Background: Autotransplantation of cryopreserved ovarian tissue is currently the main option to preserve fertility for cancer patients. To avoid cancer cell reintroduction at transplantation, a multi-step culture system has been proposed to obtain fully competent oocytes for in vitro fertilization. Current in vitro systems are limited by the low number and health of secondary follicles produced during the first step culture of ovarian tissue fragments. To overcome such limitations, bioreactor designs have been proposed to enhance oxygen supply to the tissue, with inconsistent results. This retrospective study investigates, on theoretical grounds, whether the lack of a rational design of the proposed bioreactors prevented the full exploitation of follicle growth potential. Methods: Models describing oxygen transport in bioreactors and tissue were developed and used to predict oxygen availability inside ovarian tissue in the pertinent literature. Results: The proposed theoretical analysi... [more]

Nowadays, the massive production of biodiesel leads to a surplus of glycerol. Thus, new applications of this by-product are being developed. In this study, glycerol steam reforming was carried out with Ni catalysts supported on Al2O3 rings and La-modified Al2O3. The catalysts were characterized by N2 physical adsorption, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and thermogravimetry. Both catalysts were effective in glycerol steam reforming. However, Ni/Al2O3 activity decreased over reaction time. Ni/La2O3/Al2O3 showed the best stability during the reaction. In addition, the activity of the modified support, La2O3/Al2O3, was evaluated. The modification of the support lent catalytic properties to the solid. Some conditions such as catalyst arrangement (catalyst in the first or second reactor), space velocity, and reaction temperature were studied. The highest hydrogen production was obtained when half the amount of the catalyst was located in bot... [more]

In biopharmaceutical manufacturing, a new single-use technology using disposable equipment is available for reducing the work of change-over operations compared to conventional multi-use technology that use stainless steel equipment. The choice of equipment technologies has been researched and evaluation models have been developed, however, software that can extend model exposure to reach industrial users is yet to be developed. In this work, we develop and demonstrate a prototype of an online decision-support tool for the multi-objective evaluation of equipment technologies in sterile filling of biopharmaceutical manufacturing processes. Multi-objective evaluation models of equipment technologies and equipment technology alternative generation algorithms are implemented in the tool to support users in choosing their preferred technology according to their input of specific production scenarios. The use of the tool for analysis and decision-support was demonstrated using four productio... [more]

In the thermal energy storage system, the thermal properties of phase change materials (PCM) have a great influence on the system performance. In this paper, paraffin-based composite phase change material with different graphite additive (expanded graphite, EG; graphene, GR; and graphene oxide, GO) and different concentrations (0.5 to 2.0%) are manufactured by a two-step method combining mechanical agitation and ultrasonic vibration. The characteristics of charge/discharge processes are studied, and the thermophysical properties are measured by T-history method. The experimental results show that the thermal conductivity and heat charge rate of the composite PCM are effectively improved by adding the graphite additive to the PCM, and the addition of additives can improve the melting point of the material. When the same graphite additive is added, the higher the concentration, the higher the thermal conductivity of the composite PCM, and the latent heat decreases with the increase of co... [more]

With the increasingly prominent global energy and environmental problems, more and more enterprises have been required to desulfurize the exhausted gases. Different enterprises have different demands for the desulfurization process, thus the choice of desulfurization process methods has become a focus of attention. Since the evaluation of the desulfurization process involves many factors, this paper proposes an improved fuzzy comprehensive evaluation method to evaluate the selection of desulfurization process when the traditional evaluation method is not applicable. Firstly, an evaluation system with two rating indicators was constructed, which considers the subjective and objective weights comprehensively. Secondly using the two hierarchical indicators, an effective desulfurization process method was obtained according to the principle of maximum membership degree. Finally, we took a real papermaking factory as an example to illustrate the detailed implementation processes of this met... [more]

Ship transportation plays an increasingly important role in and accounts for a large proportion of cargo transport. Therefore, it is necessary to improve the quality of the trajectory control system of the ship for improving the transport efficiency and ensuring maritime safety. This paper deals with the advanced control system for the three-degrees-of-freedom model of the underactuated ship in the condition of uncertain disturbance. Based on the three-degrees-of-freedom model of the underactuated ship, the authors built a bilinear model of the ship by linearizing each nonlinear model section. Then, the authors used the state estimator to compensate for uncertain components and random disturbances in the model. Finally, the authors built the output-feedback predictive controller based on the channel-separation principle combined with direct observation of the continuous model for controlling the motion of the underactuated ship in the case of uncertain disturbance and the bound control... [more]

