5,316 research outputs found
A coordinated voltage control approach for coordination of OLTC, voltage regulator, and DG to regulate voltage in a distribution feeder
No full textIntegration of small-scale electricity generators, known as distributed generation (DG), into the distribution networks has become increasingly popular at the present. This tendency together with the falling price of the synchronous-type generator has potential to give DG a better chance at participating in the voltage regulation process together with other devices already available in the system. The voltage control issue turns out to be a very challenging problem for the distribution engineers since existing control coordination schemes would need to be reconsidered to take into account the DG operation. In this paper, we propose a control coordination technique, which is able to utilize the ability of DG as a voltage regulator and, at the same time, minimize interaction with other active devices, such as an on-load tap changing transformer and a voltage regulator. The technique has been developed based on the concept of control zone, line drop compensation, dead band, as well as the choice of controllers' parameters. Simulations carried out on an Australian system show that the technique is suitable and flexible for any system with multiple regulating devices including DG
Pushing the Boundaries: DG Enlargement between Internal and External Environments. College of Europe EU Diplomacy Paper 7/2010
No full textStudies of EU enlargement generally take as their subject the motivations for a country’s accession; rarely do they analyse in great detail any of the steps in the process itself. My contribution to the literature is an analysis of DG Enlargement in its role as a boundary spanner during the pre-accession period. One of the key boundary-spanning tasks exercised by the DG is to provide information about the organisation, its operations, and its management to the external environment. To answer the questions to what extent DG Enlargement can be characterised as a boundary spanner, and how the relevance of this characterisation might have changed over time, I examine DG Enlargement’s performance during the 2004 enlargement round and the critical self-assessment it undertook thereafter to determine whether lessons learnt have resulted in changed behaviour. In order to maximise evidence of boundary-spanning behaviour, I have chosen DG Enlargement’s management of the Copenhagen criterion of minority rights protection as my case study: with the condition absent from the acquis, DG ELARG must persuade membership aspirants to adopt this norm by other means. I will argue that DG Enlargement did act as a boundary spanner during the 2004 enlargement round, but that its assimilation of lessons learned has not dramatically affected its current behaviour. Despite disseminating the findings of its internal evaluations widely throughout the EU, political unwillingness to come to an agreement on common standards of minority rights protection prevents DG ELARG from improving its performance other than at the margins
Glycolytic gene expression correlates with MM patient survival and increased glucose uptake can induce 2-DG-mediated oxidative and ER stress in of CD138<sup>low</sup> cells.
No full textKaplan–Meier graphs from TT2 trial clustered on glycolytic gene signatures (HK2, ALDOA, TPI1, GAPDH, PGK1, PKM2, and LDHA) showing cumulative probabilities of A. OS and B. EFS in MM patients. Glucose uptake assays in HMCLs cultured under C. normoxia or D. hypoxia for 3 days. Cells were incubated with 2-NBDG followed by APC-CD138 staining and flow analysis. For panel C, mean fluorescence values (MFI) values was normalized to CD138high cells and presented fold change. *p low and CD138high separately and depicted as hypoxia-induced fold change. *p high cells under normoxia, #p low cells under normoxia. E. MM.1S and OPM-2 cells were treated without or with 2-DG for 1.5 h followed by DHE staining and flow analysis. Normalized MFI relative to CD138high cells are shown. MM.1S and OPM-2 cells were treated with 2-DG and/or mannose or 24 h followed by F. qRT-PCR analysis of BiP or ATF4 G. Western blot analysis for BiP (78 kDa), CHOP (27 kDa) or β-actin (42 kDa, loading control), tunicamycin (TM, 5 μM is used as a positive control. The quantification of BiP after normalization to untreated control is shown below each band. For panels D-F, bars represent mean of three independent runs ± SEM; *p high or control untreated cells, #p low or 2-DG treated cells.</p
Discontinuous Galerkin Methods for Numerical Weather Prediction: DG in a large-eddy simulation
