The role of livestock diversification in ensuring household food security under a changing climate in Borana,Ethiopia

While food insecurity is a growing concern across the developing nations, accentuated by climate variability and change, it could be even worse for pastoralists given their unpredictable exposure to climate risks. The Borana herders experience food insecurity as a result of recurring droughts causing huge losses of cattle, and are thus increasingly shifting from cattle pastoralism to multi-species herding. The present study examines the role of livestock diversification in combating household food insecurity using herders’ perceptions, a modified household food insecurity access scale (mHFIAS) and dietary diversity score. Herders perceived child growth, adult height and body condition to be decreasing as a result of declining milk production and changing dietary trends. Results also revealed a high level of seasonal food insecurity and low dietary diversity with the majority (81 %) consuming one to three food groups. Livestock diversification was a major factor affecting household food security. Households practising diversification had significantly fewer months of food deficit (2.3 vs. 3.8), lower mHFIAS (5.5 vs. 8.7) and a higher average off-take in the form of livestock sales (7.4 vs. 4.0) than non-diversified ones. Diversification improved dietary intake of specific food groups and the average number of meals consumed per day. While fruits, eggs and fish are not part of the Borana diet, a large number of respondents consumed no vegetables (93 %) or meat (96 %), potentiating the risk of micronutrient deficiencies. This study highlights the particular significance of livestock diversification, among other socio-demographic factors, in attaining food security under a changing climate in the study area.     

Model of a polymer chain twisted inside a statistical segment. Poly(3‐hexylthiophene) in chloroform solutions

A set of hydrodynamic methods in extremely dilute solutions (determination of intrinsic viscosity [η ], translational diffusion D and flotation in a centrifugal field s ) was used in the studies of conformational properties, dimensions and equilibrium rigidity of individual molecules of a series of samples of poly(3‐hexylthiophene). Absolute molecular masses M _sD were determined. The Mark–Kuhn–Houwink equations for the range of M _sD from 2240 to 15 300 g mol^?1 are given. For the first time, an analysis of conformational properties and equilibrium flexibility of poly(3‐hexylthiophene) molecules was carried out using the model of a statistical segment containing a twisted polymer chain. © 2017 Society of Chemical Industry     

The design and evaluation of a tool to support software designers at the whiteboard

Despite the availability of advanced software design tools, software developers are known to frequently turn to the whiteboard when faced with a specific design problem. Free from any restrictions, they engage in an informal form of software design that relies heavily on sketching. However, whereas whiteboards afford flexibility and fluidity, they at the same time limit a designer in only being able to draw and erase content. This paper presents Calico, a novel software design tool that leverages electronic whiteboards to enhance the design experience with explicit support for the creative, exploratory aspects of design. Specifically, Calico offers a grid to partition the drawing space, scraps to organize and manipulate the content, and a reusable palette together with gesture-based input to address several natural behaviors exhibited by software designers, including frequent shifts in focus, use of low-detail models, use of a variety of notations, and a tendency to refine representations. To evaluate Calico, we performed a laboratory experiment involving the design of an educational traffic simulator. Through a three-pronged analysis examining the use of Calico’s features, design behaviors exhibited by the participants, and the nature of the design conversations, we show how Calico benefits the design process as it takes place at the whiteboard.     

Carbonation durability of blended cement pastes used for waste encapsulation

Blended cement pastes are currently used for encapsulation of low level and intermediate level nuclear waste in the UK. However, there is still little information on the long-term durability of those mixes to some chemical attacks. Accelerated testing may predict the long-term durability or at least help the selection of more durable formulations. In this work, blended blastfurnace slag (BFS)/Portland cement (OPC) pastes containing 60, 75 and 90% BFS and pulverised fuel ash (PFA)/OPC pastes with 40, 55 and 75% PFA were cured at 20 and 60°C for 90 days then submitted to natural and accelerated carbonation (5% CO₂). The effects of the curing temperature as well as the OPC replacement level on the carbonation ratio are presented. Results showed a good correlation between natural and accelerated carbonation for the pastes studied. Carbonation was found to be governed by the amount of calcium hydroxide available in the mixes before the process started.     

