1,482 research outputs found
SAR Ship Detection for Rough Sea Conditions
In the Synthetic Aperture Radar (SAR) framework many detection algorithms and techniques have been published in the recent literature; however the detection of vessels whose dimensions are in the order of the image spatial resolution is still challenging in rough sea state scenarios. This issue is addressed in the paper presented here by comparing rationale and performance of two detectors developed by the same authors: the Generalized Likelihood Ratio Test (GLRT) and the Intensity Dual-Polarization Ratio Anomaly Detector (iDPolRAD). Both detectors are tested on a dual-polarization VV/VH Interferometric Wide Swath Sentinel-1 image acquired over the Suruga Bay on the Pacific Coast of Japan. The theory is presented here and the two detectors are compared against the Cell Average-Constant False Alarm Algorithm (CA-CFAR) showing both better performance than CFAR in terms of false alarms rejection
Recovery of a medieval Brucella melitensis genome using shotgun metagenomics
Shotgun metagenomics provides a powerful assumption-free approach to the recovery of pathogen genomes from contemporary and historical material. We sequenced the metagenome of a calcified nodule from the skeleton of a 14th-century middle-aged male excavated from the medieval Sardinian settlement of Geridu. We obtained 6.5-fold coverage of a Brucella melitensis genome. Sequence reads from this genome showed signatures typical of ancient or aged DNA. Despite the relatively low coverage, we were able to use information from single-nucleotide polymorphisms to place the medieval pathogen genome within a clade of B. melitensis strains that included the well-studied Ether strain and two other recent Italian isolates. We confirmed this placement using information from deletions and IS711 insertions. We conclude that metagenomics stands ready to document past and present infections, shedding light on the emergence, evolution, and spread of microbial pathogens
SOMATIC EMBRYOGENESIS IN ZUCCHINI (CUCURBITA PEPOL.): IN VITRO INDUCTION AND BIOINFORMATIC SEARCH FOR CANDIDATE GENE SEQUENCES INVOLVED IN CELL DIFFERENTIATION
Investigation of Strength and Formability of 6016 Aluminum Tailor Welded Blanks
The automotive industry is constantly looking for innovative techniques to produce lighter,
more efficient, and less polluting vehicles to comply with the increasingly restrictive environmental regulations. One of the latest technologies, which is still developing, is based on the fabrication of the body-in-white and car parts through the stamping of aluminum tailor welded blanks. Tailor welded blanks (TWBs) are generally a combination of two/three metal sheets with different thicknesses and/or mechanical strengths, which are commonly laser butt-welded. Even though the aluminum TWBs have the main advantage of producing lightweight parts, their use is still limited by the lower formability than their parent materials and by the fact that laser welding of aluminum sheets still remains a process easily subjected to weld defects (i.e., internal porosity) and, hence, requires strict control of process parameters. This study has investigated the effects of the main laser welding process parameters (laser power, welding speed, and focus position) on the mechanical properties and formability of aluminum TWBs made of the 6xxx series. The research results show that the welding conditions highly influence the weldability of such alloys. Heat input over 70 J/mm is responsible for excessive porosity and molten pool (and consequent root concavity), which are responsible for the lowest mechanical strength and formability of joints. Differently, low amounts of imperfections have a limited influence on the mechanical behaviors of the TWB joints. Overall, a narrow weldability window is required to ensure welded joints with proper strength and limited or no porosity
Investigation of Mechanical Properties of Aluminum Tailor Welded Blanks
Nowadays, the reduction of CO2 emissions and the
decrease in energy consumption are the main aims of several
industries, especially in the automotive sector. To comply with the
increasingly restrictive regulations, the automotive industry is
constantly looking for innovative techniques to produce lighter, more
efficient, and less polluting vehicles. One of the latest technologies,
and still developing, is based on the fabrication of the body-in-white
and car parts through the stamping of aluminum Tailor Welded Blanks.
Tailor Welded Blanks (TWBs) are generally the combination of
two/three metal sheets with different thicknesses and/or mechanical
strengths, which are commonly butt-welded together by laser sources.
