scholarly journals Synthesis of SAPO-18/34 intergrowth zeolites and their enhanced stability for dimethyl ether to olefins

RSC Advances ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 939-946 ◽  
Author(s):  
Dongpu Zhao ◽  
Yan Zhang ◽  
Zhuo Li ◽  
Yan Wang ◽  
Jianqiang Yu
Keyword(s):  
Particle Size ◽  
Dimethyl Ether ◽  
Medium Particle ◽  
Medium Particle Size ◽  
Enhanced Stability

Intergrowth SAPO-18/34 catalysts with medium particle size and acidity exhibit enhanced stability for the dimethyl ether to olefin reaction.

scholarly journals Polypropylene Fibers as Reinforcements of Polyester-Based Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Gonzalo Martínez-Barrera ◽  
Enrique Vigueras Santiago ◽  
Susana Hernández López ◽  
Osman Gencel ◽  
Fernando Ureña-Nuñez
Keyword(s):  
Particle Size ◽  
Polyester Resin ◽  
Unsaturated Polyester ◽  
Polypropylene Fiber ◽  
Polymer Concrete ◽  
Polypropylene Fibers ◽  
Compressive Properties ◽  
Fiber Concentration ◽  
Medium Particle ◽  
Medium Particle Size

Effects of gamma radiation and the polypropylene fibers on compressive properties of polymer concrete composites (PC) were studied. The PCs had a composition of 30 wt% of unsaturated polyester resin and 70 wt% of marble particles which have three different sizes (small, medium, and large). The PCs were submitted to 200, 250, and 300 kGy of radiation doses. The results show that the compressive properties depend on the combination of the polypropylene fiber concentration and the applied radiation dose. The compressive strength value is highest when using medium particle size, 0.1 vol% of polypropylene fibers and 250 kGy of dose; moreover, the compressive modulus decreases when increasing the particle size.

scholarly journals Characterization of Quinoa Seeds Milling Fractions and Their Effect on the Rheological Properties of Wheat Flour Dough

2020 ◽  
Vol 10 (20) ◽  
pp. 7225
Author(s):  
Ionica Coțovanu ◽  
Ana Batariuc ◽  
Silvia Mironeasa
Keyword(s):  
Particle Size ◽  
Water Absorption ◽  
Rheological Properties ◽  
Wheat Flour ◽  
Value Added ◽  
Water Retention Capacity ◽  
Composite Flour ◽  
Medium Particle ◽  
Quinoa Flour ◽  
Medium Particle Size

Replacement of refined wheat flour with milling fractions of quinoa seeds represents a useful way for the formulation of value-added baked products with beneficial characteristics to consumers. The aim of this study was to assess the chemical composition and physical properties of different particle sizes of quinoa flour on Falling number index (FN) and dough rheological properties determined by Mixolab in a planned research based on design of experiment by using full factorial design. The ash and protein contents were higher in medium particle size, whereas the carbohydrates presented a lower value, this fraction having also the highest water absorption and water retention capacity. The reduction of particles led to an increased swelling capacity and a decreased bulk density. The particle size significantly influenced the FN values in linear and quadratic terms (p < 0.05), showing a decrease with the particle size increasing. Particle size decrease significantly increased water absorption and the rate of protein weakening due to heat (C1–2), whereas starch gelatinization rate (C3–2), starch breakdown rate related to amylase activity (C3–4) and starch retrogradation speed (C5–4) decreased. By increasing the amount of quinoa flour (QF) in wheat flour, the dough stability and the torques C2, C3, C4 and C5 followed a decreased trend, whereas water absorption and dough development time rose. Optimization, determined by particle size and level of QF added in wheat flour based on which of the combination gives the best rheological properties, showed that the composite flour containing 8.98% quinoa flour of medium particle size was the most suitable.

