Application of simultaneous ultrasonic curing on pork (Longissimus dorsi): Mass transport of NaCl,physical characteristics,and microstructure

This study aimed to investigate the effect of ultrasound curing with various working modes and frequency combinations, including mono-, dual- and tri-frequency, on the content of NaCl and tenderness of pork loins (Longissimus dorsi). The physical qualities, myoglobin, moisture migration, distribution, and microstructure of pork were also evaluated. The results displayed that the NaCl content of samples cured by simultaneous ultrasound (100 W/L) working mode with a frequency combination of 20, 40, and 60 kHz was higher than that of other ultrasound working modes. The effect of ultrasonic brining was significantly better than the static curing when the saline solution was >35 mL. In addition, the samples cured by simultaneous ultrasound had better physical qualities, including more pickling absorptivity, less cooking loss, and lower hardness, tenderness, and chewiness value. The intensity of lightness was reduced, although redness and yellowness remained unaltered compared to static curing. The myoglobin content decreased drastically without changing the oxygenation level, and the relaxation time of T_2b and T₂₁ was delayed. The microstructure indicated that the ultrasonic treatment could promote changes in meat texture. Overall, the simultaneous ultrasound at various frequencies could efficiently accelerate NaCl penetration and improve pork quality.     

Changes in Properties of Dielectric Barrier Discharge Plasma Jets for Different Gases and for Insulating and Conducting Transfer Plates

Dielectric barrier discharge (DBD) plasma jets have been studied extensively in recent years because of its wide range of applications. DBD plasmas can be produced using many different gases and can be applied to a broad variety of surfaces and substrates. This work provides comparisons of DBD plasmas generated using argon (Ar), helium (He), and nitrogen (N₂), as well as their mixtures with water vapor in order to know how some plasma properties are affected by the use of different gases. All plasmas were studied in two different conditions: using a transfer plate made of a conductive material and using a transfer plate made of an insulating one. It was observed that the process of Penning ionization of nitrogen molecules by direct collisions with metastable atoms and molecules is evident and significant only in plasmas that use He as the working gas, which means that He atoms in metastable states have greater ability to transfer energy to molecules of nitrogen in the plasma. The collisions of metastable He with N₂ molecules determine the vibrational temperature (T _vib) values in He plasmas, while in Ar and N₂ plasmas, the T _vib values are determined mainly by collisions of electrons with N₂ molecules. It was noticed that the use of an insulating or a conducting transfer plate as the sample holder affects the results of adhesion between poly(dimethylsiloxane) samples, and it is mainly due to the differences in the plasma power, with a higher plasma power leading to better adhesion.     

Fabrication of single domain GdBCO bulks with different new kind of liquid sources by TSIG technique

Single domain GdBCO bulk superconductors have been fabricated with different new kinds of liquid sources by Top Seeded Infiltration and Growth process. A conventional liquid source is a mixture of REBa₂Cu₃O_7?x and Ba₃Cu₅O₈ in a ratio of 1:1; new liquid sources are made of a mixture of RE₂BaCuO₅ + 9BaCuO₂ + 6CuO or RE₂O₃ + 10BaCuO₂ + 6CuO. The microstructures and levitation forces of the GdBCO bulks have also been investigated. The properties of the samples fabricated are nearly the same as those of samples fabricated with conventional liquid sources, which indicates that the new liquid sources are very important to reduce the cost and improve the working efficient on the fabrication of single-domain GdBCO bulk superconductors.     

Role of the volume and surface breakdown in a formation of microdischarges in a steady-state DBD

The results of an experimental study on a spatial-time behavior of microdischarges (MDs) in steady-state dielectric barrier discharge (DBD) are presented. MDs of DBD have a spatial “memory”, i.e. every subsequent MD appears exactly at the same place that was occupied by the preceding MD. In most cases each MD appears at its fixed place only once by every half-period (HP). Spatial “memory” is derived from slow recombination of plasma in the MDs channels for a period between two neighbor HPs. In steady-state DBD each plasma column was formed only one-time due to local avalanche-streamer breakdown in the very first (initial) gas gap breakdown under inception voltage U^*U^*. After that DBD is sustained under voltage lower than U^*U^*. For the plane-to-plane DBD having the restricted electrode area there is a critical voltage U ₁: DBD is in a steady-state if U > U ₁ but the DBD decays slowly at voltages below U ₁. The decay takes many HPs and occurs due to decreasing the number of MDs inside the gap because of their Brownian motion from central region to the outside of the discharge area. In steady-state DBD there is no correlation between an appearance of alone MD and phase of the applied voltage – each MD has a great scatter in its appearance at the HP. This scatter is attributed to the dispersion in a threshold voltage for local surface breakdowns around the MD base. So, in steady-state DBD the MD volume plasma is responsible for an existence of spatial “memory” (i.e. where the MD appears) but the surface charge distribution around MD is responsible for MD time dispersion (i.e. when the MD appears).     

