Search results for "Engineering and Technology"
showing 10 items of 16184 documents
Hydrodynamic characterization of a new small-scale reactor mixed by a magnetic bar
2015
International audience; The purpose of this study was to evaluate the mixing characteristics of a new milliliter-scale (mL-scale) reactor developed for studying enzymatic activity or physiological cell response. The mL-scale reactor was designed to enable the integration of several sensors to carry out dynamic measurements in a controlled environment. Rapid homogeneity of the entire system is essential to ensure reproducible and reliable results, consequently the reactor was stirred to optimize both mass and heat transfers. A comparative study using three different techniques was undertaken to study mixing performances in the system. Firstly, mixing time (4,) was estimated in the reactor us…
Valorisation of Dairy Wastes Through Kefir Grain Production
2019
The main aim of this work was to investigate on kefir grains (KGs) increase using different dairy by-products. To this purpose, whey and deproteinized whey from cow, goat and sheep milk were compared to the pasteurized milk of the corresponding animal species. Each substrate was inoculated with 3% (w/v) of KGs cultivated in ultra-high temperature cow milk and evalu- ated for pH decrease, total titratable acidity increase and development of lactic acid bacteria (LAB) and yeasts released in the matrices after 24 h incubation at three different temperatures (20, 25 and 30 °C). The genotypic characterization of the dominating microbial populations resulted in the identification of two LAB belon…
A new contribution to the alien macroalgal flora of the Ustica Island Marine Protected Area (Tyrrhenian Sea, Italy)
2018
A second record of the non-indigenous species Botryocladia madagascariensis G. Feldmann (Rhodophyta) along the coasts of the “Ustica Island” Marine Protected Area (Tyrrhenian Sea, Italy) is reported. With this additional record for the Sicilian coasts, we provide a description of collected specimens of B. madagascariensis and habitat details. Numerous fertile female gametophytes with cystocarps immersed in vesicles were also observed, for the second time in the Mediterranean Sea, and described.
Structural and Mechanical Modification Induced by Water Content in Giant Wild Reed (A. donax L.)
2018
Giant wild reed Arundo donax L. is an aggressive agricultural species with remarkable features such as fast-growing, untapped economic potential, eco-friendliness, and high specific properties (e.g., high strength/weight and modulus/weight ratios). Here, the bending properties of giant reed were studied at a molecular level to evaluate the effect of the conditions used during the preparation for their applications (also referred to as treatment conditions). The aim was to achieve new information potentially useful to suggest new possible applications of A. donax L. for structural applications in modern buildings. In this study, green reeds collected in a Sicilian plantation were dried for 2…
Combustion Properties of Birch (Betula pendula) Black Liquors From Sulfur-Free Pulping
2016
Sulfur-free pulping has an environmental advantage over the traditional kraft process. This article describes the combustion properties of the black liquors produced from silver birch (Betula pendula) sawdust using three different cooking processes: two sulfur-free cooks (soda-anthraquinone and oxygen-alkali), and one reference kraft cook. It also considers the corresponding black liquors from an integrated forest biorefinery, in which a hot-water pretreatment of feedstock was performed prior to pulping. With the same cooking time, the total burning times for the sulfur-free black liquors were higher (15–55%) than those for the conventional kraft black liquors. However, no significant diffe…
Managing the Historical Agricultural Landscape in the Sicilian Anthropocene Context. The Landscape of the Valley of the Temples as a Time Capsule
2021
The debate over whether we are entering the Anthropocene Epoch focuses on the unequal consumption of the Earth system’s resources at the expense of nature’s regenerative abilities. To find a new point of balance with nature, it is useful to look back in time to understand how the so-called “Great Acceleration”—the surge in the consumption of the planet’s resources—hastened the arrival of the Anthropocene. Some particular places—for various reasons—survived the Great Acceleration and, as time capsules, have preserved more or less intact some landscape features that have disappeared elsewhere. How can we enhance these living archives that have come down to us? Through the analysis of the case…
Fourier-transform infrared spectroscopic analyses of cellulose from different bacterial cultivations using microspectroscopy and a high-throughput sc…
2016
Abstract Broad application of bacterial cellulose (BC) has led to search for new commercially interesting producers and consequently also for low-cost screening methods to select BC with particular properties. BC produced by four symbiotic Kombucha associations and fourteen acetic acid bacteria isolated from these Kombucha associations were purified by frequent washing with distilled water and pre-treatment with alkali. The obtained native and mercerized BC pellicles were analysed by two common time-saving FT-IR spectroscopy methods—high-throughput screening (HTS) and microspectroscopy. The FT-IR spectra showed traces of microbial cells and acids entrapped between the microfibrils of BC eve…
Lignin Inter-Diffusion Underlying Improved Mechanical Performance of Hot-Pressed Paper Webs
2021
Broader use of bio-based fibres in packaging becomes possible when the mechanical properties of fibre materials exceed those of conventional paperboard. Hot-pressing provides an efficient method to improve both the wet and dry strength of lignin-containing paper webs. Here we study varied pressing conditions for webs formed with thermomechanical pulp (TMP). The results are compared against similar data for a wide range of other fibre types. In addition to standard strength and structural measurements, we characterise the induced structural changes with X-ray microtomography and scanning electron microscopy. The wet strength generally increases monotonously up to a very high pressing tempera…
Optimization of the enzyme power source for a nano drug delivery system fuelled by glucose in blood plasma
2019
A unique in vivo electrical pulse generator to improve membrane permeability for drugs and simultaneously facilitate self-powered nano devices for nano drug delivery systems (NDDS) was identified. The use of an unsupported biological catalyst component of the power supply was aimed at the NDDS instead of a conventional membrane electrode assembly (MEA). Self-powered carriers of drugs and prodrugs with improved controlled release capability to target areas using substrate available in biological matrices such as glucose in blood is envisaged. The experimental application implemented prototype designed chambers allowing the entry of premixed precursors and low ohm resistance due the absence o…
Extraction of benzaldehyde from fermentation broth by pervaporation
1996
Abstract The application of pervaporation to extract benzaldehyde produced by microorganisms is considered. A model system was used to study the influence of different parameters and attempts to understand better the mass transfer of this flavour compound. Benzaldehyde was removed from a culture medium from which it was produced by Bjerkandera adusta . The performance of these processes is compared.