scholarly journals Migration Behavior of Lubricants in Polypropylene Composites under Accelerated Thermal Aging

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1723
Author(s):  
Mun-Gyu Bak ◽  
Jong-Sung Won ◽  
Seon-Woong Koo ◽  
Arom Oh ◽  
Han-Ki Lee ◽  
...  
Keyword(s):  
Thermal Aging ◽  
Photoelectron Spectroscopy ◽  
Morphological Features ◽  
Work Of Adhesion ◽  
Infrared Spectrometry ◽  
Migration Behavior ◽  
Polypropylene Composites ◽  
Surface Migration ◽  
Aging Conditions

The surface migration of lubricants degrades the quality of thermoplastic polymer composites. In this study, the surface migration of lubricants in polypropylene composites were studied to improve the quality of the composites. Polypropylene (PP)/lubricant composites were manufactured using a co-rotating twin-screw extruder and injection molding, and the migration phenomena of the lubricant in the PP/lubricant composites were investigated under accelerated aging conditions with temperatures in the range of 20 to 90 °C and humidity of 100% for 72 h. The interrelation between the surface migration properties of PP/lubricant composites were investigated by considering their microstructural and morphological features, which were influenced by the thermal aging conditions. Further, the microstructural and morphological features were examined by contact angle, surface energy, attenuated total reflectance Fourier-transform infrared spectrometry, X-ray photoelectron spectroscopy, close-up digital imaging, and atomic force microscopy analyses. The polypropylene composites containing the magnesium stearate as the lubricant were found to exhibit a more stable migration behavior than the polypropylene composites containing a calcium stearate lubricant. This is attributed to multiple synergistic factors, such as interfacial tension and work of adhesion between PP and the lubricant. The findings of this study can be utilized to effectively manufacture high-quality thermoplastic composites for the fourth industrial revolution.

The basis of quality of sheep pelts and fur products is morphological features of the skin of sheep

2020 ◽  
pp. 50-57
Author(s):  
I. Dmitrik ◽  
G. Zavgorodnyaya
Keyword(s):  
Mechanical Strength ◽  
Breaking Load ◽  
Hair Follicles ◽  
Morphological Features ◽  
High Density ◽  
Fat Cells ◽  
High Quality ◽  
Histological Features ◽  
Weakened Zone

The morphological and histological features of the skin and wool cover of sheep as the basis for the quality of fur sheep pelts have been studied. The most important properties of sheep pelts (uniformity, thinness and density of wool) are provide the possibility of producing high-quality fur semi-finished products from them. However, the features of the histostructure of fine-wool sheep determine the low mechanical strength of the “facial” layer of skin. As a result, the “front” layer during processing often cracks to the upper border of the reticular layer or even peels off from the latter, making the sheep pelt unsuitable for use on fur products. These defects in fur practice are called “cracking” and “peeling” of the facial layer. They are mainly peculiar to sheep pelts of fine-wooled sheep. In these animals due to the high density and tone of the coat, the roots and hair follicles, root vaginas, secretory departments, excretory ducts of the glands and other structures occupy a significant share of the volume in the thickness of the Pilar layer (up to 25–30 %). The share of fibrous structures remains less volume, and these structures themselves are relatively weakly developed, located loosely and loosely intertwined with each other. The accumulations of fat cells that occur here also cannot be attributed to skin-strengthening elements. In fine-fleece sheep the pilar layer is on average 60 % of the thickness of the dermis. Therefore, more than half of its thickness is a weakened zone. The strength of the “front” layer is not the same in different fine-wool breeds of sheep and in different animals within the breed. For example, the average breaking load for cod of the “front” layer in Soviet Merino pelts is 1,25 kg, and in Precoce is 2,49 kg.

scholarly journals Neural Modeling of the Distribution of Protein, Water and Gluten in Wheat Grains during Storage

