Wyniki wyszukiwania - BazTech

1

Evaluation of the possibility of obtaining spherical powders of titanium alloy Ti 6Al 4V by supersonic reverse polarity plasma torch for use in additive manufacturing

Gao Shiyi, Korzhyk Volodymyr, Strohonov Dmytro, Tereshchenko Oleksii, Demіanov Oleksii, Ganushchak Oleg

Advances in Science and Technology. Research Journal

|

2025

|

Vol. 19, no. 8

434--448

EN

This work demonstrates the possibility of producing spherical Ti-6Al-4V Grade 5 alloy powders with superior technological properties compared to those obtained through conventional industrial gas atomization methods for additive manufacturing, by utilizing plasma atomization of a 1.0 mm diameter solid wire. The process employs supersonic plasma jets generated by a DC reverse polarity plasma torch with vortex arc stabilization. The plasma torch has a copper hollow electrode anode and a special diffusive nozzle cathode. Analysis of the particle size distribution of the powder showed the main fraction of -140 μm 96 %wt., and the amount of the finely divided fraction of -63 μm is up to 55-60 %wt. Also, using subsonic jet had been give fraction -250 μm, which is 97 %wt., and the amount of the finely-divided fraction -63 μm does not exceed 30 %wt. The study of the shape and structure properties of Ti 6Al 4V Grade 5 powder showed that the sphericity coefficient reaches up to 0.9, the number of defects in the form of satellites and irregular particles does not exceed 1 %wt. In terms of technological characteristics, Ti 6Al 4V Grade 5 powder obtained by the adopted technique is on par with the industrial method of producing spherical powders for additive manufactuing by the direct polarity plasma torches.

2

Solvent bar microextraction based on using deep eutectic solvent and multivariate optimization for simultaneous determination of antidepressant and antiepileptic drugs in biological fluids

AL-Hashimi Nabil N., El-Sheikh Amjad H., Alfawaz Alaa S., Assaf Khaleel I., Abed Alfattah Husam, Fahelelbom Khairi M.

Acta Chromatographica

|

2025

|

Vol. 37, no. 2

201--216

EN

Monitoring medications in biological fluids is an essential aspect of patient care, particularly in cases of altered mental status where accurate diagnosis, effective treatment, and even forensic examinations are crucial. In this study, a new approach combining hydrophobic-deep-eutectic and solvent-bar-microextraction (HDE-SBME) followed by a high-performance liquid chromatography-diode array detector (HPLC-DAD) was developed for the simultaneous determination of desipramine, clomipramine, as antidepressant and carbamazepine as antiepileptic agents in untreated human urine and plasma samples. The HDE solvents, synthesized using various ratios of menthol and fatty acids, were utilized in the SBME setups. Computational methods were employed to predict the structure and modes of interaction between HDE and the chosen analytes. Central composite design methodology (CCD) was used for multivariate optimization of the effects of different parameters influencing the extraction efficiency of the proposed method. Under optimized experimental conditions, the calibration graph of the spiked selected drugs in urine and plasma samples demonstrated excellent linearity (R2≥ 0.994), with limits of detection/quantification below 0.60/2.02 μg L-1. The extraction recoveries achieved were 88–97%, and the repeatability/reproducibility (RSD%, n = 5) was less than 6.12/7.57. The proposed method was successfully applied to determine selected drugs in patients’ urine and plasma samples. The proposed method detects three drugs in patients’ urine and plasma samples without using toxic volatile organic solvents. The proposed microextraction technique exhibited a confident sensitivity, feasible operation, and simplicity compared with other published methods. Thus, it can be considered a promising method for monitoring the therapeutic levels of specific antidepressant and antiepileptic drugs in urine and plasma samples.

