An experimental investigation of the swirling flow in a tall-form counter current spray dryer

This work studies the air flow in a large swirl counter-current dryer using sonic anemometry. Air velocity and turbulence fields are reported at isothermal conditions and in the absence of particles. In a tall-form unit the structure of the flow is largely influenced by the design of the exit. A contraction originates a central jet and suppresses the formation of recirculation zones despite the vortex acquires a high swirl intensity Ω (i.e. 1<Ω<2). Access to a full scale tower has permitted to: (a) identify asymmetries owed to the design of inlet and exhaust ducts, (b) present the first detailed turbulence data in production units, characterized by a highly anisotropic field and the axial decay of the turbulence kinetic energy, (c) study the flow stability, identifying the precession of the vortex core and oscillations at a constant Strouhal number and (d) study the impact that a rough wall has in the strength of the swirl. This work presents the first clear evidence of significant friction in spray dryers. The swirl intensity Ω decays exponentially in the dryer at a rate between 0.08 and 0.09, much higher than expected in pipe flow and independent of Re in the range 105-2.2{dot operator}105. Production dryers have a large characteristic wall roughness due the presence of deposits, which explains the stronger friction and the discrepancies found in the past between data at full scale or clean laboratory or pilot scale units. It is essential to address this phenomenon in current numerical models, which are validated on laboratory or pilot scale facilities and ignore the role of deposits, thus causing an overprediction of the tangential velocity above 30-40%

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery