Miracle-dz/UniFAR-FTUs huggingface dataset:
Characterization of the Static Disorder in the B850 Band of LH2

A systematic simulation study, guided by the expressions of the first-order perturbation theory, was performed for a model of the B850 band in the light harvesting complex 2 of purple bacteria. General types of Gaussian disorder, which include diagonal, off-diagonal, coexisting but independent diagonal and off-diagonal, and correlated diagonal and off-diagonal disorder, were considered. The effects of these types of disorder were studied by calculating four quantities that characterize the energy distribution of the three lowest levels, varying the magnitude of the disorder. For all the cases considered, except for one of the correlated disorder models, a common scaling relation was found among the four quantities, which is in reasonable agreement with available low temperature experimental data. On the basis of this fact and further physical reasoning, it is concluded that the disorder in the B850 is likely Gaussian and that comparable magnitudes of both diagonal and off-diagonal disorder coexist. Three .
Chemical composition and antibacterial activitiy of the essential oils of Algerian Myrtus communis L.

Myrtus communis L. leaf essential oils from Algeria were analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). A total of thirty-four components were identified accounting for 95% of the oil. The main compounds were limonene (23.4%), linalool (15.4%), geranyl acetate (10.9%), α-pinene (10.7%), linalyl acetate (8.2%) and 1,8-cineole (6.6%). The antimicrobial evaluation showed that myrtle oil exhibited good antibacterial activity against Staphylococcus aureus, Proteus mirabilis and Kleibsiella pneumonia, but differed according to the strains. Conversely, it was not active against Pseudomonas aeruginosa.
Counterion Effects on Properties of Cationic Vesicles

The effect of counterion nature and concentration on phase transition, bilayer structure, vesicle size, vesicle internal volume per mole of amphiphile, and surface potential is evaluated for cationic vesicles composed of dioctadecyldimethylammonium (DODA) acetate, chloride, or bromide. Over a range of ionic strengths (0−5 mM monovalent salt), no interdigitation was detected in the bilayer structure for the three DODA counterions. The preferential type of aggregate formed from self-assembly of DODA salts is a large vesicle composed of a single traditional and noninterdigitated bilayer. Vesicle size and zeta-potentials were inversely related, i.e., an increase in zeta-potential was accompanied by a decrease in vesicle size. The largest zeta-potentials and smallest sizes were obtained for bilayer vesicles of DODA acetate which have the largest and more hydrated counterion. The effect of ionic strength (0−5 mM NaAc, NaCl, or NaBr as monovalent salt) was a slight decrease followed by a significant increase in .
Cancellation of matrix effects and calibration by isotope dilution in isotope-selective diode laser atomic absorption spectrometry

High-resolution atomic absorption measurements of lead isotopes are performed in a graphite tube atomizer with integrated low-pressure dc discharge using frequency-doubled laser diode radiation at 405.78 nm. For the first time, calibration by isotope dilution is demonstrated in analytical laser spectroscopy. Furthermore, isotope dilution is proved to be an effective technique for cancellation of chemical as well as physical matrix effects in optical spectrochemistry.
H2O2 evolution during the photocatalytic degradation of organic molecules on fluorinated TiO2

The effect of TiO2 surface fluorination on the hydrogen peroxide evolution occurring in photocatalytic runs was investigated employing the azo dye Acid Red 1 (AR1) and two model organic molecules with acidic properties, i.e. formic acid (FA) and benzoic acid (BA), as substrates of oxidative degradation. While AR1 and BA photocatalytic degradation on fluorinated titanium dioxide (F–TiO2) was markedly faster than on unmodified TiO2, because of enhanced hydroxyl radical formation, H2O2 concentration during the photodegradation of both substrates on F–TiO2 was lower, possibly because of the reduced rate of interfacial electron transfer. By contrast, FA underwent slower photocatalytic degradation on F–TiO2, but, at the same time, hydrogen peroxide concentration was relatively high, while no H2O2 could be detected during FA photodegradation on unmodified TiO2. Photocatalytic runs in the presence of the nitrate anion, able to react with the CO2˙− species produced from FA oxidation, but not with conduction band electrons, demonstrated that CO2˙− plays a relevant role in H2O2 formation during FA degradation on F–TiO2. In fact, surface fluoride, having a shielding effect at the semiconductor–water interface, not only inhibits the photocatalytic decomposition of H2O2, but also favours CO2˙− desorption and reaction with dissolved O2, generating H2O2. By contrast, CO2˙− mainly gives electron transfer to the conduction band of naked TiO2 and surface reduction of the photocatalytically produced H2O2.
Seismic Imaging by Impulse Response for Studying Crustal Structure of the Central Tibet

