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Intermittency from photovoltaic systems can negatively impact electricity grid stability due to increased power ramp rates and temporal misalignment between generation and load. Distributed systems, especially rooftop residential systems, present a range of orientations and spatial separation that when aggregated introduce temporal diversity. If these features reduce negative impacts, they should be weighed against increased costs per delivered energy compared to larger commercial/industrial systems. We compare power production data from 60 distributed residential PV systems spread across a large municipality with medium and large commercial rooftop systems located centrally in the municipality. Power ramp rates and power output variability were calculated. The aggregated distributed residential system ramp rates never exceed 13% per 5 min, while the medium/large commercial systems experienced ramp rates up to 61% and 68% per 5 min. In aggregate the residential output variability is 3 times lower than the commercial sites. Consistent with previous literature the output variability decreases as the number of systems grows. There are however diminishing returns due to the limited geographic area, with a relative output variability for the municipality approaching 20% of the variability of a single system. Residential data was scaled up to represent 10% of electrical load and resulted in 10% more electricity grid ramp rates exceeding ±5 MW per 5 min compared to baseline. Finally, a comparison between pyranometer and photovoltaic system ramps rates shows the latter are less severe, likely because pyranometers are single points sources.

PurposeThe purpose of this paper is to report on a systematic review that examined police social work and social service collaboration strategies implemented to address social problems.Design/methodology/approachA systematic review was conducted to identify the components of police social work and social service collaboration strategies. A total of 11 databases were searched. The inclusion criteria centered on the social problem, focus population, service providers, collaboration components and geographic location. Any methodological approach was included provided that a collaboration between police and social service providers focused on addressing a social problem was implemented and described.FindingsThe database searches identified 3,065 hits. After first eliminating duplicate titles, then reviewing and eliminating titles and abstracts that did not met the inclusion criteria, 119 full-text studies were reviewed. Among the 81 studies included in the systematic review, 83 implemented collaborations were found. The most collaborations were implemented in the USA, whereas only one implemented collaboration was found among the majority of the countries. Interpersonal violence was the most frequent social problem addressed by the collaborations followed by mental illness, crime, juvenile delinquency, and alcohol and substance use and abuse. Interventions were predominantly delivered by social workers who provided referrals and collaboration with social service agencies that assisted adults.Practical implicationsGiven that police officers are first responders to a wide range of social problems, investigating and disseminating information about the characteristics of police social service collaboration strategies is an important endeavor. Whereas investigating the effectiveness of collaborations was not the aim of this review, several practical implications can be derived from the findings. These findings show the types of social problems, partners and tasks that comprise the collaborations. The present findings suggest that law enforcement agencies do not have accessible name brand social work and social service collaboration models that can be replicated. The majority of the collaborations found appear to be unique models implemented between law enforcement and social service agencies. More outcome studies are needed that investigate whether the social problem has improved among citizens that received services from the collaboration.Originality/valueThis paper is the first systematic review focused on police social work and social service collaboration strategies implemented to address social problems.

With an increasing amount of electricity generation coming from renewable sources, integrating that variable output is of concern for electricity system reliability. This study investigates the proportioning of generating capacity between three co-located but uncorrelated variable renewable resources; wind, solar, and in-stream tidal, so that they complement each other and reduce grid integration costs. One year of resource data from various sites in the province of Nova Scotia, Canada was used. These data were analysed with respect to four metrics of importance to grid operators and electric utilities; coincident minimum and maximum power production, average power output, and ramp rates. These metrics were then combined, on an equal weighting basis, to find an “optimal” combination of generating capacities. The results were also compared to electrical load during the same year to determine the impact that increasing amounts of renewable generating capacity have on the required conventional dispatchable generating capacity. It was determined that a mix of installed generating capacities of 61% wind, 27% solar, and 12% in-stream tidal optimizes the energy, power, and ramp rate metrics. However, even with three independently varying resources, a large increase in renewable generating capacity results in only a small decrease in required dispatchable generation, due to a few coincident low renewable resources occurrences throughout the year.

