Processes

21 pages, 4674 KiB

Open AccessArticle

A Blended Risk Index Modeling and Visualization Based on Hierarchical Fuzzy Logic for Water Supply Pipelines Assessment and Management

by Muhammad Fayaz, Shabir Ahmad, Israr Ullah and DoHyeun Kim

Processes 2018, 6(5), 61; https://doi.org/10.3390/pr6050061 - 22 May 2018

Cited by 19 | Viewed by 6522

Abstract

Critical infrastructure such as power and water delivery is growing rapidly in the developing world and there are developed assets that must be maintained in developed nations. One underground component that is difficult to inspect is water supply pipelines. Most of the water [...] Read more.

Critical infrastructure such as power and water delivery is growing rapidly in the developing world and there are developed assets that must be maintained in developed nations. One underground component that is difficult to inspect is water supply pipelines. Most of the water line accidents occur in buildings is due to pipeline damage. To minimize accidental loss, a risk assessment method is needed to continuously assess risk and report any abnormality for preventative maintenance. In this work, a blended hierarchical fuzzy logic model for water supply pipeline risk index assessment is proposed. Four important parameters are inputs to the proposed blended hierarchical fuzzy logic model. The blended hierarchical fuzzy logic model dramatically reduces the number of conditions in the rule base. Rule reduction is important because the transparency and interpretation are compromised by an overly large set. Further, it is challenging to accurately design a large number of rules because rule design requires expert knowledge and uncertainty in predictions can lead to unforeseen incidents. A blended hierarchical fuzzy model is designed with a structure that takes fewer rules as compared to conventional fuzzy logic. For the four parameters, the proposed model takes 85 rules and for the same four parameters, the conventional fuzzy logic approach requires 900 rules. In this paper, four parameters are considered because these are available measurements. The proposed reduction method is also applicable for systems with more parameters. The numbers of rules increase exponentially in the conventional fuzzy logic as new parameters enter into the system. The blended hierarchical fuzzy logic is deployed on a water distribution network to compute the risk index of supply pipelines. The results indicate improved performance of the blended hierarchical fuzzy logic. This approach is usable in practical applications where the calculated risk index values of the water supply pipeline are plotted on a geographic information system (GIS) map to provide a graphical interface for the caretaker. The risk index visualization is necessary to trace the risk index location and to take preemptive measures to avoid failures. Full article

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22 pages, 714 KiB

Open AccessFeature PaperArticle

EPO Dosage Optimization for Anemia Management: Stochastic Control under Uncertainty Using Conditional Value at Risk

by Jayson McAllister, Zukui Li, Jinfeng Liu and Ulrich Simonsmeier

Processes 2018, 6(5), 60; https://doi.org/10.3390/pr6050060 - 21 May 2018

Cited by 1 | Viewed by 4617

Abstract

Due to insufficient endogenous production of erythropoietin, chronic kidney disease patients with anemia are often treated by the administration of recombinant human erythropoietin (EPO). The target of the treatment is to keep the patient’s hemoglobin level within a normal range. While conventional methods [...] Read more.

Due to insufficient endogenous production of erythropoietin, chronic kidney disease patients with anemia are often treated by the administration of recombinant human erythropoietin (EPO). The target of the treatment is to keep the patient’s hemoglobin level within a normal range. While conventional methods for guiding EPO dosing used by clinicians normally rely on a set of rules based on past experiences or retrospective studies, model predictive control (MPC) based dosage optimization is receiving attention recently. The objective of this paper is to incorporate the hemoglobin response model uncertainty into the dosage optimization decision making. Two methods utilizing Conditional Value at Risk (CVaR) are proposed for hemoglobin control in chronic kidney disease under model uncertainty. The first method includes a set-point tracking controller with the addition of CVaR constraints. The second method involves the use of CVaR directly in the cost function of the optimal control problem. The methods are compared to set-point tracking MPC and Zone-tracking MPC through computer simulations. Simulation results demonstrate the benefits of utilizing CVaR in stochastic predictive control for EPO dosage optimization. Full article

(This article belongs to the Special Issue Modeling & Control of Disease States)

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14 pages, 5386 KiB

Open AccessArticle

A Facile Synthesis of Hexagonal Spinel λ-MnO₂ Ion-Sieves for Highly Selective Li⁺ Adsorption

by Fan Yang, Sichong Chen, Chentao Shi, Feng Xue, Xiaoxian Zhang, Shengui Ju and Weihong Xing

Processes 2018, 6(5), 59; https://doi.org/10.3390/pr6050059 - 17 May 2018

Cited by 32 | Viewed by 6928

Abstract

Ion-sieves are a class of green adsorbent for extraction Li⁺ from salt lakes. Here, we propose a facile synthesis of hexagonal spinel LiMn₂O₄ (LMO) precursor under mild condition which was first prepared via a modified one-pot reduction hydrothermal method [...] Read more.

