29 research outputs found
5.Uluslararası Öğrenciler Fen Bilimleri Kongresi Tam Metin Kitabı
Çevrimiçi (IX, 431 Sayfa; 26 cm.)
Muscle activation patterns in shoulder impingement patients
Introduction: Shoulder impingement is one of the most common presentations of shoulder joint problems 1. It appears to be caused by a reduction in the sub-acromial space as the humerus abducts between 60o -120o – the 'painful arc'. Structures between the humeral head and the acromion are thus pinched causing pain and further pathology 2. Shoulder muscle activity can influence this joint space but it is unclear whether this is a cause or effect in impingement patients. This study aimed to observe muscle activation patterns in normal and impingement shoulder patients and determine if there were any significant differences.
Method: 19 adult subjects were asked to perform shoulder abduction in their symptomatic arm and non-symptomatic. 10 of these subjects (age 47.9 ± 11.2) were screened for shoulder impingement, and 9 subjects (age 38.9 ± 14.3) had no history of shoulder pathology. Surface EMG was used to collect data for 6 shoulder muscles (Upper, middle and lower trapezius, serratus anterior, infraspinatus, middle deltoids) which was then filtered and fully rectified. Subjects performed 3 smooth unilateral abduction movements at a cadence of 16 beats of a metronome set at 60bpm, and the mean of their results was recorded. T-tests were used to indicate any statistical significance in the data sets. Significance was set at P<0.05.
Results: There was a significant difference in muscle activation with serratus anterior in particular showing a very low level of activation throughout the range when compared to normal shoulder activation patterns (<30%). Middle deltoid recruitment was significantly reduced between 60-90o in the impingement group (30:58%).Trends were noted in other muscles with upper trapezius and infraspinatus activating more rapidly and erratically (63:25%; 60:27% respectively), and lower trapezius with less recruitment (13:30%) in the patient group, although these did not quite reach significance.
Conclusion: There appears to be some interesting alterations in muscle recruitment patterns in impingement shoulder patients when compared against their own unaffected shoulders and the control group. In particular changes in scapula control (serratus anterior and trapezius) and lateral rotation (infraspinatus), which have direct influence on the sub-acromial space, should be noted. It is still not clear whether these alterations are causative or reactionary, but this finding gives a clear indication to the importance of addressing muscle reeducation as part of a rehabilitation programme in shoulder impingement patients
Aerodynamic measurements on a small HAWT rotor in axial and yawed flow
Current wind turbine performance codes are not yet able to predict the
rotor aerodynamic behaviour with sufficient certainty. This has led to
both the over-design of blades and to operational restrictions in
certain wind conditions.
Essentially the problem is one of aerodynamic stall. Steady
3-dimensional stall can occur near the blade root in high wind
conditions and may produce more power than predicted. Dynamic stall
can also be expected due to the effects of yawed operation,
turbulence, tower shadow and the earth's boundary layer.
The main aim of this work is to provide a coherent set of measured
aerodynamic data accounting for both axial/non-axial flow and stall in
high winds. These measurements are designed to highlight the effects
of both steady and dynamic stall on the rotor aerodynamic performance.
In addition, the data will enable current performance prediction codes
to be developed and validated.
A completely new turbine has been designed and built at Cranfield to
make aerodynamic measurements using pressure transducers. The design
has been dominated by the requirements of accommodating the transducer
signal processing equipment and allowing variation of many of the
rotor parameters. Three commercial glass fibre blades were installed
and performance curves measured on a conventional field site at a
height of 11.5m for three rotor speed settings. These measurements
show the turbine to give adequate power performance.
A mobile trailer has been used to tow the turbine at a height of 4m
along the Cranfield runways. Mobile testing facilitates an accelerated
test schedule and allows aerodynamic data to be acquired under
controlled wind conditions. A fully instrumented blade, fitted with
forty transducers, has been tested under these circumstances and
produced a large database of pressure measurements covering operation
in winds up to 25 iq/s and yaw angles between -4511 and +55°.
Analysis of the data has shown it to be of good quality and allowed
some of the effects of yaw and stall to be identified. The use of the
data base for performance prediction code validation has also been
established
RFID Technology in Intelligent Tracking Systems in Construction Waste Logistics Using Optimisation Techniques
Construction waste disposal is an urgent issue
for protecting our environment. This paper proposes a
waste management system and illustrates the work
process using plasterboard waste as an example, which
creates a hazardous gas when land filled with household
waste, and for which the recycling rate is less than 10%
in the UK. The proposed system integrates RFID
technology, Rule-Based Reasoning, Ant Colony
optimization and knowledge technology for auditing
and tracking plasterboard waste, guiding the operation
staff, arranging vehicles, schedule planning, and also
provides evidence to verify its disposal. It h relies on
RFID equipment for collecting logistical data and uses
digital imaging equipment to give further evidence; the
reasoning core in the third layer is responsible for
generating schedules and route plans and guidance, and
the last layer delivers the result to inform users. The
paper firstly introduces the current plasterboard
disposal situation and addresses the logistical problem
that is now the main barrier to a higher recycling rate,
followed by discussion of the proposed system in terms
of both system level structure and process structure.
And finally, an example scenario will be given to
illustrate the system’s utilization
MEASUREMENT AND ANALYSIS OF SEA WAVES NEAR A REFLECTIVE STRUCTURE
Merged with duplicate record 10026.1/2047 on 06.20.2017 by CS (TIS)Methods and equipment for the measurement of ocean waves were reviewed
and their suitability assessed for the aim of this project: field measurement
of sea waves near a reflective coastal structure such as a breakwater. None
was found to be suitable. The functional and performance objectives are set
out for a new system. The evolution of the final design, based on an array
of pressure sensors, is described. The whole system is intended to be
deployed on the sea-bed. It is fully self contained and independent of shore
based services. Located away from the surf zone it is well placed to survive
storm conditions and unauthorised interference.
Theoretical methods for the re-construction of surface elevation records
from measured sub-surface pressures, and the experimental findings of other
workers, are presented. Available methods of estimating the wave
directional spectrum from a spatial array of surface elevation records are
reviewed, and the most appropriate one implemented.
The system has given extensive service at a number of coastal defence sites.
The results of subsequent analysis of selected data sets are presented in
detail. They show the pronounced nodal structure in amplitude expected in
the presence of wave reflection, clearly demonstrating that a single point
measurement is likely to give misleading estimates of incident wave height.
For near-calm to moderate, shore-normal incident wave conditions the
results were found to agree with theoretical predictions both of wave height
as a function of distance offshore, and of the structure's
frequency-dependent reflection coefficient. For rougher conditions, in
which both theoretical and physical models are less applicable, the results
agreed with visual observations