Unique Properties and Behavior of Nonmercerized Type-II Cellulose Nanocrystals as Carbon Nanotube Biocompatible Dispersants

Cellulose nanocrystals or nanoparticles (CNCs) has drawn a lot of attention due to their abundance, biocompatibility, renewability and their excellent mechanical properties paving the way to innovative and sustainable applications. In the present work, the stem residues of Asclepias Syriaca, better known as milkweed and generally regarded as a weed, was used for the first time to extract CNCs with a crystalline structure type-II (CNCs-II). Structural, thermal, morphological and mechanical properties of extracted CNCs-II were characterized by means of Fourier Transform Infrared (FT-IR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), Thermogravimetric Analysis (TGA) and Atomic Force Microscopy (AFM). Asclepias Syriaca stem fibers revealed quite similar cellulose content as compared to other milkweed species and, stable suspensions made of nanosphere- and nanorod- shape CNCs-II were successfully extracted from raw milkweed fibers. In addition, after conversion from cellulose-I to cellulose-II by mercerization, milkweed cellulose-II exhibited higher thermal resistance as compared to cellulose-I with degradation temperature at 328 °C and 310 °C respectively. Finally, the transversal elastic modulus of individuals CNCs-II, as measured by atomic force microscopy, was found to be in the range of 3.5-27 GPa which is consistent with reported values for CNCs-I or -II in the literature.

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Reliability Evaluation of a Server System Considering Signature Update

International Journal of Reliability Quality and Safety Engineering ◽

10.1142/s0218539321500030 ◽

2020 ◽

Vol 28 (01) ◽

pp. 2150003

Author(s):

Mitsuhiro Imaizumi ◽

Mitsutaka Kimura

Keyword(s):

Stochastic Models ◽

Detection Methods ◽

Type Ii ◽

Type Ii Error ◽

Cyber Attack ◽

Signature Detection ◽

Optimal Policies ◽

New Type ◽

And Behavior ◽

Server System

Cyber attack on the Internet has become a problem in recent years, and it has been becoming more sophisticated and complicated. As one of schemes to detect cyber attack, IDS has been widely used. IDS can detect cyber attack based on the signature which is the pattern of cyber attack and so on. There are signature-based and anomaly-based detection methods in terms of IDS. Signature detection compares activity and behavior to signatures of known attacks. Signatures need to be updated regularly to detect a new type of attacks. This paper considers extended stochastic models for a server system with signature update. The server has the function of IDS. In this model, we consider type II error where IDS judges the occurrence of cyber attack erroneously when it occurs. We assume that the check with signature update is performed at [Formula: see text]th check or every [Formula: see text] checks. We obtain the expected costs until cyber attack is detected and discuss the optimal policies which minimize them. Finally, numerical examples are given.

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Effect of sulfuric acid reaction time on the properties and behavior of cellulose nanocrystals from Cocos nucifera var-Aurantiaca peduncle’s cellulose microfibers

Materials Research Express ◽

10.1088/2053-1591/ab5a9d ◽

2019 ◽

Vol 6 (12) ◽

pp. 125333 ◽

Cited By ~ 1

Author(s):

K J Nagarajan ◽

A N Balaji ◽

S Thanga Kasi Rajan ◽

K Sathick Basha

Keyword(s):

Sulfuric Acid ◽

Reaction Time ◽

Cellulose Nanocrystals ◽

Cocos Nucifera ◽

Cellulose Microfibers ◽

Acid Reaction ◽

And Behavior

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Characterization of Type-II Acetylated Cellulose Nanocrystals with Various Degree of Substitution and Its Compatibility in PLA Films

Polymers ◽

10.3390/polym9080346 ◽

2017 ◽

Vol 9 (12) ◽

pp. 346 ◽

Cited By ~ 12

Author(s):

Feng Dong ◽

Meiling Yan ◽

Chunde Jin ◽

Shujun Li

Keyword(s):

Cellulose Nanocrystals ◽

Degree Of Substitution ◽

Type Ii

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Nonlocal Modeling and Behavior of Carbon Nanotube-Based Sensors in Thermal Environment

Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies ◽

10.1115/smasis2018-7987 ◽

2018 ◽

Author(s):

Seyedeh Sepideh Ghaffari ◽

Samantha Ceballes ◽

Abdessattar Abdelkefi

Keyword(s):

Carbon Nanotube ◽

Thermal Effects ◽

Thermal Environment ◽

Nonlocal Parameter ◽

Nonlocal Theory ◽

Small Scale ◽

Mass Sensor ◽

Buckling Behavior ◽

Mass Detector ◽

And Behavior

An exact solution that investigates the pre-buckling characteristics of nonlocal carbon nanotube (CNT)-based mass sensor subjected to thermal load under clamped-clamped boundary condition is determined. The uniform temperature rise is utilized to study thermal effects on the sensitivity of the mechanical resonator in pre-buckling configuration. Using Eringen’s nonlocal theory, along with the Hamilton’s principle, the governing equations considering small scale and geometric nonlinearity are derived. The influences of important parameters including nonlocal parameter, temperature change, length, and diameter of the CNT on the pre-buckling behavior and frequency shift of the CNT-based mass detector are also studied. Results show that these parameters have significant impact on the dynamic characteristics of the CNT-mass sensor.

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