Dottorato in Advanced modelling, materials and technologies
Coordinatore
Prof.ssa Ilaria Cacciotti
Lingua
Italiano/Inglese
Durata
3 anni
Descrizione del progetto formativo
Il Dottorato di ricerca “AMoMAT-Advanced Modelling, MAterials and Technologies” si prefigge di fornire un terzo livello di formazione fortemente multi- e inter-disciplinare, su tematiche di ricerca ad ampio spettro e di tipo trasversale per la modellazione avanzata, la formulazione, caratterizzazione e applicazione di materiali, lo sviluppo di tecnologie innovative. Sono approfondite tematiche di ricerca in settori dell'ingegneria industriale che spaziano dall'ingegneria dei materiali, alla meccanica applicata alle macchine, alle costruzioni di macchine, alla fluidodinamica, alla tecnologia meccanica, a misure meccaniche e meccatronica, includendo aspetti trasversali di matematica e di scienza delle costruzioni. Il Dottorato AMoMAT intende formare profili di elevato spessore e altamente qualificate, in grado di rispondere e soddisfare le esigenze e le dinamiche del mondo industriale e del mercato correlato, che richiedono competenze inter-/multi-disciplinari, oltre a capacità di applicare approcci, metodologie e tecnologie innovativi alla progettazione e allo sviluppo di nuovi prodotti.
Il dottorato riguarda i seguenti settori di ricerca:
- Geometria e Algebra (area CUN 01/A), con un focus particolare sullo sviluppo di grafi, strutture matematiche in grado di modellare relazioni tra oggetti, con applicazione in numerose aree di ricerca, quali la Chimica, la Fisica, la Meccanica statistica, la Biologia, lo studio di Social network.
- Modellazione e Progettazione Meccanica (area CUN 09/A), per lo sviluppo di modelli di calcolo attraverso metodologie innovative, e lo sviluppo di sistemi per la sperimentazione e la validazione dei modelli.
- Tecnologie e Sistemi di Lavorazione (area CUN 09/B) per la produzione di materiali e manufatti innovativi, sia polimerici che compositi
- Scienza e Tecnologia dei Materiali (area CUN 09/D) (anche a partire da materiali di scarto nell’ottica della Circular Economy e dello zero waste standard) per applicazioni in vari settori, in particolare per quelli biomedicale, ambientale e alimentare
- Misure Meccaniche e Meccatronica (area CUN 09/E), con particolari competenze in progettazione di dispositivi robotici, caratterizzazione di strumenti di misura e sviluppo di metodi di misura.
- Scienza delle Costruzioni (area CUN 08/B), incentrata, in particolare, su modellazione di materiali compositi.
A tal fine, il percorso formativo prevede l'istituzione di corsi e lo svolgimento di ricerche in settori di confine tra le discipline tradizionali, valorizzando al contempo il carattere fortemente multidisciplinare del Dottorato. La molteplicità di competenze scientifiche e di attività di ricerca che caratterizzano il Collegio, insieme alla disponibilità di laboratori e a una vasta rete di cooperazioni internazionali, assicurano un ambiente stimolante per lo studio e la ricerca.
Obiettivi del corso
L’obiettivo principale del corso di Dottorato è formare esperti di elevato profilo scientifico, in grado di operare nella ricerca e sviluppo di diversi settori, con approccio metodologico omogeneo alimentato dalle esperienze culturali e di ricerca presenti nel Collegio. Diventa cruciale nella formazione di Dottori di Ricerca la cross-fertilizzazione delle conoscenze, al fine di fornire loro gli strumenti necessari a contribuire in modo efficace e concreto all’innovazione.
Saranno formati ricercatori e tecnici altamente specializzati in settori avanzati dell'Ingegneria Industriale quali:
• modellazione e progettazione di nuovi materiali, componenti e sistemi;
• modellazione fluidodinamica e dell’interazione fluido/struttura;
• messa a punto di processi di sintesi di materiali;
• sviluppo di tecnologie di processo;
• conoscenza delle principali tecniche di diagnosi ed analisi.