Time-shifted source functions along with unwanted events produce the composite seismic trace. The time-shift varies according to the travel path of the source, which is reflected back from an interface. The arrival times of the reflected waves have been estimated as time-shifted sources in a technique with the application of Fourier transformation of composite seismic trace and source functions. Accurate time-shifts and amplitude coefficients are determined using the technique in the composite seismic traces. A very small time-shift has also been shown resolved. The technique is applied to INDEPTH seismic data and impulse responses are successfully obtained. Analyzed impulse response images have given the stratigraphic idea beneath the region of the central Tibet. High amplitude impressions in the implemented images have indicated the presence of a strong support that upholding the northern geology and high probability of further crustal change of the region. The technique impulse response is considered robust for the seismic reflection sequence analysis and can be used effectively for studying the subsurface geology. Â Â Keywords : Seismic trace; Power spectrum; Impulse response; Reflection sequence; Subsurface geology. Â Â© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. Â DOI: 10.3329/jsr.v1i1. 1082
Synthesis of Cotinine and Cotinine N-oxide: Evaluation of their Interaction with Nicotine in the Insecticidal Activity

Abstract To evaluate the nature of nicotine interaction with its derivatives, cotinine and N-oxide cotinine were synthesized. In both Lucilia caesar (L. c.) and Calliphora vomitoria (C. v.) flies, nicotine is found more insecticidal than all its derivatives studied. The relative insecticidal activity, determined by the method of Wadley, of nornicotine is ≤ 73%, that of cotinine ≤ 3% and that of cotinine N-oxide ≤ 0.4%. The nature of nicotine interactions with its derivatives was studied by Wadley and Steel and Peckham methods. The two methods indicate that nicotine and nornicotine act at common levels, while nicotine and cotinine act at distinct levels. We concluded that nicotine oxidization is an efficient natural mechanism to nicotine detoxification and that nicotine and cotinine act at distinct molecular levels.
Photofragment ionization-loss stimulated Raman spectroscopy of a hydrated neurotransmitter: 2-phenylethylamine–water

Different types of spectral signatures and their interpretation provide valuable information on intra- and inter-molecular interactions that lead to unique shapes of molecules and clusters. Here, ionization-loss stimulated Raman (ILSR) spectra of the 2-phenylethylamine–water (PEA–H2O) cluster were obtained by monitoring the spectral signatures of PEA and of CH2NH2–H2O (a hydrated portion of the PEA tail) fragment ions. The ILSR spectra of both fragments were found to be similar, indicating that they are actually reminiscent of the PEA–H2O cluster signature. Comparison of the photofragment spectra to anharmonic calculated Raman spectra of the different conformers of the PEA–H2O clusters, suggests a structure with PEA similar to that of the most stable gauche conformer, with H2O hydrogen bonded to the nitrogen lone pair.
A Comprehensive Study on Infrared Spectra of 2-Hydroxyxanthone

ABSTRACT A study on the IR spectra of 2-hydroxyxanthone that was both experimental and theoretical was carried out in this work. The optimized structure and related spectral parameters were obtained by using the Becke-3-Lee-Yang-Parr (B3LYP) method with the 6-31G* and 6-311G** basis sets. The corresponding geometrical parameters were compared with each other. Detailed assignments of the vibration frequencies were performed. The agreement between the scaled theoretical frequencies and the observed frequencies was found to be quite good. Also, the calculation accuracies of the two basis sets are close.
Interactions of proteins and cells on functional group gradient surfaces

Charge gradient and comb-like polyethylene oxide (PEO) gradient surfaces were prepared on low density polyethylene (PE) sheets by corona discharge treatment with gradually increasing power and the following graft copolymerization of chargeable functional group- and PEO-containing vinyl monomers, respectively. Those gradient surfaces were used to investigate protein or cell interactions in relation to the surface functional groups and their density of polymeric materials.
Effects of a Compositionally-Graded InxGa1-xAs Base in Abrupt-Emitter InP/InGaAs Heterojunction Bipolar Transistors

