Performance of cellulose acetate propionate in polycaprolactone and starch composites: biodegradation and water resistance properties

Fracturing fluids are being increasingly used for viscosity development and proppant transport during hydraulic fracturing operations. Furthermore, the breaker is an important additive in fracturing fluid to extensively degrade the polymer mass after fracturing operations, thereby maximizing fracture conductivity and minimizing residual damaging materials. In this study, the efficacy of different enzyme breakers was examined in alkaline and medium-temperature reservoirs. The parameters considered were the effect of the breaker on shear resistance performance and sand-suspending performance of the fracturing fluid, its damage to the reservoir after gel breaking, and its gel-breaking efficiency. The experimental results verified that mannanase II is an enzyme breaker with excellent gel-breaking performance at medium temperatures and alkaline conditions. In addition, mannanase II did not adversely affect the shear resistance performance and sand-suspending performance of the fracturing fluid during hydraulic fracturing. For the same gel-breaking result, the concentration of mannanase II used was only one fifth of other enzyme breakers (e.g., mannanase I, galactosidase, and amylase). Moreover, the amount of residue and the particle size of the residues generated were also significantly lower than those of the ammonium persulfate breaker. Finally, we also examined the viscosity-reducing capability of mannanase II under a wide range of temperatures (104–158 °F) and pH values (7–8.5) to recommend its best-use concentrations under different fracturing conditions. The mannanase has potential for applications in low-permeability oilfield development and to maximize long-term productivity from unconventional oilwells.

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Resistance Tests of an Articulated Pusher Barge System in Deep and Shallow Water

10.1115/omae2021-61754 ◽

2021 ◽

Author(s):

Li Zhang ◽

Lei Xing ◽

Mingyu Dong ◽

Weimin Chen

Keyword(s):

Shallow Water ◽

Water Depth ◽

Deep Water ◽

Water Resistance ◽

Model Tests ◽

System 2 ◽

Changing Trend ◽

The Difference ◽

Transport Vessel ◽

Resistance Performance

Abstract Articulated pusher barge vessel is a short-distance transport vessel with good economic performance and practicability, which is widely used in the Yangtze River of China. In this present work, the resistance performance of articulated pusher barge vessel in deep water and shallow water was studied by model tests in the towing tank and basin of Shanghai Ship and Shipping Research Institute. During the experimental investigation, the articulated pusher barge vessel was divided into three parts: the pusher, the barge and the articulated pusher barge system. Firstly, the deep water resistance performance of the articulated pusher barge system, barge and the pusher at design draught T was studied, then the water depth h was adjusted, and the shallow water resistance at h/T = 2.0, 1.5 and 1.2 was tested and studied respectively, and the difference between deep water resistance and shallow water resistance at design draught were compared. The results of model tests and analysis show that: 1) in the study of deep water resistance, the total resistance of the barge was larger than that of the articulated pusher barge system. 2) for the barge, the shallow water resistance increases about 0.4–0.7 times at h/T = 2.0, 0.5–1.1 times at h/T = 1.5, and 0.7–2.3 times at h/T = 1.2. 3) for the pusher, the shallow water resistance increases about 1.0–0.4 times at h/T = 2.7, 1.2–0.9 times at h/T = 2.0, and 1.7–2.4 times at h/T = 1.6. 4) for the articulated pusher barge system, the shallow water resistance increases about 0.2–0.3 times at h/T = 2.0, 0.5–1.3 times at h/T = 1.5, and 1.0–3.5 times at h/T = 1.2. Furthermore, the water depth Froude number Frh in shallow water was compared with the changing trend of resistance in shallow water.

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Fungal melanins: a review

Canadian Journal of Microbiology ◽

10.1139/w98-119 ◽

1998 ◽

Vol 44 (12) ◽

pp. 1115-1136 ◽

Cited By ~ 386

Author(s):

M J Butler ◽

A W Day

Keyword(s):

Molecular Biology ◽

Analytical Methods ◽

Enzymatic Degradation ◽

Fundamental Properties ◽

Wide Range ◽

Lignin Peroxidases ◽

Fungal Melanin ◽

Relationship Of ◽

The Relationship ◽

Fungal Melanins

The relationship of polyketide melanogenesis molecular biology to that of nonmelanin-producing pathways in a wide range of fungi and other organisms is discussed. Analytical methods and fundamental properties of melanins are discussed and fungal melanin properties are compared with those of animal and bacterial melanins. The enzymatic degradation of melanins by lignin peroxidases is described.Key words: fungal melanin, polyketide melanin, DHN melanin, melanin degradation, melanin properties, melanin analysis.

