scholarly journals INFLUENCE OF THERMOPLASTIC PROCESSING PARAMETERS ON THEIR INTERNAL TEMPERATURE

2021 ◽  
Vol 20 (3) ◽  
pp. 03
Author(s):  
F. A. R. Campos ◽  
L. R. R. Da Silva
Keyword(s):  
Deposition Process ◽  
Processing Parameters ◽  
Polymer Processing ◽  
Internal Temperature ◽  
Small Temperature ◽  
Temperature Variations ◽  
Hot Air ◽  
Technological Advances ◽  
Low Efficiency ◽  
Polymer Type

With technological advances, polymers are increasingly used to manufacture various components that were previously exclusively manufactured with metals. One of the significant challenges in polymer processing is its relatively low thermal resistance, since relatively small temperature variations, especially when compared to metals and ceramics, lead to significant changes in material properties and in the final component geometry. This paper investigated how the internal temperature of polymers, subjected to an intermittent particulate jet deposition process in conjunction with a continuous flow of hot air, is affected by variation in surface roughness, polymer type, and air pressure. As the main result, low efficiency in heat transfer was caused by the combination of the convective nature of the heat exchange with the low thermal conductivity of the polymers. The variables with the most significant influence on the process were the intermittence and pressure of the particulate jet.

scholarly journals Development of an Additive Manufacturing System for the Deposition of Thermoplastics Impregnated with Carbon Fibers

2019 ◽  
Vol 3 (2) ◽  
pp. 35 ◽  
Author(s):  
Miguel Reis Silva ◽  
António M. Pereira ◽  
Nuno Alves ◽  
Gonçalo Mateus ◽  
Artur Mateus ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Additive Manufacturing ◽  
Carbon Fibers ◽  
Low Cost ◽  
Deposition Process ◽  
Processing Parameters ◽  
Yarn Diameter ◽  
Thermoplastic Matrix ◽  
Anisotropic Mechanical Properties ◽  
Long Carbon Fiber

This work presents an innovative system that allows the oriented deposition of continuous fibers or long fibers, pre-impregnated or not, in a thermoplastic matrix. This system is used in an integrated way with the filamentary fusion additive manufacturing technology and allows a localized and oriented reinforcement of polymer components for advanced engineering applications at a low cost. To demonstrate the capabilities of the developed system, composite components of thermoplastic matrix (polyamide) reinforced with pre-impregnated long carbon fiber (carbon + polyamide), 1 K and 3 K, were processed and their tensile and flexural strength evaluated. It was demonstrated that the tensile strength value depends on the density of carbon fibers present in the composite, and that with the passage of 2 to 4 layers of fibers, an increase in breaking strength was obtained of about 366% and 325% for the 3 K and 1 K yarns, respectively. The increase of the fiber yarn diameter leads to higher values of tensile strength of the composite. The obtained standard deviation reveals that the deposition process gives rise to components with anisotropic mechanical properties and the need to optimize the processing parameters, especially those that lead to an increase in adhesion between deposited layers.

scholarly journals Small temperature variations are a key regulator of reproductive growth and assimilate storage in oil palm (Elaeis guineensis)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Naoki Tani ◽  
Zubaidah Aimi Abdul Hamid ◽  
Natra Joseph ◽  
Othman Sulaiman ◽  
Rokiah Hashim ◽  
...  
Keyword(s):  
Oil Palm ◽  
Elaeis Guineensis ◽  
Reproductive Growth ◽  
Small Temperature ◽  
Temperature Variations

scholarly journals Effect of small temperature variations on the tensile behaviourof Ti-6Al-4V

2011 ◽  
Vol 10 ◽  
pp. 2330-2335 ◽  
Author(s):  
J. Galán López ◽  
J. Peirs ◽  
P. Verleysen ◽  
J. Degrieck
Keyword(s):  
Small Temperature ◽  
Temperature Variations

scholarly journals Thermoresponsive hydrogels for atmospheric water vapor harvesting

2021 ◽  
Author(s):  
Pavani Cherukupally ◽  
Boyuan Hao ◽  
Zhongshen Zhang ◽  
Daryl R Williams
Keyword(s):  
Water Vapor ◽  
Processing Parameters ◽  
Synthesis Temperature ◽  
Polymer Processing ◽  
Atmospheric Water Vapor ◽  
Atmospheric Water ◽  
Optimum Amount ◽  
Global Challenge ◽  
Adsorption Performance ◽  
The World

Currently, freshwater scarcity is a global challenge that is threatening four billion people across the world. To satisfy people’s increasing freshwater demand, harvesting atmospheric water from the air could be an alternative way. This work developed copolymer P(NIPAM-co-15%BzDMA) hydrogels to harvest atmospheric water vapor. Two methods were investigated to improve its adsorption performance: decreasing synthesis temperature below the LCST and copolymerizing with the optimum amount of quaternary ammonium salt (QAS). We found these two methods can effectively improve the water vapor uptake. After copolymerizing NIPAM with 15% QAS at 20°C, the water vapor uptake could be increased by almost 20% to 232 mg/g at 20°C and P/P0 of 0.75 compared with pure PNIPAM prepared at 60°C (194 mg/g). The significant increase can be attributed to the more uniform porous structure and the hygroscopicity of QAS. After coating PNIPAM onto the PESPU sponge skeleton, the PESPU-PNIPAM_60 could adsorb 180 mg/g gas water at 20°C and P/P0 of 0.75, and the modified sponges inherit the switchable wettability from PNIPAM. This research provides polymer processing parameters and their character for harvesting water vapor from the air with hydrogels.