3

Modeling and measurements of temperature field in the arc welding and hybrid plasma-MAG welding heat source models

Rochalski Damian, Golański Dariusz, Szulc Jacek, Połaski Przemysław

Welding Technology Review

|

2024

|

R. 96

107--116

PL

Modelowanie procesów spawania stało się w ostatnim czasie jednym z głównym narzędzi wspomagających badania eksperymentalne oraz wdrożenia produkcyjne procesów spawania. Literatura jest bardzo bogata w publikacje zawierające elementy modelowania jedno-źródłowych procesów spawania, jednak rosnące zainteresowanie przemysłu stosowaniem spawalniczych źródeł hybrydowych stwarza nowe pole do badań tych procesów z zastosowaniem symulacji numerycznych. W niniejszej pracy podjęto próbę stworzenia konwencjonalnego i hybrydowego źródła ciepła w oprogramowaniu dedykowanym do wykonywania symulacji numerycznych metodą MES – LUSAS FEA 14.7. W wyniku przeprowadzonych badań udało się zweryfikować klasyczny model Goldaka na podstawie badań pola temperatury oraz cyklu cieplnego spawania. Ponadto, badania wykazały, że zaproponowany model hybrydowego źródła ciepła, w dość dobrym stopniu odzwierciedla zmiany rozkładu temperatury przy spawaniu hybrydowym.

EN

The modelling of welding processes has recently become one of the most important tools to support the experimental research and the production implementation of welding processes. The literature is very rich in publications containing elements of single source modelling of welding processes, but the growing industrial interest in the use of hybrid welding sources creates a new field for the study of these processes using numerical simulations. In the present study, an attempt has been made to create a conventional and hybrid heat source in a software dedicated to performing numerical simulations using the FEA method - LUSAS FEA 14.7. As a result of the study, based on studies of the temperature field and thermal cycle of welding, it was possible to verify the classical Goldak model. Furthermore, the study showed that the proposed hybrid heat source model fairly well reflects the temperature distribution changes in hybrid welding.

4

UPLC-MS/MS analysis of SZJ-1207 in mouse plasma and brain and application in pharmacokinetic studies

Qi Dake, Sun Yingying, Hu Bingying, An Hai, Lin Haiyang, Fang Jinjun, Wei Yang

Acta Chromatographica

|

2024

|

Vol. 36, no. 2

99--105

EN

SZJ-1207 is an antidepressant natural product with a steroidal structure extracted from Stephanotis mucronata. It is a novel antidepressant candidate molecule and all its pharmacokinetic properties have not been reported. In this pharmacokinetic study in mice following oral administration, an accurate and sensitive UPLC-MS/MS method was established and evaluated to measure SZJ-1207 concentrations in mouse plasma and brain samples. The results provide information regarding the pharmacokinetics of SZJ-1207 as a potential antidepressant.

5

The use of an RP-HPLC-UV method for the analysis of oxcarbazepine in the presence of its preservatives; stability studies and application to human plasma Samales

Fouad Ali, Abdelkhalek Ahmed S., Elrefay Hisham, Batakoushy Hany, Soltan Moustafa K.

Acta Chromatographica

|

2024

|

Vol. 36, no. 3

247--255

EN

A simple, sensitive, selective, accurate and precise method was developed and fully validated for determination of oxcarbazepine (OXC) in presence of their preservatives and determination of oxcarbazepine (OXC) in human plasma. A reversed phase liquid chromatography (RP-HPLC) with UV detection techniques were applied for separation and quantification of studied drug OXC. Successful separation of the drug from methyl paraben (M.P.), propyl paraben (P.P.) and potassium sorbate (P.ST.) was achieved on a Kromasil C18 column (5 μm particle size, pore size 300 Å, l3I.D. 25034.6 mm). The mobile phase that contain aqueous 0.05M potassium dihydrogen phosphate buffer (pH 7): acetonitrile, (50: 50, %v/v). The method was linear over concentration ranges 5.0–50 μg mL-1 for OXC. Bioanalytical validation of the developed method was carried out according to US-FDA guidelines and revealed a good linear relations over a range of (5.0–50), (0.5–10), (0.05–0.15), and (1.0–10) μg mL-1 for OXC, M.P, P.P, and P.ST, respectively, with a correlation coefficient (R2) of more than 0.999. Limit of detection (LOD) were 1.15, 0.03, 0.01 and 0.04 μg mL-1 for OXC, M.P, P.P, and P.ST, respectively, Intra and inter-day precisions, calculated as percentage relative standard deviation (% RSD), were lower than 2.0%. The developed method can be applied for routine drug analysis, therapeutic drug monitoring and bioequivalence studies through the analysis of plasma samples taken from blood bank.

6

Simultaneous determination of dantrolene with ibuprofen and diclofenac in plasma by HPLC-DAD : application to comparative pharmacokinetic study

Abdel Moneim Mona M.

