The Spanish National Dose Registry and Spanish radiation passbooks

The Spanish National Dose Registry (BDN) is the Nuclear Safety Council's (CSN) national database of occupational exposure to radiation. Each month BDN receives records of individual external doses from approved dosimetry services. The dose records include information regarding the occupational activities of exposed workers. The dose information and the statistical analysis prepared by the BDN are a useful tool for effective operational protection of occupationally exposed workers and a support for the CSN in the development and application of the ALARA principle. The Spanish radiation passbook was introduced in 1990 and since then CSN, as regulatory authority, has required that all outside workers entering controlled areas should have radiation passbooks. Nowadays, CSN has implemented improvements in the Spanish radiation passbooks, taking into account previous experience and Directive 96/29/EURATOM.     

Winter and spring surface velocity fields in the Cape Blanc region as deduced with the maximum cross-correlation technique

The ocean surface velocity field in the Cape Blanc region, off Northwest Africa, is investigated with the maximum cross-correlation (MCC) method applied to channel-4 Advanced Very High Resolution Radiometer satellite images. An initial sensitivity analysis allows us to select the four parameters that provide maximum area coverage and the best velocity resolution, while limiting the standard deviation for each velocity component within reasonable values. These are (m, n, MV, CT)?=?(22, 32, 50, 0.6), where m and n are the number of pixels of the search window (SW) and reference window (RW), respectively, MV is the maximum possible velocity (in cm s^?1), and CT is a correlation threshold for a feature to be tracked. A total of 489 images, for years 2005 and 2006, are analysed, and 106 velocity maps are generated with good coverage of the coastal transition zone (CTZ), most of them for the winter (34) and spring (59) seasons. We remove spurious data using the method's own filters (MV, CT, and a neighbour-vector comparison), requesting the velocity components to have Gaussian distributions and smoothing the resulting velocity fields with a median-vector filter. The instantaneous velocity maps illustrate the response of the alongshore coastal jet north of Cape Blanc (and its extension along the Cape Verde frontal region) to wind forcing, as well as the presence of numerous mesoscalar features (100–300 km wide) superposed on a westward offshore transport south of Cape Blanc. We also produce mean and standard deviation winter and spring velocity maps, which are compared with the corresponding mean sea surface temperature fields. The along-shore and offshore flow is better defined and is more intense in spring than in winter, in concordance with cross-slope sharper temperature gradients during this season, and brings about a cooling of the whole region. We identify five different ubiquitous currents: a southwestward jet north of Cape Blanc, a northwestward jet off Banc d'Argin, an offshore convergent jet, a spring jet-like feature at 18° N, and a southward flow in the southwestern CTZ.     

A novel methodology to solve the CQLF problem for a finite set of stable second-order systems

A new methodology to provide conclusive information about the existence/non-existence of a common quadratic Lyapunov function (CQLF) for a finite set of stable second-order systems is presented. Despite the high complexity of the CQLF problem, even in the case of N second-order systems, the results presented in this paper have a very simple and intuitive theoretical support, including topics such as classical intersection of convex sets and properties of convex linear combinations. Illustrative examples to show the performance of the proposed methodology are provided.     

Nutritional quality and acceptability of a product formulated with mechanically deboned poultry meat,plasma and bovine red cell

The purpose of this research was to evaluate the nutritional quality and acceptability of a meat product formulated with mechanically deboned poultry meat (40%), bovine plasma (40%) and bovine red cells (3%) as major ingredients. Proteins, fat, humidity and ash were determined by AOAC procedure, iron and calcium by Atomic Absorption Spectrometry and essential amino acids by HPLC. Biological evaluation was performed using digestibility and PER procedures. To evaluate the acceptability (flavor, color and odor) of the product were used 277 children. Results indicated that 100 g of the formulated meat product contain 10.7 g of proteins, 4.4 g of fat, 68.6 g of humidity, 2.9 g of ash, 4.9 mg of iron, 46.6 mg of calcium. Essential amino acids are above the FAO requirements for a highly nutritional protein digestibility (92.4%) and PER (2.18). Acceptability was 91.3% for flavor, 81.2% for color and 92.4% for odor. The high nutritional quality and acceptability along with the low cost make this meat product suitable for government social programs.     

