Wyniki wyszukiwania - BazTech

1

Nanocząstki krzemionki jako dodatki do środków smarowych : przegląd literaturowy

Korasiak Kamil, Woch Julia, Scudło Ilona, Szymańska Katarzyna

Przemysł Chemiczny

|

2024

|

T. 103, nr 5

625--630

PL

Przedstawiono zastosowanie nanocząstek krzemionki, w szczególności jako dodatków do środków smarowych. W doniesieniach literaturowych przeważa ich zastosowanie jako nośników katalizatorów i napełniaczy polimerów. Jednym z nowych, rozwijających się obszarów zastosowania nanocząstek krzemionki są dodatki do środków smarowych, w których pełnią one funkcje m.in. zagęszczaczy i dodatków przeciwzużyciowych. Przedstawiono potencjalne korzyści ze stosowania nanocząstek krzemionki jako dodatków do środków smarowych, poparte publikowanymi w literaturze wynikami badań trybologicznych. Przedstawiono najważniejsze wyzwania związane z otrzymywaniem dyspersji zawierających nanocząstki krzemionki, z których najważniejsze są: przeciwdziałanie utracie stabilności oraz określenie wpływu funkcjonalizacji krzemionki na właściwości dyspersji.

EN

A rev., with 69 refs., of research on the possibility of using SiO₂ nanoparticles as additives to lubricants, in which they act as thickeners and anti-wear additives. The effect of functionalization of SiO₂ nanoparticles on tribol. properties of lubricants such as coeff. of friction and antiwear properties was discussed. The most important challenges in obtaining dispersions contg. SiO₂ nanoparticles were presented, the most essential of which were counteracting stability loss and detg. the effect of SiO₂ functionalization on dispersion properties.

2

Wpływ modyfikacji zaprawy cementowej wybranymi nanocząstkami na ścieralność i przypowierzchniową wytrzymałość na rozciąganie

Szymanowski Jacek

Materiały Budowlane

|

2024

|

nr 6

8--11

PL

W artykule przedstawiono analizę wpływu wybranych nanocząstek na określone parametry zaprawy warstwy wierzchniej podłogi betonowej. Badania zostały przeprowadzone na 13 seriach zapraw różniących się rodzajem dodatku oraz jego ilością. Wykazano, że dodatek każdej z badanych nanocząstek wpływa korzystnie na takie właściwości warstwy wierzchniej, jak ścieralność i przypowierzchniowa wytrzymałość na rozciąganie oraz określono optymalną ilość dodatku w przypadku każdego rodzaju nanocząstek.

EN

The article presents an analysis of the impact of selected nanoparticles on selected mortar overlay parameters in concrete floors. The tests were carried out for 13 series of mortars differing in the type of additive and its amount. It was shown that the addition of each of the tested nanoparticles had a positive effect on the overlay properties, such as abrasion and subsurface tensile strength, and the optimal amount of the additive for each type of nanoparticles was indicated.

3

Optimizing the MBBR System and Integrating Nanoparticles to Improve Wastewater Treatment Efficiency

Eid Ahmed, El-sayed Abd-Elaziz, Ayoub Mohamed, El-Morsy Ahmed

Ecological Engineering & Environmental Technology

|

2024

|

Vol. 25, iss. 2

218--229

EN

Wastewater treatment faces a growing challenge in removing nutrients and organic matter. This study aimed to evaluate the effectiveness of the moving bed biofilm reactor (MBBR) system in removing nutrients and organic from municipal wastewater. The impact of different carrier filling ratios and hydraulic retention times (HRT) on the removal efficiency was systematically investigated. Moreover, the addition of nanoparticle additives to enhance system performance was evaluated. The optimal conditions for the MBBR system were 30–45% filling ratios and a 10-hour HRT, resulting in maximum removal efficiencies for biological oxygen demand (BOD5), chemical oxygen demand (COD) and ammonia (NH4 + -N) with a percentage of 85.23%, 81.69%, and 54.45% respectively. Furthermore, adding nanoparticles improved the BOD5 and COD removal efficiencies by 6.6% and 8.0% respectively, compared to the MBBR system without nanoparticles.