Multi-component polymers can provide many advantages over their homopolymer counterparts. Terpolymers are formed from the combination of three unique monomers, thus creating a new material that will exhibit desirable properties based on all three of the original comonomers. To ensure that all three comonomers are incorporated (and to understand and/or predict the degree of incorporation of each comonomer), accurate reactivity ratios are vital. In this study, five terpolymerization studies from the literature are revisited and the ‘ternary’ reactivity ratios are re-estimated. Some recent studies have shown that binary reactivity ratios (that is, from the related copolymer systems) do not always apply to ternary systems. In other reports, binary reactivity ratios are in good agreement with terpolymer data. This investigation allows for the comparison between previously determined binary reactivity ratios and newly estimated ‘ternary’ reactivity ratios for several systems. In some of the... [more]

With the deep integration of supply chain with Internet and Internet of things, it is an important way for enterprises to win market competition and seek sustainable development to develop green new products through external green supply chain integration (GSCI). This study established a unified research framework of external GSCI, knowledge spiral (KS), green new product development (NPD), and top management’s environmental awareness (TMEA). Structural equation modeling and analytic hierarchy process are used to explore the mechanism of the established research framework. The research results of this paper are as follows: (i) Green supplier integration (SI) and green consumer integration (CI) have significant positive effects on green NPD speed (GS), green NPD quality (GQ), and KS, and KS has a significant positive effect on GS and GS, respectively. Compared with green CI, green SI has a greater impact on KS, GS, and GQ. In addition, compared with GS, KS has a greater impact on GQ; (i... [more]

In modern steam power plants, the ever-increasing complexity requires great reliability and flexibility of the control system. Hence, in this paper, the feasibility of a distributed model predictive control (DiMPC) strategy with an extended prediction self-adaptive control (EPSAC) framework is studied, in which the multiple controllers allow each sub-loop to have its own requirement flexibility. Meanwhile, the model predictive control can guarantee a good performance for the system with constraints. The performance is compared against a decentralized model predictive control (DeMPC) and a centralized model predictive control (CMPC). In order to improve the computing speed, a multiple objective model predictive control (MOMPC) is proposed. For the stability of the control system, the convergence of the DiMPC is discussed. Simulation tests are performed on the five different sub-loops of steam/water loop. The results indicate that the DiMPC may achieve similar performance as CMPC while o... [more]

The removal of undesirable compounds such as CO2 and NO2 from incineration and natural gas is essential because of their harmful influence on the atmosphere and on the reduction of natural gas heating value. The use of membrane contactor for the capture of the post-combustion NO2 and CO2 had been widely considered in the past decades. In this study, membrane contactor was used for the simultaneous absorption of CO2 and NO2 from a mixture of gas (5% CO2, 300 ppm NO2, balance N2) with aqueous sodium hydroxide solution. For the first time, a mathematical model was established for the simultaneous removal of the two undesired gas solutes (CO2, NO2) from flue gas using membrane contactor. The model considers the reaction rate, and radial and axial diffusion of both compounds. The model was verified and validated with experimental data and found to be in good agreement. The model was used to examine the effect of the flow rate of liquid, gas, and inlet solute mole fraction on the percent rem... [more]

Aquaculture is one of the fastest growing food producing industries in the world. Aquaculture effluent contains high concentrations of inorganic nutrients. Reduction of these inorganic nutrients in aquaculture effluent is crucial for fulfilling the effluent standards or reuse of aquaculture effluent. This study investigated the effective use of green macroalga Caulerpa lentillifera as a bioremediatory species for nutrient removal from aquaculture effluent by conducting an on-station experiment and measurements. The effluent of a fish culture unit was circulated through a macroalgal culture unit every four days for a total of 60 days, allowing 15 circulations. Concentrations of inorganic nutrients (NO2−-N, NO3−-N, NH3-N, and PO43−) were measured in the integrated system consisting of a fish unit, settling unit, macroalgal unit and extra tank for water circulation in triplicates. Multiple linear regression analysis revealed that the application of the bioremediation system led to a signi... [more]

This paper focuses on the effect of ultra-fine ( d < 10 µm) powders in mixtures with fine ( d < 100 µm) bulk material on compression processes and also evaluates the re-fluidization behavior of the compressed bed (history effect). Achieving this goal, different mixtures of fine and ultra-fine Ground-Carbonate-Calcium were compressed at three pressure levels. The results show that by increasing the applied pressure, the compressibility decreases due to change in compaction regime. Subsequently, for the higher pressure, the slope of packing density versus applied stress curves is noticeably different. However, this slope does not depend on the size distribution of mixtures, but on the type of material. Comparing fluidization and re-fluidization curves (bed pressure drop vs. gas velocity) shows an increase in the maximum bed pressure drop ( Δ P p e a k ) for re-fluidization. By increasing the portion of ultra-fine particles in the binary mixture, Δ P p e a... [more]