A multi-disciplinary expert group met to discuss vitamin D deficiency in the UK and strategies for improving population intakes and status. Changes to UK Government advice since the 1st Rank Forum on Vitamin D (2009) were discussed, including rationale for setting a reference nutrient intake (10 µg/d; 400 IU/d) for adults and children (4+ years). Current UK data show inadequate intakes among all age groups and high prevalence of low vitamin D status among specific groups (e.g. pregnant women and adolescent males/females). Evidence of widespread deficiency within some minority ethnic groups, resulting in nutritional rickets (particularly among Black and South Asian infants), raised particular concern. Latest data indicate that UK population vitamin D intakes and status reamain relatively unchanged since Government recommendations changed in 2016. Vitamin D food fortification was discussed as a potential strategy to increase population intakes. Data from dose–response and dietary modelling studies indicate dairy products, bread, hens’ eggs and some meats as potential fortification vehicles. Vitamin D3 appears more effective than vitamin D2 for raising serum 25-hydroxyvitamin D concentration, which has implications for choice of fortificant. Other considerations for successful fortification strategies include: (i) need for ‘real-world’ cost information for use in modelling work; (ii) supportive food legislation; (iii) improved consumer and health professional understanding of vitamin D’s importance; (iv) clinical consequences of inadequate vitamin D status and (v) consistent communication of Government advice across health/social care professions, and via the food industry. These areas urgently require further research to enable universal improvement in vitamin D intakes and status in the UK population.

To examine the potential of distributed microgrids using sustainable energy sources centered on retail store parking lots, this study provides a methodology to simulate medium‐scale solar photovoltaic (PV) + combined heat and power (CHP) + battery hybrid microgrid systems deployed at big box retail stores. First, a method is provided to agglomerate 15‐min load data for a community of residences in the region of the store to provide baseline electricity load profiles. The systems are then modeled using dispatch strategies previously shown to be stable for smaller, but more dynamic loaded systems. The methodology is demonstrated with a case study for a Walmart Supercenter located in Nova Scotia, Canada. The electricity generated by each component of the hybrid system is coupled and optimized to fulfill the electric demands of the local community. The results provide the total electricity generated by the PV + CHP + battery hybrid system, total operating hours by each unit, fuel consumed, and hourly energy produced by each unit. The results show that such microgrid systems could serve the electrical needs of ˜1000 people (350 residences) for each parking lot of 3.5 MW PV system and CHP unit of 1 MW. The technical viability of this approach warrants future work.

There are limited techniques available to assess the health of sea turtles as physical examination has little correlation to clinical findings, and blood reference intervals are broad and provide limited prognostic significance. Advances in the portability of ultrasound machines allow echocardiography to be increasingly used in the health assessments of wild animals. This study performed blood analysis and echocardiograms on 11 green sea turtles upon admission to a rehabilitation clinic and six animals before release. Significant differences were seen between groups, with admission animals having significantly smaller diameters of the cavum arteriosum at systole and diastole, smaller E-waves and an increased fractional shortening. Pre-release animals displayed significant increases in the maximum blood velocities of both the pulmonary artery and the left aorta. Significant negative correlations were seen between fractional shortening and uric acid and between the velocity time integral of the pulmonary artery and urea. The pulmonary artery velocity time integral was also significantly correlated to the E wave. Furthermore, there was asynchrony between the cavum arteriosum and the cavum pulmonale and the detection of a parasitic granuloma in the ventricular outflow tract of one animal. Overall, the results suggest that cardiac function in stranded green sea turtles is significantly impaired and that echocardiography has applications in the health assessments of green sea turtles.

As wind energy converter (WEC) become an important part of electricity systems, the limitations of wind power forecasting have become a matter of ever greater concern. While electricity grid load forecasting is well established and successful, forecasting wind speeds at wind fields, or more directly WEC power output, has room for improvement. This research uses four months of hourly wind speed data from 36 WECs in Nova Scotia, Canada to find corrections for wind forecasts generated conventionally from a nested Weather Research and Forecasting atmospheric model. Site-specific corrections are categorized by forecast conditions (wind speed and direction) and used for two new forecast techniques. The first technique is a statistically based correction for improved wind speed forecasting. By building a “correction topography” (correction as a function of forecast conditions) on ¾ of the available data, absolute wind speed forecast errors in the remaining ¼ of the data are shown to be reduced by 20–25% for forecast lead times out to 24 h. This is a standalone technique of value to wind field operators and utilities concerned with integrating wind energy. The second technique is interpolating correction topographies and instantaneous forecast errors. By interpolating errors of surrounding known sites, similar error reduction was found to be possible at distances 10s of kilometers from known sites.

