Search results for: bagging recovery
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1736

Search results for: bagging recovery

1736 Effect of Friction Parameters on the Residual Bagging Behaviors of Denim Fabrics

Authors: M. Gazzah, B. Jaouachi, F. Sakli

Abstract:

This research focuses on the yarn-to-yarn and metal-to-fabric friction effects on the residual bagging behavior expressed by residual bagging height, volume and recovery of some denim fabrics. The results show, that both residual bagging height and residual bagging volume, which is determined using image analysis method, are significantly affected due to the most influential fabric parameter variations, the weft yarns density and the mean frictional coefficients. After the applied number of fatigue cycles, the findings revealed that the weft yarn rigidity contributes on fabric bagging behavior accurately. Among the tested samples, our results show that the elastic fabrics present a high recovery ability to give low bagging height and volume values.

Keywords: bagging recovery, denim fabric, metal-to-fabric friction, residual bagging height, yarn-to-yarn friction

Procedia PDF Downloads 552
1735 Complex Shaped Prepreg Part Drapability Using Vacuum Bagging

Authors: Saran Toure

Abstract:

Complex shaped parts manufactured using out of autoclave prepreg vacuum bagging has a high quality finish. This is not only due to in the control of resin to fibre ratio in prepregs, but also to a reduction in fibre misalignment, slippage and stresses occurring within plies during compaction. In a bid to further reduce deformation modes and control failure modes, we carried experiments where, we introduced wetted fabrics within a prepreg plybook during compaction. Here are presented the results obtained from the vacuum bagging of a complex shaped part. The shape is that of a turbine fan blade with smooth curves all throughout ending with sharp edged angles. The quality of the final part made from this blade is compared to that of the same blade made from standard vacuum bagging process of prepregs, without introducing wetted fabrics.

Keywords: complex shaped part, prepregs, drapability, vacuum bagging

Procedia PDF Downloads 335
1734 Comparative Analysis of Classification Methods in Determining Non-Active Student Characteristics in Indonesia Open University

Authors: Dewi Juliah Ratnaningsih, Imas Sukaesih Sitanggang

Abstract:

Classification is one of data mining techniques that aims to discover a model from training data that distinguishes records into the appropriate category or class. Data mining classification methods can be applied in education, for example, to determine the classification of non-active students in Indonesia Open University. This paper presents a comparison of three methods of classification: Naïve Bayes, Bagging, and C.45. The criteria used to evaluate the performance of three methods of classification are stratified cross-validation, confusion matrix, the value of the area under the ROC Curve (AUC), Recall, Precision, and F-measure. The data used for this paper are from the non-active Indonesia Open University students in registration period of 2004.1 to 2012.2. Target analysis requires that non-active students were divided into 3 groups: C1, C2, and C3. Data analyzed are as many as 4173 students. Results of the study show: (1) Bagging method gave a high degree of classification accuracy than Naïve Bayes and C.45, (2) the Bagging classification accuracy rate is 82.99 %, while the Naïve Bayes and C.45 are 80.04 % and 82.74 % respectively, (3) the result of Bagging classification tree method has a large number of nodes, so it is quite difficult in decision making, (4) classification of non-active Indonesia Open University student characteristics uses algorithms C.45, (5) based on the algorithm C.45, there are 5 interesting rules which can describe the characteristics of non-active Indonesia Open University students.

Keywords: comparative analysis, data mining, clasiffication, Bagging, Naïve Bayes, C.45, non-active students, Indonesia Open University

Procedia PDF Downloads 283
1733 The Initiator Matters in Service Co-Recovery: Investigation on Attribution and Satisfaction

Authors: Chia-Ching Tsai

Abstract:

In the literature, the positive effect of service co-recovery has been evidenced, and which customers’ attribution is the key successful factor has also been indicated. There is also literature investigating on initiation of co-recovery for finding out the superior way to co-recovery, and indicating co-recovery initiated by employees causes better effect of co-recovery. This research postulates the consequences of co-recovery by different initiators affect customers’ attribution and the resultant results. Thus, this research uses a 3x2 factorial design to investigate the impact of initiator of co-recovery and consequence of co-recovery on customers’ attribution and post-recovery satisfaction. The results show initiation of co-recovery has a significant influence on internal attribution, and the employee initiator causes the highest internal attribution. The consequences of co-recovery interact with initiators of co-recovery on internal attribution significantly. Moreover, internal attribution significantly affects post-recovery satisfaction.

