scholarly journals FUNCTIONAL DEPENDENCE OF LASER POWER AND LAYUP SPEED FOR AUTOMATIC FIBRE PLACEMENT TEMPERATURE CONTROL

2019 ◽  
Vol 34 (3) ◽  
pp. 613-619
Author(s):  
Dijana Cvetkoska ◽  
Filip Kochoski
Keyword(s):  
Diode Laser ◽  
Composite Structures ◽  
Thermal Model ◽  
Functional Dependence ◽  
New Technology ◽  
Open Loop ◽  
Thermoplastic Resin ◽  
Heater Power ◽  
Thermoset Resin ◽  
The Individual

Automated Fiber Placement (AFP) is a relatively new technology that has revolutionized the production of composite structures in the aerospace and space industries for more than two decades and is nowadays increasingly used in new industries such as the wind energy. Generally, the AFP machine consists of an automatic manipulator (robot) on which a layup head is fixed for laying multiple individual composite strips at once (certainly not excluding the possibility of laying a single wider tape when it comes to Automatic Tape Placement). The layup process is performed on a mandrel or tool with a certain geometric shape. The laying head should at least include a feeder, a cutting mechanism, a compaction mechanism (usually roller) and a certain type of heater (depending on the material type). Conventionally, three types of composite materials are used in combination with AFP technology: continuous fibers reinforced with thermoset resin (usually epoxy resin), same continuous fibers reinforced with thermoplastic resin as well as bonded continuous carbon fibers. Depending on the type of material this technology uses various types of heat sources in order to achieve a good adhesion to the individual fibers that are deposited in the laying process and the pre-laid composite layers. Thermoplastic pre-impregnated material requires high temperature to reach degree of melting of the resin used to achieve complete 'welding' with the previous layers. The melting temperature varies for different materials and ranges from 130°C to 200°C for low melting thermoplastics (such as Polyamide PA and Polypropylene PP), 280°C to 350°C for Polypropylene Sulfide (PPS) up to 400°C - 450oC for Polyether Ether Ketone (PEEK). For more than two decades, hot gas torches have been used for thermoplastic layup - not a very expensive system but very difficult to control. One of the newer sources of heat close to infrared radiation (λ = 0.9-1.1 μm) is diode laser heating. This research presents a simple thermal model of the process which correlates the heater power and the layup speed with the temperature of the heating area. The deposition temperature was measured over a range of heater powers and layup speeds. The experimental data is used to define and validate a thermal model for thermoplastic material used in conjunction with a diode laser: carbon fibre reinforced thermoplastics PEEK. This enables open-loop, speed dependent heater power control, based on defining and programming the speed dependent heater power function in the machine controls. Obtained functional dependency was implemented in the AFP machine control system and tested for production of several plates with different layup angles. The achieved temperature during layup process is monitored on the thermal camera and through several pyrometers.

Development of an Industry Test Facility and Qualification Process for ILI Technology Evaluation and Enhancements: Performance Evaluation Phase

2018 ◽  
Author(s):  
Pablo Cazenave ◽  
Ming Gao ◽  
Hans Deeb ◽  
Sean Black
Keyword(s):  
Performance Evaluation ◽  
Technology Development ◽  
New Technology ◽  
Test Facility ◽  
Technology Evaluation ◽  
Team Members ◽  
Integrity Assessment ◽  
Evaluation Phase ◽  
The Individual ◽  
Pull Tests

The project “Development of an Industry Test Facility and Qualification Processes for in-line inspection (ILI) technology Evaluation and Enhancements” aims to expand knowledge of ILI technology performance and identify gaps where new technology is needed. Additionally, this project also aims to provide ILI technology developers, researchers and pipeline operators a continuing resource for accessing test samples with a range of pipeline integrity threats and vintages; and inline technology test facilities at the Technology Development Center (TDC) of Pipeline Research Council International, Inc. (PRCI), a PRCI managed facility available for future industry and PHMSA research projects. An ILI pull test facility was designed and constructed as part of this project based on industry state-of-the-art and opportunities for capability improvement. The major ILI technology providers, together with pipeline operator team members, reviewed the TDC sample inventory and developed a series of ILI performance tests illustrating one of multiple possible research objectives, culminating in 16-inch and 24-inch nominal diameter test strings. The ILI technology providers proposed appropriate inspection tools based on the types of the integrity threats in the test strings, a series of pull tests of the provided ILI tools were performed, and the technology providers delivered reports of integrity anomaly location and dimensions for performance evaluation. Quantitative measures of detection and sizing performance were confidentially disclosed to the individual ILI technology providers. For instances where ILI predictions were outside of claimed performance, the vendors were given a limited sample of actual defect data to enable re-analysis, thus demonstrating the potential for improved integrity assessment with validation measurements. In this paper, an evaluation of the ILI data obtained from repeated pull-through testing on the 16 and 24-inch pipeline strings at the TDC is performed. The resulting data was aligned, analyzed, and compared to truth data and the findings of the evaluation are presented.

