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Tytuł:
A study on the influence of printing orientation in metal printing using material extrusion technology on the mechanical properties of 17-4 stainless steel products
Autorzy:
Dang, Long Cao
Nguyen, Cuong Van
Le, Anh Hoang
Bui, Danh Thanh
Powiązania:
https://bibliotekanauki.pl/articles/28407327.pdf
Data publikacji:
2023
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
additive manufacturing
material extrusion
17-4 PH stainless steel
mechanical properties
Opis:
This study investigated the influence of print orientation on the mechanical properties of 17-4 PH stainless steel parts fabricated using material extrusion technology. Tensile test specimens were 3D printed in different orientations (flat, on-edge, and upright), and their mechanical properties were evaluated. The results showed that the print orientation significantly affected the ultimate tensile strength, yield strength, and elongation at failure of the specimens. The flat and on-edge orientations exhibited similar mechanical properties, while the upright orientation resulted in lower strength and higher fracture susceptibility. Hardness measurements also indicated variations in hardness distribution among the orientations. The findings emphasize the importance of optimizing the print orientation parameter to achieve desired mechanical characteristics in 17-4 PH stainless steel parts.
Źródło:
Journal of Machine Engineering; 2023, 23, 4; 89--100
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Controlled drug delivery systems for improved efficacy and bioavailability of flavonoids
Autorzy:
Gopikrishna, A.
Girigoswami, A.
Girigoswami, K.
Powiązania:
https://bibliotekanauki.pl/articles/24200649.pdf
Data publikacji:
2023
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
flavonoids
controlled drug delivery system
pH-responsive
electro-responsive
NIR-responsive
flawonoidy
system kontrolowanego uwalniania leku
Opis:
Purpose In past decades, experiments have been done to find the properties of plant polyphenols and their protective role in various diseases. In the present study, a brief review has been done on flavonoids’ protective role in different diseases and controlled drug delivery systems that can be feasible for improving flavonoids’ bioavailability as well as their efficacy in the biological system. Design/methodology/approach Keywords searched in PubMed, and Google Scholar are “Flavones and cardiovascular diseases, flavones and neurodegenerative diseases, isoflavones and neurodegenerative diseases, Flavonoids and ageing, Flavonoids and diseases, total flavonoid content in vegetables, total flavonoid content in fruits, controlled drug delivery system and flavonoids” and the significant recent articles are selected for writing this review. Findings Flavonoids are active components present in plant products that have been found to exert several health benefits, especially in retarding the deleterious effects of CVD, cancer, ageing, diabetes, and neurodegenerative diseases. The different clinical studies have also supported the above notions, and in this commentary, we have highlighted some important findings in the field of flavonoid research. Even though it has various bioactive efficacy, most flavonoids have less bioavailability, requiring controlled drug delivery methods that can also improve flavonoids' bioavailability and stability. pH-, electro-, infrared radiation-, redox- responsive methods of controlled drug release systems are some of the valuable techniques for improving the rate of drug release and bioavailability at the targeted site. Research limitations/implications Research is warranted in this field for improving and developing various materials that can be utilized in the formation of scaffolds/polymers that improves drug loading and controlled drug release properties at the targeted site. Originality/value This review will help the readers to design new strategies in flavonoid research with the help of controlled drug release methods for increased bioavailability and rate of drug release/ controlled drug release.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2023, 116, 2; 49--60
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of acidic saliva on monomer leaching and surface roughness of 3D-printed and milled denture-base materials
Wymywanie monomerów wywołane przez kwaśną ślinę oraz chropowatość powierzchni drukowanych w 3D i frezowanych materiałów dentystycznych
Autorzy:
Al-Otaibi, Hanan
Basaqer, Rafal
Almania, Sarah
Alfouzan, Afnan
Al Taweel, Sara
Alshehri, Huda
Labban, Nawaf
Powiązania:
https://bibliotekanauki.pl/articles/24202785.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
polymethyl methacrylate
CAD/CAM milling
3D-printed
monomer leaching
surface roughness
salivary pH
polimetakrylan metylu
frezowanie CAD/CAM
druk 3D
wymywanie monomerów
chropowatość powierzchni
pH śliny
Opis:
The study evaluated the effect of different acidic salivary pH values on monomer leaching and surface roughness of conventional and CAD/CAM processed (milled and 3D-printed) denture base materials. High-performance liquid chromatography was used to determine the quantity of residual methyl methacrylate monomer leaching after 30 days of immersion in acidic saliva. The surface roughness (Ra) before and after incubation was recorded using a non-contact optical profilometer. The monomer leaching and the surface roughness of the tested materials depended on the pH value of the saliva. The conventional denture framework material exhibited the highest and lowest leaching rates at pH=4.5 and pH=3.5, respectively, regardless of the treatment method. Among the CAD/CAM processed materials, the 3D-printed material showed the highest and lowest leaching at pH=5.5 and pH=3.5, respectively. Regardless of the pH, roughness after incubation was the lowest for conventional materials, and the highest for 3D printing.
