Miracle-dz/UniFAR-FTUs huggingface dataset:
80TH Anniversary of the discovery of the Raman Effect: a celebration

Eighty years ago on 31 March 1928, a letter dated 16 February was published in Nature by C. V. Raman (Fig. 1) and K. S. Krishnan with the title ‘A New Type of Secondary Radiation’. This letter, which is reproduced in Fig. 2, was the first account in the scientific literature of what soon became known as the Raman Effect. The experiments reported in this letter were based on the use of complementary light filters to detect the presence of modified scattered radiation using focused sunlight as an excitation source and the eye as a detector. Raman and his co-workers soon improved on this rather basic experimental procedure by using a spectroscope to examine the scattered radiation. The first Raman spectrum was reportedly obtained on 28 February 1928. On 29 February the Associated Press of India gave the first newspaper report under the heading ‘New Theory of Radiation – Prof. Raman’s Discovery’; and on 1 March 1928, The Statesman, an English language daily of Calcutta, carried an article with the title ‘Scattering of Light by Atoms – New Phenomenon – Calcutta Professor’s Discovery’ which is reproduced in Fig. 3. The paragraph heading ‘Two colours from one’ is attractive and accurate journalism, but there are several palpable scientific errors in the text. It has to be recognised that Raman’s earliest papers were couched in rather general terms and it was only in a letter submitted to Nature on 22 March and published on 5 May that a spectrum was presented, although spectra were included in a lecture by Raman in Bangalore on 16 March. Shortly after the publication of Raman and Krishnan’s letter in Nature, Landsberg and Mandelstam in Russia reported the observation of light scattering with change of frequency in quartz in a paper in Die Naturwissenschaften published on 13 July 1928 and reproduced here in Fig. 4. This paper was submitted on 6 May, one day after the official publication date of Raman and Krishnan’s definitive paper. Landsberg and Mandelstam could not have had any information in Moscow about this paper but they did refer to Raman’s earlier publications saying that they were unable to decide whether there was any connection with their work because Raman’s description was too brief and lacking in detail. The two discoveries must be regarded as quite independent. Although quantum theory was still in its infancy in the nineteen twenties, the Raman Effect had been predicted by quantum mechanics in two classic papers, one by Smekal1 published in 1923 and one by Kramers and Heisenberg2 in 1925. Figure 1. C. V. Raman.
Identification of Electrolytes in Aqueous Solutions from Near-IR Spectra

Dissolution of electrolytes causes characteristic changes in the near-IR spectrum of water. These changes result from a decrease in the concentration of water; charge-dipole interactions between ions and water molecules; formation of hydrogen bonds between oxygen or nitrogen atoms in some ions and water molecules; production of H+ and OH− ions from dissociation and hydrolysis; absorptions due to OH, NH, and CH groups in some ions; and intrinsic colors of some transition metal ions. Changes in spectra were used for identification of electrolytes in aqueous solutions. Near-IR spectra of 71 solutions of single electrolytes were measured and used to develop a spectral library. This near-IR spectral library was processed with principal component regression (PCR) and used for the identification of single and multiple electrolytes in aqueous solutions with the use of their spectra. Most of the unknown electrolytes were identified correctly. For the others, very similar electrolytes were selected with one ion identified correctly. The near-IR spectral library of aqueous solutions of electrolytes can be used as a simple and fast approach for the identification of electrolytes.
Accurate Bragg intensities for uracil: a thermal parameter refinement

Auszug Mit einem Diffraktometer und Mo-Kx-Strahlung wurden an einem UracilKristall genaue Intensitäten einer großen Anzahl von fcfcZ-Interferenzen gemessen. Die mittlere Genauigkeit ist weniger als 2°/o. Sekundärextinktion wurde durch Beugung am Kristallpulver eliminiert. Mehrfache Streuung wurde nicht beobachtet. Die Wechselwirkung zwischen den Wärmeparametern und den Beugungefaktoren wurde an einem einfachen Modell analysiert. Die Verfeinerung der anisotropen Wärmeparameter auf Grund von Interferenzen, für welche (sinö)/A größer als 0,648 Ä _ 1 ist, führt zu Werten, die sich deutlich von denen unterscheiden, welche sich bei Berücksichtigung aller Interferenzen ergeben. Die Abweichungen in den Kohlenstoff-Parametern sind im Einklang mit den neuesten Ergebnissen kombinierter Röntgenstrahlund NeutronenAnalyse. Abstract Accurate and extensive three-dimensional intensity data for a single crystal of uracil have been collected by difiractometry using MoÄS χ-radiation. The average precision in the Bragg intensities is less than 2%. Secondary extinction was eliminated by powder-diffraction measurements. Multiple diffraction could not be detected. The interaction of thermal parameters with scattering factors is analyzed with a simple model. A refinement of the anisotropic thermal parameters, based on reflections for which (sinö)/A exceeds . 648 A 1 , led to values which are significantly different from refinement based on all data. The carbon-atom parameter differences are consistent with recent studies of combined x-ray and neutron-diffraction analysis.
Repercussões clínicas e histopatológicas do dimetilsulfóxido em gerbils submetidos a isquemia cerebral experimental

