scholarly journals A Study on Liner-Reaction Speed based on the Aging of a Curing System

2021 ◽  
Author(s):  
Sungjun Park ◽  
Sunghan Choi ◽  
Jungho Park
Keyword(s):  
Aging Time ◽  
Adhesive Strength ◽  
Rocket Motor ◽  
Raw Material ◽  
Isophorone Diisocyanate ◽  
Aging Period ◽  
Activated Complex ◽  
Reaction Speed

Abstract In this study, the hardening reaction speed of a rocket motor liner based on the aging of a curing system comprised of a hardener and hardening catalyst was observed. It was indicated that as the aging time of the curing system increased, the liner viscosity build-up was accelerated. The raw material having the biggest impact on the hardening reaction of the curing system’s liner was triphenylbismuth (TPB). Stirring isophorone diisocyanate and TPB forms activated complex, and the activated complex facilitates urethane reaction. If TPB is ligand bound with isocyanate, it forms TPB-isocyanate complex. This is a type of TPB’s oxide, and the formation of activated complex through changes in its color. In addition, lining hardening time can be adjusted by the aging period of the curing system through this study, and adhesive strength with the liner and propellant can be improved.

scholarly journals Investigation of the Impact of Aging Upon the Mechanical Properties of Cocoa Pod Husk

2021 ◽  
Vol 37 (2) ◽  
pp. 146-165
Author(s):  
Renique Murray ◽  
Sanjay Bachu ◽  
Cilla Pemberton ◽  
Robert Birch
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cutting Force ◽  
Aging Time ◽  
Correlation Coefficients ◽  
Raw Material ◽  
Aging Period ◽  
Cocoa Pod Husk ◽  
New Research ◽  
The Impact

The husk of fresh cocoa pods has traditionally been considered a waste by-product in the production of chocolate and other related confectionaries. However, in recent times new research has shed light on an  increasing number of uses for this material. Of particular interest are applications that utilize the cocoa pod husk (CPH) for its mechanical properties. In most instances, the CPH raw material is allowed to age for several days before pre-processing or utilization in the intended application. Despite this, the impact of aging on its mechanical properties is an area that has not been well investigated. Consequently, this work seeksto determine the impact of aging upon the mechanical properties of CPH. To investigate this, several CPH properties were identified and selected for evaluation. These included CPH tensile strength, CPH compressive strength, cocoa pod transverse compressive strength, cocoa pod longitudinal compressive strength, CPH cutting force, cocoa pod cutting force, CPH hardness, and CPH colour. These properties were subsequently assessed over an aging period of seven days. The results obtained indicated that most CPH mechanical properties vary significantly with aging time. Moreover, CPH colour was found to bestrongly related to the mechanical properties of pod longitudinal compressive strength and CPH hardness, with correlation coefficients of -0.71 and 0.86 respectively. Further, these relationships were found to be strongly linear in nature and regression analyses indicated that up to 83% of the variation in longitudinal compressive  strength can be accounted for by changes in colour, hardness and aging time. These results provide the basis for the potential development of image analysis and computer vision approaches to CPH sorting and grading.

Fe3O4 Magnetic Preparation by Bauxite Ore Washing Fine Mud

2014 ◽  
Vol 1010-1012 ◽  
pp. 961-965
Author(s):  
Jian Qiang Xiao ◽  
Guo Wei He ◽  
Yan Jin Hu
Keyword(s):  
Particle Size ◽  
Aging Time ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Test Methods ◽  
Raw Material ◽  
Molar Ratio ◽  
Average Particle ◽  
Experimental Conditions ◽  
Particle Size Analyzer

Bauxite waste sludge as a raw material, the use of reverse chemical coprecipitation synthesize Fe3O4. Researching temperature, precipitation concentration, aging time and Fe2+/Fe3+ molar ratio effect on the particle size, morphology. Optimal experimental conditions: temperature 70 °C, the precipitant NaOH mass ratio of 10%, aging time 3h, Fe2+/Fe3+ molar ratio of 2:3. Test methods using a laser particle size analyzer, XRD analysis of the products were characterized, the product is Fe3O4, the average particle size of 0.11mm.