Computerized Image Enhancement for Visually Impaired Persons: New Technology, New Possibilities

1986 ◽  
Vol 80 (7) ◽  
pp. 849-854
Author(s):  
E. Pell ◽  
L. E. Arend ◽  
G. T. Timberlake
Keyword(s):  
Image Enhancement ◽  
Visually Impaired ◽  
Transfer Functions ◽  
Spatial Scales ◽  
New Technology ◽  
Age Related ◽  
Visual Degradation ◽  
The Individual ◽  
Visually Impaired Persons ◽  
Made In

Patients with age-related visual loss suffer reduced ability to recognize faces and other scenes in photographs and on television. Recently, progress has been made in image enhancement, using controlled distortion of digitally stored images that increases their usefulness in particular applications. Described are two approaches to image enhancement for the visually impaired. In one approach, the visual losses that characterize individual patients and disease classes are described using detailed measurements of visual degradation transfer functions, which are profiles of loss of image information at various spatial scales. The particular distortion used for image enhancement is then adjusted to the impairment of the individual patient or disease class. A second approach takes advantage of the resemblance between the visual losses of many patients and the degradation of picture information in other applications due to external limitations (e.g., fog and haze) on photography. Several enhancement algorithms have been found useful with such images and may also improve picture recognition by the visually impaired.

scholarly journals Failure to collectively assess security surveillance technologies will inevitably lead to an absolute surveillance society.

2013 ◽  
Vol 12 (1) ◽  
pp. 73-88 ◽  
Author(s):  
Timothy Mitchener-Nissen
Keyword(s):  
New Technology ◽  
Security Technology ◽  
Security Technologies ◽  
Small Rise ◽  
The Absolute ◽  
Waking Up ◽  
Surveillance Society ◽  
The Individual ◽  
Security Surveillance ◽  
The Impact

When assessing any security technology which impacts upon privacy, whether this constitutes a new technology or the novel application of existing technologies, we should do so by examining the combined effect of all security interventions currently employed within a society. This contrasts with the prevailing system whereby the impact of a new security technology is predominantly assessed on an individual basis by a subjective balancing of the security benefits of that technology against any reductions in concomitant rights, such as privacy and liberty. I contend that by continuing to focus on the individual effect, as opposed to the combined effects, of security technologies within a society the likelihood of sleep-walking into (or indeed waking-up in) an absolute surveillance society moves from a possible future to the logically inevitable future. This conclusion is based on two underlying assertions. Firstly that assessing a technology often entails a judgement of whether any loss in privacy is legitimised by a justifiable increase in security; however one fundamental difference between these two rights is that privacy is a finite resource with identifiable end-states (i.e. absolute privacy through to the absolute absence of privacy) whereas security does not have two finite end-states (while there exists the absolute absence of security, absolute security is an unobtainable yet desired goal). The second assertion, which relies upon the validity of the first, holds that one consequence of absolute security being unobtainable yet desirable is that new security interventions will continuously be developed, each potentially trading a small measure of privacy for a small rise in security. Examined individually each intervention may constitute a justifiable trade-off. However this approach of combining interventions in the search for ever greater security will ultimately reduce privacy to zero.

Control of cracks by interfaces in composites

1975 ◽  
Vol 341 (1627) ◽  
pp. 409-428 ◽  
Keyword(s):  
Composite Material ◽  
Elastic Properties ◽  
Adhesive Joint ◽  
Composite Structures ◽  
Crack Path ◽  
Brittle Materials ◽  
Novel Theory ◽  
The Individual ◽  
Model Crack

A novel theory is proposed to show how a crack may he accelerated or retarded when it meets an interface between two equally brittle materials of different elastic properties. Measurements of a model crack travelling through a brittle adhesive joint have substantially verified the theory. The results demonstrate that the toughness of a composite material, having a periodic stiffness change along the crack path, may be very much greater than the toughness of the individual components of the composite. The relevance of these ideas to the design of tough composite structures is discussed.

