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1.
Food Chem ; 462: 140925, 2025 Jan 01.
Article in English | MEDLINE | ID: mdl-39190981

ABSTRACT

Grape pomace (GP) and pecan shell (PS) are two by-products rich in phenolic compounds (PC), and dietary fiber (DF) that may be considered for the development of functional baked foods. In this study, four formulations with different GP:PS ratios (F1(8%:5%), F2(5%:5%), F3(5%:2%), F4(0%:5%), and control bread (CB)) were elaborated and characterized (physiochemical and phytochemical content). Also, their inner structure (SEM), changes in their FTIR functional group's vibrations, and the bioaccessibility of PC and sugars, including an in vitro glycemic index, were analyzed. Results showed that all GP:PS formulations had higher mineral, protein, DF (total, soluble, and insoluble), and PC content than CB. Additionally, PC and non-starch polysaccharides affected gluten and starch absorbance and pores distribution. In vitro digestion model showed a reduction in the glycemic index for all formulations, compared to CB. These findings highlight the possible health benefits of by-products and their interactions in baked goods.


Subject(s)
Bread , Dietary Fiber , Glycemic Index , Phenols , Vitis , Dietary Fiber/analysis , Dietary Fiber/metabolism , Bread/analysis , Vitis/chemistry , Phenols/chemistry , Phenols/metabolism , Humans , Digestion , Food, Fortified/analysis , Waste Products/analysis
2.
Sci Rep ; 14(1): 23103, 2024 Oct 04.
Article in English | MEDLINE | ID: mdl-39367047

ABSTRACT

Farmers' participation in pesticide packaging waste (PPW) governance is important for improving agricultural pollution and achieving sustainable agricultural development. By incorporating the theory of planned behavior, value-belief-norm theory, cognition and behavior theory etc., we construct a theoretical model comprising "ecoliteracy-farmers' WTP in PPW governance-participation in PPW governance behavior." This study investigates how ecoliteracy affects farmers' participation in PPW governance and explores the mediating effect of farmers' willingness to participate (WTP) in PPW governance. We use structural equation modeling to analyze data collected from a questionnaire survey including 1118 samples of Chinese farmers. The results show that (1) Ecoliteracy significantly affects farmers' WTP in PPW governance. Ecological cognition, emotion, values, and knowledge and skills positively affect WTP in PPW governance, while ecological cognition and ecological knowledge and skills significantly affect participation in PPW governance behavior. (2) Farmers' WTP in PPW governance mediates ecoliteracy and governance participation behavior. (3) Heterogeneity analysis reveals that different planting scales, different planting categories, and receiving/not receiving government project support have different effects on farmers' participation in governance behavior. Farmers in the large-scale group are more likely to participate in governance than those in the medium- and small-scale groups, and farmers in the mixed grain and economic category are more likely to participate in governance than those in the economic and grain categories. Furthermore, farmers who receive government support are more likely to participate in governance than those who do not. Our results can serve as a policy making reference for promoting PPW governance in various regions.

3.
Heliyon ; 10(19): e37795, 2024 Oct 15.
Article in English | MEDLINE | ID: mdl-39386767

ABSTRACT

The focus of this research is to investigate the factors that influence employee voice behaviour by examining the integration of high-performance work systems, stewardship climate, and trust in supervisor. Drawing on social exchange theory and leader-member exchange, this study investigates the positive relationship between trust in supervisor, high-performance work systems, stewardship climate and employee voice. Data were collected in three stages from 376 Nigerian telecommunications customer-contact employees. Partial Least Squares-Structural Equation Modelling was used to test the dataset. The findings indicate that high-performance work systems have a favourable association with employee voice, while stewardship climate has an adverse correlation with employee voice. Moreover, trust in supervisor is found to mediate and enhance the favourable relationship between high-performance work systems, stewardship climate, and employee voice. The relevance of this study to service industries, management research, and its practical implications is discussed.

