scholarly journals Improved Laser Ablation Method for the Production of Luminescent Carbon Particles in Liquids

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2365
Author(s):  
Agata Kaczmarek ◽  
Piotr Denis ◽  
Marcin Krajewski ◽  
Tomasz Mościcki ◽  
Artur Małolepszy ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Carbon Nanoparticles ◽  
Pure Water ◽  
Luminescent Properties ◽  
Two Stage ◽  
Carbon Particles ◽  
Second Stage ◽  
Laser Ablation Method ◽  
Carbon Structures ◽  
Stage Process

An improved method for the production of luminescent carbon nanoparticles is proposed in this work. The new method overcomes the disadvantages of commonly used approaches. It involves two-stage laser ablation in water and in aqueous solutions, where the first stage is the laser ablation of a graphite target and the second is the shredding of particles produced in the first step. The two-stage method offers the optimization of the laser pulse fluence for the performance of each process. It was found that the two-stage process of laser ablation allows producing photoluminescent carbon structures in pure water. The additional reagent may be added either in the first or second stage. The first stage performed in pure water allows avoiding the contamination of the target. Moreover, it simplifies the identification of the origin of photoluminescence. Two synthesis routes for the preparation of carbon nanoparticles by the proposed method using pure water as well as urea aqueous solution are investigated. It was found that the use of urea as a reagent results in luminescence properties similar to those obtained with other more hazardous amine-based reagents. The influence of the synthesis approach and process parameters on the structural and luminescent properties of nanoparticles is also explored in this work.

scholarly journals A new methodology for polyvalent intravenous immunoglobulin solution production with a two-stage process of viral inactivation

2010 ◽  
Vol 46 (4) ◽  
pp. 777-783
Author(s):  
Antônio Edson de Souza Lucena ◽  
Divaldo de Almeida Sampaio ◽  
Ednaldo Rosas da Silva ◽  
Virgínia Florêncio de Paiva ◽  
Ana Cláudia Santiago ◽  
...  
Keyword(s):  
Intravenous Immunoglobulin ◽  
Immunoglobulin G ◽  
Cation Exchanger ◽  
Product Analysis ◽  
Viral Inactivation ◽  
Two Stage ◽  
Second Stage ◽  
Neutralizing Capacity ◽  
Stage Process ◽  
Sodium Caprylate

Highly purified intravenous immunoglobulin G concentrate (IV IgG) was produced with the use of polyethylene glycol associated to a single-stage precipitation by ethanol, instead of the classic Cohn-Oncley process, which employs cold alcohol as the precipitating agent, in a three-stage process. Precipitation of crude fraction containing more than 95% of immunoglobulin G was performed by liquid chromatography with a cation exchanger, CM-Sepharose, as a stationary phase. During the process, the product was subjected to two-stage viral inactivation. The first stage was performed by the action of sodium caprylate, 30 mM at pH 5.1+/- 0.1, and the second stage was performed by the action of a solvent-detergent mixture. The finished product was formulated at 5% with 10% sucralose as the stabilizing agent. The process yields 3.3g of IgG/liter of plasma. The finished product analysis showed an anti-complementary activity lower than 1CH50. Polymer and aggregate percent levels were lower than 3% in the five batches studied. The analysis of neutralizing capacity showed the presence of antibacterial and antiviral antibodies in at least three times higher concentrations than the levels found in source plasma. The finished product fulfilled all purity requirements stated in the 4th edition of the European pharmacopeia.

scholarly journals Two-Stage Discrete Mechanical Modelin Three-Dimensional Space for Garment Simulation

2019 ◽  
Vol 19 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Xuan Luo ◽  
Gaoming Jiang ◽  
Honglian Cong
Keyword(s):  
Mechanical Model ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Mathematical Expression ◽  
Two Stage ◽  
Second Stage ◽  
Simulation Speed ◽  
Optimal Value ◽  
Variable Distance ◽  
Stage Process

Abstract This paper focuses on the better performance between the garment simulation result and the simulation speed. For simplicity and clarity, a notation “PART” is defined to indicate the areas between the garment and the human body satisfying some constraints. The discrete mechanical model can be achieved by the two-stage process. In the first stage, the garment can be divided into several PARTs constrained by the distance. In the second stage, the mechanical model of each PART is formulated with a mathematical expression. Thus, the mechanical model of the garment can be obtained. Through changing the constrained distance, the simulation result and the simulation speed can be observed. From the variable distance, a desired value can be chosen for an optimal value. The results of simulations and experiments demonstrate that the better performance can be achieved at a higher speed by saving runtime with the acceptable simulation results and the efficiency of the proposed scheme can be verified as well.

