International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / This paper presents the design and development of a fluorometry sensor network with LED excitation. The design of the electronics in junction with the capability of LED excitation will significantly reduce the size and costs of the flrorometer units. The coverage and effectiveness of the sensing and monitoring capability will also be greatly enhanced by the addition of the wireless networks.

A transparent conductive electrode (TCE) is an important component in many of our modern optoelectronic devices like photovoltaics, light emitting diodes and touch screens. These devices require good current injection and spreading as well as a high transparency. In this thesis we explore the use of graphene as an alternative to the current widely used indium tin oxide (ITO) as TCE in gallium nitride (GaN) based light emitting diodes (LEDs). Monolayer crystalline graphene can be produced on copper foils using chemical vapor deposition (CVD), where metals (especially copper) has a catalysing effect on the formation of graphene. However, transfer of graphene from copper foils is not suitable for an industrial scale and it results in a poor contact with the target substrate. We investigate the possibility of directly integrating graphene on GaN-based LEDs by using plasma-enhanced chemical vapor deposition (PECVD). We try to obtain the optimal conditions under these catalyst-free circumstances and propose a recipe adapted for the setup that we used. We will also study ideas of using a metal (we tried copper and nickel) to assist the direct growth that could help to increase the fraction of sp2 carbon bonds and reduce the sheet resistance. The metals are evaporated onto our samples either before or after we grow a carbon film to either assist the growth or rearrange the carbon respectively. The focus was not on trying to optimize the conditions for one metal treatment but rather to briefly explore multiple methods to find a suitable path for further studies. The direct grown pristine carbon films shows indications from Raman measurements of being nanocrystalline graphene with a sheet resistance ranging from about 20-50 kΩ/sq having a transmittance of approximately 96 % at 550 nm. A transmittance at this level is closely related to the value of an ideal monolayer graphene, which indicates that our carbon films could be close to one atom in thickness while being visually homogeneous and complete in coverage. Due to the use of a temperature close to the melting point of copper we struggled to keep the assisting copper from evaporating too fast or staying homogeneous after the treatment. Nickel has a higher melting temperature, but it appears as if this metal might be diffusing into the GaN substrate which changes the properties of both the GaN and carbon film. Even though the metal treatments that we tested did not provide any noticeable improvements, there is need for further investigations to obtain suitable treatment conditions. We suggest that the treatments involving copper are a more promising path to pursue as nickel seem to cause unavoidable intermixing problems.

Replacing metals with polymers is getting more and more popular. The main reason for this is that in a lot of cases the same requirement can still be achieved while at the same time using the benefits that polymer brings with them. In some cases the polymers can actually be the favorable choice of material. Fagerhults Belysning AB is one of the companies that traditionally have been using metals but their interest in polymers has grown. The purpose has therefore been to investigate the possibilities of implementing a polymer based material in a LED-armature which will be stationed outdoors and how this realizable potential CADconstruction in a polymer material can be measured against current requirements. The difficulty with this and the main reason why this haven’t been done yet is the general bad thermal conductivity that polymers have. The heat that is being created by the LED-lights has to be taken care of otherwise they will become too warm and will not be able to operate under the same conditions anymore. The side effects will be reduced lifetime and effect. However, if this is taken care of in a proper way and the LED-lights can operate under given temperatures the benefits of polymers can be applied. Two different requirement specifications were created to choose the right materials. The first requirement specifications takes care of the part of the armature where heat is being conducted and needs to be taken care of while the other requirement specifications takes care of the composition and exterior of the armature. Different types of polymers where then selected for the two requirement specification using material database and consultation from plastic suppliers. Another aspect that was part in taking care of the conductive heat two concepts was created. Both of these concepts where then put in a heat simulation program with the polymer that was considered having the highest thermal conductivity. The material that was used for the exterior design was a normal engineering polymer with a low thermal conductivity. However, after the heat simulations the result showed that a polymer with a high thermal conductivity was needed to be used even