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Alternatives to bisphenol A (BPA) are more and more used in thermal paper receipts. To get an overview of the situation in Switzerland, 124 thermal paper receipts were collected and analyzed. Whereas BPA was detected in most samples (n=100), some alternatives, namely bisphenol S (BPS), Pergafast® 201 and D-8 have been found in 4, 11 and 9 samples respectively. As no or few data on their endocrine activity are available, these chemicals and bisphenol F (BPF) were tested in vitro using the H295R steroidogenesis assay. 17β-Estradiol production was induced by BPA and BPF, whereas free testosterone production was inhibited by BPA and BPS. Both non-bisphenol substances did not show significant effects. The binding affinity to 16 proteins and the toxicological potential (TP) were further calculated in silico using VirtualToxLab™. TP values lay between 0.269 and 0.476 and the main target was the estrogen receptor β (84.4 nM to 1.33 μM). A substitution of BPA by BPF and BPS should be thus considered with caution, since they exhibit almost a similar endocrine activity as BPA. D-8 and Pergafast® 201 could be alternatives to replace BPA, however further analyses are needed to better characterize their effects on the hormonal system.

Recently, metapopulation models for rock-paper-scissors games have been presented. Each subpopulation is represented by a node on a graph. An individual is either rock (R), scissors (S) or paper (P); it randomly migrates among subpopulations. In the present paper, we assume victory rates differ in different subpopulations. To investigate the dynamic state of each subpopulation (node), we numerically obtain the solutions of reaction-diffusion equations on the graphs with two and three nodes. In the case of homogeneous victory rates, we find each subpopulation has a periodic solution with neutral stability. However, when victory rates between subpopulations are heterogeneous, the solution approaches stable focuses. The heterogeneity of victory rates promotes the coexistence of species.

This study employs simulated electronic paper to investigate critical issues and focuses on improving legibility of display and reducing users' visual fatigue. Three critical factors--choice of surface treatment, ambient illumination, and bending curvature--are evaluated through the method of a letter-search task. The results show that subjects performed better on legibility and felt less visual fatigue with an anti-glare treatment. Choosing the better anti-glare treatment instead of the anti-reflection series can save significant cost for manufacturers. In addition, ambient lighting of 1500 lux is more appropriate for reading on electronic paper than an environment with extreme illumination (e.g., 8000 lux). The present study also found that curvature had no impact on legibility or visual fatigue. These evaluations of simulated electronic paper may provide manufacturers useful information in fulfilling ergonomic requirements for product design.

In cooperation with the world’s second largest manufacturer of beverage cartons (SIG Combibloc®) for liquid foodstuffs an innovative off-take for neutralisation of reactive gas in a paper laminating machine was constructed. A great challenge during engineering work was ensuring a high concentration of the reactive gas where needed and at the same time minimising work place impact in a machine basically without housing. Preliminary 2D-models of the machine geometry proved to be insufficient in describing all the governing flow phenomena. A simplified 3D-geometry containing all important parts of the complex machinery was necessary for accurate predictions. It was found that the driving force of air movement and transport of reactive gas (which acts as an adhesive agent) from the reaction zone in the interior of the laminating machine to the outside is a boundary flow caused by the rapid movement of carton material and rotating cylinders. A physically correct simulation result of the boundary flow is a premise for correct prediction of air flow in and around the machinery. Lacking experimental data (due to an inaccessible geometry) a worst case scenario was constructed by generating a grid and using turbulence models that maximised mass transport in the boundary layer region and thus emission of (tracer)gas from the machine. CFD simulations were done using the geometry preprocessor Gambit ™ , and the finite volume solver Fluent ™ . The results of the analysis of the emission paths from the machine were surprising and led to the construction of an effective off-take relatively far away from the emission source. The chosen position ensures low disturbance of highly sensitive flow patterns inside the machine and diffusive mixing, dilution and contamination of the surroundings. The effect of the new off-take is an immediate and significant rise in air quality in the vicinity of the laminating machine and ensures maximum allowed concentration in the plant area. The product quality furthermore is uncompromised by the working off-take which was another important goal of this work.

The present comment refers to some doubtful results included in the above mentioned paper.

This paper is concerned with the mathematical modeling and simulation of the steady-state operation of an industrial moving bed heterogeneous reactor for the kraft pulping of Eucalyptus globulus. The cooking takes place in a single-vessel hydraulic digester adapted for isothermal cooking (ITC), a further development of the modified continuous cooking (MCC) process. A heterogeneous model is used to take into account the different phases, each with distinct profiles of temperature and concentration of organic (lignin, cellulose and hemicellulose) and inorganic (effective alkali and sulfide) compounds. The numerical solution of the model is based on a non-uniform discretization strategy to cope with special geometric and operational features of the digester. The decrease in bulk porosity caused by the compaction of the bed and the progressive increase in the voidage of chips as a result of chemical reactions are incorporated into the model as well as the resulting implications in the entrapped and free liquor flows. The model presented here can be used in optimization studies and has been validated with data from an industrial mill. http://www.sciencedirect.com/science/article/B6TFK-40GJ2MB-D/1/fd03feb4f6373ea0a583b9ddc3b427ed

In this note, we correct an error in our paper published in Communications in Nonlinear Science and Numerical Simulation in 2015 [5], in which the form of a Z2-equivariant cubic planar switching system is not correct. In this note, we add one more switching line and use the same equations given in [5] to construct a correct Z2-equivariant cubic system. Then, we prove that the new system can exhibit 15 limit cycles and therefore the conclusion given in [5] still holds.

