Spelling suggestions: "subject:"coenergy"" "subject:"conergy""
211 |
Uticaj molekularnih svojstava maltodekstrina na tehnološko ponašanje niskoenergetskih prehrambenih emulzija / Influence of molecular characteristics of maltodextrins on technological behaviour of low-energy food emulsionsDokić-Baucal Ljubica 10 May 2002 (has links)
<p>Apstrakt je obrađen tehnologijama za optičko prepoznavanje teksta (OCR).</p><p>Maltodekstini, hidrolizati skroba niskog stepena konverzije (dekstrozni ekvivalent manji od 20), imaju široku upotrebu u prehrambenoj, kozmetičkoj i farmaceutskoj industriji. U prehrambenoj industriji koriste se u niskoenergetskim prehrambenim emulzijama (majonez, salatni prelivi, namazi) kao zamena za masne materije da bi obezbedili viskozitet, poželjne senzorne osobine i smanjenje energetske vrednosti proizvoda.<br />Viskozitet razblaženih rastora maltodekstrina različitog dekstroznog ekvivalenta i botaničkog porekla meren je kapilarnim viskozimetrom i izračunate su vrednosti unutrašnjeg viskoziteta za pojedine maltodekstrine. Vrednosti untrašnjeg viskoziteta i molekulske mase pokoravaju se zavisnosti Štaudingerove jednačine, iako su molekuli maltodekstrina relativno kratki i ne spadaju u grupu polimera. Utvrđena je mogućnost odredivanja DE- vrednosti viskozimetrijskin putem i izvedene su jednačine za dva opsega DE (5-10 / 10-20).<br />Da bi se ispitalo ponašanje emulzija sa maltodekstrinima (emulgovanje) u procesnim uslovima, kao i osobine fmalnih proizvoda (tečljivost, mazivost) ispitivana je dinamika emulgovanja, veličina kapljica i reološko ponašanje, tj. uticaj različitih faktora na disperzione karakteristike emulzija suncokretovog ulja u vodi stabilizovanih prehrambenim emulgatorom, sa dodatkom maltodekstrina u kontinualnoj fazi.<br />Utvrđeno je da osobine maltodekstina kao što je stepen konverzije (DE-vrednost) tj. veličina molekula maltodekstrina, utiču na dispezione i reološke osobine emulzija. Uticaj koncentracije ulja i maltodekstrina, kao i delimična zamena ulja maltodekstrinom, na osobine emulzija su takode ispitivane. Sa povećanjem koncentracije ulja, pri istoj koncentraciji maltodekstrina u kontinualnoj fazi, emulzije menjaju tip proticanja od pseudoplastičnog preko tiksotropnog do antitiksotrpnog. Atitiksotropija izazvana smicanjem rezultat je formiranja unutrašnje strukture emulzije usled povezivanja kapljica ulja preko molekula maltodekstrina kao i orijentacije i deformacije kapljica ulja i maltodekstrina.<br />Dodatkom maltodekstrina za pri istoj koncentraciju ulja i vremenu emulgovanja dobijene su se emulzije sitnijih kapi.<br />Emulzije sa niskom koncentracijom ulja (30%) sa maltodekstrinom u kontinualnoj fazi bile su nestabilne i pokazivale efekat isplivavanja na površinu (creaming), što je posledica interakcija molekula maltodekstrina i molekula emulgatora Tween 80 u kontinualnoj fazi i na površini kapi.</p> / <p>Abstract was processed by technology for Optical character recognition (OCR).</p><p>Maltodextrins, low converted products of starch hydrolysis (dextrose equivalent less than 20), have been subject of various investigations due to their wide application in food industry, cosmetics and pharmaceuticals. They are used in various low energy food emulsions (mayonnaise, salad dressing, spreads) as fat replacer to provide desirable viscosity, texture and sensory fat-like mouthfeel.<br />Viscosity of diluted maltodextrin solutions of different dextrose equivalent and botanical origin were determined by capillary visometer and intrinsic viscosity [q] of each tested maltodextrin was calculated. The values of [q] together with molecular mass M have shown applicability of Staudinger equation, regardless maltodextrin molecules are rather short. The possibility for the determination of DE-values of maltodextrins by viscometric method has been deduced and the equation was calculated for two ranges of DE (5-10/ 10-20).