Niobium in Microalloyed Steels Unchallenged for Its Main Applications

During the past five decades niobium has emerged as the most important microalloying element in high strength steels.The first theories to explain its role were presented in the seminal publications of Woodhead,Morrison and Gray.Today niobium microalloyed steels are unchallenged for their main applications.Some examples include linepipe for gas transportation,automotive steels used in body-in-white and structural parts,shipbuilding,steel towers and steel structures in civil construction that exhibit better fire resistance and seismic load performance.Modern technology for steelmaking helped emphasize the superior overall properties that can be attained with the use of niobium.Gas linepipe is the best example of cleaner steel with carbon levels below 0.05% manufactured economically.Modern niobium microalloyed steels present the optimal balance of strength,toughness,weldability and formability.This paper describes the evolution of the technology associated with niobium in microalloyed steels,technology that secured its status as the efficient solution to solving today’s challenges:safety,energy efficiency and environmental concerns.The paper also presents evidence that enhances the case that there is a secure,stable,long-term supply of the ferroniobium used to manufacture these steels.     

Silicon sheet from silane: first results

A process to obtain self-supported thin silicon films is being developed. Films are grown by optical chemical vapour deposition (CVD) (using halogen lamps as heating system) from silane, at low temperature and relatively high growth rates, on silicon substrates with a sacrificial layer of porous Si (PS), which allows film detachment. The PS layer was formed by anodisation of the Si-substrate surface in a HF:ethanol solution. Film deposition was carried out in an optical cold wall horizontal CVD reactor, operating at atmospheric pressure, and specially designed for this study. Deposition rates and film morphology were studied as a function of substrate nominal temperature, gas concentration and flux. In the final chosen conditions, deposition occurs at a nominal temperature of 840°C, with a silicon growth rate between 2 and 4 μm/min, which is relatively high for the low temperature used. A good usage of silane gas was already achieved, with 80–85% of the silicon in the silane gas being deposited on a 40×40 mm² substrate, with very low deposition rate on the reactor wall. Films of thicknesses from 10 to 150 μm were deposited. The films were found to be continuous with surfaces coated with whiskers. Film detachment from multicrystalline substrates has proved unsuccessful so far, while it readily occurs when monocrystalline substrates are used. The reason for this is macropore collapse and film rupture, usually occurring in the smaller grain regions of the multicrystalline substrates.     

Effect of CO2 dissolution on the shelf life of ready-to-eat Octopus vulgaris

Due to the increasing commercial importance of octopus (Octopus vulgaris) and the growing demand for convenient and ready-to-eat products, soluble gas solubilisation (SGS), a relatively recent methodology of active packaging proposed to extend the shelf life of packaged fish, was tested. The effect on cooked octopus of CO₂ dissolution applied in a 2 bar saturated atmosphere for 30 min was followed by sensory, microbiological and physical/chemical quality parameters of vacuum packed products during chilled (3 °C ± 0.5 °C) and abuse temperature (24 °C ± 0.5 °C) storage for 28 days and 48 h, respectively. The SGS pre-treatment of cooked octopus with CO₂ had a positive effect on the delay of the microbial growth during chilled storage. On the other hand, during the acceptability period TMA-N and TVB-N showed similar changes during storage period and were not affected by the CO₂ treatment. Oxidation of cooked octopus did not appear to be a significant problem during chilled storage. Sensory shelf life was estimated as 10 days and 12 h in chilled and abuse temperature storage, respectively and no significant extension was visible as a function of SGS treatment. Though not enough per se to increase the shelf life of cooked octopus, the use of SGS by the food industry as a hurdle technology component with bacteriostatic effect is a valuable tool to allow an effective extension of the period of use-by date.

Industrial relevance

Common octopus (Octopus vulgaris) is a highly appreciated marine species which requires at home a cooking step that entails some expertise, in order to attain the correct sensory quality, namely suitable tenderness. Supply of ready-to-eat products that offer healthy, tasty and fast meal solutions and that solves the problem of home preparation of octopus is of particular industrial relevance and stresses the need for new ways of marketing this species, other than in the fresh state. The current study aimed to develop a new seafood product that can be introduced in the market as fresh cooked octopus in a convenient package under vacuum, either as a ready-made meal or as a ready-to-be used product, to be further processed in more elaborated food preparations. To our knowledge no such product exists in the market and this is the first study dedicated to the evaluation of the shelf life of such a product and to a new active packaging technology that can extend the use-by date. Though not enough per se to increase the shelf life of cooked octopus, it is demonstrated that utilisation of CO₂ by the food industry, as a hurdle technology component with bacteriostatic effect under the conditions proposed, is a valuable tool to allow an effective extension of the period of use-by date.     