Development and in vivo response of hydroxyapatite/whitlockite from chicken bones as bone substitute using a chitosan membrane for guided bone regeneration

Biomaterials that meet the requirements to stimulate bone tissue formation play a vital role in orthopedics and dentistry. In this work, chitosan and a biphasic, non-cytotoxic material hydroxyapatite/whitlockite were obtained from natural sources, which are available as organic waste. The osteogenic activity was assessed using a rabbit model animal with a chitosan barrier membrane in combination with a bone-filling graft substitute composed of hydroxyapatite/whitlockite. FT-IR results showed the typical absorption bands of the chitosan and hydroxyapatite. Moreover, the X-ray diffraction pattern revealed a typical hexagonal phase of hydroxyapatite and rhombohedral structures related to whitlockite. Masson's trichrome stain showed an early formation of extracellular matrix mineralized, in accord with the surface morphology of a cortical mature bond observed by Scanning Electron Microscopy. The immunocytochemistry results showed a significant increase of positive immunoreactive cells to osteonectin in the treated defects in comparison with the control defects 6 and 8 weeks postoperatively. Overall, the results confirm that the use of this low-cost and versatile biomaterial as a barrier membrane and a bone substitute graft are useful for bone tissue engineering.     

Electrical and thermal properties of recycled polypropylene-carbon black composites

Summary In the last decade the recycling of different types of waste has become a worldwide necessity. A large amount of polymeric material is generated in the health care sector and nowadays, due to a lack of technology and stiff government regulations, most of this material is incinerated thereby causing other type of problems. In this paper, a study of the degradation and possible reutilization of the polypropylene used in the fabrication of disposable syringes is done. The main idea is to use this polymer as the matrix and carbon black as the filler in an electrically conductor composite with proper a thermal properties for applications such as a heating material. Received: 11 September 2000/Revised version: 17 November 2000/Accepted: 17 November 2000     

Partial purification and enzymatic characterization of avocado (Persea americana Mill,cv. Hass) lipoxygenase

Detrimental effects on minimally processed fruits and vegetables induced by increased lipoxygenase (LOX) activity are a major concern in the food industry. Partial purification and enzymatic characterization of lipoxygenase (LOX) from avocado fruit (Persea americana Mill, cv. Hass) is presented. Avocado LOX was partially purified by fractional precipitation with ammonium sulfate, followed by anion exchange adsorption. Substrate specificity and effects of temperature, pH and calcium ion concentration on LOX activity were determined. Likewise, the in vitro ability of avocado LOX to co-oxidize β-carotene was determined. LOX showed a higher substrate affinity for linolenic than for linoleic acid. Optimum activity was reached at 40 °C, pH 6.5, and 0.20 mM of calcium ion concentration. Avocado LOX showed β-carotene co-oxidation capability. Considering the optimums and operational ranges established for each studied factor, strategies concerning the inactivation of LOX may be proposed to reduce the detrimental effects on minimally processed avocado products. Additionally, the co-oxidation capability of avocado LOX may be of interest for the avocado industry due to its potential application as a bleaching agent.     

Optimization of piers for retaining walls

The ultimate strength design of reinforced concrete members under flexure and axial loads is well known, with solutions dating back to the 1950s. There is little motivation for engineers to change solution approaches in the absence of a clear benefit, particularly given that current solution approaches are well-known and do not raise controversy. Recently, a different solution approach has been presented in the form of Reinforcement Sizing Diagrams and Optimal Domains, but applications to rectangular sections were limited and thus the approach has been mainly of academic or theoretical interest. This paper presents an application to circular sections, which allow the advantages to be realized in the commonly encountered situation of retaining walls supported by circular section piers. Using the approach presented herein, longitudinal reinforcement can be reduced up to 50% compared with traditional designs, allowing significant financial savings while also reducing the greenhouse gas emissions associated with the reinforcement component of reinforced concrete construction.