Green Electricity Market Development in the United States: Policy Analysis and Case Studies

This paper reviews green electricity development in the United States, focusing on policies that have been enacted to promote green electricity. Green power is a term that refers to electricity generated from particular renewable energy sources including wind and solar power, geothermal, low-impact hydropower, and certain forms of biomass. While there has been interest in promoting the use of renewable energy sources for a number of years, the United States currently relies heavily on nonrenewable fossil fuels for energy. The paper reviews the principal energy resources used for electricity production, considers the changing regulatory environment for the electricity industry, and describes government policies that have been used to promote green electricity in the United States. Important factors that have influenced the development of green electricity markets are discussed, including underlying economic issues, government policy measures, the regulatory environment, external costs and subsidies, and other factors

Post-Fire Assessment of Concrete Tunnel Structures

Although concrete tunnel structures can lose strength and long-term durability due to fire, the literature on the remaining capacity of structures after fire events is very scattered, and no published post-fire inspection protocols specifically for concrete tunnel structures are available. This work aims to summarize and synthesize the current state of knowledge of the deleterious effects of fire on the residual condition of concrete tunnel structures and how the extent and degree of fire damage can be assessed. The scope of this work includes an extensive literature review, heat testing of some common tunnel elements, and residual strength testing of a tunnel wall panel. The literature review includes a review of published standards, technical reports, academic papers, and a survey of post-fire inspection practices at other state DOTs and transit organizations. Topics covered in the review include the residual mechanical properties of concrete, steel, and the concrete/steel bond after fire, the residual strength and stiffness of structural members after fire, existing inspection tools and methods for assessing concrete structures after fire, and repair methods for fire-damaged concrete structures. The outcomes of the heat testing are presented, including the setup of a radiant heating system (which does not use a flame), procurement of sample specimens for testing, thermal and physical testing of specimens, and evaluation of results. Lastly, based on the literature review and experimental testing, recommendations for future work are presented

Foot kinematics in patients with two patterns of pathological plantar hyperkeratosis

Background: The Root paradigm of foot function continues to underpin the majority of clinical foot biomechanics practice and foot orthotic therapy. There are great number of assumptions in this popular paradigm, most of which have not been thoroughly tested. One component supposes that patterns of plantar pressure and associated hyperkeratosis lesions should be associated with distinct rearfoot, mid foot, first metatarsal and hallux kinematic patterns. Our aim was to investigate the extent to which this was true. Methods: Twenty-seven subjects with planter pathological hyperkeratosis were recruited into one of two groups. Group 1 displayed pathological plantar hyperkeratosis only under metatarsal heads 2, 3 and 4 (n = 14). Group 2 displayed pathological plantar hyperkeratosis only under the 1st and 5th metatarsal heads (n = 13). Foot kinematics were measured using reflective markers on the leg, heel, midfoot, first metatarsal and hallux. Results: The kinematic data failed to identify distinct differences between these two groups of subjects, however there were several subtle (generally <3°) differences in kinematic data between these groups. Group 1 displayed a less everted heel, a less abducted heel and a more plantarflexed heel compared to group 2, which is contrary to the Root paradigm. Conclusions: There was some evidence of small differences between planter pathological hyperkeratosis groups. Nevertheless, there was too much similarity between the kinematic data displayed in each group to classify them as distinct foot types as the current clinical paradigm proposes

Validity of self-assessment of hallux valgus using the Manchester scale

<p>Abstract</p> <p>Background</p> <p>Hallux valgus (HV) is a common condition involving the progressive subluxation of the first metatarsophalangeal joint due to lateral deviation of the hallux and medial deviation of the first metatarsal. The objective of this study was to evaluate the re-test reliability and validity of self-assessment of HV using a simple clinical screening tool involving four standardised photographs (the Manchester scale), in order to determine whether this tool could be used for postal surveys of the condition.</p> <p>Methods</p> <p>HV was assessed with the Manchester scale in 138 people aged 65 to 93 years of age (102 women and 36 men) as part of a larger randomised controlled trial. At the six month follow-up assessment, HV was reassessed to determine re-test reliability, and participants were asked to self-assess their degree of HV independent of the examiners. Associations between (i) baseline and follow-up assessments of the examiners and (ii) participant and examiner assessments were performed using weighted kappa statistics. Analyses were then repeated after HV was dichotomised as present or absent using unweighted kappa, and sensitivity and specificity of self-assessment of HV was determined.</p> <p>Results</p> <p>Re-test reliability of the examiners was substantial to almost perfect (weighted kappa = 0.78 to 0.90), and there was a substantial level of agreement between observations of the participants and the examiners (weighted kappa = 0.71 to 0.80). Overall, there was a slight tendency for participants to rate their HV as less severe than the examiners. When the Manchester scale scores were dichotomised, agreement was substantial to almost perfect for both re-test comparisons (kappa = 0.80 to 0.89) and substantial for comparisons between participants and examiners (kappa = 0.64 to 0.76). The sensitivity and specificity of self-assessment of HV using the dichotomous scale were 85 and 88%, respectively.</p> <p>Conclusions</p> <p>The Manchester scale demonstrates high re-test reliability, and self-assessment scores obtained by participants are strongly associated with scores obtained by examiners. These findings indicate that the tool can be used with confidence in postal surveys to document the presence and severity of HV.</p> <p>Trial registration</p> <p>ACTRN12608000065392</p

