Ionospheric Turbulence Near the Upper Hybrid Layer: Theory and Experiment

The thesis presents experimental results, simulations, and theory on turbulence excited in magnetized plasmas near the ionosphere’s upper hybrid layer. The results include: The first experimental observations of super small striations (SSS) excited by the High-Frequency Auroral Research Project (HAARP) The first detection of high-frequency (HF) waves from the HAARP transmitter over a distance of 16x10^3 km The first simulations indicating that upper hybrid (UH) turbulence excites electron Bernstein waves associated with all nearby gyroharmonics Simulation results that indicate that the resulting bulk electron heating near the upper hybrid (UH) resonance is caused primarily by electron Bernstein waves parametrically excited near the first gyroharmonic. On the experimental side we present two sets of experiments performed at the HAARP heating facility in Alaska. In the first set of experiments, we present the first detection of super-small (cm scale) striations (SSS) at the HAARP facility. We detected density structures smaller than 30 cm for the first time through a combination of satellite and ground based measurements. In the second set of experiments, we present the results of a novel diagnostic implemented by the Ukrainian Antarctic Station (UAS) in Verdansky. The technique allowed the detection of the HAARP signal at a distance of nearly 16 Mm, and established that the HAARP signal was injected into the ionospheric waveguide by direct scattering off of dekameter-scale density structures induced by the heater. On the theoretical side, we present results of Vlasov simulations near the upper hybrid layer. These results are consistent with the bulk heating required by previous work on the theory of the formation of descending artificial ionospheric layers (DIALs), and with the new observations of DIALs at HAARP’s upgraded effective radiated power (ERP). The simulations that frequency sweeps, and demonstrate that the heating changes from a bulk heating between gyroharmonics, to a tail acceleration as the pump frequency is swept through the fourth gyroharmonic. These simulations are in good agreement with experiments. We also incorporate test particle simulations that isolate the effects of specific wave modes on heating, and we find important contributions from both electron Bernstein waves and upper hybrid waves, the former of which have not yet been detected by experiments, and have not been previously explored as a driver of heating. In presenting these results, we analyzed data from HAARP diagnostics and assisted in planning the second round of experiments. We integrated the data into a picture of experiments that demonstrated the detection of SSS, hysteresis effects in simulated electromagnetic emission (SEE) features, and the direct scattering of the HF pump into the ionospheric waveguide. We performed simulations and analyzed simulation data to build the understanding of collisionless heating near the upper hybrid layer, and we used these simulations to show that bulk electron heating at the upper hybrid layer is possible, which is required by current theories of DAIL formation. We wrote a test particle simulation to isolate the effects of electron Bernstein waves and upper hybrid layers on collisionless heating, and integrated this code to work with both the output of Vlasov simulations and the input for simulations of DAIL formation.

EXPOSURE TO EXTREME HEAT EVENTS AND CHRONIC RESPIRATORY DISEASES AMONG A NATIONALLY REPRESENTATIVE SAMPLE OF THE UNITED STATES POPULATION

Previous studies have shown that extreme weather events are on the rise in response to our changing climate. Such events are projected to become more frequent, more intense, and longer lasting. A consistent exposure metric for measuring these extreme events as well as information regarding how these events lead to ill health are needed to inform meaningful adaptation strategies that are specific to the needs of local communities. Using federal meteorological data corresponding to 17 years (1997-2013) of the National Health Interview Survey, this research: 1) developed a location-specific exposure metric that captures individuals’ “exposure” at a spatial scale that is consistent with publicly available county-level health outcome data; 2) characterized the United States’ population in counties that have experienced higher numbers of extreme heat events and thus identified population groups likely to experience future events; and 3) developed an empirical model describing the association between exposure to extreme heat events and hay fever. This research confirmed that the natural modes of forcing (e.g., El Niño-Southern Oscillation), seasonality, urban-rural classification, and division of country have an impact on the number extreme heat events recorded. Also, many of the areas affected by extreme heat events are shown to have a variety of vulnerable populations including women of childbearing age, people who are poor, and older adults. Lastly, this research showed that adults in the highest quartile of exposure to extreme heat events had a 7% increased odds of hay fever compared to those in the lowest quartile, suggesting that exposure to extreme heat events increases risk of hay fever among US adults.