scholarly journals The application of a phosphorus nitrogen flame retardant curing agent in epoxy resin

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 545-554 ◽  
Author(s):  
Anxin Li ◽  
Pingli Mao ◽  
Bing Liang
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Adhesive Strength ◽  
Chemical Structure ◽  
Phosphorus Content ◽  
Raw Material ◽  
Curing Agent ◽  
Thermal Degradation Behavior ◽  
Overall Performance ◽  
The Impact

AbstractIn order to improve the compatibility of flame retardant and epoxy resin, a phosphorus nitrogen flame retardant curing agent poly(p-xylylenediamine spirocyclic pentaerythritol bisphosphonate) (PPXSPB) was synthesized. FTIR, 1HNMR, and mass spectroscopy were used to identify the chemical structure of PPXSPB. Epoxy resin (E-44) and PPXSPB as the raw material, a series of thermosetting systems were prepared. The effects of PPXSPB on flame retardancy, water resistance, thermal degradation behavior, mechanical properties and the adhesive strength of EP/PPXSPB thermosets were investigated. The results show that with the increase of phosphorus content, the oxygen index and carbon residue of the system both increased significantly, and the heat release rate gradually decreased, which is of great significance in delaying the occurrence of fire. When the phosphorus content is 3.24% in EP/PPXSPB thermosets, EP-2 can successfully pass the UL94 V-0 flammability rating, the LOI value of EP-2 can reach 31.4%, the impact strength and tensile strength was 6.58 kJ/m2 and 47.10 MPa respectively, and the adhesive strength was 13.79 MPa, the system presents a good overall performance.

Experimental Study on Using Fuxin Natural Zeolite to Prepare Molecular Sieves

2012 ◽  
Vol 454 ◽  
pp. 30-34
Author(s):  
Zhi Jun Ma ◽  
Kuan Zhang ◽  
Yi Min Zhu ◽  
Yue Xin Han
Keyword(s):  
Aging Time ◽  
Crystallization Temperature ◽  
Molecular Sieves ◽  
Natural Zeolite ◽  
Average Pore Size ◽  
Nitrogen Adsorption ◽  
Raw Material ◽  
Crystallization Time ◽  
Average Pore ◽  
Relative Crystallinity

In this paper, the natural zeolite as raw material, zeolites was prepared by organic amines hydrothermal synthesis. The results are characterized by SEM and nitrogen adsorption / de-commanded test,and study the influence of the aging time, crystallization temperature and crystallization time on zeolite crystallization. The results showed that using natural zeolite as raw material and butylamine as templating agent, average pore size of 0.77nm, the relative crystallinity of 96.34% of the zeolite was prepared in the hydrothermal system. Optimal aging time is 12h, crystallization time is 48h, crystallization temperature is 170 °C.

Adhesion Study of Kaolin and White Clay as Source Materials on Non-Metallic Substrate in Geopolymer Coating

2016 ◽  
Vol 841 ◽  
pp. 55-58
Author(s):  
Noor Fifinatasha Shahedan ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Che Mohd Ruzaidi Ghazali ◽  
Mohammed Binhussain ◽  
Kamarudin Hussin ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Glass Fiber ◽  
Adhesive Strength ◽  
Metallic Substrate ◽  
Raw Material ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced ◽  
Source Materials ◽  
White Clay

Properties of geopolymer coating on nonmetallic substrates, especially glass fiber-reinforced epoxy (GRE) have been considered based on the effect of Si/Al ratio and surface treatment at a determined proportion of solid to liquid (S/L) and curing temperature.Kaolin and white clay have been used as geopolymer raw material in study of adhesive strength in geopolymer coating. Effect Si/Al ratio and surface treatment on adhesive strength has been tested from 0.40-0.60using Elcometer 106 Pull Off. The answer shows that Si/Al ratio and surface treatment were effecting the adhesive strength of geopolymer coating. The highest adhesive strength 6.0 MPa was found ina Si / Al ratio of 3.5 with surface treatment.

