Conformational analysis of serricornin: Application of molecular mechanics calculations to stereochemical assignment of serricornin,sex pheromone of cigarette beetle (Lasioderma serricorne F.)

Conformational analysis using molecular mechanics (MM) was performed for a determination of the stereochemistry of serricornin, the sex pheromone of the cigarette beetle (Lasioderma serricorne F.). An exhaustive conformational analysis using MM2 calculations with algorithms for covering torsional energy surfaces of flexible molecules furnishes coordinates and steric energies of all local energy minimum conformers of serricornin, both acyclic and the corresponding cyclic forms. These coordinates gave angles required for the calculation of vicinal H/H coupling constants (³ J _HHs) of each energy minima by Altona's modified Karplus equation. The Boltzmann distributions of all local energy minima were calculated from their steric energies to furnish populations of each energy minimum conformer. Populationweighted averaged³ J _HHs of four enantiomeric pairs, (S ^*,S ^*,S ^*)-, (S ^*,S ^*,R ^*)-, (S ^*,R ^*,S ^*)-, and (R ^*,S ^*,S ^*)-serricornins were calculated from the data above. The observed³ J _HHs of the naturally occurring serricornin, both acyclic and cyclic forms, are fitted best to calcd.³ J _HHs of (4S ^*, 6S ^*, 7S ^*)-acyclic and (3S ^*, 5S ^*, 6S ^*)-cyclic serricornin, respectively, among those of four enantiomeric pairs of serricornin.     

Synthesis and Properties of Three N-Alkyl Bis-Quaternary Ammonium Salt Surfactants

Three N-alkyl bis-quaternary ammonium salt surfactants were synthesized by using epichlorohydrin, trimethylamine hydrochloride, and N,N-dimethylalkyl amine as raw materials in a two-step manner. The products were characterized by ¹H NMR and MS, confirming the successful synthesis of 2-Hydroxy-N¹,N¹,N³,N³-tetramethyl-N³-dodecylpropane-1,3-diammonium chloride (HPDDC), 2-Hydroxy-N¹,N¹,N³,N³-tetramethyl-N³-tetradecylpropane-1,3-diammonium chloride (HPTDC), and 2-Hydroxy-N¹, N¹, N³, N³-tetramethyl-N³-hexadecylpropane-1,3-diammonium chloride (HPHDC). Moreover, the influence of carbon chain length on surface-active properties, foaming properties, and paraffin liquid emulsion stability was investigated. Results indicated that critical micelle concentrations (cmc) decreased with increasing carbon chain length from 12 to 16, and the cmc and γ_cmc were lower than those of Dodecyl trimethyl ammonium chloride (DTAC). The products exhibited better foam properties and worse emulsifying performance than those of DTAC. The Krafft points of all products were determined to be below 0 °C. Moreover, the products also demonstrated outstanding antibacterial properties.     

An efficient method for a numerical description of virgin olive oil color with only two absorbance measurements

Four polynomial expressions are obtained that provide a good approximation and an easy, rapid calculation of the chromatic coordinates and the chroma—L ^*, a ^*, b ^*, and C—for the illuminant C and the standard observer, for a virgin or extra virgin olive oil; absorbance is measured at only 480 and 670 nm. These are as follows: L ^*=0.556458(A₄₈₀)²−2.51145A₄₈₀+0.55504(A₆₇₀)²−8.53016A₆₇₀+98.4089; a ^*=0.177372(A₄₈₀)²+2.1363A₄₈₀+1.43254(A₆₇₀)²−0.789231A₆₇₀−13.9246; b ^*=−16.0277(A₄₈₀)²+79.8932A₄₈₀−5.06558(A₆₇₀)²+3.36169A₆₇₀+31.9405; C=−15.8439(A₄₈₀)²+78.9312A₄₈₀−5.26784(A₆₇₀)²+3.56917A₆₇₀+33.3927. These give acceptable results, making the method a practical alternative to the extremely laborious Commission Internationale d’Eclairage (CIE) L ^* a ^* b ^* system, by which 391 absorbance values must be measured individually, nanometer by nanometer, before applying more complex equations. The validity of the proposed method has been confirmed by comparison, using a set of 20 sample oils different from the set of 25 oils used to generate the order of the equations. The variations between the values provided by the proposed and standard methods, respectively, had a mean of 0.00 for each of the chromatic variables—L ^* , a ^* , b ^* , and C; SD were moderate (0.71, 0.52, 1.22, and 1.22, respectively); the root mean square and the R ²-terms also confirmed the validity of the method.     

