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Thin films have a crucial role in integrated optics. The development of passive and active devices such as splitters, waveguides, multiplexers and optical amplifiers is by now established on rigid substrates. Therefore, an important further step to improve this kind of technologies and open the route to new applications is to extend these functionalities to mechanically flexible devices. One fundamental brick to obtain this features extension is the fabrication of low loss inorganic active planar waveguides on flexible glass substrate. Here, we present the preliminary results of a novel top-down fabrication of an active SiO 2 –HfO 2 :Er3+ all-glass flexible planar waveguide, via radio frequency sputtering. The waveguiding system, deposited on ultrathin flexible glass substrate, showed an attenuation coefficient lower than 0.2 dB/cm at 1.53 μm and exhibits emission in the NIR region. [ABSTRACT FROM AUTHOR]

For integrated photonics, waveguide structures based on rare-earth-activated glasses are potential candidates for implementing compact integrated light sources and amplifiers. However, rare-earth ions (REs) possess low absorption cross-section, and this limits the light emission and amplification efficiency. As long as the REs are involved, there are other phenomena detrimental to their luminescence quantum yield including ion-ion interactions and non-radiative relaxation processes. To solve such problems, photonic glass-ceramics can be strategic solutions. Transparent glass-ceramics combine interesting properties of both amorphous and crystalline phases and offer specific characteristics of capital importance in photonics. More important, photonic glass-ceramics can tailor and enhance the spectroscopic properties of the rare-earth ions depending on their compositions and nature. In this work, we studied SnO 2 -nanocrystal-based transparent glass-ceramic planar waveguides activated by rare-earths to give solutions for the problems mentioned above and enhance the rare-earth luminescence efficiency for integrated photonics. SiO 2 –SnO 2 :Er3+ planar waveguides containing 30 mol% SnO 2 nanocrystals were fabricated by sol-gel method and dip-coating technique. The planar waveguides were assessed by various characterization techniques to ensure the applicability of such glass-ceramics for integrated photonics. The experimental assessment of the SiO 2 –SnO 2 :Er3+ planar waveguides focused on the key considered photonic characteristics including the structural, morphological, spectroscopic, and especially optical waveguiding properties. The photoluminescence measurements put in evidence the role of SnO 2 nanocrystals as efficient Er3+ luminescence sensitizers. Moreover, the incorporation of Er3+ ions in SnO 2 nanocrystals was demonstrated to reduce the effect of non-radiative relaxation processes on the luminescence of the Er3+ ions and thus led to higher luminescence efficiency. Majority of the Er3+ ions (97%) was confirmed to be imbedded in the SnO 2 nanocrystals. The SiO 2 –SnO 2 :Er3+ glass-ceramic planar waveguides have confined propagation modes, step-index profile with high confinement of 82% at 1542 nm and especially, low losses of 0.6 ± 0.2 dB/cm at 1542 nm. Image 1 • 70SiO 2 –30SnO 2 (mol%) glass-ceramic planar waveguides obtained by sol-gel method. • Sol-gel route succeeded in incorporating 97% of the Er3+ ions in SnO 2 nanocrystals. • SnO 2 nanocrystals (<10 nm sizes) acted as efficient Er3+ luminescence sensitizers. • The waveguides have high confinement (82%) and low losses (0.6 dB/cm) at 1542 nm. • Embedding Er3+ in SnO 2 reduced nonradiative relaxation effects on Er3+ luminescence. [ABSTRACT FROM AUTHOR]

