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PL
Opracowano produkt powłokowy na bazie dyspersji alkidowej modyfikowanej uretanem z dodatkiem dyspersji siloksanowej, wzbogacony ekstraktami i olejkami roślinnymi, który nałożony na podłogę w kurniku, tworzy warstwę izolacyjną przeciwko patogenom. Powłoka korzystnie wpływa na wilgotność ściółki i zapylenie, a także parametry dobrostanu drobiu i wskaźniki zootechniczne hodowli wielkopowierzchniowej.
EN
A coating formulation based on com. urethane-modified alkyd and siloxane dispersions enriched with plant extracts and oils was developed and coated on a poultry house floor to create an insulating layer against pathogens. The coating had a beneficial effect on litter moisture and dust levels, as well as poultry welfare parameters and zootechnical indicators of large-scale breeding.
PL
W pracy przedstawiono przebieg i wyniki badań eksperymentalnych nośności konstrukcji powłokowej modelu podziemnego obiektu magazynowego. W przeprowadzonych badaniach wytrzymałościowych określono nośność konstrukcji modelu w wyniku oddziaływania ustalonego obciążenia siłą skupioną, a także wskazano na wielkości odkształceń elementów konstrukcyjnych modelu i zasypu gruntowego pod wpływem tego obciążenia. Ponadto określono wartość maksymalnego obciążenia, w wyniku którego uwidoczniły się na wewnętrznej powierzchni powłoki modelu, uszkodzenia w postaci rys i pęknięć. Badania eksperymentalne miały na celu potwierdzenie deklarowanej przez Producenta nośności konstrukcji i posłużą do wypracowania wniosków, mających na celu optymalizację technologii wytwarzania innych wyrobów przez producenta – Piwniczki Sp. z o.o.
EN
The paper presents the course and results of experimental tests of the load-bearing capacity of the shell structure of a model of an underground warehouse facility. In the strength tests carried out, the load-bearing capacity of the model structure was determined as a result of the impact of a fixed concentrated force load, and the amounts of deformation of the model’s structural elements and the soil backfill under the influence of this load were also indicated. In addition, the value of the maximum load was determined, as a result of which damage in the form of scratches and cracks was visible on the inner surface of the model coating. The experimental tests were aimed at confirming the load-bearing capacity of the structure declared by the manufacturer and will be used to develop conclusions aimed at optimizing the technology of producing other products by the manufacturer – Piwniczki Sp. z o.o.
EN
The paper describes the structural, optical, tribological, and mechanical properties of as‑prepared and annealed titanium dioxide (TiO₂) coatings. TiO₂ films were deposited by the electron beam evaporation (EBE) and additionally annealed at a temperature up to 800 °C using a tubular furnace. X-ray diffraction (XRD) analysis identified the amorphous phase of coatings as-prepared and annealed at 200 °C. The phase transition to anatase occurred at 400 °C, while annealing at 600 °C and 800 °C did not induce a phase transition to the rutile phase. The crystallite size increased with an annealing up to 40.4 nm at 800 °C. Raman spectroscopy confirmed the anatase phase in thin films annealed at 400 °C and above. A scanning electron microscope (SEM) images revealed surface morphology and grain structure changes after post-process high-temperature annealing. The optical transmission measurements showed a redshift in the fundamental absorption edge with increasing annealing temperature, accompanied by a decreased transparency level. The value of an optical band gap energy (Egopt) decreased to 2.77 eV for films annealed at 800 °C. Tribological tests revealed reduced scratch resistance with higher annealing temperatures, which was attributed to increased surface roughness and coating removal. Nanoindentation measurements showed a decrease in hardness with annealing temperature, attributed to changes in crystallite size and surface morphology. This comprehensive analysis of TiO2 thin-film coatings showed that the post-process annealing should be carefully controlled for films used in optoelectronic applications.
