The circumstellar environment and evolutionary status of the supergiant B[e] star Wd1-9

Context. Historically, supergiant (sg)B[e] stars have been difficult to include in theoretical schemes for the evolution of massive OB stars. Aims. The location of Wd1-9 within the coeval starburst cluster Westerlund 1 means that it may be placed into a proper evolutionary context and we therefore aim to utilise a comprehensive multiwavelength dataset to determine its physical properties and consequently its relation to other sgB[e] stars and the global population of massive evolved stars within Wd1. Methods. Multi-epoch R- and I-band VLT/UVES and VLT/FORS2 spectra are used to constrain the properties of the circumstellar gas, while an ISO-SWS spectrum covering 2.45−45μm is used to investigate the distribution, geometry and composition of the dust via a semi-analytic irradiated disk model. Radio emission enables a long term mass-loss history to be determined, while X-ray observations reveal the physical nature of high energy processes within the system. Results. Wd1-9 exhibits the rich optical emission line spectrum that is characteristic of sgB[e] stars. Likewise its mid-IR spectrum resembles those of the LMC sgB[e] stars R66 and 126, revealing the presence of equatorially concentrated silicate dust, with a mass of ~10−4M⊙. Extreme historical and ongoing mass loss (≳ 10−4M⊙yr−1) is inferred from the radio observations. The X-ray properties of Wd1-9 imply the presence of high temperature plasma within the system and are directly comparable to a number of confirmed short-period colliding wind binaries within Wd1. Conclusions. The most complete explanation for the observational properties of Wd1-9 is that it is a massive interacting binary currently undergoing, or recently exited from, rapid Roche-lobe overflow, supporting the hypothesis that binarity mediates the formation of (a subset of) sgB[e] stars. The mass loss rate of Wd1-9 is consistent with such an assertion, while viable progenitor and descendent systems are present within Wd1 and comparable sgB[e] binaries have been identified in the Galaxy. Moreover, the rarity of sgB[e] stars - only two examples are identified from a census of ~ 68 young massive Galactic clusters and associations containing ~ 600 post-Main Sequence stars - is explicable given the rapidity (~ 104yr) expected for this phase of massive binary evolution.

Production of Λ -hyperons in inelastic p+p interactions at 158 GeV/c

Inclusive production of Λ-hyperons was measured with the large acceptance NA61/SHINE spectrometer at the CERN SPS in inelastic p+p interactions at beam momentum of 158 GeV/c. Spectra of transverse momentum and transverse mass as well as distributions of rapidity and xF are presented. The mean multiplicity was estimated to be 0.120 ± 0.006 (stat.) ± 0.010 (sys.). The results are compared with previous measurements and predictions of the EPOS, UrQMD and FRITIOF models.

Rapid manufacturing of aluminum components

A manufacturing technique for the production of aluminum components is described. A resin-bonded part is formed by a rapid prototyping technique and then debound and infiltrated by a second aluminum alloy under a nitrogen atmosphere. During thermal processing, the aluminum reacts with the nitrogen and is partially transformed into a rigid aluminum nitride skeleton, which provides the structural rigidity during infiltration. The simplicity and rapidity of this process in comparison to conventional production routes, combined with the ability to fabricate complicated parts of almost any geometry and with high dimensional precision, provide an additional means to manufacture aluminum components.

Chemical reactions at nuclear fuel-clad interfaces

This thesis presents a study of the chemical reactions that may occur at the fuel- clad interfaces of fuel elements used in advanced gas-coooled reactors (A.G.R.) The initial investigation involved a study of the inner surfaces of irradiated stainless steel clad and evidence was obtained to show that fission products, in particular tellerium, were associated with reaction products on these surfaces. An accelerated rate of oxidation was observed on the inner surfaces of a failed A.G.R. fuel pin. It is believed that fission product caesium was responsible for this enhancement. A fundamental study of the reaction between 20%Cr/25%Ni/niobium stabilised stainless steel and tellerium was then undertaken over the range 350 - 850 degrees C. Reaction occurred with increasing rapidity over this range and long term exposure at ≤ 750 degrees resulted in intergranular attack of the stainless steel and chromium depletion. The reaction on unoxidised steel surfaces involved the formation of an initial iron-nickel-tellerium layer which subsequently transformed to a chromium telluride product during continued exposure. The thermodynamic stabilities of the steel tellurides were determined to be chromium telluride > nickel telluride > iron telluride. Oxidation of the stainless steel surface prior to tellerium exposure inhibited the reaction. However reaction did occur in regions where the oxide layer had either cracked or spalled.

A beruházási projektek aggregált tőkeigénye = The Aggregate Capital Needs of Investment Projects

A tanulmány abból indul ki, hogy a beruházási projektek értékelése során egyidejűleg szükséges figyelembe venni a projektben lekötött tőkét és a lekötési időt mint jövedelemtermelési lehetőséget. Definiálja a projekt aggregált tőkeigényének fogalmát és megszerkeszti a vonatkozó mérőszámot. Az aggregált tőkeigény új vállalatgazdasági kategória, mely a beruházási projektek értékelésének egy új megközelítését teszi lehetővé. A projekt aggregált tőkeigénye azt a tőkeösszeget jelenti, mely a projekt működtetéséhez annak teljes élettartama alatt szükséges. A három meghatározó tényező: a kezdőtőke, a megtérülési idő (illetőleg az élettartam) és a megtérülés gyorsasága. A számszerűsítéshez minden évre vonatkozóan meg kell határozni az adott évben lekötött tőkét, ami az adott évig még meg nem térült tőkerészt jelenti, majd ezek összegzése révén adódik az aggregált tőkeigény. A mértékegység egységnyi tőke egyévi lekötése. A tanulmány az összefüggések modellszerű levezetése mellett gazdag példaanyagot is tartalmaz. Az elemzés bővíti a nettó jelenérték tartalmára vonatkozó ismereteket, rávilágít az aggregált tőkeigény ismeretének fontosságára mind a nettó jelenérték, mind a belső kamatláb esetében. _____ The starting point of this paper is that in the evaluation process of investment projects necessary to take into account simultaneously the tied-up capital and tiedup time as the income-generating potential. For this, it defines a special content of aggregate capital needs of investment projects, and elaborates an index. The aggregate capital needs is a new business economics category, which provides a new aspect to evaluate investment projects. This means the amount of capital needed for the operation of the project during its full duration. Three factors determine the aggregate capital needs for investments projects. These are the amount of initial investment, the payback period (or the duration) and the rapidity of capital payback. The solution is to sum up the yearly tied-up capital, that is, the notreturned parts of the capital for each year. The measurement unit is one unit tied-up capital for one year. The paper formulates the main relationships as models and by way of explanation presents some examples. The analysis highlights the importance of considering the aggregate capital needs furthermore widens knowledge regarding the net present value and internal rate of return.

Angular distribution of Z(0 power) bosons in Z+jet events at the square root of S = 7 TeV

For the first time, the Z0 boson angular distribution in the center-of-momentum frame is measured in proton-proton collisions at [special characters omitted] = 7 TeV at the CERN LHC. The data sample, recorded with the CMS detector, corresponds to an integrated luminosity of approximately 36 pb–1 . Events in which there is a Z0 and at least one jet, with a jet transverse momentum threshold of 20 GeV and absolute jet rapidity less than 2.4, are selected for the analysis. Only the Z0's muon decay channel is studied. Within experimental and theoretical uncertainties, the measured angular distribution is in agreement with next-to-leading order perturbative QCD predictions.

Fish population dynamics in a seasonally varying wetland

Small fishes in seasonally flooded environments such as the Everglades are capable of spreading into newly flooded areas and building up substantial biomass. Passive drift cannot account for the rapidity of observed population expansions. To test the ‘reaction–diffusion’ mechanism for spread of the fish, we estimated their diffusion coefficient and applied a reaction–diffusion model. This mechanism was also too weak to account for the spatial dynamics. Two other hypotheses were tested through modeling. The first—the ‘refuge mechanism’—hypothesizes that small remnant populations of small fishes survive the dry season in small permanent bodies of water (refugia), sites where the water level is otherwise below the surface. The second mechanism, which we call the ‘dynamic ideal free distribution mechanism’ is that consumption by the fish creates a prey density gradient and that fish taxis along this gradient can lead to rapid population expansion in space. We examined the two alternatives and concluded that although refugia may play an important role in recolonization by the fish population during reflooding, only the second, taxis in the direction of the flooding front, seems capable of matching empirical observations. This study has important implications for management of wetlands, as fish biomass is an essential support of higher trophic levels.

