221 research outputs found
THE SOCIOLOGY OF FASHION AND REBELLION: 1900 - PRESENT
The purpose of this study is to determine the relationship between fashion and rebellion within the social construct, in its historical context as well as with its current and future patterns. To identify how fashion is used for rebellion, we first must recognize how fashion is used as a form of communication and as a representation of self within society. Once this connection has been made, we will demonstrate through historical archives and scholarly text how fashion has been used throughout time as a means of social rebellion against standardized norms, political policies, and social structures. We then will classify and highlight various movements of rebellion in recent history that have used fashion as a medium for their social statements
Solubility isotope effects in aqueous solutions of methane
The isotope effect on the Henry's law coefficients of methane in
aqueous solution (H/D and C-12/C-13 substitution) are interpreted using
the statistical mechanical theory of condensed phase isotope effects.
The missing spectroscopic data needed for the implementation of the
theory were obtained either experimentally (infrared measurements), by
computer simulation (molecular dynamics technique), or estimated using
the Wilson's GF matrix method. The order of magnitude and sign of both
solute isotope effects can be predicted by the theory. Even a crude
estimation based on data from previous vapor pressure isotope effect
studies of pure methane at low temperature can explain the inverse
effect found for the solubility of deuterated methane in water. (C)
2002 American Institute of Physics
Adsorption of butanol and water vapors in silicalite-1 films with a low defect density
Pure silica zeolites are potentially hydrophobic and have therefore been considered to be interesting candidates for separating alcohols, e.g., 1-butanol, from water. Zeolites are traditionally synthesized at high pH, leading to the formation of intracrystalline defects in the form of silanol defects in the framework. These silanol groups introduce polar adsorption sites into the framework, potentially reducing the adsorption selectivity toward alcohols in alcohol/water mixtures. In contrast, zeolites prepared at neutral pH using the fluoride route contain significantly fewer defects. Such crystals should show a much higher butanol/water selectivity than crystals prepared in traditional hydroxide (OH–) media. Moreover, silanol groups are present at the external surface of the zeolite crystals; therefore, minimizing the external surface of the studied adsorbent is important. In this work, we determine adsorption isotherms of 1-butanol and water in silicalite-1 films prepared in a fluoride (F–) medium using in situ attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy. This film was composed of well intergrown, plate-shaped b-oriented crystals, resulting in a low external area. Single-component adsorption isotherms of 1-butanol and water were determined in the temperature range of 35–80 °C. The 1-butanol isotherms were typical for an adsorbate showing a high affinity for a microporous material and a large increase in the amount adsorbed at low partial pressures of 1-butanol. The Langmuir–Freundlich model was successfully fitted to the 1-butanol isotherms, and the heat of adsorption was determined. Water showed a very low affinity for the adsorbent, and the amounts adsorbed were very similar to previous reports for large silicalite-1 crystals prepared in a fluoride medium. The sample also adsorbed much less water than did a reference silicalite-1(OH–) film containing a high density of internal defects.The results show that silicalite-1 films prepared in a F– medium with a low density of defects and external area are very promising for the selective recovery of 1-butanol from aqueous solutions
Infravörös és Raman spektroszkópia és mikroszkópia alkalmazási lehetőségeinek kutatása az emberi szervezet fiziológiai állapotának jellemzésére = Study of application possibilities of infrared and Raman spectroscopy and microscopy in characterisation of physiological condition of the human body
A pályázatban szereplő kutatók jelentős szakmai tapasztalattal rendelkeznek az infravörös és Raman spektroszkópia területén. Ezt a felhalmozott szaktudást igyekeztünk kamatoztatni az orvosi diagnosztikával kapcsolatos kutatásokban. Infravörös spektroszkópiai mérésekkel sikerült elsőként igazolni, hogy az emberi bőr és haj színképe összefügg az emberi szervezet egészségi állapotával. A haj biológiai reakciója lassú (egy hónap) ezzel szemben a bőr igen gyorsan reagál a szervezetben lejátszódó folyamtokra. Mintegy 2200 páciens alkarján lévő bőr in vivo vizsgálatából, mintegy 85% biztonsággal szűrtük ki a beteg egyéneket. Az emberi haj színképéből speciális kemometriai módszerekkel az emlőrákos pácienseket szelektálni lehetett az