Miracle-dz/UniFAR-FTUs huggingface dataset:
Surface Initiated Polymerization from Nanoparticle Surfaces

Abstract The synthesis, characterization, and development of new nanoparticle materials have both scientific and technological significance. Surface initiated polymerization (SIP) from nanoparticle surfaces involves the growth of end‐tethered polymer brushes where the length or thickness can be more than twice the radius of gyration (Rg) compared to a free polymer in solution. Different mechanisms are possible on a variety of initiators, reaction conditions, monomers, and nanoparticles. Important differences to solution and bulk polymerization can be observed where the nanoparticles with grafted initiators behave as macroinitiators. In turn, the development of these materials will allow the preparation of thermodynamically and kinetically stable nanocomposites and colloids. Through the careful use of surface sensitive spectroscopic and microscopic techniques, much has been gained from the direct and in‐situ analysis of grafted polymers on the nanoparticles with regards to the kinetics and mechanism of the polymerization process. Parallels can be drawn to SIP on flat surfaces where surface sensitive spectroscopic and microscopic measurements are complementary to analysis methods for colloidal particles. Thus, this review surveys the different polymerization mechanisms and procedures towards forming core‐shell types of hybrid inorganic–organic polymer nanoscale materials.
Current-Induced Magnetic Domain Wall Motion in a Co/Ni Nanowire with Structural Inversion Asymmetry

The authors have investigated the current-induced magnetic domain wall (DW) motion in perpendicularly magnetized Co/Ni nanowire with structural inversion asymmetry (SIA). In this system, DW motion to the direction of electric current flow, not electron flow, and high DW velocity up to 110 m/s were confirmed, which have never been observed in Co/Ni systems without SIA. In addition, we found that the DW velocity showed a strong dependence on the perpendicular magnetic field in the range of ±100 Oe. These results suggest that DW in the Co/Ni nanowire with SIA moves in the steady mode, not in the precessional mode.
Chemical controls on the solubility, transport and deposition of platinum and palladium in hydrothermal solutions; a thermodynamic approach

Thermodynamic calculations of the solubility of Pt and Pd up to 300 degrees C using isocoulombic extrapolation, the correspondence principle, linear free energy relationships, and the theory of stepwise ligand replacement indicate that, depending on physicochemical conditions, complexation by either OH (super -) , HS (super -) , or Cl (super -) can contribute to the transport of these metals in hydrothermal solutions.The soft character (in the Pearson sense) of Pt (super +2) and Pd (super +2) dictate that complexes of these ions with CO (super -2) 3 , HCO (super -) 3 , SO (super -2) 4 , PO (super -3) 4 , and F (super -) will be weak. Chloride complexing will be important only under highly oxidizing and acidic conditions. In highly saline fluids (i.e., Sigma Cl (super -) > 1.0 m), the predominant chloride complexes of Pt and Pd are PtCl (super -2) 4 and PdCl (super -2) 4 from 25 degrees to at least 300 degrees C. Approximately 10 ppb or greater of either Pt or Pd may be transported as chloride complexes in solutions in equilibrium with hematite at low pH (<3 for Pt and <4 for Pd) at 300 degrees C. Hydroxy complexes become important at slightly acidic to neutral pH and may be responsible for Pt and Pd concentrations of 1 to 10 ppb near the pyrite + pyrrhotite + magnetite triple point (i.e., near-neutral, relatively reducing conditions). The soft nature of the Pd (super +2) and Pt (super +2) ions suggests that bisulfide complexing should be important, in analogy with Au. At 300 degrees C and Sigma S = 0.1 m, it appears that Pt(HS) (super -2) 4 and Pd(HS) (super -2) 4 concentrations of at least 10 ppt may be attained near the pyrite + pyrrhotite + magnetite triple point. At Sigma S = 0.5 m, solubilities increase to 1 ppb in the same region. Under the conditions where solubility as HS (super -) complexes reaches a maximum at 300 degrees C, solubility as Cl (super -) is negligible. Between 25 degrees to 250 degrees C, solubility as HS (super -) complexes increases with temperature while solubility as Cl (super -) or OH (super -) decreases. The trend reverses above 250 degrees C. The effect of Se, Te, and As is generally to decrease the mobility of Pt and Pd, although the possibility of complexing by ligands involving Se, Te, and As cannot be entirely discounted.These calculations suggest that Pt and Pd may be mobile in a variety of environments. In kupferschiefer-type ore-forming fluids they could be transported as chloride complexes. The lack of acidic alteration and oxidized mineral assemblages in hydrothermal Pt and Pd occurrences in shear zones in metagabbroic rocks, such as those at New Rambler, Wyoming, and Rathbun Lake, Ontario, preclude Pt and Pd transport as chloride complexes during formation of these deposits. In these cases, bisulfide and/or hydroxide complexes are more likely responsible for precious metal transport.
An assessment of the impact of pollution on global cloud albedo

