scholarly journals Do wind turbines pose roll hazards to light aircraft?

2018 ◽  
Vol 3 (2) ◽  
pp. 833-843 ◽  
Author(s):  
Jessica M. Tomaszewski ◽  
Julie K. Lundquist ◽  
Matthew J. Churchfield ◽  
Patrick J. Moriarty
Keyword(s):  
United States ◽  
Wind Turbines ◽  
Wind Farm ◽  
The United States ◽  
General Aviation ◽  
Case Scenario ◽  
Worst Case ◽  
Stable Case ◽  
Increased Risk ◽  
Small Aircraft

Abstract. Wind energy accounted for 5.6 % of all electricity generation in the United States in 2016. Much of this development has occurred in rural locations, where open spaces favorable for harnessing wind also serve general aviation airports. As such, nearly 40 % of all United States wind turbines exist within 10 km of a small airport. Wind turbines generate electricity by extracting momentum from the atmosphere, creating downwind wakes characterized by wind-speed deficits and increased turbulence. Recently, the concern that turbine wakes pose hazards for small aircraft has been used to limit wind-farm development. Herein, we assess roll hazards to small aircraft using large-eddy simulations (LES) of a utility-scale turbine wake. Wind-generated lift forces and subsequent rolling moments are calculated for hypothetical aircraft transecting the wake in various orientations. Stably and neutrally stratified cases are explored, with the stable case presenting a possible worst-case scenario due to longer-persisting wakes permitted by lower ambient turbulence. In both cases, only 0.001 % of rolling moments experienced by hypothetical aircraft during down-wake and cross-wake transects lead to an increased risk of rolling.

scholarly journals Do Wind Turbines Pose Roll Hazards to Light Aircraft?

2018 ◽  
Author(s):  
Jessica M. Tomaszewski ◽  
Julie K. Lundquist ◽  
Matthew J. Churchfield ◽  
Patrick J. Moriarty
Keyword(s):  
Wind Turbines ◽  
Wind Farm ◽  
The United States ◽  
General Aviation ◽  
Open Spaces ◽  
Increased Risk ◽  
Large Eddy ◽  
Utility Scale ◽  
Turbine Wake ◽  
Small Aircraft

Abstract. Wind energy accounted for 5.6 % of all electricity generation in the United States in 2016. Much of this development has occurred in rural locations, where open spaces favorable for harnessing wind also serve general aviation airports. As such, nearly 40 % of all U.S. wind turbines exist within 10 km of a small airport. Wind turbines generate electricity by extracting momentum from the atmosphere, creating downwind wakes characterized by wind-speed deficits and increased turbulence. Recently, the concern that turbine wakes pose hazards for small aircraft has been used to limit wind farm development. Herein, we assess roll hazards to small aircraft using large-eddy simulations of a utility-scale turbine wake. Wind-generated rolling moments on hypothetical aircraft transecting the wake in stably and neutrally stratified conditions are calculated. In both cases, only 0.001 % of rolling moments experienced by hypothetical aircraft during down-wake and cross-wake transects lead to an increased risk of rolling.

Potential Impacts from a Worst Case Discharge from an United States Offshore Wind Farm

2014 ◽  
Vol 2014 (1) ◽  
pp. 869-877
Author(s):  
CDR Tim Gunter
Keyword(s):  
United States ◽  
Wind Energy ◽  
New England ◽  
Rhode Island ◽  
Wind Farm ◽  
Wind Farms ◽  
The United States ◽  
Offshore Wind ◽  
Offshore Wind Energy ◽  
Worst Case

ABSTRACT The main purpose of this research is to explore potential environmental impacts of a worst case discharge (WCD) from an offshore commercial wind farm electric service platform (ESP) in the Northeast United States. Wind farms in the continental United States are a growing industry as an energy alternative to traditional oil, coal, and natural gas energy sources. While many offshore wind farms already exist in Europe and around the world, the Cape Wind Project in New England received the first federally approved lease for an offshore wind energy production facility in the United States. While offshore wind energy is a green source of energy, wind driven energy has its own set of environmental risks, including the risks of an oil spill. A systematic review of scholarly journals, federal government websites and other academic resources was conducted to identify previous spills in the Northeast with the closest match in volume and location to the Cape Wind Project. The oil spills from the barge North Cape in 1996 near Point Judith, Rhode Island and from the barge Florida in Buzzards Bay, Massachusetts, in 1996, had the most similarities to a potential WCD spill from the Cape Wind Project. Both of these spills adversely impacted the environment, and provide useful information that can be used for the planning efforts surrounding a WCD event from the Cape Wind Project.

