5,333 research outputs found
Chemical-mineralogical approach in the characterisation of recycled aggregates for use in concrete applications.
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Identification and quantitation of 3-hydroxy-N-nitrosopyrrolidine in fried bacon and fried-out fat
No full textThe formation of 3-hydroxy-N-nitrosopyrrolidine from decarboxylation
of 4-hydroxy-N-nitrosoproline was demonstrated in model
heating system designed to simulate the conditions of frying bacon.
The identification of the nitrosamine was achieved by comparison of
its TLC R [subscript f] value, gas chromatographic retention time, and mass
spectral fragmentation pattern with those of the authentic compound.
3-Hydroxy-N-nitrosopyrrolidine was isolated from commercial
fried bacon and fried-out fat. The identification of the compound was
achieved by combined gas chromatography-mass spectrometry after
trimethylsilyl derivatization of the nitrosamine. Additional verification
of identity was obtained from coincident retention time data on a combined
gas chromatography-thermal energy analyzer.
Quantitative determination of 3-hydroxy-N-nitrosopyrrolidine
was accomplished without derivatization and was greatly facilitated
by the use of a thermal energy analyzer. Quantitative analysis by
combined gas chromatography-thermal energy analyzer did not
require as extensive cleanup as was required for identification by
combined gas chromatography-mass spectrometry.
The levels of 3-hydroxy-N-nitrosopyrrolidine occurring in five
samples of fried bacon were 0.5 to 3.9 ppb while the levels in fried-out
fat ranged from 0.3 to 2.2 ppb. These levels are lower than the
concentrations generally reported for nitrosopyrrolidine in fried
bacon.
This study, although the number of samples analyzed was
limited, suggests that low ppb levels of 3-hydroxy-N-nitrosopyrrolidine
appear fairly consistently in fried bacon
Micro-chemical/structural characterisation of thin layer masonry: a correlation with engineering performance
No full textMasonry is one of the most ancient methods of construction. The types of blocks and mortars used over the centuries have developed considerably with the introduction of various types of materials. A multidisciplinary investigative approach, involving both engineering and material sciences expertise, will be necessary for a complete evaluation of the behaviour of masonry elements. From the engineering point of view, the transverse lateral load capacity of masonry built using solid dense concrete blocks with thin layer mortar, is up to four times that of similar blockwork constructed using conventional mortar. Both the mortar and block constituent material’s properties alter the joint strength with enhancements to tensile flexural bond strength. When thin layer masonry technology (TLMT) is employed, in conjunction with solid dense concrete blocks, the masonry behaves more as a concrete plate than conventional blockwork. The engineer- ing properties of masonry elements are not only related to the engineering properties of the blocks and mortars used, but also to how the bond at their interface interacts. Testing on two different block types, and one mortar was undertaken to verify this hypothesis. Engineering testing was carried out to determine the flexural strength of the material. This approach was combined with petrographical examination of the two different types of block and the bond zone using micro-analytical techniques, (OTLM, SEM and EMPA). Observations using SEM and EMPA techniques revealed that these differences depend on the composition of both blocks and mortar, and in particular they are related to the petrographical composition of the parent material of the block. These aspects affect how the bond layer forms and influence the mechanical properties of the joint
Un-reinforced solid dense concrete block walls constructed using thin joint technology
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Modification of a gas chromatography-mass spectrometry method for the determination of acrylamide in fried snacks
