Morphology and Physical-Mechanical Parameters of Poly(3-hydroxybutyrate) – Polyvinyl Alcohol Blends

2015 ◽  
pp. 211-224
Keyword(s):  
Polyvinyl Alcohol ◽  
Mechanical Parameters

Cryogels based on composition chitosan–polyvinyl alcohol: synthesis and properties

2019 ◽  
Vol 5 (4) ◽  
pp. 56-63
Author(s):  
E.V. Dikhtiaruk ◽  
◽  
V.V. Paientko ◽  
A.K. Matkovsky ◽  
Yu.N. Nichiporuk ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Alcohol Synthesis

Synthesis and Characterisation of Polyaniline-Polyvinyl Alcohol-NiO Nanocomposite Film

2011 ◽  
Vol 3 (8) ◽  
pp. 91-93 ◽  
Author(s):  
Sindhu Honmute ◽  
◽  
Arunkumar Lagashetty ◽  
A. Venkataraman A. Venkataraman
Keyword(s):  
Polyvinyl Alcohol ◽  
Nanocomposite Film

Degradable properties of compositions based on polyethylene and plasticized polyvinyl alcohol

2019 ◽  
Vol 41 (4) ◽  
pp. 246-252
Author(s):  
T.V. Dmytriieva ◽  
◽  
S.K. Krymovska ◽  
V.I. Bortnytskyi ◽  
S.M. Kobylinskyi ◽  
...  
Keyword(s):  
Polyvinyl Alcohol

Analysis of Efficiency of Drilling of Large-Diameter Wells With a Profiled Wing Bit / Badania Efektywności Wiercenia Studni Wielkośrednicowych Świdrem Skrawającym z Profilowanymi Skrzydłami

2012 ◽  
Vol 57 (2) ◽  
pp. 363-373
Author(s):  
Jan Macuda
Keyword(s):  
Average Rate ◽  
Large Diameter ◽  
Open Pit ◽  
Mechanical Parameters ◽  
Drilling Rate ◽  
Geological Conditions ◽  
Rock Drillability ◽  
Drilling Technology ◽  
Weight On Bit ◽  
Rotary Speed

Abstract In Poland all lignite mines are dewatered with the use of large-diameter wells. Drilling of such wells is inefficient owing to the presence of loose Quaternary and Tertiary material and considerable dewatering of rock mass within the open pit area. Difficult geological conditions significantly elongate the time in which large-diameter dewatering wells are drilled, and various drilling complications and break-downs related to the caving may occur. Obtaining higher drilling rates in large-diameter wells can be achieved only when new cutter bits designs are worked out and rock drillability tests performed for optimum mechanical parameters of drilling technology. Those tests were performed for a bit ø 1.16 m in separated macroscopically homogeneous layers of similar drillability. Depending on the designed thickness of the drilled layer, there were determined measurement sections from 0.2 to 1.0 m long, and each of the sections was drilled at constant rotary speed and weight on bit values. Prior to drillability tests, accounting for the technical characteristic of the rig and strength of the string and the cutter bit, there were established limitations for mechanical parameters of drilling technology: P ∈ (Pmin; Pmax) n ∈ (nmin; nmax) where: Pmin; Pmax - lowest and highest values of weight on bit, nmin; nmax - lowest and highest values of rotary speed of bit, For finding the dependence of the rate of penetration on weight on bit and rotary speed of bit various regression models have been analyzed. The most satisfactory results were obtained for the exponential model illustrating the influence of weight on bit and rotary speed of bit on drilling rate. The regression coefficients and statistical parameters prove the good fit of the model to measurement data, presented in tables 4-6. The average drilling rate for a cutter bit with profiled wings has been described with the form: Vśr= Z ·Pa· nb where: Vśr- average drilling rate, Z - drillability coefficient, P - weight on bit, n - rotary speed of bit, a - coefficient of influence of weight on bit on drilling rate, b - coefficient of influence of rotary speed of bit on drilling rate. Industrial tests were performed for assessing the efficiency of drilling of large-diameter wells with a cutter bit having profiled wings ø 1.16 m according to elaborated model of average rate of drilling. The obtained values of average rate of drilling during industrial tests ranged from 8.33×10-4 to 1.94×10-3 m/s and were higher than the ones obtained so far, i.e. from 181.21 to 262.11%.