Precise Switching of Flagellar Gene Expression in Escherichia Coli by the FlgM–FliA Regulatory Network

A remarkable feature of flagellar synthesis in Escherichia coli is that gene expression is sequential and coupled to the assembly process. The interaction of two key proteins, the flagellar sigma factor FliA and its anti-sigma factor FlgM serves as a major checkpoint in the assembly process that temporally separates middle and late gene expression. While the sequential nature within each gene class has been studied using large-scale transcriptional data, much less is known about the timing controlled by the checkpoint mechanism. In this article, we analyze timing, sensitivity and robustness of the FlgM–FliA core regulatory mechanism based on quantitative molecule data and a detailed stochastic as well as reduced deterministic reaction kinetics model. We find that the pool of free anti-sigma factor FlgM, accumulated during middle gene expression, acts as a molecular timer that determines the delay between successful completion of the hook basal body subunit and the start of expression of flagellar filament proteins. Furthermore, we find that the number of free FliA molecules needs to be tightly controlled for a precise switch from middle to late gene expression. A sensitivity analysis based on the reduced reaction kinetics model reveals that the checkpoint mechanism is very sensitive to changes in levels of competing sigma factors, allowing the bacterium to rapidly adapt to a changing environment. In addition, we find that the reduced model also shows a high sensitivity to the effective synthesis rates of FliA and FlgM. However, this high sensitivity does not generally carry over to the original parameters of transcriptional and translational processes in the detailed model. As a consequence, care has to be taken whenever interpreting results from the robustness analysis of reaction kinetic models comprising lumped or effective parameters

An improved method for mobility prediction using a Markov model and density estimation

This is the author accepted manuscript. The final version is available from IEEE via the DOI in this recordThe prediction of an individual's future locations is a significant part of scientific researches. While a variety of solutions have been investigated for the prediction of future locations, predicting departure and arrival times at predicted locations is a task with higher complexity and less attention. While the challenges of combining spatial and temporal information have been stated in various works, the proposed solutions lack accuracy and robustness. This paper proposes a simple yet effective way to predict not only an individual's future location, but also most probable departure and arrival times as well as the most probable route from origin to destination

Identifying atypical travel patterns for improved medium-term mobility prediction

This is the author accepted manuscript. The final version is available from IEEE via the DOI in this recordDuring the last decades, concepts of Intelligent Transportation Systems (ITS) were continuously adapted and improved based on new insights into human travel behavior. Drivers for improvements are the quantity and quality of available mobility data, which increased significantly in recent years. Based on travel behavior, literature proposes a large number of different solutions for next step or future location prediction. However a holistic spatio-temporal prediction, which could further improve the quality of ITS, creates a more complex task. The prediction of medium-term mobility for one to seven days is challenging in particular for atypical travel behavior, since the weekdays’ order delivers no reliable indication for the next day’s travel behavior. With our contribution, we explore the benefits of various prediction approaches for medium-term mobility prediction and combine them dynamically to predict individual mobility behavior for a period of one week. The derived framework utilizes an exhaustive search approach to benefit from a machine learning based clustering method on location data. In conjunction with an Artificial Neural Network, the prediction framework is robust against prediction errors created by atypical behavior. With two data sets consisting of smartphone and vehicle data, we demonstrate the framework’s real-world applicability. We show that clustering an individual’s historical movement data can improve the prediction accuracy of different prediction methods that will be explained in detail and illustrate the interrelation of entropy and prediction accuracy.University of Exete

Acid rain in Europe and the United States: an update.

