Treatment of contaminated Flowback water in shale gas development

Flowback water from shale gas well drilling has a high TDS (total dissolved solids) content, ranging from 5000 ppm to 261,000 ppm, along with a TSS (total suspended solids) content of 300–3000 mg/L. Recently, the rapid expansion of shale gas production in Marcellus Formation has raised serious environmental concerns about the large amount of flowback water in this area. In this project a process based on ceramic membrane filtration and ion-exchange is optimised for the treatment of the flowback water from Marcellus Formation. Mixed bed ion-exchange will then be employed to reduce the high TDS concentration of flowback water. Finally, a preliminary cost estimation of the proposed treatment process will be conducted. The studied process contains a combination of two MF (microfiltration) membranes. After treatment, all TSS and >99% of TDS should be successfully removed from the flowback water to meet the criteria for surface discharge. The cost estimation of the treatment is expected to be around 18.4 $/m

Writing competence of junior high school students at two junior high schools in Yogyakarta

The problem limitation in this research is only about English writing competence in junior school and only compare two schools in Yogyakarta, that are MTs Negeri 1 Bantul and SMPN 1 Pengasih. To describe the student writing competencies at two junior high schools. The objectives of this study are to reveal the factors affecting the students writing competencies and to find out the solution to overcome the problem in writing competencies. In collecting data, the researcher used documentation technique. This technique was implemented by making use of teachers’ collection of the students’ writing tasks. Based on the result and analysis, so the conclusion in this research as follows the writing competencies of the ninth grade students of two junior high schools are at good enough level. The factors affecting the students English writing competencies are their ability, the learning process and classroom situation.  When the students weak in grammar, they have to make practice more, and also when they got in doing the difficult assignment. When the step of rhetoric weak, so the students must more practise in daily life, also for the make clarity of meaning and the relationship between ideas can improve by more practice in daily life, they can use the English language. About the weak vocabulary, so the teacher can practice and give more homework about the vocabulary and the task for example in writing and reading a lot of procedure text or story. The solution to overcome the problem in writing competencies such as make a lot of training or practice English in daily life, the teachers should employ active learning to support students engaged in teaching-learning proces

A Survey-Based Vision for Restructuring Concrete Business in the New Residential Communities in Egypt

Due to its evolving technology and dynamic nature, a sizeable segment of the world’s construction market that used to partly rely on traditional site-mixed concrete (SMC) had almost completely shifted to ready-mixed concrete (RMC) several decades ago in the developed countries. Likewise, this targeted trend has been observed in developing countries. The Egyptian residential sector has also adopted some corrective changes in this direction in the last decade. Nevertheless, the vast majority of builders in the Egyptian market have continued to oppose to this global paradigm shift. The observed “cultural” resistance to change seems to be chiefly driven by the difference in the unit price of SMC and RMC, overlooking the latter’s superior characteristics and its added values that fundamentally overweigh this apparent difference in cost.This study aims at promoting the use of RMC over SMC for construction of new residential communities in Egypt. Proper business measures need to be implemented for the desired change in the culture of concrete market. A mixed (qualitative and quantitative) approach was used in this survey. A customized survey, comprised of a series of interviews with consultants/contractors in the field and a detailed questionnaire targeting practitioners (developers, contractors and end users), was conducted to gage market responsiveness to the desired change. The desired market shift towards RMC (targeted variable) hinges on generic variables: price, concrete quality and customer satisfaction, and market-specific variables: local concrete culture, perception of average customers, and permitting process.The survey revealed that professional participants, a small fraction of the local concrete market, are aware of the added values of utilizing RMC. The participation rate is clearly indicative of the absence of awareness of the numerous competitive advantages of using RMC in the Egyptian market.  The resistance to change, unarguably, still hinges on the mistakenly believed difference in SMC and RMC unit prices, not the cost/benefit ratio

Split Liver Transplantation

Liver transplantation is the most effective treatment for the patients with acute liver failure or end-stage liver diseases. Liver transplantation is also indicated for patients with hepatocellular carcinoma to yield a best result if the tumor/tumors meet Milan criteria, University of California San Francisco(UCSF) criteria, or up-to-seven criteria. It is no doubt that more and more people need liver transplantation to save their lives. However, liver donation is always short to match the demand of liver transplantation. Therefore, how to expand the donor pool to increase the opportunities of liver transplantation is paramount. Splitting liver is one of the ways to expand the donor pool and offers an additional chance of liver transplantation. At the beginning of split liver transplantation (SLT), the liver was split and transplanted to an adult and a child. Now, the liver can be split into full right and left lobes and transplanted to two adults. When split liver transplantation is to be performed, there are many considerations that should be clarified. With the improvement of surgical skill, the outcomes of split liver transplantation are similar to that of deceased whole liver transplantation. It is worth to promote the policy of split liver transplantation

Auto-tuning of PID Controllers for Robotic Manipulators Using PSO and MOPSO

This work proposes two approaches to automatic tuning of PID position controllers based on different global optimization strategies. The chosen optimization algorithms are PSO and MOPSO, i. e. the problem is handled as a single objective problem in the first implementation and as a multiobjective problem in the second one. The auto-tuning is performed without assuming any previous knowledge of the robot dynamics. The objective functions are evaluated depending on real movements of the robot. Therefore, constraints guaranteeing safe and stable robot motion are necessary, namely: a maximum joint torque constraint, a maximum position error constraint and an oscillation constraint. Because of the practical nature of the problem in hand, constraints must be observed online. This requires adaptation of the optimization algorithm for reliable observance of the constraints without affecting the convergence rate of the objective function. Finally, Experimental results of a 3-DOF robot for different trajectories and with different settings show the validity of the two approaches and demonstrate the advantages and disadvantages of every method