4.
Cureus ; 16(9): e68678, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39371848

ABSTRACT

BACKGROUND: This research aims to assess the impact of oxidation heat treatment (OHT) and dual opaquing techniques on enhancing the bond strength between metal and ceramic. MATERIAL AND METHOD: Eighty rectangular patterns with dimensions of 0.5x3x25 mm (according to ISO 9693-2012) were fabricated in a custom-made silicon mold by using auto-polymerized pattern resin material. These rectangular patterns were cast using base metal alloys. The samples were split into two primary groups: group A, subjected to OHT, and group B, without oxidation treatment. Each primary group was then split up into subgroups according to the application of single layers (group A1, B1) or double layers (group A2, B2) of opaque porcelain. After pre-surface treatment and Ceramco 3 paste opaque application, dentin porcelain (Ceramco 3) was applied to the mid-region of the samples, followed by firing to achieve a standardized thickness. Flexural strength determination was conducted via a three-point bend test performed on the universal testing machine (UTM) (Instron Corp., Model 2519-107, USA), adhering to ISO standard 9693. Post-testing failure types were analyzed by morphological assessment of debonding surfaces via a scanning electron microscope (SEM). The statistical analysis was performed with SPSS version 16, incorporating ANOVA for intergroup analysis and independent t-tests for intragroup comparisons. RESULTS:  Group A2 exhibited the highest mean flexural bond strength (P<0.05) at 41.85 MPa when compared to group A1 at 37.60 MPa, group B2 at 35.47 MPa, and group B1 with the least mean flexural bond strength at 30.41 MPa. SEM observations revealed cohesive bond failure for groups A1, A2, and B2 and adhesive bond failure for groups B1. CONCLUSION:  It is evident that OHT and opaquing technique are important factors in determining the bond strength of ceramo-metal restorations. When combined, these techniques greatly increase the overall success and durability of metal-ceramic restorations, underscoring their significance in contemporary dental prostheses.

5.
Biochim Biophys Acta Gen Subj ; : 130718, 2024 Oct 05.
Article in English | MEDLINE | ID: mdl-39374847

ABSTRACT

The ability to generate polyphosphate (polyP) granules is important for survival for bacteria during resistance to diverse environmental stresses, however the genesis of polyP granules is poorly understood. Chlorobaculum tepidum (Cba tepidum) is a thermophilic green sulfur anoxygenic phototrophic bacterium which uses reduced sulfur compounds as electron donors. The presence of electron rich granules inside the Cba tepidum was reported, but no further information was provided. In this work we used cell thin sections at three different time points of cultivation to observe the biogenesis of the inclusions over time, and the in cell total phosphate concentration was monitored over time as well. Furthermore, the elemental analysis (EDS) of the electron rich inclusions showed the presence of phosphorus and oxygen. The existence of polyphosphate was demonstrated by 31P NMR spectroscopy of cell lysates. Finally, we show that the biogenesis of the phosphorus granules correlates with an abundance of proteins that are closely related to polyphosphate metabolism.

6.
Microsc Res Tech ; 2024 Oct 08.
Article in English | MEDLINE | ID: mdl-39376090

ABSTRACT

PVC nanocomposite (NC) films with cubic CeO2 and Ni-doped CeO2 (NDC) have been prepared using a conventional solution-casting technique. The prepared films were characterized with FT-IR spectrometer, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The optical and thermal properties of the films were evaluated using a UV-visible spectrophotometer and TGA/DSC. The optical study revealed a decrease in optical band gap energies (4.19 to 4.06 eV) whereas the increase in other optical constraints such as optical conductivity, Urbach energy, dispersion energy, refractive index, and dielectric constant of PVC NCs than pristine PVC was observed. The XRD patterns showed the presence of cubic crystalline NDC with a relatively narrower principal diffraction peak in the PVC matrix and the nonexistence of unexpected vibrational peaks in the FTIR spectra of PVC NCs confirmed the successful incorporation of nanostructured CeO2 and NDC into PVC. Thermogravimetric analysis showed the higher thermal stability of NDC/PVC NC than PVC whereas differential scanning calorimetry declared no significant change in the glass transition temperature (Tg) of the NCs. Moreover, a good dispersion of Ni-doped CeO2 nanofiller was noticed in scanning electron micrographs.