Preparation and Applications of Hydrophilic Nano-Carbon Particles

2013 ◽  
Vol 832 ◽  
pp. 767-772 ◽  
Author(s):  
Shoichiro Ikeda ◽  
Shinji Kawasaki ◽  
Akinari Nobumoto ◽  
Hideo Ono ◽  
Shinji Ono ◽  
...  
Keyword(s):  
Carbon Nanoparticles ◽  
Room Temperature ◽  
Ph Value ◽  
Pure Water ◽  
Solid Lubricants ◽  
Cutting Fluids ◽  
Carbon Particles ◽  
Synthetic Graphite ◽  
Nano Carbon

We have produced nanocarbon suspension in pure water, which is named as Nanocaloid®, by a simple DC electrolysis from a synthetic graphite plates as anodes and SUS plates as cathodes in purified water at room temperature. The amount of carbon nanoparticles was monitored by the conductivity and pH value of the electrolyte solution, and also by a simple gravimetric way after drying the solution. If the current density increases, the diameter of the carbon particles becomes larger and the amount of precipitates becomes also large. It takes about six weeks to obtain about 0.4 wt% carbon suspension solution under the normal electrolysis conditions. Characterization of Nanocaloid®has been conducted to show unique properties and promising epoch-making applications such as solid lubricants for non-oily cutting fluids and conductive agents for reuse of deteriorated Pb-acid batteries. The performance of nanocarbon particles in oil lubricants in addition to the preparation will be reported.

scholarly journals Two-Stage Conversion of High Free Fatty AcidJatropha curcasOil to Biodiesel Using Brønsted Acidic Ionic Liquid and KOH as Catalysts

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Subrata Das ◽  
Ashim Jyoti Thakur ◽  
Dhanapati Deka
Keyword(s):  
Ionic Liquid ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Two Stage ◽  
Second Stage ◽  
Stage Conversion ◽  
Acidic Ionic Liquid ◽  
Brønsted Acidic Ionic Liquid ◽  
Optimum Reaction ◽  
Stage Process

Biodiesel was produced from high free fatty acid (FFA)Jatropha curcasoil (JCO) by two-stage process in which esterification was performed by Brønsted acidic ionic liquid 1-(1-butylsulfonic)-3-methylimidazolium chloride ([BSMIM]Cl) followed by KOH catalyzed transesterification. Maximum FFA conversion of 93.9% was achieved and it reduced from 8.15 wt% to 0.49 wt% under the optimum reaction conditions of methanol oil molar ratio 12 : 1 and 10 wt% of ionic liquid catalyst at 70°C in 6 h. The ionic liquid catalyst was reusable up to four times of consecutive runs under the optimum reaction conditions. At the second stage, the esterified JCO was transesterified by using 1.3 wt% KOH and methanol oil molar ratio of 6 : 1 in 20 min at 64°C. The yield of the final biodiesel was found to be 98.6% as analyzed by NMR spectroscopy. Chemical composition of the final biodiesel was also determined by GC-MS analysis.

Reduction of MoO2 to Metallic Molybdenum via Carburization and Thermal Process

2015 ◽  
Vol 1087 ◽  
pp. 64-67 ◽  
Author(s):  
Alinda Samsuri ◽  
Tengku Shafazila Tengku Saharuddin ◽  
Fairous Salleh ◽  
Mohamed Wahab Mohamed Hisham ◽  
Rizafizah Othaman ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Carbon Monoxide ◽  
Thermal Process ◽  
Two Stage ◽  
Second Stage ◽  
Stage Process ◽  
Xrd Techniques

A metallic molybdenum is formed by a two-stage process that was carburized MoO2 with carbon monoxide followed by heat treatment. XRD techniques were employed to identify the phase’s changes in the sample. It was found that by the present of carbon monoxide during carburization process until 900 °C, Mo2C is formed first, compared to metallic molybdenum, due to the high thermodynamic barrier for formation of metallic molybdenum. In the second stage, Mo2C further reacts with the remaining MoO2 at 900 °C to produce metallic molybdenum.

