452 research outputs found
Development of an Exploration-Class Cascade Distillation System: Flight Like Prototype Design Status
The ability to recover and purify water through physiochemical processes is crucial for realizing long-term human space missions, including both planetary habitation and space travel. Because of their robust nature, distillation systems have been actively pursued as one of the technologies for water recovery. One such technology is the Cascade Distillation System (CDS) a multi-stage vacuum rotary distiller system designed to recover water in a microgravity environment. The CDS provides a similar function to the state of the art (SOA) vapor compressor distiller (VCD) currently employed on the International Space Station, but its control scheme and ancillary components are judged to be more straightforward and simpler to implement into a more reliable and efficient system. Through the Advanced Exploration Systems (AES) Life Support Systems (LSS) Project, the NASA Johnson Space Center (JSC) in collaboration with Honeywell International is developing a second generation flight forward prototype (CDS 2.0). A preliminary design fo the CDS 2.0 was presented to the project in September 2014. Following this review, detailed design of the system continued. The existing ground test prototype was used as a platform to demonstrate key 2.0 design and operational concepts to support this effort and mitigate design risk. A volumetric prototype was also developed to evaluate the packaging design for operability and maintainability. The updated system design was reviewed by the AES LSS Project and other key stakeholders in September 2015. This paper details the status of the CDS 2.0 design
A Modular Strategy for Expanding Electron-Sink Capacity in Noncanonical Cluster Assemblies
A modular synthetic strategy is described whereby organometallic complexes exhibiting considerable electron-sink capacity may be assembled by using only a few simple molecular components. The Fe2(PPh2)2(CO)5 fragment was selected as a common electroactive component and was assembled around aromatic cores bearing one, two, or three isocyanide functional groups, with the resultant complexes possessing electron-sink capacities of two, four, and six electrons, respectively. The latter complex is noteworthy in that its electron-sink capacity was found to rival that of large multinuclear clusters (e.g., [Ni32C6(CO)36]6– and [Ni38Pt6(CO)48]6–), which are often considered as benchmarks of electron-sink behavior. Moreover, the modular assembly bearing three Fe2(PPh2)2(CO)5 fragments was observed to undergo reduction to a hexaanionic state over a potential window of about −1.4 to −2.1 V (vs Fc/Fc+), the relatively compressed range being attributed to potential inversions operative during the addition of the second, fourth, and sixth electrons. Such complexes may be designated noncanonical clusters because they exhibit redox properties similar to those of large multinuclear clusters yet lack the extensive network of metal–metal bonds and the condensed metallic cores that typify the latter
Emergency Department Use Among Older Adults With Dementia
Although persons with dementia are frequently hospitalized, relatively little is known about the health profile, patterns of health care use, and mortality rates for patients with dementia who access care in the emergency department (ED). We linked data from our hospital system with Medicare and Medicaid claims, Minimum Data Set, and Outcome and Assessment Information Set data to evaluate 175,652 ED visits made by 10,354 individuals with dementia and 15,020 individuals without dementia over 11 years. Survival rates after ED visits and associated charges were examined. Patients with dementia visited the ED more frequently, were hospitalized more often than patients without dementia, and had an increased odds of returning to the ED within 30 days of an index ED visit compared with persons who never had a dementia diagnosis (odds ratio, 2.29; P<0.001). Survival rates differed significantly between patients by dementia status (P<0.001). Mean Medicare payments for ED services were significantly higher among patients with dementia. These results show that older adults with dementia are frequent ED visitors who have greater comorbidity, incur higher charges, are admitted to hospitals at higher rates, return to EDs at higher rates, and have higher mortality after an ED visit than patients without dementia
Extremely broadband ultralight thermally emissive metasurfaces
We report the design, fabrication and characterization of ultralight highly
emissive metaphotonic structures with record-low mass/area that emit thermal
radiation efficiently over a broad spectral (2 to 35 microns) and angular (0-60
degrees) range. The structures comprise one to three pairs of alternating
nanometer-scale metallic and dielectric layers, and have measured effective 300
K hemispherical emissivities of 0.7 to 0.9. To our knowledge, these structures,
which are all subwavelength in thickness are the lightest reported metasurfaces
with comparable infrared emissivity. The superior optical properties, together
with their mechanical flexibility, low outgassing, and low areal mass, suggest
that these metasurfaces are candidates for thermal management in applications
demanding of ultralight flexible structures, including aerospace applications,
ultralight photovoltaics, lightweight flexible electronics, and textiles for
thermal insulation
Compound-Specific Isotopic Analysis of Meteoritic Amino Acids as a Tool for Evaluating Potential Formation Pathways
Measurements of stable hydrogen, carbon, and nitrogen isotopic ratios (delta D, delta C-13, delta N-15) of organic compounds can reveal information about their origin and formation pathways. Several formation mechanisms and environments have been postulated for the amino acids detected in carbonaceous chondrites. As each proposed mechanism utilizes different precursor molecules, the isotopic signatures of the resulting amino acids may point towards the most likely of these proposed pathways. The technique of gas chromatography coupled with mass spectrometry and isotope ratio mass spectrometry provides compound-specific structural and isotopic information from a single splitless injection, enhancing the amount of information gained from small amounts of precious samples such as carbonaceous chondrites. We have applied this technique to measure the compound-specific C, N, and H isotopic ratios of amino acids from seven CM and CR carbonaceous chondrites. We are using these measurements to evaluate predictions of expected isotopic enrichments from potential formation pathways and environments, leading to a better understanding of the origin of these compounds
Item response theory analysis of Centers for Disease Control and Prevention Health-Related Quality of Life (CDC HRQOL) items in adults with arthritis
Background
Examine the feasibility of performing an item response theory (IRT) analysis on two of the Centers for Disease Control and Prevention health-related quality of life (CDC HRQOL) modules – the 4-item Healthy Days Core Module (HDCM) and the 5-item Healthy days Symptoms Module (HDSM). Previous principal components analyses confirm that the two scales both assess a mix of mental (CDC-MH) and physical health (CDC-PH). The purpose is to conduct item response theory (IRT) analysis on the CDC-MH and CDC-PH scales separately.