W pracy oceniono wpływ pH śliny na wymywanie monomerów i chropowatość powierzchni konwencjonalnych oraz wytworzonych metodą CAD/CAM (frezowanych i wydrukowanych w 3D) materiałów na podbudowy protez dentystycznych. Metodą wysokosprawnej chromatografii cieczowej oznaczono ilość wymytego monomeru (metakrylan metylu) po 30-dniowym zanurzaniu w kwaśnej ślinie. Chropowatość powierzchni (Ra) przed i po inkubacji rejestrowano za pomocą bezkontaktowego profilometru optycznego. Wymywanie monomerów oraz chropowatość powierzchni badanych materiałów zależały od wartości pH śliny. Konwencjonalny materiał na podbudowę protezy wykazywał największy i najmniejszy stopień wymywania odpowiednio przy pH=4,5 i pH=3,5, niezależnie od sposobu obróbki. Spośród materiałów poddanych obróbce CAD/CAM, materiał drukowany wykazał największe i najmniejsze wymywanie przy odpowiednio pH=5,5 i pH=3,5. Niezależnie od pH, chropowatość po inkubacji była najmniejsza w przypadku materiałów konwencjonalnych, a największa otrzymanych metodą druku 3D.
Źródło:
Polimery; 2023, 68, 3; 149--156
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of pH value on effectiveness of biopolymer-based treatment of bauxite mine slurry
Autorzy:
Meng, Jian Ping
Li, Shanmei
Yan, Rongtao
Wei, Changfu
Powiązania:
https://bibliotekanauki.pl/articles/24085778.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
pH
biopolymer
xanthan gum
bauxite mine slurry
flocculation
Opis:
Effective dehydration and flocculation of mine slurries or sludge is important for nonferrous metal industries and environmental engineering. However, the mechanisms for the flocculation of slurry remain largely unclear. This paper presents the results of a series of flocculation tests, which was conducted on the slurry suspensions treated by xanthan gum (flocculant) at different pH values. It is shown that the settlement rate of mine slurry particles can be accelerated by adding xanthan gum, and the maximum sedimentation rate was obtained at a pH value of 5.9, and the final volume of flocs is significantly increased due to the addition of the flocculant. In addition, the settlement rates of xanthan gum-treated slurry suspensions at the pH values of 3, 5 and 7 decrease slightly compared with the reference slurry suspensions with pH=5.9, and the slurries remained stable as suspensions at the pH value of 9 and 11. The zeta potential measurement and SEM image analysis show that flocculation occurs primarily due to electrostatic attraction between slurry particles and the flocculants, and the bridging effect between the carboxylic groups in the side chains of xanthan gum molecule and the suspension particles.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 3; art. no. 167949
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of ageing heat treatment temperature on the properties of DMLS additive manufactured 17-4PH steel
Autorzy:
Świetlicki, Aleksander
Wlaczak, Mariusz
Szala, Mirosław
Turek, Marcin
Chocyk, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/27311463.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
17-4PH steel
precipitation hardening
additive manufacturing
heat treatment
nanohardness
utwardzanie wydzieleniowe
produkcja dodatkowa
obróbka cieplna
nanotwardość
stal 17-4 PH
Opis:
Additive manufacturing (AM) is a modern, innovative manufacturing method that enables the production of fully dense products with high mechanical properties and complex shapes that are often impossible to obtain by traditional methods. The 17-4PH grade steel is often applied where high mechanical performance is required. 17-4PH, or AISI 630, is intended for precipitation hardening, an operation that combines solution and ageing treatments and is used to significantly change the microstructure of the steel and enhance its mechanical properties. This study investigates the effect of precipitation hardening on the properties of 17-4PH steel. To examine microstructure and morphology, metallographic tests were performed together with phase composition and chemical composition analyses. Mechanical parameters were determined via Vickers hardness testing and the Oliver-Pharr method. Samples were fabricated using direct metal laser sintering (DMLS), which is one