Search results

The focus of this article has been to analyse the machinability, with focus on surface integrity, of oxygen-free copper (OFC) and niobium during turning operations. The results from machining OFC proved that all of the tools that was tested can be used to achieve a surface roughness below Ra = 0.8 µm with the correct cutting data. From the results when machining niobium it showed that only the cem

Let A be a subset of the real line. We study the fractal dimensions of the k-fold iterated sumsets kA, defined as kA = {a(1) ... + a(k) : a(i) is an element of A}. We show that for any nondecreasing sequence {alpha(k)}(k=1)(infinity) taking values in [0,1], there exists a compact set A such that kA has Hausdorff dimension ak for all k >= 1. We also show how to control various kinds of dimensions s

Abstract is not available

This note studies lumped-delay approximations of distributed-delay elements arising in various problems involving delay compensation or preview utilization. Several approaches to reduce implementation complexity, understood as the number of delays required to attain a required accuracy level, are put forward. First, we derive the H2-optimal coefficients for a given delay pattern. This can be seen

Popular Abstract in Swedish Vår arvsmassa (DNA) finns packad i cellkärnan i de flesta kroppsceller i form av 46 kromosomer (23 par). Könscellerna innehåller ett halverat antal kromosomer. Det korrekta kromosomtalet hos människa beskrevs i Lund 1956, av Tjio och Levan. Kromosomerna innehåller tillsammans 50000-100000 gener, vilka är de delar av DNA-strängen som kan avläsas till proteiner. Cancer ärIn the present thesis benign breast lesions of various histologies, i.e., fibrocystic lesions from women with and without a known hereditary predisposition to breast cancer, fibroadenomas, phyllodes tumors, and papillomas were cytogenetically investigated with the aim to characterize the chromosomal patterns, and to relate the findings with those in breast carcinomas. No lesion-specific aberration

One of Scanias earliest castles, Grevlunda, has been reinvestigated. The first excavation in 1913 gave an interesting result but the time was not ripe for understanding what really was found. In 2002 archaeologists in corporation with historians, and culture geographers found out that the Grevlunda was a motte of a rare construction. The pottery material gave a dating to the late 12:th century. Th

Ferromagnetic Single Electron Transistors (F-SETs) comprise ferromagnetic electrodes connected to a ferromagnetic- or non-magnetic central island via tunnel barriers. These devices are important for studies of spin-transport physics in confined structures. Here we describe the development of a novel type of AFM-assembled nano-scale F-SETs suitable for spin-transport investigations at temperatures

Soils beneath former dry cleaning sites are often contaminated with the chlorinated hydrocarbons PCE and its degradation products, which are highly toxic and cancerogenic. In this study, resistivity and time domain induced polarization (DCIP) were measured at a former dry cleaning site in order to investigate if the source contamination of PCE could be detected. 80 meter long 2D-profiles were meas

Pulsed low energy positron beams provide a unique and non-destructive tool to depth probe the free volume of polymers at surfaces and interfaces. Since the employment of low energy positron beams in polymer research is an emerging technique, some focus in this thesis has been on extracting methods and equations needed to interpret the experimental data. The polymers chosen for this study were sele

The ages of the oldest stars in the Galaxy indicate when star formationbegan, and provide a minimum age of the Universe. Radioactive dating ofmeteoritic material and stars relies on comparing the present abundanceratios of radioactive and stable nuclear species to the theoreticallypredicted ratios of their production. The radioisotope 232 Th (half life14 Gyr) has been used to date Galactic stars,