Photovoltaic stand-alone modular systems, phase 2

The final hardware and system qualification phase of a two part stand-alone photovoltaic (PV) system development is covered. The final design incorporated modular, power blocks capable of expanding incrementally from 320 watts to twenty kilowatts (PK). The basic power unit (PU) was nominally rated 1.28 kWp. The controls units, power collection buses and main lugs, electrical protection subsystems, power switching, and load management circuits are housed in a common control enclosure. Photo-voltaic modules are electrically connected in a horizontal daisy-chain method via Amp Solarlok plugs mating with compatible connectors installed on the back side of each photovoltaic module. A pair of channel rails accommodate the mounting of the modules into a frameless panel support structure. Foundations are of a unique planter (tub-like) configuration to allow for world-wide deployment without restriction as to types of soil. One battery string capable of supplying approximately 240 ampere hours nominal of carryover power is specified for each basic power unit. Load prioritization and shedding circuits are included to protect critical loads and selectively shed and defer lower priority or noncritical power demands. The baseline system, operating at approximately 2 1/2 PUs (3.2 kW pk.) was installed and deployed. Qualification was successfully complete in March 1983; since that time, the demonstration system has logged approximately 3000 hours of continuous operation under load without major incident

Design description report for a photovoltaic power system for a remote satellite earth terminal

A photovoltaic (PV) power system has been installed as an adjunct to an agricultural school at Wawatobi on the large northern island of the Republic of Indonesia. Its purpose is to provide power for a satellite earth station and a classroom. The renewable energy developed supports the video and audio teleconferencing systems as well as the facility at large. The ground station may later be used to provide telephone service. The installation was made in support of the Agency for International Development's Rural Satellite Program, whose purpose is to demonstrate the use of satellite communications for rural development assistance applications. The objective of this particular PV power system is to demonstrate the suitability of a hybrid PV engine-generator configuration for remote satellite earth stations

Digital Equity in the time of COVID-19: The Access Issue

This report is a part of a series of reports on digital equity in the time of COVID-19 written by members of the MERC SY20 study team. MERC launched the SY20 project to provide rapid response, iterative research to help address immediate and enduring needs by school divisions in metropolitan Richmond. The project has the following goals: (1) To convene conversations between scholars and practitioners on critical topics in public education relevant to the moment, (2) To share examples of local efforts that illustrate innovation and best practice, (3) To encourage community engagement and dialogue on our work through broad dissemination

Digital Equity in the Time of COVID: Student Use of Technology for Equitable Outcomes

This issue brief is the third and final in a series published by the Metropolitan Educational Research Consortium (MERC) addressing digital equity in K-12 schools. It examines research regarding students’ use of and outcomes related to technology. Research finds that inequities exist in use and outcomes for students based on gender, language, ability, race, SES and other sociocultural factors. Based on these inequities, theoretical and practical recommendations are discussed

School Division Policies Related to Suicide Prevention and Response

Suicide is one of the leading causes of death among youth age 10-19, and is an increasing concern in the wake of COVID-19. K-12 schools are crucial spaces for offering mental health support to students, and can implement policies to help prevent suicidal thoughts and behaviors. This MERC research and policy brief focuses on education policy related to suicide prevention and response. It is structured to answer five questions: 1) What are recent trends in youth suicide? 2) What does research show about school division policies that are effective in suicide prevention and response? 3) What policies in Virginia and the MERC region guide the prevention of suicide in school divisions? 4) What are the key takeaways and recommendations for preventing youth suicide through education policy

Strategies for Addressing Chronic Absenteeism in the Post-Pandemic Era

Although chronic absenteeism has been an enduring concern in PK-12 schools, it has doubled since the onset of the COVID-19 pandemic. To explore strategies for addressing this issue, this MERC research and policy brief answers five questions: 1) What are trends in chronic absenteeism pre and post-pandemic?, 2) What factors contribute to chronic absenteeism and which student groups are particularly vulnerable? 3) What are the connections between chronic absenteeism and other student outcomes? 4) What strategies are effective in reducing chronic absenteeism?, and 5) What are policies at the state and school board level intended to help address chronic absenteeism? It concludes with key takeaways and recommendations for addressing chronic absenteeism in the post-pandemic era

Addressing School Bullying Since the Onset of COVID-19: A MERC Research and Policy Brief

Among the challenges presented by the COVID-19 pandemic is a shift in the nature and intensity of school bullying, perhaps symptomatic of the rapid changes and stressors that PK-12 students have endured since 2020. In this MERC research and policy brief, we explore how school bullying has changed since the onset of COVID-19 as well as research-based strategies for how educators and division leaders can best respond to it. The brief answers the following questions: 1) What is the nature of school bullying since the onset of COVID-19? 2) Which students have been particularly impacted by bullying since the pandemic? 3) What are recommended strategies for preventing school bullying since the onset of COVID-19? 4) What are current policies in Virginia and MERC school divisions related to addressing bullying? 5) What are the key takeaways and enduring questions about addressing school bullying since the onset of COVID-19

Early surgery versus initial conservative treatment in patients with spontaneous supratentorial lobar intracerebral haematomas (STICH II):a randomised trial

SummaryBackgroundThe balance of risk and benefit from early neurosurgical intervention for conscious patients with superficial lobar intracerebral haemorrhage of 10–100 mL and no intraventricular haemorrhage admitted within 48 h of ictus is unclear. We therefore tested the hypothesis that early surgery compared with initial conservative treatment could improve outcome in these patients.MethodsIn this international, parallel-group trial undertaken in 78 centres in 27 countries, we compared early surgical haematoma evacuation within 12 h of randomisation plus medical treatment with initial medical treatment alone (later evacuation was allowed if judged necessary). An automatic telephone and internet-based randomisation service was used to assign patients to surgery and initial conservative treatment in a 1:1 ratio. The trial was not masked. The primary outcome was a prognosis-based dichotomised (favourable or unfavourable) outcome of the 8 point Extended Glasgow Outcome Scale (GOSE) obtained by questionnaires posted to patients at 6 months. Analysis was by intention to treat. This trial is registered, number ISRCTN22153967.Findings307 of 601 patients were randomly assigned to early surgery and 294 to initial conservative treatment; 298 and 291 were followed up at 6 months, respectively; and 297 and 286 were included in the analysis, respectively. 174 (59%) of 297 patients in the early surgery group had an unfavourable outcome versus 178 (62%) of 286 patients in the initial conservative treatment group (absolute difference 3·7% [95% CI −4·3 to 11·6], odds ratio 0·86 [0·62 to 1·20]; p=0·367).InterpretationThe STICH II results confirm that early surgery does not increase the rate of death or disability at 6 months and might have a small but clinically relevant survival advantage for patients with spontaneous superficial intracerebral haemorrhage without intraventricular haemorrhage.FundingUK Medical Research Council