476 research outputs found

    Proposing a sample preparation procedure for sanding experiments

    Get PDF
    The Authors, during past few years, have performed research on sand production under true triaxial stress conditions. To simulate sanding, 100x100x100 mm3 cubic samples were placed in a true triaxial stress cell (TTSC) and three independent stresses were applied while the pore pressure was increased inside the cell. This resulted in sand grains to be produced through a drilled hole in the sample centre. The experiences obtained through testing several synthetic samples have indicated the significance of sample preparation to obtain valid results. Therefore, in this paper the procedure for preparation of synthetic samples suitable for a sanding experiment is proposed. Also, details of sample preparation for conventional rock mechanical tests to estimate rock physico-mechanical properties including deformability properties, strength parameters and permeability will be presented

    Comparison of original and revised reinforcement sensitivity theory in clinically-stable schizophrenia and bipolar disorder patients

    Get PDF
    ABSTRACT Introduction: The study of personality can help explicate the pathology of psychological disorders. To this end,our study compared the profile of factors from the original (o) and revised (r) reinforcement sensitivity theory (RST) of personality in schizophrenia (SC), bipolar disorder (BD) patients, both compared with healthy controls(HC). Method: 34 SC patients, 52 BD patients, and 72 matched HC completed: Yang Mania Rating Scale (YMRS), Positive and Negative Syndrome Scale (PANSS), Beck Depression Inventory (BDI), BAS/BIS scale, and the Jackson-5 scale. Data were analyzed by chi square, independent t-test, analysis of variance (ANOVA), and multivariate analysis of variance (MANOVA). Results: SC patients had lower o-BIS, r-BIS and o-BAS, and r-BAS scores than the BD and HC groups. Compared to HC, SC and BD patients had higher Freeze and Fight scores. Depression in SC was significantly higher than other two groups; and in BD it was higher than HC. Conclusion: SC, BD, and HC differ on both o-RST and r-RST; however, the more nuanced knowledge from r-RST may be helpful in the diagnosis, etiology and psychotherapy. Keywords: Original reinforcement sensitivity theory Revised reinforcement sensitivity theory Behavioral brain systems Schizophrenia Bipolar disorde

    Fracture detection from water saturation log data using a Fourier-wavelet approach

    Get PDF
    Fracture detection as applied to reservoir characterization is a key step towards modeling of fracturedreservoirs. While different methods have been proposed for detection and characterization of fractures and fractured zones, each is associated with certain shortcomings that prevent from their full use in different related engineering application environments. In this paper a new method is proposed for detection of fractured zones and fracture density in which water saturation log data is utilized. For detection of fractures, we have used wavelet transform and properties of wavelets that are highly suitable for detection of changes and local features of data. To choose the optimum mother wavelet, we have used energy matching strategy in which a wavelet with the highest energy match between spectral energy of the signal at the dominant frequency band and the coefficient energy at the same band of wavelet decomposition of the signal is selected. We have used wavelet packet for a more narrow frequency band selection and enhanced results. Decomposing the water saturation data using wavelets showed that the majority of information of theoriginal log is hidden at low frequency bands. As a result, approximated section of wavelet transform of data was used for fracture detection, while shale volume (or gamma ray) log data was used to filter part of the errors in prediction and identification of the uncertain zones. This increased the accuracy of the results by 70%. Finally, a linear relation was derived between energy of approximated section of water saturation log and fracture density, allowing us to estimate the number of fractures in each fractured zone. The method was applied to four wells belonging to one of the Iranian oilfields located in the southwest region of the country and the results are promising. The use of large volume of data and the subsequent analysis increased the generalization ability of the proposed method

    A methodology for wellbore stability analysis of drilling into presalt formations: A case study from southern Iran

    Get PDF
    Drilling into presalt formations has been a long-standing issue due to the rapid changes in the diameter of the borehole during drilling operations either because of creep or wash-out dissolution. There have been many studies on characterization of salts, with many mathematical models being presented to estimate the pressure induced due to the squeezing salt sheets. However, the results of none of these models have been fully validated against real field data and some recommendations have been made based on numerical simulations. In this study, attempts were made to introduce a methodology based on damage mechanics for wellbore stability analysis of a wells drilled in the southern part of Iran. The results obtained indicated that the presence of a thick salt layer in the well has resulted in significant wellbore closure in the intervals above the reservoir section. It was also found that the salt exhibits viscoelastic behaviour during drilling due to the homogeneous temperature which has not reached the threshold limit of viscoplastic boundary. A complicated change in the stress regime was also observed which could be linked to the existence of the thick salt layer or presences of a fault crossing the well. Therefore, it is recommended to further validate this model in other wells using the methodology presented

    The impact of poor cementing casing damage: A numerical simulation study

    Get PDF
    A good knowledge of the parameters causing casing damage is critically important due to vital role of casing during the life of a well. Cement sheath, which fills in the gap between the casing and wellbore wall, has a profound effect on the resistance of the casing against applied loads. Most of the empirical equations proposed to estimate the collapse resistance of casing ignore the effects of the cement sheath on collapse resistance and rather assume uniform loading on the casing. This paper aims to use numerical modeling to show how a bad cementing job may lead to casing damage. Two separate cases were simulated where the differences between good and bad cementation on casing resistance were studied. In both cases, the same values of stresses were applied at the outer boundary of the models. The results revealed that a good cementing job can provide a perfect sheath against the tangential stress induced by far-field stresses and reduce the chance of casing to be damaged

