Investigations of Dispersing Agents and Stabilizing Agents for Latex Mixtures, and the Behavior of Latex Mixtures When Stored

1936 ◽  
Vol 9 (2) ◽  
pp. 252-263
Author(s):  
Otto Bächle
Keyword(s):  
Chemical Industry ◽  
Ball Mill ◽  
High Efficiency ◽  
Great Sensitivity ◽  
Stabilizing Agents ◽  
Mechanical Dispersion ◽  
Dispersing Agent ◽  
Long Time ◽  
Good Medium ◽  
Dispersing Agents

Abstract The great sensitivity to mechanical as well as to chemical influences which is possessed by latex, in common with all hydrophobic colloids, leads to immediate difficulties in the preparation of its mixtures. The ingredients, which in most cases are insoluble in water, must first be finely ground and then dispersed in water before being added to the latex mixture. Good dispersion is effected only by the use of high efficiency mechanical dispersion apparatus (ball mill, pigment grinding mill, etc.) and at the same time by the use of a suitable dispersing agent. Moreover, since latex mixtures may have to be stored for a long time, and since premature coagulation may take place during the preparation of such mixtures by the ingredients added or by mechanical influences, and later by incipient vulcanization, it is necessary to stabilize these latex mixtures in practice so that they can be handled safely. Much work has already been done on the stabilization of latex and latex mixtures, as a result of which a great number of products are recommended and used today. A certain stabilizing action is obtained by the addition of water, a greater stabilizing action by aqueous solutions of alkalies. Furthermore, soaps and soap-like compounds are used, e. g., casein is in general a good medium. A few special products are offered today by the chemical industry.

scholarly journals Novel semi-analytical optoelectronic modeling based on homogenization theory for realistic plasmonic polymer solar cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zahra Arefinia ◽  
Dip Prakash Samajdar
Keyword(s):  
Solar Cells ◽  
Active Layer ◽  
Analytical Modeling ◽  
High Efficiency ◽  
Polymer Solar Cells ◽  
Scattered Light ◽  
Homogenization Theory ◽  
Computational Time ◽  
Coupled Equations ◽  
Long Time

AbstractNumerical-based simulations of plasmonic polymer solar cells (PSCs) incorporating a disordered array of non-uniform sized plasmonic nanoparticles (NPs) impose a prohibitively long-time and complex computational demand. To surmount this limitation, we present a novel semi-analytical modeling, which dramatically reduces computational time and resource consumption and yet is acceptably accurate. For this purpose, the optical modeling of active layer-incorporated plasmonic metal NPs, which is described by a homogenization theory based on a modified Maxwell–Garnett-Mie theory, is inputted in the electrical modeling based on the coupled equations of Poisson, continuity, and drift–diffusion. Besides, our modeling considers the effects of absorption in the non-active layers, interference induced by electrodes, and scattered light escaping from the PSC. The modeling results satisfactorily reproduce a series of experimental data for photovoltaic parameters of plasmonic PSCs, demonstrating the validity of our modeling approach. According to this, we implement the semi-analytical modeling to propose a new high-efficiency plasmonic PSC based on the PM6:Y6 PSC, having the highest reported power conversion efficiency (PCE) to date. The results show that the incorporation of plasmonic NPs into PM6:Y6 active layer leads to the PCE over 18%.

scholarly journals On Performance of Sparse Fast Fourier Transform Algorithms Using the Aliasing Filter

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1117
Author(s):  
Bin Li ◽  
Zhikang Jiang ◽  
Jie Chen
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
High Efficiency ◽  
Theory And Practice ◽  
Long Time ◽  
And Performance ◽  
Binary Tree Search ◽  
The One ◽  
Sparse Fast Fourier Transform ◽  
L1 And L2

Computing the sparse fast Fourier transform (sFFT) has emerged as a critical topic for a long time because of its high efficiency and wide practicability. More than twenty different sFFT algorithms compute discrete Fourier transform (DFT) by their unique methods so far. In order to use them properly, the urgent topic of great concern is how to analyze and evaluate the performance of these algorithms in theory and practice. This paper mainly discusses the technology and performance of sFFT algorithms using the aliasing filter. In the first part, the paper introduces the three frameworks: the one-shot framework based on the compressed sensing (CS) solver, the peeling framework based on the bipartite graph and the iterative framework based on the binary tree search. Then, we obtain the conclusion of the performance of six corresponding algorithms: the sFFT-DT1.0, sFFT-DT2.0, sFFT-DT3.0, FFAST, R-FFAST, and DSFFT algorithms in theory. In the second part, we make two categories of experiments for computing the signals of different SNRs, different lengths, and different sparsities by a standard testing platform and record the run time, the percentage of the signal sampled, and the L0, L1, and L2 errors both in the exactly sparse case and the general sparse case. The results of these performance analyses are our guide to optimize these algorithms and use them selectively.