scholarly journals Two-Stage Origin of K-Enrichment in Ultrapotassic Magmatism Simulated by Melting of Experimentally Metasomatized Mantle

Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 41 ◽  
Author(s):  
Michael W. Förster ◽  
Stephan Buhre ◽  
Bo Xu ◽  
Dejan Prelević ◽  
Regina Mertz-Kraus ◽  
...  
Keyword(s):  
Trace Element ◽  
Sedimentary Rock ◽  
Experimental Approach ◽  
Sedimentary Rocks ◽  
Igneous Rocks ◽  
Two Stage ◽  
Second Stage ◽  
Stage Process ◽  
First Time ◽  
Metasomatized Mantle

The generation of strongly potassic melts in the mantle requires the presence of phlogopite in the melting assemblage, while isotopic and trace element analyses of ultrapotassic rocks frequently indicate the involvement of subducted crustal lithologies in the source. However, phlogopite-free experiments that focus on melting of sedimentary rocks and subsequent hybridization with mantle rocks at pressures of 1–3 GPa have not successfully produced melts with K2O >5 wt%–6 wt%, while ultrapotassic igneous rocks reach up to 12 wt% K2O. Accordingly, a two-stage process that enriches K2O and increases K/Na in intermediary assemblages in the source prior to ultrapotassic magmatism seems likely. Here, we simulate this two-stage formation of ultrapotassic magmas using an experimental approach that involves re-melting of parts of an experimental product in a second experiment. In the first stage, reaction experiments containing layered sediment and dunite produced a modally metasomatized reaction zone at the border of a depleted peridotite. For the second-stage experiment, the metasomatized dunite was separated from the residue of the sedimentary rock and transferred to a smaller capsule, and melts were produced with 8 wt%–8.5 wt% K2O and K/Na of 6–7. This is the first time that extremely K-enriched ultrapotassic melts have been generated experimentally from sediments at low pressure applicable to a post-collisional setting.

Evaluating the efficiency of a two-stage network structure with the use of fractional programming

2017 ◽  
Vol 09 (03) ◽  
pp. 1750034 ◽  
Author(s):  
Reza Ahmadzadeh ◽  
Sohrab Kordrostami ◽  
Alireza Amirteimoori
Keyword(s):  
Linear Model ◽  
Fractional Programming ◽  
Nonlinear Models ◽  
Heuristic Method ◽  
Data Envelopment ◽  
Network Structures ◽  
Two Stage ◽  
Second Stage ◽  
Internal Structures ◽  
Stage Process

Recently, network data envelopment analysis (NDEA) models have been developed to evaluate the efficiency of decision making units (DMUs) with internal structures. The network structures range from a simple two-stage process to a complex system. Looking through the literature on two-stage network structures, we see that Li et al. (2012) extended a model by assuming that the inputs to the second stage include both the outputs from the first stage and additional inputs to the second stage. In the current study, a model is proposed to evaluate the performance of these types of general two-stage network structures. To this end, we provide a linear model using fractional programming. In fact, previous models were often nonlinear models which were solved with heuristic methods. But, since the model presented in this paper is a linear model, then it can be solved easily as a linear programming problem. In order to clarify the newly proposed approach of this study, it has been applied to a case of regional Research and Development (R&D) system related to 30 provincial level regions in China and results have been compared with the heuristic method of Li et al. (2012).

scholarly journals Simultaneous isolation of cellulose and lignin from wheat straw and catalytic conversion to valuable chemical products

2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Bowei Yu ◽  
Guozhi Fan ◽  
Sijiu Zhao ◽  
Yuchan Lu ◽  
Qiao He ◽  
...  
Keyword(s):  
Wheat Straw ◽  
Acid Concentration ◽  
Recovery Rate ◽  
Total Yield ◽  
Two Stage ◽  
Second Stage ◽  
Stage Process ◽  
Higher Temperature ◽  
Chemical Products ◽  
Lower Temperature

