Quantifying the Benefits of a Solar Home System-Based DC Microgrid for Rural Electrification

Off-grid solar home systems (SHSs) currently constitute a major source of providing basic electricity needs in un(der)-electrified regions of the world, with around 73 million households having benefited from off-grid solar solutions by 2017. However, in and of itself, state-of-the-art SHSs can only provide electricity access with adequate power supply availability up to tier 2, and to some extent, tier 3 levels of the Multi-tier Framework (MTF) for measuring household electricity access. When considering system metrics of loss of load probability (LLP) and battery size, meeting the electricity needs of tiers 4 and 5 is untenable through SHSs alone. Alternatively, a bottom-up microgrid composed of interconnected SHSs is proposed. Such an approach can enable the so-called climb up the rural electrification ladder. The impact of the microgrid size on the system metrics like LLP and energy deficit is evaluated. Finally, it is found that the interconnected SHS-based microgrid can provide more than 40% and 30% gains in battery sizing for the same LLP level as compared to the standalone SHSs sizes for tiers 4 and 5 of the MTF, respectively, thus quantifying the definite gains of an SHS-based microgrid over standalone SHSs. This study paves the way for visualizing SHS-based rural DC microgrids that can not only enable electricity access to the higher tiers of the MTF with lower battery storage needs but also make use of existing SHS infrastructure, thus enabling a technologically easy climb up the rural electrification ladder.

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Incorporation of plasma-based next-generation sequencing to improve guideline-concordant molecular testing in patients with newly diagnosed metastatic nonsquamous non-small cell lung cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2020.39.28_suppl.14 ◽

2021 ◽

Vol 39 (28_suppl) ◽

pp. 14-14

Author(s):

Charu Aggarwal ◽

Melina Elpi Marmarelis ◽

Wei-Ting Hwang ◽

Dylan G. Scholes ◽

Aditi Puri Singh ◽

...

Keyword(s):

Clinical Practice ◽

Practice Change ◽

Molecular Testing ◽

Tier 2 ◽

Newly Diagnosed ◽

Next Generation ◽

First Line ◽

Tier 1 ◽

Tier 3 ◽

The Impact

14 Background: Current NCCN guidelines recommend comprehensive molecular profiling for all newly diagnosed patients with metastatic non-squamous NSCLC to enable the delivery of personalized medicine. We have previously demonstrated that incorporation of plasma based next-generation gene sequencing (NGS) improves detection of clinically actionable mutations in patients with advanced NSCLC (Aggarwal et al, JAMA Oncology, 2018). To increase rates of comprehensive molecular testing at our institution, we adapted our clinical practice to include concurrent use of plasma (P) and tissue (T) based NGS upon initial diagnosis. P NGS testing was performed using a commercial 74 gene assay. We analyzed the impact of this practice change on guideline concordant molecular testing at our institution. Methods: A retrospective cohort study of patients with newly diagnosed metastatic non-squamous NSCLC following the implementation of this practice change in 12/2018 was performed. Tiers of NCCN guideline concordant testing were defined, Tier 1: complete EGFR, ALK, BRAF, ROS1, MET, RET, NTRK testing, Tier 2: included above, but with incomplete NTRK testing, Tier 3: > 2 genes tested, Tier 4: single gene testing, Tier 5: no testing. Proportion of patients with comprehensive molecular testing by modality (T NGS vs. T+P NGS) were compared using one-sided Fisher’s exact test. Results: Between 01/2019, and 12/2019, 170 patients with newly diagnosed metastatic non-Sq NSCLC were treated at our institution. Overall, 98.2% (167/170) patients underwent molecular testing, Tier 1: n = 100 (59%), Tier 2: n = 39 (23%), Tier 3/4: n = 28 (16.5%), Tier 5: n = 3 (2%). Amongst these patients, 43.1% (72/167) were tested with T NGS alone, 8% (15/167) with P NGS alone, and 47.9% (80/167) with T+P NGS. A higher proportion of patients underwent comprehensive molecular testing (Tiers 1+2) using T+P NGS: 95.7% (79/80) compared to T alone: 62.5% (45/72), p < 0.0005. Prior to the initiation of first line treatment, 72.4% (123/170) patients underwent molecular testing, Tier 1: n = 73 (59%), Tier 2: n = 27 (22%) and Tier 3/4: n = 23 (18%). Amongst these, 39% (48/123) were tested with T NGS alone, 7% (9/123) with P NGS alone and 53.6% (66/123) with T+P NGS. A higher proportion of patients underwent comprehensive molecular testing (Tiers 1+2) using T+P NGS, 100% (66/66) compared to 52% (25/48) with T NGS alone (p < 0.0005). Conclusions: Incorporation of concurrent T+P NGS testing in treatment naïve metastatic non-Sq NSCLC significantly increased the proportion of patients undergoing guideline concordant molecular testing, including prior to initiation of first-line therapy at our institution. Concurrent T+P NGS should be adopted into institutional pathways and routine clinical practice.