Many regions with good wind resources and aggressive renewable energy portfolio targets have achieved installed wind turbine capacity that is difficult for electricity system operators to manage. The purpose of this paper is to compare the measured output of wind farms at various locations throughout Nova Scotia, looking specifically at factors that either facilitate or hamper integration of additional capacity into the existing grid system. Special emphasis is placed on the effects of aggregating wind farms that are separated by distance and geography, and consequently experience different wind conditions at different times. The results are presented using metrics that have significance to electricity grid system operators, and new metrics that are accessible, readily interpretable, and actionable in locating new wind farms. The principle findings are that over a distance of 540 km the majority of potential correlation and 10-min ramp-rate reductions are achieved; that up to 30% improvement in effective load carrying capacity of wind farms is available for the worst electricity load hours by strategic wind farm siting; and a new metric shows several hours time shift between existing farms over this span. This timeshift is equal to or longer in length than most electricity utilities' peak demand periods

The current article introduces a method of quantifying the losses in a model predictive control scheme for morning start optimization by using a simplified statistical building model compared to a ...

This paper presents an experimental implementation of a whole building model predictive control (MPC) approach for a LEED gold certified academic building. The MPC is divided into portions for morning start and daytime optimization, to allow for specialized models to be used for the varying tasks. The MPC consists of a whole building optimization for energy that is supplemented with a zone operative temperature (ZOT) comfort metric. A ZOT based metric was used to evaluate thermal comfort, as traditional air temperature metrics neglect radiative impacts on comfort. The comfort metric is employed after the energy optimization to ensure comfort is the highest priority and maintained in each zone. A final layer of occupant feedback is incorporated to allow for users to provide feedback as to their comfort level and allow for changes in the comfort temperature range for their space. A four-month experimental test period shows a 29% HVAC electric energy reduction and a 63% thermal energy reduction compared to previous years for the same time period.

Some astronauts are returning from long-duration spaceflight with structural ocular and visual changes. We investigated both the transient and sustained effects of changes in the direction of the gravity vector acting on the eye using changes in body posture. Intraocular pressure (IOP; measured by Perkins tonometer), ocular geometry (axial length, corneal thickness, and aqueous depth-noncontact biometer), and the choroid (volume and subfoveal thickness optical coherence tomography) were measured in 10 subjects (5 males and 5 females). Measures were taken over the course of 60 min and analyzed with repeated-measures analysis of covariance to assess the effects of posture and time. In the supine position, choroidal volume increased significantly with time (average value at 3, 60 min = 9.0 ± 2.4 mm3, P = 0.03). In the prone position, IOP and axial length increased with time (IOP at 3, P < 0.001). Aqueous depth was shortened in the prone position (baseline = 3.22 ± 0.31 mm, 60 min = 3.18 ± 0.32 mm, P < 0.0001) but did not change with time. The data show that changes in the gravity vector have pronounced transient and sustained effects on the geometry and physiology of the eye. NEW & NOTEWORTHY We show that gravity has pronounced transient and sustained effects on the eye by making detailed ocular measurements over 60 min in the supine and prone postures. These data inform our understanding of how gravitational forces can affect ocular structures, which is essential for hypothesizing how ocular changes could occur with microgravity exposure.

Public Health England has set a definition for free sugars in the UK in order to estimate intakes of free sugars in the National Diet and Nutrition Survey. This follows the recommendation from the Scientific Advisory Committee on Nutrition in its 2015 report on Carbohydrates and Health that a definition of free sugars should be adopted. The definition of free sugars includes: all added sugars in any form; all sugars naturally present in fruit and vegetable juices, purées and pastes and similar products in which the structure has been broken down; all sugars in drinks (except for dairy-based drinks); and lactose and galactose added as ingredients. The sugars naturally present in milk and dairy products, fresh and most types of processed fruit and vegetables and in cereal grains, nuts and seeds are excluded from the definition.

