An Investigation of Size-Dependent Concentration of Trace Elements in Aerosols Emitted from the Oil-Fired Heating Plants

Aerosols emitted from two oil-fired heating plants were aerodynamically separated into eight size groups and were analyzed using the photon-induced X-ray emission (PIXE) technique. It was found that Zn, Mo, Ag, and Pb, and (to a lesser extent) Cd, have a tendency to concentrate preferentially on the smaller aerosols. All of these elements, in certain chemical forms, are known to be toxic. Zinc and molybdenum, although present in low concentrations in the parent fuels, show the strongest tendencies to be concentrated in finer aerosols. Selenium, previously reported to show a very strong tendency to concentration in finer fly ash from coal-fired power plants shows little preference for surface residence. Vanadium, which occurs in significant concentration in the oil fuels for both plants, also shows little preference for surface concentration. Even though the absolute concentrations of the toxic elements involved are well below the safety levels established by the National Institute for Occupational Safety and Health (NIOSH), it would be advisable to raise the heights of the heating-plant exhaust chimneys well above the neighborhood buildings to insure more efficient aerosol dispersal

PHYSICAL MUTAGENESIS BASED STRAIN IMPROVEMENT OF ASPERGILLUS SP. FOR ENHANCED PRODUCTION OF LOVASTATIN

Objective: The present investigation aimed towards the strain improvement of lovastatin maximum yielding wild-type fungal strains (Aspergillus terreus-MTCC 11045, Aspergillus terreus-MTCC 11395 and Aspergillus flavus-MTCC 11396) through physical mutagenesis by applying UV random mutations.Methods: Revival of fungal cultures on PDA plates followed by a screening of their morphological and microscopic properties. Strain improvement of screened fungi by UV (255 nm) random mutagenesis, selection of mutants based on morphological variations further submerged fermentation of selected (SmF) mutants, subsequently extraction of lovastatin from the spent broth and the extracts were analyzed for the presence of lovastatin by TLC and UV spectrophotometer scans (200-300 nm).Results: Out of eighteen screened mutant samples seven showed positive results for the lovastatin production. Among these seven positive cultures, Aspergillus terreus 11045-90 found to yield the maximum amount of lovastatin (3912 mg/l).Conclusion: The present study concludes by reporting the evidence of raised in the lovastatin titre by three-fold compared to the yield of the wild-type strain (996 mg/l) and confirms the achievement of strain improvement by UV random mutagenesis.Keywords: Aspergillus terreus, Lovastatin, UV Random mutations, Strain improvement, Submerged fermentatio

Adaptive Mechanical Properties of Topologically Interlocking Material Systems

Topologically interlocked material systems are two-dimensional granular crystals created as ordered and adhesion-less assemblies of unit elements of the shape of platonic solids. The assembly resists transverse forces due to the interlocking geometric arrangement of the unit elements. Topologically interlocked material systems yet require an external constraint to provide resistance under the action of external load. Past work considered fixed and passive constraints only. The objective of the present study is to consider active and adaptive external constraints with the goal to achieve variable stiffness and energy absorption characteristics of the topologically interlocked material system through an active control of the in-plane constraint conditions. Experiments and corresponding model analysis are used to demonstrate control of system stiffness over a wide range, including negative stiffness, and energy absorption characteristics. The adaptive characteristics of the topologically interlocked material system are shown to solve conflicting requirements of simultaneously providing energy absorption while keeping loads controlled. Potential applications can be envisioned in smart structure enhanced response characteristics as desired in shock absorption, protective packaging and catching mechanisms

Exploring of Antimicrobial Activity of Triphala Mashi—an Ayurvedic Formulation

Triphala Mashi is an ayurvedic formulation that was prepared in our lab. Aqueous and alcoholic extracts of both Triphala and Triphala Mashi were used, to evaluate antimicrobial activity. Comparative phytochemical profile of Triphala and Triphala Mashi was done by preliminary phytochemical screening, total phenolic content and thin layer chromatography (TLC). Antimicrobial activity includes isolation of pathogens from clinical samples, its characterization, testing its multiple drug resistance against standard antibiotics and antimicrobial activity of aqueous and alcoholic extracts of both Triphala and Triphala Mashi against these organisms by using agar gel diffusion method. Triphala Mashi containing phenolic compounds, tannins exhibited comparable antimicrobial activity in relation to Triphala against all the microorganisms tested. It inhibits the dose-dependent growth of Gram-positive and Gram-negative bacteria. In conclusion, it appears that Triphala Mashi has non-specific antimicrobial activity

