Constant Level Research Articles

More microscopic interfacial segregation slowers macroscopic grain growth: A case in WC-Co cemented carbides

In industrial practice, combining grain growth inhibitors (GGIs) with low carbon content effectively restrains WC grain growth in WC-Co cemented carbides. However, the intricate relationship between carbon content, WC grain microstructure, and GGI impact remains unresolved. This study investigates two WC-Co sample sets, maintaining constant VC inhibitor levels but varying carbon content near upper (HC) and lower (LC) limits. SEM analysis revealed distinct morphologies: HC displayed truncated prism shapes, exposing long basal and prismatic terraces, while LC exhibited a saw-tooth morphology with finer grains. EBSD stereology quantified anisotropic WC grain growth, revealing suppressed growth perpendicular to both basal (HC: 0.51 μm vs. LC: 0.38 μm) and prismatic planes (HC: 0.44 μm vs. LC: 0.37 μm) with decreased carbon content. Atomic-resolution EDS showed higher V solute excess in LC at WC(basal)-Co, WC(prismatic)-Co interfaces, and step corners (HC: 4.6, 0.9, and 4.4 atoms/nm2; LC: 5.5, 0.9, and 7.8 atoms/nm2). Our findings elucidate a clear physical understanding that a low carbon content enhances V atom solubility within liquid cobalt, increasing the thickness of complexions to quad-layer on WC (basal)-Co interfaces and forming V-rich nanoprecipitates at step corners. Those inhibitory effects further limited step flow, resulting in pronounced step bunching and a saw-tooth fine-grained morphology in LC sample. This study highlights that complexions housing more inhibitory solute elements exert a stronger drag effect on grain growth front migration. This approach has the potential for studying grain growth in anisotropic materials, highlighting the importance of constructing experimental complexion diagrams in engineering fine-structured ceramics and metals.

Nile tilapia (Oreochromis niloticus) show high tolerance to acute ammonia exposure but lose metabolic scope during prolonged exposure at low concentration

Ammonia is a respiratory gas that is produced during the process of protein deamination. In the unionised form (NH3), it readily crosses biological membranes and is highly toxic to fish. In the present study we examined the effects of unionized ammonia (UIA), on the resting oxygen consumption (MO2), ventilation frequency (fV), heart rate (HR) and heart rate variability (HRV) in Nile tilapia (Oreochromis niloticus). Fish were either exposed to progressively increasing UIA concentrations, up to 97 µM over a 5 h period, or to a constant UIA level of 7 µM over a 24 h period. For both treatment groups resting MO2, HR and fV were recorded as physiological variables. Relative to the control group, the fish groups exposed to the incremental UIA levels did not exhibit significant changes in their MO2, HR and fV at UIA concentrations of 4, 10, 35, or 61 µM compared to control fish. Exposure to 97 µM UIA, however, elicited abrupt and significant downregulations (p < 0.05) in all three responses, as MO2, HR and fv decreased by 25, 54 and 76 % respectively, compared to control measurements. Heart rate became increasingly irregular with increasing UIA concentrations, and heart rate variability was significantly increased at 61 and 97 µM UIA. Prolonged exposure elicited significant changes at exposure 7 µM UIA. Standard (SMR) and maximum metabolic rate (MMR) were significantly reduced, as was the corresponding fV and HR. It is evident from this study that Nile tilapia is tolerant to short term exposure to UIA up to 61 µM but experience a significant metabolic change under conditions of prolonged UIA exposures even at low concentrations.

Mechanical Properties Comparison of Isotropic vs. Anisotropic Hybrid Magnetorheological Elastomer-Fluid.

