4,796 research outputs found
Centre Commissioned External Review (CCER) of the IWMI-TATA Water Policy Research Program
Agricultural research / Research projects / Project appraisal / Financing / Institutional development / Evaluation / Water policy / Water management / Irrigation management / Groundwater
Appearance Potential Spectroscopy of Solid Surfaces
Among the techniques utilized for the study of unfilled density of states above the Fermi level in a system, appearance potential spectroscopy (APS) has emerged as one of the simplest. Some review papers on APS have appeared in the last decade. Since then APS has been applied to several interesting systems, the studies of which have been limited by other experimental techniques available. This paper reviews some of these applications of APS. We discuss briefly the one-electron theory describing the APS process and outline the basic experimental set-ups used by workers in this field. We then survey some important applications of this technique to simple, as well as, multi-component systems. The results of the applications cited are compared with those from other techniques wherever available. The electronic structure of transition metals, rare earths and their intermetallics as obtained from APS spectra are discussed. The phenomena of adsorption and fine structure which are dependent on the surface sensitivity of APS are also dealt with by including some interesting applications. Finally, we take into account the strengths and limitations of this technique and outline the prospects of this spectroscopy in attaining its importance among the various surface spectroscopies
Packing Fractions and Maximum Angles of Stability of Granular Materials
In two-dimensional rotating drum experiments, we find two separate influences
of the packing fraction of a granular heap on its stability. For a fixed grain
shape, the stability increases with packing fraction. However, in determining
the relative stability of different grain shapes, those with the lowest average
packing fractions tend to form the most stable heaps. We also show that only
the configuration close to the surface of the pile figures prominently.Comment: 4 pages, 4 figure
Excitons and Many-Electron Effects in the Optical Response of Single-Walled Boron Nitride Nanotubes
We report first-principles calculations of the effects of quasiparticle
self-energy and electron-hole interaction on the optical properties of
single-walled BN nanotubes. Excitonic effects are shown to be even more
important in BN nanotubes than in carbon nanotubes. Electron-hole interactions
give rise to complexes of bright (and dark) excitons, which qualitatively alter
the optical response. Excitons with binding energy larger than 2 eV are found
in the (8,0) BN nanotubes. Moreover, unlike the carbon nanotubes, theory
predicts that these exciton states are comprised of coherent supposition of
transitions from several different subband pairs, giving rise to novel
behaviors.Comment: 4 pages, 4 figure
Ballistic magnetoresistance in nickel single-atom conductors
Large ballistic magnetoresistance (BMR) has been measured in Ni single-atom
conductors electrodeposited between microfabricated thin films. These
measurements irrefutably eliminate any magnetostriction related artifacts in
the BMR effect.Comment: 12 pages, 3 Figure
Corporate entrepreneurship champions: mapping the past and present states of the field for future advancements
Purpose
The purpose of this study is to critically examine and review the extant research on corporate entrepreneurship champions in the broader area of corporate entrepreneurship and to uncover the avenues for advancement of the scholarship with the purpose of engaging CE champions towards the upliftment of organisations in particular, and younger workforce in general.
Design/methodology/approach
In this study, authors employ bibliometric analysis through a review of 274 papers fetched from Web of Science and Scopus databases.
Findings
The authors set the agenda for future research and policy by elucidating research themes and potential research questions by bringing out twelve themes classified into five basic themes, three niche themes, three motor themes, and one key theme, while also providing the methodological inputs for carrying out this agenda.
Originality/value
This study adopts a unique lens of investigation in contextualising the role of self-efficacy, employee engagement, and career choice for the younger workforce
Noninvasive Embedding of Single Co Atoms in Ge(111)2x1 Surfaces
We report on a combined scanning tunneling microscopy (STM) and density
functional theory (DFT) based investigation of Co atoms on Ge(111)2x1 surfaces.
When deposited on cold surfaces, individual Co atoms have a limited diffusivity
on the atomically flat areas and apparently reside on top of the upper
pi-bonded chain rows exclusively. Voltage-dependent STM imaging reveals a
highly anisotropic electronic perturbation of the Ge surface surrounding these
Co atoms and pronounced one-dimensional confinement along the pi-bonded chains.
DFT calculations reveal that the individual Co atoms are in fact embedded in
the Ge surface, where they occupy a quasi-stationary position within the big
7-member Ge ring in between the 3rd and 4th atomic Ge layer. The energy needed
for the Co atoms to overcome the potential barrier for penetration in the Ge
surface is provided by the kinetic energy resulting from the deposition
process. DFT calculations further demonstrate that the embedded Co atoms form
four covalent Co-Ge bonds, resulting in a Co4+ valence state and a 3d5
electronic configuration. Calculated STM images are in perfect agreement with
the experimental atomic resolution STM images for the broad range of applied
tunneling voltages.Comment: 19 pages, 15 figures, 3 table
N-Phenylethyl-N'-[3-(trifluoromethyl)phenyl]thiourea
The title compound, C16H15F3N2S, is a biologically active anti-implantation agent. The dihedral angle between the phenyl and trifluoromethylphenyl rings is 15.9 (2)°. The crystal structure is stabilized by intermolecular N-HS hydrogen bonds, forming dimers
4-(2-Methylprop-2-enyl)-1-[3-(trifluoromethyl)phenyl]thiosemicarbazide
The title compound, C12H14F3N3S, is a biologically active anti-implantation agent. Its crystal structure is stabilized by intermolecular N-H...S hydrogen bonds, which form dimers in a head-to-tail arrangement and link them into a polymeric chain
Isomorphs in model molecular liquids
Isomorphs are curves in the phase diagram along which a number of static and
dynamic quantities are invariant in reduced units. A liquid has good isomorphs
if and only if it is strongly correlating, i.e., the equilibrium
virial/potential energy fluctuations are more than 90% correlated in the NVT
ensemble. This paper generalizes isomorphs to liquids composed of rigid
molecules and study the isomorphs of two systems of small rigid molecules, the
asymmetric dumbbell model and the Lewis-Wahnstrom OTP model. In particular, for
both systems we find that the isochoric heat capacity, the excess entropy, the
reduced molecular center-of-mass self part of the intermediate scattering
function, the reduced molecular center-of-mass radial distribution function to
a good approximation are invariant along an isomorph. In agreement with theory,
we also find that an instantaneous change of temperature and density from an
equilibrated state point to another isomorphic state point leads to no
relaxation. The isomorphs of the Lewis-Wahnstrom OTP model were found to be
more approximative than those of the asymmetric dumbbell model, which is
consistent with the OTP model being less strongly correlating. For both models
we find "master isomorphs", i.e., isomorphs have identical shape in the
virial/potential energy phase diagram.Comment: 20 page
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