    Relationship between emotional intelligence and organizational citizenship behavior in critical and emergency nurses in south east of Iran

    Get PDF
    Background: Several factors including emotional intelligence affect the efficiency of people. It seems that organizational behavior of each person is strongly influenced by emotional intelligence. Therefore, the present study is aimed to examine the relationship between emotional intelligence and organizational citizenship behavior in critical and emergency nurses in teaching hospitals supervised by Kerman Medical University in Southeast of Iran.Methods: This study employed a descriptive cross sectional design. A census sample consisted of 150 critical and emergency nurses working in teaching hospitals supervised by Kerman Medical University participated in this study. Emotional intelligence and organizational citizenship behavior questionnaire was used to assess nurses’ emotional intelligence and organizational citizenship behavior by available sampling method.Results: The results showed that the mean age of the participants was 35 years. Most participants (94%) were females and belonged to the age group of 26-30 years. Overall mean score of organizational citizenship behavior scale was 88.21 (±10.4). In the organizational citizenship behavior categories, altruism mean score was higher than the other mean scores. Overall mean score of emotional intelligence was (121.08 ± 17.56). In the subgroups of emotional intelligence, mean score of the relationship management, was higher than the average of other factors. Pearson's correlation coefficient showed no significant relationship between emotional intelligence and organizational citizenship behavior (p ≥ 0.05).Conclusion: The study suggests that health care managers should organize systematic and dynamic policies and procedures in dealing with emotional intelligence and organizational citizenship behavior to assist critical and emergency nurses.Keywords: Emotional intelligence, Oorganizational citizenship behavior, nurse, critical ward, emergency war

    A detailed systematic anatomical study of monocephalic conjoined symmetric twin lambs

    Get PDF
    A case of conjoined twins with monocephalus, thoracopagus, partial abdominopagus, tetrabrachius and tetrascelus in lambs complicated with several defects of skeletal, cardiovascular, gastrointestinal, and urogenital systems is reported. The twins were dead and delivered by cesarean section. This case report highlights the detailed anatomical study of defects in different systems due to an abnormal birth defect.Keywords: Monocephalus, Sheep, Tetrabrachius, Tetrascelus, Thoracopagu

    Structural growth in iron oxide clusters: Rings, towers, and hollow drums

    Get PDF
    It is shown that the transition from an elementary FeO molecule to the bulk rock-salt FeO proceeds via hollow rings, towers, and drums. Our first-principles electronic structure calculations carried out within a gradient-corrected density functional framework show that small FenOn (n=2,3,4,5) clusters form single, highly stable rings. Starting at Fe6O6, these elementary rings begin to assemble into nano columnar structures to form stable Fe6O6, Fe7O7, Fe8O8, Fe9O9, Fe10O10, and Fe12O12 towers. The rings and the empty towers can be further stabilized by capping O atoms at the ends, leading to FenOn+1 and FenOn+2 sequences. The theoretical results provide insight into the progression of mass intensities in the experimental mass spectra and account for the observed peaks in the negative ion photodetachment spectra of iron oxide clusters

    Persuasive Discourse Impairments in Traumatic Brain Injury

    Get PDF
    Background: Considering the cognitive and linguistic complexity of discourse production, it is expected that individuals with traumatic brain injury (TBI) should face difficulties in this task. Therefore, clinical examination of discourse has become a useful tool for studying and assessment of communication skills of people suffering from TBI. Among different genres of discourse, persuasive discourse is considered as a more cognitively demanding task. However, little is known about persuasive discourse in individuals suffering from TBI. Objectives: The purpose of this study was to evaluate the performance of adults with TBI on a task of spoken persuasive discourse to determine the impaired linguistic measures. Patients and Methods: Thirteen TBI nonaphasic Persian speaking individuals, ranged between 19 to 40 years (Mean = 25.64 years; SD = 6.10) and 59 healthy adults matched by age, were asked to perform the persuasive discourse task. The task included asking the participants to express their opinion on a topic, and after the analysis of the produced discourse, the two groups were compared on the basis of their language productivity, sentential complexity, maze ratio and cohesion ratio. Results: The TBI group produced discourses with less productivity, sentential complexity, cohesion ratio and more maze ratio compared the control group. Conclusions: As it is important to consider acquired communication disorders particularly discourse impairment of brain injured patients along with their other clinical impairments and regarding the fact that persuasive discourse is crucial in academic and social situations, the persuasive discourse task presented in this study could be a useful tool for speech therapists, intending to evaluate communication disorders in patients with TBI

    The architecture of the middle ear in the small Indian mongoose (Herpestes Javanicus)

    Get PDF
    The small Indian mongoose (Herpestes javanicus) is native to the Middle East, Iran and much of southern Asia. For this study the middle ears of a total of 6 adult small Indian mongooses, both fresh and museum samples were explored by using of dissection and plain radiography. On the one hand, at least in some species of the mongoose vocalisations and hearings play a critical role in coordinating behaviours. On the other hand, the ear region has provided useful character relevant for mammalian phylogeny. So, the aim of the present study is a brief discussion of the various anatomic particularities of the middle ear based on a combination of existing data and the results of the authors’ study in the small Indian mongoose
    • …
    corecore