35 research outputs found

    Wind park reliable energy production based on a hydrogen compensation system. Part I: Technical viability

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    Power production from renewable energy resources is increasing day by day. In the case of Spain, in 2009, it represents the 26.9% of installed power and 20.1% of energy production. Wind energy has the most important contribution of this production. Wind generators are greatly affected by the restrictive operating rules of electricity markets because, as wind is naturally variable, wind generators may have serious difficulties on submitting accurate generation schedules on a day ahead basis, and on complying with scheduled obligations. Weather forecast systems have errors in their predictions depending on wind speed. Thus, if wind energy becomes an important actor in the energy production system, these fluctuations could compromise grid stability. In this study technical and economical viability of a large scale compensation system based on hydrogen is investigated, combining wind energy production with a biomass gasification system. Combination of two systems has synergies that improve final results. In the economical study, it is considered that all hydrogen production that is not used to compensate wind energy could be sold to supply the transportation sector.Sánchez Díaz, C.; Abad, B.; Hübner, S.; Alfonso-Solar, D.; Segura Heras, I. (2011). Wind park reliable energy production based on a hydrogen compensation system. Part I: Technical viability. International Journal of Hydrogen Energy. 36(24):15548-15560. doi:10.1016/j.ijhydene.2011.09.014S1554815560362

    Identificación de plagas de chapulín en el norte–centro de México

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    Short carbon nanotubes (CNTs) are desired for a variety of applications. As a consequence, several strategies have been reported to cut and shorten the length of as-produced CNTs via chemical and physical routes. The efficiency of a given strategy largely depends on the physico-chemical characteristics of the CNTs employed. In order to be able to directly compare the advantages and disadvantages of commonly used protocols, a single batch of chemical vapor deposition single-walled CNTs (SWCNTs) and a batch of multi-walled CNTs (MWCNTs) were subjected to four cutting/shortening strategies, namely acid cutting, piranha treatment, steam shortening and ball milling. The length distribution was assessed by means of scanning electron microscopy. Sample purity and CNT wall structure were determined by Raman spectroscopy, thermogravimetric analysis and magnetic measurements. Within the employed experimental conditions, piranha treatment turned out to be the most efficient to achieve short SWCNTs with a narrow length distribution in a good yield, whereas a mixture of sulfuric/nitric acid was preferred in the case of MWCNTs. A subsequent short steam treatment allowed to remove functional groups present in the samples, leading to median length distributions of 266 nm and 225 nm for SWCNTs and MWCNTs respectively after the combined protocols

    Polyacrylate polymers as immobilizing agents to aid phytostabilization of two mine soils

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    We evaluated the effect of polyacrylate polymers as immobilizing agents to aid phytostabilization of two mine soils. One soil had a very low pH (3.7) and a large Pb content, while the other was less acidic but had a greater content of Cu and Zn. Growth of perennial ryegrass (Lolium perenne L. cv. Victorian) was stimulated in polymer-amended soils. After ryegrass had been growing for 35 days, the amounts of water-extractable Cu, Zn and Pb (one soil only) present in the polymer-amended soils were smaller than those from soil without polymer. The number of culturable heterotrophic bacteria and the activities of dehydrogenase and b-glucosidase increased following polymer application. In contrast, the urease activity was impaired by polymer application, presumably because of the presence of ammonium as a counter ion. In another experiment, the acidic soil was limed to pH 6.5 before growth of perennial ryegrass took place. Liming the soil greatly enhanced plant growth, but by the third cut, differences between treatments became apparent, with plants from polymer-amended limed soil accumulating a greater biomass compared with limed soil without polymer. After ryegrass had been growing for 119 days (five cuts), the amount of water-extractable Pb and the urease activity in the polymer-amended soil were smaller than those from limed soil without polymer. The numbers of culturable heterotrophic bacteria and the activities of dehydrogenase, b-glucosidase and acid phosphatase increased following polymer application. The results are consistent with phytostabilization being achieved by the application of polyacrylate polymers, improving soil chemical and biological properties. In very acidic soils, the use of both a liming material and polymer together appears to give a considerable advantage

    Randomized crossover pharmacokinetic evaluation of subcutaneous versus intravenous granisetron in cancer patients treated with platinum-based chemotherapy

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    BACKGROUND: 5-HT3-receptor antagonists are one of the mainstays of antiemetic treatment, and they are administered either i.v. or orally. Nevertheless, sometimes neither administration route is feasible, such as in patients unable to admit oral intake managed in an outpatient setting. Our objective was to evaluate the bioavailability of s.c. granisetron. PATIENTS AND METHODS: Patients receiving platinum-based chemotherapy were randomized to receive 3 mg of granisetron either s.c. or i.v. in a crossover manner during two cycles. Blood and urine samples were collected after each cycle. Pharmacokinetic parameters observed with each administration route were compared by analysis of variance. RESULTS: From May to November 2005, 31 patients were included and 25 were evaluable. Subcutaneous granisetron resulted in a 27% higher area under the concentration-time curve for 0-12 hours (AUC(0-12h)) and higher levels at 12 hours, with similar values for AUC(0-24h). The maximum concentration was lower with the s.c. than with the i.v. route and was observed 30 minutes following s.c. administration. CONCLUSION: Granisetron administered s.c. achieves complete bioavailability. This is the first study that shows that s.c. granisetron might be a valid alternative to i.v. delivery. Further trials to confirm clinical equivalence are warranted. This new route of administration might be especially relevant for outpatient management of emesis in cancer patients