A compositionally-graded Inx Ga1-x As base is experimentally shown to improve electron transport properties in abrupt-emitter InP/InGaAs heterojunction bipolar transistors (HBTs). The built-in field in the base of 6 kV/cm enables a more than 50% improvement in current gains, compared to a uniform-base structure. The peak current-gain cutoff frequency f T for the graded-base HBT is 143 GHz versus 121 GHz for the uniform-base HBT. It is also shown that the graded-base structure is effective in suppressing the space charge in the vicinity of the base-collector junction. The built-in field in the base accelerates low-speed energy-relaxed electrons and thereby increases the velocity of electrons injected into the collector. The minimized base widening effect, combined with low base resistance, yields a maximum oscillation frequency f max over 200 GHz even at a collector bias voltage V CE as low as 1 V.
‘‘Aging’’ of the structure of crystals of hard colloidal spheres

We study the development of the structure of crystals of colloidal hard spheres in time when gravity effects are minimal and polydispersity is small (<3%). The initial stacking of the close-packed hexagonal layers that make up the crystals is varied by applying various types of shear stress during nucleation of the crystals. The experimental powder diffraction patterns are consistent with a fraction of a faulted-twinned face-centered cubic (fcc) structure that grows at the expense of randomly stacked crystallites. If a faulted-twinned fcc structure is generated initially, no change is found over a considerable time. The present observations rule out the possibility that a randomly stacked structure is the equilibrium structure of colloidal crystals of (nearly) hard spheres, and point to the thermodynamic or kinetic stability of faulted-twinned fcc crystals in these systems.
An Investigation into News Webpage interface Design in Kurdistan Region of Iraq

Recently the Kurdistan Region of Iraq has experienced an explosion in exposure to new technologies in different sectors especially in media and telecommunication. Internet is one of those technologies that have opened a way for information proliferation amongst a previously censored region. Developing web sites to deliver news and other information is a relatively new phenomenon in Kurdistan; this means that the design and development of web pages may lack the quality standard required. In this paper the quality of webpage interface design and usability in the field of news journalism in the KRI is examined against a set of web interface design and usability criterion. For the purpose of data collection 9 available popular news websites are chosen and 900 questionnaires are sent to 100 random users. The result is analyzed and we have found that the majority of users are satisfied with the interface design and usability of the news WebPages, however the result points out some weakness that can be improved. The outcome of this research can be used to enhance website design and usability in the field of journalism in the KRI. Keywords—KRI (Kurddistan Region of Iraq); HCI (Human Computer Interface)
FT-IR spectra of vacuum deposited clathrate hydrates of oxirane, H2S, THF, and ethane

An ability to prepare clathrate hydrates using low temperature–high vacuum techniques, originally demonstrated for the hydrate of oxirane (Bertie and Devlin), has been extended to include the structure I hydrate of H2S, the mixed structure I hydrate of oxirane and ethane, as well as the structure II simple hydrate of THF and the double hydrates of THF with oxirane and H2S. The crystalline clathrate films (∼6 μ) have been formed either by annealing amorphous host–guest deposits at ∼130 K, epitaxial growth at 110 K (oxirane and mixed ethane–oxirane), or direct deposition at 150 K (THF and its double clathrates). Use of the epitaxial approach at ∼100 K has permitted the formation of the oxirane clathrate hydrate containing intact isolated D2O molecules. This has permitted the FT–IR observation of the ν3–ν1 doublet in the O–D stretching region (2455 and 2380 cm−1 at 100 K) with the values, after correction for Fermi resonance, suggesting a splitting from intramolecular coupling of ∼56 cm−1 (2455 vs 2399 cm−1).
Solvation structures of manganese(II), iron(II), cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), and indium(III) ions in 1,1,3,3-tetramethylurea as studied by EXAFS and electronic spectroscopy. Variation of coordination number

