Comparison of the influence of cationic polysaccharides on the stability properties of montmorillonite suspensions in the presence of sodium dodecyl sulphate

2022 ◽  
Vol 278 ◽  
pp. 118985
Author(s):  
E. Godek ◽  
E. Grządka ◽  
U. Maciołek
Author(s):  
Mira Ristić ◽  
Jasenka Štajdohar ◽  
Ivana Opačak ◽  
Svetozar Musić

Precipitations by the forced hydrolysis of 0.2 M FeCl3 aqueous solutions between 2 and 72 hours in the presence of 1% sodium dodecyl sulphate (SDS) were investigated. In the absence of SDS a direct phase transformation ß-FeOOH → α-Fe2O3 via dissolution/recrystallization occured in the precipitation system. In the presence of SDS, α-FeOOH as an intermediate phase precipitated and, with a prolonged time of forced hydrolysis, also transformed to α-Fe2O3 via the dissolution/recrystallization mechanism. On the basis of Mössbauer spectra it was concluded that in the presence of SDS, α-Fe2O3 phase possessed a lower degree of crystallinity. In this precipitation process the competition between the stability of Fe(III)-dodecyl sulphate, on one side, and the formation of iron oxide phases, on the other, also played an important role. FE SEM revealed that the big α-Fe2O3 particles possessed the substructure. The elongation of primary α-Fe2O3 particles produced in the presence of SDS was noticed. This effect can be assigned to the preferential adsorption of dodecyl sulphate groups on nuclei and crystallites of FeOOH and α-Fe2O3 phase during the forced hydrolysis of FeCl3 solutions.


2018 ◽  
Vol 26 (2) ◽  
pp. 058
Author(s):  
Anna P. Roswiem ◽  
Triayu Septiani

<em>Bahan<strong> </strong>baku untuk membuat baso adalah daging hewan, pada umumnya dari daging sapi, ayam, ikan dan babi. Di beberapa daerah di Indonesia terjadi kasus baso tikus. Tujuan penelitian ini adalah menguji ada tidaknya kandungan daging tikus pada produk baso yang dijual di pasar Cempaka Putih-Kecamatan Kramat Jakarta Pusat dan di pedagang baso atau mie baso di sekitar kampus Universitas YARSI Jakarta. Daging adalah protein salah satu metode untuk mengidentifikasi protein adalah metode Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE).<strong> </strong>Hasil penelitian menunjukkan bahwa dari 6 sampel baso terindikasi ada 2 sampel baso dengan nomor 1 dan 5 yang dibuat dari campuran daging sapi dan tikus; ada 1 sampel baso dengan nomor 6 yang terbuat dari daging tikus; dan 2 sampel baso dengan nomor 2 dan 3 yang terbuat dari campuran sapi  dan babi, dan hanya 1 sampel baso dengan nomor sampel 4 yang benar-benar terbuat dari daging sapi.</em>


2018 ◽  
Vol 10 (6) ◽  
pp. 06013-1-06013-5 ◽  
Author(s):  
I. G. Vorobiova ◽  
◽  
Yu. A. Mirgorod ◽  
A. S. Chekadanov ◽  
◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2908
Author(s):  
Kazuo Umemura ◽  
Ryo Hamano ◽  
Hiroaki Komatsu ◽  
Takashi Ikuno ◽  
Eko Siswoyo

Solubilization of carbon nanotubes (CNTs) is a fundamental technique for the use of CNTs and their conjugates as nanodevices and nanobiodevices. In this work, we demonstrate the preparation of CNT suspensions with “green” detergents made from coconuts and bamboo as fundamental research in CNT nanotechnology. Single-walled CNTs (SWNTs) with a few carboxylic acid groups (3–5%) and pristine multi-walled CNTs (MWNTs) were mixed in each detergent solution and sonicated with a bath-type sonicator. The prepared suspensions were characterized using absorbance spectroscopy, scanning electron microscopy, and Raman spectroscopy. Among the eight combinations of CNTs and detergents (two types of CNTs and four detergents, including sodium dodecyl sulfate (SDS) as the standard), SWNTs/MWNTs were well dispersed in all combinations except the combination of the MWNTs and the bamboo detergent. The stability of the suspensions prepared with coconut detergents was better than that prepared with SDS. Because the efficiency of the bamboo detergents against the MWNTs differed significantly from that against the SWNTs, the natural detergent might be useful for separating CNTs. Our results revealed that the use of the “green” detergents had the advantage of dispersing CNTs as well as SDS.