PL
W artykule przedstawiono badania dotyczące wpływu powłok Cr, Ti, Cr/Ti na właściwości tribologiczne stali X38CrMo16 stosowanej, m.in. do wytwarzania form wtryskowych. Powłoki uzyskano techniką fizycznego osadzania z fazy gazowej PVD. Zwilżalność powierzchni określono za pomocą tensjometru optycznego przy użyciu metody kropli siedzącej. Testy tribologiczne przeprowadzono za pomocą tribometru TRB3 w skojarzeniu trącym kula-tarcza w ruchu posuwisto-zwrotnym w warunkach tarcia technicznie suchego. Przeciwpróbkę w badanych węzłach tarcia stanowiła kulka ze stali 100Cr6. Po testach tarciowo-zużyciowych próbki poddano obserwacjom mikroskopowym. Wartości kątów zwilżania wodą demineralizowaną wskazały, że wszystkie badane powierzchnie charakteryzują się dobrą zwilżalnością. Na podstawie uzyskanych wyników badań tribologicznych stwierdzono, że powłoki charakteryzowały się mniejszymi oporami ruchu oraz zużyciem w porównaniu do stali X38CrMo16, przy czym najmniejsze wartości uzyskano dla powłoki Cr.
EN
In this paper the influence of Cr, Ti, Cr/Ti coatings on tribological properties of X38CrMo16 steel used, among others, for the production of injection molds were examined. The coatings were obtained by the PVD gas phase physical deposition technique. The wettability of the surface was determined by an optical strain gauge using the sedentary drop method. Tribological tests were performed with the TRB3 tribometer in reciprocating ball-disc friction combination under technically dry friction conditions . The counter-sample in the friction nodes tested was a 100Cr6 steel ball. After the friction and wear tests, the samples were subjected to microscopic observations. The values of the wetting angles with demineralized water indicated that all tested surfaces are characterized by good wettability. Based on the resuIts of tribological tests, it was found that the coatings were characterized by Iower resistance to movement and wear with respect to X38CrMo16 steel, with the lowest values obtained for the coating Cr.
EN
Pure magnesium, free from toxic elements, has been identified as a promising candidate for bioabsorbable orthopaedic devices. However, its rapid corrosion in physiological environments presents a significant challenge for practical applications. Chemical coatings, such as polydopamine (PDA), offer a potential solution to improve the corrosion resistance of pure magnesium. Nevertheless, the reaction conditions must be meticulously optimized, particularly in the presence of salts, as magnesium is highly sensitive to environmental factors. In this study, a PDA coating, widely investigated for improving the corrosion resistance of magnesium alloys, was applied to pure magnesium, avoiding the conventional Tris-HCl buffer. Instead, a 0.01 mol/L NaOH aqueous solution was used successfully to coat PDA layer on the surface of pure magnesium. The corrosion behaviour of PDA-coated magnesium was evaluated using electrochemical measurements and magnesium ion elution profiles in a tissue culture medium containing 5 vol% of fetal bovine serum at 37ºC. The results demonstrated that the PDA coating effectively mitigated early-stage corrosion of the pure magnesium substrate. This method provides a straightforward approach to enhancing the corrosion resistance of pure magnesium, and the PDA layer can also function as an intermediate platform for further biofunctional surface modifications, potentially expanding its applications in biomedical fields.
EN
The quality parameters of surface layers synthesised using electrospark alloying (ESA) technology were analysed in this paper. The main focus was on the influence of equipment energy parameters on structure formation, specifically the effect of discharge energy and productivity. Microstructural analysis of the modified surface of C40 steel after nitriding by ESA using a paste containing nitrogen compounds injected into the interelectrode gap was conducted. The layer structure for all studied ESA parameters includes three areas: the upper “white layer”, the diffusion zone below it, and the substrate. The roughness of the surface is Ra ∼ 0.9 µm at low discharge energy Wp = 0.13 J and Ra ∼ 6 µm at Wp = 3.4 J. The microhardness, continuity, and surface roughness of the layers varied with Wp. The influence of ESA productivity on the structure was studied. The thickness of the hardened layer and the diffusion zone, as well as the microhardness and continuity, are affected by reduced productivity. For the same discharge energy, the thickness of the hardened layer increases by 10-18% with a decrease in productivity compared to the classical mode. Studies have shown that productivity loss has a positive effect on the quality characteristics of the coatings produced by the ESA process.