egészségesektől. Meggyőződésünk, hogy a módszerünk a jelenlegi állapotában is alkalmas tömeges szűrővizsgálatokra, megbízhatósága, gyorsasága, egyszerűsége és olcsósága ezt mindenképpen indokolja. Sikerült diagnosztizálnunk kiváló biztonsággal a bőrmérésekből a diabétesz jelenlétét, valamint a haj színképekből a prosztata rákra utaló spektrális jeleket sikerült felismernünk. Ezen a területen további kutatásokra van szükség. Ezeken kívül szuvas fogak okozta elváltozásokat detektáltunk a fogzománcban, valamint tanulmányoztuk a tengeri kagylók és korallok szerkezetét. Foglalkoztunk biológiailag fontos vegyületek és fémkomplexek spektroszkópiai és elméleti szerkezetkutatásával is. | The participants of the present project have had considerable experience in the infrared and Raman spectroscopy. The knowledge accumulated is being directed toward research connected with medical diagnosis. From infrared spectroscopic measurements, we have demonstrated for the first time that the infrared spectra of human skin and hair exhibit clear correlation with the health condition of the human body. The biological changes in hair are rather slow (about one month), but human skin reflects very quickly various biological changes in human body. In vivo measurement of forearm skin spectra on about 2200 patients were used to select ill patients the reliability was about 85%. We have demonstrated for the first time that special chemometric methods can be used to sort the hair samples of suspected breast cancer patients. We are completely sure that our methods at present stage of developments are suitable for mass screening application, its reliability, speed, simplicity and low cost fully refer to this request. Illness specific spectroscopic signals have been obtained for diagnosis of diabetes using FTIR spectra of human skin and characteristic spectral features were observed in hair spectra of breast cancer patients. We have also studied spectroscopic effects of teeth cavity, and structural studies of sea shells and corals. Spectroscopic and theoretical studies of molecules and metal complexes of biological interests have been performed as well
Hard and transparent films formed by nanocellulose-TiO2 nanoparticle hybrids
T he formation of hybrids of nanofibrillated cellulose and titania nanoparticles in aqueous media has been studied. Their transparency and mechanical behavior have been assessed by spectrophotometry and nanoindentation. The results show that limiting the titania nanoparticle concentration below 16 vol% yields homogeneous hybrids with a very high Young's modulus and hardness, of up to 44 GPa and 3.4 GPa, respectively, and an optical transmittance above 80%. Electron microscopy shows that higher nanoparticle contents result in agglomeration and an inhomogeneous hybrid nanostructure with a concomitant reduction of hardness and optical transmittance. Infrared spectroscopy suggests that the nanostructure of the hybrids is controlled by electrostatic adsorption of the titania nanoparticles on the negatively charged nanocellulose surfaces
Amine-functionalized mesoporous silica: A material capable of CO2 adsorption and fast regeneration by microwave heating
The surface of ordered mesoporous (MCM-48) silica has been subjected to covalent grafting with silane molecules containing one to three amino groups. The dielectric properties of the materials were studied in detail, and the functionalized materials were used for CO2 adsorption at room temperature, followed by regeneration under either conventional heating or microwave irradiation. It has been found that, as the intensity of functionalization with amino groups increases (from mono- to tri-amino silanes) both the CO2 load and the dielectric response at microwave frequencies increase. In particular, functionalization with a tri-amino silane derivative gave the highest CO2 adsorption and the fastest microwave heating, resulting in a fourfold acceleration of adsorbent regeneration. The grafted material was fully stable for at least 20 adsorption-regeneration cycles, making it an ideal candidate for microwave-swing adsorption (MWSA) processes. (c) 2015 American Institute of Chemical Engineers AIChE J, 62: 547-555, 2016Financial support from the European Research Council ERC-Advanced Grant HECTOR is gratefully acknowledged. Hakan Nigar also acknowledges financial support from the Spanish Ministry of Education for the FPU grant (Formacion del Profesorado Universitario-FPU12/06864).Nigar, H.; García-Baños, B.; Penaranda-Foix, FL.; Catalá Civera, JM.; Mallada, R.; Santamaria, J. (2016). Amine-functionalized mesoporous silica: A material capable of CO2 adsorption and fast regeneration by microwave heating. AIChE Journal. 62(2):547-555. https://doi.org/10.1002/aic.15118S54755562
Comparison of amine-impregnated mesoporous carbon with microporous activated carbon and 13X zeolite for biogas purification
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