An increasing number of publications include modeling. Often, such studies help us to gain a deeper insight into the phenomena studied and break down barriers between experimental and theoretical communities. However, combining experimental and theoretical work is challenging for authors, reviewers, and readers. To help maximize the usefulness and impact of combined theoretical and experimental research, this Primer describes the purpose, usefulness, and different types of models and addresses the practical aspect of integrated publications by outlining characteristics of good modeling, presentation, and fruitful collaborations.

This paper presents a reply to the discussion of the paper “Numerical simulation of moisture transport in concrete based on a pore size distribution model” by Q. Zeng and S.L. Xu.

Inspired by the acrobatics of the lizard, we present a novel robot platform capable of performing a barrel roll from a ramp. The system is modeled using Euler-Lagrange mechanics, followed by controller design and numerical simulation. A robotic platform is then designed to perform the experiments. Finally, we show that purely by the use of the actuated tail, the robot can rapidly performing a 360 degree roll rotation in under a second.

The purpose of this study is to examine emergency nurses' performance using triage scenarios characterized by type of patient population (adult versus pediatric) and mode of delivery (paper versus computer).A combination of paper-based (script alone) and computer-based (script plus still photographs) triage scenarios were used. Of the 28 scenarios used, half were written and half were computer based. Within each subgroup, there were 7 adult and 7 pediatric scenarios. Participants were asked to allocate an Australasian Triage Scale category for each triage scenario.One hundred sixty-seven participants completed a total of 2,349 adult scenarios, and 161 participants completed 2,265 pediatric scenarios. Sixty-one percent of the triage decisions made by the nurses were "expected" triage decisions, 18% were "undertriage," decisions, and 21% were "overtriage" decisions. Nurse triage allocation decisions for the scenarios containing still photographs delivered by computer demonstrated a higher average agreement percentage of 66.2% (kappa=0.56; tau b =0.77; P.0001) compared with the average agreement percentage of 55.4% (kappa=0.42; tau b =0.75; P.0001) using paper-based (text-only) scenarios.The mode of delivery appeared to have an effect on the nurses' triage performance. It is unclear whether the use of simple still photographs used in the computer mode of delivery resulted in a higher incidence of expected triage decisions and, thus, improved performance. The use of cues such as photographs and video footage to enhance the fidelity of triage scenarios may be useful not only for the education of triage nurses but also the conduct of research into triage decisionmaking. However, further exploration and research in this area are warranted.

Coulomb friction remains one of the major difficulties arising in control design for mechanical systems. Control of a translational pneumatic servoactuator is a typical example of such a problem. The aim of this paper is to demonstrate that sliding-mode control can be successfully used to compensate the friction of the piston in the cylinder, which is both viscous and Coulomb. A fourth-order nonlinear state-space model of a rodless pneumatic servoactuator will be developed with both numerical simulation and experimental validation. The comparison of sliding-mode control with classic PID control will be presented. © 1997 Elsevier Science Ltd.

This paper proposes a variable-structure regulator for robotic systems. It is based on the concept of sliding sectors, introduced by Shyu, Tsai and Yung for linear systems, which overcomes the chattering problem typical of the sliding-modes approach. The stability of the controlled system is proved; a numerical simulation is enclosed as an example. © 1997 Elsevier Science Ltd.

An overview of the contributions made at the Particle Technology Forum in the general context of multiphase flow research is presented. Recent developments in the measuring and computational simulation techniques have made significant inroads in the field. There is an increased interest on basic two-phase flow mechanisms, particularly for dense suspension flows. The numerical simulations are more sophisticated and closer to industrial design and applications. Rapidly changing technologies provide support for the non-intrusive instrumentation and on-line technology for two-phase flow. The necessity to combine experimental, theoretical and numerical simulation techniques in most research projects has highlighted the importance of a broader university education and the use of interdisciplinary research teams. Several open research issues have been identified.

We show that the numerical code used in the above mentioned paper does not take into account the multiple scattering effects of electromagnetic fields properly and is, therefore, incorrect.

In restricted waterways, ship operation is affected by the proximity of the boundaries such as the bottom, horizontal restrictions due to banks and quay walls. Numerical simulations of the ship behavior when moving in restricted water are proposed in the present paper based on a computational fluid dynamics (CFD hereafter) investigation technique. Comparisons with the corresponding numerical solutions for the unlimited water are provided to emphasize the effects of the water depths not only on the pressure distributions on the hull, but also on the sinkage, trim and overall hydrodynamic resistance.