The Impact of Material Aging on Stereolithography Reliability: An Experimental Study

2020 ◽  
Author(s):  
Jing Zhao ◽  
Yiran Yang ◽  
Lin Li
Keyword(s):  
Additive Manufacturing ◽  
Aging Time ◽  
Manufacturing Systems ◽  
Raw Materials ◽  
Geometric Dimension ◽  
Raw Material ◽  
Failure Rates ◽  
Manufactured Products ◽  
Traditional Manufacturing ◽  
The Impact

Abstract Additive manufacturing as an emerging technique, however, delivers relatively low reliability compared to traditional manufacturing. Unlike in traditional manufacturing systems that manufacturers mainly focus on the machine reliability by adopting failure rates of equipment, in additive manufacturing systems the performance of reliability is often evaluated by the consistency of measurement results. In addition, the reliability of additive manufacturing systems is not only affected by the failure rates of machine elements, the condition of the photo-sensitive raw material could also lead to variations on the overall performance of the additive-manufactured products and thus affect the reliability. In this work, the impact of raw material condition with respect to the material aging time on the reliability of the stereolithography manufactured products is evaluated experimentally. More specifically, the liquid resin is sampled and stored in a laboratory environment for 2, 6, 8, and 12 days of aging, respectively. A series of specimens are printed with the aged raw materials as well as the fresh raw material. By computing the standard deviation and correlation of the measurements among specimens, the results indicate that material aging time has a negligible impact on the geometric dimension of the specimens while it does significantly affect the hardness. In other words, the results of the work imply that the reliability of stereolithography is significantly affected by raw material aging time.

Effect of Ageing Period on Properties of Mechanically Activated Portland Cement

2018 ◽  
Vol 760 ◽  
pp. 37-42
Author(s):  
Karel Dvořák ◽  
Matěj Švéda
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Mechanical Activation ◽  
Aging Time ◽  
Ball Mill ◽  
High Speed ◽  
Aging Period ◽  
High Speed Grinding ◽  
Ageing Period ◽  
The Moment

This experiment describes the effects of the aging time since the moment of milling to Portland cements physico-mechanical properties. Possible mechanical activation effects to Portland cement particles has been found. For this experiment two kind of milling technology were used, the conventional milling in a ball mill and high-speed grinding technology in high speed disintegrator and influence of these technologies was also described. The aging period of the cement influences in particular physico-mechanical properties in the early stages of hydration but the final properties after 28 days were not influenced.

scholarly journals Effect of Aging Time on the Characteristics and Photocatalysis of Zn2+-Doped CTAB@BiOCl

NANO ◽  
2017 ◽  
Vol 12 (09) ◽  
pp. 1750106 ◽  
Author(s):  
Yichang Yu ◽  
Zhangjun Hu ◽  
Chengjun Li ◽  
Shoushuang Huang ◽  
Zhiwen Chen ◽  
...  
Keyword(s):  
Surface Area ◽  
Aging Time ◽  
Uv Light ◽  
Great Influence ◽  
Precipitation Method ◽  
Aging Period ◽  
Structure Morphology ◽  
Organic Composites ◽  
One Step ◽  
Co Precipitation

Zn[Formula: see text]-doped CTAB@BiOCl inorganic–organic composites were prepared by a co-precipitation method with different aging periods. The results show that the aging period has great influence on the structure, morphology and surface area of Zn[Formula: see text]-doped CTAB@BiOCl. The as-synthesized samples tend to form lamellar stacking structure with the increase of the aging time. In addition, the surface area and pore size distribution of samples decrease with the aging period from 0[Formula: see text]h to 48[Formula: see text]h and then increase from 48[Formula: see text]h to 96[Formula: see text]h. Besides, the content of CTAB in these composites increases along with the aging period from 0[Formula: see text]h to 3[Formula: see text]h and then decreases from 3[Formula: see text]h to 96[Formula: see text]h. Their photocatalytic performances were evaluated by the degradation of Reactive Red 3 (X3B) under UV light irradiation. It is found that the photocatalytic performance of composites increases with the prolonging of the aging time, and 100[Formula: see text]mg/L of X3B solution can be almost completely degraded within 16[Formula: see text]min by S[Formula: see text]. Moreover, the possible formation mechanism has been proposed and discussed in detail. The work can provide a new sight for broadening the application of co-precipitation in the preparation of nanomaterials and for in-situ one-step synthesis of inorganic–organic composites.