BACKGROUND Patients with unresectable GBM represent an understudied and underpowered disease subgroup for which limited outcome data exist to support treatment recommendations. In this study, we present a ten-year analysis on outcome of unresectable GBM patients at our unit. MATERIAL AND METHODS We collected data for all consecutive adult de novo IDH wild-type (IDHwt) GBM patients who had undergone biopsy at our unit (2009–18, N= 177) and analysed those that had complete data on performance status, radiology, MGMT status, and adjuvant treatment (N= 156). We used step-wise cox proportional hazards regression to analyse factors associated with survival and outcomes. RESULTS Of 156 patients, mean age was 60.8 years old (range 19–89, 34/21.8% >69 years old), 63 (40.4%) were females, and 50 (32.1%), 26 (16.7%) and 12 (7.7%) had multifocal, butterfly or both lesion types respectively. 101 (64.7%) patients had good performance status (ECOG 0–1), and 49 (31.4%) had methylated MGMT lesions. Adjuvant treatment modalities were best supportive care (41, 26.3%), RT only (33, 21.2%), TMZ only (20, 12.8%), RT and TMZ (10, 6.4%), concurrent TMZ/RT only (29, 18.6%) and concurrent TMZ/RT plus adjuvant TMZ [TMZ/RT+TMZ] (23, 14.7%). Median OS was 6.1 months (range 0–50.7), with 22% and 2% 1- and 2-year OS respectively. Patients who were MGMT methylated, had good performance status, and received TMZ/RT+TMZ had the highest survival (median OS 18.7 vs 5.5 months, P Multivariate analysis revealed factors associated with worse OS; these include male sex (HR 1.6, 95%CI 1.1–2.2), unmethylated MGMT (1.8, 1.3–2.8), poor performance status ie ECOG>1 (2.4, 1.6–3.3), not receiving TMZ/RT+TMZ (3.1, 1.8–5.1). In addition, univariate analysis initially revealed that older age (>69yrs) was significantly associated with poorer outcome, however in multivariate analysis, this effect was obliterated (HR 1.3, 95%CI 0.9–2.1). CONCLUSION In this study, we provide one of the largest series of unresectable IDHwt GBM outcome in the literature. Survival of patients harbouring unresectable IDHwt GBM can be unexpectedly long, and may even reach nearly twice that of the unselected, biopsy-only GBM patients receiving TMZ/RT+TMZ studied in the original Stupp trial (median OS of 9.4 months). For this subgroup of IDHwt GBM patients, advanced age may not necessarily predict poor outcome, once adjusted for other outcome predictors. Future randomised trials looking into unresectable IDHwt GBM should stratify patients according to the factors revealed above.

Electric vehicle (EV) batteries can provide extended value beyond EV service if they are repurposed for a “second life” in electricity grid applications. However, because batteries from different EV makes and models vary significantly by size, shape, chemistry, and thermal management, there is uncertainty regarding their relative performance in second-life applications. This experimental study evaluates seven different EV batteries in their original modules and/or packs, featuring four unique positive active materials, two negative active materials, three cell formats, and four thermal management designs. Each battery is subjected to deep-discharge cycling at 4 h, 2 h, and 1 h constant-power rates to emulate performance in electricity grid energy arbitrage. Test results are evaluated based on six battery performance metrics in three key performance categories, including two energy metrics (usable energy capacity and charge–discharge energy efficiency), one volume metric (energy density), and three thermal metrics (average temperature rise, peak temperature rise, and cycle time). Significant differences in performance arise from the variety of chemistries and thermal management systems tested, dominating any influence from battery state of health. Chevrolet Volt and EnerDel batteries (both from hybrid EVs using NMC chemistry) give the best usable energy capacity (≥94%) and energy efficiency (≥97%), while Tesla Model S batteries (from long-range EVs using NCA chemistry) give the lowest usable energy capacity (≥84%) and energy efficiency (≥89%). However, the ModelS batteries give roughly double the energy density (half the physical footprint) of the Volt and EnerDel batteries. The Volt battery experiences no more than 2 °C of warming even during a 1 h discharge, thanks to its active (forced) liquid thermal management and high energy efficiency. This contrasts with the Leaf and Lishen batteries, which use passive (natural convection) thermal management and consequently experience over 17 °C of warming during a 1 h discharge, and then require over 4 h of standby time to cool down by less than 10 °C. Novel analytical techniques are applied to the experimental results to rank the tested EV batteries in the three aforementioned performance categories to illustrate their relative commercial performance expectation in second-life energy arbitrage. This new performance ranking system can be employed by industry in conjunction with economic models to select the most appropriate used EV batteries for specific energy storage applications.

