Miracle-dz/UniFAR-FTUs huggingface dataset:
THE BEHAVIOR OF IODINE IN GRAPHITE

Abstract The adsorption of iodine on National Carbon type TSX graphite was studied at 100, 200, 500 and 800°C, over the pressure range 0.01–15 mm Hg, using a tracer technique. Above 200°C iodine was chemisorbed on a small fraction of the graphite surface. At 100°C the iodine was held on the graphite by both chemisorption and physical adsorption. The surface area of the graphite, determined from the 100°C iodine adsorption isotherm using the B.E. T. theory, was found to be in good agreement with surface area values obtained from nitrogen isotherms at −195°C. No relation was found between the amounts of iodine adsorbed on various samples and their surface area, at concentrations below one monolayer. The adsorption of iodine was enhanced by high temperature outgassing (2000°C) and contact with water vapor at 900°C. A small fraction of the iodine adsorbed at 25 and 100°C could not be removed from the graphite by heating in vacuo at 950°C. The amount of iodine irreversibly adsorbed at 25°C, in saturated iodine vapor, was approximately proportional to the reversible iodine adsorption at higher temperatures.
Physical limit of stability in supercooled D2O and D2O+H2O mixtures

The fluctuation theory of homogeneous nucleation was applied for calculating the physical boundary of metastable states, the kinetic spinodal, in supercooled D2O and D2O+H2O mixtures. The kinetic spinodal in our approach is completely determined by the surface tension and equation of state of the supercooled liquid. We developed a crossover equation of state for supercooled D2O, which predicts a second critical point of low density water–high density water equilibrium, CP2, and represents all available experimental data in supercooled D2O within experimental accuracy. Using Turnbull’s expression for the surface tension we calculated with the crossover equation of state for supercooled D2O the kinetic spinodal, TKS, which lies below the homogeneous nucleation temperature, TH. We show that CP2 always lies inside in the so-called “nonthermodynamic habitat” and physically does not exist. However, the concept of a second “virtual” critical point is physical and very useful. Using this concept we have extended .
Long-range coherence and energy storage in biological systems

Biological systems are expected to have a branch of longitudinal electric modes in a frequency region between 1011 and 1012 sec−1. They are based on the dipolar properties of cell membranes; of certain bonds recurring in giant molecules (such as H bonds) and possibly on pockets of non-localized electrons. In Section 2 it is shown quit generally that if energy is supplied above a certain mean rate to such a branch, then a steady state will be reached in which a single mode of this branch is very strongly excited. The supplied energy is thus not completely thermalized but stored in a highly ordered fashion. This order expresses itself in long-range phase correlations; the phenomenon has considerable similarity with the low-temperature condensation of a Bose gas. General consequences and proposals of experiments are discussed in section 3.
Biodiesel production from ground nut oil

Ground nut oil is widely grown in northern Nigeria and is a potential source of feed stock for biodiesel production. However, not much work has been done on the conversion to biodiesel and its characterization. The purpose of this study is to cover the gap in knowledge by extracting the oil, transesterifying it to biodiesel and characterizing it. To achieve this, the ground nut oil which contains high amount of free fatty acid was pretreated with hydrochloric acid as catalyst and anhydrous methanol at a molar ratio of 9:1 to reduce its free fatty acid to 1.5% before trans-esterification with sodium hydroxide as catalyst at a molar ratio 6:1. The oil and biodiesel were characterized and it gave for example, a kinematic velocity 6.6 mm2/s, flash point of 182℃ and cetane number 51 which are close to the properties of diesel fuel thus making it an alternate fuel for diesel engines. Gas chromatography analysis shows that it is 68.7% unsaturated and contains mainly the oleics.
An Orange-Emitting, Long-Persistent Phosphor, Ca2Si5N8 : Eu2 + , Tm3 +

An orange-emitting, long-persistent phosphor, Ca 2 Si 5 N 8 :Eu 2+ ,Tm 3+ , was developed. Afterglow of this phosphor decays more slowly than that of the conventional red-emitting, long-persistent phosphor, Y 2 O 2 S:Eu 3+ ,Ti,Mg. After 420 nm excitation, the afterglow luminance is initially lower, but, after 8 min, gets higher than luminance of Y 2 O 2 S:Eu 3 ',Ti,Mg. Long afterglow results from electron traps formed by Tm 3+ at the Ca 2+ site. The origin of two main thermoluminescence glow peaks at 220 and 350 K is discussed based on their dependence on Eu or Tm concentration and Ca/Si atomic ratio. Increased thermoluminescence intensity is observed by excitation in Eu 2+ 4f-5d transition at room temperature followed by the fundamental absorption of the host at low temperature.
Simple Aqueous Solution Route to Luminescent Carbogenic Dots from Carbohydrates

