scholarly journals Kinetic Energy Dose as a Unified Metric for Comparing Ball Mills in the Mechanocatalytic Depolymerization of Lignocellulose

2022 ◽  
Vol 9 ◽  
Author(s):  
Martin Kessler ◽  
Roberto Rinaldi
Keyword(s):  
Kinetic Energy ◽  
Ball Mill ◽  
Water Soluble ◽  
Mechanochemical Reaction ◽  
Mathematical Function ◽  
Kinematic Modeling ◽  
Ball Mills ◽  
Experimental Conditions ◽  
Experimental Parameters ◽  
Energy Dose

Mechanochemistry utilizes mechanical forces to activate chemical bonds. It offers environmentally benign routes for both (bio) organic and inorganic syntheses. However, direct comparison of mechanochemistry results is often very challenging. In mechanochemical synthetic protocols, ball mill setup (mechanical design and grinding vessel geometry) in addition to experimental parameters (milling frequency, duration, ball count and size) vary broadly. This fact poses a severe issue to further progress in this exciting research area because ball mill setup and experimental parameters govern how much kinetic energy is transferred to a chemical reaction. In this work, we address the challenge of comparing mechanochemical reaction results by taking the energy dose provided by ball mills as a unified metric into account. In this quest, we applied kinematic modeling to two ball mills functioning under distinct working principles to express the energy dose as a mathematical function of the experimental parameters. By examining the effect of energy dose on the extent of the mechanocatalytic depolymerization (MCD) of lignocellulosic biomass (beechwood), we found linear correlations between yield of water-soluble products (WSP) and energy dose for both ball mills. Interestingly, when a substrate layer is formed on the grinding jar wall and/or grinding medium, a weak non-linear correlation between water-soluble products yield and energy dose is identified. We demonstrate that the chemical reaction’s best utilization of kinetic energy is achieved in the linear regime, which presents improved WSP yields for given energy doses. In the broader context, the current analysis outlines the usefulness of the energy dose as a unified metric in mechanochemistry to further the understanding of reaction results obtained from different ball mills operating under varied experimental conditions.

Molecularly Imprinted Sensor for Ascorbic Acid Based on Gold Nanoparticles and Multiwalled Carbon Nanotubes

2020 ◽  
Vol 16 (7) ◽  
pp. 905-913
Author(s):  
Youyuan Peng ◽  
Qingshan Miao
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Ascorbic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Ph Value ◽  
Biological Fluids ◽  
Water Soluble ◽  
Multiwalled Carbon ◽  
Experimental Conditions ◽  
Molecularly Imprinted

Background: L-Ascorbic acid (AA) is a kind of water soluble vitamin, which is mainly present in fruits, vegetables and biological fluids. As a low cost antioxidant and effective scavenger of free radicals, AA may help to prevent diseases such as cancer and Parkinson’s disease. Owing to its role in the biological metabolism, AA has also been utilized for the therapy of mental illness, common cold and for improving the immunity. Therefore, it is very necessary and urgent to develop a simple, rapid and selective strategy for the detection of AA in various samples. Methods: The molecularly imprinted poly(o-phenylenediamine) (PoPD) film was prepared for the analysis of L-ascorbic acid (AA) on gold nanoparticles (AuNPs) - multiwalled carbon nanotubes (MWCNTs) modified glass carbon electrode (GCE) by electropolymerization of o-phenylenediamine (oPD) and AA. Experimental parameters including pH value of running buffer and scan rates were optimized. Scanning electron microscope (SEM), fourier-transform infrared (FTIR) spectra, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were utilized for the characterization of the imprinted polymer film. Results: Under the selected experimental conditions, the DPV peak currents of AA exhibit two distinct linear responses ranging from 0.01 to 2 μmol L-1 and 2 to 100 μmol L-1 towards the concentrations of AA, and the detection limit was 2 nmol L-1 (S/N=3). Conclusion: The proposed electrochemical sensor possesses excellent selectivity for AA, along with good reproducibility and stability. The results obtained from the analysis of AA in real samples demonstrated the applicability of the proposed sensor to practical analysis.