4

Green Nanofertilizers – The Need for Modern Agriculture, Intelligent, and Environmentally-Friendly Approaches

Al Tawaha Abdel Rahman Mohammad, Singh Abhishek, Rajput Vishnu D., Varshney Ashi, Agrawal Shreni, Ghazaryan Karen, Minkina Tatiana, Al Zoubi Omar Mahmoud, Habeeb Talaat, Dionis Lysenko, Hasan Hanan Aref, Shawaqfeh Samar

Ecological Engineering & Environmental Technology

|

2024

|

Vol. 25, iss. 1

1--21

EN

The distinctive qualities and wide array of possible applications of nanotechnology have garnered considerable attention. Nanotechnology offers a groundbreaking way for expanding agricultural output that is also ecologically benign, helpful to living things, and economically priced – all without losing quality. There is a growing trend towards using eco-friendly technologies as substitutes for conventional agricultural inputs, such as fertilizers and insecticides. With the aid of nanotechnology, the confines of conventional farming techniques can be overcome. As a result, it becomes essential for investigators to devote their energies to the noteworthy nanoparticles (NPs) in agriculture investigations that have been distributed. It offered a fresh perspective on the development and application of nanoparticles as nano-fertilizers and nano-pesticides in agriculture and a way to heighten bio-factor execution. Furthermore, we discuss the relations of NPs with plants, the perils and putrefaction of nanomaterials in plants, and the utility of NPs in the reduction of stress triggered by heavy metal toxicity and abiotic factors. It is imperative that nano-fertilizers are practiced to reduce the environmental maltreatment caused by conventional, inorganic fertilizers. Nano-fertilizers are more sensitive and have the ability to penetrate the epidermis, empowering them to promote nutrient consumption efficiency while reducing nutrient overabundance. A study found that NPs may cause oxidative stress symptoms in higher plants if they adhere to cell surfaces or organelles. Understanding the benefits and drawbacks of using nano-fertilizers instead of conventional fertilizers is valuable, and it is the purpose of this book chapter to provide this information.

5

Characterization of Metallic Gold Nanoparticles in a Colloidal State by Artificial Vision

Carbajal-Morán Hipólito, Galván-Maldonado Carlos A., Márquez-Camarena Javier F.

Ecological Engineering & Environmental Technology

|

2024

|

Vol. 25, iss. 3

287--296

EN

Gold nanoparticles in their colloidal state have different colors, and the equipment for their characterization, such as UV-Vis spectrophotometers, scanning electron microscopy (SEM), and transmission electron microscopy (TEM), has high costs. The research aimed to characterize metallic gold nanoparticles by artificial vision based on the color of the samples in the colloidal state. The sensor used for the sampling was a 50 MP triple-lens camera with the optical image stabilization (OIS) of a smartphone. The Vision Acquisition and Vision Assistant blocks in the NI LabVIEW platform were used to implement an artificial vision device. The camera interface was used to identify the color of each of the 10 samples of colloidal gold nanoparticles produced by the YAG laser and chemical reduction in 15 ml of deionized water. The characterization consisted of the determination of the size and concentration of the gold nanoparticles based on their color, which ranged from pink to red wine. As a result, the artificial Vision device adequately identified the color of the metallic gold nanoparticles in a colloidal state with a certainty of more than 95%, allowing the nanoparticles to be adequately characterized. Therefore, it is concluded that artificial Vision adequately characterized gold nanoparticles’ wavelength, absorbance, diameter, and concentration.

6

CFD-FSI analysis of textured journal bearing working with nano lubricant

Hameed Mohanad Ramadhan, Ali Sarmad Ahmed, Hadwan Hamid Hussain, Toman Ahmed Ali, Mahdi Mushrek A.

Diagnostyka

|

2024

|

Vol. 25, No. 2

art. no. 2024212

EN

This research aims to examine the compound impact of adding rectangular textures to various zones on the surface of the bearing and nanoparticles in the lubricant on the properties of journal bearing. A lubrication models with various texture depths and eccentricity ratios of journal bearing are created and simulated using CFD-FSI method to get static properties like load capacity and frictional force. Aluminum oxide nanoparticles were added in weight ratios ranging from 0.1 to 0.5 %, and the change in viscosity due to these additives in the lubricant was considered. Cavitation and the dependence of viscosity on temperature effects are also considered. The validation results show that the acquired results from the current simulation method agree well with the experimental results in the reference. The outcomes indicated that the highest load capacity and the lowest frictional force are found in the high-pressure region. It was noted that the maximum rise in load capacity was 16.51% without nanoparticles at a texture depth of 0.5 mm and eccentricity ratio of 0.1, and with the adding of 0.5 wt. % of nanoparticles to the lubricant in the same region, the load carrying capacity increased to 40.87 % compared to a bearing without textures.