Genetic Basis to Divergence of Sex Pheromones in Two Closely Related Moths, <Emphasis Type="Italic">Ostrinia scapulalis</Emphasis> and <Emphasis Type="Italic">O. zealis</Emphasis>

Crossing experiments between two closely related moths, Ostrinia scapulalis and O. zealis, were conducted to gain insight into the genetic basis of the divergence of female sex pheromones. The sex pheromone of O. scapulalis comprises (E)-11- and (Z)-11-tetradecenyl acetates (E11 and Z11), and distinct genetic variation is found in the blend of components. This variation is largely controlled by a single autosomal locus with two alleles, A^E(sca) and A^Z(sca). E-type (A^E(sca)A^E(sca)) females produce a pheromone with amean E11:Z11 ratio of 99:1, whereas Z-type (A^Z(sca)A^Z(sca)) and I-type (A^E(sca)A^Z(sca)) females produce a pheromone with a mean of 3:97 and 64:36, respectively. O. zealis is distinctive in that it has a third pheromone component, (Z)-9-tetradecenyl acetate (Z9), in addition to E11 and Z11, and the typical blend ratio is 60:35:5 (Z9:E11:Z11). Our study revealed that Z9 production in O. zealis is mainly regulated by an autosomal recessive gene phr^(zea), which is suggested to be involved in the chain-shortening of a pheromone precursor fatty acid, and linked to A^E(zea), a gene corresponding to A^E(sca) in O. scapulalis. A few mutations in a gene involved in pheromone production could explain the dramatic shift between a two-component pheromone communication system in O. scapulalis and a three-component system in O. zealis.     

Magneto‐optical effects of Ge‐Ga‐Sb(In)‐S chalcogenide glasses with diamagnetic responses

The Faraday effects of Ge‐Ga‐Sb(In)‐S serial chalcogenide glasses were investigated at the wavelengths of 635, 808, 980, and 1319 nm, respectively. The compositional dependences were analyzed and associated influencing factors including the absorption edge, the concentration of Sb³⁺/In³⁺ ions, and the wavelength dispersion of refraction index were discussed. 80GeS₂·20Sb₂S₃ composition glass was found to have the largest Verdet constant (V=0.253, 0.219, 0.149, and 0.065 min·G^?1·cm^?1 for wavelengths 635, 808, 980, and 1319 nm, respectively) in these glasses, which is larger than that of commercial diamagnetic glasses (Schott, SF 6, V=0.069 min·G^?1·cm^?1@633 nm, for example). Sb³⁺ ions with high polarizability possessing s²‐sp electron jumps involving ¹S₀→¹P₁, ³P_0,1,2 transitions are responsible for large Verdet constant, and Becquerel rule is proved to be an effective guidance for estimating the Verdet constant and further optimizing the compositions in chalcogenide glasses.     

Design of New Functional Materials Based on Complex Oxides with a Tunnel Structure of the Ramsdellite, Hollandite, and Ba2Ti9O20 Types

The phase relationships in binary, ternary, and more complex Me ₂ ⁺O–Me ²⁺O–Me ₂ ³⁺O₃–Me ⁴⁺O₂–TiO₂ systems (Me ⁺ = Li⁺, K⁺, Rb⁺, Cs⁺; Me ²⁺ = Mg²⁺, Sr²⁺, Ba²⁺, Zn²⁺; Me ³⁺ = Al³⁺, Fe³⁺, Ga³⁺; Me ⁴⁺ = Sn⁴⁺, Zr⁴⁺) are investigated in the concentration regions corresponding to the compositions of titanates with a tunnel structure: Li₂(Me ²⁺,Me ³⁺) _y (Me ⁴⁺,Ti)₄O₈ ramsdellites, (Me ⁺,Me ²⁺) _x (Me ²⁺,Me ³⁺) _y (Me ⁴⁺,Ti)₈O₁₆ hollandites, and (Ba,Me ²⁺)₂(Me ⁴⁺,Ti)₉O₂₀ phases. The homogeneity regions of the solid solutions with the above structures are determined, and their crystal chemical characteristics, phase transformations, and thermal and electrical properties are studied. The results obtained and the data available in the literature are analyzed and generalized. The general approaches to the prediction of changes in the structure and properties of the studied titanates with a variation in the chemical composition due to isomorphous substitutions in different structural positions of the crystal lattice are discussed.     