for the exterior design. Otherwise the heat would have exceeded the limit that was set for the LED-lights. Furthermore, the thermal conductive polymer was considered to be good enough to be used even for the exterior design. Thereby a couple of concepts where created for the exterior design and how it should be composed by using brainstorming, morphology and Pugh’s matrix and a final concept could then be presented. The purpose was thereby fulfilled since the possibilities of implementing a polymer based material had been done together with a realizable CAD-concept. The final result became that the heat that was being generated by the LED-lights can be managed of already existing polymers and at the same time using the benefits with polymers by integrating functions and lower the weight. The usage of a thermal conductive polymer in both the whole armature will lead to high cost for the material. High water- and dust requirements were put on the armature which led to implications in integrating more functions. / Ersättning av metall med ett polymert material blir allt vanligare. Det här för att i många fall kan samma kravbild uppnås samtidigt som fördelarna hos polymera material utnyttjas. Fagerhults Belysning AB är ett av de företag där metall traditionellt sett har använts men där det finns ett intresse för vilka möjligheter polymera material kan innebära. Syftet har därmed varit är att utreda möjligheten av implementering av polymert material i LED-armatur för utomhusmiljö och hur en potentiellt realiserbar konstruktion i valt polymert material i datorsimulerad miljö kan jämföra sig med nuvarande krav. Svårigheten, som också i högsta grad varit anledningen till varför det här inte har genomförts tidigare, är polymerernas generellt dåliga förmåga att leda värme. LED-lampornas effekt och livslängd är starkt beroende av värmeavledningen och leds värmen bort så kan LED-lamporna operera under rätt temperatur. Två olika kravspecifikationer ställdes upp för valet av material. Den ena avser den del av armaturen som främst påverkar värmeavledningen och den andra avser den sammansättande konstruktionen, det vill säga den yttre formgivningen. Materialval gjordes med avseende på de olika kravspecifikationerna med hjälp av en materialdatabas och konsultation av plastleverantörer. Konstruktion för att leda bort värme gjordes sedan och baserades på två varianter av kylflänsar. De här båda varianterna simulerades med den värmeledande polymeren som hade högst värmeledningsförmåga. Materialet för den yttre formgivningen var en enklare konstruktionsplast men efter värmesimuleringar visade resultaten att en värmeledande polymer var tvungen att användas även för den yttre formgivningen. Det här för att klara temperaturkraven hos LED-lamporna. Vidare togs flertalet olika koncept fram för hur den yttre formgivningen skulle sammansättas och med brainstorming, morfologi samt Pughs matris kunde ett slutgiltigt koncept presenteras. Syftet är därmed uppnått genom att möjligheterna har studerats och en realiserbar konstruktion har tagits fram. Resultatet är att värmehanteringen i LED-armaturen kan hanteras av befintliga polymera material samtidigt som egenskaperna hos polymerer utnyttjades då bland annat funktioner integrerats och vikten red ucerats. Användandet av den värmeledande polymeren för hela armaturen resulterar dock i höga materialkostnader samtidigt som höga krav på vatten- och dammtäthet har skapat svårigheter för integration av fler funktioner i armaturen.

Syftet med studien var att undersöka de ekonomiska vinster som kan erhållas vid byte av belysningsarmaturer i en byggnad. Studien omfattar de energi- och ekonomiska besparingar som möjliggörs via ett byte från gamla T8-armaturer till LED-armaturer. Dessutom skulle kunskap kring armaturernas påverkan på elnätet i form av övertoner tas fram. Målet var därmed att ta fram en tydlig redogörande jämförelse mellan de två armaturtyperna. Studien ”Energieffektivisering av belysningsarmaturer” utfördes på uppdrag av Caverion Sverige AB men i B&B-Tools vägnar och dess lokal belägen i Ulricehamn. För att uppfylla syftet krävdes information om armaturtyperna och hur de fungerar och därmed också god kunskap kring det berörda ämnet. Armaturerna som jämförs i denna studie är en lysrörsarmatur med T8-lysrör som installerades för ca 25 år sedan samt en modern LED-armatur från leverantören Waldmann med produktnamnet Taureo. Med hjälp av ett elkvaltitetsinstrument från företaget Metrum, som är anpassat för att utföra tillförlitliga kontroller av olika elkvalitetsparametrar, bestämdes armaturernas effekt. Dessutom uppmättes armaturernas övertonshalter som visade betydligt högre övertonshalter hos lysrörsarmaturen än för LED-armaturen. Eftersom övertoner kan medföra negativa konsekvenser på såväl enskilda komponenter som på självaste elnätet, eftersträvas så låga övertonshalter som möjligt. Genom de mätningar av effekt som gjordes under studien påvisas att ett armaturbyte skulle innebära en kraftig effektminskning motsvarande en tredjedel av det nuvarande effektuttaget. Därigenom kan större energimängd sparas, cirka 52 000 kWh/år, vilket innebär en årlig kostnadsbesparing på cirka 43 000 kr. Enligt de gjorda beräkningarna erhålls en återbetalningstid på cirka 8,5 år vilket kan bedömas som god lönsamhet i och med LED-armaturernas långa livslängd.

