Catalytic Biochar and Refuse-Derived Char for the Steam Reforming of Waste Plastics Pyrolysis Volatiles for Hydrogen-Rich Syngas

High-density polyethylene (HDPE) was pyrolyzed in a fixed-bed reactor and the derived pyrolysis volatiles passed directly to a second-stage fixed-bed reactor for catalytic steam reforming with the aim to produce hydrogen-rich syngas. The catalysts used were biochar produced from the pyrolysis of waste biomass and solid waste char produced from the pyrolysis of processed municipal solid waste in the form of refuse-derived fuel (RDF). The influence of char catalyst temperature and steam input were used to optimize the production of H2 syngas. Other types of waste plastics (low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), and poly(ethylene terephthalate) (PET)) were also investigated to compare with the production from HDPE. The highest yields of syngas (H2, CO) were produced at 3.83 g gplastic-1 for biochar as the catalyst and 2.73 g gplastic-1 for RDF char as the catalyst, when the steam input was 10 g h-1 gcatalyst-1 and catalyst temperature was 1000 °C. Increasing amounts of steam input also increased the syngas yield, but at high steam inputs, saturation of the catalyst reduced syngas yield. Of the different plastic types investigated, the polyolefin plastics (HDPE, LDPE, PP) produced the highest yield of syngas, whereas PS and PET yields were significantly lower in the presence of both biochar and RDF char catalysts. Hydrogen yields were ∼0.44 g gplastic-1 for the polyalkene plastics with the biochar catalyst but were only ∼0.32 g gplastic-1 with the RDF char catalyst. At 1000 °C, the H2 potential from the processing of plastic with RDF char as the catalyst was higher than with biochar as the catalyst, which was attributed to the higher presence of an inorganic metal in the RDF char possessing catalytic properties

Regulatory networks and connected components of the neutral space

The functioning of a living cell is largely determined by the structure of its regulatory network, comprising non-linear interactions between regulatory genes. An important factor for the stability and evolvability of such regulatory systems is neutrality - typically a large number of alternative network structures give rise to the necessary dynamics. Here we study the discretized regulatory dynamics of the yeast cell cycle [Li et al., PNAS, 2004] and the set of networks capable of reproducing it, which we call functional. Among these, the empirical yeast wildtype network is close to optimal with respect to sparse wiring. Under point mutations, which establish or delete single interactions, the neutral space of functional networks is fragmented into 4.7 * 10^8 components. One of the smaller ones contains the wildtype network. On average, functional networks reachable from the wildtype by mutations are sparser, have higher noise resilience and fewer fixed point attractors as compared with networks outside of this wildtype component.Comment: 6 pages, 5 figure

Waste derived ash as catalysts for the pyrolysis-catalytic steam reforming of waste plastics for hydrogen-rich syngas production

Ash derived from the oxidation of waste tire and processed municipal solid waste in the form of refuse-derived fuel have been investigated for their potential as catalysts in the pyrolysis catalytic steam reforming of high-density polyethylene to produce hydrogen-rich syngas. The surface morphology, element distribution, pore structure and metal composition of the ashes were characterized to explore the effects of these ash properties on the catalytic process. Further work using tire ash investigated the influence of the process parameters, catalytic temperature and catalyst plastic ratio in relation to the production of hydrogen and syngas. The results showed that tire ash had a higher specific surface area and pore volume than refuse-derived fuel ash, resulting in a slightly higher hydrogen yield compared to refuse derived fuel ash. An increase in the temperature of the catalytic steam reforming process with the tire ash catalyst significantly increased the hydrogen yield from 13.3 mmol g−1plastic at 800 °C to 83.2 mmol g−1plastic at 1000 °C. At higher catalyst:plastic ratios, the higher amounts of catalyst produced no discernable increase in hydrogen. A tentative reaction mechanism in relation to waste derived ash as catalysts for the steam reforming of plastics pyrolysis volatiles is provided