Ion-sieves are a class of green adsorbent for extraction Li⁺ from salt lakes. Here, we propose a facile synthesis of hexagonal spinel LiMn₂O₄ (LMO) precursor under mild condition which was first prepared via a modified one-pot reduction hydrothermal method using KMnO₄ and ethanol. Subsequently, the stable spinel structured λ-MnO₂ (HMO) were prepared by acidification of LMO. The as-prepared HMO shows a unique hexagonal shape and can be used for rapid adsorption-desorption process for Li⁺ adsorption. It was found that Li⁺ adsorption capacity of HMO was 24.7 mg·g⁻¹ in Li⁺ solution and the HMO also has a stable structure with manganese dissolution loss ratio of 3.9% during desorption process. Moreover, the lithium selectivity

(α_{Mg}^{Li})

reaches to 1.35 × 10³ in brine and the distribution coefficients (

K_{d}

) of Li⁺ is much greater than that of Mg²⁺. The results implied that HMO can be used in extract lithium from brine or seawater containing high ratio of magnesium and lithium. Full article

(This article belongs to the Special Issue Transport of Fluids in Nanoporous Materials)

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16 pages, 6176 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Mathematical Modeling of Metastatic Cancer Migration through a Remodeling Extracellular Matrix

by Yen T. Nguyen Edalgo and Ashlee N. Ford Versypt

Processes 2018, 6(5), 58; https://doi.org/10.3390/pr6050058 - 16 May 2018

Cited by 15 | Viewed by 8731

Abstract

The spreading of cancer cells, also known as metastasis, is a lethal hallmark in cancer progression and the primary cause of cancer death. Recent cancer research has suggested that the remodeling of collagen fibers in the extracellular matrix (ECM) of the tumor microenvironment [...] Read more.

The spreading of cancer cells, also known as metastasis, is a lethal hallmark in cancer progression and the primary cause of cancer death. Recent cancer research has suggested that the remodeling of collagen fibers in the extracellular matrix (ECM) of the tumor microenvironment facilitates the migration of cancer cells during metastasis. ECM remodeling refers to the following two procedures: the ECM degradation caused by enzyme matrix metalloproteinases and the ECM alignment due to the cross-linking enzyme lysyl oxidase (LOX). Such modifications of ECM collagen fibers result in changes of ECM physical and biomechanical properties that affect cancer cell migration through the ECM. However, the mechanism of such cancer migration through a remodeling ECM remains not well understood. A mathematical model is proposed in this work to better describe and understand cancer migration by means of ECM remodeling. Effects of LOX are considered to enable transport of enzymes and migration of cells through a dynamic, reactive tumor microenvironment that is modulated during cell migration. For validation cases, the results obtained show comparable trends to previously established models. In novel test cases, the model predicts the impact on ECM remodeling and the overall migration of cancer cells due to the inclusion of LOX, which has not yet been included in previous cancer invasion models. Full article

(This article belongs to the Special Issue Modeling & Control of Disease States)

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17 pages, 1738 KiB

Open AccessArticle

Impact of Metaheuristic Iteration on Artificial Neural Network Structure in Medical Data

by Ihsan Salman, Osman N. Ucan, Oguz Bayat and Khalid Shaker

Processes 2018, 6(5), 57; https://doi.org/10.3390/pr6050057 - 16 May 2018

Cited by 24 | Viewed by 6081

Abstract

Medical data classification is an important factor in improving diagnosis and treatment and can assist physicians in making decisions about serious diseases by collecting symptoms and medical analyses. In this work, hybrid classification optimization methods such as Genetic Algorithm (GA), Particle Swam Optimization [...] Read more.

Medical data classification is an important factor in improving diagnosis and treatment and can assist physicians in making decisions about serious diseases by collecting symptoms and medical analyses. In this work, hybrid classification optimization methods such as Genetic Algorithm (GA), Particle Swam Optimization (PSO), and Fireworks Algorithm (FWA), are proposed for enhancing the classification accuracy of the Artificial Neural Network (ANN). The enhancement process is tested through two experiments. First, the proposed algorithms are applied on five benchmark medical data sets from the repository of the University of California in Irvine (UCI). The model with the best results is then used in the second experiment, which focuses on tuning the parameters of the selected algorithm by choosing a different number of iterations in ANNs with different numbers of hidden layers. Enhanced ANN with the three optimization algorithms are tested on biological gene sequence big dataset obtained from The Cancer Genome Atlas (TCGA) repository. GA and FWA are statistically significant but PSO was statistically not, and GA overcame PSO and FWA in performance. The methodology is successful and registers improvements in every step, as significant results are obtained. Full article

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23 pages, 1248 KiB

Open AccessFeature PaperEditor’s ChoiceReview

The Spectrum of Mechanism-Oriented Models and Methods for Explanations of Biological Phenomena

by C. Anthony Hunt, Ahmet Erdemir, William W. Lytton, Feilim Mac Gabhann, Edward A. Sander, Mark K. Transtrum and Lealem Mulugeta

Processes 2018, 6(5), 56; https://doi.org/10.3390/pr6050056 - 14 May 2018

Cited by 15 | Viewed by 5984

Abstract

Developing and improving mechanism-oriented computational models to better explain biological phenomena is a dynamic and expanding frontier. As the complexity of targeted phenomena has increased, so too has the diversity in methods and terminologies, often at the expense of clarity, which can make [...] Read more.

Developing and improving mechanism-oriented computational models to better explain biological phenomena is a dynamic and expanding frontier. As the complexity of targeted phenomena has increased, so too has the diversity in methods and terminologies, often at the expense of clarity, which can make reproduction challenging, even problematic. To encourage improved semantic and methodological clarity, we describe the spectrum of Mechanism-oriented Models being used to develop explanations of biological phenomena. We cluster explanations of phenomena into three broad groups. We then expand them into seven workflow-related model types having distinguishable features. We name each type and illustrate with examples drawn from the literature. These model types may contribute to the foundation of an ontology of mechanism-based biomedical simulation research. We show that the different model types manifest and exert their scientific usefulness by enhancing and extending different forms and degrees of explanation. The process starts with knowledge about the phenomenon and continues with explanatory and mathematical descriptions. Those descriptions are transformed into software and used to perform experimental explorations by running and examining simulation output. The credibility of inferences is thus linked to having easy access to the scientific and technical provenance from each workflow stage. Full article

(This article belongs to the Special Issue Methods in Computational Biology)

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15 pages, 2875 KiB

Open AccessReview

A Review on the Separation of Lithium Ion from Leach Liquors of Primary and Secondary Resources by Solvent Extraction with Commercial Extractants

by Thi Hong Nguyen and Man Seung Lee

Processes 2018, 6(5), 55; https://doi.org/10.3390/pr6050055 - 12 May 2018

Cited by 66 | Viewed by 12637

Abstract

The growing demand for lithium necessitates the development of an efficient process to recover it from three kinds of solutions, namely brines as well as acid and alkaline leach liquors of primary and secondary resources. Therefore, the separation of lithium(I) from these solutions [...] Read more.