A simple aqueous solution route has been developed for the preparation of luminescent carbogenic dots from carbohydrates. The optical properties of the carbogenic dots can be tuned by differing the starting materials or the duration of nitric acid treatment. The multicolor emission capability and potential nontoxic nature of these carbogenic dots should enable them to find a wide range of applications in life sciences research.
Environmentally Benign Microwave-Assisted Sonogashira Preparation of Aromatic Compounds

An efficient Sonogashira-type coupling reaction of terminal alkynes and aryl bromides by microwave activation with short reaction time under mild conditions are presented. It is illustrated herein that the traditional Sonogashira coupling reaction can be achieved with a much more efficient yet environmentally friendly condition. In contrary to the usually required 10 mol% Pd loading and the use of conventional heating at 60 °C for 24 h in order for a reaction to proceed satisfactorily, with a 100 W microwave activation, the reaction of terminal alkynes with substituted aryl bromides can be achieved with only a 2.5 mol% Pd in 10 min. The yield was improved with microwave irradiation.
Calibration and Intercomparison of Filter-Based Measurements of Visible Light Absorption by Aerosols

Data on light absorption by atmospheric particles are scarce relative to the need for global characterization. Most of the existing data come from methods that measure the change in light transmission through a filter on which particles are collected. We present a calibration of a recently developed filter-based instrument for continuous measurement of light absorption (model PSAP, Radiance Research, Seattle, WA) that has been incorporated in several measurement programs. This calibration uses a reference absorption determined as the difference between light extinction and light scattering by unaltered (suspended) particles. In addition, we perform the same calibration for two other common filter-based methods: an Integrating Plate and the Hybrid Integrating Plate System. For each method, we assess the responses to both particulate light scattering and particulate light absorption. We find that each of the instruments exhibits a significant response to nonabsorbing aerosols and overestimates absorption at.
Effets cytotoxiques in vitro des PM2,5 de la ville d’Abidjan (Côte-d’Ivoire) sur des cellules pulmonaires humaines

Les etudes epidemiologiques associent la pollution atmospherique, notamment particulaire, a l’augmentation de la morbidite et de la mortalite d’origine respiratoire et cardio-vasculaire. L’Afrique, qui possede un taux d’urbanisation parmi les plus eleves du monde, y est particulierement exposee. L’« Initiative sur la qualite de l’air en Afrique subsaharienne » a montre l’importance des concentrations atmospheriques de certains polluants tels que les oxydes d’azote, le dioxyde de soufre et les particules en suspension dans l’air de diametre inferieur ou egal a 10 μm (PM10). A l’instar des grandes capitales africaines, Abidjan, capitale economique et ville la plus industrialisee de la Cote-d’Ivoire, est confrontee a une pollution atmospherique d’origine industrialo-urbaine et a ses consequences sanitaires pour sa population de pres de 6 millions d’habitants.Afin de mieux connaitre les mecanismes d’action pulmonaires consecutifs a l’exposition aux particules atmospheriques, nous nous sommes proposes de : (i) prelever par impaction en cascade dans le District d’Abidjan des particules atmospheriques (PM2,5) sous trois influences (rurale, urbaine ou industrielle) ; (ii) determiner leurs principales caracteristiques physico-chimiques ; (iii) evaluer leur cytotoxicite et leur role dans l’induction de lesions oxydatives dans un modele de cellules pulmonaires humaines (A549) en culture.L’analyse de la composition chimique des particules a montre leur heterogeneite. De nombreux elements inorganiques (Al, Ca, Fe, Mn, Zn, Ni, Cr, Cu, Pb, Mg) et composes organiques (paraffines) ont pu etre quantifies sous les differentes influences. Leurs Concentrations d’Effets (CE) a 10 % et 50 % sur les cellules A549 etaient les suivantes : influence rurale : CE10 = 5,91 μg/cm2 et CE50 = 29,55 μg/cm2, influence urbaine : CE10 = 5,45 μg/cm2 et CE50 = 27,23 μg/cm2, et influence industrielle : CE10 = 6,86 μg/cm2 et CE50 = 34,29 μg/cm2. L’exposition des cellules A549 pendant 24, 48 ou 72 h a ces particules atmospheriques a leurs CE10 ou CE50 a induit des dommages oxydatifs, comme l’ont montre la formation de malondialdehyde, les variations de l’activite enzymatique du superoxyde dismutase et l’alteration du statut en glutathion.
Qualitatively graph-theoretical study on stability and formation of fullerenes and nanotubes