Increased pollution leads to increasing particulate concentrations. Since some particles nucleatedrop formation, clouds will contain, with increasing pollution, more drops per unit volume, andhence will tend to be optically thicker and more reflecting. An opposite effect is also present, inthat increasing absorption also attends increasing pollution. Measurements suggest that theformer (brightening) effect is the dominant one for global climate and that the climatic effect isquite comparable to that of increased carbon dioxide, and acts in the opposite direction. DOI: 10.1111/j.1600-0889.1984. tb00254.x
DETERMINATION OF TRACE HEAVY METALS IN DIFFERENT VARIETIES OF VEGETABLES AND FRUITS AVAILABLE IN LOCAL MARKET OF SHORKOT PAKISTAN

Heavy metals determination in food stuffs is of vital interest because of their essential or toxic nature. In order to assess the levels and impact of different trace metals on human health, a study was carried out to determine the levels of different trace heavy metals present in commonly edible vegetables and fruits which are available in local market of Shorkot City. For this purpose, total of eleven samples of different varieties of vegetables and fruits were purchased from the market and then were analyzed for trace levels of seven essential heavy metals including Fe, Mn, Cu, Co, Ni, Cr and Zn and two toxic metals Pb and Cd. Dried samples were digested by wet digestion method in the mixture of Hydrogen peroxide (H2O2) and Nitric acid (HNO3) and then were taken to the Atomic Absorption Spectroscopy for the metal determination. Perusal of the results obtained showed that Mn was analyzed as 0.220-3.334; Ni, 0.117-1.190; Zn, 0.245-3.873; Cu, 0.109-0.401; Co, 0.007-0.462; Cr, 0.211-1.298; Fe, 3.447-41.283; Cd, 0.002-0.627 and Pb was analyzed as 0.046-1.159mg/100g of sample dry weight. These values were found to be comparable with the literature values. The determined concentrations of metals in vegetables and fruits under investigation illustrated that these do not cause any major health hazards for the local consumers.
Fabrication and Properties of Novel Polyaniline/ Poly(styrene-co-maleic anhydride)cumene Terminated/4,4′-oxydianiline/Graphite-Based Nanocomposites via Layered Polymerization

An effective route for fabrication of nanocomposites of polyaniline (PANi) and poly(styrene-co-maleic anhydride)cumene terminated (PSMA) as matrices and 4,4′-oxydianiline (ODA) as linker via an in-situ ring opening polymerization was opted. Acidic functionalization afforded functional hydroxyl and carboxyl groups on the graphite surface (F-G). FESEM disclosed dispersion of polymers on graphite surface in NF-G/PANi/PSMA/ODA nanocomposite, while in F-G/PANi/PSMA/ODA nanocomposite, graphite sheets seemed to be covered with polymer. Relative to NF-G/PANi/PSMA/ODA (T10 444; Tg 245), F-G/PANi/PSMA/ODA exhibited higher thermal stability (T10 453; Tg 350). The electrical conductivity of F-G/PANi/PSMA/ODA was also remarkably improved by the incorporation of modified graphite upto 13.88 S cm−1.
Determination of Phosphorous and Nitrogen in the Sediment of Lake ‘pamvotis’ (Greece)

Abstract Phosphorous and nitrogen nutrients in the sediment of the lake Pamvotis were determined by standard methods of analysis. The pore water of the sediment was also analyzed for orthophosphate, ammonia and nitrate content. The results give evidence that nutrient phosphorus content of the sediment is increased at the summer periods and with nitrogen content being available during the whole year gives eutrophic behavior in the lake waters. However, the winter rains reduce the phosphorous content during the spring months. The phosphorus is introduced into the lake by agricultural runoffs and by trenches from urban areas. Several isolated events originating from activities of the inhabitants of the small island and the human activities around the lake give rise to temporary pollution of the lake waters.
Chemical Studies on Tobacco Smoke LXIV. On the Analysis of Aromatic Amines in Cigarette Smoke