A wide variety of commercial cylindrical lithium-ion batteries are available for use in nanosatellites (CubeSats) that cycle in low Earth orbit (LEO). This space application differs greatly from the conditions used to create the manufacturer datasheets that CubeSat teams rely on to screen cell types and estimate performance lifetimes. To address this, we experimentally test three LIB cell types using a representative LEO CubeSat power profile in three progressively complex test representations of LEO. The first is “standardized” condition (101 kPa-abs, 20 °C), which uses only a power cycler, the second adds a thermal chamber for “low temperature” condition (101 kPa-abs, 10 °C), and the third adds a vacuum chamber for “LEO” condition (0.2 kPa-abs, 10 °C). Results indicate that general “standardized” and “low temperature” conditions do not yield representative results to what would occur in LEO. Coincidentally, the “LEO” condition gives similar capacity degradation results as manufacturer datasheets. This was an unexpected finding, but suggests that CubeSat teams use full experimental thermal-vacuum testing or default to the manufacturer datasheet performance estimates during the lithium-ion cell screening and selection process. The use of a partial representation of the LEO condition is not recommended.

In the Canadian residential sector, the end-uses of appliances, lighting, and plug loads (ALP) account for 16% of total end-use energy consumption. In an effort to reduce the impacts of this energy consumption, electricity technologies such as solar photovoltaics and smart appliances are being adopted. Evaluation of their performance requires an understanding of residential electricity use patterns. Building simulation tools can estimate the time-step performance of such technologies, but require accurate and representative ALP electricity profiles as an input. Sub-metered datasets lack in quantity and thus overall representativeness of the sector. Meanwhile, large, representative datasets are becoming available through electricity smart-metering programs, but usually consist only of whole-house electricity load and lack summary household characteristics (e.g. occupancy, floor space, appliance descriptions). However, homes which are not electrically heated (space, water) or cooled may function as ALP load profiles for simulation. This research addresses these loads with a new method of distinguishing non-electrically heated and cooled homes from a broad dataset of whole-house profiles. The method originates from a comparison of two electricity load datasets: (i) “smart-meter” 15-min time-step whole-house data for 160 homes spanning three years, and (ii) “sub-metered” 1-min time-step data for 23 residential homes. This comparison also speaks to the usefulness of whole-house electricity smart-meter information to building performance simulation.

This study employs experimental techniques to measure the changing internal resistance of flooded, flat-plate lead-acid batteries during container formation, revealing a novel indicator of formation completeness. In order to measure internal resistance during formation, d.c. current pulses are superimposed over the constant formation current at set intervals, while change in voltage is measured. The resulting “pulsed” internal resistance is divided into ohmic and interfacial components by measuring the ohmic resistance with short d.c. pulses as well as with a.c. injection. Various constant-current container formations are carried out using different current levels, plate thicknesses, and pulsing techniques, yielding an array of resistance trends which are explained using Butler-Volmer kinetic theory. Ohmic and interfacial resistance trends are shown both theoretically and experimentally to eventually decay to a predictable steady-state value as the formation proceeds, suggesting that this internal resistance method can be used to detect the completion of the formation. The same principles are shown to apply to recharge cycles as well, but with potentially limited practical implications in comparison to formation.

