Research study of droplet sizing technology leading to the development of an advanced droplet sizing system

An instrument to measure the size and velocity of droplets was developed. The instrument uses one of two techniques, as appropriate. In the first technique two small laser beams of one color identify the center of a larger laser beam of a different color. This defines a region of almost uniform intensity where the light scattered by the individual droplets can be related to their size. The first technique uses the visibility of a Doppler burst and validates it against the peak intensity of the signal's pedestal. Results are presented for monodisperse, bimodal, trimodal, and polydisperse sprays produced by the Berglund-Liu droplet generator and a pressure nozzle. Size distributions of a given spray obtained using three different size ranges show excellent self-consistency in the overlapping region. Measurements of sprays of known characteristics exhibit errors in the order of 10%. The principles of operation and design criteria of the instrument are discussed in great detail

Following the phosphorus solubilization by varying decantation times in a pilot WWTP

Motivation: Phosphorus and nitrogen are essential for organisms, but in quantities that imbalance the ecosystem, they promote the development of aquatic plants and algae to the detriment of others. This process is called Eutrophication. Wastewater treatment plants (WWTP) have an important role in reducing the flows of both elements in the waters they produce. With the main objective of knowing more in depth the biological elimination of phosphorus, two purification systems have been used: a pilot plant with SBR system (sequential biological reactor) and another with conventional system. As a complement, this behavior has also been studied in sewage samples as a function of the decantation time.Methods:With the purpose of promoting the growth of PAO organisms (polyphosphate-accumulating organism) responsible for the biological elimination of phosphorus, different aeration-not aeration cycles have been carried out in the pilot plant, since this type of organisms need aerobiosis-anaerobiosis. The concentration of soluble phosphorus and nitrate present in the water has been determined both in the pilot plant and in the samples of sewage treatment plants.Results:In the pilot plant, the different aeration-non-aeration cycles have been studied, achieving levels of phosphorus reduction that are around 15% in the conventional system and 16% in the SBR system.These levels were insufficient, so it was decided to increase the concentration of nutrients by adding glucose to the incoming water. With this, reduction levels of approximately 95% were achieved. Samples from the treatment plants have given rise, depending on the decanting time, to very different behaviors, although with correlation between some of them, taking into account the mass load and mud age.Conclusions: We can conclude therefore that the pilot plant was in nutrient deficit so it could not carry out a biological elimination process. This was solved thanks to the addition of glucose in small quantities. With respect to the samples we could say that the low mass loads are related to levels, more or less, constant of dissolved phosphorus but the behavior of the samples has been very different so we should investigate the reasons that lead to this produce in such a way

Costs Associated with Malaria in Pregnancy in the Brazilian Amazon, a Low Endemic Area Where Plasmodium vivax Predominates.

BACKGROUND: Information on costs associated with malaria in pregnancy (MiP) in low transmission areas where Plasmodium vivax predominates is so far missing. This study estimates health system and patient costs of MiP in the Brazilian Amazon. METHODS/PRINCIPAL FINDINGS: Between January 2011 and March 2012 patient costs for the treatment of MiP were collected through an exit survey at a tertiary referral hospital and at a primary health care centre in the Manaus metropolitan area, Amazonas state. Pregnant and post-partum women diagnosed with malaria were interviewed after an outpatient consultation or at discharge after admission. Seventy-three interviews were included in the analysis. Ninety-six percent of episodes were due to P. vivax and 4% to Plasmodium falciparum. In 2010, the total median costs from the patient perspective were estimated at US $45.91 and US$216.29 for an outpatient consultation and an admission, respectively. When multiple P. vivax infections during the same pregnancy were considered, patient costs increased up to US $335.85, representing the costs of an admission plus an outpatient consultation. Provider direct and overhead cost data were obtained from several sources. The provider cost associated with an outpatient case, which includes several consultations at the tertiary hospital was US$103.51 for a P. vivax malaria episode and US $83.59 for a P. falciparum malaria episode. The cost of an inpatient day and average admission of 3 days was US$118.51 and US $355.53, respectively. Total provider costs for the diagnosis and treatment of all malaria cases reported in pregnant women in Manaus in 2010 (N = 364) were US$17,038.50, of which 92.4% (US$ 15,741.14) due to P. vivax infection. CONCLUSION: Despite being an area of low risk malaria transmission, MiP is responsible for a significant economic burden in Manaus. Especially when multiple infections are considered, costs associated with P. vivax are higher than costs associated with P. falciparum. The information generated may help health policy decisions for the current control and future elimination of malaria in the area

Reducing the debt : is it optimal to outsource an investment?

International audienceWe deal with the problem of outsourcing the debt for a big investment, according two situations: either the firm outsources both the investment (and the associated debt) and the exploitation to a private consortium, or the firm supports the debt and the investment but outsources the exploitation. We prove the existence of Stackelberg and Nash equilibria between the firm and the private consortium, in both situations. We compare the benefits of these contracts. We conclude with a study of what happens in case of incomplete information, in the sense that the risk aversion coefficient of each partner may be unknown by the other partner