4,107 research outputs found
Independent Orbiter Assessment (IOA): Analysis of the life support and airlock support subsystems
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. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Life Support System (LSS) and Airlock Support System (ALSS). 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. The LSS provides for the management of the supply water, collection of metabolic waste, management of waste water, smoke detection, and fire suppression. The ALSS provides water, oxygen, and electricity to support an extravehicular activity in the airlock
Reproducibilty of partial weight bearing
Objectives: To find out whether partial weight bearing can be reproduced and retained. Design: In vivo experiment in normal subjects. Intervention: Training for partial weight bearing (25% of body weight) using bathroom scales. Main outcome measurement: Reproducibility on force platform immediately after training and after 60 min. Results: Twelve subjects were asked to reproduce 25% of their body weight through either the dominant or non-dominant limb on force platform after three practice attempts on bathroom scales with concurrent visual feedback. No feedback was provided after the measurements on force plate. The process was repeated after 1 h without any practice sessions in the interim period to find out if the weight practised could be retained. The mean 0-min reading was found to be 25.9% of body weight while the mean 60-min reading was found to be 24.4%. The p-value for the difference between the two means was found to be 0.3841. Conclusions: This study indicates that partial weight bearing instructions can be quantified and graded. Simple bathroom scales are sufficient to educate the patients and this can be practised at home after an initial period of supervision
EffectiveSan: Type and Memory Error Detection using Dynamically Typed C/C++
Low-level programming languages with weak/static type systems, such as C and
C++, are vulnerable to errors relating to the misuse of memory at runtime, such
as (sub-)object bounds overflows, (re)use-after-free, and type confusion. Such
errors account for many security and other undefined behavior bugs for programs
written in these languages. In this paper, we introduce the notion of
dynamically typed C/C++, which aims to detect such errors by dynamically
checking the "effective type" of each object before use at runtime. We also
present an implementation of dynamically typed C/C++ in the form of the
Effective Type Sanitizer (EffectiveSan). EffectiveSan enforces type and memory
safety using a combination of low-fat pointers, type meta data and type/bounds
check instrumentation. We evaluate EffectiveSan against the SPEC2006 benchmark
suite and the Firefox web browser, and detect several new type and memory
errors. We also show that EffectiveSan achieves high compatibility and
reasonable overheads for the given error coverage. Finally, we highlight that
EffectiveSan is one of only a few tools that can detect sub-object bounds
errors, and uses a novel approach (dynamic type checking) to do so.Comment: To appear in the Proceedings of 39th ACM SIGPLAN Conference on
Programming Language Design and Implementation (PLDI2018
Polyimides prepared from perfluoroisopropylidene diamine
This invention relates to a novel aromatic diamine and more particularly to the use of said diamine for the preparation of thermally stable high-molecular weight polymers including, for example, polyamides, polyamideimides, polyimides, and the like. This diamine is obtained by reacting a stoichometric amount of a disodium salt of 2,2-bis(4-hydroxyphenyl) hexafluoropropane with 4-chloronitrobenzene to obtain an intermediate, 2,2-bis[4-(4-nitrophenoxy)phenyl] hexafluoropropane, which is reduced to the corresponding 2,2-bis[4-(4-aminophenoxy)phenyl] hexafluoropropane
Fluorinated aromatic diamine
This invention relates to a novel aromatic diamine and more particularly to the use of said diamine for the preparation of thermally stable high-molecular weight polymers including, for example, polyamides, polyamideimides, polyimides, and the like. This diamine is obtained by reacting a stoichometric amount of a disodium salt of 2,2-bis(4-hydroxyphenyl) hexafluoropropane with 4-chloronitrobenzene to obtain an intermediate, 2,2-bis[4-(4-nitrophenoxy)phenyl] hexafluoropropane, which is reduced to the corresponding 2,2-bis[4-(4-aminophenoxy)phenyl] hexafluoropropane
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Black carbon physical and optical properties across northern India during pre-monsoon and monsoon seasons
Black carbon (BC) is known to have major impacts on both climate and human health and is therefore of global importance, particularly in regions close to large populations that have strong sources. The size-resolved mixing state of BC-containing particles was characterised using a single-particle soot photometer (SP2). The study focusses on the Indo-Gangetic Plain (IGP) during the pre-monsoon and monsoon seasons. Data presented are from the UK Facility for Airborne Atmospheric Measurements BAe-146 research aircraft that performed flights during the pre-monsoon (11 and 12 June) and monsoon (30 June to 11 July) seasons of 2016.