of the powder bed fusion methods. The use of a constant solution treatment temperature of 1040_C and different ageing temperatures made it possible to evaluate the effects of ageing temperature on the mechanical properties and microstructure of 17-4PH. The presence of face-centered cubic FCC g-austenite and body-centerd cubic BCC a-martensite structures were detected. The tests revealed that – similarly to the wrought material – the highest hardness of 382_10:3 HV0:2 was obtained after ageing at 450_C. The nanoindentation test showed the same H/E ratio for the sample after fabrication and after solution treatment at 0.016769, but this value increased after ageing to 127–157.5%. The sample aged at 450_C was characterized by the highest H/E ratio of 0.026367, which indicates the highest wear resistance of this material under employed treatment conditions. In general, the sample treated at 450_C showed the best performance out of all tested samples, proving to have the smallest grain size as well as high Vickers and nanoindentation hardness. On the other hand, the use of solution treatment led to reduced hardness and improved workability of the AM material.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 4; art. no. e146237
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of different variants of basalt-sulphur improver in the fertilisation of spring oilseed rape
Autorzy:
Stanisławska-Glubiak, Ewa
Korzeniowska, Jolanta
Kucharski, Mariusz
Kufka, Dominika
Powiązania:
https://bibliotekanauki.pl/articles/37233293.pdf
Data publikacji:
2023
Wydawca:
Instytut Uprawy Nawożenia i Gleboznawstwa – Państwowy Instytut Badawczy
Tematy:
oilseed rape
soil improver
basalt dust
sulphur
seed yield
fat
soil pH
Opis:
The aim of the research was to test of several variants of basalt-sulphur improver, differing in the ratio of the two components, and to select the most suitable one for oil seed rape. Basalt dust, which is a troublesome by-product of rock processing, and elemental sulphur were used to produce the improver. The study included 3 improver variants with 1, 1.5 and 2% S and a control treatment without an improver. The experiment was conducted in concreted microplots filled with two soils: sandy loam and loamy sand, in a split-block two-factor design, in 4 replicates. The most suitable variant for rapeseed was the variant containing 1.5% S, which resulted in a 12% increase in rapeseed yield on sandy loam. Moreover, for this variant, an increase in seed fat content, an increase in the bioavailable form of sulphur in the soil and an increase in the concentration of this nutrient in oilseed rape straw and seed were observed on both soils.
Źródło:
Polish Journal of Agronomy; 2023, 52; 62-70
2081-2787
Pojawia się w:
Polish Journal of Agronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of salivary pH and flow rate among exam going students of Karpaga Vinayaga Institute of Dental Sciences
Autorzy:
Raghupathy
Balasubramanian, Sasirekha
Subramaniam, Gokulapriya
Krishnan, Ishwariya
Shanmugam, Maheshwari
Santhosh, Kalaiselvi
Powiązania:
https://bibliotekanauki.pl/articles/27317670.pdf
Data publikacji:
2023-09-30
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
exam stress
psychological stress
salivary pH
salivary flow perception
Opis:
Introduction and aim. The central nervous systems control salivary pH and Flow; hence it is considered as stress biomarker. To correlate the relationships linking test performance and the cognitive along with affective aspects for the stress of the exams, flow rate and pH levels of saliva. Material and methods. Cross-sectional research was carried out on the day of their final exam and after three months. 90 dental college students provided saliva samples for measuring pH and salivary flow rate. The saliva was collected to measure stress, anxiety, and wellbeing. Results. Salivary flow and pH were increased in the after-exam period. This is mostly due to less threat, stress, and anxiety perception. Conclusion. According to this study, perceived stress can affect salivary flow rate and pH levels, which can be used to gauge the degree of physiological reactions accurately, conveniently, and affordably to tests and variable realistic stresses.