Methods
2182 patients with self-reported or physician-diagnosed arthritis completed a cross-sectional survey including HDCM and HDSM items. Besides global health, the other 8 items ask the number of days that some statement was true; we chose to recode the data into 8 categories based on observed clustering. The IRT assumptions were assessed using confirmatory factor analysis and the data could be modeled using an unidimensional IRT model. The graded response model was used for IRT analyses and CDC-MH and CDC-PH scales were analyzed separately in flexMIRT.
Results
The IRT parameter estimates for the five-item CDC-PH all appeared reasonable. The three-item CDC-MH did not have reasonable parameter estimates.
Conclusions
The CDC-PH scale is amenable to IRT analysis but the existing The CDC-MH scale is not. We suggest either using the 4-item Healthy Days Core Module (HDCM) and the 5-item Healthy days Symptoms Module (HDSM) as they currently stand or the CDC-PH scale alone if the primary goal is to measure physical health related HRQOL
The Grizzly, February 18, 2010
Every Ending Starts with a Beginning • Record-Breaking Blizzard Evokes Varied Reactions • Could Watching the Super Bowl Damage Your Heart? • Snow Storm Photos • Senior Class Gift Drive • SPINTfest \u2710 Brings New Themes for Houses • UC Goes Red to Raise Awareness About the Risks of Heart Disease • Opinion: Teenage Pregnancy TV Shows are a Big Hit, But What\u27s the Effect? • Tragedy Strikes in Early Hours of Winter Olympics • Men\u27s Basketball Shuts Down McDanielhttps://digitalcommons.ursinus.edu/grizzlynews/1806/thumbnail.jp
Antihypertensive Medication and Dementia Risk in Older Adult African Americans with Hypertension: A Prospective Cohort Study
BACKGROUND:
African Americans are especially at risk of hypertension and dementia. Antihypertensive medications reduce the risk of cardiovascular events, but may also reduce the risk of dementia.
OBJECTIVE:
To assess the longitudinal effects of antihypertensive medications and blood pressure on the onset of incident dementia in a cohort of African Americans.
DESIGN:
Prospective cohort.
PARTICIPANTS:
1236 community-dwelling patients from an inner-city public health care system, aged 65 years and older, with a history of hypertension but no history of dementia, and who had at least three primary care visits and a prescription filled for any medication.
MAIN MEASURES:
Blood pressure was the average of three seated measurements. Dementia was diagnosed using a two-stage design, with a screening evaluation every 2 to 3 years followed by a comprehensive in-home clinical evaluation for those with a positive screen. Laboratory, inpatient and outpatient encounter data, coded diagnoses and procedures, and medication records were derived from a health information exchange.
KEY RESULTS:
Of the 1236 hypertensive participants without dementia at baseline, 114 (9%) developed incident dementia during follow-up. Individuals prescribed any antihypertensive medication (n = 816) were found to have a significantly reduced risk of dementia (HR = 0.57, 95% CI 0.37-0.88, p = 0.0114) compared to untreated hypertensive participants (n = 420). When this analysis was repeated including a variable indicating suboptimally treated blood pressure (> 140 mmHg systolic or >90 mmHg diastolic), the effect of antihypertensive medication was no longer statistically significant (HR = 0.65, 95% CI 0.32-1.30, p = 0.2217).
CONCLUSIONS:
Control of blood pressure in older adult African American patients with hypertension is a key intervention for preventing dementia, with similar benefits from most of the commonly available antihypertensive medications
The Grizzly, February 12, 2010
Main Street Renovation Improves Safety • Community Brings Down Crime at Ursinus College • Annual Scottish Irish Festival This Weekend • Bonner Leaders Hold Fair in Lower Wismer • What You Should Really Expect from Study Abroad • New Member Education Starts Up Again and Looks Forward to Positive Change • UC Gymnastics is Flipping Through 2010 Season • Moliken Named New Athletic Directorhttps://digitalcommons.ursinus.edu/grizzlynews/1805/thumbnail.jp
The Grizzly, April 8, 2010
First Annual Backwards Beauty Pageant Held • Ursinus Senior to Travel Abroad for a Year with Watson • Kappa Alpha Psi and Seismic Step Emerge on Campus • UC Welcomes New Field Hockey Coach • Sex on Wheels Documentary Screening • Volunteering with St. Christopher\u27s Children\u27s Hospital • Feeling Good in The Skin We\u27re In • The Sacrifice Your Body Makes for [Better] Grades • Opinion: Kyleigh\u27s Law Profiles Drivers by Age in New Jersey • Upper Classmen Off-Campus Living • UC Gymnastics Closes Season with Successhttps://digitalcommons.ursinus.edu/grizzlynews/1810/thumbnail.jp
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