Kinetics of oxirane cleavage in epoxidized soybean oil

The kinetics of oxirane ring cleavage in epoxidized soybean oil have been studied using glacial acetic acid at 60, 70, 80 and 90°C. It was shown that the reaction can be successfully modelled as first order with respect to the epoxide concentration and second order with respect to acetic acid. The reaction velocity constant at 70°C was found to be 2 × 10⁻³ 1⁻³ hr⁻¹ mol⁻², the frequency factor, A, = 2.321 × 10⁷ hr⁻¹ and the energy of activation, E_a = 15.84 k cal mol⁻¹. The effects of the concentration of acetic acid and the temperature on the net yield of epoxides by in situ epoxidation were also studied on the basis of the predicted kinetic parameters of the reaction system.     

Efficient KNN search by linear projection of image clusters

K‐nearest neighbors (KNN) search in a high‐dimensional vector space is an important paradigm for a variety of applications. Despite the continuous efforts in the past years, algorithms to find the exact KNN answer set at high dimensions are outperformed by a linear scan method. In this paper, we propose a technique to find the exact KNN image objects to a given query object. First, the proposed technique clusters the images using a self‐organizing map algorithm and then it projects the found clusters into points in a linear space based on the distances between each cluster and a selected reference point. These projected points are then organized in a simple, compact, and yet fast index structure called array‐index. Unlike most indexes that support KNN search, the array‐index requires a storage space that is linear in the number of projected points. The experiments show that the proposed technique is more efficient and robust to dimensionality as compared to other well‐known techniques because of its simplicity and compactness. © 2011 Wiley Periodicals, Inc.     

Routing in Wireless Sensor Networks Using Optimization Techniques: A Survey

Wireless Personal Communications - Over the past few decades, one of the important advancements in wireless communication is low cost and limited power devices known as wireless sensor networks...     

Information and communication theory in molecular biology

The DNA sequencing efforts of the past years together with rapid progress in sequencing technology have generated a huge amount of sequence data available in public molecular databases. This recent development makes it statistically feasible to apply universal concepts from Shannon’s information theory to problems in molecular biology, e.g to use mutual information for gene mapping and phylogenetic classification. Additionally, the genetic information in the cell is continuously subject to mutations. However, it has to be passed from generation to generation with high fidelity, raising the question of existence of error protection and correction mechanisms similar to those used in technical communication systems. Finally, better understanding of genetic information processing on the molecular level in the cell can be acquired by looking for parallels to well established models in communication theory, e.g. there exist analogies between gene expression and frame synchronization.     

Limited descent-based mean value method for inverse reliability analysis

Engineering with Computers - The robustness and efficiency of inverse reliability methods are important issues in reliability-based design optimization (RBDO) using performance measure approach...     

Non catheter‐related bacteremia caused by Pseudomonas oryzihabitans in a patient undergoing hemodialysis

Pseudomonas oryzihabitans (P. orizyhabitans) has already been reported both as a human and a zoonotic pathogen. A few cases of P. orizyhabitans bacteremia have been reported among patients who underwent peritoneal dialysis. P. orizyhabitans bacteremia has never been reported among patients on hemodialysis. We report the first case of P. orizyhabitans bacteremia in a chronic hemodialysis patient; this patient did not have a central venous catheter angioaccess as a potential portal of entry.     

Synthesis of poly‐N‐(thiazol‐2‐yl)methacrylamide: Characterization,complexation, and bioactivity

Cu(II) complexes with N‐(thiazol‐2‐yl)methacrylamide (NTM) and its polymer PNTM have been synthesized. The ligands (NTM and PNTM) and their Cu(II) complexes have been characterized by FTIR and ¹H‐NMR. EDX was performed to know the elemental composition and X‐ray powder diffractometry (XRD) analysis was applied to detect the crystallinity of the complexes. The morphology of these complexes was investigated with scanning electron microscopy (SEM) and proves that the monomer complexes have a strongly crystalline structure compared with the polymer complexes, which show that it is only weakly crystalline. These results from SEM are in agreement with results obtained from XRD. Thermal properties of the ligands and their complexes have been studied by thermogravimetric analysis and differential scanning calorimetry. The activity of the ligands and their complexes has been screened against S. aureus, E. coli, Pseudomonas, and Candida albicans. The synthesized compounds have shown good affinity as antibacterial and antifungal agents, which increased on complexation with Cu(II) ion. The results of these studies show the Cu(II) complexes to be more thermal stable as compared with NTM and PNTM. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Role of functional groups on the microwave attenuation and electric resistivity of activated carbon fiber cloth

Virgin activated carbon fiber cloth (ACFC) samples with select degrees of activation/porosity were treated with nitric and sulfuric acids or with hydrogen. Composition, microwave attenuation constant and electric resistivity results for these samples are provided. On average, acid treatment resulted in a 677% increase in oxygen content, 89% decrease in microwave attenuation constant, and 3200% increase in electrical resistivity when comparing these properties to the corresponding ones in the virgin samples. However, hydrogen treatment resulted in a 72% decrease in oxygen content, 50% increase in microwave attenuation constant, and 63% decrease in electrical resistivity, when comparing these properties to the corresponding ones in the virgin samples. These results indicate that conduction loss dominates over the polarization loss for microwave attenuation in ACFC. Increasing the oxygen content reduces the ACFC’s ability to absorb microwaves and is expected to make ACFC more difficult to heat with microwaves. However, decreasing the oxygen content allows the ACFC to heat more readily by resistive heating. Since microwave and resistive heating techniques depend on the microwave attenuation constant and electric resistivity, respectively, controlling the density of functional groups of ACFC can significantly affect the thermal regeneration of ACFC depending on the method used to heat the ACFC.