Simple, stable, and compact multiple-reflection optical cell for very long optical paths

A new type of multiple-reflection optical cell is presented. One of the main advantages of this type of cell is that it can be made of standard mirrors without particular tolerance while allowing a great number of reflections and thus a large optical path, only limited by the reflection coefficient of the mirrors. The configuration is simple, compact, stable, and cheap. This cell consists of three mirrors as in a White cell but its principle is different. It behaves as a multiplier of a Herriott cell from which it inherits the opto-mechanical stability qualities. The Herriott cell and the White cell are two particular cases of this type of cell. As examples, a demonstrator and an absorption cell contained in a volume of 5 l are presented. The first device is usable with a laser in visible light. The second device is usable with an infrared laser diode for the detection of atmospheric trace species.     

Meat bolus properties in relation with meat texture and chewing context

During chewing the meat sample is fragmented by compressive and shear bite forces while saliva is incorporated. At the end of this process meat is transformed into a bolus with specific properties, which elicit deglutition. This study aims to analyze the mechanical properties of the boli and juice-saliva interactions in different chewing contexts. Two groups of subjects with different chewing efficiencies participated in the study: healthy dentate (n=9) and denture wearers (n=7). Meat boli were obtained from two beef samples exhibiting different textures obtained by varying aging time and cooking temperature. Variables linked to saliva-food matrix interactions (boli volume and weight, dry matter content) were not dependent on muscle fiber disorganization evaluated using shear tests. No texture effect was observed from the mechanical properties of the boli, whatever the chewing context. Denture wearers swallowed less disorganized boli but with a similar water content as dentate. Between subjects variability was the highest for saliva-food interactions and the lowest for mechanical properties. The variations obtained in meat boli characteristics could have consequences on sensory properties perception and on the digestion process.     

Doing thinking: revisiting computing with artistic research and technofeminism

ABSTRACT

In this paper, we explore how artistic research and its methodologies can create new modes of thinking and research on computational issues. We draw on experiences with the research project ‘Reconfiguring Computing Through Cyberfeminism and New Materialism’ (CF+), during which we collaboratively investigated modes and methods of knowledge production in computing. Cyberfeminist legacies and new materialism provided a historically informed and theoretically rigorous set of concerns around which artistic research and computing were brought together. We discuss collaborative experiments and three hybrid methodologies – creating situations for intra-action, diffractive reading/making and material speculation – that we employed and suggest that what emerged is a kind of ‘doing thinking’ as a material-speculative practice that re-positions research as a critical open-ended space for non-standard ways of knowing. The paper explores implications of this for ethics and responsibility in computing, materiality of knowledge production and modes of interdisciplinary collaborations.     

Ion Irradiation of Preceramic Polymer Thin Films

Thin films of two preceramic polymers, namely polycarbosilane (PCS) and a silicone resin (SR350), were deposited on Si substrates. Instead of employing conventional annealing at high temperatures in an inert atmosphere, ion irradiation was used to achieve the polymer-to-ceramic conversion. A detailed investigation of the changes in the composition, chemical structure, and hardness was performed by means of ion beam analysis (Rutherford backscattering spectrometry, nuclear reaction analysis, and elastic recoil detection analysis), FTIR, Raman and nanoindentation, respectively. This processing method yielded amorphous Si-C and Si-O-C coatings possessing high hardness and density. Compared to films heat-treated under vacuum at 1000°C, ion-irradiated ones exhibited a similar hydrogen content, a lower oxygen contamination, and a higher carbon content. Annealing at 1000°C of previously irradiated films resulted in coatings still possessing a high carbon content and a high hardness.     

Essential fatty acids in trout serum lipoproteins,vitellogenin and egg lipids

This paper describes evidence of (n−3) and particularly of 22∶6 (n−3) fatty acid enrichment in trout lipoproteins as well as in vitellogenin, egg lipovitellin and oil globule. Among the lipoproteins, HDL and LDL were the main forms of blood lipid transport, whereas phospholipids and cholesteryl esters are the preferential chemical carriers for (n−3) fatty acid transport. However, cholesteryl esters were less important as esterified fatty acid carriers than in man. Taken together with the data obtained in mammals, our results suggest that there may be a relationship between EFA activity and the distribution of the EFA among the lipoprotein lipid fractions in vertebrates, irrespective of the EFA series. Administration of an (n−3) fatty acid deficient diet for three months prior to trout spawning produced a significant increase in egg lipid content, primarily as a result of the increase of the oil globule composed almost exclusively of triacylglycerols. This diet decreased the 22∶6 (n−3), as well as the (n−3) fatty acid contents of lipoproteins, lipovitellin, vitellogenin and the oil globule. In contrast, the (n−3) fatty acid level was always higher in lipoproteins and lipovitellin than in the vitellogenin and the oil globule. Moreover, the relative levels of 22∶6 (n−3) and total (n−3) fatty acids were quite similar in lipoproteins and lipovitellin on the one hand, and in vitellogenin and the oil globule on the other. These findings suggest a direct relationship between the two forms of plasma lipid transport and the two egg compartments. During ovogenesis, dietary lipids seemed to be diverted from the adipose tissue and essentially deposited in the egg.     

Study of Deformation Mechanisms in Titanium by Interrupted Rolling and Channel Die Compression Tests

The mechanisms of small plastic deformation of titanium (T40) during cold rolling and channel die compression by means of "interrupted in situ" EBSD orientation measurements were studied. These interrupted EBSD orientation measurements allow to determine the rotation flow field which leads to the development of the crystallographic texture during the plastic deformation. Results show that during rolling, tension twins and compression twins occur and various glide systems are activated, the number of grains being larger with twins than with slip traces. In channel die compression, only tension twins are observed in some grains, whereas slip traces can be spotted in almost all observed grains. The different stress conditions and different strain rates existing under the two modes of deformation lead to the activation of different deformation mechanisms.     

Cassava Starch Processing at Small Scale in North Vietnam

In Northern Vietnam, small‐scale cassava starch processing is conducted in densely populated craft villages, where processors face difficulties to expand their activities. Three different processing systems were studied among a cluster of three communes in the Red River Delta, producing up to 430 t of starch (at 55% dry matter) per day. The first system, type A, is a cylindrical rasper and a manual sieve, the second, type B, is a cylindrical rasper and stirring‐filtering machine and the third, type C, used equipment for both the rasping and filtering stages. Moisture, starch, crude fibers and ash content analysis were carried out on samples collected from the A‐B‐C manufacturing processes to establish the mass balance of starch. Production capacity, water consumption, electrical requirements and capital‐labor costs per tonne of starch (12% moisture) were also reported. A‐B‐C manufacturing processes enabled 75% recovery of the starch present in fresh roots. No significant change was observed in the composition of starch. Upgrading from system A to B and subsequently to C resulted in an increase in the extraction capacities (up to 0.9 t of peeled roots per hour), the extraction efficiencies during the extraction stage (up to 93%), and an increase in the water consumption and electrical power (up to 21 m³ and 55 kWh per tonne of starch, respectively). The highest amount of total solids carried in the waste‐water was obtained with type C (up to 17% of the dry weight of fresh roots, compared to 10% and 13% for type A and B, respectively). This may lead to a higher chemical oxygen demand (COD) and biological oxygen demand (BOD) in waste‐water, which can result in more polluted waste‐water than compared with the type A and B technologies. Upgrading the rasping‐extraction technologies also resulted in higher profits and reduction of labor per tonne of starch (up to 18 US$ and 26 man‐hours respectively). The diagnosis proposed in this study can be applied in different contexts to recommend technological options by considering space, energy and capital‐labor availabilities.