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Study protocol for COvid-19 Vascular sERvice (COVER) study: The impact of the COVID-19 pandemic on the provision, practice and outcomes of vascular surgery

10.1101/2020.05.27.20114322 ◽

2020 ◽

Author(s):

Ruth A Benson

Keyword(s):

Vascular Surgery ◽

Service Provision ◽

British Society ◽

Tier 2 ◽

Patient Level ◽

Tier 1 ◽

Ethical Approval ◽

The Uk ◽

Tier 3 ◽

The Impact

ABSTRACTBackgroundThe novel Coronavirus Disease 2019 (COVID-19) pandemic is having a profound impact on global healthcare. Shortages in staff, operating theatre space and intensive care beds has led to a significant reduction in the provision of surgical care. Even vascular surgery, often insulated from resource scarcity due to its status as an urgent specialty, has limited capacity due to the pandemic. Furthermore, many vascular surgical patients are elderly with multiple comorbidities putting them at increased risk of COVID-19 and its complications. There is an urgent need to investigate the impact on patients presenting to vascular surgeons during the COVID-19 pandemic.Methods and AnalysisThe COvid-19 Vascular sERvice (COVER) study has been designed to investigate the worldwide impact of the COVID-19 pandemic on vascular surgery, at both service provision and individual patient level. COVER is running as a collaborative study through the Vascular and Endovascular Research Network (VERN) with the support of numerous national (Vascular Society of Great Britain and Ireland, British Society of Endovascular Therapy, British Society of Interventional Radiology, Rouleaux Club) and an evolving number of international organisations (Vascupedia, SingVasc, Audible Bleeding (USA), Australian and New Zealand Vascular Trials Network (ANZVTN)). The study has 3 ‘Tiers’: Tier 1 is a survey of vascular surgeons to capture longitudinal changes to the provision of vascular services within their hospital; Tier 2 captures data on vascular and endovascular procedures performed during the pandemic; and Tier 3 will capture any deviations to patient management strategies from prepandemic best practice. Data submission and collection will be electronic using online survey tools (Tier 1: SurveyMonkey® for service provision data) and encrypted data capture forms (Tiers 2 and 3: REDCap® for patient level data). Tier 1 data will undergo real-time serial analysis to determine longitudinal changes in practice, with country-specific analyses also performed. The analysis of Tier 2 and Tier 3 data will occur on completion of the study as per the prespecified statistical analysis plan.Ethical ApprovalEthical approval from the UK Health Research Authority has been obtained for Tiers 2 and 3 (20/NW/0196 Liverpool Central). Participating centres in the UK will be required to seek local research and development approval. Non-UK centres will need to obtain a research ethics committee or institutional review board approvals in accordance with national and/or local requirements.ISRCTN: 80453162 (https://doi.org/10.1186/ISRCTN80453162)Ethical Approval: 20/NW/0196 Liverpool Central, IRAS: 282224

