A novel method to musicalize shape and visualize music and a novel technique in music cryptography

Since many years ago, musicians have composed music based on the images that they have had in their minds. On the other hand, music affects people’s imagination while hearing it. This research provides a method that can transform shape to music and music to shape. This method defines musical notations for horizontal, diagonal and vertical line segments, filled circle and curve with different colors, which are the basis of many shapes in transforming shapes into music. Then these primary mappings are generalized to more complex forms to transform any shape. Moreover, music can be transformed into shape by this method. For this transformation, primary musical notations such as simple notes, notes joined by a legato, notes with a staccato, notes joined by a legato and have crescendo or decrescendo and notes with an accent or a trill are defined. These primary musical notations are generalized to more complex forms to transform any music into shape. Also, the method of this research can be used in music cryptography. It employs mapping of notes in a twelve-tone equal musical system into shapes and mappings of shapes with an equal line width and different colors into music.

     

Effect of short carbon fiber content on the mechanical properties of TiB2-based composites prepared by spark plasma sintering

In this study, TiB₂-30 vol% SiC composites containing 0, 5, 10, and 15 vol% short carbon fibers (C_f) were produced by spark plasma sintering (SPS). The effect of carbon fiber content on microstructure, density, and mechanical properties (micro-hardness and flexural strength) of the fabricated composites was studied. Scanning electron microscopy (SEM) results indicated that the fibers were uniformly dispersed in the TiB₂–SiC matrix using wet ball milling before SPS process. Fully dense TiB₂–SiC–C_f composites were achieved by SPS process at 1900°C for 10 min under 30 MPa. With the addition of fibers, the relative density of the composites did not change considerably. Mechanical tests revealed that microhardness was reduced about 19% by the incorporation of carbon fibers, whereas the flexural strength improved significantly. However, the flexural strength diminished by adding carbon fibers above to critical value (5 vol%) due to residual thermal stresses, nonhomogeneous structure and graphitization of carbon fibers. It was found that the composite with 5 vol% C_f had the highest flexural strength (482 MPa), which was enhanced by 20% compared with the TiB₂–SiC composite.     

The Relation Between Open‐Circuit Voltage and the Onset of Photocurrent Generation by Charge‐Transfer Absorption in Polymer : Fullerene Bulk Heterojunction Solar Cells

Photocurrent generation by charge‐transfer (CT) absorption is detected in a range of conjugated polymer–[6,6]‐phenyl C₆₁ butyric acid methyl ester (PCBM) based solar cells. The low intensity CT absorption bands are observed using a highly sensitive measurement of the external quantum efficiency (EQE) spectrum by means of Fourier‐transform photocurrent spectroscopy (FTPS). The presence of these CT bands implies the formation of weak ground‐state charge‐transfer complexes in the studied polymer–fullerene blends. The effective band gap (E_g) of the material blends used in these photovoltaic devices is determined from the energetic onset of the photocurrent generated by CT absorption. It is shown that for all devices, under various preparation conditions, the open‐circuit voltage (V_oc) scales linearly with E_g. The redshift of the CT band upon thermal annealing of regioregular poly(3‐hexylthiophene):PCBM and thermal aging of poly(phenylenevinylene)(PPV):PCBM photovoltaic devices correlates with the observed drop in open‐circuit voltage of high‐temperature treated versus untreated devices. Increasing the weight fraction of PCBM also results in a redshift of E_g, proportional with the observed changes in V_oc for different PPV:PCBM ratios. As E_g corresponds with the effective bandgap of the material blends, a measurement of the EQE spectrum by FTPS allows us to measure this energy directly on photovoltaic devices, and makes it a valuable technique in the study of organic bulk heterojunction solar cells.     

