State Fragility, Regime Survival and Spoilers in South Sudan

This paper draws on the notion of state fragility in three dimensions – Authority failures, Service delivery failures and Legitimacy failures as developed by Stewart and Brown. Using Stewart and Brown’s analysis of fragile states, the authors examine how recent events in South Sudan push the country into being the most fragile state. In furthering this three-dimensional approach, we attempt two important questions. How has South Sudan succumbed to fragility since attaining independence? Who influences peace in the country? The authors grapple with these questions by investigating events in South Sudan from the period of signing the Comprehensive Peace Agreement (CPA 1 2005), independence in 2011, signing CPA 2 in 2015 up to present. The paper singles out the desire for regime survival as the major cause of fragility. The authors further argue that insecurity and instability are exacerbated by spoiling behaviour of certain powers and individuals, whose activities undermine state authority and creates disorder

Pore wall corrugation effect on the dynamics of adsorbed H 2 studied by in situ quasi elastic neutron scattering Observation of two timescaled diffusion

The self diffusion mechanisms for adsorbed H2 in different porous structures are investigated with in situ quasi elastic neutron scattering method at a temperature range from 50 K to 100 K and at various H2 loadings. The porous structures of the carbon materials have been characterized by sorption analysis with four different gases and the results are correlated with previous in depth analysis with small angle neutron scattering method. Thus, an investigation discussing the effect of pore shape and size on the nature of adsorbed H2 self diffusion is performed. It is shown that H2 adsorbed in nanometer scale pores is self diffusing in two distinguishable timescales. The effect of the pore, pore wall shape and corrugation on the fraction of confined and more mobile H2 is determined and analyzed. The increased corrugation of the pore walls is shown to have a stronger confining effect on the H2 motions. The difference of self diffusional properties of the two H2 components are shown to be smaller when adsorbed in smoother walled pores. This is attributed to the pore wall corrugation effect on the homogeneity of formed adsorbed layer

Synthesis and Characterization of Cobalt and Nitrogen Co Doped Peat Derived Carbon Catalysts for Oxygen Reduction in Acidic Media

In this study, several peat derived carbons PDC were synthesized using various carbonization protocols. It was found that depending on the carbonization method, carbons with very different surface morphologies, elemental compositions, porosities, and oxygen reduction reaction ORR activities were obtained. Five carbons were used as carbon supports to synthesize Co N PDC catalysts, and five different ORR catalysts were acquired. The surface analysis revealed that a higher nitrogen content, number of surface oxide defects, and higher specific surface area lead to higher ORR activity of the Co N PDC catalysts in acidic solution. The catalyst Co N C 2 ZnCl2 , which was synthesized from ZnCl2 activated and pyrolyzed peat, showed the highest ORR activity in both rotating disk electrode and polymer electrolyte membrane fuel cell tests. A maximum power density value of 210 mW cm2 has been obtained. The results of this study indicate that PDCs are promising candidates for the synthesis of active non platinum group metal type catalyst

Modification of micro/mesoporous carbon synthesis method from well decomposed peat using ZnCl2 additional activation step

ZnCl2 activation method was used to synthesize micro- and mesoporous carbon material from Estonian well decomposed peat. The synthesized material with the ZnCl2 activation step has an SBET value of 1270 m2 g─1, compared to the SBET value of 270 m2 g─1 without the activation step. The material was tested as an electrode material in a supercapacitor cell with ionic liquid as an electrolyte. The cyclic voltammetry, impedance spectroscopy and constant current charge/discharge cycles data show that the material is useable for stationary electricity storage in local small-scale wind farms and local PV electricity generating fields. The constant power test data show that very high energy densities E = 50 Wh kg─1 at moderate power densities P = 10 kW kg─1 can be achieved

Preparation of structured sol-gel films using tape casting method

A modification of the tape casting method optimized for preparing either uniform or linearly structured sol-gel films is presented. It is demonstrated that molecular level homogeneous high viscosity sol-gel precursors can be used instead of slurries to prepare surface coatings by the tape casting method. Such method is especially well suited for preparing thick sol-gel films from relatively high viscosity sol precursor materials. The feasibility of the method is demonstrated using linearly structured ATO precursor films