LUNG CANCER IN NEPAL: THE ROLE OF TRADITIONAL TOBACCO PRODUCTS AND COMBUSTION RELATED HOUSEHOLD AIR POLLUTION

The burden of chronic diseases such as cancer is increasing in low and middle income countries around the globe. Nepal, one of the world’s poorest countries, is no exception to this trend, with lung cancer as the leading causes of cancer deaths. Despite this, limited data is available on the environmental and behavioral risk factors that contribute to the lung cancer etiology in Nepal. The objectives of this dissertation are to: 1) investigate the ethnic differences in consumption of local tobacco products and their role in lung cancer risk in Nepal; 2) evaluate urinary metabolite of 1,3-butadiene as a biomarker of exposure to combustion related household air pollution (CRHAP); 3) investigate the association between CRHAP exposure and lung cancer risk using urinary metabolite of 1,3-butadiene as a biomarker of exposure; 4) investigate the association between CRHAP exposure and lung cancer risk using questionnaire based measure of exposure. Lung cancer cases (n=606) and frequency matched controls (N=606) were recruited from B.P. Koirala Memorial Cancer Hospital. We obtained biological samples and information on lifestyles including cooking habits and type of fuels used. We used liquid chromatograph tandem mass spectrometer (LC-MS/MS) to quantify urinary metabolites of 1,3-butadiene in urine samples. We employed a combination of logistic and linear regression models to detect any exposure-disease associations while controlling for known confounding variables. Overall, we found that ethnic groups in Nepal use different tobacco products that have different differing cancer potency -we observed the highest odds ratios for the traditional tobacco products. The biomarker analysis showed strong evidence that monohydroxybutyl mercapturic acid is associated with biomass fuel use among participants. However, we did not find significant association between urinary MHMBA and lung cancer risk. When we used questionnaire based measure of exposure to household air pollution, we observed significant, dose-response associations between CRHAP exposure and lung cancer risk, particularly among never-smokers. Our results show that important role of local tobacco products in lung cancer risk in Nepal. Furthermore, we demonstrate that CRHAP exposure is a risk factor for lung cancer risk, independent of tobacco smoking.

Is There More to This Case than Mere Pulmonary Alveolar Proteinosis? A Clinical Case Presentation

Introduction: Pulmonary alveolar proteinosis (PAP) is a rare disease, associated with excess accumulation of surfactant proteins and lipids in the alveoli. Clinical presentation: We report the case of a 46-year-old woman with a combined presentation of PAP, myelodysplasia and recurrent miscarriages. Conclusions: The concomitant presentation of the above might be compatible with a mutation of the haematopoietic transcription factor gene GATA2.

High performance terahertz resonant tunnelling diode sources and broadband antenna for air-side radiation