7

Microplastics from Plastic Waste as a Limitation of Sustainability of the Environment

Grąz Katarzyna, Generowicz Agnieszka, Kwaśny Justyna, Gronba-Chyła Anna, Kwaśnicki Paweł, Ciuła Józef, Łapiński Jacek, Bajdur Wioletta

Rocznik Ochrona Środowiska

|

2023

|

Tom 25

367--373

EN

The massive emergence of plastics has contributed to their widespread use in everyday life. Unfortunately, the lack of appropriate technologies for processing these materials has contributed to environmental pollution by plastic particles. This study investigated the possibility of obtaining nanoparticles from selected plastics such as polyethylene and polyethylene terephthalate. Polyethylene was obtained from plastic bag waste, and polyethylene terephthalate was from crushed plastic bottles of mineral water. The first stage of nanoparticle production was to grind the collected used plastic waste, i.e., plastic bags and plastic bottles, to the smallest possible size using a cutting mill. Next, the waste was ground in a planetary-ball mill and then homogenised in a homogeniser. The particle size distribution of the obtained particles for selected waste plastics was examined using the Dynamic Light Scattering (DLS) method. The objective of the work was achieved – as a result of the performed procedures, nanoparticles of waste plastics were obtained. The following average sizes for particular materials were obtained: plastic bottles (PET) 212.81 nm, plastic bags (PE) 208.14 nm, and smaller particles, e.g. 27.74 nm.

8

Novel multicomponent functionalized biopolymers with enhanced thermal and dielectric properties

Rani Sanjeeta, Ali Syed Kashif, Kumar Pawan, Anugrah Kunwar Sugam, Saya Laishram, Gambhir Geetu, Gautam Drashya, Hooda Sunita, Verma Manisha

Polimery

|

2023

|

Vol. 68, nr 7-8

386--395

EN

A new functionalized biopolymer was obtained by modifying chitin using ethylenediaminetetraacetic acid and magnetite nanoparticles (Fe3O4). Thermogravimetric analysis was performed, and dielectric properties were examined. The obtained biopolymer showed better thermal stability, as evidenced by a higher onset temperature. The activation energy calculated using imaginary impedance data and Nyquist plots was found to be consistent. Moreover, the dielectric permittivity decreased rapidly with increasing frequency. At high frequencies, there was no dependence of dielectric loss on temperature and frequency. The obtained biopolymer can be used in many applications such as microwave devices, deflection yoke, high-frequency capacitors, sensors, etc.

PL

Otrzymano nowy funkcjonalizowany biopolimer poprzez modyfikację chityny przy użyciu kwasu etylenodiaminotetraoctowego i nanocząstek magnetytu (Fe3O4). Przeprowadzono analizę termograwimetryczną i zbadano właściwości dielektryczne. Otrzymany biopolimer wykazywał lepszą stabilność termiczną, o czym świadczyła wyższa temperatura początku rozkładu. Wykazano zgodność energii aktywacji obliczonej z wykorzystaniem danych dotyczących urojonej impedancji oraz na podstawie wykresów Nyquista. Przenikalność dielektryczna zmniejszała się gwałtownie wraz ze wzrostem częstotliwości. Przy wysokich częstotliwościach nie stwierdzono zależności stratności dielektrycznej od temperatury i częstotliwości. Otrzymany biopolimer można wykorzystać w wielu zastosowaniach, takich jak urządzenia mikrofalowe, jarzmo odchylające, kondensatory wysokiej częstotliwości, czujniki itp.

9

Effect of Magnetite Oxide Nanoparticles and Tungsten Oxide Nanoparticles on Phosphate Removal from Aqueous Solutions

