Correlations by the entrainment theory of thermodynamic effects for developed cavitation in venturis and comparisons with ogive data

A semi-empirical entrainment theory was employed to correlate the measured temperature depression, Delta T, in a developed cavity for a venturi. This theory correlates Delta t in terms of the dimensionless numbers of Nusselt, Reynolds, Froude, Weber and Peclet, and dimensionless cavity length, L/D. These correlations are then compared with similar correlations for zero and quarter caliber ogives. In addition, cavitation number data for both limited and developed cavitation in venturis are presented

Tabulation and summary of thermodynamic effects data for developed cavitation on ogive-nosed bodies

Thermodynamic effects data for developed cavitation on zero and quarter caliber ogives in Freon 113 and water are tabulated and summarized. These data include temperature depression (delta T), flow coefficient (C sub Q), and various geometrical characteristics of the cavity. For the delta T tests, the free-stream temperature varied from 35 C to 95 C in Freon 113 and from 60 C to 125 C in water for a velocity range of 19.5 m/sec to 36.6 m/sec. Two correlations of the delta T data by the entrainment method are presented. These correlations involve different combinations of the Nusselt, Reynolds, Froude, Weber, and Peclet numbers and dimensionless cavity length

Real-time measurements of dissipative solitons in a mode-locked fiber laser

Dissipative solitons are remarkable localized states of a physical system that arise from the dynamical balance between nonlinearity, dispersion and environmental energy exchange. They are the most universal form of soliton that can exist in nature, and are seen in far-from-equilibrium systems in many fields including chemistry, biology, and physics. There has been particular interest in studying their properties in mode-locked lasers producing ultrashort light pulses, but experiments have been limited by the lack of convenient measurement techniques able to track the soliton evolution in real-time. Here, we use dispersive Fourier transform and time lens measurements to simultaneously measure real-time spectral and temporal evolution of dissipative solitons in a fiber laser as the turn-on dynamics pass through a transient unstable regime with complex break-up and collision dynamics before stabilizing to a regular mode-locked pulse train. Our measurements enable reconstruction of the soliton amplitude and phase and calculation of the corresponding complex-valued eigenvalue spectrum to provide further physical insight. These findings are significant in showing how real-time measurements can provide new perspectives into the ultrafast transient dynamics of complex systems.Comment: See also M. Narhi, P. Ryczkowski, C. Billet, G. Genty, J. M. Dudley, Ultrafast Simultaneous Real Time Spectral and Temporal Measurements of Fibre Laser Modelocking Dynamics, 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference, paper EE-3.5 (2017

Potential sites of CFTR activation by tyrosine kinases

The CFTR chloride channel is tightly regulated by phosphorylation at multiple serine residues. Recently it has been proposed that its activity is also regulated by tyrosine kinases, however the tyrosine phosphorylation sites remain to be identified. In this study we examined 2 candidate tyrosine residues near the boundary between the first nucleotide binding domain and the R domain, a region which is important for channel function but devoid of PKA consensus sequences. Mutating tyrosines at positions 625 and 627 dramatically reduced responses to Src or Pyk2 without altering the activation by PKA, suggesting they may contribute to CFTR regulation

High-efficiency micromorph silicon solar cells with in-situ intermediate reflector deposited on various rough LPCVD ZnO

Light management using intermediate reflector layers (IRL) and advanced front transparent conductive oxide (TCO) morphologies is needed to rise the short-circuit current density (Jsc) of micromorph tandem solar cells above 14 mA/cm2. For micromorph cells deposited on surface-textured ZnO layers grown by low-pressure chemical vapour deposition (LPCVD), we study the interplay between the front TCO layer and the IRL and its impact on fill factor and current matching conditions. The key role of the angular distribution of the light scattered by the front LPCVD ZnO layer is highlighted. A micromorph cell with 11.1% stabilized conversion efficiency is demonstrated. By increasing the bottom cell thickness and adding an antireflection coating, a Jsc value of 13.8 mA/cm2 is achieved. This remarkably high Jsc yields 13.3% initial conversion efficiency

