scholarly journals The impact of large-scale dynamic load modeling on frequency response in the U.S. Eastern Interconnection

2020 ◽  
Vol 120 ◽  
pp. 105983 ◽  
Author(s):  
Melanie Bennett ◽  
Yilu Liu
Keyword(s):  
Frequency Response ◽  
Dynamic Load ◽  
Large Scale ◽  
Load Modeling ◽  
The Impact ◽  
The U.S

scholarly journals Impact of High PV Penetration on Regional Power Grids

2020 ◽  
Author(s):  
Shutang You
Keyword(s):  
Frequency Response ◽  
Solar Irradiance ◽  
Power Grids ◽  
Energy Price ◽  
Regional Power ◽  
Pv Penetration ◽  
The Impact ◽  
The U.S

Due to the high solar irradiance or energy price, certain regions in the U.S. may reach 100% PV penetration and experience degradation of frequency response greater than the interconnection as a whole. Therefore, in this section, the 100% PV penetration region in each interconnection is simulated to study the local high PV penetration effects. The study was performed by quantifying RoCoF, frequency nadir, and settling frequency at different regional PV penetration levels. The impact of high regional PV penetration on the compliance of grid code on frequency response is also studied.

Changing Forms of U.S. Hegemony in Puerto Rico: The Impact on the Family and Sexuality

Itinerario ◽  
2001 ◽  
Vol 25 (3-4) ◽  
pp. 90-111 ◽  
Author(s):  
Helen I. Safa
Keyword(s):  
Puerto Rico ◽  
Large Scale ◽  
The United States ◽  
The Philippines ◽  
The Family ◽  
Three Stages ◽  
Operation Bootstrap ◽  
The Impact ◽  
Constant Source ◽  
The U.S

It has been over a hundred years since the U.S. took control of Puerto Rico. In that time, the way in which the U.S. perceived Puerto Rico has changed from a colony requiring Americanisation to, in the 1950s, its showcase of democracy in the Caribbean, to today, an island that still retains geopolitical importance for the U.S., but represents an increasing economic burden. The failure of Operation Bootstrap, as the Puerto Rican industrialization program was known, resulted in permanent large-scale unemployment, with a population dependent on federal transfers for a living, and a constant source of migration to the mainland, where over half of Puerto Ricans now live. I shall trace the outline of these three stages in U.S. hegemony over Puerto Rico, and argue that throughout the U.S. Congress was reluctant to fully incorporate Puerto Rico, because its population was deemed racially and socially inferior to that of the mainland. Though the removal of Spain from Puerto Rico, Cuba and the Philippines was considered part of the its ‘manifest destiny’, the United States never intended to incorporate these people so different from the U.S. as part of the American nation, as was done with its earlier acquisitions in Texas, Alaska or even Hawaii.

Privacy Factors for Successful Ubiquitous Computing

2011 ◽  
pp. 143-160
Author(s):  
Linda Little ◽  
Pam Briggs
Keyword(s):  
Ubiquitous Computing ◽  
Social Engagement ◽  
Large Scale ◽  
New Technologies ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Computing Machinery ◽  
Large Scale Survey ◽  
The Impact ◽  
The U.S

Certain privacy principles have been established by industry, e.g. the U.S. Public Policy Committee of the Association for Computing Machinery (USACM). Over the past two years, we have been trying to understand whether such principles reflect the concerns of the ordinary citizen. We have developed a method of enquiry which displays a rich context to the user in order to elicit more detailed information about those privacy factors that underpin our acceptance of ubiquitous computing. To investigate use and acceptance, Videotaped Activity Scenarios specifically related to the exchange of health, financial, shopping and e-voting information and a large scale survey were used. We present a detailed analysis of user concerns, firstly in terms of a modified Hertzberg model that identifies a set of constructs that might reflect user-generated privacy principles, secondly those factors likely to play a key role in an individuals cost-benefit analysis, and thirdly, longer-term concerns of the citizen in terms of the impact of new technologies on social engagement and human values.

