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Abstract  

Emanation thermal analysis was used to characterize the thermal behaviour of alumina coatings as deposited on EUROFER 97 steel surface by filtered vacuum arc technique. Temperature ranges of the healing of cracks and structure irregularities observed by SEM were determined from the ETA results. Transport properties of the alumina coatings were assessed from the ETA results by the evaluation of radon diffusion parameters in the temperature range from 50 to 300°C. Healing microstructure irregularities of the alumina coatings can be expected in the range 300–700°C as indicated by the decrease of the radon release rate. From the ETA results it followed that the onset of healing the cracks observed by the SEM on the surface of one alumina coating sample can be expected at 430°C.

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Yoghurt is considered as a healthy food. Thus, it could convey functional and bioactive ingredients. Chia seeds are of great interest due to their ability to improve consumer health. In this study, chia seeds were added to stirred yoghurt at different doses (1.5, 3, 4.5, or 6%). The effects of chia seeds on physicochemical, microbiological, and sensory qualities were assessed during 28 days of refrigerated storage. The results showed that chia seeds slightly decreased post-acidification, the lowest value was obtained in yogurt with 3% chia seeds (24°D), but syneresis rose significantly (P<0.05) when 6% of chia seeds was added. Furthermore, chia seeds promote viability of yoghurt bacteria, and antioxidant activity reached 62.20±0.02% in yoghurt added with 1.5% chia seeds. However, proteolysis is not affected. The effects of chia seeds were not dose dependent as 4.5% and 6% did not follow trend. These findings were affirmed by sensory characteristics. Thus, stirred yoghurt containing 1.5 or 3% of chia seeds proved to be the most adequate choices.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
G. Lujanienė
,
P. Beneš
,
K. Štamberg
,
J. Šapolaitė
,
D. Vopalka
,
E. Radžiūtė
, and
T. Ščiglo

Abstract  

Sorption of Cs, Pu and Am on natural clay of complex composition was studied to better understand the sorption mechanisms. It was found that cesium sorption to natural clay was affected by its coatings and by the ionic strength of solution. The sorption of Pu and Am on the clay was compared with that on synthetic goethite, hematite and magnetite, representing components of the clay coatings. The sorption was quantitatively interpreted using models assuming ion exchange and/or complex formation on the “layer sites” and “edge sites” of the clay and its coatings. Constants characterizing properties of the sites and sorption equilibria were determined.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
G. Lujanienė
,
P. Beneš
,
K. Štamberg
,
K. Jokšas
,
D. Vopalka
,
E. Radžiūtė
,
B. Šilobritienė
, and
J. Šapolaitė

Abstract  

Sorption–desorption behaviour of 137Cs in the Baltic Sea and the Curonian Lagoon was studied in 1997–2009 with the aim to better understand processes responsible for redistribution and sink of 137Cs in the system. Data obtained from several sampling campaigns were analyzed and short and long-term kinetic tracer experiments using natural water and bottom sediments were carried out with particles of various sizes from 0.2 to 50 μm. Samples of suspended particles and bottom sediments collected during two sampling campaigns were fractionated according to the size, and association of 137Cs with solid phase was studied using sequential extraction. The difference in 137Cs behaviour observed between expeditions in 1999 and 2001 was attributed to seasonal variations in chemical composition of suspended particles entering the system and consequent differences between the sorption (in 1999) and the desorption (in 2001) of 137Cs in sea water. Data obtained from tracer kinetic sorption experiments with 134Cs and bottom sediment fractions of different grain size were used for finding a suitable kinetic sorption model, kinetic constants and the corresponding equilibrium K d values. It has been found that the modelled data best conform to the mechanism of ion diffusion through the so-called inert layer on the surface of the sediment particles.

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Resolution and Discovery
Authors:
Haroune Rachid Ben Zine
,
Filiz Cinar Sahin
,
Zsolt E. Horváth
,
Zsolt Czigány
,
Ákos Horváth
,
Katalin Balázsi
, and
Csaba Balázsi

The effect of the submicrometer-sized Si3N4 addition on the morphological and structural properties of the ceramic dispersion strengthened (CDS) 316L stainless steels prepared by powder technology has been studied. Two composites were prepared: 316L/0.33 wt. % Si3N4 and 316L/1 wt. % Si3N4. In order to assure a good dispersion of the ceramic particles in the stainless steel powders and a grain size reduction at the same time, the high efficient attrition milling has been used. Spark plasma sintering (SPS) was used for fast compacting of milled composites. Structural and morphological changes were studied after milling and sintering process. It was found that the amount of Si3N4 addition influenced the efficiency of milling process resulting in powder mixtures with different 316L stainless steel grain size and shapes. In the case of 0.33 wt. % Si3N4 addition, the flat 316L stainless steel grains with submicrometer size in thickness have been resulted after milling compared to 1 wt. % Si3N4 added powder mixtures which consisted of almost globular 316L stainless steel grains with 50–100 μm in diameter. The intensive milling assured an optimal coverage of 316L stainless grains with Si3N4 submicrometer-sized particles in both cases as demonstrated by energy dispersive spectroscopy (EDS) and TEM. On the other hand, the 316L phase has been maintained during and after the milling and sintering. The partial phase transformation of α-Si3N4 to SiO x was observed by EDS.