Selecting ecosystem indicators for fisheries targeting highly migratory species: An EU project to advance the operationalization of the EAFM in ICCAT and IOTC

Several international legal agreements and guidelines have set the minimum standards and key principles to guide the implementation of an ecosystem approach to fisheries management (EAFM). However, the implementation of an EAFM in tuna Regional Fisheries Management Organizations (RFMOs) has been patchy and lack a long-term plan, vision and guidance on how to operationalize it. The Specific Contract N0 2 “selecting ecosystem indicators for fisheries targeting highly migratory species-” (SC02 project) under the Framework Contract - EASME/ EMFF/2016/008 provisions of Scientific Advice for Fisheries Beyond EU Waters- addresses several scientific challenges and provides insights to support the implementation of an EAFM through collaboration and consultation with the International Commission for the Conservation of Atlantic Tunas (ICCAT) and the Indian Ocean Tuna Commission (IOTC). Specifically, this project first highlights properties of success and best practices from other regions of the world in operationalizing the ecosystem approach that potentially could be transferred to ICCAT and IOTC. Second, it delivered a list of potential ecosystem indicators of relevance to tuna RFMOs (ICCAT and IOTC) that are suitable to track the impacts of fisheries targeting tuna and tuna-like species on the broader pelagic ecosystem. Third, it designed a general framework based on a rule-based decision tree to provide guidance on how reference points could be set and used for diverse types of ecosystem indicators. Fourth, it proposed candidate ecoregions within the Atlantic and Indian Oceans which could be used to guide region-based ecosystem plans, assessments and research to ultimately provide better ecosystem-based advice to inform fisheries management. Fifth, it developed two pilot ecosystem plans for two case study regions, the tropical ecoregion within the ICCAT convention area, and the temperate ecoregion within the IOTC convention area. At this stage, these pilot ecosystem plans aim to create awareness about the need for ecosystem planning, start a discussion about the elements that need to be part of a planning process, and initiate a discussion in ICCAT and IOTC about the potential needs of ecosystem plans and their function. Finally, this project provided recommendations to foster the potential development, use, and implementation of ecosystem plans in ICCAT and IOTC

Digital reconstruction of the inner ear of Leptictidium auderiense (Leptictida, Mammalia) and North American leptictids reveals new insight into leptictidan locomotor agility

Leptictida are basal Paleocene to Oligocene eutherians from Europe and North America comprising species with highly specialized postcranial features including elongated hind limbs. Among them, the European Leptictidium was probably a bipedal runner or jumper. Because the semicircular canals of the inner ear are involved in detecting angular acceleration of the head, their morphometry can be used as a proxy to elucidate the agility in fossil mammals. Here we provide the first insight into inner ear anatomy and morphometry of Leptictida based on high-resolution computed tomography of a new specimen of Leptictidium auderiense from the middle Eocene Messel Pit (Germany) and specimens of the North American Leptictis and Palaeictops. The general morphology of the bony labyrinth reveals several plesiomorphic mammalian features, such as a secondary crus commune. Leptictidium is derived from the leptictidan groundplan in lacking the secondary bony lamina and having proportionally larger semicircular canals than the leptictids under study. Our estimations reveal that Leptictidium was a very agile animal with agility score values (4.6 and 5.5, respectively) comparable to Macroscelidea and extant bipedal saltatory placentals. Leptictis and Palaeictops have lower agility scores (3.4 to 4.1), which correspond to the more generalized types of locomotion (e.g., terrestrial, cursorial) of most extant mammals. In contrast, the angular velocity magnitude predicted from semicircular canal angles supports a conflicting pattern of agility among leptictidans, but the significance of these differences might be challenged when more is known about intraspecific variation and the pattern of semicircular canal angles in non-primate mammals