EN
This work is a study aimed at optimizing the process of superarc metallization, with a focus on the effect of stress on the properties of the spraying coatings. In this work, 30HGSA grade steel wire was used for the coating of 45 steel, widely used in mechanical engineering. The use of supersonic arc metallizer SX-600 allowed to obtain coatings at different voltages (32 V, 38 V and 44 V) and the same current strength. Various metallization process parameters such as material feed rate, voltage, current, distance and nozzle geometry are discussed in this paper. Using various analytical techniques including X-ray diffraction analysis, microscopy, microhardness and corrosion resistance tests, the qualities of the coatings were evaluated. Particular attention was paid to analyzing the phase composition of the coatings, porosity, substrate bond strength and tribological characteristics. It was found that the voltage during the electric arc metallization process has a significant effect on these characteristics. The selected optimum voltage allows to obtain dense and homogeneous coatings with improved performance properties. The results of the study revealed that the best physical and mechanical properties were exhibited by the sample processed at 38 V, which showed lower porosity and improved strength characteristics compared to the other samples. These findings can be used to improve manufacturing processes in industries such as automotive and mechanical engineering, where restoration and improved performance of worn parts is required.
8
EN
The paper presents an analysis of the operational properties of paint coatings for use in military technology in the field of masking. The assessment of the properties was performed on the basis of measurements of the surface geometric structure and adhesion using the peel method. The measurements of specular gloss, colour in the range of 400-700 nm and reflectance in the range of 350-1200 nm were made in relation to the requirements of the Polish Defence Standard NO-80-A200. Coating systems are characterised by their low roughness and good adhesion. Due to their operational properties, the developed coating systems can be used on armaments and military equipment.
PL
Celem niniejszej pracy było zbadanie wpływu dodatku skrobi modyfiko-wanej na stabilność reologiczną mieszanek powlekających zawierających węglan wapnia. Wyznaczone zostały krzywe lepkości i krzywe płynięcia z uwzględnieniem czynnika czasu zarówno dla mieszanek, jak i roztworu skrobi modyfikowanej oraz dyspersji węglanu wapnia. Zawartość skrobi modyfikowanej w mieszankach powlekających wpływa na właściwości reologiczne tych mieszanek, zwiększając ich lepkość i naprężenie ścinające. Wykazano, że mimo reostabilnego charakteru roztworu skrobi i dyspersji węglanu wapnia przygotowane mieszanki powlekające okazały się być płynami reoniestabilnymi. Ich lepkość i naprężenie ścinające zmniejszały się przy wydłużeniu czasu ścinania, co świadczy o właściwościach tiksotropowych. Im większy był dodatek skrobi, tym większa była rozpiętość ramion pętli histerezy krzywych płynięcia i lepkości. A zatem, reologiczna niestabilność mieszanek powlekających wzrastała z dodatkiem skrobi.
EN
The rheological properties of coating color affect its flow behavior during technological process. If upon constant shearing, fluid properties do not change with time, the fluid exhibits rheological stability (rheo-stability). On the other hand, a fluid is said to exhibit rheological instability (rheo-instability) if shear time (for a given shearing conditions) affects its flow behavior. The objective of the conducted research was to examine the effect of modified starch on rheological instability of the coating colors. For this purpose, viscosity curves and flow curves were determined considering the time factor. Such experiments enabled to determine time-dependent rheology. Rheological tests were carried out for calcium carbonate-based coating colors with different starch content (1 pph, 2 pph, 5 pph and 10 pph) as well as for the raw materials used for their preparation, i.e. 10% solution of modified starch and 60% calcium carbonate dispersion. During the research, the rotary rheometer Brookfield RVDV - III+ with the Rheocalc V2.3 control software was used. The measurement principle is based on the determination of the torque for a given shear rate or rotational speed. The measuring element (e.g. spindle, coaxial cylinders), immersed in the test fluid, is set in rotation. A viscous liquid resists the measuring element by generating a torque which is a function of the apparent viscosity of the liquid. During the tests, both RV spindles and DIN coaxial cylinders were used, with the rotating inner cylinder and the stationary