scholarly journals Dietary patterns related to total mortality and cancer mortality in the United States

2021 ◽  
Author(s):  
Marcela R. Entwistle ◽  
Donald Schweizer ◽  
Ricardo Cisneros
Keyword(s):  
United States ◽  
Dietary Patterns ◽  
Cancer Mortality ◽  
Cox Regression ◽  
Total Mortality ◽  
Principal Component ◽  
The United States ◽  
Red Meat ◽  
Increased Risk ◽  
All Cause Mortality

Abstract Purpose This study investigated the association between dietary patterns, total mortality, and cancer mortality in the United States. Methods We identified the four major dietary patterns at baseline from 13,466 participants of the NHANES III cohort using principal component analysis (PCA). Dietary patterns were categorized into ‘prudent’ (fruits and vegetables), ‘western’ (red meat, sweets, pastries, oils), ‘traditional’ (red meat, legumes, potatoes, bread), and ‘fish and alcohol’. We estimated hazard ratios for total mortality, and cancer mortality using Cox regression models. Results A total of 4,963 deaths were documented after a mean follow-up of 19.59 years. Higher adherence to the ‘prudent’ pattern was associated with the lowest risk of total mortality (5th vs. 1st quintile HR 0.90, 95% CI 0.82–0.98), with evidence that all-cause mortality decreased as consumption of the pattern increased. No evidence was found that the ‘prudent’ pattern reduced cancer mortality. The ‘western’ and the ‘traditional’ patterns were associated with up to 22% and 16% increased risk for total mortality (5th vs. 1st quintile HR 1.22, 95% CI 1.11–1.34; and 5th vs. 1st quintile HR 1.16, 95% CI 1.06–1.27, respectively), and up to 33% and 15% increased risk for cancer mortality (5th vs. 1st quintile HR 1.33, 95% CI 1.10–1.62; and 5th vs. 1st quintile HR 1.15, 95% CI 1.06–1.24, respectively). The associations between adherence to the ‘fish and alcohol’ pattern and total mortality, and cancer mortality were not statistically significant. Conclusion Higher adherence to the ‘prudent’ diet decreased the risk of all-cause mortality but did not affect cancer mortality. Greater adherence to the ‘western’ and ‘traditional’ diet increased the risk of total mortality and mortality due to cancer.

scholarly journals Household COVID-19 risk and in-person schooling

Science ◽  
2021 ◽  
pp. eabh2939
Author(s):  
Justin Lessler ◽  
M. Kate Grabowski ◽  
Kyra H. Grantz ◽  
Elena Badillo-Goicoechea ◽  
C. Jessica E. Metcalf ◽  
...  
Keyword(s):  
United States ◽  
Online Survey ◽  
Positive Association ◽  
The United States ◽  
Mitigation Measures ◽  
Office Work ◽  
School Based ◽  
Increased Risk ◽  
Extra Curricular Activities ◽  
Low Levels

In-person schooling has proved contentious and difficult to study throughout the SARS-CoV-2 pandemic. Data from a massive online survey in the United States indicates an increased risk of COVID-19-related outcomes among respondents living with a child attending school in-person. School-based mitigation measures are associated with significant reductions in risk, particularly daily symptoms screens, teacher masking, and closure of extra-curricular activities. A positive association between in-person schooling and COVID-19 outcomes persists at low levels of mitigation, but when seven or more mitigation measures are reported, a significant relationship is no longer observed. Among teachers, working outside the home was associated with an increase in COVID-19-related outcomes, but this association is similar to other occupations (e.g., healthcare, office work). While in-person schooling is associated with household COVID-19 risk, this risk can likely be controlled with properly implemented school-based mitigation measures.

scholarly journals Altitude and risk of sudden unexpected infant death in the United States

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Richard Johnston ◽  
Xiaohan Yan ◽  
Tatiana M. Anderson ◽  
Edwin A. Mitchell
Keyword(s):  
United States ◽  
Logistic Regression ◽  
Infant Death ◽  
The United States ◽  
Sudden Infant ◽  
Data Set ◽  
Live Births ◽  
Sudden Unexpected Infant Death ◽  
Increased Risk ◽  
Unexpected Infant Death