Blotto in the Lifeboat

Blotto in the Lifeboat is a book of poems that investigates natural processes and idiosyncrasies of human societies. Ranging from the absurd to the scientific in tone, the poems in Blotto in the Lifeboat situate themselves on the blurry-line between fact and imagination, employing a style that Thomas Lux describes as “imaginative realism.” The middle of three sections is comprised solely of the long poem, “A Compendium of the True and Wondrous,” which collages remarkable facts and anecdotes to highlight the strange realities of the world and the rapidity of change. The first and third sections contain shorter, narrative poems in which the surreal or comic is often employed. The language of the poems in BLOTTO IN THE LIFEBOAT reflects a similar desire to affix the fantastic to the familiar. Metaphors in the tradition of Elizabeth Bishop and Charles Simic rely on wild leaps of imagination to illuminate the real world.

Desenvolvimento e validação de testes de fluxo lateral para a detecção de cultivares geneticamente modificados e de aflatoxinas em produtos agrícolas

The expansion of cultivated areas with genetically modified crops (GM) is a worldwide phenomenon, stimulating regulatory authorities to implement strict procedures to monitor and verify the presence of GM varieties in agricultural crops. With the constant growing of plant cultivating areas all over the world, consumption of aflatoxin-contaminated food also increased. Aflatoxins correspond to a class of highly toxic contaminants found in agricultural products that can have harmful effects on human and animal health. Therefore, the safety and quality evaluation of agricultural products are important issues for consumers. Lateral flow tests (strip tests) is a promising method for the detection both proteins expressed in GM crops and aflatoxins-contaminated food samples. The advantages of this technique include its simplicity, rapidity and cost-effective when compared to the conventional methods. In this study, two novel and sensitive strip tests assay were developed for the identification of: (i) Cry1Ac and Cry8Ka5 proteins expressed in GM cotton crops and; (ii) aflatoxins from agricultural products. The first strip test was developed using a sandwhich format, while the second one was developed using a competitive format. Gold colloidal nanoparticles were used as detector reagent when coated with monoclonal antibodies. An anti-species specific antibody was sprayed at the nitrocellulose membrane to be used as a control line. To validate the first strip test, GM (Bollgard I® e Planta 50- EMBRAPA) and non-GM cotton leaf (Cooker 312) were used. The results showed that the strip containing antibodies for the identification of Cry1Ac and Cry8Ka5 proteins was capable of correctly distinguishing between GM samples (positive result) and non-GM samples (negative result), in a high sensitivity manner. To validate the second strip test, artificially contaminated soybean with Aspergillus flavus (aflatoxin-producing fungus) was employed. Food samples, such as milk and soybean, were also evaluated for the presence of aflatoxins. The strip test was capable to distinguish between samples with and without aflatoxins samples, at a sensitivity concentration of 0,5 μg/Kg. Therefore, these results suggest that the strip tests developed in this study can be a potential tool as a rapid and cost-effective method for detection of insect resistant GM crops expressing Cry1Ac and Cry8Ka5 and aflatoxins from food samples.

Desenvolvimento e validação de testes de fluxo lateral para a detecção de cultivares geneticamente modificados e de aflatoxinas em produtos agrícolas

The expansion of cultivated areas with genetically modified crops (GM) is a worldwide phenomenon, stimulating regulatory authorities to implement strict procedures to monitor and verify the presence of GM varieties in agricultural crops. With the constant growing of plant cultivating areas all over the world, consumption of aflatoxin-contaminated food also increased. Aflatoxins correspond to a class of highly toxic contaminants found in agricultural products that can have harmful effects on human and animal health. Therefore, the safety and quality evaluation of agricultural products are important issues for consumers. Lateral flow tests (strip tests) is a promising method for the detection both proteins expressed in GM crops and aflatoxins-contaminated food samples. The advantages of this technique include its simplicity, rapidity and cost-effective when compared to the conventional methods. In this study, two novel and sensitive strip tests assay were developed for the identification of: (i) Cry1Ac and Cry8Ka5 proteins expressed in GM cotton crops and; (ii) aflatoxins from agricultural products. The first strip test was developed using a sandwhich format, while the second one was developed using a competitive format. Gold colloidal nanoparticles were used as detector reagent when coated with monoclonal antibodies. An anti-species specific antibody was sprayed at the nitrocellulose membrane to be used as a control line. To validate the first strip test, GM (Bollgard I® e Planta 50- EMBRAPA) and non-GM cotton leaf (Cooker 312) were used. The results showed that the strip containing antibodies for the identification of Cry1Ac and Cry8Ka5 proteins was capable of correctly distinguishing between GM samples (positive result) and non-GM samples (negative result), in a high sensitivity manner. To validate the second strip test, artificially contaminated soybean with Aspergillus flavus (aflatoxin-producing fungus) was employed. Food samples, such as milk and soybean, were also evaluated for the presence of aflatoxins. The strip test was capable to distinguish between samples with and without aflatoxins samples, at a sensitivity concentration of 0,5 μg/Kg. Therefore, these results suggest that the strip tests developed in this study can be a potential tool as a rapid and cost-effective method for detection of insect resistant GM crops expressing Cry1Ac and Cry8Ka5 and aflatoxins from food samples.

