The link between the emergence of the GIM mechanism and the nature of the neutral-current parity violation

We show that minimization of the Higgs potential within the unifying symmetry [SU(4)]⁴ together with the requirement that the GIM mechanism should emerge as a consequence of spontaneous breakdown of the symmetry on the flavor side leaves us with onechoice regarding the nature of parity violation: charged current as well as neutral current parity violations must have one and the same origin; if the former is à la SU(2)_L×U(1), so must be the latter. Furthermore, there appear to be only two possible alternative forms for the low-energy electroweak symmetry: (i) the familiar SU(2)_L×U(1), and (ii) and extended symmetry SU(2)_L×U(1)_L×?(1)_R differing from the former only in the parity-conserving neutral current sector.     

Terpolymerization studies. III. Terpolymerization of acrylonitrile,styrene, and α-cyanocinnamamide

Acrylonitrile (M₁), styrene (M₂), and α-cyanocinnamamide (α-CCA) (M₃) were terpolymerized by thermal initiation to low conversion, and the monomer feed/terpolymer composition relationship was determined by Slocombe's triangular graph. The solubility, the thermal behavior, the impact strength, and the chemical resistance of the terpolymers of various compositions were investigated.     

Synthesis of copper dendrite nanostructures by a sonoelectrochemical method

Copper dendrites have been prepared by a sonoelectrochemical process from an aqueous solution of Cu(2+) in the presence of polyvinyl alcohol. A SEM image of the morpholohy of the copper formed on the electrode after one electric pulse is presented. A subsequent sonic pulse removes the copper from the electrode surface, cleaning it for the next step. The formation of the dendrites is accounted for by the "drying-mediated self-assembly of nanoparticles" theory.     

Effect of the Solvent on the Conformation of Isolated MEH‐PPV Chains Intercalated Into SnS2

Photophysical processes in conjugated polymers are influenced by two competing effects: the extent of excited state delocalization along a chain, and the electronic interaction between chains. Experimentally, it is often difficult to separate the two because both are controlled by chain conformation. Here we demonstrate that it is possible to modify intra‐chain delocalization without inducing inter‐chain interactions by intercalating polymer monolayers between the sheets of an inorganic layered matrix. The red‐emitting conjugated polymer, MEH‐PPV, is confined to the interlayer space of layered SnS₂. The formation of isolated polymer monolayers between the SnS₂ sheets is confirmed by X‐ray diffraction measurements. Photoluminescence excitation (PLE) and photoluminescence (PL) spectra of the incorporated MEH‐PPV chains reveal that the morphology of the incorporated chains can be varied through the choice of solvent used for chain intercalation. Incorporation from chloroform results in more extended conformations compared to intercalation from xylene. Even highly twisted conformations can be achieved when the incorporation occurs from a methanol:chloroform mixture. The PL spectra of the MEH‐PPV incorporated SnS₂ nanocomposites using the different solvents are in good agreement with the PL spectra of the same solutions, indicating that the conformation of the polymer chains in the solutions is retained upon intercalation into the inorganic host. Therefore, intercalation of conjugated polymer chains into layered hosts enables the study of intra‐chain photophysical processes as a function of chain conformation.     

Engineering of superhydrophobic silica microparticles and thin coatings on polymeric films by ultrasound irradiation

Superhydrophobic coatings are one of the recent hot topics in industrial applications as well as academic studies. The mimicking lotus leaves' superhydrophobic properties have been successfully transferred to real-life applications. However, the current preparation methods used to obtain superhydrophobic coatings are still complex, commonly are not transparent and/or not durable.In the present study, a new relatively simple way to prepare superhydrophobic coatings on polymeric films is described. First, superhydrophobic silica microparticles (MPs) were synthesized by fluorination of SiO₂ MPs produced by a modified Stöber method. Briefly, tetraethyl orthosilicate was polymerized in an ethanol/water continuous phase under basic conditions, and the resultant SiO₂ MPs were dispersed in heptane as a continuous phase and reacted with 1H,1H,2H,2H-perfluorododecyltrichlorosilane (FTS) to yield FTS-SiO₂ MPs, which were dried and dispersed in decane. Superhydrophobic thin coatings were then produced by a ‘throwing stones’ sonication technique and deposited onto polycarbonate, polypropylene, polyethylene, and polyurethane films. The coatings are durable, may be transparent, and exhibit self-cleaning properties for the specific practical applications. The MPs and coated polymeric films were characterized by dynamic light scattering, high-resolution scanning electron microscopy, water contact and sliding angle measurements, and infrared and x-ray photoelectron spectroscopy. This ultrasound-assisted coating process may be upscaled and applied to many polymeric films, for instance polymethyl methacrylate, polystyrene, and polyvinyl chloride. Various applications are envisaged, including but not limited to self-cleaning windows, anti-sticking of snow to antennas and windows, solar panels, roof tiles, agricultural applications, corrosion resistance, and anti-biofouling.     