Bioenergy supply chains can offer social benefits. In most related research, the total number of created jobs is used as the indicator of social benefits. Only a few of them quantify social benefits considering the different impact of economic activities in different locations. In this paper, a new method of measuring the social benefits of bioethanol supply chains is proposed that considers job creation, biomass purchase, and the different impacts of economic activities in different locations. A multi-objective mixed integer linear programming (MILP) model is developed to address the optimal design of a bioethanol supply chain that maximizes both economic and social benefits. The ε-constraint method is employed to solve the model and a set of Pareto-optimal solutions is obtained that shows the relationship between the two objectives. The developed model is applied to case studies in Liaoning Province in Northeast China. Actual data are collected as practical as possible for the feasib... [more]

Scheduling is a major component for the efficient operation of the process industries. Especially in the current competitive globalized market, scheduling is of vital importance to most industries, since profit margins are miniscule. Prof. Sargent was one of the first to acknowledge this. His breakthrough contributions paved the way to other researchers to develop optimization-based methods that can address a plethora of process scheduling problems. Despite the plethora of works published by the scientific community, the practical implementation of optimization-based scheduling in industrial real-life applications is limited. In most industries, the optimization of production scheduling is seen as an extremely complex task and most schedulers prefer the use of a simulation-based software or manual decision, which result to suboptimal solutions. This work presents a comprehensive review of the theoretical concepts that emerged in the last 30 years. Moreover, an overview of the contribut... [more]

Predictive analytics is usually cited as one of the most important pillars of the digital transformation. For the oil industry, specifically, it is a common belief that issues like integrity and maintenance could benefit from predictive analytics. This paper presents the development and the application of a process-monitoring tool in a real process facility. The PMA (Predictive Maintenance Application) system is a data-driven application that uses a multivariate analysis in order to predict the system behavior. Results show that the use of a multivariate approach for process monitoring could not only detect an early failure at a metering system days before the operation crew, but could also successfully identify, among hundreds of variables, the root cause of the abnormal situation. By applying such an approach, a better performance of the monitored equipment is expected, decreasing its downtime.

We have become aware that figures, tables, experimental data, and a whole paragraph in the results and discussion section of the published article [...]

Fuel cells are promising devices to transform chemical energy into electricity; their behavior is described by principles of electrochemistry and thermodynamics, which are often difficult to model mathematically. One alternative to overcome this issue is the use of modeling methods based on artificial intelligence techniques. In this paper is proposed a hybrid scheme to model and control fuel cell systems using neural networks. Several feature selection algorithms were tested for dimensionality reduction, aiming to eliminate non-significant variables with respect to the control objective. Principal component analysis (PCA) obtained better results than other algorithms. Based on these variables, an inverse neural network model was developed to emulate and control the fuel cell output voltage under transient conditions. The results showed that fuel cell performance does not only depend on the supply of the reactants. A single neuro-proportional−integral−derivative (neuro-PID) controller... [more]

Topological indices have been computed for various molecular structures over many years. These are numerical invariants associated with molecular structures and are helpful in featuring many properties. Among these molecular descriptors, the eccentricity connectivity index has a dynamic role due to its ability of estimating pharmaceutical properties. In this article, eccentric connectivity, total eccentricity connectivity, augmented eccentric connectivity, first Zagreb eccentricity, modified eccentric connectivity, second Zagreb eccentricity, and the edge version of eccentric connectivity indices, are computed for the molecular graph of a PolyEThyleneAmidoAmine (PETAA) dendrimer. Moreover, the explicit representations of the polynomials associated with some of these indices are also computed.

Agarwood and agarwood essential oils are commodities with great commercial value. In Vietnam, the agarwood industry has been growing, with more than 10,000 ha of forest land reserved for the cultivation of Aquilaria crassna, an agarwood-producing tree. The aim of this study was to present a hydrodistillation process to recover agarwood essential oil and to compare chemical compositions of agarwood samples harvested from various locations in Vietnam. Three agarwood samples representing products from A. crassna trees cultivated in the provinces of Bac Giang and Khanh Hoa, and on the Phu Quoc island (Kien Giang province) of Vietnam were subjected to hydrodistillation, resulting in essential oil yields of 0.32%, 0.27%, and 0.25% (w/w), respectively. Using GC−MS analysis, a total of 44 volatile compounds were identified in the obtained oils. Most of the constituents were oxygenated sesquiterpenes and had been previously found in other agarwood oil samples. Notable compounds of other chemica... [more]

