scholarly journals Study on the Inter-Electrode Process of Aluminum Electrolysis (Ⅱ)—Digital Analysis of the Anode Gas Distribution Patterns on the Anode Surface Using A See-Through Cell

2021 ◽  
Vol 11 (16) ◽  
pp. 7702
Author(s):  
Youjian Yang ◽  
Yuankun Zhang ◽  
Jiangyu Yu ◽  
Zhaowen Wang ◽  
Zhongning Shi
Keyword(s):  
Current Density ◽  
Hot Spot ◽  
Aluminum Electrolysis ◽  
Distribution Patterns ◽  
Anode Surface ◽  
Bottom Surface ◽  
Digital Analysis ◽  
Gas Distribution ◽  
Bubble Evolution ◽  
Evolution Behavior

The evolution behavior of anode gas during aluminum electrolysis has been a hot spot of research for energy saving and process control. In the present work, the bubble evolution behavior during aluminum electrolysis was investigated using a lab-scale see-though cell. The bubble evolution characters on an 11 cm2 (bottom surface area) flat anode, an 11 cm2 slotted anode, and a 50 cm2 flat anode were investigated with statistical analysis, respectively. The results showed that bubbles tended to generate and adhere to certain regions on the anode surface due to the heterogeneity of the carbon material, and the adhering regions moved when current density was increased. The anode slot lowered the actual current density on the anode significantly by reducing the anode bubble coverage. Influenced by the group effect of bubbles, the 50 cm2 flat anode behavior constituted a lower bubble coverage rate, lower average bubble size, and lower actual current density than the 11 cm2 flat anode.

scholarly journals Pendugaan Kejadian Pemutihan Karang Berdasarkan Analisis Suhu Permukaan Laut (SPL) Tahun 2015-2016 di Perairan Bali

2017 ◽  
Vol 4 (2) ◽  
pp. 286
Author(s):  
Jajang Nuryana ◽  
I Gede Hendrawan ◽  
Widiastuti Karim
Keyword(s):  
Coral Bleaching ◽  
Hot Spot ◽  
Satellite Image ◽  
Distribution Patterns ◽  
Triangle Center ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
The Difference ◽  
Level 2

National Ocean Atmospheric Administrations (NOAA) by the program coral reef Watch (CRW) has developed a method to estimate the potential of coral bleaching using Sea Surface Temperature (SST). The products are hot spot (HS) and degree heating week (DHW). HS is the SST 1°C (SSTL?1) above normal and DHW is the length of HS inhabits a place. The CRW product do not provided detail informations because it has a lower resolution. It is need a satellite image with a higher resolution to provide better informations. One of the satellite images that can be used is Moderate Resolution Imaging Spectroradiometer (MODIS) with a spatial resolution of 1 km. The purpose of this study was to know HS and DHW distribution patterns and status of coral bleaching in Bali waters seen from the analysis of HS and DHW. MODIS data is used daily, then do mosaicing process to get a weekly SPL (8 daily) and the monthly SST. Monthly SPL normally used to get maximum montly mean (MMM). HS obtained from the difference between 8 daily weekly SST and SST normal (MMM).).Location bleaching based on data Coral Triangle Center (CTC) and coralwatch.org.  SST results revealed difference of SPL in 2015 and 2016 amounted to 1.48°C. Highest DHW in Bali Hai, Nusa Penida is 10 465° C-weeks in April 2016. Based on the value HS and DHW coral reefs in Bali waters threatened bleaching level Alert 1 and Alert level 2.

scholarly journals Possible mechanisms of electrochemical processing activation ARMCO-iron

2018 ◽  
Vol 224 ◽  
pp. 01009
Author(s):  
Konstantin Rakhimyanov ◽  
Nadezhda Gaar ◽  
Aleksandr Loktionov
Keyword(s):  
Laser Radiation ◽  
Current Density ◽  
Armco Iron ◽  
Water Solution ◽  
Pulse Repetition Frequency ◽  
Anode Surface ◽  
Potential Range ◽  
Electrochemical Processing ◽  
Stationary Conditions ◽  
The Impact