The a-value of polymineral fine grain samples measured with the post-IR IRSL protocol

Recent post-IR IRSL (pIRIR) dating studies using polymineral fine grains assumed that the a-values obtained for the IRSL signal at 50 °C and the pIRIR signal at higher temperatures (e.g. 225 °C) are identical. However, the a-value of a sample depends on the stimulation method, and the assumption mentioned above remains to be tested. Using five polymineral fine grain samples, this study investigates whether a common a-value can be used for both the IR and the pIRIR signals. Applying the pIRIR protocol, the a-values were measured with three different methods of signal resetting (optical bleaching, end of SAR cycle, heating). In addition, uncorrected α- and β-irradiation induced growth curves were determined for three samples and fitted with single saturating exponential functions. For the investigated samples we found significant mean differences, 0.023 ± 0.012 and higher, in the a-values determined for the IR₅₀ and pIRIR₂₂₅ signals. Synthetic a-values deduced from uncorrected multiple-aliquot dose response curves seem to confirm this observation. Although, in summary, our results indicate that the practice of using a common a-value should be carefully re-considered, the physical reasons remain to be determined.     

On the rate constants of OH + HO2 and HO2 + HO2: A comprehensive study of H2O2 thermal decomposition using multi-species laser absorption

Hydrogen peroxide (H₂O₂) and hydroperoxy (HO₂) reactions present in the H₂O₂ thermal decomposition system are important in combustion kinetics. H₂O₂ thermal decomposition has been studied behind reflected shock waves using H₂O and OH diagnostics in previous studies (Hong et al. (2009) [9] and Hong et al. (2010) [6,8]) to determine the rate constants of two major reactions: H₂O₂ + M → 2OH + M (k₁) and OH + H₂O₂ → H₂O + HO₂ (k₂). With the addition of a third diagnostic for HO₂ at 227 nm, the H₂O₂ thermal decomposition system can be comprehensively characterized for the first time. Specifically, the rate constants of two remaining major reactions in the system, OH + HO₂ → H₂O + O₂ (k₃) and HO₂ + HO₂ → H₂O₂ + O₂ (k₄) can be determined with high-fidelity.No strong temperature dependency was found between 1072 and 1283 K for the rate constant of OH + HO₂ → H₂O + O₂, which can be expressed by the combination of two Arrhenius forms: k₃ = 7.0 × 10¹² exp(550/T) + 4.5 × 10¹⁴ exp(?5500/T) [cm³ mol^?1 s^?1]. The rate constants of reaction HO₂ + HO₂ → H₂O₂ + O₂ determined agree very well with those reported by Kappel et al. (2002) [5]; the recommendation therefore remains unchanged: k₄ = 1.0 × 10¹⁴ exp(?5556/T) + 1.9 × 10¹¹⁺exp(709/T) [cm³ mol^?1 s^?1]. All the tests were performed near 1.7 atm.     

Synthesis and visible light photocatalysis water splitting property of chromium-doped Bi4Ti3O12

Photocatalysts Bi₄Ti_3 ? xCr_xO₁₂(x = 0.00, 0.06, 0.15, 0.30, 0.40, and 0.50) with perovskite structure were synthesized by sol–gel method and their electronic structures and photocatalytic activities were investigated. The Bi₄Ti_2.6Cr_0.4O₁₂ photocatalyst exhibited the highest performance of H₂ evolution in methanol aqueous solution (58.1 μmol h^? 1 g^? 1) under visible light irradiation (λ > 400 nm) without a co-catalyst, whereas no H₂ evolution is observed for Bi₄Ti₃O₁₂ under the same conditions. The UV–vis spectra indicated that the Bi₄Ti_2.6Cr_0.4O₁₂ had strong photoabsorption in the visible light region. The results of density functional theory (DFT) calculation illuminate that the conduction bands of Bi₄Ti₃O₁₂ are mainly attributable to the Ti 3d + Bi 6p orbitals, and the valence bands are composed of O 2p + Bi 6s hybrid orbitals, while the conduction bands of chromium-doped Bi₄Ti₃O₁₂ are mainly attributable to the Ti 3d + Bi 2p + Cr 3d orbitals, and the O 2p + Cr 3d hybrid obitals are the main contribution to the valence band.     