No full textThe coarse grid of numerical weather prediction and climate models requires parametrization models to resolve atmospheric processes that are smaller than the grid size. For parametrization development, these processes are simulated by a high resolution model. At the Royal Netherlands MeteorologicalInstitute, the Dutch Atmospheric Large-Eddy Simulation (DALES) is used. This three-dimensional high resolution model uses advection schemes that are too diffusive when steep gradients are present. In this thesis, an advection scheme based on the Discontinuous Galerkin (DG) method is implementedfor DALES.The DG method is known to be dispersive. To remove those non-physical oscillations, the moment limiter of Krivodonova is used. Krivodonova constructed the limiter for one- and two-dimensions. In this thesis the moment limiter and limiting order are derived for three-dimensions. DALES is a model based on the finite difference method and uses operational splitting. Therefore, the DG advection scheme needs a mapping from each cell average to all nodal values that are needed for one DG cell, and a mapping back, which we called mapping a and b respectively. Mappings a that are discussed are taking the cell average as value for all nodal points of the DG cell (cell average a), and taking the L -projection of the cell average to the continuous finite element space (L -projection). This thesis describes mappings b that calculate cell averages of nodal DG values (cell average b)and calculate the cell averages of the tendencies of DG values (cell average of tendency). Using cell average a combined with cell average of tendency, made the DG method as diffusive as the first order upwind scheme. Substituting the cell average a method with the L -projection, the DG method becamevery dispersive, meaning that there was not enough diffusion. At last, cell average b was tested with the L -projection. Its numerical results showed that the speed of the advection was slower than the theoretical velocity. Therefore, a method is suggested which does not need mappings. An option couldbe a supergrid that takes multiple DALES cells as a DG cell.Applied Mathematic
Increasing Distributed Generation Penetration using Soft Normally-Open Points
No full textThis paper considers the effects of various voltage control solutions on facilitating an increase in allowable levels of distributed generation installation before voltage violations occur. In particular, the voltage control solution that is focused on is the implementation of `soft' normally-open points (SNOPs), a term which refers to power electronic devices installed in place of a normally-open point in a medium-voltage distribution network which allows for control of real and reactive power flows between each end point of its installation sites. While other benefits of SNOP installation are discussed, the intent of this paper is to determine whether SNOPs are a viable alternative to other voltage control strategies for this particular application. As such, the SNOPs ability to affect the voltage profile along feeders within a distribution system is focused on with other voltage control options used for comparative purposes. Results from studies on multiple network models with varying topologies are presented and a case study which considers economic benefits of increasing feasible DG penetration is also given
Dg algebras with enough idempotents, their dg modules and their derived categories
No full textWe develop the theory dg algebras with enough idempotents and their dg modules and show their equivalence with that of small dg categories and their dg modules. We introduce the concept of dg adjunction and show that the classical covariant tensor-Hom and contravariant Hom-Hom adjunctions of modules over associative unital algebras are extended as dg adjunctions between categories of dg bimodules. The corresponding adjunctions of the associated triangulated functors are studied, and we investigate when they are one-sided parts of bifunctors which are triangulated on both variables. We finally show that, for a dg algebra with enough idempotents, the perfect left and right derived categories are dual to each other.The author is highly indebted to Alexander Zimmermann for the careful reading of these notes, for his comments and for his help in improving the presentation. This work is backed by reseach projects from the Ministerio de Economía y Competitividad of Spain(MTM201346837-P and MTM201677445-P) and the Fundación ’Séneca’ of Murcia(19880/GERM/15), both with a part of FEDER funds. We thank these institutions for their support
2-DG-mediated reduction of viral protein expression.