Acta Chromatographica

|

2024

|

Vol. 36, no. 1

23--30

EN

Muscle relaxants and pain killers with their different types are widely used as combination approach for treatment of pain associated with several muscle spasm conditions. A sensitive and simple HPLC-UV detection method was developed in this work for simultaneous assay of Dantrolene (DNT) and co-administrated: Ibuprofen (IBU) and Diclofenac (DIC). After simple protein precipitation, separation was achieved using C₁₈ column (150 × 4.6 mm) with a mobile phase of acidified water with orthophosphoric acid (pH = 3.5) and acetonitrile using gradient elution with a flow rate of 1 mL/min. The DAD was adjusted at 380, 219, 280 and 240 nm to measure DNT, IBU, DIC, and dexamethasone (internal standard), respectively. Linearity was demonstrated over the range from 0.1 to 3 μg/mL, 1 to 40 μg/mL, and 0.1 to 2 μg/mL for DNT, IBU, and DIC, respectively. The validated method was applied successfully to compare the effect of co-administration of IBU or DIC on the pharmacokinetic profile of DNT.

7

Determination of morphine, codeine, thebaine, papaverine and noscapine in rat plasma by UPLC-MS/MS

Wang Ying, He Yifan, Wang Xianqin, Wen Congcong, Cao Jianbin

Acta Chromatographica

|

2024

|

Vol. 36, no. 3

179--185

EN

In this work, a UPLC-MS/MS assay was established for the determination of morphine, codeine, thebaine, papaverine and noscapine in rat plasma. ACQUITY UPLC BEH C18 column was employed for chromatographic separation with the mobile phase comprised acetonitrile-10 mmol L1 ammonium acetate aqueous solution (0.05% aqueous ammonia) using gradient elution. Midazolam was used as internal standard (IS). Electrospray ionization (ESI) in positive-ion mode with reaction monitoring (MRM) was used for quantitative analysis. The calibration curves for morphine, codeine, thebaine, papaverine and noscapine demonstrated good linearity (r > 0.995) in the range of 5–500 ng mL1 for morphine and codeine, and 1–100 ng mL1 for thebaine, papaverine and noscapine. The intra-day and inter-day precisions of morphine, codeine, thebaine, papaverine and noscapine were within 15%, the intra-day and inter-day accuracies were 89–114%, the recovery was better than 65%, and the matrix effects were 96–112%. The developed UPLC-MS/MS assay was successfully applied in the pharmacokinetics of papaverine and noscapine.

8

Investigation of low-temperature plasmas formed in low-density gases surrounding laser-produced plasmas

Majszyk Mateusz, Bartnik Andrzej, Skrzeczanowski Wojciech, Fok Tomasz, Węgrzyński Łukasz, Szczurek Mirosław, Fiedorowicz Henryk

Nukleonika

|

2023

|

Vol. 68, No. 1

11--17

EN

Low-temperature plasma production is possible as a result of photoionization using high-intensity extreme ultraviolet (EUV) and soft X-ray (SXR) pulses. Plasma of this type is also present in outer space, e.g., aurora borealis. It also occurs when high-velocity objects enter the atmosphere, during which period high temperatures can be produced locally by friction. Low-temperature plasma is also formed in an ambient gas surrounding the hot laser-produced plasma (LPP). In this work, a special system has been prepared for investigation of this type of plasma. The LPP was created inside a chamber fi lled with a gas under a low pressure, of the order of 1–50 mbar, by a laser pulse (3–9 J, 1–8 ns) focused onto a gas puff target. In such a case, the SXR/EUV radiation emitted from the LPP was partially absorbed in the low-density gas. In this case, high- and low-temperature plasmas (Te ~100 eV and ~1 eV, respectively) were created locally in the chamber. Investigation of the EUV-induced plasmas was performed mainly using spectral methods in ultraviolet/visible (UV/VIS) light. The measurements were performed using an echelle spectrometer, and additionally, spatial–temporal measurements were performed using an optical streak camera. Spectral analysis was supported by the PGOPHER numerical code.