Collagen-g-poly(Sodium Acrylate-co-Acrylamide)/sodium montmorillonite superabsorbent nanocomposites: synthesis and swelling behavior

Nanocomposite superabsorbents were synthesized by graft copolymerization of mixture of acrylamide (AAm) and acrylic acid (AA) onto collagen using potassium persulfate (KPS) as a free radical initiator and methylenebisacrylamide (MBA) as a crosslinker. Nanoclay sodium montmorillonite (MMt) was introduced as filler into superabsorbent. The chemical structure of the Collagen-g-poly(Sodium Acrylate-co-Acrylamide)/MMt nanocomposite was characterized by means of FTIR spectroscopy, XRD patterns, and TGA thermal methods. Morphology of the sample was examined by scanning electron microscopy (SEM). The effects of reaction variables were systematically optimized to achieve a superabsorbent with swelling capacity as high as possible. Under the optimized conditions concluded, the maximum swelling capacity in distilled water was 950 g/g. Dewatering of nanocomposite and clay-free superabsorbent revealed that inclusion of nanoclay into superabsorbents can improve water retention of superabsorbent under heating. The swelling ratio in various salt solution and kinetic of dewatering was also determined and additionally, the swelling of nanocomposite superabsorbent was measured in solution with pH ranged 1–13. The synthesized nanocomposite exhibited a pH-responsive characteristic.     

Poly(acrylic acid–sodium styrene sulfonate) organogels: Preparation,characterization, and alcohol superabsorbency

Polymeric organogels based on acrylic acid and sodium styrene sulfonate (SSS) were synthesized and characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, dynamic mechanical thermal analysis (DMTA), and rheometrical analyses. The organogels exhibited medium alcohol absorbency because of counterion binding that formed in solvents with low dielectric constants. After acid treatment, the possibility of counterion binding was decreased, and the organogels achieved superabsorbency in alcohols, for example, about 80 and 50 g/g in methanol and ethanol, respectively. The superabsorbency was also measured in higher alcohols (i.e., n‐propanol and isopropyl alcohol) and polyols (i.e., ethylene glycol, propylene glycol, 1,3‐propanediol, and glycerol). The dielectric constant, viscosity, and structural features of the alcohols were investigated as important parameters determining the alcohol superabsorbency. DMTA of dried samples showed two glass‐transition temperatures (T_g's), that is, the matrix T_g and the complex T_g, which increased with increasing SSS content. The tan δ peak intensity increased after the acid treatment. With increasing SSS, the storage modulus of the dried gel increased; whereas that of the rheometrically measured hydrated gel decreased. Tan δ decreased with increasing SSS because of enhanced counterion binding. These alcohol‐specific superabsorbing organogels are suggested as excellent candidates for the manufacture of products with high alcohol contents, such as hand sanitizers and fuel gels. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Protection and Functionalizing of Stainless Steel Surface by Graphene Oxide-Polypyrrole Composite Coating

The corrosion inhibition of metallic substrates is a prime issue for many potential applications where corrosion plays a crucial role. The development of carbon based on functionalized coatings could increase the lifetime of metallic substrates by inhibiting the corrosion process. Present work is an effort to develop a corrosion inhibiting composite coating of graphene oxide and polypyrrole for AISI （American Iron and Steel Institute） type 304 stainless steel substrates. The electrochemical galvanostatic deposition process was applied for coating development. The coating morphology and ability to cover the substrate surface was analyzed with a high-resolution scanning electron microscope. The coating＇s structural and electronic properties were analyzed with Raman spectroscopy. The investigation of corrosion inhibition involved open circuit potential, Tafel, and voltammetry analysis. The standard salt test ASTM （American Society for Testing and Materials） G48A for stainless steel substrate has also been studied. Significant enhancement of corrosion potential as well as pitting potential for the composite coated substrates has been noted. Furthermore, corrosion and breakdown potential increased upon changing the material from graphene oxide to its composite coating. During the salt test analysis, the durability of the composite coating was noted up to 72 h, which is the standard time scale. Based on experimental analysis, this composite material can be used as an effective carbon based on functionalized corrosion inhibitor for stainless steel substrates to increase their lifetime.     

