7,321 research outputs found
Yeast metabolism in fresh and frozen dough : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, Palmerston North, New Zealand
No full textAuthor also known as SM LovedayFresh bakery products have a very short shelf life, which limits the extent to which manufacturing can be centralised. Frozen doughs are relatively stable and can be manufactured in large volumes, distributed and baked on-demand at the point of sale or consumption. With appropriate formulation and processing a shelf life of several months can be achieved.Shelf life is limited by a decline in proofing rate after thawing, which is attributed to a) the dough losing its ability to retain gas and b) insufficient gas production, i.e. yeast activity. The loss of shelf life is accelerated by delays between mixing and freezing, which allow yeast cells the chance to ferment carbohydrates.This work examined the reasons for insufficient gas production after thawing frozen dough and the effect of pre-freezing fermentation on shelf life. Literature data on yeast metabolite dynamics in fermenting dough were incomplete. In particular there were few data on the accumulation of ethanol, a major fermentation end product which can be injurious to yeast.Doughs were prepared in a domestic breadmaker using compressed yeast from a local manufacturer and analysed for glucose, fructose, sucrose, maltose and ethanol. Gas production after thawing declined within 48 hours of frozen storage. This was accelerated by 30 or 90 minutes of fermentation at 30;C prior to freezing.Sucrose was rapidly hydrolysed and yeast consumed glucose in preference to fructose. Maltose was not consumed while other sugars remained. Ethanol, accumulated from consumption of glucose and fructose, was produced in approximately equal amounts to CO2, indicating that yeast cells metabolised reductively.Glucose uptake in fermenting dough followed simple hyperbolic kinetics and fructose uptake was competitively inhibited by glucose. Mathematical modelling indicated that diffusion of sugars and ethanol in dough occurred quickly enough to eliminate solute gradients brought about by yeast metabolism
Genetic diversity trends in twentieth century crop cultivars: a meta analysis
No full textIn recent years, an increasing number of papers has been published on the genetic diversity trends in crop cultivars released in the last century using a variety of molecular techniques. No clear general trends in diversity have emerged from these studies. Meta analytical techniques, using a study weight adapted for use with diversity indices, were applied to analyze these studies. In the meta analysis, 44 published papers were used, addressing diversity trends in released crop varieties in the twentieth century for eight different field crops, wheat being the most represented. The meta analysis demonstrated that overall in the long run no substantial reduction in the regional diversity of crop varieties released by plant breeders has taken place. A significant reduction of 6% in diversity in the 1960s as compared with the diversity in the 1950s was observed. Indications are that after the 1960s and 1970s breeders have been able to again increase the diversity in released varieties. Thus, a gradual narrowing of the genetic base of the varieties released by breeders could not be observed. Separate analyses for wheat and the group of other field crops and separate analyses on the basis of regions all showed similar trends in diversity
Reversible expression of sm α-actin protein and sm α-actin mRNA in cloned cerebral endothelial cells
No full textAbstractThe expression of smooth muscle (sm) α-actin was studied in cloned capillary cerebral endothelial cells of two phenotypes. Type I cells were cultured in medium containing 10% FCS, heparin and ECGS (or α-ECGF) and stained positive for a specific endothelial cell marker (Bandeiraea simplicifolia). Depletion of heparin and ECGS resulted in a smooth muscle-like appearance after 2–3 days. Cells of this phenotype, (type II) stained positive for the endothelial cell marker and for sm α-actin. In contrast to type I cells, type II cells expressed sm α-actin protein and mRNA as evidenced by Immunoblots and Northern blots. This phenotypic switch was shown to be reversible and so was the expression of sm α-actin
Converting SrI <sub>2</sub> :Eu <sup>2+</sup> into a near infrared scintillator by Sm <sup>2+</sup> co-doping
No full text The luminescence and scintillation properties of SrI 2 single crystals doped with 5% Eu 2+ and 0.05%, 0.2% and 0.5% Sm 2+ are evaluated. X-ray excited and photoluminescence measurements show energy transfer from excited Eu 2+ ions to Sm 2+ ions. At a concentration of 0.5% Sm 2+ , the luminescence consists almost entirely of 740 nm emission from Sm 2+ 5d-4f transitions. Co-doping SrI 2 :5% Eu 2+ with Sm 2+ provides a novel method to bypass the self-absorption problem encountered in large SrI 2 :Eu 2+ crystals and, at the same time, provides a unique near-infrared emitting scintillator with a light yield of approximately 40,000 photons/MeV. Accepted Author ManuscriptRST/Fundamental Aspects of Materials and EnergyRST/Luminescence Material
Small-signal modelling and stability analysis of a traditional generation unit and a virtual synchronous machine in grid-connected operation
