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Fallolyckor är en vanlig orsak till skador hos äldre vilket leder till stort lidande för den enskilde. Dessutom medför fallolyckor hos äldre stora kostnader för samhället. När antalet äldre ökar så kommer också lidandet och kostnaderna orsakade av fallolyckor att öka. Sjuksköterskor har ett ansvar i sitt omvårdnadsarbete att förebygga fallolyckor. Vårt syfte med denna studie var att beskriva sjuksköterskors erfarenhet av fallpreventivt arbete hos äldre på särskilt boende. Metoden som användes i denna studie var kvalitativ metod genom intervjuer med sjuksköterskor. Data analyserades med kvalitativ innehållsanalys. Två teman framkom, att man gemensamt ser individen och miljön är inte alltid tillräckliga åtgärder samt hinder finns för att arbeta fallförebyggande Dessa teman kunde sedan beskrivas genom sex olika kategorier som benämndes mångfasetterad fysisk miljö, åtgärder kan vara otillräckliga, individuell bedömning, samarbete behövs, behov av ökade kunskaper, samt tidsbrist. Resultatet av vår studie visade att sjuksköterskor upplevde kommunens ekonomi som ett hinder då de på grund av detta inte fick utbildning och tillgång till ny kunskap samt hjälpmedel att använda i sitt fallförebyggande arbete. Sjuksköterskorna beskrev också att de hade tidsbrist vilket resulterade i att de individuella bedömningar och uppföljningar av fallrisk inom särskilda boenden inte hanns med i den utsträckning de önskade. / Falling accidents are a common reason for injuries among elderly people which leads to great suffering for the individual. Falling accidents among elderly also causes high costs for the society. As the number of elderly people increases the suffering and the cost due to falling accidents will also increase. Nurses have a responsibility in their work to prevent falling accidents. Our intention with this study was to describe nurse´s experience preventing falling accidents among elderly in nursing homes. The method used in this study was a qualitative method by interviews with nurses. Data was analyzed with qualitative content analysis. Two themes emerged, that you jointly look at the individual and the environment are not always sufficient actions and there are obstacles in the work of preventing falling accidents. These themes could then be described by six different categories: diverse natural environment, actions may be insufficient, individual estimation, need for cooperation, need for increased knowledge and lack of time. The result of our study showed that nurses experienced the economy of the municipality as an obstacle when they due to this did not get education and access to new knowledge and technical aids to use in the work of preventing falling accidents. The nurses also described that they did not have the time they wished, for the individual estimation for following up the risk of falling in the nursing homes.

An experimental investigation of heat and mass transfer in a horizontal tube falling-film ammonia-water absorber was conducted. A tube bank consisting of four columns of six 9.5 mm (3/8 ) nominal OD, 0.292 m (11.5 ) long tubes was installed in an absorber shell that allowed heat and mass transfer measurements and optical access. A test facility consisting of all the components of a functional absorption chiller was fabricated specifically for this investigation. Several variations of the basic system set up were fabricated to enable testing over the wide range of conditions (nominally, desorber solution outlet concentrations of 5 - 40% for three nominal absorber pressures of 150, 345 and 500 kPa, over solution flow rates of 0.019 0.034 kg/s.) Measurements at the absorber were used to determine heat transfer rates, overall thermal conductances, solution-side heat and vapor-side mass transfer coefficients for each test condition. For the range of experiments conducted, the solution heat transfer coefficient varied from 923 to 2857 W/m2-K while the vapor mass transfer coefficient varied from 0.0026 to 0.25 m/s and the liquid mass transfer coefficient varied from 5.51×10-6 to 3.31×10-5 m/s depending on the test condition. The solution heat transfer coefficient increased with increasing solution flow rate; however, the vapor and liquid mass transfer coefficients seem to remain unaffected with the variations in solution flow rate and were found to be primarily determined by the vapor and solution properties. The experimental heat and mass transfer coefficients were compared with the relevant studies from the literature. Based on the observed trends, heat transfer correlations and mass transfer correlations in the vapor and liquid phases were developed to predict heat and mass transfer coefficients for the range of experimental conditions tested. These correlations can be used to design horizontal tube falling-film absorbers for ammonia-water absorption systems.