Magnetorheological (MR) materials are smart materials that can change their rheological characteristics when exposed to a magnetic field. Such rheological properties include viscosity and dynamic modulus. MR materials have emerged as one of the most efficient smart materials that can modify mechanical and viscoelastic characteristics. Depending on the medium used, MR materials can be classified into two types: magnetorheological fluids (MRFs) and magnetorheological elastomers (MREs). MREs are classified as isotropic or anisotropic based on CIP distribution inside the elastomer matrix. A unique hybrid material incorporating MRE and MRF is constructed in this work to investigate, compare, and the dynamic properties of isotropic, anisotropic, hybrid isotropic, and hybrid anisotropic MREs under various magnetic fields (0, 104, and 160.2 mT). The created samples are subjected to extensive testing, including static and dynamic evaluations. In the static tests, experiments use a compression linear displacement mode with a fixed maximum gap change of 3 mm. The temperature is maintained at a constant level of 24 °C throughout the 40 s test duration for each test, and the magnetic field is incrementally increased by varying the number of magnets, ranging from 0 to 160.2 mT for dynamic qualities using compression oscillations on a dynamic mechanical analyzer (DMA), including frequency and strain-dependent data. These experiments, carried out using sinusoidal shear movements, include an excitation frequency range of 0.1 Hz to 15 Hz while preserving, with a fixed shear strain of 2%.

The Invstigation of Lipid Profile in Saudi Healthy Population and the Effects of Lifestyle

In this study differences in the response of plasma total cholesterol, triglycerides, Low Density Lipoprotein Cholesterol and High Density Lipoprotein Cholesterol were investigated in normal healthy Saudi population according to sex, age and lifestyle (rural and urban). This study was carried out for a total of (873) subjects (475 males and 398 females). Each of these two sex groups is classified into six subgroups according to ages ([0-14],[15-24],[25-40],[41-55],[56-69],[70+]). For the all tested people the blood was drawn after overnight fasting period (12-14hrs) using heparinized tubes. For all the required parameters (total cholesterol, triglycerides, LDL-C, HDL-C) enzymatic colorimetric method is used and the mean values were obtained accordingly. For plasma total cholesterol, triglycerides, HDL-C and LDL-C, the results showed lower Total Cholesterol, Triglycerides and Low Density Lipoprotein Cholesterol levels through childhood group (0-14) in both males and females. However HDL-C remains high in children with similar values as in adults in both males and females between city and village population. Neonatal and children plasma contains proportionately higher HDL-C than that of adult, decreases during adolescence to a constant value and remains constant up to the age of 55 years in both sexes, then it starts to rise to a constant level and remain constant throughout life. For both males and females at birth and through early years of life (infants and children) there were no considerable differences in all parameters (T.C, HDL-C, LDL-C, TG) tested and that is may be due to absolute and close similarity of dietary habits and lifestyle between villagers and city populations for infants and children respectively. These levels increase with increasing of age for both sexes depending deeply upon the diet, and the increase of total cholesterol is significant or close to significant up to the age of 69 years in males, then it starts to fall, but it continued to rise in women. Similarly LDL-C level increases up to the age of 69 in males and then it remains constant through all the rest of the life, but for females it continues on increasing throughout life. Triglyceride levels increase up to the age of 55 in males where it started to fall throughout life, whereas in females it follow the same manner as T.C and LDL-C since it increases throughout life. The increasing of LDL-C is quite obvious throughout life in females, whereas it remains constant after the age of 69 in males. On the other hand it seems that differences of dietary habits and lifestyle are much more effective in the adult groups of age (15-24), (25-40), (41-55), (56-69), (70+), since there are significant or nearly significant differences between villagers and city populations in plasma total cholesterol, LDL-C, HDL-C and triglycerides. It is quite obvious that the variability in plasma lipids and lipoproteins (T.C, TG, HDL-C and LDL-C) among populations precludes the establishment of universally acceptable limits. What may be considered "normal" for one populations group may not necessarily be applicable to another. Even within a country, these reference intervals may vary from a city to a village due to differences in dietary habits and lifestyle and also markedly age and sex.

Association between Fusarium head blight resistance and grain colour in wheat (Triticum aestivum L.)