Recombination channels of molecular ions He 2 + and electrons

The dependence of the intensities of atomic lines and molecular bands emitted in the afterglow of a helium discharge on the electron temperature is used to identify the processes in which states of He and He ₂ ^* are populated. It is established that the formation of He^* atoms (n = 3, 4) in decaying helium plasma occurs principally on account of the associative recombination of vibrationally excited He ₂ ⁺ ions and electrons. Analysis of the experimental reuslts leads to the conclusion that the distribution of the molecular ions He ₂ ⁺ over vibrational states is strongly nonequilibrium.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 67–72, February, 1984.It remains to thank N. P. Penkin for discussions and for his interest in the work.     

Thermal diffusivity and electrical conductivity in fast ion conducting composites: A correlation

The thermal diffusivity and electrical conductivity have been measured for two ion conducting polyethylene oxide (PEO) based polymer–ceramic composites viz. (PEO:NH₄I) + xAl₂O₃, (PEO:LiBF₄) + xBa_0.70Sr_0.30TiO₃ and two solid–solid composites viz. AgI + xAl₂O₃, AgI +xBa_0.70Sr_0.30TiO₃. The thermal diffusivity has been measured by the novel photoacoustic technique while the electrical conductivity has been measured by impedance spectroscopy technique using complex impedance plots. The pattern of variation in the electrical conductivity (σ) vs. composition plot and that in the thermal diffusivity (α_s) vs. composition plot are similar. Interestingly, the correlation between α_s and σ is not only qualitative but is quantitative as well in the sense that the ratio (α_s / σ) remains constant for all the samples within the same system (though their conductivities are different) similar to Wiedmann–Franz law applicable to metallic conductors.     

Electrical transport and crystallization in Cu+ ion substituted AgI–Ag2O–V2O5 glassy superionic system

A new glassy solid electrolyte system Cu_xAg_1 − xI–Ag₂O–V₂O₅ has been synthesized. The structural, thermal and electrical properties of the samples have been investigated. The glassy nature of the samples is confirmed by X-Ray diffraction and Differential Scanning Calorimetry studies. The electrical conductivity of these samples increases with CuI content and approaches a maximum value of ∼ 10⁻² Ω^− 1 cm^− 1 for x = 0.35 at room temperature. Ionic mobility measurements suggest that enhancement in the conductivity with Cu⁺ ion substitution may be attributed to increase in the mobility of Ag⁺ ions. The electrical conductivity versus temperature cycles carried out at well-controlled heating rate above T_g and T_c reveal interesting thermal properties. For lower CuI content samples conductivity exhibits anomalous rise above T_g and subsequent fall at T_c. It is also found that CuI addition into AgI–Ag₂O–V₂O₅ matrix reduces the extent of crystallization.     

High field ESR measurements of quantum antiferromagnetic chain substances BaCu2(Si1−xGex)2O7

High field ESR measurements of S=1/2 one-dimensional quantum antiferromagnetic (AF) system BaCu₂(Si_1−xGe_x)₂O₇ have been performed using powder samples and pulsed magnetic field. High field electron paramagnetic resonance at 352 GHz and 86 K enabled us to determine the x dependence of g-values even when we used the powder samples. The x dependence will be discussed in connection with the crystal field. Moreover, antiferromagnetic resonances of x=0 and x=1 samples below T_N were observed and their frequency–field relations suggest the existence of Dzyaloshinsky–Moriya interaction.     

The surface modification of nanoporous SiOx thin films with a monofunctional organosilane

The surfaces of nanostructured, porous SiO_x/Si (air-oxidized Si) and SiO_x thin films, deposited by excimer laser ablation in He and He + O₂ gas ambients, respectively, have been modified by the deposition of a monofunctional organosilane. They were characterized using photoacoustic Fourier-transform infrared (FTIR) X-ray photoelectron (XPS) spectroscopies, and field-emission scanning electron microscopy (FESEM). Photoacoustic FTIR analysis indicates that the organosilane has hydrolyzed to form a silanol, which has chemically reacted with SiO_x through its surface silanol (SiOH) group, to form siloxane (SiOSi) structures. An enhanced IR spectral signal is found, due to the expansion and contraction of both the pores of the solid and the gas within them.     

