EVALUATION OF HARVESTING TIME EFFECTS AND CULTIVARS OF KENAF ON PAPERMAKING

This study investigates the effect of six cultivars named Cubano, Niger, Cubano 2032, 9277, 7551 and, 7566, of kenaf and three harvesting time stages on pulp and handsheet paper properties of kenaf, which were accomplished in north of Iran. Six cultivars of an Iranian kenaf (Hibiscus Cannabinus L.), were planted on 19 May 2007, and harvested at 85, 105, and 135 days after planting. It was understood that with the increase of plant age, the fiber yield increased. Maximum yield at each of three harvesting time stages was related to Niger. Consequently, if a high fiber yield is sought, Niger can be recommended. But if a paper with high strength properties is to be requested, Cubano 2032 is strongly associated with significant burst, tear, breaking length, and fold endurance even though its yield shows a bit lesser than Niger at short harvesting times. Moreover, at second harvesting time stage, maximum strength properties of handsheets such as burst, tear, breaking length, and fold endurance were related to Cubano, though the fiber yield of this cultivar was a bit lesser than Niger, but it was still more than Cubano 2032. In comparison between harvesting time stages, it is clearly understood from the composition of harvesting time of third stage to first and second stage, a minor positive effect on the handsheets properties with increasing harvesting times has appeared

The Evolution of Criticality in Deep Reinforcement Learning

In Reinforcement Learning (RL), certain states demand special attention due to their significant influence on outcomes; these are identified as critical states. The concept of criticality is essential for the development of effective and robust policies and to improve overall trust in RL agents in real-world applications like autonomous driving. The current paper takes a deep dive into criticality and studies the evolution of criticality throughout training. The experiments are conducted on a new, simple yet intuitive continuous cliff maze environment and the Highway-env autonomous driving environment. Here, a novel finding is reported that criticality is not only learnt by the agent but can also be unlearned. We hypothesize that diversity in experiences is necessary for effective criticality quantification which is majorly driven by the chosen exploration strategy. This close relationship between exploration and criticality is studied utilizing two different strategies namely the ex ponential ε-decay and the adaptive ε-decay. The study supports the idea that effective exploration plays a crucial role in accurately identifying and understanding critical states

Removal of recalcitrant organic compounds from an industrial complex effluent by heterogeneous Fenton-type treatment

Because of their chemical complexity, industrial chemi-mechanical pulping effluents are evaporated and burned, in spite of the high associated cost involved in these processes. The aim of this study was to remove recalcitrant compounds from this kind of wastewater using a Fenton-type treatment. The main parameters involved in the process and their influence on the results were determined. Homemade catalysts based on CuO, Fe2O3, NiO and ZnO, supported on γ-Al2O3 have been tested for catalytic oxidation, and the CuO/γ- Al2O3 catalysts showed the greatest effect on total organic carbon (TOC) reduction (52.7%). A series of twolevel factorial experiments was subsequently applied to evaluate the most favorable range of conditions for CuO/γ-Al2O3 application. The studied variables were hydrogen peroxide concentration ([H2O2], g/L), active phase content (metal oxide supported on alumina, %), mass of catalyst (metal oxide/alumina system, g), and reaction temperature (°C). The highest reduction of all parameters was obtained at the superior level of all variables with CuO/γ-Al2O3, achieving reductions of chemical oxygen demand (COD) and TOC between 40 and 50%. Increasing catalyst mass did not produce additional benefit. This variable has a significant effect only on the reduction of aromatic compounds. At its low level, reduction in aromatic content exceeded 80%. Color reduction was influenced only by temperature (maximum reduction of 90%)Fil: Covinich, Laura Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Felissia, Fernando Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Fenoglio, Rosa Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Area, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentin

Design and Development of a New Innovative Transcatheter Mitral Valve

Mitral regurgitation is the most common valvular insufficiency, affecting more than 10% of people older than 75 years old in the United States. This translates into approximately 4 million people suffering from significant mitral regurgitation and 250,000 new cases of severe mitral regurgitation every year. The objective of this thesis is to design and test a novel transcatheter mitral valve with in-stent artificial chordae tendineae that better reproduces the native mitral complex as well as studying the cruciality of the role of chordae tendineae as a part of mitral valve apparatus. For this purpose, numerous valves were designed and tested under physiological conditions before the optimal design was obtained. In order to study vorticity fields, viscous energy dissipation, and mitral regurgitation, the data collected from PIV measurements containing velocity fields were post processed. Particle trajectory was also performed to trace the particles inside the ventricle, during systole. Findings of this study show that addition of the artificial chordae leads to a better performance of the mitral valve in terms of leaflet coaptations. In addition to what has been said, presence of the artificial chordae leads to significant improvements in terms of flow patterns, vortex formation, viscous energy dissipation and mitral valve regurgitation compared to the case in which the chordae were removed

