Relation Between Adhesion Properties and Microscopic Characterization of Polyphosphoric Acid Composite SBS Modified Asphalt Binder

The purpose of this study was to investigate the adhesive properties of polyphosphoric acid compounded SBS (PPA/SBS) modified asphalt. Three base asphalt binders, one SBS, one dibutyl phthalate (DBP), one furfural extraction oil, and two polyphosphoric acids (PPA), were used to produce the modified binders. The adhesive properties tested in this study included contact angle, cohesive work, adhesive work, and peak area ratio. Cohesive work and adhesive work indicators were calculated from the contact angle, the contact angle between PPA/SBS modified asphalt and three liquids (distilled water, glycerin, formamide) were tested by the contact angle tester, and the peak area ratio of the microscopic adhesion performance index by AFM. The relation between the microscopic adhesion performance characterization method (peak area ratio) and the macroscopic adhesion performance index (cohesive work, adhesion work) was established. The test results indicated that the PPA/SBS modified asphalt had the highest cohesive work and adhesion work under the conditions of 0.5% PPA, 1% DBP, 1.5% extracted oil, and 3.5% SBS, which was clearly greater than the original SBS modified asphalt, while the peak area ratio was consistent with the cohesive work and adhesive work, in which the correlation coefficient between the peak area ratio and cohesive work was 0.77788, and that between the peak area ratio and adhesion work was 0.87203. We recommend adopting the peak area ratio to characterize PPA/SBS modified asphalt’s microscopic adhesion properties.

Effects of pyrolysis parameters on the distribution of pyrolysis products of Miscanthus

This work presents a comprehensive study on the effects of pyrolysis parameters (pyrolysis temperature, residence time, and heating rate) on the distribution of pyrolysis products of Miscanthus. Py-GC/MS (Pyrolysis-gas chromatography/mass) was conducted to identify building blocks of value-added chemical from Miscanthus. The results showed that the main pyrolysis products of Miscanthus were ketone, aldehyde, phenol, heterocycles, and aromatic compounds. The representative compounds of ketone and aldehyde compounds produced at different pyrolysis temperatures changed obviously, while the representative compounds of phenolic, heterocyclic, and aromatic compounds had no obvious change. Large-scale pyrolysis of Miscanthus had begun at 400°C, and the relative content of pyrolysis products from Miscanthus reached the maximum of 98.34% at 700°C. The relative peak area ratio of phenol and aromatic compounds reached the maximum and minimum at the residence time of 5 and 10 s, while the relative peak area ratio of ketone compounds showed the opposite trend. The relative peak area ratio of aldehyde compounds was higher under shorter or longer residence time. For heterocyclic compounds, the relative peak area ratio reached the maximum of 27.0% at residence time of 10 s. The faster or slower heating rate was beneficial to the production of aldehyde and phenol compounds. The relative peak area ratio of ketone compounds reached the maximum at 10,000°C/s, 70°C/s, and 10°C/s, and the relative peak area ratio tendency of heterocyclic compounds was similar to ketone. For aromatic compounds, the overall fluctuations were large, and the relative peak area ratio was the highest at the heating rate of 100°C/s.

Altered brain energy metabolism in lithium-resistant bipolar disorder detected by photic stimulated 31P-MR spectroscopy

Background. Previous 31P-MRS (magnetic resonance spectroscopy) studies suggested altered brain energy metabolism in bipolar disorder. This study characterized brain energy metabolism in lithium-resistant bipolar disorder using the photic-stimulation paradigm.Methods. Subjects were 19 patients with DSM-IV bipolar disorder (nine responders and 10 non-responders, 13 with bipolar I and six with bipolar II) in the euthymic state and 25 healthy volunteers. Energy metabolism in the occipital region was examined by 31P-MRS during photic stimulation (PS). Six 31P-MR spectra were obtained, one was before PS (Pre), two during 12 min of PS (PS1, PS2), and three after the PS (Post 1, Post 2, Post 3).Results. Significant effect of diagnosis (lithium-responsive bipolar disorder, lithium-resistant bipolar disorder, and control) was found for the phosphocreatine peak area ratio during the course of the photic stimulation (P<0·05 by repeated measures ANOVA). The phosphocreatine peak area ratio was significantly decreased at Post 1 and Post 2 compared with Pre in lithium-resistant bipolar patients (P = 0·01 and P = 0·01 by Dunnett's multiple comparison).Conclusions. The finding that phosphocreatine decreased after photic stimulation may be compatible with mitochondrial dysfunction. It is possible that mitochondrial function is impaired in lithium-resistant bipolar disorder.

Determination of 2-Propanol Residue in Some Fruits Dewaxed with Alcohol Vapors

A quantitative method is described for the determination of 2-propanol in apples and grapes exposed to alcohol vapors. This method was also applied to eggplants. The procedure includes the following: homogenizing the product in a blender and filtering the slurry; weighing an aliquot of the filtrate into a serum bottle containing 1-propanol, the internal standard; equilibrating the liquid and gas phases; sampling the headspace vapor and analyzing by gas-solid chromatography (GSC). A time-temperature study using model alcohol systems indicated that equilibration at 65 °C for 60 min gave the most constant peak area ratios of 2- propanol: 1-propanol as measured by GSC. The peak area ratio was directly proportional to the concentration of 2-propanol over the range 0舓180 ppm. The recovery of 2-propanol added to untreated apple juice was excellent within this range.