<p>Fallolyckor är en vanlig orsak till skador hos äldre vilket leder till stort lidande för den enskilde. Dessutom medför fallolyckor hos äldre stora kostnader för samhället. När antalet äldre ökar så kommer också lidandet och kostnaderna orsakade av fallolyckor att öka. Sjuksköterskor har ett ansvar i sitt omvårdnadsarbete att förebygga fallolyckor. Vårt syfte med denna studie var att beskriva sjuksköterskors erfarenhet av fallpreventivt arbete hos äldre på särskilt boende. Metoden som användes i denna studie var kvalitativ metod genom intervjuer med sjuksköterskor. Data analyserades med kvalitativ innehållsanalys. Två teman framkom, att man gemensamt ser individen och miljön är inte alltid tillräckliga åtgärder samt hinder finns för att arbeta fallförebyggande Dessa teman kunde sedan beskrivas genom sex olika kategorier som benämndes mångfasetterad fysisk miljö, åtgärder kan vara otillräckliga, individuell bedömning, samarbete behövs, behov av ökade kunskaper, samt tidsbrist. Resultatet av vår studie visade att sjuksköterskor upplevde kommunens ekonomi som ett hinder då de på grund av detta inte fick utbildning och tillgång till ny kunskap samt hjälpmedel att använda i sitt fallförebyggande arbete. Sjuksköterskorna beskrev också att de hade tidsbrist vilket resulterade i att de individuella bedömningar och uppföljningar av fallrisk inom särskilda boenden inte hanns med i den utsträckning de önskade.</p> / <p>Falling accidents are a common reason for injuries among elderly people which leads to great suffering for the individual. Falling accidents among elderly also causes high costs for the society. As the number of elderly people increases the suffering and the cost due to falling accidents will also increase. Nurses have a responsibility in their work to prevent falling accidents. Our intention with this study was to describe nurse´s experience preventing falling accidents among elderly in nursing homes. The method used in this study was a qualitative method by interviews with nurses. Data was analyzed with qualitative content analysis. Two themes emerged, that you jointly look at the individual and the environment are not always sufficient actions and there are obstacles in the work of preventing falling accidents. These themes could then be described by six different categories: diverse natural environment, actions may be insufficient, individual estimation, need for cooperation, need for increased knowledge and lack of time. The result of our study showed that nurses experienced the economy of the municipality as an obstacle when they due to this did not get education and access to new knowledge and technical aids to use in the work of preventing falling accidents. The nurses also described that they did not have the time they wished, for the individual estimation for following up the risk of falling in the nursing homes.</p>

Falling by older people is of significant global concern as the population ages, because of subsequent injury, disability, admission to long-term care and mortality. Older people experiencing dementia are twice as likely to fall with more severe consequences. Unsurprisingly, carer-burden increases when a care-recipient falls. Older people are rarely asked about their falls experiences and those with dementia less so. The studies presented in this thesis explore the experiences of falling of older people with dementia and memory problems, and their carers. The studies were informed by contextualism and the primary study used interpretative phenomenological analysis to explore the experiences of nine older people with dementia and their 10 carers, using one-to-one and joint interviews, and three focus groups with nine older people experiencing memory problems and 12 carers from a branch of the Alzheimer’s society. Analysis of the data considered the falls experience itself and the perceived consequences of falls within two higher level themes: ‘Falling as a malevolent force’ as two themes - ‘Going back to the experience’, ‘Reactions, responses and coming to terms with events’, and ‘Falling as the manifestation of dementia’ as two themes - ‘Self, identity and falling’, ‘The caring relationship’. The secondary study elaborated upon primary study data using an inductive interpretative approach unaligned to any tradition. Older people recently diagnosed with dementia and carers from another Alzheimer’s Society branch participated in two focus groups. Participants discussed stimulus cards with quotations from primary study participants. Thematic analysis suggested four major themes: Making sense of falls, The personal and social significance of falling, Falling, self and identity and Struggling to care. The findings demonstrate how falling and dementia are enmeshed and embodied experiences for participants. Spouse-carers’ discussion of their own falls emphasise the need for joint assessment and intervention to reduce carerburden and preserve couplehood.

