978 resultados para Straight cosmic string


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Fa uns mesos, en un viatge que vaig fer als UA, vaig tenir ocasió de visitar les restes de diversos pobles construïts pels nadius americans segles abans de l'arribada dels europeus, incloent-hi ciutats, temples, granges, estadis esportius i un gran nombre de gravats i pintures rupestres, tots ells magnífics representants d'una important i civilitzada cultura al santípodes dels cànons imposats per Hollywood. En un d'aquests llocs vaig poder llegir un advertiment que, traduït al català, deia: "Es processarà els lladres del temps". Lladres del temps. Què volien dir amb aquesta expressió? No tenia pas cap intenció d'incórrer en un delicte pel qual pogués ser processat [...].

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This project addresses methodological and technological challenges in the development of multi-modal data acquisition and analysis methods for the representation of instrumental playing technique in music performance through auditory-motor patterning models. The case study is violin playing: a multi-modal database of violin performances has been constructed by recording different musicians while playing short exercises on different violins. The exercise set and recording protocol have been designed to sample the space defined by dynamics (from piano to forte) and tone (from sul tasto to sul ponticello), for each bow stroke type being played on each of the four strings (three different pitches per string) at two different tempi. The data, containing audio, video, and motion capture streams, has been processed and segmented to facilitate upcoming analyses. From the acquired motion data, the positions of the instrument string ends and the bow hair ribbon ends are tracked and processed to obtain a number of bowing descriptors suited for a detailed description and analysis of the bow motion patterns taking place during performance. Likewise, a number of sound perceptual attributes are computed from the audio streams. Besides the methodology and the implementation of a number of data acquisition tools, this project introduces preliminary results from analyzing bowing technique on a multi-modal violin performance database that is unique in its class. A further contribution of this project is the data itself, which will be made available to the scientific community through the repovizz platform.

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Raman imaging spectroscopy is a highly useful analytical tool that provides spatial and spectral information on a sample. However, CCD detectors used in dispersive instruments present the drawback of being sensitive to cosmic rays, giving rise to spikes in Raman spectra. Spikes influence variance structures and must be removed prior to the use of multivariate techniques. A new algorithm for correction of spikes in Raman imaging was developed using an approach based on comparison of nearest neighbor pixels. The algorithm showed characteristics including simplicity, rapidity, selectivity and high quality in spike removal from hyperspectral images.

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Hydrogels have been prepared by free-radical solution copolymerization of acrylamide and sodium acrylate (NaAc), with molar ratio ranging from 25/75 to 80/20, respectively, using methylene bisacrylamide as the crosslinking agent. A FTIR spectroscopy procedure to determine the acrylate/acrylamide ratio in these hydrogels was proposed based on absorbance at 1410 cm-1 (nCOO-) and 2940 cm-1 (nCH and nCH2). A straight line with a good linear correlation coefficient (0.998) was obtained by plotting the acrylate content (Ac%) versus relative absorbance (Arel = A1410/A2940). Results were confirmed by the amount of sodium cation released in acid medium determined by atomic absorption spectrometry.

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The species Eremanthus mattogrossensis, known as "veludo do cerrado" (cerrado velvet), is native to the Brazilian Cerrado. Because the amount of metabolites present in plants may be influenced by biological and environmental factors, here we conducted an HPLC-DAD-MS/MS investigation of the metabolite concentrations found in the MeOH/H2O extract of the leaves of this species. The main compounds were identified and quantified, and the metabolites were grouped by chemical class (caffeoylquinic acids, flavonoids, and sesquiterpene lactone). Statistical analysis indicated a straight correlation between the quantity of metabolites and seasonality, suggesting that environmental properties elicit important metabolic responses.

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The aim of this paper was to use colorimetric assays for hydroxamic acid to quantify the biodiesel content in diesel and compare it with the traditional method (infrared spectroscopy, using the EN 14078 method). Samples were prepared from B2 to B10 with two kinds of diesel - S500 (red) and S50 (yellow) - to obtain two calibration curves. Through statistical methods it was shown that the slopes of the straight lines obtained for the different types of diesel were the same. Thus, the type of diesel did not influence the results of the colorimetric assay for hydroxamic acid. Real samples collected from gas stations were analyzed by both methods (colorimetry and EN 14078). By applying Student's t-test it was concluded that the methods could be considered statistically equivalent. Therefore, it was confirmed that the colorimetric assay for hydroxamic acid is suitable for detecting and quantifying the content of biodiesel in biodiesel/diesel blends and can also be easily adapted to field analyses.