The growing demand for lithium necessitates the development of an efficient process to recover it from three kinds of solutions, namely brines as well as acid and alkaline leach liquors of primary and secondary resources. Therefore, the separation of lithium(I) from these solutions by solvent extraction was reviewed in this paper. Lithium ions in brines are concentrated by removing other metal salts by crystallization with solar evaporation. In the case of ores and secondary resources, roasting followed by acid/alkaline leaching is generally employed to dissolve the lithium. Since the compositions of brines, alkaline and acid solutions are different, different commercial extractants are employed to separate and recover lithium. The selective extraction of Li(I) over other metals from brines or alkaline solutions is accomplished using acidic extractants, their mixture with neutral extractants, and neutral extractants mixed with chelating extractants in the presence of ferric chloride (FeCl₃). Among these systems, tri-n-butyl phosphate (TBP)- methyl isobutyl ketone (MIBK)-FeCl₃ and tri-n-octyl phosphine oxide (TOPO)- benzoyltrifluoroacetone (HBTA) are considered to be promising for the selective extraction and recovery of Li(I) from brines and alkaline solutions. By contrast, in the acid leaching solutions of secondary resources, divalent and trivalent metal cations are selectively extracted by acidic extractants, leaving Li(I) in the raffinate. Therefore, bis-2,4,4-trimethyl pentyl phosphinic acid (Cyanex 272) and its mixtures are suggested for the extraction of metal ions other than Li(I). Full article

(This article belongs to the Special Issue Transport of Fluids in Nanoporous Materials)

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14 pages, 2171 KiB

Open AccessArticle

Synthesis and Characterization of Ampholytic Flocculant CPCTS-g-P (CTA-DMDAAC) and Its Flocculation Properties for Microcystis Aeruginosa Removal

by Lei Chen, Cuiyun Liu, Yongjun Sun, Wenquan Sun, Yanhua Xu and Huaili Zheng

Processes 2018, 6(5), 54; https://doi.org/10.3390/pr6050054 - 11 May 2018

Cited by 15 | Viewed by 4690

Abstract

The ampholytic chitosan based flocculant carboxylated chitosan graft-(3-chloro-2-hydroxypropyl) trimethylammonium chloride-dimethyl diallyl ammonium chloride (CPCTS-g-P (CTA-DMDAAC)) was synthesized by photo polymerization using carboxylated chitosan (CPCTS), 3-chloro-2-chloropropyltrimethylammonium chloride (CTA) and dimethyldiallylammonium chloride (DMDAAC) as the cationic co-monomers. The effects of monomer concentration, the ratio of [...] Read more.

The ampholytic chitosan based flocculant carboxylated chitosan graft-(3-chloro-2-hydroxypropyl) trimethylammonium chloride-dimethyl diallyl ammonium chloride (CPCTS-g-P (CTA-DMDAAC)) was synthesized by photo polymerization using carboxylated chitosan (CPCTS), 3-chloro-2-chloropropyltrimethylammonium chloride (CTA) and dimethyldiallylammonium chloride (DMDAAC) as the cationic co-monomers. The effects of monomer concentration, the ratio of CPCTS and cationic monomers, cationic degree, initiator time, photoinitiator concentration, and pH value on the properties of CPCTS-g-P (CTA-DMDAAC) were studied. The microcystis aeruginosa that was cultured in laboratory was used for CPCTS-g-P (CTA-DMDAAC) flocculation tests. The effects of CPCTS-g-P (CTA-DMDAAC) dosage, pH value and G value on flocculation performance were investigated. The maximum removal rate of chlorophyll-a (Chl-a) and chemical oxygen demand (COD) that were obtained by CPCTS-g-P (CTA-DMDAAC) were 98.8% and 96.5% under the conditions of dosage 4 mg/L, pH 7 and G value 200 s⁻¹, respectively. The flocculation experiments showed that chitosan-based flocculant CPCTS-g-P (CTA-DMDAAC) had better flocculation performance than commercially available flocculants cationic polyacrylamide (CPAM), Polyferric Sulfate (PFS), and polymeric aluminium (PAC). Full article

(This article belongs to the Special Issue Wastewater Treatment Processes)

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21 pages, 7799 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

A Systematic Framework for Data Management and Integration in a Continuous Pharmaceutical Manufacturing Processing Line

by Huiyi Cao, Srinivas Mushnoori, Barry Higgins, Chandrasekhar Kollipara, Adam Fermier, Douglas Hausner, Shantenu Jha, Ravendra Singh, Marianthi Ierapetritou and Rohit Ramachandran

Processes 2018, 6(5), 53; https://doi.org/10.3390/pr6050053 - 10 May 2018

Cited by 19 | Viewed by 11110

Abstract

As the pharmaceutical industry seeks more efficient methods for the production of higher value therapeutics, the associated data analysis, data visualization, and predictive modeling require dependable data origination, management, transfer, and integration. As a result, the management and integration of data in a [...] Read more.

