Relationships between Process Parameters, Microstructure and Adhesion Strength of HVOF Sprayed IN718 Coatings

Fundamental understanding of relationships between process parameters, particle in-flight characteristics and adhesion strength of HVOF sprayed coatings is important to achieve the high coating adhesion that is needed in aeronautic repair applications. In this study statistical Design of Experiments (DoE) was utilized to identify the most important process parameters that influence adhesion strength of IN718 coatings sprayed on IN718 substrates. Special attention was given to the parameters combustion ratio, total gas mass flow, spray distance and external cooling, since these parameters were assumed to have a significant influence on particle temperature and velocity. Relationships between these parameters and coating microstructure were evaluated to fundamentally understand the relationships between process parameters and adhesion strength

Healthy workplaces for women and men of all ages

The aim of this knowledge compilation is to contribute with know-ledge about the work environment in relation to the ever-older workforce. How do employee needs and possibilities change from a course of life perspective? What should the employer and other work environment actors think about in order for the workforce to be able to and want to work to a high age? The Swedish Work Environment Authority wishes to give an overar-ching knowledge profile of different aspects of the work environment and the ageing workforce, and we therefore asked seven researchers to summarise the research-based knowledge within each of their are-as, from a course of life and gender perspective. An eighth researcher acted as an editor for the anthology, and has also written the preface. In summary, the report shows that we are becoming even healthier, living ever longer and working to an ever higher age. Older people in the workforce are positive for the economy because productivity increases, and the business sector can make use of competent and experienced staff for a longer time. But for the older labour force to be healthy and want to work at higher ages, one needs to take into consideration how ageing influences health and the capacity to work. With age, all people are affected to different degrees by reduced vision, hearing and physical capacity, as well as longer reaction times. Even their cognitive capacity changes. Certain cognitive abilities are strengthened with rising age, while others deteriorate. With an ageing workforce, more employees have chronic illnesses, which, however, seldom affect the actual working ability. Changes in working life also affect health and wellbeing, for example deregulated work and the technical development. Age and previous experiences impact upon our ability to adapt to these changes. One factor that promotes adap-tation is partly resilience (that is to say, resistance and the ability to adapt to the new), partly compensation strategies when the mental and physical resources change. There are no great differences bet-ween gender when it comes to the consequences of ageing on health and wellbeing in the work. On the other hand, the public health trend shows increasing differences in health between the lower educated and the higher educated - a difference increasing more quickly among women than among men. The gender-segregated labour market also means that more women than men work in physical and mentally burdensome work. Attitudes at the workplace also affect wellbeing and the will to continue working at higher ages. Men tend to be more sensitive to age discrimination while women run the risk of double discrimination, that is to say based upon both gender and age. Work 10 environment and the attitude to an older workforce are central to the considerations that an employee makes in the choice between continuing to work and retiring. Other prerequisites that influence the decision are one’s own health, private finances and self-fulfilling activities. The employer can do a great deal to lengthen and improve their employees’ working life. Systematic work environment management benefits everyone, and it can contribute to everyone keeping their working ability and to older people wanting to and being able to work for longer. Occupational health services of good quality also play an important role. Technical aids and adaptation of the working pace and working tasks are other measures that improve the work environment for the older workforce. The employer can also contri-bute to stimulating work arrangements and organisational support for the employees in order to strengthen their resilience and promote the development of compensation strategies

Learning English with the use of ICT : An action research study on students' attitudes

The purpose of this study is to outline students’ attitudes towards ICT in the learning of English. The research was carried out as action research at a vocational high school in Sweden. The study aims at giving answers to the questions what the students’ attitudes towards ICT are, to what extent they think that ICT affects their learning and if ICT use changes their attitudes towards English. The students had little or no previous experience of ICT. For a period of two months, they used ICT in their English studies. This work was organized according to Svensson’s (2008) definitions ICT as a tutor, ICT as a tool and ICT as an arena, which are connected to behavioristic, cognitive/constructive and social constructivist/socio-cultural learning perspectives, respectively. For example, the students read and listened to texts online, wrote their own dialogues for a movie and maintained their own blogs. After each module, they evaluated the method and at the end of the project they were interviewed. The study shows that most of the students were positive towards ICT in learning English. They were most positive towards ICT as a tutor, which was interesting given that behavioristic ways of learning are often criticized by today’s scholars. Furthermore, the students claimed that ICT gives them new opportunities to learn. Not surprisingly, to learn in a way that suits the individual learner was seen as positive. They stated that it was difficult to comment on the impact that ICT might have had on their performance after such a limited period of time, but they indicated that they thought that they had improved at least a little. During the interviews, a few students claimed to have changed their attitudes towards English a little, in a positive way, but it was difficult to confirm this after such short time