Over the IGP, BC mass concentrations were greater (1.95 µg m−3) compared to north-west India (1.50 µg m−3) and north-east India (0.70 µg m−3) during the pre-monsoon season. Across northern India, two distinct BC modes were recorded; a mode of small BC particles (core diameter <0.16 µm and coating thickness <50 nm) and a mode of moderately coated BC (core diameter <0.22 µm and coating thickness of 50–200 nm). The IGP and north-east India locations exhibited moderately coated black carbon particles with enhanced coating thicknesses, core sizes, mass absorption cross sections, and scattering enhancement values compared to much lower values present in the north-west. The coating thickness and mass absorption cross section increased with altitude (13 %) compared to those in the boundary layer. As the monsoon arrived across the region, mass concentration of BC decreased over the central IGP and north-east locations (38 % and 28 % respectively), whereas for the north-west location BC properties remained relatively consistent. Post-monsoon onset, the coating thickness, core size, mass absorption cross section, and scattering enhancement values were all greatest over the central IGP much like the pre-monsoon season but were considerably reduced over both north-east and north-west India. Increases in mass absorption cross section through the atmospheric column were still present during the monsoon for the north-west and central IGP locations, but less so over the north-east due to lack of long-range transport aerosol aloft. Across the Indo-Gangetic Plain and north-east India during the pre-monsoon and monsoon seasons, solid-fuel (wood burning) emissions form the greatest proportion of BC with moderately coated particles. However, as the monsoon develops in the north-east there was a switch to small uncoated BC particles indicative of traffic emissions, but the solid-fuel emissions remained in the IGP into the monsoon. For both seasons in the north-west, traffic emissions form the greatest proportion of BC particles.
Our findings will prove important for greater understanding of the BC physical and optical properties, with important consequences for the atmospheric radiative forcing of BC-containing particles. The findings will also help constrain the regional aerosol models for a variety of applications such as space-based remote sensing, chemistry transport modelling, air quality, and BC source and emission inventories
Open-closed homotopy algebra in mathematical physics
In this paper we discuss various aspects of open-closed homotopy algebras
(OCHAs) presented in our previous paper, inspired by Zwiebach's open-closed
string field theory, but that first paper concentrated on the mathematical
aspects. Here we show how an OCHA is obtained by extracting the tree part of
Zwiebach's quantum open-closed string field theory. We clarify the explicit
relation of an OCHA with Kontsevich's deformation quantization and with the
B-models of homological mirror symmetry. An explicit form of the minimal model
for an OCHA is given as well as its relation to the perturbative expansion of
open-closed string field theory. We show that our open-closed homotopy algebra
gives us a general scheme for deformation of open string structures
(-algebras) by closed strings (-algebras).Comment: 38 pages, 4 figures; v2: published versio
Retroperitoneal Liposarcoma
Liposarcoma is a rare tumor of fatty tissue. The retroperitoneal site accounts for 0.01-O.l% of all malignancies. The location makes early detection difficult and by the time the patient comes to surgery the large size deters surgeons from attempting resection. This is a report of a patient from whom a 10 kilogram retroperitoneal liposarcoma was successfully removed and one year later a recurrent tumour ling 13.8 kilogram was excised. Size d not be a deterrent to operability if vital s are not involved.Key words: liposarcoma, retroperitoneu
Psychosocial outcomes of an inclusive adapted sport and adventurous training course for military personnel.
PURPOSE: To explore the psychosocial outcomes of an inclusive adapted sport and adventurous training course that aims to support the rehabilitation and personal development of military personnel who have sustained physical and/or psychological disability. METHOD: Narrative life story interviews were conducted with 11 men aged 20-43 taking part in one of the 5-day courses. A thematic narrative analysis was conducted, focusing on accounts that provided insights into personally meaningful psychosocial outcomes of the course. FINDINGS: We identified six themes, falling into two distinct clusters. "Bringing me back to myself" was achieved through the themes of (1) returning to activity, (2) rediscovering a sense of purpose, and (3) reconnecting to others. "New rooms to explore" was realised through (4) experiencing new activities, (5) being valued/respected/cared for and (6) being inspired by other people. CONCLUSION: Involvement in the course stimulated a balance of present- and future-oriented psychosocial outcomes through which participants both recreated aspects of themselves that had been lost through injury/trauma and moved forward with their lives as a result of new horizons of possibility. IMPLICATIONS FOR REHABILITATION: This 5-day inclusive adapted sport and adventurous training course offered meaningful psychosocial outcomes among military personnel who had experienced physical and/or psychological disability. The course helped participants recover aspects of their previous life and self through becoming physically active again, rediscovering a sense of purpose and reconnecting to others. Participants describe a broadening of life horizons as a result of the course, through new activities, being valued/respected/cared for, and being inspired by other people
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