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The Influence of Advanced DSM on Performance of Distribution Networks with Renewable Generation
No full textThis paper presents an analysis of the possible effects that load-follow-generation programs facilitated by demand side management (DSM) can have on different aspects of distribution network performance. It introduces an algorithm for DSM considering realistic load model and taking into account limited load flexibility and load payback. It then assesses the effectiveness of deployed DSM to achieve set goals when considering realistic constraints. The analysis demonstrates the importance of inclusion of realistic constraints and appropriate load modelling when assessing the effectiveness of wide-scale DSM programs on different aspects of performance of distribution networks with renewable generation
Prediction of stillbirth: an umbrella review of evaluation of prognostic variables
No full textBackground: Stillbirth accounts for over 2 million deaths a year worldwide, and rates remains stubbornly high. Multivariable prediction models may be key to individualised monitoring, intervention or early birth in pregnancy to prevent stillbirth.Objectives: To collate and evaluate systematic reviews of factors associated with stillbirth in order to identify variables relevant to prediction model development.Search strategy: Medline, Embase, DARE and Cochrane Library databases and reference lists were searched up to November 2019.Selection criteria: We included systematic reviews of association of individual variables with stillbirth without language restriction.Data collection and analysis: Abstract screening and data extraction were conducted in duplicate. Methodological quality was assessed using AMSTAR and QUIPS criteria. The evidence supporting association with each variable was graded.Results: The search identified 1198 citations. 69 systematic reviews reporting 64 variables were included. The most frequently reported were maternal age (n=5), BMI (n=6) and maternal diabetes (n=5). Uterine artery Doppler appeared to have the best performance of any single test for stillbirth. The strongest evidence of association was for nulliparity and pre-existing hypertension.Conclusion: We have identified variables relevant to the development of prediction models for stillbirth. Age, parity and prior adverse pregnancy outcomes had a more convincing association than the best performing tests which were PAPP-A, PlGF and UtAD. The evidence was limited by high heterogeneity and lack of data on intervention bias
Simplifying differential diagnoses of orofacial conditions - a guide to surgical sieves and red flags
No full textFormulation of a differential diagnosis with appropriate diagnostic tests is critical in day to day clinical practice. Many specialists or hospital-based practitioners in specialties such as oral medicine and oral surgery will be familiar with the use of surgical sieves and the term red-flags in their practice. However, it is the authors’ experience that General Dental Practitioners may not be as familiar with such tools. Primary care practitioners are often the first port of call for patients with uncommon symptoms, it is vital that appropriate and timely referrals are made and the use of a surgical sieve and awareness of ‘red-flags’ will assist the practitioner
Predictors of subclinical systemic sclerosis primary heart involvement characterised by microvasculopathy and myocardial fibrosis
No full textObjectives Systemic sclerosis primary heart involvement (SSc-pHI) is a significant cause of mortality. We aimed to characterise and identify predictors of subclinical SSc-pHI using cardiovascular magnetic resonance (CMR). Methods Eighty-three SSc patients with no history of cardiovascular disease or pulmonary arterial hypertension and 44 healthy controls (HC) underwent 3Tesla contrast-enhanced CMR including T1 mapping and quantitative stress perfusion. High-sensitivity troponin I (Hs-TnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were also measured. Results CMR revealed lower myocardial perfusion reserve (MPR) compared to HC [median (IQR) 1.9 (1.6, 2.4) vs 3 (2, 3.6), p<0.001]. Late gadolinium enhancement (LGE), indicating focal fibrosis was observed in 17/83 patients but in no HC, with significantly higher