I dottorandi di ricerca acquisiranno competenze necessarie a identificare e affrontare in modo opportuno e efficace le problematiche e criticità associate ai settori di ricerca specifici, applicando, in modo autonomo, strategie di problemi solving. Svilupperanno soft skills, quali capacità di lavorare in team, di organizzare e gestire le proprie attività, di condividere competenze a livello interdisciplinare, di divulgare i risultati acquisiti in modo conciso e chiaro, sia per iscritto tramite pubblicazione di articoli scientifici, che in modalità orale tramite presentazioni a conferenze. Corsi dedicati saranno finalizzati a acquisire conoscenze multidisciplinari, approcci metodologici avanzati, gli strumenti utili per effettuare la ricerca bibliografica di documenti scientifici in maniera opportuna, come anche per la stesura di report e articoli scientifici, competenze tecnico/scientifiche orientate alla ricerca applicata e spendibili concretamente nel mercato del lavoro, grazie all’interazione con imprese ed enti di ricerca, coinvolte nella progettazione del Corso.
Sbocchi occupazionali e professionali previsti
La qualificazione professionale acquisita rende i Dottori di Ricerca idonei a collaborazioni di livello nazionale ed internazionale, con istituzioni pubbliche e private quali università, enti di ricerca, amministrazioni centrali e periferiche, aziende, che operano in tutti i settori scientifici caratterizzanti il Corso di Dottorato, soprattutto nell’ambito dell'innovazione e dello sviluppo della produzione, della progettazione avanzata, della pianificazione, programmazione e gestione di sistemi complessi.
I principali sbocchi occupazionali previsti sono relativi a:
• ricerca accademica (borse di post-dottorato, assegni di ricerca o contratti da ricercatori in università italiane e straniere),
• ricerca negli enti pubblici e privati, sviluppo e/o servizi, trasferimento tecnologico,
• aziende aeronautiche e agenzie spaziali,
• industrie per l'automazione e la robotica,
• imprese manifatturiere per la produzione, l'installazione, il collaudo, la manutenzione e la gestione di macchine,
• professionista in aziende operanti nel settore manifatturiero e dei servizi, dell’automazione industriale e IT applicato all’industria.
Ph.D. Course in Advanced modelling, materials and technologies-AMoMAT
Coordinator
Prof. Ilaria Cacciotti
Language
Italian/English
Duration
3 years
Description of the Training Program
The PhD program “AMoMAT – Advanced Modelling, MAterials and Technologies” aims to provide a highly multi- and interdisciplinary third-level education on broad and transversal research topics, including advanced modeling, material formulation, characterization and application, and the development of innovative technologies. Research themes in industrial engineering are explored extensively, ranging from materials engineering, applied mechanics, machine design, fluid dynamics, mechanical technology, mechanical measurements, and mechatronics, including transversal aspects of mathematics and structural science.
The AMoMAT PhD seeks to train highly qualified professionals capable of meeting the evolving needs of the industrial sector and related markets, requiring inter-/multi-disciplinary expertise as well as the ability to apply innovative approaches, methodologies, and technologies to the design and development of new products.
The PhD covers the following research areas:
- Geometry and Algebra (CUN Area 01/A): Focused on the development of graphs and mathematical structures capable of modeling relationships between objects, with applications in Chemistry, Physics, Statistical Mechanics, Biology, and Social Network analysis.
- Mechanical Modeling and Design (CUN Area 09/A): Development of computational models using innovative methodologies and systems for experimental validation.
- Technologies and Manufacturing Systems (CUN Area 09/B): Production of innovative polymeric and composite materials and artifacts.
- Materials Science and Technology (CUN Area 09/D): Including work with waste materials in the perspective of Circular Economy and zero-waste standards, for applications in biomedical, environmental, and food sectors.
- Mechanical Measurements and Mechatronics (CUN Area 09/E): With particular expertise in robotic device design, measurement instrumentation, and the development of measurement methods.
- Structural Engineering (CUN Area 08/B): Particularly focused on modeling of composite materials.
To this end, the training program includes the establishment of courses and the conduct of research in areas at the intersection of traditional disciplines, emphasizing the strongly multidisciplinary nature of the PhD. The breadth of scientific expertise and research activities within the Doctoral Board, together with access to laboratories and an extensive international collaboration network, ensures a stimulating environment for study and research.
Program Objectives
The main objective of the PhD program is to train researchers of high scientific caliber, capable of operating in research and development across multiple sectors, with a consistent methodological approach enriched by the cultural and research experiences of the Doctoral Board. Cross-fertilization of knowledge is crucial for PhD training, providing students with the necessary tools to contribute effectively to innovation.
