An advanced 10.6-micro laser communication experiment

Carbon dioxide laser capability of high data rate intersatellite communicatio

In HspA from Helicobacter pylori vicinal disulfide bridges are a key determinant of domain B structure

Helicobacter pylori produces a heat shock protein A (HspA) that is unique to this bacteria. While the first 91 residues (domain A) of the protein are similar to GroES, the last 26 (domain B) are unique to HspA. Domain B contains eight histidines and four cysteines and was suggested to bind nickel. We have produced HspA and two mutants: Cys94Ala and Cys94Ala/Cys111Ala and identified the disulfide bridge pattern of the protein. We found that the cysteines are engaged in three disulfide bonds: Cys51/Cys53, Cys94/Cys111 and Cys95/Cys112 that result in a unique closed loop structure for the domain

Performances of a Y-type structured packing produced by 3D foam-printing for the intensification of gas absorption processes

In this work, we report pilot-scale tests on a new design of Y-type corrugated polylactic acid (PLA) packing (Prototype FT.Y), produced by an innovative additive manufacturing process consisting of a one-step 3D foam-printing process. The design characteristics of the packing and the surface texture of the prototype, which is analyzed with optical measurements, are presented. The performances of the FT.Y packing are characterized and compared with those of a benchmark commercial Mellapak 250Y packing, through experimental tests aimed to estimate pressure drops and mass transfer coefficients. The new packing is also tested for a reference absorption case study, the wet Flue Gas Desulfurization (wet-FGD), for its large application in the process industry and as a lab testing method. The 3D foam printing technology allows for an easy tailor-made design of the packing, providing lower weights and interesting surface properties. These translate in low pressure drops and high mass transfer coefficients, which are comparable or superior to those of the Mellapak 250.Y. Indeed, the FT.Y packing provides high liquid-film mass transfer coefficients, which allows desulfurization efficiencies up to 42 % higher than those expected for the benchmark packing. Beyond the potential manufacturing advantages provided by the 3D-foam printing, the FT.Y packing performances make this unit a valuable alternative for process intensification in absorption and distillation processes, especially in those cases when the liquid-film mass transfer resistance has a relevant role in the process design

Foamed structured packing for mass-transfer equipment produced by an innovative 3D printing technology

Packed columns are largely adopted for multi-phase reactors and separators, i.e., distillation, production or purification of commercial products, flue-gas treatment, conditioning and requalification of air for indoor systems, and cooling of industrial waters. In this work, we report the results of a first experimental study on the pressure drops and the mass transfer rates of an innovative 3D foam-printed packing that has the advantages to be light, cost effective, and easy-to-produce. The physical properties of the 3D foam-printed packing are characterized in terms of density, wettability, and surface roughness. Subsequently, the packing is tested in a pilot-scale flue-gas desulphurization (FGD) plant using tap water to estimate the pressure drops in dry and wet conditions and the overall mass transfer rate for a typical absorption experiments, largely adopted for packing characterization. The results show that the new packing has slightly higher mass transfer efficiency and pressure drops than other similar commercial packing in the same ranking range of nominal surface area. A comparison with former experiments with state-of-art Mellapak 250X in Hastelloy, tested in our previous works with the same experimental setup, show that the improvement in mass transfer rate overwhelms the increase of pressure drops, so that the overall performances of the new packing on for FGD applications appeared as more convenient than the Mellapak 250X packing, in the investigated conditions. The experimental results are explained in terms of the superficial properties of the packing, in particular: both pressure drops and mass transfer rate data can be correlated with the morphology of the packing surface roughness, in turn both deriving from the printing and the foaming processes, and the larger thickness of the sheet. Besides, the same printing material has higher wettability than the Mellapak 250X in Hastelloy, improving the liquid distribution on the packing surface. Finally, they are probably influenced by a new mechanical design of baffles, which reduces liquid maldistribution. The overall performance and the production process advise for further investigations on the use of 3D foam-printed packings for large-scale industrial units

Hb J-Cape Town [alpha92(FG4)Arg-->Gln (alpha1), CGG-->CAG] in Southern Italy found in a patient with erythrocytosis.

A high oxygen affinity hemoglobin (Hb) variant, Hb J-Cape Town [α92(FG4)Arg→Gln (α1), CGG→CAG] was identified in a 30-year-old woman patient from Cosenza (Southern Italy) who had previously been diagnosed with juvenile polycythemia in other hospitals. The occurrence of the variant Hb was assessed by both cation exchange chromatography and liquid chromatography-mass spectrometry (LC-MS) analyses. A detailed structural and functional characterization of the variant was performed at both the protein and DNA level. Structural investigation of the Hb variant by mass spectrometric methodologies and peptide sequencing identified the amino acid replacement as Arg→Gln at α92. The corresponding DNA mutation CGG→CAG was assigned to codon 92 of the α1 gene by DNA sequencing. These findings highlight the importance of investigating the hypothesis of a high affinity variant in the presence of a polycythemia so as to avoid unnecessary bone marrow examination or radioactive treatment. This report represents the first observation of the Hb J-Cape Town variant in Ital