Implementation of a rational drying process for fish conservation

Fishing is a traditional activity that is widespread in West Africa. One of the greatest problems for fishermen and a cause of lack of food accessibility is the difficulty in conserving fish. Drying is a widely used technique in sub-Saharan Africa for preservation of fish. However, drying is a complex process, making the construction and calibration of efficient drying devices challenging. This paper presents the construction and calibration of five mobile fish dryers in Mali and, for one of them, development of a method for its use. The performances achieved far exceeded those of traditional solar dryers as drying was faster and the fish were not contaminated by being exposed to flies. Furthermore, construction and user manuals were written for the local fishermen which were well understood as the fishermen were able to disassemble and reassemble the dryers when they were required to be moved.     

Predictive Guidance-Based Navigation for Mobile Robots: A Novel Strategy for Target Interception on Realistic Terrains

This paper presents a novel online trajectory planning method for the autonomous robotic interception of mobile targets in the presence of dynamic obstacles. The objective is time-optimal position and velocity matching (also referred to as rendezvous) while traversing realistic terrains with uneven topologies. The primary novelty of the proposed interception method lies in its ability to minimize rendezvous time with the target, as well as energy consumption, by directly considering the dynamics of the obstacles and the target while accurately determining a feasible way to travel through the realistic terrain. This objective is achieved by computing rendezvous maneuvers using an advanced predictive guidance law. The method is designed to effectively cope with maneuvering targets/obstacles by predicting their future velocities and accelerations. Obstacle avoidance and terrain navigation are seamlessly integrated. Extensive simulation and experimental analyses, some of which are reported in this paper, have clearly demonstrated the time efficiency of the proposed rendezvous method.     

Preparation of pseudocapacitor electrodes via electrodeposition of polyaniline on nonwoven carbon fiber fabrics

Aniline has been polymerized via electrodeposition onto various nonwoven carbon fiber fabric (CFF) substrates for use as a pseudocapacitive electrochemical capacitor. Four types of CFF were initially tested for double layer capacitance before polyaniline deposition, and again for specific capacitance after deposition. A binder‐free CFF was selected for further analysis due to its high capacitance change following PANI deposition (three orders of magnitude). The aniline monomer concentration, deposition potential, and deposition time were varied and resulting materials were characterized using chrono‐potentiometry, cyclic voltammetry, and scanning electron microscopy. The deposition potential range yielding highest capacitance was found to be between 0.744 and 0.777 V. A solution concentration of 0.5M aniline at a 20 min deposition time resulted in the highest specific capacitance (>80 F/g based on total electrode mass and >300 F/g based on PANI mass) within this study. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43315.     

Ferroelectricity and high tunability in novel strontium and tantalum based layered perovskite materials

The present study reveals the ferroelectric nature of the novel (Sr₂Ta₂O₇)_100-x(La₂Ti₂O₇)_x layered perovskite materials and highlights a large variation of their permittivity under electric fields associated with very low dielectric loss in the radio-frequency range. More precisely, an ideal solid solution has been evidenced within the composition range 0?≤?x?≤?5 with lattice parameters and cell volume varying linearly with x. The relative permittivity also depends on the composition and reaches a maximum value (365 @10?kHz, RT), associated with a high tunability (17.6% @0.38?kV/mm) with very low dielectric loss lower than 2.10^?3. Variation of the relative permittivity as a function of the temperature is also demonstrated, with the existence of a temperature maximum, increasing with the composition. Polarization-electric field (P-E) measurements feature hysteresis loops for compositions x?≥?1.85, in conjunction with current peaks in the I-E curves originating from ferroelectric domains switching.     