O objetivo do presente estudo foi investigar as acoes neuroprotetoras do dimetilsulfoxido nas alteracoes clinico-comportamentais e histopatologicas do encefalo de gerbils submetidos a isquemia cerebral experimental atraves da oclusao permanente da arteria carotida comum esquerda. Os animais foram divididos em 5 grupos com 6 animais cada. Os animais controles foram os nao operados (grupo I), falsos operados (grupo II - sham) e isquemiados nao tratados (grupo III). Os animais que recebeam DMSO foram dos grupos IV e V. Trinta minutos antes da cirurgia experimental, 215mg/kg de DMSO a 10% foi administrado intraperitonealmente nos animais do grupo IV (DMSO I) e 645mg/kg de DMSO a 10% nos animais do grupo V (DMSO II). Sinais clinicos de lesao neurologica foram observados no 1° dia pos-isquemia. O comportamento motor exploratorio foi avaliado atravpes da frequencia de cruzamentos e levantamentos observados na arena circular durante os quatro dias subsequentes a isquemia. Eutanasia foi realizada no 7° dia pos-0isquemia para posterior analise histologica do encefalo. Para analise estatistica utilizou-se o teste ANOVA (significância estatistica p<0,05). A taxa de mortalidade apos a isquemia foi de 60% no grupo isquemiado nao tratado, 33,4% no grupo DMSO I e 14,3% no grupo DMSO II. Os animais nao tratados apresentaram sinais clinicos de lesao, como flexao da pata dianteira (hemiparesia), marcha espontânea em circulo e ptose palpebral. Os animais tratados (DMSO I e II) apresentaram apenas pstose palpebral. Os animais tratados (DMSO I e II) apresentaram maior frequencia de cruzamentos no 2°, 3° e 4° dias em relacao ao grupo isquemiado nao tratado. O grupo DMSO I apresentou maior frequencia de levantamentos no 2° e 4° dias e o grupo DMSO II em todos os dias de avaliacao em relacao ao grupo isquemiado nao tratado. Os resultados histopatologicos evidenciaram extensas areas de necrose de celulas nervosas no hipocampo e cortex frontal, parietal e temporal no grupo isquemiado nao tratado. Nos animais tratados as areas isquemnicas foram reduzidas. O grupo DMSO II apresentou menor porcentagem de neuronios isnquemicos hicocampais (46,1 + ou - 3,4) em relacao ao grupo DMSO I (54,6 + ou - 11,7) e grupo isquemiado nao tratado (71,17 + ou - 10). DMSO reduziu mortalidade pos-isquemia, permitiu melhor comportamento motor exploratorio e reduziu lesoes isquemicas encefalicas, sugerindo efeito neuroprotetor para estes animais.
Detection of ivermectin residues in bovine liver using an enzyme immunoassay

Ivermectin, a member of the avermectin group, is frequently used to control parasites in many food producing animal species. A method for the detection and quantification of ivermectin residues in bovine liver has been developed. Liver samples (4 g) were extracted with acetonitrile and applied to a competitive enzyme immunoassay using a polyclonal antiserum raised in rabbits against an ivermectin-transferrin conjugate. The limit of detection of the assay (mean ± 3s) calculated from the analysis of 24 known negative samples was 1.6 ng g–1. Intra- and inter-assay RSDs were determined as 8.8 and 14.6%, respectively, using a negative bovine liver sample fortified with 100 ng g–1 of ivermectin. Four Friesian steers were treated with a pour-on application of ivermectin at a dose rate of 0.5 mg kg–1 body mass then withdrawn and killed at 7, 14, 21 and 28 d. Livers were removed and ivermectin residue concentrations determined using the proposed immunoassay procedure. Seven days post-treatment the ivermectin liver concentration was determined as 52.7 ng g–1, decreasing to 4.1 ng–1 at 28 d. All immunoassay results were confirmed using high-performance liquid chromatography (HPLC). The immunoassay and HPLC results for invermectin ranged from 1 to 58 ng g–1 and were in close correlation (r = 0.99).
Scanning Near-Field Exciton Microscopy: Detection of Single Molecules on an Organic Surface

