Valuable information from reliability analysis of pile foundation

The work presented in this paper was developed under the PhD thesis entitled “Reliability and Cost Models of Pile Foundations”. Our main goal is to present guidelines for geotechnical engineers to carry out reliability based designs (RBD). This analyses help evaluate the probability of a particular behavior in a time period, with the knowledge of the input parameters randomness (uncertainties). The biggest benefit is that it quantifies and gives information about the parameters that mostly influence the behavior under study. This capacity is important, not only because of the new regulation codes and social concerns, but also because these probabilistic formats support decision making under uncertainties, providing qualitative judgments and investments, very important in geotechnical area. Based on that, this work shows valuable information that a geotechnical engineers can obtain from a simple reliability analysis of a pile foundation, such as the most influential uncertainties in pile design or the minimum dimensions of the pile (Figure 3a) and maximum load (Figure 3b) that lead to a previously established probability of failure. Furthermore, a comparison between two widely known RBD methodologies was done, First Order Reliability Method (FORM) and Monte Carlo Simulations (MCS). FORM is the most traditional one, an approximate method (level II of reliability), while ordinary MCS has a higher level of accuracy (level III, pure probabilistic) and is a very straight forward method. Nevertheless, FORM has some limitations when complex performance functions are necessary and it is not possible to approximate normal distributions. The uncertainties considered in this work and the methodology scheme is presented in Figure 1 (Honjo et al., 2010 and Honjo et al., 2011).FC

Stress, cognitive appraisal, and psychological health: testing instruments for health professionals

The job of health professionals, including nurses, is considered inherently stressful (Lee & Wang, 2002; Rutledge et al., 2009), and thus it is important to improve and develop specific measures that are sensitive to the demands that health professionals face. This study analysed the psychometric properties of three instruments that focus on the professional experiences of nurses in aspects related to occupational stress, cognitive appraisal, and mental health issues. The evaluation protocol included the Stress Questionnaire for Health Professionals (SQHP; Gomes, 2014), the Cognitive Appraisal Scale (CAS; Gomes, Faria, & Gonçalves, 2013), and the General Health Questionnaire-12 (GHQ-12; Goldberg, 1972). Validity and reliability issues were considered with statistical analysis (i.e. confirmatory factor analysis, convergent validity, and composite reliability) that revealed adequate values for all of the instruments, namely, a six-factor structure for the SQHP, a five-factor structure for the CAS, and a two-factor structure for the GHQ-12. In conclusion, this study proposes three consistent instruments that may be useful for analysing nurses’ adaptation to work contexts

Fed-batch versus batch cultures of Yarrowia lipolytica for γ-decalactone production from methyl ricinoleate

Constant medium feeding rate and intermittent fed-batch fermentation strategies were investigated aiming to increase the yields of γ-decalactone production by Yarrowia lipolytica, using methyl ricinoleate as substrate and ricinoleic acid source. The accumulation of another compound, 3-hydroxy-γ-decalactone, was also analyzed since it derives from the direct precursor of γ-decalactone thereby providing information about the enzymatic activities of the pathway. Both strategies were compared with the traditional batch mode in terms of overall productivity and yield in respect to the substrate. Although the productivity of γ-decalactone was considerably higher in the batch mode (168 mg l−1 h−1), substrate conversion to lactone (73 mg γ-decalactone g−1) was greater in the intermittent fed-batch giving 6.8 g γ-decalactone l−1. This last strategy therefore has potential for γ-decalactone production at an industrial level.The authors acknowledge Fundacao para a Ciencia e Tecnologia (FCT) for the financial support provided (SFRH/BD/28039/2006)

Empirical modelling as an experimental approach to optimize lactone production

The biotransformation of ricinoleic acid, carried out by Yarrowia lipolytica, leads to the formation of gama-decalactone, a well-known peach-like aroma compound, interesting to produce and to use in the flavouring industry, reason why it is imperative to define the most appropriate conditions for its production. Thus, the aim of this work is the optimization of operating conditions for this lactone. However, as the accumulation of another compound, namely 3-hydroxy-g-decalactone (the precursor of two other aromatic compounds, dec-2-enolide and dec-3-enolide), may also occur simultaneously in the biotransformation medium, and since this compound may as well be of interest for the flavouring industry, the operating conditions for its production were also a focus of attention. Therefore, a 3^2 level full-factorial design was used to determine the effect of pH and dissolved oxygen concentration (DO) on the production of gama-decalactone and 3-hydroxy-gama-decalactone. Since both factors were found to influence the two lactones production, a response surface methodology (RSM) analysis was also applied to identify the optimal conditions for the production of those two compounds. The statistical model pointed out pH = 6.17 and DO = 44.4% as the best conditions optimizing gama-decalactone production. Using these optimalconditions, the maximal gama-decalactone concentration achieved was 680.9 mg/L, which was quite similar to the predicted value of 718.7 mg gama-decalactone per liter. Among the range of operating conditions tested, no optimization was possible for 3-hydroxy-gama-decalactone production, since all possible solutions corresponded to operating conditions not analyzed.The authors aknowledge Fundacao para a Ciencia e Tecnologia (FCT) for the financial support provided (SFRH/BD/28039/2006) and Hector Ruiz for the help provided with MATLAB