The Role of Religious Orientation and PsyCap in Mitigating Technostress

2021 ◽  
Vol 18 (5) ◽  
pp. 358-374
Author(s):  
Dwi Wijayanti ◽  
Alex Riza ◽  
Casmini ◽  
Musthofa
Keyword(s):  
Religious Orientation ◽  
Mental Health Problems ◽  
Business Students ◽  
New Technology ◽  
Learning System ◽  
Learning Activities ◽  
Internal Factors ◽  
Work From Home ◽  
The Individual

The government's work from home policy because of COVID-19 Pandemic has had an impact on changing the learning system. This policy necessitates that students use technology to carry out learning activities. This causes the individual to experience difficulties. The digitization of learning activities has an impact on mental health problems such as technostress. Technostress refers to a modern adaptation disease caused by an inability to cope with new technology. The level of technostress of each individual varies depending on their religious orientation and level of psychological capital (PsyCap). Based on these two internal factors, this study examines how religious orientation and PsyCap influence technostress levels as observed among business students in Indonesia. This study provides empirical evidence suggesting that intrinsic religious orientation and PsyCap can encourage individuals to endure challenges and rising demand, thereby reducing the stress caused by technology. These outcomes assist policymakers to implement programs oriented towards individuals' PsyCap.

New Technology Communication in American State Governments

2012 ◽  
pp. 1806-1823
Author(s):  
Hyun Jung Yun ◽  
Cynthia Opheim
Keyword(s):  
Political Participation ◽  
New Technology ◽  
State Level ◽  
Electronic Systems ◽  
State Governments ◽  
Individual Level ◽  
Political Exclusion ◽  
The Individual ◽  
Combined Data

This study examines the effects of states’ e-government efforts, more specifically the progress of e-service and e-democracy, on citizens’ general political engagement and electoral participation. Utilizing the combined data with the state level of West’s e-Government measures (2008) and the individual level of the 2008 American Election Study, this study finds a strong link between state sponsored efforts at e-Government and traditional forms of the public’s political participation. State sponsored digital services and outreach increase general political participation more than campaign activities, and the implementation of e-democracy has a greater effect on mobilization than e-service. The results imply that e-government has potential to ameliorate political exclusion by letting the politically disadvantaged access a higher quality of information with an equalized accessibility through state governments’ electronic systems.

New Technology Communication in American State Governments

2012 ◽  
pp. 573-590
Author(s):  
Hyun Jung Yun ◽  
Cynthia Opheim
Keyword(s):  
Political Participation ◽  
New Technology ◽  
State Level ◽  
Electronic Systems ◽  
State Governments ◽  
Individual Level ◽  
Political Exclusion ◽  
The Individual ◽  
Combined Data

This study examines the effects of states’ e-government efforts, more specifically the progress of e-service and e-democracy, on citizens’ general political engagement and electoral participation. Utilizing the combined data with the state level of West’s e-Government measures (2008) and the individual level of the 2008 American Election Study, this study finds a strong link between state sponsored efforts at e-Government and traditional forms of the public’s political participation. State sponsored digital services and outreach increase general political participation more than campaign activities, and the implementation of e-democracy has a greater effect on mobilization than e-service. The results imply that e-government has potential to ameliorate political exclusion by letting the politically disadvantaged access a higher quality of information with an equalized accessibility through state governments’ electronic systems.

scholarly journals Closed-loop conductance scanning tunneling spectroscopy: demonstrating the equivalence to the open-loop alternative

2015 ◽  
Vol 6 ◽  
pp. 1116-1124 ◽  
Author(s):  
Chris Hellenthal ◽  
Kai Sotthewes ◽  
Martin H Siekman ◽  
E Stefan Kooij ◽  
Harold J W Zandvliet
Keyword(s):  
Closed Loop ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Open Loop ◽  
Scanning Tunneling ◽  
Image Charge ◽  
Tunneling Barrier ◽  
Molecular Systems ◽  
Individual Contributions ◽  
The Individual