Keywords: service co-recovery, initiation of co-recovery, attribution, post-recovery satisfaction

Procedia PDF Downloads 234
1732 The Impact of Level and Consequence of Service Co-Recovery on Post-Recovery Satisfaction and Repurchase Intent

Authors: Chia-Ching Tsai

Abstract:

In service delivery, interpersonal interaction is the key to customer satisfaction, and apparently, the factor of human is critical in service delivery. Besides, customers quite care about the consequences of co-recovery. Thus, this research focuses on service failure caused by other customers and uses a 2x2 factorial design to investigate the impact of consequence and level of service co-recovery on post-recovery satisfaction and repurchase intent. 150 undergraduates were recruited as participants, and assigned to one of the four cells randomly. Every participant was requested to read the scenario and then rated the post-recovery satisfaction and repurchase intent. The results show that under the condition of failed co-recovery, level of co-recovery has no effect on post-recovery satisfaction, while under the condition of successful co-recovery, high-level co-recovery causes significantly higher post-recovery satisfaction than low-level co-recovery. Moreover, post-recovery satisfaction has significantly positive impact on repurchase intent. In the system of service delivery, customers interact with other customers frequently. Therefore, comparing with the literature, this research focuses on the service failure caused by other customers. This research also supplies a better understanding of customers’ view on consequences of different levels of co-recovery, which is helpful for the practitioners to make use of co-recovery.

Keywords: service failure, service co-recovery, consequence of co-recovery, level of co-recovery, post-recovery satisfaction, repurchase intent

Procedia PDF Downloads 390
1731 Efficacy of Different Pest Control Strategies against Citrus Rind Borer (Prays Eendolemma Diakonoff) Infesting Pummelo (Citrus maxima)

Authors: Larry V. Aceres, Jesryl B. Paulite, Emelie M. Pelicano, J. A. Esteban, Mamangun

Abstract:

Citrus rind borer still the most important pest infesting pummelo in the Philippines particularly in the Davao region. Hence, management of the pest is very important for successful pummelo production. This study was conducted to assess the effectiveness of the different control strategies against citrus rind borer; to determine the best treatment in controlling citrus rind borer; and to calculate the profitability of the various treatments in pummelo production. The experiment was laid-out in Completely Randomized Design (CRD) with five treatments replicated three times. The treatments were: T1- curry tree leaf leachate, T2- neem tree leaf leachate, T3- bagging with an ordinary net, T4- treated check (chlorpyrifos & betacyflutrin) and T5- untreated check. Data were analyzed using the Analysis of Variance and the differences among treatment means were computed using the Tukey’s Honest Significant Difference. The results of the study revealed that the curry tree leaf leachate and bagging treatments provide significant protection to the pummelo fruits which is comparable with the treated check (chlorpyrifos & betacyflutrin). Neem tree leaf leachate is not effective in controlling citrus rind borer which is comparable with the untreated check. In cost and return analysis, the most economical and effective is the bagging treatment using ordinary net.

Keywords: curry tree, neem tree, bagging, citrus rind borer

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1730 Autonomic Recovery Plan with Server Virtualization

Authors: S. Hameed, S. Anwer, M. Saad, M. Saady

Abstract:

For autonomic recovery with server virtualization, a cogent plan that includes recovery techniques and backups with virtualized servers can be developed instead of assigning an idle server to backup operations. In addition to hardware cost reduction and data center trail, the disaster recovery plan can ensure system uptime and to meet objectives of high availability, recovery time, recovery point, server provisioning, and quality of services. This autonomic solution would also support disaster management, testing, and development of the recovery site. In this research, a workflow plan is proposed for supporting disaster recovery with virtualization providing virtual monitoring, requirements engineering, solution decision making, quality testing, and disaster management. This recovery model would make disaster recovery a lot easier, faster, and less error prone.