• Biology of reduviid Sycanus falleni were determined and comparative. • Predatory ability and body weight of S. falleni were determined and comparative. • The number of four preys were killed by reduviid S. falleni were different. • The body weight I, V nymphal instars and adults weren't different. The reduviid Sycanus falleni Stal (Heteroptera: Reduviidae) is an important predatory insect in biological control pests in vegetable, soybean, corn and rice plants. It is omnivorous species and has a wide range of prey. The influence of fed on four different preys as Pieris rapae (Linnaeus), Spodoptera litura (Fabricius), Plutela xylostella (Linnaeus) and Corcyra cephalonica (Stainton) on biological parameters, ability to eat prey and body weight of the nymph and adult of S. falleni were evaluated in laboratory conditions (26 ± 2 °C, 75 ± 5% RH and light:dark 14:10 h) in Vietnam. The biological parameters of reduviid S. falleni reared on the laboratory were determined by observing the development stage of egg, development stage of nymph, pre-oviposition period, life cycle, longevity of adult, number of eggs laid, sex ratio. The nymph and adults of reduviid S. falleni consumption the number of P. xylostella, P. rapae , S. litura and C. cephalonica larvae were different, and an adult female consumed more than an adult male while the body weight of the I and V nymphal instars, male and female adults of reduviid S. falleni wasn't significantly different (P < 0.01). [ABSTRACT FROM AUTHOR]

Reduced reliance on fossil fuels is a critical issue, and electrification of agricultural machinery is a solution for lowering greenhouse gas emissions in non-road transportation. By separating the load and drive from the engine, electrification the implement allows the engine to operate at higher efficiency. This study suggests a series hybrid design that combines a snow blower with battery support and a tractor with a reduced engine size to meet the fuel consumption reduction target while maintaining its performance. Accordingly, the Particle Swarm Optimization (PSO) algorithm is employed to size the battery that meets the constraints. Additionally, the motors of actuators are designed based on efficiency maps. Moreover, the rule-based energy management strategy is also proposed to assess the solution. This suggestion is analyzed using simulation and compared to a traditional tractor as a benchmark. The simulation results demonstrate the effectiveness of the strategy in lowering emissions from non-road machinery. Furthermore, this approach can be applied to various different types of implements attached to the tractor. • Series hybrid snow blowing implement for agricultural vehicle proposed. • Models validated by experimental measurements of a commercial snow blowing tractor. • Comprehensive design of motors, generator, battery, and reduced engine conducted. • Practical energy management ensuring charge-sustaining and fuel reduction developed. • Fuel consumption reduced up to 33.4% comparing to conventional snow blowing tractor. [ABSTRACT FROM AUTHOR]

Abstract This paper reports the fabrication of silicon nanowires (SiNWs) by silver (Ag) metal-assisted chemical etching (MACE) method. N-type Si (100) wafers, doped with phosphorus with the resistivity from 1 ÷ 10 Ω×cm, were selected for sample preparation. Ag particles of about 30 nm in diameter, which were used as the catalytic metal, were aggregated on the surface of the Si wafer immersed in HF (4.6 M) and AgNO 3 solution, with the variation concentration of 15–35 mM, for one minute. Consequently, the Si wafers covered with Ag particles were etched in HF (4.8 M) and H 2 O 2 (0.4 M) solution for the formation of vertically aligned SiNWs. We found that the size and density of SiNWs decreased with the increase of AgNO 3 concentration. After a delay time of about 30–40 min, the SiNWs growth depended linearly on the etching time. The light emission from the prepared SiNWs observed at room temperature was well resolved with two bands at around 450 nm (~ 2.75 eV) and 700 nm (~ 1.77 eV). The origins of the two emission bands and the comparative aspects are presented and discussed. [ABSTRACT FROM AUTHOR]

Viet Nam is challenged by extensive marine plastic pollution, however, remediation efforts are hampered by undefined sources to the coastal environment. This study surveyed the abundance, type, and source of beached plastic litter at seven beaches along the coast of Nha Trang, Viet Nam. A total of 4754 beached plastic litter items (>2 cm) yielded a mean abundance of 19.8 ± 19.5 items m−2 corresponding to 116 ± 226 g DW m−2. Our results demonstrate that plastic litter related to fishing and aquaculture constituted at least 62 % of the total by weight and 38 % by number, showing that these two sectors are responsible for a significant part of the plastic pollution along the coast. Hence, we argue that improved management of the fishing and aquaculture sectors could substantially reduce marine plastic pollution along Viet Nam's coast. • Viet Nam is a hotspot for beached marine plastic litter. • In order to reduce plastic pollution along the coast of Viet Nam the sectors of fishing and aquaculture should be targeted. • Food containers constituted the majority of litter from households whereas thermal boxes and ropes made up the majority of litter from fishing and aquaculture sectors. • Plastic pollution must be reported by weight and by number to fully account for plastic debris in a region. [ABSTRACT FROM AUTHOR]

