Comprehensive design and propagation study of a compact dual band antenna for healthcare applications

In this paper, a dual band planar inverted F antenna (PIFA) has been investigated for cooperative on- and off-body communications. Free space and on-body performance parameters like return loss, bandwidth, radiation pattern and efficiency of this antenna are shown and investigated. The on- and off-body radio propagation channel performance at 2.45 GHz and 1.9 GHz have been investigated, respectively. Experimental investigations are performed both in the anechoic chamber and in an indoor environment. The path loss exponent has been extracted for both on- and off-body radio propagation scenarios. For on-body propagation, the path loss exponent is 2.48 and 2.22 in the anechoic chamber and indoor environment, respectively. The path loss exponent is 1.27 for off-body radio propagation situation. For on-body case, the path loss has been characterized for ten different locations on the body at 2.45 GHz, whereas for off-body case radio channel studies are performed for five different locations at 1.9 GHz. The proposed antenna shows a good on- and off-body radio channel performance

Erosion Losses from Banana-Pineapple Intercropping and Soil Loss Prediction Using Rusle

Soil erosion in agricultural upland conditions was investigated in Puchong Farm, UPM from an intercropping system of banana-pineapple. To study the effectiveness of this intercropping system four erosion plots of same length but different width were prepared on a 9% slope. One plot was planted with banana crop, second with pineapple and third with intercrop of banana and pineapple, whereas one plot was kept as bare with regular cultivation every fortnight. All the plots were kept in weed-free condition. Each plot was equipped with sediment tanks, for the collection of soil loss and runoff from the plots. Measurement of soil loss and runoff was made after every erosive rainfall. The sediments and runoff water were analyzed for major nutrients after every growth period. The data indicate that the site soil is very susceptible to erosion. The highest soil loss during the nine months period was obtained from bare plot (105.5 mt/ha) followed by banana plot (40.6 mt/ha) whereas total soil loss from intercrop and pineapple plots were 26.5 and 25.0 mt/ha respectively. Total runoff from bare, banana, intercrop and pineapple were 11.1 x l06, 9.3xl06, 6.3xl06 and 7.2xl06 L/ha respectively. These came as a result of total rainfall of 2020 mm which was about 25% higher than the average of 10 previous years. Comparison of soil loss and runoff in different growth periods showed that, in the early growth period when the canopy cover was around 1 5%, soil loss and runoff were not significantly different among the plots. But after the establishment of crop canopy and root network, soil loss and run off were reduced significantly as compared to bare plot. The relationship of EI30 index with soil loss and runoff and the relationship of soil loss with runoff were significant at 1 % probability level for all the plots. The analysis of fertility status showed that at the top of the slope there was decrease in the fertility except for K in intercrop and C, N, P and K for pineapple as compared to the center and bottom of the slope for every plot

Sustainable student housing:urban village in Milan

Abstract. This diploma thesis represents a sustainable housing design proposal for students co-living in Campus Polimi in Milan, based on integrating urban farming and landscape productivity. This urban village for students is located on an existing green plot on Polytechnic University’s campus. This urban village accommodates 87 community-based living units for students. The topic of the thesis appeared with the emergence of a shortage in housing for bachelor and master students who do not receive organized support since they are not recognized as a vulnerable group of people to housing demand. This issue is addressed with a multi-functional program to optimize the well-being of students. Sustainability is demonstrated via the social and ecological aspects of the design proposal. This prototype is a building consisting of multi-functional spaces providing communal activities like urban farming and co-working areas. As a result of the research part based on both historical and climatic inspections, an adaptive design based on expanding modularity is produced. This modularity made mixing semi-public spaces with private spaces possible to create a flexible program that can adapt and change to future needs. This thesis is divided into two parts. The first part briefly investigates the historical and climatic background of the design context through different analyzing methods in terms of historical and climatic visions. In the second part, the investigation’s result is instilled into the design process of the building with architectural drawings and diagrams supporting the design proposal

Propriétés magnétiques d'hétérostructures à base d'oxydes pour la réfrigération magnétique et la spintronique