The use of aluminum TWBs has several advantages such as low
density and corrosion resistance adequate. However, their use is still
limited by the lower formability with respect to the parent materials
and the more intrinsic difficulty of laser welding of aluminum sheets
(i.e., internal porosity) that, although its use in automated industries is
constantly growing, remains a process to be further developed and
improved. This study has investigated the effect of the main laser
welding process parameters (laser power, welding speed, and focal
distance) on the mechanical properties of aluminum TWBs made of
6xxx series. The research results show that a narrow weldability
window can be found to ensure welded joints with high strength and
limited or no porosity
Volatilome and Bioaccessible Phenolics Profiles in Lab-Scale Fermented Bee Pollen
Bee-collected pollen (BCP) is currently receiving increasing attention as a dietary supplement
for humans. In order to increase the accessibility of nutrients for intestinal absorption, several
biotechnological solutions have been proposed for BCP processing, with fermentation as one of the
most attractive. The present study used an integrated metabolomic approach to investigate how the
use of starter cultures may affect the volatilome and the profile of bioaccessible phenolics of fermented
BCP. BCP fermented with selected microbial starters (Started-BCP) was compared to spontaneously
fermented BCP (Unstarted-BCP) and to unprocessed raw BCP (Raw-BCP). Fermentation significantly
increased the amount of volatile compounds (VOC) in both Unstarted- and Started-BCP, as well as
modifying the relative proportions among the chemical groups. Volatile free fatty acids were the
predominant VOC in Unstarted-BCP. Started-BCP was differentiated by the highest levels of esters
and alcohols, although volatile free fatty acids were always prevailing. The profile of the VOC was
dependent on the type of fermentation, which was attributable to the selected Apilactobacillus kunkeei
and Hanseniaspora uvarum strains used as starters, or to the variety of yeasts and bacteria naturally
associated to the BCP. Started-BCP and, to a lesser extent, Unstarted-BCP resulted in increased
bioaccessible phenolics, which included microbial derivatives of phenolic acids metabolism
Functional Exploitation of Carob, Oat Flour, and Whey Permeate as Substrates for a Novel Kefir-Like Fermented Beverage: An Optimized Formulation
This study investigated the fortification of a carob-based kefir-like beverage (KLB) with
whey permeate (WP) and oat flour (OF). The response surface method was used to show the effect of
WP and OF concentrations on lactic acid bacteria and yeast cell densities, pH, total titratable acidity
(TTA), total phenolics content (TCP), DPPH radical scavenging activity, and overall acceptability
(OA) in KLB. The statistical design provided thirteen formulations where OF concentration varied
from 3% to 5% and WP from 10% to 15%. The enrichment of carob pods decoction with WP and OF
had a positive effect on biomass production. Overall fermentation was shown to increase TPC of
KLB. Furthermore, OF supplementation led to the higher levels of TPC and antiradical activity. WP
negatively affected OA at linear and quadratic levels, whereas no effect of OF was observed at the
linear level. The optimum point was found by using WP at 11.51% and OF at 4.77%. Optimized KLB
resulted in an enrichment of bioavailable phenolics derivatives and highly digestible proteins
Date Seeds Flour Used as Value-Added Ingredient for Wheat Sourdough Bread: An Example of Sustainable Bio-Recycling
Our study proposed date seeds flour (DSF) as an innovative ingredient for sourdough
bread production through sustainable bio-recycling. We isolated autochthonous lactic
acid bacteria and yeasts from DSF and DSF-derived doughs to build up a reservoir
of strains from which to select starters ensuring rapid adaptation and high ecological
fitness. The screening based on pro-technological criteria led to the formulation of a
mixed starter consisting of Leuconostoc mesenteroides, Lactiplantibacillus plantarum,
and Saccharomyces cerevisiae strains, which allowed obtaining a mature type I
sourdough after consecutive refreshments, in which an aliquot of the durum wheat
flour (DWF) was replaced by DSF. The resulting DSF sourdough and bread underwent
an integrated characterization. Sourdough biotechnology was confirmed as a suitable
procedure to improve some functional and sensory properties of DWF/DSF mixture
formulation. The radical scavenging activity increased due to the consistent release
of free phenolics. Perceived bitterness and astringency were considerably diminished,
likely because of tannin degradation
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