461 research outputs found
Finitely presented left orderable monsters
A left orderable monster is a finitely generated left orderable group all of
whose fixpoint-free actions on the line are proximal: the action is
semiconjugate to a minimal action so that for every bounded interval and
open interval , there is a group element that sends into . In his
2018 ICM address, Navas asked about the existence of left orderable monsters.
By now there are several examples, all of which are finitely generated but not
finitely presentable. We provide the first examples of left orderable monsters
that are finitely presentable, and even of type . The construction
itself is elementary, and these groups satisfy several additional properties
separating them from the previous examples: they are not simple, they act
minimally on the circle, and they have an infinite-dimensional space of
homogeneous quasimorphisms. Our construction is flexible enough that it
produces infinitely many isomorphism classes of finitely presented (and type
) left orderable monsters.Comment: 12 pages. v2: Final version, to appear in Ergodic Theory and
Dynamical System
PHOTOCATALYTICDEGRADATION OF RHODAMIN-B USING METAL COMPLEXES AND HYDROGEN PEROXIDE
ABSTRACT
The photocatalytic degradation has been considered to be an efficient process for degradation of organic
pollutants, which are present in the effluents released by industries. Thephotocatalytic bleaching was carried out on
rhodamin-B (cationic dye) in the presence of iron (III) complex, hydrogen peroxide and was observed
spectrophotometrically. The effect of various operating variables like pH, concentration of complex and dye, amount
of HzOzand light intensity etc. was also observed on the efficiency of the reaction. A tentative mechanism has also
been proposed for this photocatalytic degradation of rhodamin-B.
Keywords: Photocatalytic degradation, rhodamin-B, metal complexes, hydrogen peroxide
Negative Giant Longitudinal Magnetoresistance in NiMnSb/InSb: An interface effect
We report on the electrical and magneto-transport properties of the contact
formed between polycrystalline NiMnSb thin films grown using pulsed laser
deposition (PLD) and n-type degenerate InSb (100) substrates. A negative giant
magnetoresistance (GMR) effect is observed when the external magnetic field is
parallel to the surface of the film and to the current direction. We attribute
the observed phenomenon to magnetic precipitates formed during the magnetic
film deposition and confined to a narrow layer at the interface. The effect of
these precipitates on the magnetoresistance depends on the thermal processing
of the system.Comment: 14 pages, 4 figure
Surface and interface study of pulsed-laser-deposited off-stoichiometric NiMnSb thin films on Si(100) substrate
We report a detailed study of surface and interface properties of
pulsed-laser deposited NiMnSb films on Si (100) substrate as a function of film
thickness. As the thickness of films is reduced below 35 nm formation of a
porous layer is observed. Porosity in this layer increases with decrease in
NiMnSb film thickness. These morphological changes of the ultra thin films are
reflected in the interesting transport and magnetic properties of these films.
On the other hand, there are no influences of compositional in-homogeneity and
surface/interface roughness on the magnetic and transport properties of the
films.Comment: 13 pages, 7 figures, Submitted to Phys. Rev.