Improvement of Ti/RuO2–IrO2 Anode Lifetime and Electrocatalytical Properties by Using an Eco-Friendly Thermal Decomposition Method Using Polyvinyl Alcohol as Solvent

2019 ◽  
Author(s):  
Charlys Bezerra ◽  
Géssica Santos ◽  
Marilia Pupo ◽  
Maria Gomes ◽  
Ronaldo Silva ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Polyvinyl Alcohol ◽  
High Efficiency ◽  
Electrochemical Impedance ◽  
Pechini Method ◽  
Low Cost ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Calcination Temperatures ◽  
Service Lifetime

<p>Electrochemical oxidation processes are promising solutions for wastewater treatment due to their high efficiency, easy control and versatility. Mixed metal oxides (MMO) anodes are particularly attractive due to their low cost and specific catalytic properties. Here, we propose an innovative thermal decomposition methodology using <a>polyvinyl alcohol (PVA)</a> as a solvent to prepare Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes. Comparative anodes were prepared by conventional method employing a polymeric precursor solvent (Pechini method). The calcination temperatures studied were 300, 400 and 500 °C. The physical characterisation of all materials was performed by X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy, while electrochemical characterisation was done by cyclic voltammetry, accelerated service lifetime and electrochemical impedance spectroscopy. Both RuO<sub>2</sub> and IrO<sub>2</sub> have rutile-type structures for all anodes. Rougher and more compact surfaces are formed for the anodes prepared using PVA. Amongst temperatures studied, 300 °C using PVA as solvent is the most suitable one to produce anodes with expressive increase in voltammetric charge (250%) and accelerated service lifetime (4.3 times longer) besides reducing charge-transfer resistance (8 times lower). Moreover, the electrocatalytic activity of the anodes synthesised with PVA toward the Reactive Blue 21 dye removal in chloride medium (100 % in 30 min) is higher than that prepared by Pechini method (60 min). Additionally, the removal total organic carbon point out improved mineralisation potential of PVA anodes. Finally, this study reports a novel methodology using PVA as solvent to synthesise Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes with improved properties that can be further extended to synthesise other MMO compositions.</p>

RADIATION-INDUCED DECOMPOSITION AND POLYMERIZATION OF POLYVINYL ALCOHOL IN AQUEOUS SOLUTIONS

2013 ◽  
Vol 12 (7) ◽  
pp. 1323-1328 ◽  
Author(s):  
Lujun Chen ◽  
Weihua Sun ◽  
Jinping Tian ◽  
Jianlong Wang ◽  
Shijun He
Keyword(s):  
Polyvinyl Alcohol ◽  
Aqueous Solutions ◽  
Radiation Induced ◽  
Induced Decomposition

Crystallization Behavior of Polyvinyl Alcohol with 1,2-Diol Side-Chains

2018 ◽  
Vol 33 (2) ◽  
pp. 234-244 ◽  
Author(s):  
M. Shibutani ◽  
T. Yamamoto ◽  
K. Inoue ◽  
K. Tokumitsu
Keyword(s):  
Polyvinyl Alcohol ◽  
Crystallization Behavior ◽  
Side Chains

Effects of extrusion on mechanical damage and mechanical parameters of litchi

2014 ◽  
Vol 39 (6) ◽  
pp. 688-692
Author(s):  
Yan CHEN ◽  
He-ping XIANG ◽  
Jian-hao TAN ◽  
Xiang-jun ZOU ◽  
Guo-gang HUANG ◽  
...  
Keyword(s):  
Mechanical Damage ◽  
Mechanical Parameters
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