Hydrogels are gaining attention in drug delivery systems due to their large surface area and absorption capacity, which enhance interaction with surrounding media. This study focuses on the release of tannic acid (TA) from alginate hydrogels and reduced graphene oxiswe (rGO) in a phosphate-buffered saline (PBS) solution at 37°C and pH 7.4, simulating physiological conditions similar to those found in wounds. The release profiles reveal two distinct patterns: hydrogels with 9% reduced graphene oxide (rGO) release TA rapidly, reaching equilibrium within 80 minutes. This quick release may result from poorly adhered TA transitioning into the medium, which aligns with previous findings on alginate/chitosan/tannic acid hydrogels. Conversely, hydrogels containing 4.5% rGO exhibited a controlled, sustained release throughout the experiment, with the highest TA release noted at 21.3% and 26.4% for Alg/rGO_4.5/TA₉ and Alg/rGO₉/TA₉, respectively. Furthermore, the antioxidant capacity of the hydrogels was evaluated using the DPPH method, which assesses their electron donation capability. The results indicated that only the TA functionalized hydrogels exhibited antioxidant properties, with notable improvement over time, particularly in the Alg/rGO₉/TA₉ material, which reached 15% antioxidant capacity. Comparatively, prior studies showed higher antioxidant capacities due to differences in experimental conditions. Overall, the findings emphasize the potential of these hydrogels as effective agents in reducing reactive oxygen species levels, thereby promoting wound healing.

Background: Confectionery products and, in particular, caramel have a low nutritional value and a high glycemic index. Overcoming these shortcomings is possible by including new-generation sugar substitutes such as polyols and fortifying agents based on dried plant powders in the formulation of candy caramel.

Object: The purpose of this study was to develop the technology of candy caramel as a functional product with a lower glycemic index. The index reduction was achieved by including sugar substitute such as isomaltitol in the caramel formulation. As a fortifying agent with a significant amount of bioactive compounds and at the same time a natural colorant, the dried powder of the wild plant Berberis vulgaris L. was used in an amount of 1, 2.5, 5 and 10% (w/w).

Methods: The microstructural characteristics of the powder were determined by laser diffraction. The elemental composition was confirmed by atomic adsorption spectroscopy. Physicochemical methods and sensory analysis were used to evaluate candy caramel samples.

Results: The technology for the production of candy caramel using isomaltitol, invert syrup and barberry powder was developed. Dry barberry powder was used to prepare the samples, characterized by an optimal average particle size of 37.4 μm and a width of the SPAN particle distribution curve of 2.94 μm. The addition of barberry powder in quantity made it possible to enrich candies with trace elements such as sodium, potassium, iron, manganese and zinc. When the amount of barberry in the caramel recipe is increased, the acidity significantly increases from 1.02 to 10.2 mg/100 g of the sample in the equivalent of citric acid and changes the pH from 3.45 to 3.12. Sensory analysis allowed us to establish that the optimal amount of barberry powder inclusion in caramel formulations is 2.5-5%.

Conclusion: The result was a candy caramel with a potential as a functional food.

Public tertiary institutions in Nigeria have been beneficiaries of the Tertiary Education Trust Fund
(TETFUND), aimed at enhancing the quality of education by providing essential structures. The TETFUNDis a government agency in Nigeria, established by an Act in 2011 to provide financial support to public
tertiary institutions in the country. Despite this initiative, many projects encounter setbacks such as budget
overruns and suboptimal resource allocation, leading to uncompleted or abandoned building construction
projects. Deployment of technologies has enhanced the concept of intelligent construction, which has
impacted the processes of building construction. These stalled projects hamper the universities’ ability to
expand infrastructure, improve educational quality, and accommodate growing student populations.
Identifying the root causes of project abandonment and exploring the potential role of technology in
addressing these issues is crucial for utilizing available funds. This study examines how technology can
enhance the efficiency and transparency of TETFUND construction projects in public universities in Delta
State, Nigeria. The research methodology to be adopted is a descriptive approach where a review of the literature
would be performed and advantages drawn from them. The focus was on TETFUND-sponsored buildings
randomly selected from the research population. Technology can enhance the projects by optimizing
material usage, reducing waste, and improving energy efficiency, thus contributing to more sustainable
university campuses. TETFUND building construction projects involve multiple stakeholders, including
Architects, Project Managers, Contractors, Academia, Universities, and TETFUND. Understanding how
leveraging technology impacts these stakeholders can help improve collaboration and communication
throughout the project lifecycle.
Keywords: artificial intelligence

Electronic descriptors extracted from Density Functional Theory (DFT) calculations are a powerful tool in designing new perovskite-based materials that could catalyze oxygen reduction (ORR) and oxygen evolution (OER) reactions [1]. In particular, a good correlation has been found between the O 2p-band center and the charge transfer energy, the oxygen vacancy formation energy, the adsorption energy, or the overpotential. While such correlations are proven for simple ABO₃ perovskites, there are few studies dealing with oxides presenting high chemical and structural complexity. In this work, the layered perovskite system YSr₂Cu₂FeO_7+δ (YSCFO) [2] is investigated to analyze the effects of oxygen non-stoichiometry and vacancy ordering in the O 2p-band center values. In YSCFO, the formal oxidation states range from Fe⁴⁺ and mixed Cu³⁺/Cu²⁺ (δ =1 ) to Fe³⁺ and Cu²⁺( δ =0 ). To establish a comparison with a single-TM oxide, band centers are also extracted for the Ruddlesden Popper Sr_2-xLa_xFe₂O₄ phase with 0 < x < 2 (formally, from Fe(IV) to Fe(II)).