Dynamic load modeling in large scale stability studies

1988 ◽  
Vol 3 (3) ◽  
pp. 1039-1045 ◽  
Author(s):  
E. Vaahedi ◽  
H.M.Z. El-Din ◽  
W.W. Price
Keyword(s):  
Dynamic Load ◽  
Large Scale ◽  
Stability Studies ◽  
Load Modeling

scholarly journals DISTRIBUTIONAL IMPLICATIONS OF A NATIONAL CO2 TAX IN THE U.S. ACROSS INCOME CLASSES AND REGIONS: A MULTI-MODEL OVERVIEW

2018 ◽  
Vol 09 (01) ◽  
pp. 1840004 ◽  
Author(s):  
JUSTIN CARON ◽  
JEFFERSON COLE ◽  
RICHARD GOETTLE ◽  
CHIKARA ONDA ◽  
JAMES MCFARLAND ◽  
...  
Keyword(s):  
Low Income ◽  
Large Scale ◽  
Scale Economy ◽  
Model Assessment ◽  
Welfare Impacts ◽  
Revenue Recycling ◽  
Capital Tax ◽  
Household Incomes ◽  
The Impact ◽  
The U.S

This paper presents a multi-model assessment of the distributional impacts of carbon pricing. A set of harmonized representative CO2 taxes and tax revenue recycling schemes is implemented in five large-scale economy-wide general equilibrium models. Recycling schemes include various combinations of uniform transfers to households and labor and capital income tax reductions. Particular focus is put on equity — the distribution of impacts across household incomes — and efficiency, evaluated in terms of household welfare. Despite important differences in the assumptions underlying the models, we find general agreement regarding the ranking of recycling schemes in terms of both efficiency and equity. All models identify a clear trade-off between efficient but regressive capital tax reductions and progressive but costly uniform transfers to households; all agree upon the inferiority of labor tax reductions in terms of welfare efficiency; and all agree that different combinations of capital tax reductions and household transfers can be used to balance efficiency and distributional concerns. A subset of the models go further and find that equity concerns, particularly regarding the impact of the tax on low income households, can be alleviated without sacrificing much of the double-dividend benefits offered by capital tax rebates. There is, however, less agreement regarding the progressivity of CO2 taxation net of revenue recycling. Regionally, the models agree that abatement and welfare impacts will vary considerably across regions of the U.S. and generally agree on their broad geographical distribution. There is, however, little agreement regarding the regions which would profit more from the various recycling schemes.

scholarly journals Musculoskeletal Injuries and United States Army Readiness. Part II: Management Challenges and Risk Mitigation Initiatives

2020 ◽  
Vol 185 (9-10) ◽  
pp. e1472-e1480 ◽  
Author(s):  
Joseph M Molloy ◽  
Timothy L Pendergrass ◽  
Ian E Lee ◽  
Keith G Hauret ◽  
Michelle C Chervak ◽  
...  
Keyword(s):  
United States ◽  
Risk Reduction ◽  
Injury Risk ◽  
Large Scale ◽  
Musculoskeletal Injuries ◽  
Chronic Injury ◽  
Early Management ◽  
The Impact ◽  
The U.S

