A Volumetric Study of Aqueous Butanol Solutions

Alcohol molecules consist of two distinct regions: a polar, hydrophilic alcohol group, and an aliphatic hydrocarbon chain. These regions interact with solvent water molecules in different ways. While the alcohol group acts as a solvent structure breaker by hydrogen bonding with nearby water molecules, the hydrophobic carbon chain acts instead as a solvent structure maker and causes the surrounding water molecules to align themselves in a Clathrate structure. The presence of these two contrasting solute-solvent interactions affects the properties of the solution, among them the molar volume. The partial molar volume of the alcohol is analyzed with respect to three variables: the size and location of the hydrophilic moiety, the concentration of the alcohol-water solution, and the temperature at which the density measurement is made. We show that all three of these variables have a noticeable effect on the interactions between the solute and solvent molecules, and thus the volume of the solution

Spitzer Observations of Gamma-Ray Burst Host Galaxies: A Unique Window into High Redshift Chemical Evolution and Star-formation

We present deep Spitzer 3.6 micron observations of three z~5 GRB host galaxies. Our observations reveal that z~5 GRB hosts are a factor of 3 less luminous than the median rest-frame V-band luminosity of spectroscopically confirmed z~5 galaxies in the GOODS fields and the UDF. The strong connection between GRBs and massive star formation implies that not all star-forming galaxies at these redshifts are currently being accounted for in deep surveys and GRBs provide a unique way to measure the contribution to the star-formation rate density from galaxies at the faint end of the galaxy luminosity function. By correlating the co-moving star-formation rate density with co-moving GRB rates at lower redshifts, we estimate a lower limit to the star-formation rate density of 0.12+/-0.09 and 0.09+/-0.05 M_sun/yr/Mpc^3 at z~4.5 and z~6, respectively. Finally, we provide evidence that the average metallicity of star-forming galaxies evolves as (stellar mass density)^(0.69+/-0.17) between $z\sim5$ and $z\sim0$, probably indicative of the loss of a significant fraction of metals to the intergalactic medium, particularly in low-mass galaxies.Comment: ApJ, in pres

Characteristics comparison of Biodiesel-Diesel Blend (B20) Fuel with Alcohol Additives

The effect of properties like density, viscosity and flashpoint with alcohol additives in biodiesel blend fuel has been studied. Biodiesel blend fuel (B20) is used for characterization to compare with 5% and 10% of ethanol and methanol. The results indicated that flash point of B20 decrease drastically at 5% alcohols and increases at higher percentages. Increase in flash point as blend concentration increase may be considered better with respect to safety in fuel handling. In case of viscosity and density, cetane number and acid values decrease as the percentage of alcohol increases. Alcohols lower the flash point slightly and reduces the viscosity and density of blend fuel marginally, with this fuel ignition can start at lower temperature and able to burn completely. The combustion rate of fuel is increased due to more oxygen availability in alcohol that results in reducing the levels of pollutants in exhaust gases

Linkage group assignments for two Neurospora crassa catalase genes: the Metzenberg RFLP mapping kit applied to an enzyme polymorphism.

Linkage group assignments for two Neurospora crassa catalase genes: the Metzenberg RFLP mapping kit applied to an enzyme polymorphism

Interconnections of Reactive Oxygen Species Homeostasis and Circadian Rhythm in Neurospora crassa.

Abstract Significance: Both circadian rhythm and the production of reactive oxygen species (ROS) are fundamental features of aerobic eukaryotic cells. The circadian clock enhances the fitness of organisms by enabling them to anticipate cycling changes in the surroundings. ROS generation in the cell is often altered in response to environmental changes, but oscillations in ROS levels may also reflect endogenous metabolic fluctuations governed by the circadian clock. On the other hand, an effective regulation and timing of antioxidant mechanisms may be crucial in the defense of cellular integrity. Thus, an interaction between the circadian timekeeping machinery and ROS homeostasis or signaling in both directions may be of advantage at all phylogenetic levels. Recent Advances: The Frequency-White Collar-1 and White Collar-2 oscillator (FWO) of the filamentous fungus Neurospora crassa is well characterized at the molecular level. Several members of the ROS homeostasis were found to be controlled by the circadian clock, and ROS levels display circadian rhythm in Neurospora. On the other hand, multiple data indicate that ROS affect the molecular oscillator. Critical Issues: Increasing evidence suggests the interplay between ROS homeostasis and oscillators that may be partially or fully independent of the FWO. In addition, ROS may be part of a complex cellular network synchronizing non-transcriptional oscillators with timekeeping machineries based on the classical transcription-translation feedback mechanism. Future Directions: Further investigations are needed to clarify how the different layers of the bidirectional interactions between ROS homeostasis and circadian regulation are interconnected. Antioxid. Redox Signal. 00, 000-000