A method for the analysis of aromatic amines in tobacco smoke has been developed. The amines from the smoke are trapped in dilute hydrochloric acid and are enriched together with the basic portion, derlvatlzed to pentafluoroproplonamides and determined by gas chromatography with a 63-NI. electron capture detector (detection limit 50 pg aniline/ cigarette). The mainstream smoke of one U.S. 85-mm cigarette without filter tip contained 102 ng of aniline, 61 ng of 2-,3-, and 4-toluidine, 55.8 ng of ethyl- and dimethylaniline, 4.3 ng of 1-naphthylamine, 6.9 ng of 2-,3-, and 4-aminobiphenyl, and 5.8 ng of 2-methyl-l-naphthylamine. Sldestream smoke contained levels of aromatic amines 20 to 68 times' higher than those in the mainstream smoke. The results from smoke analyses of experimental cigarettes support the concept that the nitrate content and the protein content of tobacco are determining factors for the smoke yields of aromatic amines. The possible biologic implications of this study are discussed.
Beneficial effects of commercial Assam green tea infusion on the microbial growth and oxidative stability of cooked beef

Natural preservatives having the great antioxidant and antimicrobial activity have been utilized in the food industry for many years. In the present study, the effect of of two brands of commercial Assam green tea infusion (represented by A and B) and 0.02% BHA/BHT on microbial growth, anti-lipid oxidation and color change were investigated in cooked beef. The green tea concentration has influenced to the results. It was found that A and B at the concentration of 250 mg/mL significantly reduced the population of Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium and E. coli in the cooked beef to an undetectable level within 2 days of storage at 4 o C. A and B also exhibited higher anti-lipid oxidation activity compared to 0.02% BHA/BHT, and control. Assam green tea infusions in cooked beef significantly increased ∆ L * value and decreased ∆ a * and ∆ b * value (p ≤ 0.05). These indicate that Assam green tea infusion might be a potential candidate as a natural preservative for beef and other types of food.
Harvest time residues of pendimethalin in tomato, cauliflower, and radish under field conditions

Herbicides applied to vegetables play an important role in higher production of vegetables due to effective and timely control of weeds but at the same time herbicides residue may produce numerous environmental problems. The aim of this study was to determine whether application of herbicide for control of annual weeds in vegetable growing areas at recommended levels resulted in residues at the time of harvest. Thus, terminal residues of pendimethalin in vegetables such as tomato, cauliflower, and radishes were studies under field conditions. Pendimethalin was applied as pre-emergence herbicides at 1 kg a.i. ha−1 to tomato, cauliflower, and radish crops. Soil and vegetables samples were collected from pendimethalin-treated plots at maturity to determine harvest time residues of pendimethalin. At harvest, 0.008, 0.001, and 0.014 μg/g residues of pendimethalin were found in tomato, cauliflower, and radishes, respectively.
Are CEOS Really Paid Like Bureaucrats

A common view of CEO compensation is that there is essentially no correlation between firm performance and CEO pay. This calls into question an important component of effective corporate governance. This zero correlation' belief is based on the widely cited result that CEO wealth rises by only $3.25 for every $1,000 increase in firm value (Jensen and Murphy, 1990b) and findings that the elasticity of CEO salary and bonus with respect to firm market value is only 0.1. We use a new 15-year panel data set of CEOs in the largest U.S. firms and focus on a broad measure of compensation' that includes changes in the value of CEO holdings of stock and stock options. We find very large pay to performance sensitivity. For example, for a moderate change in firm performance (moving from a median stock price performance to a 70th percentile performance), the compensation of the median CEO in our sample increases by more than 50 percent, which represents an increase in CEO wealth of $1.8 million. We estimate a median elasticity of CEO compensation with respect to firm value of 3.9 for 1994. This value is about 30 times larger than previous elasticity estimates that ignore the effects of changes in the value of stock stock option holdings. We also document that both the level of CEO compensation and th sensitivity of CEO compensation to firm performance have grown dramatically over the past 15 years. In our sample, the direct compensation (salary and bonus plus stock option grants) of the mean (median) CEO increased by 209 percent (136 percent) from 1980 to 1994. Because of the large increase in stock option awards and in the value of stock holdings in the past 15 years, measures of CEO pay-to-performance sensitivity increased during the period by factors of 2 to nearly 7.
Land and ocean carbon cycle feedback effects on global warming in a simple Earth system model