9

Capabilities of Thomson parabola spectrometer in various laser-plasma- and laser-fusion-related experiments

Tchórz Przemysław, Szymański Maciej, Rosiński Marcin, Chodukowski Tomasz, Borodziuk Stefan

Nukleonika

|

2023

|

Vol. 68, No. 1

29--36

EN

The Thomson parabola spectrometer (TPS) [1] is a well-known, universal diagnostic tool that is widely used in laser plasma experiments to measure the parameters of accelerated ions. In contrast to other popular ion diagnostics, such as semiconductor detectors or ion collectors, the TPS is not greatly affected by electromagnetic pulses generated during high-power laser interaction with matter and can be tuned to acquire data in various energy ranges of accelerated ions, depending on the goal of the experiment. Despite the many advantages of this diagnostic device, processing the collected data is a diffi cult task and requires a lot of caution during interpretation of gathered results. In this work, we introduce the basic principles of operation and data analysis based on the numerical tool created specifi cally for the TPS designed at the Institute of Plasma Physics and Laser Microfusion, present a range of data obtained during various recent experiments in which our TPS was used, and highlight the diffi culties in data analysis depending on the purpose of the experiment and the experimental setup.

10

Slip regime MHD 2-liquid plasma heat transfer flow with hall currents between parallel plates

Linga Raju T., Satish P.

International Journal of Applied Mechanics and Engineering

|

2023

|

Vol. 28, no. 3

65--85

EN

The influence of the slip factor on the MHD 2-liquid heat transfer flow of ionized gases within a channel between two non-conducting plates with Hall currents is investigated theoretically. Slip conditions were used to obtain solutions for the velocity and temperature fields, as well as the heat transfer rates. The flow characteristics of the two liquids are studied for estimates of the leading parameters, for instance the magnetic parameter, Hall and slip factors, viscosity, density, height, electrical conductivity and the thermal conductivity ratios. It was observed that an upsurge in temperature in the two zones is caused by the thermal conductivity proportion. The rate of heat transfer coefficient diminishes up to a certain point, after that it starts to increase as the magnetic and Hall parameters increase.

11

An unsteady electro-magnetohydrodynamic two-liquid plasma flow along a channel of insulating porous plates with Hall currents

Rao V. Gowri Sankara, Raju T. Linga

International Journal of Applied Mechanics and Engineering

|

2023

|

Vol. 28, no. 2

90--112

EN

It is proposed to use the Hall currents to model the transient magneto-hydrodynamic two liquid flows and heat transfer of ionized gases propelled by a common pressure gradient via a horizontal channel consisting of parallel porous plates. For the distributions of velocity and temperature, the principal partial differential equations that explain heat transfer flow under the chosen constraints are resolved. Graphical representations are given for the distributions of velocity, temperature, and heat transfer rates. This research will be carried out using non-conducting porous plate’s channel.

12

Plazma zamiast chemikaliów

Dozór Techniczny

|

2023

|

z. 3

24--25

PL

Czystość powierzchni elementów ma istotne znaczenie w procesie produkcji. Kolejne etapy procesu obróbki, takie jak spawanie, klejenie, uszczelnianie, lakierowanie, wykonywanie nadruków czy lutowanie, wymagają wcześniej usunięcia zabrudzeń, w celu zapewnienia odpowiedniej jakości. Przemysłowe czyszczenie powierzchni z użyciem systemu Acerios, czyli opracowanej przez firmę Fronius technologii gorącej plazmy, wyróżnia się nieszkodliwością i efektywnością.

13

Structural changes and chemical composition changes during the plasma cutting process

Rzeźnikiewicz Agnieszka, Górka Jacek

Biuletyn Instytutu Spawalnictwa w Gliwicach

|

2023

|

Vol. 67, No. 1

14--20

EN

Cutting is usually one of the initial and primary operations used when making welded structures and fabricating structural elements. Increasingly often, the preparation of elements involves the use of thermal, in particular plasma arc, cutting. The plasma arc cutting process consists in melting and ejecting liquid metal from the cut gap by highly concentrated plasma electric arc burning between a non-consumable electrode and a workpiece. The article presents results of tests concerning the influence of plasma gas on structural changes and chemical composition changes resulting from the cutting of unalloyed steel using air plasma arc. The tests revealed that the application of the air plasma arc cutting process led to the formation of an amorphous layer characterized by a very high nitrogen content (of approximately 1.6%) and a hardness of 750 HV 0.2. This high nitriding effect was triggered by the diffusion of nitrogen from the plasma gas. At the same time, the effect of air plasma arc gases on the liquid metal led to the carburising of the cut surface (up to approximately 0.5%) as well as to the burnout of alloying components (in accordance with the theory of selective oxidation of chemical elements). After the air plasma cutting process, the material structure revealed features intermediate between those of the structure formed through oxygen cutting and those of the structure formed as a result of nitrogen plasma cutting. The tests also revealed that the argon-hydrogen plasma cutting process had the lowest effect on the material subjected to cutting.