Automated Synthesis of (rac)‐, (R)‐, and (S)‐[18F]Epifluorohydrin and Their Application for Developing PET Radiotracers Containing a 3‐[18F]Fluoro‐2‐hydroxypropyl Moiety

To introduce the 3‐[¹⁸F]fluoro‐2‐hydroxypropyl moiety into positron emission tomography (PET) radiotracers, we performed automated synthesis of (rac)‐, (R)‐, and (S)‐[¹⁸F]epifluorohydrin ([¹⁸F] 1 ) by nucleophilic displacement of (rac)‐, (R)‐, or (S)‐glycidyl tosylate with ¹⁸F^? and purification by distillation. The ring‐opening reaction of (R)‐ or (S)‐[¹⁸F] 1 with phenol precursors gave enantioenriched [¹⁸F]fluoroalkylated products without racemisation. We then synthesised (rac)‐, (R)‐, and (S)‐ 2‐{5‐[4‐(3‐[¹⁸F]fluoro‐2‐hydroxypropoxy)phenyl]‐2‐oxobenzo[d]oxazol‐3(2H)‐yl}‐N‐methyl‐N‐phenylacetamide ([¹⁸F] 6 ) as novel radiotracers for the PET imaging of translocator protein (18 kDa) and showed that (R)‐ and (S)‐[¹⁸F] 6 had different radioactivity uptake in mouse bone and liver. Thus, (rac)‐, (R)‐, and (S)‐[¹⁸F] 1 are effective radiolabelling reagents and can be used to develop PET radiotracers by examining the effects of chirality on their in vitro binding affinities and in vivo behaviour.     

Thermodynamical approach to polymer rheology

The model of pseudocrosslink is extended to polymer rheology. There exist various sizes b of 4–16 between transition points A and B. Each link is connected with a chain having length n_b and relaxation time τ_b. n_b is equal to b² and τ_b is proportional to n_b². A, B, and C (polymer terminal) divide the stress-relaxation spectrum into four zones. In the AB zone, successive dissociation of links occurs from a small size to a large one and rigidity G is decreased with time t as G ∝? t^?0.5 and viscosity η is increased as G ∝? t^0.5. In the BC zone, dissociation of the B link proceeds along a molecule of length n in a mode of squeezing of molecule and η becomes constant, but G still decreases due to increase of unperturbed end-to-end distance of chain and G ∝? t^?0.5. However, dynamic elasticity becomes constant due to a small amplitude. At high shear, links are loosened and G and η are much decreased. Beyond C, molecule flows and η increases as η ∝? γ^?0.8 n^3.5, but high shear rate γ diminishes the effect of n due to extension of the molecule. Extensional viscosity η^* is affected by the change of shape as η^* ∝? t^1.5 and gives an overshoot. Under load, creep occurs and it is proportional to t^1/2–1/3. © 1995 John Wiley & Sons, Inc.     

Spectroscopic investigations of Eu<Superscript>3+</Superscript> and Tb<Superscript>3+</Superscript>: Cadmium lead boro tellurite glasses

This paper reports on the preparation and spectral properties of europium (Eu³⁺) and terbium (Tb³⁺) ions doped cadmium lead boro tellurite (CLBT) glasses. For reference glasses, physical properties have been evaluated. From the [measurements of X-ray diffraction (XRD), glass amorphous nature of these [glasses has been studied. From the emission spectra of Eu³⁺: CLBT glasses, five [transitions (⁵ D ₀ → ⁷ F ₀, ⁷ F ₁, ⁷ F ₂, ⁷ F ₃ and ⁷ F ₄) at 579, 591, 613, 652 and 701 nm are observed with λ_exci = 392 nm (⁷ F ₀ → ⁵ L ₆) and in the case of Tb³⁺: CLBT glasses, four emission transitions ⁵ D ₄ → (⁷ F ₆, ⁷ F ₅, ⁷ F ₄ and ⁷ F ₃) are observed at 489, 543, 584 and 621nm respectively monitered with λ_exci = 376 nm (⁷ F ₆ → ⁵ G ₆).     

