Torque Rheological Properties of Bamboo Flour/PP Composites

2011 ◽  
Vol 391-392 ◽  
pp. 138-142
Author(s):  
Wen Bin Yang ◽  
Ming Xin Zhang ◽  
En Hui Chen
Keyword(s):  
Rheological Behavior ◽  
Flow Behavior ◽  
Orthogonal Test ◽  
Weight Percentage ◽  
Two Factors ◽  
Pp Composites ◽  
Bamboo Flour ◽  
Reinforced Thermoplastics ◽  
The Given ◽  
Made In

The rheological behavior of plant flour reinforced thermoplastics composites is very important to practical industry, however few research especially research about bamboo flour reinforced polypropylene(PP) composites is available regarding rheological field. In this paper, the torque rheometer made in Shanghai was used to examine the flow behavior of bamboo flour filled PP composites. The orthogonal test was adopted to analyze how three factors(weight percentage of bamboo, weight percentage of MAPP and rotate speed) influence the behavior of composites. The result indicated that bamboo flour filled PP composites was pseudo-plastics or shear-thinning flow under the experimental condition investigated. The effect of weight percentage of bamboo on rheological peoperties was signigficant,but the effect of both of the rest of two factors on rheological was not significant under the given experimental condition.

Formally Normal Operators Having no Normal Extensions

1965 ◽  
Vol 17 ◽  
pp. 1030-1040 ◽  
Author(s):  
Earl A. Coddington
Keyword(s):  
Hilbert Space ◽  
Linear Operator ◽  
Null Space ◽  
Normal Operator ◽  
Closed Linear Operator ◽  
Normal Operators ◽  
The Given ◽  
Densely Defined ◽  
Made In

The domain and null space of an operator A in a Hilbert space will be denoted by and , respectively. A formally normal operatorN in is a densely defined closed (linear) operator such that , and for all A normal operator in is a formally normal operator N satisfying 35 . A study of the possibility of extending a formally normal operator N to a normal operator in the given , or in a larger Hilbert space, was made in (1).

scholarly journals Rheological Behavior of Fresh Cement Pastes

Fluids ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 106 ◽  
Author(s):  
Francisco-José Rubio-Hernández
Keyword(s):  
Rheological Behavior ◽  
Flow Behavior ◽  
Viscoelastic Behavior ◽  
Alternative Methods ◽  
Chemical Additives ◽  
Research Activity ◽  
Cement Pastes ◽  
Blended Cements ◽  
Flow Models ◽  
Mineral Additions

Rheology of a concrete is mainly controlled by the rheological behavior of its cement paste. This is the main practical reason for the extensive research activity observed during 70 years in this research subfield. In this brief review, some areas of the research on the rheological behavior of fresh cement pastes (mixture method influence, microstructure analysis, mineral additions influence, chemical additives influence, blended cements behavior, viscoelastic behavior, flow models, and flow behavior analysis with alternative methods) are examined.

scholarly journals Injectable and Gellable Chitosan Formulations Filled with Cellulose Nanofibers for Intervertebral Disc Tissue Engineering

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1202 ◽  
Author(s):  
Ingo Doench ◽  
Maria Torres-Ramos ◽  
Alexandra Montembault ◽  
Paula Nunes de Oliveira ◽  
Celia Halimi ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Rheological Behavior ◽  
Biomedical Application ◽  
Flow Behavior ◽  
Cellulose Nanofibers ◽  
Nanofibrillated Cellulose ◽  
The Body ◽  
Mechanical Reinforcement ◽  
Invasive Approach

The development of non-cellularized injectable suspensions of viscous chitosan (CHI) solutions (1.7–3.3% (w/w)), filled with cellulose nanofibers (CNF) (0.02–0.6% (w/w)) of the type nanofibrillated cellulose, was proposed for viscosupplementation of the intervertebral disc nucleus pulposus tissue. The achievement of CNF/CHI formulations which can gel in situ at the disc injection site constitutes a minimally-invasive approach to restore damaged/degenerated discs. We studied physico-chemical aspects of the sol and gel states of the CNF/CHI formulations, including the rheological behavior in relation to injectability (sol state) and fiber mechanical reinforcement (gel state). CNF-CHI interactions could be evidenced by a double flow behavior due to the relaxation of the CHI polymer chains and those interacting with the CNFs. At high shear rates resembling the injection conditions with needles commonly used in surgical treatments, both the reference CHI viscous solutions and those filled with CNFs exhibited similar rheological behavior. The neutralization of the flowing and weakly acidic CNF/CHI suspensions yielded composite hydrogels in which the nanofibers reinforced the CHI matrix. We performed evaluations in relation to the biomedical application, such as the effect of the intradiscal injection of the CNF/CHI formulation in pig and rabbit spine models on disc biomechanics. We showed that the injectable formulations became hydrogels in situ after intradiscal gelation, due to CHI neutralization occurring in contact with the body fluids. No leakage of the injectate through the injection canal was observed and the gelled formulation restored the disc height and loss of mechanical properties, which is commonly related to disc degeneration.