EL-Baz Amro, Mokhtar Mona, Abdo Ahmed

Journal of Ecological Engineering

|

2023

|

Vol. 24, nr 3

287--303

EN

Phosphate (P) removal from aqueous solutions were studied by a new mineral adsorbent, tungsten (VI) oxide (WO3) nanoparticles (NPs), which has not been the subject of much research in the field of removing P contaminants from agricultural wastewater. In this paper, P was removed from aqueous solutions by a new mineral adsorbent, WO3 NPs and it was compared with magnetite (iron IV) oxide (Fe3O4) nanoparticles (NPs) under the same ambient operating conditions i.e., The influence of the dosage of adsorbents, initial P concentration, contact time, pH and temperature. The values that achieved the best removal were recorded. It was concluded that the best limits for pH were at 2–3, contact time at 40 minutes, temperature at 45 °C and adsorbent dose at 1.0 g/L. Best results of the variables were applied on samples of real agricultural wastewater, which achieved removal ratio of 77.3% and 75.42% for Fe3O4 and WO3 NPs, respectively. SEM, EDX and FTIR images and analyses were conducted to describe the characteristics of nano-adsorbents used before and after P adsorption in aqueous solutions. The P adsorption kinetics for aqueous solutions were examined by fitting results of the experiment to both the first & second pseudo-kinetically models. The outcome indicated that kinematic data fit better with pseudo-second-order kinetic models. Moreover, the information captured from equilibrium adsorption was analyzed using isothermal methods (by Langmuir & Freundlich Forms). Their results showed that the Freundlich form is considered more suitable than Langmuir form in analyzing the biosorption of P ions. The thermodynamic demeanor of P adsorption by Fe3O4 and WO3 NPs was analyzed and evaluated, and the thermodynamic data analyses confirmed the process of P adsorption was spontaneous. The ΔG° value was negative, while ΔH° and ΔS° values found to be positive, which means that the adsorption of P was a spontaneous, random and endothermic operation. In general, Fe3O4 and WO3 nanoparticles had a high efficiency in removing phosphate from water. In addition, WO3 NPs has been identified as one of the most promising adsorbents due to its rapid and effective adsorption of pollutants.

10

Combined Effect of Silicon Dioxide and Titanium Dioxide Nanoparticles on Concrete Properties

Al-Rbaihat Raed, Al-Marafi Mohammad Nour

Journal of Ecological Engineering

|

2023

|

Vol. 24, nr 12

319--335

EN

Nanoconcrete is an attractive research area because of its recent practical applications in building materials technologies. This study investigates the individual and combined effects of using nanoparticles in concrete mixtures as a cement substitute. Microscopic images are also used to determine changes in the microstructure of modified concrete in the present study. Concrete’s thermal and mechanical properties, including thermal conductivity (k), specific heat capacity (C), thermal diffusivity (α), and compressive strength (σ), are the leading concrete characteristics examined. The current study used different percentages (0%, 1%, 3%, and 5%) of nano-SiO2, nano-TiO2, and combined nano-SiO2/TiO2 particles as cement substitutes for 7 and 28 days of curing to examine the characteristics of nanoconcrete compared to conventional concrete (CC). The results indicated that adding individual nanoparticles to CC could improve concrete’s thermal and mechanical properties. Among the investigated nanomaterials (nano-SiO2, nano-TiO2, and combined nano-SiO2/TiO2 particles), nano-SiO2 was superior in that context. The optimal thermal properties of nanoconcrete were achieved when 5% nano-SiO2 (C-S5 specimen) was added. The k and α coefficients of sample C-S5 compared to the CC specimen were reduced by 65.6% and 80.3%, respectively, while the C coefficient was increased by 12.8%. Meanwhile, the optimal compressive strength coefficient of nanoconcrete was achieved when 3% nano-SiO2 (C-S3 specimen) was added, where the compressive strength coefficient of sample C-S3 compared to sample CC was increased by 19.6%. In contrast, for the combined effect, the thermal properties of concrete were improved, but the compressive strength coefficient of concrete was reduced. Overall, the present experimental findings offer valuable information about the impact of nanotechnology on high-performance concrete to save energy in buildings.

11

Analysis of the Influence of an XY Electronic Mechanism with UV-Vis Spectroscopy on the Production of Gold Nanoparticles by Laser Ablation for Applications in Environmental Nanosensing

Carbajal-Morán Hipólito, Márquez-Camarena Javier F., Ingaruca-Álvarez Ever F., Zárate-Quiñones Rosa H.

Journal of Ecological Engineering

|

2023

|

Vol. 24, nr 8

52--61

EN

The work consisted in analyzing the influence of an electronic positioning mechanism of an Au metal plate in the XY axes; to optimize the production of Au metal nanoparticles by laser ablation in sterile water samples as well as to obtain morphology and size required for environmental nanosensors. The positioning mechanism is constituted by two M35SP stepper motors of 5 V DC with a rotation angle of 7.5° per step; the one that generates the displacement for each axis of XY coordinates, controlled by an algorithm implemented in Arduino Nano ATmega328, being the driver of the stepper motors the H-bridge of the L298N module, with which it was possible to set the speed to 2 mm/s, which enabled to make the wear of the metal plate uniform in the process of generation of gold nanoparticles (AuNPs). With the pulsed laser generator with ablation frequency of 10 Hz and wavelengths of 532 nm and 1064 nm, the Au metal plate was irradiated for 10 min, 20 min and 30 min. AuNPs were generated in colloidal state both for the process with fixed position of the metal plate and for the process using the electronic mechanism of XY positioning; they were characterized by UV-Vis spectroscopy with range from 300 nm to 850 nm. It was found that the production of AuNPs with the Au plates mobilized by the mechanism under study, generates colloids of spherical AuNPs of smaller diameter, close to 10 nm, with an average reduction of 19% in relation to that generated with the fixed position plate; likewise, the concentration of the AuNPs increased by 20.40%; therefore, the influence of the XY positioning electronic mechanism was positive in the production of AuNPs with morphology and sizes suitable for use in environmental nanosensors.