Texture analysis of computed tomography images of acute ischemic stroke patients

Computed tomography (CT) images are routinely used to assess ischemic brain stroke in the acute phase. They can provide important clues about whether to treat the patient by thrombolysis with tissue plasminogen activator. However, in the acute phase, the lesions may be difficult to detect in the images using standard visual analysis. The objective of the present study was to determine if texture analysis techniques applied to CT images of stroke patients could differentiate between normal tissue and affected areas that usually go unperceived under visual analysis. We performed a pilot study in which texture analysis, based on the gray level co-occurrence matrix, was applied to the CT brain images of 5 patients and of 5 control subjects and the results were compared by discriminant analysis. Thirteen regions of interest, regarding areas that may be potentially affected by ischemic stroke, were selected for calculation of texture parameters. All regions of interest for all subjects were classified as lesional or non-lesional tissue by an expert neuroradiologist. Visual assessment of the discriminant analysis graphs showed differences in the values of texture parameters between patients and controls, and also between texture parameters for lesional and non-lesional tissue of the patients. This suggests that texture analysis can indeed be a useful tool to help neurologists in the early assessment of ischemic stroke and quantification of the extent of the affected areas.1076107

The Second Step In The Construction Of A Stigma Scale Of Epilepsy

Rationale: The issue of stigmatization is one of the most common psychosocial problems faced by people with epilepsy. Purpose: A second step towards the development of a scale to measure epilepsy stigma. Method: We applied a closed questionnaire to 12 patients and 32 relatives from the Epilepsy Outpatient Clinic at the University Hospital of Campinas. Results: The results are grouped in three main domains: medical, social and personal areas. Medical: the subjects did not know exactly what epilepsy is or how it is caused; nonetheless they know how to treat it. Social: the most important areas that people with epilepsy are discriminated are at work and social relationships. Patients also complained about their lack of freedom and limits on recreation activities. Personal Area: subjects apparently have the same feelings and thoughts about epilepsy and seizures. Conclusion: This study analyzed the most common aspects presented in the questionnaire to assess epilepsy stigma for the Brazilian culture which are the base to the elaboration of a stigma scale of epilepsy.632 B395398Fernandes, P.T., Souza, E.A., Identification of family variables in parents' groups of children with epilepsy (2001) Arq Neuropsiquiatr, 59, pp. 854-858Li, L.M., Sander, J.W., National demonstration project on epilepsy in Brazil (2003) Arq Neuropsiquiatr, 61, pp. 153-156Leidy, N.K., Rentz, A.M., Grace, E.M., Evaluating health-related quality of life outcomes in clinical trials of antiepileptic drug therapy (2004) Epilepsia, 39, pp. 965-977Baker, G.A., Brooks, J., Buck, D., Jacoby, A., The stigma of epilepsy: A European perspective (2000) Epilepsia, 41, pp. 98-104Baker, G.A., Nashef, L., Van Hout, B.A., Current issues in the management of epilepsy: The impact of frequent seizures on cost of illness, quality of life, and mortality (1997) Epilepsia, 38 (SUPPL. 1), pp. S1-S8Baker, G.A., Jacoby, A., Chadwick, D.W., The associations of psychopathology in epilepsy: A community study (1996) Epilepsy Res, 25, pp. 29-39Jacoby, A., Felt versus enacted stigma: A concept revisited. Evidence from a study of people with epilepsy in remission (1994) Soc Sci Med, 38, pp. 269-274Placencia, M., Farmer, P.J., Jumbo, L., Sander, J.W., Shorvon, S.D., Levels of stigmatization of patients with previously untreated epilepsy in northern Ecuador (1995) Neuroepidemiology, 14, pp. 147-154Ratsepp, M., Oun, A., Haldre, S., Kaasik, A.E., Felt stigma and impact of epilepsy on employment status among Estonian people: Exploratory study (2000) Seizure, 9, pp. 394-401Scambler, G., Hopkins, A., Generating a model of epileptic stigma: The role of qualitative analysis (1990) Soc Sci Med, 30, pp. 1187-1194Ryan, R., Kempner, K., Emlen, A.C., The stigma of epilepsy as a self-concept (1980) Epilepsia, 21, pp. 433-444Fernandes, P.T., Salgado, P.C., Ala, N., Barbosa, F.D., Souza, E.A., Li, L.M., Stigma Scale of Epilepsy: Conceptual issues (2004) J Epilep Clin Neuropshysiology, 10, pp. 213-218McLin, W.M., De Boer, H.M., Public perceptions about epilepsy (1995) Epilepsia, 36, pp. 957-95