Introduction. Our nation suffers from a shortage in surgeons. This deficiency must be addressed at the medical student level. Increasing faculty and resident interaction with junior students augments surgical interest. Our surgical interest group has recently redefined its role to address these concerns. Methods. A multifocal approach has been implemented to increase interest in the surgical specialties. Each academic year, senior students recruit first and second year students to our group to establish early exposure. Members receive didactic presentations from surgical faculty, addressing various topics, on a biweekly basis. In addition, scrubbing, knot-tying, and suturing workshops address technical skills throughout the semester. Membership and match data were collated and analyzed. Results. Over the past 5 years, the enrollment in the student interest group increased significantly from 112 to 150. Accordingly, we have observed a parallel increase in the number of students who have successfully matched into surgical residencies. A record number of students (37) from the class of 2013 matched into surgical specialties, representing an 85% increase over the last decade. After creating bylaws and electing societal officers, the group has been recognized by the school’s Student Council and given financial support. At present, the group is fiscally solvent with support from the institution, surgery department, and faculty. Conclusion. As the demand for surgeons increases so too does the need to increase student interest in surgery. Our school has been successful because of our surgical interest group, and we encourage other schools to adopt a similar approach.

Intraocular pressure (IOP) initially increases when an individual enters microgravity compared with baseline values when an individual is in a seated position. This has been attributed to a headward fluid shift that increases venous pressures in the head. The change in IOP exceeds changes measured immediately after moving from seated to supine postures on Earth, when a similar fluid shift is produced. Furthermore, central venous and cerebrospinal fluid pressures are at or below supine position levels when measured initially upon entering microgravity, unlike when moving from seated to supine postures on Earth, when these pressures increase. To investigate the effects of altering gravitational forces on the eye, we made ocular measurements on 24 subjects (13 men, 11 women) in the seated, supine, and prone positions in the laboratory, and upon entering microgravity during parabolic flight. IOP in microgravity (16.3 ± 2.7 mmHg) was significantly elevated above values in the seated (11.5 ± 2.0 mmHg) and supine (13.7 ± 3.0 mmHg) positions, and was significantly less than pressure in the prone position (20.3 ± 2.6 mmHg). In all measurements, P < 0.001. Choroidal area was significantly increased in subjects in a microgravity environment ( P < 0.007) compared with values from subjects in seated (increase of 0.09 ± 0.1 mm2) and supine (increase of 0.06 ± 0.09 mm2) positions. IOP results are consistent with the hypothesis that hydrostatic gradients affect IOP, and may explain how IOP can increase beyond supine values in microgravity when central venous and intracranial pressure do not. Understanding gravitational effects on the eye may help develop hypotheses for how microgravity-induced visual changes develop.

Repurposing retired electric vehicle lithium ion batteries into stationary electricity grid storage will increase their utilization and correspondingly reduce their environmental footprint prior to recycling. In this work, we investigated the performance characteristics of leading commercial cell types repurposed into electricity grid services. Two different positive active materials were compared: (1) a lithium nickel manganese cobalt oxide blended with lithium manganese oxide (LiNiMnCoO2+ LiMn2O4, termed ``NMC+LMO'') and (2) lithium iron phosphate (LiFePO4, termed ``LFP''). The bulk electricity service of energy arbitrage and the ancillary power electricity service of frequency regulation were tested. Performance was evaluated for energy capacity degradation and round-trip energy efficiency throughout cycle life. Half cell testing and electrochemical voltage spectroscopies were used to investigate the origin of degradation. The results gave useful insight into which chemistries are most appropriate for repurposing into which electricity grid service application. It was found that energy arbitrage service degrades energy capacity approximately twice as fast as frequency regulation service. NMC+LMO degrades approximately twice as fast as LFP. The main energy capacity degradation mechanism comes from loss of lithium inventory. We note that inter-cell capacity degradation differences appear to be a function of overall degradation level. Consequently, the battery management system for repurposed applications must have greater ability to manage inter-cell differences than factory electric vehicle systems. NMC+LMO was more energy efficient than LFP (96% vs 94%) and no degradation of energy efficiency was noted over the first 1200 complete cycle equivalents. This indicates that the thermal management systems applied for electric vehicle purposes is sufficient for repurposed applications. The choice of chemistry type thus depends on the service conducted as some services do not demand long life and some are insensitive to the cost of energy inefficiencies.

