scholarly journals Particle Characterization of Washing Process Effluents by Laser Diffraction Technique

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7781
Author(s):  
Mirjana Čurlin ◽  
Tanja Pušić ◽  
Branka Vojnović ◽  
Nino Dimitrov

The dominant type of polymer particles in water, sediment, and various organisms partly derives from natural and synthetic fibres released in the washing process. Pollution of aquatic recipients with these particles poses an interdisciplinary problem throughout the world. Wastewater from washing represents a dispersion system with different particle sizes that is also loaded with the source of the particles. Due to this complex system, the qualification and quantification of this type of pollution is difficult. In this paper, the laser diffraction technique was applied to characterize particles in effluents from washing and rinsing materials made of a mixture of cotton and polyester. The results obtained through the analysis prove that the laser diffraction technique is acceptable for the characterization of a composite effluent sample. The advanced statistical technique of multivariate analysis confirmed the interrelationship of the parameters of this complex dispersion system.

Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).


Author(s):  
Marylyn Bennett-Lilley ◽  
Thomas T.H. Fu ◽  
David D. Yin ◽  
R. Allen Bowling

Chemical Vapor Deposition (CVD) tungsten metallization is used to increase VLSI device performance due to its low resistivity, and improved reliability over other metallization schemes. Because of its conformal nature as a blanket film, CVD-W has been adapted to multiple levels of metal which increases circuit density. It has been used to fabricate 16 MBIT DRAM technology in a manufacturing environment, and is the metallization for 64 MBIT DRAM technology currently under development. In this work, we investigate some sources of contamination. One possible source of contamination is impurities in the feed tungsten hexafluoride (WF6) gas. Another is particle generation from the various reactor components. Another generation source is homogeneous particle generation of particles from the WF6 gas itself. The purpose of this work is to investigate and analyze CVD-W process-generated particles, and establish a particle characterization methodology.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nathalie Raharimalala ◽  
Stephane Rombauts ◽  
Andrew McCarthy ◽  
Andréa Garavito ◽  
Simon Orozco-Arias ◽  
...  

AbstractCaffeine is the most consumed alkaloid stimulant in the world. It is synthesized through the activity of three known N-methyltransferase proteins. Here we are reporting on the 422-Mb chromosome-level assembly of the Coffea humblotiana genome, a wild and endangered, naturally caffeine-free, species from the Comoro archipelago. We predicted 32,874 genes and anchored 88.7% of the sequence onto the 11 chromosomes. Comparative analyses with the African Robusta coffee genome (C. canephora) revealed an extensive genome conservation, despite an estimated 11 million years of divergence and a broad diversity of genome sizes within the Coffea genus. In this genome, the absence of caffeine is likely due to the absence of the caffeine synthase gene which converts theobromine into caffeine through an illegitimate recombination mechanism. These findings pave the way for further characterization of caffeine-free species in the Coffea genus and will guide research towards naturally-decaffeinated coffee drinks for consumers.


2021 ◽  
Vol 22 (11) ◽  
pp. 5781
Author(s):  
Janarthanan Supramaniam ◽  
Darren Yi Sern Low ◽  
See Kiat Wong ◽  
Loh Teng Hern Tan ◽  
Bey Fen Leo ◽  
...  

Cellulose nanofibers (CNF) isolated from plant biomass have attracted considerable interests in polymer engineering. The limitations associated with CNF-based nanocomposites are often linked to the time-consuming preparation methods and lack of desired surface functionalities. Herein, we demonstrate the feasibility of preparing a multifunctional CNF-zinc oxide (CNF-ZnO) nanocomposite with dual antibacterial and reinforcing properties via a facile and efficient ultrasound route. We characterized and examined the antibacterial and mechanical reinforcement performances of our ultrasonically induced nanocomposite. Based on our electron microscopy analyses, the ZnO deposited onto the nanofibrous network had a flake-like morphology with particle sizes ranging between 21 to 34 nm. pH levels between 8–10 led to the formation of ultrafine ZnO particles with a uniform size distribution. The resultant CNF-ZnO composite showed improved thermal stability compared to pure CNF. The composite showed potent inhibitory activities against Gram-positive (methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative Salmonella typhi (S. typhi) bacteria. A CNF-ZnO-reinforced natural rubber (NR/CNF-ZnO) composite film, which was produced via latex mixing and casting methods, exhibited up to 42% improvement in tensile strength compared with the neat NR. The findings of this study suggest that ultrasonically-synthesized palm CNF-ZnO nanocomposites could find potential applications in the biomedical field and in the development of high strength rubber composites.


Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 459
Author(s):  
Ignacio Cazcarro ◽  
Albert E. Steenge

This article originates from the theoretical and empirical characterization of factors in the World Trade Model (WTM). It first illustrates the usefulness of this type of model for water research to address policy questions related to virtual water trade, water constraints and water scarcity. It also illustrates the importance of certain key decisions regarding the heterogeneity of water and its relation to the technologies being employed and the prices obtained. With regard to WTM, the global economic input–output model in which multiple technologies can produce a “homogeneous output”, it was recently shown that two different mechanisms should be distinguished by which multiple technologies can arise, i.e., from “technology-specific” or from “shared” factors, which implies a mechanism-specific set of prices, quantities and rents. We discuss and extend these characterizations, notably in relation to the real-world characterization of water as a factor (for which we use the terms technology specific, fully shared and “mixed”). We propose that the presence of these separate mechanisms results in the models being sensitive to relatively small variations in specific numerical values. To address this sensitivity, we suggest a specific role for specific (sub)models or key choices to counter unrealistic model outcomes. To support our proposal we present a selection of simulations for aggregated world regions, and show how key results concerning quantities, prices and rents can be subject to considerable change depending on the precise definitions of resource endowments and the technology-specificity of the factors. For instance, depending on the adopted water heterogeneity level, outcomes can vary from relatively low-cost solutions to higher cost ones and can even reach infeasibility. In the main model discussed here (WTM) factor prices are exogenous, which also contributes to the overall numerical sensitivity of the model. All this affects to a large extent our interpretation of the water challenges, which preferably need to be assessed in integrated frameworks, to account for the main socioeconomic variables, technologies and resources.


2005 ◽  
Vol 39 (6) ◽  
pp. 1409-1419 ◽  
Author(s):  
Chul-Un Ro ◽  
HeeJin Hwang ◽  
HyeKyeong Kim ◽  
Youngsin Chun ◽  
René Van Grieken

1997 ◽  
Vol 1 (1) ◽  
pp. 52-65
Author(s):  
Hye-Joon Yoon

Area studies, as a newly fashionable field of academic research, needs to recognize its less likely precedents if it is going to secure for itself a fresh start. The question of “desire” is relevant here because it indicates the less value-free aspects in its genealogy. As shown in Emma Bovary's embellished representation of Paris at her provincial home, an understanding of an area often reflects the particular needs and desires of the one who understands that area. Such restricted and restricting views of an area repeats itself outside the world of literary fictions, as is shown by the example of Guizot's picture of Europe in which his own country is given a privileged place as the very center of Western civilization itself. An instructive case showing the thin line between the projected desire of one who strives to know a geographical area and the scientific purity of the labor itself is further offered by Napoleon Bonaparte's heavy reliance on Orientalist scholarship in his invasion of Egypt. Moving further east from Egypt to China, we witness the denigrating remarks on China made by the great German thinkers of the past century, Hegel and Weber. Although their characterization of Chinese culture could find echoes in unbiased empirical research, they reveal all the same the trace of Europeans' desire to affirm their superiority over the supposedly inferior and false civilization of the East. Similarly, the Americans who divided the Korean peninsular at the 38th Parallel, with unquestioning confidence in their knowledge of the area and in the justice of their action, rightfully deserve their place in the tradition of Western area studies of serving the needs to dominate, control and exploit an objectified overseas territory. He assumed that words had kept their meaning, that desires still pointed in a single direction, and that ideas retained their logic; and he ignored the fact that the world of speech and desires has known invasions, struggles, plundering, disguises, ploys. From these elements, however, genealogy retrieves an indispensable restraint: it must record the singularity of events outside of any monotonous finality; it must seek them in the most unpromising places, in what we tend to feel is without history—in sentiments, love, conscience, instincts; it must be sensitive to their recurrence, not in order to trace the gradual curve of their evolution, but to isolate the different scenes where they engaged in different roles. — Michel Foucault, “Nietzsche, Genealogy, History” (Foucault 139–40).


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