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The third and final phase of the Sudbury Neutrino Observatory (SNO) experiment utilized a series of 3He proportional counters called Neutral Current Detectors (NCDs) to detect the neutrons produced by the neutral current interactions of solar neutrinos in the detector. The number of neutrons detected by the NCDs, and hence the total flux of 8B solar neutrinos, has been determined using two novel signal extraction techniques which were designed to be robust against potential unexpected behaviour in the NCD background. These techniques yield total 8B solar neutrino flux measurements of 5.04(+0.42-0.40(stat))(+/-0.28(syst))x10E6/cm2/s and (4.40 - 6.43)x10E6/cm2/s, which are in good agreement with previous SNO results and with solar model predictions, and which confirm that previous NCD analyses were not unduly affected by unexpected background behaviour. The majority of the hardware from the now-completed SNO experiment will be reused to create a new liquid scintillator based neutrino experiment called SNO+. An important part of the SNO+ physics program will be a search for neutrinoless double beta decay, carried out by dissolving 150Nd into the scintillator. The sensitivity of the SNO+ experiment to neutrinoless double beta decay has been evaluated. If loaded at 0.1% (w/w) with natural neodymium, after 1 kTa of data taking SNO+ would have a 90%C.L. sensitivity equivalent to a neutrinoless double beta decay half life of 8.0x10E24a or better 50% of the time; if the experiment were run with neodymium enriched to 50% in 150Nd this limit improves to 57x10E24a. Under a reasonable choice for the 150Nd neutrinoless double beta decay matrix element, these half lives correspond to upper limits on the effective Majorana neutrino mass of 112 meV and 42 meV, respectively. These limits are competitive with those expected from all other near-term neutrinoless double beta decay experiments. / Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2009-09-10 21:07:00.25

The SNO+ experiment will be the SNO detector filled with a neodymium-loaded liquid scintillator instead of heavy water. SNO+ will be used to detect neutrinos of much lower energy. Also, SNO+ will conduct a search for neutrinoless double beta decay with Nd-150. The Nd-loaded scintillator in SNO+ will be made from linear alkylbenzene (LAB). Both the LAB solvent and the Nd loading are new developments. The optical properties of this scintillator and information about radioactive backgrounds should be studied. A calibration source known as the scintillator bucket was deployed in the water-filled SNO detector in order to study some optical properties of Nd-loaded scintillator, raw LAB scintillator and distilled LAB scintillator. Using a neutron source attached to the bucket to produce events with known energy, with a model of the scintillator bucket simulated by an analysis tool called RAT, the light yield of the scintillator could be determined by comparing data measurements with simulations. This allowed the light yield, one of the main optical properties of the scintillator, to be measured and that value to be corrected in the Monte Carlo. The bucket was deployed both at the centre of the detector and at the bottom. After subtracting backgrounds from radon introduced in the scintillator during preparation and filling, constraints on the amount of Po-210 were obtained. Estimates on the K-40 content of the Nd-loaded scintillator were obtained by analyzing the radon-subtracted background spectra. By comparing the background spectra with the bucket deployed at the bottom of the acrylic vessel with spectra from the bucket at the centre, it was possible to estimate the K-40 content of the acrylic vessel. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2010-09-22 11:55:44.351

In this paper we have introduced a concept of analyzing the performance of dynamic network organization (NO) in response to multiple input objectives of network organization (NO) and input set of unpredictable external environment, and we have correlated plasticity of NO with this performance measure. A three stage conceptual model of the process has been described which comprised of dynamic system of multi-agent network, multiple objectives and input goals of network driver (S n), unpredictable external environment (ϵ). Dynamic system of the network organization takes through its two phase and processes this based on time and system response variables. Processing of input information by the system variables gives a ratio of system response variable and input. Further analysis is based on the value of this performance values. This model suggests a performance measuring technique which takes an input set of objectives from network driver of the NO, a set of input from external environment (ϵ) state and processes this input based on the existing state of the dynamic system in the NO. This process output shows dynamic system performance in dynamic environment and how this performance coefficient correlates with the Plasticity of network organization. We have presented several examples, mathematical models and graph by analyzing true scenarios on UAV patrolling zone.