Electromigration of sodium ions and electro-osmotic flow in water-saturated, compacted Na-montmorillonite

Sodium ions spiked with ²²Na as a tracer were migrated by electromigration and electro-osmosis in the water-saturated compacted Na-montmorillonite at dry densities 1.0×10³ kg m⁻³, under an electric potential gradient. Dissolved helium was also migrated by electro-osmosis in the montmorillonite. After migration, concentration profiles of the sodium ions and helium were obtained by γ-spectrometry and mass-spectrometric methods, respectively. From the profiles of both chemical species, not only migration due to electrokinetic phenomena but also mechanical dispersion was observed in the montmorillonite. The dispersion coefficients, D_i, and apparent migration rates, U_i^a, of ²²Na and helium were found in the compacted Na-montmorillonite at 1.0×10³ kg m⁻³. The migration of helium in the montmorillonite under an electric potential gradient reflects that of water because helium migrates as an electrically neutral species. The parameters D_He^m, U_He^a, and α_He correspond to those of water. The mechanical dispersion coefficients, D_Na^m, of ²²Na⁺ ions are much smaller than those of water obtained by helium. The dispersivity parameters, α_Na, for ²²Na⁺ obtained from these D_Na and U_Na^a values are 10⁻⁵ m and those for water (α_He) are 10⁻³ m. This indicates that ²²Na⁺ ions migrate in different spaces than water in the compacted montmorillonite under a potential gradient. This finding suggests that the migration of Na⁺ ions occurs in the interlayer and/or on the outer surfaces of the montmorillonite; whereas dissolved helium migrates in the pore water.     

Predicting Blast Waves from the Axial Direction of a Cylindrical Charge

Bare, cylindrical, explosive charges produce secondary shock waves in the direction of least presented area. Whilst the source of these shock waves was explored in the 1940’s, no attempt was made to predict them. This paper describes the detonation of bare, cylindrical charges of PE4 (RDX binder 88/12 %), mass 0.2 to 0.46 kg and with a length to diameter ratio of 4 to 1. High speed camera footage showed (i) the formation of the separate, primary, shock waves from the sides and ends of the charge, (ii) Mach reflection of these separate shock waves, giving rise to reflected, secondary shock waves, and (iii) the secondary shock waves catching and merging with the primary shock wave. In the axial direction, the secondary shock wave’s peak overpressure and impulse exceeded that of the primary shock wave for scaled distances, Z=R/M^1/3 ≥3.9 m kg^−1/3, where M is the mass in kg and R the distance from the charge in m. It was found possible to predict the primary peak overpressure, P, at all distances in the axial direction, for a constant length to diameter ratio, using P=3075 Z⁻³−1732 Z⁻²+305 Z⁻¹. Close in the primary peak overpressure is proportional to M/R³ in the axial direction. It was not possible to predict the secondary peak overpressure with the data obtained. The total impulse from both shock waves, I, in the axial direction can be predicted using I=746(M^2/3/R)³−708(M^2/3/R)²+306(M^2/3/R).     

