Diri Nasyonal ou Diri Miami? Food, agriculture and US-Haiti relations

The US government has made agricultural development a major pillar of its strategy to support Haiti’s reconstruction following the 2010 earthquake, and has offered the largest bilateral pledge of agricultural development-related resources for reconstruction. The United States has also designated Haiti as a beneficiary of the US presidential Feed the Future Initiative, a major effort to promote smallholder farmer-based agricultural development and improved human nutrition worldwide. US agricultural aid to Haiti focuses primarily on boosting the productivity of staple crops for local markets, including rice. Assistance in exporting crop produce receives less emphasis. While US assistance is contributing to agricultural development and food security, a number of steps could be taken to improve its effectiveness. In addition, the United States has aggressively promoted trade liberalization in Haiti. The country is now the second largest market for US rice exports. US rice producers receive substantial government payments, and ship nearly half their produce overseas. In contrast, between 2000 and 2005, the Haitian government devoted just 4 % of its budgetary expenditures to agriculture, even though the sector employs more than half the workforce and accounts for a quarter of national income. This article assesses US aid to Haitian agriculture, examines the political economy of the incoherence between US agricultural assistance on the one hand and US agricultural trade policy on the other, and proposes policy alternatives.     

Egg yolk: structures,functionalities and processes

Hen egg yolk is an ideal example of natural supramolecular assemblies of lipids and proteins with different organization levels. These assemblies are mainly due to interactions between proteins and phospholipids, and these interactions are essential in understanding and controlling the production of food made with yolk, and particularly emulsions. Furthermore, these assemblies can be modulated by external constraints among which thermo‐mechanical and high‐pressure treatments. This review focuses on multi‐scale structures present in egg yolk, and their modulation by processes, in relation with their emulsifying properties. Egg yolk is mainly composed of two fractions—plasma and granules—which are natural nano‐ and micro‐assemblies. These two fractions possess different composition, structures and functionalities and exhibit specific behaviour under treatments such as high pressure and temperature. Plasma contains a large quantity of lipids structured as lipoproteins (low‐density lipoproteins), whereas granules are mainly composed of proteins aggregated in micrometric assemblies. If plasma is responsible for the important emulsifying properties of yolk, granules bring interesting emulsifying properties when assemblies are in the form of micelles in presence of salts. High‐pressure or thermal treatments, applied before or after emulsion fabrication, alter their functionalities and could be used to commercially exploit these fractions. © 2013 Society of Chemical Industry     

Microstructure and bioaccessibility of different carotenoid species as affected by high pressure homogenisation: A case study on differently coloured tomatoes

The effect of high pressure homogenisation (HPH) on structure (Bostwick consistency, particle size distribution and microstructure) and carotenoid in vitro bioaccessibility of different tomato pulps was investigated. HPH decreased tomato particle size due to matrix disruption and increased product consistency, probably due to the formation of a fibre network. Homogenisation also resulted in a decrease of in vitro bioaccessibility of lycopene, ζ-carotene, and lutein. Such decrease was attributed to the structuring effect of HPH. An inverse relation between tomato consistency and carotenoid in vitro bioaccessibility was found. This dependency was affected by carotenoid species and its localisation within the matrix. It could be observed that one matrix (e.g. (homogenised) red tomato pulp) can contain carotenoids with a very low bioaccessibility (lycopene) as well as carotenoids with a very high bioaccessibility (lutein), indicating that carotenoid bioaccessibility is not solely dependent on the matrix.     

Scope and Post‐Transformations for the Borane‐Isocyanide Multicomponent Reactions: Concise Access to Structurally Diverse Heterocyclic Compounds

A recently described family of multicomponent reactions (MCRs) involving isocyanides, aldehydes, dipolarophiles and alkylboranes that yield highly substituted aziridines, oxazolidines and pyrrolidines has been studied in detail. In this work the scope of these processes is significantly increased by preparing the borane input through hydroboration of alkenes or organometallic processes, in tandem with the MCR. The aldehyde range is also expanded, and indole‐3‐carbaldehydes yield reactive imines and bis‐indolyloxazolidines, depending on the electron density of the heterocycle. Finally, the obtained adducts constitute an ideal platform to generate structurally diverse compounds using simple post‐condensation modifications. In this way, indole imines undergo stereoselective hydrocyanation and oxazolidines are reductively opened to give amino alcohols. Additionally, palladium‐, ruthenium‐ and gold‐catalyzed processes lead to a variety of complex heterocycles. The methodology is simple, efficient and highly divergent, leading to an array of interesting scaffolds for medicinal chemistry.