outer one. Programs in the B.E.A.V.I.S (Brookfield Engineering Advanced Viscometer Instruction Set) programming language were developed to control the rheometer and collect measurement results. This enabled the experiments to be performed automatically. In order to examine the influence of shear time on the flow and viscosity curves, measurements were made at time intervals of 10, 30 and 60 seconds (the measurement was carried out after 10, 30 or 60 s from the moment of changing the shear conditions, i.e. shear rate or rotational speed). The effect of time on viscosity for constant shear conditions was also investigated. Measurements were made within 4 minutes, and data were collected every 2 seconds. Time factor studies enabled to research rheo-stability and/or rheo-instability (time-dependent rheology). For all tested properties, at least 7 measurements were carried out, and the coefficients of variation did not exceed 4.75%. The starch solution exhibited rheo-stable shear-thinning behavior, whereas calcium carbonate dispersion was a rheo-stable shear thickening fluid. This means that the rheological properties of these liquids depended on shear field but did not depend on shear time (for a given shearing conditions). The content of modified starch in coating colors affects the rheological properties of these liquids, increasing their viscosity and shear stress. It was found that despite the rheo-stable character of both the starch solution and the calcium carbonate dispersion, the prepared coating colors were rheologically unstable as they exhibited time-dependent flow behavior. The viscosity of the coating colors decreased not only with the increase in rotational speed, but also with the increase in shear time. The decrease in their viscosity and shear stress with increasing shear time proves that the tested coating colors exhibited rheo-unstable thixotropic flow behaviors. Additionally, the higher the addition of starch was, the wider was the span of the hysteresis loop arms for both the flow and viscosity curves. Thus, the rheological instability increased with increasing starch content.
EN
The effect of fluoride use on the color change and surface characteristics of coated nickel and titanium (NiTi) orthodontic archwires was investigated. Epoxy resin, PTFE or rhodium-coated archwires were exposed to acidulated phosphate fluoride (APF) or sodium fluoride (NaF) or artificial saliva (AS), simulating three-month clinical trials. Color changes (ΔE) were assessed using a laboratory spectrophotometer in the three-dimensional CIELab color space. The roughness (Ra) and surface structure of the archwires were examined using a non-contact profilometer and scanning electron microscopy (SEM), respectively. Data were analyzed using two-way and one-way variance (ANOVA) and post-hoc Bonferroni test (α=0.05). The average values of ΔE and Ra were the highest for epoxy-APF archwires and the lowest for rhodium-AS archwires. A significant relationship was found between the archwires surface treatment method and the ΔE and Ra values. After three months, greater changes in color and roughness were observed with APF than with AS.
PL
Zbadano wpływ stosowania fluorków na zmianę koloru i charakterystykę powierzchni powlekanych łuków ortodontycznych z niklu i tytanu (NiTi). Łuki powlekane żywicą epoksydową, PTFE lub rodem poddano działaniu zakwaszonego fluorku fosforanu (APF) lub fluorku sodu (NaF) lub sztucznej śliny (AS), symulując trzymiesięczne próby kliniczne. Zmianę koloru (ΔE) oceniano za pomocą spektrofotometru laboratoryjnego w trójwymiarowej przestrzeni kolorów CIELab. Chropowatość (Ra) i strukturę powierzchni łuków badano za pomocą odpowiednio bezkontaktowego profilometru i skaningowej mikroskopii elektronowej (SEM). Do analizy danych zastosowano dwuczynnikową i jednoczynnikową wariancję (ANOVA) oraz test Bonferroniego post-hoc (α=0,05). Wartości średnie ΔE i Ra były największe dla łuków epoksydowych-APF, a najmniejsze dla rodowych-AS. Stwierdzono istotną zależność pomiędzy metodą obróbki powierzchni łuków a wartością ΔE i Ra. Po trzech miesiącach większe zmiany koloru i chropowatości zaobserwowano w przypadku działania APF niż AS.
EN
The effect of coating silica with polyethylene glycol on the adsorption of iron and phosphate ions in industrial wastewater was investigated. Variable factors were temperature and time of coating, PEG concentration, and PEG to silica ratio. Infrared spectroscopy and scanning electron microscopy were used to evaluate the chemical structure and morphology of PEG-coated silica. Optimum iron and phosphate ions removal efficiency was obtained using a coating temperature of 50°C, a coating time of 15 min, a PEG concentration of 20%, and a PEG to silica ratio of 1:3.