Keywords: autonomous intelligence, disaster recovery, cloud computing, server virtualization

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1729 Educational Data Mining: The Case of the Department of Mathematics and Computing in the Period 2009-2018

Authors: Mário Ernesto Sitoe, Orlando Zacarias

Abstract:

University education is influenced by several factors that range from the adoption of strategies to strengthen the whole process to the academic performance improvement of the students themselves. This work uses data mining techniques to develop a predictive model to identify students with a tendency to evasion and retention. To this end, a database of real students’ data from the Department of University Admission (DAU) and the Department of Mathematics and Informatics (DMI) was used. The data comprised 388 undergraduate students admitted in the years 2009 to 2014. The Weka tool was used for model building, using three different techniques, namely: K-nearest neighbor, random forest, and logistic regression. To allow for training on multiple train-test splits, a cross-validation approach was employed with a varying number of folds. To reduce bias variance and improve the performance of the models, ensemble methods of Bagging and Stacking were used. After comparing the results obtained by the three classifiers, Logistic Regression using Bagging with seven folds obtained the best performance, showing results above 90% in all evaluated metrics: accuracy, rate of true positives, and precision. Retention is the most common tendency.

Keywords: evasion and retention, cross-validation, bagging, stacking

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1728 Forecasting 24-Hour Ahead Electricity Load Using Time Series Models

Authors: Ramin Vafadary, Maryam Khanbaghi

Abstract:

Forecasting electricity load is important for various purposes like planning, operation, and control. Forecasts can save operating and maintenance costs, increase the reliability of power supply and delivery systems, and correct decisions for future development. This paper compares various time series methods to forecast 24 hours ahead of electricity load. The methods considered are the Holt-Winters smoothing, SARIMA Modeling, LSTM Network, Fbprophet, and Tensorflow probability. The performance of each method is evaluated by using the forecasting accuracy criteria, namely, the mean absolute error and root mean square error. The National Renewable Energy Laboratory (NREL) residential energy consumption data is used to train the models. The results of this study show that the SARIMA model is superior to the others for 24 hours ahead forecasts. Furthermore, a Bagging technique is used to make the predictions more robust. The obtained results show that by Bagging multiple time-series forecasts, we can improve the robustness of the models for 24 hours ahead of electricity load forecasting.

Keywords: bagging, Fbprophet, Holt-Winters, LSTM, load forecast, SARIMA, TensorFlow probability, time series

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1727 Forensic Nursing Culture and Recovery-Oriented Practice: A Focused Ethnography

Authors: Monica Ginn

Abstract:

Providing recovery-oriented practice in forensic settings is often a contentious issue. This paper focuses on recovery with how it is influenced by the forensic population and how it is impacted by forensic nurses’ attitudes and practices. Understanding the culture of forensic nursing and how forensic nurses experience and perceive recovery for forensic patients provided insights into how forensic nurses use recovery-oriented practices to enhance nursing care in secure settings and facilitate successful reintegration back into community care and society. Interviews were completed with nurses who work with the Not Criminally Responsible patient population in an inpatient setting to discuss and explore how they use recovery-oriented practice in their practice in spite of their role in assessing and managing risk.

Keywords: forensic nursing culture, not criminally responsible, offender recovery, recovery-oriented practice, secure recovery

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1726 Measurements of Recovery Stress and Recovery Strain of Ni-Based Shape Memory Alloys

Authors: W. J. Kim

Abstract:

The behaviors of the recovery stress and strain of an ultrafine-grained Ni-50.2 at.% Ti alloy prepared by high-ratio differential speed rolling (HRDSR) were examined by a specially designed tensile-testing set up, and the factors that influence the recovery stress and strain were studied. After HRDSR, both the recovery stress and strain were enhanced compared to the initial condition. The constitutive equation showing that the maximum recovery stress is a sole function of the recovery strain was developed based on the experimental data. The recovery strain increased as the yield stress increased. The maximum recovery stress increased with an increase in yield stress. The residual recovery stress was affected by the yield stress as well as the austenite-to-martensite transformation temperature. As the yield stress increased and as the martensitic transformation temperature decreased, the residual recovery stress increased.

Keywords: high-ratio differential speed rolling, tensile testing, severe plastic deformation, shape memory alloys

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1725 Blogging Towards Recovery: The Benefits of Blogging about Recovery

Authors: Jayme R. Swanke

Abstract:

This study examined the benefits of maintaining public blogs about substance use disorder recovery. The data analyzed for this study included statements about the benefits derived by individuals who blogged about their recovery. The researcher developed classifications of statements that expressed what these individuals gained from blogging into common themes and developed an emerging theory based on these patterns. The findings indicate that these individuals in recovery benefit from blogging by developing connections, processing emotions, remaining accountable, as well as enjoying.