AbstractThe global yield of wheat is limited by Fusarium head blight (FHB), the most damaging disease of wheat accompanied by mycotoxin contamination. Use of resistant cultivars, from an economical point of view, is the most effective control method for plant diseases. Many naturally occurring secondary metabolites in plants are involved in resistance mechanisms against FHB, especially phenolic compounds with antioxidant properties which caused various colouration of the grain in wheat. The objective of this paper was to evaluate the resistance of wheat with different grain colour on the base of accumulation of deoxynivalenol (DON) in grain and other important FHB traits after inoculation with Fusarium culmorum. Visual symptom score (VSS), Fusarium damaged kernels (FDK) and reduction of grain weight per spike (GWS-R) were determined. This study compared current conventional red wheat cultivars and coloured-grain wheat cultivars or lines with blue aleurone, purple pericarp, red grain and white grain. It was found that the cultivars with a purple pericarp (e.g. Rufia) had the lowest DON content and FDK. Statistically significant interactions between grain colour and year were found for all the variables: DON, VSS, FDK, GWS-R. Red grain materials had the lowest DON levels of all the groups studied in 2016 and 2017, but not in 2018. The most constant and second lowest DON levels in all three years were found in the cultivars/lines with purple pericarp.

Impact of pre-veraison cluster treatments with nordihydroguaiaretic acid on the composition of verdejo grapes and wines

In warmer growing regions, climate change is imposing a general increment of the temperature to the vineyards, with a greater frequency of extreme phenomena such as heat waves and droughts. The global warming is advancing and accelerating the ripening process of the grapes, which produces wines with higher alcoholic degree, lower acidity and poorer sensory characteristics. The abscisic acid (ABA) accumulation in grapes plays a crucial role in the onset of ripening, so that applying ABA inhibitors as nordihydroguaiaretic acid (NDGA) could provide musts with better sugar/acidity balance as maturation process occurs later, under lower temperatures. In a field experiment, we studied the effects of pre-veraison NDGA treatments to clusters on the composition of Verdejo must and wine. Treatments consisting of three repeated applications with 100 mM NDGA each delayed the harvest date by 4 days versus untreated controls. Total acidity, tartaric acid concentration and total polyphenol index of the must increased in treated plants, at a constant level of total soluble solid content. Data from the analysis of volatile organic compounds indicated that NDGA could contribute to the coupling of technological and aromatic maturity of grapes, then improving the aromatic profile of wines by decreasing the concentrations of total acids. Our results demonstrate that NDGA applications are potentially useful to mitigate the negative effects of global warming on the quality of wines, by increasing the acidity and polyphenol content of the musts and improving the aromatic profile of the wines.

Design and development of energy management system for solar electric vehicle with dynamic power split approach

ABSTRACT The integration of on-roof solar photovoltaic (PV) systems in electric vehicles (EVs) represents a groundbreaking advancement in the evolution of sustainable transportation. The objective of the research is to design and validate an integrated system for on-roof solar PV integration in EVs, optimising energy utilisation and reducing reliance on grid electricity. This paper explores the implementation of an Adaptive Maximum Power Point Tracking (MPPT) system, which maintains the output of the PV system at a constant level, leading to a significant improvement of approximately 10.20% in energy output compared to conventional MPPT systems. Additionally, a dynamic power split approach (DPAS) is employed to intelligently manage the allocation of power between the solar PV system and the vehicle battery, ensuring continuous fulfilment of energy demand while simultaneously recharging the battery. The proposed system reduces 65% of energy demand from grid and hence, reliance on grid. Furthermore, the dynamic power split approach enable substantial reductions in battery capacity requirements, with a potential decrease of 25–35% observed. These advancements not only enhance the performance and efficiency of EVs but also contribute to cost savings and the transition towards a cleaner and more sustainable transportation ecosystem.

Molecular Characterization of the Allergenic Arginine Kinase from the Edible Insect Hermetia illucens (Black Soldier Fly).