PL
Zbadano wpływ powlekania krzemionki glikolem polietylenowym na adsorpcję jonów żelaza i fosforanów ze ścieków przemysłowych. Czynnikami zmiennymi były temperatura i czas powlekania, stężenie PEG oraz stosunek PEG do krzemionki. Do oceny budowy chemicznej i struktury krzemionki powlekanej PEG stosowano spektroskopię w podczerwieni i skaningową mikroskopię elektronową. Optymalną skuteczność usuwania jonów żelaza i fosforanów uzyskano stosując temperaturę powlekania 50°C, czas powlekania 15 minut, stężenie PEG 20% oraz stosunek PEG do krzemionki 1:3.
EN
The study’s aim was to develop a novel sorbent for removing the color Congo red (CR) from water by precipitating (Mg/Al)-layered double hydroxide (LDH) at the nanoscale onto the waterworks sludge surface as a byproduct. To achieve an effective sorbent with the removal of over 91.19%, The utilization of nanoparticles, the addition of 1 g of sludge to 50 mL of water, and a molar ratio of 2 (Mg/Al) were the optimal production conditions for sorbent. In batch experiments, the optimal operating parameters were found to be 0.5 g of adsorbent in 50 mL of CR, pH of CR solution equal to 3, and a contact time of 3 hours at 200 rpm with 25 mg/L dyes. According to the study, the adsorption capacity was 23.576 mg/g. Additionally, the pseudo-second-order and Langmuir models provided accurate descriptions of the sorption data.
PL
W pracy przedstawiono ogólną charakterystykę piwniczek (ziemianek) jako obiektów podziemnych z głównym przeznaczeniem do przechowywania produktów spożywczych w celu przedłużenia ich trwałości. Wskazano na zalety funkcjonowania obiektów i korzyści związane z ich eksploatacją. Zwrócono uwagę na budowę obiektów w środowisku naturalnym i ciągłym kontakcie z naturą. Ponadto poruszono kwestie związane z trudnościami w jednoznacznym określeniu podstawowych wymagań formalnych dla piwniczek lub ziemianek, uwzględniając aktualnie obowiązujące przepisy w tym zakresie. W pracy dokonano także przeglądu technologii stosowanych podczas budowy podziemnych obiektów magazynowych typu ziemianka. Na przykładzie piwniczek wykonywanych w technologii PwK, wskazano na innowacyjność rozwiązań materiałowo-technicznych stosowanych w realizacjach piwniczek. W związku z dużym potencjałem technologii PwK przedstawiono interesujące tendencje rozwojowe i plany producentów. Całość opracowania podsumowano wnioskami, które dotyczą rozwoju i doskonalenia rozwiązań materiałowo-technicznych, wykorzystywanych przy budowie piwniczek w technologii PwK.
EN
The paper presents the general characteristics of cellars (dugouts) as underground facilities with the main purpose of storing food products in order to extend their durability. The advantages of the functioning of the facilities and the benefits associated with their operation were indicated. Attention was paid to the construction of objects in a natural environment and continuous contact with nature. Moreover, issues related to the difficulties in clearly defining the basic formal requirements for cellars or dugouts were raised, taking into account the current regulations in this regard. The work also reviews the technologies used during the construction of underground storage facilities of the dugout type. On the example of cellars made in the PwK technology, it was indicated on the innovativeness of materiaI and technical solutions used in the construction of cellars. Due to the great potential of the PwK technology, interesting development trends and manufacturers plans were presented. The entire study is summarized with conclusions regarding the development and improvement of material and technical solutions used in the construction of cellars (dugouts) in PwK technology.
EN
In this paper, polypyrrole coated conductive fabrics were prepared using pyrrole as the monomer, p-toluene sulfonic acid as the doping agent and ammonium persulfate as the oxidant, adopting the simple method of situ polymerization of the liquid phase. Six types of conductive polypyrrole coated fabrics were prepared adopting polyester-cotton blended fabrics, nylon fabrics, wool fabrics, silk fabrics, basalt fabrics and aramid fabric respectively as base materials and using the same process conditions; its electrical conductivity was compared, and the distribution and resistance of the washing fastness of polypyrrole on the surface of those fabrics were studied. Results showed that under the same process conditions, the conductivity of polypyrrole coated terylene fabrics was the best, followed by the polypyrrole coated nylon fabrics and polypyrrole coated wool fabrics. Observed by electron microscope, the distribution of polypyrrole was more homogeneous on different base cloths. After washing, it was concluded that the combination fastness of polypyrrole with polyester-cotton, nylon and wool was better, while the combination fastness of polypyrrole with basalt and aramid was poor.