Graduates will acquire advanced expertise in industrial engineering fields such as:
- Modeling and design of new materials, components, and systems;
- Fluid dynamics modeling and fluid-structure interaction;
- Development of material synthesis processes;
- Process technology development;
- Knowledge of key diagnostic and analytical techniques.
PhD candidates will develop the skills to identify and address research challenges effectively, applying problem-solving strategies independently. They will also acquire soft skills, including teamwork, activity planning and management, interdisciplinary knowledge sharing, and effective communication of results, both in writing through scientific publications and orally at conferences. Dedicated courses will provide multidisciplinary knowledge, advanced methodological approaches, tools for literature research, report and article writing, and technical-scientific skills applicable to the labor market, through interaction with companies and research institutions involved in the program design.
Career Opportunities and Professional Prospects
The qualification acquired enables PhD graduates to engage in national and international collaborations with public and private institutions, including universities, research centers, central and local administrations, and companies operating across all scientific sectors represented in the PhD program, particularly in innovation, production development, advanced design, planning, programming, and management of complex systems.
Key career opportunities include:
- Academic research (postdoctoral fellowships, research grants, or research contracts at Italian and foreign universities);
- Research in public and private entities, development and/or services, technology transfer;
- Aerospace companies and space agencies;
- Automation and robotics industries;
- Manufacturing companies involved in production, installation, testing, maintenance, and management of machinery;
- Professional roles in companies operating in manufacturing, industrial automation, and IT applied to industry.
Coordinator
Prof.ssa Ilaria Cacciotti ,
Role: Professore Ordinario
Institution: Università degli Studi Unicusano Roma, Italia
SSD: IMAT-01/A
Members
Prof. Daniele Chiappini
Role: Professore Ordinario
Institution: Università degli Studi Unicusano Roma, Italia
SSD: IIND-01/F
Prof. Alfredo Donno
Role: Professore Ordinario
Institution: Università degli Studi Unicusano Roma, Italia
SSD: MATH-02/B
Prof. Oliviero Giannini
Role: Professore Ordinario
Institution: Università degli Studi Unicusano Roma, Italia
SSD: IIND/02/A
Prof. Stefano Guarino
Role: Professore Ordinario
Institution: Università degli Studi Unicusano Roma, Italia
SSD: IIND-04/A
Prof.ssa Ilaria Mileti
Role: Professore Associato
Institution: Università degli Studi Unicusano Roma, Italia
SSD: IMIS-01/A
Prof.ssa Francesca Nerilli
Role: Professore Associato
Institution: Università degli Studi Unicusano Roma, Italia
SSD: CEAR/06 A
Prof. Tiziano Pagliaroli
Role:Professore Associato
Institution: Università degli Studi Unicusano Roma, Italia
SSD: IIND-01/F
Prof. Riccardo Panciroli
Role: Professore Ordinario
Institution: Università degli Studi Unicusano Roma, Italia
SSD: IIND/03 A
Prof. Gennaro Salvatore Ponticelli
Role: Professore Associato
Institution: Università degli Studi Unicusano Roma, Italia
SSD: IIND-04/A
Prof. Iulian Vasile Antoniac
Institution: University Politehnica Of Bucharest, Romania
SSD: IMAT-01/A
Prof. Michael Hanss
Institution: Universität Stuttgart, Germania
SSD: IIND/02/A
Prof. Verena Krausel
Institution: Fraunhofer Institute For Machine Tools And Forming Technology Iwu, Germania
SSD: IIND-04/A
Prof. Mario Monzon
Institution: Universidad De Las Palmas De Gran Canaria, Spagna
SSD: IMAT-01/A
Regolamento del Corso
Missioni fuori sede
Soggiorno all'estero
Attestazione Esami & Corsi
Acquisto materiale per la ricerca
- Richiesta di autorizzazione all’acquisto di materiale per la ricerca
- Domanda di liquidazione acquisto materiale
Esame finale
Courses, seminars, conferences
XLI Cycle
Jordan Carducci
Biography
Bachelor's degree in Industrial and Management Engineering from the Niccolò Cusano University, with a thesis on Operational Research and applications of graph theory. I obtained my Master's degree from the same university with a thesis on the implementation of algorithms for risk management.