7.
Behav Res Methods ; 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-39354129

ABSTRACT

Closed-form (asymptotic) analytical power estimation is only available for limited classes of models, requiring correct model specification for most applications. Simulation-based power estimation can be applied in almost all scenarios where data following the model can be estimated. However, a general framework for calculating the required sample sizes for given power rates is still lacking. We propose a new model-implied simulation-based power estimation (MSPE) method for the z-test that makes use of the asymptotic normality property of estimates of a wide class of estimators, the M-estimators, and give theoretical justification for the approach. M-estimators include maximum-likelihood, least squares estimates and limited information estimators, but also estimators used for misspecified models, hence, the new simulation-based power modeling method is widely applicable. The MSPE employs a parametric model to describe the relationship between power and sample size, which can then be used to determine the required sample size for a specified power rate. We highlight its performance in linear and nonlinear structural equation models (SEM) for correctly specified models and models under distributional misspecification. Simulation results suggest that the new power modeling method is unbiased and shows good performance with regard to root mean squared error and type I error rates for the predicted required sample sizes and predicted power rates, outperforming alternative approaches, such as the naïve approach of selecting a discrete selection of sample sizes with linear interpolation of power or simple logistic regression approaches. The MSPE appears to be a valuable tool to estimate power for models without an (asymptotic) analytical power estimation.

8.
Discov Nano ; 19(1): 164, 2024 Oct 03.
Article in English | MEDLINE | ID: mdl-39361062

ABSTRACT

Antibiotic resistance is currently becoming a more serious threat to global health, especially in severe nosocomial infections treatment by multidrug-resistant bacteria. This research provides a new way of synergizing green-synthesis for zinc oxide quantum dots (ZnO-QDs with hexagonal crystals) that are 7 nm in diameter and zero-valent Ag cubic crystals that are 67 nm in size embedded with nitazoxanide substrate (NAZ). Instrumental characterization like SEM, TEM, EDAX, and FT-IR and comprehensive antimicrobial studies were conducted to study the incorporation behavior of composites based on Ag NPs/ZnO QDs/NAZ. This combination has not been hitherto addressed anywhere else in the published literature, as well as commercial viability. In this context, we have precisely tuned nanoparticle to nitazoxanide ratio for designing the formulation demonstrating potent activity against MDR infections. By employing nitazoxanide as a scaffold and careful decoration thereof antimicrobial potency has been unlocked overriding conventional therapies. In addition, Ag NPs/ZnO-QDs/nitazoxanide (G6) formula exhibited a therapeutic efficacy span of 96.15 ± 1.68% to 99.57 ± 0.20% against MDR human infections post 48 h incubation; a breakthrough in therapeutic efficacy levels has been achieved by our method. Accordingly, ZnO QDs/Ag NPs/NAZ composite offered potential multidrug resistant human pathogens as a new trend of revolutionizing antimicrobial treatment.