Assessing the differential affinity of small molecules for noncanonical DNA structures

The targeting of higher-order DNA structures has been thoroughly developed with G-quadruplex DNA but not with other structures like branched DNA (also known as DNA junctions). Because these alternative higher-order DNA architectures might be of high biological relevance, we implemented a high-throughput version of the FRET melting assay that enabled us to map the interactions of a candidate with four different DNA structures (duplex- and quadruplex DNA, three- and four-way junctions) in a rapid and reliable manner. We also introduce a novel index, the BONDS (branched and other noncanonical DNA selectivity) index, to conveniently quantify this differential affinity.     

EXPERIMENTAL AND THEORETICAL STUDY OF THE PORE STRUCTURE AND DIFFUSION PROPERTIES OF AN EVOLVING HETEROGENEOUS MATERIAL: APPLICATION TO RADIOACTIVE BITUMINIZED WASTE

Placed in a geological repository, radioactive bituminized waste (BW) could be altered in the long term by water, leading to the release of chemical and radioactive elements. The main difficulty, in terms of experimental characterization, comes from the fact that the BW material evolves in time due to the swelling associated to the water osmotic flux. To overcome this difficulty, a new approach is proposed in this work, based on the leaching of BW samples in aqueous solutions where the chemical activity of water is controlled. These specific leaching conditions allow one to control the swelling of the degraded BW matrix. The chemical activity of water being fixed, the pore structure of the leached BW samples was quantitatively studied by ESEM pictures further treated by image analysis. In parallel, diffusion cells using radioactive tracers were used in order to measure mass transfer characteristics in the leached BW. Coupling image analysis with diffusion experiments for each degradation state leads to a diffusion coefficient-porosity relation that is then compared to standard diffusion models in biphasic materials.     

Achievement goal promotion at university: Social desirability and social utility of mastery and performance goals.

The present research examines the ambivalence of achievement goal promotion at university, and more specifically in the psychology curriculum. On the one hand, psychology teachers explicitly encourage mastery but not performance (neither approach nor avoidance) goals. On the other hand, the selection process encourages the endorsement of not only mastery but also performance-approach goals. In fact, it would seem that both performance-approach and mastery goals are valued in a university context. Two pilot studies verified the above assumptions. Subsequently, Experiments 1, 2, and 3 showed that each of these goals corresponds to different aspects of social value. Indeed, high endorsement of mastery goals was associated with being judged as both likable (social desirability) and likely to succeed (social utility). High endorsement of performance-approach goals enhanced social utility judgments but reduced perceived likability. Performance-avoidance goals only enhanced perceived likability. The discussion focuses on the 2 functions of university, namely education (apparent in the official discourse of teachers) and selection (apparent in the university structure), and on the perceived value of achievement goals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Low humidity after harvest changes the abscission site in bunch cherry tomatoes

BACKGROUND: In bunch cherry tomatoes (BCTs) abscission of the fruit from the bunch, rather than deterioration of fruit determines the life‐span of the produce. Two abscission sites have been characterised: the joint (AJ) in the middle of the pedicel, and at the receptacle (AR) at the fruit‐pedicel interphase. The type of abscission is sensitive to growth conditions; joint abscission is typical of winter harvests whereas receptacle abscission is dominant in summer harvests. The aim of the present study was to determine the effect of relative humidity (RH) in terms of water vapour pressure deficit (WVPD) during storage and shelf life on the course and site of abscission of BCTs. RESULTS: The rachis composes only about 2% of the bunch weight, and therefore most of the water loss originated from the fruit. When the bunch lost almost 10% of its weight under low humidity, the relative weight of the rachis was reduced to one‐quarter of its original value. Storage at low WVPD resulted in dominance of AJ whereas storage at high WVPD resulted in dominance of AR. BCTs that exhibited primarily AJ after cold storage was prone to either AJ or AR in high or low shelf‐life RH, respectively. BCTs subjected to elevated temperature and high WVPD after harvest developed receptacle abscission. CONCLUSION: Dehydration of the receptacle abscission zone makes it prone to abscission and this process can be prevented by high‐RH storage. Copyright © 2009 Society of Chemical Industry