     

Improved Thermal Behavior of Multiple Linked Arrays of Silicon Nanowires Integrated into Planar Thermoelectric Microgenerators

Low-dimensional structures have been shown to be promising candidates for enhancing the thermoelectric properties of semiconductors, paving the way for integration of thermoelectric generators into silicon microtechnology. With this aim, dense arrays of well-oriented and size-controlled silicon nanowires (Si NWs) obtained by the chemical vapor deposition (CVD)-vapor–liquid–solid (VLS) mechanism have been implemented into microfabricated structures to develop planar unileg thermoelectric microgenerators (μTEGs). Different low-thermal-mass suspended structures have been designed and microfabricated on silicon-on-insulator (SOI) substrates to operate as microthermoelements using p-type Si NW arrays as the thermoelectric material. To obtain nanowire arrays with effective lengths larger than normally attained by the VLS technique, structures composed of multiple ordered arrays consecutively bridged by transversal microspacers have been fabricated. The successive linkage of multiple Si NW arrays enabled the development of larger temperature differences while preserving good electrical contact. This gives rise to small internal thermoelement resistances, enhancing the performance of the devices as energy harvesters.     

Laterally chromatically dispersed, spectrally encoded interferometer

We present a single-shot line sensor based on spectral interferometry. Light of a broadband laser source is chromatically dispersed by a grating and focused onto a line on the surface such that each focal point on this line is formed by another wavelength. The entire height profile is obtained by applying a phase evaluation algorithm to the registered interference signal, followed by a model-based approach. The sensor concept is finally verified by experimental results.     

Facile synthesis of bismuth ferrite nanoparticles for ppm-level isopropanol gas sensor

Journal of Materials Science: Materials in Electronics - Breath gas detection has attracted significant attention for the early screening of lung cancer. In this paper, we synthesized bismuth...     

Distribution of soap in a membrane reactor in the production of fame from waste cooking oil

A continuous‐flow membrane reactor was constructed for the production of fatty acid methyl ester (FAME) from waste vegetable oil with high free fatty acid (FFA) content. FAME was produced via base‐catalysed transesterification with methanol at two FFA levels: 4.8 and 10 mass%. The effect of the ceramic membrane pore size on the separation of soap and triglycerides from the FAME in the reactor was investigated. In all cases, the triglyceride was completely retained in the reactor, yielding free and total glycerine contents in the produced FAME significantly below the maximum limits of the ASTM D6751 standard. The soaps produced in the reaction mixture were not completely retained in the reactor and did not affect the FAME production process. © 2012 Canadian Society for Chemical Engineering     

Structure of plasma-sprayed zirconia coatings tailored by controlling the temperature and velocity of the sprayed particles

The correlation between particle temperature and velocity with the structure of plasma-sprayed zirconia coatings is studied to determine which parameter most strongly influences the coating structure. The particle temperature and velocity are measured using an integrated optical monitoring system positioned normal to the spraying axis. The total porosity, angular crack distribution, and thermal diffusivity are correlated with the particle temperature and velocity. Results show that the temperature of the sprayed particles has a larger effect on the coating properties than the velocity in the conditions investigated.     

Interaction of Foundry Sands with Geosynthetics

Excess foundry sands from gray-iron casting are a mixture of sand, bentonite, and additives that can have properties desirable for structural fills and hydraulic barriers, depending on their bentonite content. To facilitate beneficial reuse of foundry sands, typical strength parameters need to be available so that designers can make comparisons with designs employing virgin earthen materials. To provide typical design parameters, a testing program was conducted to characterize the strength of foundry sands and their interaction with geosynthetics. Small-scale direct shear tests, large-scale multistage interface shear tests, and pullout tests were conducted using foundry sands with bentonite contents representing the range normally found in the casting industry and three geosynthetics (geotextile, geogrid, and geomembrane). The results indicate that foundry sands can be used effectively in geotechnical construction. Friction angles of the as-compacted foundry sands generally ranged between 39° and 43°, and the as-compacted cohesions ranged between 17 and 28 kPa. Drained friction angles were similar to as-compacted friction angles except at high bentonite content. Typical interface friction angles ranged between 25° and 35°, with efficiencies ranging between 0.5 and 0.9. Interaction coefficients from the pullout tests ranged between 0.2 and 1.7.