Low severity Fischer-Tropsch synthesis for the production of synthetic hydrocarbon fuels

Currently, the main source for the production of liquid transportation fuels is petroleum, the continued use of which faces many challenges including depleting oil reserves, significant oil price rises, and environmental concerns over global warming which is widely believed to be due to fossil fuel derived CO2 emissions and other greenhouse gases. In this respect, lignocellulosic or plant biomass is a particularly interesting resource as it is the only renewable source of organic carbon that can be converted into liquid transportation fuels. The gasification of biomass produces syngas which can then be converted into synthetic liquid hydrocarbon fuels by means of the Fischer-Tropsch (FT) synthesis. This process has been widely considered as an attractive option for producing clean liquid hydrocarbon fuels from biomass that have been identified as promising alternatives to conventional fossil fuels like diesel and kerosene. The resulting product composition in FT synthesis is influenced by the type of catalyst and the reaction conditions that are used in the process. One of the issues facing this conversion process is the development of a technology that can be scaled down to match the scattered nature of biomass resources, including lower operating pressures, without compromising liquid composition. The primary aims of this work were to experimentally explore FT synthesis at low pressures for the purpose of process down-scaling and cost reduction, and to investigate the potential for obtaining an intermediate FT synthetic crude liquid product that can be integrated into existing refineries under the range of process conditions employed. Two different fixed-bed micro-reactors were used for FT synthesis; a 2cm3 reactor at the University of Rio de Janeiro (UFRJ) and a 20cm3 reactor at Aston University. The experimental work firstly involved the selection of a suitable catalyst from three that were available. Secondly, a parameter study was carried out on the 20cm3 reactor using the selected catalyst to investigate the influence of reactor temperature, reactor pressure, space velocity, the H2/CO molar ratio in the feed syngas and catalyst loading on the reaction performance measured as CO conversion, catalyst stability, product distribution, product yields and liquid hydrocarbon product composition. From this parameter study a set of preferred operating conditions was identified for low pressure FT synthesis. The three catalysts were characterized using BET, XRD, TPR and SEM. The catalyst selected was an unpromoted Co/Al2O3 catalyst. FT synthesis runs on the 20cm3 reactor at Aston were conducted for 48 hours. Permanent gases and light hydrocarbons (C1-C5) were analysed in an online GC-TCD/FID at hourly intervals. The liquid hydrocarbons collected were analyzed offline using GC-MS for determination of fuel composition. The parameter study showed that CO conversion and liquid hydrocarbon yields increase with increasing reactor pressure up to around 8 bar, above which the effect of pressure is small. The parameters that had the most significant influence on CO conversion, product selectivity and liquid hydrocarbon yields were reactor temperature and catalyst loading. The preferred reaction conditions identified for this research were: T = 230ºC, P = 10 bar, H2/CO = 2.0, WHSV = 2.2 h-1, and catalyst loading = 2.0g. Operation in the low range of pressures studied resulted in low CO conversions and liquid hydrocarbon yields, indicating that low pressure BTL-FT operation may not be industrially viable as the trade off in lower CO conversions and once-through liquid hydrocarbon product yields has to be carefully weighed against the potential cost savings resulting from process operation at lower pressures.

Crystal structure and magnetic behaviour of a five-coordinate iron(III) complex of pyridoxal-4-methylthiosemicarbazone

The crystal structure and magnetic properties of a penta-coordinate iron(III) complex of pyridoxal-4-methylthiosemicarbazone, [Fe(Hmthpy)Cl](CHCHSO), are reported. The synthesised ligand and the metal complex were characterised by spectroscopic methods (H NMR, IR, and mass spectroscopy), elemental analysis, and single crystal X-ray diffraction. The complex crystallises as dark brown microcrystals. The crystal data determined at 100(1) K revealed a triclinic system, space group P over(1, ¯) (Z = 2). The ONSCl geometry around the iron(III) atom is intermediate between trigonal bipyramidal and square pyramidal (t = 0.40). The temperature dependence of the magnetic susceptibility (5-300 K) is consistent with a high spin Fe(III) ion (S = 5/2) exhibiting zero-field splitting. Interpretation of these data yielded: D = 0.34(1) cm and g = 2.078(3). © 2007 Elsevier B.V. All rights reserved.

