Estudio técnico-económico de una planta desaladora de agua de mar por ósmosis inversa

En el següent escrit: Estudi técnic-económic d’una planta desaladora d’aigua de mar per osmosis inversa, es pretén donar al lector una idea del procés d’Osmosis Inversa; el qual, ja el podríem ubicar dins dels processos de separació per membranes. Es pretén que aquesta idea sigui el més pràctica possible, sense deixar de banda els aspectes teòrics corresponents, però descartant aquells que, encara tenir relativa importància, l’únic que se aconseguiria amb el seu estudi, seria ampliar el contingut de l’anomenat projecte sense aportarnos això cap benefici relacionat amb l’essència del tema, com es la desalació d’aigua de mar per osmosis inversa. Es per aquest motiu que l’estudi que segueix, es divideix en cinc volums. El primer recull tots els aspectes teórico-práctics, on el lector pot trobar els diferents processos de separació per membranes, les consideracions sobre l’aigua i tot el relacionat amb el fonament fisico-químic que ens pertoca, o sia, la ósmosis inversa: definicions, conceptes bàsics, procés, membranes, etc. L’aspecte pràctic al que ens referim ve reflexat en petits sub-apartats, tals com: neteja eficaç de les membranes, o en seccions posteriors, en petits apartats on es donen recomanacions pràctiques, de instal•lació i inclòs de fabricació d’aparells per postratament. El volum segon és una descripció detalla de l’instal•lació, on s’estudia des de la presa d’aigua de mar fins l’obtenció d’aigua producte, nomenant-se tots els equips, vàlvules, bombes, filtres, etc., que l’aigua travessa en el seu procés. Els tres volums restants corresponen al aspecte més tècnic, on es mostren, por ordre: càlculs, plànols i pressupost o memòria econòmica

Heat transfer and hydraulic stability in boiling-water reactors

Fundamental work on heat removal by bubble formation and by increased heat diffusivity as a result of increased turbulence in boundary layers is described. A math. model was constructed of the heat transfer loop that is in operation under pressures up to 40 atm. at input powers up to 600 kw., and inlet subcooling up to 40 Deg. The model is compared with the exptl. results obtained from the loop. The on-set of flow instability is studied, and the nature of the instabilities is characterized in the region up to burnout by means of analysis of power d. curves. The dynamic characteristics of the loop are studied by means of transfer function analysis. The validity of the underlying linearization is discussed and the resulting transfer functions are compared with those obtained from noise analysis. Systematic burnout studies of rod bundles are reported, including the analysis of flow instability preceding burnou

Applying the InterVA-4 model to determine causes of death in rural Ethiopia

BACKGROUND: In Ethiopia, most deaths take place at home and routine certification of cause of death by physicians is lacking. As a result, reliable cause of death (CoD) data are often not available. Recently, a computerized method for interpretation of verbal autopsy (VA) data, called InterVA, has been developed and used. It calculates the probability of a set of CoD given the presence of circumstances, signs, and symptoms reported during VA interviews. We applied the InterVA model to describe CoD in a rural population of Ethiopia. OBJECTIVE: VA data for 436/599 (72.7%) deaths that occurred during 2010-2011 were included. InterVA-4 was used to interpret the VA data into probable cause of death. Cause-specific mortality fraction was used to describe frequency of occurrence of death from specific causes. RESULTS: InterVA-4 was able to give likely cause(s) of death for 401/436 of the cases (92.0%). Overall, 35.0% of the total deaths were attributed to communicable diseases, and 30.7% to chronic non-communicable diseases. Tuberculosis (12.5%) and acute respiratory tract infections (10.4%) were the most frequent causes followed by neoplasms (9.6%) and diseases of circulatory system (7.2%). CONCLUSION: InterVA-4 can produce plausible estimates of the major public health problems that can guide public health interventions. We encourage further validation studies, in local settings, so that InterVA can be integrated into national health surveys.Berhe Weldearegawi, Yohannes Adama Melaku, Mark Spigt, and Geert Jan Dinan

Combining intensive practice nurse counselling or brief general practitioner advice with varenicline for smoking cessation in primary care: study protocol of a pragmatic randomized controlled trial

Introduction: Combining behavioural support and pharmacotherapy is most effective for smoking cessation and recommended in clinical guidelines. Despite that smoking cessation assistance from the general practitioner can be effective, dissemination of clinical practice guidelines and efforts on upskilling has not lead to the routine provision of smoking cessation advice among general practitioners. Intensive counselling from the practice nurse could contribute to better smoking cessation rates in primary care. However, the effectiveness of intensive counselling from a practice nurse versus usual care from a general practitioner in combination with varenicline is still unknown. Materials and methods: A pragmatic randomized controlled trial was conducted comparing: (a) intensive individual counselling delivered by a practice nurse and (b) brief advice delivered by a general practitioner; both groups received 12-weeks of open-label varenicline. A minimum of 272 adult daily smoking participants were recruited and treated in their routine primary care setting. The primary outcome was defined as prolonged abstinence from weeks 9 to 26, biochemically validated by exhaled carbon monoxide. Data was analysed blinded according to the intention-to-treat principle and participants with missing data on their smoking status at follow-up were counted as smokers. Secondary outcomes included: one-year prolonged abstinence, short-term incremental cost-effectiveness, medication adherence, and baseline predictors of successful smoking cessation. Discussion: This trial is the first to provide scientific evidence on the effectiveness, cost-effectiveness, and potential mechanisms of action of intensive practice nurse counselling combined with varenicline under real-life conditions. This paper explains the methodology of the trial and discusses the pragmatic and/or explanatory design aspects