COVID-19 Lockdowns May Reduce Resistance Genes Diversity in the Human Microbiome and the Need for Antibiotics

Recently, much attention has been paid to the COVID-19 pandemic. Yet bacterial resistance to antibiotics remains a serious and unresolved public health problem that kills hundreds of thousands of people annually, being an insidious and silent pandemic. To contain the spreading of the SARS-CoV-2 virus, populations confined and tightened hygiene measures. We performed this study with computer simulations and by using mobility data of mobile phones from Google in the region of Lisbon, Portugal, comprising 3.7 million people during two different lockdown periods, scenarios of 40 and 60% mobility reduction. In the simulations, we assumed that the network of physical contact between people is that of a small world and computed the antibiotic resistance in human microbiomes after 180 days in the simulation. Our simulations show that reducing human contacts drives a reduction in the diversity of antibiotic resistance genes in human microbiomes. Kruskal–Wallis and Dunn’s pairwise tests show very strong evidence (p < 0.000, adjusted using the Bonferroni correction) of a difference between the four confinement regimes. The proportion of variability in the ranked dependent variable accounted for by the confinement variable was η² = 0.148, indicating a large effect of confinement on the diversity of antibiotic resistance. We have shown that confinement and hygienic measures, in addition to reducing the spread of pathogenic bacteria in a human network, also reduce resistance and the need to use antibiotics.     

A new biotechnological process to enhance the soymilk bioactivity

Equol, a daidzein metabolite produced exclusively by intestinal bacteria in some, but not all, humans, exhibits a wide range of beneficial health effects owing to its superior nutraceutical effect compared with isoflavones of soy. The aim of this work was to develop bioprocesses capable of increasing the bioactive properties of soymilk and, most importantly, increase the equol content by a biotechnological process in vitro. Biotransformation processes based on soymilk fermentation by probiotic lactic bacteria and application of the enzyme tannase caused an increase in the bioactive isoflavones and antioxidant capacity of soymilk. Furthermore, these processes approximately resulted in a 10-fold increase in the equol content of the soymilk. This is the first study to produce a significant equol concentration in soymilk using enzymatic processing only. The results suggest a new and effective biotechnological process, with major commercial potential, capable of producing a bioactive soy extract that intends to be “functional for everyone.”     

Food poisoning by clenbuterol in Portugal.

This paper describes the occurrence of four cases of acute food poisoning, involving a total of 50 people, due to the ingestion of lamb and bovine meat containing residues of clenbuterol. Symptoms shown by the intoxicated people may be generally described as gross tremors of the extremities, tachycardia, nausea, headaches and dizziness. Analytical methodology developed for the determination of clenbuterol in meat, liver and blood samples is described. Procedures are described which should be followed when the described symptoms are evident in a group of people who have ingested contaminated meat, and particularly liver of ruminants.     

A Rapid and Specific Biosensor for <Emphasis Type="Italic">Salmonella</Emphasis> Typhimurium Detection in Milk

This paper reports the application of an amperometric biosensor for rapid and specific Salmonella Typhimurium detection in milk. This device was developed from self-assembled monolayer technique on a gold screen-printed electrode, using cysteamine thiol. Polyclonal antibodies were oriented by protein A immobilization. The biosensor structure was characterized by cyclic voltammetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. The analytical response was obtained by a chronoamperometry technique, using a direct-sandwich peroxidase-labeled system. The biosensor device showed a qualitative behavior with a very low limit of detection of 10 CFU mL^?1 and a detection time of 125 min. The biosensor specificity was demonstrated in pure and mixed samples with strains of Escherichia coli and Citrobacter freundii. The performance of the biosensor was found satisfactory, and the device was tested in skimmed and whole milk samples, being able to detect S. Typhimurium quickly, without an enrichment step. This structure of immunosensor assembly can be expended in future studies for other food matrices and bacterial species, making it a useful tool to ensure food safety.     

Using concepts of content‐based image retrieval to implement graphical testing oracles

Automation of testing is an essential requirement to render it viable for software development. Although there are several testing techniques and criteria in many different domains, developing methods to test programs with complex outputs remains an unsolved challenge. This setting includes programs with graphical output, which produce images or interface windows. One possible approach towards automating the testing activity is the use of automatic oracles in which a reference image, taken as correct, can be used to establish a correctness measure in the tested program execution. A method that uses concepts of content‐based image retrieval to facilitate oracle automation in the domain of programs with graphics output is presented. Two case studies, one using a computer‐aided diagnostic system and one using a Web application, are presented, including some reflections and discussions that demonstrate the feasibility of the proposed approach. Copyright © 2011 John Wiley & Sons, Ltd.