Experimental and statistical analysis of dielectric barrier discharge plasma effect on sonochemically TiO2 coated cotton fabric using complete composite design

A single step ultrasonic biosynthesis method was used to synthesize and coat TiO₂ nanoparticles onto DBD plasma functionalized raw cotton. Titanium isopropoxide was reduced with aloe vera plant extract into TiO₂ nanoparticles. The effect of DBD plasma treatment on self-cleaning property of TiO₂ coated fabric was optimized statistically by using a complete composite design. To induce functional groups on the cotton fabric surface, the fabric was pre-treated with DBD plasma over various periods of time. The plasma exposure time, molarity of solution and ultrasonication time were optimized using complete composite design package. TiO₂ nanoparticles revealed spherical shape and anatase phase with average crystallite size of 10.46 nm. The statistically optimized plasma exposure time, molarity and sonication time was 7 min, 0.80 and 75 min, respectively. The plasma activation of fabric significantly improved the adsorption, tensile strength and self-cleaning ability of TiO₂ coated fabric.     

Dopant distribution, oxygen stoichiometry and magnetism of nanoscale Sn0.99Co0.01O2

In recent work, we have shown that chemically synthesized Sn_1−xCo_xO₂ nanoscale powders with x≤0.01 are ferromagnetic at room temperature when prepared by annealing the reaction precipitate in the narrow temperature window of 350-600 ^°C. Combined high resolution x-ray photoelectron spectroscopy (on as-prepared and Ar⁺ ion sputtered samples), x-ray diffraction and magnetometry measurements showed that the Co distribution is more uniform throughout the individual Sn_0.99Co_0.01O₂ particles when prepared at lower annealing temperatures of 350-600 ^°C and this uniform dopant distribution is essential to produce stable high temperature ferromagnetism. However, surface segregation of the dopant atoms in samples annealed at >600 ^°C destroys the room-temperature ferromagnetic behavior and reduces the Curie temperature to <300 K.     

Effect of Y2O3 doping on the electrical transport properties of Sr2MnNiFe12O22 Y-type hexaferrite

Y₂O₃ doped Y-type composite hexa-ferrites Sr₂MnNiFe₁₂O₂₂ + xY₂O₃ (x = 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%) were synthesized successfully using sol-gel auto combustion technique. X-ray diffraction analysis reveals Y-type hexagonal structure with few traces of secondary phases. The decrease in grain size as a function of Yttrium content is attributed to the fact that Yttrium acts as a grain inhibitor. The DC resistivity was observed to increase with increasing Yttrium-contents due to the unavailability of Fe³⁺ ions at octahedral sites. Activation energy showed that the samples with high resistivity have high value of activation energy and vice versa. Permittivity decreases with the increase of frequency following Maxwell Wagner Model. In addition, the doped samples exhibit very low dielectric constant and low loss tangent in frequency range 20 Hz–1 MHz. The sample x = 5 wt% exhibit the lowest value of dielectric constant. The variation in imaginary part of dielectric constant and loss tangent with frequency show normal dielectric behavior for all the samples. The frequency dependent ac conductivity increases with increase in frequency and decrease with Y₂O₃ doping. These characteristics may be suitable for their potential applications in electromagnetic attenuation materials and microwave devices. The conductivity mechanism so determined was hopping mechanism. The dc resistivity of the doped ferrites measured in our case is about 10¹⁰ Ω-cm that meets the requirement for fabrication of components by electroplating.     

On the spin and hyperfine splittings in the X2Σ+ ground states of AlO and AlS

A re-analysis of the A′²Π_i–X²Σ⁺ band system of the AlS radical has been performed. The previously published material has been refined and extended to approximately 36,000 line assignments. The line material has been fitted to a ²Σ⁺ hyperfine Hamiltonian, in the same manner as in the recently published work on the B²Σ⁺–X²Σ⁺ and A²Π_i–X²Σ⁺ systems of AlO. The present analysis shows the same trends for the ground state γ-values as in AlO, i.e. decreasing γ-values upon increasing v. It has been confirmed that the spin splittings of the X²Σ⁺ (v = 0) levels in both molecules are mainly due to nuclear hyperfine interaction and second order spin–orbit effects due to the high-lying regular ²Π state (C²Π in AlO and B²Π in AlS), while the influence of the low-lying inverted ²Π state on γ increases dramatically with increasing v, resulting in negative γ-values starting from v = 2.     