By using EDEM−Fluent codes and coupling the continuous fluid medium with a solid particle discrete element, the solid−liquid two-phase flow field in a centrifugal pump was simulated under the same inlet conditions of the particle volume fraction and three flow conditions of 0.7Qd, 1.0Qd and 1.3Qd. By introducing the Archard wear model, the wear was calculated, and the wear law was obtained for the pump flow parts such as the leading edge of the impeller blade, blade tip, blade pressure side, blade suction side, impeller shroud, hub and volute. The results demonstrate that the wear of volute is about 70% of the total wear of pump. The wear in the impeller mainly occurs in the blade leading edge, the junction of the hub and the trailing part of the blade pressure side, and the junction of the shroud and the rear part of the blade suction side. Under lower flow conditions, the wear in the impeller shroud is relatively considerable. As the flow rate increases, the wear in the blade pressur... [more]

The unique situation of utility power curtailment unveils opportunities in the fields of energy management and digital resource management. During utility load shedding events, campuses are typically driven as Photo Voltaic (PV)−diesel generator hybrid systems, of which the main fossil resource driver is diesel. With the appropriate Supervisory Control and Data Acquisition (SCADA) systems, discrete departmental energy policies along with control, forecasting and Internet of Things (IoT) infrastructure, the campus hybrid system could be optimized on a short timescale during the shedding event. In this paper the optimization methodology, required technology infrastructure, possible forecasting algorithms and potential implementation will be discussed.

Concentrated solar power (CSP) is a leading renewable energy technology, and the parabolic trough (PT) is one of the most used configurations of CSP. In the present study, the performance improvement and energy cost reduction of a 50 MWe PT plant for Abu Dhabi, United Arab Emirates (UAE) is presented. The simulations were carried out using the System Advisor Model software. The analyses of a PT plant with different technologies/parameters are undertaken in the first instance for seven cases. These cases include solar multiple, solar collectors, receivers, heat transfer fluid, cooling system (evaporative and air-cooled), thermal energy storage system (4−12 h), and fossil dispatch mode (0.25 to 1.0). Based on these analysis, the eighth case, which is found to be the best-case scenario in this study, was considered by taking into account the best of preceding case results and was determined to be the most suitable both in terms of performance and cost reduction. It is, therefore, conclude... [more]

It is of paramount importance to understand the hydration swelling and weakening properties of clay minerals, such as montmorillonite, to determine their mechanical responses during deep underground argillaceous engineering. In this study, the mineral components and microscopic structure of mudstone were characterised using X-ray powder diffraction and field-emission scanning electron microscopy. Experimental schemes were devised to determine the properties of mudstone under the influence of underground water and stress; these involved compacting montmorillonite particles with various water contents and conducting uniaxial compression tests. Experimental results demonstrated that compaction stress changes the microscopic structure of the montmorillonite matrix and affects its properties, and stress independency was found at particular water and stress conditions. Two equations were then obtained to describe the swelling and weakening properties of the montmorillonite matrix based on th... [more]

In the present study, the effects of operating parameters, namely, rotor speed, feed rate, and inlet air velocity, on the cut diameter of a cage-type separator were studied. The design of experiments (DOE) method was used to investigate the relationship between the operating parameters and the cut size. The experimental results were statistically analyzed using MINITAB 16 software. Both the rotor speed and air inlet velocity had significant main effects on the cut size. The feed rate was also significant but had a weak effect with respect to the rotor speed and inlet air velocity effects. The cut size decreased with an increase in rotor speed and increased with an increase in air inlet velocity. However, the cut size slightly decreased with an increase in feed rate. An empirical multiple-variable linear model for predicting the cut size of the classification was created and presented. The results derived from the statistical analysis were in good agreement with those from the experimen... [more]

The A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences has developed an original active pharmaceutical ingredient based on an oxidized cyclodextrin oligosaccharide, which is a bisulfite derivative. Conducted pharmacological studies proved its antiviral activity in vitro and in vivo experiments against the influenza A (H1N1) virus. The aim of this work was to optimize the technology of obtaining the active pharmaceutical ingredient based on the bisulfite derivative of oxidized cyclodextrin to increase the efficiency and safety of the process. For this, a scaled method of oligosaccharide oxidation was tested on pilot plants in accordance with the requirements of green chemistry. As a result, the reaction time was reduced from three to five days (laboratory conditions) to 1.5 h, and the safety and environmental friendliness of process was ensured. The use of cross-flow filtration and the method of freeze-drying eliminated 96% of ethyl alcohol,... [more]