Keywords: substance use disorder recovery, connection, blogging, accountability, processing emotions

Procedia PDF Downloads 140
1724 Random Subspace Ensemble of CMAC Classifiers

Authors: Somaiyeh Dehghan, Mohammad Reza Kheirkhahan Haghighi

Abstract:

The rapid growth of domains that have data with a large number of features, while the number of samples is limited has caused difficulty in constructing strong classifiers. To reduce the dimensionality of the feature space becomes an essential step in classification task. Random subspace method (or attribute bagging) is an ensemble classifier that consists of several classifiers that each base learner in ensemble has subset of features. In the present paper, we introduce Random Subspace Ensemble of CMAC neural network (RSE-CMAC), each of which has training with subset of features. Then we use this model for classification task. For evaluation performance of our model, we compare it with bagging algorithm on 36 UCI datasets. The results reveal that the new model has better performance.

Keywords: classification, random subspace, ensemble, CMAC neural network

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1723 Dielectric Recovery Characteristics of High Voltage Gas Circuit Breakers Operating with CO₂ Mixture

Authors: Peng Lu, Branimir Radisavljevic, Martin Seeger, Daniel Over, Torsten Votteler, Bernardo Galletti

Abstract:

CO₂-based gas mixtures exhibit huge potential as the interruption medium for replacing SF₆ in high voltage switchgears. In this paper, the recovery characteristics of dielectric strength of CO₂-O₂ mixture in the post arc phase after the current zero are presented. As representative examples, the dielectric recovery curves under conditions of different gas filling pressures and short-circuit current amplitudes are presented. A series of dielectric recovery measurements suggests that the dielectric recovery rate is proportional to the mass flux of the blowing gas, and the dielectric strength recovers faster in the case of lower short circuit currents.

Keywords: CO₂ mixture, high voltage circuit breakers, dielectric recovery rate, short-circuit current, mass flux

Procedia PDF Downloads 163
1722 The Effect of Temperature, Contact Time and Agitation Speed During Pre-Treatment on Elution of Gold

Authors: T. P. Oladele, C. A. Snyders, S. M. Bradshaw, G. Akdogan

Abstract:

The effect of temperature, contact time and agitation during pre-treatment was investigated on the elution of gold from granular activated carbon at fixed caustic-cyanide concentration and elution conditions. It was shown that there are interactions between parameters during pre-treatment. At 80oC, recovery is independent of the contact time while the maximum recovery is obtained in the absence of agitation (0rpm). Increase in agitation speed from 0 rev/min to 1200 rev/min showed a decrease in recovery of approximately 20 percent at 80°C. Recovery with increased time from 15 minutes to 45 minutes is only pronounced at 25°C with approximately 4 percent increase at all agitation speeds. The results from elution recovery are aimed to give insight into the mechanisms of pre-treatment under the combinations of the chosen parameters.

Keywords: gold, temperature, contact time, agitation speed, recovery

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1721 Energy and Economic Analysis of Heat Recovery from Boiler Exhaust Flue Gas

Authors: Kemal Comakli, Meryem Terhan

Abstract:

In this study, the potential of heat recovery from waste flue gas was examined in 60 MW district heating system of a university, and fuel saving was aimed by using the recovered heat in the system as a source again. Various scenarios are intended to make use of waste heat. For this purpose, actual operation data of the system were taken. Besides, the heat recovery units that consist of heat exchangers such as flue gas condensers, economizers or air pre-heaters were designed theoretically for each scenario. Energy analysis of natural gas-fired boiler’s exhaust flue gas in the system, and economic analysis of heat recovery units to predict payback periods were done. According to calculation results, the waste heat loss ratio from boiler flue gas in the system was obtained as average 16%. Thanks to the heat recovery units, thermal efficiency of the system can be increased, and fuel saving can be provided. At the same time, a huge amount of green gas emission can be decreased by installing the heat recovery units.

Keywords: heat recovery from flue gas, energy analysis of flue gas, economical analysis, payback period

Procedia PDF Downloads 257
1720 Protecting the Cloud Computing Data Through the Data Backups

Authors: Abdullah Alsaeed

Abstract:

Virtualized computing and cloud computing infrastructures are no longer fuzz or marketing term. They are a core reality in today’s corporate Information Technology (IT) organizations. Hence, developing an effective and efficient methodologies for data backup and data recovery is required more than any time. The purpose of data backup and recovery techniques are to assist the organizations to strategize the business continuity and disaster recovery approaches. In order to accomplish this strategic objective, a variety of mechanism were proposed in the recent years. This research paper will explore and examine the latest techniques and solutions to provide data backup and restoration for the cloud computing platforms.