In Situ Observation of Pressure Modulated Reversible Structural Changes in the Graphitic Domains of Carbide Derived Carbons

Carbons are important in a multitude of applications, and thus, the reversible control of carbon structures is of high interest. Here we report the reversible formation of graphitic structures with three distinct interlayer distances in case of two carbide derived carbons CDCs loaded under hydrogen pressure observed with in situ neutron scattering methods. The formation of these graphitic structures determined with in situ neutron diffraction is brought forth by the confinement of H2 in the porous structure when the temperature, T, is increased from T 20 K to 50 K under H2 loading from 68 mbar to 10 bar. The confinement of the desorbing H2 causes the pressure to increase inside the CDC structure and this increase of pressure is the cause for the reversible formation of graphitic domains. The confinement of H2 at T 50 K is possible due to the presence of ultramicropores and suitable curved carbon structures. The three distinct formed graphitic domains correspond to a highly pressurized, conventional highly ordered graphitic, and disoriented graphitic domains with possible H2 H intercalation. In situ quasi elastic neutron scattering and gas adsorption methods are used to determine the H2 transport properties and interactions with the CDC

Fibroblast growth on micro- and nanopatterned surfaces prepared by a novel sol–gel phase separation method

Physical characteristics of the growth substrate including nano- and microstructure play crucial role in determining the behaviour of the cells in a given biological context. To test the effect of varying the supporting surface structure on cell growth we applied a novel sol–gel phase separation-based method to prepare micro- and nanopatterned surfaces with round surface structure features. Variation in the size of structural elements was achieved by solvent variation and adjustment of sol concentration. Growth characteristics and morphology of primary human dermal fibroblasts were found to be significantly modulated by the microstructure of the substrate. The increase in the size of the structural elements, lead to increased inhibition of cell growth, altered morphology (increased cytoplasmic volume), enlarged cell shape, decrease in the number of filopodia) and enhancement of cell senescence. These effects are likely mediated by the decreased contact between the cell membrane and the growth substrate. However, in the case of large surface structural elements other factors like changes in the 3D topology of the cell’s cytoplasm might also play a role

Peat derived hard carbon electrodes with superior capacity for sodium ion batteries

Herein we demonstrate how peat, abundant and cheap biomass, can be successfully used as a precursor to synthesize peat derived hard carbons PDCs , applicable as electrode materials for sodium ion batteries SIB . The PDCs were obtained by pre pyrolysing peat at 300 800 C, removing impurities with base acid solution treatment and thereafter post pyrolysing the materials at temperatures T from 1000 to 1500 C. By modification of pre and post pyrolysis temperatures we obtained hard carbons with low surface areas, optimal carbonization degree and high electrochemical Na storage capacity in SIB halfcells. The best results were obtained when pre pyrolysing peat at 450 C, washing out the impurities with KOH and HCl solutions and then post pyrolysing the obtained carbon rich material at 1400 C. All hard carbons were electrochemically characterized in half cells vs. Na Na and capacities as high as 350 mA h g 1 at 1.5 V and 250 mA h g 1 in the plateau region E lt; 0.2 V were achieved at charging current density of 25 mA g 1 with an initial coulombic efficiency of 8

Transport properties of H2 confined in carbide derived carbons with different pore shapes and sizes

Hydrogen sorption in highly porous carbon with well defined pores, with three different shapes, and different sizes ranging from sub to nanometers is investigated. Using combined approach of volumetric gas adsorption method and in situ quasi elastic neutron scattering method the relationship between final macroscopic intake properties, details of the local adsorbent structure and the molecular behaviour of confined hydrogen is established. It is shown that sub nanometer pores of spherical and cylindrical shape strongly limit the diffusion of H2, and thus, enhance the H2 storage capability of carbons with well tailored pore structure. In mesoporous carbide derived carbon, the formation of a hydrogen layer with reduced mobility close to the pore walls is observed. With the increase in the amount of confined hydrogen and the occupation of the centre pore area, the mobility of confined hydrogen increases in a jump like fashion. Surprisingly, the increase of hydrogen diffusion is also observed at higher hydrogen loadings, indicating that cooperative H2 H2 interactions might play a rol