16-year phytoplankton data were analysed to assess ENSO and anthropogenic impacts on biodiversity and community structure at 3 locations (Nha-Trang and Phan-Thiet Bays and near Phu-Qui Island) in South Centre Viet Nam to understand (1) the primary scales of change in phytoplankton community structure, and traditional and taxonomic diversity indices; (2) the significance of environmental changes and/or climate variability on phytoplankton diversity; and (3) the usefulness of these long-term data for analysing future impacts of anthropogenic and climate changes. Traditional and taxonomic diversity indices were compared and tested in linkage with environmental conditions and ENSO. Nutrient data indicated stronger environmental impacts in Phan-Thiet Bay, milder in Nha-Trang Bay and less noticeable near Phu-Qui Island. There were measurable impacts of both anthropogenic and ENSO on phytoplankton at different locations in various parameters, e.g. species number, diversity and community structures. The lowest diversity was recorded in the most anthropogenically impacted site, Phan-Thiet Bay. Although a stronger impact on phytoplankton was recorded in ENSO year in Phan Thiet Bay, quantitative separation between anthropogenic and ENSO impacts using phytoplankton biodiversity indices was impossible. In the waters with less anthropogenic impacts, ENSO effects on taxonomic diversity was better indicated by negative phytoplankton responses to the ONI index (Nha-Trang Bay) and recovery of phytoplankton after the ENSO events (near Phu-Qui Island). Among the diversity indices, the taxonomic diversity indices (e.g. Δ + and Λ + ) better described impacts of ENSO than the traditional ones. [ABSTRACT FROM AUTHOR]

We performed a feasibility test of the cosmetic ingredient kinetin (KT)-gold nanoparticle (AuNP) conjugates by means of vibrational Raman spectroscopy and quantum mechanical calculations. The adsorptions of KT on AuNP surfaces were examined by absorption spectra and surface-enhanced Raman scattering (SERS). The size of KT at the initial concentrations of 10-5 M with the AuNP composites was measured to be 22 nm. Density functional theory (DFT) calculations were performed to estimate the energetic stabilities of KT on an Au cluster atom. The two tautomeric forms of 9H-amino and 7H-amino in KT are predicted to have similar energies on Au. The N3-coordinating geometries in both 9H-amino and 7H-amino forms of KT are predicted to be most stable on an Au cluster. Vibrational analysis also suggested that the two tautomers of KT should coexist in the adsorbed state on Au. The concentration-dependent SERS spectra of KT indicated that 5 x 10-5 M exhibited the highest SERS signals. [ABSTRACT FROM AUTHOR]

Abstract: The DISFAT project is a French project financially supported by the French National Agency for Research (ANR). It aims at a deeper understanding of mechanisms leading to crack initiation in metals and alloys under Very High Cycle Fatigue loading (VHCF). The VHCF regime is associated with stress magnitudes lower than the conventional fatigue limit and as a result, numbers of cycles higher than 109. Tests were carried out using an ultrasonic technique at loading frequency of 20 kHz. In the case of pure copper polycrystals, we previously showed that slip band (SB) activity and intrinsic dissipation were closely related. Dissipation and slip band amount increased with the number of cycles. At very small stress amplitudes, no slip band appeared at the specimen surface up to 108 cycles but the material was found to dissipate energy. These results revealed that the material never reached a steady state and so could break at higher number of cycles. In this paper, the morphology and the location of slip bands were characterized. Different types of slip bands depending on the stress amplitudes appeared at the specimen surface. The stress amplitude required to show the first slip bands decreases with the number of cycles. It is twice lower than the stress amplitude required to break the specimen for the same number of cycles. At the smallest stress amplitudes, slip bands were mostly found at twin boundaries. Quasi 3D finite element simulations taking into account the polycrystalline nature of the material emphasized the key role of the elastic anisotropy in slip band initiation. A criterion for slip band appearance was finally proposed. [Copyright &y& Elsevier]