A conspicuous feature of plants responding to pathogen invasion is the synthesis of nitric oxide (NO), a redox signal. NO regulates protein function by S-nitrosylation, the addition of an NO moiety to a cysteine thiol to form an S-nitrosothiol. A key theme of NO function is reprogramming plant immune-related gene expression. However, it is still not clear how the NO signal is translated into transcriptional changes. Here we explored the potential role of a sub-group of SNO Regulated Genes (SRGs) uncovered by global expression profiling. Firstly, transgenic plants containing the SRG1 or SRG3 promoter fused to glucuronidase gene GUS together with qRT-PCR assays confirmed that transcripts of SRGs could be induced by NO and pathogen challenge, suggesting that SRGs may be involved in NO signalling related to plant immunity. More importantly, transient and stable overexpression of SRG genes induced hypersensitive response (HR)-like cell death development, which is often associated with pathogen effector-triggered immunity. Furthermore, transgenic plants constitutively expressing SRG genes exhibited enhanced ROS accumulation, PR1 transcript accumulation, and increased resistance to Pseudomonas syringae (Pst) DC3000 compared with Col-0 wild type plants. In contrast, lines with T-DNA insertions into SRG genes exhibited susceptibility to Pst DC3000. These data suggested SRGs act as the positive regulators in plant immunity. In order to further explore how NO regulates these SRGs in plant immunity, we focused on SRG1 and found SRG1 could be S-nitrosylated in vitro and in vivo. Moreover, electrophoretic mobility shift assays showed SRG1 could bind to an AGT motif and the transcriptional activity was blunted in the presence of NO, suggesting that the DNA binding activity of SRG1 is redox-modulated. Further, a transient repression activity assay showed that SRG1 has repression activity and this activity was impaired in the gsnor1-3 mutant, which has a high S-nitrosothiols level. These data suggested NO could block SRG1 transcriptional activity in vitro and in vivo. Furthermore when the SRG1 overexpression line was crossed with gsnor1-3 the SRG1-mediated resistance related phenotypes were suppressed. These data demonstrated NO negatively regulates SRG1 transcriptional activity during plant immunity. SRG1 may therefore be an important regulator of NO signalling and subsequent regulate transcription during plant immunity. Additionally, NO may negatively feedback to inhibit transcriptional activity of SRG1 to control its repression activity, to enable the activation of plant immunity.

Sn (II) oxide finds numerous applications in different fields such as thin film transistors1, solar cells2 and sensors.3 In this study we present the fabrication of tin monoxide SnO by using Sn (II) ketoacid oximate complexes as precursors. Tin (II) ketoacidoximates of the type [HON=CRCOO]2Sn where R= Me 1, R= CH2Ph 2, and [(MeON=CMeCOO)3Sn]- NH4 +.2H2O 3 were synthesized by in situ formation of the ketoacid oximate ligand. The crystal structures were determined via single crystal X- ray diffraction of the complexes 1-3 revealed square planar and square pyramidal coordination environments for the Sn atom. Intramolecular hydrogen bonding is observed in all the complexes. Furthermore, the complexes were characterized by Infrared (IR), Nuclear Magnetic Resonance (NMR) and elemental analysis. From thermogravimetric analysis of 1-3, it was found that the complexes decomposed in the range of 160 – 165 oC. Analysis of the gases evolved during decomposition indicated complete loss of the oximato ligand in one step and the formation of SnO. Spin coating of 1 on silicon or glass substrate show uniform coating of SnO. Band gaps of SnO films were measured and found to be in the range of 3.0 – 3.3 eV by UV-Vis spectroscopy. X-ray photoelectron spectroscopy indicated surface oxidation of the SnO film. Heating 1 above 140 oC in air gives SnO of size ranging from 10 – 500 nm and is spherical in shape. The SnO nanomaterial is characterized by powder X-ray diffraction(XRD), Raman spectroscopy, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM).