Uma abordagem baseada em filtragem colaborativa integrada a mapas de saliência para a recomendação de imagens

Nowadays, the amount of customers using sites for shopping is greatly increasing, mainly due to the easiness and rapidity of this way of consumption. The sites, differently from physical stores, can make anything available to customers. In this context, Recommender Systems (RS) have become indispensable to help consumers to find products that may possibly pleasant or be useful to them. These systems often use techniques of Collaborating Filtering (CF), whose main underlying idea is that products are recommended to a given user based on purchase information and evaluations of past, by a group of users similar to the user who is requesting recommendation. One of the main challenges faced by such a technique is the need of the user to provide some information about her preferences on products in order to get further recommendations from the system. When there are items that do not have ratings or that possess quite few ratings available, the recommender system performs poorly. This problem is known as new item cold-start. In this paper, we propose to investigate in what extent information on visual attention can help to produce more accurate recommendation models. We present a new CF strategy, called IKB-MS, that uses visual attention to characterize images and alleviate the new item cold-start problem. In order to validate this strategy, we created a clothing image database and we use three algorithms well known for the extraction of visual attention these images. An extensive set of experiments shows that our approach is efficient and outperforms state-of-the-art CF RS.

Rapid quantification and validation of lipid concentrations within liposomes

Quantification of the lipid content in liposomal adjuvants for subunit vaccine formulation is of extreme importance, since this concentration impacts both efficacy and stability. In this paper, we outline a high performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) method that allows for the rapid and simultaneous quantification of lipid concentrations within liposomal systems prepared by three liposomal manufacturing techniques (lipid film hydration, high shear mixing, and microfluidics). The ELSD system was used to quantify four lipids: 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), cholesterol, dimethyldioctadecylammonium (DDA) bromide, and D-(+)-trehalose 6,6′-dibehenate (TDB). The developed method offers rapidity, high sensitivity, direct linearity, and a good consistency on the responses (R2 > 0.993 for the four lipids tested). The corresponding limit of detection (LOD) and limit of quantification (LOQ) were 0.11 and 0.36 mg/mL (DMPC), 0.02 and 0.80 mg/mL (cholesterol), 0.06 and 0.20 mg/mL (DDA), and 0.05 and 0.16 mg/mL (TDB), respectively. HPLC-ELSD was shown to be a rapid and effective method for the quantification of lipids within liposome formulations without the need for lipid extraction processes.

Seawater carbonate chemistry and sperm swimming speed of the polychaete Galeolaria caespitosa in lab experiment

The rapidity of ocean acidification intensifies selection pressure for resilient phenotypes, particularly during sensitive early life stages. The scope for selection is greater in species with greater within-species variation in responses to changing environments, thus enhancing the potential for adaptation. We investigated among-male variation in sperm swimming responses (percent motility and swimming speeds) of the serpulid polychaete Galeolaria caespitosa to near- (delta pH 0.3) and far-future ocean acidification (delta pH 0.5). Responses of sperm swimming to acidification varied significantly among males and were overall negative. Robust sperm swimming behavior under near-future ocean acidification in some males may ameliorate climate change impacts, if traits associated with robustness are heritable, and thereby enhance the potential for adaptation to far-future conditions. Reduced sperm swimming in the majority of male G. caespitosa may decrease their fertilization success in a high CO2 future ocean. Resultant changes in offspring production could affect recruitment success and population fitness downstream.