Abstract: Satellite pictures and in situ observations indicate strong phytoplankton blooms including harmful algae blooms (HABs) during southwest (SW) summer monsoon in the Vietnamese upwelling area. In this period, nutrients are provided by coastal upwelling and by the very high river runoff from the Mekong River. During SW monsoon, in general two circulation patterns exist which allow the prediction of advection and diffusion of HAB patches. A Lagrangian HAB model that is driven by a circulation model and applied to HABs in Vietnamese waters is presented. Advection which is the most complicated part in modelling transport of passive substances is validated with a Lagrangian sediment trap experiment. The model produces realistic results compared to in situ observations and satellite images and might be used for real time forecast in the future. [Copyright &y& Elsevier]

Abstract: Transparent conductive oxide (TCO) films of polycrystalline Nb-doped TiO2 (TNO) were fabricated by post-annealing reactively sputtered amorphous films under H2 atmosphere. Carrier transport properties of the H2-annealed films were found to be strongly dependent on substrate temperature T s and oxygen content in sputtering atmosphere. A minimum resistivity (ρ) of 9.5×10−4 Ω cm and an average visible transmittance of ∼75% were obtained at T s =RT and oxygen content of 10%. This ρ value is of the same order as those of epitaxial TNO films, indicating that polycrystalline TNO has sufficient potential as a practical TCO suitable for large-area applications. [Copyright &y& Elsevier]

Species in the epi-benthic dinoflagellate genus Gambierdiscus produce ciguatoxins (CTXs) and maitotoxins (MTXs), which are among the most potent marine toxins known. Consumption of fish contaminated with sufficient quantities of CTXs causes Ciguatera Fish Poisoning (CFP), the largest cause of non-bacterial food poisoning worldwide. Maitotoxins, which can be found in the digestive system of fish, could also contribute to CFP if such tissues are consumed. Recently, an increasing number of Gambierdiscus species have been identified; yet, little is known about the variation in toxicity among Gambierdiscus strains or species. This study is the first assessment of relative CTX- and MTX-toxicity of Gambierdiscus species from areas as widespread as the North-Eastern Atlantic Ocean, Pacific Ocean and the Mediterranean Sea. A total of 13 strains were screened: (i) seven Pacific strains of G. australes , G. balechii , G. caribaeus , G. carpenteri , G. pacificus , G. scabrosus and one strain of an undetermined species ( Gambierdiscus sp. Viet Nam), (ii) five strains from the North-Eastern Atlantic Ocean (two G. australes , a single G. excentricus and two G. silvae strains), and (iii) one G. carolinianus strain from the Mediterranean Sea. Cell pellets of Gambierdiscus were extracted with methanol and the crude extracts partitioned into a CTX-containing dichloromethane fraction and a MTX-containing aqueous methanol fraction. CTX-toxicity was estimated using the neuro-2a cytoxicity assay, and MTX-toxicity via a human erythrocyte lysis assay. Different species were grouped into different ratios of CTX- and MTX-toxicity, however, the ratio was not related to the geographical origin of species (Atlantic, Mediterranean, Pacific). All strains showed MTX-toxicity, ranging from 1.5 to 86 pg MTX equivalents (eq) cell −1 . All but one of the strains showed relatively low CTX-toxicity ranging from 0.6 to 50 fg CTX3C eq cell −1 . The exception was the highly toxic G. excentricus strain from the Canary Islands, which produced 1426 fg CTX3C eq cell −1 . As was true for CTX, the highest MTX-toxicity was also found in G. excentricus . Thus, the present study confirmed that at least one species from the Atlantic Ocean demonstrates similar toxicity as the most toxic strains from the Pacific, even if the metabolites in fish have so far been shown to be more toxic in the Pacific Ocean. [ABSTRACT FROM AUTHOR]

