Time Reversed Electromagnetic Wave Propagation as a Novel Method of Wireless Power Transfer

We investigate the application of time-reversed electromagnetic wave propagation to transmit energy in a wireless power transmission system. “Time reversal” is a signal focusing method that exploits the time reversal invariance of the lossless wave equation to direct signals onto a single point inside a complex scattering environment. In this work, we explore the properties of time reversed microwave pulses in a low-loss ray-chaotic chamber. We measure the spatial profile of the collapsing wavefront around the target antenna, and demonstrate that time reversal can be used to transfer energy to a receiver in motion. We demonstrate how nonlinear elements can be controlled to selectively focus on one target out of a group. Finally, we discuss the design of a rectenna for use in a time reversal system. We explore the implication of these results, and how they may be applied in future technologies.

Do you what I say? people reconstruct the syntax of anomalous utterances

We frequently experience and successfully process anomalous utterances. Here we examine whether people do this by ‘correcting’ syntactic anomalies to yield well-formed representations. In two structural priming experiments, participants’ syntactic choices in picture description were influenced as strongly by previously comprehended anomalous (missing-verb) prime sentences as by well-formed prime sentences. Our results suggest that comprehenders can reconstruct the constituent structure of anomalous utterances – even when such utterances lack a major structural component such as the verb. These results also imply that structural alignment in dialogue is unaffected if one interlocutor produces anomalous utterances.

Endovascular treatment of multiple anomalous splenic artery aneurysms in a Jehovah witness

Purpose. The present report describes a full endovascular treatment of a multiple anomalous (Splenic artery aneurysms) SAA with combination of coils embolization and proximal occlusion of the splenic artery with the Amplatzer vascular plug. Case report. A 53-year-old Jehovah witness woman presented with multiple aneurysms arising from an anomalous splenic artery. An endovascular treatment was performed by implantation of multiple coils and an Amplatzer Vascular Plug. A CT scan 2 months after the procedure showed complete thrombosis of the aneurysms. Discussion. Aneurysms involving an anomalous or aberrant splenic artery are rarely reported in the literature. Their surgical treatment involves potential difficulties as a consequence of anatomical position and vascular anomalies. A fully endovascular technique can be much more attractive compared to any surgical management, providing an effective and minimally invasive option. Splenic artery - Aberrant splenic artery - Aneurysm - Endovascular treatment - Jehovah witness.

3D Ionospheric Effects on HF Propagation and Heating

The thesis uses a three-dimensional, first-principles model of the ionosphere in combination with High Frequency (HF) raytracing model to address key topics related to the physics of HF propagation and artificial ionospheric heating. In particular: 1. Explores the effect of the ubiquitous electron density gradients caused by Medium Scale Traveling Ionospheric Disturbances (MSTIDs) on high-angle of incidence HF radio wave propagation. Previous studies neglected the all-important presence of horizontal gradients in both the cross- and down-range directions, which refract the HF waves, significantly changing their path through the ionosphere. The physics-based ionosphere model SAMI3/ESF is used to generate a self-consistently evolving MSTID that allows for the examination of the spatio-temporal progression of the HF radio waves in the ionosphere. 2. Tests the potential and determines engineering requirements for ground- based high power HF heaters to trigger and control the evolution of Equatorial Spread F (ESF). Interference from ESF on radio wave propagation through the ionosphere remains a critical issue on HF systems reliability. Artificial HF heating has been shown to create plasma density cavities in the ionosphere similar to those that may trigger ESF bubbles. The work explores whether HF heating may trigger or control ESF bubbles. 3. Uses the combined ionosphere and HF raytracing models to create the first self-consistent HF Heating model. This model is utilized to simulate results from an Arecibo experiment and to provide understanding of the physical mechanism behind observed phenomena. The insights gained provide engineering guidance for new artificial heaters that are being built for use in low to middle latitude regions. In accomplishing the above topics: (i) I generated a model MSTID using the SAMI3/ESF code, and used a raytrace model to examine the effects of the MSTID gradients on radio wave propagation observables; (ii) I implemented a three- dimensional HF heating model in SAMI3/ESF and used the model to determine whether HF heating could artificially generate an ESF bubble; (iii) I created the first self-consistent model for artificial HF heating using the SAMI3/ESF ionosphere model and the MoJo raytrace model and ran a series of simulations that successfully modeled the results of early artificial heating experiments at Arecibo.

On the sound waves propagation in the Persian Gulf

In this research I focused on the propagation of acoustic rays in shallow water areas then I selected the Persian Gulf and described sound transmission in this region with emphasize on physical properties of water masses and of sediments. Finally I studied on the sound speed variations and sound attention with data collected from this area (NE of Farsi Island & 50 kilometers south of Delware). Sound speed deviation in western part of Strait of Hormuz in winter is between 20-30 m/s and it is between 5-20 m/s in the Oman Sea. Minimum sound speed deviation is at 23-24 degree north & 60-62 degree east. In spring, this deviation varies from 25-35 m/s, which is greater than in winter. In winter, at east of 56 degree east, greater speed are in shallow water coastal areas. In summer, sound speeds are greater than in spring and vary from 35 to 55 m/s at western part of Strait of Hormuz and 20 to 40 m/s in Oman Sea. Finally in autumn, sound speed deviation is 30-45 m/s west of 56 degree east and in Oman Sea is the same. The greatest attenuation rate caused by absorption in Bandar Dayer is between 17 to 27 meters depth, which is from water masses with different densities.