HST and Spitzer Observations of the Host Galaxy of GRB 050904: A Metal-Enriched, Dusty Starburst at z=6.295

We present deep Hubble Space Telescope and Spitzer Space Telescope observations of the host galaxy of GRB 050904 at z=6.295. The host is detected in the H-band and marginally at 3.6 micron. From these detections, and limits in the z'-band and 4.5 micron, we infer an extinction-corrected absolute magnitude, M(UV)=-20.7 mag, or ~L*, a substantial star formation rate of 15 solar masses per year, and a stellar mass of a few 10^9 solar masses. A comparison to the published sample of spectroscopically-confirmed galaxies at z>5.5 reveals that the host of GRB 050904 would evade detection and/or confirmation in any of the current surveys due to the lack of detectable Ly-alpha emission, which is likely the result of dust extinction (A[1200]~1.5 mag). This suggests that not all luminous starburst galaxies at z~6 are currently being accounted for. Most importantly, using the metallicity of Z~0.05 solar inferred from the afterglow absorption spectrum, our observations indicate for the first time that the observed evolution in the mass- and luminosity-metallicity relations from z=0 to z~2 continues on to z>6. The ease of measuring redshifts and metallicities from the afterglow emission suggests that in tandem with the next generation ground- and space-based telescopes, a GRB mission with dedicated near-IR follow-up can provide unique information on the evolution of stars and galaxies through the epoch of re-ionization.Comment: Submitted to ApJ; 11 pages, 5 figures; A high-resolution version of figure 1 can be found at http://www.ociw.edu/~eberger/fig1.050904.berger.ep

Valeurs comparées des activités cholinestérasiques sanguines dans quelques espèces animales

Chary R., Jayot R., Bocquet P. Valeurs comparées des activités cholinestérasiques sanguines dans quelques espèces animales. In: Bulletin de l'Académie Vétérinaire de France tome 112 n°4, 1959. pp. 225-233

Far-ultraviolet imaging of the Hubble Deep Field-North: Star formation in normal galaxies at z < 1

We present far-ultraviolet (FUV) imaging of the Hubble Deep Field-North (HDF-N) taken with the Solar Blind Channel of the Advanced Camera for Surveys (ACS SBC) and the FUV MAMA detector of the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope. The full WFPC2 deep field has been observed at 1600 Å. We detect 134 galaxies and one star down to a limit of FUV_(AB) ~ 29. All sources have counterparts in the WFPC2 image. Redshifts (spectroscopic or photometric) for the detected sources are in the range 0 < z < 1. We find that the FUV galaxy number counts are higher than those reported by GALEX, which we attribute at least in part to cosmic variance in the small HDF-N field of view. Six of the 13 Chandra sources at z < 0.85 in the HDF-N are detected in the FUV, and those are consistent with starbursts rather than active galactic nuclei. Cross-correlating with Spitzer sources in the field, we find that the FUV detections show general agreement with the expected L_(IR)/L_(UV) versus β relationship. We infer star formation rates (SFRs), corrected for extinction using the UV slope, and find a median value of 0.3 M_☉ yr^(-1) for FUV-detected galaxies, with 75% of detected sources having SFR < 1 M_☉ yr^(-1). Examining the morphological distribution of sources, we find that about half of all FUV-detected sources are identified as spiral galaxies. Half of morphologically selected spheroid galaxies at z < 0.85 are detected in the FUV, suggesting that such sources have had significant ongoing star formation in the epoch since z ~ 1

AN IOT BASED WEB PAGE CONTROLLED DIGITAL NOTICE BOARD

In this proposed system the idea of IOT Based Web Controlled Digital Notice Board Using GSM Technology has been presented. So our main aim is to reduce paper work and time At present, when information has to be updated in a notice board, it has to be done manually. To change message on display, it needs to change microcontroller program code again. By adding web controlled IOT based communication interface to this system, we can make smart noticeboard to overcome these limitations. So we have interfaced web controlled IOT based SIM800L modem with microcontroller and implemented a text transmission and reception technique