Quality enhancement of the abundant under‐valued crustacean,lobster krill (Munida spp.), during its chilled storage

Lobster krill (Munida genus) represents an under‐valued crustacean frequently caught on European fishing banks. In this work, its sensory, microbiological and biochemical qualities were evaluated during chilled storage. Additionally, the effects of a prestorage antimelanosic treatment consisting of soaking in sodium metabisulphite (SMB) solutions at two different concentrations (0.25% and 0.75%) were also studied. SMB prestorage treatment provided lobster specimens that still exhibited acceptable sensory quality after 10 days of storage, while control specimens were unacceptable at that time. SMB treatment also resulted in a significant (P < 0.05) inhibition of microbial growth, mainly of Enterobacteriaceae, psychrotrophes and proteolytic bacteria. Low lipid oxidation levels were observed for all batches; however, a significantly higher (P < 0.05) retention of polyunsaturated fatty acids was found in SMB‐treated lobster, especially in the 0.75% SMB batch. The results presented here open the way to the potential commercialisation of currently under‐utilised lobster krill as a chilled product.     

GC–MS Characterization of Volatile Compounds in Habanero Pepper (Capsicum chinense Jacq.) by Optimization of Headspace Solid-Phase Microextraction Conditions

Food Analytical Methods - The habanero pepper (Capsicum chinense Jacq.) is very aromatic and is the hottest pepper in the world. In this study, a headspace solid-phase microextraction/gas...     

A practical assessment of risk-averse approaches in production lot-sizing problems

ABSTRACT

This paper presents an empirical assessment of four state-of-the-art risk-averse approaches to deal with the capacitated lot-sizing problem under stochastic demand. We analyse two mean-risk models based on the semideviation and on the conditional value-at-risk risk measures, and alternate first and second-order stochastic dominance approaches. The extensive computational experiments based on different instances characteristics and on a case-study suggest that CVaR exhibits a good trade-off between risk and performance, followed by the semideviation and first-order stochastic dominance approach. For all approaches, enforcing risk-aversion helps to reduce the cost-standard deviation substantially, which is usually accomplished via increasing production rates. Overall, we can say that very risk-averse decision-makers would be willing to pay an increased price to have a much less risky solution given by CVaR. In less risk-averse settings, though, semideviation and first-order stochastic dominance can be appealing alternatives to provide significantly more stable production planning costs with a marginal increase of the expected costs.     

Evanescently coupled photodiodes integrating a double-stage taper for 40-Gb/s applications-compared performance with side-illuminated photodiodes

The design, fabrication, and performance of double-stage taper photodiodes (DSTPs) are reported. The objective of this work is to develop devices compatible with 40-Gb/s applications. Such devices require high efficiency, ultrawide band, high optical power handling capability, and compatibility with low-cost module fabrication. The integration of mode size converters improves both the coupling efficiency and the responsivity with a large fiber mode diameter. Responsivity of 0.6 A/W and 0.45 A/W are achieved with a 6-/spl mu/m fiber mode diameter and cleaved fiber, respectively, providing relaxed alignment tolerances (/spl plusmn/1.6 /spl mu/m and /spl plusmn/2 /spl mu/m, respectively), compatible with cost-effective packaging techniques. DSTPs also offer a wide bandwidth greater than 40 GHz and transverse-electric/transverse-magnetic polarization dependence lower than 0.2 dB. Furthermore, a DSTP saturation current as high as 11 mA results in optical power handling greater than +10 dBm and a high output voltage of 0.8 V. These capabilities allow the photodiode to drive the decision circuit without the need of a broad-band electrical amplifier. The DSTP devices presented here demonstrate higher responsivities with large fiber mode diameter and better optical power handling capabilities and are compared with classical side-illuminated photodiodes.     

An integrated system to remote monitor and control anaerobic wastewater treatment plants through the internet.

The TELEMAC project brings new methodologies from the Information and Science Technologies field to the world of water treatment. TELEMAC offers an advanced remote management system which adapts to most of the anaerobic wastewater treatment plants that do not benefit from a local expert in wastewater treatment. The TELEMAC system takes advantage of new sensors to better monitor the process dynamics and to run automatic controllers that stabilise the treatment plant, meet the depollution requirements and provide a biogas quality suitable for cogeneration. If the automatic system detects a failure which cannot be solved automatically or locally by a technician, then an expert from the TELEMAC Control Centre is contacted via the internet and manages the problem.     

