Morphological Keys for the Identification of Tunisian Culicoides Biting Midges (Diptera: Ceratopogonidae)

Culicoides biting midges are tiny blood-feeding insects of several diseases with veterinary and public health significance, including Bluetongue in ruminants, African horse sickness in equids and filarial diseases like Onchocercosis and Mansonellosis affecting various species such as humans. Their identification depends basically on the microscope examination of key morphological characters. Consequently, identification keys are important to any non experiment working with these biting midges. The Tunisian fauna of Culicoides biting midges consists of 35 species, whose morphological delineation may be troublesome for non-taxonomists. In response to this situation, and for the first time a key to the adult Culicoides species in Tunisia was prepared.

Assessment of Fit on Ten Screw-Retained FrameworksRealized through Digital Full-Arch Implant Impression

Background: Discordant opinions have emerged among clinicians and researchers regarding a digital impression for full-arch implant-supported fixed dental prostheses (FDPs). The purpose of this study was to assess the fit of screw-retained milled frameworks on six implants realized from digital impressions through the Sheffield test. Methods: One patient received a maxillary full-arch implant-supported FDP. Six months after the surgical procedure, ten intraoral full-arch digital impressions were performed to mill ten frameworks. To clinically assess the fit, the Sheffield test was applied for all frameworks. The gaps among the frameworks and the implant analogs were measured using a microscope on the master model realized with a traditional impression. The Wilcoxon sum-rank test was used to compare the misfit value among the different implant positions. Results: The Sheffield test did not show gaps in the framework–implant interfaces when the screw was completely tightened on the more distal implant for all the milled frameworks. The mean misfit value calculated after microscope examination was 38 ± 5 μm. Differences that were statistically significant emerged when the misfit values of central positions were compared with other values. Conclusions: The use of full-arch implant digital impressions represents a viable alternative to traditional impressions for the fabrication of implant-supported FDPs.

Biostratigraphy of Yamama Formation in Faihaa Oil Field, Southern Iraq

The Yamama Formation was studied in three wells (Fh-1, Fh-2, and Fh-3) within Faihaa oil field, south Iraq. Thin sections were studied by using the polarizing microscope examination in order to determine microfossils and biozone. Thirty-five species of benthic foraminifera were recognized, including four index species. In addition, twelve species of calcareous green algae were recognized, including two index species. Other fossils that were recognized in Yamama Formation include Gastropoda, Bryozoa, Coral, Rudist, and Pelecypoda. Six biozones were observed, which are Charentia cuvillieri sp. (Range Zone of Berriasian age), Psudochryalidina infracretacea sp. (Range Zone of Berriasian age), Pseudocyclammina Lituus sp. (Range Zone of Valanginian age), Nezzazata Perforate sp.andChoffatella sp.(Assemblage Zoneof Berriasian-Valanginian age), Desycladales Green Algae- Cylindroporella sp. (Range Zone of Early Cretaceous- Berriasian age), and Desycladales Green Algae- Salpingoporella cf. circassa sp. (Range Zone of Valanginian age). According to these biozones, the age of Yamama Formation was distinguished to be the Berriasian-Valanginian.

Retained Austenite Destabilization during Tempering of Low-Temperature Bainite

The thermal stability of nanostructured microstructures consisting of a mixture of bainitic ferrite and carbon-enriched retained austenite has been studied in two steels containing 0.6 C (wt %) by tempering cycles of 1 h at temperatures ranging from 450 to 650 °C. Volume changes due to microstructural transformations during thermal treatments were measured by high-resolution dilatometry. The correlation of these results with the detailed microstructural characterization performed by X-ray diffraction and scanning electron microscope examination showed a sequence of different decomposition events beginning with the precipitation of very fine cementite particles. This precipitation, which starts in the austenite thin films and then continues in retained austenite blocks, decreases the carbon content in this phase so that fresh martensite can form from the low-carbon austenite on cooling to room temperature. In a subsequent tempering stage, the remaining austenite decomposes into ferrite and cementite, and due to carbide precipitation, the bainitic ferrite loses its tetragonality, its dislocation density is reduced, and the bainitic laths coarsen.

First findings of the rare chiton Acanthochitona leopoldi (Mollusca: Polyplacophora) in the South China Sea

The rare chiton Acanthochitona leopoldi (Leloup, 1933) is recorded for the first time from the Spratly Islands (Truong Sa), Vietnam. The species is redescribed based on the scanning electron microscope examination of the recently collected specimens. Age variability of the shell, radula and perinotum of this species is also given.

Discovery and material study of the missing feet part from Magritte’s L’évidence éternelle of 1954

One of the two missing canvases from L’évidence éternelle of 1954, the one of the feet, has been discovered beneath a small woman portrait painted in 1958, La toile de Pénélope. Indeed, the underlying woman’s feet revealed through the IRR and XRR images leave little doubt about the identity of the hidden composition. All the more so as the canvas dimensions perfectly match with the format ascribed to the feet part in the diagram Magritte made of the 1954 variant of L’évidence éternelle. This paper presents the main results of the material study conducted on La toile de Pénélope by means of non-invasive and complementary imaging and analytical techniques. Furthermore, it proposes a virtual colorized reconstruction of the hidden picture, built on the basis of the XRR and IRR images, the elemental information provided by the MA-XRF analysis, the Raman results and the microscope examination of the painting surface.

Problems of Pad Welding Structural Steels with Martensitic Filler Metal

There is a problem in obtaining a suitable impact strength of the padding weld after cladding with a martensitic filler metal. Too low annealing temperature below 580°C and the excessive annealing temperature above 650°C do not provide adequate impact strength of the padding weld. A heat treatment technology for mixed joints has been developed based on the results of the microscopic observations, X-ray diffraction measurements and transmission electron microscope examination. The problem was identified and a special technology of heat treatment for the dissimilar joint was elaborated. This technology provides a high impact resistance of the padding weld and an appropriate properties of the base material.

Fluidized glass beads reduce fouling in a novel anaerobic membrane bioreactor

This study focuses on the use of fluidized glass beads as turbulence promoters in a laboratory-scale anaerobic membrane bioreactor treating municipal wastewater at 20 °C. The addition of fluidized glass beads into an external tubular ceramic membrane enabled the operation at low crossflow velocities of 0.053–0.073 m/s (mean fluxes between 5.5 and 9.7 L/(m2·h)) with runtimes >300 h. Glass beads with a diameter of 1.5 mm were more effective than smaller ones with a diameter of 0.8–1.2 mm. Increasing the bed voidage from 74 to 80% did not show any beneficial effect. As scanning electron microscope examination showed, the fluidized glass beads damaged the used membrane by abrasion. The overall total chemical oxygen demand (COD) removal was between 77 and 83%, although mean hydraulic retention times were only between 1.3 and 2.3 h. The production of total methane was increased about 30% in comparison to the bioreactor without membrane. The increased methane production is presumably attributed to biological conversion of rejected, dissolved and particulate organic matter. The total required electrical energy was predicted to be about 0.3 kWh/m3.