Currently a PhD student in Advanced Modelling, Materials and Technologies (cycle XLI).
Research interests include optimisation and control systems applied to Additive Manufacturing processes, failure risk management and fuzzy logic applications for modelling interactions between process factors and their impact on the mechanical properties of components.
Description of phd thesis
According to scientific literature, the thermal history in Additive Manufacturing processes is one of the critical factors in the development of defects in the final part. Thermal gradients, which are established differently depending on the geometry and process conditions, make the analysis of heat exchange phenomena complex. In particular, it is difficult to exercise accurate control over the thermo-viscoelastic properties of the material at the smallest scales of investigation.
The PHD research focuses on identifying the causes that lead to failures in additive manufacturing, using simulation and control methodologies based on multi-sensor fusion, numerical modelling, statistical approaches and fuzzy logic.
The ultimate goal is to build a model capable of describing the interactions between different scales (micro, meso and macro) using multiphysical approaches and identification and control systems, in order to reduce the gap between theoretical analysis and actual behaviour in additive manufacturing processes.
Maria Strazza
Biography
My name is Maria Strazza, after completing my Bachelor's degree in Chemical Engineering at Sapienza University of Rome, I decided to pursue a Master's degree focused on the development of more sustainable processes, with particular attention to circular economy principles. I graduated in Chemical Engineering for Sustainable Development at Campus Bio-Medico University of Rome.
Following my studies, I gained one year of experience in the pharmaceutical industry, where I worked in automation engineering. However, I later decided to reconnect with my strong interest in science, particularly chemistry and materials science.
In November, I began my PhD program in Advanced Modelling, Materials and Technologies at University Niccolò Cusano in Rome, under the supervision of Prf. Ilaria Cacciotti.
Brief description of PhD thesis topic
Approximately one-third of all food produced globally (around 2.5 billion tons per year) is lost or wasted, representing a major environmental and economic challenge. However, food waste such as fruit residues, eggshells, grape pomace, and meat and fish by-products are rich in biopolymers, minerals, and bioactive compounds that can be valorized into high-added-value materials.
This PhD project aims to extract and characterize bioactive compounds from selected food waste sources and to investigate their potential applications in sustainable biomaterials for food packaging and biomedical fields. Computational approaches, including Quantitative Structure–Activity Relationship (QSAR) modelling, will be used to correlate chemical structure with biological activity and guide material design.
In parallel, process simulation tools (e.g., Aspen Plus) will be employed to model and optimize extraction and thermal treatments (such as calcination of mineral-rich waste), evaluating process efficiency, scalability, and environmental impact.
The project integrates waste valorization, computational modelling, and process engineering to support circular economy strategies and the development of sustainable materials.
Pasquale Scarmozzino
Biography
My name is Pasquale Scarmozzino and I am a young mechanical engineer with a solid academic background and practical experience in the fields of numerical simulation, CAD design and experimental prototyping. During my studies at the Niccolò Cusano University, which I completed with a master's degree in Mechanical Engineering with a specialisation in Automotive, I combined my theoretical training with various applied research activities. In particular, I actively participated in the European projects H2020 FutPrint50 and Horizon Europe HASTA, focused on advanced technologies for mobility and aerospace, contributing to the design of mechanical components, the implementation of CFD and FEM models, and the development of simulation interfaces in Python. These experiences have allowed me to develop a solid mastery of tools such as Autodesk Inventor, Catia, Ansys Fluent, LS-Dyna, and MatLab/Simulink. In November, I was awarded a doctoral scholarship thanks to the project proposed below.