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The Impact of the November 2020 English National Lockdown on COVID-19 case counts

10.1101/2021.01.03.21249169 ◽

2021 ◽

Author(s):

Paul R Hunter ◽

Julii Brainard ◽

Alastair Grant

Keyword(s):

Reproductive Rate ◽

Tier 2 ◽

New Variant ◽

Tier System ◽

Obvious Benefit ◽

Beneficial Impact ◽

R Value ◽

The Uk ◽

Tier 3 ◽

The Impact

In the UK the epidemic of COVID-19 continues to pose a significant threat to public health. On the 14th October the English government introduced a tier system for control of the epidemic but just 3 weeks later a National lockdown across all areas of England was implemented. When English areas emerged from Lockdown many were placed in different tiers (most typically moved up at least one tier). However, the effectiveness of the tier system has been challenged by the emergence of a new variant of SARS-CoV-2 which appears to be much more infectious. In addition, from early November a trial mass testing service was being run in Liverpool. We used publicly available data of daily cases by local authority (local government areas) and estimated the reproductive rate (R value) of the epidemic based on 7-day case numbers compared with the previous 7-day period. There was a clear surge in infections from a few days before to several days after the lockdown was implemented. But this surge was almost exclusively associated with Tier 1 and Tier 2 authorities. In Tier 3 authorities where hospitality venues were only allowed to operate as restaurants there was no such surge. After this initial surge, cases declined in all three tiers with the R value dropping to a mean of about 0.7 independent of tier. London, The South East and East of England Regions saw rising infection rates in the last week or so of lockdown primarily in children of secondary school age. We could find no obvious benefit of the trial mass screening programme in Liverpool city. We conclude that in Tiers 1 and 2 much of the beneficial impact of the national lockdown was lost probably because of the leak of its likely implementation five days early leading to increased socialising in these areas before the start of lockdown. We further conclude that given that the new variant is estimated to have an R value of between 0.39 and 0.93 greater than previous variants, any lockdown as strict as the November one would be insufficient to reverse the increase in infections by itself. The value of city-wide mass testing to control the epidemic remains uncertain.

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Study protocol for COvid-19 Vascular sERvice (COVER) study: The impact of the COVID-19 pandemic on the provision, practice and outcomes of vascular surgery

PLoS ONE ◽

10.1371/journal.pone.0243299 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0243299

Author(s):

Ruth A. Benson ◽

Sandip Nandhra ◽

Keyword(s):

Vascular Surgery ◽

Service Provision ◽

Resource Scarcity ◽

Research Network ◽

Tier 2 ◽

Longitudinal Changes ◽

Patient Level ◽

Tier 1 ◽

Tier 3 ◽

The Impact

Background The novel Coronavirus Disease 2019 (COVID-19) pandemic is having a profound impact on global healthcare. Shortages in staff, operating theatre space and intensive care beds has led to a significant reduction in the provision of surgical care. Even vascular surgery, often insulated from resource scarcity due to its status as an urgent specialty, has limited capacity due to the pandemic. Furthermore, many vascular surgical patients are elderly with multiple comorbidities putting them at increased risk of COVID-19 and its complications. There is an urgent need to investigate the impact on patients presenting to vascular surgeons during the COVID-19 pandemic. Methods and analysis The COvid-19 Vascular sERvice (COVER) study has been designed to investigate the worldwide impact of the COVID-19 pandemic on vascular surgery, at both service provision and individual patient level. COVER is running as a collaborative study through the Vascular and Endovascular Research Network (VERN), an independent, international vascular research collaborative with the support of numerous national and international organisations). The study has 3 ‘Tiers’: Tier 1 is a survey of vascular surgeons to capture longitudinal changes to the provision of vascular services within their hospital; Tier 2 captures data on vascular and endovascular procedures performed during the pandemic; and Tier 3 will capture any deviations to patient management strategies from pre-pandemic best practice. Data submission and collection will be electronic using online survey tools (Tier 1: SurveyMonkey® for service provision data) and encrypted data capture forms (Tiers 2 and 3: REDCap® for patient level data). Tier 1 data will undergo real-time serial analysis to determine longitudinal changes in practice, with country-specific analyses also performed. The analysis of Tier 2 and Tier 3 data will occur on completion of the study as per the pre-specified statistical analysis plan.