scholarly journals Biodiesel deposit characterization on hot chamber test rig with biodiesel fuels (B20) and bioaditif essential oil (atsiri)

2018 ◽  
Vol 67 ◽  
pp. 02016 ◽  
Author(s):  
Muchammad Taufiq Suryantoro ◽  
Bambang Sugiarto ◽  
Hari Setiapraja ◽  
Siti Yubaidah ◽  
Ary Budi Mulyono ◽  
...  
Keyword(s):  
Essential Oil ◽  
Deposition Process ◽  
Biodiesel Fuel ◽  
Test Rig ◽  
Deposit Formation ◽  
Hot Plate ◽  
Release Process ◽  
Temperature Variations ◽  
Biodiesel Fuels ◽  
Enclosed Space

In this study, the deposit formation of B20-NA biodiesel with the addition of bioadditive Essential Oil with different variations, B20 + Essential Oil 1:2000, B20 + Essential Oil 1:3000, B20 + Essential Oil 1: 4000 and B20 + Essential Oil 1:5000 method of hot plate drops to know the characteristics and mechanisms of deposit formation on each variation of fuel. The research is carried out by the deposition process and evaporation of Diesel fuels carried out repeatedly on a hot plate. The plate is heated with temperature variations inside the enclosed space so that the conditions are close to the real conditions of the engine. This test uses a hot chamber test rig. The use of bioadditive essential oils (atsiri) which have turpentine contents bind water content and residues in biodiesel fuel is expected to accelerate the process of excessive deposit release in the combustion chamber. This study aims to find the optimum fuel and temperature variations so that the deposit release process can be accelerated.

Fiber Laser Deposition of Nickel-Based Superalloys Using Filler Wire Feed

2015 ◽  
Author(s):  
Y. N. Zhang ◽  
X. Cao ◽  
P. Wanjara
Keyword(s):  
Fiber Laser ◽  
Continuous Wave ◽  
Deposition Process ◽  
Processing Parameters ◽  
Laser Deposition ◽  
Filler Wire ◽  
Fiber Laser Welding ◽  
Heat Treated ◽  
Direct Laser ◽  
Wire Feed

In this work, a continuous wave fiber laser welding system was used to deposit nickel-based superalloys Inconel 718 (IN 718) and Waspaloy using filler wire feed sources. The multi-bead and multi-layer deposits that were manufactured were characterized in terms of the macro- and microstructures, defects, and hardness in both the as-deposited and fully heat treated conditions. The tensile properties of the deposits in the heat treated condition were also determined and compared to the existing aerospace materials specifications. Using optimized laser processing parameters, high strength deposits could be manufactured, though minor weld metal liquation cracking for IN718 and strain-age cracking for Waspaloy were present, which compromised slightly the ductility as compared to wrought aerospace specifications for the two alloys. The successful development of the direct laser deposition process using wire feeding indicates the potential of employing the fiber laser technology to manufacture nickel-based superalloy aerospace components.

Use of Constant Temperature and Sodium Borohydride in the Trihydroxyindole Method for Catecholamines

1966 ◽  
Vol 12 (10) ◽  
pp. 659-669 ◽  
Author(s):  
Elizabeth Carlsen Gerst ◽  
Odd S Steinsland ◽  
William W Walcott
Keyword(s):  
Ascorbic Acid ◽  
Constant Temperature ◽  
Sodium Borohydride ◽  
Small Temperature ◽  
Temperature Variations ◽  
Stabilizing Agent ◽  
Fluorescent Analysis

Abstract Small temperature variations during fluorescent analysis with the trihydroxyindole method can introduce significant errors in the measurement of 15µg./L. or less of epinephrine or norepinephrine. To minimize temperature differences, we have devised a simple, constant-temperature system for the Farrand fluorometer. Decomposition of ascorbic acid prior to and during analysis also must be prevented. Sodium borchydride was found to be an effective stabilizing agent that contributes negligible fluorescence.These modifications minimize or eliminate much of the difficulty previously encountered in the use of the trihydroxyindole method.

Physical Characteristics and Behaviour of Pink Salmon Fry at McClinton Creek, B.C.

1944 ◽  
Vol 6c (3) ◽  
pp. 217-227 ◽  
Author(s):  
A. L. Pritchard
Keyword(s):  
Pink Salmon ◽  
Qualitative Description ◽  
Oncorhynchus Gorbuscha ◽  
Small Temperature ◽  
Temperature Variations ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Fry ◽  
Significant Difference ◽  
The Hours ◽  
Effect Of Light

High temperatures appear to shorten and low temperatures lengthen the incubation period of pink salmon (Oncorhynchus gorbuscha) eggs. The fry migrate to sea during spring when the yolk sac is almost completely absorbed. There is no significant difference from year to year in qualitative description or in certain countable physical characters. Migration is usually swift and vigorous. The effect of light is demonstrated by the fact that movement is limited to the hours of darkness and slowed by direct moonlight. Rainfall does not initiate migration but causes fry already in motion to proceed more quickly. Small temperature variations have little effect. Oxygen content and pH of the water vary coincidentally with rainfall.

Sign in / Sign up

Export Citation Format

Share Document