extracellular volume (ECV), suggestive of diffuse fibrosis in SSc vs HC [mean (SD) 31 (4) vs 25 (2), p<0.001]. Presence of LGE and higher ECV associated with skin score (OR=1.115, p=0.048; R2=0.353, p=0.004), and ECV and MPR associated with the presence of digital ulcers at multivariate analysis (R2=0.353, p<0.001; R2=0.238, p=0.011). Hs-TnI was significantly higher in patients with LGE, and NT-proBNP associated with ECV (p<0.05). Conclusion Subclinical SSc-pHI is characterised by myocardial microvasculopathy, diffuse and focal myocardial fibrosis but preserved myocardial contractile function. This subclinical phenotype of SSc-pHI associates with Hs-TnI, NT-proBNP, SSc disease severity and complicated peripheral vasculopathy. These data inform on the underlying pathophysiological processes and provide a basis to identify individuals at risk of SSc-pHI
Improvement of high-added value carotenoid production from Rhodotorula glutinis CCT-2186 yeasts: A biorefinery perspective
No full textBiorefining is a sustainable processing approach for the conversion of biomass into multiple valuable bioproducts through an integrated platform. Rhodotorula strains can produce various bioproducts i.e., carotenoids and lipids, make it a potential microorganism for application in a biorefinery concept. With this in mind, here the production of carotenoids, β-carotene, torularhodin, torulene, and lipids by Rhodotorula glutinis is evaluated. Two statistical experimental designs were applied to enhance carotenoid production: a first 25-1 fractional factorial design to evaluate the influence of independent variables pH, nitrogen source (organic or inorganic), glucose, KH2PO4 and MgSO4; and a second 22 central factorial design to optimize the pH and nitrogen sources. After the 22 factorial design optimization, R. glutinis was able to produce 297.84 µg/mL of β-carotene, 286.06 µg/mL of torularhodin and 37.35 µg/mL of torulene, with low nutritional requirements of glucose (10 g/L) and nitrogen content (organic-10 g/L; inorganic-4 g/L). Moreover, 45% (m/m) of the R. glutinis biomass corresponded to lipid content. After the optimization, the process was scaled-up to a 5L stirred-tank bioreactor. Switching to a bioreactor allowed and improvement of aeration and agitation conditions, which led to an increase in production yield (m/v) of, approximately, 25.83%, 11.88%, 24.50%, 12.40% and 40.31% for β-carotene, torularhodin, torulene and lipids, respectively. R. glutinis is a promising source of carotenoids and lipids in the production of high-value compounds for nutritional and pharmaceutical applications, making it a promising host for use in a biorefinery approach
Public Happiness through Manufacturing and Innovation: The Theory of Industrialization of Johann Heinrich Gottlob von Justi (1717-1771)
No full textDevelopment of a Dual-temperature Test Cell for Laboratory Ageing Experiment of Transformer Insulation Systems
No full textAs accelerated ageing tests in full-size transformers are impractical, laboratory ageing experiments are often used to understand the ageing process of transformer insulation systems. Three main types of ageing experiment setup can be identified in literature: a functional life test model, a dual-temperature test cell and a single temperature test cell. A functional life test model is a scaled-down representation of transformer operation, but it is very expensive to run. A single temperature test cell is the simplest and most widely used laboratory test set-up but it cannot reflect the different temperature profiles and gradients found inside a real transformer. The dual-temperature test cell is less complicated and less costly than the transformer model and still has the ability to simulate the different temperatures experienced by transformer insulation. In a dual temperature cell the solid and liquid insulation temperatures are independently controlled, thereby overcoming the main disadvantage of the single temperature test cell method. In this paper, the design and construction of a dual-temperature test system based on the IEC TS 62332-1 technical specification is described and test results are provided to show that the test system fulfils the desired functions with stable conductor and liquid temperatures
Bridged and Unbridged Nickel-Nickel Bonds Supported by Cyclopentadienyl and Phosphine Ligand-Sets
