An investigation on the role of ytterbium in ytterbium promoted y-alumina-supported nickel catalysts for dry reforming of methane

Addition of low quantities of ytterbium to sol-gel prepared Ni/yAl2O3 catalysts has been shown to lead to significant increases in catalytic activity and long term stability in the catalytic conversion of CO2 and CH4 into syngas (H2 and CO). The role of ytterbium in these catalysts was investigated in this study through detailed investigations on the structure and composition of ytterbium promoted Ni/y-Al2O3 catalysts using the following techniques: synchrotron X-ray diffraction, X-ray Photoemission Spectroscopy, Transmission Electron Microscopy, Scanning Electron Microscopy/Energy Dispersive X-ray analysis, Temperature Programmed Reduction techniques and N2 adsorption-desorption isotherms. The results obtained indicated that ytterbium, at small quantities (up to 2 wt%), interacted strongly with the support which in turn altered the interaction between nickel and the support (most notably it was found to completely inhibit the formation of NiAl2O4). This decreased interaction between Ni and the support also led to a higher quantity of Ni being present in the catalyst in the form of Ni

Regional patterns of transition at Çadir Höyük in the Byzantine period

Byzantine archaeological sites tend to be seen as representative of the empire as a whole, with little concern given to regional context. Within the imperial narrative that shapes Byzantine history, sites—whether urban or rural—are often used to explain and illustrate imperial trends. However, when we remove that overarching narrative, the sites in Anatolia provide the potential to view them as singular examples of local and regional identity. In this article, we have separated out four types of data: fortifications, coins, faunal material, and archaeobotanical evidence to illustrate how a close examination of the data provides new ways of understanding regional identity. In doing so, we posit that the Byzantine empire needs to be seen as a collection of local identities working alongside one another, but always expressing individual needs and resources

Comparison of some chemical parameters of a naturally debittered olive (Olea europaea L.) type with regular olive varieties

Some olives grown in Karaburun peninsula in the west part of Turkey and mostly coming from Erkence variety lose their bitterness while still on the tree and are called Hurma among locals. This olive type does not require further processing to remove the bitter compounds. In this study, sugar, organic acid and fatty acid profiles of Hurma, Erkence (not naturally debittered) and Gemlik (commonly consumed as table olive) olives were determined throughout 8 weeks of maturation period for two consecutive harvest seasons, and the results were analysed by principal component analysis (PCA). PCA of sugar and organic acid data revealed a differentiation in terms of harvest year but not on variety. Hurma olive is separated from others due to its fatty acid profile, and it has higher linoleic acid content compared to others. This might be an indication of increased desaturase enzyme activity for Hurma olives during natural debittering phase.TUBITAK (TOVAG-110O780

Wild food plants of popular use in Sicily

In the present work the authors report the result of their food ethnobotanical researches, which have been carried out in Sicily during the last thirty years. Data concerning 188 wild species used in the traditional Sicilian cuisine are reported. The authors underline those species that are partially or completely unknown for their culinary use and they illustrate other species that local inhabitants suggested in the prevention or treatment of symptomatologies caused by a refined diet, poor in vegetables. These data want to contribute to avoid the loss of traditional knowledge on uses and recipes concerning wild food botanicals, and to encourage further studies for those species that have not yet been sufficiently researched in their food chemical and nutritional profile. These studies may also suggest new applications for a few botanicals in medico-nutritional fields. The work includes also a short review of the seaweeds and mushrooms traditionally gathered and consumed in Sicily

Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

Biohydrogen production from kitchen based vegetable waste: Effect of pyrolysis temperature and time on catalysed and non-catalysed operation

Pyrolysis of kitchen based vegetable waste (KVW) was studied in a designed packed bed reactor. The effect of process parameters like temperature, time and catalyst on bio-gas yield and its composition was studied. The total bio-gas yield was found to be maximum with non-catalysed operation (260 ml/g) at 1073 K (180 min). Higher hydrogen (H2) yield with non-catalysed operation (32.68%) was observed at 1073 K (180 min) while with catalysed operation the requisite temperature (873 K) and time (120 min) reduced with both silica gel (33.34%) and sand (41.82%) thus, saving energy input. Methane (CH4) yield was found to be highest (4.44 times than non-catalysed and 1.42 with silica gel) in presence of sand (71.485 ml/g) at medium temperature (873 K) and time (60 min). The catalyst operation reduced the carbondioxide (CO2) share from 47.29% to 41.30% (silica gel catalysed) and 21.91% (sand catalysed) at 873 K

A comparison study on carbon dioxide reforming of methane over Ni catalysts supported on mesoporous SBA-15, MCM-41, KIT-6 and gamma-Al2

The activity of Ni supported on mesoporous SBA-15, MCM-41, KIT-6, and a sol-gel prepared Ni/g-Al2O3, for catalysing methane dry reforming was investigated. . The chemical and physical characteristics of the catalysts before and after catalytic testing were investigated using X-Ray diffraction, X-ray Photoemission Spectroscopy, Transmission Electron Microscopy, Scanning Electron Microscopy / Energy Dispersive X-ray analysis, Thermogravimeteric Analysis, Temperature Programmed Reduction techniques and N2 adsorption-desorption isotherms. The type and nature of support displayed significant influence on catalytic activity and stability. Among all the supported catalysts tested, the Ni/SBA-15 exhibited excellent catalytic performance in terms of catalytic conversion and long-term stability. The activity for the silica framework catalysts correlated strongly with the surface area and pore diameter of these materials with the degree of CH4 and CO2 conversions observed increasing with decreasing surface area and increasing pore diamete

An investigation on the role of lanthanide promoters in promoted gamma-alumina-supported nickel catalysts for dry reforming of methane

The influence of promoters (Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er and Tm) on the catalytic performance of sol-gel prepared Ni/g-Al2O3 catalysts in CO2 reforming of methane was investigated. The catalysts investigated were characterised using the following techniques: synchrotron X-Ray diffraction, X-ray Photoemission Spectroscopy, a Temperature Programmed Reduction technique and N2 adsorption-desorption isotherms. It was found that there was almost a linear relationship between catalyst activity and the extent to which nickel was reduced in the catalysts tested

Effect of pyrolysis parameters on yield and composition of gaseous products from activated sludge: towards sustainable biorefinery

Pyrolysis of activated sludge from sewage treatment was investigated in the presence and absence of silica and sand under varying conditions (temperature and retention time) in a fixed bed reactor. The presence of silica and sand had a significant impact on the amount of hydrogen and methane generated under the conditions studied, with both of these substances causing a significant reduction in hydrogen and methane yields compared to those obtained in the absence of these substances. The maximum yield of hydrogen was observed under the following conditions: no silica/sand, 1,073 K, 180 min. Maximum methane yield was observed to be under the following conditions: no silica/sand, 1,073 K, 180 min