Tunable color emission in LaScO3:Bi3+,Tb3+,Eu3+ phosphor

LaScO₃:xBi³⁺,yTb³⁺,zEu³⁺ (x = 0 − 0.04, y = 0 − 0.05, z = 0 − 0.05) phosphors were prepared via high-temperature solid-state reaction. Phase identification and crystal structures of the LaScO₃:xBi³⁺,yTb³⁺,zEu³⁺ phosphors were investigated by X-ray diffraction (XRD). Crystal structure of phosphors was analyzed by Rietveld refinement and transmission electron microscopy (TEM). The luminescent performance of these trichromatic phosphors is investigated by diffuse reflection spectra and photoluminescence. The phenomenon of energy transfer from Bi³⁺ and Tb³⁺ to Eu³⁺ in LaScO₃:xBi³⁺,yTb³⁺,zEu³⁺ phosphors was investigated. By changing the ratio of x, y, and z, trichromatic can be obtained in the LaScO₃ host, including red, green, and blue emission with peak centered at 613, 544, and 428 nm, respectively. Therefore, two kinds of white light-emitting phosphors were obtained, LaScO₃:0.02Bi³⁺,0.05Tb³⁺,zEu³⁺ and LaScO₃:0.02Bi³⁺,0.03Eu³⁺,yTb³⁺. The energy transfer was characterized by decay times of the LaScO₃:xBi³⁺, yTb³⁺, zEu³⁺ phosphors. Moreover absolute internal QY and CIE chromatic coordinates are shown. The potential optical thermometry application of LaScO₃:Bi³⁺,Eu³⁺ was based on the temperature sensitivity of the fluorescence intensity ratio (FIR). The maximum S_a and S_r are 0.118 K⁻¹ (at 473.15 K) and 0.795% K⁻¹ (at 448.15 K), respectively. Hence, the LaScO₃:Bi³⁺,Eu³⁺ phosphor is a good material for optical temperature sensing.     

Improved Synthesis and X‐Ray Structure of 5‐Aminotetrazolium Nitrate

5‐Aminotetrazolium nitrate was synthesized in high yield and characterized using Raman and multinuclear NMR spectroscopy (¹H, ¹³C, ¹⁵N). The molecular structure of 5‐aminotetrazolium nitrate in the crystalline state was determined by X‐ray crystallography: monoclinic, P 2₁/c, a=1.05493(8) nm, b=0.34556(4) nm, c=1.4606(1) nm, β=90.548(9)°, V=0.53244(8) nm³, Z=4, ϱ=1.847 g cm⁻³, R₁=0.034, wR₂ (all data)=0.090. The thermal stability of 5‐aminotetrazolium nitrate was determined using differential scanning calorimetry; the compound decomposes at 167 °C. The enthalpy of combustion (Δ_combH) of 5‐aminotetrazolium nitrate ([CH₄N₅]⁺[NO₃]⁻) was determined experimentally using oxygen bomb calorimetry: Δ_combH([CH₄N₅]⁺[NO₃]⁻)=−6020±200 kJ kg⁻¹. The standard enthalpy of formation (Δ_fH°) of [CH₄N₅]⁺[NO₃]⁻ was obtained on the basis of quantum chemical computations at the electron‐correlated ab initio MP2 (second order Møller‐Plesset perturbation theory) level of theory using a correlation consistent double‐zeta basis set (cc‐pVTZ): Δ_fH°([CH₄N₅]⁺[NO₃]⁻(s))=+87 kJ mol⁻¹=+586 kJ kg⁻¹. The detonation velocity (D) and the detonation pressure (P) of 5‐aminotetrazolium nitrate were calculated using the empirical equations by Kamlet and Jacobs: D([CH₄N₅]⁺[NO₃]⁻)=8.90 mm μs⁻¹ and P([CH₄N₅]⁺[NO₃]⁻)=35.7 GPa.     

Air Quality Profile of Inorganic Ionic Composition of Fine Aerosols at Two Sites in Mumbai City

The levels of PM ₁₀ , PM _2.5 , and NO ₂ were studied at a kerbsite and ambient site in Mumbai. Measurements were also made for eight inorganic ions (F ^? , Cl ^? , NO ₃ ^? , SO ^2? ₄ , Na ⁺ , K ⁺ , NH ₄ ⁺ , Ca ²⁺ , and Mg ²⁺ ) in the PM _2.5 fraction. During the study period, PM _2.5 , PM ₁₀ and NO ₂ levels ranged between 11–91, 18–125, and 8–64 μ g m ^{? 3} at a ambient site whereas at the kerbsite the ranges were 10–176, 21–189, and 4–55 μ g m ^?3 respectively. Average PM _2.5 values were 42 μ g m ^{? 3} at ambient and 69 μ g m ^?3 at the kerbsite. The measured ions accounted for about 50% of the PM _2.5 mass. Non-sea-salt (nss) sulfate contributed 91% and 85% of the ionic mass at the ambient and kerbsite sites respectively. Due to biomass sources of K, only about 5% of K ⁺ was from seas salt. The average equivalent ratio of NH ₄ ⁺ to nss- SO ² ₄ ^? , and NO ₃ ^? was over 1, indicating high source strength of ammonia.     