Resonant tunnelling diode (RTD) is known to be the fastest electronics device that can be fabricated in compact form and operate at room temperature with potential oscillation frequency up to 2.5 THz. The RTD device consists of a narrow band gap quantum well layer sandwiched between two thin wide band gap barriers layers. It exhibits negative differential resistance (NDR) region in its current-voltage (I-V) characteristics which is utilised in making oscillators. Up to date, the main challenge is producing high output power at high frequencies in particular. Although oscillation frequencies of ~ 2 THz have been already reported, the output power is in the range of micro-Watts. This thesis describes the systematic work on the design, fabrication, and characterisation of RTD-based oscillators in microwave/millimetre-wave monolithic integrated circuits (MMIC) form that can produce high output power and high oscillation frequency at the same time. Different MMIC RTD oscillator topologies were designed, fabricated, and characterised in this project which include: single RTD oscillator which employs one RTD device, double RTDs oscillator which employs two RTD devices connected in parallel, and coupled RTD oscillators which combine the powers of two oscillators over a single load, based on mutual coupling and which can employ up to four RTD devices. All oscillators employed relatively large size RTD devices for high power operation. The main challenge was to realise high oscillation frequency (~ 300 GHz) in MMIC form with the employed large sized RTD devices. To achieve this aim, proper designs of passive structures that can provide small values of resonating inductances were essential. These resonating inductance structures included shorted coplanar wave guide (CPW) and shorted microstrip transmission lines of low characteristics impedances Zo. Shorted transmission line of lower Zo has lower inductance per unit length. Thus, the geometrical dimensions would be relatively large and facilitate fabrication by low cost photolithography. A series of oscillators with oscillation frequencies in the J-band (220 – 325 GHz) range and output powers from 0.2 – 1.1 mW have been achieved in this project, and all were fabricated using photolithography. Theoretical estimation showed that higher oscillation frequencies (> 1 THz) can be achieved with the proposed MMIC RTD oscillators design in this project using photolithography with expected high power operation. Besides MMIC RTD oscillators, reported planar antennas for RTD-based oscillators were critically reviewed and the main challenges in designing high performance integrated antennas on large dielectric constant substrates are discussed in this thesis. A novel antenna was designed, simulated, fabricated, and characterised in this project. It was a bow-tie antenna with a tuning stub that has very wide bandwidth across the J-band. The antenna was diced and mounted on a reflector ground plane to alleviate the effect of the large dielectric constant substrate (InP) and radiates upwards to the air-side direction. The antenna was also investigated for integration with the all types of oscillators realised in this project. One port and two port antennas were designed, simulated, fabricated, and characterised and showed the suitability of integration with the single/double oscillator layout and the coupled oscillator layout, respectively.

Viability of probiotic bacteria and some chemical and sensory characteristics in cornelian cherry juice during cold storage

Background: Increased popularity of vegetarianism, lactose intolerance, and the high cholesterol content in dairy products, are all factors that have recently increased the demand for nondairy probiotic products. The objective of this study is to evaluate the effect of refrigeration on the viability of probiotics and asses someof the chemical and sensory characteristics in cornelian cherry juice. Results: The Iranian native probiotic strain (L. casei T4) showed greater viability compared to industrial types (viable count of 8.67 log cfu/mL versus <6.0 log cfu/mL at d 28). However, this most tolerant Iranian strain, could not withstand the conditions of ‘Natural juice’ at pH 2.6 for more than 7 d. Following a pH adjusted treatment (to pH ~3.5), the viability of the strain was improved to 28 d with some evidence of increased growth of the probiotic. However, the level of antioxidant activity, anthocyanin and phenolic compounds, revealed a slight decrease during cold storage. The changes in the chemical profile of the sample containing L. casei T4 indicated fermentation activity during cold storage. Sensory evaluation results showed significant differences between samples containing L. casei TD4 and other samples in taste, odor and overall acceptance in a complimentary way. Conclusions: The results showed that low pH and presence of inhibitor phenolic compounds of cornelian cherry juice have negative effect on viability of probiotics, especially industrial strains during refrigerated storage.

Preparation of Ni-P electroless and its corrosion resistance against sea water

Electroless coating is much appropriate process at engineering surface. Since the discovery of electroless nickel-phosphorus coating in 3996, due to technical and economic advantages as well as desirable characteristics such as resistance to corrosion, abrasion and a high hardness has found wide application at engineering industries. Properties of electroless nickel-phosphorus coating depend on the characteristics of the used bath and heat treatment. In this study, optimal conditions and concentration of sodium citrate, sodium acetate and lactic acid in the bath of electroless nickel-phosphorus coating to the steel ck67 surface was determined. Structure, chemical composition and phases occurring in the coating were investigated using Scanning Electron Microscope (SEM) and X-ray diffraction analysis (XRD). The corrosion behavior of coatings in solution 3.5٪ NaCl was studied using electrochemical. The results showed that corrosion resistance of the coating with composition sodium citrate, sodium acetate and lactic acid decreased respectively.