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ESMO Management and treatment adapted recommendations in the COVID-19 era: Lung cancer

ESMO Open ◽

10.1136/esmoopen-2020-000820 ◽

2020 ◽

Vol 5 (Suppl 3) ◽

pp. e000820 ◽

Cited By ~ 13

Author(s):

Antonio Passaro ◽

Alfredo Addeo ◽

Christophe Von Garnier ◽

Fiona Blackhall ◽

David Planchard ◽

...

Keyword(s):

Lung Cancer ◽

Cancer Care ◽

Negative Impact ◽

Well Being ◽

Tier 2 ◽

Optimal Care ◽

Tier 1 ◽

Global Spread ◽

Tier 3 ◽

The Impact

The COVID-19 pandemic, characterised by a fast and global spread during the first months of 2020, has prompted the development of a structured set of recommendations for cancer care management, to maintain the highest possible standards. Within this framework, it is crucial to ensure no disruption to essential oncological services and guarantee the optimal care.This is a structured proposal for the management of lung cancer, comprising three levels of priorities, namely: tier 1 (high priority), tier 2 (medium priority) and tier 3 (low priority)—defined according to the criteria of the Cancer Care Ontario, Huntsman Cancer Institute and Magnitude of Clinical Benefit Scale.The manuscript emphasises the impact of the COVID-19 pandemic on lung cancer care and reconsiders all steps from diagnosis, staging and treatment.These recommendations should, therefore, serve as guidance for prioritising the different aspects of cancer care to mitigate the possible negative impact of the COVID-19 pandemic on the management of our patients.As the situation is rapidly evolving, practical actions are required to guarantee the best patients’ treatment while protecting and respecting their rights, safety and well-being. In this environment, cancer practitioners have great responsibilities: provide timely, appropriate, compassionate and justified cancer care, while protecting themselves and their patients from being infected with COVID-19. In case of shortages, resources must be distributed fairly. Consequently, the following recommendations can be applied with significant nuances, depending on the time and location for their use, considering variable constraints imposed to the health systems. An exceptional flexibility is required from cancer caregivers.

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The Energy Lock-In Effect of Solar Home Systems: A Case Study in Rural Nigeria

Energies ◽

10.3390/en13246682 ◽

2020 ◽

Vol 13 (24) ◽

pp. 6682

Author(s):

Olumide Hassan ◽

Stephen Morse ◽

Matthew Leach

Keyword(s):

Solar Pv ◽

Household Energy ◽

Rural Nigeria ◽

Sub Saharan ◽

Lock In Effect ◽

Solar Home System ◽

Lock In ◽

Electricity Access ◽

The Impact

Ongoing reductions in the costs of solar PV and battery technologies have contributed to an increased use of home energy systems in Sub-Saharan African regions without grid access. However, such systems can normally support only low-power end uses, and there has been little research regarding the impact on households unable to transition to higher-wattage energy services in the continued absence of the grid. This paper examines the challenges facing rural energy transitions and whether households feel they are energy ‘locked in’. A mixed-methods approach using questionnaire-based household energy surveys of rural solar home system (SHS) users was used to collect qualitative and quantitative data. Thematic analysis and a mixture of descriptive and inferential statistical analyses were applied. The results showed that a significant number of households possessed appliances that could not be powered by their SHS and were willing to spend large sums to connect were a higher-capacity option available. This implied that a significant number of the households were locked into a low-energy future. Swarm electrification technology and energy efficient, DC-powered plug-and-play appliances were suggested as means to move the households to higher tiers of electricity access.

