In recent years, the rapid development of wireless communications has resulted in much better quality of life due to easiness and multitudes in communications. The most representative products are the mobile phones. The product is so popular that in developed countries nearly everyone owns a mobile phone; that applies not only to adults, but also young students. In view of this wide spreading phenomenon, the mobile phone industry has inescapable health related responsibilities for its users, especially for the younger ones. While enjoying the great convenience of the product, the users are advised to understand the possible health related effects caused by electromagnetic radiation. One of the very important considerations is Specific Absorption Rate (SAR), in which absorption of electromagnetic energy by a medium (for example, a human head) is measured. Before a mobile phone is brought into the market, it is important to understand how the SAR values can be affected by the metallic accessories around the human head. This thesis uses software package, SEMCAD, to analyze the metallic accessories on the human head which might influence the SAR value. We would discuss in this thesis three object, eyeglasses, earrings and rings which could affect the maximum SAR value in the human head. For eyeglasses and earring, we would suggest why these metallic accessories at different position could cause different SAR value to suggest people which gesture should be avoided while using the cell phone. For ring, this thesis would use the shape of the ring and place it at special position to decrease the maximum SAR value in the human head to reduce the possible harm from the electromagnetic radiation of mobile phone and ensure the safety while using a cell phone.

Hepatic steatosis is common in the general population and is present in 13.25% of donor organs. It can affect graft survival and recovery of the donor after partial hepatectomy. Liver biopsy is the standard method to measure the degree of hepatic steatosis, but it¡¦s also an invasive procedure and may have sampling error. Non-invasive tools, such as computed tomography and magnetic resonance image, are generally utilized and developed. This study was designed to build a standard model for the quantification of the fat content in a fat-water mixed phantom model. Pork fat and pure water were mixed in different ratios by volume (from 0% fraction of fat to 100% fat in steps of 5%), and then measured for fat content in different concentrations of fat-water mixed phantom by using (1) CT number (Hounsfield unit; HU), (2) Dixon method (in-phase & opposed-phase), and (3) 1H spectroscopy (SVS30 & SVS136, without water suppression). The CT number decreased with increasing fat concentration. The Hounsfield units of pure fat were about -122 HU. At Dixon method, the fat image intensity increased to its maximum when the fat concentration reached 25% and then decreased. Fat concentration higher than 25% and lower than 25% both had the same value of the fat image intensity. Combined with SVS30 water/fat peak height ratio, the fat concentration could be estimated. Furthermore, the fat image could be utilized to observe the topographic distribution of hepatic steatosis. Then a rat fatty liver model fed with a choline deficient and iron supplemented L-amino acid defined (CDAA) diet was established. Fatty liver grade was evaluated by radiological and biochemical assessments. CT and MRS technique displayed the highest fat contents the same with histological examination in CDAA diet rats at 6 weeks. The results showed that MRS was a suitable method for quantifying fat to water concentration. As a result of this study, model of measurement scale can be established to measure fat concentration both in phanatoms and animal. Further study in human fatty liver was expected.

A chemical solution composed of paraffin wax, chloroform, and methyl yellow biological indicator was shaped into a solid 3-D apple phantom to determine absorbed dose from e-beams and X-rays. The purpose of this research was to determine the most uniform irradiation treatment on apple-phantoms (a complex shaped target) and GAFCHROMIC® HD-810 films using electron beams from (1) a 2 MeV Van de Graaff (VDG) accelerator, (2) a 10 MeV Linear Accelerator (LINAC), and (3) X-rays from a 5 MeV LINAC. Irradiation with the VDG accelerator confirmed that tilting the apple-phantom yaxis towards the e-beam source by 90 degrees, 45, and 22.5 degrees resulted in more uniform treatment in both the methyl yellow apple phantom and HD-810 film. The phantoms were over-exposed at the top and bottom regions when their y-axis was oriented exactly parallel to the e-beam at 22.5-degrees. The 45-degree orientation ensured uniformity throughout the whole apple surface without overexposing it at the top and bottom. In contrast, the 90-degree orientation resulted in the least effective treatment with the bottom and top region not receiving any radiation. A 10 MeV dual e-beam showed uniform penetration from top to bottom in the HD-810 film and apple phantoms. The HD-810 film responded linearly with doses up to 1.5 kGy while the methyl yellow response was non-linear up to 0.5 kGy maximum. The X-ray irradiation completely penetrated the apple phantoms from top to bottom showing excellent lateral uniformity at different penetration depths.

This dissertation examines subfunctors of Ext relative to covering (enveloping) classes and the theory of covering (enveloping) ideals. The notion of covers and envelopes by modules was introduced independently by Auslander-Smalø and Enochs and has proven to be beneficial for module theory as well as for representation theory. The first few chapters examine the subfunctors of Ext and their properties. It is showed how the class of precoverings give us subfunctors of Ext. Furthermore, the characterization of these subfunctors and some examples are given. In the latter chapters ideals, the subfunctors of Hom, are investigated. The definition of cover and envelope carry over to the ideals naturally. Classical conditions for existence theorems for covers led to similar approaches in the ideal case. Even though some theorems such as Salce’s Lemma were proven to extend to ideals, most of the theorems do not directly apply to the new case. It is showed how Eklof & Trlifaj’s result can partially be extended to the ideals generated by a set. In that case, one also obtains a significant result about the orthogonal complement of the ideal. We relate the existence theorems for covering ideals of morphisms by identifying the morphisms with objects in A2 (which is the category of all representations of 2-quiver by R-modules) and obtain a sufficient condition for the existence of covering ideals in a more general setting. We finish with applying this result to the class of phantom morphisms.

