Synthesis, anti-inflammatory and analgesic activity evaluation of some 2-(9-acridinylamino )pyridines and 2-(9-acridinylamino/imino)thiazolines

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Latent variables and route choice behavior

In the last decade, a broad array of disciplines has shown a general interest in enhancing discrete choice models by considering the incorporation of psychological factors affecting decision making. This paper provides insight into the comprehension of the determinants of route choice behavior by proposing and estimating a hybrid model that integrates latent variable and route choice models. Data contain information about latent variable indicators and chosen routes of travelers driving regularly from home to work in an urban network. Choice sets include alternative routes generated with a branch and bound algorithm. A hybrid model consists of measurement equations, which relate latent variables to measurement indicators and utilities to choice indicators, and structural equations, which link travelers' observable characteristics to latent variables and explanatory variables to utilities. Estimation results illustrate that considering latent variables (i.e., memory, habit, familiarity, spatial ability, time saving skills) alongside traditional variables (e.g., travel time, distance, congestion level) enriches the comprehension of route choice behavior

Number preferences in lotteries

We explore people's preferences for numbers in large proprietary data sets from two different lottery games. We find that choice is far from uniform, and exhibits some familiar and some new tendencies and biases. Players favor personally meaningful and situationally available numbers, and are attracted towards numbers in the center of the choice form. Frequent players avoid winning numbers from recent draws, whereas infrequent players chase these. Combinations of numbers are formed with an eye for aesthetics, and players tend to spread their numbers relatively evenly across the possible range

Remaining life assessment of service exposed reactor and distillation column materials of a petrochemical plant

Mechanical property evaluation is a powerful tool for estimating the residual life of in-service components and health monitoring. In the present investigation such an assessment was carried out to estimate the remaining life of in-service plain carbon steels that had been in use for 45 years in a feed processing unit (FPU) of a petrochemical plant. Health assessment of both base and weld joints of the material has been carried out through accelerated stress rupture tests and other mechanical property evaluation. At the operating conditions, it is noted that the materials still have about 10 years of residual life. However, surprisingly weld joints of the column of this unit exhibited poor notch toughness (5–10 J). It could not be proved beyond doubt, if the weld developed poor notch toughness during fabrication or degraded during service. Annealing of weld joints at 530 °C for 1.5 h improved the notch toughness significantly, hence is recommended accordingly

Health assessment of radiant heater tube

A radiant heater tube in an oil refinery made of a particular grade of austenitic steel and service exposed for 61,000 hours was investigated for health assessment and safety. Experimentally determined yield strength and ultimate tensile strength as well as estimated 10,000 hours - 100,000 hours rupture strength as obtained from experimental data in the temperature range of 773 to 873K exhibit a decreasing trend with increasing temperature. Microstructural study did not reveal any significant degradation in terms of creep cavities, cracks, graphitization etc. Analysis of hot tensile and accelerated stress rupture data revealed that the service exposed radiant heater tube could remain in service for a length of more than ten years at the operating hoop stress level and maximum allowable skin temperature (158.78 MPa / 865 K), provided no localised damage in the form of cracks or dents had developed. It is recommended that a similar health check of these tubes should be carried out after 50,000 hours of service exposure at the desired operating conditions

Mechanical strength and microstructural observations for remaining life assessment of service exposed 24Ni–24Cr–1.5Nb cast austenitic steel reformer tubes

Reformer furnace heater tubes made of cast austenitic alloy steels serve in the temperature range of 1073–1173 K and pressure around 3–4 MPa. Though the design life is about 100,000 h (11.4 years), premature failures within 3–8 years are more common, mainly caused by premature creep induced by overheating. The cast tube material undergoes microstructural changes with service exposure and as a consequence, degradation in strength. Microstructural changes, tensile strength and accelerated stress rupture strength of 96,000, 105,120 and 131,400 h service exposed tubes of 24%Ni24%Cr1.5%Nb alloy (equivalent to IN-519) served in a reformer furnace were analysed. Presence of coarsened carbides at the interdendritic boundaries, absence of significant amount of secondary carbides in the intra-dendritic regions together with sigma (σ) phase at both inter and intra-dendritic regions and isolated creep cavities indicated severity of service induced ageing and damage process accumulation. However, the stress rupture life obtained through Larson–Miller parametric method was good for further life extension. Attempts to correlate the microstructural changes to remaining creep life assessment (RLA) proved to be difficult as errors were mainly arising from the fact that temperature experienced by the individual tubes in a furnace differs and for a single tube through out its vertical length it varies. Non-destructive ultrasonic scan method employed too could not estimate the creep damage level accurately and the results vary with destructive test results. Lack of data on both microstructural changes and mechanical strength of the service exposed tube materials makes RLA more difficult

Influence of Dietary Protein Deficiency on Lead-Copper Interaction in Rats

The influence of dietary protein deficiency on the effects of exposure to lead or its combination with copper was investigated in rats. The administration of lead (100 ppm in drinking water) inhibited the activity of blood δ-aminolevulinic acid dehydratase; decreased hemoglobin, brain dopamine, and 5-hydroxytryptamine; and increased urinary excretion of δ-aminolevulinic acid, blood zinc protoporphyrin, and tissue accumulation of lead more markedly in animals fed a protein-deficient diet (10% casein) than in those fed a normal diet (21% casein). The simultaneous supplementation of copper (100 ppm in diet) reduced some of the lead-induced alterations and body uptake of lead more efficiently in animals fed a normal diet than in those fed a protein-deficient diet, which shows that the beneficial effects of copper in lead toxicity are adversely affected by low dietary protein