We investigate the detection of single molecules on an organic surface using a scanning molecular exciton microscope in the collection mode. To that end we present a theoretical framework to determine the detected intensity in dependence on the wavelength of the incident electric field and the distance between tip and sample. The tip and sample are treated quantum mechanically and are modeled as an ensemble of organic molecules with a single resonant energy level and a transition dipole moment. The electronic excitations are described by Frenkel excitons. Dipole−dipole interaction causes the energy transport via exciton transfer. The electromagnetic field is described by the classical Maxwell equations. Using a self-consistent solution of the Schrodinger equation and the Maxwell equations we calculate the induced polarization in the tip molecule and from this the intensity which is observed in the far field. By means of numerical investigations we are able to explain the realization of the contrast in the.
Biological nitrate removal using waste-derived extracts as sole carbon source

Waste-derived multicomponent extracts were investigated as carbon source for biological nitrate removal. Aerobic and anaerobic sludge from a municipal wastewater treatment plant and leachate from an anaerobic digester treating food waste were studied. Alkaline-heat treatment was used for sludge solubilisation. More than 90% carbon was recovered at pH 10–11. The extracts contain very high volatile fatty acids (VFAs), protein and carbohydrate. The protein/carbohydrate ratio was 2/1 for both aerobic and anaerobic sludge extracts and 9/1 for leachate. Of the total chemical oxygen demand (COD), 60% was solubilised in both the aerobic and anaerobic sludge extracts, while 80% was solubilised in the leachate. The extracts were successfully tested in batch experiments for different time intervals as a sole carbon source for biological nitrate removal in synthetic wastewater. More than 95% nitrate removal was achieved in 24 h batch studies at carbon-to-nitrate (C/N) ratio of 8 and at 35oC. The nitrate removal performance was comparable to that obtained with glucose as the external carbon source. Further, the nitrate removal efficiency of all the three extracts is similar. Thus, the result of this study shows the potential of these waste derived materials for the low-cost treatment of nitrate rich wastewaters characterised by low C/N ratio that are generated from many industries.
Synthesis and Electronic Spectra of Substitutedp-Distyrylbenzenes for the Use in Light-Emitting Diodes

The influence of substitution on the absorption and Luminescence spectra of oligo(phenylenevinylene)s has been studied using distyrylbenzene (DSB) as a model compound. The degree, character, and pattern of substitution was varied systematically, altering the electronic properties of the DSB, the wavelength of the emitted light could be tuned over a range of 100 nm. The syntheses of 6b—h were performed by twofold Wittig Horner-olefinations of bisphoshonates 1a, b with substituted benzaldehydes 2a—i, 6ivia Heck-reaction of the dibromosulfonylbenzene 3, 6k by Siegrist-reaction of 4 with N-phenylbenzaldimine and the Knoevenagel-reaction of benzyl cyanide with 5 led to 6l.
The effect of electric fields on Ag(001)

The electronic structure of Ag(001) with an adsorbed overlayer of Xe is calculated in external electric fields of varying strength. The screening mostly takes place on the top of the surface Ag atoms, with polarization of the Xe atom. The variation in the centroid of the screening charge (the image plane) with field strength is studied, and it is found that the adsorption of Xe reduces the non-linear response compared with that of the clean Ag surface. The distribution of screening charge between the various atoms is found using a generalized effective charge, and it is found that the screening charge on Ag atoms directly underneath Xe is enhanced. The generalized effective charge gives the derivative of the force at the surface with respect to the electric field, and the phenomena of field-induced chemisorption and field desorption are discussed in these terms.
UTILIZATION OF TURMERIC AS A NATURAL PIGMENT IN RAS CHEESE