12

Nowa era medycyny. Potencjał i innowacje nanonośników leku

Sala Katarzyna, Ziarkowska Maria, Ruta-Kowalczyk Dagmara, Galas Julia, Bańkosz Magdalena, Tyliszczak Bożena

Inżynieria Materiałowa

|

2023

|

Vol. 44, nr 6

5--11

PL

Artykuł koncentruje się na rozwijającym się polu nanomedycyny i jej wpływie na nowoczesne leczenie. Celem pracy jest przedstawienie przeglądu najnowszych osiągnięć i potencjalnych zastosowań nanonośników lekowych w medycynie. Artykuł rozpoczyna się od wprowadzenia w podstawowe koncepcje nanotechnologii i jej zastosowania w dostarczaniu leków. Następnie omawiane są różne typy nanonośników, w tym liposomy, dendrymery, nanocząstki metaliczne i polimerowe, wraz z ich unikalnymi właściwościami i mechanizmami działania. Podkreślono również wyzwania i ograniczenia związane z rozwojem i wdrożeniem nanonośników lekowych, takie jak toksyczność, stabilność i specyficzność dostarczania. Podkreślono znaczenie nanonośników i ich potencjalną rolę w przełomowych terapiach i indywidualizowanym leczeniu. Celem tego przeglądu jest zwiększenie świadomości na temat obecnego stanu nanomedycyny.

EN

The article focuses on the growing field of nanomedicine and its impact on modern medical treatment. The purpose of the paper is to provide an overview of recent developments and potential applications of drug nanocarriers in medicine. The article begins with an introduction to the basic concepts of nanotechnology and its applications in drug delivery. It then discusses various types of nanocarriers, including liposomes, dendrimers, metallic and polymeric nanoparticles, along with their unique properties and mechanisms of action. Challenges and limitations associated with the development and implementation of drug nanocarriers, such as toxicity, stability and specificity of delivery, were also highlighted. The importance of nanocarriers and their potential role in breakthrough therapies and individualized treatment is highlighted. The goal of this review is to raise awareness of the current state of nanomedicine.

13

Herbal Extract-Induced Silver Nanoparticles for Antibacterial Cotton Fabric

Rajput Sanjeev Kumar, Singh Mukesh Kumar, Shakyawar Dinesh Babu

Fibres & Textiles in Eastern Europe

|

2023

|

Vol. 31, no. 3

22--29

EN

Herbal extract-induced metallic nanoparticles have replaced the traditionally synthesized nanoparticles to achieve sustainability in antimicrobial textiles. Silver nanoparticles (NPs) were created by the bio-reducion of silver nitrate with eucalyptus corymbia leaf extract. The bi-lateral activities of herbal extract, like the reduction and capping of silver nanoparticles, have added new dimensions in the bactericidal sector. Silver nanoparticles were characterized by UV-visible spectroscopy, a particle size analyzer, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and X-ray diffractometry. In this study these biosynthesized nanoparticles were applied on cotton fabric alone and along with chitosan by the pad-dry-cure method to create antibacterial clothing. Antibacterial efficiency was characterized using the colony counting method (serial dilution method). The treated fabric shows excellent antibacterial efficiency.

14

Free vibration analysis of composite face sandwich plate strengthens by Al2O3 and SiO2 nanoparticles materials

