Control of Energy Storage with Market Impact: Lagrangian Approach and Horizons

We study the control of large scale energy storage operating in a market. Re-optimization of deterministic models is a common pragmatic approach when prices are stochastic. We apply Lagrangian theory to develop such a model and to establish decision and forecast horizons when storage trading affects these prices, an important aspect of some energy markets. The determination of these horizons also provides a simple and efficient algorithm for the determination of the optimal control. The forecast horizons vary between one and fifteen days in realistic electricity storage examples. These examples suggest that modelling price impact is important

Increased epidermal thickness and abnormal epidermal differentiation in keloid scars

Background: The pathogenesis underlying keloid formation is still poorly understood. Research has focused mostly on dermal abnormalities, while the epidermis has not yet been studied. Objectives: To identify differences within the epidermis of mature keloid scars compared with normal skin and mature normotrophic and hypertrophic scars. Methods: Rete ridge formation and epidermal thickness were evaluated in tissue sections. Epidermal proliferation was assessed using immunohistochemistry (Ki67, keratins 6, 16 and 17) and with an in vitro proliferation assay. Epidermal differentiation was evaluated using immunohistochemistry (keratin 10, involucrin, loricrin, filaggrin, SPRR2, SKALP), reverse-transcriptase polymerase chain reaction (involucrin) and transmission electron microscopy (stratum corneum). Results: All scars showed flattening of the epidermis. A trend of increasing epidermal thickness correlating to increasing scar abnormality was observed when comparing normal skin, normotrophic scars, hypertrophic scars and keloids. No difference in epidermal proliferation was observed. Only the early differentiation marker involucrin showed abnormal expression in scars. Involucrin was restricted to the granular layer in healthy skin, but showed panepidermal expression in keloids. Normotrophic scars expressed involucrin in the granular and upper spinous layers, while hypertrophic scars resembled normotrophic scars or keloids. Abnormal differentiation was associated with ultrastructural disorganization of the stratum corneum in keloids compared with normal skin. Conclusions: Keloids showed increased epidermal thickness compared with normal skin and normotrophic and hypertrophic scars. This was not due to hyperproliferation, but possibly caused by abnormal early terminal differentiation, which affects stratum corneum formation. Our findings indicate that the epidermis is associated with keloid pathogenesis and identify involucrin as a potential diagnostic marker for abnormal scarring

Random-phase approximation and its applications in computational chemistry and materials science

The random-phase approximation (RPA) as an approach for computing the electronic correlation energy is reviewed. After a brief account of its basic concept and historical development, the paper is devoted to the theoretical formulations of RPA, and its applications to realistic systems. With several illustrating applications, we discuss the implications of RPA for computational chemistry and materials science. The computational cost of RPA is also addressed which is critical for its widespread use in future applications. In addition, current correction schemes going beyond RPA and directions of further development will be discussed.Comment: 25 pages, 11 figures, published online in J. Mater. Sci. (2012

Differential Detection of Genetic Loci Underlying Stem and Root Lignin Content in Populus

In this study, we established a comprehensive genetic map with a large number of progeny from a three-generation hybrid Populus intercross, and phenotyped the lignin content, S/G ratio and 28 cell wall subcomponents both in stems and roots for the mapping individuals. Phenotypic analysis revealed that lignin content and syringyl-to-guaiacyl (S/G) ratio using pyrolysis molecular beam mass spectroscopy (pyMBMS) varied among mapping individuals. Phenotypic analysis revealed that stem lignin content is significantly higher than that in root and the quantified traits can be classified into four distinct groups, with strong correlations observed among components within organs. Altogether, 179 coordinating QTLs were detected, and they were co-localized into 49 genetic loci, 27 of which appear to be pleiotropic. Many of the detected genetic loci were detected differentially in stem and root. This is the first report of separate genetic loci controlling cell wall phenotypes above and below ground. These results suggest that it may be possible to modify lignin content and composition via breed and/or engineer as a means of simultaneously improving Populus for cellulosic ethanol production and carbon sequestration

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Modification and re-validation of the ethyl acetate-based multi-residue method for pesticides in produce

