NonPAS: A Program for Nonlinear Analysis of Flexible Pavements

The primary step in design of a pavement using Mechanistic-Empirical (M-E) method is the analysis of pavement and calculation of the critical responses of pavement under various loadings. This confirms the need for developing pavement analysis software as an analytical base of the M-E method. To this end, NonPAS program has been developed for linear and nonlinear analysis of flexible pavements. Developed program allows nonlinear analysis of flexible pavements using five nonlinear models, including K-θ, Uzan, Uzan-Witczak, MEPDG 2002 and Bilinear models. Nonlinear Analysis of flexible pavements by utilizing these constitutive models provides a more accurate modeling of granular material behavior. Developed program can be used to analyze a pavement system consists of maximum of 10 layers, which is subjected to a maximum of six circular loads. Developed program allows for calculating the responses at 400 different points of pavement. In order to validate the results of linear and nonlinear analysis, responses obtained from NonPAS have been compared with responses obtained using Kenlayer program. Results show very good agreement between responses, which are obtained using both linear and nonlinear analysis and approve that developed program can be used with high reliability for the purposes of pavement analysis and design

Prediction of Frequency for Simulation of Asphalt Mix Fatigue Tests Using MARS and ANN

Fatigue life of asphalt mixes in laboratory tests is commonly determined by applying a sinusoidal or haversine waveform with specific frequency. The pavement structure and loading conditions affect the shape and the frequency of tensile response pulses at the bottom of asphalt layer. This paper introduces two methods for predicting the loading frequency in laboratory asphalt fatigue tests for better simulation of field conditions. Five thousand (5000) four-layered pavement sections were analyzed and stress and strain response pulses in both longitudinal and transverse directions was determined. After fitting the haversine function to the response pulses by the concept of equal-energy pulse, the effective length of the response pulses were determined. Two methods including Multivariate Adaptive Regression Splines (MARS) and Artificial Neural Network (ANN) methods were then employed to predict the effective length (i.e., frequency) of tensile stress and strain pulses in longitudinal and transverse directions based on haversine waveform. It is indicated that, under controlled stress and strain modes, both methods (MARS and ANN) are capable of predicting the frequency of loading in HMA fatigue tests with very good accuracy. The accuracy of ANN method is, however, more than MARS method. It is furthermore shown that the results of the present study can be generalized to sinusoidal waveform by a simple equation

Intelligent Prediction of Unconfined Compressive Strength and Young’s Modulus of Lean Clay Stabilized with Iron Ore Mine Tailings and Hydrated Lime Using Gaussian Process Regression

Chemical stabilization is used to enhance and increase the strength characteristics of soft and problematic soils. In this research, Gaussian Process Regression (GPR) is employed to estimate the unconfined compressive strength (UCS) and the Young’s modulus (E) of lean clay soils stabilized with iron ore mine tailing (IOMT) and hydrated lime (HL) percentage. In this regard, four inputs including the moisture content (MC), IMOT percentage, HL percentage, and curing time (CT) were used. The value of R2 for estimating the UCS and the E were 0.9825 and 0.9633 for all data, respectively. The RMSE for predicting the UCS and the E were 0.1875 and 19.868 for all data, respectively. The result of the sensitivity analysis demonstrated that MC, CT, HL, and IOMT percentage have the highest contribution to the UCS of the stabilized lean clay, respectively. Also, MC, HL, IOMT percentage, and CT have the highest impact on the E of the stabilized lean clay, respectively. The parametric study also revealed that increasing the HL content and the curing time led to an increase in the UCS and the E of stabilized lean clay, while IOMT content and the moisture content has an inverse relationship with the UCS and the E of stabilized lean clay soils

An Explicit Formulation for Estimation of Structural Number (SN) of Flexible Pavements in 1993 AASHTO Design Guide using Response Surface Methodology (RSM)