Kekule structures of different carbon species have been determined. On the basis of Kekule structure and C-C bond counts as well as the surface curvature, stability of diverse carbon species, driving force for curling of graphite fragments and formation of fullerenes and nanotubes, have been discussed. Curling of graphite flat fragments, end-capping of nanotubes, and closure of curved structures are driven by a tremendous increase in Kekule structures as terminal carbon atoms couple their dangling bonds into C-C σ bonds. The increasing tendency becomes particularly striking for large cages and nanotubes. Resonance among numerous Kekule structures will stabilize the curved structure and dominate formation of closed carbon species. For similar carbon cages with comparable Kekule structure counts in magnitude, the surface curvature of carbon cages, as a measure for the strain energy, also plays an important role in determining their most stable forms.
Segmented Polythiourethane Elastomers Through Sequential Thiol-ene and Thiol-isocyanate Reactions

Highly elastic polythiourethanes were synthesized through sequential thiol reactions involving 1,6-hexanedithiol (HDT), 1,4-butanediol diacrylate (BDDA), and several diisocyanates (ISO). Thiol-terminated prepolymers prepared by the phosphine-catalyzed thiol Michael addition of HDT and BDDA form flexible thioether oligomers which were then incorporated as soft segments into polythiourethane main chains through a triethylamine-catalyzed thiol−isocyanate reaction with HDT and ISO to give polymers with both hard and soft segments. Real-time FTIR, used to investigate the kinetic conversion profiles of both reactions, and NMR showed that both the thiol Michael addition and the thiol−isocyanate reactions are very fast and efficient, having the chemical attributes generally associated with thiol−ene radical click reactions. The effects of the soft and hard segment length, soft/hard segment weight ratio, and chemical structure of the ISO on thermal and dynamic thermal mechanical properties was characterized in ter.
Micromorphic media : interpretation by homogenisation

In order to develop more and more resource-saving strategies for engineering tasks, the efficient application of cellular materials, such as various open cell foams, is of high interest in science and technology. Strongly influenced by their underlying microtopology, cellular materials feature a complex material behaviour. Modelling aspects to be taken into account are e.g. the deformation induced evolution of anisotropy and porosity on the one hand and the description of size dependent stiff or soft boundary layers, activated by the interaction close to material interfaces, on the other hand. The present contribution is focusing on that second feature by introducing a numerical homogenisation procedure. It allows to replace the heterogeneous microcontinuum by a homogeneous micromorphic macrocontinuum. Doing so, the microstructural deformation mechanisms can be geometrically interpreted as generalised degrees of freedom, which can be transferred on the macroscopic level. In the context of a FE2 strategy, the macroscopic constitutive equations are replaced by the computation of a nested microscopic boundary value problem in each macroscopic material point. The power of the proposed interpretation of the micromorphic degrees of freedom in combination with the numerical homogenisation approach is demonstrated for several microstructures in various numerical experiments validated in comparison to numerical reference calculations. In einer Welt immer knapper werdender Rohstoffe kommt dem ressourcenschonenden Einsatz von anwendungsspezifisch optimierten Materialien eine immer hohere Bedeutung zu. Vor diesem Hintergrund werden zellulare Materialien wie z.B. offenporige Schaume sowohl im Bereich des konstruktiven Leichtbaus als auch fur diverse weitere Anwendungsgebiete eingesetzt. Aufgrund ihrer ausgepragten Mikrotopologie zeichnen sich diese Materialien durch ein komplexes mechanisches Verhalten aus. Fur die Materialmodellierung mussen dabei sowohl die Anisotropie und die Porositat Berucksichtigung finden als auch Masstabseffekte an Materialgrenzen, die sich in steifen oder weichen Randschichten ausern. Eben diese Masstabseffekte stehen im Mittelpunkt der vorliegenden Arbeit. Zu ihrer Modellierung wird das zu Grunde liegende heterogene Mikrokontinuum durch ein homogenes mikromorphes Makrokontinuum ersetzt. Dazu mussen die mikroskopischen Deformationsprozesse einer makroskopischen Interpretation als erweiterte Freiheitsgrade zugefuhrt werden. Dies geschieht mit Hilfe eines numerischen Homogenisierungsverfahrens. Die Formulierung einer makroskopischen Konstitutivbeziehung wird umgangen, indem an jeden makroskopischen materiellen Punkt ein mikroskopisches Randwertproblem geheftet und im jeweiligen Deformationszustand berechnet wird. Die Leistungsfahigkeit der vorgestellten Homogenisierungstechnik wird anschliesend am Beispiel verschiedener Mikrostrukturen und geeigneter Referenzberechnungen nachgewiesen.
FT-IR Spectroscopy in Medicine