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Venäjän lainsäädäntö mahdollistaa erilaisten rajoitusten asettamisen liikenteelle kelirikkoajan aikana ja alhaisten painorajoitusten asettaminen on tällöin yleistä. Kelirikon aikaisiin rajoituksiin liittyvä lainsäädäntö on pääosin tarkoituksenmukainen, mutta sitä sovelletaan tavalla, jolla vaikeutetaan huomattavasti yritysten toimintaa ja tarvittavien kuljetusten järjestämistä. Diplomityössä tutkitaan kelirikon vaikutuksia liiketoimintaan erityisesti caseyksikössä, joka on metsäteollisuusyhtiön Venäjällä sijaitseva tuotantoyksikkö. Venäläinen liiketoimintaympäristö eroaa huomattavasti suomalaisesta, ja kelirikon aikana korostuvat etenkin korruption ja henkilökohtaisten suhteiden merkitys. Suuri osa havaituista sallitun painon ylityksistä hoidetaan kelirikon aikana maksamalla epävirallisia maksuja suoraan tarkastajille. Myös virallisia kulkulupia myydään, mutta niiden hankinta on kallista ja aikaa vievää. Työn lähtökohta kiteytyy lainsäädännön, viranomaisten tulkinnan ja todellisen tilanteen välisten ristiriitojen avaamiseen ja selvittämiseen, ja tavoitteena on ollut mahdollisimman objektiivisen kokonaiskuvan luominen tilanteesta. Case-yksikössä on kehitetty vaihtoehtoisia toimintamalleja kelirikkoajan kuljetusten varmistamiseksi. Rautatiekuljetusten määrää on lisätty huomattavasti ja välivarastointiterminaalin rakentamista on suunniteltu. Vaihtoehtoiset toimintamallit aiheuttavat kuitenkin huomattavia lisäkustannuksia. Tutkimuksen tuottamien tietojen avulla case-yhtiössä voidaan jatkossa arvioida todellisia riskejä sekä vaihtoehtoisten toimintamallien tarpeellisuutta ja kustannustehokkuutta aikaisempaa tarkemmin.

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Tässä diplomityössä tarkastellaan tietomallintamista eng. BIM (Building Information Modeling) LVI-suunnittelun näkökulmasta sekä esitellään tietomallintamisen vaikutuksia ja hyötyjä suunnitteluprosessiin. Tietomallintaminen mahdollistaa esimerkiksi LVI-suunnittelijan tuottaman määräluettelon 3D-mallista, jonka seurauksena eri toimijoiden väliset rajapinnat tulevat luultavasti kokemaan muutoksia. Työssä vertaillaan käsin laskettuja ja 3D-mallista tuotettuja määräluetteloita toisiinsa. Työhön sisällytetään myös urakoitsijoiden haastatteluja, joissa pyritään selvittämään heidän näkemyksiään suunnittelijan tuottamiin määrätietoihin.

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Photosystem II (PSII) is susceptible to light-induced damage defined as photoinhibition. In natural conditions, plants are capable of repairing the photoinhibited PSII by on-going degradation and re-synthesis of the D1 reaction centre protein of PSII. Photoinhibition is induced by both visible and ultraviolet light and photoinhibition occurs under all light intensities with the same efficiency per photon. In my thesis work, I studied the reaction kinetics and mechanism of photoinhibition of PSII, as well as photoprotection in leaves of higher plants. Action spectroscopy was used to identify photoreceptors of photoinhibition. I found that the action spectrum of photoinhibition in vivo shows resemblance to the absorption spectra of manganese model compounds of the oxygen evolving complex (OEC) suggesting a role for manganese as a photoreceptor of photoinhibition under UV and visible light. In order to study the protective effect of non-photochemical quenching, the action spectrum was measured from leaves of wild type Arabidopsis thaliana and two mutants impaired in nonphotochemical quenching of chlorophyll a excitations. The findings of action spectroscopy and simulations of chlorophyll-based photoinhibition mechanisms suggested that quenching of antenna excitations protects less efficiently than would be expected if antenna chlorophylls were the only photoreceptors of photoinhibition. The reaction kinetics of prolonged photoinhibition was studied in leaves of Cucurbita maxima and Capsicum annuum. The results indicated that photoinhibitory decrease in both the oxygen evolution activity and ratio of variable to maximum fluorescence follows firstorder kinetics in vivo. The persistence of first-order kinetics suggests that already photoinhibited reaction centres do not protect against photoinhibition and that the mechanism of photoinhibition does not have a reversible intermediate. When Cucurbita maxima leaves were photoinhibited with saturating single-turnover flashes and continuous light, the light response curve of photoinhibition was found to be essentially a straight line with both types of illumination, suggesting that similar photoinhibition mechanisms might function during illumination with continuous light and during illumination with short flashes.