The peculiarities of the electrochemical dissolving of ARMCO-iron in the 15% water solution of the sodium chloride during electrochemical dissolving the material and under the impact of laser radiation with a wavelength of 1.06 micrometer are considered. The investigations were conducted at a special installation by the potentiodynamic method. It is established that the material passivation at a potential range of 1.26 – 2.6 V is observed during electrochemical dissolving the material in the stationary conditions. The increase in the value of the current density by 45 times occurs in introducing the laser radiation in the process of anode dissolving and the passivation areas are not observed. The dissolution process takes place actively in the whole range of potentials from 0 to 5 V. It is shown that the main mechanisms of laser activation of electrochemical dissolving the materials is the depassivation of the anode surface and the acceleration of electrochemical reactions. It is determined that the maximum current density is achieved during laser-electrochemical processing of ARMCO-iron at a pulse repetition frequency of laser radiation equal to 3 kHz.

Modeling and Optimization for Gas Distribution Patterns on Biomass Gasification Performance of a Bubbling Spout Fluidized Bed

2020 ◽  
Vol 34 (2) ◽  
pp. 1750-1763
Author(s):  
Panxing Kang ◽  
Xiayi Eric Hu ◽  
Yujian Lu ◽  
Kuang Wang ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Distribution Patterns ◽  
Biomass Gasification ◽  
Gas Distribution ◽  
Modeling And Optimization

Conjugate Mixed Convection With Surface Radiation and Substrate Conduction in Laminar Channel Flow With Discrete Flush-Mounted Heat Sources

2010 ◽  
Author(s):  
Jing He ◽  
Anthony M. Jacobi
Keyword(s):  
Mixed Convection ◽  
Hot Spot ◽  
Surface Radiation ◽  
Bottom Surface ◽  
Heat Sources ◽  
Thick Substrate ◽  
Laminar Channel Flow ◽  
Uniform Temperature Field ◽  
Influence Of Substrate ◽  
High Reynolds

Thermal analysis employing a full conjugation model is performed in this study for laminar airflow in a parallel-plate channel with discrete flush-mounted heat sources. The numerical model accounts for mixed convection, surface radiation, and two-dimensional conduction in the substrate. The effects of Reynolds number, surface emissivity of walls and heat sources, as well as thickness and thermal conductivity of the substrate, are analyzed in detail. It is shown that participation of radiation brings the wall temperatures closer, and the trend of temperature variation along the top wall is drastically altered. Such effects are pronounced for black enclosures and diminished for high Reynolds numbers. The influence of substrate conductivity and thickness is very similar in that a large value for both parameters would facilitate redistribution of heat and tend to yield a uniform temperature field in the substrate. For highly conductive or thick substrate, the ‘hot spot’ cools down and may move upstream to the penultimate source. Radiation loss to the ambient increases with substrate conductivity and thickness due to the elevated temperature near the inlet and outlet, yet the total heat transfer over the bottom surface by convection and radiation remains unaltered.

Chemical Etching of TiO2 Nanorods Greatly Improves Current Generation of S. loihica PV-4 on a Carbon Paper Electrode

2018 ◽  
Vol 875 ◽  
pp. 14-18
Author(s):  
Li Dong ◽  
Tao Yin ◽  
Lin Su ◽  
De Gang Fu
Keyword(s):  
Electron Transfer ◽  
Current Density ◽  
Chemical Etching ◽  
Nanorod Array ◽  
Etching Process ◽  
Anode Surface ◽  
Extracellular Electron Transfer ◽  
Carbon Paper ◽  
Local Concentration ◽  
Electron Mediators

Anode surface plays important role for extracellular electron transfer (EET) of exoelectrogenic microbes in microbial fuel cell (MFC). In this report, the electrochemical performance of a TiO2nanorod array modified carbon paper electrode (TiO2NRs/CP) is greatly improved by controlled chemical etching process. The etching process keeps the array morphology but yields obvious hollows on tops of TiO2nanorods. The etched electrode (TiO2NRs-HOT/CP) exhibits better hydrophilicity than carbon paper (CP) and TiO2NRs/CP electrode as seen from smaller contact angle (CA) and more attached microbes S.loihica PV-4. Meanwhile, the hollows allow higher local concentration of microbial self-secreted flavins that can act as electron mediators for interfacial electron transfer of PV-4 through in-direct pathway. Accordingly, PV-4 produces larger current density at TiO2NRs-HOT/CP electrode with maximum current density of 0.038 mA cm–2, which was much higher than that at CP electrode, and almost five times higher than that at un-etched TiO2NRs/CP electrode.

