Using computational fluid dynamics to predict head losses in the auxiliary elements of a microirrigation sand filter

It is often assumed that total head losses in a sand filter are solely due to the filtration media and that there are analytical solutions, such as the Ergun equation, to compute them. However, total head losses are also due to auxiliary elements (inlet and outlet pipes and filter nozzles), which produce undesirable head losses because they increase energy requirements without contributing to the filtration process. In this study, ANSYS Fluent version 6.3, a commercial computational fluid dynamics (CFD) software program, was used to compute head losses in different parts of a sand filter. Six different numerical filter models of varying complexities were used to understand the hydraulic behavior of the several filter elements and their importance in total head losses. The simulation results show that 84.6% of these were caused by the sand bed and 15.4% were due to auxiliary elements (4.4% in the outlet and inlet pipes, and 11.0% in the perforated plate and nozzles). Simulation results with different models show the important role of the nozzles in the hydraulic behavior of the sand filter. The relationship between the passing area through the nozzles and the passing area through the perforated plate is an important design parameter for the reduction of total head losses. A reduced relationship caused by nozzle clogging would disproportionately increase the total head losses in the sand filter

Coneixement i gestió del dol patològic per part dels infermers/es a l'atenció primària de Girona

Per entendre l’experiència d’una pèrdua i dur a terme una intervenció amb una valoració holística del pacient amb dol, és útil conèixer que aquesta pèrdua és present a la vida humana i que tota persona és susceptible a viure-la. Cada pas que fem en el nostre camí perdem coses, des de persones a un objecte significatiu, fins a les coses més efímeres com és la joventut, els somnis o les idees que ens permeten l’enfrontament a les dures “realitats de la vida”L’objectiu d’aquest estudi és valorar el coneixement del concepte de dol, dol patològic i dóna a conèixer quin és el procés de dol a partir de la teoria de les etapes d’ Elisabet Kübler-Ross, Parkes i Worden com els pares de les tasques d’aquest procés. Per altra banda pretén, donar a conèixer la detecció d’un dol per així evitar la cronificació d’aquest i que el pacient pugui dur a terme un bonacompanyament del dolLa metodologia es realitzarà a partir d’un estudi d’anàlisis qualitatiu i quantitatiu, descriptiu i bivariant en els professionals d’infermeria de les àrees bàsiques de salut de la ciutat de Girona: Girona 1(CAP Santa Clara), Girona 2 (CAP Can Gibert del Pla), Girona 3 (CAP de Montilivi) i Girona 4(CAP Taialà)Per l’anàlisi estadística descriptiva i bivariant s’utilitzarà el programa SPSS v20 per l’anàlisi quantitativa i el programa N-Vivo 10 per l’anàlisi qualitativa. I per l’obtenció dels resultats es realitzarà una anàlisis descriptiva bivariant. Els resultats obtinguts en aquest estudi ens ajudaran a detectar necessitats relacionades amb la formació i l’aprenentatge dels professionals de l’atenció primària i la manca de recursos en relació al dol

Estimation of age- and stage-specific Catalan breast cancer survival functions using US and Catalan survival data

During the last part of the 1990s the chance of surviving breast cancer increased. Changes in survival functions reflect a mixture of effects. Both, the introduction of adjuvant treatments and early screening with mammography played a role in the decline in mortality. Evaluating the contribution of these interventions using mathematical models requires survival functions before and after their introduction. Furthermore, required survival functions may be different by age groups and are related to disease stage at diagnosis. Sometimes detailed information is not available, as was the case for the region of Catalonia (Spain). Then one may derive the functions using information from other geographical areas. This work presents the methodology used to estimate age- and stage-specific Catalan breast cancer survival functions from scarce Catalan survival data by adapting the age- and stage-specific US functions. Methods: Cubic splines were used to smooth data and obtain continuous hazard rate functions. After, we fitted a Poisson model to derive hazard ratios. The model included time as a covariate. Then the hazard ratios were applied to US survival functions detailed by age and stage to obtain Catalan estimations. Results: We started estimating the hazard ratios for Catalonia versus the USA before and after the introduction of screening. The hazard ratios were then multiplied by the age- and stage-specific breast cancer hazard rates from the USA to obtain the Catalan hazard rates. We also compared breast cancer survival in Catalonia and the USA in two time periods, before cancer control interventions (USA 1975–79, Catalonia 1980–89) and after (USA and Catalonia 1990–2001). Survival in Catalonia in the 1980–89 period was worse than in the USA during 1975–79, but the differences disappeared in 1990–2001. Conclusion: Our results suggest that access to better treatments and quality of care contributed to large improvements in survival in Catalonia. On the other hand, we obtained detailed breast cancer survival functions that will be used for modeling the effect of screening and adjuvant treatments in Catalonia