scholarly journals Optimal synthesis of a four-bar linkage by method of controlled deviation

2004 ◽  
Vol 31 (3-4) ◽  
pp. 265-280 ◽  
Author(s):  
Radovan Bulatovic ◽  
Stevan Djordjevic
Keyword(s):  
Objective Function ◽  
Optimal Synthesis ◽  
Straight Line ◽  
Individual Comparison ◽  
Four Bar Linkage ◽  
The Given ◽  
Initial Selection ◽  
Selection Of ◽  
Process Calculation ◽  
Made In

This paper considers optimal synthesis of a four-bar linkage by method of controlled deviations. The advantage of this approximate method is that it allows control of motion of the coupler in the four-bar linkage so that the path of the coupler is in the prescribed environment around the given path on the segment observed. The Hooke-Jeeves?s optimization algorithm has been used in the optimization process. Calculation expressions are not used as the method of direct searching, i.e. individual comparison of the calculated value of the objective function is made in each iteration and the moving is done in the direction of decreasing the value of the objective function. This algorithm does not depend on the initial selection of the projected variables. All this is illustrated on an example of synthesis of a four-bar linkage whose coupler point traces a straight line, i.e. passes through sixteen prescribed points lying on one straight line. .

Circles on the Complex Plane

2021 ◽  
pp. 3-12
Author(s):  
A. Girsh
Keyword(s):  
Euclidean Space ◽  
Complex Plane ◽  
Euclidean Plane ◽  
Complex Space ◽  
Radical Center ◽  
Special Cases ◽  
Different Types ◽  
Different Dimensions ◽  
The Given ◽  
Made In

The Euclidean plane and Euclidean space themselves do not contain imaginary elements by definition, but are inextricably linked with them through special cases, and this leads to the need to propagate geometry into the area of imaginary values. Such propagation, that is adding a plane or space, a field of imaginary coordinates to the field of real coordinates leads to various variants of spaces of different dimensions, depending on the given axiomatics. Earlier, in a number of papers, were shown examples for solving some urgent problems of geometry using imaginary geometric images [2, 9, 11, 13, 15]. In this paper are considered constructions of orthogonal and diametrical positions of circles on a complex plane. A generalization has been made of the proposition about a circle on the complex plane orthogonally intersecting three given spheres on the proposition about a sphere in the complex space orthogonally intersecting four given spheres. Studies have shown that the diametrical position of circles on the Euclidean E-plane is an attribute of the orthogonal position of the circles’ imaginary components on the pseudo-Euclidean M-plane. Real, imaginary and degenerated to a point circles have been involved in structures and considered, have been demonstrated these circles’ forms, properties and attributes of their orthogonal position. Has been presented the construction of radical axes and a radical center for circles of the same and different types. A propagation of 2D mutual orthogonal position of circles on 3D spheres has been made. In figures, dashed lines indicate imaginary elements.

Impact of the Slurry Pond of the Tyrnyauz Tungsten-Molybdenum Complex on the Mountain Territories Environment

2018 ◽  
Vol 931 ◽  
pp. 1070-1075 ◽  
Author(s):  
Buzgigit M. Huchunayev ◽  
Oksana O. Dakhova ◽  
Svetlana A. Bekkiyeva ◽  
Svetlana B. Hatefova
Keyword(s):  
Negative Impact ◽  
Scientific Work ◽  
Land Resources ◽  
Molybdenum Complex ◽  
Atmospheric Air ◽  
Impact Reduction ◽  
The Given ◽  
Made In

The results of the Tyrnyauz tungsten-molybdenum Plant (TTMP) slurry pond settler environment impacts assessment are given in this scientific work, and the recommendations about the negative impact reduction on the environment are made. In the given work the characteristics of the environment state are investigated: atmospheric air, water objects and land resources.

Time-Dependent Rheological Behavior of Fluids For Electronics Packaging

2005 ◽  
Vol 127 (4) ◽  
pp. 370-374 ◽  
Author(s):  
X. B. Chen
Keyword(s):  
Rheological Behavior ◽  
Printed Circuit Boards ◽  
Flow Behavior ◽  
Electronics Packaging ◽  
Time Dependent ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Fluid Behavior ◽  
Surface Mounting

In electronics packaging, one of the key processes is dispensing fluid materials, such as adhesive, epoxy, encapsulant, onto substrates or printed circuit boards for the purpose of surface mounting or encapsulation. In order to precisely control the dispensing process, the understanding and characterization of the flow behavior of the fluid being dispensed is very important, as the behavior can have a significant influence on the dispensing process. However, this task has proven to be very challenging due to the fact that the fluids for electronics packaging usually exhibit the time-dependent rheological behavior, which has not been well defined in literature. In the paper a study on the characterization of the time-dependent rheological behavior of the fluids for electronics packaging is presented. In particular, a model is developed based on structural theory and then applied to the characterization of the decay and recovery of fluid behavior, which happen in the dispensing process due to the interruption of process. Experiments are carried out to verify the effectiveness of the model developed.