2020 ◽  
Vol 12 (12) ◽  
pp. 5050
Author(s):  
Katarzyna Szwedziak ◽  
Ewa Polańczyk ◽  
Żaneta Grzywacz ◽  
Gniewko Niedbała ◽  
Wiktoria Wojtkiewicz
Keyword(s):  
Total Protein ◽  
Near Infrared ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Quality Parameters ◽  
Neural Modeling ◽  
Infrared Spectrometry ◽  
Stored Grain ◽  
Stored Wheat

An important requirement in the grain industry is to obtain fast information on the quality of purchased and stored grain. Therefore, it is of great importance to search for innovative solutions aimed at the monitoring and fast assessment of quality parameters of stored wheat The results of the evaluation of total protein, water and gluten content by means of near infrared spectrometry are presented in the paper. Multiple linear regression analysis (MLR) and neural modeling were used to analyze the obtained results. The results obtained show no significant changes in total protein (13.13 ± 0.15), water (10.63 ± 0.16) or gluten (30.56 ± 0.54) content during storage. On the basis of the collected data, a model artificial neural network (ANN) MLP 52-6-3 was created, which, with the use of four independent features, allows us to determine changes in the content of water, protein and gluten in stored wheat. The chosen network returned good error values: learning, below 0.001; testing, 0.015; and validation, 0.008. The obtained results and their interpretation are an important element in the warehouse industry. The information obtained in this way about the state of the quality of stored grain will allow for a fast reaction in case of the threat of lowering the quality parameters of the stored grain.

Mechanical Properties of Epoxy Adhesive Under Thermal Aging and Their Chemical Degradation Behavior

2021 ◽  
Vol 21 (8) ◽  
pp. 4444-4449
Author(s):  
Bongjin Chung ◽  
Shin Sungchul ◽  
Jaeho Shim ◽  
Seongwoo Ryu
Keyword(s):  
Mechanical Properties ◽  
Thermal Aging ◽  
Photoelectron Spectroscopy ◽  
Thermal Exposure ◽  
Chain Scission ◽  
Epoxy Adhesive ◽  
Chemical Degradation ◽  
Adhesive Properties ◽  
Noticeable Reduction

Epoxy adhesive was analyzed under long term thermal aging and mechanical properties and chemical degradation were observed by X-ray photoelectron spectroscopy (XPS). Long term thermal exposure of epoxy causes a noticeable reduction in adhesive properties. We developed a predictive model of temperature and time dependent aging. The temperature dependent aging behavior of epoxy adhesive shows good agreement with conventional Arrhenius equations. Using XPS analysis, we also discovered a correlation between chemical degradation and the adhesive properties. Decay of C–C bonding ratio induced chain-scission of epoxy adhesive; increase of total numbers of C–O and C═O induced oxidation of epoxy adhesive during thermal exposure.

Optimising the Growth of Few-Layer Graphene on Silicon Carbide by Nickel Silicidation

2013 ◽  
Vol 740-742 ◽  
pp. 121-124 ◽  
Author(s):  
Enrique Escobedo-Cousin ◽  
Konstantin Vassilevski ◽  
Toby Hopf ◽  
Nick G. Wright ◽  
Anthony O’Neill ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Sample Surface ◽  
Device Fabrication ◽  
Solid Phase Epitaxy ◽  
X Ray ◽  
Graphene Films ◽  
Few Layer Graphene ◽  
The Impact

Few-layers graphene films (FLG) were grown by local solid phase epitaxy on a semi-insulating 6H-SiC substrate by annealing Ni films deposited on the Si and C-terminated faces of the SiC. The impact of the annealing process on the final quality of the FLG films is studied using Raman spectroscopy. X-ray photoelectron spectroscopy was used to verify the presence of graphene on the sample surface. We also demonstrate that further device fabrication steps such as dielectric deposition can be carried out without compromising the FLG films integrity.

scholarly journals Electromagnetic Shielding by MXene-Graphene-PVDF Composite with Hydrophobic, Lightweight and Flexible Graphene Coated Fabric

