Examining a catalyst sample for demercaptanization process

Abstract

This paper studies the results of experimental analysis on the demercaptanization of various crude distillation products by using a catalyst that was produced by Caravan sulfur catalyst company (CSC). This process is very important due to the removal of sulfur compounds and the most of desulfurization is carried out in a catalytic manner. According to the analysis, this catalyst is suitable for use in demercaptanization processes with 10% caustic solution.     

Jointly solving the group scheduling and machining speed selection problems: A hybrid tabu search and simulated annealing approach

In a cellular manufacturing environment, once the machines and parts have been grouped the remaining tasks are sequencing part families and scheduling operations for the parts within each part family so that some planning goals such as minimization of tardiness can be achieved. This type of problem is called group scheduling and will be analysed in this paper. The solution of the group scheduling is affected by the machining speed specified for each operation since the completion time of each operation is a function of machining speed. As such, the group scheduling and machining speed selection problems should be simultaneously solved to provide meaningful solutions. This, however, further complicates the solution procedure. In view of this, a hybrid tabu-simulated annealing approach is proposed to solve the group scheduling problem. The main advantage of this approach is that a short term memory provided by the tabu list can be used to avoid solution re-visits while preserving the stochastic nature of the simulated annealing method. The performance of this new method has been tested and favourably compared with two other algorithms using tabu search and simulated annealing alone.     

Flow balancing in die design of wood flour/HDPE composite extrusion profiles with consideration of rheological effect

This article presents an experimental study on the flow balance of an extrusion die for various wood flour (WF)/high‐density polyethylene (HDPE) compositions. Flow balancing, in the design of a thermoplastic extrusion die, is dependent on the material rheological properties so that a change in the material, in some cases, may result in a total redesign of the die. To investigate the importance of this particular effect, the flow balance of an extrusion die, with a U‐shaped profile having uneven wall thicknesses, was undertaken. The main feature of the die was an adjustable restrictor implemented for fine balancing similar to that employed in the slit dies. The rheological influence of wood plastic composites (WPCs) on the flow balance of the die via loading various WF contents, 40, 60, and 70% by weight, was experimentally investigated; flow balancing was performed via varying the height of the restrictor bar. Interestingly, the results showed that, for a high WF content (above 60%), the issue of flow balancing for an uneven wall thickness profile is much less complicated because of the plug flow behavior of the composite. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

An energy-aware virtual machines consolidation method for cloud computing: Simulation and verification

Cloud systems have become an essential part of our daily lives owing to various Internet-based services. Consequently, their energy utilization has also become a necessary concern in cloud computing systems increasingly. Live migration, including several virtual machines (VMs) packed on in minimal physical machines (PMs) as virtual machines consolidation (VMC) technique, is an approach to optimize power consumption. In this article, we have proposed an energy-aware method for the VMC problem, which is called energy-aware virtual machines consolidation (EVMC), to optimize the energy consumption regarding the quality of service guarantee, which comprises: (1) the support vector machine classification method based on the utilization rate of all resource of PMs that is used for PM detection in terms of the amount' load; (2) the modified minimization of migration approach which is used for VM selection; (3) the modified particle swarm optimization which is implemented for VM placement. Also, the evaluation of the functional requirements of the method is presented by the formal method and the non-functional requirements by simulation. Finally, in contrast to the standard greedy algorithms such as modified best fit decreasing, the EVMC decreases the active PMs and migration of VMs, respectively, 30%, 50% on average. Also, it is more efficient for the energy 30% on average, resources and the balance degree 15% on average in the cloud.     

A low loss and power efficient micro-electro-thermally actuated RF MEMS switch for low power and low loss applications

Microsystem Technologies - A novel laterally and micro-electro-thermally actuated RF MEMS switch is presented in this paper. Despite many RF MEMS switches requiring continuous actuation voltage to...     