No full textThe virtual synchronous machine (VSM) concept has emerged as an approach to provide flexible distributed control of power electronic converters interfacing distributed energy resources with the grid. It supports power system operation by providing ancillary services, and facilitates a seamless transition between grid-connected and islanded operation. In this work, previous small-signal modelling and analysis carried out for a VSM implementation has been adapted and expanded to include a synchronous machine (SM) with a control scheme similar to those of traditional generation units and to the one used in the VSM implementation. A nonlinear state-space analytical model has been developed for a traditional power generation unit in grid-connected mode (SM system). The model allows the study of the SM system in similar conditions/context as the grid-connected VSM implementation (VSM system), and facilitates their comparison. Moreover, it can represent the most relevant dynamic characteristics of a round or salient-pole rotor SM, including the amortisseur circuits or the representation of the corresponding damping torque in the swing equation of a reduced-order version of the model. The developed model has been linearised analytically, to obtain the respective small-signal model. The eigenvalue analysis of the modelled systems has indicated that most of the SM system eigenvalues (modes) are slower or not as well damped as the VSM system ones. Moreover, most SM system modes have shown to be relatively fixed and determined mainly by non-tunable parameters. The modelled exciter has presented little capability of increasing the damping of oscillations, and its integral gain has demonstrated to be the tunable parameter that can most easily cause instability in the SM system. The location of the 4 slowest and least damped SM system eigenvalues has shown to be limited by non-tunable parameters, indicating that the performance or robustness of such system cannot be significantly improved. A trade-off has been observed in the placement of the VSM system critical modes: increasing the virtual inductance improves the damping of oscillations, while making the system response slower. However, parametric sweep analysis has indicated that a good compromise between performance and robustness could be achieved by decreasing the virtual inductance and increasing the phase lock loop proportional gain.European Wind Energy MasterElectrical Sustainable EnergyElectrical Engineering, Mathematics and Computer Scienc
'Laws 'Needefull in Later to be Abrogated': Intersex and the Sources of Christian Theology
No full textThis is the author accepted manuscript. The final version is available from Palgrave Macmillan via the DOI in this record
Introduction: Troubling Bodies?
No full textThis is the author accepted manuscript. The final version is available from Palgrave Macmillan via the DOI in this record
Intrafullerene electron transfers in Sm-containing metallofullerenes: Sm@C-2n (74 <= 2n <= 84)
No full textThe electronic properties of Sm-containing metallofullerenes, Sm@C-74, Sm@C-76 (I, II), Sm@C-78, Sm@C-80, Sm@C-82 (I, II, III) and Sm@C-84 (I, II, III), are characterized by UV-Vis-NIR absorption spectroscopy and electron energy-loss spectroscopy (EELS). the UV-Vis-NIR absorption spectra of Sm@C-74, Sm@C-80, Sm@C-82 (I, II, III) and Sm@C-84 (I, II) are quite similar to those of the corresponding Ca, Sr, Ba, Eu, Tm, Yb-based metallofullerenes. In contrast, the absorption spectra of Sm@C-76 (I, II), Sm@C-78 and Sm@C-84(III) show a novel feature: the onset for Sm@C-78 is observed similar to 2600 nm, which corresponds to a small band gap (similar to0.5 eV). Furthermore, the oxidation states of Sm atom in the various fullerene cages are investigated by EELS, which reveals that the Sm atom takes +2 oxidation state in the fullerene cages. A probable rationale for the tendency to have the Sm2+ state is presented based on a simple thermochemical cycle model. (C) 2001 by Elsevier Science Inc.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000168906500014&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Biochemical Research MethodsBiochemistry & Molecular BiologyComputer Science, Interdisciplinary ApplicationsCrystallographyMathematical & Computational BiologySCI(E)EI30ARTICLE2244-2511
beta-decay spectroscopy of neutron-rich Sm-160,Sm-161,Sm-162 isotopes
No full textNeutron-rich Sm-160,Sm-161,Sm-162 isotopes have been populated at the RIBF, RIKEN via beta decay for the first time. beta-coincident gamma rays were observed in all three isotopes including gamma rays from the isomeric decay of Sm-160 and Sm-162. The isomers in Sm-160 and Sm-162 have previously been observed but have been populated via beta decay for the first time. The isomeric state in Sm-162 is assigned a 4(-) nu 7/2(+)[633]circle times nu 1/2(-)[521] configuration based on the decay pattern. The level schemes of Sm-160 and Sm-162 are presented. The ground states in the parent nuclei Pm-160 and Pm-162 are both assigned a 6(-) nu 7/2(+)[633]circle times pi 5/2(-)[532] configuration based on the population of states in the daughter nuclei. Blocked BCS calculations were performed to further investigate the spin-parities of the ground states in Pm-160, Pm-161, and Pm-162, and the isomeric state in Sm-162.CPCI-S(ISTP)[email protected]
Discovering the Similarities between SM Communities and Other Organizations
No full textThe current research study is comparing and contrasting the demographic diversity of Sadomasochist (SM) organizations and other community organizations by surveying an SM organization and a non-SM organization. A confidential online survey was used to collect data. Fourteen general questions were asked: age, gender, sexual orientation, relationship status, number of children, ethnicity, highest level of education completed, employment, hours worked, income, religious affiliation, personality, infidelity and self esteem. Data was analyzed using Levene\u27s test and t-tests. Relationship status and religion were two differences between the SM group and the non SM group. The author discusses limitations and future directions of this study
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