12 research outputs found

    Improved THETA-1 for light olefins oligomerization to diesel: Influence of textural and acidic properties

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    The increase in diesel demand, especially in Europe, and the need for high fuel quality requirements are forcing refiners to move into additional processes for production of high cetane diesel in order to meet the present market trends. Oligomerization of light olefins into middle distillate range products is a viable option. The fuel produced through this technology is environmentally friendly, free of sulfur and aromatics, and the adequate choice of the heterogeneous catalyst will direct the selectivity towards low branched oligomers, which will result in a high quality product. In this work we show the benefits of combining basic desilication treatments for generation of additional mesoporosity in mono-directional Theta-1 zeolite, with selective acid dealumination steps that restore not only the microporosity to values close to those of the parent samples, but also the total and strong Bronsted acidity. These modified Theta-1 zeolites present an outstanding catalytic behavior for oligomerization of propene, with a largely increased initial activity, a much higher resistance to deactivation with time on stream, and an improved selectivity to products in the diesel fraction, as compared to the original microporous Theta-1.The authors thank BP Products of North America for their financial support and permission to publish this work, and Consolider Ingenio 2010-Multicat, the "Severo Ochoa Program", and MAT2012-31657 for financial support. R. Sanchis is acknowledged for technical support.Martínez, C.; Doskocil, EJ.; Corma Canós, A. (2014). Improved THETA-1 for light olefins oligomerization to diesel: Influence of textural and acidic properties. Topics in Catalysis. 57(6-9):668-682. https://doi.org/10.1007/s11244-013-0224-xS668682576-9Bellussi G, Mizia F, Calemma V, Pollesel P, Millini R (2012) Microporous Mesoporous Mater 164:127–134Bellussi G, Carati A, Millini R (2010) In: Cejka J, Corma A, Zones S (eds) Zeolites and Catalysis. Wiley-VCH Verlag GmbH & Co., Weinheim, pp 449–491Martinez C, Corma A (2011) Coord Chem Rev 255:1558–1580de Klerk A (2005) Ind Eng Chem Res 44:3887–3893de Klerk A (2006) Energy Fuels 20:439–445de Klerk A (2006) Energy Fuels 20:1799–1805Egloff G (1936) Ind Eng Chem Res 28:1461–1467Degnan TF Jr, Smith CM, Venkat CR (2001) Appl Catal A Gen 221:283–294Apelian MR, Boulton JR, Fung AS (1994) US5284989, to Mobil OilQuann RJ, Green LA, Tabak SA, Krambeck FJ (1988) Ind Eng Chem Res 27:565–570Tabak SA, Krambeck FJ, Garwood WE (1986) AIChE J 32:1526–1531Corma A, Martínez C, Doskocil EJ (2013) J Catal 300:183–196Martens JA, Ravishankar R, Mishin IE, Jacobs PE (2000) Angew Chem Int Ed Engl 39:4376–4379Martens JA, Verrelst WH, Mathys GM, Brown SH, Jacobs PA (2005) Angew Chem Int Ed Engl 117(5833–583):6Pater JPG, Jacobs PA, Martens JA (1998) J Catal 179:477–482Tabak SA (1981) US4254295, to Mobil OilOccelli ML, Hsu JT, Galya LG (1985) J Mol Catal A: Chem 32:377–390Tabak SA (1984) US4504693, to Mobil Oil CorpKholer E, Schmidt F, Wernicke HJ, Pontes MD, Roberts HL (1995, Summer) Hydrocarbon Technology InternationalMartens JA, Verduijn JP (1995) WO95/19945, to Exxon Chemical Patents Inc.Verrelst WH (1995) Martens LRM, WO95/22516, to Exxon Chemical Patents Inc.Verrelst WH, Martens LRM (2000) US6143942, to Exxon Chemical Patents Inc.Verrelst WH, Martens LRM, Verduijn JP (2006) US6013851, to Exxon Chemical Patents Inc.Dakka JM, Mathys GMK, Puttemans MPH (2003) WO03/035583 to Exxon-Mobil Chemical LimitedMatias P, Sa CC, Graca I, Lopes JM, Carvalho AP, Ramoa RF, Guisnet M (2011) Appl Catal A 399:100–109Chal R, Gérardin C, Bulut M, van Donk S (2011) ChemCatChem 3:67–81Perez-Ramirez J, Christensen CH, Egeblad K, Groen JC (2008) Chem Soc Rev 37:2530–2542Verboekend D, Perez-Ramirez J (2011) Catal Sci Technol 1:879–890Serrano DP, Escola JM, Pizarro P (2013) Chem Soc Rev 42:4004–4035Verboekend D, Chabaneix AM, Thomas K, Gilson JP, Perez-Ramirez J (2011) Cryst Eng Comm 13:3408–3416Emeis CA (1993) J Catal 141:347–354Perego C, Peratello S (1999) Catal Today 52:133–145Abello S, Bonilla A, Perez-Ramirez J (2009) Appl Catal A Gen 364:191–198Corma A, Martinez C, Doskocil EJ, Yaluris G (2011) WO2011002631A2, to BP Oil International Limited. BP Corporation North America Inc., UKCorma A, Martinez C, Doskocil EJ, Yaluris G (2011) WO2011002630A2, to BP Oil International Limited. BP Corporation North America Inc, UKHan S, Heck RH, DiGuiseppi FT (1993) US5234875, to Mobil Oil CorporationPeratello S, Molinari M, Bellussi G, Perego C (1999) Catal Today 52:271–27