As the pharmaceutical industry seeks more efficient methods for the production of higher value therapeutics, the associated data analysis, data visualization, and predictive modeling require dependable data origination, management, transfer, and integration. As a result, the management and integration of data in a consistent, organized, and reliable manner is a big challenge for the pharmaceutical industry. In this work, an ontological information infrastructure is developed to integrate data within manufacturing plants and analytical laboratories. The ANSI/ISA-88.01 batch control standard has been adapted in this study to deliver a well-defined data structure that will improve the data communication inside the system architecture for continuous processing. All the detailed information of the lab-based experiment and process manufacturing, including equipment, samples and parameters, are documented in the recipe. This recipe model is implemented into a process control system (PCS), data historian, as well as Electronic Laboratory Notebook (ELN) system. Data existing in the recipe can be eventually exported from this system to cloud storage, which could provide a reliable and consistent data source for data visualization, data analysis, or process modeling. Full article

(This article belongs to the Special Issue Feature Papers for the Fifth Year Anniversary of the Founding of Processes)

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26 pages, 4834 KiB

Open AccessFeature PaperArticle

An Integrated Approach to Water-Energy Nexus in Shale-Gas Production

by Fadhil Y. Al-Aboosi and Mahmoud M. El-Halwagi

Processes 2018, 6(5), 52; https://doi.org/10.3390/pr6050052 - 08 May 2018

Cited by 32 | Viewed by 6844

Abstract

Shale gas production is associated with significant usage of fresh water and discharge of wastewater. Consequently, there is a necessity to create proper management strategies for water resources in shale gas production and to integrate conventional energy sources (e.g., shale gas) with renewables [...] Read more.

Shale gas production is associated with significant usage of fresh water and discharge of wastewater. Consequently, there is a necessity to create proper management strategies for water resources in shale gas production and to integrate conventional energy sources (e.g., shale gas) with renewables (e.g., solar energy). The objective of this study is to develop a design framework for integrating water and energy systems including multiple energy sources, the cogeneration process and desalination technologies in treating wastewater and providing fresh water for shale gas production. Solar energy is included to provide thermal power directly to a multi-effect distillation plant (MED) exclusively (to be more feasible economically) or indirect supply through a thermal energy storage system. Thus, MED is driven by direct or indirect solar energy and excess or direct cogeneration process heat. The proposed thermal energy storage along with the fossil fuel boiler will allow for the dual-purpose system to operate at steady-state by managing the dynamic variability of solar energy. Additionally, electric production is considered to supply a reverse osmosis plant (RO) without connecting to the local electric grid. A multi-period mixed integer nonlinear program (MINLP) is developed and applied to discretize the operation period to track the diurnal fluctuations of solar energy. The solution of the optimization program determines the optimal mix of solar energy, thermal storage and fossil fuel to attain the maximum annual profit of the entire system. A case study is solved for water treatment and energy management for Eagle Ford Basin in Texas. Full article

(This article belongs to the Special Issue Modeling and Simulation of Energy Systems)

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14 pages, 31348 KiB

Open AccessArticle

Key Parameters of Gob-Side Entry Retaining in A Gassy and Thin Coal Seam with Hard Roof

by Shuai Yan, Tianxiao Liu, Jianbiao Bai and Wenda Wu

Processes 2018, 6(5), 51; https://doi.org/10.3390/pr6050051 - 07 May 2018

Cited by 30 | Viewed by 3848

Abstract

Gob-side entry retaining (GER) employed in a thin coal seam (TCS) can increase economic benefits and coal recovery, as well as mitigate gas concentration in the gob. In accordance with the caving style of a limestone roof, the gas concentration and air pressure [...] Read more.

Gob-side entry retaining (GER) employed in a thin coal seam (TCS) can increase economic benefits and coal recovery, as well as mitigate gas concentration in the gob. In accordance with the caving style of a limestone roof, the gas concentration and air pressure in the gob were analyzed, and a roof-cutting mechanical model of GER with a roadside backfill body (RBB) was proposed, to determine the key parameters of the GER-TCS, including the roof-cutting resistance and the width of the RBB. The results show that if the immediate roof height is greater than the seam height, the roof-cutting resistance and width of the RBB should meet the requirement of the immediate roof being totally cut along the gob, for which the optimal roof-cutting resistance and width of RBB were determined by analytical and numerical methods. The greater the RBB width, the greater its roof-cutting resistance. The relationship between the supporting strength of the RBB and the width of the RBB can be derived as a composite curve. The floor heave of GER increases with increasing RBB width. When the width of the RBB increased from 0.8 m to 1.2 m, the floor heave increased two-fold to 146.2 mm. GER was applied in a TCS with a limestone roof of 5 m thickness; the field-measured data verified the conclusions of the numerical model. Full article

(This article belongs to the Special Issue Fluid Flow in Fractured Porous Media)

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17 pages, 2884 KiB

Open AccessArticle

Membrane Fouling Characteristics of a Side-Stream Tubular Anaerobic Membrane Bioreactor (AnMBR) Treating Domestic Wastewater

by Nsanzumukiza Martin Vincent, Juan Tong, Dawei Yu, Junya Zhang and Yuansong Wei

Processes 2018, 6(5), 50; https://doi.org/10.3390/pr6050050 - 05 May 2018

Cited by 30 | Viewed by 6127

Abstract

A lab-scale of a side stream anaerobic membrane bioreactor (AnMBR) equipped with a tubular membrane operated at the mesophilic temperature of 37.0 ± 1.2 °C for treating domestic wastewater was tested to investigate its performance and fouling characteristics at two organic loading rates [...] Read more.