Oxygen effect in γ-decalactone production through biotransformation of ricinoleic acid

γ-Decalactone can be produced biotechnologically from the degradation of ricinoleic acid by yeasts, namely Yarrowia lipolytica. Preliminary studies using two different ricinoleic acid sources (methyl ricinoleate and castor oil) at different concentrations were tested as substrates, in flask experiments. Although high amounts of γ-decalactone (up to 2 g L-1) were achieved with oil concentrations of 3% and 5% (v/v) for each substrate, the productivity of the process was small (10 to 14.5 mg L-1 h-1). In order to increase these values, essays were conducted in a 2-L bioreactor, with 3% (v/v) methyl ricinoleate at different aeration and agitation rates, in the herein presented work. Under these conditions, the highest amount of γ-decalactone achieved was lower (approximately 1 g L-1). However, the productivity of the process was much higher: 87 mg L-1 h-1. Furthermore, another compound derived from the direct precursor of γ-decalactone, 3-hydroxy-γ-decalactone, was detected in large amounts (up to 8 g L-1), which implies a change in the metabolic pathway control

Oxygen mass transfer in a biphasic medium: influence on the biotransformation of methyl ricinoleate into γ-decalactone by the yeast Yarrowia lipolytica

In this work, an empirical correlation is proposed to describe kLα as a function of operating conditions (agitation and aeration rates) and of oil and surfactant volumetric fractions in a biotransformation medium, an oil-in-water dispersion. An interaction effect between the oil and the surfactant effects was found, since oil presence increased kLα in the absence of the surfactant but had an opposite effect when Tween 80 was available in the medium. The biotransformation of methyl ricinoleate (MR) into γ-decalactone (an aroma compound of industrial interest), by the yeast Yarrowia lipolytica, was carried out at different conditions of operation, to evaluate the influence of kLα on the production of the aroma. It was demonstrated that kLα had an influence on the aroma production; however, for the low hydrophobic substrate concentration used (1.08% v/v) and cellular density of 2.0 × 10 7 cells mL−1, a minimal kLα value of 70 h−1 was necessary to attain the maximal aroma production

Geoquímica dos minerais dos filões W>Sn e das águas das antigas minas de Murções (NE de Portugal)

Na região mineira de Murçós, a exploração de scheelite e cassiterite em filões hidrotermais de quartzo com W>Sn ocorreu em quatro cortas a céu aberto e em galerais subterrâneas, entre 1948 e 1976. Como resultado da exploração mineira formaram-se três lagoas confinadas e permanentes, nas quais foram aplicadas técnicas de fitoremediação com macrófitas, entre 2005 e 2007. Os filões W>Sn de Murçós contêm essencialmente quartzo, moscovite, turmalina, scheelite, cassiterite, volframite, pirrotite, arsenopirite, pirite, esfalerite, calcopirite, galena, bismuto nativo, rara pirrotite e estanite, para além de minerais tardios como bismutinite, joseite, matildite, anglesite, zavaritskite, escorodite e roosveltite. A área mineira abandonada localiza-se próximo de zonas rurais, sendo as águas utilizadas na agricultura e algumas para consumo humano. As águas das lagoas de mina são ácidas, com elevados valores de condutividade eléctrica e de SO42-, Ca, Mg, Mn, Al, Zn, Sr, Ni e Co. Contudo, a maioria das águas da área apresentam baixos teores de metais, sendo classificadas como cálcio-sulfatadas e de tipo misto. Estas águas não devem ser usadas para consumo humano nem para a agricultura devido aos teores elevados de As, Fe, Mn, Al, Cd, Ni e SO42-

Quality scoreboard: a proposal

Purpose: The assessment of “macroquality” or the assessment of the degree to which the quality practices are implemented in a country or a region should not be only based on “tangible” indicators such as the number of certified companies according to the ISO 9001 or ISO 14001 standards, or others. By adopting only these two indicators (or similar ones) a large amount of companies, those ones that are not certified, are not considered when assessing the “macroquality”. Less tangible features, such as the number of persons trained in quality management or the number of members of quality management associations among other features, contribute themselves and seem appropriate to assess the level of “macroquality”. This paper intends to report a “macroquality” index that is composed by tangible and less tangible features, concerning the quality practices implementation concept- The Quality Scoreboard. Design/methodology/approach: An expert’s panel was conducted with the aim of evaluating a set of several indicators that could be used to assess and to monitor the “macroquality” level of a country. Nine tangible indicators were proposed and been analysed by the experts’ panel according to an importance scale (1 to 5). Additionally, the experts were encouraged to propose other indicators that could reflect the quality state-of-the-art of a country or region. Findings: Experts find that tangible indicators are not enough to express the level of “macroquality”. According to the results, less tangible features should be considered too. A total of 43 indicators were suggested by the experts. Among them, the following suggested indicators should be highlighted: the number of persons trained in quality management, the number of members of quality management associations, the number of quality related courses at the universities and the number of certified auditors. Based on the survey results a Quality Scoreboard was developed. Originality/value: As far as we were able to find out this is the first attempt to develop a Quality Scoreboard, as it had been already done to innovation. This new approach allows one to characterize the quality state-of-the-art of a region, based on a set of potential “quality indicators”. Furthermore, the results provide an additional important contribution to the worldwide study of quality approaches diffusion and evolution