PL

Cięcie jest zwykle jedną z początkowych i podstawowych operacji procesu wytwarzania konstrukcji spawanych oraz wykonywania gotowych elementów konstrukcji. Coraz częściej do przygotowania elementów używa się cięcia termicznego, a w szczególności cięcia łukiem plazmowym. Proces cięcia łukiem plazmowym polega na stopieniu i wyrzuceniu ciekłego metalu ze szczeliny cięcia silnie skoncentrowanym plazmowym łukiem elektrycznym, jarzącym się między elektrodą nietopliwą a ciętym przedmiotem. W artykule przedstawiono wyniki badań wpływu gazu plazmowego na zmiany strukturalne i zmiany składu chemicznego powstałe w wyniku procesu cięcia łukiem plazmy z zastosowaniem powietrza w stali niestopowej. Wykazano, że w wyniku procesu cięcia plazmą z zastosowaniem powietrza na powierzchni cięcia powstaje warstwa bezpostaciowa o bardzo dużej zawartości azotu (około 1,6%) i twardości rzędu 750 HV 0,2. To silne naazotowanie jest spowodowane dyfuzją azotu z gazu plazmowego. Jednocześnie w wyniku oddziaływania gazów łuku plazmy z zastosowaniem powietrza na ciekły metal dochodzi do nawęglenia powierzchni cięcia (do około 0,5%) i wypalenia składników stopowych, w myśl teorii selektywnego utleniania pierwiastków chemicznych. Po procesie cięcia plazmą z zastosowaniem powietrza struktura materiału wykazuje cechy pośrednie między strukturą powstałą po procesie cięcia tlenem a plazmą z zastosowaniem azotu. Najmniejszy wpływ na materiał cięty wywiera proces cięcia plazmą z zastosowaniem mieszanki argon-wodór.

14

The effect of air plasma cutting on the quality, structural transformations and changes in the chemical composition of structural steel

Górka Jacek

Archives of Civil and Mechanical Engineering

|

2023

|

Vol. 23, no. 3

art. no. e215, 2023

EN

The article presents results of tests concerning the effect of technological parameters of the plasma arc cutting process (involving the use of air as plasma gas) on the quality of cut surfaces as well as on structural transformations and changes in the chemical composition of 14 mm-thick plates made of steel S235JR. The tests revealed that the adjustment of optimum parameters of the cutting process enabled the obtainment of cut surfaces representing quality class I in accordance with the ISO 9013 standard. Only the surfaces processed using the maximum cutting rates represented quality class II. The chemical composition analysis was performed using an ICXA 733 X-ray microanalyser (Jeol) equipped with an energy-dispersive spectrometer (EDS) and an ISIS 300 analytical system (OXFORD). The cut surfaces were observed and their characteristic areas were photographed using an X-ray microanalyser and the backscattered electrons (BSE) technique. The phase analysis was performed using a PHILIPS PW 1050 X’Change machine operated in the B–B (Bragg–Brentano) geometry. It was observed that the application of the air plasma cutting process led to the formation of an amorphous phase on the cut surface. The amorphous phase was characterised by a very high nitrogen content (of approximately 1.6%) and a hardness of 750 HV 0.2. The intense nitration resulted from the diffusion of nitrogen from the plasma gas. At the same time, the effect of air plasma arc gases on the liquid metal was responsible for the carburising of the cut surface (up to approximately 0.5%) and the burnout of alloying components (in accordance with the theory of the selective oxidation of chemical elements). The quality of the cut surfaces was primarily affected by the cutting rate. An increase in the cutting rate was accompanied by the deterioration of the geometric features of cut surfaces. In addition, higher cutting rates also translated into the significant reduction of the HAZ width and that of the size of the zone of chemical composition changes. The tests revealed that, in terms of the 14 mm-thick plates made of steel S235JR, the optimum cutting rates were restricted within the range of 600 mm/min to 1500 mm/min. The tests carried out made it possible to determine the influence of the active plasma gas (oxygen, nitrogen) both on changes in the chemical composition of the tested steel and on the quality of the cut surfaces obtained.