Parametric equations are used to represent the pathway of an object in terms of time or another changing variable. This allows, for example, for equations that are written using two variables to be examined in terms of the passage of time. In this paper the author examines two traditional application problems whose solutions can be enriched through the use of parametric equations. In the first, the falling ladder problem, a ladder is leaned against a wall then pulled away with a constant velocity. Deriving parametric equations for this scenario permits the pathway of the ladder to be plotted. Parametric equations also make it possible for the horizontal and vertical velocities of the ladder to be examined separately. The second problem is that of maximizing the length of a ladder that can fit around a hallway corner. In this problem an envelope algorithm is first developed, then parametrized to further investigate this scenario. Using these two situations, this report ultimately shows how parametric equations can be used to give a more thorough approach to some of today’s most classic calculus problems. / text

Evaporation is used in the dairy industry to reduce the production costs of powder production (including milk powder) as it is more energy efficient to remove water by evaporation than by drying. There are significant economic reasons why gaining a greater understanding of the complex interactions occurring between the liquid and vapour phases in evaporators is advantageous. The multiphase flows in industrial dairy falling film evaporators were studied. Several computational fluid dynamic (CFD) models were created using Ansys CFX 10. Two case studies were chosen. The first case involved modelling the dispersed droplets that require separation from the water vapour evaporated from the feed of the evaporator. The CFD results were able to show that fouling was not caused by a lack of separation. The predicted separation agreed with experimental measurements. The atomisation process was found to be critical in the prediction of the separation. The atomisation process is not well understood and introduced the greatest error to the model. A plug flow assumption is currently used as a basis for the design the separators. The CFD solutions found no validity to this assumption. The second case study aimed to model and solve the distribution of the feed into the heat transfer tubes at the top of the falling film evaporators. The goal of this study was to be able to accurately predict wetting of the tubes. The volume of fluid (VOF) method using the continuum surface force method (CSF) to account for surface tension was chosen to model the system. The poor curvature estimate of the CSF method was found to produce parasitic currents that limited the stability of the solutions. Small VOF timesteps prevented the solver from diverging and the parasitic currents would oscillate the interface around the correct location. The small timesteps required significantly more computational power than was available and the model for the distribution process could not be solved. The CSF VOF method showed considerable promise, particularly because it can predict free surface topography without user input. There are still questions about numerical creeping of films, but the method was able to correctly predict several different surface tension and contact angle dominated film flows expected to be needed to accurately model the distribution of the falling film evaporator. Validated solutions of jet, meniscus, sessile, "overfall" and 3-D weir models were obtained and these agreed with published results in literature. A 2-D weir solution showed qualitative agreement with the expected form of the film. A 2-D hydraulic jump model without surface tension was created and agreed with experimental work in the literature to within 22%. The 3-D hydraulic jump solution only showed partial agreement with published experimental, the solutions were not mesh independent and not well converged so few conclusions can be drawn. The solutions of a rivulet model showed qualitative similarities with experimental work. The predicted wetting rate did not agree with values in the published literature because the spatial domain modelled was believed to be too narrow. An extended model of rivulet flow agreed with the idealised rivulet profile in literature and the predicted wetting rate agreed with some of the published literature. Again the solutions were not mesh independent so few conclusions can be confirmed.

The present study is the first investigation of falling-film evaporation over horizontal rectangular tubes. This geometry is representative of the external profile of microchannel tubes. Incorporating these designs into shell-and-tube heat exchangers has the potential to provide compact, high-performance components for a wide range of applications. This fluid flow was investigated experimentally, targeting three areas: measurements of heat transfer coefficients, quantification of flow characteristics, and the performance of flow distributors. Falling-film evaporation experiments were conducted using water on a rectangular test section with dimensions of 203 × 1.42 × 27.4 mm (length × width × height), measuring heat transfer coefficients over a range of saturation temperatures, test section spacings, heat fluxes, and film Reynolds numbers. This was supported by a flow visualization study that quantified droplet and wave parameters using image analysis of high speed videos. Finally, the performance of eight liquid distributors, which are used to establish falling-film flows, was quantified and the size of the generated droplets and jets was measured. Three models were developed to predict the flow regime, wetted tube area, and heat transfer coefficient. The flow regime model is based on a thermodynamic analysis, while the wetted tube area is found with a hydrodynamic model based on idealized flow assumptions. Finally, the heat transfer model relies on a relationship with the classic Nusselt (1916) film theory. Each of these models demonstrated good agreement with the experimental data, as well as trends in the literature. The increased understanding of falling-film evaporation gained in this study will enable the accurate design of shell-and-tube heat exchangers with microchannel tubes.

