Stochastic Hosting Capacity in LV Distribution Networks

Hosting capacity is defined as the level of penetration that a particular technology can connect to a distribution network without causing power quality problems. In this work, we study the impact of solar photovoltaics (PV) on voltage rise. In most cases, the locations and sizes of the PV are not known in advance, so hosting capacity must be considered as a random variable. Most hosting capacity methods study the problem considering a large number of scenarios, many of which provide little additional information. We overcome this problem by studying only cases where voltage constraints are active, with results illustrating a reduction in the number of scenarios required by an order of magnitude. A linear power flow model is utilised for this task, showing excellent performance. The hosting capacity is finally studied as a function of the number of generators connected, demonstrating that assumptions about the penetration level will have a large impact on the conclusions drawn for a given network

Compost and Cover Crop Effects in Dryland Organic Wheat

Producers of dryland organic wheat (Triticum aestivum L.) in the western USA struggle to maintain adequate soil fertility due to the high cost of organic fertilizers and concerns over moisture use of cover crops. Low soil fertility results in decreased wheat yield and quality, and increased year-to-year variability in yield and quality based on weather. This study was conducted to measure the effects of, and interactions between, cover crop mixes and a one-time compost application on soil health and winter wheat yield and quality. The study was located on three adjacent certified organic wheat farms near Snowville, UT, each with a calcareous silt loam soil under conventional tillage in a wheat-fallow system. Four composted steer manure treatments (0, 12.5, 25, and 50 Mg ha-1) and three cover crop treatments (oat [Avena sativa]- pea [Pisum sativum] mixture, vetch [Vicia villosa]- pea mixture, and a mechanically tilled fallow control) were evaluated from fall 2014 to 2017. Treatments were arranged in a randomized complete block split-split plot with three replications, with each farm hosting a single replicate. In 2015, the oat-pea cover crop treatment decreased grain yield, while compost amendment caused yields to more than double. However, neither compost nor cover crops affected yield in 2017. The 2015 crop year was much drier than 2017, suggesting that grain yield and quality benefits may be dependent on other factors such as the precipitation patterns of a particular year. The vetch-pea cover crop treatment increased total soil N in 2017 only, and compost amendment increased nitrogen fixation in the vetch-pea cover crop in that year. Compost treatments increased soil N, P, K, and organic C, both years without affecting soil EC or pH long-term. Nitrogen fixing cover crops may be a viable option for producers to increase soil N when sufficient soil moisture is present, however may be detrimental in a dry year. Compost amendment was shown to increase soil nutrition for multiple years, although that may only translate into increased grain yield when prerequisite weather conditions are present

On Heaven's Lathe: State, Rule of Law, and Economic Development

AbstractWe propose a theoretical framework for understanding the evolution of the rule of law state, which is conceived as the equilibrium of a societal game in which actors accept the legitimacy of publicly enunciated legal rules. A meta-norm of respect for the sovereign legal power of the state is not self-forming on the basis of private conduct, but requires the coevolution of impersonal market exchange with effective state capacity to constitute and regulate markets. A functioning legal system must acquire the means not just to control private power but to constrain other organs of government. The emergence of such a ‘self-limiting state’ is an historical process which, while complementary to a market order, is also contingent and path-dependent, and is not preordained. Illustrating our argument with empirical evidence drawn from the contemporary experience of middle-income countries, with a focus on China, we argue that alternatives to the rule of law state, including interpersonal trust, closed networks and authoritarian political control, can only achieve limited scale and scope effects, and are prone to high deadweight costs arising from corruption and the capture of the public sphere by private interests. We also discuss the potential of transplants of legal rules and institutions to catalyse the transition to impersonal trade based on the rule of law, and present evidence, from time-series econometric analysis, that the diffusion of shareholder protection laws has the potential to support financial development in emerging markets. Evolution towards the rule of law state is, we conclude, one possible developmental path for middle-income countries.This is the final version of the article. It first appeared from De Gruyter via http://dx.doi.org/10.1515/ldr-2014-003

Concussion in motorsport: incidence, awareness and future directions.