With the increasing demands for the high efficiency of pulp-mixing, which is adapted to the fine particles entering into flotation section, an intensification pulp-mixing device with novel design has been developed. On the basis of numerical simulation, which indicated efficient circulation and shear effect of the “maleic-cutting” configuration equipped with static-guide-blade, the power dissipation amount PV, mixing time θm, power number NP, mixing time number Nθ, CS which reflects shear property, suspension percentage φ/Φ(%), and concentration variance σ2 were measured, analyzed and compared with the ordinary agitated tank. Combining with actual mineral separation tests, performance of the efficient pulp-mixing device characterized by “multi-stage and compulsory” has been validated: the “multi-stage and compulsory” mixing device corresponds to a different circulation/shear energy; under the same operating conditions, the absolute advantages in the aspect of mixing time are the root cause for the increase of mixing efficiency; the “maleic-cutting” configuration is less influenced by pulp-mixing time and has the characteristics of achieving fast mixing; the strong shear effect mechanism is the root cause for the realization of pulp-mixing intensification on fine-particle and microfine-particle materials. Therefore, the “multi-stage and compulsory” mixing device designed by this research successfully accomplished intensification of pulp-mixing effect.

Highlights • RNA-dependent RNA polymerase (RdRp), Spike (S) and glycoprotein (M) were selected. • Both S and M were chosen for the development of a chimeric vaccine. • siRNAs were also designed for S and M gene silencing. • Six new drug candidates were suggested that might inhibit the activity of RdRp., Coronavirus disease-2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), has become an immense threat to global public health. In this study, we performed complete genome sequencing of a SARS-CoV-2 isolate. More than 67,000 genome sequences were further inspected from Global Initiative on Sharing All Influenza Data (GISAID). Using several in silico techniques, we proposed prospective therapeutics against this virus. Through meticulous analysis, several conserved and therapeutically suitable regions of SARS-CoV-2 such as RNA-dependent RNA polymerase (RdRp), Spike (S) and Membrane glycoprotein (M) coding genes were selected. Both S and M were chosen for the development of a chimeric vaccine that can generate memory B and T cells. siRNAs were also designed for S and M gene silencing. Moreover, six new drug candidates were suggested that might inhibit the activity of RdRp. Since SARS-CoV-2 and SARS-CoV-1 have 82.30% sequence identity, a Gene Expression Omnibus (GEO) dataset of Severe Acute Respiratory Syndrome (SARS) patients were analyzed. In this analysis, 13 immunoregulatory genes were found that can be used to develop type 1 interferon (IFN) based therapy. The proposed vaccine, siRNAs, drugs and IFN based analysis of this study will accelerate the development of new treatments.

The current SARS-CoV-2 pandemic has imposed new challenges and demands for health systems, especially in the development of new vaccine strategies. Vaccines for many pathogens were developed based on the display of foreign epitopes in the variable regions of the human adenovirus (HAdV) major capsid proteins (hexon, penton and fiber). The humoral immune response against the HAdV major capsid proteins was demonstrated to play a role in the development of an immune response against the epitopes in display. Through the immunoinformatic profiling of the major capsid proteins of HAdVs from different species, we developed a modular concept that can be used in the development of vaccines based on HAdV vectors. Our data suggests that different immunomodulatory potentials can be observed in the conserved regions, present in the hexon and penton proteins, from different species. Using this modular approach, we developed a HAdV-5 based vaccine strategy for SARS-CoV-2, constructed through the display of SARS-CoV-2 epitopes indicated by our prediction analysis as immunologically relevant. The sequences of the HAdV vector major capsid proteins were also edited to enhance the IFN-gamma induction and antigen presenting cells activation. This is the first study proposing a modular HAdV platform developed to aid the design of new vaccines by inducing an immune response more suited for the epitopes in display., Highlights • The SARS-CoV-2 pandemic increases the need for vaccine strategies. • Sequences from the SARS-CoV-2 structural proteins can be displayed in HAdV vectors. • HAdV conserved regions from different species elicit different immune responses. • In silico tools can aid the development of HAdV based vectors.

The results of the theoretical and experimental studies of the ignition processes of a new class of fuel: bio-water-coal (Bio-WCF) have been presented. The latter has been a water-coal suspension with the addition of 10% leaf or coniferous litter of various tree species, as well as charcoal. It has been established that the addition of biomass to the structure of a water-coal suspension leads to a decrease in the ignition delay time (tign) by 30% under conditions of relatively low oxidizing temperatures. It has been established that when drops of fuel are heated with the addition of charcoal before ignition, dispersion occurs. A mathematical model of the process of ignition of a complex structured bio-water-coal suspension has been developed. According to the results of a numerical simulation, the ignition delay times have been established. A comparative analysis of the theoretical and experimental values of tign has shown their good agreement. Based on the results of the experimental and theoretical studies, the possibility of a significant reduction in the ignition delay time of water-coal suspensions with the introduction of biomass in their structure has been substantiated.

Switchgrass (Panicum virgatum), alfalfa stems (Medicago sativa), second year growth hybrid poplar (Populus) and willow (Salix spp.) were examined to determine fiber characteristics, pulping behavior and paper properties. Alfalfa stems and switchgrass both showed length weighted average fiber length (LWW) of 0.78 mm, a very narrow fiber length distribution and high fines content. Willow and hybrid poplar have lower fines content but a very low average fiber length (0.42 and 0.48 mm LWW). In addition, the four biomass species showed distinctly different chemical compositions. Switchgrass was defibered successfully using Soda and Soda Anthraquinone (AQ) pulping and demonstrated good paper properties. Both fast-growing wood species pulped well using the Kraft process, and showed acceptable tensile strength, but low tear strength. Alfalfa stems reacted very poorly to Soda and Soda AQ pulping but responded well to Kraft and Kraft AQ. Pulps with tensile and tear strength considerably higher than those found for commercial aspen pulps were observed for alfalfa. All four biomass species examined demonstrated low pulp yield. The highest yields were obtained with poplar and switchgrass (around 43%). Considering the short fibers and low yields, all four biomass types will likely only be used in paper manufacturing if they offer considerable economic advantage over traditional pulp wood.