Äldre bilförare och det begränsade körkortet

Det begränsade körkortet som finns idag är till för att förare som inte fullt ut klarar det medicinska kraven för ett körkort, ändå skall kunna köra bil. Till exempel att om man har ett lindrigare synfel så skall man endast få köra dagtid. Problemet är att det inte riktigt fungerar, dels är det omständigt och dels efterföljs inte reglementet som finns. Ett utav problemen som finns idag är att man först måste få sitt körkort återkallat för att senare kunna få det begränsat. Ett av problemen är också att få ut information som gör att alla parter kan agera som de borde. Att till exempel informera läkarna tydligare om vad de är skyldiga att göra. I våran rapport har vi valt att skriva om åldrandet och hur körvanorna och attityderna är hos äldre bilförare. Vi har tagit upp lite om vilka sjukdomar som påverkar köregenskaperna och i vilka typer av olyckor de äldre är överrepresenterade i. Sedan tar vi upp hur och vilka instanser som kan begränsa och återkalla körkort. Vi har även tagit upp ett exempel om hur det fungerar i vårat grannland, Finland. Slutligen tar vi även upp om det finns några organisationer som hjälper de äldre i trafiken, under detta avsnitt har vi även presenterat ett projekt för de äldre bilförarna, ”65 PLUS”. Informationsinhämtning har skett genom redan befintligt material skrivna av inom området kunniga författare. Dels har vi även pratat med involverade personer inom arbetet med äldre i trafiken

Advanced Coatings by Thermal Spray Processes

Coatings are pivotal in combating problems of premature component degradation in aggressive industrial environments and constitute a strategic area for continued development. Thermal spray (TS) coatings offer distinct advantages by combining versatility, cost-effectiveness, and the ability to coat complex geometries without constraints of other in-chamber processes. Consequently, TS techniques like high-velocity oxy-fuel (HVOF) and atmospheric plasma spray (APS) are industrially well-accepted. However, they have reached limits of their capabilities while expectations from coatings progressively increase in pursuit of enhanced efficiency and productivity. Two emerging TS variants, namely high-velocity air-fuel (HVAF) and liquid feedstock thermal spraying, offer attractive pathways to realize high-performance surfaces superior to those hitherto achievable. Supersonic HVAF spraying provides highly adherent coatings with negligible porosity and its low processing temperature also ensures insignificant thermal ‘damage’ (oxidation, decarburization, etc.) to the starting material. On the other hand, liquid feedstock derived TS coatings, deposited using suspensions of fine particles (100 nm–5 µm) or solution precursors, permits the production of coatings with novel microstructures and diverse application-specific architectures. The possibility of hybrid processing, combining liquid and powder feedstock, provides further opportunities to fine tune the properties of functional surfaces. These new approaches are discussed along with some illustrative examples

Visual Symptoms and Risk Assessment Using Visual Ergonomics Risk Assessment Method (VERAM)

A visual environment impaired by e.g. glare can cause eyestrain, visual symptoms and musculoskeletal strain. A Visual Ergonomics Risk Assessment Method (VERAM) consisting of both a subjective questionnaire and an objective risk assessment, have been used at 217 workplaces, mainly computer work. VERAM can be used to examine and prevent deficiencies and increase wellbeing as well as detecting risks in the visual work environment and suggest measures that can be used to reduce the risks. The questionnaire showed that eyestrain, visual symptoms and musculoskeletal strain are common among Swedish workers. The overall risk assessments for glare and amount of illuminance on work surface are divided into three categories, green – no risk, yellow – risk, and red – high risk. Risk of glare and insufficient illuminance was present at 66% and 49% of the assessed workplaces, respectively. When the risk of glare and illuminance levels was rated as red, the frequency of the subjective strain was higher