A lab-scale of a side stream anaerobic membrane bioreactor (AnMBR) equipped with a tubular membrane operated at the mesophilic temperature of 37.0 ± 1.2 °C for treating domestic wastewater was tested to investigate its performance and fouling characteristics at two organic loading rates (OLR) of 0.25 kg COD m⁻³d⁻¹, and 0.70 kg COD m⁻³d⁻¹, respectively. The AnMBR was operated for 600 days at sludge retention time (SRT) of 100 days. This AnMBR exhibits excellent chemical oxygen demand (COD) removal of 91% at 0.25 kg COD m⁻³d⁻¹, and 94% at 0.7 kg COD m⁻³d⁻¹ respectively, with effluent-soluble COD below 50 mg/L. Chemically-enhanced cleaning method using NaOH, NaOCl, and citric acid solution were introduced for fouling investigation at these two stages. The results showed that sequential chemical cleaning of alkaline and acid were most effective to recover the membrane flux. The alkaline cleaning was effective at removing organic foulants, while citric acid cleaning was effective at removing the scalants. The analyses of the excitation emission matrix, gel permeation chromatography, and extracellular polymeric substances indicated that major components of membrane foulants were proteins, carbohydrates, humic, and fulvic acids. At 0.25 kg COD m⁻³d⁻¹, organic fouling was more prone to be trapped in the cake layers and responsible for membrane pore blockage, inorganic fouling exhibited marginal contribution to the membrane fouling behavior. However, at 0.70 kg COD m⁻³d⁻¹, high concentrations of organic and inorganic foulants supported an essential role of organic and inorganic fouling on membrane fouling behavior. Full article

(This article belongs to the Special Issue Membrane Materials, Performance and Processes)

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13 pages, 3182 KiB

Open AccessArticle

The Effect of Joint Dip Angle on the Mechanical Behavior of Infilled Jointed Rock Masses under Uniaxial and Biaxial Compressions

by Guansheng Han, Hongwen Jing, Yujing Jiang, Richeng Liu, Haijian Su and Jiangyu Wu

Processes 2018, 6(5), 49; https://doi.org/10.3390/pr6050049 - 03 May 2018

Cited by 21 | Viewed by 4635

Abstract

Due to the complex formation process of a rock mass, a large number of fissures, joints, faults, other defects exist and the defects commonly contain infilled materials. The jointed rock masses are in a complex geological environment, in which the geometric distribution and [...] Read more.

Due to the complex formation process of a rock mass, a large number of fissures, joints, faults, other defects exist and the defects commonly contain infilled materials. The jointed rock masses are in a complex geological environment, in which the geometric distribution and the boundary condition can greatly affect the mechanical behavior of the infilled jointed rock mass. In this study, the infilled jointed rock mass specimens with different dip angles are prepared using similar materials, and the uniaxial and biaxial compression tests on the specimens are conducted. The effect of the joint dip angle on the mechanical behavior of the infilled jointed rock mass under uniaxial and biaxial compressions is investigated. The results show that the uniaxial compressive strength shows a W-shaped variation, and the biaxial compressive strength shows a V-shaped variation with an increase in the dip angle. Most of the cracks appear in pairs around the joint and occur symmetrically in a bilateral distribution, and the existence of the infilled joints induces a nonlinear mechanical behavior in the specimen. In addition, the specimens exhibit three failure modes under uniaxial compression: splitting failure, step-path failure and planar failure. The specimens present two failure modes under biaxial compression: splitting failure and planar failure. Full article

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25 pages, 1231 KiB

Open AccessArticle

Optimal Control Strategy for TB-HIV/AIDS Co-Infection Model in the Presence of Behaviour Modification

by Temesgen Debas Awoke and Semu Mitiku Kassa

Processes 2018, 6(5), 48; https://doi.org/10.3390/pr6050048 - 01 May 2018

Cited by 20 | Viewed by 6375

Abstract

A mathematical model for a transmission of TB-HIV/AIDS co-infection that incorporates prevalence dependent behaviour change in the population and treatment for the infected (and infectious) class is formulated and analyzed. The two sub-models, when each of the two diseases are considered separately are [...] Read more.

A mathematical model for a transmission of TB-HIV/AIDS co-infection that incorporates prevalence dependent behaviour change in the population and treatment for the infected (and infectious) class is formulated and analyzed. The two sub-models, when each of the two diseases are considered separately are mathematically analyzed. The theory of optimal control analysis is applied to the full model with the objective of minimizing the aggregate cost of the infections and the control efforts. In the numerical simulation section, various combinations of the controls are also presented and it has been shown in this part that the optimal combination of both prevention and treatment controls will suppress the prevalence of both HIV and TB to below 3% within 10 years. Moreover, it is found that the treatment control is more effective than the preventive controls. Full article

(This article belongs to the Special Issue Modeling & Control of Disease States)

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13 pages, 2756 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Substrate Effect on Carbon/Ceramic Mixed Matrix Membrane Prepared by a Vacuum-Assisted Method for Desalination

by Yingjun Song, Julius Motuzas, David K. Wang, Greg Birkett, Simon Smart and João C. Diniz da Costa

Processes 2018, 6(5), 47; https://doi.org/10.3390/pr6050047 - 01 May 2018

Cited by 6 | Viewed by 4538

Abstract

This work investigates the effect of various membrane substrates and coating conditions on the formation of carbon/ceramic mixed matrix membranes for desalination application. The substrates were impregnated with phenolic resin via a vacuum-assisted method followed by carbonization under an inert gas. Substrates with [...] Read more.