Motivée par leur grand potentiel d’applications technologiques dans plusieurs domaines, la recherche sur les matériaux et composants à base d’oxydes de type pérovskite comme les manganites et les doubles pérovskites demeure très active et d’actualité. Dans la présente thèse, la spintronique et la réfrigération magnétique sont les deux cibles principales. Le manganite semi-métallique ferromagnétique La2/3Sr1/3MnO3 (LSMO) et le double pérovskite isolant ferromagnétique La2NiMnO6 (LNMO) sont d’intérêt puisqu’ils peuvent être utilisés en réfrigération magnétique et pour des jonctions à effet tunnel magnétiques grâce à leur grande température de transition magnétique, leur grande aimantation et leur grande polarisation magnétique. Dans la première partie de cette thèse, nous étudions l’effet magnétocalorique (EMC) d’hétérostructure de LSMO etLNMOsimulant des composites. Les buts de cette première étude sont d’étendre l’intervalle de température avec un effet magnétocalorique significatif et d’améliorer leurs performances en modifiant les propriétés magnétiques de multicouches grâce à des effets de contraintes structurales entre les couches et le substrat. Les propriétés magnétiques et magnétocaloriques des couches de LSMO et LNMO incluses dans les hétérostructures peuvent être contrôlées et même ajustées en les soumettant à différents champs de contraintes, tout particulièrement pour le double pérovskite LNMO pour lequel les propriétés magnétiques sont très sensibles au niveau d’ordre cationique sur les sites B/B’. Nous démontrons comment la proportion d’ordre cationique dansLNMOpeut être ajusté dans les hétérostructures simplement en changeant l’ordre de succession des couches provoquant des effets différents des contraintes structurales. La présence de plusieurs transitions magnétiques dans le LNMO multi-domaine permet le design de structures artificielles présentant un EMC de type "table-top" (constant sur une large gamme de température). Cependant, la présence de plusieurs domaines avec différentes propriétés est parfois difficile à confirmer en utilisant seulement l’aimantation permettant d’évaluer l’EMC. D’autres approches, par exemple l’effet tunnel au travers LNMO, peut être une avenue intéressante pour les détecter. Dans la deuxième partie de la thèse, nous exploitons la nature isolante du double pérovskite LNMO pour étudier l’effet d’une barrière ferromagnétique sur la magnétorésistance tunnel (TMR) d’une jonction à effet tunnel magnétique (MTJ). Nous montrons que la TMR ne dépend pas seulement de l’orientation relative de l’aimantation des deux électrodes métalliques, mais dépend aussi de l’orientation de l’aimantation de la barrière de LNMO par rapport à celles des électrodes. Il est proposé que la conduction au travers la barrière de LNMO se produit via des canaux pour électrons et pour des trous impliquant des états eg vides ou pleins près du niveau de Fermi dans la barrière. Se basant sur l’observation de TMR jusqu’à la température de transition maximale observée pour le LNMO, on constate que ces composants MTJ peuvent être utilisés comme sondes très sensibles de la présence de phases magnétiques dans différents domaines, et ceci en très faible quantité.Abstract: There has been an active, ongoing research on perovskite-structured oxides such as manganites and double perovskites due to their great potential for a wide range of technological applications in many fields. In the present thesis, spintronics and magnetic refrigeration are the main targets. Half-metallic ferromagnetic manganite La2/3Sr1/3MnO3 (LSMO) and ferromagnetic insulating double perovskite La2NiMnO6 (LNMO) are of particular interest as they can be used in magnetic refrigeration and magnetic tunnel junctions due to their high and tunable transition temperature, large magnetization and large spin polarization. In the first part of this thesis, we study the magnetocaloric effect (MCE) of composite-like heterostructures of LSMO and LNMO. The goal is to extend the MCE and improve its performance by altering the magnetic properties in multilayers using epitaxial strain. The magnetic and magnetocaloric properties of LSMO and LNMO layers can be controlled and tuned by subjecting them to different strain fields, especially for LNMO double perovskite where its magnetic properties are very sensitive to the level of cationic ordering at the B/B’ sites. We demonstrate how the ratio of cation ordering in LNMO can be adjusted in heterostructures simply by changing the layout of the layers triggering contrasting strain effects. The presence of multiple transitions in a multi-domain LNMO allows the design of artificial structures with table-top-like MCE. The presence of several domains with different properties is often difficult to perceive using only magnetization. Other approaches, like tunneling through LNMO, may be an interesting avenue to explore its multi-domain aspect. In the second part, we exploit the insulating nature of LNMO double perovskite to study the effect of a ferromagnetic barrier on the tunnel magnetoresistance (TMR) of a magnetic tunnel junction (MTJ). We show that the TMR does not depend only on the relative orientation of the magnetization in the two metallic electrodes, but also depends on the orientation of magnetization in the LNMO barrier with respect to those of the two electrodes. It is proposed that the conduction occurs through the LNMO barrier via electron and hole channels involving empty and filled eg states around the Fermi level in the barrier. Based on the observation of TMR up to the maximum transition temperature of LNMO, these MTJ devices can also be used as a sensitive probe to detect magnetic phases in the barrier coming from different domains in the same film