AbstractThe effect of altitude on the risk of sudden infant death syndrome (SIDS) has been reported previously, but with conflicting findings. We aimed to examine whether the risk of sudden unexpected infant death (SUID) varies with altitude in the United States. Data from the Centers for Disease Control and Prevention (CDC)’s Cohort Linked Birth/Infant Death Data Set for births between 2005 and 2010 were examined. County of birth was used to estimate altitude. Logistic regression and Generalized Additive Model (GAM) were used, adjusting for year, mother’s race, Hispanic origin, marital status, age, education and smoking, father’s age and race, number of prenatal visits, plurality, live birth order, and infant’s sex, birthweight and gestation. There were 25,305,778 live births over the 6-year study period. The total number of deaths from SUID in this period were 23,673 (rate = 0.94/1000 live births). In the logistic regression model there was a small, but statistically significant, increased risk of SUID associated with birth at > 8000 feet compared with < 6000 feet (aOR = 1.93; 95% CI 1.00–3.71). The GAM showed a similar increased risk over 8000 feet, but this was not statistically significant. Only 9245 (0.037%) of mothers gave birth at > 8000 feet during the study period and 10 deaths (0.042%) were attributed to SUID. The number of SUID deaths at this altitude in the United States is very small (10 deaths in 6 years).

scholarly journals Time to First Cigarette and Self-Reported Health Among US Adult Smokers

2019 ◽  
Vol 12 ◽  
pp. 1179173X1882526 ◽  
Author(s):  
Baksun Sung
Keyword(s):  
United States ◽  
Propensity Score ◽  
Odds Ratio ◽  
Adjusted Odds Ratio ◽  
Smoking Behavior ◽  
The United States ◽  
Elevated Risk ◽  
Poor Health ◽  
Increased Risk ◽  
Reported Health

Background: Numerous studies have reported that shorter time to first cigarette (TTFC) is linked to elevated risk for smoking-related morbidity. However, little is known about the influence of early TTFC on self-reported health among current smokers. Hence, the objective of this study was to examine the association between TTFC and self-reported health among US adult smokers. Methods: Data came from the 2012-2013 National Adult Tobacco Survey (NATS). Current smokers aged 18 years and older (N = 3323) were categorized into 2 groups based on TTFC: ≤ 5 minutes (n = 1066) and >5 minutes (n = 2257). Propensity score matching (PSM) was used to control selection bias. Results: After adjusting for sociodemographic and smoking behavior factors, current smokers with early TTFC had higher odds for poor health in comparison with current smokers with late TTFC in the prematching (adjusted odds ratio [AOR] = 1.65; 95% confidence interval [CI] = 1.31-2.08) and postmatching (AOR = 1.60; 95% CI = 1.22-2.09) samples. Conclusions: In conclusion, smokers with early TTFC were associated with increased risk of poor health in the United States. To reduce early TTFC, elaborate efforts are needed to educate people about harms of early TTFC and benefits of stopping early TTFC.

scholarly journals Trissolcus japonicus (Hymenoptera: Scelionidae) Causes Low Levels of Parasitism in Three North American Pentatomids Under Field Conditions

2019 ◽  
Vol 19 (4) ◽  
Author(s):  
Joshua M Milnes ◽  
Elizabeth H Beers
Keyword(s):  
North American ◽  
Native Species ◽  
Classical Biological Control ◽  
The United States ◽  
Host Finding ◽  
Pest Species ◽  
Case Scenario ◽  
Worst Case ◽  
Egg Masses ◽  
Trissolcus Japonicus

