Numerical investigation into the effect of various surcharge loadings on propped wall excavations and embankments

Several guidance and formulation have been developed in the literature to account for the analysis of external surcharges adjacent to a propped excavation but less attention has been paid to the presence of sloping ground or embankments. However, CIRIA C760 states that the actual ground profile should be modelled and analysed as a series of surcharge loading over the extent of the active side of the wall. In this research, two braced excavation models were analysed of which one was the actual ground profile and the second with a series of surcharge loading representing the embankment adjacent to the excavation. The accuracy, efficiency, and conservation of the proposed approaches were examined on a propped cantilever wall excavation using a finite element geotechnical analysis software PLAXIS 2D. The models were analysed and examined in terms of the bending moment and deflection of the diaphragm wall and the prop load, the model with the actual ground profile was also investigated for any thrust load on the support system should the embankment or sloping ground fail in shear. The results were presented, and comparisons were made. Merits and advantages of the proposed numerical approach were discussed

Interpersonal relationships and depression among adolescents living in Tehran's shelters

This report explores the connection between interpersonal relationships and depression among adolescents living in Tehran’s shelters. A total 103 Iranian adolescents from nine governmental shelters in Tehran, comprising 69 males and 34 females between the ages of 13 and 15 years, were included in this research. A correlational design was employed in this study and a convenience sampling method was used to select respondents. The results revealed significant negative correlations for depression and difficulties with interpersonal relationships with roommates, classmates, social workers, and guardians. The results of this study will help guardians, social workers, and psychologists to organize intervention programmes that assist with relationship formation as a means for reducing depression among adolescents in Tehran’s youth shelters

Growth response and nutrient uptake of blue pine (Pinus wallichiana) seedlings inoculated with rhizosphere microorganisms under temperate nursery conditions

Microbial inoculants (Trichoderma harzianum, Pseudomonas fluorescens,Laccaria laccata) inoculated either individually or in combinationsignificantly improved the growth and biomass of blue pine seedlings. The ECM fungus Laccaria laccata, when inoculated individually, showed significantly higher plant growth, followed by Pseudomonas fluorescens and Trichoderma harzianum. The combined inoculation of rhizosphere microorganisms showed synergistic growth promoting action and proved superior in enhancing the growth of blue pine than individual inoculation. Co-inoculation of L. laccata with P. fluorescens resulted in higher ectomycorrhizal root colonization. Uptake of nutrients (N, P, K) was significantly improved by microbial inoculants, tested individually or in combination. Combined inoculation of L. laccata with T. harzianum and P. fluorescens significantly increased in N, P and K contents in blue pine seedlings as compared to control. Acid phosphatase activity in the rhizosphere of blue pine seedlings was also enhanced by these microorganisms. L. laccata exhibited higher acid phosphatase activity followed by P. fluorescens

Does mechanical locking-base ceramic brackets reduce cracks at debonding?

Objectives: Debonding of chemically bonded ceramic brackets has been mostly led to enamel damages. This study aimed to evaluate enamel cracks followed by debonding ceramic brackets with mechanical retention. Study Design: Sixty extracted human premolar teeth were randomly divided into two groups. Metallic brackets and recently available ceramic brackets with mechanical retention were bonded to the teeth in first (MB) and second (CB) group respectively. After a week, the brackets were debonded using a pair of bracket-removing pliers assembled to a testing machine. Optical stereomicroscope and trans-illumination techniques were used to calculate the cracks and measure their length before bonding and after debonding. Paired t-test, independent t-test and McNemar's test were used for statistical analysis. Results: Metallic brackets showed higher mechanical bond strength compared to ceramic brackets with mechanical locks. In both groups, higher numbers of teeth with enamel cracks and a significant increase in the length of enamel cracks were evident subsequent to debonding. Inter-group deference in the number of teeth with cracks and the length of enamel cracks before or after debonding was not significant. Conclusions:The risk of producing enamel cracks after debonding of ceramic brackets with mechanical retention is the same as metallic brackets

Association between interpersonal relationships and depression among children living in Tehran`s shelters