A simple Earth system model is developed by coupling a box model of the global carbon cycle to an energy-balance approximation of global temperature. The model includes a range of feedback mechanisms between atmospheric CO2, surface temperature and land and ocean carbon cycling. It is used to assess their effect on the global change being driven by anthropogenic CO2 emissions from fossil fuel burning and land-use change. When tuned to reach the 1990 level of atmospheric CO2, the model CO2 predictions for 1832–1990 are reasonably close to ice-core and instrumental records, observed global warming of ~0.6 K from 1860–1990 is accurately predicted and the land and ocean carbon sinks for the 1980s are close to IPCC central estimates. The ocean sink is reduced by ~0.3 GtC yr-1 when the ocean surface is assumed to warm at the same rate as global surface temperature. Land and oceanic carbon sinks are predicted to be growing at present and hence buffering the rate of rise of atmospheric CO2. In the basic model, the current land carbon sink is assumed to be due to CO2 fertilisation of photosynthesis. The slight warming that has occurred enhances soil respiration (carbon loss) and net primary productivity (carbon uptake) by similar amounts. When the model is forced with a “business as usual”(IS92a) emissions scenario for 1990–2100 followed by a linear decline in emissions to zero at 2200, CO2 reaches a peak of 985 ppmv in 2170 and temperature peaks at +5.5 K in 2180. Peak CO2 is ~135 ppmv higher than suggested by IPCC for the same forcing, principally because global warming first suppresses the land carbon sink then generates a land carbon source. When warming exceeds ~4.5 K, soil respiration “overtakes” the CO2 fertilisation of NPP, triggering a release of ~70 GtC from terrestrial ecosystems over ~100 years. When the effects of temperature on photosynthesis, respiration and soil respiration are removed, peak levels of CO2 are reduced by ~100 ppmv and peak temperature by ~0.5 K. Distinguishing separate soil carbon pools with different residence times does not significantly alter the timing of the switch to a land carbon source or its effect on peak CO2, but it causes the source to persist for longer. If forest re-growth or nitrogen deposition are assumed to contribute to the current land carbon sink, this implies a weaker CO2 fertilisation effect on photosynthesis and generates a larger future carbon source. Peak CO2 levels are also sensitive by about ±80 ppmv to upper and lower limits on the temperature responses of photosynthesis, plant respiration and soil respiration. By forcing the model with a range of future emission scenarios it is found that the creation of a significant land carbon source requires rapid warming, exceeding ~4.5 K, and its magnitude increases with the rate of forcing. The carbon source is greatest for the most rapid burning of the largest reserve of fossil fuel. It is concluded that carbon loss from terrestrial ecosystems may significantly (~10%) amplify global warming under “business as usual” or more extreme scenarios.
Comb-Branched Polymers: Monte Carlo Simulation and Scaling

The Monte Carlo simulation technique (the bond fluctuation model) has been used for the study of the equilibrium conformations of comb-branched polymers consisting of a long flexible main chain and side chains grafted at a regular separation onto the main chain. The solvent has been supposed to be good (athermal) for the main and side chains. The global conformation and the gyration radius of the polymer, as well as the local conformational structure of the comb, have been analyzed as functions of the length of the side chains and spacers. The effect of induced rigidity of the comb due to the interaction between side chains has been observed. We have found the results of the simulation to be in reasonable agreement with the predictions of the scaling theory of comb-branched polymers.
DNA binding studies and site selective fluorescence sensitization of an anthryl probe

(9-Anthrylmethyl)ammonium chloride (AMAC, 1) binds to natural and synthetic DNA sequences with a high affinity, as deduced from the absorption and fluorescence spectral data. Scatchard plots constructed from these data gave binding constants in the range (2-8)×10 4 M -1 of base pairs. Extensive hypochromism, broadening, and red shifts in the absorption spectra were observed when AMAC binds to various sequences of synthetic and natural DNA. Upon binding to DNA, the fluorescence from the anthryl chromophore was efficiently quenched by the DNA bases and the fluorescence spectra at high concentrations of CT DNA show significant broadening of the vibronic bands
A powder diffraction study of the phase transition in LaAlO3