This work investigates the effect of various membrane substrates and coating conditions on the formation of carbon/ceramic mixed matrix membranes for desalination application. The substrates were impregnated with phenolic resin via a vacuum-assisted method followed by carbonization under an inert gas. Substrates with pore sizes of 100 nm required a single impregnation step only, where short vacuum times (<120 s) resulted in low quality membranes with defects. For vacuum times of ≥120 s, high quality membranes with homogeneous impregnation were prepared leading to high salt rejection (>90%) and high water fluxes (up to 25 L m⁻² h⁻¹). The increase in water flux as a function of the vacuum time confirms the vacuum etching effect resulting from the vacuum-assisted method. Substrates with pore sizes of 140 nm required two impregnation steps. These pores were too large for the ceramic inter-particle space to be filled with phenolic resin via a single step. In the second impregnation step, increasing the concentration of the phenolic resin resulted in membranes with lower water fluxes. These results indicate that thicker films were formed by increasing the phenolic resin concentration. In the case of substrates with pores of 600 nm, these pores were too large and inter-particle space filling with phenolic resin was not attained. Full article

(This article belongs to the Special Issue Membrane Materials, Performance and Processes)

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16 pages, 1730 KiB

Open AccessArticle

A Distributed Approach towards Improved Dissemination Protocol for Smooth Handover in MediaSense IoT Platform

by Shabir Ahmad, Ishfaq Hussain, Muhammad Fayaz and Do-Hyeun Kim

Processes 2018, 6(5), 46; https://doi.org/10.3390/pr6050046 - 01 May 2018

Cited by 15 | Viewed by 4152

Abstract

Recently, the Internet has been utilized by many applications to convey time-sensitive messages. The persistently expanding Internet coverage and its easy accessibility have offered to ascend to a problem which was once regarded as not essential to contemplate. Nowadays, the Internet has been [...] Read more.

Recently, the Internet has been utilized by many applications to convey time-sensitive messages. The persistently expanding Internet coverage and its easy accessibility have offered to ascend to a problem which was once regarded as not essential to contemplate. Nowadays, the Internet has been utilized by many applications to convey time-sensitive messages. Wireless access points have widely been used but these access points have limitations regarding area coverage. So for covering a wider space, various access points need to be introduced. Therefore, when the user moves to some other place, the devices expected to switch between access points. Packet loss amid the handovers is a trivial issue. MediaSense is an Internet of Things distributed architecture enabling the development of the IoT application faster. It deals with this trivial handover issue by utilizing a protocol called Distributed Context eXchange Protocol. However, this protocol is centralized in nature and also suffers in a scenario when both sender and receiver address change simultaneously. This paper presents a mechanism to deal with this scenario and presents a distributed solution to deal with this issue within the MediaSense platform. The proposed protocol improves dissemination using retransmission mechanism to diminish packet loss. The proposed protocol has been delineated with a proof of concept chat application and the outcomes have indicated a significant improvement in terms of packet loss. Full article

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12 pages, 6373 KiB

Open AccessArticle

Ionic Liquid (1-Butyl-3-Metylimidazolium Methane Sulphonate) Corrosion and Energy Analysis for High Pressure CO₂ Absorption Process

by Aqeel Ahmad Taimoor, Saad Al-Shahrani and Ayyaz Muhammad

Processes 2018, 6(5), 45; https://doi.org/10.3390/pr6050045 - 01 May 2018

Cited by 7 | Viewed by 4586

Abstract

This study explores the possible use of ionic liquids as a solvent in a commercial high-pressure CO₂ removal process, to gain environmental and energy benefits. There are two main constraints in realizing this: ionic liquids can be corrosive, specifically when mixed with [...] Read more.

This study explores the possible use of ionic liquids as a solvent in a commercial high-pressure CO₂ removal process, to gain environmental and energy benefits. There are two main constraints in realizing this: ionic liquids can be corrosive, specifically when mixed with a water/amine solution with dissolved O₂ & CO₂; and CO₂ absorption within this process is not very well understood. Therefore, scavenging CO₂ to ppm levels from process gas comes with several risks. We used 1-butyl-3-methylimidazoium methane sulphonate [bmim][MS] as an ionic liquid because of its high corrosiveness (due to its acidic nature) to estimate the ranges of expected corrosion in the process. TAFEL technique was used to determine these rates. Further, the process was simulated based on the conventional absorption–desorption process using ASPEN HYSYS v 8.6. After preliminary model validation with the amine solution, [bmim][MS] was modeled based on the properties found in the literature. The energy comparison was then provided and the optimum ratio of the ionic liquid/amine solution was calculated. Full article

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10 pages, 2179 KiB

Open AccessFeature PaperArticle

Cuboid Packed-Beds as Chemical Reactors?

by Raja Ghosh

Processes 2018, 6(5), 44; https://doi.org/10.3390/pr6050044 - 01 May 2018

Cited by 6 | Viewed by 7023

Abstract

Columns are widely used as packed-bed or fixed-bed reactors in the chemical process industry. Packed columns are also used for carrying out chemical separation techniques such as adsorption, distillation, extraction and chromatography. A combination of the variability in flow path lengths, and the [...] Read more.

Columns are widely used as packed-bed or fixed-bed reactors in the chemical process industry. Packed columns are also used for carrying out chemical separation techniques such as adsorption, distillation, extraction and chromatography. A combination of the variability in flow path lengths, and the variability of velocity along these flow paths results in significant broadening in solute residence time distribution within columns, particularly in those having low bed height to diameter ratios. Therefore, wide packed-column reactors operate at low efficiencies. Also, for a column of a particular bed height, the ratio of heat transfer surface area to reactor volume varies inversely as the radius. Therefore, with wide columns, the available heat transfer area could become a limiting factor. In recent papers, box-shaped or cuboid packed-bed devices have been proposed as efficient alternatives to packed columns for carrying out chromatographic separations. In this paper, the use of cuboid packed-beds as reactors for carrying out chemical and biochemical reactions has been proposed. This proposition is primarily supported in terms of advantages resulting from superior system hydraulics and narrower residence time distributions. Other potential advantages, such as better heat transfer attributes, are speculated based on geometric considerations. Full article