Abstract Trissolcus japonicus (Ashmead), an Asian parasitoid of Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), was first detected in North America in 2014. Although testing in quarantine facilities as a candidate for classical biological control is ongoing, adventive populations have appeared in multiple sites in the United States, Canada, and Europe. Extensive laboratory testing of T. japonicus against other North American pentatomids and H. halys has revealed a higher rate of parasitism of H. halys, but not complete host specificity. However, laboratory tests are necessarily artificial, in which many host finding and acceptance cues may be circumvented. We offered sentinel egg masses of three native pentatomid (Hemiptera: Pentatomidae) pest species (Chinavia hilaris (Say), Euschistus conspersus Uhler, and Chlorochroa ligata (Say)) in a field paired-host assay in an area with a well-established adventive population of T. japonicus near Vancouver, WA. Overall, 67% of the H. halys egg masses were parasitized by T. japonicus during the 2-yr study. Despite the ‘worst case’ scenario for a field test (close proximity of the paired egg masses), the rate of parasitism (% eggs producing adult wasps) on all three native species was significantly less (0.4–8%) than that on H. halys eggs (77%). The levels of successful parasitism of T. japonicus of the three species are C. hilaris > E. conspersus > C. ligata. The potential impact of T. japonicus on these pentatomids is probably minimal.

scholarly journals Sickle Cell Trait and Renal Function in Hispanics in the United States: the Northern Manhattan Study

2017 ◽  
Vol 27 (1) ◽  
pp. 11 ◽  
Author(s):  
Nicole D. Dueker ◽  
David Della-Morte ◽  
Tatjana Rundek ◽  
Ralph L. Sacco ◽  
Susan H. Blanton
Keyword(s):  
United States ◽  
Chronic Kidney Disease ◽  
African Americans ◽  
Kidney Disease ◽  
Sickle Cell ◽  
Sickle Cell Trait ◽  
The United States ◽  
Genetic Mutation ◽  
Single Mutation ◽  
Increased Risk

<p class="Pa7">Sickle cell anemia (SCA) is a common hematological disorder among individu­als of African descent in the United States; the disorder results in the production of abnormal hemoglobin. It is caused by homozygosity for a genetic mutation in HBB; rs334. While the presence of a single mutation (sickle cell trait, SCT) has long been considered a benign trait, recent research suggests that SCT is associated with renal dysfunction, including a decrease in estimated glomerular filtration rate (eGFR) and increased risk of chronic kidney disease (CKD) in African Americans. It is currently unknown whether similar associations are observed in Hispanics. Therefore, our study aimed to determine if SCT is associated with mean eGFR and CKD in a sample of 340 Dominican Hispanics from the Northern Manhattan Study. Using regression analyses, we tested rs334 for association with eGFR and CKD, adjusting for age and sex. eGFR was estimated using the Chronic Kidney Disease Epidemiology Collaboration equa­tion and CKD was defined as eGFR &lt; 60 mL/min/1.73 m2. Within our sample, there were 16 individuals with SCT (SCT carriers). We found that SCT carriers had a mean eGFR that was 12.12 mL/min/1.73m2 lower than non-carriers (P=.002). Additionally, SCT carriers had 2.72 times higher odds of CKD compared with non-carriers (P=.09). Taken together, these novel results show that Hispanics with SCT, as found among African Americans with SCT, may also be at increased risk for kidney disease.</p><p class="Pa7"><em>Ethn Dis. </em>2017; 27(1)<strong>:</strong>11-14; doi:10.18865/ed.27.1.11.</p><p class="Pa7"> </p>

The MacArthur Maze Fire and Roadway Collapse: A “Worst Case Scenario” for Spent Nuclear Fuel Transportation?

2012 ◽  
Author(s):  
Christopher S. Bajwa ◽  
Earl P. Easton ◽  
Harold Adkins ◽  
Judith Cuta ◽  
Nicholas Klymyshyn ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Steel Structure ◽  
Nuclear Regulatory Commission ◽  
The United States ◽  
Severe Accident ◽  
Case Scenario ◽  
Worst Case ◽  
Work Related ◽  
Regulatory Commission

In 2007, a severe transportation accident occurred near Oakland, California, at the interchange known as the “MacArthur Maze.” The accident involved a double tanker truck of gasoline overturning and bursting into flames. The subsequent fire reduced the strength of the supporting steel structure of an overhead interstate roadway causing the collapse of portions of that overpass onto the lower roadway in less than 20 minutes. The US Nuclear Regulatory Commission has analyzed what might have happened had a spent nuclear fuel transportation package been involved in this accident, to determine if there are any potential regulatory implications of this accident to the safe transport of spent nuclear fuel in the United States. This paper provides a summary of this effort, presents preliminary results and conclusions, and discusses future work related to the NRC’s analysis of the consequences of this type of severe accident.

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