The structure of LaAlO3 has been investigated around the phase transition at Tc ≈ 800 K by neutron powder diffraction in vacuum and by X-ray powder diffraction under nitrogen atmosphere as well as by a very high resolution synchrotron experiment in air. The results were analysed in frame of the Landau theory using the fluctuation-dissipation theorem to relate the susceptibility to the atomic displacement parameters. The room temperature structure is a rhombohedrally distorted perovskite structure, space group R-3c , which undergoes a transition to the ideal perovskite structure, space group Pm-3m , at high temperatures. The order parameter is a rotation of the O6-octahedron described by one x(O)-parameter. This parameter and the spontaneous strain (c/a-√6), as well as the relevant atomic displacement parameter Uop11(O) in the order parameter system, show a critical behaviour in agreement with a second order phase transition. Although the critical exponents of the order parameter and strain show the expected coupling behaviour, there is a striking difference of the transition temperature: the metric becomes cubic roughly 30 K below the proper Tc. This is related to spontaneous formation of domains imposing the average cubic symmetry via internal stresses.
Calcium phosphate nanoparticles in biomineralization and biomaterials

Recent developments in biomineralization and biomaterials have demonstrated that nano-calcium phosphate particles play an important role in the formation of hard tissues in nature. It is suggested that the basic inorganic building blocks of bone and enamel are nanosized apatite although their hierarchical structures differ. Nanoparticles can confer on biominerals remarkable physical and chemical characteristics such as enhanced mechanical strength and self-preservation in biological fluids. In living organisms, tens to hundreds of nano-blocks, under the control of an organic matrix, combine into self-assembled biominerals. It is also confirmed experimentally that enamel- or bone-like apatite can be achieved by oriented aggregation by using nano-calcium phosphates as the raw materials, determined by the biomolecules. Interestingly, features of smaller hydroxyapatite (HAP) nanoparticles may more closely approximate features of HAP during biomineralization than features of the larger HAP particles that are conventionally used. The application and prospective use of nano-calcium phosphate in the biological repair of bone and enamel are also introduced. It is emphasized that the cell experiments reveal improved cytophilicity of nanophase calcium phosphate minerals. Greater cell viability and proliferation of bone marrow mesenchymal stem cells are measured on smaller calcium phosphates. Furthermore, studies of amorphous calcium phosphate and crystallized HAP particles are used to investigate the effect of crystallinity of nanoparticles on living cells, and show that the differentiation of stem cells is promoted significantly by nano-HAP. It is suggested that nano-HAP may be the ideal biomaterial due to its good biocompatibility and bone/enamel integration. Lots of studies of calcium phosphates are expected in the nano-zone such as for drug delivery systems and resorbable scaffolds. In this feature article, a new view on calcium phosphates highlights the importance of size and phase controls in the application of biomedical materials.
Quantum scattering calculations for vibrational and rotational excitation of CO by hot hydrogen atoms

Collision cross sections were calculated for vibrational and rotational excitation of CO by H atoms at collisional kinetic energies from 0.7 to 1.9 eV. The BBH [J. M. Bowman, J. S. Bittman, and L. B. Harding, J. Chem. Phys. 85, 911 (1986)] potential energy surface was used and collision dynamics were treated within the quantum coupled states approximation, which is shown to be quite accurate for this system, and also using the infinite order sudden approximation for the rotational degree of freedom, which is shown to be less accurate than expected. Results are compared with experimental data and with quasiclassical trajectory values.
Effects of soil compaction and chipped aspen residue on aspen regeneration and soil nutrients

The effects of soil compaction and depth of chipped aspen residue on aspen regeneration, plant community development, decomposition, and nutrient cycling were tested on an Orthic Gray Luvisol in the Lower Foothills of Alberta. Twenty-seven 100-m × 15-m plots were established in 1992. Three depths of chipped aspen residue (0, 1–5 cm and >10 cm) and three levels of compaction (no compaction, 6 and 16 skidder passes) were applied following whole-tree harvesting in 1993. Sixteen skidder passes and chip residue depths >10 cm resulted in reduced plant cover and aspen sucker densities for at least 2 yr following treatment. Nutrient concentrations of the chip residue and surface organic horizon (LFH) were similar for the three compaction treatments. The initial total nitrogen (N) concentration of the chipped aspen residue was 3.6 g kg−1. Ammonium (NH4+-N) concentrations in the LFH of the chip residue treatments, particularly at the >10-cm residue depth, were lower compared with the no-residue treatment. However, .