Micromegas TPC studies at high magnetic fields using the charge dispersion signal

The International Linear Collider (ILC) Time Projection Chamber (TPC) transverse space-point resolution goal is 100 microns for all tracks including stiff 90 degree tracks with the full 2 meter drift. A Micro Pattern Gas Detector (MPGD) readout TPC can achieve the target resolution with existing techniques using 1 mm or narrower pads at the expense of increased detector cost and complexity. The new MPGD readout technique of charge dispersion can achieve good resolution without resorting to narrow pads. This has been demonstrated previously for 2 mm x 6 mm pads with GEMs and Micromegas in cosmic ray tests and in a KEK beam test in a 1 Tesla magnet. We have recently tested a Micromegas-TPC using the charge dispersion readout concept in a high field super-conducting magnet at DESY. The measured Micromegas gain was found to be constant within 0.5% for magnetic fields up to 5 Tesla. With the strong suppression of transverse diffusion at high magnetic fields, we measure a flat 50 micron resolution at 5 Tesla over the full 15 cm drift length of our prototype TPC.Comment: 7 pages, 3 figure

Expandability, reversibility, and optimal capacity choice

We develop continuous-time models of capacity choice when demand fluctuates stochastically, and the firm's opportunities to expand or contract are limited. Specifically, we consider costs of investing or disinvesting that vary with time, or with the amount of capacity already installed. The firm's limited opportunities to expand or contract create call and put options on incremental units of capital; we show how the values of these options affect the firm's investment decisions.Research supported by the National Science Foundation and by the MIT Center for Energy and Environmental Policy Research

The new option view of investment

This paper provides a simple introduction to the new option view of investment. We explain the shortcomings of the orthodox theory, and then outline the basic ideas behind the option framework. Several industry examples are briefly discussed.Supported by the MIT Center for Energy and Environmental Policy Research, and the U.S. Department of Energy. Supported by the National Science Foundation

Combined Effect of Multistage Processing and Treatment Methods on the Physical, Chemical, and Microstructure Properties of Recycled Concrete Aggregates

This research aims to examine the effects of multi-stage processing on reducing the old cement fractions and enhancing the quality of CRA (concrete recycled aggregate). The investigation involves the use of demolished concrete debris and subsequent treatments in both single and multi-stage processes. The recycled aggregates (RA) were obtained using a multi-stage jaw crushing process followed by utilising natural aggregate, untreated RA, RA treated with hydrochloric acid and sodium silicate immersion (single stage treatment) and RA treated with mechanical scrubbing and sodium silicate immersion in two separate stages (multi-stage treatment). The subsequent phase of the experimental inquiry involves assessing the physical attributes of both treated and untreated RA. This is followed by conducting microstructural examinations utilising techniques such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry-differential thermal analysis (TG-DTA). The findings indicate that employing a two-step process, involving mechanical abrasion followed by immersion in sodium silicate, yields high-quality CRA. This conclusion is reinforced by the favourable physical performance observed. The water absorption values of CRA were lowered by 78% through single-stage treatments such as immersion in hydrochloric acid. The similar treatment is found to show densest concrete with Ca/Si ratio reduced to around 81% to that of untreated CRA. Additionally, for single stage treated CRA samples, microstructural study using FTIR verified the creation of additional hydration products, whereas for two stages treated CRA specimens, TGA analysis demonstrated the formation of stable CSH. According to the findings, it is advised to use a multi-stage process of jaw crushing, then treating it with mechanical abrasion and sodium silicate. This has the ability to improve the physical, chemical, and microstructural properties of CRA

RF amplification property of the MgO-based magnetic tunnel junction using field-induced ferromagnetic resonance

The radio-frequency (RF) voltage amplification property of a tunnel magnetoresistance device driven by an RF external-magnetic-field-induced ferromagnetic resonance was studied. The proposed device consists of a magnetic tunnel junction (MTJ) and an electrically isolated coplanar waveguide. The input RF voltage applied to the waveguide can excite the resonant dynamics in the free layer magnetization, leading to the generation of an output RF voltage under a DC bias current. The dependences of the RF voltage gain on the static external magnetic field strength and angle were systematically investigated. The design principles for the enhancement of the gain factor are also discussed.Comment: 12 pages, 3 figure

Electric field Induced Patterns in Soft Visco-elastic films: From Long Waves of Viscous Liquids to Short Waves of Elastic Solids

We show that the electric field driven surface instability of visco-elastic films has two distinct regimes: (1) The visco-elastic films behaving like a liquid display long wavelengths governed by applied voltage and surface tension, independent of its elastic storage and viscous loss moduli, and (2) the films behaving like a solid require a threshold voltage for the instability whose wavelength always scales as ~ 4 x film thickness, independent of its surface tension, applied voltage, loss and storage moduli. Wavelength in a narrow transition zone between these regimes depends on the storage modulus.Comment: Accepted for Publication in Physical Review Letter

Phyto-pharmacology of Momordica dioica Roxb. ex. Willd: A Review

Momordica dioica Roxb. ex. Willd (Cucurbitaceae ) is commonly known as a biiter gourd. It is traditionally used as astringent, febrifuge, antiseptic, anthelmintic, spermicidal. Also Used in bleeding piles, urinary infection and as a sedative. Studies indicate that it possesses antioxidant, hepatoprotective, antibacterial, anti-inflammatory, anti-lipid peroxidative, hypoglycemic and analgesic properties.This review aims to highlight the ethnobotany, pharmacognostic and pharmacological uses of Momordica dioicaKeywords: Momordica dioica, Cucurbitaceae, phytochemical constituents, pharmacological actions, Parora , kakor