Syntheses and Characterization of Two New M(II)-5,5′-dimethyl-2,2′-bipyridine (M = Cd and Pb) Coordination Polymers and Study of Their Thermal and Electrochemical Properties

Two new cadmium(II) and lead(II)-thiocyanato coordination polymers with 5,5′-dimethyl-2,2′-bipyridine (5,5′-dm-2,2′-bpy) as chelating ligands were synthesized and characterized by elemental analysis, IR and ¹H NMR spectroscopy and by X-ray crystallography. Thermal and electrochemical properties were also studied as well. These complexes have formed formula [Cd(5,5′-dm-2,2′-bpy)(NCS)₂]_n (1) and [Pb(5,5′-dm-2,2′-bpy)(CH₃COO)(NCS)]_n (2). The coordination numbers of Cd^II in 1 and Pb^II in 2 are six (CdN₄S₂) and seven (PbN₃O₃S₂), respectively. In 2, “stereo-chemically active” electron lone pairs and the coordination spheres were hemidirected. Bridging properties of thiocyanato anions in 1 and 2 created one- and two-dimensional coordination polymers, respectively. The supramolecular features in these complexes were guided and controlled by weak directional intermolecular interactions.     

Conversion of CO into CO2 by high active and stable PdNi nanoparticles supported on a metal-organic framework

The solubility of Pd(NO₃)₂ in water is moderate whereas it is completely soluble in diluted HNO₃ solution. Pd/MIL-101(Cr) and Pd/MIL-101-NH₂(Cr) were synthesized by aqueous solution of Pd(NO₃)₂ and Pd(NO₃)₂ solution in dilute HNO₃ and used for CO oxidation reaction. The catalysts synthesized with Pd(NO₃)₂ solution in dilute HNO₃ showed lower activity. The aqueous solution of Pd(NO₃)₂ was used for synthesis of mono-metal Ni, Pd and bimetallic PdNi nanoparticles with various molar ratios supported on MOF. Pd₇₀Ni₃₀/MIL-101(Cr) catalyst showed higher activity than monometallic counterparts and Pd+ Ni physical mixture due to the strong synergistic effect of PdNi nanoparticles, high distribution of PdNi nanoparticles, and lower dissociation and desorption barriers. Comparison of the catalysts synthesized by MIL-101(Cr) and MIL-101-NH₂(Cr) as the supports of metals showed that Pd/MIL-101-NH₂(Cr) outperforms Pd/MIL-101-(Cr) because of the higher electron density of Pd resulting from the electron donor ability of the NH₂ functional group. However, the same activities were observed for Pd₇₀Ni₃₀/MIL-101(Cr) and Pd₇₀Ni₃₀/MIL-101-NH₂(Cr), which is due to a less uniform distribution of Pd nanoparticles in Pd₇₀Ni₃₀/MIL-101-NH₂(Cr) originated from amorphization of MIL-101-NH₂(Cr) structure during the reduction process. In contrast, Pd₇₀Ni₃₀/MIL-101(Cr) revealed the stable structure and activity during reduction and CO oxidation for a long time.     

Keys to improve the efficiency of nanoparticle-stabilized foam injection based on influential mechanisms

The effect of the existence of nanoparticles on foam stability, foamability, and the oil recovery factor (RF) has been studied experimentally, and influential phenomena and mechanisms have been examined. A sequence of experiments, including, ‘foam bulk-static experiments’, ‘surface tension (ST) measurements,’ and ‘micromodel foam flood,’ were designed and then implemented to study the foam behaviour in two foam systems: (1) anionic-nanoparticles + cationic-surfactant and (2) anionic-nanoparticles + anionic-surfactant. This study provides a comprehensive insight into the mechanisms affecting the stability of nanoparticle-stabilized foam. Also, despite previous studies, the effect of Marangoni flow on nanoparticle-stabilized foam has been discussed briefly. Results show that the interactions of effective mechanisms work differently in the two series. In the like-charge system, surfactant molecules accumulate in the interface of lamellas due to repulsive forces; therefore, stability and foamability improve as surface tension and molecular diffusion reduce. Additionally, Marangoni flow restitutes the negative impact of gravity drainage. In the unlike-charge system, observations illustrate that nanoparticles reach the interface. The presence of nanoparticles at the interface increases detachment energy significantly, and as a result, the stability is boosted. The accumulation of nanoparticles in the interface changes it to a solid-like surface with limited diffusibility and viscosity. Although Marangoni flow is lost, reducing molecular diffusion improves foam stability. Flooding tests show that foam stability increment improves sweep efficiency at near-wellbore areas even when foamability is weak. Finally, it can be claimed that in the unlike-charge system, the sweep efficiency and foam stability increase to a greater extent.