Abstract Introduction Noncombat injuries (“injuries”) threaten soldier health and United States (U.S.) Army medical readiness, accounting for more than twice as many outpatient medical encounters among active component (AC) soldiers as behavioral health conditions (the second leading cause of outpatient visits). Noncombat musculoskeletal injuries (MSKIs) account for more than 80% of soldiers’ injuries and 65% of medically nondeployable AC soldiers. This review focuses on MSKI risk reduction initiatives, management, and reporting challenges within the Army. The authors will summarize MSKI risk reduction efforts and challenges affecting MSKI management and reporting within the U.S. Army. Materials/Methods This review focuses on (1) initiatives to reduce the impact of MSKIs and risk for chronic injury/pain or long-term disability and (2) MSKI reporting challenges. This review excludes combat or battle injuries. Results Primary risk reduction Adherence to standardized exercise programming has reduced injury risk among trainees. Preaccession physical fitness screening may identify individuals at risk for injury or attrition during initial entry training. Forward-based strength and conditioning coaching (provided in the unit footprint) and nutritional supplementation initiatives are promising, but results are currently inconclusive concerning injury risk reduction. Secondary risk reduction Forward-based access to MSKI care provided by embedded athletic trainers and physical therapists within military units or primary care clinics holds promise for reducing MSKI-related limited duty days and nondeployability among AC soldiers. Early point-of-care screening for psychosocial risk factors affecting responsiveness to MSKI intervention may reduce risk for progression to chronic pain or long-term disability. Tertiary risk reduction Operational MSKI metrics enable commanders and clinicians to readily identify soldiers with nonresolving MSKIs. Monthly injury reports to Army leadership increase command focus on soldiers with nonresolving MSKIs. Conclusions Standardized exercise programming has reduced trainee MSKI rates. Secondary risk reduction initiatives show promise for reducing MSKI-related duty limitations and nondeployability among AC soldiers; timely identification/evaluation and appropriate, early management of MSKIs are essential. Tertiary risk reduction initiatives show promise for identifying soldiers whose chronic musculoskeletal conditions may render them unfit for continued military service. Clinicians must document MSKI care with sufficient specificity (including diagnosis and external cause coding) to enable large-scale systematic MSKI surveillance and analysis informing focused MSKI risk reduction efforts. Historical changes in surveillance methods and injury definitions make it difficult to compare injury rates and trends over time. However, the U.S. Army’s standardized injury taxonomy will enable consistent classification of current and future injuries by mechanism of energy transfer and diagnosis. The Army’s electronic physical profiling system further enables standardized documentation of MSKI-related duty/work restrictions and mechanisms of injury. These evolving surveillance tools ideally ensure continual advancement of military injury surveillance and serve as models for other military and civilian health care organizations.

scholarly journals Aerosol Responses to Precipitation Along North American Air Trajectories Arriving at Bermuda

2021 ◽  
Author(s):  
Hossein Dadashazar ◽  
Majid Alipanah ◽  
Miguel Ricardo A. Hilario ◽  
Ewan Crosbie ◽  
Simon Kirschler ◽  
...  
Keyword(s):  
North America ◽  
North American ◽  
Large Scale ◽  
East Coast ◽  
Aerosol Particles ◽  
Air Mass ◽  
Wet Scavenging ◽  
The Impact ◽  
The U.S ◽  
Volume Size

Abstract. North American pollution outflow is ubiquitous over the western North Atlantic Ocean, especially in winter, making this location an ideal natural laboratory for investigating the impact of precipitation on aerosol particles along air mass trajectories. We take advantage of observational data collected at Bermuda to seasonally assess the sensitivity of aerosol mass concentrations and volume size distributions to accumulated precipitation along trajectories (APT). The mass concentration of particulate matter with aerodynamic diameter less than 2.5 µm normalized by the enhancement of carbon monoxide above background (PM2.5/∆CO) at Bermuda was used to estimate the degree of aerosol loss during transport to Bermuda. Results for December–February (DJF) show most trajectories come from North America and have the highest APTs, resulting in significant reduction (by 53 %) in PM2.5/∆CO under high APT conditions (> 13.5 mm) relative to low APT conditions (< 0.9 mm). Moreover, PM2.5/∆CO was most sensitive to increases in APT up to 5 mm (−0.044 µg m−3 ppbv−1 mm−1) and less sensitive to increases in APT over 5 mm. While anthropogenic PM2.5 constituents (e.g., black carbon, sulfate, organic carbon) decrease with high APT, sea salt in contrast was comparable between high and low APT conditions owing to enhanced local wind and salt emissions in high APT conditions. The greater sensitivity of the fine mode volume concentrations (versus coarse mode) to wet scavenging is evident from AERONET volume size distribution data. A combination of GEOS-Chem model simulations of 210Pb submicron aerosol tracer and its gaseous precursor 222Rn reveal that (i) surface aerosol particles at Bermuda are most impacted by wet scavenging in winter/spring (due to large-scale precipitation) with a maximum in March, whereas convective scavenging plays a substantial role in summer; and (ii) North American 222Rn tracer emissions contribute most to surface 210Pb concentrations at Bermuda in winter (~75–80 %), indicating that air masses arriving at Bermuda experience large-scale precipitation scavenging while traveling from North America. A case study flight from the ACTIVATE field campaign on 22 February 2020 reveals a significant reduction in aerosol number and volume concentrations during air mass transport off the U.S. East Coast associated with increased cloud fraction and precipitation. These results highlight the sensitivity of remote marine boundary layer aerosol characteristics to precipitation along trajectories, especially when the air mass source is continental outflow from polluted regions like the U.S. East Coast.

