Purity and entanglement of two-photon polarization states generated by spontaneous parametric down-conversion

We elucidate the dependence of purity and entanglement of two-photon states generated by spontaneous parametric down-conversion on the parameters of the source, such as crystal length, pump beam divergence, frequency bandwidth, and detectors angular aperture. The effect of crystal anisotropy is taken into account. Numerical simulations are presented for two types of commonly used source configurations. (C) 2009 Elsevier B.V. All rights reserved.

Detection of microwaves using the organic semiconductor poly(p-phenylenevinylene)

We report a new procedure to convert the polymer precursor poly(xylylidene tetrahydrothiophenium chloride) (PTHT) into poly(p-phenylenevinylene) (PPV) using microwave irradiation. Spin-coated PTHT films were irradiated at room temperature under ambient conditions in a commercial microwave oven, with varying power from 20W to 100W. Complete conversion was reached within only 5 min of irradiation for powers above 50W, yielding PPV films with absorption and photoluminescence spectra that are practically indistinguishable from the spectra of thermally converted PPV films, which require ca. 2 h of a high temperature (similar to 200 degrees C) thermal treatment. In addition to a much faster conversion procedure, the irradiation with microwaves led to a red shift in the absorption spectrum of a PTHT film, which varied linearly with the time of irradiation. These films can then be used as low-cost, easy-to-use detectors of microwaves. (C) 2010 Elsevier B.V. All rights reserved.

Trigger and aperture of the surface detector array of the Pierre Auger Observatory

The surface detector array of the Pierre Auger Observatory consists of 1600 water-Cherenkov detectors, for the study of extensive air showers (EAS) generated by ultra-high-energy cosmic rays. We describe the trigger hierarchy, from the identification of candidate showers at the level of a single detector, amongst a large background (mainly random single cosmic ray muons), up to the selection of real events and the rejection of random coincidences. Such trigger makes the surface detector array fully efficient for the detection of EAS with energy above 3 x 10(18) eV, for all zenith angles between 0 degrees and 60 degrees, independently of the position of the impact point and of the mass of the primary particle. In these range of energies and angles, the exposure of the surface array can be determined purely on the basis of the geometrical acceptance. (C) 2009 Elsevier B.V. All rights reserved.

Restoring the azimuthal symmetry of lateral distributions of charged particles in the range of the KASCADE-Grande experiment

The reconstruction of Extensive Air Showers (EAS) observed by particle detectors at the ground is based on the characteristics of observables like the lateral particle density and the arrival times. The lateral densities, inferred for different EAS components from detector data, are usually parameterised by applying various lateral distribution functions (LDFs). The LDFs are used in turn for evaluating quantities like the total number of particles or the density at particular radial distances. Typical expressions for LDFs anticipate azimuthal symmetry of the density around the shower axis. The deviations of the lateral particle density from this assumption arising from various reasons are smoothed out in the case of compact arrays like KASCADE, but not in the case of arrays like Grande, which only sample a smaller part of the azimuthal variation. KASCADE-Grande, an extension of the former KASCADE experiment, is a multi-component Extensive Air Shower (EAS) experiment located at the Karlsruhe Institute of Technology (Campus North), Germany. The lateral distributions of charged particles are deduced from the basic information provided by the Grande scintillators - the energy deposits - first in the observation plane, then in the intrinsic shower plane. In all steps azimuthal dependences should be taken into account. As the energy deposit in the scintillators is dependent on the angles of incidence of the particles, azimuthal dependences are already involved in the first step: the conversion from the energy deposits to the charged particle density. This is done by using the Lateral Energy Correction Function (LECF) that evaluates the mean energy deposited by a charged particle taking into account the contribution of other particles (e.g. photons) to the energy deposit. By using a very fast procedure for the evaluation of the energy deposited by various particles we prepared realistic LECFs depending on the angle of incidence of the shower and on the radial and azimuthal coordinates of the location of the detector. Mapping the lateral density from the observation plane onto the intrinsic shower plane does not remove the azimuthal dependences arising from geometric and attenuation effects, in particular for inclined showers. Realistic procedures for applying correction factors are developed. Specific examples of the bias due to neglecting the azimuthal asymmetries in the conversion from the energy deposit in the Grande detectors to the lateral density of charged particles in the intrinsic shower plane are given. (C) 2011 Elsevier B.V. All rights reserved.

Investigation of the properties of galactic cosmic rays with the KASCADE-Grande experiment

The properties of galactic cosmic rays are investigated with the KASCADE-Grande experiment in the energy range between 10(14) and 10(18) eV. Recent results are discussed. They concern mainly the all-particle energy spectrum and the elemental composition of cosmic rays. (C) 2010 Elsevier B.V. All rights reserved.

The Pierre Auger Observatory scaler mode for the study of solar activity modulation of galactic cosmic rays

Since data-taking began in January 2004, the Pierre Auger Observatory has been recording the count rates of low energy secondary cosmic ray particles for the self-calibration of the ground detectors of its surface detector array. After correcting for atmospheric effects, modulations of galactic cosmic rays due to solar activity and transient events are observed. Temporal variations related with the activity of the heliosphere can be determined with high accuracy due to the high total count rates. In this study, the available data are presented together with an analysis focused on the observation of Forbush decreases, where a strong correlation with neutron monitor data is found.