Chikungunya Infection in India: Results of a Prospective Hospital Based Multi-Centric Study
Chikungunya (CHIKV) has recently seen a re-emergence in India with high morbidity. However, the epidemiology and disease burden remain largely undetermined. A prospective multi-centric study was conducted to evaluate clinical, epidemiological and virological features of chikugunya infection in patients with acute febrile illness from various geographical regions of India.A total of 540 patients with fever of up to 7days duration were enrolled at Karnataka Institute of Medical Sciences (KIMS), Karnataka (South); Sawai Man Singh Medical College (SMS) Rajasthan (West), and All India Institute of Medical Sciences (AIIMS) New Delhi (North) from June 2008 to May 2009. Serum specimens were screened for chikungunya infection concurrently through RT-PCR and serology (IgM). Phylogenetic analysis was performed using Bioedit and Mega2 programs. Chikungunya infection was detected in 25.37% patients by RT-PCR and/or IgM-ELISA. Highest cases were detected in south (49.36%) followed by west (16.28%) and north (0.56%) India. A difference in proportion of positives by RT-PCR/ELISA with regard to duration of fever was observed (p<0.05). Rashes, joint pain/swelling, abdominal pain and vomiting was frequently observed among chikungunya confirmed cases (p<0.05). Adults were affected more than children. Anti-CHIK antibodies (IgM) were detected for more than 60days of fever onset. Phylogenetic analysis based on E1 gene from KIMS patients (nβ=β15) revealed βΌ99% homology clustering with Central/East African genotype. An amino acid change from lysine to glutamine at position 132 of E1 gene was frequently observed among strains infecting children.The study documented re-emergence of chikungunya in high frequencies and severe morbidity in south and west India but rare in north. The study emphasizes the need for continuous surveillance for disease burden using multiple diagnostic tests and also warrants the need for an appropriate molecular diagnostic for early detection of chikungunya virus
Solvent evaporation driven entrapment of magnetic nanoparticles in mesoporous frame for designing a highly efficient MRI contrast probe
The present work reports a novel strategy of assembling maghemite (?-Fe2O3) nanoparticles (NPs) in mesoporous silica host for developing a highly efficient MRI contrast probe. Shrinkage of hydrophobic environment due to the continuous evaporation of chloroform from Chloroform-in-Water emulsions pushes the hydrophobic ?-Fe2O3 NPs towards the hydrophobic pores of silica spheres resulting in a water soluble dense assembly structure. Mesoporous silica only with straight pores is found to be suitable for this particular entrapment process, while with curved and twisted pores, NPs are found to be seated on the surface only. So-developed assembly system has retained the superparamagnetic behaviour of its comprising NPs and exhibited high colloidal stability and biocompatibility. A significant enhancement in MRI transverse relaxivity to 386.2?mM?1?s?1 from 191.8?mM?1?s?1 of isolated primary ?-Fe2O3 NPs, has been obtained due to the strong magnetic field generated by the large number of NPs packed in the porous channels and consequent faster relaxation process. The fabrication strategy can be extended for the development of designed secondary nanostructures with new magnetic effects and physical properties
Comparative efficacy of biological control agents for the management of cumin wilt caused by Fusarium oxysporum f.sp. cumini
Field experiments were conducted during rabi 2008-09 and 2009-10 for the management of cumin wilt caused by Fusarium oxysporum f.sp. cumini. The results showed that seed treatment with Trichoderma viride (10 g kg-1 of seed) and soil application (2.5 kg ha-1) recorded minimum percent disease incidence (PDI) of 18.5 (disease reduction of 51.8%) versus 38.4 in the control. It was on par with seed treatment and soil application with Aspergillus versicolor at 10 g kg-1 of seed and 2.5 kg ha-1, respectively which reduced the disease incidence by 45.4%. The chemical treatment i.e. seed treatment with carbendazim at 2.5 g kg-1 seed recorded PDI of 23.9 with 37.7% disease reduction. Among different treatments seed treatment and soil application with A. versicolor gave a seed yield of 246 kg ha-1 followed by P. fluorescens (222.6 kg ha-1). Treatment T. viride, recorded the highest yield of 258.2 kg ha-1. Hence, seed treatment at 10 g kg-1 and soil application at 2.5 kg ha-1 of T. viride was the most effective, eco-friendly disease management.
 
X-ray standing wave and reflectometric characterization of multilayer structures
Microstructural characterization of synthetic periodic multilayers by x-ray
standing waves have been presented. It has been shown that the analysis of
multilayers by combined x-ray reflectometry (XRR) and x-ray standing wave (XSW)
techniques can overcome the deficiencies of the individual techniques in
microstructural analysis. While interface roughnesses are more accurately
determined by the XRR technique, layer composition is more accurately
determined by the XSW technique where an element is directly identified by its
characteristic emission. These aspects have been explained with an example of a
20 period Pt/C multilayer. The composition of the C-layers due to Pt
dissolution in the C-layers, PtC, has been determined by the XSW
technique. In the XSW analysis when the whole amount of Pt present in the
C-layers is assumed to be within the broadened interface, it l eads to larger
interface roughness values, inconsistent with those determined by the XRR
technique. Constraining the interface roughness values to those determined by
the XRR technique, requires an additional amount of dissolved Pt in the
C-layers to expl ain the Pt fluorescence yield excited by the standing wave
field. This analysis provides the average composition PtC of the
C-layers .Comment: 12 pages RevTex, 10 eps figures embedde
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