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Direction of luxury fashion retailers' post-entry expansion – the evidence from China

International Journal of Retail & Distribution Management ◽

10.1108/ijrdm-06-2020-0218 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Huifeng Bai ◽

Julie McColl ◽

Christopher Moore ◽

Weijing He ◽

Jin Shi

Keyword(s):

Local Market ◽

Tier 2 ◽

Content Type ◽

Tier System ◽

Brick And Mortar ◽

International Retailing ◽

Post Entry ◽

Tier 3 ◽

The Impact ◽

Initial Entry

PurposeThis empirical study, from the international retailing perspective, examines the direction of retailers' further expansion after initial entry into overseas host market in the context of the luxury fashion retail market in China.Design/methodology/approachThe research adopts qualitative multiple case studies.FindingsAfter initial entry into China, luxury fashion retailers further expand their retail operations through three directional patterns: cautious, regional and countrywide expansions. The stepwise expansion from tier-1 to tier-2 and tier-3 cities remains popular; however, the importance of the tier system of Chinese cities has been weakened because tier-3 cities in affluent regions are perceived to have more potential than some tier-2 cities in less developed regions. The retailers assess a potential local market through interrelated criteria, including location and strategic importance, economic development, available store locations and staff, a high degree of urbanisation and tourism, debatable favourable policies and offers, and popularity of e- and m-commerce. There is a positive relationship between popularity of e- and m-commerce in a city and the potential of that city to run brick-and-mortar stores.Originality/valueThe paper offers an insight into the current international retailing literature by examining the direction of luxury fashion retailers' further expansion after their initial market entry. Particularly, the research considers a set of criteria which can be used to assess a potential local market, and the impact of e- and m-commerce on local market choices for brick-and-mortar stores.

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Assessment of the Impact of Electric Vehicle Batteries in the Non-Linear Control of DC Microgrids

Applied Sciences ◽

10.3390/app11104415 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4415

Author(s):

Pierre Samuel ◽

Rachid Eddaaif ◽

Andrés González-Zumba ◽

Jean-Michel Clairand

Keyword(s):

Nonlinear Control ◽

Electric Vehicle ◽

Energy Production ◽

Environmental Issues ◽

Dc Microgrid ◽

Dc Microgrids ◽

Vehicle Load ◽

Nonlinear Control Theory ◽

Stability Issues ◽

The Impact

Several efforts need to be performed in transportation and energy production to mitigate the current environmental issues that are related to fossil fuel use. The implementation of DC microgrids and the use of electric vehicles seem to be an adequate solution. However, various technical challenges have to be addressed, like grid stability issues. Thus, this case report assesses the impact of an electric vehicle load in a DC microgrid, subject to nonlinear control theory. The EV battery pack is modeled and simulated. Subsequently, it is included as a load in an available model of nonlinear control of DC microgrids. The results demonstrate high stability with this new load and the feasibility of its implementation.

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Evaluating the impacts of tiered restrictions introduced in England, during October and December 2020 on COVID-19 cases: A synthetic control study

10.1101/2021.03.09.21253165 ◽

2021 ◽

Author(s):

Xingna Zhang ◽

Gwilym Owen ◽

Mark Green ◽

Iain Buchan ◽

Ben Barr

Keyword(s):