(This article belongs to the Special Issue Feature Papers for the Fifth Year Anniversary of the Founding of Processes)

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8 pages, 3156 KiB

Open AccessArticle

Recovery of Filtered Graphene Oxide Residue Using Elastic Gel Packed in a Column by Cross Flow

by Yuji Takaoka, Manoka Miyoshi, Koichi Sakaguchi, Shintaro Morisada, Keisuke Ohto and Hidetaka Kawakita

Processes 2018, 6(5), 43; https://doi.org/10.3390/pr6050043 - 25 Apr 2018

Cited by 5 | Viewed by 4154

Abstract

To recover the filtered residues on a gel layer in a column, the method using the elasticity of the gel layer and flowing water in a cross-flow manner is proposed. Polymerized spherical gel (40 μm) was packed in a column to a set [...] Read more.

To recover the filtered residues on a gel layer in a column, the method using the elasticity of the gel layer and flowing water in a cross-flow manner is proposed. Polymerized spherical gel (40 μm) was packed in a column to a set height of 0.7 cm. The suspensions of graphene oxide at various sizes and shapes were injected on the top of the gel layer and then water was flowed at a flow rate of 1000 mL·h⁻¹ until 0.10 MPa. By releasing the applied pressure, the elastic gel layer rose up, and the filtered graphene oxide also rose above the layer. This rise of the gel layer is due to the difference of pressure between the gel layer, including the filtered graphene oxide, and the open bottom of the column, using the flow of water. The cross flow of water through the column carried away the larger-sized filtered graphene oxide floating above the gel layer. The elasticity of the gel layer and cross flow through the column has the potential to recover the filtered particles. Full article

(This article belongs to the Special Issue Membrane Materials, Performance and Processes)

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14 pages, 2743 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

ADAR Mediated RNA Editing Modulates MicroRNA Targeting in Human Breast Cancer

by Justin T. Roberts, Dillon G. Patterson, Valeria M. King, Shivam V. Amin, Caroline J. Polska, Dominika Houserova, Aline Crucello, Emmaline C. Barnhill, Molly M. Miller, Timothy D. Sherman and Glen M. Borchert

Processes 2018, 6(5), 42; https://doi.org/10.3390/pr6050042 - 25 Apr 2018

Cited by 15 | Viewed by 6240

Abstract

RNA editing by RNA specific adenosine deaminase acting on RNA (ADAR) is increasingly being found to alter microRNA (miRNA) regulation. Editing of miRNA transcripts can affect their processing, as well as which messenger RNAs (mRNAs) they target. Further, editing of target mRNAs can [...] Read more.

RNA editing by RNA specific adenosine deaminase acting on RNA (ADAR) is increasingly being found to alter microRNA (miRNA) regulation. Editing of miRNA transcripts can affect their processing, as well as which messenger RNAs (mRNAs) they target. Further, editing of target mRNAs can also affect their complementarity to miRNAs. Notably, ADAR editing is often increased in malignancy with the effect of these RNA changes being largely unclear. In addition, numerous reports have now identified an array of miRNAs that directly contribute to various malignancies although the majority of their targets remain largely undefined. Here we propose that modulating the targets of miRNAs via mRNA editing is a frequent occurrence in cancer and an underappreciated participant in pathology. In order to more accurately characterize the relationship between these two regulatory processes, this study examined RNA editing events within mRNA sequences of two breast cancer cell lines (MCF-7 and MDA-MB-231) and determined whether or not these edits could modulate miRNA associations. Computational analyses of RNA-Seq data from these two cell lines identified over 50,000 recurrent editing sites within human mRNAs, and many of these were located in 3′ untranslated regions (UTRs). When these locations were screened against the list of currently-annotated miRNAs we discovered that editing caused a subset (~9%) to have significant alterations to mRNA complementarity. One miRNA in particular, miR-140-3p, is known to be misexpressed in many breast cancers, and we found that mRNA editing allowed this miRNA to directly target the apoptosis inducing gene DFFA in MCF-7, but not in MDA-MB-231 cells. As these two cell lines are known to have distinct characteristics in terms of morphology, invasiveness and physiological responses, we hypothesized that the differential RNA editing of DFFA in these two cell lines could contribute to their phenotypic differences. Indeed, we confirmed through western blotting that inhibiting miR-140-3p increases expression of the DFFA protein product in MCF-7, but not MDA-MB-231, and further that inhibition of miR-140-3p also increases cellular growth in MCF-7, but not MDA-MB-231. Broadly, these results suggest that the creation of miRNA targets may be an underappreciated function of ADAR and may help further elucidate the role of RNA editing in tumor pathogenicity. Full article

(This article belongs to the Special Issue Methods in Computational Biology)

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3 pages, 157 KiB

Open AccessEditorial

Special Issue: Microbial Community Modeling: Prediction of Microbial Interactions and Community Dynamics

by Hyun-Seob Song

Processes 2018, 6(5), 41; https://doi.org/10.3390/pr6050041 - 24 Apr 2018

Cited by 1 | Viewed by 3489

Abstract

n/a Full article

(This article belongs to the Special Issue Microbial Community Modeling: Prediction of Microbial Interactions and Community Dynamics)

22 pages, 4855 KiB

Open AccessArticle

Advanced Heterogeneous Fenton Treatment of Coalbed Methane-Produced Water Containing Fracturing Fluid

by Meng Zhang and Wei Gu

Processes 2018, 6(5), 40; https://doi.org/10.3390/pr6050040 - 24 Apr 2018

Cited by 9 | Viewed by 4680

Abstract

This study investigated the heterogeneous Fenton treatment to process coalbed methane-produced water containing fracturing fluid and chose the development region of coalbed methane in the Southern Qinshui Basin as a research area. We synthesized the catalyst of Fe-Co/γ-Al₂O₃ by homogeneous [...] Read more.

