X-ray microanalysis of mitochondrial deposits in ischemic myocardium

The x-ray microanalysis technique was used to determine the chemical composition of intramitochondrial electron-dense deposits in ischemic myocardial cells. Semi-thin sections were cut from Araldite-embedded tissue and analyzed in a scanning electron microscope equipped with energy- and wavelength-dispersive spectrometers. The energy dispersive spectrum revealed calcium and phosphorus peaks over many mitochondrial deposits. Peak to background ratios of calcium, phosphorus and magnesium obtained with the wavelength dispersive spectrometer were 1.7, 8.8 and 1.2, respectively. There was no consistent relationship in the characteristic peaks of calcium and phosphorus in a given mitochondrial granule. Magnesium appears to be negligible, except in some mitochondrial deposits which lacked calcium, where it was present with a peak to background ratio of two. These results suggest formation of calcium or magnesium phosphate in the mitochondria during ischemia. X-ray microanalysis can provide detailed information on subcellular electrolyte distribution in normal and ischemic myocardial cells and should be attempted with improved methods of tissue preparation.     

Denotational semantics of a synchronous VHDL subset

A denotational definition for a single clock synchronous subset of VHDL is proposed. The different domains for variables and signals, the elaboration of static environments, and the formulation of a simulation algorithm for the sub-language characterize this definition, and distinguish it from more traditional denotational semantics of programming languages.     

A special beam element for the analysis of thin-walled structural components

A new beam element is described which is capable of depicting the non-linear elastic mode interaction of overall bending/buckling with local buckling in thin-walled beam-columns. In addition to being capable of describing overall biaxial bending and twisting, the element has shape functions which contain implictly the relevant local buckling deformation. The mode interaction occurs by virtue of the non-linear coupling of the overall and local buckling deformation. The local and post-local buckling displacement fields are computed a priori in an efficient manner using the finite strip technique. The modulation of the local buckling amplitudes is also accounted for in the element. In general, the beam element incorporates three companion local modes, all of which may become important in the process of interaction. Examples are presented which illustrate the efficacy of the element for problems involving interaction of local and flexural buckling modes and the combined interaction of local, flexural and flexural--torsional modes.     

Levels,Sources, and Risk Assessment of Polychlorinated Biphenyls (PCBs) in Soils from Industrial Areas: A Case Study from Saudi Arabia

ABSTRACT

The objective of this study was to assess the pollution levels, sources, and human health risk of polychlorinated biphenyls (PCBs) in soils of industrial areas of the central and eastern regions of Saudi Arabia. Therefore, the surface soil samples from industrial areas (cement kiln, oil refinery, electric power plant, steel industry, and desalination plant) were collected and analyzed by High-Resolution Gas Chromatography-Mass Spectrometry/Mass Spectrometry-Time of Flight (HRGC-MS/MS-TOF) to quantify the levels of 26 PCBs (including 12 dioxin-like PCBs and 14 indicator-PCBs). The investigated 26 PCBs were detected in all soil samples. The total PCBs concentration (from tri-CBs to hepta-CBs) ranged from 171 to 4892 pg g^?1 with an average of 1369 pg g^?1 in soils of the central region and of 142–1231 pg g^?1 with an average of 302 in soils of the eastern region, showing higher values at cement factory and/or oil refinery sites. Overall, the indicator-PCBs were the main congeners and contributed dominantly to the total mass of PCBs in comparison with the dioxin-like PCB congeners, with the most abundant for PCB-180 in the soil samples of the central region. Among individual dioxin-like PCBs, PCB-126 had the highest average value of the toxicity equivalence (TEQ). The TEQ values of ∑12dioxin-like PCBs did not exceed the Canadian soil quality guidelines of dioxin (4 pg TEQ g^?1). Based on human health risk assessment via ingestion, dermal contact, and inhalation, low adverse effects of PCBs could be expected as indicated by lower values of cancer risk (≤10^?6). The principal component analysis indicated that there is a different source of PCBs with similar or different PCB profiles.     

EFFECT OF MTBE BLENDING ON THE PROPERTIES OF GASOLINE

ABSTRACT

The effect of blending MTBE in the gasoline was evaluated. MTBE effectively boost the octane numbers of gasoline without adversely effecting its other properties. However, MTBE is not as efficient as leadalkyl compounds as far as the specific octane number improvements are concerned. The addition of 5 to 30 volume percent MTBE increases 1.9 to 11.8 RON of a typical gasoline. MTBE addition also extends the volume of gasoline produces for a given crude by adding volume to the gasoline pool. MTBE provides much higher FEON to the gasoline in comparison with other gasoline components. A higher FEON increases the efficiency of the engine. MTBE is not affected by the lead level of the gasoline. For this reason, lost octane in future lead reductions of the gasoline in Saudi Arabia can be made up with MTBE. MTBE addition to the Saudi gasoline increases the RVP but within the specification of the gasoline. MTBE has favorable effect on the distillation characteristics of the gasoline. MTBE addition lowers the distillation temperature which improves driveability and cold engine operation. MTBEgasoline blends were found free of gums and peroxides after long term storage and pose no phase separation problems in the presence of water. MTBE is miscible in gasoline in all proportions and its solubility in water is low.     