In this paper, the main results obtained in the framework of a National French Agency project called DISFAT, standing for “Dissipation in Fatigue”, are presented. The project was dedicated to the microplastic mechanisms leading to crack initiation in the case of ductile metals loaded in very high cycle fatigue. Fatigue tests were carried out at 20 kHz using an ultrasonic facility. In order to investigate the microplastic mechanisms, slip markings at the surface of the specimens were observed and the self-heating of the specimen during the tests was measured by thermography to deduce the dissipated energy. Polycrystalline copper, α-brass and α-iron were investigated. A good correlation was found between persistent slip bands and dissipated energy. The dissipated energy for the three materials was of the same order of magnitude but while α-iron reached a stable dissipative state, the dissipated energy in the case of copper and α-brass was found to continue to increase gradually with increasing numbers of cycles. That change in dissipated energy during cycling was consistent with the development of persistent slip bands. Both were discussed with regard to the materials. [ABSTRACT FROM AUTHOR]

Abstract: The cosmopolitan alga Phaeocystis globosa forms large blooms in shallow coastal waters off the Viet Nam coast, which impacts the local aquaculture and fishing industries substantially. The unusual feature of this alga is that it forms giant colonies that can reach up to 3cm in diameter. We conducted experiments designed to elucidate the ecophysiological characteristics that presumably favor the development of giant colonies. Satellite images of chlorophyll fluorescence showed that the coastal bloom was initiated in summer and temporally coincident with the onset of monsoonally driven upwelling. While determining the spatial distribution of Phaeocystis was not feasible, we sampled it in the near-shore region. A positive relationship was found between colony size and colonial cell densities, in contrast to results from the North Sea. Mean chlorophyll a concentration per cell was 0.45pgcell−1, lower than in laboratory or temperate systems. The contribution of mucous carbon ranged from 63–95% of the total carbon; furthermore, mucous carbon per unit of colony surface area appeared to decrease with colony size, suggesting that the mucoid sheath became thinner as colonies grew larger. Sinking rates averaged 189md−1, strongly suggesting that giant colonies could only persist in shallow, turbulent environments. No relationship between colony size and sinking rates was observed. DOC concentrations of intracolonial fluid averaged 5940μM, 25 times greater than ambient concentrations. Estimated diffusion coefficients of ions across the mucous envelope were ca. 1.0±0.3×10−7 cm2 s−1 for colonies with diameters of ca. 1.0cm. In total, the characteristics of the giant colonies suggest that the Vietnamese strain is substantially different from that found in temperate environments, and that it has a number of unusual features that influence its growth and development in coastal Vietnamese waters. [Copyright &y& Elsevier]

Abstract: Ciguatera fish poisoning characterizes the intoxication caused by consumption of fish from tropical and subtropical areas, which have accumulated ciguatoxins (CTXs). The observed pattern of ciguatoxins in fish highly depends on the marine region and the causative organisms. It is evident that differences exist between ciguatoxins produced by certain strains of the dinoflagellate Gambierdiscus toxicus and other Gambierdiscus spp. In this context cultured strains purchased from the Provasoli–Guillard National Center for Culture of Marine Phytoplankton (CCMP) and strains from Vietnam were analyzed. Besides, lyophilized samples of several Gambierdiscus spp. from the National Oceanic and Atmospheric Administration (NOAA), USA and lyophilized samples of G. toxicus from Vietnam were analyzed. The latter has been cultured at different salinities. We observed differences between the toxin ratios of the analogues in the strain from Vietnam depending on the salinity. The CTX profiles of the Vietnamese samples were compared with cultures of Gambierdiscus spp. from CCMP and the National Oceanic and Atmospheric Administration (NOAA) resulting in an overview of toxins in cultures from different regions. Hence, it was obvious that the strain from Vietnam forms a characteristic CTX profile which is not directly comparable to CTX pattern observed in other tropical marine regions. [ABSTRACT FROM AUTHOR]