Arginine kinase (AK) is an important enzyme for energy metabolism of invertebrate cells by participating in the maintenance of constant levels of ATP. However, AK is also recognized as a major allergen in insects and crustaceans capable of cross-reactivity with sera of patients sensitized to orthologous proteins. In the perspective of introducing insects or their derivatives in the human diet in Western world, it is of primary importance to evaluate possible risks for allergic consumers. This work reports the identification and characterization of AK from Hermetia illucens commonly known as the black soldier fly, a promising insect for human consumption. To evaluate allergenicity of AK from H. illucens, putative linear and conformational epitopes are identified by bioinformatics analyses, and Dot-Blot assays are carried out by using sera of patients allergic to shrimp or mites to validate the cross-reactivity. Gastrointestinal digestion reduces significantly the linear epitopes resulting in lower allergenicity, while the secondary structure is altered at increasing temperatures supporting the possible loss or reduction of conformational epitopes. The results indicate that the possible allergenicity of AK should be taken in consideration when dealing with novel foods containing H. illucens or its derivatives.

The translational content and expression of intracellular sensors under endoplasmic re-ticulum stress in diabetic rats

Endoplasmic reticulum stress (ER stress) activates the unfolded protein response (UPR) as a defense mechanism for maintaining cellular vital activity. Data on interaction between pathways of UPR-sensors, their role and participation in the recovery of regulatory proteins at constant level are currently being accumulated. An experimental model of type 2 diabetes mellitus (T2DM) was reproduced in male rats fed on 3-month high-fat diet with additional streptozotocin administration. Rats in different groups were treated with metformin, propionate, and their combination for 2 weeks. We analyzed the expression of the GRP78, PERK, IRE-1, and ATF6 genes in gastric glandulocytes using PCR primers. The quantitation of protein content of the GRP78, PERK, IRE-1, and ATF6 genes was performed using western blotting. Statistical intergroup differences were calculated using a one-way ANOVA test followed by Tukey’s post-hoc. Comparison of mRNA and protein contents at rest state, in condition of ER stress and drug treatment, as well as the study of correlations between UPR-sensors, provides a basis for the development of the concept of defense mechanism activation in gastric glandulocytes under T2DM conditions. Under stress, chaperone GRP78 plays a crucial role to prevent protein misfolding: it dissociates from ER, enters cisternae and inactivates misfolded proteins. The ATF6 pathway is activated in all conditions. It probably activates transcription of the corresponding content turnover sites in both GRP78 and ATF6. The IRE-1 and PERK pathways are activated in glandulocytes under different circumstances, and they probably target to different regulatory actions. Combination drug treatment in T2DM conditions induces activation of all signaling sensors in the UPR system with simultaneous maximal downregulation of GRP78, causing a balance in the intracellular homeostasis system.

Cell wall water induced dimensional changes of beech and pine wood

Hygroexpansion in timber construction is a phenomenon that occurs as a result of changes in the cell wall structure of wood caused by water. In this study, beech (Fagus sylvatica) and pine (Pinus taeda L.) wood were conditioned at different relative humidities with saturated salt solutions and saturated through vacuum pressure impregnation. The moisture content and dimensions of the samples were evaluated under various adsorption equilibrium states, as well as during drying from water saturation to an air-dried state. The results obtained using the two-dimensional time-domain nuclear magnetic resonance technique revealed two distinct types of cell wall water in both wood species, designated as B-water and C-water, as they displayed different mobilities. With increasing moisture content, the mobility of cell wall water increased; however, B-water maintained a constant level of mobility and formed water clusters when it accumulated in the high humidity region and at slightly above the fiber saturation point (FSP), which is evidence of the occurrence of free-bound water. The B-water, located in the amorphous region of microfibrils and their surrounding hemicellulose, exerted a predominant influence on the dimensional changes of the wood both under equilibrium and nonequilibrium conditions, in comparison to the C-water which located in the matrix of hemicellulose and lignin.