Effect of particle sizes on the mechanical behaviour of limestone-reinforced hybrid plastics

2019 ◽  
Vol 28 (6) ◽  
pp. 410-420 ◽  
Author(s):  
R Vinayagamoorthy
Keyword(s):  
Particle Size ◽  
Mechanical Characteristics ◽  
Comparative Investigation ◽  
Particle Sizes ◽  
Particle Reinforcement ◽  
Medium Particle ◽  
Effect Of Particle Size ◽  
Polypropylene Matrix ◽  
Woven Reinforcement ◽  
Medium Particle Size

The present research has been made to investigate the characteristics of a new composite material made up of limestone as particle reinforcement. New composites are made by taking limestone particles in five different sizes and jute as woven reinforcement in polypropylene matrix. Mechanical characteristics of the composites that include strengths against tension, compression, flexural, impact and hardness are evaluated and a comparative investigation is made among the composites. The effect of particle size on the properties is analysed and found that the composite with medium particle size bears the highest strength in all aspects. In addition, microscopic image analysis is carried out to investigate the distribution of particles, bonding capacity and other morphologies. The results showed that limestone will be apt particle reinforcement and its presence enhances all the characteristics of the composite.

Effect of Heat Treatment on Properties of Mineral Attapulgite

2008 ◽  
Vol 58 ◽  
pp. 41-46 ◽  
Author(s):  
Qing Guo Tang ◽  
Jin Sheng Liang ◽  
Jun Ping Meng ◽  
Fei Wang ◽  
Li Wei Li ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Free Energy ◽  
Surface Free Energy ◽  
Water Vapor Adsorption ◽  
Heat Temperature ◽  
Heat Treated ◽  
Dispersion Component ◽  
Medium Particle ◽  
Medium Particle Size

Mineral attapulgite powders were heat treated at different temperature from 100°C to 800°C. The effect of heat treatment on properties of attapulgite were studied by particle size distribution, surface free energy, and water vapor adsorption performance. The results show that the medium particle size and surface free energy of attapulgite increase and hygroscopic capacity promptly reduce with the increase of heat temperature .The medium particle size of the raw palygorskite is 3.09 μm, and it becomes 14.12 μm after heat treatment at 800 °C. The surface free energy, polarity component and dispersion component of the natural attapulgite are 45.16mN•m-1, 13.92mN•m-1, 31.24mN•m-1, respectively, and they become 116.22 mN•m-1，116.22 mN•m-1，0.0 mN•m-1 after heat treatment at 800°C. Moreover, the hygroscopic capacity of attapulgite in 24h decreases from 17.1 % to 5.6% after heat treatment at 800°C.

The Effect of Porous Medium Particle Size on Groundwater Recharge Clogging

2013 ◽  
Vol 765-767 ◽  
pp. 2934-2937
Author(s):  
Jun Pan ◽  
Ming Zhong Wang ◽  
Ming Cen Jiang
Keyword(s):  
Particle Size ◽  
Porous Medium ◽  
Groundwater Recharge ◽  
Soil Column ◽  
Water Flux ◽  
Column Experiment ◽  
Water Source ◽  
Initial Water ◽  
Medium Particle ◽  
Medium Particle Size

In order to grasp the effect of porous medium particle size on groundwater recharge clogging. Measure the water flux of porous medium with different particle, by indoor soil column experiment simulating the process of groundwater recharge clogging. The results show that porous medium particle size is proportional to the initial water flux and the clogging occurred time, and is negatively correlative to clogging degree. When lay out wells in the water source heat pump works, should give full consideration to the effect of local hydrogeological conditions on groundwater recharge. It provides a scientific reference to prevent groundwater recharge clogging and the choice of recharge wells location.

Suspended Particles Transport and Deposition in Saturated Granular Porous Medium: Particle Size Effects

2013 ◽  
Vol 100 (3) ◽  
pp. 377-392 ◽  
Author(s):  
Lyacine Bennacer ◽  
Nasre-Dine Ahfir ◽  
Abderrazak Bouanani ◽  
Abdellah Alem ◽  
Huaqing Wang
Keyword(s):  
Particle Size ◽  
Porous Medium ◽  
Size Effects ◽  
Suspended Particles ◽  
Particle Size Effects ◽  
Medium Particle ◽  
Medium Particle Size
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