In the 1993 AASHTO flexible pavement design equation, the structural number (SN) cannot be calculated explicitly based on other input parameters. Therefore, in order to calculate the SN, it is necessary to approximate the relationship using the iterative approach or using the design chart. The use of design chart reduces the accuracy of calculations and, on the other hand, the iterative approach is not suitable for manual calculations. In this research, an explicit equation has been developed to calculate the SN in the 1993 AASHTO flexible pavement structural design guide based on response surface methodology (RSM). RSM is a collection of statistical and mathematical methods for building empirical models. Developed equation based on RMS makes it possible to calculate the SN of different flexible pavement layers accurately. The coefficient of determination of the equation proposed in this study for training and testing sets is 0.999 and error of this method for calculating the SN in most cases is less than 5%. In this study, sensitivity analysis was performed to determine the degree of importance of each independent parameter and parametric analysis was performed to determine the effect of each independent parameter on the SN. Sensitivity analysis shows that the log(W8.2) has the highest degree of importance and the ZR parameter has the lowest one

Modeling of unconfined compressive strength and Young's modulus of lime and cement stabilized clayey subgrade soil using Evolutionary Polynomial Regression (EPR)

In this study, the evolutionary polynomial regression (EPR) method has been employed to develop simple models with reasonable accuracy to predict the compressive strength and Young's modulus of the lime/cement stabilized clayey subgrade soil. For this purpose, the different specimens with the various cement and lime contents, at three moisture contents (dry side, wet side, and optimum moisture content) were fabricated and were cured for 7, 14, 21, 28 and, 60 days to conduct the unconfined compressive strength (UCS) test. According to the test results, a dataset consisting of 75 records for each additive was prepared. Results of this study show that the R2 value of the developed model for predicting UCS of cement-stabilized clay soil is equal to 0.96 and 0.95 for training and testing sets, respectively. These two values for lime-stabilized soil are 0.91 and 0.87, respectively. Moreover, the R2 for predicting Young's modulus of cement-stabilized clay soil is equal to 0.90 and 0.89 for training and testing set, respectively. These two values for predicting Young's modulus of lime-stabilized soil are 0.88 and 0.94, respectively. The sensitivity analysis showed that for the Portland cement stabilized clayey subgrade, the percentage of the Portland cement and moisture content are the most significant parameters for predicting the UCS and Young's modulus, respectively. In contrast, for the lime-stabilized clayey subgrade soil, the most important parameters are the moisture content and the UCS, respectively

Comparison of analgesic effects of intravenous and intranasal ketorolac in patients with mandibular fracture-A Randomized Clinical Trial

Similarity of pharmacokinetics of intranasal ketorolac to the intravenous form and other advantages have promoted its application. This study compared the analgesic effects of intravenous and intranasal ketorolac in patients undergoing mandibular fracture surgery. In this clinical trial study, Sixty-four patients with unilateral mandibular fracture were divided randomly into two groups. In group 1, 30 mg of intravenous (IV) ketorolac was injected every 8 hours and in group 2, intranasal (IN) ketorolac spray was used as a 100-µL puff in each nostril (31.5 mg) every 6 hours. After each patient regained consciousness, pain intensity was measured based on visual analogue scale for 48 hours. Finally, the total dose of the opioid analgesic agent (pethidine) and the time for the first request for an analgesic agent were recorded for each patient, and their means were compared in each group with proper statistical tests. Mean pain intensity of patients at baseline was significantly higher than that at other intervals and then, it decreased significantly (P0.05). Application of intranasal ketorolac spray decreased pain after mandibular fracture surgery, especially at 8-hour interval after surgery, decreasing the need for opioids