scholarly journals A flexible ChIP-sequencing simulation toolkit

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
An Zheng ◽  
Michael Lamkin ◽  
Yutong Qiu ◽  
Kevin Ren ◽  
Alon Goren ◽  
...  
Keyword(s):  
Ground Truth ◽  
Peak Calling ◽  
Simulation Framework ◽  
Experimental Conditions ◽  
Ground Truth Data ◽  
Chip Sequencing ◽  
Genome Wide ◽  
Experimental Parameters ◽  
Differential Binding ◽  
The Impact

Abstract Background A major challenge in evaluating quantitative ChIP-seq analyses, such as peak calling and differential binding, is a lack of reliable ground truth data. Accurate simulation of ChIP-seq data can mitigate this challenge, but existing frameworks are either too cumbersome to apply genome-wide or unable to model a number of important experimental conditions in ChIP-seq. Results We present ChIPs, a toolkit for rapidly simulating ChIP-seq data using statistical models of key experimental steps. We demonstrate how ChIPs can be used for a range of applications, including benchmarking analysis tools and evaluating the impact of various experimental parameters. ChIPs is implemented as a standalone command-line program written in C++ and is available from https://github.com/gymreklab/chips. Conclusions ChIPs is an efficient ChIP-seq simulation framework that generates realistic datasets over a flexible range of experimental conditions. It can serve as an important component in various ChIP-seq analyses where ground truth data are needed.

scholarly journals Formation of complement subcomponent C1q-immunoglobulin G complex. Thermodynamic and chemical-modification studies

1982 ◽  
Vol 205 (2) ◽  
pp. 361-372 ◽  
Author(s):  
E J Emanuel ◽  
A D Brampton ◽  
D R Burton ◽  
R A Dwek
Keyword(s):  
Immunoglobulin G ◽  
Water Soluble ◽  
Small Peptide ◽  
Experimental Conditions ◽  
Salt Ions ◽  
Salt Range ◽  
Lysine Residues ◽  
Arginine Residues ◽  
Equilibrium Process ◽  
Glycine Ethyl Ester

The interaction between the complement subcomponent C1q and immunoglobulin G was investigated under a variety of experimental conditions. Formation of the subcomponent C1q-immunoglobulin G complex was shown to be an equilibrium process. Thermodynamic studies of the effect of varying the ionic strength indicate that over the salt range 0.15-0.225 M-NaCl the binding of subcomponent C1q to immunoglobulin aggregates releases 9-12 salt ions (Na+ and/or Cl-), illustrating the importance of ionic interactions for the formation of the complex. The effects of small peptide and organic ion inhibitors support this conclusion. Chemical modifications of carboxylate residues on immunoglobulin G by glycine ethyl ester/water-soluble carbodi-imide (up to 12 residues modified per whole molecule of immunoglobulin G) and of lysine residues by acetic anhydride (3 residues per whole molecule of immunoglobulin G) or methyl acetimidate (19 residues per whole molecule of immunoglobulin G) lowered the binding affinity of immunoglobulin for subcomponent C1q. Modification of arginine residues by cyclohexane-1,2-dione-1,2 (14 residues per whole molecule of immunoglobulin G) and of tryptophan by hydroxynitrobenzyl bromide (2 residues per whole molecule of immunoglobulin G), however, had little or no effect. The results are consistent with the proposal that the subcomponent-C1q-binding site on immunoglobulin G is to be found on the last two beta-strands of the Cv2 domain [Burton, Boyd, Brampton, Easterbrook-Smith, Emanuel, Novotny, Rademacher, van Schravendijk, Sternberg & Dwek (1980) Nature (London) 288, 338-344].