A case series of percutaneous tension band wiring technique for fixation of fractures of olecranon and patella

There are several advantages in the treatment of fractures by means of closed reduction. Percutaneous fixation is a type of biological fixation. The aim and objectives of this study are to demonstrate the technique of percutaneous tension band wiring in cases of transverse, non- comminuted olecranon and patella fractures and to decrease the soft tissue dissection, blood loss, chances of infection and to ensure speedy mobilization using the innovative percutaneous fixation technique. This retrospective study includes ten patients of olecranon and ten patients of patella operated by the same surgeon. All patients were operated with percutaneous tension band wiring for olecranon and patella. There were six males and four females with olecranon fractures. There were seven males and three females who suffered patella fractures. The average duration of surgery was 55 minutes and average follow up was 24±6 weeks. The suture removal was done at 2 weeks. All patients had full range of movements at six weeks with significantly improved DASH score and Oxford knee score. None of the patients had any complications. Percutaneous fixation decreases the chances of bleeding secondary to unnecessary soft tissue dissection, thereby decreasing the post-operative morbidity. It also, convincingly, decreases the chances of post-operative infection and promotes early mobilization. Closed reduction with percutaneous fixation is believed to be an innovative, safe, reliable and efficient method of managing these difficult fractures

Comparison of exact solution with Eikonal approximation for elastic heavy ion scattering

A first-order optical potential is used to calculate the total and absorption cross sections for nucleus-nucleus scattering. The differential cross section is calculated by using a partial-wave expansion of the Lippmann-Schwinger equation in momentum space. The results are compared with solutions in the Eikonal approximation for the equivalent potential and with experimental data in the energy range from 25A to 1000A MeV

Nuclear Spin Relaxation for Higher Spin

We study the relaxation of a spin I that is weakly coupled to a quantum mechanical environment. Starting from the microscopic description, we derive a system of coupled relaxation equations within the adiabatic approximation. These are valid for arbitrary I and also for a general stationary non--equilibrium state of the environment. In the case of equilibrium, the stationary solution of the equations becomes the correct Boltzmannian equilibrium distribution for given spin I. The relaxation towards the stationary solution is characterized by a set of relaxation times, the longest of which can be shorter, by a factor of up to 2I, than the relaxation time in the corresponding Bloch equations calculated in the standard perturbative way.Comment: 4 pages, Latex, 2 figure

Physics of the Insulating Phase in the Dilute Two-Dimensional Electron Gas

We propose to use the radio-frequency single-electron transistor as an extremely sensitive probe to detect the time-periodic ac signal generated by sliding electron lattice in the insulating state of the dilute two-dimensional electron gas. We also propose to use the optically-pumped NMR technique to probe the electron spin structure of the insulating state. We show that the electron effective mass and spin susceptibility are strongly enhanced by critical fluctuations of electron lattice in the vicinity of the metal-insulator transition, as observed in experiment.Comment: 5 pages, 2 figures, uses jetpl.cls (included). v.4: After publication in JETP Letters, two plots comparing theory and experiment are added, and a minor error is correcte

Skyrmion Dynamics and NMR Line Shapes in QHE Ferromagnets

The low energy charged excitations in quantum Hall ferromagnets are topological defects in the spin orientation known as skyrmions. Recent experimental studies on nuclear magnetic resonance spectral line shapes in quantum well heterostructures show a transition from a motionally narrowed to a broader `frozen' line shape as the temperature is lowered at fixed filling factor. We present a skyrmion diffusion model that describes the experimental observations qualitatively and shows a time scale of $\sim 50 \mu{\rm sec}$ for the transport relaxation time of the skyrmions. The transition is characterized by an intermediate time regime that we demonstrate is weakly sensitive to the dynamics of the charged spin texture excitations and the sub-band electronic wave functions within our model. We also show that the spectral line shape is very sensitive to the nuclear polarization profile along the z-axis obtained through the optical pumping technique.Comment: 6 pages, 4 figure