Źródło:
European Journal of Clinical and Experimental Medicine; 2023, 3; 534-538
2544-2406
2544-1361
Pojawia się w:
European Journal of Clinical and Experimental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Factors determining the occurrence and number of bacteria of the genus Azotobacter in the soil environment
Autorzy:
Kozieł, Monika
Powiązania:
https://bibliotekanauki.pl/articles/26917707.pdf
Data publikacji:
2023
Wydawca:
Instytut Uprawy Nawożenia i Gleboznawstwa – Państwowy Instytut Badawczy
Tematy:
soil properties
pH
Azotobacter spp.
atmospheric nitrogen fixation
Opis:
Bacteria belonging to the genus Azotobacter are microorganisms commonly found in various soils all over the world and capable of fixing atmospheric nitrogen. The biological nitrogen fixation (BNF) process annually supplies approximately140–170 million tons of this element to the nitrogen cycle, which is of great importance from an ecological and practical point of view. Although the efficiency of atmospheric nitrogen fixation by Azotobacter spp. is relatively high and amounts to 20 mg N per1 g of glucose used, these bacteria are sensitive to various environmental factors, including soil reaction, contents of organic matter, soil humidity or nutrient content, and their abundance in soils is small. These bacteria secrete numerous biologically active substances into the soil environment, which have a beneficial effect on the development of plants, which from the ecological point of view plays an important role in the functioning of agricultural ecosystems. An additional advantage of bacteria belonging to the genus Azotobacter, which speaks for their use in agriculture, is the ability to produce antifungal and solubilization of insoluble phosphates. Research on Azotobacter spp. proves that the concentration of hydrogen ions (pH) is a significant factor which determines the presence of this group of bacteria in the soil environment. Many other soil properties have a large impact on the presence and development of this important agricultural group of bacteria. The aim of the work was to systematize the knowledge on the known occurrence conditions and ecological relationships and interactions between environmental factors and the presence and abundance of Azotobacter bacteria in soils.
Źródło:
Polish Journal of Agronomy; 2023, 52; 14-21
2081-2787
Pojawia się w:
Polish Journal of Agronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heavy Metals Contamination of Local and Imported Rice in Semarang, Central Java, Indonesia
Autorzy:
Wahyuningsih, Nur Endah
Setiawan, Henry
Nabiha, Puteri Inandin
Kartasurya, Martha Irene
Azam, Mahalul
Powiązania:
https://bibliotekanauki.pl/articles/27323834.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
pH
heavy metals
rice
local
import
Opis:
This study defined the heavy metal concentration in rice, a commonly consumed staple food in Indonesia that is domestically produced and also imported from other countries due to its high demand. A total of six rice samples, comprising of four domestic and two foreign were randomly taken from Semarang stores and analyzed using the Atomic Absorbance Spectrometer (AAS). The laboratory results revealed that three varieties of rice, two from Indonesia (MW and PW; 0.561 and 0.456 mg/kg, each), and one from the United States (B; 0.307 mg/kg), exceeded the Indonesian dietary standard for lead (Pb) (SNI). Furthermore, the concentration of chromium (Cr) in two rice that are imported (B, 0.241 mg/kg and J, 0.723 mg/kg) were greater than the 0.2 mg/kg threshold established by the Chinese government. However, all samples had acceptable levels of As and Hg, and none had detectable levels of Cd. In terms of pH levels, domestically produced rice had a wider range (3.88–5.78) compared to imported rice (4.96–5.68). Although locally grown and imported rice had acceptable levels of LCR, only one local rice sample and two imported rice samples exceeded the Target Hazard Quotient (THQ) as well as Hazard Index (HI) values. In conclusion, consuming heavy metals contamination rice on a regular basis poses carcinogenic as well as non-carcinogenic health risks.