Characterization of the Time-Dependent Rheological Behavior of Fluids for Electronics Packaging

2003 ◽  
Author(s):  
X. B. Chen ◽  
W. J. Zhang ◽  
G. Schoenau ◽  
B. W. Surgenor
Keyword(s):  
Rheological Behavior ◽  
Flow Behavior ◽  
Electronics Packaging ◽  
Structural Theory ◽  
Time Dependent ◽  
Fluid Behavior ◽  
Proposed Model ◽  
Key Issues

To effectively control the dispensing process by which fluids are delivered onto substrates in electronics packaging, one of the key issues is to understand and characterize the flow behavior of the fluids being dispensed. However, this task has proven to be a demanding one as the fluids used for electronics packaging usually exhibit the time-dependent rheological behavior, which has not been well documented in the literature. In this paper, the characterization of time-dependent rheological behavior of fluids is studied. In particular, a model using the structural theory is proposed and applied to the characterization of the decay and recovery of fluid behavior, which are typically encountered in a dispensing process. Experiments are conducted to validate the proposed model.

Viscoelastic, thermal, and morphological properties of nanocomposites based on modified PVA using a twin-screw melt extrusion process

2019 ◽  
Vol 33 (11) ◽  
pp. 1555-1568
Author(s):  
B Rajeswari ◽  
N Malarvizhi ◽  
Dhanasekaran Prakash ◽  
Sellamuthu N Jaisankar
Keyword(s):  
Polymer Nanocomposites ◽  
Flow Behavior ◽  
Extrusion Process ◽  
Morphological Properties ◽  
Screw Extruder ◽  
Weight Percentage ◽  
Bonding System ◽  
Increase With Increase ◽  
Twin Screw ◽  
Melting Endotherm

Melt polymer nanocomposites were prepared using polyvinyl alcohol (PVA) with the different weight percentage of calcined clays (CCs) in a twin-screw extruder at 210°C and 70 r min−1 for 8 min. Bentonite was surface functionalized with benzidine using dilute hydrochloric acid at 60°C and calcined at 600°C for 6 h. The CCs were incorporated into the PVA matrix to study their morphology and rheological properties. The melt viscosities of the composites were measured by the cone-plate rheometer, the rheogram show non-Newtonian and thixotropic flow behavior. Scanning electron microscope confirmed the degree of exfoliated nanocomposites. The polymer and functionalized nanoclay interactions were reflected in the enhancement of thermal stability and mechanical properties. The melting endotherm temperature ( T m) and glass transition temperature ( T g) of the nanocomposites tend to increase with increase in weight percentage of the calcined nanoclays. Thermal properties show that addition of calcined nanoclays would improve the thermal decomposition temperatures from 295°C to 307°C when CC content was 2 wt% in covalent or ionic bonding system.

scholarly journals Cutting Parameter Selection for Efficient and Sustainable Repair of Holes Made in Hybrid Mg–Ti–Mg Component Stacks by Dry Drilling Operations

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1369 ◽  
Author(s):  
Eva Rubio ◽  
María Villeta ◽  
José Valencia ◽  
José Sáenz de Pipaón
Keyword(s):  
Cutting Parameters ◽  
Dry Drilling ◽  
Average Analysis ◽  
Two Factors ◽  
Drilling Operations ◽  
Small Cracks ◽  
Drilling Conditions ◽  
Machining Operations ◽  
Full Factorial ◽  
Made In

Drilling is one of the most common machining operations in the aeronautic and aerospace industries. For assembling parts, a large number of holes are usually drilled into the parts so that they can be joined later by rivets. As these holes are subjected to fatigue cycles, they have to be checked regularly for maintenance or repair, since small cracks or damage in its contour can quickly cause breakage of the part, which can have dangerous consequences. This paper focuses on finding the best combinations of cutting parameters to perform repair and maintenance operations of holes in stacked hybrid magnesium–titanium–magnesium components in an efficient, timely, and sustainable (without lubricants or coolants) manner, under dry drilling conditions. For the machining trials, experiments were designed and completed. A product of a full factorial 23 and a block of two factors (3 × 2) was used with surface roughness as the response variable measured as the mean roughness average. Analysis of variance (ANOVA) was used to examine the results. A set of optimized tool and cutting conditions is presented for performing dry drilling repair operations.

Sign in / Sign up

Export Citation Format

Share Document