Custom, resistance and politics : local experiences of improvement in early modern England

This thesis discusses popular participation in politics in early modern England and focqses on four inter-related themes that are central to our understanding of this subject: custom, improvement, public policy and resistance. These themes have been prominent in the recent historiographies either of public policy or of social relations in early modern England, but there has, as yet, been little attempt to relate these historiographies, and still less to study their central themes in the context of local experience. Full-scale case-studies of two series of enclosure riots that occurred during the 1640s, one in Duffield Frith (Derbyshire) and the other in Whittlesey (Cambridgeshire), examine closely both the micro-politics of the defence of custom within these communities and the implications ofrecent redefinitions of 'politics'. Research was undertaken not only in national but also in local archives. Indeed the two series ofriots were specifically selected because it was evident that sufficient local records had survived to permit reconstructions of the two economies upon which 'improvement' was imposed and of social relationships within the two communities. It has, moreover, been possible to recover details of various revenueraising policies implemented by the early Stuart kings or their 'ministers that have previously been studied only briefly. The discussion synthesises the contributions ofthose historians who have done 'so much in recent years to reinvigorate the historiography ofrural social and political relations, and argues that the complex rehitionships between crown policy, local resistance and popular politics can best be reconstructed through the exploration of the micro-politics of custom. It also argues that participation in politics by ordinary people went much further than many recent historians have believed. Such participation was cohflned neither to local 'horizontal' politics, nor to 'vertical' politics in terms of petitioning parliament or waging law in the central courts, but even encompassed actively choosing to vote in parliamentary elections.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Controlled growth of hexagonal GaN pyramids and InGaN QDs

Gallium-nitride (GaN) and its related alloys are direct band gap semiconductors, with a wide variety of applications. The white light emitting diode (LED) is of particular importance as it is expected to replace energy inefficient light bulb and hazardous incandescent lamps used today. However, today’s planar hetero epitaxial grown LEDs  structures contain an unavoidable number of dislocations, which serves as non-radiative recombination centers. The dislocations harm the luminous efficiency of the LEDs and generate additional heat. Pseudomorphically grown quantum dots (QDs) are expected to be dislocation free thus the injected carriers captured by the QDs essentially recombine radiatively since the dislocations remain outside the QD. Furthermore the continuous character of the density of states in bulk materials is redistributed when the size of the dot is reduced within the Bohr radius of the material. Fully discret energy levels are eventually reached, which offers additional control of the optical properties. The Coulomb interaction between the confined carriers also has influence on the emission energy of the recombining carriers, which opens up the possibility of manufacturing novel light sources such as the single photon emitter. Single photon emitters are essential building blocks for quantum cryptography and teleportation applications. The main contribution of the present work is the investigation of growth and characterization of sitecontrolled indium-gallium-nitride QDs embedded in GaN matrixes. The goal has been to demonstrate the ability to grow site-controlled InGaN QDs at the apex of hexagonal GaN pyramids in a controlled way using hot-wall metal organic chemical vapor deposition (MOCVD). Strong emphasis was set on the controlled growth of InGaN QDs. For example the growth of a single InGaN QD located at the apex of hexagonal GaN pyramids with tunable emission energy, the QD emission energy impact on the mask design, and a novel approach for the growth of InGaN QDs with polarization deterministic photon vectors were reported. The thesis is mainly based on experimental investigations by secondary electron microscope (SEM), micro photo-luminescence (μPL), and scanning transition electron microscopy ((S)TEM) characterization techniques. In Paper 1 and 2, we present the growth of symmetric GaN hexagonal pyramids which served as template for the InGaN QDs grown. In paper 1, it was concluded that the selective area growth (SAG) of hexagonal GaN pyramids by MOCVD through symmetric openings in a SIN mask roughly can be divided in two regimes where either the pyramid expands laterally or not. When the pyramid expanded laterally the resulting pyramid apex became (0001) truncated even after prolonged growth times. Lateral expansion also had major impact on the pyramid-to-pyramid uniformity. In paper 2, the MOCVD process parameter impact on the pyramid morphology was investigated. By tuning the growth temperature, the ammonia, and TMGa-flows a self limited pyramid structure with only {1101} facets visible was achieved. The presence of the {1101}, {1102}, and {1100} facets were discussed from surface stabilities under various growth conditions. Paper 3 and 4 concern the growth of InGaN QDs located at the apex of hexagonal GaN pyramids. In paper 3, we showed that it is possible to grow single QDs at the apex of hexagonal pyramids with emission line widths in the Ångström range. The QD emission energy was demonstrated to be tunable by the growth temperature. Basic spectroscopy data is also presented on a single QD in paper 3. In paper 4, the growth mechanisms of the QDs presented in paper 3 are presented. We concluded that (0001) truncated GaN pyramid base initiated the growth of InGaN QDs which gave rise to narrow luminescence peaks in the μPL spectra. In paper 5, the QD emission energy impact of the mask design was investigated. To our big surprise the QD emission energy increased with increasing pyramid pitch while the emission energy of the InGaN quantum wells located on the {1101} facets of the pyramids energetically shifted towards lower energies. The energy shift at the apex was found to be associated with the (0001) truncation diameter of the underlying GaN pyramid since no energy shift was observed for (0001) truncated pyramids with truncation diameters larger than 100 nm. In paper 6, the symmetry of the GaN pyramids were intentionally broken through the introduction of elongated openings in the SiN mask (symmetric openings was used in the previous five papers). The emission polarization vectors of the subsequently grown InGaN QDs were deterministically linked to the in-plane orientation of the pyramid it was nucleated upon, implying that the QDs inhibit an inplane anisotropy directly inherited from the pyramid template. Finally, paper 7 describes a hot-wall MOCVD reactor improvement by inserting insulating pyrolytic boron-nitride (PBN) stripes in the growth chamber. By doing this, we have completely eliminated the arcing problem between different susceptor parts. As a consequence, the reactor gained run-to-run reproducibility. Growth of state of the art advanced aluminum-gallium-nitride high electron mobility transistor structures on a 100 mm wafer with electron mobility above 2000 Vs/cm2 was demonstrated by the improved process

