Nickel-based Catalysts for Gasification of Glucose in Supercritical Water

Gasification of waste biomass to form hydrogen, H2, is a promising new source of green energy; while providing the additional benefit of treating challenging and hazardous waste streams that pollute the environment. Gasification of biomass in supercritical water (SCW) offers an attractive alternative to avoid the energy intensive drying process. In this approach, biomass is hydrolyzed by water into smaller molecules in the presence of a suitable catalyst. This study was aimed at developing an alumina supported nickel based non-noble metal catalyst suitable for biomass gasification in SCW. A lack of detailed characterization on fresh and spent catalysts in SCW has held back progress in this field and is critical due to the highly unusual properties of SCW at high pressure and temperature compared to ambient water. Typically hydrogen rich gaseous product from gasification of biomass in SCW requires temperatures higher than 700 °C, while low temperature processes (300-500 °C) produce methane rich gases. Use of suitable catalysts can lower the activation energy of the reaction, and hydrogen rich gaseous products can be achieved at low temperatures thus lower the operating cost. Use of suitable catalysts also can reduce the formation of chars and tars formed during the gasification process in SCW. Moreover, non-noble catalysts could be beneficial in terms of availability and cost. A kinetic study of SCW gasification is still under development due to the numerous intermediate and final products and complex reaction pathways. In this research, supercritical water gasification (SCWG) and partial oxidation (SCWPO) of a model biomass compound was studied to produce hydrogen rich syngas at lower temperatures (400-500 °C). In this respect non-noble nickel catalysts were synthesized, evaluated and characterized (fresh and spent) to study the catalyst role in SCWG. The catalysts studied were synthesized via incipient wetness impregnation of metal salts on synthesized θ-alumina nanofibers and commercial gamma alumina (converted to theta) pellets (3mm average diameter) as catalyst supports. To synthesize nano structured catalyst supports (alumina nanofibers); a one-pot sol-gel route in scCO2 was adopted without using any hazardous organic solvents, surfactants or other additives for the first time. Aerogel nano catalysts were also directly synthesized via a sol-gel technique using isopropanol as solvent and supercritical carbon dioxide (scCO2) as the drying agent. In this research, it was found that introduction of oxidant after gasification is beneficial in terms of gaseous products and reducing the chemical oxygen demand (COD) in the liquid effluents. Another finding is that nickel (Ni) loading on alumina above 11 wt% consumed carbon dioxide with a simultaneous increase in methane attributed to hydrogen consumption by the methanation reaction. However, lanthanum (La) modified Ni/θ-Al2O3 enhanced production of hydrogen by retarding the methanation reaction and promoting the water gas shift (WGS) reaction. In addition, adsorption of CO2, one of the main products, by La was attributed to shifting the reaction equilibrium to the products and thus contributed to enhance hydrogen production. Nano catalysts showed higher activity towards hydrogen production, carbon gasification efficiency and total organic carbon (TOC) destruction in the liquid effluent compared to coarser heterogeneous catalysts. However, hydrogen production using aerogel catalysts where metals were loaded directly through sol-gel reaction was found comparatively less than nanofiber catalysts where metals were impregnated on the nano support. This phenomenon was attributed to the formation of Ni-La-Al-O nano structure complex by direct addition of metals during sol-gel reaction. Unlike impregnated catalysts, incorporation of La to the main structure of the sol-gel derived catalysts could not contribute to enhance the WGS reaction. The fresh and spent catalysts were characterized using different physicochemical techniques which revealed that the catalysts were active in SCW even though the metallic sites of nickel agglomerated when exposed to SCW conditions, oxidized and reacted with the support alumina. It was found that lanthanum retards the formation of graphitic coke, and adsorbed carbon dioxide during supercritical water gasification. To our knowledge, hydrogen yield, total organic carbon destruction and gasification efficiency were significantly higher using La modified Ni/θ-Al2O3 nano catalyst fibers than that of any other reported results of SCWG of any biomass compound at moderate temperatures (~500 °C) and pressures (~28 MPa). However, exposing the nanofiber catalysts to the SCW environment led to disintegration of the fibrous structure. A global kinetic model for TOC destruction in supercritical water was developed using non-linear regression, which convincingly fit with the experimental results