Observations of the post shock break-out emission of SN 2011dh with XMM-Newton

After the occurrence of the type cIIb SN 2011dh in the nearby spiral galaxy M 51 numerous observations were performed with different telescopes in various bands ranging from radio to gamma-rays. We analysed the XMM-Newton and Swift observations taken 3 to 30 days after the SN explosion to study the X-ray spectrum of SN 2011dh. We extracted spectra from the XMM-Newton observations, which took place ~7 and 11 days after the SN. In addition, we created integrated Swift/XRT spectra of 3 to 10 days and 11 to 30 days. The spectra are well fitted with a power-law spectrum absorbed with Galactic foreground absorption. In addition, we find a harder spectral component in the first XMM-Newton spectrum taken at t ~ 7 d. This component is also detected in the first Swift spectrum of t = 3 - 10 d. While the persistent power-law component can be explained as inverse Compton emission from radio synchrotron emitting electrons, the harder component is most likely bremsstrahlung emission from the shocked stellar wind. Therefore, the harder X-ray emission that fades away after t ~ 10 d can be interpreted as emission from the shocked circumstellar wind of SN 2011dh.Comment: Accepted for publication as a Research Note in Astronomy and Astrophysic

Non-existence of stationary two-black-hole configurations: The degenerate case

In a preceding paper we examined the question whether the spin-spin repulsion and the gravitational attraction of two aligned sub-extremal black holes can balance each other. Based on the solution of a boundary value problem for two separate (Killing-) horizons and a novel black hole criterion we were able to prove the non-existence of the equilibrium configuration in question. In this paper we extend the non-existence proof to extremal black holes.Comment: 18 pages, 2 figure

Perception And Attitudes Towards Epilepsy: Point Of View Of Professionals Allied To Medicine From Mobile Emergency Service In Campinas

Introduction: Epilepsy is very prevalent in our society, but unfortunately lack of knowledge is still very common, contributing to psycho-social difficulties to people with epilepsy. Purpose: The aim of this study was to assess the epilepsy' perception and attitudes by professionals of emergency medical service in Campinas, Brazil. Material and methods: This study was carried out with professionals of SAMU-192, who participated on the VII Stroke Workshop of Campinas in November 2007. Results: One hundred-forty nine (149) professionals answered the questionnaire (49% women, average age of 37 years, range from 21 to 59 year). Ninety (60%) were professionals allied to medicine (nurses, health auxiliary, dentists), six (4%) were physicians and 53 (36%) were other professions (secretary, driver). In overall, a great majority of the subjects had an appropriate knowledge regarding epilepsy. But, some beliefs are still present. In relation to epilepsy' perception, some wrong ideas appeared, as epilepsy is a contagious disease, people with epilepsy can not practice physical exercise or to work. Also, the doubts regarding pregnancy and treatment of epilepsy were observed. Regarding attitudes during an epileptic seizure, some inadequate attitudes appeared: to put something in patient's mouth, to restrict the patients' movements or give something strong to smell (alcohol or vinegar) in order to stop the seizure. Conclusion: In this context, it is necessary a continuous education programs to the allied health professionals to improve the perception and attitudes, bringing epilepsy out of the shadows.153119122Fernandes, P.T., Li, L.M., (2005) Estigma na Epilepsia Departamento de Neurologia, , FCM/UNICAMP;Fernandes, P.T., Salgado, P.C., Noronha, A.L.A., de Boer, H.M., Prilipko, L., Sander, J.W., Epilepsy stigma perception in an urban area of a limited resource country (2007) Epilepsy Behav, 11 (1), pp. 25-32Guerreiro, C.A., Guerreiro, M.M., Cendes, F., Lopes-Cendes, I., (2000) Considerações gerais, pp. 1-10. , Lemos Editorial. Epilepsia. 3rd edLi, L.M., Sander, J.W., National demonstration project on epilepsy in Brazil] (2003) Arq Neuropsiquiatr, 61 (1), pp. 153-156. , Mar;Marchetti, R.L., de Castro, A.P., Daltio, C.S., Cremonese, E., Ramos, J.M., Neto, J.G., Attitudes of Brazilian psychiatrists toward people with epilepsy (2004) Epilepsy Behav, 5 (6), pp. 999-1004. , Dec;Marchetti, R.L., Epilepsy in the shadow of Brazilian psychiatry] (2004) Rev Bras Psiquiatr, 26 (1), pp. 67-68. , Mar;Jacoby, A., Chadwick, D., Psychosocial problems in epilepsy (1992) BMJ, 305 (6845), p. 117. , July;Jacoby, A., Gorry, J., Gamble, C., Baker, G.A., Public knowledge, private grief: A study of public attitudes to epilepsy in the United Kingdom and implications for stigma (2004) Epilepsia, 45 (11), pp. 1405-1415. , Nov;Baker, G., The Psychosocial Burden of Epilepsy (2002) Epilepsia, 43 (SUPPL. 6), pp. 26-30Austin, J.K., Shafer, P.O., Deering, J.B., Epilepsy familiarity, know-ledge, and perceptions of stigma: Report from a survey of adolescents in the general population (2002) Epilepsy Behav, 3 (4), pp. 368-375. , Aug;Suurmeijer, T.P., Reuvekamp, M.F., Aldenkamp, B.P., Social functioning, psychological functioning, and quality of life in epilepsy (2001) Epilepsia, 42 (9), pp. 1160-1168. , Sept;Fernandes, P.T., Li, L.M., Percepção de estigma na epilepsia. (2006) Journal of Epilepsy and Clinical Neurophysiology, 12 (4), pp. 207-218Jacoby, A., Impact of epilepsy on employment status: Findings from a UK study of people with well-controlled epilepsy (1995) Epilepsy Res, 21 (2), pp. 125-132. , June;Fernandes, P.T., Noronha, A.L., Sander, J.W., Bell, G.S., Li, L.M., Training the trainers and disseminating information: A strategy to educate health professionals on epilepsy (2007) Arq Neuropsiquiatr, 65 (SUPL 1), pp. 14-22Noronha, A.L., Fernandes, P.T., Andrade, M.G.G., Santiago, S.M., Sander, J.W., Li, L.M., Training medical students to improve the management of people with epilepsy (2007) Arq Neuropsiquiatr, 65 (SUPL 1), pp. 23-27Fernandes, P.T., Salgado, P.C., Noronha, A.L.A., Barbosa, F.D., Souza, E.A., Li, L.M., Stigma Scale of Epilepsy: Conceptual issues (2004) Journal of Epilepsy and Clinical Neurophysiology, 10 (4), pp. 213-218Reno, B.A., Fernandes, P.T., Bell, G.S., Sander, J.W., Li, L.M., Stigma and attitudes on epilepsy: A study with secondary school students (2007) Arq Neuropsiquiatr, 65 (SUPL 1), pp. 49-5