Rapporten behandlar ett examensarbete för högskoleingenjörsprogrammet inom innovationsteknik och design, utfört av Rebecca Magyar. Uppdragsgivare för projektet var Home Structures Sweden AB och arbetet riktade sig till det egna varumärket Irislights med Peter Nordin som handledare på företaget.   Irislights är en produkt som består av en LED-slinga för inomhusbruk. Produkten är tänkt att vara kreativ för kunden färg- och formmässigt vilket låter kunderna själva kombinera handgjorda bomullsbollar som fästs kring en diod på slingan. Projektets huvudsakliga uppgift var att generera en lösning för fästning av befintlig produkt med avseende på kundernas behov i att hänga upp slingan. Den valda lösningen ska ge kunden utrymme för att utnyttja sin egen kreativitet.   Arbetet utgick ifrån designprocessen där en förstudie var inledande fas för arbetets uppbyggnad. Förstudien innefattade en kartläggning av kommande trender inom inrednings- och belysningsbranschen, undersökning av kundernas behov och reflekterande arbete kring framtidens inredningsuttryck. Undersökning av teknik ingick även i förstudien för att få mer information kring befintlig produkt samt krav denna kom att ställa på det framtagna koncept som rapporten berör. Eftersom nuvarande produkt och den framtagna upphängningskonstruktionen ska samverka med varandra kommer uppställda krav vara av betydelse för utformningen. Ifrån detta skapades idéer som sedan genererades fram till slutgiltigt produkt förslag.   Den valda utformningen presenteras genom skisser, CAD-konstruktion, ritningar samt en skalenlig prototyp. Ett materialval gjordes även på produkten i materialvals programmet CES EduPack för att ge förslag på ett miljövänligt alternativ sett till framställning av materialet vid preliminär produktion. / This report describes a Bachelor Theisis of Science in Innovation and Design, conducted by Rebecca Magyar. The project was carried out for Home Structures Sweden AB directed to their own brand Irislights with Peter Nordin as task manager.   The existing product Irislights consists of one product, a LED trail for indoor use. The product is supposed to be creative in terms of color and pattern and let the customers combine and create a personalized light trail. The project's main task was to generate a fastening function for the existing product with consideration to customer needs. Also develop the chosen soulution with oppurtunity to provide the customer oppurtunity to us their own creativity.   The implementation of the work was based on a survey of future trends in interior design and in the lightning industry, also by analysing customer needs. Requirements was developed after creating understanding about the existing technology in Irislights which affected the chosen concept so it could be practicable in reality. Based on a feasibility study ideas was created which generated a final product suggestion. The chosen concept was presented through sketches, a modell in 3D-CAD , CAD-drawings and a full-scale prototype. The selection of material was also made in the program CES EduPack to give suggestions on an environmentally friendly alternative in terms of energy consumption in the primary production of a material.

