scholarly journals Research on strength distribution of natural pumice concrete based on precast porosity

2021 ◽  
Vol 657 (1) ◽  
pp. 012095
Author(s):  
Bai Yan ◽  
Wang Hailong ◽  
An Yongjiannan ◽  
Li Aize
Keyword(s):  
Strength Distribution

Performance of Ag-HZSM-5 Zeolite Catalysts in n-heptane Conversion

2017 ◽  
Vol 68 (1) ◽  
pp. 116-120
Author(s):  
Iuliean Vasile Asaftei ◽  
Neculai Catalin Lungu ◽  
Lucian Mihail Birsa ◽  
Ioan Gabriel Sandu ◽  
Laura Gabriela Sarbu ◽  
...  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Metal Content ◽  
Pulse Method ◽  
Acid Strength ◽  
Strength Distribution ◽  
Zeolite Catalysts ◽  
Benzene Toluene ◽  
Acid Strength Distribution ◽  
Silver Cations ◽  
Heptane Conversion

The conversion of n-heptanes into aromatic hydrocarbons benzene, toluene and xylenes (BTX), by the chromatographic pulse method in the temperature range of 673 - 823K was performed over the HZSM-5 and Ag-HZSM-5 zeolites modified by ion exchange with AgNO3 aqueous solutions. The catalysts, HZSM-5 (SiO2/Al2O3 = 33.9), and Ag-HZSM-5 (Ag1-HZSM-5 wt. % Ag1.02, Ag2-HZSM-5 wt. % Ag 1.62; and Ag3-HZSM-5 wt. % Ag 2.05 having different acid strength distribution exhibit a conversion and a yield of aromatics depending on temperature and metal content. The yield of aromatic hydrocarbons BTX appreciably increased by incorporating silver cations Ag+ into HZSM-5.

Synthesis and Evaluation of Levulinic Ester as Biodiesel Additives

2020 ◽  
Vol 71 (8) ◽  
pp. 21-26
Author(s):  
Elena-Emilia Oprescu ◽  
Cristina-Emanuela Enascuta ◽  
Elena Radu ◽  
Vasile Lavric
Keyword(s):  
Maximum Yield ◽  
Strength Distribution ◽  
Point Of View ◽  
Reaction Parameters ◽  
X Ray ◽  
Ethyl Levulinate ◽  
Ft Ir ◽  
Ir Analysis ◽  
Biodiesel Blend ◽  
Acid Strength Distribution

In this study, the SO42-/TiO2-La2O3-Fe2O3 catalyst was prepared and tested in the conversion of fructose to ethyl levulinate . The catalyst was characterized from the point of view of the textural analysis, FT-IR analysis, acid strength distribution, X-ray powder diffraction and pyridine adsorption IR spectra. The influence of the reaction parameters on the ethyl levulinate yield was study. The maximum yield of 37.95% in levulinate esters was obtained at 180 �C, 2 g catalyst and 4 h reaction time. The effect of ethyl levulinate addition to diesel-biodiesel blend in different rates, i.e, 0.5, 1, 2.5, 5 (w.t %) on density, kinematic viscosity and flash point was evaluated and compared with the European specification.

scholarly journals A Method for Autonomous Navigation and Positioning of UAV Based on Electric Field Array Detection

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1146 ◽  
Author(s):  
Yincheng Li ◽  
Wenbin Zhang ◽  
Peng Li ◽  
Youhuan Ning ◽  
Chunguang Suo
Keyword(s):  
Mathematical Model ◽  
Power Systems ◽  
Transmission Lines ◽  
Autonomous Navigation ◽  
Strength Distribution ◽  
Field Source ◽  
Navigation Algorithm ◽  
Safety Warning ◽  
Positioning Algorithm ◽  
Navigation Equipment

At present, the method of using unmanned aerial vehicles (UAVs) with traditional navigation equipment for inspection of overhead transmission lines has the limitations of expensive sensors, difficult data processing, and vulnerable to weather and environmental factors, which cannot ensure the safety of UAV and power systems. Therefore, this paper establishes a mathematical model of spatial distribution of transmission lines to study the field strength distribution information around transmission lines. Based on this, research the navigation and positioning algorithm. The data collected by the positioning system are input into the mathematical model to complete the identification, positioning, and safety distance diagnosis of the field source. The detected data and processing results can provide reference for UAV obstacle avoidance navigation and safety warning. The experimental results show that the positioning effect of the positioning navigation algorithm is obvious, and the positioning error is within the range of use error and has good usability and application value.

