Application of silver in microtubular solid oxide fuel cells

In this paper, the behaviour of silver as cathode conductive material, interconnect wire, and sealing for anode lead connection for microtubular solid oxide fuel cells (µSOFC) is reported. The changes in silver morphology are examined by scanning electron microscopy on cells that had been operated under reformed methane. It is found that using silver in an solid oxide fuel cell (SOFC) stack can improve the cell performance. However, it is also concluded that silver may be responsible for cell degradation. This report brings together and explains all the known problems with application of silver for SOFCs. The results show that silver is unstable in interconnect and in cathode environments. It is found that the process of cell passivation/activation promotes silver migration. The difference in thermal expansion of silver and sealant results in damage to the glass. It is concluded that when silver is exposed to a dual atmosphere condition, high levels of porosity formation is seen in the dense silver interconnect. The relevance of application of silver in SOFC stacks is discussed

Applications of yeast flocculation in biotechnological processes

A review on the main aspects associated with yeast flocculation and its application in biotechnological processes is presented. This subject is addressed following three main aspects – the basics of yeast flocculation, the development of “new” flocculating yeast strains and bioreactor development. In what concerns the basics of yeast flocculation, the state of the art on the most relevant aspects of mechanism, physiology and genetics of yeast flocculation is reported. The construction of flocculating yeast strains includes not only the recombinant constitutive flocculent brewer’s yeast, but also recombinant flocculent yeast for lactose metabolisation and ethanol production. Furthermore, recent work on the heterologous β-galactosidase production using a recombinant flocculent Saccharomyces cerevisiae is considered. As bioreactors using flocculating yeast cells have particular properties, mainly associated with a high solid phase hold-up, a section dedicated to its operation is presented. Aspects such as bioreactor productivity and culture stability as well as bioreactor hydrodynamics and mass transfer properties of flocculating cell cultures are considered. Finally, the paper concludes describing some of the applications of high cell density flocculation bioreactors and discussing potential new uses of these systems.Fundação para a Ciência e a Tecnologia (FCT) – PRAXIS XXI - BD11306/97

Socio Demographic and Clinical Features of The Malaria Cases

Objective: To study the sociodemographic profile of malaria cases admitted on the basis of clinical features. Methods: With purposive sampling 100 cases were taken in these studies who were admitted with clinical findings of fever at Sayajirav Gyakwad Hospital, Vadodara. The indoor patients from April 2006 to October 2006 were retrieved using a prepared case sheet performa on the basis of patient’s demographic profile and clinical findings. Results: Out of 100 cases 66 patients were male and 44 female. Highest age group among male (46.96) as well as female (47.05) patients were more than 30 year age. The infection rate was higher among the younger age group. Hepatomegaly (46%), spleenomegaly (56%) and jaundice (49%) were associated with malaria. Interpretation and Conclusion: Malaria is responsible for major health concern in this region, particularly in rainy season and is found to affect comparatively the younger adult population

Clinical profile, outcome and clinical indicators for poor prognosis in full term babies born with severe birth asphyxia: study from tertiary care hospital from western India

Background: The World Health Organization describes birth asphyxia as failure to initiate and sustain default breathing at birth. The aim of the study was to study the clinical profile and outcome at 3 months of age of full term babies born with severe birth asphyxia and to analyze risk factors associated with adverse outcome.Methods: This was a prospective observational study carried out over period of 12 months in year 2015-16. All full term babies born with severe birth asphyxia (n = 45) during four months period were enrolled and were followed up for 3 months. Severe birth asphyxia was defined as APGAR score 3 or less at 1 minute. Baseline characteristics, clinical profile and outcome were noted. HIE was graded as per Sarnat and Sarnat staging. Neurological Assessment at 7th day and on discharge was done and were assessed by Amiel Tison Scale at 3 months. Multivariate analysis by linear regression was done to find risk factors associated with adverse outcome. Results: Of total 45 babies with SBA, 35 developed HIE, of which 13 (28.8%) were in HIE grade II and 13 (28.8%) were in HIE III. Mortality found was 20% while 28.5% of survivors had abnormal neurological outcome at 3 months. Multivariate analysis of risk factors shows that abnormal neurological finding on 7th day of life, APGAR ≤ 6 at 10 minute and HIE grade II or more where associated with abnormal outcome(p = 0.01). The risk factors associated with mortality were multiorgan dysfunction, difficult to control seizures, APGAR ≤4 at 10 minute (p = 007).Conclusions: Full term neonates with severe birth asphyxia has significant mortality and significant number of survivors has abnormal neurological outcome at 3 months of age. Presence of certain clinical indicators is associated with increased risk of adverse outcome.</jats:p

Revealing pyrolysis chemistry for biofuels production: Conversion of cellulose to furans and small oxygenates

Biomass pyrolysis utilizes high temperatures to produce an economically renewable intermediate (pyrolysis oil) that can be integrated with the existing petroleum infrastructure to produce biofuels. The initial chemical reactions in pyrolysis convert solid biopolymers, such as cellulose (up to 60% of biomass), to a short-lived (less than 0.1 s) liquid phase, which subsequently reacts to produce volatile products. In this work, we develop a novel thin-film pyrolysis technique to overcome typical experimental limitations in biopolymer pyrolysis and identify α-cyclodextrin as an appropriate small-molecule surrogate of cellulose. Ab initio molecular dynamics simulations are performed with this surrogate to reveal the long-debated pathways of cellulose pyrolysis and indicate homolytic cleavage of glycosidic linkages and furan formation directly from cellulose without any small-molecule (e.g., glucose) intermediates. Our strategy combines novel experiments and first-principles simulations to allow detailed chemical mechanisms to be constructed for biomass pyrolysis and enable the optimization of next-generation biorefineries