The purpose of this paper was to examine the correlation between interpersonal relationship and depression among children living in Tehran’s shelters. A correlational design was employed in this study and convenience sampling method was used to select respondents. A total number of 162 Iranian children, including 101 males and 61 females between the ages 7 to 15 years old, from 9 governmental shelters in Tehran were included in this research. The results revealed a negative significant correlation between various interpersonal relationship and depression. No significant difference in depression among male and female respondents. Two kinds of interpersonal relationship variables namely, relationship with roommates and guardians were potentially related to the depression after controlling for other variables

Protective effects of kombucha tea and silimarin against thioacetamide induced hepatic injuries in wistar rats

Plants consumed by human contain thousands of phenolic compounds. The effects of dietary polyphenols is of great interest due to their antioxidative and possible anticarcinogenic activities. Liver is one of the organ in the body exposed to many of oxidant and carcinogen agents; therefore; the antioxidant compounds are beneficial for liver healt. In this study the hepatoprotective effects of Kombucha tea and silimarin and thioacetamide (TAA) induced liver toxicity in wistar rats are investigated and compared. In this study we used 36 male white wistar rats groups of six: (control group, group of treated with thioacetamide (TAA) for 3weeks, group treated with TAA and Kombucha tea (for 3 weeks), groups treated with Kombucha tea (for 3 weeks) and TAA, group of treated with TAA and silimarin (for 3 weeks), group of treated with TAA, silimarin and Kombucha tea (for 3 weeks). The level of serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) Lactate dehydrogenase(LDH), total bilirubin monitored to assess hepatotoxicity and hepatoprotection. The data here showed that TAA significantly has increase AST, ALT, ALP, LDH butnot the same for bilirubin. The treatment by silimarin and Kombucha tea produced a significant reduction in serum enzyme levels (AST, ALT, ALP, LDH) and reduction in bilirubin content. The results show that the protective effects of silimarin and Kombucha tea against the thioacetamide induced hepatotoxicity that may be due to the existence of polyphenol substances in the plants, these substances have an antioxidant function. © IDOSI Publications, 2013

An evolutionary modelling approach to predicting stress-strain behaviour of saturated granular soils

Purpose: To develop a unified framework for modelling triaxial deviator stress - axial strain and volumetric strain – axial strain behaviour of granular soils with the ability to predict the entire stress paths, incrementally, point by point, in deviator stress versus axial strain and volumetric strain versus axial strain spaces using an evolutionary-based technique based on a comprehensive set of data directly measured from triaxial tests without pre-processing. 177 triaxial test results acquired from literature were used to develop and validate the models. Models aimed not only to be capable of capturing and generalising the complicated behaviour of soils but also to explicitly remain consistent with expert knowledge available for such behaviour. Methodology: Evolutionary polynomial regression was used to develop models to predict stress - axial strain and volumetric strain – axial strain behaviour of granular soils. EPR integrates numerical and symbolic regression to perform evolutionary polynomial regression. The strategy uses polynomial structures to take advantage of favourable mathematical properties. EPR is a two-stage technique for constructing symbolic models. It initially implements evolutionary search for exponents of polynomial expressions using a genetic algorithm (GA) engine to find the best form of function structure, secondly it performs a least squares regression to find adjustable parameters, for each combination of inputs (terms in the polynomial structure). Findings: EPR-based models were capable of generalizing the training to predict the behaviour of granular soils under conditions that have not been previously seen by EPR in the training stage. It was shown that the proposed EPR models outperformed ANN and provided closer predictions to the experimental data cases. The entire stress paths for the shearing behaviour of granular soils using developed model predictions were created with very good accuracy despite error accumulation. Parametric study results revealed the consistency of developed model predictions, considering roles of various contributing parameters, with physical and engineering understandings of the shearing behaviour of granular soils. Originality/Value: In this paper, an evolutionary-based data-mining method was implemented to develop a novel unified framework to model the complicated stress-strain behaviour of saturated granular soils. The proposed methodology overcomes the drawbacks of artificial neural network-based models with black box nature by developing accurate, explicit, structured and user-friendly polynomial models, and enabling the expert user to obtain a clear understanding of the system