Multi-state analysis functional models using Bayesian networks

Multilevel Flow Modeling (MFM) model maps functionality of components in a system through logical interconnections and is effective in predicting success rates of tasks undertaken. However, the output of this model is binary, which is taken at its extrema, i.e., success and failure, while in reality, the operational status of plant components often spans between these end. In this paper, a multi-state model is proposed by adding probabilistic information to the modelling framework. Using a heat exchanger pilot plant as a case study, the MFM model is transformed into its fault tree [1] equivalent to incorporate failure probability information. To facilitate computations, the FT model is transformed into Bayesian Network model, and applied for fault detection and diagnosis problems. The results obtained illustrate the effectiveness and feasibility of the proposed method

Hemi-Slant Warped Product Submanifolds of Nearly Kaehler Manifolds

Hemi-slant warped product submanifolds of nearly Kaehler manifolds are studied and some interesting results are obtained. Moreover, an inequality is established for squared norm of second fundamental form and equality case is also discussed. The results obtained are also true if ambient manifold is replaced by a Kaehler manifold. These results generalize several known results in the literature

Entrepreneurship in Oman: policies and practices.

Oman provides an interesting context to examine how formal institutions encourage local enterprise. We examine the views of local entrepreneurs about the effectiveness of government policies that are intended to foster indigenous small business. We ask how they evaluate the entrepreneurial ecosystem. We provide an overview of the remarkable context, the Sultanate of Oman; a thriving oil based economy, but characterised by a high percentage of expatriate business ownership. Moreover, the current industrial and commercial structure looks unlikely to be able to provide sufficient satisfying jobs for the rapidly expanding youthful population. The government has responded by creating modern formal institutions to facilitate enterprise and by providing a number of well funded programs to enable local entrepreneurship. This forms the basis of our research problem, establishing how local entrepreneurs respond to these initiatives to address the low levels of local entrepreneurship. We conducted a face to face interview survey with 60 Omani SME owners asking about how well the initiatives had addressed their cultural and practical 'requirements'. We found that many respondents were motivated by a quest for independence coupled with the need for a 'good' job. However we also found that the sheer joy of entrepreneuring delighted some respondents. The initiatives had provided the means of achieving this self determination. The formal structures were very supportive; initial funding for example was readily available. However, we also found the informal structures were less developed. There was evidence of an emergent cognitive appeal and approval for entrepreneurship. We argue that there is need to develop such informal institutions to help existing businesses to grow and to cultivate an Omani enterprise culture

Performance evaluation of the time delay digital tanlock loop architectures

This article presents the architectures, theoretical analyses and testing results of modified time delay digital tanlock loop (TDTLs) system. The modifications to the original TDTL architecture were introduced to overcome some of the limitations of the original TDTL and to enhance the overall performance of the particular systems. The limitations addressed in this article include the non-linearity of the phase detector, the restricted width of the locking range and the overall system acquisition speed. Each of the modified architectures was tested by subjecting the system to sudden positive and negative frequency steps and comparing its response with that of the original TDTL. In addition, the performance of all the architectures was evaluated under noise-free as well as noisy environments. The extensive simulation results using MATLAB/SIMULINK demonstrate that the new architectures overcome the limitations they addressed and the overall results confirmed significant improvements in performance compared to the conventional TDTL system

Complications of Bone Plating Following Different Facial Bones Fractures

The Aim of our study was to evaluate the complication of bone plating fixation used for treatment of multiple type of facial fracture, reconstruction procedure and bone graft in maxillofacial trauma. This prospective study was performed on 42 patients to evaluates complications of the bone plates had been used in fixation of multiple facial fractures, between October 2013 and March 2015, The age of the patients ranged from 17 – 65 years The mean age of the patients was (31.7± 9.4) years. There were 31 males and 11 females, with male to female ratio (2.81:1), patients were followed up for minimum 6 months. Seventy-one plates were inserted over 17 months. Among the 42 patients there were 45 fracture sites, 26 (57.8%) were mandibular fractures, 15 (33.3%) were ZMC fractures, and four (8.9%) were maxillary; it is worth mentioning that some patients had fracture at more than one site. Complications due to fracture fixation with bone plating were 33 represented 46.5% of the total 71 plates inserted, which included Infection/wound dehiscence 15 (21.1%), Discomfort/ palpability 9 (12.7%), Plate exposure 4 (5.6%), hardware failure (broken plate & loosening screw) 1 (1.4%), Cold/heat intolerance 3 (4.2%) and Pain (TMJ) account for one plate (1.4%). According to this study, there will be a need for hardware removal in a portion of patients treated with metallic osteosynthesis devices. This study states that the infection is most common reason for plate removal, followed by discomfort due to cold/heat climate, particularly in those facial regions that provide only thin soft tissue cover over the plate

Extraction conditions of polyphenol oxidase from banana peel

Polyphenol oxidase (PPO) is an enzyme containing copper, presents in various fruits and vegetables. It is responsible for the browning reactions when the cells are damaged during handling. The best conditions for extraction of polyphenol oxidase from banana peel was by using an extraction buffer containing phosphate buffer (0.05 M, pH 7), 0.01 M ascorbic acid and 0.5% polyethylene glycol, with extraction ratio 1:4 (w:v) for one minute by using blender. The enzyme activity was measured spectrophotometrically at 425 nm. PPO was studied to prevent the browning of banana peel which results in the loss of their marketability. The aim of this study was to determine the optimum conditions for polyphenol oxidase extraction from banana peel