) of HD~101584 it is found that most of the neutral and single ionized metallic lines are in emission. The forbidden emission lines of [OI] 6300\AA and 6363\AA and [CI] 8727\AA are detected, which indicate the presence of a very low excitation nebula. The H$\alpha$, FeII 6383\AA, NaI D$_{1}$, D$_{2}$ lines and the CaII IR triplet lines show P-Cygni profiles indicating a mass outflow. The H$\alpha$ line shows many velocity components in the profile. The FeII 6383\AA also has almost the same line profile as the H$\alpha$ line indicating that they are formed in the same region. From the spectrum synthesis analysis we find the atmospheric parameters to be T$_{eff}$=8500K, log g=1.5, V$_{turb}$=13km~s$^{-1}$ and [Fe/H]=0.0. From an analysis of the absorption lines the photospheric abundances of some of the elements are derived. Carbon and nitrogen are found to be overabundant. From the analysis of Fe emission lines we derived T$_{exi}$=6100K$\pm$200 for the emission line region.Comment: To appear in A&A, 15 pages, 11 figure

Transformations of q-boson and q-fermion algebras

We investigate the algebras satisfied by q-deformed boson and fermion oscillators, in particular the transformations of the algebra from one form to another. Based on a specific algebra proposed in recent literature, we show that the algebra of deformed fermions can be transformed to that of undeformed standard fermions. Furthermore we also show that the algebra of q-deformed fermions can be transformed to that of undeformed standard bosons.Comment: 7 pages, RevTe

Optimum solids concentration in an agitated vessel

Particle suspension in high-concentration slurries has been studied using radial-, mixed-, and axial-flow impellers. Impeller power measurements in this study were linked to the mass of solids suspended in the agitation system rather than the suspension volume. This approach was based on the consideration that the rate of dissolution or reaction depends to a large extent on the exposed surface area or mass of solids and might not be affected by the suspension volume, once off-bottom suspension is achieved. It was found that the specific power, based on the mass of solids, can be minimized by operating the system at relatively higher solids concentrations in the range of 0.20-0.35 (v/v) for the solids, impeller types, and geometrical conditions used in this work. Overall, improved energy efficiency can be achieved by using higher-power-number impellers under unbaffled conditions over a range of solids concentrations. A case example is illustrated to demonstrate the benefits of adopting some of the optimization methods highlighted in this article

Assessment of the ecological health of Vellar and Ennore estuarine ecosystems using health indices

1580-1592Coastal and marine environments face various perturbations which include a variety of industrial wastes and other toxic compounds accruing from shore line industries. Dumping of fly ash slurry and coolant water from thermal power plant is known to affect the physico-chemical nature of the estuarine environment and thereby cause severe damage to the benthic organisms. To combat this, the European Water Framework Directive (WFD) developed a suite of health indices, of which, the AMBI (AZTI- Marine Biotic Index) index is proved to be efficient in assessing the ecological status of marine environment by using the macro benthic communities. In this backdrop, the present study was made to ascertain the ecological health of Vellar and Ennore estuarine regions using AMBI and M-AMBI (Multivariate- AZTI Marine Biotic Index) indices. The AMBI values (0.391 to1.13) and M-AMBI (0.92 to 0.96) calculated for the Vellar estuary indicated relatively undisturbed nature and high ecological quality while the values calculated for Ennore estuary (AMBI: 2.032 to 4.146 and M-AMBI: 0.27 to 0.76) signaled moderately disturbed nature and poor ecological quality of the system. The present study proves that there is an immense scope for application of AMBI & M-AMBI in ecological health assessment studies

Five-year findings of a comparison of ambulatory short course chemotherapy with radical surgery plus chemotherapy for tuberculosis of the spine in Madras

A controlled clinical trial was undertaken to compare the efficacy of short course chemotherapy given alone or combined with radical surgery in the treatment of spinal tuberculosis without paraplegia. Patients with active spinal tuberculosis involving the vertebral bodies and without paraplegia were randomly allocated to one of the following three regimens. (a) Rad 6 : Radical anterior resection with bone grafting plus six months of daily isoniazid and rifampicin. (b) Amb 6 : Ambulatory chemotherapy with six months of daily isoniazid and rifampicin, without surgery. (c) Amb 9 : Same as (b) but the duration being nine months. The patients were intensively followed up for five years from the start. At five years, 98% of 86 Amb 9, 91% of 82 Amb 6 and 88% of 82 Rad 6 patients had a favourable status. It is concluded that ambulatory chemotherapy for 6 or 9 months is highly effective in the treatment of spinal tuberculosis. Radical surgery did not enhance the efficacy of the short course regimen

Percolating through networks of random thresholds: Finite temperature electron tunneling in metal nanocrystal arrays

We investigate how temperature affects transport through large networks of nonlinear conductances with distributed thresholds. In monolayers of weakly-coupled gold nanocrystals, quenched charge disorder produces a range of local thresholds for the onset of electron tunneling. Our measurements delineate two regimes separated by a cross-over temperature $T^*$. Up to $T^*$ the nonlinear zero-temperature shape of the current-voltage curves survives, but with a threshold voltage for conduction that decreases linearly with temperature. Above $T^*$ the threshold vanishes and the low-bias conductance increases rapidly with temperature. We develop a model that accounts for these findings and predicts $T^*$.Comment: 5 pages including 3 figures; replaced 3/30/04: minor changes; final versio

Short-course chemotherapy for tuberculosis of the spine : A comparison between ambulant treatment and radical surgery - a ten year report.

We perfomed a randomised, controlled clinical trial to compare ambulant short-course chemotherapy with anterior spinal fusion plus short-course chemotherapy for spinal tuberculosis without paraplegia. Patients with active disease of vertebral bodies were randomly allocated to one of three regimens: a) radical anterior resection with bone grafting plus six months of daily isoniazid plus rifampicin (Rad6); b) ambulant chemotherapy for six months with daily isoniazid plus rifampicin (Amb6); or c) similar to b) but with chemotherapy for nine months (Amb9). Ten years from the onset of treatment, 90% of 78 Rad6, 94% of 78 Amb6 and 99% of 79 Amb9 patients had a favourable status. Ambulant chemotherapy for a period of six months with daily isoniazid plus rifampicin (Amb6) was an effective treatment for spinal tuberculosis except in patients aged less than 15 years with an initial angle of kyphosis of more than 30° whose kyphosis increased substantially