scholarly journals Ecological Aspects of the Performed Thermal Reclamation

2015 ◽  
Vol 60 (1) ◽  
pp. 329-333
Author(s):  
M. Łucarz
Keyword(s):  
Thermal Analysis ◽  
Process Control ◽  
Thermal Analyses ◽  
Process Efficiency ◽  
Loss On Ignition ◽  
Ecological Aspects ◽  
Gas Consumption ◽  
Moulding Sand ◽  
Better Than

AbstractThe thermal analysis results of the selected group of binders and the thermal reclamation of one spent moulding sand with organic binder, are presented in the paper. The reclaiming process of the quartz matrix was performed on the basis of the own method of selecting the reclamation temperature. Taking into account thermogravimetric (TG) analysis results of the binder, the temperature range - required for performing the efficient reclamation of spent moulding sand containing this binder - was indicated. In order to confirm the assumptions, the thermal reclamation operations were carried out at a temperature similar to the determined on the TG basis and - for comparisons - at lower and higher temperatures. During the reclamation operation the reclaim samples were taken for the loss on ignition testing, aimed at the determination of the process efficiency. Temperature in the reclaimer chamber and gas consumptions were also recorded. On the bases of the thermal analyses, loss on ignition, gas consumption and temperatures of the reclaimed moulding sand bed the recommendations for the realisation of the thermal reclamation were given. These recommendations will allow a better, than currently available, process control in an aspect of decreasing the pyrolysis effect and limiting the emission of substances harmful for the environment.

scholarly journals Comparison of loss on ignition and thermal analysis stepwise methods for determination of sedimentary organic matter

2009 ◽  
Vol 19 (1) ◽  
pp. 24-33 ◽  
Author(s):  
Gretel Frangipane ◽  
Mario Pistolato ◽  
Emanuela Molinaroli ◽  
Stefano Guerzoni ◽  
Davide Tagliapietra
Keyword(s):  
Thermal Analysis ◽  
Organic Matter ◽  
Sedimentary Organic Matter ◽  
Loss On Ignition

Study Regarding the Bahaviour of an Insulating Vegetable Oil Exposed to Accelerated Thermal Aging

2017 ◽  
Vol 68 (11) ◽  
pp. 2514-1528
Author(s):  
Petru Budrugeac ◽  
Iosif Lingvay ◽  
Alexandra Pica ◽  
Beatrice Gabriela Sbarcea
Keyword(s):  
Thermal Analysis ◽  
Thermal Aging ◽  
Thermal Analyses ◽  
Accelerated Aging ◽  
Simultaneous Thermal Analysis ◽  
General Mechanism ◽  
Oxidative Reactivity ◽  
Catalytic Role ◽  
Accelerated Thermal Aging

The simultaneous thermal analysis method (thermogravimetry/derivative thermogravimetry + differential thermal analysis (TG/DTG+DTA) and determination of iodine index have been used for characterization of an experimental vegetable insulating oil exposed to thermal cyclic and isothermal accelerated aging in pure state and in contact with red copper. The results obtained by thermal analyses show that three main successive processes of thermo-oxidation occur at progressive heating of initial (un-aged) and thermal aged oil samples. The accelerated thermal aging determines the change of composition and thermal properties of oil, which involves the formation of sites with an oxidative reactivity greater than those from initial (un-aged) oil. It has been put in evidence the catalytic role of red copper in the process of oil oxidation. The change of composition of oil as result of thermal aging also results from the decrease of iodine index. The general mechanism of auto-oxidation of vegetable oils gives a qualitative explanation of obtained results.