Interaction of dioxouranium(VI) ion with EDTA at different ionic strengths

The formation of complex species of dioxouranium(VI) ion with EDTA was studied in the pH range of 1–3.5 and at 25 °C using a combination of potentiometric and spectrophotometric techniques. Results showed evidence for formation of the following species: [UO₂H₄EDTA]²⁺, [UO₂H₃EDTA]⁺, and [UO₂H₂EDTA]. Investigations were performed in sodium perchlorate as background electrolyte at 0.1, 0.3, 0.5, 0.7, and 1.0 mol dm^? 3. The parameters based on the formation constants were calculated, and the dependences of protonation and the stability constants on ionic strength are described. The dependence on ionic strength of the formation constants was analyzed using the specific ion interaction theory (SIT) model. The stability constant values at infinite dilution, obtained using SIT model, are log β°₁₄₁ = 6.77, log β°₁₃₁ = 5.99 and log β°₁₂₁ = 9.29, where indexes for the overall stability constant, β_pqr, refer to the equilibrium pUO₂²⁺ + qH⁺ + rL^4? ? M_pH_qL_r^{(2p + q ? 4r)}. The specific interaction coefficients are also reported.     

7Li and 51V NMR study on Li+ ionic diffusion in lithium intercalated LixV2O5

Li_xV₂O₅ (0.4 < x < 1.4) prepared by solid-state reaction were studied by ⁷Li and ⁵¹V NMR spectroscopy. ⁷Li NMR spectra showed a narrowing of the line width in relation to Li⁺ionic diffusion. Analysis of Li_xV₂O₅ using a Debye-type relaxation model showed a low activation energy ∼0.07 eV in the sample of x = 0.4 below room temperature, and revealed a Li⁺ionic diffusion with larger activation energy ∼0.5 eV above 450 K in lithium-rich samples. The latter is ascribed to the existence of a multi-phase system comprising stable ɛ- and γ-phases, resulting from complicated phase transitions at high temperature. These shapes and shifts enable the classification of the β-, ɛ-, δ-, and γ-phases. The ionic diffusion of Li⁺ ions is discussed in relation to the complicated phase transitions.     

Colossal permittivity in (Li + Nb) co-doped Fe2O3 ceramics

(Li + Nb) co-doped (Li + Nb)_xFe_2-xO₃ (with x = 0.0005, 0.005, 0.05, and 0.1) ceramics were prepared by sol-gel method. Their structural, dielectric, humidity, and magnetic properties were investigated. Colossal permittivity (~10⁴) was approached or achieved in all doped samples even with a very small doping level of x = 0.0005. The colossal permittivity behavior is composed of two dielectric relaxations with the low-temperature one being a polaron relaxation due to electrons hopping between Fe³⁺ and Fe⁴⁺ ions and the high-temperature one being a Maxwell-Wagner relaxation caused by humidity-sensing properties.     

Soot low-temperature combustion on Cu–Zr/ZSM-5 catalysts in O2/He and NO/O2/He atmospheres

Zirconium doped Cu/ZSM-5 catalysts were prepared and characterized in this investigation. Catalytic activity during soot combustion was determined in both O₂/He and NO/O₂/He atmospheres by temperature-programmed oxidation. The use of zirconium reduces the temperature of maximum soot oxidation rate by 229 °C in O₂/He atmosphere and 270 °C in NO/O₂/He atmosphere. The promoting effect of zirconium is discussed in terms of surface dispersion, enrichment of active components, and creation of oxygen vacancies where molecular oxygen or NO_x is adsorbed forming basic surface oxygen species active for soot oxidation. The NO₂ formed at the copper–zirconium interface sites leads to the ignition temperature being significantly decreased to 93 °C, which is inside the exhaust temperature range of diesel engines. To understand the combustion reaction kinetics, the activation energy and reaction order of soot combustion were evaluated. According to the Redhead method, the activation energy for non-catalyzed reaction is 164 kJ/mol under the O₂/He atmosphere. For the Cu/ZSM-5 and Cu–Zr/ZSM-5, the activation energies under the O₂/He atmosphere (134–151 kJ/mol) are slightly higher than those under the NO/O₂/He atmosphere (128–135 kJ/mol). The Freeman–Carroll method is suitable to describe the soot combustion in the NO/O₂/He atmosphere, with the activation energies for the catalysts in the range of 97–112 kJ/mol and the average value of reaction order equal to 1.36.