Design and construction of a two dimensional duct equipped with a wave generator and a variable coastal slope and an ocean wave energy conversion system (OWC)

The aims of this thesis were evaluation the type of wave channel, wave current, and effect of some parameters on them and identification and comparison between types of wave maker in laboratory situations. In this study, designing and making of two dimension channels (flume) and wave maker for experiment son the marine buoy, marine building and energy conversion systems were also investigated. In current research, the physical relation between pump and pumpage and the designing of current making in flume were evaluated. The related calculation for steel building, channels beside glasses and also equations of wave maker plate movement, power of motor and absorb wave(co astal slope) were calculated. In continue of this study, the servo motor was designed and applied for moving of wave maker’s plate. One Ball Screw Leaner was used for having better movement mechanisms of equipment and convert of the around movement to linear movement. The Programmable Logic Controller (PLC) was also used for control of wave maker system. The studies were explained type of ocean energies and energy conversion systems. In another part of this research, the systems of energy resistance in special way of Oscillating Water Column (OWC) were explained and one sample model was designed and applied in hydrolic channel at the Sheikh Bahaii building in Azad University, Science and Research Branch. The dimensions of designed flume was considered at 16 1.98 0. 57 m which had ability to provide regular waves as well as irregular waves with little changing on the control system. The ability of making waves was evaluated in our designed channel and the results were showed that all of the calculation in designed flume was correct. The mean of error between our results and theory calculation was conducted 7%, which was showed the well result in this situation. With evaluating of designed OWC model and considering of changes in the some part of system, one bigger sample of this model can be used for designing the energy conversion system model. The obtained results showed that the best form for chamber in exit position of system, were zero degree (0) in angle for moving below part, forty and five (45) degree in front wall of system and the moving forward of front wall keep in two times of height of wave.

Economic development and Environmental quality: The environmental Kuznets curve for water pollution

The main aim of this study was to analyze evidence of an environmental Kuznets curve for water pollution in the developing and developed countries. The study was conducted based on a panel data set of 54 countries – that were categorized into six groups of “developed countries”, “developing countries”, “developed countries with low income”, “developed countries with high income” and “coastal countries”- between the years 1995 to 2006. The results do not confirm the inverted U-shape of EKC curve for the developed countries with low income. Based on the estimated turning points and the average GDP per capita, the study revealed at which point of the EKC the countries are. Furthermore, impacts of capital-and-labor ratio as well as trade openness are drawn by estimating different models for the EKC. The magnitude role of each explanatory variable on BOD was calculated by estimating the associated elasticity.

Antimicrobial and bond strength properties of a dental adhesive containing zinc oxide nanoparticles

Aim: To assess the effect of adding zinc oxide nanoparticles to dental adhesives on their anti-microbial and bond strength properties. Methods: 45 human premolars were cut at the cement enamel junction (CEJ) and the crowns were sliced into buccal and lingual halves. The specimens were classified into three groups, etched with 37% phosphoric acid for 15 s and rinsed for 30 s. Single Bond, Single Bond+5% zinc oxide and Single Bond+10% zinc oxide were used in the first, second and third groups. A cylinder of Z250 composite was bonded and cured for 40 s. For anti-bacterial testing, 10 samples of each group were assessed by direct contact test; 10 μL of bacterial suspension was transferred into tubes containing adhesives and incubated for one hour; 300 μL of brain heart infusion (BHI) broth was added to each tube and after 12 h, 50 μL of bacteria and broth were spread on blood agar plates and incubated for 24 h. Results: The colony count decreased significantly in the second and third groups compared to the first. Conclusions: Incorporation of zinc oxide nanoparticles into dental adhesives increases their anti-microbial properties without affecting their bond strength.