<p> Part One deals with thin films of SnO₂ which were prepared by ion-beam sputtering, reactive sputtering and anodic oxidation. The films were found to be either amorphous or crystalline in their prepared state. </p> <p> The structure of the as-deposited amorphous films, as revealed by transmission electron microscopy, presented interesting features: there was a continuous structure in the case of high-temperature deposition, whereas an "island structure" was revealed in the case of low-temperature deposition. Furthermore, heat treatment of films having an "island structure" showed this structure to be maintained provided the heating was done with unsupported films, while the structure became continuous when heat treatment was performed on supported specimens. </p> <p> The crystalline form of the films has been worked out, and found to generally be cassiterite; nevertheless a phase different from cassiterite has been occasionally noticed during this work. In some cases it could be tentatively identified as SnO, while other cases it remains unidentified. Crystallization temperatures found here are somewhat different from those indicated in the literature, namely: 500, 300, 225ºC according to substrate temperature and nature and type of heat treatment. Anodic oxidation of tin has been performed(apparently for the first time) in a non-solvent electrolyte, the films being consistently crystalline. </p> <p> The results obtained in the case of films deposited on water-cooled substrates, have revealed a dependence of film structure on film thickness and this effect has been confirmed in supplementary experiments. Thus thick films appear to crystallize spontaneously at room temperature. </p> <p> Part Two deals with radiation damage studies. Our experiments on krypton-ion bombarded SnO₂ films show that amorphous specimens remain amorphous following ion bombardment. The electron-microscope evidence of whether crystalline SnO₂ is amorphized by ion bombardment was tentatively negative, while the gas-release evidence was strongly negative. </p> Part Three deals with diffusion in inert-gas implanted SnO₂. In the first section we give the theoretical background that enabled us to deduce from our experiments rough estimates of the melting temperature, self-diffusion temperature. and activation-energy for self-diffusion of the less mobile ion in SnO₂. In particular, we obtain the following results: </p> <p> T_melting = 2600 - 3000ºK </p> <p> T_self-diffusion = 1480 - 1870ºK for a 2 min. time scale and 134±44Å distance scale. </p> <p> ∆H_self-diffusion = 87,200 - 131,00 cal/mole </p> <p> Note that the melting point for tine oxide is variously reported in different handbooks to lie between 1400 and 2200ºK. From a comparison with other work we have concluded that our value for ∆H is very likely that for oxygen-ion diffusion. </p> / Thesis / Master of Science (MSc)

