Estimation of Fatigue Index for a Pump Assembly Operation Using Ergonomics Study

Pflege ◽  
2006 ◽  
Vol 19 (4) ◽  
pp. 214-222
Author(s):  
Miriam Unger ◽  
Rebecca Spirig

In der Schweiz leben zwischen 15000 und 16000 Menschen mit HIV/AIDS. Diese Population leidet unter einer Vielzahl von Symptomen und Beschwerden. Besonders schwerwiegend und häufig ist die Fatigue, welche gemäß aktueller Studien bei 20 bis 74% der HIV-infizierten Menschen auftritt. Das Symptom beeinträchtigt alle Aktivitäten des täglichen Lebens, das Empfinden körperlicher und mentaler Gesundheit sowie die Lebensqualität der Betroffenen stark. An der HIV-Sprechstunde des Universitätsspitals Basel, Schweiz, äußern viele Patienten und Patientinnen Beschwerden, die auf das Bestehen von Fatigue hinweisen, oder sprechen direkt über ihre starke Erschöpfung. Eine systematische Literatursuche wurde durchgeführt und ein evidenzbasiertes Praxisprogramm erarbeitet, um den Betroffenen eine angepasste Betreuung bieten zu können. Das Programm enthält die Elemente: Screening, systematisches Assessment, Interventionen und Beratung. Für das Assessment werden der adaptierte Global Fatigue Index und eine visuelle Analogskala eingesetzt. Die Patientinnen werden durch systematische Interventionen bei der Verbesserung ihres Selbstmanagements unterstützt. Ziel der vorliegenden Arbeit ist es, Pflegenden, die HIV-infizierte Menschen betreuen, eine Zusammenfassung der aktuellen Literatur bezüglich HIV-induzierter Fatigue zu präsentieren und die Elemente, den Ablauf sowie des Praxisprogramms darzustellen. Es kann davon ausgegangen werden, dass mit Hilfe des Praxisprogramms Menschen, die mit HIV/AIDS leben und unter Fatigue leiden, positiv beim Management dieses Symptoms ihrer chronischen Erkrankung unterstützt werden können.


2020 ◽  
Vol 10 (2) ◽  
pp. 82-93
Author(s):  
Eduardo Rosa ◽  
Ola Eiken ◽  
Mikael Grönkvist ◽  
Roger Kölegård ◽  
Nicklas Dahlström ◽  
...  

Abstract. Fighter pilots may be exposed to extended flight missions. Consequently, there is increasing concern about fatigue. We investigated the effects of fatigue and cognitive performance in a simulated 11-hr mission in the 39 Gripen fighter aircraft. Five cognitive tasks were used to assess cognitive performance. Fatigue was measured with the Samn–Perelli Fatigue Index. Results showed that performance in the non-executive task degraded after approximately 7 hr. Fatigue ratings showed a matching trend to the performance in this task. Performance in tasks taxing executive functions did not decline. We interpreted that fatigue can be overridden by increased attentional effort for executive tasks but not for non-executive components of cognition. Participants underestimated their performance and metacognitive accuracy was not influenced by fatigue.


Author(s):  
Boris A. Sokolov ◽  
Nikolay N. Tupitsyn

The paper presents results of engineering studies and research and development efforts at RSC Energia to analyze and prove the feasibility of using the mass-produced oxygen-hydrocarbon engine 11D58M with 8.5 ton-force thrust as a basis for development of a high-performance multifunctional rocket engine with oxygen cooling and 5 ton-force thrust, which is optimal for upper stages (US), embodying a system that does not include a gas generator. The multi-functionality of the engine implies including in it additional units supporting some functions that are important for US, such as feeding propellant from US tanks to the engine after flying in zero gravity, autonomous control of the engine automatic equipment to support its firing, shutdown, adjustments during burn and emergency protection in case of off-nominal operation, as well as generating torques for controlling the US attitude and stabilizing it during coasting, etc. Replacing conventional engine chamber cooling that uses high-boiling hydrocarbon fuel with the innovative oxygen cooling makes it possible to get rid of the internal film cooling circuits and eliminate their attendant losses of fuel, while the use of the oxygen gasified in the cooling circuit of the chamber to drive the turbo pump assembly permits to design an engine that does not have a gas generator. Key words: Multifunctional rocket engine, oxygen cooling, gas-generatorless design, upper stage.