The structures of solvated complexes of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and In(III) ions in 1,1,3,3-tetramethylurea (TMU) have been determined by means of EXAFS (extended X-ray absorption fine structure) and electronic spectroscopy. The solvation structures in TMU are square pyramidal for the Mn(II) and Ni(II) ions, distorted tetrahedral for the Co(II) and Cu(II) ions, tetrahedral for the Zn(II) ion, and octahedral for the Cd(II) and In(III) ions, while in water all these metal ions are six-coordinated octahedrons. The solvation structure of Fe(II) ion is square pyramidal or trigonal bipyramidal. In the bulky TMU solvent, the coordination number should be reduced for relaxation of the sterically repulsive interaction around the solvated metal ions
Kinetics of DNA translocase SpoIIIE studied by dual optical tweezers

DNA translocase SpoIIIE protein is a kind of motor proteins, which transports DNA from one side of the membrane to the other side, so it plays an important role in cell division. In experiment, λDNA is labeled on one end with biotin and the other with digoxigenin. In this work we study kinetics of DNA translocase SpoIIIE by means of dual optical tweezers. In our experiment, λDNA is tethered between streptavidin-coated polystyrene bead and antidigoxigenin-coated polystyrene bead held by dual optical tweezers. One trap is immovable, and the other is movable. When SpoIIIE protein transports DNA, the length of DNA changes. The length change can be calculated according to the displacement of the trapped bead, which is detected by quadrant photodiode. When SpoIIIE transports DNA, DNA is shortened by up to about 500nm, then as the translocation stops, the DNA returns to its normal length, and this process repeats time and time again. The most probable speed that SpoIIIE transports DNA is 710nm/s.
Fate and transport of plutonium-239+240 and americium-241 in the soil of Rocky Flats, Colorado

Actinides contamination of soils around Rocky Flats, CO, resulted from leaking drums of Pu-contaminated oil stored at an outdoor site. The transport of these actinides through the soil to groundwater was studied using an advanced monitoring system (MS). The fully automated, remotely controlled MS gathered real-time data on soil water content, groundwater level, and timing of gravitationally flowing water. Controlled rain simulations coupled with measurements of volume flux and actinide activities provided essential information about the fate and transport of Pu-239 + 240 and Am-241. Volume fluxes at most sampling locations were similar, regardless of the antecedent moisture or the duration, frequency, and intensity of the simulated rain. Actinide activities were not correlated with the measured volume flux, or the duration, frequency, and intensity of the simulated rain. Flow was facilitated primarily via macropore channeling. The relatively short residence time precluded a continuous interaction between the soil and the flowing water, which minimized the movement of actinides in the soil. Actinide activities in the interstitial water collected from the upper 20 cm of the soil were significantly higher (P>0.001) than water collected at deeper sampling depths (20-70 cm). Actinide activity in water samples from the deepest sampling depth (40-70 cm)more » did not exceed 0.4 Bq/L. These results suggest that, under the experimental conditions, the movement of actinides was restricted to the top 20 cm. A transport mechanism involving discrete Pu oxide particles, coupled with macropore channeling is proposed to explain the observed actinide activities in the soil. 31 refs., 6 figs., 7 tabs. « less
Product branching in predissociation of the e 1Πu, e’ 1Σ+u, and b’ 1Σ+u states of N2

A measurement of the N(2D0) and N(2P0) yields in predissociation of the e 1Πu, e’ 1Σ+u, and b’ 1Σ+u states of molecular nitrogen is reported using photofragment spectroscopy. These states are prepared by laser excitation from the long‐lived a‘ 1Σ+g (v=0) level in a fast molecular beam. A position‐ and time‐sensitive detector is used to monitor the two correlated fragments produced by single molecular dissociation events. The translational energy imparted in the fragments establishes the electronic energy of the resulting nitrogen atoms and hence the branching among the available dissociation limits of nitrogen. Extremely pronounced rotational dependence in the branching yields is observed for the e and e’ members. The dependence mimics, in part, known molecular perturbation of the Rydberg states, and it reveals a complex competition among continuum states for the population in the Rydbergs.
Absolute rate parameters for the reactions of formaldehyde with O atoms and H atoms over the temperature range 250–500 K