As of today, around 19% of all electricity that is produced around the world goes toward lighting roads and cities. The light is also produced in a wasteful manner, creating disturbances in nature as well as for people. Recent developments in light emitting diodes offers remedy to these problems but the technology needs a proper revision of street lighting’s purposes. Light emitting diodes use a fraction of the energy needed for previous lighting methods. They offer unique implementation opportunities in physical construction as well as being highly controllable which makes them highly adaptable. The thesis looks at how aesthetics can be used to optimally introduce the upcoming worldwide installation of the new technology. Its unique characteristics were looked at and used to create a Korean styled luminaire and an interactive street lighting system in two separate design processes. The results of the developments were firstly, a modular luminaire which combines Korean architectural aesthetics with a cost effective construction. The second result was an interactive urban street lighting system which suggests a dimmable lighting that through an adaptable computer control responds to pedestrians’ presences. This is a master’s thesis (D7014A) is a project in product design at the education of industrial design engineering at Luleå University of Technology and is worth 30 credits. The project spanned 20 weeks during the spring semester of 2016. The project was conducted in collaboration with Pukyong National University’s industrial design department, in Busan, South Korea. / Omkring 19% av all elektricitet som produceras idag runtom i världen åtgår till att belysa vägar och städer. Ljuset som produceras även i ett slösaktigt utförande som skapar störningar i natur såväl som för människor. Nya utvecklingar kring ljusdioder kan bringa bot till dessa problem men teknologin kräver en passande revision av gatubelysningars roller i samhället. Dioderna använder nämligen en bråkdel av energin äldre belysningsmetoder kräver och medför en revolution i fysiska implementeringsmöjligheter medans de även låter sig kontrolleras till en hög grad. Dessa egenskaper gör att de har en oöverträffad anpassningsbarhet. Examensarbetet ser till hur estetik kan användas för att optimalt introducera lamporna i den världomfattande installationen dem. Lampornas unika möjligheter undersöktes och användes till att utveckla ett Koreansk-inspirerat gatulyse och ett interaktivt belysningssystem i två separata designprocesser. Resultatet av utvecklingarna var först, en modulbaserad armatur med en kostnadseffektiv konstruktion. Det andra resultatet var ett interaktivt stadsbelynsingssystem som föreslår ett dämpningsbart system vilket genom en adapterbar dator svarar på fotgängares närvaro. Detta examensarbete (D7014A) är ett projekt inom industriell design på utbildningen Teknisk design vid Luleå Tekniska Universitet och innefattar 30 högskolepoäng. Projektet sträckte sig över 20 veckor under vårterminen 2016. Arbetet utfördes i samarbete med Pukyong National Universitys institution för industriell design i Busan, Sydkorea.

III–V nitride quantum-confined structures embedded in nanowires (NWs), also known as quantum-disks-in-nanowires (Qdisks-in-NWs), have recently emerged as a new class of nanoscale materials exhibiting outstanding properties for optoelectronic devices and systems. It is promising for circumventing the technology limitation of existing planar epitaxy devices, which are bounded by the lattice-, crystal-structure-, and thermal- matching conditions. This work presents significant advances in the growth of good quality GaN, InGaN and AlGaN Qdisks-in-NWs based on careful optimization of the growth parameters, coupled with a meticulous layer structure and active region design. The NWs were grown, catalyst-free, using plasma assisted molecular beam epitaxy (PAMBE) on silicon (Si) substrates. A 2-step growth scheme was developed to achieve high areal density, dislocation free and vertically aligned NWs on Ti/Si substrates. Numerical modeling of the NWs structures, using the nextnano3 software, showed reduced polarization fields, and, in the presence of Qdisks, exhibited improved quantum-confinement; thus contributing to high carrier radiative-recombination rates. As a result, based on the growth and device structure optimization, the technologically challenging orange and yellow NWs light emitting devices (LEDs) targeting the ‘green-yellow’ gap were demonstrated on scalable, foundry compatible, and low-cost Ti coated Si substrates. The NWs work was also extended to LEDs emitting in the ultraviolet (UV) range with niche applications in environmental cleaning, UV-curing, medicine, and lighting. In this work, we used a Ti (100 nm) interlayer and Qdisks to achieve good quality AlGaN based UV-A (320 - 400 nm) device. To address the issue of UV-absorbing polymer, used in the planarization process, we developed a pendeo-epitaxy technique, for achieving an ultra-thin coalescence of the top p-GaN contact layer, for a self-planarized Qdisks-in-NWs UV-B (280 – 320 nm) LED grown on silicon. This process constitutes a significant advancement in simplifying the UV-B and UV-C fabrication process favoring light extraction. Addressing the issue of poor white light quality in the conventional blue laser diode (LD) and YAG:Ce3+ technology, a number of applications related investigations was conducted. Notably, the orange and yellow emitting InGaN/GaN Qdisks-in-NWs LEDs were implemented as an “active phosphor” to achieve intensity- and bandwidth-tunability for high color-quality solid-state lighting.