2021 ◽  
pp. 088307382199988
Author(s):  
Giuseppina Pilloni ◽  
Martin Malik ◽  
Raghav Malik ◽  
Lauren Krupp ◽  
Leigh Charvet

Aim: To adopt a computer-based protocol to assess grip fatigability in patients with pediatric-onset multiple sclerosis to provide detection of subtle motor involvement identifying those patients most at risk for future decline. Method: Pediatric-onset multiple sclerosis patients were recruited during routine outpatient visits to complete a grip assessment and compared to a group of healthy age- and sex-matched controls. All participants completed a computer-based measurement of standard maximal grip strength and repetitive and sustained grip performance measured by dynamic and static fatigue indices. Results: A total of 38 patients with pediatric-onset multiple sclerosis and 24 healthy controls completed the grip protocol (right-hand dominant). There were no significant group differences in maximal grip strength bilaterally (right: 21.8 vs 19.9 kg, P = .25; left: 20.4 vs 18.7 kg, P = .33), although males with pediatric-onset multiple sclerosis were significantly less strong than healthy controls (right: 26.53 vs 21.23 kg, P = .009; left; 25.13 vs 19.63 kg, P = .003). Both dynamic and static fatigue indices were significantly higher bilaterally in pediatric-onset multiple sclerosis compared with healthy control participants (left-hand dynamic fatigue index: 18.6% vs 26.7%, P = .003; right-hand static fatigue index: 28.3% vs 41.3%, P < .001; left-hand static fatigue index: 31.9% vs 42.6%, P < .001). Conclusion: Brief repeatable grip assessment including measures of dynamic and sustained static output can be a sensitive indicator of upper extremity motor involvement in pediatric-onset multiple sclerosis, potentially identifying those in need of intervention to prevent future disability.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 830
Author(s):  
Prasangi Rajapaksha ◽  
Isoiza Ojo ◽  
Ling Yang ◽  
Ankit Pandeya ◽  
Thilini Abeywansha ◽  
...  

The RND family efflux pump AcrAB-TolC in E. coli and its homologs in other Gram-negative bacteria are major players in conferring multidrug resistance to the cells. While the structure of the pump complex has been elucidated with ever-increasing resolution through crystallography and Cryo-EM efforts, the dynamic assembly process remains poorly understood. Here, we tested the effect of overexpressing functionally defective pump components in wild type E. coli cells to probe the pump assembly process. Incorporation of a defective component is expected to reduce the efflux efficiency of the complex, leading to the so called “dominant negative” effect. Being one of the most intensively studied bacterial multidrug efflux pumps, many AcrA and AcrB mutations have been reported that disrupt efflux through different mechanisms. We examined five groups of AcrB and AcrA mutants, defective in different aspects of assembly and substrate efflux. We found that none of them demonstrated the expected dominant negative effect, even when expressed at concentrations many folds higher than their genomic counterpart. The assembly of the AcrAB-TolC complex appears to have a proof-read mechanism that effectively eliminated the formation of futile pump complex.


2019 ◽  
Vol 6 ◽  
pp. 205566831982580 ◽  
Author(s):  
Ruslinda Ruslee ◽  
Jennifer Miller ◽  
Henrik Gollee