Effect of chronic stress on the degree of acrylamide toxicity in rats

Introduction. Chronic stress plays an important role in the development of a wide range of mental, somatic and behavioural disorders, and therefore is a risk factor for the health in living organisms. A negative effect on the state of the nervous system is also observed when the body is poisoned with acrylamide, which is a substance of the second class of danger and is considered toxic and carcinogenic. Exposure of the body to mental and toxic stressors leads to autonomic and neuroendocrine activation, which, in turn, manifests itself as special behavioural patterns. &#x0D; The purpose of the experiment was to assess the effect of chronic stress on the degree of acrylamide toxicity in rats.&#x0D; Materials and methods. The experiment was conducted on white outbred rats with an average weight of 200 g of both sexes (n=60), which were evenly distributed into five groups: negative control, chronic stress, acrylamide, acrylamide + treatment, acrylamide + chronic stress. Throughout the study, the animals were kept under standard conditions with 12 hours of artificial lighting during the day, a relatively constant level of humidity (30–70%) and an air temperature of 20–25 °C. Behavioural tests were conducted once a week for one calendar month using a 40×40 hole board, a multifunctional cage to assess general activity, and an elevated plus maze with an ANY-maze video tracking system. Biochemical parameters were assessed in accordance with the manufacturer’s instructions.&#x0D; Results. Analysis of behaviour on a board with holes did not reveal statistically significant results (H=8.987; p=0.061). When comparing vertical and horizontal motor activity between groups, statistically significant differences were found (p&lt;0.05). AST levels were higher in the stress groups, while cholesterol levels in the same groups were lower (p&lt;0.05).&#x0D; Limitations. Laboratory animals of only one biological species were used for the experiment. The toxicant was used only in one concentration.&#x0D; Conclusion. Chronic stress may influence on acrylamide toxicity in rats to a certain extent.

Effects of constant high water levels in winter on waterbird diversity in Caizi Lakes: A functional perspective

The middle and lower Yangtze River floodplain lakes are important stopover and wintering sites for migratory birds on the East Asian–Australasian Flyway. The periodic water level fluctuation of the lakes plays a critical role in the aggregation of waterbirds. However, the construction of a series of gates and dams has impeded the hydrological connectivity between rivers and lakes and disrupted the natural water level fluctuation patterns of lakes. The water level status of lakes influences habitat utilization by waterbirds. In recent years, Caizi Lakes, the gate-controlled lakes connected to the Yangtze River due to the need for water level regulation requirements, has experienced sustained high water levels in winter, which can reduce habitat quality and in turn influence waterbirds activity. In the present study, wintering waterbirds in Caizi Lakes were surveyed during the 2021–2022 (W1) and 2022–2023 (W2) wintering periods. Moreover, we explored the effects of constant high water levels in winter on waterbird assemblages by comparing species richness, abundance, and functional alpha and beta diversity. Correlation analyses were then performed to elucidate the relationship between habitat factors and water level changes during the wintering period of migratory waterbirds and between changes in various habitat factors and wintering waterbird assemblages under different hydrological conditions. The results showed that functional beta diversity was more sensitive to changes in waterbird assemblages in Caizi Lakes than functional alpha diversity. Moreover, constant high water levels in the mid-wintering period decreased suitable habitats for wintering waterbirds, increased functional turnover among waterbird assemblages, increased total dissimilarity among assemblages significantly, and decreased the level of functional nestedness significantly. Additionally, the areas of the three wetland habitats in Caizi Lakes were significantly correlated with water level changes during W1 and relatively less affected by water level changes under constant high water level conditions during W2. The changes in habitat area were influenced primarily by anthropogenic activities, with an increase in meadow area favorable for species richness and abundance, as well as functionally nested components. Water level regulation should take into consideration the natural hydrological rhythms of the declining water level to ensure that adequate and suitable habitats are provided for wintering waterbirds.