A New Prediction Model on the Luminance of OLEDs Subjected to Different Reverse Biases for Alleviating Degradation in AMOLED Displays

2014 ◽  
Author(s):  
Paul C.-P. Chao ◽  
Yen-Ping Hsu ◽  
Yung-Hua Kao ◽  
Kuei-Yu Lee
Keyword(s):  
Reverse Bias ◽  
High Efficiency ◽  
Life Time ◽  
Density Currents ◽  
High Brightness ◽  
Light Emitting ◽  
Wide Viewing Angle ◽  
Time Operation ◽  
Long Time ◽  
History Of

Organic light-emitting diodes (OLEDs) have drawn much attention in areas of displays and varied illumination devices due to multiple advantages, such as high brightness, high efficiency, wide viewing angle, and simple structure. However, the long-time degradation of OLED emission is a serious drawback. This degradation was investigated by past works, which pointed out that the degradation was induced by high-density currents through OLED component under the long-time operation [1][2]. Proposed by a past work [3], different reverse biases was imposed on OLED components in display frames to alleviate the long-time degradation on OLEDs. Most recently, along with the reverse bias, new pixel circuits [4][5] for AMOLED displays are designed to alleviate OLED degradation, thus successfully extending OLED life time. However, since emission luminances in different frame times during AMOLED displaying differs significantly for displaying varied images, the OLED degradation evolves in a highly unpredictable fashion. In this study, based on valid theories, the voltage across the OLED is first used as indicator for OLED degradation. Then the relation between the level of OLED degradation, in terms of OLED’s cross voltage, and the history of imposing reverse biases are precisely modeled. With the model, the degradation of the OLED under reverse bias to extend lifetime can be successfully predicted. Based on this model, engineers can then optimize the applied reverse bias on OLEDs to maximize the OLED lifetime for varied display requirement.

scholarly journals Development of COVID-19 vaccines utilizing gene therapy technology

2021 ◽  
Author(s):  
Hironori Nakagami
Keyword(s):  
Viral Vectors ◽  
High Efficiency ◽  
Genetic Disorders ◽  
Rapid Development ◽  
Adenovirus Vector ◽  
Phase 3 ◽  
Double Blind ◽  
Time Period ◽  
Short Period ◽  
Long Time

Abstract There is currently an outbreak of respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Coronavirus disease 2019 (COVID-19) is caused by infection with SARS-CoV-2. Individuals with COVID-19 have symptoms that are usually asymptomatic or mild in most initial cases. However, in some cases, moderate and severe symptoms have been observed with pneumonia. Many companies are developing COVID-19 vaccine candidates using different technologies that are classified into four groups (intact target viruses, proteins, viral vectors and nucleic acids). For rapid development, RNA vaccines and adenovirus vector vaccines have been urgently approved, and their injection has already started across the world. These types of vaccine technologies have been developed over more than 20 years using translational research for use against cancer or diseases caused by genetic disorders but the COVID-19 vaccines are the first licensed drugs to prevent infectious diseases using RNA vaccine technology. Although these vaccines are highly effective in preventing COVID-19 for a short period, safety and efficiency evaluations should be continuously monitored over a long time period. As the time of writing, more than 10 projects are now in phase 3 to evaluate the prevention of infection in double-blind studies. Hopefully, several projects may be approved to ensure high-efficiency and safe vaccines.

Effect of the modified dispersing agent and milling time on the properties and particle size distribution of inkjet ink formulation for textile printing

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
H. Abd El-Wahab ◽  
A.M. Nasser ◽  
H.M. Abd ElBary ◽  
M. Abd Elrahman ◽  
M. Hassanein
Keyword(s):  
Surface Tension ◽  
Particle Size ◽  
Milling Time ◽  
Polyester Fabric ◽  
Light Fastness ◽  
Content Type ◽  
Textile Printing ◽  
Dispersing Agent ◽  
Dispersing Agents ◽  
Ink Formulation