Introduction: Functional electrical stimulation is a common technique used in the rehabilitation of individuals with a spinal cord injury to produce functional movement of paralysed muscles. However, it is often associated with rapid muscle fatigue which limits its applications. Methods: The objective of this study is to investigate the effects on the onset of fatigue of different multi-electrode patterns of stimulation via multiple pairs of electrodes using doublet pulses: Synchronous stimulation is compared to asynchronous stimulation patterns which are activated sequentially (AsynS) or randomly (AsynR), mimicking voluntary muscle activation by targeting different motor units. We investigated these three different approaches by applying stimulation to the gastrocnemius muscle repeatedly for 10 min (300 ms stimulation followed by 700 ms of no-stimulation) with 40 Hz effective frequency for all protocols and doublet pulses with an inter-pulse-interval of 6 ms. Eleven able-bodied volunteers (28 ± 3 years old) participated in this study. Ultrasound videos were recorded during stimulation to allow evaluation of changes in muscle morphology. The main fatigue indicators we focused on were the normalised fatigue index, fatigue time interval and pre-post twitch–tetanus ratio. Results: The results demonstrate that asynchronous stimulation with doublet pulses gives a higher normalised fatigue index (0.80 ± 0.08 and 0.87 ± 0.08) for AsynS and AsynR, respectively, than synchronous stimulation (0.62 ± 0.06). Furthermore, a longer fatigue time interval for AsynS (302.2 ± 230.9 s) and AsynR (384.4 ± 279.0 s) compared to synchronous stimulation (68.0 ± 30.5 s) indicates that fatigue occurs later during asynchronous stimulation; however, this was only found to be statistically significant for one of two methods used to calculate the group mean. Although no significant difference was found in pre-post twitch–tetanus ratio, there was a trend towards these effects. Conclusion: In this study, we proposed an asynchronous stimulation pattern for the application of functional electrical stimulation and investigated its suitability for reducing muscle fatigue compared to previous methods. The results show that asynchronous multi-electrode stimulation patterns with doublet pulses may improve fatigue resistance in functional electrical stimulation applications in some conditions.


1995 ◽  
Vol 15 (1) ◽  
pp. 34-34
Author(s):  
Clive Loughlin

Examines the development of a flexible assembly machine, GENASYS [Generic Assembly System] which has been designed to produce a range of components. The machine comprises two manipulator arms, a tool changer and a shuttle system for the pallets on which the assembly operations are performed. Each manipulator is able to select a different tool from a carousel tool change mechanism that can accommodate up to 20 different tools. The machine can easily be programmed for a specific assembly operation and low batch numbers can be produced economically. Timescales for the design and installation of the machine are considerably shorter than for a dedicated assembly line and once installed in a factory new product variants can be accommodated within very short timescales and with low‐retooling costs.


2015 ◽  
Vol 118 (9) ◽  
pp. 1128-1135 ◽  
Author(s):  
Karin Harumi Uchima Koecklin ◽  
Chiho Kato ◽  
Yukiha Funaki ◽  
Maya Hiranuma ◽  
Takayoshi Ishida ◽  
...  

Mouth breathing caused by nasal obstruction affects the normal growth and development of craniofacial structures, including changes in the orofacial muscles. Tongue muscles play an important role in patency of the pharyngeal airway, and changes in the breathing pattern may influence tongue function. The purpose of this study was to evaluate the effect of unilateral nasal obstruction during growth on contractile properties of the tongue-protruding muscles. Sixty 6-day-old male Wistar albino rats were divided randomly into control ( n = 30) and experimental ( n = 30) groups. Rats in the experimental group underwent a unilateral nasal obstruction after cauterization of the external nostril at the age of 8 days, and muscle contractile characteristics were measured at 5, 7, and 9 wk of age. The specific parameters measured were twitch force, contraction time, half-decay time, tetanic force, and fatigue index. Repeated-measures multivariate analysis of variance was used for intergroup and intragroup statistical comparisons. Twitch contraction force and half-decay time were significantly increased in the experimental group at all ages. Tetanic forces at 60 and 80 Hz were significantly higher in the experimental group at all ages. The fatigue index was decreased significantly in the experimental group at the age of 5 wk. These results suggest that early unilateral nasal obstruction may increase the contraction force of the tongue-protruding muscles and prolong the duration of muscle contraction, which may influence the shape and development of the craniofacial complex.


Sign in / Sign up

Export Citation Format

Share Document