Absolute rate coefficients for the reaction of H atoms and O atoms with formaldehyde were determined over the temperature range of 250 to 500 K. Linear Arrhenius behavior was observed in log(ki) vs 1/T plots for both reactions and the following rate parameters were obtained: k1(T) = (3.27±1.61) ×10−11 exp (−3670±365/RT) cm3 molec−1 s−1, k2(T) = (2.78±0.32) ×10−11 exp (−3030±80/RT) cm3 molec−1 s−1. Indicated error limits are two standard deviations. These results are compared with those of previous studies and are further discussed in terms of extrapolation to higher temperatures.
1:1 Cocrystal of 2,5-di-4-pyridyl-1,3,4-oxadiazole and hydroquinone

Hydrogen bonding is important in the areas of crystal engineering, supramolecular chemistry, materials science and biological recognition (Desiraju, 1989; Jeffrey & Saenger, 1991; Holman et al., 2001). Recently, angular dipyridyl-donor basic compounds, such as 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (bpo), have been used to produce a series of infinite/discrete coordination polymers/supramolecules with interesting structures and properties (Dong et al., 2003; Du et al., 2005). In our search to identify the properties of cocrystal materials of diols with linear/angular base components and to further understand the role of synthons in crystal engineering, we have prepared and determined the crystal structure of the acid– base cocrystal consisting of bpo and hydroquinone (Fig. 1).
Simultaneous Raman micro–spectroscopy of optically trapped and stacked cells

The combination of Raman spectroscopy and optical trapping holds great promise for single-cell studies and is an emergent theme in microfluidic environments. Here, the evolution of the Raman signal intensity with an axial increment of the mass of the substance of interest inside a specific Raman excitation volume is investigated. Whilst Raman spectroscopy may be applied to tissue samples, solutions and single cells, there are no easily available methods to rapidly acquire signals from small cell populations. We show a simple but powerful method to record the Raman intensity signal simultaneously from a small number of trapped cells or colloidal particles using the technique of optical stacking. The Raman spectra of stacks of red blood cells and yeast cells show that this method can be applied to biological systems. We demonstrate how we may reveal biochemical fingerprints that would otherwise require long integration times for each single cell or averaging over many sequentially acquired cell spectra. There is potential to apply this method to directly attain Raman spectra from sorted sub-populations of normal, abnormal and tumour cell lines. Copyright © 2007 John Wiley & Sons, Ltd.
THERMODYNAMIC PROPERTIES AND PHASE EQUILIBRIA IN THE TERNARY Cu-Pb-Fe SYSTEM

Using experimental data available in the literature, two binary systems, namely Cu-Pb and Fe-Pb were recalculated. Next, accepting Cu-Fe phase diagram assessment as given by Ansara and Jansson, the ternary Cu-Fe-Pb system was analyzed. Calculated equilibrium lines and thermodynamic functions are compared with existing experimental data. Good agreement was found between the calculated diagram and the experimental results. Having the system optimized, functional dependences of the logarithms of the activity coecients on temperature and concentrations for Cu, Fe and Pb in the liquid solution are given.
Institutional Factors Affecting Mathematics Performance In Morogoro (Urban) District Primary Schools, Tanzania

The study focused on “Institutional Factors Affecting Mathematics Performance in Morogoro (Urban) District Primary Schools”. The study was guided by four objectives to:examine the causes of unsatisfactory performance in Mathematics in primary schools; identify teaching methods used by primary school Mathematics teachers to improve the performance; analyze the pupils‟ and teachers‟ attitude towards Mathematics performance and find out classroom factors which influence performance in Mathematics.Amixed research design was used. Data were collected through interview, questionnaires and observation methods. The study findings showedthat 211(60.1%) pupils agreed that lack of pupils‟ Mathematics background,lack of teaching and learning materials, large classes, poor school infrastructures and lack of pupils and teacher motivation contributed to poor mathematics performance anmong the pupils in Morogoro. Also 326 (93.3%) of pupils revealed that small group discussion method, questioning method, problem solving method and demonstration methods was rarely used in Mathematics teaching because most of time lecture method dominated. Further more the findings showed that the students hated the mathematics subject and this could be the reason for the poor academic performance in mathematics among these students in Morogoro.The study recommends that the Ministry of Education, Science and Technology should provide efforts to improve teaching and learning environment in primary schools, along with reviving the mathematics subject clubs in primary schools.