Abstract This paper discusses the evolution of science and policies to control acid rain in Europe and the United States over the past several decades. Acid rain gained prominence in the late 1960s because of its perceived effects on ecosystem integrity. Extensive research efforts in both Europe and the United States, however, have concluded that the effects of acid rain-at least those on terrestrial ecosystems-were less serious than originally believed. More recently, interest in controlling acid rain precursors stems primarily from health concerns, particularly their effects in the form of fine particulate matter. The paper discusses the emergence of acid rain as an environmental concern, scientific evidence about the effects of acidic deposition on natural ecosystems, US and European acid rain control policies, studies of the costs and benefits of reducing acid rain, and different policy contexts in Europe and the United States

Simultaneous Calibration of Grapevine Phenology and Yield with a Soil–Plant–Atmosphere System Model Using the Frequentist Method

Reliable estimations of parameter values and associated uncertainties are crucial for crop model applications in agro-environmental research. However, estimating many parameters simultaneously for different types of response variables is difficult. This becomes more complicated for grapevines with different phenotypes between varieties and training systems. Our study aims to evaluate how a standard least square approach can be used to calibrate a complex grapevine model for simulating both the phenology (flowering and harvest date) and yield of four different variety–training systems in the Douro Demarcated Region, northern Portugal. An objective function is defined to search for the best-fit parameters that result in the minimum value of the unweighted sum of the normalized Root Mean Squared Error (nRMSE) of the studied variables. Parameter uncertainties are estimated as how a given parameter value can determine the total prediction variability caused by variations in the other parameter combinations. The results indicate that the best-estimated parameters show a satisfactory predictive performance, with a mean bias of −2 to 4 days for phenology and −232 to 159 kg/ha for yield. The corresponding variance in the observed data was generally well reproduced, except for one occasion. These parameters are a good trade-off to achieve results close to the best possible fit of each response variable. No parameter combinations can achieve minimum errors simultaneously for phenology and yield, where the best fit to one variable can lead to a poor fit to another. The proposed parameter uncertainty analysis is particularly useful to select the best-fit parameter values when several choices with equal performance occur. A global sensitivity analysis is applied where the fruit-setting parameters are identified as key determinants for yield simulations. Overall, the approach (including uncertainty analysis) is relatively simple and straightforward without specific pre-conditions (e.g., model continuity), which can be easily applied for other models and crops. However, a challenge has been identified, which is associated with the appropriate assumption of the model errors, where a combination of various calibration approaches might be essential to have a more robust parameter estimation

Uncertainty in the measurement of indoor temperature and humidity in naturally ventilated dairy buildings as influenced by measurement technique and data variability

[EN] The microclimatic conditions in dairy buildings affect animal welfare and gaseous emissions. Measurements are highly variable due to the inhomogeneous distribution of heat and humidity sources (related to farm management) and the turbulent inflow (associated with meteorologic boundary conditions). The selection of the measurement strategy (number and position of the sensors) and the analysis methodology adds to the uncertainty of the applied measurement technique. To assess the suitability of different sensor positions, in situations where monitoring in the direct vicinity of the animals is not possible, we collected long-term data in two naturally ventilated dairy barns in Germany between March 2015 and April 2016 (horizontal and vertical profiles with 10 to 5 min temporal resolution). Uncertainties related to the measurement setup were assessed by comparing the device outputs under lab conditions after the on-farm experiments. We found out that the uncertainty in measurements of relative humidity is of particular importance when assessing heat stress risk and resulting economic losses in terms of temperature-humidity index. Measurements at a height of approximately 3 m-3.5 m turned out to be a good approximation for the microclimatic conditions in the animal occupied zone (including the air volume close to the emission active zone). However, further investigation along this cross-section is required to reduce uncertainties related to the inhomogeneous distribution of humidity. In addition, a regular sound cleaning (and if possible recalibration after few months) of the measurement devices is crucial to reduce the instrumentation uncertainty in long-term monitoring of relative humidity in dairy barns (C) 2017 The Authors. Published by Elsevier Ltd on behalf of IAgrE.The work was financially supported by the German Federal Ministry of Food and Agriculture (BMEL) through the Federal Office for Agriculture and Food (BLE), grant number 2814ERA02C.Hempel, S.; König, M.; Menz, C.; Janke, D.; Amon, B.; Banhazi, T.; Estellés, F.... (2018). Uncertainty in the measurement of indoor temperature and humidity in naturally ventilated dairy buildings as influenced by measurement technique and data variability. Biosystems Engineering. 166:58-75. https://doi.org/10.1016/j.biosystemseng.2017.11.004S587516