The fluorescence detector of the Pierre Auger Observatory

The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array. The fluorescence detector comprises 24 large telescopes specialized for measuring the nitrogen fluorescence caused by charged particles of cosmic ray air showers. In this paper we describe the components of the fluorescence detector including its optical system, the design of the camera, the electronics, and the systems for relative and absolute calibration. We also discuss the operation and the monitoring of the detector. Finally, we evaluate the detector performance and precision of shower reconstructions. (C) 2010 Elsevier B.V All rights reserved.

Water-soluble Cu, Fe, Mn and Zn species in nuts and seeds

An approach was developed to estimate molecular weight distribution of water-soluble Cu, Fe, Mn and Zn species in Brazil nut, cupuassu seed and coconut pulp by size exclusion chromatography (SEC) coupled on-line to ultra-violet (UV) and off-line to graphite furnace atomic absorption spectrometry (GF-AAS) detectors and matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF-MS). SEC-UV analytical signals showed the prevalence of high molecular weight (HMW) species (79-1.7 kDa for Brazil nut, 50-1.7 kDa for coconut pulp, and 34-1.7 kDa for cupuassu seeds). The Brazil nut SEC-UV, GF-AAS and MALDI-TOF mass spectra gave confirmation of the association of the elements with water-soluble compounds. The elemental profiles were associated with fractions of compounds of molecular weight 1.2-16 kDa for Brazil nut, 1.7-13 kDa for coconut pulp, and 1.2-7.6 kDa for cupuassu seeds. (C) 2009 Elsevier Inc. All rights reserved.

Investigating the formation and the properties of monoalkyl carbonates in aqueous medium using capillary electrophoresis with capacitively coupled contactless conductivity detection

Although alkyl carbonic acids (ACAs) and their salts are referred to as instable species in aqueous medium, we demonstrate that a monoalkyl carbonate (MAC) can in fact be easily formed from bicarbonate and an alcohol even in the presence of a high amount of water. A CE system with two capacitively coupled contactless conductivity detectors (C(4)Ds) was used to obtain different parameters about these species and their reactions. Based on the mobilities obtained for a series of alcohols ranging from 1 to 5 carbons, the coefficients of diffusion and the hydrodynamic radii were calculated. When compared with the equivalent carboxylates, MACs have radii systematically smaller. Although the precise pK(a) values of the ACAs could not be obtained, because of the fast decomposition in acid medium, it was possible, for the first time, to show that they are below 4.0. This result suggests that the acidity of an ACA is quite similar to the first hydrogen of H(2)CO(3). Using a new approach to indirectly calibrate the C(4)D, the kinetic constants and the equilibrium constants of formation were also obtained. The results suggest that the increase in the chain length makes the MACs less stable and more inert.

Optical and structural properties of PbI(2) thin films

Lead iodide thin films were fabricated using the spray pyrolysis technique. Milli-Q water and N.N-dimethylformamide were used as solvents under varying deposition conditions. Films as thick as 60 mu m were obtained. The optical and structural properties of the samples were investigated using Photoluminescence, Raman scattering, X-ray diffraction, and Scanning electron microscopy. In addition, the study included also the electronic properties which were investigated by measuring the dark conductivity as a function of temperature. The deposition technique seems to be promising for the development of thick films to be used in medical imaging.

A photographic journey through Vietnam

This degree project consists of “A photographic journey through Vietnam”. One month was spent in Vietnam where the different aspects of the Vietnamese life were documented in images. The journey began in Hanoi and descended down the country to Ho Chi Minh City.The report describes the compositional elements of photography and makes an attempt to describe what a “good” image is. Furthermore it explains what equipment that is necessary for such a journey and how you can interact with the local population.When the journey came to an end, a photographic book consisting of 200 images was created. The report details the used workflow step by step. Finally the author has commented 20 of the selected images regarding their photographic composition.

Outdoor performance of forest seedlings pre-cultivated under artificial lights : effects of the light spectra used for pre-cultivation on the future establishment and development

Forest nurseries are essential for producing good quality seedlings, thus being a key element in the reforestation process. With increasing climate change awareness, nursery managers are looking for new tools that can help reduce the effects of their operations on the environment. The ZEPHYR project, funded by the European Commission under the Seventh Framework Programme (FP7), has the objective of finding new alternatives for nurseries by developing innovative zero-impact technologies for forest plant production. Due to their direct relationship to the energy consumption of the nurseries, one of the main elements addressed are the grow lights used for the pre-cultivation. New LED luminaires with a light spectrum tailored to the seedlings’ needs are being studied and compared against the traditional fluorescent lamps. Seedlings of Picea abies and Pinus sylvestris were grown under five different light spectra (one fluorescent and 4 LED) during 5 weeks with a photoperiod of 16 hours at 100 μmol∙m-2∙s-1 and 60% humidity. In order to evaluate if these seedlings were able cope with real field stress conditions, a forest field trial was also designed. The terrain chosen was a typical planting site in mid-Sweden after clear-cutting. Two vegetation periods after the outplanting, the seedlings that were pre-cultivated under the LED lamps have performed at least as well as those that were grown under fluorescent lights. These results show that there is a good  potential for lightning substitution in forestry nurseries.