Ultraviolett strålning och hälsa : ett kunskapsunderlag

Ultraviolet radiation and health Exposure to ultraviolet radiation can cause adverse effects on skin, eyes, and the immune system. Some effects are acute : they appear after short duration of exposure to ultraviolet radiation. Such effects are erythema, increased pigmentation, photokeratitis and photoconjunctivitis. Other effects such as elastosis and certain forms of skin cancer are regarded as irreversible and appear after chronic exposure. The acute effects and the photoageing of the skin are commonly occurring, while the more serious cancer forms are less common : but their occurrences have increased in recent years. This is considered to be at least partly attributed to an increased exposure to ultraviolet radiation. Thus, there is an obvious need to limit the total exposure to ultraviolet radiation. Internationally, ICNIRP have developed guidelines for the limitation of exposure to ultraviolet radiation. These limitations give individuals with normal sensitivity a protection against acute effects on skin and eyes, and are also thought to protect against some of the long-term effect (e.g. certain cancer forms). Several forms of malignant melanoma are, on the other hand, thought to be a result of single episodes of heavy exposure. High levels of UV radiation can occur within Swedish industry at e.g. welding and UV curing of surface coatings. The possibilities to locally measure and control these levels at a relevant cost have improved during the last decade.Ultraviolett strålning (UV) indelas vanligen i UVA, UVB och UVC. Den dos som ger upphov till en definierad skada kallas tröskeldos. Tröskeldosen plottad som funktion av våglängd benämns aktionsspektrum. Lämplig längsta expositionstid kan beräknas på basis av aktionsspektrum genom att addera de viktade doskomponenterna från varje våglängdsområde i en exponering. UV orsakar skador på lipider och proteiner i cellmembran och inne i cellen samt på DNA. UV har flera olika skadeeffekter på huden som beror på intensitet, exponeringstid och våglängdsområde (UVA eller/och UVB). UV kan skada arvsanlagen i hudens celler samt orsaka hudrodnad, brännskador, elastos (förtjockad och rynkig hy) samt godartade och elakartade former av hudcancer. En liten andel av befolkningen har hud som är abnormt känslig för UV. Hornhinnan blockerar all UV med kortare våglängd än 290 nm. Linsen filtrerar bort merparten av all UV mellan 290-400 nm. En överdos av UV mot ögat ger akut ögonlocksrodnad och svullnad och inflammatorisk reaktion i bindehinna och hornhinna som är reversibel inom 1-2 dygn. Om dosen är mycket hög uppkommer irreversibel grå starr. Långvarig exponering av ögat för UV är associerat till förändringar i bindehinnan, hornhinnan och linsen. Iakttagelser att UV-strålning har en hämmande effekt på immunsystemet har gjorts såväl i djurexperiment som i studier på människor. Solljusexponering reducerade bl a mängden cirkulerande T-lymfocyter och naturliga mördarceller i blodet hos friska kontrollpersoner. De immunhämmande effekterna av UV-strålning kan tänkas ha negativa hälsoeffekter genom att nedsätta motståndskraften för infektioner samt eventuellt främja tumöruppkomst. Det föreligger en individuell variabilitet i känslighet för immunsuppression efter UVB-bestrålning. Den skyddande effekten av solskyddskrämer mot UV-inducerad immunsuppression är fortfarande otillräckligt studerad. Tidigare ansatser att erhålla en bättre kontroll av yrkesmässig exponering för UV-strålning har försvårats av bristen på praktiskt och ekonomiskt försvarbara mätinstrument. Numera finns sådana instrument för mätning av absolutnivåer samt även olika former av billiga och tillförlitliga persondosimetrar vilket kan vara ett alternativ för övervakning av UV-exponering hos utsatta yrkesgrupper. Den i arbetslivet mest frekventa exponeringen för UV-strålning är självfallet utomhusvistelse. Vid inomhusarbete kan dock exponering för väsentligt högre nivåer av UV-strålning uppkomma vid bristande avskärmning av ljuskällan i samband med UV-härdning av akrylatlacker, elektrosvetsning och lasersvetsning. Även lysrör för medicinska UV-behandlingar och ofiltrerade halogenlampor kan medföra höga nivåer

Lighting at computer workstations.

The visual conditions for computer work are complex and include several factors that need to be well controlled. These factors include the lighting system, the design of the computer and screen itself, the screens position and orientation within the room, the surface reflectances and colours of the room, and the visualability of the worker