Źródło:
Journal of Ecological Engineering; 2023, 24, 7; 49--60
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heavy Metals in Soil and Plants During Revegetation of Coal Mine Spoil Tips and Surrounded Territories
Autorzy:
Kucher, Larisa
Krasnoshtan, Igor
Nedilska, Uliana
Muliarchuk, Oksana
Manzii, Olena
Menderetsky, Vadim
Boroday, Vira
Beregniak, Evgeniy
Voitsekhivskyi, Volodymyr
Myronycheva, Olena
Powiązania:
https://bibliotekanauki.pl/articles/27323823.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
spoil tip
rock waste
heavy metals
threshold limiting value
soil
pH
ordinary chernozem
plant biomass
Opis:
Coal mining in Donbas is a global problem as it causes the destabilization of ecological landscapes. Spoil tips, covering almost 52% of the territory, alter the topography of the land, affect the ecosystem, and decrease soil fertility. The soils become degraded and are unsuitable for agricultural use. The occupation of the Donetsk region by the Russian Federation has suspended the observation and research of man-made influence on this territory, which is a major concern for the scientific community. To reduce the negative impact of spoil tips, it is necessary to slow down the process of pyrite oxidation and the formation of toxic substances, as well as the migration of heavy metals due to erosion. Biological reclamation with grass and woody plants can help in achieving this goal. Another urgent issue is the constant supervision and assessment of the suitability of the bedrock of coal mines for agricultural use. The study investigated the total and mobile content of heavy metals in the rock samples from the “South Donbaska-1” mine, ordinary chernozem (background soil), and vegetation growing on the spoil tip. The results showed that the content of Co, Cr, Cu, and Fe in the rock of the spoil tip is higher than in the background soils. The content of heavy metals gradually decreases as the distance from the spoil tip increases. The content of Pb in ordinary chernozem and rock is practically the same, indicating its active migration. An analysis of the biomass of plant samples growing on the spoil tip showed that the content of Co, Cu, and Zn was within the limits of the threshold limiting values. However, the content of other studied elements exceeded the permissible norms. The research results provide information on the ecological state of the spoil tip and can be used for recreational as well as reclamation works in these areas.
Źródło:
Journal of Ecological Engineering; 2023, 24, 7; 234--245
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hyperborejczycy w mocarstwowej ideologii niemieckiej w XVII, XVIII i XIX wieku
Hyperboreans in the German Superpower Ideology in the 17th, 18th and 19th Centuries
Autorzy:
Kochanek, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/41540390.pdf
Data publikacji:
2023
Wydawca:
Wyższa Szkoła Gospodarki w Bydgoszczy. Wydawnictwo Uczelniane
Tematy:
Hyperboreans
Superpower Ideology
Germany
Ph. Clüver
G.W. Leibnitz
A.L. von Schlözer
J.W. Uphagen
K. Mannert
Ch.K. Barth
J.G. Radlof
A.B. Wilhelm
K. Halling
M.E. Meyen
G.F.P. Rauschnick
J.H. Krause
A. Riese
J.C. Spenera
Opis:
The article aims to show the role that the ancient myth of the Hyperboreans played in the German superpower ideology. In this aspect, the opinions of fourteen German scholars from 1616 to 1875, i.e. over a period of 259 years, were analysed. These opinions prove that the Hyperborean myth was used to emphasize the ethical and moral values of the German nation. In turn, these values were to prove that Germany’s aspirations to the role of a superpower were right. Referring to the Hyperborean myth was at the same time referring to the Hellenic idea of the chosen nation. This, in turn, was a justification for the German feeling of superiority over other nations. This conviction grew gradually over several generations and was a source of German national pride. The most important elements of this pride were briefly summarized by A. Riese: „Gerechtigkeit, Tapferkeit, Freiheit”. This phrase can probably be considered a German response to the French, revolutionary postulate – „Liberté, Égalité, Fraternité”.