Literary Love Making in Nicholas Sparks Novels: Finding the Balance Between the Writer's Life and Writer's Work in Bestselling Romantic Love

For almost a decade now Nicholas Sparks has been writing love stories. Not only has he been publishing his stories, but they have received high acclaim in each of their installments. Several of his novels have been made into major motion pictures and increased his popularity quite significantly. His status as a successful romantic fiction writer is undeniable, but the question is, why? What is it about Nicholas Sparks that makes his novels so engaging, and personally, what do I need to do as an aspiring novelist to try and acquire the same literary status? Sparks’s novels reach readers at a number of different levels, thus giving them appeal no matter the intellectual intent of the reader. Theoretically, Sparks engages reader response techniques as well as formalist processes such as “habitualization” and “defamiliarization,” while also developing engaging plot lines that represent many of the experiences from his own life. His writing is not only academically redeemable, but it is also creatively stimulating; between the two, Sparks represents the thunder and lightning combination all writers strive for while trying to achieve literary success. This project also offers a creative element in which I attempt to exemplify many of the traits discussed in the analytical sections of this document, by recreating them in a creative, fictitious fashion. Themes such as: motion versus stasis, life versus death, and the ordinary versus the extraordinary all exist within the narrative structure of my short story “Trip to Fall.” Besides these thematic elements, the creative section strives to represent the balance Sparks achieves between the experiences of his own life and the fictitious world he creates. Overall, this project delves into the life of Nicholas Sparks to better understand the inspiration for his writing at the level of form as well as content, while also paying tribute to Sparks’s style through a representation of his work in my own words.

Literary love making in Nicholas Sparks novels: Finding the balance between the writer’s life and the writer’s work in bestselling Romantic Literature

For almost a decade now Nicholas Sparks has been writing love stories. Not only has he been publishing his stories, but they have received high acclaim in each of their installments. Several of his novels have been made into major motion pictures and increased his popularity quite significantly. His status as a successful romantic fiction writer is undeniable, but the question is, why? What is it about Nicholas Sparks that makes his novels so engaging, and personally, what do I need to do as an aspiring novelist to try and acquire the same literary status? Sparks’s novels reach readers at a number of different levels, thus giving them appeal no matter the intellectual intent of the reader. Theoretically, Sparks engages reader response techniques as well as formalist processes such as “habitualization” and “defamiliarization,” while also developing engaging plot lines that represent many of the experiences from his own life. His writing is not only academically redeemable, but it is also creatively stimulating; between the two, Sparks represents the thunder and lightning combination all writers strive for while trying to achieve literary success. This project also offers a creative element in which I attempt to exemplify many of the traits discussed in the analytical sections of this document, by recreating them in a creative, fictitious fashion. Themes such as: motion versus stasis, life versus death, and the ordinary versus the extraordinary all exist within the narrative structure of my short story “Trip to Fall.” Besides these thematic elements, the creative section strives to represent the balance Sparks achieves between the experiences of his own life and the fictitious world he creates. Overall, this project delves into the life of Nicholas Sparks to better understand the inspiration for his writing at the level of form as well as content, while also paying tribute to Sparks’s style through a representation of his work in my own words.

Protecting Your Search Privacy: A Lesson Plan

Each year search engines like Google, Bing and Yahoo, complete trillions of search queries online. Students are especially dependent on these search tools because of their popularity, convenience and accessibility. However, what students are unaware of, by choice or naiveté is the amount of personal information that is collected during each search session, how that data is used and who is interested in their online behavior profile. Privacy policies are frequently updated in favor of the search companies but are lengthy and often are perused briefly or ignored entirely with little thought about how personal web habits are being exploited for analytics and marketing. As an Information Literacy instructor, and a member of the Electronic Frontier Foundation, I believe in the importance of educating college students and web users in general that they have a right to privacy online. Class discussions on the topic of web privacy have yielded an interesting perspective on internet search usage. Students are unaware of how their online behavior is recorded and have consistently expressed their hesitancy to use tools that disguise or delete their IP address because of the stigma that it may imply they have something to hide or are engaging in illegal activity. Additionally, students fear they will have to surrender the convenience of uber connectivity in their applications to maintain their privacy. The purpose of this lightning presentation is to provide educators with a lesson plan highlighting and simplifying the privacy terms for the three major search engines, Google, Bing and Yahoo. This presentation focuses on what data these search engines collect about users, how that data is used and alternative search solutions, like DuckDuckGo, for increased privacy. Students will directly benefit from this lesson because informed internet users can protect their data, feel safer online and become more effective web searchers.