The ethyl acetate-based multi-residue method for determination of pesticide residues in produce has been modified for gas chromatographic (GC) analysis by implementation of dispersive solid-phase extraction (using primary–secondary amine and graphitized carbon black) and large-volume (20 μL) injection. The same extract, before clean-up and after a change of solvent, was also analyzed by liquid chromatography with tandem mass spectrometry (LC–MS–MS). All aspects related to sample preparation were re-assessed with regard to ease and speed of the analysis. The principle of the extraction procedure (solvent, salt) was not changed, to avoid the possibility invalidating data acquired over past decades. The modifications were made with techniques currently commonly applied in routine laboratories, GC–MS and LC–MS–MS, in mind. The modified method enables processing (from homogenization until final extracts for both GC and LC) of 30 samples per eight hours per person. Limits of quantification (LOQs) of 0.01 mg kg−1 were achieved with both GC–MS (full-scan acquisition, 10 mg matrix equivalent injected) and LC–MS–MS (2 mg injected) for most of the pesticides. Validation data for 341 pesticides and degradation products are presented. A compilation of analytical quality-control data for pesticides routinely analyzed by GC–MS (135 compounds) and LC–MS–MS (136 compounds) in over 100 different matrices, obtained over a period of 15 months, are also presented and discussed. At the 0.05 mg kg−1 level acceptable recoveries were obtained for 93% (GC–MS) and 92% (LC–MS–MS) of pesticide–matrix combinations

The Sun Health Research Institute Brain Donation Program: Description and Eexperience, 1987–2007

The Brain Donation Program at Sun Health Research Institute has been in continual operation since 1987, with over 1000 brains banked. The population studied primarily resides in the retirement communities of northwest metropolitan Phoenix, Arizona. The Institute is affiliated with Sun Health, a nonprofit community-owned and operated health care provider. Subjects are enrolled prospectively to allow standardized clinical assessments during life. Funding comes primarily from competitive grants. The Program has made short postmortem brain retrieval a priority, with a 2.75-h median postmortem interval for the entire collection. This maximizes the utility of the resource for molecular studies; frozen tissue from approximately 82% of all cases is suitable for RNA studies. Studies performed in-house have shown that, even with very short postmortem intervals, increasing delays in brain retrieval adversely affect RNA integrity and that cerebrospinal fluid pH increases with postmortem interval but does not predict tissue viability

The study of atmospheric ice-nucleating particles via microfluidically generated droplets

Ice-nucleating particles (INPs) play a significant role in the climate and hydrological cycle by triggering ice formation in supercooled clouds, thereby causing precipitation and affecting cloud lifetimes and their radiative properties. However, despite their importance, INP often comprise only 1 in 10³–10⁶ ambient particles, making it difficult to ascertain and predict their type, source, and concentration. The typical techniques for quantifying INP concentrations tend to be highly labour-intensive, suffer from poor time resolution, or are limited in sensitivity to low concentrations. Here, we present the application of microfluidic devices to the study of atmospheric INPs via the simple and rapid production of monodisperse droplets and their subsequent freezing on a cold stage. This device offers the potential for the testing of INP concentrations in aqueous samples with high sensitivity and high counting statistics. Various INPs were tested for validation of the platform, including mineral dust and biological species, with results compared to literature values. We also describe a methodology for sampling atmospheric aerosol in a manner that minimises sampling biases and which is compatible with the microfluidic device. We present results for INP concentrations in air sampled during two field campaigns: (1) from a rural location in the UK and (2) during the UK’s annual Bonfire Night festival. These initial results will provide a route for deployment of the microfluidic platform for the study and quantification of INPs in upcoming field campaigns around the globe, while providing a benchmark for future lab-on-a-chip-based INP studies

Formation of a quasicrystalline phase in Al–Mn base alloys cast at intermediate cooling rates

Al-rich 94Al–6Mn and 94Al–4Mn–2Fe alloys were suction-cast to evaluate thefeasibility of obtaining bulk quasicrystal-strengthened Al-alloys at intermediatecooling rates alloyed with non-toxic, easily accessible and affordable additions.The influence of different cooling rates on the potential formation of a quasicrystallinephase was examined by means of scanning and transmissionelectron microscopy, X-ray diffraction and differential scanning calorimetry.Increased cooling rates in the thinnest castings entailed a change in samplephase composition. The highest cooling rates turned out to be insufficient toform an icosahedral quasicrystalline phase (I-phase) in the binary alloy. Instead,an orthorhombic approximant phase occurred (L-phase). The addition of Fe tothe 94Al–6Mn binary alloy enhanced the formation of a quasicrystalline phase.At intermediate cooling rates of 102–103 K/s, various metastable phases wereformed, including decagonal and icosahedral quasicrystals and their approximants.Rods (1 mm in diameter) composed of I-phase particles embedded in Almatrix exhibited a hardness of 1.5 GPa, much higher than the 1.1 GPa of 94Al–6Mn