Sökning: "metal accumulation"

Visar resultat 21 - 25 av 99 avhandlingar innehållade orden metal accumulation.

1. 21. Effects of heavy metal contamination on carbon and nitrogen cycling : An ecological approach to assess risks to soil functions

   Författare :Ingrid Rijk; Alf Ekblad; Dan Berggren Kleja; Erik Karltun; Örebro universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; heavy metals; soil contamination; stable isotopes; N cycling microbial guilds; 13C; 15N; nitrification; denitrification; biochar; soil respiration; microbial activity; bioavailability;

   Sammanfattning : Soil contamination with heavy metals may disrupt soil microorganisms with important roles in carbon (C) and nitrogen (N) cycling. However, there is a lack of understanding on how microorganisms are affected in soil, which may lead to a mismatch when assessing risks of contaminants to field soils. LÄS MER

3. 22. Single-Electron Tunneling Spectroscopy in Magnetic Nanoparticles and Molecular Magnets

   Författare :Lukasz Michalak; Fasta tillståndets fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; master equation; magnetic nanoparticles; spin accumulation; molecular magnets; TMR; tunneling magnetoresistance; F-SET; ferromagnetic single-electron transistor; single-electron tunneling; nanomagnetism; spintronics; Coulomb blockade;

   Sammanfattning : This thesis deals with single-electron tunneling in transistor-like devices in which the central electrode is either a metal nanoparticle (possibly ferromagnetic) or a molecular magnet. The investigated systems split into two different categories, depending on the size of the central island. LÄS MER

4. 23. Electronic structure of clean and adsorbate-covered InAs surfaces

   Författare :Karolina Szamota-Leandersson; Ulf Otto Karlsson; Vladimir Chab; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; angle-resolved photoemission; electronic structure; accumulation layer; adatoms; reconstruction; Surfaces and interfaces; Ytor och mellanytor;

   Sammanfattning : This thesis is the result of investigations regarding the processes in InAs III-V semiconductor surfaces induced by additional charge incorporated by adsorbates. The aim of the project is to study the development of the accumulation layer on the metal/InAs(111)A/B surfaces and its electronic structure. LÄS MER

5. 24. Low-frequency noise characterization, evaluation and modeling of advanced Si- and SiGe-based CMOS transistors

   Författare :Martin von Haartman; Mikael Östling; Cor Claeys; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MOSFET; SOI; SiGe; strain; high-k; metal gate; 1 f noise; low-frequency noise; mobility fluctuations; phonons; number fluctuations; traps; buried channel; mobility; substrate bias; Electronics; Elektronik;

   Sammanfattning : A wide variety of novel complementary-metal-oxide-semiconductor (CMOS) devices that are strong contenders for future high-speed and low-noise RF circuits have been evaluated by means of static electrical measurements and low-frequency noise characterizations in this thesis. These novel field-effect transistors (FETs) include (i) compressively strained SiGe channel pMOSFETs, (ii) tensile strained Si nMOSFETs, (iii) MOSFETs with high-k gate dielectrics, (iv) metal gate and (v) silicon-on-insulator (SOI) devices. LÄS MER

7. 25. Ultrathin Oxides in Metal-Oxide-Silicon Structures: Defects and Characterization

   Författare :Lars-Åke Ragnarsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PMA; interface state densities; silicon; aluminum oxide; Pb; ultrathin; RPECVD; MOS;

   Sammanfattning : The properties of metal-oxide-silicon (MOS) structures with ultrathin oxide layers (15-30 Å) have been investigated by means of electrical characterization. The characterization methods used were mainly capacitance voltage (C-V), current voltage (I-V) and constant voltage stress (I-t) measurements. LÄS MER