Keywords: data backup, data recovery, cloud computing, business continuity, disaster recovery, cost-effective, data encryption.

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1719 The Shape Memory Recovery Properties under Load of a Polymer Composite

Authors: Abdul Basit, Gildas Lhostis, Bernard Durand

Abstract:

Shape memory polymers (SMPs) are replacing shape memory alloys (SMAs) in many applications as SMPs have certain superior properties than SMAs. However, SMAs possess some properties like recovery under stress that SMPs lack. SMPs cannot give complete recovery even under a small load. SMPs are initially heated close to their transition temperature (glass transition temperature or the melting temperature). Then force is applied to deform the heated SMP to a specific position. Subsequently, SMP is allowed to cool keeping it deformed. After cooling, SMP gets the temporary shape. This temporary shape can be recovered by heating it again at the same temperature that was given it while heating it initially. As a result, it will recover its original position. SMP can perform unconstrained recovery and constrained recovery, however; under the load, it only recovers partially. In this work, the recovery under the load of an asymmetrical shape memory composite called as CBCM-SMPC has been investigated. It is found that it has the ability to recover under different loads. Under different loads, it shows powerful complete recovery in reference to initial position. This property can be utilized in many applications.

Keywords: shape memory, polymer composite, thermo-mechanical testing, recovery under load

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1718 Effects of the Different Recovery Durations on Some Physiological Parameters during 3 X 3 Small-Sided Games in Soccer

Authors: Samet Aktaş, Nurtekin Erkmen, Faruk Guven, Halil Taskin

Abstract:

This study aimed to determine the effects of 3 versus 3 small-sided games (SSG) with different recovery times on soma physiological parameters in soccer players. Twelve soccer players from Regional Amateur League volunteered for this study (mean±SD age, 20.50±2.43 years; height, 177.73±4.13 cm; weight, 70.83±8.38 kg). Subjects were performing soccer training for five days per week. The protocol of the study was approved by the local ethic committee in School of Physical Education and Sport, Selcuk University. The subjects were divided into teams with 3 players according to Yo-Yo Intermittent Recovery Test. The field dimension was 26 m wide and 34 m in length. Subjects performed two times in a random order a series of 3 bouts of 3-a-side SSGs with 3 min and 5 min recovery durations. In SSGs, each set were performed with 6 min duration. The percent of maximal heart rate (% HRmax), blood lactate concentration (LA) and Rated Perceived Exertion (RPE) scale points were collected before the SSGs and at the end of each set. Data were analyzed by analysis of variance (ANOVA) with repeated measures. Significant differences were found between %HRmax in before SSG and 1st set, 2nd set, and 3rd set in both SSG with 3 min recovery duration and SSG with 5 min recovery duration (p<0.05). Means of %HRmax in SSG with 3 min recovery duration at both 1st and 2nd sets were significantly higher than SSG with 5 min recovery duration (p<0.05). No significant difference was found between sets of either SSGs in terms of LA (p>0.05). LA in SSG with 3 min recovery duration was higher than SSG with 5 min recovery duration at 2nd sets (p<0.05). RPE in soccer players was not different between SSGs (p>0.05).In conclusion, this study demonstrates that exercise intensity in SSG with 3 min recovery durations is higher than SSG with 5 min recovery durations.

Keywords: small-sided games, soccer, heart rate, lactate

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1717 Studies on Mechanical Behavior of Kevlar/Kenaf/Graphene Reinforced Polymer Based Hybrid Composites

Authors: H. K. Shivanand, Ranjith R. Hombal, Paraveej Shirahatti, Gujjalla Anil Babu, S. ShivaPrakash

Abstract:

When it comes to the selection of materials the knowledge of materials science plays a vital role in selection and enhancements of materials properties. In the world of material science a composite material has the significant role based on its application. The composite materials are those in which two or more components having different physical and chemical properties are combined to create a new enhanced property substance. In this study three different materials (Kenaf, Kevlar and Graphene) been chosen based on their properties and a composite material is developed with help of vacuum bagging process. The fibers (Kenaf and Kevlar) and Resin(vinyl ester) ratio was maintained at 70:30 during the process and 0.5% 1% and 1.5% of Graphene was added during fabrication process. The material was machined to thedimension ofASTM standards(300×300mm and thickness 3mm)with help of water jet cutting machine. The composite materials were tested for Mechanical properties such as Interlaminar shear strength(ILSS) and Flexural strength. It is found that there is significant increase in material properties in the developed composite material.