Evaluation of autotrophic process influencing extracellular polymeric substances in aerobic membrane bioreactor with expanded ASM model

A mathematical model was developed to predict the formation of both the autotrophic and heterotrophic extracellular polymeric substances (EPS) in the aerobic membrane bioreactor (MBR). Batch experimental results and 45-day operation data on a pilot MBR at a sludge retention time (SRT) of 20 d were used to calibrate and validate the model. Simulated MBR setup results demonstrated the key role of the influent COD and NH4+-N in governing the composition of heterotrophic and autotrophic EPS in the MBR. These results also revealed that the autotrophic EPS process was non-ignorable in the system. According to the autotrophic EPS simulation in the MBR, the EPS yield increased with increasing influent COD/NH4+-N ratio towards a constant level. The EPS yield was significantly influenced by the SRT, attributed to the autotrophic process's impact on EPS. Simulation results revealed a slight increase in EPS yield with an SRT of up to 5 days, followed by a rapid decrease beyond that threshold.

A Study on the Treatment and Recovery of Sodium Sulfate (Na&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;) Generated When Recovering Valuable Metals (Ni, Co, Mn, Li) from Waste Lithium Ion Batteries(LIBs)

Concerns have arisen regarding the high concentrations of sodium sulfate in wastewater resulting from the waste Li-ion battery wet recycling process. In addressing this issue, Bipolar electrodialysis was employed to desalinate high-concentration sodium sulfate and recover it as sulfuric acid and sodium hydroxide. The investigation encompassed various experimental variables, such as applied voltage (maintained at a constant level), feed solution concentration, the initial concentrations of sulfuric acid and sodium hydroxide, and volume ratio (F/A/B). Optimal conditions were determined by assessing water migration (%), the recovery rates (%) of sulfuric acid and sodium hydroxide, concentration of the recovered substances, process time, and energy consumption. A higher applied voltage was found to reduce process time while increasing energy consumption, with the 25 V condition considered preferable. When utilizing a high-concentration feed solution, energy consumption rises; however, it decreases per unit of processed solution, rendering a 1.30 M Na&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; feed solution preferable. Increasing initial concentrations of sulfuric acid and sodium hydroxide substantially prolonged process time and increased energy consumption, emphasizing the advantage of commencing with low initial concentrations. Adjusting the volume ratio facilitated the concentration and recovery of sulfuric acid and sodium hydroxide with minimal impact on process time or energy consumption. Under the identified optimal conditions, the recovery of 1.70 M sulfuric acid and 2.44 M sodium hydroxide was achieved.

Verification of Sustainable Asphalt Concrete through the Energy Dissipation

The kinetic energy created in the asphalt concrete due to practicing dynamic loading is absorbed and consumed to retain the properties of the asphalt mixture through its flexibility; however, part of the energy is dissipated in the initiation of microcracking and other types of distresses. In this work, the influence of additives (fly ash and silica fumes) on controlling the energy dissipation of asphalt concrete mixtures was assessed. Beam specimens of asphalt mixture were obtained from the roller compacted slab samples and tested for fatigue under three constant strain levels by implementation of the four points bending beam. It was noticed that for fly ash treated mixture, the consumed time for energy dissipation decline by (75, and 97.5) % while the dissipated energy declines by (84.8, and 99.5) % when the constant strain level increases from (250 to 400 and 750) micro strain respectively. However, for silica fumes treated mixture, the energy dissipation declines by (3.3, and 95) % when the constant strain level rises from (250 to 400, and 750) micro strain respectively. It was noticed that the damage resistance as indicated by the increment in dissipated energy increases by (60, and 140) % when fly ash and silica fumes were implicated respectively. However, the silica fumes additive consumes the energy at lower time of 60 seconds than the case of control mixture. The fly ash additive exhibits no significant variation in consuming the energy when compared with the control mixture.