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

DETERMINATION OF THE JUICE EVAPORATION MATHEMATICAL MODELS EFFICIENCY FOR AUTOMATED PROCESS CONTROL SYSTEMS

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
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◽  
�. ʳ�� ◽  
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...  
Keyword(s):  
Process Control ◽  
Mathematical Models ◽  
Control Systems ◽  
Process Control Systems ◽  
Automated Process

Determination of trace concentrations of copper by FIA-FAAS after preconcentration on chelating sorbents

1989 ◽  
Vol 54 (7) ◽  
pp. 1785-1794 ◽  
Author(s):  
Vlastimil Kubáň ◽  
Josef Komárek ◽  
Zbyněk Zdráhal
Keyword(s):  
Sampling Frequency ◽  
Copper Determination ◽  
Flow Rates ◽  
Sample Injection ◽  
Injection Flow ◽  
Chelating Sorbents ◽  
Set Up ◽  
Trace Concentrations ◽  
Better Than

A FIA-FAAS apparatus containing a six-channel sorption equipment with five 3 x 26 mm microcolumns packed with Spheron Oxin 1 000, Ostsorb Oxin and Ostsorb DTTA was set up. Combined with sorption from 0.002M acetate buffer at pH 4.2 and desorption with 2M-HCl, copper can be determined at concentrations up to 100, 150 and 200 μg l-1, respectively. For sample and eluent flow rates of 5.0 and 4.0 ml min-1, respectively, and a sample injection time of 5 min, the limit of copper determination is LQ = 0.3 μg l-1, repeatability sr is better than 2% and recovery is R = 100 ± 2%. The enrichment factor is on the order of 102 and is a linear function of time (volume) of sample injection up to 5 min and of the sample injection flow rate up to 11 ml min-1 for Spheron Oxin 1 000 and Ostsorb DTTA. For times of sorption of 60 and 300 s, the sampling frequency is 70 and 35 samples/h, respectively. The parameters of the FIA-FAAS determination (acetylene-air flame) are comparable to or better than those achieved by ETA AAS. The method was applied to the determination of traces of copper in high-purity water.

LC–MS-MS Method for the Determination of Antidepressants and Benzodiazepines in Meconium

2020 ◽  
Vol 44 (6) ◽  
pp. 580-588
Author(s):  
A López-Rabuñal ◽  
E Lendoiro ◽  
M Concheiro ◽  
M López-Rivadulla ◽  
A Cruz ◽  
...  
Keyword(s):  
Extraction Efficiency ◽  
Solid Phase ◽  
Gradient Methods ◽  
Reversed Phase ◽  
Process Efficiency ◽  
Limit Of Quantification ◽  
Mode 2 ◽  
Positive Mode ◽  
Compound Method

Abstract An LC–MS-MS method for the determination of 14 benzodiazepines (BZDs) (alprazolam, α-hydroxyalprazolam, clonazepam, bromazepam, diazepam, nordiazepam, lorazepam, lormetazepam, oxazepam, flunitrazepam, 7-aminoflunitrazepam, triazolam, midazolam and zolpidem) and 15 antidepressants (ADs) (amitriptyline, nortriptyline, imipramine, desipramine, clomipramine, norclomipramine, fluoxetine, norfluoxetine, sertraline, norsertraline, paroxetine, venlafaxine, desmethylvenlafaxine, citalopram and desmethylcitalopram) in meconium was developed and validated. Meconium samples (0.25 ± 0.02 g) were homogenized in methanol and subjected to mixed-mode cation exchange solid-phase extraction. Chromatographic separation was performed in reversed phase, with a gradient of 0.1% formic acid in 2 mM ammonium formate and acetonitrile. Two different chromatographic gradient methods were employed, one for the separation of ADs and another for BZDs. Analytes were monitored by tandem mass spectrometry employing electrospray positive mode in MRM mode (2 transitions per compound). Method validation included: linearity [n = 5, limit of quantification (LOQ) to 400 ng/g], limits of detection (n = 6, 1–20 ng/g), LOQ (n = 9, 5–20 ng/g), selectivity (no endogenous or exogenous interferences), accuracy (n = 15, 90.6–111.5%), imprecision (n = 15, 0–14.6%), matrix effect (n = 10, −73 to 194.9%), extraction efficiency (n = 6, 35.9–91.2%), process efficiency (n = 6, 20.1–188.2%), stability 72 h in the autosampler (n = 3, −8.5 to 9%) and freeze/thaw stability (n = 3, −1.2 to −47%). The method was applied to four meconium specimens, which were analyzed with and without hydrolysis (enzymatic and alkaline). The authentic meconium samples tested positive for alprazolam, α-hydroxyalprazolam, clonazepam, diazepam, nordiazepam, fluoxetine, norfluoxetine, clomipramine and norclomipramine. Therefore, the present LC–MS-MS method allows a high throughput determination of the most common BZDs and ADs in meconium, which could be useful in clinical and forensic settings.