An epidemiological survey of psychiatric disorders in Iran

BACKGROUND: The nation-wide epidemiological survey of psychiatric disorders in term of lifetime prevalence is not adequately known in Iran. The prevalence of lifetime psychiatric disorders was estimated among the population of aged 18 and over on gender, age group, educational level, occupational status, marital status, and residential area. METHODS: The subjects were 25,180 individuals selected through a clustered random sampling method. The psychiatric disorders were diagnosed on the bases of Diagnostic and Statistical Manual of Mental Disorders-IV criteria. It is the first study in which the structured psychiatric interview administered to a representative sample of the Iranian population age 18 and over by the 250 trained clinical psychologist interviewers. The data was entered through EPI-Info software twice in an attempt to prevent any errors and SPSS-11 statistical software was also used for analyses. The odds ratios and their confidence intervals estimated by using logistic regression. RESULTS AND DISCUSSION: The prevalence of psychiatric disorders was 10.81%. It was more common among females than males (14.34% vs. 7.34%, P < 0.001). The prevalence of anxiety and mood disorders were 8.35% and 4.29% respectively. The prevalence of psychotic disorders was 0.89%; neuro-cognitive disorders, 2.78% and dissociative disorders, 0.77%. Among mood disorders, major depressive disorder (2.98%) and among anxiety disorders, phobic disorder (2.05%) had the higher prevalence. The prevalence of psychiatric disorders among divorced and separated 22.31%; residents of urban areas 11.77%; illiterates 13.80%; householders 15.48%; unemployed 12.33% that were more than other groups. CONCLUSION: The mental health pattern in Iran is similar to the western countries, but it seems that the prevalence of psychiatric disorders in Iran may be lower than these countries. It is estimated that at least about 7 millions of Iranian population suffer from one or more of the psychiatric disorders. It shows the importance of the role of the psychiatric disorders in providing preventive and management programs in Iran

Compatibility of Clinical and Histopathological Diagnosis of Oral Lesions in Iranian Patients

Objective: To determine compatibility between clinical diagnosis and the pathological reports of biopsies from oral lesions. Material and Methods: In this descriptive study, 1146 clinical files of patients referring to Tabriz Faculty of Dentistry from 2004 to 2016 were retrieved and evaluated. The kappa coefficient was calculated for each file for compatibility of clinical and pathological diagnosis. Results: In relation to clinical (40.2%) and pathological (39.2%) diagnosis, irritational lesions of soft tissues exhibited the highest frequency. In 72.3% of cases, the clinical and pathological diagnosis were compatible and in 27.7% of cases these diagnosis were not compatible. The highest compatibility rates were detected for irritational lesions of soft tissues (81.5%) and mucocutaneous lesions (76.9%). There was no compatibility for osseous malignant tumors, inflammatory tissues, granulation tissues, metastatic lesions and hematologic disorders. Conclusion: Approximately one-third of clinical and histopathological diagnosis were not compatible. Therefore, to reach a correct diagnosis, the clinical, radiographic and histopathological views should be evaluated simultaneously

Prevalence of obsessive-compulsive disorder in Iran

BACKGROUND: Estimates of the annual prevalence for Obsessive Compulsive Disorder (OCD) were consistent across the international sites range, 1.9% – 2.5%. The nine population surveys, which used Diagnostic Interview Schedule, estimated a six-month prevalence of OCD ranging from 0.7% to 2.1%. This study performed in order to determine the prevalence of OCD in a population-based study among Iranian adults aged 18 and older and to study the association of them with factors such as sex, marital status, education, type of occupation and residential area. METHODS: A cross-sectional nationwide epidemiological study of the Iranian population aged 18 and older was designed to estimate the prevalence of psychiatric disorders and their association with the above mentioned factors. 25180 individuals were selected and interviewed through a randomized systematic and cluster sampling method from all Iranian households. Schedule for Affective Disorders and Schizophrenia (SADS) and Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) criteria were used in diagnosis of OCD. 250 clinical psychologists interviewed the selected subjects face to face at their homes. RESULTS: The prevalence of OCD in Iran is 1.8% (0.7% and 2.8% in males and females; respectively). 50.3% of the survey sample were men, 49.9% women, 29.1% single, 67.45% married, 0.4% separated or divorced, 2.5% widow/widower and 4% undetermined. All of the above-mentioned factors were examined in the univariate and multivariate logistic regression models. Although the data did not fit the models well, but in univariate models, sex, the category "single" of marital status, age, the categories "business" and "housewife" and residential areas showed significant effect adjusting for the factors, but the models didn't fit the data properly. CONCLUSION: The study suggests that the prevalence of OCD is not rare in the community of Iran and is within the range of other countries. Similar to prior studies in other communities, OCD is more common in females than males