Źródło:
Heteroglossia- studia kulturoznawczo-filologiczne; 2023, 15; 203-218
2084-1302
Pojawia się w:
Heteroglossia- studia kulturoznawczo-filologiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the effectiveness of the new inhibitor in different aggressive media
Badanie skuteczności nowego inhibitora w różnych środowiskach o dużej aktywności chemicznej
Autorzy:
Gurbanov, Huseyn R.
Talybov, Gulahmad M.
Adygezalova, Mehpara B.
Zhang, Yu X.
Powiązania:
https://bibliotekanauki.pl/articles/31343889.pdf
Data publikacji:
2023
Wydawca:
Instytut Nafty i Gazu - Państwowy Instytut Badawczy
Tematy:
carbon dioxide
hydrogen sulfide
corrosion
protective effect
inhibitor
pH
reagent
corrosion rate
concentration
dwutlenek węgla
siarkowodór
korozja
działanie ochronne
odczynnik
tempo korozji
stężenie
Opis:
The corrosion protection effect of the new S-1 reagent in media with the pH values of 2.0, 4.0, 6.0, as well as carbon dioxide and hydrogen sulfide added separately and combined to the mentioned media, was first tested under laboratory conditions. The protective effect of reagent S-1 was weak in the corrosion medium without hydrogen sulfide and carbon dioxide. However, as the acidity of the medium and the concentration of the reagent increases, the corrosion protection efficiency of the inhibitor also increases. The highest effect is observed at pH = 2.0 and reagent concentration of 30 mg/l. The corrosion protection effect of the reagent reaches 97% under these conditions. In the media with pH = 4.0 and pH = 6.0 without carbon dioxide and hydrogen sulfide, the protective effect of the inhibitor at the optimal concentration of 30 mg/l is 66% and 64%, respectively. In the medium with added carbon dioxide, the protective effect of inhibitor S-1 decreases at pH = 2.0 and, on the contrary, increases at the values of pH = 4.0 and pH = 6.0. Also, as the pressure of carbon dioxide in the medium increases, the protective effect of inhibitor S-1 increases. When hydrogen sulfide is added to the medium, it causes an increase in the corrosion rate and the protection efficiency of inhibitor S-1. However, in the medium without inhibitor, the increase of hydrogen sulfide concentration only up to CH2S = 400 mg/l is accompanied by an increase in the corrosion rate at all values of pH. The addition of 1000 mg/l of hydrogen sulfide to the corrosion medium leads to the decrease in the corrosion rate in the medium without inhibitors and a slight decrease in the protective effect at the concentration of the inhibitor Cinh = 10 mg/l. As the concentration of inhibitor S-1 increases in the medium with the addition of carbon dioxide and hydrogen, its corrosion protection effect also increases. In the range of Cinh = 10–30 mg/l, when PCO2 = 0.5 atm and CH2S = 200 mg/l, the protective effect is estimated at 38–99%, and when CH2S = 1000 mg/l, it is estimated at 17–79%. At PCO2 = 1.0 atm, the value of protective effect is 22–95% and 14–76%, and finally at PCO2 = 2.0 atm, the value of the corrosion protection effect of inhibitor S-1 is estimated at 44–92% and 15–75%, respectively. The coexistence of carbon dioxide and hydrogen sulfide in an aggressive medium leads to an increase in the protective effect of inhibitor S-1 compared to the medium containing only carbon dioxide, and reduces it in comparison to the medium with hydrogen sulfide. An increase in carbon dioxide pressure in the presence of hydrogen sulfide causes a decrease in the protective effect of inhibitor S-1. The protective effect of inhibitor S-1 is lower in the medium with hydrogen sulfide concentration of 1000 mg/l compared to a concentration of 200 mg/l. This case is also observed in the carbon dioxide free medium.