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1803 ◽  
Author(s):  
Kanthasamy Raagulan ◽  
Ramanaskanda Braveenth ◽  
Hee Jang ◽  
Yun Seon Lee ◽  
Cheol-Min Yang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Spray Coating ◽  
Cost Effective ◽  
Work Of Adhesion ◽  
Shielding Effectiveness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Highest Weight ◽  
Coated Fabric ◽  
Hydrophobic Nature

MXene and graphene based thin, flexible and low-density composite were prepared by cost effective spray coating and solvent casting method. The fabricated composite was characterized using Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray (EDX). The prepared composites showed hydrophobic nature with higher contact angle of 126°, −43 mN·m−1 wetting energy, −116 mN·m−1 spreading Coefficient and 30 mN·m−1 lowest work of adhesion. The composites displayed excellent conductivity of 13.68 S·cm−1 with 3.1 Ω·sq−1 lowest sheet resistance. All the composites showed an outstanding thermal stability and constrain highest weight lost until 400 °C. The MXene-graphene foam exhibited excellent EMI shielding of 53.8 dB (99.999%) with reflection of 13.10 dB and absorption of 43.38 dB in 8–12.4 GHz. The single coated carbon fabric displayed outstanding absolute shielding effectiveness of 35,369.82 dB·cm2·g−1. The above results lead perspective applications such as aeronautics, radars, air travels, mobile phones, handy electronics and military applications.

scholarly journals Assessment of the Quality of Newly Formed Bone around Titanium Alloy Implants by Using X-Ray Photoelectron Spectroscopy

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Hiroshi Nakada ◽  
Toshiro Sakae ◽  
Yasuhiro Tanimoto ◽  
Mari Teranishi ◽  
Takao Kato ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Cortical Bone ◽  
Photoelectron Spectroscopy ◽  
X Ray

The aim of this study was to evaluate differences in bones quality between newly formed bone and cortical bone formed around titanium alloy implants by using X-ray photoelectron spectroscopy. As a result of narrow scan measurement at 4 weeks, the newly formed bone of C1s, P2p, O1s, and Ca2p were observed at a different peak range and strength compared with a cortical bone. At 8 weeks, the peak range and strength of newly formed bone were similar to those of cortical bone at C1s, P2p, and Ca2p, but not O1s. The results from this analysis indicate that the peaks and quantities of each element of newly formed bone were similar to those of cortical bone at 8 weeks, suggestive of a strong physicochemical resemblance.

scholarly journals Structural, Surface Morphology and Optical Properties of ZnS Films by Chemical Bath Deposition at Various Zn/S Molar Ratios

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Fei-Peng Yu ◽  
Sin-Liang Ou ◽  
Pin-Chuan Yao ◽  
Bing-Rui Wu ◽  
Dong-Sing Wuu
Keyword(s):  
Chemical Bath Deposition ◽  
Photoelectron Spectroscopy ◽  
Visible Region ◽  
Film Surface ◽  
Optical Transmittance ◽  
Molar Ratio ◽  
Infrared Spectrometry ◽  
X Ray ◽  
Molar Ratios ◽  
Zns Films

In this study, ZnS thin films were prepared on glass substrates by chemical bath deposition at various Zn/S molar ratios from 1/50 to 1/150. The effects of Zn/S molar ratio in precursor on the characteristics of ZnS films were demonstrated by X-ray diffraction, scanning electron microscopy, optical transmittance, X-ray photoelectron spectroscopy, and Fourier transform infrared spectrometry. It was found that more voids were formed in the ZnS film prepared using the precursor with Zn/S molar ratio of 1/50, and the other ZnS films showed the denser structure as the molar ratio was decreased from 1/75 to 1/150. From the analyses of chemical bonding states, the ZnS phase was indeed formed in these films. Moreover, the ZnO and Zn(OH)2also appeared due to the water absorption on film surface during deposition. This would be helpful to the junction in cell device. With changing the Zn/S molar ratio from 1/75 to 1/150, the ZnS films demonstrate high transmittance of 75–88% in the visible region, indicating the films are potentially useful in photovoltaic applications.

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