Hydrodynamic slip can align thin nanoplatelets in shear flow

The large-scale processing of nanomaterials such as graphene and MoS2 relies on understanding the flow behaviour of nanometrically-thin platelets suspended in liquids. Here we show, by combining non-equilibrium molecular dynamics and continuum simulations, that rigid nanoplatelets can attain a stable orientation for sufficiently strong flows. Such a stable orientation is in contradiction with the rotational motion predicted by classical colloidal hydrodynamics. This surprising effect is due to hydrodynamic slip at the liquid-solid interface and occurs when the slip length is larger than the platelet thickness; a slip length of a few nanometers may be sufficient to observe alignment. The predictions we developed by examining pure and surface-modified graphene is applicable to different solvent/2D material combinations. The emergence of a fixed orientation in a direction nearly parallel to the flow implies a slip-dependent change in several macroscopic transport properties, with potential impact on applications ranging from functional inks to nanocomposites.Energy Technolog

2-Aminoethoxydiphenyl borate (2-APB) is a reliable blocker of store-operated Ca²⁺ entry but an inconsistent inhibitor of InsP₃-induced Ca²⁺ release

Since its introduction to Ca2+ signaling in 1997, 2-aminoethoxydiphenyl borate (2-APB) has been used in many studies to probe for the involvement of inositol 1,4,5-trisphosphate receptors in the generation of Ca2+ signals. Due to reports of some nonspecific actions of 2-APB, and the fact that its principal antagonistic effect is on CaCa2+ entry rather than Ca2+ release, this compound may not have the utility first suggested. However, 2-APB has thrown up some interesting results, particularly with respect to store-operated Ca2+ entry in nonexcitable cells. These data indicate that although it must be used with caution, 2-APB can be useful in probing certain aspects of Ca2+ signalin

Multifaceted impacts of sustainable land management in drylands: A review

Biophysical restoration or rehabilitation measures of land have demonstrated to be effective in many scientific projects and small-scale environmental experiments. However circumstances such as poverty, weak policies, or inefficient scientific knowledge transmission can hinder the effective upscaling of land restoration and the long term maintenance of proven sustainable use of soil and water. This may be especially worrisome in lands with harsh environmental conditions. This review covers recent efforts in landscape restoration and rehabilitation with a functional perspective aiming to simultaneously achieve ecosystem sustainability, economic efficiency, and social wellbeing. Water management and rehabilitation of ecosystem services in croplands, rangelands, forests, and coastlands are reviewed. The joint analysis of such diverse ecosystems provides a wide perspective to determine: (i) multifaceted impacts on biophysical and socio-economic factors; and (ii) elements influencing effective upscaling of sustainable land management practices. One conclusion can be highlighted: voluntary adoption is based on different pillars, i.e. external material and economic support, and spread of success information at the local scale to demonstrate the multidimensional benefits of sustainable land management. For the successful upscaling of land management, more attention must be paid to the social system from the first involvement stage, up to the long term maintenance. © 2016 by the authors

Public Policy Failure or Historical Debacle? A Study of Eritrea's Relations With Ethiopia Since 1991

Public policy transcends the domain of domestic policies and encompasses or even determines the type of relations that countries build with each other. It is well known that policies are nothing but decisions of governments as formal authorization on the given issue at hand. In other words, policy is a sum total of decisions made by the authority and hence it involves what governments actually do and not what they intend to do. Public opinion is a powerful criterion especially in democracies. It is provided in the constitutions and the people's role in policymaking is confirmed through this. Political parties, mass media, newspapers, and such others claim to represent public opinion. Rationality is another criteria in policymaking in which the leadership takes supposedly rational decisions on different issues of concern particularly those relating to foreign affairs. The criteria on political and economic situation depends on the actions of politicians, the legacy of the past, the nature of government organizations/institutions, and the constraints posed by domestic economic situations and conditions. Although policymakers enjoy complete independence from external control, unfortunately Third World countries such as those in Africa are not free to make their policies due to various reasons such as interdependence, and the domestic political and economic situations, compelling them to take a cue from external factors or power centers. The many conceptual models of public policy offer a wide variety of understanding on how they can be applied to different countries and to different situations. In fact, most policies are a combination of rational planning, instrumentalism, interest group activity, elite preferences, systemic forces, game planning, public choice, political processes and institutional influences. However, at times we find not all of these may be applicable to all countries. It in effect depends on the rational calculations of the countries in question how they would make or have their policies consonant with their national interests. The case of Eritrea and Ethiopia is a classic example that fits into the above paradigm and in which to enquire how their policies varied in spite of being friendly neighbors but later turning into hostile foes. What went wrong and how? Was it a product of their policy failures or was it due to historical debacles? This article therefore is an attempt to explore the current state of relations between Eritrea and Ethiopia in the light of the above-mentioned conceptual framework by showing how their mutual policies were not compatible enough to solidify their initial cordiality and friendliness. In order to do this a brief sketch of historical background is provided to help understand and analyze the impact it had on contemporary policies between them. The internal political dynamics and ideological doctrines of Eritrea are the focus of next discussion. The period of cordiality and later the period of hostility are discussed next. Finally, recent trends and future prospects are put forward. Copyright 2006 by The Policy Studies Organization.

Electro-optical characterization of cyanine-based GUMBOS and nanoGUMBOS

© 2014, The Korean Institute of Metals and Materials and Springer Science+Business Media Dordrecht. Over the last decade in materials science, molecular electronics has emerged as one of the most rapidly developing interdisciplinary research areas with the prospects of ultimate miniaturization and integration of functional organic species with traditional silicon based semiconductor technology. To this end, fundamental studies to investigate the electrical and optical properties of organic nanomaterials deserve special attention. In this work, conductive probe atomic force microscopy (CP-AFM) and Raman spectroscopy have been performed on a new class of ionic materials, referred to as group of uniform materials based on organic salts (GUMBOS) and nanoparticles derived from these GUMBOS, termed as nanoGUMBOS. The GUMBOS investigated in this study are 1,1′-Diethyl-2,2′-cyanine bis (trifluoromethanesulfonyl) imide ([PIC][NTf2]) and 1,1′-Diethyl-2,2′-cyanine bis (pentafluoromethanesulfonyl) imide ([PIC][BETI]), which have been synthesized by use of a facile, template free anion exchange reaction between their respective parent compounds, followed by an ultrasonication assisted, additive free re-precipitation reaction to obtain the nanoscale particles (nanoGUMBOS). The ([PIC][NTf2] nanoGUMBOS were found to self-assemble into distinct diamond-like, trapezoid structures whereas [PIC][BETI] exhibited rod-like structures. [PIC][NTf2] nanoGUMBOS induced ~25 and ~38 times enhancement in the Raman signal intensity as compared to the parent compound [PIC][I] and [PIC][BETI] nanoGUMBOS respectively. In conjunction with the results of Raman spectra, the current-voltage (I-V) data obtained by CP-AFM are also presented as first-time evidence of electrical performance exhibited by these unique class of materials. The results reported in this study are indicative of their potential incorporation into next generation organic thin film applications in optoelectronics, dye-sensitized solar cells, and chemical sensors