Keywords: Kevlar, Kenaf, graphene, vacuum bagging process, Interlaminar shear strength test, flexural test

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1716 Influence of Measurement System on Negative Bias Temperature Instability Characterization: Fast BTI vs Conventional BTI vs Fast Wafer Level Reliability

Authors: Vincent King Soon Wong, Hong Seng Ng, Florinna Sim

Abstract:

Negative Bias Temperature Instability (NBTI) is one of the critical degradation mechanisms in semiconductor device reliability that causes shift in the threshold voltage (Vth). However, thorough understanding of this reliability failure mechanism is still unachievable due to a recovery characteristic known as NBTI recovery. This paper will demonstrate the severity of NBTI recovery as well as one of the effective methods used to mitigate, which is the minimization of measurement system delays. Comparison was done in between two measurement systems that have significant differences in measurement delays to show how NBTI recovery causes result deviations and how fast measurement systems can mitigate NBTI recovery. Another method to minimize NBTI recovery without the influence of measurement system known as Fast Wafer Level Reliability (FWLR) NBTI was also done to be used as reference.

Keywords: fast vs slow BTI, fast wafer level reliability (FWLR), negative bias temperature instability (NBTI), NBTI measurement system, metal-oxide-semiconductor field-effect transistor (MOSFET), NBTI recovery, reliability

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1715 Use of Microbial Fuel Cell for Metal Recovery from Wastewater

Authors: Surajbhan Sevda

Abstract:

Metal containing wastewater is generated in large quintiles due to rapid industrialization. Generally, the metal present in wastewater is not biodegradable and can be accumulated in living animals, humans and plant tissue, causing disorder and diseases. The conventional metal recovery methods include chemical, physical and biological methods, but these are chemical and energy intensive. The recent development in microbial fuel cell (MFC) technology provides a new approach for metal recovery; this technology offers a flexible platform for both reduction and oxidation reaction oriented process. The use of MFCs will be a new platform for more efficient and low energy approach for metal recovery from the wastewater. So far metal recover was extensively studied using chemical, physical and biological methods. The MFCs present a new and efficient approach for removing and recovering metals from different wastewater, suggesting the use of different electrode for metal recovery can be a new efficient and effective approach.

Keywords: metal recovery, microbial fuel cell, wastewater, bioelectricity

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1714 Metrics and Methods for Improving Resilience in Agribusiness Supply Chains

Authors: Golnar Behzadi, Michael O'Sullivan, Tava Olsen, Abraham Zhang

Abstract:

By definition, increasing supply chain resilience improves the supply chain’s ability to return to normal, or to an even more desirable situation, quickly and efficiently after being hit by a disruption. This is especially critical in agribusiness supply chains where the products are perishable and have a short life-cycle. In this paper, we propose a resilience metric to capture and improve the recovery process in terms of both performance and time, of an agribusiness supply chain following either supply or demand-side disruption. We build a model that determines optimal supply chain recovery planning decisions and selects the best resilient strategies that minimize the loss of profit during the recovery time window. The model is formulated as a two-stage stochastic mixed-integer linear programming problem and solved with a branch-and-cut algorithm. The results show that the optimal recovery schedule is highly dependent on the duration of the time-window allowed for recovery. In addition, the profit loss during recovery is reduced by utilizing the proposed resilient actions.