2020 ◽  
Vol 18 (1) ◽  
pp. 377-390
Author(s):  
Dina El Sherbiny ◽  
Mary E. K. Wahba

AbstractA stability-indicating hybrid micelle liquid chromatography accompanied by UV detection was developed for the simultaneous analysis of either paracetamol (PCA) or pseudoephedrine hydrochloride (PSU) with their synthetic impurities. Mixture I contains PCA with p-amino phenol and p-nitro phenol, while mixture II involves the estimation of PSU with benzaldehyde and benzoic acid. Both mixtures were separated using a C18 column that was thermostatically maintained at 40°C and operating under a flow rate of 1.5 mL/min, applying UV detection at 240 nm for mixture I and 220 nm for mixture II. In both cases, the mobile phase consisted of 0.1 M sodium dodecyl sulfate, acetonitrile, and triethylamine (90:10:0.3, v/v/v) and adjusted to pH 4 (mixture I) or pH 3.7 (mixture II) using 2.0 M O-phosphoric acid. The proposed method was validated and successfully applied to assay different pharmaceuticals containing PCA or PSU. Moreover, the stability-indicating nature of the proposed method was proved through applying photolytic degradation procedures for PCA.


Meccanica ◽  
2021 ◽  
Author(s):  
Dóra Patkó ◽  
Ambrus Zelei

AbstractFor both non-redundant and redundant systems, the inverse kinematics (IK) calculation is a fundamental step in the control algorithm of fully actuated serial manipulators. The tool-center-point (TCP) position is given and the joint coordinates are determined by the IK. Depending on the task, robotic manipulators can be kinematically redundant. That is when the desired task possesses lower dimensions than the degrees-of-freedom of a redundant manipulator. The IK calculation can be implemented numerically in several alternative ways not only in case of the redundant but also in the non-redundant case. We study the stability properties and the feasibility of a tracking error feedback and a direct tracking error elimination approach of the numerical implementation of IK calculation both on velocity and acceleration levels. The feedback approach expresses the joint position increment stepwise based on the local velocity or acceleration of the desired TCP trajectory and linear feedback terms. In the direct error elimination concept, the increment of the joint position is directly given by the approximate error between the desired and the realized TCP position, by assuming constant TCP velocity or acceleration. We investigate the possibility of the implementation of the direct method on acceleration level. The investigated IK methods are unified in a framework that utilizes the idea of the auxiliary input. Our closed form results and numerical case study examples show the stability properties, benefits and disadvantages of the assessed IK implementations.


Metabolites ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 277
Author(s):  
Sabrina Krautbauer ◽  
Raquel Blazquez ◽  
Gerhard Liebisch ◽  
Marcus Hoering ◽  
Philip Neubert ◽  
...  

Lipids are a ubiquitous class of structurally complex molecules involved in various biological processes. In the fast-growing field of lipidomics, preanalytical issues are frequently neglected. Here, we investigated the stability of lipid profiles of murine liver, brain, lung, heart, and spleen homogenates by quantitative flow injection analysis using tandem mass spectrometry and high-resolution mass spectrometry. Storage of tissue homogenates at room temperature showed substantial alterations of the lipid profiles reflecting lipolytic action. Therefore, ratios of ceramide to sphingomyelin, lysophosphatidylethanolamine to phosphatidylethanolamine, lysophosphatidylcholine to phosphatidylcholine, and diglyceride to triglyceride were applied to monitor sample stability and the effect of sodium dodecyl sulfate (SDS) as a potential stabilizing agent. The addition of SDS led to a concentration-dependent stabilization of lipid profiles in liver, brain, and heart homogenates, while in lung and spleen homogenates, in particular, the lysophosphatidylethanolamine to phosphatidylethanolamine ratio increased upon addition of SDS. In conclusion, we demonstrated that lipid class ratios reflecting lipolytic activity could be applied to evaluate both the stability of samples and the influence of stabilizers.


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