Conjugate Thermal Analysis of Air-Cooled Discrete Flush-Mounted Heat Sources in a Horizontal Channel

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Jing He ◽  
Liping Liu ◽  
Anthony M. Jacobi
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Hot Spot ◽  
Horizontal Channel ◽  
Bottom Surface ◽  
Comprehensive Treatment ◽  
Heat Sources ◽  
Surface Emissivity ◽  
Thick Substrate ◽  
Uniform Temperature Field

Thermal analysis with comprehensive treatment of conjugate heat transfer is performed in this study for discrete flush-mounted heat sources in a horizontal channel cooled by air. The numerical model accounts for mixed convection, radiative exchange and two-dimensional conduction in the substrate. The model is first used to simulate available experimental work to demonstrate its accuracy and practical utility. A parametric study is then undertaken to assess the effects of Reynolds number, surface emissivity of walls and heat sources, as well as thickness and thermal conductivity of substrate, on flow field and heat transfer characteristics. It is shown that due to radiative heat transfer, the wall temperatures are brought closer, and the trend of temperature variation along the top wall is significantly altered. Such effects are more pronounced for higher surface emissivity and/or lower Reynolds numbers. The influence of substrate conductivity and thickness is related in that a large value of either substrate conductivity or thickness facilitates redistribution of heat and tends to yield a uniform temperature field in the substrate. For highly conductive or thick substrate, the “hot spot” cools down and may occur in upstream sources. Radiation loss to the ambient increases with substrate conductivity and thickness due to the elevated temperature near the openings, yet the total heat transfer over the bottom surface by convection and radiation remains essentially unaltered.

Comparison of Manual and Digital Assessment of KI-67 in Neuroendocrine Tumors

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S125-S125
Author(s):  
B S Raju ◽  
M Quinton ◽  
L Hassell
Keyword(s):  
Image Analysis ◽  
Neuroendocrine Tumors ◽  
Digital Image ◽  
Digital Image Analysis ◽  
Hot Spot ◽  
World Health ◽  
Proliferation Index ◽  
Digital Analysis ◽  
Ki 67 ◽  
Digital Assessment

Abstract Introduction/Objective Proliferative activity is an essential prognostic and treatment indicator for neuroendocrine tumors (NET). Ki-67 proliferation index, if reported by unaided microscopic estimation on hot-spot locations could lead to variability and inconsistencies. This study aims to compare the Ki-67 assessment of NETs by visual estimation versus automated digital image analysis (Roche iCoreo/Virtuoso). Methods 212 patients with Ki-67-graded GI NETs (117 G1; 61 G2; 34 G3) from 2010 to 2019 were reassessed using digital image analysis quantification of hot spot areas of at least 500 cells (average 800 cells). Revised tumor grades were assigned according to the European Neuroendocrine Tumor Society guidelines and the 2010 World Health Organization classification and compared to initially reported grade. Results We found 75% concordance for G1, with 22% of cases upgraded to G2 and 3% of cases upgraded to G3. For G2, there was 70.5% agreement, with 13.1% of cases downgraded to G1 and 16.4% upgraded to G3. For G3, there was 100% agreement, (kappa=0.64, overall). Retrospective review of discordant G3 cases revealed cases with known metastasis, small fragments of tissue, or polyps. Scanning and scoring required approximately 10 minutes per case. Conclusion Our data shows the time/effort difference of visually estimating versus automated digital analysis may lead to significant classification errors in these tumors. Although digital analysis has limitations, including tumor heterogeneity, misidentification of tumor cells, and poor immunostaining which could require manual counting by a pathologist, this rigor should be reinforced and explicitly stated to increase accuracy and reproducibility of grading.

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