PhD Project
In my PhD project, I will study how phase synchronisation between two side-by-side propellers affects not only aerodynamic noise, as already widely demonstrated in recent literature, but above all aerodynamic performance, in particular the thrust generated and propulsive efficiency. Several studies have shown that modifying the relative phase between synchronised rotors can lead to significant noise reductions due to constructive and destructive interference phenomena between the acoustic fields. However, it remains unclear whether these same phase configurations improve or worsen the propellers' ability to produce thrust, due to the interactions between the motion fields induced by the two rotors. To investigate this aspect, I will carry out a high-precision experimental campaign using a specially designed test bench. Two co-rotating propellers are electronically synchronised via a PID control system in a master-slave configuration, which allows me to precisely impose different phase shifts (e.g. 0°, 45°, 75°, etc.). In addition, I am testing different distances between the propeller hubs (d/D = 1.02, 1.10, 1.20) to analyse how the aerodynamic interaction changes as the spacing varies. During the experiments, I will measure thrust, torque, rotational speed and angular position with high accuracy, with the aim of understanding how aerodynamic interference, modified by phase and distance, alters local inflow conditions and therefore thrust production. At the same time, I will use Proper Orthogonal Decomposition (POD) techniques to perform advanced analysis of aerodynamic and aeroacoustic fields and link the observed phenomena to a theoretical interference model already developed in the field of acoustics. The ultimate goal of my work is to validate this model from an aerodynamic point of view, identify the optimal phase and distance configurations that maximise thrust and minimise noise, and provide useful design criteria for the design of new-generation UAVs and multirotor aircraft.
Silvia Benedetti
Biography
My name is Silvia Benedetti, I am currently a first-year PhD candidate in AMOMAT. I took a Master’s Degree in Mechanical Engineering in July 2025, developing a solid academic background in thermofluid dynamics, heat transfer, and numerical modeling.
During my studies, I focused on the analysis of thermal systems and computational approaches for engineering applications; in particular, my research concentrated on phase change materials for thermal energy storage, examining melting and solidification dynamics and performance under cyclic thermal loading.
My current research activity concerns the CFD modeling and performance optimization of passive thermal management devices for space applications, with particular attention to phase-change phenomena and microgravity conditions.
Through my doctoral work, I aim to contribute to the development of reliable and efficient thermal control solutions for advanced aerospace systems.
Brief description of PhD thesis topic
My PhD research focuses on the CFD modelling and analysis of heat pipes and vapor chambers for space applications, with the aim of investigating their thermal and fluid dynamic behavior under microgravity conditions.
Thermal management represents a critical challenge in space systems due to the absence of natural convection and the presence of extreme environmental conditions. Passive devices such as heat pipes and vapor chambers offer an efficient solution, as they rely on phase-change mechanisms to transfer heat without mechanical components.
The project aims to develop advanced numerical models able to simulate two-phase flow, evaporation, and condensation processes using Computational Fluid Dynamics tools. Particular attention will be given to the influence of geometry, working fluid properties, wick structure, and thermal load distribution on overall performance.
A key aspect of the project will be the investigation of innovative wick architectures, including open-cell metal foams, to enhance capillary-driven flow and heat transfer mechanisms.
The main objective of the research is to provide a reliable and versatile numerical model to support the design and optimization of passive thermal control systems for future space missions.
XL Cycle
Marco Bonavita
Biography
My name is Marco Bonavita . I was born and raised in Genoa, where I received my degree in Physics in 1985.
Afterwards I kept working in Electronics industry for 37 years, from 1986 to 2023 where my interests ranged from Electronic circuits for telecommunications design to Algorithms for submarine ranging and detection.
In 2019 I graduated in Electronics Engineering at Unicusano University where I am now attending courses to catch a Phd in EE.
My Phd topics
My commitment is about designing of Quantum Wires and Quantum Dots structures , expecially by simulating them in Multiphysics environment like TiberCad code.
Simulation are aimed at reproducing experimental results already available in literature, in order to validate the models as a base for future design of real devices.
Structures like Quantum Wells and Quantum Lattice are also being simulated by F.E.M. and they consitute a background for the whole topic.
Federico Negro
Biography
I am a 29-year-old engineer with a background spanning both Mechanical Engineering and Aerospace Engineering. After earning my Bachelor’s degree in Mechanical Engineering at the University of Rome “Tor Vergata”, I went on to complete a Master’s degree in Space and Astronautical Engineering at the University of Rome “La Sapienza”. Following an initial period as a graduate researcher at the same university, I stepped away from academia for the next three years and began working as an aerospace thruster designer at Avio S.p.A. Over the past year, I have returned to academic studies by starting a PhD program at Niccolò Cusano University, where I work on numerical simulation applied to the solution of Maxwell’s equations and to plasma physics more broadly.