Al-Shablle Marwan, Njim Emad Kadum, Jweeg Mushin J., Al-Waily Muhannad

Diagnostyka

|

2023

|

Vol. 24, No. 2

art. no. 2023205

EN

The main novelty of the paper is that analytical, experimental, and numerical analyses are used to investigate the free vibration problem of a sandwich structure in which Nanocomposites skins (SiO2/epoxy and Al2O3/epoxy) at different densities are used as the face sheet. The volume fraction's of nanoparticle addition varies (0% to 2.5%). The present free vibration was derived based on Kirchhoff's theory and aspiration to obtain the natural frequency. The results show that in structures with SiO2 nanoparticles with a density of 1180 kg⁄m3, the optimum increase (VF = 2.5%) is 50% in Young's modulus and 22% in natural frequency, while at a density of 1210 kg⁄m3 is 56 % in Young's modulus and 24.5% in natural frequency. Furthermore, the same structures reinforced with Al2O3 Nano-particles show that at the density of 1180 kg⁄m3 , the optimum (VF=2.5%) parentage increase in Young's modulus is 41% and 19% in natural frequency, while at the density of 1210 kg⁄m3 is 46% in Young's modulus and 21% in natural frequency. A numerical investigation was used to validate the obtained results of the analytical solution. The findings also show an acceptable convergence between analytical and numerical techniques with a maximum discrepancy not exceeding 3%.

15

Przegląd zastosowania nanopłynów oraz materiałów porowatych w pośrednim chłodzeniu wyparnym

Stefaniak Łukasz, Rajski Krzysztof, Danielewicz Jan

Ciepłownictwo, Ogrzewnictwo, Wentylacja

|

2023

|

T. 54, nr 12

33--40

PL

Pośrednie chłodzenie wyparne staje się coraz bardziej popularne ze względu na wykorzystanie przyjaznych dla środowiska czynników chłodniczych: powietrza (R-729) i wody (R-718). Istotą procesu jest wymiana ciepła i masy, która zachodzi w wymienniku. Opracowania zagraniczne szeroko opisują nowoczesne technologie wspomagające ten proces, podczas gdy polskojęzyczna literatura nie porusza zagadnienia niemalże w ogóle. W artykule skupiono się na dwóch głównych innowacjach wynikających z przeglądu literatury (od 2010 roku): wprowadzeniu nanopłynów opartych na wodzie oraz zastosowaniu materiałów porowatych na powierzchni kanału mokrego. Przeanalizowano kluczowe parametry stosowane do opisu urządzeń do chłodzenia wyparnego takie jak sprawności: termometru mokrego, punktu rosy oraz egzergetyczną, wydajność chłodniczą, EER oraz COP. Przedstawiono wyniki badań nanopłynów jedno-, dwu- i trzyskładnikowych. Analiza wykazała poprawę parametrów charakteryzujących pośrednie urządzenia wyparne wynoszące od kilku do kilkudziesięciu procent przy zastosowaniu nanopłynów w zależności od temperatury powietrza na wlocie. Dokonano przeglądu stosowanych materiałów porowatych stanowiących powierzchnie kanału mokrego. Wydzielono cztery główne typy stosowanych materiałów: porowate ceramiczne oraz włókna naturalne, polimerowe i tekstylne. Zestawiono wady oraz zalety stosowania tych materiałów w wymiennikach pośrednich w celu ułatwienia wyboru rodzaju materiału. Określono, że spośród dwóch omawianych modyfikacji w pierwszej kolejności należy skupić się na aplikacji materiałów porowatych, jako że są one związane bezpośrednio z konstrukcją wymiennika. Natomiast nanopłyny można zastosować w urządzeniach istniejących. W podsumowaniu stwierdzono, że rozwój technologii pośredniego chłodzenia wyparnego może stanowić istotne oraz ekologiczne uzupełnienie obecnie stosowanych sprężarkowych systemów chłodzenia.

EN

Indirect evaporative cooling is becoming increasingly popular due to the use of environmentally friendly refrigerants: air (R-729) and water (R-718). The main idea of the process is the heat and mass transfer that takes place in the exchanger. Foreign studies extensively describe modern technologies supporting this process, while the Polish-language literature does not cover the issue almost at all. The article focuses on two main innovations resulting from the literature review (as of 2010): the introduction of water-based nanofluids and the use of porous materials on the surface of the wet channel. Main parameters used to describe evaporative cooling devices include wet thermometer, dew point, and exergetic efficiencies, cooling capacity, EER, and COP. Results for single-, two-, and three-component nanofluids are presented. The analysis showed performance improvements for indirect evaporative units of several to tens of percent with nanofluids, depending on the inlet air temperature. The applied porous materials used on the surface of the wet channel were reviewed. Four main types of materials used have been distinguished: porous ceramic and natural fibers, polymer fibers, and fabric fibers. The advantages and disadvantages of using these materials in indirect heat exchangers were summarized to facilitate the choice of material type. It was determined that of the two modifications discussed, the application of porous materials should be focused on first, since they are directly related to the construction of the heat exchanger. In contrast, nanofluids can be applied to existing devices. Eventually, it was pointed out that the development of indirect evaporative cooling technology can be an important and ecological complement to the currently used compressor systems.