Characterization of AlGaN HEMT structures

During the last decade, AlGaN High Electron Mobility Transistors (HEMTs) have been intensively studied because their fundamental electrical properties make them attractive for highpower microwave device applications. Despite much progress, AlGaN HEMTs are far from fully understood and judged by the number of published papers the understanding of advanced structures is even poorer. This work is an exploration of the electrical and structural properties of advanced HEMT structure containing AlN exclusionlayer and double heterojunctions. These small modifications had great impact on the electrical properties. In this work, AlGaN HEMT structures grown on SiC substrates by a hot-wall MOCVD have been characterized for their properties using optical microscopy, scanning electron microscopy, transmission electron microscopy, capacitance/voltage, eddy-current resistivity, and by homebuilt epi-thickness mapping equipment. A high electron mobility of 1700 [cm2/Vs] was achieved in an AlN exclusion-layer HEMT. A similar electron mobility of 1650 [cm2/Vs] was achieved in a combination of a double heterojunction and exclusion-layer structure. The samples had approximately the same electron mobility but with a great difference: the exclusion-layer version gave a sheet carrier density of 1.58*1013 [electrons/cm2] while the combination of double heterojunction and exclusion-layer gave 1.07*1013 [electrons/cm2]. A second 2DEG was observed in most structures, but not all, but was not stable with time. The structures we grew during this work were also simulated using a one-dimensional Poisson-Schrödinger solver and the simulated electron densities were in fairly good agreement with the experimentally obtained. III-nitride materials, the CVD concept, and the onedimensional solver are shortly explained

