Landsat approaches to map agro-pastoral farming in the wetlands of southern Sudan

Machine-learning algorithms (MLA) are coming of age within satellite remote sensing (SRS). This study compares the performance of a number of MLAs with more traditional indices and algorithms to map annual agro-pastoralist farming activity in southern Sudan. Two Landsat images from the early dry season 2014 and 2015 were analysed thoroughly and evaluated by interpretation of farming cover from very high resolution (VHR) images on Google Earth (GE). Traditional SRS indices based upon red and near infrared (NIR) bands used for monitoring rangelands did not perform well for the wet rangeland conditions compared to the use of blue and shortwave infrared (SWIR) bands. The species distribution model programme, MaxEnt, was used to produce a continuous farming activity indices using only Landsat-derived variables. Compared to other SRS classification approaches, maximum entropy (MaxEnt) showed the best overall performance to map farming activity followed by classification tree analysis (CTA). Overall mapping agreement >95.0% was reached for most methodologies, with MaxEnt showing very high mapping agreement (≥98.5%) for both years. When the result of MaxEnt’s good performance is put together in a 2014–15 or a 1999–2002 change detection scenario, it corroborates ground reports on massive human abuses that have taken place in Unity state of southern Sudan.     

How to prepare polished cement product surfaces for optical microscopy without introducing visible cracks

It is shown that preparation procedures may introduce cracks in epoxy impregnated hardened cement paste specimens. This is of vital importance for optical microscopic examination. A method which gives no visible cracks due to preparation is described.     

Note on flash and distillation systems

Flash and distillation systems evolving on the equilibrium manifold possess stable steady states when the molar flows and the boundary conditions are fixed and a vapor and liquid phase is present at all times. The results extend the range of validity of a local stability theorem for linear, constant molar overflow systems due to Acrivos and Amundson. The approach to stability analysis is motivated by the tangent plane method developed by Gibbs to open systems as it takes advantage of the negative curvature of the entropy surface to construct a Lyapunov function. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3322–3332, 2013     

Processing-structure-multi-functional property relationship in carbon nanotube/epoxy composites

The novel properties of carbon nanotubes have generated scientific and technical interest in the development of nanotube-reinforced polymer composites. In order to utilize nanotubes in multi-functional material systems it is crucial to develop processing techniques that are amenable to scale-up for high volume, high rate production. In this research we investigate a scalable calendering approach for achieving dispersion of CVD-grown multi-walled carbon nanotubes through intense shear mixing. Electron microscopy was utilized to study the micro and nanoscale structure evolution during the manufacturing process and optimize the processing conditions for producing highly-dispersed nanocomposites. After processing protocols were established, nanotube/epoxy composites were processed with varying reinforcement fractions and the fracture toughness and electrical/thermal transport properties were evaluated. The as-processed nanocomposites exhibited significantly enhanced fracture toughness at low nanotube concentrations. The high aspect ratios of the carbon nanotubes in the as-processed composites enabled the formation of a conductive percolating network at concentrations below 0.1% by weight. The thermal conductivity increased linearly with nanotube concentration to a maximum increase of 60% at 5 wt.% carbon nanotubes.     

Darstellung,Konfigurationen und NMR-Daten der Säuren CH3(SR)  CHCOOH (R  C6H5, CH2C6H5, CH2COOH)

Preparation, Configurations and N.M.R. Dates of the Acids CH₃(SR)CHCOOH (R  C₆H₅, CH₂C₆H₅, CH₂COOH) The cis and trans isomers of the acids CH₃(SR)CHCOOH (R  C₆H₅, CH₂C₆H₅, CH₂COOH) were prepared by addition of HSR to CH₃CCCOOH in alkaline water solution and by alkaline hydrolysis of CH₃C(SR)₂CH₂COOC₂H₅ (R  C₆H₅, CH₂C₆H₅, CH₂COOC₂H₅). The oxidation products CH₃C(SO₂R)  CHCOOH (R  C₆H₅, CH₂COOH) were also prepared. The n.m.r. dates of the acids were obtained and some relations between them were discussed.     