In the literary works of the early nineteenth-century German writer Heinrich von Kleist there is little certainty. Kleist’s characters experience catastrophic natural and social disasters – earthquakes, revolution and war – and, as if this were not trauma enough, are subject to extreme behaviours and repeated mishaps. Characters leap from windows and break legs, stumble, faint or fall; incidents which lay bare inner psychological states that are as precarious as the external circumstances in which they find themselves. Yet into these violent events Kleist invariably interjects a suspended moment – a moment that might be considered one of intolerable exposure. Although sudden moments and momentary suspension define almost all of Kleist’s novellas and dramas, nowhere is this phenomenon so visible as in Kleist’s tragedy Penthesilea. Taking into account German critic Karl Bohrer’s concept of ‘suddenness’ (Der romantische Brief: Die Entstehung ästhetischer Subjektivität and Suddenness: On the Moment of Aesthetic Appearance), secondary literature on Kleist, scholarship on gender as well as Kleist’s biography, this project will focus on falling and suspended moment within Penthesilea, paying particular attention to vulnerability.

Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: This work focussed on a local multiple chamber falling film evaporator (FFE). The FFE is currently under operator control and experiencing large amounts of lost production time due to excessive fouling. Furthermore, the product milk dry mass fraction (WP) is constantly off specification, negatively influencing product quality, while the first effect temperature (TE1) runs higher than the recommended 70°C (this is a main cause of fouling). A two month period of historical data were received with the aim to develop a controller that could outperform the operators by keeping both control variables, WP and TE1, at desired set points while also increasing throughput and maintaining product quality. Access to the local plant was not possible and as such available process data were cleaned and used to identify two data based models, transfer function and autoregressive with exogenous inputs (ARX) models, as well as a semi-empirical-model. The ARX model proved inadequate to predict TE1 trends, with an average TE1 correlation to historical data of 0.36, compared to 0.59 and 0.74 for the transfer function and semi-empirical-models respectively. Product dry mass correlations were similar between the models with the average correlations of 0.47, 0.53 and 0.51 for the semi-empirical, transfer function and ARX models respectively. Although the semi-empirical showed the lowest WP correlation, it was offset by the TE1 prediction advantage. Therefore, the semi-empirical model was selected for controller development and comparisons. The success of the semi-empirical model was in accordance with previous research [1] [2] [3], yet other studies have concluded that ARX modelling was more suited to FFE modelling [4]. Three controllers were developed, namely: a proportional and integral (PI) controller as base case, a linear quadratic regulator (LQR) as an optimal state space alternative and finally, to make full use of process knowledge, a predictive fuzzy logic controller (PFC). The PI controller was able to offer zero offset set point tracking, but could not adequately reject a feed dry mass (WF) disturbance (as proposed and reported by Winchester [5]). The LQR was combined with a Kalman estimator and used pre-delay states. In order to offer increased disturbance rejection, the feedback gains of the disturbance states were tuned individually. The altered LQR and PFC solutions proved to adequately reject all modelled disturbances and outperform a cascade controller designed by Bakker [6]. The maximum deviation in WP was a fractional increase of 0.007 for LQR and 0.005 for FPC, compared to 0.012 for PI and 0.0075 for the cascade controller [6] (WF disturbance fractional increase of 0.01). All the designed controllers managed to reduce the standard deviation of operator controlled WP and TE1 by at least 700% and 450%, respectively. The same level of reduction was seen for maximum control variable deviations (370%), the integral of the absolute error (300%) and the mean squared error (900%). All these performance metrics point to the controllers performing better than the operator based