scholarly journals Measuring the quartic Higgs self-coupling at a multi-TeV muon collider

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
M. Chiesa ◽  
F. Maltoni ◽  
L. Mantani ◽  
B. Mele ◽  
F. Piccinini ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Center Of Mass ◽  
Mass Energy ◽  
Simple Analysis ◽  
Proton Proton ◽  
Coupling Interaction ◽  
Center Of Mass Energy ◽  
Muon Collider ◽  
Better Than

Abstract Measuring the shape of the Higgs boson potential is of paramount importance, and will be a challenging task at current as well as future colliders. While the expectations for the measurement of the trilinear Higgs self-coupling are rather promising, an accurate measurement of the quartic self-coupling interaction is presently considered extremely challenging even at a future 100 TeV proton-proton collider. In this work we explore the sensitivity that a muon collider with a center of mass energy in the multi-TeV range and luminosities of the order of 1035cm−2s−1, as presently under discussion, might provide, thanks to a rather large three Higgs-boson production and to a limited background. By performing a first and simple analysis, we find a clear indication that a muon collider could provide a determination of the quartic Higgs self-coupling that is significantly better than what is currently considered attainable at other future colliders.

scholarly journals Application of Bar Adsorptive Microextraction for the Determination of Levels of Tricyclic Antidepressants in Urine Samples

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3101
Author(s):  
Mariana N. Oliveira ◽  
Oriana C. Gonçalves ◽  
Samir M. Ahmad ◽  
Jaderson K. Schneider ◽  
Laiza C. Krause ◽  
...  
Keyword(s):  
Tricyclic Antidepressants ◽  
Matrix Effects ◽  
Activated Carbons ◽  
Process Efficiency ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Experimental Conditions ◽  
Analytical Methodology ◽  
Low Efficiency

This work entailed the development, optimization, validation, and application of a novel analytical approach, using the bar adsorptive microextraction technique (BAμE), for the determination of the six most common tricyclic antidepressants (TCAs; amitriptyline, mianserin, trimipramine, imipramine, mirtazapine and dosulepin) in urine matrices. To achieve this goal, we employed, for the first time, new generation microextraction devices coated with convenient sorbent phases, polymers and novel activated carbons prepared from biomaterial waste, in combination with large-volume-injection gas chromatography-mass spectrometry operating in selected-ion monitoring mode (LVI-GC-MS(SIM)). Preliminary assays on sorbent coatings, showed that the polymeric phases present a much more effective performance, as the tested biosorbents exhibited low efficiency for application in microextraction techniques. By using BAμE coated with C18 polymer, under optimized experimental conditions, the detection limits achieved for the six TCAs ranged from 0.2 to 1.6 μg L−1 and, weighted linear regressions resulted in remarkable linearity (r2 > 0.9960) between 10.0 and 1000.0 μg L−1. The developed analytical methodology (BAμE(C18)/LVI-GC-MS(SIM)) provided suitable matrix effects (90.2–112.9%, RSD ≤ 13.9%), high recovery yields (92.3–111.5%, RSD ≤ 12.3%) and a remarkable overall process efficiency (ranging from 84.9% to 124.3%, RSD ≤ 13.9%). The developed and validated methodology was successfully applied for screening the six TCAs in real urine matrices. The proposed analytical methodology proved to be an eco-user-friendly approach to monitor trace levels of TCAs in complex urine matrices and an outstanding analytical alternative in comparison with other microextraction-based techniques.

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