Pore defects related to slurry character and their relevance to strength distribution in alumina ceramics

2003 ◽  
Vol 134 (1-2) ◽  
pp. 58-64 ◽  
Author(s):  
Hiroya Abe ◽  
Makio Naito ◽  
Tadashi Hotta ◽  
Hidehiro Kamiya ◽  
Keizo Uematsu
Keyword(s):  
Strength Distribution ◽  
Alumina Ceramics

Mechanical Properties of SiO2 vs. SiO2-TiO2 Bulk Glasses and Fibers

1991 ◽  
Vol 244 ◽  
Author(s):  
Suresh T. Gulati
Keyword(s):  
Mechanical Properties ◽  
Optical Fibers ◽  
Mechanical Performance ◽  
Fatigue Behavior ◽  
Deformation Mode ◽  
Strength Distribution ◽  
Fused Silica ◽  
Space Applications ◽  
Silica Glasses ◽  
Silica And Titania

ABSTRACTThe mechanical properties of silica and titania-doped silica glasses, in bulk and fiber forms, are presented. These include the elastic properties (E and ν), strength distribution (in tension and bending), fatigue behavior (dynamic and static loading) and fracture toughness. Following a brief review of above properties for fused silica and ULE™ glasses (Coming Codes 7940 and 7971), used primarily for space applications, the mechanical properties data for silica and titania-doped silica-clad optical fibers are presented. The enhancement of mechanical performance of titania-doped silica clad fiber is also discussed.The effect of titania doping on fundamental properties like stress-free activation energy, crack tip pH, and deformation mode of Si-O-Si bond is discussed. In addition, the crack velocity data obtained from DCDC specimens of homogeneous silica and titania-doped silica glasses are compared in an attempt to understand the role titania plays in improving the fatigue resistance of optical fibers.

Limitation of degree information for analyzing the interaction evolution in online social networks

2014 ◽  
Vol 25 (10) ◽  
pp. 1450056 ◽  
Author(s):  
Ke-Ke Shang ◽  
Wei-Sheng Yan ◽  
Xiao-Ke Xu
Keyword(s):  
Social Networks ◽  
Social Network ◽  
Social Services ◽  
Online Social Networks ◽  
Dynamic Network ◽  
Interaction Network ◽  
Strength Distribution ◽  
Customer Churn ◽  
Dynamic Social Network ◽  
Temporal Interactions

Previously many studies on online social networks simply analyze the static topology in which the friend relationship once established, then the links and nodes will not disappear, but this kind of static topology may not accurately reflect temporal interactions on online social services. In this study, we define four types of users and interactions in the interaction (dynamic) network. We found that active, disappeared, new and super nodes (users) have obviously different strength distribution properties and this result also can be revealed by the degree characteristics of the unweighted interaction and friendship (static) networks. However, the active, disappeared, new and super links (interactions) only can be reflected by the strength distribution in the weighted interaction network. This result indicates the limitation of the static topology data on analyzing social network evolutions. In addition, our study uncovers the approximately stable statistics for the dynamic social network in which there are a large variation for users and interaction intensity. Our findings not only verify the correctness of our definitions, but also helped to study the customer churn and evaluate the commercial value of valuable customers in online social networks.

Investigating the testing procedure limits for measuring particle strength distribution

2013 ◽  
Vol 237 ◽  
pp. 489-496 ◽  
Author(s):  
D. Portnikov ◽  
H. Kalman ◽  
S. Aman ◽  
J. Tomas
Keyword(s):  
Testing Procedure ◽  
Strength Distribution ◽  
Particle Strength
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