Keywords: agribusiness supply chain, recovery, resilience metric, risk management

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1713 Oil Recovery Study by Low Temperature Carbon Dioxide Injection in High-Pressure High-Temperature Micromodels

Authors: Zakaria Hamdi, Mariyamni Awang

Abstract:

For the past decades, CO2 flooding has been used as a successful method for enhanced oil recovery (EOR). However, high mobility ratio and fingering effect are considered as important drawbacka of this process. Low temperature injection of CO2 into high temperature reservoirs may improve the oil recovery, but simulating multiphase flow in the non-isothermal medium is difficult, and commercial simulators are very unstable in these conditions. Furthermore, to best of authors’ knowledge, no experimental work was done to verify the results of the simulations and to understand the pore-scale process. In this paper, we present results of investigations on injection of low temperature CO2 into a high-pressure high-temperature micromodel with injection temperature range from 34 to 75 °F. Effect of temperature and saturation changes of different fluids are measured in each case. The results prove the proposed method. The injection of CO2 at low temperatures increased the oil recovery in high temperature reservoirs significantly. Also, CO2 rich phases available in the high temperature system can affect the oil recovery through the better sweep of the oil which is initially caused by penetration of LCO2 inside the system. Furthermore, no unfavorable effect was detected using this method. Low temperature CO2 is proposed to be used as early as secondary recovery.

Keywords: enhanced oil recovery, CO₂ flooding, micromodel studies, miscible flooding

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1712 Surfactant Improved Heavy Oil Recovery in Sandstone Reservoirs by Wettability Alteration

Authors: Rabia Hunky, Hayat Kalifa, Bai

Abstract:

The wettability of carbonate reservoirs has been widely recognized as an important parameter in oil recovery by flooding technology. Many surfactants have been studied for this application. However, the importance of wettability alteration in sandstone reservoirs by surfactant has been poorly studied. In this paper, our recent study of the relationship between rock surface wettability and cumulative oil recovery for sandstone cores is reported. In our research, it has been found there is a good agreement between the wettability and oil recovery. Nonionic surfactants, Tomadol® 25-12 and Tomadol® 45-13, are very effective in wettability alteration of sandstone core surface from highly oil-wet conditions to water-wet conditions. By spontaneous imbibition test, Interfacial tension, and contact angle measurement these two surfactants exhibit the highest recovery of the synthetic oil made with heavy oil. Based on these experimental results, we can further conclude that the contact angle measurement and imbibition test can be used as rapid screening tools to identify better EOR surfactants to increase heavy oil recovery from sandstone reservoirs.

Keywords: EOR, oil gas, IOR, WC, IF, oil and gas

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1711 Simulation of Utility Accrual Scheduling and Recovery Algorithm in Multiprocessor Environment

Authors: A. Idawaty, O. Mohamed, A. Z. Zuriati

Abstract:

This paper presents the development of an event based Discrete Event Simulation (DES) for a recovery algorithm known Backward Recovery Global Preemptive Utility Accrual Scheduling (BR_GPUAS). This algorithm implements the Backward Recovery (BR) mechanism as a fault recovery solution under the existing Time/Utility Function/ Utility Accrual (TUF/UA) scheduling domain for multiprocessor environment. The BR mechanism attempts to take the faulty tasks back to its initial safe state and then proceeds to re-execute the affected section of the faulty tasks to enable recovery. Considering that faults may occur in the components of any system; a fault tolerance system that can nullify the erroneous effect is necessary to be developed. Current TUF/UA scheduling algorithm uses the abortion recovery mechanism and it simply aborts the erroneous task as their fault recovery solution. None of the existing algorithm in TUF/UA scheduling domain in multiprocessor scheduling environment have considered the transient fault and implement the BR mechanism as a fault recovery mechanism to nullify the erroneous effect and solve the recovery problem in this domain. The developed BR_GPUAS simulator has derived the set of parameter, events and performance metrics according to a detailed analysis of the base model. Simulation results revealed that BR_GPUAS algorithm can saved almost 20-30% of the accumulated utilities making it reliable and efficient for the real-time application in the multiprocessor scheduling environment.

Keywords: real-time system (RTS), time utility function/ utility accrual (TUF/UA) scheduling, backward recovery mechanism, multiprocessor, discrete event simulation (DES)

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1710 Evaluating the effects of Gas Injection on Enhanced Gas-Condensate Recovery and Reservoir Pressure Maintenance

Authors: F. S. Alavi, D. Mowla, F. Esmaeilzadeh

Abstract:

In this paper, the Eclipse 300 simulator was used to perform compositional modeling of gas injection process for enhanced condensate recovery of a real gas condensate well in south of Iran here referred to as SA4. Some experimental data were used to tune the Peng-Robinson equation of state for this case. Different scenarios of gas injection at current reservoir pressure and at abandonment reservoir pressure had been considered with different gas compositions. Methane, carbon dioxide, nitrogen and two other gases with specified compositions were considered as potential gases for injection. According to the obtained results, nitrogen leads to highest pressure maintenance in the reservoir but methane results in highest condensate recovery among the selected injection gases. At low injection rates, condensate recovery percent is strongly affected by gas injection rate but this dependency shifts to zero at high injection rates. Condensate recovery is higher in all cases of injection at current reservoir pressure than injection at abandonment pressure. Using a constant injection rate, increasing the production well bottom hole pressure results in increasing the condensate recovery percent and time of gas breakthrough.