Controlled growth of hexagonal GaN pyramids and InGaN QDs

Gallium-nitride (GaN) and its related alloys are direct band gap semiconductors, with a wide variety of applications. The white light emitting diode (LED) is of particular importance as it is expected to replace energy inefficient light bulb and hazardous incandescent lamps used today. However, today’s planar hetero epitaxial grown LEDs  structures contain an unavoidable number of dislocations, which serves as non-radiative recombination centers. The dislocations harm the luminous efficiency of the LEDs and generate additional heat. Pseudomorphically grown quantum dots (QDs) are expected to be dislocation free thus the injected carriers captured by the QDs essentially recombine radiatively since the dislocations remain outside the QD. Furthermore the continuous character of the density of states in bulk materials is redistributed when the size of the dot is reduced within the Bohr radius of the material. Fully discret energy levels are eventually reached, which offers additional control of the optical properties. The Coulomb interaction between the confined carriers also has influence on the emission energy of the recombining carriers, which opens up the possibility of manufacturing novel light sources such as the single photon emitter. Single photon emitters are essential building blocks for quantum cryptography and teleportation applications. The main contribution of the present work is the investigation of growth and characterization of sitecontrolled indium-gallium-nitride QDs embedded in GaN matrixes. The goal has been to demonstrate the ability to grow site-controlled InGaN QDs at the apex of hexagonal GaN pyramids in a controlled way using hot-wall metal organic chemical vapor deposition (MOCVD). Strong emphasis was set on the controlled growth of InGaN QDs. For example the growth of a single InGaN QD located at the apex of hexagonal GaN pyramids with tunable emission energy, the QD emission energy impact on the mask design, and a novel approach for the growth of InGaN QDs with polarization deterministic photon vectors were reported. The thesis is mainly based on experimental investigations by secondary electron microscope (SEM), micro photo-luminescence (μPL), and scanning transition electron microscopy ((S)TEM) characterization techniques. In Paper 1 and 2, we present the growth of symmetric GaN hexagonal pyramids which served as template for the InGaN QDs grown. In paper 1, it was concluded that the selective area growth (SAG) of hexagonal GaN pyramids by MOCVD through symmetric openings in a SIN mask roughly can be divided in two regimes where either the pyramid expands laterally or not. When the pyramid expanded laterally the resulting pyramid apex became (0001) truncated even after prolonged growth times. Lateral expansion also had major impact on the pyramid-to-pyramid uniformity. In paper 2, the MOCVD process parameter impact on the pyramid morphology was investigated. By tuning the growth temperature, the ammonia, and TMGa-flows a self limited pyramid structure with only {1101} facets visible was achieved. The presence of the {1101}, {1102}, and {1100} facets were discussed from surface stabilities under various growth conditions. Paper 3 and 4 concern the growth of InGaN QDs located at the apex of hexagonal GaN pyramids. In paper 3, we showed that it is possible to grow single QDs at the apex of hexagonal pyramids with emission line widths in the Ångström range. The QD emission energy was demonstrated to be tunable by the growth temperature. Basic spectroscopy data is also presented on a single QD in paper 3. In paper 4, the growth mechanisms of the QDs presented in paper 3 are presented. We concluded that (0001) truncated GaN pyramid base initiated the growth of InGaN QDs which gave rise to narrow luminescence peaks in the μPL spectra. In paper 5, the QD emission energy impact of the mask design was investigated. To our big surprise the QD emission energy increased with increasing pyramid pitch while the emission energy of the InGaN quantum wells located on the {1101} facets of the pyramids energetically shifted towards lower energies. The energy shift at the apex was found to be associated with the (0001) truncation diameter of the underlying GaN pyramid since no energy shift was observed for (0001) truncated pyramids with truncation diameters larger than 100 nm. In paper 6, the symmetry of the GaN pyramids were intentionally broken through the introduction of elongated openings in the SiN mask (symmetric openings was used in the previous five papers). The emission polarization vectors of the subsequently grown InGaN QDs were deterministically linked to the in-plane orientation of the pyramid it was nucleated upon, implying that the QDs inhibit an inplane anisotropy directly inherited from the pyramid template. Finally, paper 7 describes a hot-wall MOCVD reactor improvement by inserting insulating pyrolytic boron-nitride (PBN) stripes in the growth chamber. By doing this, we have completely eliminated the arcing problem between different susceptor parts. As a consequence, the reactor gained run-to-run reproducibility. Growth of state of the art advanced aluminum-gallium-nitride high electron mobility transistor structures on a 100 mm wafer with electron mobility above 2000 Vs/cm2 was demonstrated by the improved process