DFT calculations (SCAN, PBE+U) are performed using the ab initio total energy program (VASP). The O 2p-band centers are extracted from the calculated DOSs. For RP-Sr_2-xLa_xFe₂O₄, the O p-band center displays a linear trend with the Fe oxidation state. In the complex system YSCFO, the interplay between Cu and Fe 3d states breaks the linearity. In addition, for a given oxygen content, the O 2p-band center varies with the oxygen/vacancy ordering in the FeO_1+δ layers. Importantly, the O 2p-band center values calculated for the YSCFO system suggest that these materials may possess electrocatalytic activity, as the obtained values are between -1.0 and -1.8 eV [1].

1. Jacobs, R.; Mayeshiba, T.; Booske, J.; Morgan, D. Advanced Energy Materials 2018, 8, doi:10.1002/aenm.201702708.
2. Gómez-Toledo, M.; López-Paz, S.A.; García-Martín, S.; Arroyo-de Dompablo, M.E. Inorganic Chemistry 2023, doi:10.1021/acs.inorgchem.2c03475.

Phase-field models are used to represent the geometry of defects in a diffuse manner, without introducing sharp discontinuities. Due to this feature, these models demonstrate a high level of efficiency in simulating crack propagation compared to numerical techniques that rely on a discrete crack model. This particular advantage becomes exceptionally evident when confronted with complex crack models, highlighting the superior capabilities of phase-field models to accurately represent the complex behaviors exhibited by cracks, and the phase field method can essentially be treated as a multi-field problem, even for a purely mechanical problem. The current study focuses on the area of ​​crack modeling in brittle materials, using the phase-field methodology specifically adapted to these materials. In the field of computational mechanics, many research efforts have focused on the complex task of fracture modeling through the use of phase fields. Among this body of academic work, the present study stands out for its use of a phase-field model to describe crack initiation and propagation in brittle two-dimensional materials using the finite element method (FEM). Numerical simulations are meticulously presented and carefully studied to vividly illustrate the remarkable efficiency and robust capability of the phase field method to address and handle this particular type of modeling.

Molybdenum, a transition metal, is well regarded for its diverse applications due to its ability to adopt multiple oxidation states and form various complexes. Molybdenum Schiff base complexes, which are created by coordinating molybdenum with Schiff base ligands, resulting from the condensation of primary amines and carbonyl compounds, demonstrate unique and valuable properties [1]. These complexes are extensively documented for their significant roles across various fields. Biologically, molybdenum is crucial as a component of several key enzymes [2]. Industrially, these complexes are essential in processes like petroleum refining and chemical manufacturing. They are especially notable for their catalytic activity in oxidation, hydrogenation, and olefin metathesis reactions, contributing to various chemical synthesis processes [1]. In material science, they are instrumental in developing advanced materials with distinctive electronic and structural properties, which are beneficial for enhancing energy conversion and environmental remediation [3,4].

In the current study, a Schiff base ligand was synthesized via the condensation of salicylaldehyde and oxalyldihydrazide and then coordinated to the [MoO₂]²⁺ core. This synthesis, performed in methanol, resulted in the formation of the complex [Mo₂O₄(L)(MeOH)₂]·2 H₂O. The complex was exposed to vapors of water, methanol, ethanol, and propanol, leading to the desolvatatation and decoordination of solvent molecules and the coordination of vapor molecules. Characterization was conducted using IR-ATR spectroscopy and thermogravimetric analysis (TG), with molecular and crystal structures determined through X-ray diffraction. Impedance spectroscopy (IS) confirmed structural changes. Additionally, these complexes were tested as catalysts for the oxidation of benzyl alcohol, demonstrating their potential in catalytic applications.

[1] A. Bafti, M. Razum, E. Topić, D. Agustin, J. Pisk, V. Vrdoljak, Mol. Catal. 512 (2021) 111764.

[2] R. Hille, J. Hall, P. Basu, Chem. Rev. 114 (2014) 3963-4038.

[3] J. Sarjanović, M. Stojić, M. Rubčić, L. Pavić, J. Pisk, J. Materials 16 (2023) 1064.

[4] J. Pisk, M. Šušković, E. Topić, D. Agustin, N. Judaš, L. Pavić, Int. J. Mol. Sci. 25 (2024) 4859.