16

Thermal Decomposition of Ammonium Perchlorate Encapsulated with Copper(II)/Iron(III) Oxide Nanoparticles

Gržetić Jelena D., Mijatov Slavko, Fidanovski Bojana, Kovačević Tihomir, Pavlović Vladimir B., Brzić Saša, Bajić Danica

Central European Journal of Energetic Materials

|

2023

|

Vol. 20, no. 2

114-137

EN

Thermal decomposition of ammonium perchlorate (AP), as a high energy oxidizer in composite solid rocket propellants (CSRP), greatly affects the burning rate of the propellant. This paper summarizes the results of a study of the synergistic catalytic activity of nano-CuO/Fe₂O₃ nanoparticles on thermal decomposition of AP. AP micro-particles are efficiently encapsulated with 1 and 5 wt.% of nano-CuO and/or nano-Fe₂O₃ nanoparticles by the fast-crash solventantisolvent technique. The efficiency of the encapsulation method was confirmed using FT-IR spectroscopy. Morphological characterization, performed using SEM-EDS microscopy, showed that encapsulation provides recrystallization and deagglomeration of AP and uniform nano-catalyst distribution. The catalytic efficiency of nano-CuO/ nano-Fe₂O₃ nanoparticles on the thermal decomposition of AP was investigated using DSC, and an increase in released heat was observed from 1453 to 1628 J/g. The catalytic activities of performed nano-catalysts were proven by decreasing the HTD and merging with the low decomposition temperature peak. The highest catalytic effect was obtained after encapsulating with 5 wt.% of nano-CuO and nano-Fe₂O₃ combined in a 50/50 mass ratio due to multiple mechanisms of catalytic activity of nano-Fe₂O₃. The effect of AP encapsulation with nano-Fe₂O₃ on the burning rate of CSRP was investigated and the obtained results showed a favorable effect on the combustion rate law.

17

Biomedical applications of nanoparticles of chitosan from marine waste

Ann Mary S., Sandhiya R., Prince S., Venkatraman J. M., Vignesh S., Hikku G. H., Ramachandran S.

Archives of Materials Science and Engineering

|

2023

|

Vol. 124, nr 2

71--75

EN

Purpose: The review focuses on chitosan nanoparticle synthesis and its biomedical applications. The review briefly explains the biomedical applications of antimicrobials, cancer therapy, gene therapy, and anti-ageing. Notably, the chitosan biological activity can be further increased by coating metal ions such as iron oxide nanoparticles, gold nanoparticles, etc. Design/methodology/approach: Chitosan is the N-acetyl derivative of chitin, which has the unique properties of biodegradability, non-toxicity, polycationic property and biocompatibility— no reports of ZnO sulphated chitosan nanoparticles being produced for antibacterial. We hope for the conduction of antibacterial research of ZnO sulphated chitosan nanoparticles. Findings: The study establishes that metal oxide nano-CH, characterised by an expanded size range beyond conventional parameters, exhibits a broad spectrum of biomedical applications. Its commendable biological attributes, encompassing biocompatibility, non-toxicity, and biodegradability, make it a vehicle for drug delivery in medicine. Research limitations/implications: Nanomedicine is an emerging branch of medicine that applies tools and the basis of nanotechnology for disease prevention, treatment and diagnosis. Moreover, it helps overcome conventional medicine's limitations, including adverse side effects, poor pharmacokinetics and lack of selectivity. Originality/value: Using chitosan extracted from marine waste presents economic advantages. Furthermore, when coated with metal oxide nanoparticles, it enhances biomedical efficacy. Chitosan is an effective drug delivery vehicle, and its theranostic applications are valuable in the biomedical sector.

18

Effect of the lubrication on the friction characteristics of EN AW-2024-T3 aluminium alloy sheets

Krasowski Bogdan, Kubit Andrzej

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

|

2022

|

z. 94

23--35

EN

The article presents the results of friction tests conducted on EN AW-2024 Alclad aluminium alloy sheets. The lubrication efficiency of oleic acid, mineral and vegetable oils with the addition of SiO2 and TiO2 nanoparticles was determined using the strip drawing test to assess the friction conditions in the flange area in the deep drawing process. The samples in the form of sheet metal strips were pulled between countersamples with a rounded surface at a speed of 2.5 mm/s. Gear oil and oleic acid demonstrated the lowest value of the coefficient of friction (COF) in the whole range of nominal pressures investigated. The lowest efficiency in reducing the COF was shown by hydraulic oil, olive oil and machine oil. A high content of TiO2 nanoparticles (0.5-0.9%wt%) is beneficial in the friction process involving oleic acid.