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The condition of Baltic Sea has weakened considerably because of eutrophication which has caused massive increase of devalued fish. The condition of Baltic Sea can be helped by fishing these fish. This study handles three different ways to approach those fish utilizations and counts carbon footprint for those three chains. Environmental point of views are also examined. There are three different fish processing chains. Every processing chain begins with fishing the fish in Baltic Sea. After that the fishes are prepared by crushing and some formic acid is added to ensure preservation. In the first processing chain the fishes are processed as biodiesel. The waste from the biodiesel process is taken to the anaerobic digestion and the forming methane is used as energy. In the second chain the fishes are taken straight to the anaerobic digestion after preparing. In the third chain, the fish will be first prepared and then taken to fur farms as forage. The carbon footprint has been calculated for 1000 kg fish. The carbon footprint in the first chain is 164-178 kg CO2e, in the second chain 313 – 333 kg CO2e and in the third chain 363 kg CO2e. In the processing chains the bioenergy is produced from the biodiesel, anaerobic digestion and from the glycerol, which is by-product of the biodiesel. The energy produced from the biodiesel is so-called emission neutral, which is not taken into account when calculating emissions. The energy is used to compensate the emissions caused by fossil fuels. The PAS 2050 was used to calculate the carbon footprint. Only carbon dioxide and methane were used when calculating the carbon footprint.

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The objective of the work is to study fluid flow behavior through a pinch valve and to estimate the flow coefficient (KV ) at different opening positions of the valve. The flow inside a compressed valve is more complex than in a straight pipe, and it is one of main topics of interest for engineers in process industry. In the present work, we have numerically simulated compressed valve flow at different opening positions. In order to simulate the flow through pinch valve, several models of the elastomeric valve tube (pinch valve tube) at different opening positions were constructed in 2D-axisymmetric and 3D geometries. The numerical simulations were performed with the CFD packages; ANSYS FLUENT and ANSYS CFX by using parallel computing. The distributions of static pressure, velocity and turbulent kinetic energy have been studied at different opening positions of the valve in both 2D-axisymmetric and 3D experiments. The flow coefficient (KV ) values have been measured at different valve openings and are compared between 2D-axisymmetric and 3D simulation results.

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Colloid chemical behavior of indole dihydropyrimidines in non-aqueous solvent mixture benzene-methanol of varying composition has been investigated by viscometric measurements at 303K± 0.1. The viscosity of the system increases with the increase in concentration. The Trend Change Point (TCP) values have been determined by intersection of two straight lines, which are found to be dependent on the composition of solvent mixtures. The study confirms that the nature of synthesized compounds agglomerate formed below and above 50% benzene concentration is quite different. The viscometric data have been analyzed in terms of Einstein, Vand, Moulik and Jones-Dole equations. These well known equations have been successfully applied to explain the results of viscosity measurements and the viscometric parameters show that the behavior of compound changes in the proximity of 50% benzene concentration.

