The Dirac oscillator in a spinning cosmic string spacetime

We examine the effects of gravitational fields produced by topological defects on a Dirac field and a Dirac oscillator in a spinning cosmic string spacetime. We obtain the eigenfunctions and the energy levels of the relativistic field in that background and consider the effect of various parameters, such as the frequency of the rotating frame, the oscillator's frequency, the string density and other quantum numbers.Comment: 12 pages, 3 figure

The DKP oscillator with a linear interaction in the cosmic string space-time

We study the relativistic quantum dynamics of a DKP oscillator field subject to a linear interaction in cosmic string space-time in order to better understand the effects of gravitational fields produced by topological defects on the scalar field. We obtain the solution of DKP oscillator in the cosmic string background. Also, we solve it with an ansatz in presence of linear interaction. We obtain the eigenfunctions and the energy levels of the relativistic field in that background.Comment: 14 pages, no figure, comments are welcom

Incidence of cleft lip and palate in Gorgan - Northern Iran: An epidemiological study

Objective: Cleft lip with or without cleft palate is the most common orofacial congenital anomaly among live births. This study was carried out to determine the incidence rate of oral clefting in Gorgan, Northern Iran during 2004-2009. Methods: This descriptive hospital-based study was performed on 35,009 live newborns in Dezyani Hospital in Gorgan, Northern Iran during 2004-2009. All newborns were screened for oral clefts. Data including birth date, gender, type of oral clefts, parents' consanguinity, parental ethnicity and presence of other congenital anomalies were recorded for analysis. Result: The overall incidence rate of oral clefts during this 6-year period was 1.05 per 1000, or 1 per 946 live births. The incidence of cleft lip and isolated cleft palate was 0.08 and 0.37 per 1,000 live births, respectively. The ratio for different cleft types was 1:7:4 (CL: CLP: CP). The incidence of oral clefting was 1.2 per 1,000 male births and 0.86 per 1,000 female births (RR=1.40; 95% CI: 0.73-2.71). According to parental ethnicity, the incidence of oral clefting was 0.7, 1.7 and 1.26 per 1,000 in Native Fars, Turkman and Sistani, respectively. The relative risk for oral clefting in Turkman to native Fars group was 2.56 (p<0.02). In this study, 56.7% of clefts were CL+P, 8.1% were CL and 35.1% of cases were CP. CP was more common among girls (54%) than among boys (46%) but CL was more common among boys. Conclusion: The results showed that the incidence of oral clefts in the study population as being 1.05 per 1,000 live births, which has increased from 0.97 per 1,000 live births reported in an earlier study in this area. © OMSB, 2012

Nonlinear Behavior of RC Buildings under Seismic Sequences

Since after every single earthquake, a structure faces a stiffness and strength degradation, it may not be able to withstand subsequent shaking especially when seismic retrofit is not an option due to the short time intervals between the successive earthquakes. Therefore, it is necessary to consider the effects of repeated shaking on the behavior of structures prone to multiple earthquakes. Although many studies have been performed so far, there are some significant deficits which need more attention. Some of the important limitations in most of the recent studies include: (1) the use of ground motion data from uncorrelated events occurring at different locations and times; (2) utilization of simple models that do not contain appropriate damage features; and (3) no proper consideration to the effects of earthquake direction, aftershock polarity, structure irregularity, and the vertical component of the earthquake. The objective of this study is twofold, first to remedy the aforementioned limitations by using a robust finite element model that simulates the degrading behavior of reinforced concrete structures subjected to as-recorded seismic sequences, as opposed to replicate or uncorrelated random earthquakes. Second, to derive fragility relationships for RC structures under different limit states while considering the effects of damage accumulation in structures subjected to multiple-earthquake scenarios. For this purpose, the nonlinear response of different types of reinforced concrete buildings (both regular and irregular in elevation) will be evaluated and the effects of the overlooked parameters in previous research will be investigated. The results presented in this study indicate that earthquake direction (in the irregular building), structure irregularity, and the vertical earthquake component can have a considerable effect on the response of structures subjected to multiple earthquakes. Findings also show that aftershock polarity can significantly change the response of the irregular structure. Based on the results, considering damage from previous events, number of stories, and earthquake region significantly affect fragility curves. Results also indicated that as-recorded seismic sequences do not have a significant effect on period elongation