AbstractConvertible cellulose and lignin were simultaneously isolated from wheat straw using a two-stage process via simply varying temperature and H2SO4 concentration. At the first-stage, cellulose was obtained by pretreating wheat straw at lower temperature and acid concentration using an organosolv process. The purity, yield and recovery rate of cellulose reached 86.8 wt%, 55.2 and 92.8% at 150 °C with 1 wt% H2SO4. At the second stage, the residual liquid was further treated at higher temperature and acid concentration, giving 17.4% lignin yield with 86.6% recovery rate and 93.2 wt% purity at 180 °C with 1.5 wt% H2SO4. The conversion of the as-isolated cellulose and lignin into chemicals was further investigated. The total yield of 5-hydroxymethylfurfural and glucose derived from wheat straw cellulose reached 82.5%, and 18.3% yield of monophenolic compounds from lignin were obtained, respectively. These results indicated that the two-stage process was effective for obtaining high-quality cellulose and lignin from wheat straw. Both of them displayed excellent convertible property.

scholarly journals How contractual terms determine fiduciary duties: a two-stage process

2019 ◽  
Vol 70 (2) ◽  
pp. 242-262
Author(s):  
David Gibbs-Kneller ◽  
Derek Whayman
Keyword(s):  
Fiduciary Duty ◽  
Single Factor ◽  
Two Stage ◽  
Fiduciary Duties ◽  
Second Stage ◽  
Stage Process ◽  
Duty Of Loyalty ◽  
Two Stages

The determination of the scope of the fiduciary duty of loyalty, when created by contract, is not a unitary process. It is raised following a multi-factorial enquiry, which considers the nature of the engagement, in a first stage. Here, no single factor is conclusive. It is then, in a separate, second stage, reduced by qualifying contractual terms, which are applied almost strictly logically. This second stage uses the contractual doctrines of interpretation and implication. However, since it is a form of the fiduciary doctrine of authorisation, those contractual doctrines are modified according to fiduciary principles. We argue this follows from the underlying nature of the fiduciary obligation as a way of resolving its internal tensions. While this division has not yet been fully recognised in the cases, the courts have been inching towards it. However, not fully recognising this inevitable division and eliding the two stages has led to defective reasoning and outcomes.

The Poliheuristic Theory of Crisis Decision Making and Applied Decision Analysis

2021 ◽  
Author(s):  
Inbal Hakman ◽  
Alex Mintz ◽  
Steven B. Redd
Keyword(s):  
Decision Making ◽  
Decision Analysis ◽  
High Stress ◽  
Decision Makers ◽  
Decision Task ◽  
Two Stage ◽  
Second Stage ◽  
Choice Sets ◽  
Stage Process ◽  
Choice Set

Poliheuristic theory addresses the “why” and “how” of decision making. It focuses on how decision makers use heuristics en route to choice by addressing both the process and the choice related to the decision task. More specifically, decision makers use a two-stage process wherein a more complicated choice set is reduced to one that is more manageable through the use of these heuristics, or cognitive shortcuts. In the second stage, decision makers are more likely to employ maximizing and analytical strategies in making a choice. Poliheuristic theory also focuses on the political consequences of decision making, arguing that decision makers will refrain from making politically costly decisions. While poliheuristic theory helps us better understand how decision makers process information and make choices, it does not specifically address how choice sets and decision matrices were created in the first place. Applied decision analysis (ADA) rectifies this shortcoming by focusing on how leaders create particular choice sets and matrices and then how they arrive at a choice. It does so by first identifying the decision maker’s choice set or decision matrix; that is, the alternatives or options available to choose from as well as the criteria or dimensions upon which the options will be evaluated. ADA then focuses on uncovering the decision maker’s decision code through the use of multiple decision models. Combining poliheuristic theory with ADA allows researchers to more fully explain decision making in general and crisis decision making in particular. An application of poliheuristic theory and ADA to decision making pertaining to the Fukushima nuclear disaster reveals that even in this high-stress crisis environment decision makers followed the two-stage process as predicted by poliheuristic theory. More specifically, in the first stage, decision makers simplified the decision task by resorting to cognitive heuristics (i.e., decision making shortcuts) to eliminate politically damaging alternatives such as voluntary evacuation. In the second stage, decision makers conducted a more analytical evaluation of the compulsory evacuation options.

Sign in / Sign up

Export Citation Format

Share Document