Validation of putative biomarkers of furan exposure through quantitative analysis of furan metabolites in urine of F344 rats exposed to stable isotope labeled furan

Humans are chronically exposed to furan, a potent liver toxicant and carcinogen that occurs in a variety of heat-processed foods. Assessment of human exposure based on the furan content in foods is, however, subject to some uncertainty due to the high volatility of furan. Biomarker monitoring is thus considered an alternative or complementary approach to furan exposure assessment. Previous work suggested that urinary furan metabolites derived from the reaction of cis-2-butene-1,4-dial (BDA), the reactive intermediate of furan, with glutathione (GSH) or amino acids may serve as potential biomarkers of furan exposure. However, some metabolites were also reported to occur in urine of untreated animals, indicating either background contamination via animal feed or endogenous sources, which may limit their suitability as biomarkers of exposure. The overall aim of the present study was to accurately establish the correlation between external dose and concentration of furan metabolites in urine over time and to discriminate against endogenous formation and furan intake via feed. To this end, the furan metabolites GSH-BDA (N-[4-carboxy-4-(3-mercapto-1H-pyrrol-1-yl)-1-oxobutyl]-L-cysteinylglycine), NAcLys-BDA (R-2-(acetylamino)-6-(2,5-dihydro-2-oxo-1H-pyrrol-1-yl)-1-hexanoic acid), NAcCys-BDA-NAcLys (N-acetyl-S-[1-[5-(acetylamino)-5-carboxypentyl]-1H-pyrrol-3-yl]-L-cysteine) and NAcCys-BDA-NAcLys sulfoxide (N-acetyl-S-[1-[5-(acetylamino)-5-carboxypentyl]-1H-pyrrol-3-yl]-L-cysteine sulfoxide) were simultaneously analyzed by stable isotope dilution ESI–LC–MS/MS as unlabeled and [13C4]-furan dependent metabolites following oral administration of a single oral dose of isotopically labelled [13C4]-furan (0.1, 1, 10, 100 and 1000 µg/kg bw) to male and female F344/DuCrl rats. Although a linear correlation between urinary excretion of [13C4]-furan-dependent metabolites was observed, analysis of unlabeled NAcLys-BDA, NAcCys-BDA-NAcLys and NAcCys-BDA-NAcLys sulfoxide revealed substantial, fairly constant urinary background levels throughout the course of the study. Analysis of furan in animal feed excluded feed as a source for these background levels. GSH-BDA was identified as the only furan metabolite without background occurrence, suggesting that it may present a specific biomarker to monitor external furan exposure. Studies in humans are now needed to establish if analysis of urinary GSH-BDA may provide reliable exposure estimates.

Creep compliance of functionalized graphene-epoxy nanocomposites

Creep behavior is observed even at room temperature in polymers and polymer composites under constant stress. In the design of structural elements using these materials, the determination of creep compliance for structural strength and performance analysis is crucial in terms of reliability and usability. In this study, the creep compliance of pure epoxy and functionalized graphene-reinforced epoxy nanocomposites were experimentally investigated and compared at room temperature at constant stress levels of 50, 100, and 200 MPa representing the viscoelastic region, yielding region and viscoplastic region, respectively. To reveal the effect of temperature as well as stress level on this behavior, the creep compliance of epoxy and graphene-epoxy nanocomposites was investigated at 65°C in addition to room temperature after the pure graphene used as a reinforcement element was functionalized with Triton X-100, nanocomposite production was carried out. In 2h creep tests, it was observed that as the constant stress level increased, the creep compliance increased and the creep compliance of the nanocomposite was lower than that of the epoxy at all stress levels. The creep compliance of the epoxy was improved by 65% with the addition of functionalized graphene at room temperature and a stress level of 100 MPa. As the temperature increased, the creep compliance of both epoxy and functionalized graphene-epoxy nanocomposite increased due to molecular mobility and viscous flow. However, at high temperatures, the positive effect of functionalized graphene on the compliance of the epoxy is higher. At 65°C and a stress level of 100 MPa, the improvement rate of creep compliance is 78%. Functionalized graphene exhibited a more effective behavior on creep resistance at high temperatures. The obtained results showed that creep compliance was significantly affected by stress level and temperature.