Experimental characterisation of the impact of neighbouring modulation-formats on 43Gb/s P-DPSK over SSMF and LEAF

We report an experimental characterisation examining the impact of differing 50GHz neighbouring modulation formats and bit rates on the performance of 43Gb/s P-DPSK over 1300km of SSMF and LEAF types. Performance is shown to be robust for hybrid P-DPSK and OOK systems. © VDE VERLAG GMBH.

Cu and Fe oxides dispersed on SBA-15:a Fenton type bimetallic catalyst for N,N-diethyl-p-phenyl diamine degradation

A bimetallic oxidation catalyst has been synthesized via wet impregnation of copper and iron over a mesoporous SBA-15 silica support. Physicochemical properties of the resulting material were characterized by XRD, N2 physisorption, DRUVS, FTIR, Raman, SEM and HRTEM, revealing the structural integrity of the parent SBA-15, and presence of highly dispersed Cu and Fe species present as CuO and Fe2O3. The CuFe/SBA-15 bimetallic catalyst was subsequently utilized for the oxidative degradation of N,N-diethyl-p-phenyl diamine (DPD) employing a H2O2 oxidant in aqueous solution.

Dielectric relaxation of polysiloxanes and kerr effect of p-phenylene vinylene oligomers

The dielectric relaxation behaviour of a series of cyclic and linear poly(dimethylsiloxanes) with overline nn in the range 28 to 99 has been studied, as a function of temperature (142.0K-157.5K) and frequency (12-105Hz). Activation energies for the -relaxation process, Davidson-Cole empirical distribution factors, , and mean-square dipole moments per repeat unit, < 2> , have been calculated. Differences in values of H_act reflected restricted dipolar rotation for the cyclic structures, compared to the linear structures, over the range of molecular weights studied. The dielectric relaxation behaviour of a series of linear oligomers of methyl phenyl siloxane, with n in the range 4 to 10, a series of linear fractions of poly(methyl phenyl siloxane), with overline n_n in the range 31 to 1370, and a cyclic oligomer of mehyl phenyl siloxane, with n = 10, has been studied as a function of temperature (155.5K-264.0K) and frequency (12-105Hz). Activation energies for the -relaxation process, Davidson-Cole and Cole-Cole empirical distribution factors, and , respectively, and mean-square dipole moments per repeat unit have been calculated. The reduced flexibility of short methyl phenyl siloxane chains, compared to dimethyl siloxane chains, was apparent from a comparison of dipole moment ratios. The dilectric relaxation behaviour of poly(methyl hydrogen siloxane) and poly(n-hexyl methyl siloxane) has been studied as a function of temperature and frequency. A polysiloxane liquid crystal has been synthesised and its dielectric relaxation behaviour has been studied, as a function of temperature and frequency, in the liquid crystalline phase and below T_g. Poly(p-phenylene vinylene) and related oligomers have been synthesised and characterised by a variety of experimental techniques. The Kerr effect of two oligomeric fractions, in solution in PPG 2025, has been measured. The electrical conductivities of the undoped and I_2-doped polymer and oligomers have been measured.