Działanie antykorozyjne nowego odczynnika S-1 w agresywnych mediach o pH 2,0; 4,0; 6,0, a także dwutlenku węgla i siarkowodoru dodawanych osobno lub łącznie do tych mediów, zostało najpierw zbadane w warunkach laboratoryjnych. Działanie ochronne odczynnika S-1 było słabe w środowisku korozyjnym bez siarkowodoru i dwutlenku węgla. Jednak wraz ze wzrostem kwasowości medium i stężenia odczynnika wzrasta również skuteczność inhibitora w ochronie przed korozją. Najlepsze działanie antykorozyjne odnotowano przy wartości pH = 2,0 i stężeniu odczynnika 30 mg/l. Skuteczność ochronna odczynnika wynosi wówczas 97%. W medium o pH = 4,0 i pH = 6,0 bez dwutlenku węgla i siarkowodoru skuteczność ochronna inhibitora przy optymalnym stężeniu 30 mg/l wynosi odpowiednio 66 i 64%. W medium z dodatkiem dwutlenku węgla działanie ochronne inhibitora S-1 maleje przy wartości pH = 2,0 i odwrotnie wzrasta przy wartościach pH = 4,0 i pH = 6,0. Ponadto, wraz ze wzrostem ciśnienia dwutlenku węgla w środowisku wzrasta skuteczność ochronna inhibitora S-1. Dodanie siarkowodoru do medium powoduje wzrost tempa korozji i skuteczności ochronnej inhibitora S-1. Jednak w medium bez inhibitora wzrostowi stężenia siarkowodoru nawet do tak niskiej wartości jak CH2S = 400 mg/l towarzyszy wzrost tempa korozji przy wszystkich wartościach pH. Dodanie 1000 mg/l siarkowodoru do medium korozyjnego prowadzi do zmniejszenia tempa korozji w medium bez inhibitorów i nieznacznego zmniejszenia działania ochronnego przy stężeniu inhibitora Cinh = 10 mg/l. Wraz ze wzrostem stężenia inhibitora S-1 w medium z dodatkiem dwutlenku węgla i siarkowodoru, zwiększa się również jego działanie antykorozyjne. W zakresie Cinh = 10–30 mg/l, gdy PCO2 = 0,5 atm i CH2S = 200 mg/l, skuteczność ochronną szacuje się na 38–99%, natomiast przy CH2S = 1000 mg/l na 17–79%. Dla PCO2 = 1,0 atm skuteczność ochronna wynosi od 22–95% do 14–76%, a przy PCO2 = 2,0 atm skuteczność antykorozyjną inhibitora S-1 szacuje się odpowiednio na 44–92% i 15–75%. Jednoczesne występowanie dwutlenku węgla i siarkowodoru w agresywnym medium zwiększa skuteczność ochronną inhibitora S-1 w stosunku do medium zawierającego tylko dwutlenek węgla i zmniejsza ją w porównaniu do medium z siarkowodorem. Wzrost ciśnienia dwutlenku węgla w obecności siarkowodoru powoduje zmniejszenie skuteczności ochronnej inhibitora S-1. Ulega ona także zmniejszeniu w środowisku o stężeniu siarkowodoru 1000 mg/l w porównaniu do stężenia 200 mg/l. Ten przypadek obserwuje się również w środowisku bez dodatku dwutlenku węgla.