Flame-propagation rates in ammonia-air combustion at high pressure

The reluctance of ammonia to be ignited easily and the necessity to advance the spark for optimum performance in combustion engines led to this investigation. Ionization gap techniques showed that long induction times and slow flame speed were both contributors to the observed phenomena. The most important factor in determining combustion characteristics of ammonia was found to be the extent of predissociation prior to attempted ignition. There was evidence from combustion gas analysis that NO + was the probable most abundant ion contributing to succesful application of the ionization gap techniques, and that the NO + was probably produced in the pyrolysis of ammonia rather than by equilibrium reactions. © 1967 Combustion Institute.

Anomalous transport in plasmas

The application of stochastic methods to the problem of particle and energy transport in turbulent plasmas is briefly reviewed. The "classical" Corrsin approximation is shown to be valid only in the limit of weak turbulence. The recently developed method of decorrelation trajectories is applicable over the whole range of turbulence intensities and yields the correct asymptotic behavior in the limit of very strong turbulence (subdiffusion). © 2004 Wiley Periodicals, Inc.

Bacterial and pathological study of caudal fin rot in brood stocks of Salmo trutta caspius from the propagation and breeding center of Shahid Bahonar of Kelardasht region

In order to study caudal fin rot with emphasis on Aeromonas hydrophila and Pseudomonas fluorescens in Salmo trutta caspius from the salmonids propagation and breeding center of Shahid Bahonar of kelardasht region, One hundred and eighty brood stocks having fin damage symptoms were chosen. Two bacterial samples from each fish were cultured on Aeromonas and Pseudomonas specific media. Biochemical tests, API2OE identification system and antibiogram test using six antibiotic disks were performed for diagnosing isolates bacteria and finding suitable antibiotic. Thirty samples from caudal fin of damaged fishes were fixed in 10% formalin and 51.tm microscopic sections were prepared using standard scatological methods and then stained by Haematoxylin-Eosin staining method to observe the pathological changes and also Maccallum-Goodpasture staining method to observe the bacterial colonies. In second stage of the study, bacterial samples were taken from thirty brood stocks using similar method at the first stage of sampling. For isolation and biochemical diagnosis of Aeromonas and Pseudormonas genus, the samples were analyzed by molecular research included PCR amplification (using 16S rDNA genes of the genus pseudomonas and 16S-23S rDNA intergenic spacer of the genus Aeromonas) and restriction analysis by four restriction enzymes for each genus. The results of biochemical tests showed that isolated bacteria were belonged to Aeromonas caviae and Aeromonas hydrophila (subspecies anaerogenes), Pseudomonas fluorescens, Pseudomonas putida and Pseudomonas alcaligenes while the results of API2OE identification system showed that the isolated bacteria belonged to Aeromonas hydrophila, Pseudomonas fluorescens, Pseudomonas putida and Pseudomonas aeruginosa. Restriction analysis of Aeromonas samples with Hin6l, Csp6I, Taql, and Tasl revealed three samples were different from others while restriction analysis of Pseudomonas samples with Alul, Hinfl, Rsal, and Trull showed at least five species or biovars. The results of antibiogram test showed all Aeromonas samples were sensitive to Trimethoprim, Chloramphenicol and Nitrofurazone, mostly to Nalidixic acid and Chloramphenicol, while most of samples were resistant to Erythromycin and Oxytetracycline. Pseudomonas samples were only sensitive to Nitrofurazone and mostly resistant to Oxytetracycline, Nalidixic acid, Erythromycin, Trimethoprim and Chloramphenicol. The results of light microscope study showed hyperplasia and spongiosis of the malpigian cells of epidermis, increasing of melanin pigments underlying epidermis; sever necrosis in both epidermis and dermis and also sloughing the epidermis in some cases. Occurrence of clefts through the epithelium, neovascularization, hyperemia and mild inflammatory response in dermis and separation of the fin rays also were observed. No bacterial colonies were found in the sections.