On the hydrophobicity of peptides:comparing empirical predictions of peptide log P values

Peptides are of great therapeutic potential as vaccines and drugs. Knowledge of physicochemical descriptors, including the partition coefficient logP, is useful for the development of predictive Quantitative Structure-Activity Relationships (QSARs). We have investigated the accuracy of available programs for the prediction of logP values for peptides with known experimental values obtained from the literature. Eight prediction programs were tested, of which seven programs were fragment-based methods: XLogP, LogKow, PLogP, ACDLogP, AlogP, Interactive Analysis's LogP and MlogP; and one program used a whole molecule approach: QikProp. The predictive accuracy of the programs was assessed using r(2) values, with ALogP being the most effective (r( 2) = 0.822) and MLogP the least (r(2) = 0.090). We also examined three distinct types of peptide structure: blocked, unblocked, and cyclic. For each study (all peptides, blocked, unblocked and cyclic peptides) the performance of programs rated from best to worse is as follows: all peptides - ALogP, QikProp, PLogP, XLogP, IALogP, LogKow, ACDLogP, and MlogP; blocked peptides - PLogP, XLogP, ACDLogP, IALogP, LogKow, QikProp, ALogP, and MLogP; unblocked peptides - QikProp, IALogP, ALogP, ACDLogP, MLogP, XLogP, LogKow and PLogP; cyclic peptides - LogKow, ALogP, XLogP, MLogP, QikProp, ACDLogP, IALogP. In summary, all programs gave better predictions for blocked peptides, while, in general, logP values for cyclic peptides were under-predicted and those of unblocked peptides were over-predicted.

Parental confidence in managing food allergy:development of the Food Allergy Self-Efficacy Scale for parents (FASE-P)

Background: Food allergy is often a life-long condition that requires constant vigilance in order to prevent accidental exposure and avoid potentially life-threatening symptoms. Parents’ confidence in managing their child’s food allergy may relate to the poor quality of life anxiety and worry reported by parents of food allergic children. Objective: The aim of the current study was to develop and validate the first scale to measure parental confidence (self-efficacy) in managing food allergy in their child. Methods: The Food Allergy Self-Efficacy Scale for Parents (FASE-P) was developed through interviews with 53 parents, consultation of the literature and experts in the area. The FASE-P was then completed by 434 parents of food allergic children from a general population sample in addition to the General Self-Efficacy Scale (GSES), the Food Allergy Quality of Life Parental Burden Scale (FAQL-PB), the General Health Questionnaire (GHQ12) and the Food Allergy Impact Measure (FAIM). A total of 250 parents completed the re-test of the FASE-P. Results: Factor and reliability analysis resulted in a 21 item scale with 5 sub-scales. The overall scale and sub-scales has good to excellent internal consistency (α’s of 0.63-0.89) and the scale is stable over time. There were low to moderate significant correlations with the GSES, FAIM and GHQ12 and strong correlations with the FAQL-PB, with better parental confidence relating to better general self-efficacy, better quality of life and better mental health in the parent. Poorer self-efficacy was related to egg and milk allergy; self-efficacy was not related to severity of allergy. Conclusions and clinical relevance: The FASE-P is a reliable and valid scale for use with parents from a general population. Its application within clinical settings could aid provision of advice and improve targeted interventions by identifying areas where parents have less confidence in managing their child’s food allergy.

[Review of] Ivo Mijnssen, The Quest for an Ideal Youth in Putin’s Russia I. Back to Our Future! History, Modernity and Patriotism According to Nashi, 2005–2012. Soviet and Post-Soviet Politics and Society, Stuttgart: Ibidem Verlag, 2012, 202pp., e 34.90 p/b

