Aerosol scattering of ultraviolet sunlight in the tropical maritime atmosphere

The effects of atmospheric aerosol scattering on the vertical profile of solar ultraviolet radiation are investigated. Measurements of diffuse and total ultraviolet radiation were made using a rocketborne optical sonde in the marine atmosphere of Antigua. During observations, the sun was at zenith. Vertical profiles of directly transmitted solar radiation were calculated by subtraction of the diffuse component from the total radiance. Using these values of direct downward solar UV-flux, the optical thickness of the atmosphere was derived as a function of altitude. Absorption by ozone was also considered. In the troposphere the values of observed optical thickness were in general equal to or lower than those expected theoretically from Rayleigh scattering alone. The measured radiation profiles were compared with those computed for a multiple scattering model atmosphere. Some computations regarding the interaction of UV-sunlight with maritime aerosols are presented

A flexible method to create wave file features

Digital audio signal is one of the most important data type at present, it is used in various vital applications, such as human knowledge, security and banking applications, most applications require signal identification and recognition, and to increase the efficiency of these applications we must seek a method to represent the audio file by a small set of values called a features vector. In this paper research we will introduce an enhanced method of features extraction based on k-mean clustering. The method will be tested and implemented to show how the proposed method can reduce the efforts of voice identification, and can minimize the recognition time a set of voice extracted features must be used instead of using the voice wave file

Extraction conditions of polyphenol oxidase from banana peel

Polyphenol oxidase (PPO) is an enzyme containing copper, presents in various fruits and vegetables. It is responsible for the browning reactions when the cells are damaged during handling. The best conditions for extraction of polyphenol oxidase from banana peel was by using an extraction buffer containing phosphate buffer (0.05 M, pH 7), 0.01 M ascorbic acid and 0.5% polyethylene glycol, with extraction ratio 1:4 (w:v) for one minute by using blender. The enzyme activity was measured spectrophotometrically at 425 nm. PPO was studied to prevent the browning of banana peel which results in the loss of their marketability. The aim of this study was to determine the optimum conditions for polyphenol oxidase extraction from banana peel

Study the effect of increasing Gamma ray doses on some physical properties of Carboxy methyl cellulose

In this study some of the physical properties of Carboxymethyle cellulose dissolves in distilled water with different concentration had been studies before and after irradiation by gamma ray of variable dose (5000rad, 7000rad, 9000rad).These properties are firstly the Rheological properties such as shear viscosity, relative viscosity specific viscosity and reduced viscosity are measured, secondly the mechanical properties such as ultrasonic velocity had been measured at frequency (40KHz). Other mechanical properties had been calculated such as absorption coefficient of ultrasonic waves, relaxation time, relaxation amplitude, specific acoustic impedance, bulk modules and compressibility. The results show that all these properties are affected with variation in density and viscosity because of the intermolecular interactions Gamma radiation made degradation to polymer molecular chains that affect the physical properties as a result ultrasonic absorption increased and molecular weight decreased after irradiation. Keywords: CMC solution, ultrasound technique, degradation, rheological properties, mechanical properties

Post Surgical Spinal Evaluation

One of the most challenging areas of diagnosis is to be found in acquiring and interpreting medical images in the patient who has undergone lumbosacral surgery for spinal degenerative disease. The section illustrates the features of expected and abnormal postsurgical spinal imaging. These discussions provide the background, practical information, and graphic examples necessary to enable the medical imaging physician to better approach the clinicoradiologic evaluation of the postsurgical patient.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145202/1/cpmia0808.pd

Is reduction in the risk of vision loss the only benefit of photodynamic therapy in predominantly classic subfoveal choroidal neovascularization?

Nicola G Ghazi, rian P Conway, James S Tiedeman, Steven J YoonUniversity of Virginia Health System, Department of Ophthalmology, Charlottesville, VA, USAPurpose: To emphasize the effect of photodynamic therapy (PDT) on the size and progression of the neovascular lesion (NL) and evolution of the disciform scar (DS) in predominantly classic subfoveal choroidal neovascularization (SFCNV).Methods: A retrospective study of 62 eyes treated with PDT for SFCNV was performed. The greatest linear dimension (GLD) before and at last follow-up after treatment and the size of the DS post-PDT were analyzed. A subgroup of patients with DS in their fellow eye at presentation without prior PDT was also studied. The size of the scar in these eyes was compared to that following PDT.Results: After an average follow-up at 9 months, the size of the NL was stabilized or reduced in 64% of the study eyes with absence of fluorescein leakage in 45%. Only 3 eyes (5%) developed DS. At presentation, 14 patients already had DS in their fellow eye, the size of which was significantly larger than that post-PDT (p = 0.044). It was also significantly larger than that of the potential scar in the study eyes of the same subgroup of patients (p = 0.002) and of the rest of the patients (p = 0.0001).Conclusion: This study demonstrates a beneficial effect for PDT on the size of the NL and DS in SFCNV, which might be of great significance, particularly when PDT fails to prevent severe vision loss.Keywords: age-related macular degeneration, choroidal neovascularization, classic choroidal neovascularization, disciform scarring, fluorescein angiography, photodynamic therap

Dynamics & Predictions in the Co-Event Interpretation

Sorkin has introduced a new, observer independent, interpretation of quantum mechanics that can give a successful realist account of the 'quantum microworld' as well as explaining how classicality emerges at the level of observable events for a range of systems including single time 'Copenhagen measurements'. This 'co-event interpretation' presents us with a new ontology, in which a single 'co-event' is real. A new ontology necessitates a review of the dynamical & predictive mechanism of a theory, and in this paper we begin the process by exploring means of expressing the dynamical and predictive content of histories theories in terms of co-events.Comment: 35 pages. Revised after refereein