Psychological Aspects in Children and Adolescents With Major Thalassemia: A Case-Control Study

Background: Thalassemia is an inherited blood disease. It is a serious public health problem throughout the Mediterranean region, the Middle East and the Indian subcontinent, as well as in Southeast Asia. Objectives: Thalassemia is an inherited blood disease. It is a serious public health problem. In this study we assessed psychological aspects in Iranian children and adolescents with thalassemia major. Patients and Methods: In this case-control study sixty healthy subjects aged 7-18 years and Sixty Patients with confirmed diagnosis of major thalassemia were enrolled. After obtaining informed consent from parents of all participating thalassemia patients and healthycontrols, we assessed psychological aspects and quality of life by Pediatric Quality of LifeTM (PedsQL™), Strengths and Difficulties Questionnaires (SDQ), State and Trait Anxiety, Children's Depression Inventory (CDI). Results: The results of this study indicate that there are significant changes in depression, anxiety, QOL and behavioral screening between children with thalassemia major compared with healthy subjects by means of both parents and children reports. According to the results, children with thalassemia major have more psychological problems than healthy ones. Patients with thalassemia have a lower QOL than their peers (P = 0.001), the rate of depression is higher in this group (P = 0.015), Also behavioral problems in these children are more than healthy subjects (P = 0.009). Conclusions: We recommend appropriate treatment and counseling procedures in addition to specific treatment of thalassemia. According to the results we suggest to establish pediatric psychiatric clinics beside thalassemic clinics to cure psychological aspects of the disease.

Penile Skin Involvement as the First Presentation of Henoch-Schonlein Purpura Report of Nine Cases and Review of Literature

Introduction: Involvement of penis is a rare presentation in henoch-schonlein purpura (HSP). The presentations are mainly due to the deposition of immunoglobulin A (IgA) into the vessel walls. In this report, we present the clinical history of nine HSP cases that presented with penile skin involvement. Case Presentation: All patients were referred in the acute phase of HSP. Penile skin involvement was evident as erythema, edema, ecchymosis, or induration of prepuce and/or penile shaft, that appeared simultaneously with skin rash in seven patients. Gastrointestinal involvement was positive in six patients. Patients were treated with steroids and follow up visits were normal except for one patient that developed crescentic glomerulonephritis. Conclusions: We present nine cases of HSP with penile involvement in order to indicate another rare aspect of HSP and its possible complications as well as its appropriate treatment.

Multi-drug resistant Staphylococcus aureus isolated from emergency ward of an Iranian hospital

Purpose: To study the prevalence of resistant strains of Staphylococcus aureus isolated from surfaces, beds and various equipment of an Iranian hospital emergency ward. Methods: Two hundred swab samples were collected from the surfaces, beds, trolleys, surgical equipment and diagnostic medical devices in emergency ward. Samples were cultured and those that were S. aureus-positive were confirmed using polymerase chain reaction (PCR). Antimicrobial resistance pattern was analyzed using disk diffusion method. Results: Nine of 200 samples (4.5 %) collected were positive for S. aureus. Surfaces (8.8 %), beds (5 %) and trolleys (5 %) were the most commonly contaminated. S. aureus isolates exhibited varying levels of resistance against antibiotics with the following being the highest: tetracycline (88.8 %), penicillin (88.8 %) and ampicillin (77.7 %). The prevalence of resistance against methicillin, oxacillin and azithromycin were 44.4, 33.3 and 33.3 %, respectively. There was no pattern of resistance against imipenem. Conclusion: Efficient disinfection of surfaces, beds, trolleys and surgical instruments should be performed periodically to reduce colonization of resistant strains of S. aureus in various areas of emergency health care centers.