THE YOUTH MOVEMENT NASHI (OURS) WAS FOUNDED IN THE SPRING of 2005 against the backdrop of Ukraine’s ‘Orange Revolution’. Its aim was to stabilise Russia’s political system and take back the streets from opposition demonstrators. Personally loyal to Putin and taking its ideological orientation from Surkov’s concept of ‘sovereign democracy’, Nashi has sought to turn the tide on ‘defeatism’ and develop Russian youth into a patriotic new elite that ‘believes in the future of Russia’ (p. 15). Combining a wealth of empirical detail and the application of insights from discourse theory, Ivo Mijnssen analyses the organisation’s development between 2005 and 2012. His analysis focuses on three key moments—the organisation’s foundation, the apogee of its mobilisation around the Bronze Soldier dispute with Estonia, and the 2010 Seliger youth camp—to help understand Nashi’s organisation, purpose and ideational outlook as well as the limitations and challenges it faces. As such,the book is insightful both for those with an interest in post-Soviet Russian youth culture, and for scholars seeking a rounded understanding of the Kremlin’s initiatives to return a sense of identity and purpose to Russian national life.The first chapter, ‘Background and Context’, outlines the conceptual toolkit provided by Ernesto Laclau and Chantal Mouffe to help make sense of developments on the terrain of identity politics. In their terms, since the collapse of the Soviet Union, Russia has experienced acute dislocation of its identity. With the tangible loss of great power status, Russian realities have become unfixed from a discourse enabling national life to be constructed, albeit inherently contingently, as meaningful. The lack of a Gramscian hegemonic discourse to provide a unifying national idea was securitised as an existential threat demanding special measures. Accordingly, the identification of those who are ‘notUs’ has been a recurrent theme of Nashi’s discourse and activity. With the victory in World War II held up as a foundational moment, a constitutive other is found in the notion of ‘unusual fascists’. This notion includes not just neo-Nazis, but reflects a chain of equivalence that expands to include a range of perceived enemies of Putin’s consolidation project such as oligarchs and pro-Western liberals.The empirical background is provided by the second chapter, ‘Russia’s Youth, the Orange Revolution, and Nashi’, which traces the emergence of Nashi amid the climate of political instability of 2004 and 2005. A particularly note-worthy aspect of Mijnssen’s work is the inclusion of citations from his interviews with Nashicommissars; the youth movement’s cadres. Although relatively few in number, such insider conversations provide insight into the ethos of Nashi’s organisation and the outlook of those who have pledged their involvement. Besides the discussion of Nashi’s manifesto, the reader thus gains insight into the motivations of some participants and behind-the-scenes details of Nashi’s activities in response to the perceived threat of anti-government protests. The third chapter, ‘Nashi’s Bronze Soldier’, charts Nashi’s role in elevating the removal of a World War II monument from downtown Tallinn into an international dispute over the interpretation of history. The events subsequent to this securitisation of memory are charted in detail, concluding that Nashi’s activities were ultimately unsuccessful as their demands received little official support.The fourth chapter, ‘Seliger: The Foundry of Modernisation’, presents a distinctive feature of Mijnssen’s study, namely his ethnographic account as a participant observer in the Youth International Forum at Seliger. In the early years of the camp (2005–2007), Russian participants received extensive training, including master classes in ‘methods of forestalling mass unrest’ (p. 131), and the camp served to foster a sense of group identity and purpose among activists. After 2009 the event was no longer officially run as a Nashi camp, and its role became that of a forum for the exchange of ideas about innovation, although camp spirit remained a central feature. In 2010 the camp welcomed international attendees for the first time. As one of about 700 international participants in that year the author provides a fascinating account based on fieldwork diaries.Despite the polemical nature of the topic, Mijnssen’s analysis remains even-handed, exemplified in his balanced assessment of the Seliger experience. While he details the frustrations and disappointments of the international participants with regard to the unaccustomed strict camp discipline, organisational and communication failures, and the controlled format of many discussions,he does not neglect to note the camp’s successes in generating a gratifying collective dynamic between the participants, even among the international attendees who spent only a week there.In addition to the useful bibliography, the book is back-ended by two appendices, which provide the reader with important Russian-language primary source materials. The first is Nashi’s ‘Unusual Fascism’ (Neobyknovennyi fashizm) brochure, and the second is the booklet entitled ‘Some Uncomfortable Questions to the Russian Authorities’ (Neskol’ko neudobnykh voprosov rossiiskoivlasti) which was provided to the Seliger 2010 instructors to guide them in responding to probing questions from foreign participants. Given that these are not readily publicly available even now, they constitute a useful resource from the historical perspective.