Źródło:
Nafta-Gaz; 2023, 79, 7; 478-483
0867-8871
Pojawia się w:
Nafta-Gaz
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the Hydrosystem and Environmental Monitoring of Water Quality of the Ponds and Water Sources in the National Dendrological Park "Sofiyivka" of the NAS of Ukraine
Autorzy:
Balabak, Oleksandr
Muzyka, Hryhorii
Balabak, Alla
Vasylenko, Olha
Nikitina, Olha
Hnatiuk, Nataliia
Rumiankov, Yurii
Porokhniava, Olha
Tsybrovska, Nadiia
Hurskyi, Ihor
Powiązania:
https://bibliotekanauki.pl/articles/24201634.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
water
pH value
total hardness
chlorides
sulfates
nitrates
nitrites
Opis:
At present, the problem of the availability of high-quality fresh water is urgent. The reservoirs from which water is extracted are running low. The amount of fresh water on the planet has decreased significantly in recent years. A big problem for the use of fresh water is its pollution. Groundwater remained relatively clean, but even when used, it needs to be controlled. Goal of research was the quality control of water from ponds and water sources in the National Dendrological Park (NDP) "Sofiyivka" of the National Academy of Sciences (NAS) of Ukraine in terms of physicochemical and bacteriological indicators and a study of the park's hydrosystem. When conducting research, potentiometric, gravimetric, titrimetric, colorimetric and spectrophotometric methods were used. The hydrosystem of the NDP "Sofiyivka" of the NAS of Ukraine, created during the period of its foundation, has basically retained its planning forms and all its artificial structures. The water system is an important environmental factor that contributes to the quality development of plants, and also has an aesthetic value. The analysis of the results of a study of the physicochemical and bacteriological composition of drinking water from the studied water catchments showed that the water is safe for consumption in terms of such indicators as the content of sulfates, nitrites, chlorides, but contains a significant amount of nitrates and has a high hardness, which can contribute to the development of a number of diseases. Long-term consumption of such water will have a negative impact on the human body. In all water samples from the capture, the growth of common coliforms in 100 cm3 and the presence of Escherichia coli were found, which is dangerous when drinking unboiled water and can bring to intestinal infectious diseases. According to the obtained experimental results of the quality of the studied water samples from the Krasnostavsky, Upper and Lower ponds of the NDP "Sofiyivka" NAS of Ukraine, the general physical and chemical indicators fully comply with the established standards, but the results of studies of the ponds in terms of bacteriological indicators, namely the index of lactose-positive E. coli indicate their significant excess and non-compliance with the standards in the Krasnostavsky and Verkhny ponds by 48 and 12 times, respectively.
Źródło:
Journal of Ecological Engineering; 2023, 24, 3; 178--187
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of the Parameters of Robotic TIG Welding on the Microstructure of 17-4PH Stainless Steel Welded Joint
Autorzy:
Nalborczyk-Kazanecka, Agnieszka
Mrowka-Nowotnik, Grażyna
Powiązania:
https://bibliotekanauki.pl/articles/2203752.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
welding
17-4PH stainless steel
precipitation hardening
heat treatment
Opis:
17-4PH stainless steel finds application in the aerospace industry owing to its good mechanical properties and corrosion resistance. In the literature, this steel is described as good for welding, but research shows that it may be problematic due to the formation of defects. In this study, the welded joints were made by the robotic TIG welding method with various welding speeds (2 and 3 mm/s). The joints were subjected to non-destructive testing and were free from defects. The microstructure was observed by light microscopy and scanning electron microscopy. Changes in the microstructure of the heat affected zone were observed and discussed. Based on the observation of the microstructure and the change in the hardness profile, the heat affected zone was divided into 4 characteristic regions. δ-ferrite and NbC were observed in the martensite matrix. The welded joints were subjected to heat treatment consisting of solution and aging in 550°C for 4 h. The microstructure of the heat affected zone become homogenized as a result of the heat treatment. The content of stable austenite in the welded joint after the heat treatment was about 3%.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 1; 339--344
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time-dependent reliability analysis of corroded RC beams based on the phase-type fitting method
Autorzy:
Li, Junxiang
Chen, Jianqiao
Zhang, Xinxin
Wu, Zijun
Powiązania:
https://bibliotekanauki.pl/articles/27320977.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
chloride penetration
uncertainties
time-dependent reliability analysis
PH fitting method
corroded reinforced concretebeams
Opis:
It remains an important challenge to quantitatively describe the corrosion of reinforced concrete (RC) structures under chloride penetration. When considering the uncertainties encountered throughout the life cycle of RC structures exposed to a corrosive environment and evaluating their safety and reliability, the complexity of the problem intensifies. To address these issues, this paper focuses on the time-dependent reliability analysis of corroded RC beams, utilizing the phase-type (PH) fitting method. Initially, a model for the time-dependent reliability of corroded RC beams is established, incorporating the time-dependent chloride diffusion coefficient. Subsequently, a novel PH fitting method is proposed. The effectiveness of this new method is demonstrated through numerical examples. Furthermore, the time-dependent reliability analysis of corroded RC beams is compared using both the PH fitting method and the Monte Carlo simulation. The results reveal that the proposed method can accurately and efficiently deal with time-dependent reliability problems.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 4; art. no. 172442
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 376

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