Lossen Rearrangements under Heck Reaction Conditions

The classical Lossen rearrangement converts activated hydroxamic acids to isocyanates that form numerous products upon their reaction with nucleophiles. We report a simple and highly efficient method of using Heck reaction conditions to initiate Lossen rearrangements of hydroxamic acids. In addition, Lossen rearrangements occur in the presence of palladium(II) acetate or triethylamine, components of the Heck reaction, alone. A potential mechanism is provided to explain this reactivity and these results show that Heck reactions and Lossen rearrangements occur under the same conditions and may provide new methods for facile initiation of Lossen rearrangements.

     

Date consumption and dietary significance in the United Arab Emirates

Date consumption in the United Arab Emirates was determined among different subgroups of the nation's society. Adult consumers of both sexes and different age groups (18–30 and 30–60) and occupations (students, workers, at home) were surveyed for information on their daily consumption of six date food groups (rutab, tamr, seh, debbs, batheeth and madlouj). Percentage distribution of portion size, frequency of consumption and season, over different consumer groups per date food group, were determined. Differences in the daily consumption of every date food group within and among the different population groups were tested. The most consumed date food groups were rutab and tamr, with rutab being more frequently consumed than tamr during the summer season. Overall, no major differences were observed in average daily consumption per capita of most of the date food groups between males and females, between employed and home‐based consumers, and between students and individuals of 18–30 years old. On average, daily consumption of dates per capita was 114.3 g, equivalent to 10 date fruits. However, it was noted that the younger population does not consume dates as much as the older population does. Nevertheless, data obtained highlighted the significance of dates in the UAE nation's diet considering the relatively high average consumption of dates per capita. Copyright © 2006 Society of Chemical Industry     

Synthesis of Co3O4 Nanoparticles-Decorated Bi12O17Cl2 Hierarchical Microspheres for Enhanced Photocatalytic Degradation of RhB and BPA

Three-dimensional (3D) hierarchical microspheres of Bi₁₂O₁₇Cl₂ (BOC) were prepared via a facile solvothermal method using a binary solvent for the photocatalytic degradation of Rhodamine-B (RhB) and Bisphenol-A (BPA). Co₃O₄ nanoparticles (NPs)-decorated BOC (Co₃O₄/BOC) heterostructures were synthesized to further enhance their photocatalytic performance. The microstructural, morphological, and compositional characterization showed that the BOC microspheres are composed of thin (~20 nm thick) nanosheets with a 3D hierarchical morphology and a high surface area. Compared to the pure BOC photocatalyst, the 20-Co₃O₄/BOC heterostructure showed enhanced degradation efficiency of RhB (97.4%) and BPA (88.4%). The radical trapping experiments confirmed that superoxide (^•O₂⁻) radicals played a primary role in the photocatalytic degradation of RhB and BPA. The enhanced photocatalytic performances of the hierarchical Co₃O₄/BOC heterostructure are attributable to the synergetic effects of the highly specific surface area, the extension of light absorption to the more visible light region, and the suppression of photoexcited electron-hole recombination. Our developed nanocomposites are beneficial for the construction of other bismuth-based compounds and their heterostructure for use in high-performance photocatalytic applications.     

Effects of freeze-thawing cycles on the physical and mechanical properties of basaltic and dolomitic rocks evaluated with a decay function model

Bulletin of Engineering Geology and the Environment - Basalts from Çorlu Karatepe and dolomite from Kırklareli subjected to freeze-thawing (F-T) cycles were studied, and the resulting...     

Implementation of an operating procedure for quality control at production level in a RMG industry and assessment of quality improvement

Appropriate operating procedure plays a vital role in any production process for improving the quality of the final product An export oriented knit apparel manufacturing industry in Bangladesh was assessed initially and an Operating Procedure for Quality Conformation (OPQC) was applied at production process for quality improvement. The improvements were assessed twice. First assessment was done at seventh month and second assessment at ninth month after implementation of OPQC. Actions were taken considering the feedbacks from each assessment. As a result fabric (in terms of garment) loss % from cutting to final inspection was reduced and found 5.42, 4.65 and 1.19 at initial, first and second assessment, respectively. Assessment by process capability analysis shows the improvements of C_p and C_pk from 0.38 to 0.78 and ?0.35 to 0.44 from start to end of process at second assessment. Similarly Taguchi quality loss (% of order value) was reduced in each assessment and was found 10.88, 9.66 and 3.98% at initial, first and second assessment respectively. Moreover, process capability analysis and Taguchi quality loss analysis directed the manufacturer to the next steps for quality improvement.     

Drillability studies on the rotary blasthole drilling of lignite overburden series

ABSTRACT

This paper describes the results of drillability studies on rotary blasthole drillings for lignite overburden series at open pit lignite mines in Turkey. Field and laboratory studies are carried out at 96 different locations of 16 lignite mines to determine formation properties and to obtain drill performance data such as penetration rate, thrust, RPM. The obtained data analysed and the relation between some rock properties such as uniaxial compressive strength, cohesion, tensile strength, unit weight, impedance and penetration rate have been established. Among these rock properties, uniaxial compressive strength has been selected as a single parameter giving the highest correlation coefficient and to produce simple and practical relation. Finally thrust and RPM requirements are investigated and a chart based on uniaxial compressive strength is proposed to estimate thrust, RPM and corresponding penetration rate.     

浅论燃气轮机烧重油

燃气轮机以重油作为燃料 ,可有效地降低运行成本 ,因此颇受重视。本文简要说明了燃气轮机燃用重油技术的成熟性 ,并对我国目前燃用重油燃气轮机的情况进行了统计。文章分析了燃气轮机烧重油在燃烧、结垢、腐蚀等方面所产生问题的原因及后果 ,并针对这些问题提出了在燃油处理、燃烧系统、燃油系统和机组运行维护等方面所应采取的对策。