Equilibrium Studies of the System'(Fe,Co)O'–(Fe,Co)3O4 by Solid-State emf Measurements in the Temperature Range 970 to 1370 K

The equilibrium reaction 3'(Fe, Co)O'( ss ) +1/2O₂ ( g ) ⇄ (Fe, Co)₃O₄( ss ) was studied in the temperature range 970 to 1370 K for seven different total compositions of molar ratios 0.5 < Fe/(Fe + Co) ≤ 1.0. The equilibrium pressures of oxygen were determined by using galvanic cells incorporating calcia stabilized zirconia as solid electrolyte and the Fe/Co ratios in the solid-solution phases by wavelength dispersive spectrometry microprobe analyses. The activities of 'FeO' in the cobaltowüstite phase were then derived from the experimental results obtained.     

Temperature-Dependent Re-alignment of the Short Multifunctional Peptide BP100 in Membranes Revealed by Solid-State NMR Spectroscopy and Molecular Dynamics Simulations

BP100 is a cationic undecamer peptide with antimicrobial and cell-penetrating activities. The orientation of this amphiphilic α-helix in lipid bilayers was examined under numerous conditions using solid-state ¹⁹F, ¹⁵N and ²H NMR. At high temperatures in saturated phosphatidylcholine lipids, BP100 lies flat on the membrane surface, as expected. Upon lowering the temperature towards the lipid phase transition, the helix is found to flip into an upright transmembrane orientation. In thin bilayers, this inserted state was stable at low peptide concentration, but thicker membranes required higher peptide concentrations. In the presence of lysolipids, the inserted state prevailed even at high temperature. Molecular dynamics simulations suggest that BP100 monomer insertion can be stabilized by snorkeling lysine side chains. These results demonstrate that even a very short helix like BP100 can span (and thereby penetrate through) a cellular membrane under suitable conditions.     

A Method for Evaluating Lignin Mobility Distributions Obtained by Capillary Zone Electrophoresis

Abstract

The profile of the mobility distribution of lignin-containing samples depends on type of sample. To facilitate comparison, a procedure for determining the average mobility (μ_av), i.e. the average charge density, of lignin is presented. The procedure is applied to black liquor (Sb), isolated dissolved lignin (Sd) and isolated residual (Sr) lignin samples, obtained from flow-through kraft cooks of softwood. The μ_av of the isolated lignin samples is compared with the concentration of phenol and carboxyl groups and relative molecular size. As the cook proceeds the μ_av for a particular type of lignin sample increases, reflecting an increase in average charge density. The μ_av, measured at pH 12, decreases in the order Sd>Sb>Sr, except at the end of the cook, when the average charge densities of the Sb and Sr samples are similar. Associations between lignin and carbohydrate fragments are proposed to cause the lower mobility of black liquor compared to isolated dissolved lignin. Characterisations performed at pH 10 indicate that the isolated dissolved lignin samples may have a higher pK_a in the middle of the cook than the other samples.     

Sorption of Pyrene to Two Estonian Soils

Two typical Estonian soils, Brown pseudopodzolic and Rendzina, were used for sorption studies with pyrene. The soil samples were subjected to a variety of chemical and physical tests. The specific surface area reached 3.05 m² g^?1 for Rendzina, and 0.87 m² g^?1 for Brown pseudopodzolic soil. The Rendzina type of soil was characterized also by a high organic matter content (22.9%) compared with the Brown pseudopodzolic soil (6.64%). A batch technique was used to perform all adsorption studies. K_oc values 2.7 × 10⁴ mg g^?1 for Rendzina and 4.5 × 10⁴ mg g^?1 for Brown pseudopodzolic were obtained. The results suggets that pyrene sorption behaviour could be in some instances mainly influenced by the composition of organic compounds in the soil, not so much by the overall organic matter content. Also the mineral part of the soil can have a impact to pyrene sorption through Ca-binded humic substances.