On the irreducible action of psl(2, r) on the 3-dimensional einstein universe

We describe the orbits of the irreducible action of PSL(2, R) on the 3-dimensional Einstein universe Ein 1,2. This work completes the study in [2], and is one element of the classification of cohomo-geneity one actions on Ein 1,2 ([5])

Evaluation and financial risk management of urban renewal projects in partnership with public and private

Financing plays an important role for renewal of old city building is find suitable financing plan. A proper financial management in one hand has a direct relationship with project main factors such as: time, cost and quality of the project, and on the other hand, achieving project goals requires a comprehensive insight of project, stockholders as well as other relative situation in regard with the project. Considering the complication of execution such projects and the number of shareholders, one of the best attitudes towards the project management is risk management. This research is a qualitative and practical, which reviews the effects of project management factors on financial return of urban renewal sachem. The required information gained through a survey and via questionnaire and interviews with specialists. This article first describes the public private financial partnership and then, based on the results gained from a case study done on one of the renewal schemes in Mashhad metropolitan areas. Next, it identifies and evaluates of positive and negative risks, which lead to threats and opportunities will be performed and will attempt to respond the existent risks. Finally, we provide a framework for the risk assessment of the housing units

Rheological Model for Wood

Wood as the most important natural and renewable building material plays an important role in the construction sector. Nevertheless, its hygroscopic character basically affects all related mechanical properties leading to degradation of material stiffness and strength over the service life. Accordingly, to attain reliable design of the timber structures, the influence of moisture evolution and the role of time- and moisture-dependent behaviors have to be taken into account. For this purpose, in the current study a 3D orthotropic elasto-plastic, visco-elastic, mechano-sorptive constitutive model for wood, with all material constants being defined as a function of moisture content, is presented. The corresponding numerical integration approach, with additive decomposition of the total strain is developed and implemented within the framework of the finite element method (FEM). Moreover to preserve a quadratic rate of asymptotic convergence the consistent tangent operator for the whole model is derived. Functionality and capability of the presented material model are evaluated by performing several numerical verification simulations of wood components under different combinations of mechanical loading and moisture variation. Additionally, the flexibility and universality of the introduced model to predict the mechanical behavior of different species are demonstrated by the analysis of a hybrid wood element. Furthermore, the proposed numerical approach is validated by comparisons of computational evaluations with experimental results.Comment: 37 pages, 13 figures, 10 table

Elastic Reconfiguration of Bending and Twisting Rods in Air Flow

RÉSUMÉ Les plantes sont généralement flexibles et se déforment significativement lorsqu’elles sont soumises à un écoulement aérodynamique. Ce changement de forme, qui généralement réduit la traînée, est appelée reconfiguration. Plusieurs études dans la littérature ont apporté une compréhension fondamentale de la reconfiguration des plantes en la modélisant comme une poutre en flexion. Bien que cette approche permette de capturer l’essence de la flèche bidimensionnelle des plantes, leur flèche tridimensionnelle est ignorée. En effet, en raison de leur structure fibreuse, les plantes se tordent significativement sous un écoulement, montrant une reconfiguration tridimensionnelle. De plus, de nombreuses plantes ont une morphologie chirale, ce qui induit une flèche très complexe. Le présent travail de recherche vise à étudier l’effet de la torsion et de la chiralité dans la reconfiguration des plantes en combinant expérimentation et modélisation pour comprendre comment une tige élastique se plie et se tord avec grande amplitude sous le vent. Pour l’étude expérimentale, des tiges composites sont fabriquées en mousse de polyuréthane et renforcées à l’aide de fibres de nylon qui apportent un couplage de torsion-flexion à la structure finale. Pour reproduire une structure chirale, les fibres suivent un patron hélicoïdal le long dans la tige. Afin d’enrichir l’étude expérimentale, des rubans chiraux en plastique ABS sont aussi conçues. Tous les spécimens sont testés dans une soufflerie sous différentes conditions d’écoulement. Pour l’étude numérique, la reconfiguration tridimensionnelle des tiges et des rubans sera simulée utilisant la théorie de tiges de Kirchhoff couplée avec une formulation semi-empirique pour introduire les forces aérodynamiques. Les résultats de ces études montrent que ces structures, fortement anisotropes, se tordent pour ensuite fléchir selon la direction de moindre rigidité en flexion. De plus, la reconfiguration tridimensionnelle d’une tige peut être caractérisée par une flexion bidimensionnelle en choisissant le bon ensemble de paramètres adimensionnelles. Il est aussi constaté que les rubans chiraux font face à un compromis, en fonction la configuration géométrique, entre la résistance au flambage plus élevé mais aussi le moment de flexion plus élevé à la base. Finalement, la chiralité rend la flèche de ces structures moins dépendante de la direction de chargement.----------ABSTRACT Plants are generally flexible and deform significantly when subjected to flow. This deformation which generally leads to a drag reduction is termed reconfiguration. Fundamental understanding of this phenomenon has been sought by modeling them as bending beams. Although bending beams capture the essence of the two-dimensional deformation of plants, their three-dimensional deformation is ignored. Because of their fibrous structure, plants twist significantly under fluid loading showing a threedimensional reconfiguration. Moreover, many plants are found with a chiral morphology which undergo a complex deformation under loading. The present research aims to model the reconfiguration of plants with an elastic rod undergoing a large deformation, to study the effect of torsion and chirality in reconfiguration. In the experimental investigation, composite rods are made of polyurethane foam and reinforced using nylon fibers which have a bending-torsion coupling. To simulate a chiral structure, the reinforcing fibers are twisted along the length of the rod. Moreover, chiral ribbons are made using ABS plastic. All the specimens are tested in a wind tunnel for a variety of flow and structural properties. The three-dimensional reconfiguration of rods and ribbons is also modeled numerically using the Kirchhoff theory of rods coupled with a semi-empirical drag formulation and the blade element theory. It is shown that a rod with structural anisotropy twists in such a way to bend in its less rigid direction. Moreover, the three dimensional reconfiguration of a rod can be characterized as a two dimensional bending by choosing the right set of dimensionless parameters. It is found that chiral ribbons face a trade-off between higher self-buckling strength but also higher root bending moment. Moreover, chirality renders the deformation of rods and ribbons less dependent to the loading direction