Infrared spectroscopy has been widely applied for the characterisation of various substances. Due to its sensitivity to the chemical information and architecture of the molecule, infrared spectroscopy can play an important role in new applications such as in the life-science field and not only in the traditional fields of physics and chemistry. Spectroscopic techniques are simple, reproducible, non-destructive without particular sample preparation. As a result, they provide information for the functional groups, bonds and molecular structure.
Thermal Jamming in Colloidal Star−Linear Polymer Mixtures

We probe the reversible thermal solidification of crowded solutions of colloidal star polymers in a marginal solvent upon addition of linear homopolymer chains consisting of the same monomers, and for two different linear polymer molecular weights we find that they have a dramatic impact on this phenomenon. If the linear chain molecular weight is much smaller than the star arm molecular weight, penetration is favored, the stars swell (the linear polymer solution acts as a good solvent for the stars), and the jamming temperature drops for a given star concentration. On the other hand, if the linear chain molecular weight exceeds that of the star arm, the stars shrink and the mixture exhibits liquidlike behavior over a wide range of star concentrations and temperatures. These results offer new possibilities for molecular control of the flow properties of soft colloids.
Designing oligoarginine-associated PECA nanoparticles for enhanced cellular uptake

i Acknowledgements iii Publications and Conferences/Presentations v List of Figures xii List of Tables xvii List of Equations xix List of Abbreviations xx 1. General introduction 1 1.1. Challenges in oral drug delivery 1 1.2. Understanding the gastrointestinal absorption mechanisms 2 1.3. General mechanisms of cellular uptake 5 1.4. Oral formulations 7 1.4. 1. Poly(alkylcyanoacrylate) (PACA) nanoparticles 8 1.4. 2. Cell-penetrating peptides (CPPs) as penetration enhancers 11 1.4. 2.1. Method of CPP association to bioactive 13 1.4. 2.2. Uptake mechanisms of CPPs 15 1.4. 2.3. Oligoarginine as a CPP 21 1.4. 3. Incorporation of CPPs in polymeric nanoparticles 24 1.5. Interaction at the bio-interface 26 1.6. Aims of thesis 28 2. Design and characterization of oligoarginine-associated PECA nanoparticles . 30 2.
Catalysts for the selective catalytic reduction of NOx with NH3 at low temperature

Selective catalytic reduction of NOx with NH3 (NH3-SCR) at low temperature is a major challenge in environmental catalysis. In recent years, great efforts have been devoted to the development of low-temperature SCR catalysts for both stationary sources and diesel engines. Mn-based catalysts have attracted great attention due to their excellent low-temperature activity. However, vulnerability to SO2 and H2O poisoning and preference for N2O formation make these catalysts still far away from industrial application. V2O5 loaded on carbon materials has shown both high SCR activity and SO2 tolerance at low-temperature. This type of catalyst is very promising for applications in low-temperature SCR for stationary sources. Recently, Cu-containing small pore zeolites, such as Cu-SSZ-13 and Cu-SAPO-34 with a CHA structure and Cu-SSZ-39 and Cu-SAPO-18 with an AEI structure, were shown to have very high activity at low temperature and excellent hydrothermal stability at high temperature and thus received much attention for applications on diesel vehicles. In this review, we will focus on the recent studies on low-temperature NH3-SCR catalysts. In addition, the future directions of low-temperature SCR development will also be discussed.
Density functional theory study on organically surface-modified silicene