IOT based smart street light fault detection management system

In the contemporary landscape of urbanization and technological progress, efficient resource management, particularly in energy consumption, is paramount. Street lighting stands out as a significant energy consumer in urban environments. This paper proposes a Smart Street Light Fault Detection System utilizing Internet of Things (IoT) technology, a NodeMCU microcontroller, Light Dependent Resistor (LDR), street lights, and the ThingSpeak. The system employs the NodeMCU microcontroller to monitor ambient light conditions through the LDR sensor, enabling automatic control of street lights to optimize energy usage. Furthermore, it integrates fault detection mechanisms to identify abnormalities in street light operations, such as constant light levels amidst changing environmental conditions, indicative of potential faults. Through the ThingSpeak, users can remotely monitor real-time LDR readings, receive notifications about detected faults, and take necessary actions, empowering city authorities or maintenance personnel with timely information for addressing issues and ensuring smooth infrastructure operation. This smart system offers advantages like energy efficiency, automated control, and proactive fault detection, facilitating significant energy savings, reduced maintenance costs, and enhanced sustainability in urban environments, thereby showcasing a practical implementation of IoT technology for smarter and more sustainable cities.

Impact of research and development expenses on the profitability of assets: The case of textile and clothing industry in Portugal

The study aims to examine the financial efficiency of the textile and clothing industries in Portugal using official statistical data. The main objective is to assess the relationship between spending on research and development and return on assets. The study analyzes the performance of various subsectors of the textile and clothing industries, presenting the relationship between investments in research and development and the operating return on assets over various economic periods. The study adopted data envelopment analysis, classifying decision-making units based on average efficiency levels. The results highlight sectors of manufacture of textiles for technical and industrial use, manufacture of other textiles, production of outerwear, and manufacture of workwear as the most efficient. In contrast, sectors of manufacture of clothing and accessories, manufacture of knitwear, and leather clothing show lower levels of efficiency. From 2003 to 2022, the textile industry exhibited the highest levels of financial efficiency, with an above-average ratio between spending on research and development and return on assets. However, sectors of knitwear manufacturing and textile finishing have maintained a more or less constant level of financial efficiency. The analysis highlights the need for targeted interventions to increase the financial efficiency of different subsectors within the textile and clothing industries. It is evident that there are varying levels of financial efficiency across these sectors, and the need for benchmarking periods can help identify areas for improvement and set achievable goals. AcknowledgmentThis article is financed by Instituto Politécnico de Setúbal [Polytechnic Institute of Setúbal].

Post-creep residual tensile properties of multi-walled carbon nanotube/epoxy nanocomposites

Epoxy resin as a thermoset polymer is vulnerable to creep loading even at room temperature due to its viscoelastic nature. This study investigated the effect of reinforcing epoxy resin with different functionalized multi-walled carbon nanotubes (MWCNT) contents on the creep response and post-creep residual tensile properties of nanocomposites. The creep tests were performed on the nanocomposite specimens containing different filler contents and the neat epoxy specimen at 40°C under a constant load level of 200 N. It was found that the nanocomposites containing 0.3 wt% MWCNTs experienced 29.6%, 69.1%, and 74.1% decreases in the elastic strain, creep strain, and steady-state creep strain rate, respectively, compared to the neat epoxy. Furthermore, the tensile strength and stiffness of the neat epoxy and nanocomposite specimens were evaluated before and after a partial creep test (at a load level of 200 N for 150 min) by conducting tensile tests. The nanocomposites containing 0.3 wt% MWCNTs demonstrated considerable improvements of 35.9%, 41.2%, 27.9%, and 28.1% in strength, residual strength, stiffness, and residual stiffness, respectively, compared to the neat epoxy. Furthermore, scanning electron microscopy assessment was utilized to investigate the fracture surfaces of the nanocomposite specimens.