9.
Antonie Van Leeuwenhoek ; 118(1): 15, 2024 Oct 05.
Article in English | MEDLINE | ID: mdl-39367931

ABSTRACT

During extensive field explorations of the Lateritic area in West Bengal, one remarkable wild Russuloid macrofungus, ethnically termed "Kend Patra," was collected. The species was known to enrich the diet of the local people, being considered as income source for some tribal groups. Using morphological characters and molecular analysis of this collection, provide a unique placement of the taxon in the Russula subgenus Compactae (Fr.) Bon. Further in order to find functional constituents for biopharma applications, methanolic extract was prepared that shows the existence of a substantial amounts of phenol, flavonoid, ascorbic acid and carotenoids. Antioxidant activity was determined where the fraction demonstrated strong DPPH, ABTS, and nitric oxide radical scavenging activities, high Fe2+ ion chelating ability, and a reducing power with EC50 values ranging from 538.69 to 891.75 µg/ml. The extract was found to be effective against Listeria monocytogenes, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi and Staphylococcus aureus. In addition, the extract exhibited potent anticancer activities as it inhibited A549 cell proliferation, caused morphological changes, elevated ROS levels, hindered the clonogenic ability and migratory potential of cancerous cells, arrested cell cycle progression at S phase, and induced apoptosis by modulating the intrinsic mitochondrial pathway. Overall, this study contributes a new species to the world's myco-diversity and presents an exciting opportunity for future researchers to conduct comprehensive investigations on this unique species in order to uncover potential new medications for human use.


Subject(s)
Antineoplastic Agents , Antioxidants , Humans , Antioxidants/pharmacology , Antioxidants/chemistry , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Basidiomycota/chemistry , Basidiomycota/classification , Microbial Sensitivity Tests , A549 Cells , Cell Proliferation/drug effects , Apoptosis/drug effects , Bacteria/drug effects , Bacteria/classification , Bacteria/genetics
10.
Front Psychol ; 15: 1293610, 2024.
Article in English | MEDLINE | ID: mdl-39355298

ABSTRACT

Extensive attention in organizational research has been dedicated to workplace bullying, primarily focusing on its frequency and impact on both the victim and the bully, emphasizing interpersonal dynamics. This study extends current research by shifting the focus to the organizational level, examining the relationship between organizational culture and affective commitment, mediated by workplace bullying. Utilizing data from two surveys (N = 650 in 2012 and N = 553 in 2017), the study reveals that dimensions of organizational culture, such as assertiveness, performance orientation, and ingroup collectivism significantly influence work-related workplace bullying. Performance orientation and assertiveness are positively associated with increased bullying, whereas ingroup collectivism serves as a deterrent. In turn, work-related bullying negatively impacts affective commitment, while a culture characterized by high ingroup collectivism not only links negatively with bullying but also links positively with affective commitment. This work is one of the first studies to investigate the interplay among several dimensions of organizational culture, workplace bullying, and affective commitment, underscoring the importance of supportive organizational cultures in fostering healthy work environments.

11.
Environ Monit Assess ; 196(11): 1007, 2024 Oct 03.
Article in English | MEDLINE | ID: mdl-39358618

ABSTRACT

Limited research has been conducted on microplastic (MP) contamination in the rivers of Goa. To address this gap, this study examines the levels of MP contamination in the surface water of the Zuari River, Goa. We investigate the abundance, characteristics (size, shape, colour, and polymer composition), and risk assessment of MPs. MPs were detected at all sampling stations in the Zuari River, with concentrations varying from 0.01 particles/L (S3) to 1.38 particles/L (S13). The average abundance of MPs in the water samples was 0.28 ± 0.35 particles/L. MPs were more common in the 0.3-1 mm size range (51.70%) than in the 1-5 mm range (48.30%). The most common MP shapes observed were fibers (37.88%) and fragments (29.66%). FTIR analysis confirmed the presence of polyethylene terephthalate, high-density polyethylene, polypropylene, and polyacrylamide carboxyl-modified MPs. The Pollution Load Index (PLI) showed an average value of 3.8, indicating significant contamination (PLI > 1). Scanning electron microscopy (SEM) revealed various degradation features such as pits, scratches, grooves, and cracks on the MPs surfaces, while energy dispersive X-ray spectroscopy (EDS) detected metals on the MP's surfaces. This study provides key insights into MP pollution in the Zuari River's surface water and lays the groundwork for future research and management strategies in the region.