INHIBITORY EFFECTS OF WILD BARLEY (HORDEUM SPONTANEUM Koch.) RESIDUES ON GERMINATION AND SEEDLING GROWTH OF WHEAT (TRITICUM AESTIVUM L.) AND ITS OWN PLANT

Laboratory studies were conducted to examine the effects of different concentrations of wild barley (Hordeum spontaneum Koch.) shoot and seed extracts on germination and seedling growth of wheat (Triticum aestivum L.) and wild barley. In this study, all wild barley shoot extract concentrations (with exception of lowest concentration) significantly reduced wheat seed germination after 7 days. Shoot extract concentrations of 60 and 120 g / L significantly reduced shoot and root lengths, shoot fresh and dry weights, and, root fresh and dry weights of wheat. Seed germination of wheat was not affected by intermediate wild barley seed extracts. Considerably, some extracts of wild barley seeds stimulated the germination and growth of wheat. Wild barley shoot and seed extracts at low level stimulated the growth of its own plant, however, its germination and seedling growth were inhibited at higher shoot extract concentrations. The results of this investigation show that wild barley shoot extracts exert more allelopathic effects on germination and growth of wheat and its own plant than those of seed extracts

A State of the Art on Railway Simulation Modelling Software Packages and Their Application to Designing Baggage Transfer Services

There is a new baggage transfer service suggested in Newcastle Central Station. In order to prove that this service is feasible, a simulation model can be developed to test the concept and operating pattern behind. For the purposes of this paper, we intend to organize a literature review on simulation modelling software packages employed to study service design. Specifically, this paper has compared five different simulation software packages used by the railway industry to study service-related challenges. As a result, it is suggested that SIMUL8, a macroscopic discrete event-based software package, should be used among the five compared ones because of its simplicity and the ability to give practical results for the design and performance of such a baggage transfer system

Model-based Control of Large-scale Baggage Handling Systems: Leveraging the Theory of Linear Positive Systems for Robust Scalable Control Design

Large-scale baggage handling systems, or large-scale logistic networks, for that matter, pose interesting challenges to model-based control design. These challenges concern computational complexity, scalability, and robustness of the proposed solutions. This thesis tackles these issues in a collection of papers organized in two overlapping parts. The first part concerns modeling and Model Predictive Control (MPC) design of large-scale baggage handling systems (BHSs), where a modeling framework for BHSs is proposed that is subsequently used to develop an MPC scheme for control of large-scale BHSs. The MPC controller optimizes for the timely arrival of pieces of baggage at their destination within the BHS network under capacity constraints while minimizing the overall cost of transporting pieces of baggage. Several formulations for the resulting constrained optimization problem are proposed, and they are compared with each other in terms of closed-loop performance and computational complexity. It is shown, via simulation studies, that the proposed solutions can outperform a heuristics-based approach commonly used for control of BHSs while scaling well to larger BHS network instances. In its second part, the thesis focuses on robustness of control design in the face of a partially known disturbance input (i.e., input baggage demand), and especially on developing a scalable tube-based MPC scheme. For this purpose, considering the BHS model essentially as a linear positive system, a linear-programming-based approach is proposed for the joint calculation of a robustly positively invariant subset and a constrained state feedback controller that minimizes the disturbance-driven L∞ norm of the output over this set. A tube-based MPC control scheme is finally developed by coupling the state feedback controller with a nominal MPC controller, guaranteeing recursive feasibility and asymptotic stability. It is shown via simulation studies that the proposed tube-based approach is effective against unpredictable disturbances. In addition, since the design of both the nominal MPC controller and the state feedback controller involves only linear programs, the proposed tube-based approach scales well to BHS networks of larger size.Linear positive systems are of interest in several branches of engineering, logistics, biochemistry, and economics. As a spin-off topic and inspired by the applications of the theory of linear positive systems to modeling and control design of systems in the mentioned domains, the third part of the thesis focuses on the reachability analysis of discrete-time linear positive systems. More specifically, we revisit the problem of characterizing the subset of the state space that is reachable from the origin for discrete-time linear positive systems. This problem is of interest in topics such as optimal control of linear positive systems and realization theory of linear positive systems. It is established in this thesis that the reachable subset can be either a polyhedral or a nonpolyhedral cone. For the single-input case, a characterization is provided of when the infinite-time and the finite-time reachable subsets are polyhedral. Finally, for the case of polyhedral reachable subsets, a method, based on solving a set of linear equations, is provided to verify whether a target set can be reached from the origin using positive inputs.TRAIL Thesis Series no. T2022/8, the Netherlands TRAIL Research SchoolTeam DeSchutte