<br />In order to assess behavior of sunflower oil in water emulsions stabilized with food grade emulsifier with addition of maltodextrins in continuous phase in processing (emulsification), as well as end products in application (pouring, spreading) the emulsification dynamics, globule size changes and rheological behavior, as well as, the influence of different factors on dispersion characteristics of such emulsions were studied.<br />Dispersion and viscous properties of emulsions were influenced by certain specific maltodextrin characteristics such as degree of conversion (DE value) i.e. size of maltodextrin molecules. Influence of oil and maltodextrin concentration and partial substitution of oil with equivalent quantity of maltodextrin were investigated too. With increase of oil concentration at the same concentration of maltodextrin in continuous phase, emulsions undergo changes in flow type from shear-thinning to thixotropic and antithixotropic. Antithxotropy induced by shear, was result of formation of network due to two competing factors; linking of oil droplets through maltodextrin molecules as well as orientation of deformed oil droplets and maltodextrin molecules.<br />Addition of maltodextrin, at the same oil concentration and emulsification time, resulted in formation of emulsions with smaller oil droplets.<br />Emulsions with low oil concentration (30%) with maltodextrin in continuous phase were unstable, showing so called creaming effect. This was mainly due to interactions between maltodextrin and emulsifier Tween 80 molecules which took place in continuous phase and on droplet surfaces.</p>
|
212 |
Dynamique de collisions moléculaires à très basse énergie : mise en évidence expérimentale de résonances quantiques / Molecular collision dynamics at very low energyChefdeville, Simon 12 December 2014 (has links)
Les calculs théoriques prévoient que la dynamique d’excitation rotationnelle desmolécules CO et O2, induite par collision avec H2, est dominée par des résonancesquantiques aux très basses énergies. Leur mise en évidence expérimentale estrendue difficile par la nécessité d’obtenir des énergies de collision très faibles et unegrande résolution en énergie. Les expériences menées grâce à un montage defaisceaux moléculaires croisés à angle d’intersection variable, nous permettent ainsid’observer le seuil des transitions j = 0 1 de CO à 3,85 cm-1 et Nj = 10 11 de O2à 3,96 cm-1. Ces énergies correspondent à l’énergie cinétique moyenne d’un gaz àune température inférieure à 4 K. Les pics dans le tracé des sections efficacesintégrales en fonction de l’énergie de collision, constituent la première observationexpérimentale de résonances pour des processus inélastiques. Le bon accord avecles calculs théoriques permet de valider les potentiels d’interaction et ainsi dedéduire les constantes de vitesse pour la modélisation du milieu interstellaire. Nosrésultats expérimentaux mettent en relief la nature quantique des interactionsmoléculaires aux très basses énergies. / Theoretical calculations predict that the dynamics of rotational excitation of CO or O2molecules, induced by collisions with H2, are dominated by quantum scatteringresonances at very low energies. However, experimental observation of these effectsis challenging: very low collision energies and high energy resolution are bothrequired. Experiments performed with a crossed molecular beam apparatus withvariable intersection angle allow us to observe the thresholds of the CO (j = 0 1)transition at 3.85 cm-1 and the O2 (Nj = 10 11) transition at 3.96 cm-1, whichcorrespond to the average kinetic energy of a gas below 4 K. The peaks in theintegral cross section’s collision energy dependence constitute the first experimentalobservation of resonances in an inelastic process. The good agreement betweentheory and experiment reinforces the confidence in the interaction potentials used todeduce rate coefficients for modeling the interstellar medium in the 1-20 K range. Ourexperimental results highlight the quantum nature of molecular interactions at verylow energies.