EN
Surface coating technology, as the main technology to improve the fatigue life of mechanical systems, has been well applied in mechanical equipment. The present study aimed to explore low-cost surface coating preparation technology using inexpensive rice husk as the research object, and the pyrolysis process behavior of rice husk was analyzed. The Ni60/SiO2 coating was prepared on the surface of the 45# steel substrate using the pyrolysis product SiO2 fiber as the reinforcing phase and supersonic plasma-spraying equipment. The results showed no defects such as cracks, pores, and inclusions in the prepared coating. The nanohardness of the Ni60/SiO2 coating reached 6506 μN, and the average friction coefficient reached 0.42. In the friction-and-wear experiment, the Ni60/SiO2 coating was manifested as an abrasive wear mechanism.
EN
Purpose: Measurement of the adhesion of a Ti coating applied by cold spraying on metal substrates with different elastic modulus. An attempt to analytically describe the experimental results, considering cold gas spray parameters such as working gas, pressure p and temperature T. Design/methodology/approach: Ti coating was sprayed on flat bars made of metal: copper, magnesium, brass, titanium, Al 7075, Al 2024 and steel with dimensions of 4x50x400 mm. All coatings were applied under the same spray conditions (p = 3.8 MPa, T = 800ºC, spray distance l = 50 mm, and spray spead V = 400 mm/s). The state of plastic deformation of coatings and substrates was examined using optical methods, and the adhesion strength was measured with the POSITEST tester. Findings: The experimental results are presented graphically. The adhesion force as a function of the relative modulus of elasticity showed a maximum. At this time, the mutual penetration depth of the coating and the substrate showed a minimum. The extremes of the relationships mentioned above occurred for points where the relative modulus of elasticity took the value one. The curve described by formula (1) was fitted to the distribution of adhesion points as a function of the relative elastic modulus. The function parameter described by formula (1) is related to the spray parameters (p, T). Research limitations/implications: To achieve a better accuracy of the analytical description of the adhesion of coatings deposited with cold gas, tests should be carried out on a larger number of substrates. The validity of the presented interpretation should be checked by applying coatings from other materials. Practical implications: In coating technologies, adhesion is a key concept. A coating with high adhesion strength is used primarily in regeneration and anti-corrosion protection processes. The analytical relationship between adhesion, relative modulus of elasticity and cold gas spray parameters will significantly speed up the selection of optimal spray parameters. Cold spray technology is a cost-intensive technology, so the economic element is not without significance. Originality/value: The article presents a method for limiting the number of variables on which the quality of the applied coatings depends. The relationship between the adhesion force, the relative elastic modulus and the selected spray parameters are indicated.
EN
An analysis of the operating conditions of gas turbine engines, their components, and the destruction causes was carried out. The designer problems of tribo-joints operating under difficult conditions of force and temperature loads are singled out. The study aimed at obtaining the comparable quantitative dependences of blade material wear, taking into account the role of both cyclical changes in the temperature of the gas flow under the conditions close to real ones, and their frictional characteristics. Deformable heat-resistant nickel alloys and foundry heat-resistant nickel alloys from which T-shaped samples were made, were chosen for the research. The tests were carried out on the developed gas dynamic stand, which simulates the working conditions of the bandage joints of the bladed turbomachines of gas turbine installations. The intensity of wear was determined as the ratio of the worn material volume to the number of load cycles under different temperature conditions. The wear resistance of three-way connections operating under the conditions of non-stationary thermal loads and fluctuations in the contact was considered. It was shown that thermal cycling leads to a decrease in the wear resistance of heat-resistant nickel alloys by 2–3 times and depends on the average temperature of the cycle. It was found that resistance to the wear, and also the character of change of coefficient of friction is mainly determined by the terms of education and destruction of the protective superficial layer. Basic factors managing tribology processes in the zone of contact were determined.