Laminated sediment cores in the Bering Sea

During the last glacial termination, the upper North Pacific Ocean underwent dramatic and rapid changes in oxygenation that lead to the transient intensification of oxygen minimum zones (OMZs), recorded by the widespread occurrence of laminated sediments on circum-Pacific continental margins. We present a new laminated sediment record from the mid-depth (1100 m) northern Bering Sea margin that provides insight into these deglacial OMZ maxima with exceptional, decadal-scale detail. Combined ultrahigh-resolution micro-X-ray-fluorescence (micro-XRF) data and sediment facies analysis of laminae reveal an alternation between predominantly terrigenous and diatom-dominated opal sedimentation. The diatomaceous laminae are interpreted to represent spring/summer productivity events related to the retreating sea ice margin.We identified five laminated sections in the deglacial part of our site. Lamina counts were carried out on these sections and correlated with the Bølling-Allerød and Preboreal phases in the North Greenland Ice Core (NGRIP) oxygen isotope record, indicating an annual deposition of individual lamina couplets (varves). The observed rapid decadal intensifications of anoxia, in particular within the Bølling-Allerød, are tightly coupled to short-term warm events through increases in regional export production. This dependence of laminae formation on warmer temperatures is underlined by a correlation with published Bering Sea sea surface temperature records and d18O data of planktic foraminifera from the Gulf of Alaska. The rapidity of the observed changes strongly implies a close atmospheric teleconnection between North Pacific and North Atlantic regions.We suggest that concomitant increases in export production and subsequent remineralization of organic matter in the Bering Sea, in combination with oxygen-poor waters entering the Being Sea, drove down oxygen concentrations to values below 0.1ml/l and caused laminae preservation. Calculated benthic-planktic ventilation ages show no significant variations throughout the last deglaciation, indicating that changes in formation rates or differing sources of North Pacific mid-depth waters are not prime candidates for strengthening the OMZ at our site. The age models established by our correlation procedure allow for the determination of calendar age control points for the Bølling-Allerød and the Preboreal that are independent of the initial radiocarbon-based chronology. Resulting surface reservoir ages range within 730-990 yr during the Bølling-Allerød, 800-1100 yr in the Younger Dryas, and 765-775 yr for the Preboreal.

Os efeitos nucleares em processos de produ¸c˜ao de quarkonium no Relativistic Heavy Ion Collider (RHIC) e no Large Hadron Collider (LHC)

Neste trabalho de disserta¸c˜ao, investigamos os efeitos nucleares em processos de produ¸c˜ao de quarkonium no Relativistic Heavy Ion Collider (RHIC) e no Large Hadron Collider (LHC). Para tanto, consideramos o Modelo de Evapora¸c˜ao de Cor (CEM), baseado em processos partˆonicos calculados mediante a QCD perturbativa e em intera¸c˜oes n˜ao perturbativas via troca de gl´uons suaves para a forma¸c˜ao do quarkonium. Supress˜ao de quarkonium ´e um dos sinais de forma¸c˜ao do assim chamado Plasma de Quarks e Gl´uons (QGP) em colis˜oes ultrarelativ´ısticas de ´ıons pesados. No entanto, a supress˜ao n˜ao ´e somente causada em colis˜oes n´ucleo-n´ucleo (AA) devido `a forma¸c˜ao do QGP. De fato, a supress˜ao de quarkonium tamb´em foi observada em colis˜oes pr´oton-n´ucleo (pA). A fim de separar os efeitos da mat´eria quente (devidos ao QGP) e fria (efeitos n˜ao devidos ao QGP), pode-se olhar primeiro para colis˜oes pA, onde somente efeitos de mat´eria fria desempenham um papel fundamental, e depois aplicar esses efeitos em colis˜oes AA, uma vez que parte da supress˜ao ´e devido a efeitos de mat´eria fria. No regime de altas energias, a produ¸c˜ao do quarkonium ´e fortemente dependente da distribui¸c˜ao de gl´uons nuclear, o que viabiliza uma oportunidade ´unica de estudar o comportamento de pequeno x dos gl´uons dentro do n´ucleo e, consequentemente, restringir os efeitos nucleares. Estudamos os processos nucleares utilizando distintas parametriza¸c˜oes para as distribui¸c˜oes partˆonicas nucleares. Calculamos a raz˜ao nuclear para processos pA e AA em fun¸c˜ao da vari´avel rapidez para a produ¸c˜ao de quarkonium, o que permite estimar os efeitos nucleares. Al´em disso, apresentamos uma compara¸c˜ao com os dados do RHIC para a produ¸c˜ao do m´eson J/Ψ em colis˜oes pA, demonstrando que a an´alise deste observ´avel ´e uma quest˜ao em aberto na literatura. Adicionalmente, estimamos a produ¸c˜ao de quarks pesados e quarkonium na etapa inicial e durante a fase termal de uma colis˜ao ultrarelativ´ıstica de ´ıons pesados. O objetivo deste estudo ´e estimar as distintas contribui¸c˜oes para a produ¸c˜ao e de alguns efeitos do meio nuclear.