A Monte Carlo simulation in a novel approach is used for studying the problem of the outbreak and spread dynamics of the new COVID-19 pandemic in this work. In particular, our goal was to generate epidemiological data based on natural mechanism of transmission of this disease assuming random interactions of a large-finite number of individuals in very short distance ranges. In the simulation we also take into account the stochastic character of the individuals in a finite population and given densities of people. On the other hand, we include in the simulation the appropriate statistical distributions for the parameters characterizing this disease. An important outcome of our work, besides the generated epidemic curves, is the methodology of determining of the effective reproductive number during the main part of the new daily cases of the epidemic. Since this quantity constitutes a fundamental parameter of the SIR-based epidemic models, we also studied how it is affected by small variations of the incubation time and the crucial distance distributions, and furthermore, by the degree of quarantine measures. In addition, we compare our qualitative results with those of selected real epidemiological data.

Epidemiological and molecular characterization of SARS-CoV-2 is essential for identifying the source of the virus and for effective control of the spread of local strains. We estimated case fatality rate, cumulative recovery number, basic reproduction number (R0) and future incidence of COVID-19 in Bangladesh. We illustrated the spatial distribution of cases throughout the country. We performed phylogenetic and mutation analysis of SARS-CoV-2 sequences from Bangladesh. As of July 31, 2020, Bangladesh had a case fatality rate of 1.32%. The cases were initially clustered in Dhaka and its surrounding districts in March but spreads throughout the country over time. The R0 calculated as 1.173 in Exponential Growth method. For the projection, a 20% change in R0 with subsequent infection trend has been calculated. The genomic analysis of 292 Bangladeshi SARS-CoV-2 strains suggests diverse genomic clades L, O, S, G, GH, where predominant circulating clade was GR (83.9%; 245/292). The GR clades' phylogenetic analysis revealed distinct clusters (I to XIII) with intra-clade variations. The mutation analysis revealed 1634 mutations where 94.6% and 5.4% were non-synonymous and unique mutation, respectively. The Spike, Nucleocapsid, NSP2, and RdRP showed substantially high mutation but no mutation was recorded in NSP9 and NSP11 protein. In spike (S) protein, 355 predominant mutations were recorded, highest in D614G. Alternatively, I120F in NSP2 protein, R203K and G204R in nucleocapsid protein, and P323L in RdRp were more recurrent. The Bangladeshi genomes belonged to phylogenetic lineages A, B, B.1, B.1.1, B.1.1.23, B.1.1.25, B.1.113, and B.1.36, among which 50.0% sequences owned by the pangolin lineage B.1.1.25. The study illustrates the spatial distribution of SARS-CoV-2, and molecular epidemiology of Bangladeshi isolates. We recommend continuous monitoring of R0 and genomic surveillance to understand the transmission dynamics and detect new variants of SARS-CoV-2 for proper control of the current pandemic and evaluate the effectiveness of vaccination globally.

This study explores the boosted regression trees (BRT), artificial neural network (ANN) and response surface methodology (RSM) to model and optimize the operational variables for the simulation of the Photolytic degradation of Sulfamethoxazole (SMX) and concurrent total organic carbon (TOC) removal, based on the experimental data set. Four candidate variables involving initial pH (2–11), initial SMX concentration (50–200 mg L−1), temperature (15–45 °C) and time (6–120 min) were considered for simultaneous optimization of SMX and TOC degradation. The result revealed that all the three models are statistically considerable as the values of R, R2, adj-R2 are >0.85, thus be deemed to work well in data fitting, prediction, and optimization, nevertheless, the values of R, R2, adj-R2, RMSE, MAE and AAD are far better for ANN and BRT than RSM method. The ∼100% SMX degradation conditions were found to be as follows: treatment time: 25 min, pH: 2.0, temperature: 35 °C and SMX concentration: 50 mg L−1, while the maximum possible removal of TOC under the given conditions was ∼25%. The percentage contribution (PC) of each variable was deduced by ANOVA analysis of proposed quadratic models which indicated that time and pH are important factors than temperature and SMX concentration. The photolytic intermediates and inorganic ions of SMX, were identified and a potential route of transformation was also proposed.

We studied the influence of the operational variables (viz. ethylene-glycol concentrations of 50–70%, temperatures of 155–185 °C, times of 30–90 min and numbers of PFI beating revolutions of 500–1500) on pulp yield and various paper properties (breaking length, stretch, burst index, tear index and brightness) obtained in the ethylene-glycol pulping of vine shoots, cotton stalks, leucaena ( Leucaena leucocephala ) and tagasaste ( Chamaecytisus proliferus ). The fuzzy neural network models used reproduced the experimental results with errors less than 15% and smaller than those provided by second-order polynomial models in all cases. An ethylene-glycol concentration of 65% at 180 °C for 75 min and 1500 PFI beating revolutions were found to provide substantial savings in energy, chemicals and facility investments as a result of operating under milder conditions than the strongest ones studied in this work. Tagasaste was found to be the most suitable raw material among those tested as it provided the paper sheets with the highest breaking length (4644 m), stretch (2.87%), burst index (2.46 kN/g), tear index (0.33 m Nm 2 /g) and brightness (40.92%); its pulp yield was also high (62.88%), which reflects efficient use of this raw material.