Dissertation No. 1464 Controlled growth of hexagonal

intense peak originates from an InGaN QD. The small bump located ~1 cm to the left of the intense peak is believed to be the first negatively charged exciton observed in the InGaN/GaN material system. Back page: Broad bump originating from an InGaN QW located on the {11�01} facets of the same pyramid. issn 0345-7524 Gallium-nitride (GaN) and its related alloys are direct band gap semiconductors, with a wide variety of applications. The white light emitting diode (LED) is of particular importance as it is expected to replace energy inefficient light bulb and hazardous incandescent lamps used today. However, today’s planar hetero epitaxial grown LEDs structures contain an unavoidable number of dislocations, which serves as non-radiative recombination centers. The dislocations harm the luminous efficiency of the LEDs and generate additional heat. Pseudomorphically grown quantum dots (QDs) are expected to be dislocation free thus the injected carriers captured by the QDs essentially recombine radiatively since the dislocations remain outside the QD. Furthermore the continuous character of the density of states in bulk materials is redistributed when the size of the dot is reduced within the Bohr radius o

Cognitive impairment evaluation of multiple sclerosis patients with different clinical progress

Ievads: Tēmu par kognitīvajiem traucējumiem multiplās sklerozes pacientiem es izvēlējos tāpēc, ka tā ir ļoti aktuāla problēma, jo kognitīvie traucējumi var būtiski ietekmēt darbspējas, sociālo aktivitāti un aprūpes nepieciešamību. Darba mērķis: Izvērtēt kognitīvos traucējumus multiplās sklerozes pacientiem ar dažādu klīnisko norisi; Metodes un materiāli: Pētījumā analizēju 120 dažāda vecuma pacientus, no kuriem 60 multiplās sklerozes pacienti ar dažādu klīnisko norisi, kuri ārstējas Latvijas Jūras medicīnas centra Latvijas Multiplās sklerozes centrā un 60 pacienti kontroles grupa, kam nav diagnosticēta multiplā skleroze. Šim nolūkam izmantoju standartizētus testus – SDMT, BVMT-R un CvLT II, kas ļāva izvērtēt kognitīvos traucējumus. Pētījumā analizēju arī pacientu EDSS un to saistību ar kognitīvajiem traucējumiem. Rezultāti: Multiplās sklerozes pacientiem kognitīvie traucējumi ir sastopami 46 – 78 % gadījumu. Vidējais kopējais iegūto punktu skaits CvLT II multiplās sklerozes pacientiem ir 42,98 (SD± 14,66), bet vidējais kopējais iegūto punktu skaits CvLT II kontroles grupā ir 58,20 (SD± 11,43)(p=0,01). Vidējais kopējais punktu skaits BVMT – R multiplās sklerozes pacientiem ir 19,00 (SD± 8,49), bet vidējais kopējais punktu skaits BVMT – R kontroles grupā ir 26,85 (SD± 6,65)(p=0,01). Vidējais kopējais punktu skaits SDMT multiplās sklerozes pacientiem ir 36,38 (SD± 15,10), bet vidējais kopējais punktu skaits SDMT kontroles grupā ir 47,53 (SD± 9,36). Šī sakarība ir statistiski ticama (p=0,01). Vērtējot kopumā visus BICAMS testos vidējo kopējo iegūto punktu skaitu, multiplās sklerozes pacientiem tas ir 32,78 (SD± 12,38) bet, vidējais kopējais iegūto punktu skaits kontroles grupā ir 44,19 (SD± 15,93)(p=0,01). Pētījumā izdevās pierādīt pacientu EDSS saistību ar kognitīviem traucējumiem (p=0,01), kā arī pacientu slimības formu saistību ar kognitīviem traucējumiem (p=0,05). Secinājumi: Pētījumā secināts, ka ar konkrētajiem testiem var ātri diagnosticēt kognitīvos traucējumus. Atkarībā no testa veida multiplās sklerozes pacientiem kognitīvie traucējumi ir sastopami 46 – 78 % gadījumu. Pacientiem ar augstāku EDSS, sliktāk veicas ar dažādu kognitīvo testu izpildi. Pētījumā iegūtie rezultāti, norāda, ka pacientiem ar primāri progresējošu un sekundāri progresējošu slimības formu ir izteiktāki kognitīvie traucējumi nekā multiplās sklerozes pacientiem ar recidivējoši remitējošu slimības formu.Introduction: I chose the subject of cognitive impairment evaluation of multiple sclerosis patients with different clinical progress, because it is very common problem. Cognitive impairment may have a significant impact on patients health, social activity and care needs. Aim: assessing cognitive disorders of multiple sclerosis patients with different clinical progress; Methods and materials: 120 patients of various ages were included in this study, from which 60 are multiple sclerosis patients with different clinical progress, were treated in Latvian Maritime Medical Centre, in the Multiple sclerosis centre of the Latvia and 60 patients in control group who do not have approved diagnosis of multiple sclerosis. For this purpose I used standardised tests – SDMT, BVMT–R and CvLT II, which make it possible to assess the cognitive impairment. In this study I also analysed the EDSS and its relationship to cognitive disorders. Results: 46 – 78% multiple sclerosis patients have cognitive impairment. The average total number of points obtained CvLT II in multiple sclerosis patients is 42,98 (SD 14,66), but the total number of points obtained CvLT II control group is 58,20 (SD 11,43)(p = 0,01). The average total score BVMT – R multiple sclerosis patients is 19,00 (SD 8,49) and the total number of points BVMT – R in the control group was 26,85 (SD 6,65)(p = 0,01). The average total score SDMT multiple sclerosis patients is 36,38 (SD 15,10) and the total number of points in the control group SDMT is 47,53 (SD 9,36). This relationship is statistically significant (p = 0,01). In general, all BICAMS tests assessing the total number of points acquired in multiple sclerosis patients is 32,78 (SD 12,38) and the total number of points obtained in the control group was 44,19 (SD 15,93) (p = 0,01). The study show relationship between EDSS and patients cognitive disabilities (p = 0,01) and also relationship between the form of the disease and cognitive disabilities (p = 0,05). Conclusion: the study concluded that with these tests we can quickly diagnose the cognitive impairment. 46 – 78% multiple sclerosis patients have cognitive impairment. Patients with higher EDSS have worse results in various cognitive tests. The results of the study indicate that patients with primary and secondary progressive form of the disease is more common cognitive impairment than multiple sclerosis patients with the relapsing-remitting form of the disease