A Practical Approach for the Auto-tuning of PD Controllers for Robotic Manipulators using Particle Swarm Optimization

An auto-tuning method of PD controllers for robotic manipulators is proposed. This method suggests a practical implementation of the particle swarm optimization technique in order to find optimal gain values achieving the best tracking of a predefined position trajectory. For this purpose, The integral of the absolute error IAE is used as a cost function for the optimization algorithm. The optimization is achieved by performing the desired movement of the robot iteratively and evaluating the cost function for every iteration. Therefor, the necessary constraints that guarantee a safe and stable movement of the robot are defined, which are: a maximum joint torque constraint, a maximum position error constraint and an oscillation constraint. A constraint handling approach is suggested for the optimization algorithm in order to adapt it to the problem in hand. Finally, the efficiency of the proposed method is verified through a practical experiment on a real robot

Testing the weak-form efficiency in Middle Eastern financial markets: empirical evidence from the Palestine Exchange and its main competitors

The Efficient Market Hypothesis can be defined by the simple statement that “security prices fully reflect all available information”. (Fama 1991, p. 1575) While there are different levels of market efficiency, the focus of this paper is the weak-form, in which information sets include only historical prices and “how well do past returns predict future returns?” (ibid.) This dissertation investigates the weak-form efficiency of the Palestine Exchange and its main competitors (Amman Stock Exchange and Dubai Financial Market) for the post 2010 period, in which these markets are characterized by illiquidity and thin trading. Main indexes daily closings for the markets under study during the period 2010-2013 were used to examine efficiency, by employing a number of the most common econometric techniques seen in recent empirical results covering Middle East North Africa (MENA) financial markets. Hence Augmented Dickey-Fuller test was conducted to examine the presence of unit root, then serial autocorrelations of returns at various lags were estimated, followed by employing a non-parametric runs test to investigate the randomness of returns. This research also takes into account the possible costs of infrequent trading, which may increase the tendency of rejecting market efficiency hypothesis even if it is true. Therefore to avoid the effect of thin trading, the econometrics techniques mentioned were applied again, using adjusted returns rather than observed daily indexes returns. Results obtained using the observed indexes returns reveal that the Palestine Exchange and Dubai Financial Market were found to be weak-form efficient during post 2010 period. On the other hand Amman Stock Exchange was found to be weak-form inefficient during the same period. However when adjusting returns for infrequent trading using the approach proposed by Miller et al (1994) – explained in chapter 4.2.4 – no conclusion could been drawn, as conflicting and contradicting results were obtained. This lead to the assumption that the proposed model cannot be used for markets under examination without further modifications, as it was developed for more sophisticated and liquid markets. Investigating the further attempts needed to develop a more suitable model for adjusting infrequent trading effect in the markets under study will be left for future research

Radiographic Analysis Of Umbrella Technique Combined With Sticky Bone in horizontal ridge augmentation

Abstract: Aim of the study: To evaluate the efficacy of umbrella technique combined with sticky bone in horizontal ridge augmentation using Buccolingual width changes measured in CBCT. Materials and Methods: 15 male and female Patients were selected . Buccal and lingual Infiltration anaethesia to mandibular posterior area (area of interest), crestal incision flap. Decortication using round bur and straight hand piece then drilling using screw drills with 90 degrees to the buccal cotical plate. Umbrella Screw insertion using screw holder with 6 mm length and 1.6 mm diameter where 3 mm inserted in the bone and 3 mm are kept outside. The bone graft and the I PRF are placed into sterile dish, mixed together till sticky bone is formed. Application of the sticky bone buccally, on and in between the bone screws with proper condensation. Results: At baseline, the mean radiographic bone width value was (3.31), the standard deviation was (0.87), the median was (3.75), and the interquartile range was (1.01). After 6 months, the mean was (6.08), the standard deviation was (0.78), the median was (6.33) and the interquartile range was (0.99). For the radiographic difference after 6 months, the mean value was (2.62), the standard deviation was (0.15), the median was (2.66) and the interquartile range was (0.20). For the percentage change the mean value was (76.30), the standard deviation was (11.25), the median was (72.94) and the interquartile range was (10.60). Conclusion: Umbrella technique using bone screws has predictable results in the horizontal ridge augmentation. Tenting of the periosteum and soft tissue using tenting screws maintains space and minimizes resorption of the particulate graft volume

Optimization of a P/PI Cascade Motion Controller for a 3-DOF Delta Robot

An auto-tuning method for a Delta robot’s P/PI cascade motion controller using multi-objective optimization algorithm is proposed. The implemented control structure consists of two controllers: A feedforward controller based on a model of the inverse dynamics of the robot, and a cascade P/PI controller to compensate for unmodeled effects. The auto-tuning is achieved in the sense of optimizing the control parameters in three stages. In the first stage, the feedback control parameters are optimized after neglecting the feedforward control term. The goal is to minimize the position error in tracking an excitation trajectory, which is used as well to identify the dynamic model parameters in the second stage. After that, the feedforward compensation term is computed offline based on the desired trajectory. In the final stage, the P/PI parameters are optimized again after adding the feedforward controller. Experimental results on an industrial 3-dof Delta robot validates the efficiency of the proposed method