Polymer solutions and gels are frequently used to control excessive water production in oil and gas wells by reducing the permeability to water flow to a greater extent than to oil or gas flow (Relative Permeability Modifiers, RPM, or disproportionate permeability reduction, DPR). RPM and DPR can be used as synonymous in this study; however, specialists use RPM term for the cases in which permeability reduction is less compare to DPR. The significance of RPM agents, chemicals using in water-shutoff treatments, is that their placement does not require mechanical isolation. However, the performance of RPM treatment is still poor in field applications. This study applied numerical simulation methods to investigate the factors impacting RPM treatments on reservoir (Macroscopic) level. Furthermore, Design of Experiments (DOE) was used to rank these factors based on their influence on RPM performance (water cut reduction and oil recovery improvement). The results indicated that there are nine parameters which can enhance or downgrade the success of DPR treatments, treatments at oil/gas wells when use of DPR polymer or gel results in Disproportionate Permeability Reduction of treated formation. The performance of DPR treatment was more pronounced at low oil density, low oil viscosity, high gel penetration depth, and at high permeability heterogeneity among layers (linear flow is more dominated). However, the performance of DPR treatments was downgraded if the treatments were applied at high production flowrate, low ratio of residual resistance factor for water (Frrw) to residual resistance factor for oil (Frro), and high G-shape (crossflow indicator) values. Moreover, when the capillary forces dominate the flow (capillary-viscous number > 10), RPM results were not largely encouraging due to water blocking effect. On the other side, in the viscous dominated flow, RPM performance was more pronounced. These factors which were studied in this work can promote a short-term successful remedy, a long-term successful treatment, or even a failed treatment. Some of these factors can be controlled; the operator can choose the optimum level of the parameter, like production flowrate. However, other factors cannot be controlled, but the value of this study is still increase probability of success the treatment prior to field application.

In the organosolv pulping of the oil palm fronds, the influence of the operational variables of the pulping reactor (viz. cooking temperature and time, ethanol and NaOH concentration) on the properties of the resulting pulp (yield and kappa number) and paper sheets (tensile index and tear index) was investigated using a wavelet neural network model. The experimental results with error less than 0.0965 (in terms of MSE) were produced, and were then compared with those obtained from the response surface methodology. Performance assessment indicated that the neural network model possessed superior predictive ability than the polynomial model, since a very close agreement between the experimental and the predicted values was obtained.

Stress peening forming is widely used in the aeronautics industry to induce curvatures in wing skins. Most of the investigations of stress peen forming are empirical and experimental. In this paper, a three step numerical model that can simulate this process was developed. First, an implicit Finite Element Analysis (FEA) with ANSYS where a prebending moment along the spanwise direction of the component was performed. Then, an explicit FEA with LS-DYNA simulating shot impacts on the pre-stressed component was executed in order to obtain the resulting stresses inside the component. Finally, an implicit FEA with ANSYS was performed for calculating the arc heights and the curvature radii of the component in chordwise and spanwise directions. Numerical analysis of the process shows that the prebending moments have an influence not only on the residual stress profiles but also on the curvatures of the deformed component in chordwise and spanwise directions. This model was used to establish a relationship between the prebending moment and the resulting arc heights and residual stress profiles. The numerical strategies developed in this paper supply a useful tool for studying and optimizing the stress peening process. © 2011 Elsevier Ltd. All rights reserved.

Cognitive processing by intelligent systems involves the deletion of information in favor of higher level abstractions. This process can be addressed through the physics of computation but a formal model that explains this process has not been proposed yet. In this short paper, we propose a model that through physical constraints only generates optimal solution to the collapse of n objects into n sets. A numerical simulation of the model results in a logarithmic function of information loss and condensation that perfectly fits our knowledge of cognitive processes.

We study numerically orientation of rigid fibres in a turbulent flow. Instead of a Lagrangian approach, i.e. following fibres along trajectories and analyzing orientations after simulations, we are using a fibre orientation probability distribution (FOPD) model. The mathematical model predicting the two spherical orientation angles (in a three-dimensional computational domain) is presented and solved in a coupled manner, which is the novelty of our approach. Furthermore, numerical predictions are validated with experiments. The origin of the problem is in the papermaking industry, that is, distributing and orienting fibres optimally into a paper sheet produced.

The productivity of the Acetone Butanol Ethanol (ABE) fermentation can be significantly increased by application of various in situ product recovery (ISPR) techniques. There are numerous technically viable processes, but it is not clear which is the most economically viable in practice. There is little available information about the energy requirements and economics of ISPR for the ABE fermentation. This work compares various ISPR techniques based on UniSim process simulations of the ABE fermentation. The simulations provide information on the process energy and separation efficiency, which is fed into an economic assessment. Perstraction was the only technique to reduce the energy demand below that of a batch process, by approximately 5%. Perstraction also had the highest profit increase over a batch process, by 175%. However, perstraction is an immature technology, so would need significant development before being integrated to an industrial process.