15

Simple HPLC method for simultaneous quantification of nicotine and cotinine levels in rat plasma after exposure to two different tobacco products

Alhusban Ala A., Hammad Alaa M., Alzaghari Lujain F.

Acta Chromatographica

|

2023

|

Vol. 35, no. 1

106--114

EN

Purpose: Development and validation of a selective analytical method to accurately and precisely quantify nicotine and cotinine levels in rat's plasma after exposure to tobacco cigarettes and tobacco water-pipe. Methods: An easy HPLC-Photodiode-Array Detection (PDA) method was developed and validated for simultaneous determination of nicotine and cotinine levels in plasma of 15 rats (10 rats after tobacco products exposure and 5 control rats). Nicotine and cotinine were extracted in one step from plasma using acetonitrile and concentrated to lowest volume using nitrogen stream. Results: The developed method offered a rapid analysis time of 14 min with single step of analytes extraction from rat's plasma with recovery percentage range between 93 and 95% and excellent linearity with correlation factor more than 0.994 with analytical range between 50 and 1000 ng mL⁻¹ and LOD of 25 ng mL⁻¹ and 23 ng mL⁻¹ for nicotine and cotinine, respectively. The analysis of rat's plasma after 28 days of exposure to tobacco cigarettes and tobacco water-pipe revealed that the average concentrations of 376 ng mL⁻¹ for cotinine and 223 ng mL⁻¹ for nicotine were obtained after tobacco cigarettes exposure, and 220 ng mL⁻¹ for cotinine and 192 ng mL⁻¹ for nicotine after tobacco water-pipe exposure. Conclusion: Higher nicotine and cotinine levels were found in plasma after tobacco cigarettes exposure than water-pipe exposure which may have potential undesirable effects on passive smokers in both cases.

16

Analiza możliwości zastosowania palników plazmowych do spalania paliw nietypowych

Pawlak-Kruczek Halina, Mączka Tadeusz, Ostrycharczyk Michał, Baranowski Marcin, Czerep Michał, Sadowski Krzysztof, Hulisz Patryk

Rynek Energii

|

2022

|

Nr 1

28--33

PL

Problem spalania koksików powstających np. z niezupełnego spalania pyłu węglowego i/lub biomasy wymaga specjalnych warunków z powodu niskiej reaktywności koksików. Koksiki te charakteryzują się dużą zawartością substancji mineralnych i brakiem części lotnych, co między innymi powoduje, że mają wysoką temperaturę zapłonu i względnie stałą szybkość spalania w szerokim zakresie temperatur cząstek. Analiza termograwimetryczna dla różnych szybkości nagrzewu pokazała, że ze wzrostem szybkości nagrzewania do temperatury zapłonu jest możliwe uzyskanie zupełnego spalania. Takie warunki nagrzewu koksików gwarantuje zarówno plazma mikrofalowa jak i łukowa. Wstępne badania w reaktorze przepływowym potwierdziły oczekiwania co do stopnia wypalenia. Kolejno w pracy przedstawiono badania nad zastosowaniem palnika plazmowego do spalania koksików.

EN

The problem of minimizing high content of char in fly ash obtained under incomplete combustion of coal or biomass requires special conditions due to the low reactivity of coke. These coke are characterized by a high content of mineral substances and the low concentration of volatile matter, which means high ignition temperature and relatively constant combustion rate in a wide range of particle temperatures. Thermogravimetric analysis for different heating rates shows that with the increase of the heating rate to the ignition temperature, it is possible to obtain complete combustion of analysed fuel. Such conditions for heating the char are guaranteed by both microwave and arc plasma. Initial experimental tests in the flow reactor confirmed the expectations regarding the degree of burnout. In the paper research on the use of a plasma burner for coke is presented.

17

Bonding methods of ceramic materials with deposited carbon layers

Matusiak Tomasz, Kaszczyszyn Jakub, Dąbrowski Arkadiusz

Przegląd Elektrotechniczny

|

2022

|

R. 98, nr 1

55--58

EN

In this paper, we present a proposed bonding technology of ceramic materials. It could be applied for manufacturing the excitation source for detection of elements by means of Optical Emission Spectroscopy (OES) method. The biggest challenge was choice of proper bonding technology for materials with screen printed carbon layers as an excitation electrodes. It was caused by a need to avoid a deterioration of electrical properties of the carbon layer during the bonding process. The bonding at low temperature with various glaze layers was verified with addition of noble elements and plasma modification. The results were promising, without any significant destruction of carbon layers.

