Fiber Optic Gyro-Based Attitude Determination for High-Performance Target Tracking

Small satellite-enabled terrestrial target tracking applications from low-Earth orbit are demanding stringent pointing performance, prompting the need for developing high-precision attitude estimation and control systems that adhere to cost and mass constraints. The attitude determination and control system onboard the Space Flight Laboratory’s NEMO-class satellite platforms uses an extended Kalman filter and low-cadence (1Hz) star-tracker measurements to constrain the attitude and rate estimation errors to within 0.05° and 0.04°/s (2-σ), respectively. In addition, the pointing error of this satellite platform is constrained to below 0.3° (2-σ) for ground target tracking applications. However, in order to meet the stability requirements of future missions that require precise target-tracking capabilities, a combination of star tracker and high frequency gyro-measurements is preferred. Leveraging high-grade miniaturized and commercially-accessible fiber optic gyroscopes (FOGs) with sampling frequencies of ≥ 2Hz, a high-performance attitude determination and control system suitable for target tracking micro- and nano-satellites is under development at the Space Flight Laboratory of Toronto, Canada. This paper discusses the design of an attitude estimation filter tailored to constrain the ground target pointing error of NEMO-class satellites to well below 0.3° (3-σ). To evaluate the performance of this filter, precision target tracking simulations were conducted, and the results demonstrated significant improvement in some state estimates when a combination of three-orthogonally mounted FOGs operating at high cadence (5Hz) and a single star tracker operating at 1Hz were implemented

Quality in Industrial Engineering School: Universidad Tecnica De Manabi

The paper presents a conceptual analysis related to quality in higher education, highlighting the peculiarities in Ecuador, presenting the content structure of the evaluation system of the quality required by the CEAACES and quality environment is addressed in the UTM, analysis related to the results of research on the quality of development in the career of Industrial Engineering of higher learning was obtained, proving that there are still weaknesses that can affect academic excellence, so it requires constant effort on the part of the institutions, which can be realized through research projects aimed at maintaining self-control of quality in universities

Using Wavelets to reject background in Dark Matter experiments

A method based on wavelet techniques has been developed and applied to background rejection in the data of the IGEX dark matter experiment. The method is presented and described in some detail to show how it efficiently rejects events coming from noise and microphonism through a mathematical inspection of their recorded pulse shape. The result of the application of the method to the last data of IGEX is presented.Comment: 14 pages, 8 figures. Submitted to Astrop. Phy

Pre-surgical Caregiver Burden and Anxiety Are Associated with Post-Surgery Cortisol over the Day in Caregivers of Coronary Artery Bypass Graft Surgery Patients.

BACKGROUND: The relationship between pre-surgical distress and diurnal cortisol following surgery has not been investigated prospectively in caregivers of coronary artery bypass graft (CABG) patients before. We aimed to examine the relationship between pre-surgical anxiety and caregiver burden and diurnal cortisol measured 2 months after the surgery in the caregivers of CABG patients. METHOD: We used a sample of 103 caregivers of elective CABG patients that were assessed 28.86 days before and 60.94 days after patients' surgery. Anxiety and caregiver burden were assessed using the anxiety subscale of the Hospital Anxiety and Depression Scale and the Oberst Burden Scale respectively. Saliva samples were collected to measure cortisol area under the curve with respect to ground (AUCg) and diurnal cortisol slope. Anxiety and caregiver burden were entered into linear regression models simultaneously. RESULTS: While high levels of pre-surgical anxiety were positively associated with increased follow-up levels of AUCg (β = 0.30, p = 0.001), greater pre-surgery perceived burden score was associated with steeper cortisol slope (β = 0.27, p = 0.017) after controlling for a wide range of covariates. CONCLUSION: These outcomes support the utility of psychological interventions aimed to increase the awareness of caregiving tasks and demands in informal caregivers

Neutron background at the Canfranc Underground Laboratory and its contribution to the IGEX-DM dark matter experiment

A quantitative study of the neutron environment in the Canfranc Underground Laboratory has been performed. The analysis is based on a complete set of simulations and, particularly, it is focused on the IGEX-DM dark matter experiment. The simulations are compared to the IGEX-DM low energy data obtained with different shielding conditions. The results of the study allow us to conclude, with respect to the IGEX-DM background, that the main neutron population, coming from radioactivity from the surrounding rock, is practically eliminated after the implementation of a suitable neutron shielding. The remaining neutron background (muon-induced neutrons in the shielding and in the rock) is substantially below the present background level thanks to the muon veto system. In addition, the present analysis gives us a further insight on the effect of neutrons in other current and future experiments at the Canfranc Underground Laboratory. The comparison of simulations with the body of data available has allowed to set the flux of neutrons from radioactivity of the Canfranc rock, (3.82 +- 0.44) x 10^{-6} cm^{-2} s^{-1}, as well as the flux of muon-induced neutrons in the rock, (1.73 +- 0.22(stat) \+- 0.69(syst)) x 10^{-9} cm^{-2} s^{-1}, or the rate of neutron production by muons in the lead shielding, (4.8 +- 0.6 (stat) +- 1.9 (syst)) x 10^{-9} cm^{-3} s^{-1}.Comment: 17 pages, 8 figures, elsart document class; final version to appear in Astroparticle Physic

Numerical simulation and experiments of the multiphase flow in a liquid-liquid cylindrical cyclone separator

A Liquid-Liquid Cylindrical Cyclone separator (LLCC) is a device used in the petroleum industry to separate the oil-water mixture obtained from the well. The use of this device has not been widespread due to the lack of tools for predicting its separation capability. This paper presents a numerical and experimental study of the fluid dynamic performance of this type of cylindrical cyclone separators. The use of numerical simulations would reduce the time and cost necessary to obtain information for predicting the behavior of the equipment. The objective of this study is to determine if CFD (Computational Fluid Dynamics) techniques are able to reproduce the behavior of a LLCC separator. The CFD software examined was ANSYS-CFX 5.6TM and numerical simulations were carried out using the dispersed model with oil as the dispersed phase. The oil and water mixture entering the separator is divided due to centrifugal and buoyancy forces in an upper (oil rich) exit and a bottom (water rich) exit. The separation capability is determined as the maximum amount of water removed from the mixture with the minimum amount of oil content in the water rich exit. The experiments were conducted in a transparent LLCC separator that allows the visualization of the mixture and the measurement of the oil content. Experiments were conducted for three variables: mixture velocity and water content at the entrance, and the split ratio. The split ratio is defined as the bottom exit flow rate divided by the water flow rate at the entrance. The results showed that CFD tools are able to reproduce the oil content obtained from the experiments for all analyzed conditions. Additionally, the mixture distribution images from numerical and experimental data showed good agreement. This study confirms the capacity of CFD tools for the multiphase flow analysis of LLCC separators

Status of the ANAIS Dark Matter Project at the Canfranc Underground Laboratory

The ANAIS experiment aims at the confirmation of the DAMA/LIBRA signal. A detailed analysis of two NaI(Tl) crystals of 12.5 kg each grown by Alpha Spectra will be shown: effective threshold at 1 keVee is at reach thanks to outstanding light collection and robust PMT noise filtering protocols and the measured background is well understood down to 3 keVee, having quantified K, U and Th content and cosmogenic activation in the crystals. A new detector was installed in Canfranc in March 2015 together with the two previous modules and preliminary characterization results will be presented. Finally, the status and expected sensitivity of the full experiment with 112 kg will be reviewed.Comment: Contributed to the 11th Patras Workshop on Axions, WIMPs and WISPs, Zaragoza, June 22 to 26, 201