Petrology and diagenesis of the limestones of the Qom formation (Oligo-Miocene), Qom region, Central Iran

Imperial Users onl

In-vitro Evaluation of Accuracy of Conventional and CAD/CAM Removable Partial Denture Frameworks

Purpose: Computer-aided design/computer-aided manufacturing (CAD/CAM) technology is gaining popularity in dentistry, and more recently, to fabricate removable partial dentures (RPD). The purpose of this study was 1) to evaluate the overall accuracy and fit of conventional versus CAD/CAM fabricated printed RPD frameworks based on STL data analysis, and 2) to evaluate the accuracy and fit of each component of the RPD framework. Materials and Methods: A maxillary metal framework was designed for a Kennedy class III modification I situation. The master model was scanned and used to compare the fit and accuracy of the RPD frameworks. A total of 40 impressions (conventional and digital) of the master cast were made and divided into 4 groups based on fabrication method: Group I, conventional method (Lost-wax technique); group II, CAD-rapid prototyping (CAD-RP); group III, CAD-rapid prototyping from stone model (CAD-RPS); and group IV, Lost-wax technique from resin model (LWTR). RPD frameworks were fabricated in cobaltchromium alloy. All frameworks were scanned and the gap distance to the original master model in 8 different locations were measured, as well as color mapping with a comprehensive metrology software. Data were statistically analyzed using the Kruskall- Wallis analysis of variance and post hoc comparisons, followed by the Bonferroni method for pairwise comparisons (α = 0.05). Results: Color mapping revealed distinct discrepancies in major connectors amongst the groups. When compared to 3D printed frameworks, conventional cast frameworks fabricated either from dental stone or 3D printed resin models revealed significantly better fit (P\u3c0.05) with the major connectors and guide plates. The biggest gap (\u3e0.3mm) was observed with the anterior strap of the major connector with the printed frameworks (groups II and III). The method of fabrication did not affect the adaptation of the rests or reciprocation plates. Conclusions: Within the limitations of this study, although both methods revealed clinically acceptable adaptation, the conventional processed RPD groups revealed better overall fit and accuracy

Geomechanical analysis of caprock integrity

To safely store carbon dioxide in enhanced oil recovery/ CO2 sequestration projects it is important to ensure the integrity of the caprock during and after production and injection. A change in fluid pressure and temperature within a porous reservoir will generally induce stress changes within the reservoir and the rocks that surround it. Amongst the potential hazards resulting from these induced stress changes is the reactivation of existing faults or fractures and inducing new fractures, which may breach the hydraulic integrity of the caprock that bounds the reservoir. The theories of inclusions and inhomogeneities have been used in this research to derive semi-analytical and closed-form solutions for induced stress change during pore pressure change within a reservoir and in the surrounding rock, under plane strain and axisymmetric conditions. Methods have been developed to assess fault reactivation and induced fracturing during injection or production within a reservoir. The failure stress change concept for a Coulomb failure criterion has been used to study the likelihood of fault reactivation and induced fracturing within the reservoir. Formulations have been adopted to calculate the critical pressure change for fault reactivation and induced fracturing within the reservoir and in the surrounding rock during injection and production. Sensitivity analysis has been performed to study the effects of different parameters such as initial in-situ stress, reservoir geometry, reservoir depth, reservoir “tilt” or dip , material property contrast between the reservoir and surrounding rock, fault geometry, fault strength, and intact rock strength. General patterns of induced stress change, in-situ stress evolution, fault reactivation, and induced fracturing have been identified. The developed methodologies have been applied to six different case studies: fault reactivation analysis in the entire field for a synthetic case study; induced fracturing analysis in the entire field in a synthetic case study; fault reactivation and induced stress change analysis within the Ekofisk oil reservoir in North Sea; fault reactivation analysis in the Lacq gas reservoir in France; the Weyburn-Midale EOR/CO2 Storage project in southeast Saskatchewan; and acid gas injection in Zama oil field, Alberta. The results of these case studies show good consistency with field observation, and physical and numerical models. The generality, simplicity, and straightforwardness of the developed methodologies, along with their flexibility to model different plausible scenarios and their ease of implementation for systematic sensitivity analyses makes them suitable for decision-making and uncertainty management, specifically in early stages of reservoir development or site assessment for geological sequestration of carbon dioxide