Seed and vegetative propagation methods for the rare Florida native species Chionanthus pygmaeus (pygmy fringetree)

Chionanthus pygmaeus Small (pygmy fringetree) (Oleaceae) is an endemic and rare Florida species, which has an attractive, small habit giving it great potential for use in managed landscapes. Members of the genus Chionanthus are difficult to propagate via cuttings and possess complex seed dormancies that are not well understood. Conservation of pygmy fringetree and its potential for commercial propagation for use in managed landscapes is contingent on a better understanding of its complex seed dormancy and enhancement of its propagation. I conducted two experiments to assess sexual and asexual propagation methods for pygmy fringetree. The first experiment was conducted to determine what factors are involved in overcoming seed dormancy. Various scarification treatments, which mimicked conditions seeds are exposed to in the wild, were investigated to determine their effects on germination of 20-year-old seeds originally collected from the species’ native range. Treatments included endocarp removal, sulfuric acid, boiling-water, and smoke-water treatments. Prior to treatment initiation, seed viability was estimated to be 12%. Treated seeds went through two cold- and two warm-stratification periods of 4°C and 25°C, respectively, in a dark growth chamber. After 180 days, none of the treatments induced early germination. Seeds were then tested for viability, which was 11%. Seed dormancy of the species is apparently complex, allowing some of the seeds to retain some degree of viability, but without dormancy requirements satisfied. The second experiment was conducted to assess if pygmy fringetree could be successfully propagated via hardwood or root cuttings if the appropriate combination of environmental conditions and hormones were applied. Hardwood and root cuttings were treated with either 1000 ppm IBA talc, 8000 ppm IBA talc, or inert talc. All cuttings were placed on a mist bench in a greenhouse for 9 weeks. Hardwood cuttings were supplemented with bottom heat at 24 °C. No treatments were successful in inducing adventitious root formation. I conclude that pygmy fringetree seeds possess complex dormancy that was not able to be overcome by the treatments utilized. However, this result is confounded by the age of the seeds used in the experiment. I also conclude that vegetative propagation of pygmy fringetree is highly dependent on the time of year cuttings are harvested. Further research of both seed and asexual propagation methods need to be explored before pygmy fringetree can be propagated on a commercial scale.

The Influence of Propagation Model and Sectorization over WCDMA Capacity

In this paper we use a dynamic model that we have developed for WCDMA capacity analysis using MATLAB and a GIS based planning tool, to estimate the capacity of a mobile system under different conditions like number of cells, propagation model, sectorization and handover margin.

Laser beam control, combining, and propagation in atmospheric turbulence

This dissertation is concerned with the control, combining, and propagation of laser beams through a turbulent atmosphere. In the first part we consider adaptive optics: the process of controlling the beam based on information of the current state of the turbulence. If the target is cooperative and provides a coherent return beam, the phase measured near the beam transmitter and adaptive optics can, in principle, correct these fluctuations. However, for many applications, the target is uncooperative. In this case, we show that an incoherent return from the target can be used instead. Using the principle of reciprocity, we derive a novel relation between the field at the target and the scattered field at a detector. We then demonstrate through simulation that an adaptive optics system can utilize this relation to focus a beam through atmospheric turbulence onto a rough surface. In the second part we consider beam combining. To achieve the power levels needed for directed energy applications it is necessary to combine a large number of lasers into a single beam. The large linewidths inherent in high-power fiber and slab lasers cause random phase and intensity fluctuations occurring on sub-nanosecond time scales. We demonstrate that this presents a challenging problem when attempting to phase-lock high-power lasers. Furthermore, we show that even if instruments are developed that can precisely control the phase of high-power lasers; coherent combining is problematic for DE applications. The dephasing effects of atmospheric turbulence typically encountered in DE applications will degrade the coherent properties of the beam before it reaches the target. Finally, we investigate the propagation of Bessel and Airy beams through atmospheric turbulence. It has been proposed that these quasi-non-diffracting beams could be resistant to the effects of atmospheric turbulence. However, we find that atmospheric turbulence disrupts the quasi-non-diffracting nature of Bessel and Airy beams when the transverse coherence length nears the initial aperture diameter or diagonal respectively. The turbulence induced transverse phase distortion limits the effectiveness of Bessel and Airy beams for applications requiring propagation over long distances in the turbulent atmosphere.

Propagation des ondes longitudinales dans le noyau terrestre d'après les séismes profonde des Iles Fidji

Observations from three deep focus earthquakes, of focal depth 600 km, originating in the Fiji Islands region, have permitted to trace the travel-time curves for the longitudinal waves travelling through the earth's core. Of principal importance is the travel-time table for the phase PKP1 which has been given upto 158° and for which the data so far were incomplete. Other important phases observed between 103 and 143° have been illustrated and their travel-time curves drawn.

Propagation des ondes longitudinales dans le noyau terrestre: résumé et conclusion

Six earthquakes (magnitude 6 to 7) in the Fiji Islands, New Hebrides and Sulawesi, divided in two groups of depth h=100 to 200 km and h= 600 km, were studied through more than a thousand of seismographic observations in 16 months.

Sistematic, population genetics, propagation and conservation of Prunus azorica (Rosaceae)

Tese de Doutoramento, Biologia (Ecologia Vegetal), 25 de Junho de 2013, Universidade dos Açores.

Sistematics, population genetics, propagation and conservation of Picconia azorica (Tutin) Knobl. (Oleaceae)

Tese de Doutoramento, Biologia (Ecologia Vegetal), 24 de Junho de 2013, Universidade dos Açores.