|
213 |
Low Energy (e,2e) Studies of Inner Valence IonizationHaynes, Matthew, n/a January 2002 (has links)
This thesis presents a series of electron impact ionization measurements on the gas phase targets of argon and krypton. The (e,2e) coincidence technique has been employed to measure the triple differential cross section (TDCS) using a new coincidence spectrometer designed to operate in the low energy regime (2 to 5 times the ionization energy) and in the coplanar geometry. The spectrometer is a conventional device utilizing a non-energy selected electron gun and two 1800 hemispherical electron analysers fitted with channel electron multipliers for detection of the outgoing electrons. A series of TDCS measurements were performed on the 3s inner-valence and 3p valence orbitals of argon employing coplanar asymmetric kinematics. Measurements for both orbitals were performed at an incident energy of 113.5 eV, ejected energies of 10, 7.5, 5 and 2 eV and a scattering angle of -15°. The energy of the scattered electron in each case was chosen to satis~' energy conservation and is dependent on the ionization energies of the different orbitals. The experimental cross sections are compared to theoretical TDCS calculations using the distorted wave Born approximation (DWBA) and variations of the DWBA in an attempt to investigate the role that post collisional interaction (PCI), polarization and electron exchange play in describing the TDCS in the low energy regime. To further extend this analysis, a series of TDCS measurements were performed on the 3s and 4s. orbitals of argon and krypton, respectively, employing coplanar symmetric kinematics. Measurements were performed for the 3s orbital at outgoing energies of 50, 20, 10 and 4eV and for the 4s orbital at outgoing energies of 85, 50, 20 and 10 eV. The kinematics were chosen to coincide with several of the (e,2e) measurements made in the same geometry on the 3p orbital of argon by Rouvellou et al (1998). The experimental results were again compared to a DWBA calculation and similar variations to those employed for the asymmetric measurements.
|
214 |
. Nanostructuration de la muscovite : Une étude par diffraction d'électrons lents en mode oscillant.DOREL, Sébastien 17 July 2000 (has links) (PDF)
Nous avons étudié la structure de la surface de mica muscovite clivée à l?air par diffraction d?électrons lents en mode oscillant. Cette nouvelle méthode d?analyse structurale, que nous avons développée à partir d?un système optique standard de résolution conventionnelle, possède une grande sensibilité. En outre, elle permet de former des images de diffraction entières sans procéder, comme le font les autres diffractomètres à haute résolution, à une reconstitution ligne par ligne. Cette caractéristique permet aussi de réaliser des acquisitions d?image qui sont corrélées temporellement avec une excitation extérieure, ce qui rend possible toute une gamme d?expériences nouvelles, notamment dans le cadre de la réponse thermodynamique d?une surface au voisinage d?une transition de phase. Notre étude de la surface du mica muscovite par diffraction d?électrons lents en mode oscillant a permis pour la première fois de mettre en évidence la nanostructuration de sa couche superficielle. Notre interprétation est que lors du clivage, la surface du mica s?auto-organise pour former un arrangement d?îlots à l?intérieur desquels les atomes de potassium occupent les sites réguliers du cristal. Les îlots sont soit de taille définie soit séparés par une distance définie. Dans les zones interstitielles qui les séparent, les ions potassium, en concentration beaucoup plus faible, formeraient une couche amorphe.
