Composition of clove (Syzygium aromaticum) bud oil extracted using carbon dioxide

Analysis of clove (Syzygium aromaticum L) bud oil extracted with liquid and supercritical carbon dioxide shows significant qualitative and quantitative compositional differences compared with oil obtained by the conventional hydrodistillation process. The parameters of pressure, temperature, contact time etc, and also the clove oil components, affect the extraction of the bud flavour from the spice.     

媒染剂和染料用量对红土染料染色棉织物色牢度的影响

从红土中提取天然染料并将其应用于棉织物.改变媒染剂用量和染液用量进行染色试验.结果表明,与不使用媒染剂的试样相比,使用媒染剂的天然红土染色织物试样表现出较好的耐水洗、耐光和耐摩擦色牢度,且色牢度随着媒染剂用量的增加而提升.染料用量的增加未导致织物试样的色牢度明显提升.     

A comparative study of the D.C. conductivities for certain Eu3 : Fluoroborate glasses

This short note brings out the study of D.C. conductivity of certain newly prepared Eu³⁺ -doped fluoroborate glasses.     

Precedence relationship performance of an indirect matrix solver

A highly parallel truncated accelerated Neuman series preconditioner is presented. Results from using this preconditioner are compared with those obtained using a traditional truncated Neumann series preconditioner and the Jacobi method on matrices whose numerical content is characteristic of the bus admittance matrices used in the analysis of faulted power system problems. These results show that the number of precedence relationships experienced by this technique are of the same order of magnitude as the number encountered when using direct methods     

Evidence that mitochondrial respiration is a source of potentially toxic oxygen free radicals in intact rabbit hearts subjected to ischemia and reflow

Previous in vitro studies have shown that isolated mitochondria can generate oxygen radicals. However, whether a similar phenomenon can also occur in intact organs is unknown. In the present study, we tested the hypothesis that resumption of mitochondrial respiration upon reperfusion might be a mechanism of oxygen radical formation in postischemic hearts, and that treatment with inhibitors of mitochondrial respiration might prevent this phenomenon. Three groups of Langendorff-perfused rabbit hearts were subjected to 30 min of global ischemia at 37 degrees C, followed by reflow. Throughout ischemia and early reperfusion the hearts received, respectively: (a) 5 mM KCl (controls), (b) 5 mM sodium amobarbital (Amytal, which blocks mitochondrial respiration at Site I, at the level of NADH dehydrogenase), and (c) 5 mM potassium cyanide (to block mitochondrial respiration distally, at the level of cytochrome c oxidase). The hearts were then processed to directly evaluate oxygen radical generation by electron paramagnetic resonance spectroscopy, or to measure oxygen radical-induced membrane lipid peroxidation by malonyl dialdehyde (MDA) content of subcellular fractions. Severity of ischemia, as assessed by 31P-nuclear magnetic resonance measurements of cardiac ATP, phosphocreatine, and pH, was similar in all groups. Oxygen-centered free radical concentration averaged 3.84 +/- 0.54 microM in reperfused control hearts, and it was significantly reduced by Amytal treatment (1.98 +/- 0.26; p < 0.05), but not by KCN (2.58 +/- 0.96 microM; p = not significant (NS)), consistent with oxygen radicals being formed in the mitochondrial respiratory chain at Site I. Membrane lipid peroxidation of reperfused hearts was also reduced by treatment with Amytal, but not with KCN. MDA content of the mitochondrial fraction averaged 0.75 +/- 0.06 nM/mg protein in controls, 0.72 +/- 0.06 in KCN-treated hearts, and 0.54 +/- 0.05 in Amytal-treated hearts (p < 0.05 versus both groups). Similarly, MDA content of lysosomal membrane fraction was 0.64 +/- 0.09 nM/mg protein in controls, 0.79 +/- 0.15 in KCN-treated hearts, and 0.43 +/- 0.06 in Amytal-treated hearts (p < 0.05 versus both groups). Since the effects of Amytal are known to be reversible, in a second series of experiments we investigated whether transient mitochondrial inhibition during the initial 10 min of reperfusion was also associated with beneficial effects on subsequent recovery of cardiac function after wash-out of the drug. At the end of the experiment, recovery of left ventricular end-diastolic and of developed pressure was significantly greater in those hearts that had been treated with Amytal during ischemia and early reflow, as compared to untreated hearts.(ABSTRACT TRUNCATED AT 400 WORDS)     

Neutron structural study of the Bi-monolayer compound (Bi0.5Cu0.5)Sr2(Y0.8Cu0.2)Cu2O7 + δ—the Role of excess oxygen in superconductivity

Comparative neutron structural investigations are made on nonsuperconducting (slow-cooled) and superconducting (liquid-nitrogen quenched;T _c ^onset=70 K andR=0 at 20 K) samples of (Bi_0.5Cu_0.5)Sr₂(Y_0.8Cu_0.2)Cu₂O_{7 + δ} in order to examine the role of excess oxygen on the superconducting behavior of this “1212”-phase compound. Analysis of refined structural parameters shows that the two main factors which influence the superconductivity in (Bi, Cu)-1212 are: (i) the extent of occupancy of excess oxygen at O(5), the 2(e) site located in between the two CuO₂ pyramidal layers, and (ii) the length of the apical Cu(2)-O(2) bond. The (Bi, Cu)-O monolayer plays the role of the “charge reservoir” quite effectively as reflected by the substantial increase in the length of the apical (bridging) Cu(2)-O(2) bond due to depletion of excess oxygen in this layer. Surprisingly, vacancies at as many as 10% of the O(1) site belonging to the CuO₂ planes do not appear to disrupt the flow of current in the Cu(3d)-O(2p) planar network in the superconducting state. Relevant features of the structure of the (Bi, Cu)-1212 phase, in particular the role of excess oxygen and its occupancy at different sites, are discussed in the light of the available data on the isostructural (Pb, Cu)-1212 phase and the (La, Sr, Ca)₃-Cu₂O_{6 + δ} phase superconductors.     

Performance and modeling of broadband LiNbO3 travelingwave optical intensity modulators

The design, fabrication and characterization of a traveling wave Ti:LiNbO₃ Mach-Zehnder interferometric modulator are discussed. The dependence of the velocity match condition on electrode thickness and wall angle is demonstrated experimentally and with finite element calculations. A set of test electrode structures is fabricated to study electrical losses in the modulator electrode. Loss coefficients are assigned to different sections of the device, and dielectric and radiative losses are shown to play an important role at high frequencies. This information is used in conjunction with finite-element calculations to develop accurate models for both the electrical and optical responses. The frequency dependence of the half-wave voltage is measured and shown to be in good agreement with a model     

Multiparty gaze preservation through perspective switching for interactive elearning environments

Multimedia Tools and Applications - Existing live tele-teaching systems enable eye-contact between interacting participants, however, they are often incomplete as they neglect finer levels of...     

Computational completeness of simple semi-conditional insertion–deletion systems of degree (2,1)

Natural Computing - Insertion–deletion (or ins–del for short) systems are simple models of bio-inspired computing. They are well studied in formal language theory, especially regarding...