Integrated Cost Index for Inherently Safer Design Alternatives

Inherently Safer Design (ISD) is an approach in process industry to prevent any loss and injuries especially in the design and operation of facilities that use hazardous chemical. The sole purpose is to minimize the frequency and potential impact of chemical plant incident such as fires, explosion and acute toxic exposure. There are four strategies for designing inherently safer process which is substitute, minimize, moderate and simplify. These strategies can either be to choose only one strategy or to apply all of the strategies best at the preliminary stage in designing a plant. Considering the lifetime cost of a process and its operation, an inherent safety approach can lead to a cost optimal option. However, it is still a big question to chemical industry whether the cost is affordable when applying ISD. Therefore, in this this report, safety and economic evaluation have been made for three alternatives chosen from the MMA process routes. Index used in evaluating safety is Prototype Index for Inherent Safety (PIIS). A framework to evaluate modification cost which comprises material and equipment purchasing cost has been developed for the economic evaluation purpose. These two cost evaluations are made to determine the impact of cost towards the inherent safety implementation. This works has shown that inherently safer design does affect the economic feasibility of a process where the safest design does not necessarily be the cheapest design alternative

DIFFERENTIAL EVOLUTION FOR OPTIMIZATION OF PID GAIN IN ELECTRICAL DISCHARGE MACHINING CONTROL SYSTEM

ABSTRACT PID controller of servo control system maintains the gap between Electrode and workpiece in Electrical Dis- charge Machining (EDM). Capability of the controller is significant since machining process is a stochastic phenomenon and physical behaviour of the discharge is unpredictable. Therefore, a Proportional Integral Derivative (PID) controller using Differential Evolution (DE) algorithm is designed and applied to an EDM servo actuator system in order to find suitable gain parameters. Simulation results verify the capabilities and effectiveness of the DE algorithm to search the best configuration of PID gain to maintain the electrode position. Keywords: servo control system; electrical discharge machining; proportional integral derivative; con- troller tuning; differential evolution

Integrated Cost Index for Inherently Safer Design Alternatives

Inherently Safer Design (ISD) is an approach in process industry to prevent any loss and injuries especially in the design and operation of facilities that use hazardous chemical. The sole purpose is to minimize the frequency and potential impact of chemical plant incident such as fires, explosion and acute toxic exposure. There are four strategies for designing inherently safer process which is substitute, minimize, moderate and simplify. These strategies can either be to choose only one strategy or to apply all of the strategies best at the preliminary stage in designing a plant. Considering the lifetime cost of a process and its operation, an inherent safety approach can lead to a cost optimal option. However, it is still a big question to chemical industry whether the cost is affordable when applying ISD. Therefore, in this this report, safety and economic evaluation have been made for three alternatives chosen from the MMA process routes. Index used in evaluating safety is Prototype Index for Inherent Safety (PIIS). A framework to evaluate modification cost which comprises material and equipment purchasing cost has been developed for the economic evaluation purpose. These two cost evaluations are made to determine the impact of cost towards the inherent safety implementation. This works has shown that inherently safer design does affect the economic feasibility of a process where the safest design does not necessarily be the cheapest design alternative

Prediction of classroom reverberation time using neural network

In this paper, an alternative method for predicting the reverberation time (RT) using neural network (NN) for classroom was designed and explored. Classroom models were created using Google SketchUp software. The NN applied training dataset from the classroom models with RT values that were computed from ODEON 12.10 software. The NN was conducted separately for 500Hz, 1000Hz, and 2000Hz as absorption coefficient that is one of the prominent input variable is frequency dependent. Mean squared error (MSE) and regression (R) values were obtained to examine the NN efficiency. Overall, the NN shows a good result with MSE 0.9. The NN also managed to achieve a percentage of accuracy of 92.53% for 500Hz, 93.66% for 1000Hz, and 93.18% for 2000Hz and thus displays a good and efficient performance. Nevertheless, the optimum RT value is range between 0.75 – 0.9 seconds

PSO-BP algorithm implementation for material surface image identification

Implementation of neural network for acoustic computation is not ne w. In this paper, a new improved method in predicting material surface from photographic image was implemented using a hybrid of particle swarm optimization and back-propagation neural network (PSO-BP) algorithm. Before the system clas sified the data using PSO-BP algorithm, the photographic images of room surfaces need to be extracted using Gray Level Co-occurrence Matrix (GLCM) and Modified Zernike Moments. The result indicated that the PSO-BP algorithm have a hig her accuracy compared to the BP algorithm, managed to record highest accuracy of 88% as opposed to 81.3% for the latter