Study of extensive air showers at sea level

The zenith angle distribution of EAS over the size range 10(^4) -1.4.10(^6) particles at sea level has been studied. Representing the zenith angle distribution by 1(θ) = I(O)cos(^n)θ it is found that n = 8.4 (^+) (_-) 0.3 over the size range 5.10(^10) 1.4.10(^6) particles. For the smallest sizes studied 10(^4) 25m(^-2) The evidence is based on the observation of an excess of ionising events (4.4 standard deviations above the background) occurring in the 85-95 us time domain before the arrival of the main shower front at sea level

Thermodynamical description of interacting entropy-corrected new agegraphic dark energy

To explain the accelerating universe driven by dark energy, a so-called "entropy-corrected new agegraphic dark energy" (ECNADE), was recently proposed with the help of quantum corrections to the entropy-area relation in the framework of loop quantum cosmology. Using this definition, we study its thermodynamical features including entropy and energy conservation. We discuss the thermodynamical interpretation of the interaction between ECNADE and dark matter in a non-flat universe bounded by the apparent horizon. We obtain a relation between the interaction term of the dark components and thermal fluctuation.Comment: 8 pages, version accepted for publication in Europhysics Letters (2011

Evaluation of Heavy Metals (Cadmium and Lead) in Groundwater of Razi Industrial Park, Isfahan

Groundwater is the most important resource to provide drinking water and the water used in agriculture in most parts of Iran and since industrial cities and particularly their sewage is significantly important in polluting these water resources, in this study we tried to recognize heavy metals' pollution like Cadmium and lead available in groundwater of Razi industrial park of Isfahan by sampling the downstream watershed areas under study and this city's share in the level and kind of heavy metals of water. The results of this study showed that the amount of these metals in the area's groundwater was so negligible and the city did not have a significant role in the content of these metals in these water resources

Evaluation of Heavy Metals (Cadmium and Lead) in Groundwater of Razi Industrial Park, Isfahan

Groundwater is the most important resource to provide drinking water and the water used in agriculture in most parts of Iran and since industrial cities and particularly their sewage is significantly important in polluting these water resources, in this study we tried to recognize heavy metals' pollution like Cadmium and lead available in groundwater of Razi industrial park of Isfahan by sampling the downstream watershed areas under study and this city's share in the level and kind of heavy metals of water. The results of this study showed that the amount of these metals in the area's groundwater was so negligible and the city did not have a significant role in the content of these metals in these water resources

Extraction of Nucleolus Candidate Zone in White Blood Cells of Peripheral Blood Smear Images Using Curvelet Transform

The main part of each white blood cell (WBC) is its nucleus which contains chromosomes. Although white blood cells (WBCs) with giant nuclei are the main symptom of leukemia, they are not sufficient to prove this disease and other symptoms must be investigated. For example another important symptom of leukemia is the existence of nucleolus in nucleus. The nucleus contains chromatin and a structure called the nucleolus. Chromatin is DNA in its active form while nucleolus is composed of protein and RNA, which are usually inactive. In this paper, to diagnose this symptom and in order to discriminate between nucleoli and chromatins, we employ curvelet transform, which is a multiresolution transform for detecting 2D singularities in images. For this reason, at first nuclei are extracted by means of K-means method, then curvelet transform is applied on extracted nuclei and the coefficients are modified, and finally reconstructed image is used to extract the candidate locations of chromatins and nucleoli. This method is applied on 100 microscopic images and succeeds with specificity of 80.2% and sensitivity of 84.3% to detect the nucleolus candidate zone. After nucleolus candidate zone detection, new features that can be used to classify atypical and blast cells such as gradient of saturation channel are extracted