We demonstrate the validity of using closed-loop z(V) conductance scanning tunneling spectroscopy (STS) measurements for the determination of the effective tunneling barrier by comparing them to more conventional open-loop I(z) measurements. Through the development of a numerical model, the individual contributions to the effective tunneling barrier present in these experiments, such as the work function and the presence of an image charge, are determined quantitatively. This opens up the possibility of determining tunneling barriers of both vacuum and molecular systems in an alternative and more detailed manner.

scholarly journals A path analysis on the direct and indirect effects of the unit environment on eating dependence among cognitively impaired nursing home residents

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Alvisa Palese ◽  
Luca Grassetti ◽  
Valentina Bressan ◽  
Alessandro Decaro ◽  
Tea Kasa ◽  
...  
Keyword(s):  
Nursing Home ◽  
Nursing Homes ◽  
Nursing Care ◽  
Indirect Effects ◽  
Functional Dependence ◽  
Cognitively Impaired ◽  
Direct And Indirect Effects ◽  
Care Level ◽  
Individual Level ◽  
The Individual

Abstract Background This study aims to estimate the direct and indirect effects of the unit environment alongside individual and nursing care variables on eating dependence among residents who are cognitively impaired and living in a nursing home. Method A multicentre observational study was carried out in 2017: 13 Italian nursing homes were involved in data collection. Included residents were aged > 65 at baseline, living in the considered facility for the last 6 months and during the entire study period and having received at least one comprehensive assessment. Data were collected (a) at the individual level: eating dependence using the Edinburgh Feeding Evaluation in Dementia Scale and other clinical variables; (b) at the nursing care level with daily interventions to maintain eating independence assessed with a checklist; and (c) at the nursing home level, using the Therapeutic Environment Screening Survey for Nursing Homes. Results One thousand twenty-seven residents were included with an average age of 85.32 years old (95% CI: 84.74–85.89), mainly female (781; 76%). The path analysis explained the 57.7% variance in eating dependence. Factors preventing eating dependence were: (a) at the individual level, increased functional dependence measured with the Barthel Index (β − 2.374); eating in the dining room surrounded by residents (β − 1.802) as compared to eating alone in bed; and having a close relationship with family relatives (β − 0.854), (b) at the nursing care level, the increased number of interventions aimed at promoting independence (β − 0.524); and (c) at the NH level, high scores in ‘Space setting’ (β − 4.446), ‘Safety’ (β − 3.053), ‘Lighting’ (β − 2.848) and ‘Outdoor access’ (β − 1.225). However, environmental factors at the unit level were found to have also indirect effects by influencing the degree of functional dependence, the occurrence of night restlessness and the number of daily interventions performed by the nursing staff. Conclusion Eating dependence is a complex phenomenon requiring interventions targeting individual, nursing care, and environmental levels. The NH environment had the largest direct and indirect effect on residents’ eating dependence, thus suggesting that at this level appropriate interventions should be designed and implemented.

Time Headway in Car following and Operational Performance during Unexpected Braking

1997 ◽  
Vol 84 (3_suppl) ◽  
pp. 1247-1257 ◽  
Author(s):  
Wim Van Winsum ◽  
Wiebo Brouwer
Keyword(s):  
Driving Simulator ◽  
Theoretical Perspective ◽  
Open Loop ◽  
Braking Performance ◽  
Individual Level ◽  
Car Following ◽  
Time Headway ◽  
Motor Component ◽  
Visual Motor ◽  
The Individual

The relation between car-following behaviour and braking performance was studied in a driving simulator. The theoretical perspective was that individual differences in tactical car-driving behaviour may be related to skills on the operational level of the driving task via a process of adaptation. In a sample of 16 young and middle-aged experienced drivers independent assessments were made of preferred time headway during car following and of braking skill. Starting from modern theories of visual-motor learning, braking performance was analyzed in terms of a reaction time component, an open-loop visual-motor component, and a closed-loop visual-motor component involving the precise adjustment of braking (timing and force) to the situation. The efficiency of the visual-motor component of braking was a strong and significant predictor of choice of time headway to the lead vehicle in such a way that less efficient braking indicated a preference for a longer time headway. This result supports the theory of adaptation on the individual level.

Sign in / Sign up

Export Citation Format

Share Document