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