Process integration for energy and water saving,increasing efficiency and reducing environmental impact

This article provides an introduction to the current Special Issue of the journal of Applied Thermal Engineering, which contains eight carefully selected articles from the 12th Conference Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction – PRES’09. This issue builds upon the multi-year co-operation between the PRES conference planners and the journal. The articles cover important subjects of increased energy and resource efficiency in industrial production and emission reduction. The first paper is based on the conference plenary presentation and is providing an overview of the historical developments in the Process Integration (PI) area and the apparently significant contribution of the PRES series of conferences. This is followed by a second group of two papers dedicated to important PI topics – retrofit of Heat Exchanger Networks and simultaneous minimisation of water and energy consumption. The third group contains three contributions dedicated to energy savings via the application of PI in specific industrial sectors. The final fourth group of two papers is dedicated to the implementation of energy conversion technologies. Those papers are discussing environmental impact of waste-to-energy processes and heat exchanger improvements.     

OBSERVER-BASED STABILIZATION OF SYSTEMS WITH MONOTONIC NONLINEARITIES

We design an observer-based control law for a class of systems that include monotonic nonlinearities of the unmeasured states. Our observer results in nonlinear error dynamics which can be represented as the feedback interconnection of a linear system and a time-verying multivariable sector nonlinearity. The convergence of the estimation error is guaranteed by an observer matrix that renders the linear part passive, and is computable with LMI software. The feedback design is completed by combining the observer with a control law that renders the plant input-to-state stable with respect to the state estimation error.     

Synthetic Biology and Tissue Engineering: Toward Fabrication of Complex and Smart Cellular Constructs

Tissue engineering approaches, with the goals of replacing or recovering damaged or diseased tissues, or of reconstituting tissues in vitro for disease modeling and drug development, have the potential to make significant contributions to medicine. Advances in stem cell biology, biomaterial synthesis and characterization, and microscale technologies have made engineered tissues a reality. However, the classic tools used to build tissues in the lab do not allow for complete control of cell behaviors. More recently, synthetic biology principles have developed robust and versatile approaches to program cells with artificial genetic circuits, where cell behavior and function can be manipulated. At the interface between synthetic biology and tissue engineering, there is space for a new area of investigation where material engineering and cellular engineering complement and sustain each other. In this progress report, synthetic biology principles and how they have been used to engineer cells with potential to dictate cell behavior and function in tissue constructs of the future are briefly described. It is believed that this research area still needs further exploration to fully exploit synthetic biology to make smart and functional cellular constructs for therapeutic and in vitro applications.     

Toward persistent autonomous intervention in a subsea panel

Intervention autonomous underwater vehicles (I-AUVs) have the potential to open new avenues for the maintenance and monitoring of offshore subsea facilities in a cost-effective way. However, this requires challenging intervention operations to be carried out persistently, thus minimizing human supervision and ensuring a reliable vehicle behaviour under unexpected perturbances and failures. This paper describes a system to perform autonomous intervention—in particular valve-turning—using the concept of persistent autonomy. To achieve this goal, we build a framework that integrates different disciplines, involving mechatronics, localization, control, machine learning and planning techniques, bearing in mind robustness in the implementation of all of them. We present experiments in a water tank, conducted with Girona 500 I-AUV in the context of a multiple intervention mission. Results show how the vehicle sets several valve panel configurations throughout the experiment while handling different errors, either spontaneous or induced. Finally, we report the insights gained from our experience and we discuss the main aspects that must be matured and refined in order to promote the future development of intervention autonomous vehicles that can operate, persistently, in subsea facilities.     

