Analytical Modeling and Diagnosis of Penetration Rate Performance of PDC Bits

The high cost of drilling deep (15000+ ft) wells, due to slow rate of penetration (ROP) at depth, has severely limited the utilization and economic significance of deep hydrocarbon resources. The overall objective of this study was to obtain a better understanding of the major cause(s) of slow ROP in deep drilling. An analysis of field data demonstrated the impact of the problem and identified shale and limestone as the primary lithologies where slow ROP occurs at depth. Previous researchers have concluded that interactions between rock, drilling fluid, cuttings, and the bit control ROP. More specifically, several researchers have concluded that bit balling is the major cause of slow ROP in deep shales drilled using water base mud (WBM). Lab and field examples of bit balling in oil base mud (OBM), although uncommon, were also found. This study developed analytical models to describe some of these interactions. The other questions addressed were whether some form of balling causes slow ROP in deep shales drilled with OBM and whether diagnostic symptoms could be defined to determine which form(s) of balling causes severely low ROP. An analytical model for single cutter drilling was adapted from a model of machining metal and then scaled up as a full scale polycrystalline diamond compact (PDC) bit model. The models compared well with laboratory test results by predicting penetration rate performance based on the strength and internal friction angle of the rock, confining pressure, and cutter and bit design. Multi-scale analyses of field cuttings were also performed. These provided knowledge of the cuttings structure and potential accumulation mechanisms that was used in developing models to explicitly account for the effects of cutter balling and global balling. The full scale bit model was applied to bit test data and shown to be useful in detecting drilling inefficiencies and for early diagnosis of global balling. Global balling when drilling both Mancos and Catoosa shales with OBM caused significant decreases in ROP and had essentially the same diagnostic symptoms as balling in WBM. This may indicate that the causal mechanisms of bit balling, and consequently, of slow ROP, in oil base mud are similar to those in water base mud

Finite Element Analysis of Functionally Graded Beams using Different Beam Theories

The present study deals with buckling, free vibration, and bending analysis of Functionally Graded (FG) and porous FG beams based on various beam theories. Equation of motion and boundary conditions are derived from Hamilton’s principle, and the finite element method is adopted to solve problems numerically. The FG beams are graded through the thickness direction, and the material distribution is controlled by power-law volume fraction. The effects of the different values of the power-law index, porosity exponent, and different boundary conditions on bending, natural frequencies and buckling characteristics are also studied. A new function is introduced to approximate the transverse shear strain in higher-order shear deformation theory. Furthermore, shifting the position of the neutral axis is taken into account. The results obtained numerically are validated with results obtained from ANSYS and those available in the previous work. The results of this study specify the crucial role of slenderness ratio, material distribution, and porosity condition on the characteristic of FG beams. The deflection results obtained by the proposed function have a maximum of six percent difference when the results are compared with ANSYS. It also has better results in comparison with the Reddy formulae, especially when the beam becomes slender. Doi: 10.28991/cej-2020-03091604 Full Text: PD

A domestic model for successful implementation of enterprise resource planning (ERP) systems in Iranian manufacturing enterprises

This research investigates the human-behavioral dimension of technology acceptance in enterprises. It is evident that accepting a technology depends on the underlying circumstances of the environment. We have approached this issue from two different angles of social and technological architecture. The research tries to explore proper enterprise architecture for ERP system acceptance. Social Architecture (SA) is defined as the set of circumstances that makes people behave in a particular way. So behavior of persons (employees of an enterprise) can be a function of SA. Hence acceptance of a system can be dictated by SA and manipulating SA can result in desirable success for a technology system. We have achieved various variables of social architecture and have examined their relevance to system acceptance and success in related enterprises (research domain) beside technological architecture variables. The results have indicated that a special form of social and technological architecture can lead to success for ERP system in the enterprises of the research domain. This gave us a model of architecture

Partial Purification and Characterization of Rhodanese from Rainbow Trout (Oncorhynchus mykiss) Liver

Cyanide is one of the most toxic substances present in a wide variety of food materials that are consumed by animals. Rhodanese, a ubiquitous enzyme, can catalyse the detoxification of cyanide by sulphuration reaction. In this study, rhodanese was partially purified and characterized from the liver tissue homogenate of the rainbow trout. The enzyme was active in a broad range of pH, from 5 to 12. The optimal activity was found at a high pH (pH 10.5), and the temperature optimum was 25°C. The enzyme was heat labile, losing > 50% of relative activity after only 5 min of incubation at 40°C. The Km values for KCN and Na2S2O3 as substrates were 36.81 mM and 19.84 mM, respectively. Studies on the enzyme with a number of cations showed that the activity of the enzyme was not affected by Sn2+, but Hg2+, Ba2+, Pb2+, and Ca2+ inhibited and Cu2+ activated the enzyme with a concentration-dependent manner

A Novel Scheme for Intelligent Recognition of Pornographic Images

Harmful contents are rising in internet day by day and this motivates the essence of more research in fast and reliable obscene and immoral material filtering. Pornographic image recognition is an important component in each filtering system. In this paper, a new approach for detecting pornographic images is introduced. In this approach, two new features are suggested. These two features in combination with other simple traditional features provide decent difference between porn and non-porn images. In addition, we applied fuzzy integral based information fusion to combine MLP (Multi-Layer Perceptron) and NF (Neuro-Fuzzy) outputs. To test the proposed method, performance of system was evaluated over 18354 download images from internet. The attained precision was 93% in TP and 8% in FP on training dataset, and 87% and 5.5% on test dataset. Achieved results verify the performance of proposed system versus other related works

Contextualization-Emotionalization Interface: A Case of Teacher Effectiveness

Given the prominence of cognitive and affective factors in teacher effectiveness, this study intends to look at the issue from a different perspective and examine the roles of contextualization and emotionalization in teacher success. In so doing, 305 English as a Foreign Language (EFL) learners rated their English teachers to determine the extent to which they contextualize and emotionalize their instructions. During the first phase of the study, a pair of scales were constructed and substantiated via Confirmatory Factor Analysis (CFA) to serve the abovementioned purpose. As for the second phase, Structural Equation Modeling (SEM) was utilized to shed light on any probable relationships among the independent variables and teacher success. The results indicated that, teachers who contextualize and emotionalize their instructional practices, enjoy an enhanced level of success. Moreover, it was revealed that, in the close competition between contextualization and emotionalization, contextualization was identified as a slightly better predictor of teacher success. Building upon the rather strong links between the sub-construct of contextualization and emotionalization, it was further inferred that, mutual juxtaposition of the two concepts contribute to teacher success. In the end, the results were discussed in the realm of English language education