The starting SNO+ experiment, successor to the Sudbury Neutrino Observatory, is a neutrino detector using LAB based liquid scintillator as active medium. Situated in the SNOLab deep underground laboratory in Sudbury, Canada, the rock overburden amounts to about 6 km.w.e., providing an effective shielding against cosmic rays. The residual muon rate is 63 μ/day going through the detector volume. About 780 t of an LAB mixture inside an acrylic sphere with a 6 m radius will be observed by ≈ 9300 photomultipliers, surrounded by a ≈ 7000 t water shielding. SNO+ will be searching for low energy solar-, geo-, reactor- and supernova neutrinos, but the main goal is the observation of the neutrinoless double beta decay in Te-130. Under operating conditions, the scintillator will be cooled to about 12° C. This work investigated the effect of temperature changes on the light output of LAB based liquid scintillator in a range from -5° C to 30° C with α-particles and electrons in a small scale setup. Assuming a linear behaviour, a combined negative temperature coefficient of (−0.29 ± 0.01) %/° C is found. Considering hints for a particle type dependency, electrons show (−0.17 ± 0.02) %/° C whereas the temperature dependency seems stronger for α-particles (−0.35 ± 0.03) %/° C. A pulse shape analysis shows increased strength of a slow decay component at lower temperatures, pointing to reduced non-radiative triplet state de-excitations at lower temperatures. Furthermore, this work found upper bounds for the in-situ muon-induced isotope production via scaling calculations and simulations with Geant4 based software. For the most concerning isotope C-11, an upper limit of about 1.3 × 10^3 decays/kt/yr is found and a reduction technique, developed by the Borexino collaboration, can be effectively applied for SNO+. Also a muon reconstruction algorithm is implemented, performing reasonably well, but not good enough to improve the background reduction scheme. / Das zukünftige SNO+ experiment, Nachfolger des Sudbury Neutrino Observatory, ist ein Neutrino-Detektor mit LAB basierten Flüssigszintillator als aktivem Medium. Im SNOLab Untertagelabor (Sudbury, Kanada) gelegen, ist es durch die Felsüberdeckung von 6 km.w.e. hervorragend gegen kosmische Strahlung abgeschirmt. Die Rate der übrigen Myonen die das Detektorvolumen durchdringen beträgt ca. 63 μ/Tag. In einer Acrylkugel, mit einem Radius von 6 m, wird eine LAB Mischung von ≈ 9300 Photomultipliern beobachtet und von einer Wasserabschirmung von ≈ 7 kt umgeben. SNO+ wird nach niederenergetischen solaren-, Geo-, Reaktor- und Supernova Neutrinos suchen, aber das Hauptziel ist die Beobachtung von neutrinolosen doppelten Betazerfällen in Te-130. Unter den Betriebsbedingungen wird der Flüssigszintillator eine Temperatur von ca. 12° C annehmen. Diese Arbeit hat den Einfluss von Temperaturveränderungen in einem Bereich von -5° C to 30° C auf die erzeugte Lichtmenge untersucht. Dazu wurden α-Teilchen und Elektronen in einem kleineren Versuchaufbau beobachtet. Unter der Annahme eines linearen Verhaltens, wurde ein globaler negativer Temperaturkoeffizient von (−0.29 ± 0.01) %/° C gefunden. Unter Berücksichtigung von Hinweisen auf eine Teilchenartabhängigkeit, findet sich für Elektronen ein Koeffizient von (−0.17 ± 0.02) %/° C, wohingegen α-Teilchen eine stärkere Abhängikeit von (−0.35 ± 0.03) %/° C aufweisen. Eine Pulsformanalyse zeigt eine bei tieferen Temperaturen stärker ausgeprägte langsame Zerfallskomponente, was darauf hinweist dass die nicht-radiativen Abregungen der Triplet-Zustände bei niedrigeren Temperaturen reduziert sind. Weiterhin wurden in dieser Arbeit obere Ausschlußgrenzen für in-situ Myon-induzierte Isotopenproduktion gefunden, wozu Skalierungsrechnungen und Simulation mit auf Geant4 basierender Software benutzt wurden. Für das wichtigste Isotop C-11 wurde eine obere Grenze von 1.3 × 10^3 Ereignisse/kt/Jahr gefunden und eine Technik zur Reduzierung des Untergrundes, entwickelt von der Borexino Kollaboration, kann effektiv für SNO+ angewendet werden. Darüber hinaus wurde eine Myon Spurrekonstruktion implementiert, die sinnvolle Ergebnisse liefert, aber nicht gut genug ist um die Untergrund Reduzierung zu unterstützen.

The SNO+ experiment is a multipurpose liquid scintillator detector whose rst goal is to measure neutrinoless double beta decay. This thesis describes two important components: simulations to optimize the time window for the prompt peak of an optical calibration source, the \laserball" and the search for gloves to handle calibration sources while maintaining stringent background conditions. Non-direct light found in laserball runs creates challenges for optical calibration. By changing the time pro le from the standard 4ns to an asymmetric pro le of +2 4 ns this contribution of non-direct light can be reduced up to 45%. Gloves provide an access point to manipulate calibration sources during deployment inside the detector and as barrier to 222Rn, a known background to the experiment. However, typical glove materials are found to permeate large amounts radon. Through a careful selection process the material Silver Shield was chosen for use in SNO+ with a permeation rate of 1:1 10 6 radon atoms/hour.