control. In order to prevent manipulated variable saturation and optimise the feed flow rate (F1), a fuzzy feed optimiser (FFO) was developed. The FFO focussed on maximising the available evaporative capacity of the FFE by optimising the motive steam pressure (PS), which supplied heat to the effects. By using the FFO for each controller the average feed flow rate was increased by 4.8% (±500kg/h) compared to the operator control. In addition to flow rate gain, the controllers kept TE1 below 70°C and WP on specification. As such, the overall product quality also increased as well as decreasing the down time due to less fouling. / AFRIKAANSE OPSOMMING: Hierdie projek het op ‘n vallende film verdamper (VFV) gefokus. Die VFV word tans beheer deur operateurs en ondervind groot hoeveelhede verlore produksie tyd a.g.v oormatige aangroeisels. Die vorming van aangroeisels is grootliks te danke aan die eerste effek temperatuur (TE1) wat gereeld 70°C oorskrei. Die produk droë massa fraksie (WP) is ook telkens nie op die gewenste vlak nie, wat produk kwaliteit negatief beinvloed. Data, wat oor ‘n twee maand periode strek, was verkry met die doelstelling om ‘n beheerder te ontwerp wat beter sou vaar as die operateurs, deur beide WP en TE2 om ‘n nou stelpunt te beheer. Ter selfde tyd moet die ontwerpte beheerder die produksie tempo en produk kwaliteit verhoog. Geen toegang tot die plaaslikke VFV was moontlik nie, dus was die data skoongemaak en gebruik om twee data gebasseerde modelle te identifiseer, nl. oordragsfunksie en outoregressiwe met eksogene insette (ORX) modelle, asook ‘n semi-empiriese model. Die ORX model kon nie TE1 goed voorspel nie, met ‘n korrelasie faktor (tot die historiese data) van 0.36, vergeleke met die 0.59 en 0.74 van die oordragsfunksie en semi-empiriese modelle onderskeidelik. WP korrelasie faktore was meer konstant tussen die modelle, met waardes van 0.47, 0.53 en 0.51 vir die semi-empiriese, oordragsfunskie en ORX modelle onderskeidelik. Alhoewel die semi-empiriese model die laagste WP korrelasie vertoon het, was die tekortkoming vergoed deur die beter TE1 voorspelling. Gevolglik was die semi-empiriese model gebruik vir beheerder ontwerp en vergelyking. Die sukses van die semiempiriese model stem ooreen met vorige studies [1] [2] [3], tog het ander studies al bevind dat die ORX model beter gepas is vir die VFV proses [4]. Drie beheerders was ontwikkel, nl. ‘n proporsionele en integreerder (PI) beheerder as basis geval, ‘n liniêre kwadratiese reguleerder (LKR) as optimale toestands beheer alternatief en laastens ‘n voorspellende wasige logika beheerder (VWB) om volle gebruik van proseskennis te maak. Die PI beheerder kon foutlose volging van die stelpunte lewer, maar kon nie ‘n inset voer droë massa fraksie (WF) versteuring (soos voorgestel en weergegee deur Winchester [5]) na wense verwerp nie. Die LKR was saamgevoeg met ‘n Kalman afskatter en het gebruik gemaak van onvertraagde toestande. Die versteuringstoestande was individueel verstel om beter versteurings verweping te weeg te bring. Die aangepaste LKR en VWB kon beide die WF versteuring verwerp en het beter gevaar as ‘n kaskade beheer oplossing wat deur Bakker [6] ontwerp was. Die WP afwyking is beperk tot ‘n fraksie droë masse verandering van 0.007 vir LKR en 0.005 vir VWB, vergeleke met die afwykings van 0.012 vir die PI beheerder asook die 0.0075 van die kaskade beheerder [6]. Die ontwerpte beheerder kon ook die standaard afwyking van beide WP en TE1 met ten minste 700% en 450% onderskeidelik verminder. Soortgelyke verbeterings was gesien vir die maksimum beheer veranderlikke afwyking (370%), die integraal van die absolute fout (300%) en die gemiddelde fout (900%). Dus het die ontwerpte beheerders wesenlik verbeter op die operateur beheer. Ten einde om gemanipuleerde veranderlikke versadiging te voorkom, asook die voer vloei (V1) te optimiseer, was ‘n wasige logika optimiseerder (WVO) ontwerp. Die WVO het die beskikbare verdampingskapasiteit ten volle benut deur te sorg dat die stoom druk (PS), wat energie verskaf vir verdamping, ge-optimiseerd bly. ‘n Gemiddelde V1 stygging van 4.8% (±500kg/uur), vergeleke met operateur beheer, is waargeneem. Al die beheerders kon steeds die WP en TE1 stelpunte volg en dus TE1 onder 70°C hou (wat verminderde vormasie van aangroeisels tot gevolg gehad het). Daarom het die produk kwailiteit verhoog en die verlore produksie tyd verminder.