Ocena wpływu przygotowania próbek na uzyskiwane wyniki analiz pirolitycznych

Nafta-Gaz ◽  
2021 ◽  
Vol 77 (5) ◽  
pp. 299-312
Author(s):  
Marek Janiga ◽  
◽  
Małgorzata Kania ◽  
Agnieszka Wciślak ◽  
Karol Spunda ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Organic Carbon ◽  
Sample Preparation ◽  
Carbon Content ◽  
Ball Mill ◽  
Organic Carbon Content ◽  
Ball Mills ◽  
Pyrolysis Products ◽  
Two Samples ◽  
Analysis Error

The aim of the work, the results of which are presented in the article, was to evaluate the influence of the method of sample preparation on the results of pyrolytic analyses: RockEval, Py-GC-FID (gas chromatography with FID detector) and Py-GC-IRMS (isotope mass spectrometry with gas chromatography). Mortars and ball mills are most often used to grind the samples. Three rock samples with a higher organic carbon content (shales) and five with a lower organic carbon content (including two samples of dolomites and three of anhydrites) were prepared. The rocks were homogenized and divided into three parts. Each part was ground: by hand in a mortar, in a ball mill for 5 minutes, and in a ball mill for 15 minutes. A total of 24 RockEval analyses, 48 Py-GC-FID analyses (two pyrolysis temperatures corresponding to RockEval pyrolysis conditions) and 24 Py-GC-IRMS analyses were performed. The grinding of the samples for the RockEval analyses is insignificant. The differences in the results seem to indicate the influence of the analysis error and the nature of the sample. For the Py-GC-FID methodology, the influence of milling on the results of desorption carried out at the temperature of 300ºC for most of the tested samples can be considered insignificant and negligible. At the temperature of 500ºC, various types of samples show some correlations, but they are insufficient to reject one of the methods of sample preparation. Therefore, it is important to analyze the results comprehensively, taking into account both the group composition and the distribution of pyrolysis products. In the case of the isotopic composition analyses (Py-GC-IRMS), also no differences in δ13C values related to different types of grinding samples can be found. Summarizing, all the results show a negligible influence of the method of grinding the samples on the results of pyrolysis analyses. Nevertheless, it is important that only one method of sample preparation is used for a separate sample series.

Performance Evaluation of Al2O3 Powder Dispersion by Bead and Ball Mills

2014 ◽  
Vol 682 ◽  
pp. 32-34 ◽  
Author(s):  
N.S. Belousova ◽  
O.A. Goryaynova ◽  
E.V. Melnikova
Keyword(s):  
Particle Size ◽  
Performance Evaluation ◽  
Ball Mill ◽  
Aqueous Suspension ◽  
Ball Mills ◽  
Powder Dispersion ◽  
Maximum Particle Size ◽  
Bead Mill ◽  
Maximum Particle

In this paper the results of alumina aqueous suspension disaggregation with the help of bead and ball mills are shown. The changing of maximum particle size for50 wt. % and 90 wt. % of powder (from lowest to highest size) in suspension dispersed by a bead mill for one hour and ball mill for 48 hours was fixed. In order to achieve powder parameters given by the manufacturer disaggregating process sets was defined.

Homeopathy in parasitic diseases

2021 ◽  
Vol 11 (40) ◽  
pp. 168-169
Author(s):  
Denise Lessa Aleixo ◽  
Leoni Vilano Bonamin ◽  
Silvana Marques De Araujo
Keyword(s):  
Basic Research ◽  
Farm Animals ◽  
Parasitic Infections ◽  
Experimental Conditions ◽  
Traditional Medicines ◽  
Short Period ◽  
Experimental Parameters ◽  
Daily Dose ◽  
Sanitary Conditions ◽  
Main Effects