    Impact of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients: A nationwide study in Spain

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    Objective To assess the effect of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients in Spain. Settings The initial flood of COVID-19 patients overwhelmed an unprepared healthcare system. Different measures were taken to deal with this overburden. The effect of these measures on neurosurgical patients, as well as the effect of COVID-19 itself, has not been thoroughly studied. Participants This was a multicentre, nationwide, observational retrospective study of patients who underwent any neurosurgical operation from March to July 2020. Interventions An exploratory factorial analysis was performed to select the most relevant variables of the sample. Primary and secondary outcome measures Univariate and multivariate analyses were performed to identify independent predictors of mortality and postoperative SARS-CoV-2 infection. Results Sixteen hospitals registered 1677 operated patients. The overall mortality was 6.4%, and 2.9% (44 patients) suffered a perioperative SARS-CoV-2 infection. Of those infections, 24 were diagnosed postoperatively. Age (OR 1.05), perioperative SARS-CoV-2 infection (OR 4.7), community COVID-19 incidence (cases/10 5 people/week) (OR 1.006), postoperative neurological worsening (OR 5.9), postoperative need for airway support (OR 5.38), ASA grade =3 (OR 2.5) and preoperative GCS 3-8 (OR 2.82) were independently associated with mortality. For SARS-CoV-2 postoperative infection, screening swab test <72 hours preoperatively (OR 0.76), community COVID-19 incidence (cases/10 5 people/week) (OR 1.011), preoperative cognitive impairment (OR 2.784), postoperative sepsis (OR 3.807) and an absence of postoperative complications (OR 0.188) were independently associated. Conclusions Perioperative SARS-CoV-2 infection in neurosurgical patients was associated with an increase in mortality by almost fivefold. Community COVID-19 incidence (cases/10 5 people/week) was a statistically independent predictor of mortality. Trial registration number CEIM 20/217

    Consens d’escales i eines per a la valoració multidimensional de les persones a Catalunya

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    Model d'atenció integral; Valoració multidimensional; DiagnòsticModelo de atención integral; Valoración multidimensional; DiagnósticoComprehensive care model; Multidimensional valuation; DiagnosisActualment no existeix a Catalunya un consens sobre quin hauria de ser el mínim comú denominador d’escales i eines d’elecció per a la valoració de les diferents dimensions de les persones grans amb multimorbiditat, fragilitat, cronicitat complexa o avançada. Aquest escenari fa evident la necessitat de disposar d’escales i eines consensuades i compartides que facilitin l’aproximació multidimensional a aquestes persones de forma objectiva i pragmàtica, amb l’objectiu d'ajudar els professionals en aquest procés d’individualització de l’atenció. És per aquest motiu que, impulsat per la Direcció General de Planificació i Recerca en Salut i per l’oficina eSalut, s’ha promogut i desenvolupat aquest consens i es vol assegurar que la proposta pugui ser suportada en l’entorn digital

    Common variants in Alzheimer’s disease and risk stratification by polygenic risk scores

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    Funder: Funder: Fundación bancaria ‘La Caixa’ Number: LCF/PR/PR16/51110003 Funder: Grifols SA Number: LCF/PR/PR16/51110003 Funder: European Union/EFPIA Innovative Medicines Initiative Joint Number: 115975 Funder: JPco-fuND FP-829-029 Number: 733051061Genetic discoveries of Alzheimer's disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer's disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer's disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer's disease

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Comparative study of shortening and cutting strategies of single-walled and multi-walled carbon nanotubes assessed by scanning electron microscopy

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    Short carbon nanotubes (CNTs) are desired for a variety of applications. As a consequence, several strategies have been reported to cut and shorten the length of as-produced CNTs via chemical and physical routes. The efficiency of a given strategy largely depends on the physico-chemical characteristics of the CNTs employed. In order to be able to directly compare the advantages and disadvantages of commonly used protocols, a single batch of chemical vapor deposition single-walled CNTs (SWCNTs) and a batch of multi-walled CNTs (MWCNTs) were subjected to four cutting/shortening strategies, namely acid cutting, piranha treatment, steam shortening and ball milling. The length distribution was assessed by means of scanning electron microscopy. Sample purity and CNT wall structure were determined by Raman spectroscopy, thermogravimetric analysis and magnetic measurements. Within the employed experimental conditions, piranha treatment turned out to be the most efficient to achieve short SWCNTs with a narrow length distribution in a good yield, whereas a mixture of sulfuric/nitric acid was preferred in the case of MWCNTs. A subsequent short steam treatment allowed to remove functional groups present in the samples, leading to median length distributions of 266 nm and 225 nm for SWCNTs and MWCNTs respectively after the combined protocols
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