The research on curcumin has received a considerable attention due to its pronounced medical and industrial properties. Turmeric as a natural pigment with its active component curcumin was used in this study in the manufacture of Ras cheese as a replacer to annatto. Ras cheese was manufactured in triplicate with replacement of annatto by addition of 0%, 0.5, 1%, 1.5%, 2% and 2.5% turmeric. Cheeses were ripened at 12±2°C for 3months. Chemical analysis for moisture, fat, salt in moisture, pH, acidity, total nitrogen content (TN), water soluble nitrogen (WSN) and total volatile fatty acids (TVFA) were determined as well as bacteriological analysis to the treatments. Sensory evaluation of Ras cheese was performed when fresh and during ripening every month . The cheeses were graded for characteristics “Flavor/aroma, body/texture and appearance”. The percentage of moisture decreased and the salt % increased in all matured Ras cheese especially in the samples ripened for 90 days. The fat content %, the mean values for TN%, WSN/TN% and TVFA increased along with the increase in turmeric concentrations in all of the treatments. Sensory evaluation of the Ras cheese samples manufactured with 0.5 % and 1% turmeric exhibited more acceptable sensory evaluations than the cheese samples made with higher turmeric concentrations compared with the control cheese manufactured with annatto. To conclude, turmeric could be used as a natural pigment in the dairy products that may help focus on its beneficial medical and industrial properties.
Investigation of a system capable of photoinitiating radical polymerizations in thick pigmented media

A new system consisting of a xanthenic dye, a ferrocenium salt, a hydroperoxide, and an amine, capable of photoinitiating the radical polymerization of thick and pigmented films exhibiting a thickness of ca. 100 microns was studied. This is a one-step process, with a working speed of 10 m min 1 , involving four 80-W cm -1 lamps. This is one present-day system capable of working under industrial conditions. The photolysis investigation in solvent medium of its various components is a first approach to discuss the photochemical mechanism involved in this four-component system. Thus, one can assume that both mechanisms could occur through charge transfer: dye/amine interaction and dye/ferrocenium salt interaction, the latter one being presumably the most efficient.
A model of hindered solute transport in a poroelastic shale

Theories for the transport of solvent and solute through an imperfect semi-permeable membrane are used as the basis for a model of transport through shale. The flow of solute is reduced, relative to that of solvent, by a transmission coefficient λ ≼ 1. In this model, it is assumed that the chemical composition of the pore fluid has no direct effect upon the swelling of the shale, other than via the thermodynamic pressure p. Invasion is governed by a pair of coupled diffusion equations. There is an initial, rapid diffusion of pressure, leading to a swelling pressure (1-λ)RT∆x/Vw, where RT∆x/Vw is the van’t Hoff osmotic pressure difference due to a change in solute mole fraction ∆x. A subsequent slow diffusion process, dominated by diffusion of the solute, then occurs. A change in solute concentration has been assumed to have no direct effect upon the rock, and ultimately has no effect upon the pore pressure and stress. Nevertheless, imperfect exclusion of solute can lead to transient changes in pore pressure which might destabilize the shale before the final steady state is achieved. This is demonstrated by a poroelastic analysis of pressure and solute diffusion into rock surrounding a wellbore.
Metal-Based Molecular Design Tuning Biochemical Behavior: Synthesis, Characterization, and Biochemical Studies of Mixed Ligand Complexes Derived From 4-Aminoantipyrine Derivatives

ABSTRACT Biosensitive mixed ligand complexes of metals (Fe(III), Co(II), Ni(II), Cu(II), and Zn(II)) with the Schiff bases of L1 and HL2 (L1: obtained through the condensation of 4-aminoantipyrine with furfuraldehyde; HL2: derived from 2-aminophenol and 3-nitrobenzaldehyde) were synthesized. They were characterized using elemental analysis, magnetic susceptibility, molar conductance, proton nuclear magnetic resonance spectroscopy, ultraviolet–visible spectroscopy, infrared, and electron spin resonance techniques. Cyclic voltammogram of the complexes in dimethylsulfoxide solution at 300 K was recorded and their salient features were summarized. The X-band electron spin resonance spectrum of the copper complex in dimethylsulfoxide solution at 300 and 77 K was recorded. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, and Pseudomonas aeruginosa and the fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola, and Candida albicans by disc diffusion method. Comparative study of inhibition values of the Schiff bases and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligands. DNA binding studies of metal complexes using ultra-violet-visible spectroscopy and cyclic voltammetry paved the way to probe their DNA binding abilities. The solvatochromism and superoxide dismutase activity of these complexes have also been examined.
L'effet de serre atmosphérique : plus subtil qu'on ne le croit !