Purpose This paper aims to study the effect of the new modified dispersing agent, milling time of the properties and particle size distribution (PSD) of inkjet ink formulation for polyester fabric printing. Design/methodology/approach The study’s methods include preparation of different formulations of textile inkjet inks based on different types of dispersing agents, then applying and evaluating the prepared formulations on the polyester fabric. The properties of the prepared ink formulations were analyzed by measuring viscosity, surface tension and particle size. The current work is including the study of the effect of using different doses of different dispersing agents and the milling time on their characteristics. Also, the study was extended to evaluate the printed polyester by using the prepared inks according to light fastness, washing fastness, alkali perspiration fastness and crock fastness. Findings The results showed that the used dispersing agents and the different milling time enhanced the viscosity and dynamic surface tension in the accepted range, but it was largely cleared in the PSD which tends to perform the inks on the printhead and prevent clogging of nozzles. Light fastness, washing fastness, alkali perspiration fastness and crock fastness gave good results in agreement with this type of inkjet inks for textile printing. Research limitations/implications In this work, good results were obtained with this type of dispersing agent for inkjet ink formulations, but for other dispersing agents, other tests could be performed. The inkjet ink could also be formulated with other additives to prevent clogging of nozzles on the printhead. Practical implications These ink formulations could be used for printing on polyester fabric by the inkjet printing. Originality/value Recently, there was a considerable interest in the study of the effect of PSD on the inkjet inks to prevent clogging of nozzles on the printhead and to improve the print quality on the textile fiber.

scholarly journals Electromechanical Modeling and Simulation of Piezoelectric Vibration based Energy Harvester Interfaced with MPPT based Electrical Circuit using Matlab Simulink

2019 ◽  
Vol 8 (2S11) ◽  
pp. 36-40
Keyword(s):  
Energy Harvester ◽  
High Efficiency ◽  
Electrical Circuit ◽  
Vibration Energy Harvester ◽  
Matlab Simulink ◽  
Electromechanical Model ◽  
Wind Vibration ◽  
Long Time ◽  
Piezoelectric Vibration ◽  
High Output

Wind vibration based energy harvester using piezoelectric material has been of great concern to researchers for a long time for low power generation and applications. In this paper, wind generated vibrations are used to develop electromechanical model of piezoelectric vibration energy harvester to generate electrical output using MATLAB simulink and comparision has been drawn between an electromechanical model of piezoelectric harvester interfaced with P&O MPPT based electrical model and without it. It has been found that overall model with MPPT provides high output with high efficiency

A Study on the Efficiency Improvement of Dye-Sensitized Solar Cell (DSSC) by Repeated Dye Coating

2015 ◽  
Vol 15 (10) ◽  
pp. 7706-7710
Author(s):  
Young Ho Seo ◽  
Eun Chang Choi ◽  
Byungyou Hong
Keyword(s):  
Solar Cell ◽  
High Efficiency ◽  
Dye Adsorption ◽  
Working Environment ◽  
Dye Sensitized Solar Cell ◽  
Coating Process ◽  
Cell Efficiency ◽  
Dye Sensitized ◽  
Long Time ◽  
Low Efficiency

Dye-sensitized solar cell (DSSC) is being extensively investigated as the next generation energy source. Despite of the attractive features like simple fabrication process and its economic efficiency, there are some problems such as low efficiency, long fabrication time and low long-term stability. Conventionally, the dye adsorption on TiO2 photo-electrode film needs long time in the solvent with low concentration of dye to get the high efficiency. In this work, the dye coating process was considerably shortened, albeit plenty of dye was used comparing with the conventional way. Our needs were met for the best result in our working environment and the relevant conditions to our work were obtained, which were the coating temperature of 70 °C, the dye concentration of 10 mM and the coating time of 3 min. And this coating process was successively repeated several times to maximize the dye adsorption and to improve the cell efficiency. Therefore, the efficiency increased by 13% in the proper condition.

Synthesis and Dispersion of Ni-Doped Cu2ZnSnS4

2020 ◽  
Vol 860 ◽  
pp. 42-50
Author(s):  
Camellia Panatarani ◽  
Hera Redianti ◽  
Ferry Faizal ◽  
Eka Cahya Prima ◽  
Brian Yuliarto ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Transformation ◽  
Zeta Potential ◽  
Elemental Analysis ◽  
High Energy ◽  
Future Application ◽  
Dispersing Agent ◽  
Higher Temperature ◽  
Average Size ◽  
Dispersing Agents