Thesis topic
The idea behind the PhD research is to carry out numerical studies on the physical phenomena associated with the operation of electric propulsion thrusters. In general, the aim is to develop a computational code based on suitable physical models and numerical schemes, capable of providing as complete and exhaustive a characterization as possible of plasma physics in general. The final objective will therefore be to validate a library that can be used as a research and performance-optimization tool, while trying to limit computational costs by employing a Finite Volume scheme and leveraging Adaptive Mesh Refinement and Immersed Boundary techniques. At present, the test case to be analyzed is the operation of a rotating magnetic field thruster, whose results will be compared with those obtained from simpler, already validated models and with the corresponding experimental data.
Nicola Mancano
Biography
My name is Nicola Mancano and I am a PhD student in Advanced Modelling, Materials and Technologies (Cycle XL) at Niccolò Cusano University, where I conduct my research under the supervision of Prof. Ilaria Cacciotti and Prof. Marianna Gallo.
My academic journey began at the University of Naples Federico II, where I earned both my Bachelor’s and Master’s degrees in Molecular and Industrial Biotechnology. During my studies, I developed a strong passion for applied microbiology, driven by the conviction that the future of industrial production lies in biological sustainability.
Currently, my work focuses on the development of innovative biomaterials, with the goal of transforming food industry by-products into high-added-value resources, combining scientific rigour with the principles of the circular economy.
Thesis topic
My PhD project focuses on the transition to a circular economy by addressing the global issue of food waste. Through the valorization of a significant food waste product, such as stale bread, I aim to convert it into bioplastics and biodegradable composite materials with high added value.
Following an extensive bibliographic research phase to identify the most promising scientific pathways, I have outlined two main methodological approaches that form the core of my research:
- Fermentation approach: This involves utilizing the action of specific microorganisms. Through the controlled fermentation of the bread-based substrate, these microorganisms produce precursors or polymers directly useful for the synthesis of biodegradable materials, such as polyhydroxyalkanoates (PHAs)—including PHB and PHBV—or polylactic acid (PLA).
- Engineering Approach: This involves the physical mixing of thermoplastically treated ground bread (TPB) with commercial biodegradable polymers, such as PBAT or PLA. This approach aims to develop new composite materials with improved properties, utilizing the bread component as a functional additive.
Building on protocols and production data available in current literature, the specific objective of my work is to optimize and improve key operating parameters to increase process efficiency and yield. The ultimate goal is to define robust and scalable protocols, transforming the challenge of waste bread into a strategic resource for sustainable bioplastic production.
Antonio Pugliese
Biography
My name is Antonio Pugliese, and I am currently a Ph.D. candidate in Advanced Modelling, Materials and Technologies at Università Niccolò Cusano in Rome, under the supervision of Prof. Tiziano Pagliaroli. I obtained my bachelor’s degree in industrial engineering (L-9) from Università Niccolò Cusano in July 2021, presenting the thesis entitled “Analisi sperimentale di un sistema di accumulo termico con materiali a cambiamento di fase immersi in schiume metalliche.” In March 2024, I earned a first-level academic diploma in jazz singing from the Conservatory “Santa Cecilia” in Rome. My studies continued with a master’s degree in mechanical engineering (LM-33), completed in July 2024 at Università Niccolò Cusano, with the thesis entitled “Analisi del mixing e della generazione di inquinanti in un bruciatore ciclonico tramite applicazione della Proper Orthogonal Decomposition su dati LES.” From May to November 2024, I worked as a research collaborator at the University of Roma Tre, contributing to research activities focused on advanced data analysis techniques such as Proper Orthogonal Decomposition (POD) and spectral-POD. In 2025 (first session), I passed the state examination for industrial engineering and am currently registered with the Order of Engineers of Rome (Section A – industrial engineering).
Brief description of PhD thesis topic
My Ph.D. research focuses on advanced modelling strategies and data-driven analysis techniques for complex physical systems. The main objective is to develop and apply reduced-order methodologies capable of extracting meaningful information from high-dimensional numerical and experimental datasets. The work is centered on modal decomposition approaches, such as Proper Orthogonal Decomposition and related extensions, which enable the identification of dominant patterns, coherent structures, and underlying dynamical features in nonlinear systems. These techniques are employed to achieve dimensionality reduction, improve interpretability, and support the development of simplified yet physically consistent models. At the current stage, the developed framework is being applied to the analysis of mixing phenomena in a gas turbine burner configuration, with particular attention to the characterization of coherent structures governing scalar transport. The ongoing study aims to provide a deeper understanding of the mechanisms controlling mixing and flow organization.