Core Cross-Linked Amphiphilic Star-Block Copolymers with (Meth)acrylic Acid Shells Prepared by Atom Transfer Radical Polymerization

Core cross-linked amphiphilic star-block copolymers were prepared by hydrolysis of the outer shell of star-block copolymers prepared using copper mediated atom transfer radical polymerization (ATRP). In an arm-first approach, linear poly(tert-butyl methacrylate) macroinitiators (PtBMA-Cl) were extended with styrene to yield PtBMA-b-PS-Cl and then cross-linked with divinylbenzene (DVB) in order to yield (PtBMA-b-PS)_arms-PDVB_core star-block copolymers. Then, PMAA-b-PS block and (PMAA-PS)_arms-PDVB_core star-block copolymers were obtained by hydrolysis of the PtBMA blocks in both linear and cross-linked copolymers, as confirmed by ¹H NMR analyses. The amphiphilic character of these copolymers was confirmed by solubilisation in water. Several factors affecting the polymer aggregation and solubility such as the length, the composition of the arms and the catalyst used were studied. An acrylate analogue, that is, (PAA-b-PS)_arms-PDVB_core, was also prepared for comparison purposes. Atomic force microscopy (AFM) and differential scanning calorimetry (DSC) were used to elucidate the morphology and the thermal behaviour of the star-block copolymers.     

Evaluation of Carbon Partitioning in New Generation of Quench and Partitioning (Q&P) Steels

Quenching and partitioning (Q&P) and a novel combined process of hot straining (HS) and Q&P (HSQ&P) treatments have been applied to a TRIP-assisted steel in a Gleeble®3S50 thermomechanical simulator. The heat treatments involved intercritical annealing at 800 °C and a two-step Q&P heat treatment with a partitioning time of 100 seconds at 400 °C. The “optimum” quench temperature of 318 °C was selected according to the constrained carbon equilibrium (CCE) criterion. The effects of high-temperature deformation (isothermal and non-isothermal) on the carbon enrichment of austenite, carbide formation, and the strain-induced transformation to ferrite (SIT) mechanism were investigated. Carbon partitioning from supersaturated martensite into austenite and carbide precipitation were confirmed by means of atom probe tomography (APT) and scanning transmission electron microscopy (STEM). Austenite carbon enrichment was clearly observed in all specimens, and in the HSQ&P samples, it was significantly greater than in Q&P, suggesting an additional carbon partitioning to austenite from ferrite formed by the deformation-induced austenite-to-ferrite transformation (DIFT) phenomenon. By APT, the carbon accumulation at austenite/martensite interfaces was observed, with higher values for HSQ&P deformed isothermally (≈ 11 at. pct), when compared with non-isothermal HSQ&P (≈ 9.45 at. pct) and Q&P (≈ 7.6 at. pct). Moreover, a local Mn enrichment was observed in a ferrite/austenite interface, indicating ferrite growth under local equilibrium with negligible partitioning (LENP).

     

Cobalt nanoparticles prepared by three different methods

This work aimed to study cobalt nanoparticles (Co-NPs) preparation using three different methods in order to evaluate the effect of synthesis variables that can influence the nanoparticle size distribution and particle shape. The synthesised nanoparticles were characterised by Transmission Electron Microscopy. The first synthesis employed decomposition of Co₂(CO)₈, at high temperatures. This procedure resulted in spherical nanoparticles with low size distribution. The size of Co-NPs could be tuned by modification of precursor/surfactant, nevertheless the stirring and injection time influenced the size distribution. Using polyol process, at high temperatures, it was produced undefined-shape nanoparticles. This result suggests that the solution composition, i.e. the amount of trioctylphosphine and oleic acid was not suitable to control both size and shape of nanoparticles. Finally, the method based on reduction with NaBH₄ resulted spherical nanoparticles with tiny sizes, indicating that in this case a variation on amount of reductant would be more efficient on the particle size control than a variation in concentration of oleic acid. These results indicated that, for each method, a different variable exists for the control of the distribution size and the shape of the formed particles.     

Mexico’s regional output convergence after NAFTA: a dynamic panel data analysis

This paper examines Mexico’s output convergence across its 32 states for 1993–2006, a period including the start of NAFTA. Employing dynamic panel data methods, our estimates provide interesting new results. First, we find positive rates of output absolute convergence across Mexican regions: varying from 1.5% for the years 1993–2006 to 9.4% for the years 1996–2006. Second, trade, capital inflows and international migration exert positive effects on output per capita growth. Third, rolling panels suggest the Border-North region faces increasing output convergence speed (from 8.9 to 11.2%), while the South-Center experiences a declining trend (from 12 to 7.6%) more recently.