scholarly journals Novel Approach for Fine Ilmenite Flotation Using Hydrophobized Glass Bubbles as the Buoyant Carrier

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 231
Author(s):  
Pan Chen ◽  
Youchuan Chen ◽  
Hang Liu ◽  
Haoyu Li ◽  
Xujian Chai ◽  
...  
Keyword(s):  
Froth Flotation ◽  
Interaction Force ◽  
Optical Microscope ◽  
Dlvo Theory ◽  
Microscope Observation ◽  
Base Interaction ◽  
Simple Modification ◽  
Fine Grained ◽  
Novel Approach ◽  
Hydrophobic Particles

Ilmenite disseminated grain size is relatively fine, and it must be finely ground to fully separate ilmenite from gangue and then produce fine-grained minerals, which deteriorates flotation. A novel method using buoyant carriers to improve the recovery of fine ilmenite in froth flotation was introduced in this study. Hydrophobized glass bubbles (HGB) as carrier materials were obtained by an efficient, simple modification of ordinary glass bubbles. The carrier flotation of fine ilmenite in the presence of HGB was investigated by micro flotation tests, X-ray diffractometer analysis, Fourier transform infrared (FTIR), optical microscope observation, and the extended DLVO theory (XDLVO). Micro-flotation results showed that the recovery of fine ilmenite in presence of HGB was 37.7% higher than that when using NaOL alone at pH 6. FTIR analysis and optical microscope observation revealed that fine ilmenite particles can be closely attached on the HGB surface to increase apparent particle size considerably. The data calculated from the DLVO theory indicated that the acid–base interaction force determined the adsorption between two hydrophobic particles.

scholarly journals Explaining Neural Networks Using Attentive Knowledge Distillation

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1280
Author(s):  
Hyeonseok Lee ◽  
Sungchan Kim
Keyword(s):  
Neural Networks ◽  
Model Prediction ◽  
Saliency Map ◽  
Model Parameters ◽  
Learning Capability ◽  
Fine Grained ◽  
Network Layers ◽  
Saliency Maps ◽  
Novel Approach ◽  
Knowledge Distillation

Explaining the prediction of deep neural networks makes the networks more understandable and trusted, leading to their use in various mission critical tasks. Recent progress in the learning capability of networks has primarily been due to the enormous number of model parameters, so that it is usually hard to interpret their operations, as opposed to classical white-box models. For this purpose, generating saliency maps is a popular approach to identify the important input features used for the model prediction. Existing explanation methods typically only use the output of the last convolution layer of the model to generate a saliency map, lacking the information included in intermediate layers. Thus, the corresponding explanations are coarse and result in limited accuracy. Although the accuracy can be improved by iteratively developing a saliency map, this is too time-consuming and is thus impractical. To address these problems, we proposed a novel approach to explain the model prediction by developing an attentive surrogate network using the knowledge distillation. The surrogate network aims to generate a fine-grained saliency map corresponding to the model prediction using meaningful regional information presented over all network layers. Experiments demonstrated that the saliency maps are the result of spatially attentive features learned from the distillation. Thus, they are useful for fine-grained classification tasks. Moreover, the proposed method runs at the rate of 24.3 frames per second, which is much faster than the existing methods by orders of magnitude.

Direct measurement of the absolute value of the interaction force between the fiber probe and the sample in a scanning near-field optical microscope

2002 ◽  
Vol 81 (8) ◽  
pp. 1503-1505 ◽  
Author(s):  
D. A. Lapshin ◽  
V. S. Letokhov ◽  
G. T. Shubeita ◽  
S. K. Sekatskii ◽  
G. Dietler
Keyword(s):  
Direct Measurement ◽  
Near Field ◽  
Interaction Force ◽  
Optical Microscope ◽  
Fiber Probe ◽  
Absolute Value ◽  
The Absolute

Evolutions of Microstructure for Multilayered Al-Mg Alloy Composites by Accumulation Roll Bonding (ARB) Process