Doping nanoparticles into polymers and ceramics using ultrasound radiation

In materials science, sonochemistry is mostly used for the fabrication of nanomaterials, but it has also been used for the polymerization of monomers. The current review is aimed at introducing a new application of sonochemistry to materials science, i.e., the doping of nanoparticles into polymers and ceramic bodies. The introduction will present a short overview of sonochemistry, and will outline the advantages of sonochemistry as a tool for fabricating nanomaterials.     

Are sonochemically prepared α-amylase protein microspheres biologically active?

Using high-intensity ultrasound, we have synthesized alpha-amylase microspheres. The paper presented characterization as well as catalytic experiments of the sonochemically-produced microspheres. It also provided an estimate of the efficiency of the sonochemical process in converting the native protein to microspheres. These microspheres showed a very good enzymatic activity compared with the native alpha-amylase. The enzymatic activity of the amylase microspheres was 27% of that of the native protein after a short reaction time (3 min), while over a longer reaction time (1 h) it reached 56% of the activity of the native protein.     

Sonochemical polymerization of diphenylmethane

Sonolysis of diphenylmethane (DPhM) has been studied under the effect of 20 kHz ultrasound (absorbed acoustic power 0.45 W/ml, surface area of sonotrode 1 cm(2), volume of sonicated solution 100 ml) under argon at 60 degrees C. The solid product of the sonolysis was characterized by elemental analysis, FTIR, 13C MAS NMR, TGA/DSC, XRD and TEM techniques. It was found that the sonolysis of DPhM causes formation of the polymer with the composition similar to crosslinked polystyrene. Assumed mechanism of DPhM sonolysis consists of DPhM molecules dissociation inside the cavitating bubble. Secondary radical scavenging and radical recombination processes yields the sonopolymer in the liquid phase. The breakdown of the aromatic ring during DPhM sonolysis confirms that a very high temperature established in the cavitating bubble.     

A comparison between hot-hydrolysis and sonolysis of various Mn(II) salts

A variety of manganese salts ranging from completely soluble and ionized to insoluble compounds have been subjected to ultrasonic radiation in aqueous medium at pH approximately 8.3. All of the manganese salts yielded a product identified as nanoparticles of Mn(3)O(4), expect for MnCO(3), which yields of mixture of phases. The characteristics of the products obtained are compared with those obtained under vigorous stirring conditions. The shapes of nanocrystals varied from sharp-edged crystals to smooth particles.     

Complexes of molecular and ionic character in the same matrix layer: infrared studies of the sulfuric acid/ammonia system

The atmospherically important interaction products of sulfuric acid and ammonia molecules have been firstly observed by matrix isolation Fourier transform infrared spectroscopy (MIS-FTIR). Infrared spectra of solid argon matrix layers, in which both H(2)SO(4) and NH(3) molecules were entrapped as impurities, were analyzed for bands not seen in matrix layers containing either of the parent molecules alone. Results were interpreted on the basis of spectral changes, experimental conditions, and semiempirically scaled frequencies from the B3LYP/aug-cc-pVTZ and B3LYP/aug-cc-pVQZ calculations. Bands were assigned to complexes of the H(2)SO(4)·NH(3) and H(2)SO(4)·[NH(3)](2) general formulas. They differ significantly: the 1:1 H(2)SO(4)·NH(3) complex is a strongly hydrogen bonded complex, an analogue of the H(2)SO(4)·H(2)O complex, studied previously. For the 1:2 H(2)SO(4)·[NH(3)](2) complex, spectral results indicate an almost complete proton transfer forming a complex of essentially the two ionic moieties HSO(4)(-) and [H(3)N···H···NH(3)](+), an analogue of the [H(2)O···H···OH(2)](+) "Zundel ion".