Improvement of the impact strength of ethylene‐propylene random copolymers by nucleation

Five ethylene‐propylene random copolymers were nucleated with two soluble nucleating agents. Ethylene content changed between 1.7 and 5.3 wt %, while nucleating agent content was adjusted according to the solubility of the additive. It changed from 0 to 5000 ppm for the sorbitol (1,2,3‐tridesoxy‐4,6:5,7‐bis‐O‐[(4‐propylphenyl) methylene]‐nonitol) and from 0 to 500 ppm for the trisamide compound (1,3,5‐benzene‐trisamide) used. Crystalline structure was analyzed in detail by various methods (DSC, XRD, and SEM). Mechanical properties were characterized by tensile and instrumented impact measurements. The results showed that most properties changed moderately upon nucleation, but impact resistance increased considerably. Spherulitic structure was not detected, but instead in the presence of the soluble nucleating agents used a microcrystalline structure formed. The large increase of impact resistance could not be related directly to changes in crystalline morphology. On the other hand, local rearrangement of morphology was detected by XRD and SEM analysis including an increase of lamella thickness, crystal orientation, and the formation of shish‐kebab structures in the core of the injection molded specimens. A small increase in the γ‐phase content of PP was also observed. These changes increased crack propagation energy considerably leading to the large improvement observed in impact resistance. Although the phenomenon could be related to ethylene content, differences in molecular weight also helped to explain the changes observed. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43823.     

Modeling of liver metastatic disease with applied drug therapy

Colorectal carcinoma is acknowledged as the second leading cause of total cancer-related death in the European Region. The majority of deaths related to colorectal carcinoma are connected with liver metastatic disease. Approximately, in 25% of all patients, liver metastatic disease is diagnosed at the same time as the primary diagnosis, while up to a quarter of others would develop liver metastases in the course of the illness. In this study, we developed reaction-diffusion model and analyzed the effect of drug therapy on liver metastatic disease for a specific patient. Tumor volumes in specific time points were obtained using CT scan images. The nonlinear function for cell proliferation rate as well as data about clinically applied drug therapy was included in the model. Fitting procedure was used for parameter estimation. Good agreement of numerical and experimental results shows the feasibility and efficacy of the proposed system.     

Strategies to enhance dry reforming of methane: Synthesis of ceria-zirconia/nickel–cobalt catalysts by freeze-drying and NO calcination

To improve the activity of nickel–cobalt (NiCo) catalyst supported on ceria-zirconia (CeZr) in the dry reforming of methane (DRM) with carbon dioxide, and to lower the coking rate in this process, 1.5 wt.% and 2.5 wt.% NiCo catalysts were prepared using two approaches, i.e. freeze-drying (FD) and NO calcination for comparison against oven-drying (OD) and air calcination (air), respectively. Their impact was studied for 20 h of DRM at 750 ^°C and 1.2 bar, with undiluted CH₄–CO₂ feed simulating the real conditions. NO-calcined samples show, on average, more pronounced improvement through increased conversion of CH₄ (90%), followed by FD samples (85%) from the air and OD-prepared samples (both 82%). Coking content varied between 0.67 and 0.82 wt.%. The observed slow catalyst deactivation might be caused by sintering of the catalysts. Higher quantity of CO than H₂ for syngas production was obtained, owing to concurrent reverse water-gas shift side reaction, and high redox properties of the defective CeZr lattice that enabled surface carbon gasification by continuous replenishment of oxygen from the support to produce CO, of which the latter phenomenon also explains the low carbon deposition. H₂/CO ratio between 0.42 and 0.85 was achieved, with FD and NO samples fared better (0.83–0.85) over the ones prepared by conventional methods (0.73–0.82) for 2.5%NiCo loaded catalysts.     

Evaluation of in vitro activity of ofloxacin against 73 strains of Chlamydia trachomatis isolated from gynecologic infections

Perfluorocarbon liquids have gained wide acceptance as intraoperative tools that can simplify vitreoretinal surgical maneuvers. These low-viscosity liquids facilitate injection into the eye and removal from the eye during surgery. Tolerance to perfluoroperhydrophenanthrene and the development of proliferative vitreoretinopathy with its extended use are not clear. The authors present the clinical and histologic findings of a patient, previously lost to follow-up, who was examined after several weeks of intraocular tamponade with perfluoroperhydrophenanthrene. Damage to the retina was seen in response to the long-term postoperative use of perfluoroperhydrophenanthrene.     

New approach for equalising phase velocities in coupled microstriplines

A new method for correcting the difference between the phase velocities of even and odd modes in coupled microstrip lines is suggested. The method is based on use of a biisotropic substrate with an appropriate value of the parameter ξ²/εμ