State-of-the-art radiative models can be used to calculate in a rigorous and accurate manner the atmospheric greenhouse effect, as well as its variation with concentration in water vapour or carbon dioxide. A simple explanation of this effect uses an analogy with the greenhouse effect produced by a glass window. While this analogy has pedagogical virtues and provides a first order explanation of the mean temperature of the Earth, it has an important drawback; it is not able to explain why the greenhouse effect increases with increasing carbon dioxide concentration. Indeed, absorption of infrared radiation by carbon dioxide is, under this scheme, almost at its maximum and depends very weakly on CO2 concentration. It is said to be saturated. In this paper, we explore this question and propose an alternative model which, while remaining simple, correctly takes into account the various mechanisms and provides an understanding of the increasing greenhouse effect with CO2 concentration, together with the corresponding climate warming. The role of the atmospheric temperature gradient is particularly stressed.
Supercritical carbon dioxide separation of bergamot essential oil by a countercurrent process

The efﬁciency of separation of bergamot essential oil, performed by a countercurrent column ﬁlled with Raschig rings and using supercritical carbon dioxide as partition solvent, is affected by various parameters. In the experiments explained in this work, the direct effect of CO2 density was shown and the ratio between the amount of oil loaded to on the column and the amount of CO2 used were discussed. The conditions that produced extracts with a similar volatile fraction composition of starting material and with a high yield (more than 80% of recovery) were those with a low feed:solvent ratio; the lowest bergaptene content was obtained at low CO2 density or at high feed:solvent ratio. A good result was observed at a CO2 density of 206 g/dm3 (8 MPa of pressure and a temperature gradient of 46–50–54 °C) and a feed:solvent ratio of 9.4–9.6; in this separation, a yield of 74–77% and a bergaptene content lower than 0.01% was measured. Copyright © 2003 John Wiley & Sons, Ltd.
The Effect of Functional Nanoclays in Enhancing the Fire Performance of Fibre-forming Polymers

This paper reviews the present interest in the use of functionalised nanoclays as additives for improving tensile properties and fire performance in fibre-forming polymers. However, evidence over the last three years suggests that, when present by themselves, they will not be able to fulfil all the required features of an ideal flame-retardant, such as conferring ignition-resistance, self-extinguishability, and char-forming propensity. By using cast films as models for eventual fibre geometries, recent work in our own laboratories suggests that nanoclays may increase the effectiveness of more conventional normal flame-retardants (FRs) and thus enable lower quantities to be used, an especially important requirement in synthetic-fibre production and processing. In this paper, we also extend earlier work and report the effect of introducing two commercial nanoclays of known chemical structure into films of polyamide 6 and 6.6 in combination with selected phosphorus-containing flame-retardants. By using the limiting-oxygen index as a means of measuring increased flame-retardant properties, it is shown that the addition of low levels (2% w/w) of nanoclay does increase the over-all flame-retardant behaviour of films in the presence of defined concentrations (11–27% w/w) of flame-retardant, thus enabling lower concentrations of the latter to be used. As a means of understanding such synergistic activity and in order to be able to develop more effective combined nanoclay-FR systems, a simple model is proposed.
Chromium removal from tannery wastewater using ground shrimp shells

Crustacean shells contain high levels of chitin, a biopolymer that can be used to chelate metal ions. This study investigated the use of crustacean shells for chromium removal from tannery wastewater. Preliminary experiments aimed to determine whether chromium removal was due to adsorption by the carbohydrate's chemical groups or to formation of insoluble chromium hydroxide due to the pH increase from addition of the polysaccharide to the wastewater. These experiments were performed using synthetic wastewater and commercial chitosan, a chemical compound obtained by chitin deacetylation. Subsequent experiments, carried out using tannery wastewater, were performed to determine whether chromium could be recovered from the sludge. Finally, different amounts of ground shrimp shells from fi shery waste were used to remove chromium from tannery wastewater. The results showed that chromium removal was mediated primarily by adsorption and that chromium recovery from sludge was possible at very low pH. Ground shrim.