Three types of 18-65 cylindrical lithium-ion cells with different positive active materials (NCA – nickel cobalt aluminium, NMC – nickel manganese cobalt, LFP – lithium iron phosphate), negative active material graphite average particle sizes (2 – 30 µm) and electrode designs (high power, high energy) were tested using an accelerated low earth orbit (LEO) CubeSat power profile cycle. Each design yields a unique energy density, power capability and cycle life. Each cell type was tested in a 3P group configuration at 10°C in atmospheric pressure (101 kPa-abs) and under vacuum (0.2 kPa-abs). Cell groups were operated in their respective pressure condition until they failed to successfully execute the accelerated LEO cycle. In atmospheric pressure and vacuum, both NMC groups failed due to internal resistance (IR) growth. The atmospheric pressure NCA group failed due to excessive internal gas build-up triggering the current interrupt device (CID) to electrically disconnect. The NCA group in vacuum failed from both IR growth and capacity degradation. The LFP groups both in atmospheric pressure and vacuum have completed approximately 5078 LEO cycles or 2800 equivalent cycles of initial measured coulombic capacity and are still operational with 19% and 21% capacity degradation from their initial measured coulombic capacity, respectively.

Combining intermittent renewable generation with energy storage in the electricity grid has become a preferred route to maintaining stability and reliability while decarbonizing. The effects of combining three uncorrelated intermittent resources with energy storage are not well understood. This study reports on a data-driven model and control strategy that optimizes relative installed capacities of wind, solar, and in-stream tidal generation with energy storage for smoothing and shaping to follow electrical load perturbations. The model is applied to a case study in Nova Scotia, Canada which has strong wind and tidal resources, and moderate solar resources. For load-perturbation control on hour shaping timescales the total system capital costs are approximately 20% greater than the costs of the renewable generation without energy storage and output shaping. Shaping timescales of days and weeks favour greater installed wind, solar, and tidal generating capacity and the use of curtailment for economic optimization, with less installed energy storage capacity. Hour-timescale shaping uses the energy storage to mitigate power variability in intermittent generation, which benefits short-term electricity generation dispatch and reliability. Day-timescales shaping uses the energy storage to supply the load’s variable energy needs using for day-ahead or future electricity generation scheduling.

With the expansion of intermittent renewable energy sources, and the development of economical and scalable energy storage technologies, the management of the electrical grid has the potential to fundamentally change. Under the current grid management paradigm, balancing and stabilizing a grid with a large penetration of intermittent renewables tends to require that those balancing resources ramp power output up and down more rapidly and more frequently to compensate for output variations of intermittent resources, as well as those of load. This paper describes a strategy of combined wind, solar, and in-stream tidal intermittent generation with energy storage. The new control strategy operates dispatchable generation with the objective of keeping the energy storage at a neutral state of charge in preparation for unpredicted upcoming imbalances between intermittent generation output and system load, while limiting power ramp rates within an acceptable envelope. A case study in Nova Scotia, Canada is examined. The model reveals that approximately 4 h of storage is sufficient to permit up to 70% intermittent generation contribution to the grid at a cost about 50% higher than that of the least cost renewable generation alone.

Repurposing of electric vehicle (EV) batteries for a “second life” in electricity grid applications is a potential dual solution for extending the value of these high-quality batteries beyond EV service while reducing the capital cost of grid-scale energy storage. Given the diversity among EV batteries in terms of size, shape, chemistry, performance, and thermal management, it is expected that the practicality and performance of different brands and models will vary in a second-life application. To develop this energy storage technology, common EV battery types must be characterized and ranked according to their performance in different grid services. This experimental study evaluates six different EV batteries with different EV use histories for performance in electricity grid frequency regulation (FR) service using a novel methodology based on the protocol developed by Sandia National Laboratories. For each battery, the applied FR power signal is scaled to greater magnitudes in sequential tests to evaluate trends in energy efficiency and thermal performance. It is found that dc energy efficiency of EV batteries in FR service is primarily influenced by positive active material type and ranges from 92% (NCA) to 99% (NMC) for mid-range FR power magnitudes. Batteries featuring active air or active liquid thermal management are found to maintain safe operating temperatures at substantially higher FR power magnitudes compared to passive thermal management. The results are used to rank the tested EV batteries for commercial performance in second-life FR service, with practical consideration of the trade-offs between metrics in relation to different potential project constraints.