Concussion in contact sport is a contentious issue and represents a growing proportion of injuries sustained by athletes worldwide. Motorsport is no exception, yet the published evidence on the incidence, severity and recovery from this condition remains scarce [1]. Motorsport is unique among extreme sports, since competitors are frequently subject to high velocity, high G forces with a large rotational component, even without impact [2,3]. The ongoing challenge for practitioners is threefold; making a diagnosis of concussion trackside, evaluating competitors in the medical center and approaching the return-to-race decision.ND Deakin receives expenses in exchange for performing baseline and post-concussion neurocognitive testing for the British Touring Car Championship and its associated racing series. PJ Hutchinson is supported by a NIHR Research Professorship and the BRC Cambridge NIHR. PJ is also Chief Medical Officer for the FIA Formula 1 British Grand Prix at Silverstone. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed

Posttranslational modifications of alpha-tubulin: acetylated and detyrosinated forms in axons of rat cerebellum.

The distribution of acetylated alpha-tubulin in rat cerebellum was examined and compared with that of total alpha-tubulin and tyrosinated alpha-tubulin. From immunoperoxidase-stained vibratome sections of rat cerebellum it was found that acetylated alpha-tubulin, detectable with monoclonal 6-11B-1, was preferentially enriched in axons compared with dendrites. Parallel fiber axons, in particular, were labeled with 6-11B-1 yet unstained by an antibody recognizing tyrosinated alpha-tubulin, indicating that parallel fibers contain alpha-tubulin that is acetylated and detyrosinated. Axonal microtubules are known to be highly stable and the distribution of acetylated alpha-tubulin in other classes of stable microtubules suggests that acetylation and possibly detyrosination may play a role in the maintenance of stable populations of microtubules

The Value of Reactive Power for Voltage Control in Lossy Networks

Reactive power has been proposed as a method of voltage control for distribution networks, providing a means of increasing the amount of energy transferred from distributed generators to the bulk transmission network. The value of reactive power can therefore be measured according to an increase in transferred energy, where the transferred energy is defined as the total generated energy, less the total network losses. If network losses are ignored, an error in the valuation of a given amount of reactive power will be observed (leading to reactive power provision being under- or over-valued). The non-linear analytic solution of a two-bus network is studied, and non-trivial upper and lower bounds are determined for this `valuation error'. The properties predicted by this two-bus network are demonstrated to hold on a three-phase unbalanced distribution test feeder with good accuracy. This allows for an analytic assessment of the importance of losses in the valuation of reactive power in arbitrary networks

Short-term reliability of inflammatory mediators and response to exercise in the heat.

Prospective application of serum cytokines, lipopolysaccharide (LPS), and heat shock proteins (eHSPs) requires reliable measurement of these biomarkers that can signify exercise-induced heat stress in hot conditions. To accomplish this, both short-term (7 day) reliability (at rest, n = 12) and the acute responsiveness of each biomarker to exercise in the heat (pre and post 60-min cycling, 34.5°C and 70% RH, n = 20) were evaluated. Serum was analysed for the concentration of C-reactive protein (CRP), interleukin-6 (IL-6), heat shock protein 72 (eHSP72), immunoglobulin M (IgM) and LPS. Test–retest reliability was determined as the coefficient of variation (CV). Biomarkers with the least short-term within-participant variation were IL-6 (19%, ±20%; CV, ±95% confidence limits (CL)) and LPS (23%, ±13%). Greater variability was observed for IgM, eHSP72 and CRP (CV range 28–38%). IL-6 exhibited the largest increase in response to acute exercise (95%, ±11%, P = < 0.001) and although CRP had a modest CV (12%, ±7%), it increased substantially post-exercise (P = 0.02, ES; 0.78). In contrast, eHSP72 and LPS exhibited trivial changes post-exercise. It appears variation of common inflammatory markers after exercise in the heat is not always discernible from short-term (weekly) variation