Organic surface modification may be critical to the practical use of silicene, which is a novel two-dimensional layered material. It is intriguing to know if organic surface modification seriously impacts the structural, electronic and optical properties of silicene. In this work, we focus on four hydrogenation-based organic surface modification schemes (hydrosilylation, alkoxylation, aminization and phenylation) with the experimentally demonstrated surface coverage of ∼33%. The geometrical structures, band structures and optical absorption of organically surface-modified silicene have been compared with those of silicene and hydrogenated silicene (H-silicene) in the framework of density functional theory. It is found that organic surface modification leads to the increase of the buckling distance of silicene, while causing the angles of bonds in the honeycomb structure of silicene to decrease. Although the initial hydrogenation makes silicene become an indirect-bandgap semiconductor, the subsequent organic surface modification schemes further change the band structure of silicene. Hydrosilylation, phenylation, alkoxylation and amination all give rise to the reduction of the bandgap of H-silicene. Hydrosilylated and phenylated silicene are indirect-bandgap semiconductors, while alkoxylated and aminated silicene are direct-bandgap semiconductors. Changes of the optical absorption induced by organic surface modification are well correlated to the corresponding changes of the band structure.
Isolation and crystal structure of xanthones from Swertia chirayita

In order to study the relationship between biological and pharmacological activities with their structures, a series of tri- and tetra-oxygenated xanthones including 1-hydroxyl-2,3,4,7-tetramethoxy xanthone 1, 1-hydroxyl-2,3,4,5-tetramethoxyl xanthone 2, 1-hydroxyl-3,5-dimethoxyxanthone 3,1,8-dihydroxyl-3,5-dimethoxyl xanthone 4 and 1,5,8-trihydroxyl-3-methoxy xanthone 5 have been isolated from Swertia chirayita. Their structures were established on the basis of spectral and chemical evidences. The crystal structure of 5 was also investigated by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic system, space group P1 with a = 7.1540(10), b = 7.520(2), c = 10.671(2) Angstrom, V = 562.7(2) Angstrom(3), alpha = 86.50(3), beta = 80.06(3), gamma = 85.00(3)degrees, Z = 2, D-c = 1.618 g/m(3), R = 0.0405, wR = 0.1028 and F(000) = 284. The molecular structure of 5 is nearly planar and four substituents are much closer to the plane. Compound 5 contains three intermolecular hydrogen bonds. A recent study shows that phenolic hydroxyls in xanthones are the main active groups capable of scavenging (OH)-O-. and O-2(.).
A comparison of CdTe grown on GaAs by molecular beam and organometallic vapor phase epitaxy

CdTe has been grown on (100)GaAs by molecular beam epitaxy (MBE), organometallic vapor phase epitaxy (OMVPE), and photoassisted OMVPE (POMVPE). Optimum conditions for OMVPE are governed by the thermodynamics of the Cd–Te system. The conditions for growing (100) or (111) material for each technique are presented. (111) growth is shown to proceed via the formation of a relatively Te‐poor Ga–As–Te surface phase. Surface treatments which result in different surface structures and yield (100) growth are presented.
Global Lightning Nitrogen Oxides Production

The intense heating of air molecules by a lightning discharge and subsequent rapid cooling of the hot lightning channel results in the production of nitrogen oxides (Chameides, 1986). The lightning nitrogen oxides, or “LNOx”for brevity (where NOx = NO + NO2), indirectly influences our climate since these molecules are important in controlling the concentration of ozone (O3) and hydroxyl radicals (OH) in the atmosphere (Huntrieser et al., 1998; see also Crutzen 1970, 1973, 1979; Chameides and Walker, 1973; Hidalgo and Crutzen, 1977). Analyses of Tropospheric Emission Spectrometer (TES) data show that tropical upper tropospheric ozone has the largest radiative impact (Aghedo et al., 2011). In addition, the distribution of ozone forcing can have a substantial influence on regional rainfall patterns, even more so than its global mean annual average forcing would suggest (Shindell etal., 2012). Since LNOx controls ozone and is the most important source of NOx in the upper troposphere (particularly in the tropics), lightning is important to climate (see the review by Schumann and Huntrieser, 2007). Furthermore, a substantial amount of LNOx is transported to higher latitudes via the stratosphere, extending its influence even farther (Grewe et al., 2002, 2004).
Fundamentals of Shaped Charges

History of shaped charges applications the Gurney velocity approximation shaped charge jet formation the visco-plastic jet formation theory comments on explosive welding, bonding and forming the breakup of shaped charge jets shaped charge jet penetration models other aspects of shaped charges computational aspects of explosive-metal interactions wave propagation codes for shaped charge studies shaped charge generalities.