YAARC: yet another approach to further reducing the rate of conflict misses

Traditional set associative caches are seriously prone to conflict misses. We propose an adapted new skewed associative architecture as an attempt to alleviate this problem. It has already been shown that skewed associative caches can reduce the rate of conflict misses by using different hash functions to index different banks. Building on this observation, we propose yet another approach to further reduce the rate of conflict misses, nicknamed YAARC (Yet Another Approach to Reducing Conflicts) that uses different hash functions to index into a single bank. Mathematical modeling and simulation results are exploited to evaluate the impact of YAARC on the rate of conflict misses. Mathematical analysis show the superiority of YAARC caches over set and skewed associative caches from the conflict miss point of view. Simulations, using some benchmarks from SPEC CPU2000 benchmark suit that former researchers have reported them as the best candidates for cache performance evaluation, also show nearly 43% conflict miss rate improvement for the skewed associative cache over the set associative cache, and nearly 31% improvement for the YAARC cache over the skewed associative cache. This implies that YAARC caches considerably outperform set and skewed associative caches from the conflict miss point of view. Since production of YAARC caches require a dispensable amount of hardware overhead, they can be considered as a cost effective approach to minimize the rate of conflict misses.

An ergonomics action research demonstration: integrating human factors into assembly design processes

In action research (AR), the researcher participates ‘in’ the actions in an organisation, while simultaneously reflecting ‘on’ the actions to promote learning for both the organisation and the researchers. This paper demonstrates a longitudinal AR collaboration with an electronics manufacturing firm where the goal was to improve the organisation's ability to integrate human factors (HF) proactively into their design processes. During the three-year collaboration, all meetings, workshops, interviews and reflections were digitally recorded and qualitatively analysed to inform new ‘actions’. By the end of the collaboration, HF tools with targets and sign-off by the HF specialist were integrated into several stages of the design process, and engineers were held accountable for meeting the HF targets. We conclude that the AR approach combined with targeting multiple initiatives at different stages of the design process helped the organisation find ways to integrate HF into their processes in a sustainable way.

Practitioner Summary: Researchers acted as a catalyst to help integrate HF into the engineering design process in a sustainable way. This paper demonstrates how an AR approach can help achieve HF integration, the benefits of using a reflective stance and one method for reporting an AR study.     

On using a new strain of Acidithiobacillus ferridurans for bioleaching of low-grade uranium

ABSTRACT

In the present investigation, isolation and determination of a new strain of Acidithiobacillus ferridurans SBU-SH2 from an Iranian sulfur hot spring are carried out and then it is used to evaluate the performance of uranium bioleaching from a low-grade natural resource host. The efficiency of uranium recovery is studied by considering the influence of experimental factors like pulp density, pH value, temperature, and source of energy. Experimental tests reveal that more than 96% of uranium is recovered at 35°C, initial pH 2.5, agitation speed of 120 rpm, and pulp density of 5% in about 1 week.     

3D human pose estimation from image using couple sparse coding

Recent studies have demonstrated that high-level semantics in data can be captured using sparse representation. In this paper, we propose an approach to human body pose estimation in static images based on sparse representation. Given a visual input, the objective is to estimate 3D human body pose using feature space information and geometrical information of the pose space. On the assumption that each data point and its neighbors are likely to reside on a locally linear patch of the underlying manifold, our method learns the sparse representation of the new input using both feature and pose space information and then estimates the corresponding 3D pose by a linear combination of the bases of the pose dictionary. Two strategies for dictionary construction are presented: (i) constructing the dictionary by randomly selecting the frames of a sequence and (ii) selecting specific frames of a sequence as dictionary atoms. We analyzed the effect of each strategy on the accuracy of pose estimation. Extensive experiments on datasets of various human activities show that our proposed method outperforms state-of-the-art methods.     

Adaptive temperature control for simulated annealing: a comparative study

In this paper, two variations of simulated annealing method have been proposed and tested on the minimum makespan job shop scheduling problems. In the conventional simulated annealing, the temperature declines constantly, providing the search with a higher transition probability in the beginning of the search and lower probability toward the end of the search. In the first proposed method, an adaptive temperature control scheme is used that changes temperature based on the number of consecutive improving moves. In the second method, a tabu list has been added to the adaptive simulated annealing algorithm in order to avoid revisits. The performance of these two algorithms is evaluated and favorably compared with the conventional simulated annealing.