Cancer cells frequently up-regulate DNA replication and repair proteins such as the multifunctional DNA2 nuclease/helicase, counteracting DNA damage due to replication stress and promoting survival. Therefore, we hypothesized that blocking both DNA replication and repair by inhibiting the bifunctional DNA2 could be a potent strategy to sensitize cancer cells to stresses from radiation or chemotherapeutic agents. We show that homozygous deletion of DNA2 sensitizes cells to ionizing radiation and camptothecin (CPT). Using a virtual high throughput screen, we identify 4-hydroxy-8-nitroquinoline-3-carboxylic acid (C5) as an effective and selective inhibitor of DNA2. Mutagenesis and biochemical analysis define the C5 binding pocket at a DNA-binding motif that is shared by the nuclease and helicase activities, consistent with structural studies that suggest that DNA binding to the helicase domain is necessary for nuclease activity. C5 targets the known functions of DNA2 in vivo: C5 inhibits resection at stalled forks as well as reducing recombination. C5 is an even more potent inhibitor of restart of stalled DNA replication forks and over-resection of nascent DNA in cells defective in replication fork protection, including BRCA2 and BOD1L. C5 sensitizes cells to CPT and synergizes with PARP inhibitors., Highlights • C5 binds to the helicase domain of DNA2 and inhibits its nuclease, ATPase, and helicase activities. • C5 inhibits DNA end resection for DNA double strand break repair and restart of stalled replication forks. • C5 suppresses over-resection of nascent DNA in cells defective in fork protection. • C5 sensitizes cancer cells to chemotherapeutic agents. Most chemotherapeutics introduce DNA lesions that block DNA replication to kill cancer cells. Upregulation of DNA repair proteins in cancer cells is a major reason for human cancer to become resistant to chemotherapeutics. DNA repair proteins such as DNA2 nuclease/helicase have long been proposed as targets for sensitization of cancer cells to chemotherapy. We identify a selective DNA2 inhibitor (C5) and demonstrate that DNA2 inhibition by C5 suppresses cancer cells to rescue stalled replication forks. Consequently, it sensitizes cancer cells to replication fork stalling agents such as camptothecin. Thus, C5 is a promising lead compound for developing new anticancer drugs.

Distillers' grains (DG), a co-product of a dry grind ethanol process, is an excellent source of supplemental proteins in livestock feed. Studies have shown that, due to its high polymeric sugar contents and ease of hydrolysis, the distillers' grains have potential as an additional source of fermentable sugars for ethanol fermentation. The benefit of processing the distillers' grains to extract fermentable sugars lies in an increased ethanol yield without significant modification in the current dry grind technology. Three different potential configurations of process alternatives in which pretreated and hydrolyzed distillers' grains are recycled for an enhanced overall ethanol yield are proposed and discussed in this paper based on the liquid hot water (LHW) pretreatment of distillers' grains. Possible limitations of each proposed process are also discussed. This paper presents a compositional analysis of distillers' grains, as well as a simulation of the modified dry grind processes with recycle of distillers' grains. Simulated material balances for the modified dry grind processes are established based on the base case assumptions. These balances are compared to the conventional dry grind process in terms of ethanol yield, compositions of its co-products, and accumulation of fermentation inhibitors. Results show that 14% higher ethanol yield is achievable by processing and hydrolyzing the distillers' grains for additional fermentable sugars, as compared to the conventional dry grind process. Accumulation of fermentation by-products and inhibitory components in the proposed process is predicted to be 2-5 times higher than in the conventional dry grind process. The impact of fermentation inhibitors is reviewed and discussed. The final eDDGS (enhanced dried distillers' grains) from the modified processes has 30-40% greater protein content per mass than DDGS, and its potential as a value-added process is also analyzed. While the case studies used to illustrate the process simulation are based on LHW pretreated DG, the process simulation itself provides a framework for evaluation of the impact of other pretreatments.

The influence of temperature (150–170 °C), pulping time (15–45 min) and soda concentration (5–10%) in the pulping of abaca on the yield, kappa, viscosity, breaking length, stretch and tear index of pulp and paper sheets, was studied. Using a factorial design to identify the optimum operating conditions, equations relating the dependent variables to the operational variables of the pulping process were derived that reproduced the former with errors lower than 25%. Using a high temperature, and a medium time and soda concentration, led to pulp that was difficult to bleach (kappa 28.34) but provided acceptable strength-related properties (breaking length 4728 m; stretch 4.76%; tear index 18.25 mN m2/g), with good yield (77.33%) and potential savings on capital equipment costs. Obtaining pulp amenable to bleaching would entail using more drastic conditions than those employed in this work.

The influence of chip size and moisture content on the combined sugar recovery after steam pretreatment of lodgepole pine and subsequent enzymatic hydrolysis of the cellulosic component were investigated using response surface methodology. Chip size had little influence on sugar recovery after both steam pretreatment and enzymatic hydrolysis. In contrast, the moisture of the chips greatly influenced the relative severity of steam pretreatment and, as a result, the combined sugar recovery from the hemicellulosic and cellulosic fractions. Irrespective of chip size and the pretreatment temperature, time, and SO2 loading that were used, the relative severity of pretreatment was highest at a moisture of 30–40 w/w%. However, the predictive model indicated that an elevated moisture content of roughly 50 w/w% (about the moisture content of a standard softwood mill chip) would result in the highest, combined sugar recovery (80%) over the widest range of steam pretreatment conditions.