Ultra-low power mixed-signal frontend for wearable EEGs

Electronics circuits are ubiquitous in daily life, aided by advancements in the chip design industry, leading to miniaturised solutions for typical day to day problems. One of the critical healthcare areas helped by this advancement in technology is electroencephalography (EEG). EEG is a non-invasive method of tracking a person's brain waves, and a crucial tool in several healthcare contexts, including epilepsy and sleep disorders. Current ambulatory EEG systems still suffer from limitations that affect their usability. Furthermore, many patients admitted to emergency departments (ED) for a neurological disorder like altered mental status or seizures, would remain undiagnosed hours to days after admission, which leads to an elevated rate of death compared to other conditions. Conducting a thorough EEG monitoring in early-stage could prevent further damage to the brain and avoid high mortality. But lack of portability and ease of access results in a long wait time for the prescribed patients. All real signals are analogue in nature, including brainwaves sensed by EEG systems. For converting the EEG signal into digital for further processing, a truly wearable EEG has to have an analogue mixed-signal front-end (AFE). This research aims to define the specifications for building a custom AFE for the EEG recording and use that to review the suitability of the architectures available in the literature. Another critical task is to provide new architectures that can meet the developed specifications for EEG monitoring and can be used in epilepsy diagnosis, sleep monitoring, drowsiness detection and depression study. The thesis starts with a preview on EEG technology and available methods of brainwaves recording. It further expands to design requirements for the AFE, with a discussion about critical issues that need resolving. Three new continuous-time capacitive feedback chopped amplifier designs are proposed. A novel calibration loop for setting the accurate value for a pseudo-resistor, which is a crucial block in the proposed topology, is also discussed. This pseudoresistor calibration loop achieved the resistor variation of under 8.25%. The thesis also presents a new design of a curvature corrected bandgap, as well as a novel DDA based fourth-order Sallen-Key filter. A modified sensor frontend architecture is then proposed, along with a detailed analysis of its implementation. Measurement results of the AFE are finally presented. The AFE consumed a total power of 3.2A (including ADC, amplifier, filter, and current generation circuitry) with the overall integrated input-referred noise of 0.87V-rms in the frequency band of 0.5-50Hz. Measurement results confirmed that only the proposed AFE achieved all defined specifications for the wearable EEG system with the smallest power consumption than state-of-art architectures that meet few but not all specifications. The AFE also achieved a CMRR of 131.62dB, which is higher than any studied architectures.Open Acces

Formalising ambush marketing as a marketing communications activity: a framework for planning, implementation and control

A thesis submitted to the University of Bedfordshire, in partial fulfilment of the requirements for the degree of Doctor of Philosophy.The UK is reporting record numbers of television and digital audiences of international sports broadcasts. Sponsoring these events represents highly lucrative and sought after opportunities for brands to reach these large audience numbers. However the immense costs of organising these events mean that the costs of such sponsorships are also immense. Therefore these sponsorship opportunities are accessible only to large multinational and global brands. Ambush marketing represents an alternative approach whereby brands can participate in marketing communication activities similar to sponsors without becoming official sponsors. Ambushers have to develop creative and imaginative campaigns to emulate sponsors without infringing on their rights. The aim of this study is to conceptualise the operational aspects of ambush marketing from the perspective of ambushers. It explores ambushing as an alternative strategic marketing communications activity to corporate sponsorship of sports. A systematic literature review has been conducted to discover the background and development of ambush marketing and ascertain the gap in research by comparing the extant research on ambush marketing to corporate sponsorship of sports. Where there is saturation in empirical consumer oriented research on brand recognition and recall, there is no research on the planning, development and implementation of ambush marketing or the day to day operations and strategies involved in ambushing sports. Furthermore research has so far not involved actual ambushers. In order to fulfil this gap, an exploratory, qualitative study has been designed. A single case study strategy has been applied with eight embedded units of analysis represented by eight actual ambushers of recent UK sports broadcasts. Participants in this unprecedented study are senior marketing and management officials of these companies. The study is interpretative with an ideographic philosophical stance allowing the exploration of UK ambush marketing within its own ethnographic context. A number of reliability and validity measures have been incorporated in the research design. The analysis of data in the form of interviews, documents and multimedia content found six main themes with a number of subthemes regarding the decision, planning and implementation of ambush marketing campaigns. These six themes are decision making, objective setting, developing ambush strategies, targeting ambush audiences, ambush expenditure and ambush outcomes. They represent sequential individual stages in the organisational process of ambush marketing found to be common in all participating companies. This study contributes to potential UK ambushers by providing a standardised approach to ambushing international sports broadcasts specifically from the industries represented by the participants, namely the betting industry and the food and beverage industry. Research also highlights the changing nature of ambush marketing from the traditional parasitic image to a contemporary image as a parallel, mutually beneficial activity. The benchmarking tool represented by the diagrammatic framework of the ambush marketing process will allow ambushers to chart their progress against a standardised approach while highlighting contemporary and innovative ideas and ways to avoid illegal and unethical practices. Lastly this study contributes to future research in ambush marketing by demonstrating that direct ambush marketer involvement is possible and making specific and valuable recommendations for further study