No full textAcrylamide is a toxic and probably carcinogenic compound and also neurotoxin in humans and animals that is formed naturally in certain foodstuffs, especially those rich in carbohydrate, during heat processing or cooking at high temperatures. This study was carried out to develop and validate the determination of acrylamide in fried snacks using gas chromatography-mass spectrometry (GCMS). The developed method involved the extraction of acrylamide with water followed by a cleanup treatment using Oasis HLB and MCX solid-phase extraction cartridges, bromination using reduced amount of saturated bromine water (from 15 to 2.5 ml due to bromine vapour is harmful and inhalation may be fatal as a result of spasm, inflammation, edema of the larynx and bronchi, also causes respiratory tract irritation with possible burns), then dehydrobromination by adding sodium thiosulfate solution until the yellow color has disappeared and using triethylamine to convert 2,3-dibromopropionamide to 2-bromopropenamide. This derivative is less polar compared to the acrylamide and is therefore easily soluble in non–polar organic solvents like ethyl acetate and hexane. The limit of detection (LOD) and limit of quantitation (LOD) of the method were 5 and 15 μg kg-1, respectively, and the regression coefficient was 0.9997. The recoveries of acrylamide in banana fritter samples at low, medium and high concentrations of 100, 200 and 4000 μg kg-1, respectively, were in the range of 84 to 109%. The repeatability and reproducibility values of the method ranged to 3-10 and 0.6–6, 0.3–8 for different days and different operators, respectively
Similar roles for recovery capital but not stress in women and men recovering from gambling disorder
No full textBackground: Understanding gender-related differences is important in recovery processes. Previous studies have investigated gender-related differences in factors associated with gambling disorder (GD), but none to date have considered both positive and negative resources related to recovery. Using a recovery capital (RC) framework that considers multiple resources available during recovery, this study examined gender-related similarities and differences in associations between positive resources (RC, spirituality) and negative experiences and states (stressful life events, depression, and anxiety) and GD symptom improvement. Method: One hundred and forty individuals with lifetime GD (101 men) were assessed using DSM-5 diagnostic criteria for GD (past-year and lifetime prior to past-year), the Brief Assessment of RC, the Intrinsic Spirituality Scale, the Stressful Life-events Scale, the Generalized Anxiety Disorder Scale, and the Patient Health Questionnaire 9 for depression. Multiple linear regression and Bayesian statistical analyses were conducted. Results: RC was positively and significantly associated with GD symptom improvement in women and men. Stressful life events were negatively associated with GD symptom improvement only in men. Conclusions: RC is an important positive resource for men and women recovering from GD and should be considered in treating both women and men. Understanding specific RC factors across gender groups and stressors, particularly in men, may aid in developing improved interventions for G
The association of fried foods consumption with constipation and functional constipation in Iranian adults
No full textBackground: The linkage between consumption of fried foods and constipation was less studied. We aimed to assess the relationship between fried foods intake with constipation and functional constipation and its components in a large group of Iranian adults. Methods: In this cross-sectional study on 4517 adults, fried foods intake was assessed using an eating-behavior questionnaire. Subjects were classified into four categories based on their fried foods intake: "never", "1-3 times per week", "4-6 times per week" and "every day". The prevalence of functional constipation and its components was defined according to Rome III criteria. Findings: The prevalence of functional constipation and constipation among study population was 15.3 and 33.5, respectively. After adjustment for potential confounding factors, individuals who ate 4 to 6 meals of fried foods per week had lower odds ratios for functional constipation (OR: 0.67; 95 CI: 0.45-0.99), in comparison to those in the lowest category of fried food intake; more adjustment for dietary fiber intake disappeared this association. However, fried foods intake raised the risk of "sensation of incomplete evacuation" and "fewer than three defecations per week" by 36 (OR: 1.36; 95 CI: 1.02-1.79) and 159 (OR: 2.59; 95 CI: 1.00-6.71) in females as well as frequency and severity of these symptoms in whole population. Conclusion: There was no significant association between fried foods intake and odds ratios for functional constipation. However, fried foods intake raised frequency and severity of some components of functional constipation. © 2016, Isfahan University of Medical Sciences(IUMS). All rights reserved
Deux destins révolutionnaires : Lénine et Eugen Fried
No full textCœuré Sophie. Deux destins révolutionnaires : Lénine et Eugen Fried. In: Revue d’histoire moderne et contemporaine, tome 46 N°2, Avril-juin 1999. pp. 365-370
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