SPORL (Sulfite Pretreatment to Overcome Recalcitrance of Lignocellulose) pretreatment was applied to switchgrass and optimized through an experimental design using Response Surface Methodology within the range of temperature (163-197 °C), time (3-37 min), sulfuric acid dosage (0.8-4.2% on switchgrass), and sodium sulfite dosage (0.6-7.4% on switchgrass). Performance of SPORL was compared with that of dilute acid (DA) and alkali (AL) in switchgrass pretreatment. Results indicated that SPORL pretreatment improved the digestibility of switchgrass through sufficiently removing hemicellulose, partially dissolving lignin, and reducing hydrophobicity of lignin by sulfonation. The removal of hemicellulose was more critical to substrate digestibility than the removal of lignin during SPORL pretreatment. SPORL pretreated switchgrass had better enzymatic digestibility than DA and AL pretreated ones. The SPORL pretreated switchgrass could be hydrolyzed by 83% within 48 h with 15 FPU (filter paper unit) cellulase and 30 CBU (cellobiose unit) β-glucosidase/g cellulose.

This paper based on the experiment simulated the short circuit of the electrical fire situation, and with the help of the theoretical calculation and numerical simulation, sets out to study the copper wire short circuit melted bead ignition capability for the combustible. From the experiment and calculation, it is found that the melted bead diameter and the fallen height that is from wire box to the combustible are important factors for the melted bead ignition capability. Meanwhile, to further study two related factors, the melted bead diameter is the key factor for the ignition capability for the combustible to some extent.

Yield and composition of pyrolysis oil in direct and indirect pyrolysis process were investigated which indicated that pyrolysis of defatted microalgae provided a potential way to convert protein and carbohydrate to biofuels. Defatted microalgae pyrolysis with lipid extraction has higher total oil yield than only microalgae direct pyrolysis. There was an increase for N-heterocyclic compounds and phenols and a decrease for hydrocarbons in defatted microalgae pyrolysis oil. There is an apparent decrease from C12 to C16 and nearly no carbon distribution from C17 to C22 for defatted microalgae pyrolysis. Based on composition of pyrolysis feedstock, pyrolysis oil yields were simulated by Compounds Biofuel Model and their accuracy was less than ±4.4%. Considering total oil yield and characteristics, microalgae pyrolysis after lipid extraction process is a promising way for microalgae utilization.

Different model structures were compared to simulate the characteristic process variables of the anaerobic digestion of maize, sugar beet and grain silage. Depending on the type and number of the required components, it can be shown that in comparison to the complex Anaerobic Digestion Model No. 1 (ADM1) different simplified model structures can describe the gas production rate, ammonia nitrogen and acetate concentration or pH value equally well. Since the reduction of the predominantly fast kinetics of the methanogenesis, acetogenesis or acidogenesis will only have little effect on the simulation of the specific gas production, it can be proven that the hydrolysis is the rate-limiting step during the uninhibited anaerobic digestion of complex particulate substrates. However, the stoichiometric comparison reveals that the model protein gelatine is not suitable for a representative characterization of agricultural energy crops.

A field measurement and computer modeling effort was made to assess the dilution field of pulped waste materials discharged into the wake of a US Navy frigate. Pulped paper and fluorescein dye were discharged from the frigate’s pulper at known rates. The subsequent particle and dye concentration field was then measured throughout the wake by a following vessel using multiple independent measures. Minimum dilution of the pulped paper reached 3.2 × 105 within 1900 m behind the frigate, or about 8 min after discharge. Independent measures typically agreed within 25% of one another and within 20% of model predictions. Minimum dilution of dye reached 2.3 × 105 at a down-wake distance of approximately 3500 m, or roughly 15 min. Comparison to model measurements were again within 20%. The field test was not only successful at characterizing wake dilution under one set of at-sea conditions, but was successful at validating the computer model used for assessing a wide range of ships and conditions.

The present work targeted the understanding of the influence of nine different hardwood species as feedstock on ethanol production yield and costs. It was found that the minimum ethanol revenue (MER) ($ per gallon to the producer) to achieve a 12% internal rate of return (IRR) on invested capital was smaller for low lignin content samples and the influence of species characteristics remained restricted to high residual lignin content. We show that if the pretreatment being applied to the feedstock targets or is limited to low lignin removal, one can expect the species to have a significant impact on overall economics, playing important role to project success. This study also showed a variation of up to 40% in relative MER among hardwood species, where maple, globulus and sweet gum varied the least. Sensitivity analysis showed ethanol yield per ton of feedstock had the largest influence in MER, followed by CAPEX.

The effects of 1-hydroxybenzotriazole (HBT) and the natural laccase mediators gallic acid, caffeic acid and p-hydroxybenzoic acid, on the enzymatic bleaching of flax pulp were compared. The treatment was performed under atmospheric air and oxygen pressure, and, for the first time, monitored by thermogravimetric analysis (TGA) for comparison with chemical analysis, FTIR and X-ray diffraction (XRD) spectroscopies. Thermogravimetric data were simulated by applying a nucleation kinetic equation to a combustion model based on four pseudo-components (hemicellulose, amorphous and crystalline cellulose, and lignin). The results thus obtained show that the effects of the natural mediators are similar to those of HBT and lead to increased order in cellulose microfibril surfaces. An increase in pulp crystallinity was additionally exposed by the XRD and FTIR techniques, and a reduction in microfibril equatorial size by the XRD patterns. Simulated DTG curves were used to determine the kinetic parameters for thermal degradation.