This study investigated the heterogeneous Fenton treatment to process coalbed methane-produced water containing fracturing fluid and chose the development region of coalbed methane in the Southern Qinshui Basin as a research area. We synthesized the catalyst of Fe-Co/γ-Al₂O₃ by homogeneous precipitation method and characterized it by BET, XRD, SEM-EDS, FTIR, and XPS. Based on the degradation rate, we studied the influences of the heterogeneous Fenton method on the coalbed methane output water treatment process parameters, including initial pH, H₂O₂ concentration, and the catalyst concentration. We also investigated the impacts of overall reaction kinetics of heterogeneous catalytic oxidation on coalbed methane-produced water containing fracturing fluid. Results showed that Fe-Co/γ-Al₂O₃ as a Fenton catalyst has a good catalytic oxidation effect and can effectively process coalbed methane-produced water. This reaction also followed first-order kinetics. The optimal conditions were as follows: the initial pH of 3.5, a H₂O₂ concentration of 40 mol L⁻¹, a catalyst concentration of 4 g/L, and an apparent reaction rate constant of 0.0172 min⁻¹. Our results provided a basis to establish methods for treating coalbed methane-produced water. Full article

(This article belongs to the Collection Process System Engineering for More Efficient Power and Chemicals Production)

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10 pages, 3684 KiB

Open AccessArticle

FluxVisualizer, a Software to Visualize Fluxes through Metabolic Networks

by Tim Daniel Rose and Jean-Pierre Mazat

Processes 2018, 6(5), 39; https://doi.org/10.3390/pr6050039 - 24 Apr 2018

Cited by 5 | Viewed by 6656

Abstract

FluxVisualizer (Version 1.0, 2017, freely available at https://fluxvisualizer.ibgc.cnrs.fr) is a software to visualize fluxes values on a scalable vector graphic (SVG) representation of a metabolic network by colouring or increasing the width of reaction arrows of the SVG file. FluxVisualizer does not aim [...] Read more.

FluxVisualizer (Version 1.0, 2017, freely available at https://fluxvisualizer.ibgc.cnrs.fr) is a software to visualize fluxes values on a scalable vector graphic (SVG) representation of a metabolic network by colouring or increasing the width of reaction arrows of the SVG file. FluxVisualizer does not aim to draw metabolic networks but to use a customer’s SVG file allowing him to exploit his representation standards with a minimum of constraints. FluxVisualizer is especially suitable for small to medium size metabolic networks, where a visual representation of the fluxes makes sense. The flux distribution can either be an elementary flux mode (EFM), a flux balance analysis (FBA) result or any other flux distribution. It allows the automatic visualization of a series of pathways of the same network as is needed for a set of EFMs. The software is coded in python3 and provides a graphical user interface (GUI) and an application programming interface (API). All functionalities of the program can be used from the API and the GUI and allows advanced users to add their own functionalities. The software is able to work with various formats of flux distributions (Metatool, CellNetAnalyzer, COPASI and FAME export files) as well as with Excel files. This simple software can save a lot of time when evaluating fluxes simulations on a metabolic network. Full article

(This article belongs to the Special Issue Methods in Computational Biology)

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27 pages, 5371 KiB

Open AccessFeature PaperArticle

Measuring Cellular Biomass Composition for Computational Biology Applications

by Ashley E. Beck, Kristopher A. Hunt and Ross P. Carlson

Processes 2018, 6(5), 38; https://doi.org/10.3390/pr6050038 - 24 Apr 2018

Cited by 37 | Viewed by 18720

Abstract

Computational representations of metabolism are increasingly common in medical, environmental, and bioprocess applications. Cellular growth is often an important output of computational biology analyses, and therefore, accurate measurement of biomass constituents is critical for relevant model predictions. There is a distinct lack of [...] Read more.

Computational representations of metabolism are increasingly common in medical, environmental, and bioprocess applications. Cellular growth is often an important output of computational biology analyses, and therefore, accurate measurement of biomass constituents is critical for relevant model predictions. There is a distinct lack of detailed macromolecular measurement protocols, including comparisons to alternative assays and methodologies, as well as tools to convert the experimental data into biochemical reactions for computational biology applications. Herein is compiled a concise literature review regarding methods for five major cellular macromolecules (carbohydrate, DNA, lipid, protein, and RNA) with a step-by-step protocol for a select method provided for each macromolecule. Additionally, each method was tested on three different bacterial species, and recommendations for troubleshooting and testing new species are given. The macromolecular composition measurements were used to construct biomass synthesis reactions with appropriate quality control metrics such as elemental balancing for common computational biology methods, including flux balance analysis and elementary flux mode analysis. Finally, it was demonstrated that biomass composition can substantially affect fundamental model predictions. The effects of biomass composition on in silico predictions were quantified here for biomass yield on electron donor, biomass yield on electron acceptor, biomass yield on nitrogen, and biomass degree of reduction, as well as the calculation of growth associated maintenance energy; these parameters varied up to 7%, 70%, 35%, 12%, and 40%, respectively, between the reference biomass composition and ten test biomass compositions. The current work furthers the computational biology community by reviewing literature regarding a variety of common analytical measurements, developing detailed procedures, testing the methods in the laboratory, and applying the results to metabolic models, all in one publicly available resource. Full article

(This article belongs to the Special Issue Methods in Computational Biology)

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Processes, Volume 6, Issue 5 (May 2018) – 24 articles

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