Programmed polymer light-scattering data

An ALGOL computer program has been devised to manipulate light-scattering data from the Brice-Phoenix photometer. The input consist of experimental values of the galvanometer deflections and filter factors used for each concentration c and angle of measurement θ. These are transformed to the appropriate variables in the fundamental equation including the particle scattering factor, viz: c/Qθ = (W/K^*)M?_w^?1[1 + (16/3) × π²n₁²λ〈S²〉 sin² (θ/2)] + (W/K^*)2A₂c + (W/K^*)3A₃c² in which Qθ is a corrected from of the Rayleigh ratio and (W/K^*) is a composite constant term for the instrument and polymer–solvent system. By writing X?_ij for the variable c/Q_θ at θ_i and c_j, a function X is found by least squares to fit X?_ij, thus X = l + m sin (θ/2) + nc_j + bc_j². The equations arising from minimizing Σ_i^K=1 Σ_j^L=1 (X_ij ? X?_ij)² are solved by the computer to yield the best-fitting coefficients l, m, n, and b. These can then be related simply to the molecular weight, root-mean-square radius of gyration, second and third virial coefficients, respectively. The final portion of the program is designed to check the fit of these coefficients. It yields a table of the differences between all experimental c/Qθ values and the coressponding ones obtained by inserting the derived l, m, n, and b into the fundamental equation. The procedure has been tested satisfactorily by using a well-standardized sample of polystyrene in toluene at 30°C. and a wavelength of 436 mμ.     

Kinetic study of the polymerization of dimethyldiallylammonium chloride and acrylamide

The kinetics of the polymerization of dimethyldiallylammonium chloride (DMDAAC) and acrylamide (AM) with different monomer molar ratios initiated by an ammonium persulfate–sodium bisulfate redox complex in an aqueous solution were studied. The polymerization rate (R_p) equation, the activation energy (E_a), and the reactivity ratio were measured. The results show that when the n_DMDAAC:n_AM values were 1 : 9, 2 : 8, 3 : 7, 4 : 6, and 5 : 5, the copolymerization rate equation were R_p1 = k[M]^2.61[I_O]^0.51[I_R]^0.52, R_p2 = k[M]^2.70[I_O]^0.50[I_R]^0.53, R_p3 = k[M]^2.73[I_O]^0.50[I_R]^0.56, R_p4 = k[M]^2.77[I_O]^0.51[I_R]^0.59, and R_p5 = k[M]^2.84[I_O]^0.51[I_R]^0.61 (where [M] is the total monomer concentration, [I_O] is the oxidant concentration, and [I_R] is the reductant concentration), respectively when the temperature was 45°C. The E_a values were E_a1 = 79.10 kJ/mol, E_a2 = 81.39 kJ/mol, E_a3 = 85.15 kJ/mol, E_a4 = 88.88 kJ/mol, and E_a5 = 90.61 kJ/mol in the temperature range 35–55°C, respectively. The reactivity ratios of DMDAAC and AM were r_DMDAAC = 0.14 and r_AM = 6.11 when the temperature was 45°C. The structure of PDA was characterized by Fourier transform infrared spectroscopy and ¹H-NMR. The results of the kinetic parameters explained the differences in the copolymerization rate and intrinsic viscosity of PDA with different cationicities. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis of polymers and copolymers of c-(N-AcrLys-Sar) and their interaction with small molecules in solution