|
215 |
Establishing low-energy x-ray fields and determining operational dose equivalent conversion coefficientsLarsson, Ylva January 2008 (has links)
<p>Reference radiation fields for x-ray qualities are described by the International Organization of Standards (ISO). This study describes the procedure to establish nine different low energy X-ray qualities at the national metrology laboratory, Swedish Radiation Protection Authority, following the document ISO 4037. Measurements of tube voltage, half-value layer, mean energy and spectral resolution have been performed for qualities N-15, N-20, N-25, N-30, N-40, L-20, L-30, L-35 and L-55. Furthermore, dose equivalent conversion coefficients for operational quantities ambient dose equivalent, personal dose equivalent and directional dose equivalent have been calculated by folding the mono-energetic conversion factors with measured spectral distributions of the x-ray qualities. The spectral distributions were unfolded from pulse-height distributions to photon distributions using simulated data of the semi-conductor detector used for measurements, generated with the Monte Carlo code PENELOPE.</p>
|
216 |
Lågenergihus : Att bygga energisnåltKarlsson, Camilla January 2010 (has links)
<p>A large proportion of the energy consumption is in the building industry and a large part goes to heating our homes and premises. In the developing countries' development now threatens the large consumption of energy in our earth's climate. It is in the West world that we must be good role models in terms of energy efficiency. One solution to reduce energy consumption for heating of buildings may be to continue to build low energy houses and passive houses, but it is also about rebuilding the buildings that currently have high energy consumption such as the old Million program Houses. These buildings will be standing many years and their energy consumption will not diminish over time by itself and energy prices will certainly not diminish in the future. This report will touch on the subject mainly new construction, how to build an energy efficient building, but a smaller portion will touch on the subject rebuilding, particularly the solutions that can fit into economic terms.</p><p><strong> </strong></p><p>Calculations have been done to link the concepts of U<sub>mean</sub> of a building and its energy consumption. This was done by calculations using an Excel document created in connection with this thesis.</p><p> </p><p>The buildings and architectural solutions addressed in this report will focus on apartment buildings where the partner of this thesis is Eskilstuna Municipal Building. Eskilstuna Municipality Property manages buildings and premises to Eskilstuna Municipality, but also owns their own house with rental apartments.<strong></strong></p>
|
217 |
Establishing low-energy x-ray fields and determining operational dose equivalent conversion coefficientsLarsson, Ylva January 2008 (has links)
Reference radiation fields for x-ray qualities are described by the International Organization of Standards (ISO). This study describes the procedure to establish nine different low energy X-ray qualities at the national metrology laboratory, Swedish Radiation Protection Authority, following the document ISO 4037. Measurements of tube voltage, half-value layer, mean energy and spectral resolution have been performed for qualities N-15, N-20, N-25, N-30, N-40, L-20, L-30, L-35 and L-55. Furthermore, dose equivalent conversion coefficients for operational quantities ambient dose equivalent, personal dose equivalent and directional dose equivalent have been calculated by folding the mono-energetic conversion factors with measured spectral distributions of the x-ray qualities. The spectral distributions were unfolded from pulse-height distributions to photon distributions using simulated data of the semi-conductor detector used for measurements, generated with the Monte Carlo code PENELOPE.
|
218 |
Low-Power High-Performance Ternary Content Addressable Memory CircuitsMohan, Nitin January 2006 (has links)
Ternary content addressable memories (TCAMs) are hardware-based parallel lookup tables with bit-level masking capability. They are attractive for applications such as packet forwarding and classification in network routers. Despite the attractive features of TCAMs, high power consumption is one of the most critical challenges faced by TCAM designers. This work proposes circuit techniques for reducing TCAM power consumption. The main contribution of this work is divided in two parts: (i) reduction in match line (ML) sensing energy, and (ii) static-power reduction techniques. The ML sensing energy is reduced by employing (i) positive-feedback ML sense amplifiers (MLSAs), (ii) low-capacitance comparison logic, and (iii) low-power ML-segmentation techniques. The positive-feedback MLSAs include both resistive and active feedback to reduce the ML sensing energy. A body-bias technique can further improve the feedback action at the expense of additional area and ML capacitance. The measurement results of the active-feedback MLSA show 50-56% reduction in ML sensing energy. The measurement results of the proposed low-capacitance comparison logic show 25% and 42% reductions in ML sensing energy and time, respectively, which can further be improved by careful layout. The low-power ML-segmentation techniques include dual ML TCAM and charge-shared ML. Simulation results of the dual ML TCAM that connects two sides of the comparison logic to two ML segments for sequential sensing show 43% power savings for a small (4%) trade-off in the search speed. The charge-shared ML scheme achieves power savings by partial recycling of the charge stored in the first ML segment. Chip measurement results show that the charge-shared ML scheme results in 11% and 9% reductions in ML sensing time and energy, respectively, which can be improved to 19-25% by using a digitally controlled charge sharing time-window and a slightly modified MLSA. The static power reduction is achieved by a dual-VDD technique and low-leakage TCAM cells. The dual-VDD technique trades-off the excess noise margin of MLSA for smaller cell leakage by applying a smaller VDD to TCAM cells and a larger VDD to the peripheral circuits. The low-leakage TCAM cells trade off the speed of READ and WRITE operations for smaller cell area and leakage. Finally, design and testing of a complete TCAM chip are presented, and compared with other published designs.