Keywords: gas-condensate reservoir, case-study, compositional modelling, enhanced condensate recovery, gas injection

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1709 Recovery of Petroleum Reservoir by Waterflooding Technique

Authors: Zabihullah Mahdi, Khwaja Naweed Seddiqi, Shigeo Honma

Abstract:

Through many types of research and practical studies, it has been identified that the average oil recovery factor of a petroleum reservoir is about 30 to 35 %. This study is focused on enhanced oil recovery by laboratory experiment and graphical investigation based on Buckley-Leverett theory. Horizontal oil displacement by water, in a petroleum reservoir is analyzed under the Buckley-Leverett frontal displacement theory. The extraction and prerequisite of this theory are based and pursued focusing on the key factors that control displacement. The theory is executable to the waterflooding method, which is generally employed in petroleum engineering reservoirs to sustain oil production recovery, and the techniques for evaluating the average water saturation behind the water front and the oil recovery factors in the reservoirs are presented. In this paper, the Buckley-Leverett theory handled to an experimental model and the amount of recoverable oil are investigated to be over 35%. The irreducible water saturation, viz. connate water saturation, in the reservoir is also a significant inspiration for the recovery.

Keywords: Buckley-Leverett theory, waterflooding technique, petroleum engineering, immiscible displacement

Procedia PDF Downloads 216
1708 Ultrasound Assisted Cooling Crystallization of Lactose Monohydrate

Authors: Sanjaykumar R. Patel, Parth R. Kayastha

Abstract:

α-lactose monohydrate is widely used in the pharmaceutical industries as an inactive substance that acts as a vehicle or a medium for a drug or other active substance. It is a byproduct of dairy industries, and the recovery of lactose from whey not only boosts the improvement of the economics of whey utilization but also causes a reduction in pollution as lactose recovery can reduce the BOD of whey by more than 80%. In the present study, levels of process parameters were kept as initial lactose concentration (30-50% w/w), sonication amplitude (20-40%), sonication time (2-6 hours), and crystallization temperature (10-20 oC) for the recovery of lactose in ultrasound assisted cooling crystallization. In comparison with cooling crystallization, the use of ultrasound enhanced the lactose recovery by 39.17% (w/w). The parameters were optimized for the lactose recovery using Taguchi Method. The optimum conditions found were initial lactose concentration at level 3 (50% w/w), amplitude of sonication at level 2 (40%), the sonication time at level 3 (6 hours), and crystallization temperature at level 1 (10 °C). The maximum recovery was found to be 85.85% at the optimum conditions. Sonication time and the initial lactose concentration were found to be significant parameters for the lactose recovery.

Keywords: crystallization, lactose, Taguchi method, ultrasound

Procedia PDF Downloads 180
1707 Hydrogen Peroxide: A Future for Well Stimulation and Heavy Oil Recovery

Authors: Meet Bhatia

Abstract:

Well stimulation and heavy oil recovery continue to be a hot topic in our industry, particularly with formation damage and viscous oil respectively. Cyclic steam injection has been recognised for most of the operations related to heavy oil recovery. However, the cost of implementation is high and operation is time-consuming, moreover most of the viscous oil reservoirs such as oil sands, Bitumen deposits and oil shales require additional treatment of well stimulation. The use of hydrogen peroxide can efficiently replace the cyclic steam injection process as it can be used for both well stimulation and heavy oil recovery simultaneously. The decomposition of Hydrogen peroxide produces oxygen, superheated steam and heat. The increase in temperature causes clays to shrink, destroy carbonates and remove emulsion thus it can efficiently remove the near wellbore damage. The paper includes mechanisms, parameters to be considered and the challenges during the treatment for the effective hydrogen peroxide injection for both conventional and heavy oil reservoirs.

Keywords: hydrogen peroxide, well stimulation, heavy oil recovery, steam injection

Procedia PDF Downloads 304