Fa’aaliyyah tathbiiq al-wasaail al-sam’iyyah al-syafahiyyah li tarqiyyah mahaarah al-kalam lada thullaab madrasah As’ad al-mutawassithah al-Islaamiyyah bi madinah Jambi

Teaching aids have an important role in achieving educational goals, but teachers and students face problems in applying educational aids because of machine challenges. In order to create effective learning, teachers need to use teaching aids that can capture students' interest so that students can immediately gain meaning during the learning process. The aim of this research is to find out the effectiveness of applying audio and verbal means to improve the speaking skill of the students of Asaad Intermediate Islamic School in Jambi. As for the entrance to this research, it is quantitative research with the type of objective statistics, and the method used is experimental research and data collection and analysis using the Phi coefficient using random testing, homogeneity testing, and normality testing. Based on calculations using a t-test done like this 0,05 8 < 0,40 So Ha received, this means that there is a significant difference between the speech skills of students who use auditory-verbal aids and those who do not use auditory-verbal aids. The conclusion of this research indicates that audio-oral means are necessary in promoting speaking skill

Successful Transplantation of Primary Hepatocytes from DsRed Mice into Fah-/-;Scid/Scid Mice; A Future In Vivo Model System for Receiving Human Hepatocytes

We have developed a system for studying hepatocellular growth potential in which liver cells are introduced into the diseased livers of Fah-/-; Scid/Scid double knockout mice. To use this system to study cell transplantation, DsRed  liver cells were introduced into severe immunodeficient Fah-/-; Scid/Scid double knockout  mice. In regenerated recipient livers, up to 20% of the mouse liver is repopulated by DsRed mouse hepatocytes demonstrating the creation of a functional mouse liver in which parenchyma is derived from DsRed mouse hepatocytes. The severe immunodeficient Fah-/-;Scid/Scid double knockout mice provide a tool for studying hepatocellular biology. Keywords: Human Hepatocytes, Transplantation, DsRed and Fah-/-;Scid/Scid Mice

Guillain-Barré syndrome following varicella-zoster virus infection

We describe the frequency, clinical features, and electrophysiological and immunological phenotypes of Guillain-Barré Syndrome (GBS) patients treated at a single institution in Bangladesh who had preceding chicken pox (primary Varicella-zoster virus [VZV] infection) within 4 weeks of GBS onset. A literature review of GBS cases preceding VZV infection is also provided. Diagnosis of GBS was based on the National Institute of Neurological Disorders and Stroke criteria for GBS. Serum anti-VZV IgM and IgG antibodies were quantified by indirect chemiluminescence immunoassay (CLIA); anti-Campylobacter jejuni IgG, IgM, and IgA antibodies and anti-ganglioside GM1 IgM and IgG antibodies, by enzyme-linked immunosorbent assays. Neurophysiologic subtypes were categorized following the Hadden criteria. Of 536 patients with GBS, 7 (1.3%) had chicken pox within 4 weeks before GBS onset. Four of the seven cases were male (age range, 23 to 40 years old). All seven patients were bed-bound, six had sensory symptoms, and three required mechanical ventilation for respiratory failure. All seven patients had CSF albuminocytologic dissociation and evidence of demyelination in nerve conduction studies. Anti-VZV IgM antibodies were present and anti-GM1 and anti-Campylobacter jejuni lipo-oligosaccharides (LOS) were negative in all cases. All patients had excellent outcome at 1 year (able to run). A systematic literature review of GBS cases related to VZV revealed 39 previously reported patients with comparable clinical presentations and outcomes, of which 36 had neurophysiologic evidence of demyelination. VZV infection is associated with the demyelinating subtype of GBS, clearly distinct from the axonal form of GBS that predominate in countries like Bangladesh