Camel Abortion Status in Iran- A Mini Review

About 180,000 old world camels (OWCs) including one-humped (Camelus Dromedarius) and two-humped (Camelus Bactrianus) camels (only 100–300 individuals) live in Iran. Abortion is one of the problems of camel breeders in Iran at various aspects, i.e. economical, animal healthcare or zoonotic. So far, some epizootological studies have been conducted on infectious diseases of Iranian camels. However, there is the absence of comprehensive information on the camel abortion status in Iran. We aimed at collecting all the available information on abortion in Dromedary and Bactrian camels in Iran to have a better picture of the situation in the country. Based on studies that examined the causes of abortion of dromedary camels in different provinces; Brucellosis, trypanosomiasis, leptospirosis, salmonellosis, bovine viral diarrhea, infectious bovine rhinotracheitis and aspergillosis are common factors of abortion in the country. This review can provide baseline information for future research and give significant contributions to figuring the disease control strategies

The Effect of Informing Parents or Caregivers of Patients on Their Anxiety from Anesthesia Risks during Their Child’s Surgery

Background: Each patient who needs a surgical operation is going under general anesthesia with many risks. The purpose of this investigation was to determine whether the provision of detailed anesthetic risk information is associated with increased parental anxiety.Methods: In this randomized clinical trial study 140 caregivers of patients admitted for surgery, was selected in order of their reference and they were asked to fulfill the test. In the next step, persons were distributed into two groups of the control group with an even number and the intervention group with odd number (according to the numbers on questionnaire). The routine information about the risks of anesthesia was given to the control group with an even number at the operation date in holding area, and they were asked to re-fulfill the questionnaire.Results: The majority of parents (> 95%) preferred to have comprehensive information concerning their child’s perioperative period, including information about all possible complications. For selected items, increased parental educational level was associated with increased desire for information (P < 0.050). For Phase 2, when the intervention group was compared with the control group, there were no significant differences in parental anxiety over the 4 time points [F(1,45) = 0.6, P = 0.410]. Furthermore, the interaction between time and group assignment was not significant [F(3,135) = 1.66, P = 0.181].Conclusions: We conclude that parents of children undergoing surgery desire comprehensive perioperative information. Moreover, when provided with highly detailed anesthetic risk information, the parental anxiety level did not increase

The effect of low level laser therapy on Pemphigus vulgaris lesions: A Pilot Study

Background: Pemphigus vulgaris is a chronic blistering skin disease. Management of recalcitrant pemphigus ulcers is a great problem. Low Level Laser Therapy (LLLT) is known to supply direct biostimulative light energy to body cells. Objective: This study evaluates the efficacy of low power laser in the healing of pemphigus lesions.Methods: Ten patients with pemphigus vulgaris were enrolled in the trial. The LED-LLLT system used was the Thor LED clusters (109, 69 or 19 diode) (ENGLAND) with 660 nm wave length in continuous wave (CW) and 30 MW energy. Both sides of the patients’ lesion were photographed prior to the study and in each laser therapy sessions.Results: The pattern of changes in QWS patterns differed significantly over time between the two therapies (treatment × time interactions, p<.0001). When compared to the routine therapy, the laser therapy showed more decreases in mean QWS in all sessions in comparison with baseline.Limitations: This is a pilot study.Conclusion: Application of Low Level Laser simultaneously with conventional therapy could result in sensational healing of ulcers especially in patients who do not respond to conventional treatment or suffering from recalcitrant lesions