PL

W artykule przedstawiono wyniki badań tarcia blach ze stopu aluminium EN AW-2024-T3 Alclad. Efektywność smarowania za pomocą kwasu oleinowego, olejów mineralnych oraz roślinnych z dodatkami nanocząstek SiO2 oraz TiO2 została określona za pomocą testu przeciągania blachy używanego do oceny warunków tarcia panujących w kołnierzowej części wytłoczki w procesie głębokiego wytłaczania. Próbki w postaci pasów blachy przeciągano pomiędzy przeciwpróbkami o zaokrąglonej powierzchni (R = 200 mm) z prędkością 2,5 mm/s. Olej przekładniowy oraz kwas oleinowy zapewniły najmniejszą wartość współczynnika tarcia w całym zakresie analizowanych nacisków nominalnych. Najmniejszą efektywność zmniejszania współczynnika tarcia wykazały olej hydrauliczny, oliwa z oliwek oraz olej maszynowy. Najkorzystniejszy efekt zmniejszenia wartości współczynnika tarcia wynikający z dodatku nanocząstek SiO2 jest widoczny dla kwasu oleinowego przy zawartości nanocząstek 0,5% (wagowo). Wysoka zawartość nanocząstek TiO2 (0,5-0,9% wagowo) jest korzystna podczas procesu tarcia z udziałem kwasu oleinowego.

19

Wykorzystanie nanotechnologii w dystrybucji energii elektrycznej

Wajda Józef

Wiadomości Elektrotechniczne

|

2022

|

R. 90, nr 2

12--16

PL

Ciągły wzrost zapotrzebowania na energię elektryczną w skali globalnej wiąże się z coraz wyższymi kosztami jej produkcji, wymuszającymi wdrażanie nowych rozwiązań technicznych, mniej szkodliwych dla środowiska naturalnego. Dotychczasowe metody produkcji energii elektrycznej pozyskiwanej z paliw kopalnych, emitujące do atmosfery ogromne ilości spalin i zagrażające egzystencji milionów żywych istnień są zastępowane energią odnawialną: wiatru, wody i słońca (elektrownie wodne, wiatrowe, fotowoltaiczne). Duży problem stanowi dostarczenie energii do często odległych odbiorców, co w znacznym stopniu ułatwiają już wdrażane osiągnięcia nanotechnologiczne.

EN

The continuous increase in demand for electricity on a global scale is associated with ever higher production costs, forcing the implementation of new technical solutions that are less harmful to the natural environment. The existing methods of producing electricity obtained from fossil fuels, emitting a huge amount of exhaust gases into the atmosphere and threatening the existence of millions of living creatures, is replaced by renewable energy of wind, water and sun (hydro, wind, photovoltaic power plants). A big problem is the supply of energy to often distant recipients, which is largely facilitated by the already implemented nanotechnology achievements.

20

Nanomateriały w spektrometrii mas z laserową desorpcją/jonizacją wspomaganą powierzchnią

Arendowski Adrian

Wiadomości Chemiczne

|

2022

|

[Z] 76, 9-10

735--754

EN

Laser desorption/ionization (LDI) is one of the most popular ionization techniques currently used in mass spectrometry (MS). This technique is most commonly used in a variant of matrix-assisted laser desorption/ionization (MALDI), which uses low molecular weight organic acid mixed with the sample to support the ionization process. However, this approach has some shortcomings such as: high chemical background in the spectral region below m/z 700 making it difficult to analyze compounds giving signals in this spectral region, inhomogeneous co-crystallization of analyte and matrix leading to the formation of so-called "sweet spots", i.e. inhomogeneous distribution of analyte in the crystallizing matrix. For these reasons, increasing research attention is focused on the possibilities offered by the use of matrix-free systems based on nanostructures in laser methods, which are referred to as surface-assisted laser desorption/ionization (SALDI). The use of nanostructures in LDI MS has made it possible to analyze low molecular compounds, often at very low concentrations, without the presence of matrix-derived chemical background, contributing to more applications of the LDI MS method. This work describes what the SALDI technique is and reviews the nanomaterials used in different variations of the approach. Among the described materials used in SALDI there are nanomaterials based on carbon and silicon, including the DIOS method, as well as techniques based on nanoparticles of gold, silver, platinum and titanium oxide. For each method, application examples are given for the detection of different classes of chemical compounds, often also in complex biological mixtures.