EN
Phenol is an internal browning (IB) enzymatic reaction substrate and endogenous abscisic acid (ABA) used to suppress IB incidence in the Comte de Paris cultivar (Queen type). There is no information on the correlation between pineapple IB to endogenous total phenol content (TPC), ABA, and gibberellic acid 3 (GA3) after postharvest applications of decrowning. Therefore, this research aimed to analyze the relationship of IB incidence to total TPC, ABA, and GA3 after postharvest treatments of decrowning and coating in GP3 and MD2 pineapple clones. The structure was based on a completely randomized design with 3 factors, namely clone (GP3 and MD2), decrowning (crown and crownless), and coating [50 mg L-1 ABA, 1% chitosan, ABA+Chitosan mixture, and control (H2O)]. The results showed that the MD2 had a lower IB incidence and higher TPC than the GP3 stored at 7°C for 37 days. The increased TPC was positively correlated with IB incidence. TPC was also negatively correlated with ABA but positively with endogenous GA3 2 weeks earlier. Coating with 50 mg L-1 ABA and 1% chitosan on MD2 decreased IB incidence. Pineapple crown pruning decreased ABA and increased TPC, GA3, and IB incidence.
EN
Cavendish banana is a climacteric fruit with a fast response to ethylene and a very high respiration rate during storage. Previous studies revealed that these characteristics shortened the green-life and fastened fruit damage, affecting the economic value. Therefore, this study aims to examine the effects of fruit maturity levels, coatings, and storage temperatures on the qualities and green-life of Cavendish banana. The result showed that the level of fruit maturity significantly increased the green-life duration, as well as maintained firmness, diameter loss, acidity, and starch content, but it had no effect on weight loss, oBrix, and glucose. Meanwhile, low temperature was able to delay senescence, promote starch degradation, as well as detain firmness and diameter loss. The results also showed that the combined application of maturity levels + temperatures affected all parameters, while maturities + coatings as well as coatings + storage had effects on firmness, acidity, and starch content. The 1% chitosan coating coverage was analyzed with a Scanning Electron Microscope (SEM), which showed fully covered surface of M1 finger rind tip and some crack points on finger rind base. Furthermore, there was full coverage on M2, and some crack points on M3.
EN
The present study discusses the influence of an a-C:H coating on the tribological parameters of sliding pairs under mixed friction. Using the PVD method, the a-C:H coating was formed on specimens made from AISI 4337 steel. The sliding friction and wear process was carried out on the pairs of AISI 4337 steel and SAE48 bearing alloy, which were lubricated with 10W40 biodegradable engine oil. The investigation showed significant differences in the friction coefficient and temperature in the tested pairs with the steel surface layer and the a-C:H coating. In the friction pairs with the a-C:H coating, the tested parameters of friction were higher than in pairs with the steel surface layer. The pairs with the a-C:H coating showed more intensive wear of the SAE-48 bearing alloy than those with a steel surface. The surface layer used in a friction pair leads to the deterioration of the lubricating properties of engine oil and reduces its resistance to scuffing.
PL
W pracy przedstawiono wpływ powłoki a-C:H na parametry tribologiczne par ciernych w warunkach tarcia mieszanego. Powłoka a-C:H została wytworzona na próbkach wykonanych ze stali AISI 4337 metodą PVD. Proces tarcia ślizgowego i zużycia realizowano w skojarzeniu stal AISI 4337 i stop łożyskowy SAE-48 smarowanych biodegradowalnym olejem silnikowym 10W40. Badania wykazały istotne różnice w wartości współczynnika tarcia i temperatury w badanych parach ze stalową warstwą wierzchnią i powłoką a-C:H. W parach z powłoką a-C:H rejestrowane parametry tarcia były wyższe niż w parach ze stalową warstwą wierzchnią. Pary z powłoką a-C:H wykazywały intensywniejsze zużycie stopu łożyskowego SAE-48 niż pary z powierzchnią stalową. Warstwa wierzchnia zastosowana w parze ciernej prowadzi do pogorszenia właściwości smarnych oleju silnikowego i zmniejsza jego odporność na zacieranie.
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