Interaction Analysis ◽

Socioeconomic Deprivation ◽

Control Group ◽

Marginal Effect ◽

Synthetic Control ◽

Tier 2 ◽

Detection Rates ◽

Wide Range ◽

Tier 3 ◽

The Impact

AbstractBackgroundIn 2020, a second wave of COVID-19 cases unevenly affected places in England leading to the introduction of a tiered system of controls with different geographical areas subject to different levels of restrictions. Whilst previous research has examined the impact of national lockdowns on transmission, there has been limited research examining the marginal effect of differences in localised restrictions or how these effects vary between socioeconomic contexts. We therefore examined how Tier 3 restrictions in England implemented between October-December 2020, which included additional restrictions on the hospitality sector and people meeting outdoors affected COVID-19 case rates, compared to Tier 2 restrictions, and how these effects varied by level of deprivation.MethodsWe used data on weekly reported COVID-19 cases for 7201 neighbourhoods in England and adjusted these for changing case-detection rates to provide an estimate of weekly SARS-CoV-2 infections in each neighbourhood. We identified those areas that entered Tier 3 restrictions at two time points in October and December, and constructed a synthetic control group of similar places that had entered Tier 2 restrictions, using calibration weights to match them on a wide range of covariates that may influence transmission. We then compared the change in weekly infections between those entering Tier 3 to the synthetic control group to estimate the proportional reduction of cases resulting from Tier 3 restrictions compared to Tier 2 restrictions, over a 4-week period. We further used interaction analysis to estimate whether this effect differed based on the level of socioeconomic deprivation in each neighbourhood and whether effects were modified by the prevalence of a new more infectious variant of SARS-CoV-2 (B.1.1.7) in each area.ResultsThe introduction of Tier 3 restrictions in October and December was associated with a 14% (95% CI 10% to 19%) and 20% (95% CI 13% to 29%) reduction in infections respectively, compared to the rates expected if only Tier 2 restrictions had been in place in those areas. We found that effects were similar across levels of deprivation and limited evidence that Tier 3 restrictions had a greater effect in areas where the new more infectious variant was more prevalent.InterpretationAdditional restrictions on hospitality and meeting outdoors introduced in Tier 3 areas in England had a moderate effect on transmission and these restrictions did not appear to increase inequalities, having a similar impact across areas with differing levels of socioeconomic deprivation. Where transmission risks vary between geographical areas a tiered approach of local restrictions on outdoor mixing and hospitality can contribute to control of SARS-CoV-2 and is unlikely to increases inequalities in transmission.

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Sustainable Rural Electrification Through Solar PV DC Microgrids—An Architecture-Based Assessment

Processes ◽

10.3390/pr8111417 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1417

Author(s):

Mashood Nasir ◽

Saqib Iqbal ◽

Hassan A. Khan ◽

Juan C. Vasquez ◽

Josep M. Guerrero

Keyword(s):

Distributed Generation ◽

Distributed Storage ◽

Rural Electrification ◽

Solar Photovoltaic ◽

Power Electronic ◽

Dc Microgrid ◽

Dc Microgrids ◽

Loss Analysis ◽

Study Results ◽

Central Storage

Solar photovoltaic (PV) direct current (DC) microgrids have gained significant popularity during the last decade for low cost and sustainable rural electrification. Various system architectures have been practically deployed, however, their assessment concerning system sizing, losses, and operational efficiency is not readily available in the literature. Therefore, in this research work, a mathematical framework for the comparative analysis of various architectures of solar photovoltaic-based DC microgrids for rural applications is presented. The compared architectures mainly include (a) central generation and central storage architecture, (b) central generation and distributed storage architecture, (c) distributed generation and central storage architecture, and (d) distributed generation and distributed storage architecture. Each architecture is evaluated for losses, including distribution losses and power electronic conversion losses, for typical power delivery from source end to the load end in the custom village settings. Newton–Raphson method modified for DC power flow was used for distribution loss analysis, while power electronic converter loss modeling along with the Matlab curve-fitting tool was used for the evaluation of power electronic losses. Based upon the loss analysis, a framework for DC microgrid components (PV and battery) sizing was presented and also applied to the various architectures under consideration. The case study results show that distributed generation and distributed storage architecture with typical usage diversity of 40% is the most feasible architecture from both system sizing and operational cost perspectives and is 13% more efficient from central generation and central storage architecture for a typical village of 40 houses. The presented framework and the analysis results will be useful in selecting an optimal DC microgrid architecture for future rural electrification implementations.

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