Deformations of the hemisphere that increase scalar curvature

Consider a compact Riemannian manifold M of dimension n whose boundary \partial M is totally geodesic and is isometric to the standard sphere S^{n-1}. A natural conjecture of Min-Oo asserts that if the scalar curvature of M is at least n(n-1), then M is isometric to the hemisphere S_+^n equipped with its standard metric. This conjecture is inspired by the positive mass theorem in general relativity, and has been verified in many special cases. In this paper, we construct counterexamples to Min-Oo's conjecture in dimension n \geq 3.Comment: Revised version, to appear in Invent. Mat

Extreme Active Molecular Jets in L1448C

The protostellar jet driven by L1448C was observed in the SiO J=8-7 and CO J=3-2 lines and 350 GHz dust continuum at ~1" resolution with the Submillimeter Array (SMA). A narrow jet from the northern source L1448C(N) was observed in the SiO and the high-velocity CO. The jet consists of a chain of emission knots with an inter-knot spacing of ~2" (500 AU) and a semi-periodic velocity variation. The innermost pair of knots, which are significant in the SiO map but barely seen in the CO, are located at ~1" (250 AU) from the central source, L1448C(N). Since the dynamical time scale for the innermost pair is only ~10 yr, SiO may have been formed in the protostellar wind through the gas-phase reaction, or been formed on the dust grain and directly released into the gas phase by means of shocks. It is found that the jet is extremely active with a mechanical luminosity of ~7 L_sun, which is comparable to the bolometric luminosity of the central source (7.5 L_sun). The mass accretion rate onto the protostar derived from the mass-loss rate is ~10^{-5} M_sun/yr. Such a high mass accretion rate suggests that the mass and the age of the central star are 0.03-0.09 M_sun and (4-12)x10^3 yr, respectively, implying that the central star is in the very early stage of protostellar evolution. The low-velocity CO emission delineates two V-shaped shells with a common apex at L1448C(N). The kinematics of these shells are reproduced by the model of a wide opening angle wind. The co-existence of the highly-collimated jets and the wide-opening angle shells can be explained by the unified X-wind model" in which highly-collimated jet components correspond to the on-axis density enhancement of the wide-opening angle wind. The CO $J$=3--2 map also revealed the second outflow driven by the southern source L1448C(S) located at ~8.3" (2000 AU) from L1448C(N).Comment: 45 pages, 13 figures, Accepted for the publication in the Astrophysical Journa