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The aim of this study was to simulate blood flow in thoracic human aorta and understand the role of flow dynamics in the initialization and localization of atherosclerotic plaque in human thoracic aorta. The blood flow dynamics in idealized and realistic models of human thoracic aorta were numerically simulated in three idealized and two realistic thoracic aorta models. The idealized models of thoracic aorta were reconstructed with measurements available from literature, and the realistic models of thoracic aorta were constructed by image processing Computed Tomographic (CT) images. The CT images were made available by South Karelia Central Hospital in Lappeenranta. The reconstruction of thoracic aorta consisted of operations, such as contrast adjustment, image segmentations, and 3D surface rendering. Additional design operations were performed to make the aorta model compatible for the numerical method based computer code. The image processing and design operations were performed with specialized medical image processing software. Pulsatile pressure and velocity boundary conditions were deployed as inlet boundary conditions. The blood flow was assumed homogeneous and incompressible. The blood was assumed to be a Newtonian fluid. The simulations with idealized models of thoracic aorta were carried out with Finite Element Method based computer code, while the simulations with realistic models of thoracic aorta were carried out with Finite Volume Method based computer code. Simulations were carried out for four cardiac cycles. The distribution of flow, pressure and Wall Shear Stress (WSS) observed during the fourth cardiac cycle were extensively analyzed. The aim of carrying out the simulations with idealized model was to get an estimate of flow dynamics in a realistic aorta model. The motive behind the choice of three aorta models with distinct features was to understand the dependence of flow dynamics on aorta anatomy. Highly disturbed and nonuniform distribution of velocity and WSS was observed in aortic arch, near brachiocephalic, left common artery, and left subclavian artery. On the other hand, the WSS profiles at the roots of branches show significant differences with geometry variation of aorta and branches. The comparison of instantaneous WSS profiles revealed that the model with straight branching arteries had relatively lower WSS compared to that in the aorta model with curved branches. In addition to this, significant differences were observed in the spatial and temporal profiles of WSS, flow, and pressure. The study with idealized model was extended to study blood flow in thoracic aorta under the effects of hypertension and hypotension. One of the idealized aorta models was modified along with the boundary conditions to mimic the thoracic aorta under the effects of hypertension and hypotension. The results of simulations with realistic models extracted from CT scans demonstrated more realistic flow dynamics than that in the idealized models. During systole, the velocity in ascending aorta was skewed towards the outer wall of aortic arch. The flow develops secondary flow patterns as it moves downstream towards aortic arch. Unlike idealized models, the distribution of flow was nonplanar and heavily guided by the artery anatomy. Flow cavitation was observed in the aorta model which was imaged giving longer branches. This could not be properly observed in the model with imaging containing a shorter length for aortic branches. The flow circulation was also observed in the inner wall of the aortic arch. However, during the diastole, the flow profiles were almost flat and regular due the acceleration of flow at the inlet. The flow profiles were weakly turbulent during the flow reversal. The complex flow patterns caused a non-uniform distribution of WSS. High WSS was distributed at the junction of branches and aortic arch. Low WSS was distributed at the proximal part of the junction, while intermedium WSS was distributed in the distal part of the junction. The pulsatile nature of the inflow caused oscillating WSS at the branch entry region and inner curvature of aortic arch. Based on the WSS distribution in the realistic model, one of the aorta models was altered to induce artificial atherosclerotic plaque at the branch entry region and inner curvature of aortic arch. Atherosclerotic plaque causing 50% blockage of lumen was introduced in brachiocephalic artery, common carotid artery, left subclavian artery, and aortic arch. The aim of this part of the study was first to study the effect of stenosis on flow and WSS distribution, understand the effect of shape of atherosclerotic plaque on flow and WSS distribution, and finally to investigate the effect of lumen blockage severity on flow and WSS distributions. The results revealed that the distribution of WSS is significantly affected by plaque with mere 50% stenosis. The asymmetric shape of stenosis causes higher WSS in branching arteries than in the cases with symmetric plaque. The flow dynamics within thoracic aorta models has been extensively studied and reported here. The effects of pressure and arterial anatomy on the flow dynamic were investigated. The distribution of complex flow and WSS is correlated with the localization of atherosclerosis. With the available results we can conclude that the thoracic aorta, with complex anatomy is the most vulnerable artery for the localization and development of atherosclerosis. The flow dynamics and arterial anatomy play a role in the localization of atherosclerosis. The patient specific image based models can be used to diagnose the locations in the aorta vulnerable to the development of arterial diseases such as atherosclerosis.

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Kirjallisuusarvostelu

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This report describes a leiomyoma of the inferior third section of the esophagus removed during laparoscopic cholecystectomy. The patient is a woman 55-years-age, carrying esophageal myoma of 40 mm in diameter wide, situated in the posterior wall of the lower esophagus. Indications for surgery were based mainly on the growth of the mass (6 mm when discovered 7 years previously, increased to 40 mm). Recently the patient returned suffering from pain, which could be attributed to his litiasic cholecystopaty. A small degree of low disphagia could also be observed. Radiologic imaging, direct endoscopic examination and endoscopic ultrasound showed that the mioma protruded on to the oesophagic lumen, discreetly diminishing there. A laparoscopic esophageal myomectomy was indicated at the same session of the laparoscopic cholecystectomy. Once the pneunoperitoneum was installed, five ports were placed as if for a hiatus hernia surgery. The cholecystectomy was uneventful. Next, an esophagoscopy was performed so as to determine the precise area covering the base of the tumour; at the right-lateral site. Longitudinal and circular fibres of the esophagus was severed over the lesion and the enucleation of the tumour was performed alternating the monopolar dissection, bipolar and hidrodisection. Control-endoscopy was carried out to verify mucosa integrity. Four suture points with poliglactine 3-0 string so as to close the musculature followed this. One suture was placed in for diminution of the size of the esophagean hiatus. Total time of intervention: two hours (30m for the cholecystectomy and one hour and thirty minutes for the myomectomy). Postoperative period: uneventful. Disappearance of the disphagia was observed. Radiologic transit control with water-soluble contrast at 4th post-operative day: good passage. Diagnosis from laboratory of pathology: conjunctive tumour formed by muscle non-striated cells: leiomyoma. The patient was re-examined on the two-month postoperative follow-up. General conditions were good and there were no complain of dysphagia. Neither there were any symptoms of gastro-esophageal reflux.