scholarly journals A direct method for the simultaneous characterization of thermal diffusivities of a bi-layer material consisting of a thin coating deposited on a substrate

2021 ◽  
Vol 91 ◽  
pp. 614-631
Author(s):  
Elissa El Rassy ◽  
Yann Billaud ◽  
Didier Saury
Author(s):  
Blaise Nsom ◽  
Noureddine Latrache

To get a better knowledge of discharging flows of ensiled granular materials, a small scale silo was designed and built. It is equipped with a flat bottom and it has a rectangular cross section. Moreover, it is entirely transparent for image processing purpose. First of all, a physical and mechanical characterization of wood granules (inert materials) was performed using a shear box testing. Then, silo emptying flows were generated. Flow regimes and flow rate were determined using spatiotemporal diagrams extracted from images of the free surface of the ensiled material. The same method was then used to measure the flow rate of discharging flows of soya, colza and rye seeds which were characterized in a previous study. For each material studied, the flow rate measured with this non intrusive method was successfully compared with a direct method consisting in weighing a volume of grains discharged during a unit time and with Berveloo’s formula.


2010 ◽  
Vol 74 ◽  
pp. 196-204 ◽  
Author(s):  
Antonio Parretta ◽  
Andrea Antonini ◽  
Maria Angela Butturi ◽  
Emiliano Milan ◽  
Pierangelo Di Benedetto ◽  
...  

The light collection properties of different types of solar concentrators have been investigated by applying conventional and innovative methods of characterization [1, 2]. Four types of optical methods were applied: i) a “direct” method using a laser beam as light source; ii) a “direct” method using a parallel beam simulating the direct component of solar light; iii) a “direct” integral method using a lambertian light source simulating the diffuse component of solar light; iv) an “inverse” method using a lambertian light source applied at the receiver side, thereby reversing the light path. The optical properties derived by applying the above three methods were: i) the local optical collection efficiency, resolved on the entrance point and direction of incidence ii) the overall optical collection efficiency under collimated light, resolved on direction of incidence; iii) the spatial and angular distribution of flux on the receiver.


2015 ◽  
Vol 116 ◽  
pp. 97-105 ◽  
Author(s):  
Xian-jie Liu ◽  
Wei-cong Zhu ◽  
Yu-bin Su ◽  
Chang Guo ◽  
Zhao-hai Zeng ◽  
...  

Author(s):  
Songquan Sun ◽  
Richard D. Leapman

Analyses of ultrathin cryosections are generally performed after freeze-drying because the presence of water renders the specimens highly susceptible to radiation damage. The water content of a subcellular compartment is an important quantity that must be known, for example, to convert the dry weight concentrations of ions to the physiologically more relevant molar concentrations. Water content can be determined indirectly from dark-field mass measurements provided that there is no differential shrinkage between compartments and that there exists a suitable internal standard. The potential advantage of a more direct method for measuring water has led us to explore the use of electron energy loss spectroscopy (EELS) for characterizing biological specimens in their frozen hydrated state.We have obtained preliminary EELS measurements from pure amorphous ice and from cryosectioned frozen protein solutions. The specimens were cryotransfered into a VG-HB501 field-emission STEM equipped with a 666 Gatan parallel-detection spectrometer and analyzed at approximately −160 C.


2021 ◽  
Vol 7 (17) ◽  
pp. eabf8283
Author(s):  
Sibao Liu ◽  
Pavel A. Kots ◽  
Brandon C. Vance ◽  
Andrew Danielson ◽  
Dionisios G. Vlachos

Single-use plastics impose an enormous environmental threat, but their recycling, especially of polyolefins, has been proven challenging. We report a direct method to selectively convert polyolefins to branched, liquid fuels including diesel, jet, and gasoline-range hydrocarbons, with high yield up to 85% over Pt/WO3/ZrO2 and HY zeolite in hydrogen at temperatures as low as 225°C. The process proceeds via tandem catalysis with initial activation of the polymer primarily over Pt, with subsequent cracking over the acid sites of WO3/ZrO2 and HY zeolite, isomerization over WO3/ZrO2 sites, and hydrogenation of olefin intermediates over Pt. The process can be tuned to convert different common plastic wastes, including low- and high-density polyethylene, polypropylene, polystyrene, everyday polyethylene bottles and bags, and composite plastics to desirable fuels and light lubricants.


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