No full text24 h after seeding, A549 cells were infected with SC35M at the depicted MOIs for 30 min and were incubated with 25 mM glucose and the indicated concentrations of 2-DG for a total of (A-E) 24 h or (F-J) 8 h. Protein lysates of triplicates were unified to yield sufficient protein amounts. Proteins were separated via SDS-PAGE. Visualization was done using primary antibodies against PA (rabbit), M1 (mouse), NP (rabbit), NS1 (rabbit) and ERK2 (rabbit) and fluorescence-labelled anti-mouse (donkey) and anti-rabbit (donkey) secondary antibodies. Depicted are representative protein bands from one out of three independent experiments. (B-E, G-J) Densitometric analyses were performed to quantify protein accumulation by first normalizing viral proteins to the loading control ERK2 and then normalizing all other samples to the infected but untreated sample. Depicted are the means ± SD of three independent experiments. Statistical significances were determined via unpaired one-way ANOVA and Dunnett’s correction, comparing all other samples to the infected but untreated sample (second lane). p-values are indicated as follows: < 0.05 = *, < 0.01 = **, < 0.001 = ***, < 0.0001 = ****.</p
Life cycle comparison of petroleum- and bio-based paper binder from distillers grains (DG)
No full textAbstractThis study presents a comparative cradle-to-gate life cycle assessment (LCA) of distillers grain (DG) gum, a bio-based paper coating binder, and polyvinyl alcohol (PVA). Non-renewable energy use, greenhouse gas (GHG) emissions, and eutrophication potential were assessed for each binder. Economic, mass, and energy allocation were used to allocate the impacts of DG gum production with co-products (ethanol and livestock feed). DG production non-renewable energy use (269 to 183MJ) surpassed that associated with PVA production (168MJ). GHG emissions from DG gum production under mass and energy allocations were 28% and 37% lower than PVA production emissions, respectively. Corn cultivation is responsible for 55% to 78% of the eutrophication impacts of DG gum production under energy and economic allocation, respectively. Changes to natural gas consumption and fertilizer runoff had the largest influence on total energy use, GHG emissions, and eutrophication potential of DG gum production
The DG-category of secondary cohomology operations
No full textWe study track categories (i.e., groupoid-enriched categories) endowed with additive structure similar to that of a 1-truncated DG-category, except that composition is not assumed right linear. We show that if such a track category is right linear up to suitably coherent correction tracks, then it is weakly equivalent to a 1-truncated DG-category. This generalizes work of the first author on the strictification of secondary cohomology operations. As an application, we show that the secondary integral Steenrod algebra is strictifiable
Coderived and contraderived categories of locally presentable abelian DG-categories
No full textThe concept of an abelian DG-category, introduced by the first-named author in arXiv:2110.08237, unites the notions of abelian categories and (curved) DG-modules in a common framework. In this paper we consider coderived and contraderived categories in the sense of Becker. Generalizing some constructions and results from the preceding papers by Becker arXiv:1205.4473 and by the present authors arXiv:2101.10797, we define the contraderived category of a locally presentable abelian DG-category with enough projective objects and the coderived category of a Grothendieck abelian DG-category . We construct the related abelian model category structures and show that the resulting exotic derived categories are well-generated. Then we specialize to the case of a locally coherent Grothendieck abelian DG-category , and prove that its coderived category is compactly generated by the absolute derived category of finitely presentable objects of , thus generalizing a result from the second-named author\u27s preprint arXiv:1412.1615. In particular, the homotopy category of graded-injective left DG-modules over a DG-ring with a left coherent underlying graded ring is compactly generated by the absolute derived category of DG-modules with finitely presentable underlying graded modules. We also describe compact generators of the coderived categories of quasi-coherent matrix factorizations over coherent schemes.LaTeX 2e with xy-pic and one mathb symbol; 76 pages, 1 figure; v.2: a discussion of quasi-coherent matrix factorizations over coherent schemes added in a new Section 9; new Corollary 0.4, Sections 1.10 and 2.7, Examples 3.15, 6.12, 7.8, 8.8, and 8.10 inserted; a paragraph added at the end of Section 2.1, 4th paragraph of the introduction expanded; v.3: several misprints correcte
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