No full textA series of Ni complexes [Ni(Cl)2(PR3)2] with R = Me (1-Me), nPr (1-nPr) and n Bu (1-nBu) and nickelocenes [Ni(η5 -C5H4R′)2] with R′ = H (2-H), Me (2-Me), SiMe3 (2-SiMe3) were synthesized and characterized. From these complexes, the synthesis of the Ni complexes [NiCl(PR3)(η5-C5H4R′)] R = Me, R′ = H (3-Me), R= n Bu, R′ = H (3- nBu), R =n Pr, R′ = H (3- nPr), R = Et, R′ = Me (4) and R = Et, R′ = SiMe3 (5) was achieved. All complexes were fully characterized, including single crystal X-ray crystallography. Complexes 3-R, 4 and 5 were then used to obtain homobimetallic Ni complexes with rare examples of unbridged Ni-Ni bonds [{Ni(η5 -C5H5)(PR3)}2], with R = Me (7-Me) and R = n Pr (7- nPr) being structurally characterized by single crystal X-ray diffraction. In order to probe the effect of bridging ligands on the Ni-Ni bond, the bridged complex [{Ni(µ:η5 -C5H4CH2CH2P(t Bu)2}2] (8) was synthesized from the monomeric precursor [Ni(Cl)(k1 -η5 -C5H4CH2CH2Pt Bu2)] (6). The Ni-Ni distances in 7-Me, 7- nPr, and 8 were found to be 2.407(1), 2.3931(6), and 2.6027(17) Å, respectively, the latter seemingly lengthened compared to the other two due to the tethered nature of the bridging ligand. DFT calculations confirm the presence of unbridged σ-bonds between the Ni-atoms in 7-Me and 7-nPr and show that the bridging ligand in 8 has a minimal effect on the character of the Ni-Ni bond
A Novel Combination of Mycielski-Markov, Regime Switching and Jump Diusion Models for Solar Energy
No full textWith renewable energy sources growing, solar power generation is becoming ever more popular around the world, soforecasting and scenario analysis of Solar Photovoltaic production is benecial for grid operators and investors. In thispaper, we introduce a novel combination of a Mycielski-Markov model, standard regime switching, and jump diusionmodels to generate 1-minute Global Horizontal Irradiance time series over any time scale. It can simulate dierentscenarios of solar irradiance in the future after being trained on empirical data. We verify our model using statisticaltests to compare our simulations with those from an observed time-series in Mauritius. The resulting model is able togenerate simulations retaining the statistical properties of the data. Further, we nd the proposed calibration process tobe robust, and identied that splitting the day into 16 periods to be perfect balance to counter overtting. The proposedmodel has the potential to better understand the eects of including large scale Solar Photovoltaic generation into anenergy network, value future investments, or even allow for a cost-benet analysis of subsidies
Dynamics of Colloidal Cubes and Cuboids in Cylindrical Nanopores
No full textUnderstanding how colloidal suspensions behave in confined environments has a striking relevance in practical applications.Despite the fact that the behaviour of colloids in the bulk is key to identify the main elements affectingtheir equilibrium and dynamics, it is only by studying their response under confinement that one can ponder the useof colloids in formulation technology. In particular, confining fluids of anisotropic particles in nanopores provides theopportunity to control their phase behaviour and stabilise a spectrum of morphologies that cannot form in the bulk.By properly selecting pore geometry, particle architecture and system packing, it is possible to tune thermodynamic,structural and dynamical properties for ad hoc applications. In the present contribution, we report Grand Canonical andDynamic Monte Carlo simulations of suspensions of colloidal cubes and cuboids constrained into cylindrical nanoporesof different size. We first study their phase behaviour, calculate the chemical potential vs density equation of state andcharacterise the effect of the pore walls on particle anchoring and layering. In particular, at large enough concentrations,we observe the formation of concentric nematic-like coronas of oblate or prolate particles surrounding an isotropic core,whose features resemble those typically detected in the bulk. We then analyse the main characteristics of their dynamicsand discover that these are dramatically determined by the ability of particles to diffuse in the longitudinal and radialdirection of the nanopore