Improved hot-wall MOCVD growth of highly uniform AlGaN/GaN/HEMT structures

The inherent advantages of the hot-wall metal organic chemical vapor deposition (MOCVD) reactor (low temperature gradients, less bowing of the wafer during growth, efficient precursor cracking) compared to a cold-wall reactor make it easier to obtain uniform growth. However, arcing may occur in the growth chamber during growth, which deteriorates the properties of the grown material. By inserting insulating pyrolytic BN (PBN) stripes in the growth chamber we have completely eliminated this problem. Using this novel approach we have grown highly uniform, advanced high electron mobility transistor (HEMT) structures on 4 semi-insulating (SI) SiC substrates with gas-foil rotation of the substrate. The nonuniformities of sheet resistance and epilayer thickness are typically less than 3% over the wafer. The room temperature hall mobility of the 2DEG is well above 2000 cm(2)/V s and the sheet resistance about 270 Omega/sqr.Original Publication: Urban Forsberg, Anders Lundskog, A Kakanakova-Georgieva, Rafal Ciechonski and Erik Janzén, Improved hot-wall MOCVD growth of highly uniform AlGaN/GaN/HEMT structures, 2009, JOURNAL OF CRYSTAL GROWTH, (311), 10, 3007-3010. http://dx.doi.org/10.1016/j.jcrysgro.2009.01.045 Copyright: Elsevier Science B.V., Amsterdam. http://www.elsevier.com