The effect of inhibition on the firing variability is examined in this paper using the biologically-inspired temporal noisy-leaky integrator (TNLI) neuron model. The TNLI incorporates hyperpolarising inhibition with negative current pulses of controlled shapes and it also separates dendritic from somatic integration. The firing variability is observed by looking at the coefficient of variation (CV) (standard deviation/mean interspike interval) as a function of the mean interspike interval of firing (ΔtM) and by comparing the results with the theoretical curve for random spike trains, as well as looking at the interspike interval (ISI) histogram distributions. The results show that with 80% inhibition, firing at high rates (up to 200 Hz) is nearly consistent with a Poisson-type variability, which complies with the analysis of cortical neuron firing recordings by Softky and Koch [1993, J. Neurosci. 13(1) 334-530]. We also demonstrate that the mechanism by which inhibition increases the CV values is by introducing more short intervals in the firing pattern as indicated by a small initial hump at the beginning of the ISI histogram distribution. The use of stochastic inputs and the separation of the dendritic and somatic integration which we model in TNLI, also affect the high firing, near Poisson-type (explained in the paper) variability produced. We have also found that partial dendritic reset increases slightly the firing variability especially at short ISIs. Copyright © 2000 Elsevier Science Ireland Ltd. 58 1-3 41 48 Cited By :18

Foldcore is an origami-like structural sandwich core which is manufactured by folding a planar base material into a three-dimensional structure. The manufacturing technology is open to a variety of base materials and also a range of unit cell geometries is feasible. FE-simulation is used to support mechanical testing of foldcores. Required input data for FE-simulation is a material model of the base material. So a test programme for aramid paper, the actual standard base material for foldcore production, is developed. A material model is extracted from test data and implemented in commercial FE-codes.

This paper describes rapid techniques to evaluate the methane potential and biomass yield of solid wastes. A number of solid wastes were mixed to provide a range of C:N ratios. Empirical formulae were calculated for each waste based on the results of chemical analysis and these formulae were used to estimate the COD equivalent and stoichiometric methane potential (SMP). The actual COD and biochemical methane potential (BMP) were determined experimentally for each waste and for both parameters there was a good agreement between the empirical and experimental values. The potential of adenosine triphosphate (ATP) to act as an indicator of biomass yield (mg VSS mg−1 COD removed) was determined during the anaerobic digestion process. The biomass yield determined from ATP analysis was in the range 0.01–0.25 mg VSS mg−1 COD removed which corroborated well with previously reported studies. Empirical formula based SMP together with ATP measurement were shown to provide rapid methods to replace or augment the traditional BMP and VSS measurements and are useful for evaluating the bioenergy and biomass potential of solid wastes for anaerobic digestion.

In this study, the optimal conditions for biomass torrefaction were determined by comparing the gain of energy content to the weight loss of biomass from the final products. Torrefaction experiments were performed at temperatures ranging from 220 to 280 °C using 20-80 min reaction times. Polynomial regression models ranging from the 1st to the 3rd order were used to determine a relationship between the severity factor (SF) and calorific value or weight loss. The intersection of two regression models for calorific value and weight loss was determined and assumed to be the optimized SF. The optimized SFs on each biomass ranged from 6.056 to 6.372. Optimized torrefaction conditions were determined at various reaction times of 15, 30, and 60 min. The average optimized temperature was 248.55 °C in the studied biomass when torrefaction was performed for 60 min.

Cellulosic biomass can be used as a feedstock for biofuel manufacturing. Pelleting of cellulosic biomass can increase its bulk density and thus improve its storability and reduce the feedstock transportation costs. Ultrasonic vibration-assisted (UV-A) pelleting can produce biomass pellets whose density is comparable to that processed by traditional pelleting methods (e.g. extruding, briquetting, and rolling). This study applied response surface methodology to the development of a predictive model for the energy consumption in UV-A pelleting of wheat straw. Effects of pelleting pressure, ultrasonic power, sieve size, and pellet weight were investigated. This study also optimized the process parameters to minimize the energy consumption in UV-A pelleting using response surface methodology. Optimal conditions to minimize the energy consumption were the following: ultrasonic power at 20%, sieve size at 4 mm, and pellet weight at 1g, and the minimum energy consumption was 2.54 Wh.

The present study investigated the feasibility of using Chlorella sorokiniana for CO2 sequestration from industrial flue gas. The flue gas emitted from the oil producing industry contains mostly CO2 and H2S (15.6% (v/v) and 120 mg L−1, respectively) along with nitrogen, methane, and other hydrocarbons. The high concentration of CO2 and H2S had an inhibitory effect on the growth of C. sorokiniana. Some efforts were made for the maximization of the algal biomass production using different techniques such as diluted flue gas, flue gas after passing through the scrubber, flue gas passing through serially connected photobioreactors and two different reactors. The highest reduction in the CO2 content of inlet flue gas was 4.1% (v/v). Some new pigments were observed in the flue gas sequestered biomass. Fatty acid composition in the total lipid was determined to evaluate its suitability for food, feed, and biofuel.