    Acute ingestion of a novel whey-derived peptide improves vascular endothelial responses in healthy individuals: a randomized, placebo controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Whey protein is a potential source of bioactive peptides. Based on findings from <it>in vitro </it>experiments indicating a novel whey derived peptide (NOP-47) increased endothelial nitric oxide synthesis, we tested its effects on vascular function in humans.</p> <p>Methods</p> <p>A randomized, placebo-controlled, crossover study design was used. Healthy men (n = 10) and women (n = 10) (25 ± 5 y, BMI = 24.3 ± 2.3 kg/m<sup>2</sup>) participated in two vascular testing days each preceded by 2 wk of supplementation with a single dose of 5 g/day of a novel whey-derived peptide (NOP-47) or placebo. There was a 2 wk washout period between trials. After 2 wk of supplementation, vascular function in the forearm and circulating oxidative stress and inflammatory related biomarkers were measured serially for 2 h after ingestion of 5 g of NOP-47 or placebo. Macrovascular and microvascular function were assessed using brachial artery flow mediated dilation (FMD) and venous occlusion strain gauge plethysmography.</p> <p>Results</p> <p>Baseline peak FMD was not different for Placebo (7.7%) and NOP-47 (7.8%). Placebo had no effect on FMD at 30, 60, and 90 min post-ingestion (7.5%, 7.2%, and 7.6%, respectively) whereas NOP-47 significantly improved FMD responses at these respective postprandial time points compared to baseline (8.9%, 9.9%, and 9.0%; <it>P </it>< 0.0001 for time × trial interaction). Baseline reactive hyperemia forearm blood flow was not different for placebo (27.2 ± 7.2%/min) and NOP-47 (27.3 ± 7.6%/min). Hyperemia blood flow measured 120 min post-ingestion (27.2 ± 7.8%/min) was unaffected by placebo whereas NOP-47 significantly increased hyperemia compared to baseline (29.9 ± 7.8%/min; <it>P </it>= 0.008 for time × trial interaction). Plasma myeloperoxidase was increased transiently by both NOP-47 and placebo, but there were no changes in markers inflammation. Plasma total nitrites/nitrates significantly decreased over the 2 hr post-ingestion period and were lower at 120 min after placebo (-25%) compared to NOP-47 (-18%).</p> <p>Conclusion</p> <p>These findings indicate that supplementation with a novel whey-derived peptide in healthy individuals improves vascular function.</p

    Reciprocal effects of victimization and routine activities

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    Although there is much research on the relationship between routine activities and victimization, we have little knowledge about the reciprocal effects of victimization and routine activities. The current paper is framed within the Once Bitten Twice Shy perspective proposed by Hindelang et al. (Victims of personal crime: an empirical foundation for a theory of personal victimization. Ballinger, Cambridge, 1978) which argues that victimization decreases risky routine activities and that this in turn decreases the risk of victimization. The current paper tests these propositions by using longitudinal data from the National Crime Victimization Survey, which allows us to tease out victimization and routine activities over time. Both violent and household victimization are examined. Variables pertaining to how often respondents go out for shopping, how often they go away at night and whether they have household devices are used as indicators for routine activities. Results indicate that the reciprocal effects of victimization and routine activities are limited. Consequences for routine activities theory are discusse
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