|
219 |
Lågenergihus : Att bygga energisnåltKarlsson, Camilla January 2010 (has links)
A large proportion of the energy consumption is in the building industry and a large part goes to heating our homes and premises. In the developing countries' development now threatens the large consumption of energy in our earth's climate. It is in the West world that we must be good role models in terms of energy efficiency. One solution to reduce energy consumption for heating of buildings may be to continue to build low energy houses and passive houses, but it is also about rebuilding the buildings that currently have high energy consumption such as the old Million program Houses. These buildings will be standing many years and their energy consumption will not diminish over time by itself and energy prices will certainly not diminish in the future. This report will touch on the subject mainly new construction, how to build an energy efficient building, but a smaller portion will touch on the subject rebuilding, particularly the solutions that can fit into economic terms. Calculations have been done to link the concepts of Umean of a building and its energy consumption. This was done by calculations using an Excel document created in connection with this thesis. The buildings and architectural solutions addressed in this report will focus on apartment buildings where the partner of this thesis is Eskilstuna Municipal Building. Eskilstuna Municipality Property manages buildings and premises to Eskilstuna Municipality, but also owns their own house with rental apartments.
|
220 |
Passivhusen på OxtorgetBrandt, Fredrik, Jonsson, Mathilda January 2008 (has links)
Syftet med vårt examensarbete är att undersöka hur passivhus eller så kallade nollenergihus skiljer sig i funktion samt uppbyggnad från konventionella hus. I vår undersökning tar vi upp hur utformning, orientering, material samt ett väl fungerande klimatskal påverkar energiförbrukningen. Vi har tittat närmare på faktorer som sparar energi samt hur ett typiskt passivhus är uppbyggt. För att se hur teorin fungerar i praktiken har vi tittat närmare på befintliga passivhus, nämligen de på Oxtorget i Värnamo. Vi har kommit fram till att passivhus fungerar och vi anser det som väldigt viktigt att man fortsätter driva fram arbetet och informera om dess betydelse för miljön. Passivhus blir mer och mer uppmärksammat. De är något dyrare att bygga, men man tjänar in det i längden. Lönsamheten är dock inte det viktigaste utan känslan av att man gör något bra för miljön. / The main purpose with our diploma work is to examine how passive houses or so called zero energy houses differ in function and construction compared to conventional houses. In our research we present different things such design, orientation, materials and how a fully functional climate shell affects the energy consumption. We’ve looked closer at some factors that save energy and how a typical passive house is constructed. To see how theory works in practice we have looked at existing passive houses, and that is the passive houses on Oxtorget in Värnamo. We have come to the conclusion that the passive houses works and we believe that it is very important that we continues to carry on the work and inform people about its importance to the environment. Passive houses are becoming more and more noticed. They are somewhat more expensive to build but in time you will earn the money spent back. The profit is not the most important but the feeling that you do something good for the environment.
|
Page generated in 0.0362 seconds