Independent Orbiter Assessment (IOA): Assessment of the remote manipulator system FMEA/CIL

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Remote Manipulator System (RMS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were than compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. The results of that comparison for the Orbiter RMS hardware are documented. The IOA product for the RMS analysis consisted of 604 failure mode worksheets that resulted in 458 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 45 FMEAs and 321 CIL items. This comparison produced agreement on all but 154 FMEAs which caused differences in 137 CIL items

Independent Orbiter Assessment (IOA): Analysis of the remote manipulator system

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items (PCIs). To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Orbiter Remote Manipulator System (RMS) are documented. The RMS hardware and software are primarily required for deploying and/or retrieving up to five payloads during a single mission, capture and retrieve free-flying payloads, and for performing Manipulator Foot Restraint operations. Specifically, the RMS hardware consists of the following components: end effector; displays and controls; manipulator controller interface unit; arm based electronics; and the arm. The IOA analysis process utilized available RMS hardware drawings, schematics and documents for defining hardware assemblies, components and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Of the 574 failure modes analyzed, 413 were determined to be PCIs

Vibration Characteristics of Lightweight Floors Using Cold-formed Steel Joist

Presented in this paper are the results of a recent study carried out at the University of Waterloo on vibration characteristics of cold-formed steel-supported residential floor systems and different design criteria available for the evaluation of lightweight floor systems. Laboratory tests were conducted for the floors with different spans and assemblies. Both static and dynamic tests were carried out on the floor systems. The static tests were used to evaluate the stiffness and the load sharing among the joists, while the dynamic tests were used to evaluate the relevant dynamic characteristics, such as natural frequencies and damping ratios, of the floor systems. The test results were then compared with those obtained from different design methods. Concluding remarks regarding the acceptance criteria from the comparison are also presented

Calibrattions of Cold-Formed Steel Welded Connections

The purpose of this project was to recalibrate the welded connection equations currently contained in the American Iron and Steel Institute (AISI) Specification for the Design of Cold Formed Steel Structural Members (AISI 1996a). Only one factor of safety of 2.50 is presented for the each of the various types of welded connections when using allowable stress design (ASD), but different respective resistance factors are given for load and resistance factor design (LRFD). The data used was solely taken from the research conducted by Pekoz and McGuire (Pekoz and McGuire 1979). Calibrations were carried out and based on both the AISI Specification (AISI 1996a) and the Canadian Sl36 Standard (CSA 1994). The results of this study have already been adopted by both of these cold formed steel design agencies, as well as by the North American Specification for the Design of Cold-Formed Steel Structural Members (NAS 2001)

The Use of Infrared Thermography fort he Monitoring of Udder Teat Stress Caused by Milking Machines

The aim of this study was to test infrared thermography (IRT) as a possible tool for scoring teat color changes after cluster removal; thus, indirectly, to classify the short-term stress of teats caused by milking machines. Thermographic images (n = 137) from three farms were collected and evaluated to calculate the average and maximum skin surface temperatures (SSTs) at the base, center, and tip of each teat (Tavg,B, Tavg,C, Tavg,T, Tmax,B, Tmax,C, and Tmax,T). Obtained results confirmed a significant relationship between the indicators Tavg, Tmax and the levels of teat color change (level one: pink-colored teat; level two: red-colored teat; level three: blue or purple-colored teat). Nevertheless, when a teat was considered to be stressed because its scoring fell in level 3 of the color-change scale used, sensitivity and specificity in the classification of the teat status ranged respectively between 45.6% and 54.3%, and 54.4% and 59.2%, for the indicators Tavg; and 56.5% and 60.9%, and 59.7% and 61.8%, for the indicators Tmax. When a teat was considered stressed because its scoring fell between the levels 2 and 3 of the scale adopted, sensitivity and specificity were between 49.0% and 55.8%, and 58.3% and 61.8%, for the indicators Tavg; and 55.8% and 59.9%, and 60.6% and 61.4%, for the indicators Tmax. As a consequence, the low values of sensitivity and specificity do not seem to justify the development of an ad hoc infrared device for the monitoring of udder teat stress. Nonetheless, this technology can be a viable solution for a preliminary evaluation of the mechanical stress of teats if a milking system would be equipped with an infrared sensor already in place for other purposes (e.g., the monitoring of udder health status)

Candidemia in intensive care unit : a nationwide prospective observational survey (GISIA-3 study) and review of the European literature from 2000 through 2013

BACKGROUND: Candida bloodstream infections (BSI) represent an important problem in Intensive Care Units (ICUs). The epidemiology of candidemia is changing with an increase in the proportion of Candida (C.) non-albicans. OBJECTIVES: An Italian 2-year observational survey on ICU was conducted to evaluate the species distribution and possible differences between BSI caused by C. albicans and C. non-albicans. For comparative purposes, we performed a European literature-based review to evaluate distribution and frequency of Candida spp. causing ICU candidemia, during the period 2000-2013. MATERIALS AND METHODS: This laboratory-based survey involved 15 microbiology centers (GISIA-3 study). All candidemia episodes in adult patients were considered. Data were prospectively collected from 2007 to 2008. PubMed was searched for peer-reviewed articles. RESULTS: In total, 462 candidemia episodes were collected. C. albicans accounted for 49.4% of the isolates, followed by C. parapsilosis (26.2%) and C. glabrata (10.4%). Mortality was higher in patients with C. non-albicans than C. albicans (47.3% vs. 32.4 %, p > 0.05). Among risk factors, parenteral nutrition was more common (p = 0.02) in non-albicans candidemia, while surgery was more frequent (p = 0.02) in C. albicans candidemia. Twenty-four relevant articles were identified. C. albicans was the predominant species in almost all studies (range 37.9% -76.3%). C. glabrata was commonly isolated in the German-speaking countries, France, UK and North Europe; C. parapsilosis in Turkey, Greece and Spain. CONCLUSIONS: Although C. non-albicans BSI is increasing, our study shows that C. albicans is still the predominant species in ICU candidemia. There are differences in the epidemiology of Candida BSI among European countries, with a prevalence of C. glabrata and C. parapsilosis in Northern and Southern countries, respectively

LOGIC PROGRAMMING IN GROUNDWATER RESOURCES MANAGEMENT

This paper deals with a computer model able to verify whether there is groundwater in a given place, the quantity available and its quality. The knowledge base has been constructed using degrees of certainty and other factors. The model has been applied to a region in Southern Italy, where data are available. The first results are encouraging and further questions about groundwater quantity and quality are being examined. -from Authors