Chlorination,Nitration, and Amination Reactions of Asphaltene

Asphaltenes are well known for their problematic characterstics during petroleum refining as well as dubiously complex structure. In this work, chlorination of various types of asphaltenes have been achieved by sulfuryl chloride with and without AIBN initiator, while nitraion and reactions with amines (aniline, triethylamine, t-butyl amine, and piperidine) were accomplished through nitrous acid and diazotization process, respectively. The charaterization of the products obtained were performed by FTIR spectroscopy. The data regarding the composition of the asphaltenes generated in this work will surely enhance our understanding toward the asphaltenes. It is envisaged that such reactions will provide an opportunity to investigate further the reacting behavior of asphaltenes for better industrial use.     

Apple Volatiles Synergize the Response of Codling Moth to Pear Ester

Codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), is a major cosmopolitan pest of apple and other pome fruits. Ethyl (E,Z)-2,4-decadienoate (pear ester) has been identified as a host-derived kairomone for female and male codling moths. However, pear ester has not performed similarly in different fruit production areas in terms of the relative magnitude of moth catch, especially the proportion of females caught. Our work was undertaken to identify host volatiles from apples, and to investigate whether these volatiles can be used to enhance the efficacy of host kairomone pear ester for monitoring female and male codling moths. Volatiles from immature apple trees were collected in the field using dynamic headspace sampling during the active period of codling moth flight. Using gas chromatography-electroantennogram detector (GC/EAD) analysis, six compounds elicited responses from antennae of females. These compounds were identified by GC/mass spectrometry (MS) and comparisons to authentic standards as nonanal, (E)-4,8-dimethyl-1,3,7-nonatriene, methyl salicylate, decanal, (Z,E)-α-farnesene, and (E,E)-α-farnesene. When the EAD-active compounds were tested individually in the field, no codling moths were caught except for a single male with decanal. However, addition of (E)-4,8-dimethyl-1,3,7-nonatriene, methyl salicylate, decanal, or (E,E)-α-farnesene to pear ester in a binary mixture enhanced the efficacy of pear ester for attracting female codling moths compared to pear ester alone. Addition of the 6-component blend to the pear ester resulted in a significant increase in the number of males attracted, and enhanced the females captured compared to pear ester alone; the number of males and females caught was similar to that with the pear ester plus acetic acid combination lure. Our results demonstrate that it is possible to synergize the response of codling moth to host kairomone by using other host volatiles. The new apple–pear ester host kairomone blend should be helpful for monitoring female codling moth, and may provide the basis for further improvement of codling moth kairomone.     

Reinforcing potential of nanofibrillated cellulose from nonwoody plants

In the present work the reinforcing potential of nanofibrillated cellulose (NFC) from five different non‐woody plants, namely; abaca, sisal, hemp, jute and flax was investigated. Nanocomposite materials were prepared by casting a mixture of NFC suspension and a polymer waterborne latex dispersion, and their mechanical properties in both linear and nonlinear ranges as well as the optical properties of the ensuing films were analyzed. Irrespective of their origin, the incorporation of the NFC within the polymer matrix brings about a huge reinforcing effect above the glass transition. The percolation approach has been shown to give a reasonably accurate prediction of the stiffness over the whole range of volume fraction investigated. The evolution of the magnitude of tan δ vs. the NFC content was also analyzed and discussed in term of the effective interfacial thickness. The optical transparency of the nanocomposite film at different NFC content was also studied and compared according to the NFC origin. POLYM. COMPOS., 34:1999–2007, 2013. © 2013 Society of Plastics Engineers     

Adsorption Parameter and Heat of Adsorption of Activated Carbon/HFC-134a Pair

This article presents the adsorption isotherms of HFC-134a and activated carbon Maxsorb III measured using the constant-volume–variable-pressure method. The adsorption isotherms cover temperature ranges from 293 to 338 K and pressures up to 0.7 MPa. The trends of the experimental isotherms for activated carbon are found to be identical in all cases with previous studies except that the vapor uptake is slightly higher. The adsorption characteristic of the Dubinin–Ashtakov equation has been regressed from the experimental isotherms data and the maximum specific uptake is 2.15 kg of adsorbate adsorbed per kilogram of activated carbon. The heat of adsorption, which is concentration and temperature dependent, has also been extracted from the experiments.