Simultaneous sulfide and acetate oxidation under denitrifying conditions using an inverse fluidized bed reactor

BACKGROUND: Simultaneous removal of sulfur, nitrogen and carbon compounds from wastewaters is a commercially important biological process. The objective was to evaluate the influence of the CH₃COO^?/NO₃^? molar ratio on the sulfide oxidation process using an inverse fluidized bed reactor (IFBR). RESULTS: Three molar ratios of CH₃COO^?/NO₃^? (0.85, 0.72 and 0.62) with a constant S^2?/NO₃^? molar ratio of 0.13 were evaluated. At a CH₃COO^?/NO₃^? molar ratio of 0.85, the nitrate, acetate and sulfide removal efficiencies were approximately 100%. The N₂ yield (g N₂ g^?1 NO₃^?‐N consumed) was 0.81. Acetate was mineralized, resulting in a yield of 0.65 g inorganic‐C g^?1 CH₃COO^?‐C consumed. Sulfide was partially oxidized to S⁰, and 71% of the S^2? consumed was recovered as elemental sulfur by a settler installed in the IFBR. At a CH₃COO^?/NO₃^? molar ratio of 0.72, the efficiencies of nitrate, acetate and sulfide consumption were of 100%, with N₂ and inorganic‐C yields of 0.84 and 0.69, respectively. The sulfide was recovered as sulfate instead of S⁰, with a yield of 0.92 g SO₄^2?‐S g^?1 S^2? consumed. CONCLUSIONS: The CH₃COO^?/NO₃^? molar ratio was shown to be an important parameter that can be used to control the fate of sulfide oxidation to either S⁰ or sulfate. In this study, the potential of denitrification for the simultaneous removal of organic matter, sulfide and nitrate from wastewaters was demonstrated, obtaining CO₂, S⁰ and N₂ as the major end products. Copyright © 2008 Society of Chemical Industry     

Nanocrystalline TiO2 photosensitized with natural polymers with enhanced efficiency from 400 to 600 nm

TiO₂ sensitization for solar applications requires not only efficient but also stable and inexpensive sensitizers. Different condensed tannins extracted from bark wastes of tropical wood trees were studied as possible sensitizers of TiO₂. These natural polymers adhere strongly to the TiO₂ even from aqueous solutions. Absorption spectra are presented for 1 mM aqueous sensitizing solutions prepared with lyophilized condensed tannins which absorb light in the visible range. Spectral photocurrent measurements and I–V characterization show that no bias is required for electron injection to the TiO₂ from all studied condensed tannins. Incident photon to current efficiency (IPCE) analysis indicates that surface complexation originates absorption bands with different electron injection efficiencies. These play a dominant role in determining IPCE spectral shape. We propose that surface modification by the sensitizer changes the surface trap density, thereby decreasing recombination losses.     

Infrequent association: massive inguinoscrotal bladder hernia, multiple scrotal lithiasis, and bilateral obstructive uropathy]

BACKGROUND AND AIMS OF THE STUDY: Surgical treatment of functional tricuspid regurgitation associated with advanced valvular disease remains controversial, mainly due to the difficulty in choosing between valve replacement or reconstructive surgery. Failure to correct tricuspid regurgitation during valvular surgery carries a poor prognosis, as reoperation may represent a significant risk to the patient. Thus correct tricuspid valve surgery is vital to achieve improved early and long-term clinical results. METHODS: A total of 142 patients underwent concomitant tricuspid annuloplasty with mitral valve replacement and their clinical outcome was assessed. RESULTS: Overall hospital mortality rate was 11.3%. Seven patients died during follow up. The overall actuarial survival rate for 10 years was 74.1 +/- 14.2%. Postoperatively, 75.8% of the patients had no residual tricuspid insufficiency, while 24.2% had first- or second-degree tricuspid insufficiency and were treated medically. All patients were in NHYA functional class I or II postoperatively. CONCLUSION: Clinically, it is important to assess the severity of functional tricuspid insufficiency before and/or during the operation. Bicuspidalization annuloplasty for functional tricuspid insufficiency has provided good results, with a low incidence of reoperation and significant clinical improvement. The technique could be used in most patients with functional tricuspid regurgitation.