No description available.

Thirty-eight mastectomy patients who reported phantom breasts were compared to 23 women who did not experience these sensations for the purpose of developing a predictive psychological profile of the phantom breast patient. The Adjective Check List, WAIS—short form, Fundamental Interpersonal Relationship Orientation Scale—Behavior, a social-medical questionnaire, and a Body Image Scale were administered. The Body Image Scale was also given to 25 women who had not had breast cancer. Hemispheric dominance was also assessed by means of conjugate lateral eye movements.

Shear Wave Elastography (SWE) is an ultrasound based technique which is able to measure tissue stiffness through the speed of induced shear waves. Tissue stiffness is often related to pathological conditions and detecting mechanical changes can help the recognition of potential diseases. The clinical use of SWE is limited to isotropic tissue due to the difficulty in assessing a theoretical model for more complex tissue and this project therefore aimed to evaluate the possibility of obtaining a full mechanical characterization of a transversely isotropic (TI) phantom with dual-probe SWE. A TI hydrogel phantom was developed and mechanical tests were performed to verify its anisotropy and determine the elastic moduli in both the perpendicular and longitudinal directions. Shear moduli were estimated using conventional and dual-probe SWE comparing the results to theoretical pure-transverse (PT) and quasi-transverse (QT) wave propagation modes. Both mechanical and SWE tests showed that the phantoms were transversely isotropic ET/EL=0.81. Moreover, multiple wave propagation modes calculated with dual-probe SWE showed a good agreement with the theoretical curves and indicated the possibility of measuring all the elasticity constants needed to fully characterize an incompressible, TI tissue with dual-probe SWE.

At the School of Technology and Health (STH) on KTH, a micro- CT is beeing build. The micro-CT-system need to be aligned in order to function correctly. The purpose of this bachelor thesis was to create an application that, from the micro-CT images, could calculate all the necessary parameters to make the alignment pos- sible. During the projekt, LabView-code for aligning a micro-CT system has been modified to being compatible with the micro-CT at the School of Technology and Health (STH) on KTH. The code has also partly been translated into the open-source and platform independent programming language Java. Due to delays in building the micro-CT at STH, neither the LabView- or Javacode could be validated with it. However, successful attempts have been made with images from another micro-CT and on simulated images of a phantom in a micro-CT.

Begreppet drönare för de flesta utomstående förknippas oftast med hobbyverksamhet i form av foto- och videoskapande. Det senaste åren har allt fler byggföretag valt att satsa på arbetsmetoder där drönare tillåts ersätta befintlig utrustning. Detta examensarbete utfördes för att kartlägga potentialen hos drönarserien Phantom 4, samt de rådande för- och nackdelar med tekniken. Aktuellt är bland annat att studera hur planering-, utförande och bearbetningsskedet påverkas då drönare tillåts användas inom projekt. Syftet med denna studie är att planlägga vid vilka projekt dagens drönarteknik (Phantom 4) kan tillämpas samt de möjligheter som så kallad RTK-teknik kan ha för vidare betydelse för aktörer som vill uppgradera sin drönaranvändning och utrustning. Under arbetets gång har information granskats ifrån tidigare arbeten, litteraturstudier samt intervjuer med nyckelpersoner på Pontarius AB. Dessa personer arbetar dagligen med frågor och projekt som berör ämnesområdet, vilket varit användbart för att styrka det slutsatser som rapporten slutligen kunnat dra. Studien bekräftar att Phantom 4 serien har möjligheten att underlätta planeringen, utförandet och bearbetningen. Genom att göra arbetsmiljön säkrare uti fält, men också genom att minska mängden data som behöver korrigeras manuellt i efterhand. Samtidigt föreligger i dagsläget vissa begränsningar för drönartekniken. Däribland återfinns det faktum att drönaren inte når den precision i alla lägen som en traditionell inmätning gör och att den är begränsad av yttre faktorer, såsom vindkänslighet, väderberoende samt begränsad batteritid. Sammanfattningsvis kan studien konstatera att kunder till Pontarius AB fäller en avgörande roll inför vilken riktning som drönartekniken tillåts utvecklas inom företaget. Efterfrågan på den information som Phantom 4 kan tillhandahålla saknas i mångt och mycket ifrån kundens sida. Detta gör att tekniken inte kan nå sin fulla potential då den inte naturligt tillåts inkluderas i alla avseenden. Trots detta anser vi att en investering i en Phantom 4 RTK bör övervägas å Pontarius AB´s vägnar då denna drönartyp kan bidra med högre inmätningsnoggrannhet och enklare bearbetning av insamlat material.

Through a series of paintings, drawings, videos, and large-scale sculptures/installation, I intend to create an environment that explores relationships between the safe and the unsafe place, the sweet and the grotesque, the dream and the reality, and the remembered and the forgotten. I am investigating landscape and how it relates to the body, human relationships, memory, and status of being.