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Fabrication and finite element analysis of vibrating parallel film actuator made with cellulose acetate for potential haptic application

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406215598802 ◽

2016 ◽

Vol 230 (15) ◽

pp. 2720-2727 ◽

Cited By ~ 1

Author(s):

Md Mohiuddin ◽

Asma Akther ◽

Eun Byul Jo ◽

Hyun Chan Kim ◽

Jaehwan Kim

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Cellulose Acetate ◽

Vibration Characteristics ◽

Experimental Results ◽

Vibration Velocity ◽

Frequency Range ◽

Actuation Frequency ◽

Element Analysis ◽

Wide Range

The present study investigates a film actuator made with dielectric cellulose acetate films separated by narrow spacers as a means of electrostatic actuation for potential haptic application. Fabrication process for the actuator is explained along with experiments conducted over a wide frequency range of actuation frequency. A valid finite element simulation of the actuator is made on the quarter section of the actuator by using full 3D finite elements. Vibration characteristics such as fundamental natural frequency, mode shape and output velocity in the frequency range for haptic feeling generation are obtained from the finite element analysis and compared with the experimental results. Experimental results demonstrate that the finite element model is practical and effective enough in predicting the vibration characteristics of the actuator for haptic application. The film actuator shows many promising properties like high transparency, wide range of actuation frequency and high vibration velocity for instance.

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Cellulose Acetate Propionate

Springer Lexikon Kosmetik und Körperpflege ◽

10.1007/978-3-540-71095-0_1741 ◽

2007 ◽

pp. 95-95

Author(s):

Marina Bährle-Rapp

Keyword(s):

Cellulose Acetate ◽

Cellulose Acetate Propionate

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Bioresorbable Composites and Implant

Design, Development, and Optimization of Bio-Mechatronic Engineering Products - Advances in Mechatronics and Mechanical Engineering ◽

10.4018/978-1-5225-8235-9.ch003 ◽

2019 ◽

pp. 57-76

Author(s):

Divya Zindani

Keyword(s):

Mechanical Properties ◽

Surface Modification ◽

Degradation Rate ◽

Clinical Applications ◽

The Body ◽

Metal Alloys ◽

Medical Sciences ◽

Intended Function ◽

Wide Range ◽

Modification Rate

Different biomaterials in the form of ceramics, metal alloys, composites, glasses, polymers, etc. have gained wide-range acceptance in the realm of medical sciences. Bioimplants from such biomaterials have been constructed and used widely for different clinical applications. With the continual progress, biomaterials that may be resorbed inside the body have been developed. These have done away with the major challenge of removal of an implant after it has served its intended function. Important factors are taken into consideration in design and development of implants from such biomaterials are mechanical properties, degradation rate, surface modification, rate of corrosion, biocompatibility, and non-toxicity. Given the importance of such materials in clinical applications, the chapter presents an overview of the bioresorable composites and their implants. The related properties and the functions served have been outlined briefly. Further, the challenges associated and the remedies to overcome them have also been delineated.

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Bioresorbable Composites and Implant

Research Anthology on Emerging Technologies and Ethical Implications in Human Enhancement ◽

10.4018/978-1-7998-8050-9.ch022 ◽

2021 ◽

pp. 443-456

Author(s):

Divya Zindani

Keyword(s):

Mechanical Properties ◽

Surface Modification ◽

Degradation Rate ◽

Clinical Applications ◽

The Body ◽

Metal Alloys ◽

Medical Sciences ◽

Intended Function ◽

Wide Range ◽

Modification Rate

Different biomaterials in the form of ceramics, metal alloys, composites, glasses, polymers, etc. have gained wide-range acceptance in the realm of medical sciences. Bioimplants from such biomaterials have been constructed and used widely for different clinical applications. With the continual progress, biomaterials that may be resorbed inside the body have been developed. These have done away with the major challenge of removal of an implant after it has served its intended function. Important factors are taken into consideration in design and development of implants from such biomaterials are mechanical properties, degradation rate, surface modification, rate of corrosion, biocompatibility, and non-toxicity. Given the importance of such materials in clinical applications, the chapter presents an overview of the bioresorable composites and their implants. The related properties and the functions served have been outlined briefly. Further, the challenges associated and the remedies to overcome them have also been delineated.

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