An acrylamide derivative having a mono-N-methylated cyclic dipeptide as a substituent, c-(N^εAcrLys-Sar), was synthesized and polymerized by radical polymerization, giving homopolymers and copolymers with styrene, 4-vinylpyridine, and N-dodecylacrylamide. The relative reactivities of these monomers in the radical polymerization decreased in the following order: styrene > 4-vinylpyridine > N-dodecylacrylamidec-(N^ε-AcrLys-Sar). Poly[c-(N^ε-AcrLys-Sar)] was soluble in water and the usual organic solvents except diethylether and n-hexane. In mixed solvent, poly[c-(N^ε-AcrLys-Sar)] interacted most strongly with Ba²⁺ among alkali and alkaline-earth metal cations. A cyclic dipeptide, which is equivalent to the side chain of poly[c-(N^ε-AcrLys-Sar)], did not interact with these cations, indicating that the side chain ligand groups of poly[c-(N^ε-AcrLys-Sar)] interacts specifically with Ba²⁺ by intramolecular cooperation. However, the copolymer of c-(N^ε-AcrLys-Sar) with styrene interacts more strongly with larger alkali cations, and equally well with Ba²⁺ and Ca²⁺. These results indicate that the styrene units in the copolymer influence its solubility and regulate the intramolecular cooperation of the cyclic dipeptide ligand groups as spacer groups. The copolymer of c-(N^ε-AcrLys-Sar) with 4-vinylpyridine interacted very strongly with Ba²⁺ as a result of the intramolecular cooperation of a pyridyl group and a cyclic dipeptide group. The formation constant of the ternary complex was determined to be 10⁹ M⁻³, which is larger by 10² fold than that by a polymer carrying benzo-15-crown-5 in the side chain. The copolymer of c-(N^ε-AcrLys-Sar) with N-dodecylacrylamide was found to bind methyl orange in aqueous solution by hydrophobic interaction. The copolymer of c-(N^ε-AcrLys-Sar) with styrene was found to extract phenylalanine from an aqueous solution to a n-octanol phase. However, the extraction was not enantiomer-selective.     

Structural Characterization of the Orthorhombic Phase M1 in MoVNbTeO Propane Ammoxidation Catalyst

The structure of the orthorhombic phase in the MoVNbTeO propane ammoxidation catalyst system has been characterized and refined using a combination of TEM, synchrotron X-ray powder diffraction (S-XPD), and neutron powder diffraction (NPD). This phase, designated as M1 by Ushikubo et al. [1], crystallizes in the orthorhombic space group Pba2 (No. 32) with a = 21.134(2) Å, b = 26.658(2) Å, and c = 4.0146(3) Å. The formula unit is Mo_7.5V_1.5NbTeO₂₉. Bond valence sum calculations indicate the presence of d ¹ metal sites neighbored by d ⁰ metal sites. The d ¹ sites are occupied by a distribution of Mo⁵⁺ and V⁴⁺, whereas the d ⁰ sites are occupied by a distribution of Mo⁶⁺ and V⁵⁺. Out-of-center distortions in d ⁰ octahedra are consistent with the second-order Jahn–Teller effect and lattice effects. We argue that the V⁵⁺–O–V⁴⁺/Mo⁵⁺ moieties adjacent to Te⁴⁺ and Mo⁶⁺ sites in the [001] terminal plane provide a spatially isolated active site at which the selective ammoxidation of propane occurs.     

Mass Transfer of Ozone Using a Microporous Diffuser Reactor System

An ozone reactor was constructed using a tubular gas diffuser made of microporous stainless steel to significantly reduce gas bubble size and increase overall mass transfer area. Overall mass transfer coefficient, K_La [s ^?1], was correlated with gas (G) and liquid (L) flow rates using K_La = AL^αG^β , with A = 3.96 × 10 ⁸ [s^?1], α = 1.53, and β = 0.40, with L and G in [m ³s^?1]. The reactor is essentially plug flow at high G or L. This system achieves one of the highest ozone mass transfer rates observed in the literature.     

Kinetic parameter determination of vegetable oil oxidation under Rancimat test conditions

In this research, five different vegetable oils were oxidized at four different temperatures (373, 383, 393, and 403 K) under Rancimat test conditions. An increasing rate of oxidation could be observed as temperature increased. The natural logarithms of the kinetic rate constant (k value) varied linearly with respect to temperature, with the temperature coefficients (T_Coeff) ranging from 6.95×10^–2 to 7.40× 10^–2 K^–1 for the vegetable oils. On the basis of the Arrhenius equation and the activated complex theory, frequency factors (A), activation energies (E_a), Q₁₀ numbers, activation enthalpies (ΔH⁺⁺), and activation entropies (ΔS⁺⁺) for oxidative stability of the vegetable oils were calculated. The A, E_a, Q₁₀, ΔH⁺⁺, and ΔS⁺⁺ values for the vegetable oils ranged from 6.38×10³ to 28.03×10³ h^–1, from 86.86 to 92.42 kJ/mol, from 2.08 to 2.18, from 83.64 to 89.20 kJ/mol, and from –116.66 to –104.35 J/mol K, respectively.