Subject(s)
Environmental Monitoring , Microplastics , Rivers , Water Pollutants, Chemical , India , Water Pollutants, Chemical/analysis , Rivers/chemistry , Microplastics/analysis , Water Pollution, Chemical/statistics & numerical data
12.
World J Microbiol Biotechnol ; 40(11): 336, 2024 Oct 03.
Article in English | MEDLINE | ID: mdl-39358660

ABSTRACT

Soil and wastewater samples contaminated by petroleum-related industries were collected from various locations in Saudi Arabia, a country known for its vast oil reserves. The samples were analyzed for their physicochemical properties, including the presence of metals, petroleum hydrocarbons, and aromatic compounds. A total of 264 fungal isolates were analyzed and categorized into eight groups of Aspergillus (194 isolates) and four groups of Penicillium (70 isolates). The potential of these fungal groups to grow in oil or its derivatives was investigated. Two isolates, Aspergillus tubingensis FA-KSU5 and A. niger FU-KSU69, were utilized in two remediation experiments-one targeting wastewater and the other focusing on polluted soil. The FA-KSU5 strain demonstrated complete removal of Fe3+, As3+, Cr6+, Zn2+, Mn2+, Cu2+ and Cd2+, with bioremediation efficiency for petroleum hydrocarbons in the wastewater from these sites ranging between 90.80 and 98.58%. Additionally, the FU-KSU69 strain achieved up to 100% reduction of Co2+, Ba2+, B3+, V+, Ni2+, Pb2+ and Hg2+, with removal efficiency ranging from 93.17 to 96.02% for aromatic hydrocarbons after 180 min of wastewater treatment. After 21 days of soil incubation with Aspergillus tubingensis FA-KSU5, there was a 93.15% to 98.48% reduction in total petroleum hydrocarbons (TPHs) and an 88.11% to 97.31% decrease in polycyclic aromatic hydrocarbons (PAHs). This strain exhibited the highest removal rates for Cd2+ and As3+ followed by Fe3+, Zn2+, Cr6+, Se4+ and Cu2+. Aspergillus niger FU-KSU69 achieved a 90.37% to 94.90% reduction in TPHs and a 95.13% to 98.15% decrease in PAHs, with significant removal of Ni2+, Pb2+ and Hg2+, followed by Co2+, V+, Ba2+ and B3+. The enzymatic activity in the treated soils increased by 1.54- to 3.57-fold compared to the polluted soil. Although the mixture of wastewater and polluted soil exhibited high cytotoxicity against normal human cell lines, following mycoremediation, all treated soils and effluents with the dead fungal biomass showed no toxicity against normal human cell lines at concentrations up to 500 µL/mL, with IC50 values ≥ 1000 µL/mL. SEM and IR analysis revealed morphological and biochemical alterations in the biomass of A. tubingensis FA-KSU5 and A. niger FA-KSU69 when exposed to petroleum effluents. This study successfully introduces non-toxigenic and environmentally friendly fungal strains play a crucial role in the bioremediation of contaminated environments. Both strains serve as low-cost and effective adsorbents for bio-remediating petroleum wastewater and oil-contaminated soil. Heavy metals and hydrocarbons, the primary pollutants, were either completely removed or reduced to permissible levels according to international guidelines using the dead biomass of FA-KSU5 and FA-KSU69 fungi. Consequently, the environments associated with this globally significant industry are rendered biologically safe, particularly for humans, as evidenced by the absence of cytotoxicity in samples treated with A. tubingensis FA-KSU5 and A. niger FA-KSU69 on various human cell types.


Subject(s)
Aspergillus , Biodegradation, Environmental , Petroleum , Soil Microbiology , Soil Pollutants , Wastewater , Wastewater/microbiology , Wastewater/chemistry , Petroleum/metabolism , Soil Pollutants/metabolism , Aspergillus/metabolism , Aspergillus/isolation & purification , Aspergillus/growth & development , Aspergillus/classification , Penicillium/metabolism , Penicillium/isolation & purification , Saudi Arabia , Petroleum Pollution , Fungi/metabolism , Fungi/classification , Fungi/isolation & purification , Metals/metabolism , Soil/chemistry , Hydrocarbons/metabolism
13.
Microscopy (Oxf) ; 2024 Sep 20.
Article in English | MEDLINE | ID: mdl-39300968

ABSTRACT

In this study, we experimentally analyzed the charging phenomenon when an insulating resist film on a conductive layer formed on bulk glass is irradiated by electron beams. To quantify the charging potential induced, an electrostatic force microscope device was installed in the scanning electron microscope sample chamber, and potential distributions formed under various exposure conditions were obtained. Based on the results obtained, a model for charge accumulation within the sample, explaining positive and negative charging and their transitions, was developed. At an electron beam acceleration voltage of 30 kV, the following observations were made: "global charging" could be avoided by applying -5V to the sample. Regarding "local charging" near the exposure area of the electron beam, at low exposure doses, emission of secondary electrons from the sample surface induced positive charging, while the accumulation of incident electrons within the sample induced negative charging. At exposure doses where the effects of both are balanced, the sample exhibited zero potential, revealing the appearance of the "first zero-cross exposure dose". At higher exposure doses, the sample transitions from negative to positive as the exposure dose increases due to the electron beam induced conduction, resulting in the so-called "second zero-cross exposure dose". The exposure dose dependence of the charging potential distribution at various acceleration voltages was obtained. In particular, we found that at an acceleration voltage of 0.6 kV, the sample surface is not charged even when exposed to small to very large doses of electron beams.

14.
Funct Integr Genomics ; 24(5): 174, 2024 Sep 25.
Article in English | MEDLINE | ID: mdl-39320439

ABSTRACT

Many organisms have adapted to survive in environments with high levels of arsenic (As), a naturally occurring metalloid with various oxidation states and a common element in human activities. These organisms employ diverse mechanisms to resist the harmful effects of arsenic compounds. Ten arsenic-resistant bacteria were isolated from contaminated wastewater in this study. The most efficient bacterial isolate able to resist 15,000 ppm Na2HAsO4·7H2O was identified using the 16S rRNA gene and whole genome analysis as Enterobacter cloacae FACU. The arsenic E. cloacae FACU biosorption capability was analyzed. To further unravel the genetic determinants of As stress resistance, the whole genome sequence of E. cloacae FACU was performed. The FACU complete genome sequence consists of one chromosome (5.7 Mb) and two plasmids, pENCL 1 and pENCL 2 (755,058 and 1155666 bp, respectively). 7152 CDSs were identified in the E. cloacae FACU genome. The genome consists of 130 genes for tRNA and 21 for rRNAs. The average G + C content was found to be 54%. Sequencing analysis annotated 58 genes related to resistance to many heavy metals, including 16 genes involved in arsenic efflux transporter and arsenic reduction (five arsRDABC genes) and 42 genes related to lead, zinc, mercury, nickel, silver, copper, cadmium and chromium in FACU. Scanning electron microscopy (SEM) confirmed the difference between the morphological responses of the As-treated FACU compared to the control strain. The study highlights the genes involved in the mechanism of As stress resistance, metabolic pathways, and potential activity of E. cloacae FACU at the genetic level.


Subject(s)
Arsenic , Enterobacter cloacae , Genome, Bacterial , Enterobacter cloacae/genetics , Enterobacter cloacae/drug effects , Arsenic/metabolism , Arsenic/toxicity , RNA, Ribosomal, 16S/genetics , Whole Genome Sequencing
15.
Foods ; 13(18)2024 Sep 20.
Article in English | MEDLINE | ID: mdl-39335911

ABSTRACT

In recent years, artificial intelligence (AI) has been developing rapidly and has had a broad impact on the food industry, with food produced from AI-generated recipes already appearing to actually go on sale. However, people's trust and willingness to purchase AI food are still unclear. This study builds an integrated theoretical model based on cognitive trust and affective trust, taking into account consumers' quality value orientations, social norms, and perceived risks of AI food, with the aim of predicting and exploring consumers' trust and acceptance of AI food. This study utilized the questionnaire method and 315 questionnaires were collected. The results of structural equation modeling (PLS-SEM) indicated that food quality orientation, subjective norms, perceived trust, and affective trust all had a significant positive effect on consumers' purchase intentions. Perceived risk had a negative effect on affective trust and consequently on consumers' purchase intention, but the effect on cognitive trust was not significant. The results also suggest that cognitive trust is the basis of affective trust and that consumer trust and acceptance of AI food can be enhanced by augmenting two antecedents of cognitive trust (food quality orientation and subjective norms). Possible practical implications and insights from the current findings are discussed.

16.
Materials (Basel) ; 17(18)2024 Sep 10.
Article in English | MEDLINE | ID: mdl-39336193

ABSTRACT

Material development in acoustic engineering plays a significant role in various applications, such as industrial noise control. It is important and relevant to consider alternative materials capable of reducing noise levels in different frequency ranges. One commonly used material in engineering structures is epoxy adhesive compositions. Favoring the use of adhesive compositions are their main characteristics, including weight reduction in structures, corrosion resistance, relatively low manufacturing costs, and high mechanical strength. This paper aims to discuss the relationship between the mechanical properties of modified epoxy adhesives, their structure, and sound absorption efficiency. The subjects of this study were specimens of an epoxy composition in the cured state. Acoustic absorption coefficients were evaluated using a dual-microphone impedance tube, and tensile, compressive, and bending strength properties were determined using a testing machine. The impact strength of the compositions was also investigated. An analysis of the structure of the adhesives in the cured state was carried out using a scanning electron microscope. The test specimens were made from Epidian 5 epoxy resin cured with a polyamide PAC curing agent. Nanobent ZR2 aluminosilicate in an amount of 1%, CaCO3 calcium carbonate in an amount of 5%, and CWZ-22 activated carbon in an amount of 20% were used as modifiers. The conducted studies revealed that the highest tensile strength was obtained for the adhesive composition with the addition of ZR2 filler. The highest compressive strength was exhibited by the adhesive composition with the addition of CWZ-22 filler. The highest flexural strength was demonstrated by the unmodified composition. For all the tested adhesive compositions, low sound absorption values were achieved, with a maximum of approximately 0.18. From the perspective of the reduction index R, it was observed that these samples performed better in reduction than in absorption. The best values were achieved in the compositions modified with CaCO3.

17.
Materials (Basel) ; 17(18)2024 Sep 11.
Article in English | MEDLINE | ID: mdl-39336203

ABSTRACT

Due to its super plasticity, low weight, and high mechanical resistance properties, generally, Ti6Al4V is used for aeronautical applications. However, it has low resistance to plastic shearing. In addition, it has poor wear resistance. For these reasons, a lot of techniques have been developed to improve its wear resistance. Investigations of microstructure and interfacial reactions of diffusion bonding of Ni and Ti6Al4V materials have been performed experimentally. Ni samples were prepared with 50 ± 5 µm Ni powders in cylindrical shape. For diffusion bonding, Ag foil was used for improving the interlayer and connection quality. Nickel and its alloys can be joined by using some different processes, and the use of an interlayer can further facilitate the joining process and improve the joint quality. The experiments were carried out under the protected atmosphere. Argon gas was used for protection. The experiments were performed under 5 MPa pressure for 60 min duration at 850 °C, 900 °C, and 950 °C thermal conditions. Investigations of metallurgical structure occurring in the interface areas were examined by optic analysis of EDS, SEM, and X-ray. The strength of the joints was tested by lap-shear tests. From observations, the best quality of the coalescence at interfaces was indicated at elevated temperatures.