scholarly journals China’s Policy of Economic Sanctions: Legislation and Enforcement

2021 ◽  
Vol 13 (4) ◽  
pp. 24-38
Author(s):  
Polina V. Bakulina ◽  
◽  
Ksenia A. Kuzmina ◽  
Keyword(s):  
International Law ◽  
Large Scale ◽  
Domestic Economy ◽  
Strategic Competition ◽  
Blocking Mechanisms ◽  
Trade War ◽  
Restrictive Measures ◽  
The Impact ◽  
Target Country ◽  
The U.S

This article aims at analyzing the People’s Republic of China’s sanctions policy. The authors put special emphasis on the review of the current Chinese legislation on countering foreign unilateral measures targeting China. The emergence of a legal anti-sanctions framework in China is a development of 2020–2021, driven by the growing number of sanctions against China imposed by the U.S. and its allies against the background of trade war and global strategic competition. At the official level, Beijing remains vocal in condemning unilateral and extraterritorial sanctions by certain countries as violations of international law. Despite that, even before the current large-scale confrontation with the U.S, Chinese policymakers have used restrictive measures against third countries, though they have been traditionally adopted in an informal and opaque manner. Those measures have mostly been used as retaliation for certain acts of other states viewed by China as threats to its sovereignty and territorial integrity, and they have been specifically refined to maximize the impact on the target country while minimizing the damage to the domestic economy. The growing number of anti-China sanctions by the U.S. and its allies based on special legal instruments prompted the PRC to follow suit and create its own framework for introducing countermeasures and blocking mechanisms, although their implementation procedures still largely remain intransparent. China’s first steps were to officially introduce individual restrictions, but the persisting confrontational trends in PRC’s relations with the West might bring about formal or informal broadening of Chinese restrictions to transnational corporations and sectors of economy and promote further formalization of sanctions regimes.

Impact of COVID-19 on Nuclear Medicine in Germany, Austria and Switzerland: An International Survey in April 2020

2020 ◽  
Vol 59 (04) ◽  
pp. 294-299 ◽  
Author(s):  
Lutz S. Freudenberg ◽  
Ulf Dittmer ◽  
Ken Herrmann
Keyword(s):  
Nuclear Medicine ◽  
Health Systems ◽  
Personal Protective Equipment ◽  
Large Scale ◽  
Diagnostic Procedures ◽  
Protective Equipment ◽  
Current Crisis ◽  
Web Based ◽  
Public Versus Private ◽  
The Impact

Abstract Introduction Preparations of health systems to accommodate large number of severely ill COVID-19 patients in March/April 2020 has a significant impact on nuclear medicine departments. Materials and Methods A web-based questionnaire was designed to differentiate the impact of the pandemic on inpatient and outpatient nuclear medicine operations and on public versus private health systems, respectively. Questions were addressing the following issues: impact on nuclear medicine diagnostics and therapy, use of recommendations, personal protective equipment, and organizational adaptations. The survey was available for 6 days and closed on April 20, 2020. Results 113 complete responses were recorded. Nearly all participants (97 %) report a decline of nuclear medicine diagnostic procedures. The mean reduction in the last three weeks for PET/CT, scintigraphies of bone, myocardium, lung thyroid, sentinel lymph-node are –14.4 %, –47.2 %, –47.5 %, –40.7 %, –58.4 %, and –25.2 % respectively. Furthermore, 76 % of the participants report a reduction in therapies especially for benign thyroid disease (-41.8 %) and radiosynoviorthesis (–53.8 %) while tumor therapies remained mainly stable. 48 % of the participants report a shortage of personal protective equipment. Conclusions Nuclear medicine services are notably reduced 3 weeks after the SARS-CoV-2 pandemic reached Germany, Austria and Switzerland on a large scale. We must be aware that the current crisis will also have a significant economic impact on the healthcare system. As the survey cannot adapt to daily dynamic changes in priorities, it serves as a first snapshot requiring follow-up studies and comparisons with other countries and regions.

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