2011 ◽  
Vol 411 ◽  
pp. 527-531
Author(s):  
Bing Zhang ◽  
Zhong Wei Chen ◽  
Shou Qian Yuan ◽  
Tian Li Zhao
Keyword(s):  
Multilayer Structure ◽  
Optical Microscope ◽  
Alloy Layer ◽  
Mg Alloy ◽  
Micro Hardness ◽  
Roll Bonding ◽  
Fine Grained ◽  
Hardness Tester ◽  
Average Grain Size ◽  
Evolution Of Microstructure

In this paper, accumulative roll bonding (ARB) has been used to prepare the Al/Mg alloy multilayer structure composite materials with 1060Al sheet and MB2 sheet. The evolution of microstructure of the cladding materials during ARB processes was observed by optical microscope, scanning electron microscopy, and micro-hardness was measured by micro-hardness tester. The results show that a multilayer structure material of Al/Mg alloy with excellent bonding characteristics and fine grained microstructure was prepared by ARB processes. With the ARB cycles increasing, Mg alloy layer in multilayer composite material was necked and fractured, and the hardness of the Al and Mg alloy was increased. Average grain size was less than 1μm after ARB4 cycles.

The Effect of Preliminary Mechanical Activation on the Structure and Mechanical Properties of Ni3Al+B Material Obtained by SPS

2017 ◽  
Vol 743 ◽  
pp. 19-24 ◽  
Author(s):  
Lilia I. Shevtsova ◽  
Anatoliy A. Bataev ◽  
Vyacheslav I. Mali ◽  
Maksim A. Esikov ◽  
Veronika V. Sun Shin Yan ◽  
...  
Keyword(s):  
Mechanical Activation ◽  
Bending Strength ◽  
Stoichiometric Composition ◽  
Initial Mixture ◽  
Optical Microscope ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Fine Grained Structure ◽  
Spark Plasma ◽  
Almost All

In the present study, a mixture of powders (87.9 at.% Ni, 12 at.% Al, 0.1 at.% B) was used as the initial material to produce sintered Ni3Al + B alloy. Spark Plasma Sintering (SPS) method was used to compact the powder. The powder mixtures were previously prepared in two ways: mixing the initial powders in a mortar (М1) and mechanical activation (М2). The microstructure was observed using optical microscope (OM). The addition of small amount of boron to the initial mixture of nickel and aluminum improves the density of the sintered Ni3Al intermetallic compound (98.8%). The results of density, bending and microhardness tests showed, that the provisional three-minute mechanical activation improves almost all properties of the sintered material. The compact obtained by SPS by M2 contributes to the formation of a homogeneous fine-grained structure of the material. It leads to further increase in flexural bending strength up to 2200 MPa. This value is almost 8 times the strength of the intermetallic Ni3Al stoichiometric composition obtained by SPS.

scholarly journals A novel approach: combining dental enamel hypoplasia and paleoparasitological analysis in medieval Islamic individuals buried in Santarém (Portugal)

2017 ◽  
pp. 111-133 ◽  
Author(s):  
Daniela Cunha ◽  
Ana Luísa Santos ◽  
António Matias ◽  
Luciana Sianto
Keyword(s):  
Physiological Stress ◽  
Intestinal Parasites ◽  
Dental Enamel ◽  
Optical Microscope ◽  
Enamel Hypoplasia ◽  
Exact Test ◽  
Helminth Infections ◽  
Novel Approach ◽  
Linear Enamel Hypoplasia ◽  
Long Term Impact

Paleopathological and paleoparasitological studies seek evidences to understand health and disease in past populations. These two approaches are often used independently despite the obvious importance of its complementary. This paper aims to explore the possible relation between a common indicator of childhood stress and infection by intestinal parasites. Thirty adult individuals from the Islamic necropolis of Santarém (9th-12th cent. AD) were macroscopically examined for linear enamel hypoplasia. Sediment from the pelvis and skull of each skeleton were observed under the optical microscope in search of helminth eggs. Hypoplasic defects were identified in 46.67% of the individuals, mostly on canines and incisors. Eggs from Ascaris lumbricoides and Trichuris trichiura were identified respectively in 4 and 2 individuals. The Fisher’s exact test was performed to analyze whether the individuals with evidences of stress in early childhood were more prone to helminth infections or death at younger ages. Although these variables were shown to be independent, this exploratory study highlights the contribution of combining paleopathological and paleoparasitological methods to address the long-term impact of the physiological stress exposure in early life on the immune system. Furthermore, variety of factors that could have influenced these results are discussed and interpreted in a biocultural perspective.

scholarly journals Microscope observation of cracks of clay

2019 ◽  
Vol 92 ◽  
pp. 03007
Author(s):  
Chen Liang ◽  
Yilin Gui ◽  
Cees van der Land
Keyword(s):  
Moisture Content ◽  
Drying Shrinkage ◽  
Optical Microscope ◽  
Microscope Observation ◽  
Microscopic Images ◽  
Engineered Barriers

Clay has wide application in engineered barriers. However, it is prone to crack if moisture content decreases at most circumstances. This research aimed to microscopically study drying shrinkage and associated cracking of two different clays: kaolin and sodium-based bentonite, using optical microscope-Leica DM2700 M, under controlled condition. The samples used were cylindrical with 20mm in diameter and 1mm in depth. During the observation, microscopic images were captured and saved. These images were used to analyse the cracking behaviour due to drying. The testing results showed that cracks initially occur in the middle of the sample and then propagate to the sample boundary. The length and width of the crack was increased as moisture decreased.

Near-field optical microscope observation of dye-containing nano-domains

2004 ◽  
Vol 213 (2) ◽  
pp. 135-139 ◽  
Author(s):  
N. Yamamoto ◽  
T. Mizokuro ◽  
H. Mochizuki ◽  
S. Horiuchi ◽  
T. Hayakawa ◽  
...  
Keyword(s):  
Near Field ◽  
Optical Microscope ◽  
Microscope Observation

Effect of Fine-Grained Microstructure Induced by Induction-Heating Fine Particle Peening Treatment on Fatigue Properties of Structural Steel (0.45%C)

2014 ◽  
Vol 891-892 ◽  
pp. 1482-1487
Author(s):  
Kazue Murai ◽  
Ryota Toyama ◽  
Jun Komotori ◽  
Kengo Fukazawa ◽  
Yoshitaka Misaka ◽  
...  
Keyword(s):  
Residual Stress ◽  
Fatigue Strength ◽  
Structural Steel ◽  
Grain Refinement ◽  
Induction Heating ◽  
Fine Particle ◽  
Optical Microscope ◽  
Treatment Temperature ◽  
Fatigue Properties ◽  
Fine Grained

To improve the fatigue properties of structural steel, a novel surface modification process which combines high-frequency induction heating (IH) with fine particle peening (FPP) was developed. IH-FPP treatment was performed on the surface of structural steel specimens (0.45%C) at temperatures from 600 to 750 °C, with peening times of 60 and 120 s. To determine the characteristics of the treated surfaces, the microstructure was observed using an optical microscope and a scanning electron microscope. Vickers hardness and residual stress distributions were also measured. The characteristics of fine-grained microstructures were examined by electron backscatter diffraction. Furthermore, in order to investigate the effect of the grain refinement achieved by IH-FPP treatment, rotational bending fatigue tests were performed on treated specimens. Results showed that IH-FPP treatment created fine-grained microstructures beneath the surfaces of steel samples. The average ferrite grain size was 4.06 μm for a treatment temperature of 700 °C, and finally 0.76 μm for 600 °C . This was due to dynamic recrystallization in the processed region. IH-FPP treated specimens exhibited a higher fatigue strength than untreated specimens. As almost no compressive residual stress was measured in the treated or untreated specimens, the increase in fatigue strength resulting from IH-FPP treatment was due solely to grain refinement.

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