ABSTRACT: What is culture? What is the culture of the city? The premise of this study is that the construction of an official rationality of culture, as a concept that underlies culture-led urban regeneration and place-marketing, is often limiting and exclusionary. The official concept of culture often overlooks the important political nuances and complexities that are involved in the representation and appropriation of cultural identities. It also neglects the value of the symbols and practices that are produced in the everyday life of the city, which may provide a real inclusionary, socially relevant understanding of identity and difference in the city. The study explains the need to prompt urban practitioners and theorists to begin to deconstruct prevailing interpretations of urban culture so that we may begin engaging with alternative interpretations of identities, cultures and difference to more authentically reflect the fluid meanings produced in the realm of urban everyday life. Beginning with a brief glimpse into the various meanings constructed for culture over time, the study then proceeds to analyse the official documented discourse on culture constructed for the city of Johannesburg. These ideas are then distilled into four critical themes acting as a conceptual framework relating to the interpretation of culture in the city. These four themes lead to an exploration of the space of everyday life as an alterative source of the multiple shifting meanings and identities being formed daily in the everyday life of the city. This study extends an invitation to urban theorists and practitioners to embark upon the task of critically deconstructing the realities and political complexities of prevailing interpretations of culture in the city that underlies urban regeneration. In this way the study aims to stimulate the development of alternative rationalities in urban planning about the nuances and representations of social life, identities and difference in the city, urging a 9 critical review and critique of urban decision making and its consequences for the everyday social experience of the city. This research concludes by suggesting that the concept of culture be deprivileged in the context of urban regeneration and that a new direction in practising urban regeneration and place-marketing be explored in the spaces of everyday life.

Le travail de cette thèse a été consacré au développement d’une nouvelle méthode de détection pour un système anticollision par la mesure de trajectographie, ce qui pourrait contribuer aux systèmes d’aide à la conduite. Pour obtenir une haute probabilité de détection, nous avons choisi la solution de vidéo stéréoscopique coopérative : la coopération entre véhicules rend la détection plus facile et fiable. Il y a deux participants dans le système : les véhicules « porteurs du système » aussi bien que les « suiveurs », sont équipés de caméras stéréoscopiques, c’est à dire de deux capteurs d’image, appartenant à des familles technologique à haute cadence; les véhicules « cibles » sont équipés des feux à Leds modulés, dont la fréquence de modulation est déjà connue par les véhicules « suiveurs ». Après filtrage dans l’espace temporel, le système ne détecte que des signaux issus des feux modulés, ce qui réduit fortement l’information à traiter par rapport aux calculs de trajectographie traditionnels. La détection de feux modulés est donc réalisée par le filtrage par traitement numérique des images, qui est adapté à la fréquence de modulation recherchée. Pour cela, nous avons proposé 3 types de filtres adaptés à la fréquence de modulation et conçus de façon à rejeter au mieux les signaux de fond.Pour évaluer les performances tant en détection qu’en réjection des fausses alarmes, nous avons d’abord effectué des simulations numériques en prenant en compte des signaux artificiels, puis des calculs sur vrais signaux obtenus dans les expérimentations avec véhicule d’essai statique, puis roulant. Les roulages étaient de différentes vitesses, de 30km/h jusqu’à 100km/h, ce qui nous a permis d’analyser le signal issu du feu ainsi que le comportement de nos filtres à des vitesses angulaires de feu nulles, faibles ou élevées. Le résultat de ces expérimentations montre que le filtrage permet de détecter les feux à Leds de type DRL jusqu’à 140m sans aucune fausse détection sur le fond. Ces expérimentations sont une étape essentielle pour définir de façon plus précise un tel système, en particulier dans le choix du seuil. Nous avons aussi évalué des technologies qui peuvent améliorer la performance du système, mais qui ne sont pas encore prêtes à industrialiser. Par exemple, les « rétines » artificielles nous permettent d’utiliser les filtres analogiques intégrés, et ainsi de réduire leurs bandes passantes. / This thesis was devoted to the development of a new detection method for vehicular collision avoidance system based on trajectory measurement, which could contribute to driver assistance systems.In order to obtain high detection probability, we have chosen the cooperative stereoscopic video solution: the cooperation between vehicles makes it easier and more reliable when they aim to detect each other. There are two participants in the system: the “system carriers" vehicles, or the " followers" are equipped with stereoscopic cameras (two image sensors), who belong to high speed technology families; the "targets" vehicles are equipped with modulated LED lights, with the modulation frequency being already known by the "followers". After space-time filtering, the system detects the signals emitted bymodulated lights sources, which greatly reduces the amount of information to be processed comparing to traditional trajectory calculations methods. The detection of modulated light is achieved by filtering based on digital image processing, which is adapted to the desired modulation frequency. We have proposed three types of filters suitable for detecting the modulation at this frequency and at the same time for rejecting the background as well as possible.In order to be able to evaluate the performances of both detecting signals and rejecting false alarms, we first performed numerical simulations based on the model signals, then calculations on real signals acquired in static and driving experiments. The tested speeds were from 30km/h up to 100km/h, which allowed us to analyze the signals emitted from vehicle lights as well as the behavior of our filters under different angular velocities of the lights (zero, low and high). The result of these experiments showed that our method of filtering could detect LED-type DRL lights up to 140m without any false alarm. This is essential to define more precisely the values of thresholds of such systems. We have also evaluated technologies that are possible to improve system performance in the future, which are not yet ready to be used in industry productions. For example, artificial "retinas" could allow us to integrate analog filters in the chips, and thus to reduce bandwidth of the filters.

A hernia frequently complicates abdominal stoma formation. The aetiology of parastomal herniation is claimed to be multi-factorial but currently only age and trephine diameter have been shown to independently predict its development. Open or laparoscopic repair of a symptomatic parastomal hernia is frequently challenging and is associated with unsatisfactory recurrence rates. As a result, many affected patients are managed non-operatively. Prevention of parastomal herniation by prophylactic mesh reinforcement of the stoma site is a new strategy that may reduce its incidence. Manual mesh implantation, however, is thought to increase the operating time and is considered cumbersome, particularly in laparoscopic surgery. As a result, routine reinforcement of the stoma site is not currently standard practice within the National Health Service. Thus, there is a need for a simple and quick technique for stoma formation which avoids creating an oversized defect and simultaneously reinforces the trephine with mesh. The aims of this thesis included: (i) understanding the aetiopathogenesis of parastomal herniation, assessing its impact on patients’ quality of life and examining the outcomes associated with current therapeutic strategies in order to find novel therapies that may lead to its prevention; (ii) assessing the safety, reproducibility and efficacy of the Stapled Mesh stomA Reinforcement Technique (SMART) in preventing parastomal herniation and (iii) investigating the contribution of the rectus abdominis muscle to the development of herniation. A detailed literature review of PubMed and Medline databases confirmed that stoma formation through the rectus muscle is complicated by parastomal herniation in 50%-80% of 4 cases. Surgeons have underestimated its impact on patients’ quality of life. There is no conclusive evidence that alternative techniques (e.g. extraperitoneal, lateral rectus abdominis positioned stoma) are superior. Open and laparoscopic parastomal hernia repair have similar recurrence rates up to 50%. Prophylactic reinforcement of the stoma trephine with mesh in the sublay or subperitoneal position is safe and appears to reduce the herniation rate but it is difficult laparoscopically and does not address the issue of trephine size when a defect <25mm is associated with a reduced herniation risk. The Stapled Mesh stomA Reinforcement Technique (SMART) obviates the technical issues associated with routine stoma formation and reinforcement. In a pilot study with patients at high risk for herniation, SMART was found to be safe and reproducible and reduced the herniation rate to 18%. Preliminary results of the international multicentre randomised controlled trial in all patients undergoing permanent stoma formation show that SMART reduces the herniation rate compared to the standard technique, without added morbidity and minimal impact on the operating time. A radiological study assessing the contribution of the rectus abdominis muscle into the development of parastomal herniation showed that the abdominal musculature undergoes postoperative changes consistent with atrophy with postoperative muscle density being higher in patients without parastomal herniation. In conclusion, at this moment in time, prophylactic mesh reinforcement should be offered to all patients undergoing elective permanent stoma formation. The SMART procedure has the potential to change current surgical practice. The contribution of the rectus muscle to the development of herniation warrants further research since improving muscle repair and regeneration may result in therapeutic benefits.