Open access
Acta Chromatographica
Authors:
Samiuela Lee
,
Christa E. Nath
,
Ben W. R. Balzer
,
Craig R. Lewis
,
Toby N. Trahair
,
Antoinette C. Anazodo
, and
Peter J. Shaw

Alectinib is a central nervous system-active small molecule anaplastic lymphoma kinase (ALK) inhibitor that is effective in the treatment of patients with ALK positive tumors, including advanced non-small cell lung cancers and lymphomas. A simple, isocratic high-performance liquid chromatography–photo diode array detection (HPLC–PDA) assay for measurement of alectinib in human plasma is described. Alectinib is extracted from the plasma matrix by addition of methanol, followed by centrifugation and acidification with 0.1% formic acid. It elutes with a run time of 4.6 min using a 250 mm × 4.6 mm RP-C18 column with 0.1% aqueous formic acid and methanol (35:65, v/v) and a flow rate of 1 mL/min. Detection was at 339 nm. Linear calibration plots were achieved in the range of 0.1–20 μg/mL for alectinib (r 2 = 0.9996). With limits of detection and quantification of 0.05 and 0.1 μg/mL, respectively, and excellent precision (%CV < 10%), accuracy (bias < ±12%), and recovery (>97%) within the 1–20 μg/mL concentration range, this assay was suitable for measuring pre-dose alectinib concentrations in an adolescent receiving 600-mg doses twice daily.

Open access
Journal of Flow Chemistry
Authors:
F. Benaskar
,
A. Ben-Abdelmoumen
,
N. G. Patil
,
E. V. Rebrov
,
J. Meuldijk
,
L. A. Hulshof
,
V. Hessel
,
U. Krtschil
, and
J. C. Schouten

Abstract

An extended cost study consisting of 14 process scenarios was carried out to envisage the cost impact of microprocessing and microwaves separately or in combination for two liquid-phase model reactions in fine-chemicals synthesis: (1) Ullmann C–O cross-coupling reaction and (2) the aspirin synthesis. The former, a Cu-catalyzed substitution reaction, was based on an experimental investigation, whereas the latter, a noncatalyzed aromatic esterification reaction, was based on literature data. The cost of 4-phenoxypyridine production, as a pharmaceutical intermediate in the synthesis of vancomycin or vancocin, was compared with that of the synthesis of aspirin, a key example of large-scale fine-chemical production plants. The operating costs in the Ullmann synthesis were found to be related to material-based process (reactant excess, pretreatment, and catalyst synthesis), whereas those in the aspirin synthesis appeared to be related to downstream-based process (workup, waste treatment). The impact of an integrated microwave heating and microprocessing system on profitability was demonstrated with respect to operational cost and chemical productivity. Different modes of microwave heating and catalyst supply were studied and compared with conventional oil-bath-heated systems in batch and continuous processes. The overall costs including profitability breakthrough for a competitive market price of product were obtained from various combinations of heating and processing. In case of the Ullmann synthesis, the CAPEX (capital expenditure) was negligible compared to the OPEX (operational expenditure), whereas in the aspirin synthesis, the CAPEX was found around 40%, both at a production scales of 1–10 kg/day using proposed upscale methods. The source of the catalyst strongly determined the profitability of a continuously operated Ullmann process due to its effect on the chemical performance. Higher energy efficiencies could be attained using single-mode microwave irradiation; however, the energy contribution to the overall cost was found to be negligible. Different scenarios provided a cost-feasible and profitable process; nevertheless, an integrated microwave heating and microflow processing led to a cost-efficient system using a micropacked-bed reactor in comparison to wall-coated microreactor, showing a profit margin of 20%.

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Abstract

Human milk (HM) of healthy, well-nourished, lactating mothers is a unique and ideal source of nutritive factors, like hormones, cytokines, chemokines, growth factors that ensures the proper growth and development of infants. Among the main components of HM, fat is an important energy source and a regulatory factor. The quality of milk fat depends on its fatty acid (FA) composition. Gas chromatography coupled with flame ionisation detection is one of the most common methods for analysis of the FA profile of HM. The aim of this study was to evaluate the FA composition of HM, collected from mothers with different health conditions (normal Body Mass Index (nBMI); overweight and obese) using GC-FID method. The results showed that saturated FAs were present in the highest amount in the HM samples, of which palmitic acid was the main representative. The major monounsaturated FA was oleic acid, while linoleic acid was the most abundant of the polyunsaturated FAs (PUFA). Overweight and obese women have lower levels of PUFA in their breast milk. The data were subjected to principal component and quadratic discriminant analysis (QDA). QDA classified nBMI and overweight and obese mother milk samples with 88.24% accuracy. Significant differences were found between normal and overweight and obese HM samples in case of C10:0 and C18:3 FAs. Higher maternal BMI was associated with a higher n-6/n-3 PUFA ratio.

Open access