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

The effects of aqueous ginger extract on aluminium chloride (AlCl3) induced alteration in lipid profile of male wister rats

Background: This study was aimed at investigating the effects of aluminium chloride (AlCl3) in altering the serum lipid profiles and ways to reduce its effect using two different doses of ginger extract 500mg/kg and 1000mg/kg body weight in male wister rats.Methods: The rats were randomly divided into 4 groups consisting of 5 animals in each group. Groups II, III and IV received AlCl3 100mg/kg bodyweight single dose, Groups III and IV receiving an additional daily oral single dose of ginger plant extract through a stomach tube. All animals were fasted before the treatment. All rats were weighed before the start of the experiment and at the end of the experiment. The blood was collected firstly at the beginning of the experiment, then on the 45th day. The collected blood was left to clot then centrifuged at 3500 rpm for 5 min. The serum was separated and stored at - 80°C for later analyses.Results: This study shows that a single dose of 100mg/kg aluminium chloride causes a rise in total body weight, TC (total cholesterol), LDL (low density lipoproteins) and TG (triglycerides) levels in the rat, and aqueous Zingiber officinal (ginger) extract reduces this rise in TC, LDL and TG levels in the rats.Conclusions: Ginger was effective in lowering serum cholesterol levels levels in the ginger treated rats to almost normal value. These results indicate that treatment with aqueous extract of ginger may be effective in lowering lipid levels in AlCl3 induced hyperlipidemia in rats

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

Synthesis and pharmacological screening of new isatin-3-[N2-(benzimidazol-1- acetyl)]hydrazone

Twenty new isatin-3-[N2-(benzimidazol-1-acetyl)]hydrazones (IV) were synthesized from ten different isatin-3-[N2–(chloroacetyl)] hydrazones (III) by reacting with benzimidazole and 2-methyl benzimidazole. The intermediates were obtained from isatin hydrazones (II) on condensation with chloroacetyl chloride. These compounds were characterized by IR, 1H NMR and mass spectra. All the compounds were screened for antimicrobial, antioxidant and cytotoxic activity. Some of the new compounds showed promising antibacterial and antifungal activity.               KEY WORDS: Antibacterial activity, Antifungal activity, Antioxidant activity, Cytotoxic activity, Benzimidazole, Isatin Bull. Chem. Soc. Ethiop. 2019, 33(2), 321-329. DOI: https://dx.doi.org/10.4314/bcse.v33i2.1

Contribution to Unresolved Infrared Fluctuations from Dwarf Galaxies at Redshifts of 2-3

In order to understand the origin of clustered anisotropies detected in Spitzer images between 3.6 and 8 microns, we stack the Spitzer IRAC/Great Observatories Origins Deep Survey (GOODS) images at pixel locations corresponding to faint, z_{AB}~27 mag, optical sources with no obvious IR counterparts. We obtain a strong detection of the sources with a stacked median flux at 3.6 microns of 130+/-5 nJy above the background. The wealth of multi-wavelength imaging data in GOODS enables a similar stacking analysis to be undertaken at various wavelengths between the ultraviolet and near-infrared bands. We obtain strong stacked detections of these optically faint sources over the entire wavelength range which places constraints on the average properties of these sources. We find that the flux spectrum of the median, stacked source is consistent with a L<0.03 L_{*,UV} galaxy with a 90% confidence interval for the redshift of 1.9-2.7. These sources produce a 3.6 micron absolute background intensity between 0.1 and 0.35 nW/m^2/sr and the clustered IR light could account for ~30-50% of fluctuation power in the IR background at 4 arcminute angular scales. Although the exact redshift distribution of these sources is unknown, these galaxies appear to contain 5-20% of the co-moving stellar mass density at z~2.5.Comment: 14 pages, 3 figures, ApJ in press (too long for letters), results unchanged, text clarifie

Preconcentration and Heavy Minerals Separation with Low Grade Beach Sand Sample from Narsapur Coast, West Godavari District, Andhra Pradesh

India is blessed with large reserves of strategic and economically important heavy minerals such as Ilmenite, Rutile, Leucoxene, Zircon, Monazite, Garnet and Sillimanite. These deposits are mostly located in the coastal stretches of peninsular India covering states of Orissa, Andhra pradesh, Tamil nadu, Kerala and Maharastra

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