Optimization of the Process Parameters for the Synthesis Process of Battery-Grade Ferrous Oxalate by Response Surface Method

NANO ◽  
2016 ◽  
Vol 11 (11) ◽  
pp. 1650123 ◽  
Author(s):  
Keyu Zhang ◽  
Xiaoyan Yang ◽  
Jian Wu ◽  
Xiaopeng Huang ◽  
Yaochun Yao
Keyword(s):  
Particle Size ◽  
Aging Time ◽  
Reaction Temperature ◽  
Ferrous Sulfate ◽  
Raw Material ◽  
Precipitation Method ◽  
Synthesis Process ◽  
Preparation Conditions ◽  
Ferrous Oxalate ◽  
Crystallographic Planes

This study investigates the optimal conditions for the synthesis of battery-grade ferrous oxalate as a raw material for preparing cathode material. Ferrous oxalate was prepared by liquid-phase precipitation method using ferrous sulfate and oxalic acid. Central composite design (CCD) was used to determine the effects of three preparation variables on purity and particle size: reaction temperature, aging time and concentration of ferrous sulfate. Based on CCD, the significant factors on each experimental design response identified the analysis of variance (ANOVA). The optimum ferrous oxalate preparation conditions were obtained reaction temperature of 31.32[Formula: see text]C, aging time of 56.52[Formula: see text]min, and ferrous sulfate concentration of 5%. Under these optimum conditions, ferrous oxalate with purity of 99.69% and particle size of 4.92[Formula: see text][Formula: see text]m was obtained as best product which met and exceed the requirements of battery-grade ferrous oxalate. In addition, the special morphologies of ferrous oxalate prepared under different dispersant proportion was characterized by scanning electron microscope (SEM) to analyze the mechanism of synthesis. Morphology control study revealed that the dispersant could effectively change the surface energy between crystallographic planes, then result in anisotropic growth of the crystal structure and change the morphology of synthetic products.

scholarly journals The effect of breed, sex and aging time on tenderness of beef meat

2011 ◽  
Vol 80 (2) ◽  
pp. 191-196 ◽  
Author(s):  
Šárka Hanzelková ◽  
Jana Simeonovová ◽  
David Hampel ◽  
Aleš Dufek ◽  
Jan Šubrt
Keyword(s):  
Aging Time ◽  
Compression Test ◽  
Shear Force ◽  
Textural Properties ◽  
Cooking Loss ◽  
Significance Level ◽  
Meat Juice ◽  
Aging Period ◽  
Production Factors ◽  
Instrumental Measurement

Our study was conducted to determine the effect of production factors (breed, sex) and aging time on the textural properties of beef using instrumental measurement of tenderness. Meat was obtained from Galloway, Simmental, Charolais, Czech Fleckvieh breeds and their crossbreeds. Meat was either unaged or aged for 14, 28 or 42 days. The tenderness was characterized by Warner-Bratzler test and compression test using Tira-test device. The cooking loss of meat juice was also evaluated. Analysis of variance at 5% significance level showed that tenderness was influenced by all tested factors (breed, sex, aging time). The shear force decreased with aging of meat. The correlation between shear force and compression test was 0.257 (p ≤ 0.001). The differences in tenderness were found among breeds. The highest initial shear force was measured in Simmental (151.98 N). Compression test showed better tenderness in Czech Fleckvieh and Galloway than in Simmental, Charolais and crossbreeds. Meat from bulls was significantly (p ≤ 0.001) less tender than from heifers. There was a significant (p ≤ 0.001) increase of cooking loss of meat juice during aging from 25.3% after slaughter to 34.0% after aging period. The research results could be useful for determination whether specific cattle breeds can produce tender meat with good aging patterns. According to findings of the current study it is especially necessary to emphasize that factor of aging time exceeded the influence of breed and sex on tenderness. The study also suggests extending of aging period to 6 week to assure tenderness of beef.

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