Two-axis flux gate magnetometer

Magnetometer uses single sensing head to measure magnetic flux density along two axes simultaneously. The sensor head consists of permalloy core and four windings. Two windings perform a multivibrator function, the two remaining windings sense magnetic fields. The smaller magnetometer performs same functions as more complex devices

The MAGSAT vector magnetometer: A precision fluxgate magnetometer for the measurement of the geomagnetic field

A description of the precision triaxial fluxgate magnetometer to be flown aboard the MAGSAT spacecraft is presented. The instrument covers the range of + or - 64,000 nT with a resolution of + or - 0.5 nT, an intrinsic accuracy of + or - 0.001% of full scale and an angular alignment stability of the order of 2 seconds of arc. It was developed at NASA's Goddard Space Flight Center and represents the state-of-the-art in precision vector magnetometers developed for spaceflight use

Robust control stability using the error loop

The paper briefly formulates the error loop as a tool for designing robust stability control systems in front of structured and unstructured uncertainties. The error loop indicates that a tool for accommodating such uncertainties is the noise estimator, which is the unique feedback channel from plant to control. It is shown that the causality constraint preventing perfect cancellation of causal uncertainties (unknown disturbance), makes also control law to play a role, offering a further degree of freedom. Employing asymptotic expansions of the closed-loop transfer functions, simple, explicit design formulae derive from stability inequalities: they relate closed-loop eigenvalues to model parameter and requirements. A simple example is provided from a ball and beam plan

Profile of the Older Population Living in Miami-Dade County, Florida

Abstract Florida has the greatest proportion (19%) of older population (65 years or older) in the United States. The age distribution of its residents, in conjunction with a major shift in the leading cause of death within all age groups from acute illnesses to chronic disease, creates unprecedented health care challenges for the state. The objective of this study is to profile the older population living in Miami-Dade County (MDC) using 3 population-based, household-based surveys conducted over the past 5 years. This study examined cross-sectional data (demographics, health outcomes, risk factors, health assess, and utilization) collected from probability-sampled, household-based surveys conducted in 3 areas of MDC: north Miami-Dade, Little Haiti, and South Miami. The questionnaire was administered face-to-face by trained interviewers in English, Spanish, French, or Creole. Analyses were restricted to households containing at least 1 member aged 65 years or older (n?=?935). One consenting adult answered the questionnaire on behalf of household members. The mean age of the respondent (60% females) was 60 years. Overall, respondents were predominantly African-Americans, Hispanics, and blacks of Haitian origin. One-third of all households fell below the US poverty thresholds. One-quarter of all households had at least 1 member who was uninsured within the year before the survey. Twenty percent of households had at least 1 member with an acute myocardial infarction or stroke during the year before the survey. Bone density tests and blood stool tests were strikingly underutilized. The health outcomes most prevalent within household members were cardiovascular diseases followed by cancer, anxiety/depression, obesity, asthma, and bone fractures. Twenty percent of households reported having at least 1 current smoker. Overall, emergency rooms were the most commonly used places of care after doctor\u27s offices. Findings of 3 household-based surveys show a predominantly elderly, female, uninsured, and poor minority populations living in MDC, FL. The reported use of preventive services was constrained, and emergency room use was often reported as a main resource for health care. Cardiovascular disease, cancer, bone fractures, and related risk factors were the most prevalent health outcomes

Association of gender and length of stay among Puerto Ricans hospitalized with decompensated heart failure

Heart failure (HF) is a serious, chronic, and progressive condition which may require hospitalization if decompensated. Each year, in the UnitedStates, there are approximately 1 million hospitalizations due to decompensated HF at a cost of $39 billion. Because limited information examining the association between gender and length of stay (LOS) is available in the published literature for Puerto Ricans hospitalized with decompensated HF, we aim to investigate gender differences related to LOS in this population. This study is a secondary data analysis of the Puerto Rico Cardiovascular Disease Surveillance System database, which is a nonconcurrent prospective study carried out in 2007 and 2009. LOS was dichotomized into ≤5 days or ≥6 days (extended) categories. The χ(2) test was used to examine associations between categorical variables. Binary logistic regression was used to estimate unadjusted and adjusted odds ratios of extended LOS. Collinearity was assessed using Pearson correlation coefficients. A P value of 0.05 and 95% confidence intervals were used to evaluate statistical significance. A total of 1724 patients (47.6% women) comprised our study population. The average age of women was 72.5 ± 13.4 years; the average age of men was 67.2 ± 14.5 years. For both women and men, median LOS was 5 days (interquartile range = 5 days). Women were more likely than men to have diabetes mellitus, hypertension, and dyslipidemia, but current smoking was higher in men than in women. The proportion of patients with extended LOS was similar for men (43.3%) and women (45.1%) (P = 0.448). Likewise, the odds for extended LOS was comparable for both genders (OR = 1.1, 95% CI = 0.9, 1.4). Patients admitted with recurrent decompensated HF hospitalizations had shorter LOS than patients with initial episodes (OR = 0.7, 95% CI = 0.6, 0.9). However, factors that prolonged the LOS included the presence of renal failure (OR = 1.7; 95% IC = 1.3, 2.1) and ejection fraction (EF) <35% (OR 0.7; 95% CI 0.6, 0.9). Although we were not able to find statistically significant association between LOS and gender in Puerto Rican patients hospitalized with decompensated HF our findings suggest that incidental episodes and having an EF <35% increase the odds of extended LOS