Introduction: The use of homeopathic medicines has increased, once traditional medicines sometimes do not produce the desired effects and because side effects sometimes compromise the treatment. In recent years, research on homeopathy has clearly developed, both in the implementation of more consistent methodologies and in the description of the data and published methods, improvement are still required in these matters. The acknowledgment of homeopathy depends on the credibility of the groups researching this topic Objective: list and criticize articles highlighting main effects, schedule of treatment and potencies used in different animals models. Material and Methods: A review of articles published since 2000 in journals indexed in the PubMed/Scielo databases was performed. Keywords used were parasitosis/homeopathy and parasitosis/ultra-diluted, in English and Portuguese. Specialized journals such as Homeopathy, International Journal of High Dilution Research, and Brazilian Homeopathic Journal were also used. The contents of each issue of these journals were examined for the "Use of highly diluted medication in parasitic infections." Results and Discussion: Thirty nine papers have been gathered. The methodology of the articles surveyed did not meet the requirements listed in the REHBaR[1]. Thirty seven reports have shown the benefits/effects of highly diluted medicine in the treatment of infectious diseases. In models where experimental conditions are carefully controlled, the conclusions follow the same pattern as those observed in the treatment of farm animals, where, even without completely controlled conditions, clinical result is positive. In fourteen reports using the same model, eight where animals were treated in a constant and prolonged way shown a better result, compared with six reports in which animals were treated for a short period of time, receiving a single daily dose. Several authors have conducted clinical trials using commercial formulas, which do not always provide their composition and/or dynamization, making it difficult to reproducing the experiment. In some of the articles, it was not mentioned if the experiments were repeated at least twice. Conclusions: In parasitic infections, the effect of homeopathic medications is still controversial, and the experimental parameters for evaluation shoud be carefully chosen to avoid isolated analyses of data. Researchers should consider results regarding environmental and sanitary conditions of the animal as a whole. The improvement of techniques and expansion of knowledge about highly diluted medicines may lead to a viable alternative to treat parasitic infections. Precise and detailed descriptions will contribute to advances in the use of homeopathy, so that the wider community can benefit, in practice, from these findings. Keywords: homeopathy, parasitic infections, CAM (Complementary and Alternative Medicine). Reference [1] Lüdtke R, Musial F, Wijk R, Witt C, Baumgartner S. Reporting experiments in homeopathic basic research (REHBaR) – A detailed guideline for authors. Homeopathy. 2009; 98:287-298.

scholarly journals 5-Phenyl-10,15,20-Tris(4-sulfonatophenyl)porphyrin: Synthesis, Catalysis, and Structural Studies

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3363 ◽  
Author(s):  
Aitor Arlegui ◽  
Zoubir El-Hachemi ◽  
Joaquim Crusats ◽  
Albert Moyano
Keyword(s):  
Alder Reaction ◽  
Water Soluble ◽  
Experimental Conditions ◽  
One Pot ◽  
Force Microscopy ◽  
Diels Alder Reaction ◽  
Transmission Electron ◽  
Porphyrin Synthesis ◽  
The One ◽  
Water Soluble Porphyrin

A convenient protocol for the preparation of 5-phenyl-10,15,20-tris(4-sulfonatophenyl)porphyrin, a water-soluble porphyrin with unique aggregation properties, is described. The procedure relies on the one-pot reductive deamination of 5-(4-aminophenyl)-10,15,20-tris(4-sulfonatophenyl)porphyrin, that can be in turn easily obtained from 5,10,15,20-tetraphenylporphyrin by a known three-step sequence involving mononitration, nitro to amine reduction and sulfonation of the phenyl groups. This method provides the title porphyrin in gram scale, and compares very favorably with the up to now only described procedure based on the partial sulfonation of TPP, that involves a long and tedious chromatographic enrichment of the final compound. This has allowed us to study for the first time both the use of its zwitterionic aggregate as a supramolecular catalyst of the aqueous Diels–Alder reaction, and the morphology of the aggregates obtained under optimized experimental conditions by atomic force microscopy and also by transmission electron cryomicroscopy.