We perform a detailed analysis of the migratory motion of human embryonic stem cells in two-dimensions, both when isolated and in close proximity to another cell, recorded with time-lapse microscopic imaging. We show that isolated cells tend to perform an unusual locally anisotropic walk, moving backwards and forwards along a preferred local direction correlated over a timescale of around 50 min and aligned with the axis of the cell elongation. Increasing elongation of the cell shape is associated with increased instantaneous migration speed. We also show that two cells in close proximity tend to move in the same direction, with the average separation of [Formula: see text]m or less and the correlation length of around 25 μm, a typical cell diameter. These results can be used as a basis for the mathematical modelling of the formation of clonal hESC colonies.

Digby, Nova Scotia, is a largely rural area with a wealth of renewable energy resources, principally wind and tidal. Digby’s electrical load is serviced by an aging 69 kV transmission line that often operates at the export capacity limit because of a local wind energy converter (WEC) field. This study examines the potential of smart charging of electric vehicles (EVs) to achieve two objectives: (1) add load so as to increase export capacity; (2) charge EVs using renewable energy. Multiple survey instruments were used to determine transportation energy needs and travel timing. These were used to create EV charging load timeseries based on “convenience”, “time-of-day”, and idealized “smart” charging. These charging scenarios were evaluated in combination with high resolution data of generation at the wind field, electrical flow through the transmission system, and electricity load. With a 10% adoption rate of EVs, time-of-day charging increased local renewable energy usage by 20% and enables marginal WEC upgrading. Smart charging increases charging by local renewable energy by 73%. More significantly, it adds 3 MW of load when power exports face constraints, allowing enough additional renewable electricity generation capacity to fully power those vehicles.

This article describes the results of a systematic review examining police shootings of unarmed African American males. Each source was evaluated by two reviewers and coded based on topic relevance and inclusion criteria. Because of the weak external validity found among the experimental studies, the authors made a substantive decision not to synthesize studies in a meta-analysis. Social work practice implications are gleaned from secondary data obtained from coroner, medical examiner, toxicology, police reports, and the experimental studies included in the systematic review. Individual, community, and police departmental policy factors were most often reported to explain such shootings when excluding sources that examined armed African American males. Implications for micro and macro–social work practice are summarized as individual, community, and police departmental policy factors.

A model predictive control strategy method is developed for a LEED silver community college building that contains an advanced common loop heat pump HVAC system. MPC is performed using persistence based climate forecasting with two scenarios examined: fixed temperature setpoint pairs; and a deadband of 1 °C between the heating/cooling setpoint. EnergyPlus acts as the “real” building and is linked with R software for model predictive control via the Building Controls Virtual Test Bed. A statistical based building response model is created in R using training data from a calibrated EnergyPlus model. A brute force optimization strategy is used for solving the objective function. A piece-wise objective function maintains thermal comfort during occupied periods with a focus on reducing energy consumption during other periods. Results when using fixed setpoint pairs exhibit a 4% reduction in HVAC energy consumption, and deadband setpoints exhibit a 9% reduction in HVAC energy consumption, compared with reactive rule based control. Of interest is that the type of energy savings (thermal energy vs electricity) varies depending upon the setpoint options. The results are promising given the strict thermal comfort requirement employed, minimal search space, use of simplistic persistence forecasting, and the sophisticated HVAC system.

The modeling and simulation of domestic hot water systems, including solar thermal and co-generation technologies, relies on accurate, high time-step resolution water consumption profiles. Due to the expensive nature of field studies, previous profiles have been limited in number of participants, or have been generated synthetically using probabilistic modelling techniques. The Solar City program in Halifax has measured hot water flow rate and temperature data in 119 homes at a time-step of 1 min; and includes a survey of occupancy rates and other relevant meta-data. In this paper, we discuss the data acquisition and processing (with a focus on flow rate data), and conduct analysis to reveal consumption trends and produce a new set of time-step profiles for modeling and simulation. Average hot water consumption per household is 172 L/day with a strong dependency on number of occupants. The hourly profile peaks twice daily, and shifts by several hours on Sunday. The average draw temperature was found to be 51.8 °C, which is lower than the default value of 55 °C applied by many building modeling/simulation packages. The average cold water supply temperature was found to be roughly sinusoidal about 12.4 °C with approximately one-month lag compared to ambient air temperature.