Practices and Challenges of Growth Monitoring and Promotion in Ethiopia: A Qualitative Study

The use of growth monitoring and promotion (GMP) has become widespread. It is a potential contributor towards achieving the Millennium Development Goals of halving hunger and reducing child mortality by two-thirds within 2015. Yet, GMP appears to be a prerequisite for good child health but several studies have shown that there is a discrepancy between the purpose and the practice of GMP. The high prevalence of malnutrition in many developing countries seems to confirm this fact. A descriptive qualitative study was carried out from April to September 2011. Focus group discussions and in-depth interviews were conducted amongst mothers and health workers. Data were analyzed using a qualitative content analysis technique, with the support of ATLAS.ti 5.0 software. The results suggest that most mothers were aware of the need for regular weight monitoring while health workers also seemed to be well-aware and to practise GMP according to the international guidelines. However, there was a deficit in maternal knowledge with regard to child-feeding and a lack of basic resources to keep and/or to buy healthful and nutritionally-rich food. Furthermore, the role of the husband was not always supportive of proper child-feeding. In general, GMP is unlikely to succeed if mothers lack awareness of proper child-feeding practices, and if they are not supported by their husbands

Increased postvoid residual volume after measuring the isovolumetric bladder pressure using the noninvasive condom catheter method

OBJECTIVE: To test, in an ongoing noninvasive longitudinal study in healthy men, whether the condom catheter method (a noninvasive urodynamic test to assess bladder function and bladder outlet obstruction) inhibits bladder function and whether this affects the reliability of the measured isovolumetric bladder pressure (P(ves.iso)). SUBJECTS AND METHODS: Subjects (754, aged 40-79 years) voided three times, i.e. one free void and two condom measurements. The postvoid residual volume (PVR) was measured after each void using transabdominal ultrasonography. The statistical significance of differences was tested using Wilcoxon rank test and the Mann-Whitney U-test. RESULTS: After free voiding the median (interquartile range) PVR was 18 (37) mL, and independent of the amount of fluid intake. In a subgroup of volunteers, when the free void was done last, the PVR was no different (P = 0.25), suggesting that the bladder did not become exhausted during the protocol. The PVR after two subsequent condom measurements was significantly higher than after free voiding, at 45 (78) and 57 (88) (both P < 0.05), independent of the number of interruptions in voiding. After supplementary fluid intake before the condom measurements, the PVR was double that with a normal fluid intake (P = 0.03). The median P(ves.iso) was 3 cmH(2)O higher in the second condom measurement than in the first (P < 0.05), although this small difference was not clinically relevant. CONCLUSIONS: The condom measurement is associated with a significantly higher PVR, partly caused by supplementary fluid intake. This effect was only temporary and did not affect the measured P(ves.iso)

Primary care nurses: effects on secondary care referrals for diabetes

Background: Primary care nurses play an important role in diabetes care, and were introduced in GP-practice partly to shift care from hospital to primary care. The aim of this study was to assess whether the referral rate for hospital treatment for diabetes type II (T2DM) patients has changed with the introduction of primary care nurses, and whether these changes were related to the number of diabetes-related contacts in a general practice. Methods: Healthcare utilisation was assessed for a period of 365 days for 301 newly diagnosed and 2124 known T2DM patients in 2004 and 450 and 3226 patients in 2006 from general practices that participated in the Netherlands Information Network of General Practice (LINH). Multilevel logistic and linear regression analyses were used to analyse the effect of the introduction of primary care nurses on referrals to internists, ophthalmologists and cardiologists and diabetes-related contact rate. Separate analyses were conducted for newly diagnosed and known T2DM patients. Results: Referrals to internists for newly diagnosed T2DM patients decreased between 2004 and 2006 (OR:0.44; 95%CI:0.22-0.87) in all practices. For known T2DM patients no overall decrease in referrals to internists was found, but practices with a primary care nurse had a lower trend (OR:0.59). The number of diabetes-related contacts did not differ between practices with and without primary care nurses. Cardiologists’ and ophthalmologists’ referral rate did not change. Conclusions: The introduction of primary care nurses seems to have led to a shift of care from internists to primary care for known diabetes patients, while the diabetes-related contact rate seem to have remained unchanged.