PL

W tym artykule przedstawiamy proponowaną technologię łączenia materiałów ceramicznych która może być zastosowana przy wytwarzaniu źródła wzbudzenia do detekcji pierwiastków w metodzie optycznej spektroskopii emisyjnej. Wybór odpowiedniej technologii łączenia materiału z warstwami węglowymi wytwarzanymi metodą sitodruku był wyzwaniem z powodu konieczności uniknięcia degradacji właściwości elektrycznych węgla podczas procesu łączenia. Zweryfikowano łączenie w niskiej temperaturze z różnymi warstwami szkliwa z dodatkiem pierwiastków szlachetnych i modyfikacją plazmową. Wyniki były obiecujące, bez znacznego zniszczenia warstw węglowych.

18

Quantitative assessment of the influence of plasma hardfacing parameters on the metallurgical melting of an austentic steel coating with a substrate material made of C45 steel

Bazychowska Sylwia, Starosta Robert, Dudzik Krzysztof

Journal of KONBiN

|

2022

|

Vol. 52, iss. 3

27--51

EN

In this paper, based on a quantitative analysis of the parameters of plasma hardfacing of C45 steel with CastoMag 45554S wire, an optimisation of the hardfacing process parameters has been carried out. Experimental researches were carried out on the basis of an orthogonal plan, and the optimum hardfacing parameters, e.g.: intensity, voltage, wire feeding speed, were determined by the multiple regression method and the Taguchi method. It was found that the main current of the plasma arc had the greatest influence on the value of the fusion index. The highest S/N value was obtained for the following parameters: I = 120 A, U = 31 V, vn = 0.75 m/min, vd = 3.9 m/min, z = 12 mm.

PL

W oparciu o ilościową analizę parametrów napawania plazmowego stali C45 drutem CastoMag 45554S dokonano optymalizacji parametrów procesu napawania. Badania realizowano na podstawie planu ortogonalnego, a optymalne parametry napawania np.: natężenie, napięcie, prędkość podawania drutu zostały wyznaczone metodą regresji wielokrotnej oraz metodą Taguchi. Ustalono, że największy wpływ na wartość współczynnika wtopienia ma natężenie prądu głównego łuku plazmowego. Największą wartość współczynnika S/N uzyskano przy parametrach: I = 120 A, U = 31 V, vn = 0,75 m/min, vd = 3,9 m/min, z = 12 mm.

19

Unsteady electro-magneto hydrodynamic flow and heat transfer of two ionized fluids in a rotating system with Hall currents

Raju T. Linga, Rao B. Venkat

International Journal of Applied Mechanics and Engineering

|

2022

|

Vol. 27, no. 1

125--145

EN

An unsteady flow and heat transmission of ionized gases via a horizontal channel enclosed by non-conducting plates in a rotating framework with Hall currents is examined using electro-magnetohydrodynamic (EMHD) two-fluid heat flow. The Hall current impact is taken into account by assuming that the gases are totally ionized, the applied transverse magnetic field is very strong. For temperature and velocity distributions in two-fluid flow regions, the governing equations are solved analytically. For numerous physical parameters such as the Hartmann number, Hall parameter, rotation parameter, viscosity ratio, and so on, numerical solutions are visually displayed. It was discovered that an increase in temperature in the two regions is caused by the thermal conductivity ratio. It was also realized that an increase in rate of heat transfer coefficient at the plates is caused by either the Hartman number or the Hall parameter.

20

The Hall effect on MHD 2-fluid unsteady heat transfer flow of plasma in a rotating system via a straight channel between conducting plates

Raju T. Linga, Rao B. Venkata

International Journal of Applied Mechanics and Engineering

|

2022

|

Vol. 27, no. 3

137--162

EN

Hall currents are used to investigate MHD unsteady two fluid flows and heat transport of plasma along a straight channel of conducting plates. In the two liquid zones, the velocity and temperature fields for the case of conducting side plates are obtained by solving the governing equations using a two-term series under the specified conditions. The distribution profiles are graphically resolved and examined. The distributions are thought to be dependent on the electron-to-total pressure ratio. The flow and heat transfer factors are also influenced by other parameters such as the Hartmann number, Hall parameter, rotation parameter, thermal conductivity and viscosity ratio.