18.
Materials (Basel) ; 17(18)2024 Sep 11.
Article in English | MEDLINE | ID: mdl-39336205

ABSTRACT

In this work, pine and birch wood were modified by graphene oxide using a single vacuum impregnation method. The research results indicate that the impregnation of wood with graphene oxide increases the crystallinity of cellulose in both pine and birch wood, and the increase in crystallinity observed in the case of birch was more significant than in the case of pine. FT-IR analyses of pine samples impregnated with graphene oxide showed changes in intensity in the absorption bands of 400-600, 700-1500 cm-1, and 3200-3500 cm-1 and a peak separation of 1102 cm-1, which may indicate new C-O-C connections. In the case of birch, only some differences were noticed related to the vibrations of the OH group. The proposed modification also affects changes in the color of the wood surface, with earlywood containing more graphene oxide than latewood. Analysis of scanning electron microscope images revealed that graphene oxide adheres flat to the cell wall. Considering the differences in the anatomical structure of both wood species, the research showed a statistically significant difference in water absorption and retention of graphene oxide in wood cells. Graphene oxide does not block the flow of water in the wood, as evidenced by the absorbability of the working liquid at the level of 580-602 kg/m3, which corresponds to the value of pure water absorption by wood in the impregnation method using a single negative pressure. In this case, higher graphene oxide retention values were obtained for pine wood.

19.
Materials (Basel) ; 17(18)2024 Sep 13.
Article in English | MEDLINE | ID: mdl-39336240

ABSTRACT

The oxide layer development of X6CrNiNb18-10 (AISI 347) during exposure to high-temperature water has been investigated. Stainless steels are known to form a dual oxide layer in corrosive environments. The secondary Fe-rich oxide layer has no significant protective effect. In contrast, the primary Cr-rich oxide layer is known to reach a stabilized state, protecting the base metal from further oxidation. This study's purpose was to determine the development of oxide layer dimensions over exposure time using SEM, TEM and EDX line scans. While a parabolic development of Cr in the protective primary layer and Fe in the secondary layer was observed, the dimensions of the Ni layer remained constant. Ni required the presence of a pronounced Fe-rich secondary layer before being able to reside on the outer secondary layer. With increasing immersion time, the Ni element fraction surpassed the Cr element fraction in the secondary layer. Oxide growth on the secondary layer could be observed. After 480 h, nearly the entire surface was covered by the outer oxide layer. In the metal matrix, no depletion of Cr or Ni could be observed over time; however, an increased presence of Cr and Ni in the primary layer was found at the expense of Fe content. The Nb-stabilized stainless steel was subject to the formation of Niobium pentoxide (Nb2O5), with the quantity and magnitude of element fraction increasing over exposure time.

20.
Article in English | MEDLINE | ID: mdl-39348081

ABSTRACT

This study aimed to evaluate the antimicrobial effect of coated orthodontic molar tubes (COMT) with zinc oxide nanoparticles (ZnO NPs) using an electrophoretic deposition method (EPD) and to evaluate the orthodontic molar tubes (OMT) bond failure rate. Seventy-two orthodontic molar tubes (OMTs) for second molars were divided into two groups 36 each; one group coated with ZnO NPs and the other control negative uncoated. The OMT was coated using the EPD method with ZnO NPs in a concentration of 10 g/l. The OMTs were randomly allocated using a split-mouth, cross-quadrant design. After 2 weeks of appliance placement, swabs were taken from the surface of the OMTs for microbial assessment against Streptococcus mutans, Lactobacillus acidophilus, and total bacterial counts; additionally, plaque and gingival indices were assessed. The patient was followed for 3 months to evaluate the bond failure rate. The COMT showed a statistically significant reduction in total bacterial accounts, S. mutans, and L. acidophilus compared to UOMT (P < 0.001). Furthermore, the plaque and gingival indices near COMT were significantly less than that of UOMT. The bond failure rate was not significant between the COMT and UOMT. The COMT with ZnO NPs has potent antibacterial activity against the tested pathogens with a reduction in the amount of plaque accumulation. The use of the EPD method was feasible without adverse effects on the orthodontic molar tubes bond failure rate.

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