A Compact Microcontrolled Microfluidic System for Photometric Determination of Phosphate in Natural Water Samples

2015 ◽  
Vol 68 (7) ◽  
pp. 1108 ◽  
Author(s):  
Osmundo Dantas Pessoa-Neto ◽  
Tiago Almeida Silva ◽  
Vagner Bezerra dos Santos ◽  
Orlando Fatibello-Filho
Keyword(s):  
Light Emitting Diode ◽  
Flow Analysis ◽  
Photometric Determination ◽  
Microfluidic System ◽  
Experimental Conditions ◽  
Light Emitting ◽  
Experimental Parameters ◽  
Led Photometer

A compact environmentally friendly microcontrolled microfluidic device ideal for in situ phosphate determination was developed based on a microsystem based on low-temperature co-fired ceramics (LTCC) coupled to a light-emitting diode (LED)–photometer with a multicommutation flow analysis (MCFA) approach. The experimental parameters of the MCFA analyzer were optimized by chemometric studies. Under the best experimental conditions, limits of detection and quantification of 0.02 mg P L–1 and 0.07 mg P L–1, respectively, and a sampling frequency of 67 h–1 were estimated. Moreover, a low sample consumption of only 60 μL per determination was the other advantage that fully meets the requirements of sustainable research and green chemistry purposes.

scholarly journals Electromechanical Dynamic Behaviour and Start-Up Evaluation of Tumbling Ball Mills

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Weidong Lv ◽  
Guoqiang Wang ◽  
He Tian
Keyword(s):  
Dynamic Model ◽  
Ball Mill ◽  
Electromechanical Coupling ◽  
Coupling Model ◽  
Angular Speed ◽  
Experimental Results ◽  
Ball Mills ◽  
Start Up ◽  
Dynamic Simulator ◽  
Simulation Results

This paper presents a dynamic simulator of the electromechanical coupling start-up of a ball mill. The electromechanical coupling model based on the dynamic model of the ball mill, the characteristic equation of the clutch, and the dynamic model of the induction motor is established. Comparison between the simulation results of angular speed, load torque and current obtained from the model, and the experimental results is conducted to validate the correctness of these simulation results. Results show that the simulation results of the electromechanical model are highly consistent with the experimental results. Two indexes are proposed for evaluation. Finally, a 4500 kW ball mill is used to analyse the start-up process with different operation parameters of the air clutch. The effect of the engagement time and the pressure of the air clutch on the torque, current, and shock extent is analysed. Moreover, the optimum inflation time is determined.

Mechanochemical Reaction Between Sulfur and Ilmenite

1998 ◽  
Vol 51 (10) ◽  
pp. 947 ◽  
Author(s):  
Nicholas J. Welham
Keyword(s):  
Closed System ◽  
Thermal Processing ◽  
Ball Mill ◽  
Inert Gas ◽  
Iron Sulfate ◽  
Mechanochemical Reaction ◽  
X Ray Diffraction ◽  
Rutile Tio2 ◽  
X Ray ◽  
Closed Tube

An ilmenite (FeTiO3) concentrate has been milled with sulfur in a laboratory-scale ball mill for 100 h under a variety of conditions. X-Ray diffraction and thermal processing have shown that reaction occurs within the mill forming pyrite (FeS2) and rutile (TiO2). The reaction was of greatest extent in a mill run under 400 kPa of inert gas; some reaction occurred in a mill under 10-2 Pa, whereas little reaction was observed when either water or air was present. Annealing of the product powders showed that reaction to TiO2 and FeS2 could be achieved in a closed system after 1 h at 400C but with the evolution of SO2, whereas annealing at 800C also gave TiO2 and FeS2, but without formation of SO2 which was thought to have disproportionated to form iron sulfate(VI). Closed-tube annealing of unmilled sulfur and milled ilmenite showed the same reactions as milled powders but of much greater extent.

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