This paper reports the preliminary study on the synthesis of Ni doped CZTS (Cu2ZnSnS4:Ni) particle 5 at.% of Cu by solution method and dispersion of the obtained particles by beads mill method at various dispersing agents (SDS, CTAB, and Tween80). The phase transformation of the obtained particles was analyzed from the XRD spectra and XRF elemental analysis. The phase transformation and amount of Ni-doped to particles was predicted employing commercially available analytical software tool Match! Version 2.x. Moreover, the dispersion characteristics were investigated includes size, size distribution, and zeta potential of bare particles in comparison to various dispersing agents. This characteristic related to the future application of CZTS as an absorber in a thin-film based PV. The XRD analysis showed that the obtained particle contained crystal structure of copper sulfate pentahydrate (75.9 %), Ni(HN2S2)2 (12.5 %), and Cu2ZnSnS4 (11.6%). The XRF elemental analysis showed that amount of Ni-doped was 6.8 at.%; it was higher than the initial design amount of Ni doping. The dispersion of suspended particles was the majority (90%) with an average size of 3.06 µm and only 10 % with size 255 nm. Beads-milling of particles without dispersing agents did not disintegrate agglomerated particles. It is highlighted dispersion only using magnetic stirred with SDS dispersing agent provides the best suspension with a majority (60%) in 166 nm and only 30 % with average size 3.06 µm with relatively high zeta potential (-17 mV). It was concluded that the presence of a multi-phase crystal needs to be resolved either by proper calcination at a higher temperature than 400°C or further heating at a higher temperature during film preparation. High-energy centrifugation of zirconia beads mill caused desorption of adsorbed steric stabilization of dispersing agent under investigation. Further investigation on the coating process to facilitated laboratory fabrication of thin-film absorber with SDS as a dispersing agent is necessary to carry out concerning the properties of the thin-film.

scholarly journals Effect of Sodium Carbonate Concentration in Calgon on Hydrometer Analysis Results

2018 ◽  
Author(s):  
Arshdeep Kaur ◽  
George C. Fanourakis
Keyword(s):  
Sodium Carbonate ◽  
Clay Content ◽  
The Other ◽  
Sodium Hexametaphosphate ◽  
Carbonate Content ◽  
Fine Grained ◽  
Carbonate Concentration ◽  
Dispersing Agent ◽  
Effective Combination ◽  
Dispersing Agents

Calgon (a combination of sodium hexametaphosphate and sodium carbonate) has proved to be the most effective dispersing agent in determining the grain size distribution of fine-grained soils by means of the hydrometer analysis. Previous research on the effect of the sodium hexametaphosphate content of dispersing agents on the clay contents showed that the addition of sodium carbonate to sodium hexametaphosphate increases its dispersing effectiveness. Hence, Calgon 35:7 was used /recommended by many researchers/methods and proved to be the most effective dispersing agent. Although previous work focusing on the effect of varying the concentration of sodium hexametaphosphate in Calgon has been reported, the effect of the concentration of sodium carbonate in Calgon has not been assessed and reported. For this reason, in this investigation a series of hydrometer test analyses were conducted using the 152H and ASTM 152H: E100 hydrometers with Calgon in ratios of 35:0, 35:20 and 35:30.  It was observed that with any increase in sodium carbonate content beyond 7 grams, the percentage clay content actually decreased tremendously in the case of hydrometer 152H. However, for the other hydrometer, Calgon (35:0) proved to be most effective combination. Thus, the increase in the sodium carbonate content in Calgon, beyond 7 g/ litre, is not recommended.

Improved Reversibility of Liquid Lithium-Ammonia Solutions in Vacuum Tube

2014 ◽  
Vol 605 ◽  
pp. 306-309
Author(s):  
Miae Kim ◽  
Ji Beom Kim ◽  
Joon Hyeon Jeon
Keyword(s):  
Power Generation ◽  
Thermoelectric Power ◽  
Conversion Efficiency ◽  
High Efficiency ◽  
Liquid Lithium ◽  
Thermoelectric Power Generation ◽  
Thermoelectric Conversion ◽  
Pressure Equilibrium ◽  
Long Time ◽  
Solution Reaction

Lithium-ammonia (Li-NH3) solutions are possible to be successfully made under the vacuum condition but there still remains a problem of undergoing stable and reliable decomposition in vacuum for high-efficiency thermoelectric power generation. This paper describes a new method, which uses a tube giving pressure equilibrium between closed ends, for improving the thermoelectric conversion efficiency of Li-NH3solutions in vacuum. Thermoelectric experimental results show that solution reaction in the tube proceeds stably and efficiently, and this potentially leads to the improved reversibility of the reaction for deriving the long-time, high-efficiency thermoelectric power.

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