Comparison between GLCM and modified Zernike moments for material surfaces identification from photo images

Types of materials are one of an important data for research in acoustic engineering. This paper compares methods for extracting texture data of material surfaces for classification. Gray Level Co-occurrence Matrix (GLCM) and modified Zernike moments that is applied for image extraction are tested and compared with back propagation neural network used for classification. These methods are also applied to the Brodatz texture database as a general comparison. The GLCM method shows a good performance and regression, R>0.9 for the Brodatz database while the collected surfaces datasets using GLCM and modified Zernike moments as well as the Brodatz datasets using modified Zernike moments method had only managed an acceptable performance and regression of R>0.8

Thermodynamic evaluation of the aqueous stability of rare earth elements in sulfuric acid leaching of monazite through pourbaix diagram

The objective of this study is to construct Pourbaix diagram (Eh-pH diagram) for Lanthanum (La), Cerium (Ce) and Neodymium (Nd) elements at elevated temperatures. The Pourbaix diagram is able to map the stability area of the aqueous system, which will be useful to determine the process conditions that favor dissolution and possible rare earth (RE) metals that may be present in the system. In this work the process condition is based on the sulfuric acid leaching of monazite concentrate and it is carried out using HSC Chemistry 8.0 software. Addition of the sulfate ions from the sulfuric acid as the leaching solvent, introduces soluble metal-sulfate complexes. With temperature increase, the stability of these complexes increases. This can be observed based on the increased area in the Eh-pH diagram. Comparing the 3 rare earth elements in this study, it was determined that at elevated temperatures the order of stability is Ce>Nd>La

Simulation of leaching process of gold by cyanidation

This paper presents a simulation study of leaching process of gold by using HSC Chemistry software (HSC). Cynide (NaCN) has been used to recover gold from gold bearing ores since 1890’s and until today it still playing an important role in the beneficiation process of the gold. This work aims to develop a simulation process model of this solid-liquid leaching process by using cyanide solvent for the dissolution of gold by using HSC simulator. The simulation of the leaching process was carried out in a continuous steady-state condition. The results from this simulation were compared with other researcher which employed Aspen Plus and it shows very good agreement with very small error (less than 1.5%). A case study was carried out using the developed process model where hydrochloric acid (HCl) was used as solvent in order to recover the gold from the ores. The results from the case study show that the chlorination process gives higher amount of gold (Au) dissolved in the solvent compared to cyanidation process. Another case study was carried out in order to study the effect of different concentration of Au in ores and the effect of different concentration of solvent as a leaching reagent. As a conclusion, the develop process model provide an effective means for studying the solid liquid leaching process in the future

Modelling and simulation of lanthanum (La) and neodymium (Nd) leaching from monazite ore using METSTM

Digestion and leaching are known as part of the main processing pre-treatment method in the extraction of rare earth elements (REEs). This work aims to carry out the sensitivity analysis of the liquid–solid (L/S) ratio, the type of acids as well as the number of reactors for the recovery of REEs, namely lanthanum (La) and neodymium (Nd) from monazite concentrate through the leaching process. A model was developed and simulated by using METSIM, a software for modelling metallurgical processes. The process was modelled as a two-step process; the first is the digestion, followed by the leaching process to produce monazite leachate. The results show that the optimum L/S ratio was 8:1 to recover the highest amount of REEs, with HCl was found to perform better as a solvent for the recovery of REEs compared to H2SO4. In addition, the optimum recovery of REEs was achieved by using three reactors, which is in the range of 70-95%

Sustainable forest management contribution to food security: A stakeholders' perspectives in Sabah, Malaysia

Implementing Sustainable Forest Management (SFM) policy has contributed to conserving and protecting the forests to remain relevant for future generations. This study determines stakeholders' viewpoint on the relationship between the implementation of SFM and food security in Sabah. The study was conducted by distributing online questionnaires through the SurveyMonkey platform using convenience sampling methods. Most of the respondents agreed that the forestry sector is still relevant to the development and generation of the economy and revenue to the state of Sabah. Apart from nature-based tourism, wood-based manufacturing, furniture industry, and agroforestry practices, other potential economic-generation segments are indigenous forest food productions, such as wild honey, fruits, vegetables, and game animals. The forestry sector could contribute to food security for Sabah by advancing the current practices and the use of local resources of forest foods. Other prospects are integrating natural and plantation forest management programs with the generation of forest food resources. Factors that could foster the forestry sector's contribution to food security, among others, are research and innovation, education, involvement of local communities, and the role of government policy on forestry and food security in Sabah