Bioactive packaging is a term that has become increasingly widespread in society. This packaging enhances the effectiveness against food deterioration and inhibiting microbial growth, which is often associated with food loss and waste (1). Natural extracts from agro-industrial by-products have been shown to improve packaging properties, including physical and mechanical characteristics, while also potentially providing antioxidant and antimicrobial effects. Which can extend food shelf life and reduce dependence on synthetic additives (2). This research focuses on Castanea sativa hedgehog extracts obtained from northeastern Portugal. This by-product extract is rich in bioactive components, including both condensed and hydrolysable tannins, phenolic acids (such as ellagic and gallic acids), and flavonoids (including catechin, epicatechin, apigenin, quercetin, and rutin), all of which exhibit important antioxidant and antimicrobial activities (3,4). The purpose of this study is to evaluate the possibility of incorporating C. sativa hedgehog extracts as bioactive compounds in composite films. The biological properties of this extract, such as its antibiofilm, antimicrobial, and antioxidant characteristics, were assessed. The results obtained show high antioxidant activity, with free radical scavenging values of 0.17 mMTrolox/g and 0.43 mMTrolox/g, as determined by the Ferric Reducing Antioxidant Power and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) assays, respectively. In terms of antimicrobial assays against key pathogens, the extracts demonstrated broad-spectrum efficacy, achieving activity rates of 78% against Staphylococcus aureus, 75% against Escherichia coli, and 51% against Klebsiella pneumoniae. Furthermore, biofilm reduction was observed, with decreases of 75% for S. aureus, 54% for E. coli, and 36% for K. pneumoniae. These results support the statement that C. sativa hedgehog extracts represent a promising natural source of bioactive compounds for future applications in bioactive packaging materials.

The ZrO₂ is an increasingly used material for various applications in different fields such as optoelectronics, medicine and environmental monitoring. Its main advantages are due to almost unique properties, such as high mechanical and thermal resistances, high dielectric constant and refractive index, wide range of optical transparency and capability for diverse nanostructuring.

Among different methods applied for synthesis of metal-oxide nanostructures, the electrochemical deposition is an attractive method – it is cost-effective, environmentally compatible, requires relatively simple apparatus and offers easy control of morphology of produced nanostructures by varying the deposition parameters.

The aim of our work is to study the morphological and sensing properties of nanostructured ZrO₂ layers, electrochemically deposited on the gold electrodes of AT-cut quartz resonators. The deposition is carried out in aqueous solution containing 5 mM of ZrOCl₂ and 100 mM of KCl. The layers sensing abilities towards ammonia and ethanol vapors are measured by using Quartz Crystal Microbalance (QCM) method. The influence of electrodeposition conditions (the temperature and time) on layers morphology and sensing characteristics is measured and analyzed.

The layers morphology significantly depends on deposition temperature that leads to nanostructured grains with different size, shape, surface density, and roughness. The results for gas sensing show low sensitivity to ethanol and high sensitivity to ammonia. As a whole, the work confirms the suitability of ZrO₂ electrochemical deposition for the further design and development of QCM gas sensing devices.

Two-dimensional (2D) nanostructures can be both single-atomic layers (e.g., graphene, graphite oxide, reduced graphite oxide) and lamellas made of a few atomic layers (e.g., Molybdenum disulphide, Tungsten disulphide, gold nanoplatelets). The small thickness of 2D nanostructures, frequently of only a few angstroms, is needed in order to allow for the arising of anomalous physical properties in the solid phase as a consequence of quantum-confinement effects, prevalence of surface on bulk atoms, high surface free-energy content, etc. Owing to the strict correlation existing between structure and properties in nanomaterials, their morphological characterization represents the first essential information that is required. Electron microscopy techniques (SEM and TEM) are commonly used as approaches for investigating the structure of this very tiny matter form. However, the observation of 2D nanostructures by SEM needs suitable expedients to achieve highly informative images. Indeed, the extremely thin thickness of a single-layer nanostructure makes really challenging the microscopical characterization. Here, a special approach, based on specimen tilting from the 90° sample positioning, has been used to allow for the imaging of single 2D layers of graphene and MoS₂ and WS₂. Usually, the standard operation of sample tilting from the 0° positioning is unable to provide images with enough contrast. Sample morphology is clearly visualized by using this tilting approach and a number of morphological features (e.g., presence of ripples in the layer, edge structure and defects, holes, etc.) appears in the electronic micrograph. In order to evidence the efficacy of the proposed method, a comparison with the classical top view SEM observation is also provided for these selected 2D nanostructures.

Global warming and pollution instigated by fossil fuel combustion have led environmental agencies to advocate for eco-friendly renewable fuels. Biodiesel is a green and renewable fuel produced by the transesterification reaction of vegetable oil/animal fat with short-chain alcohol in the presence of a catalyst. Biodiesel production has been affected by the cost of production mainly due to the cost of feedstock. This work presents biodiesel production using waste margarine oil and response surface methodology (RSM) for process optimisation. The transesterification of waste margarine oil was carried out using sodium hydroxide (NaOH) as a catalyst under atmospheric pressure in a lab-scale batch reactor. Central composite design (CCD) was used to optimise four parameters: methanol-to-oil ratio (3-15 mol/mol), catalyst ratio (0.3-1.5 wt.%), reaction time (30-90min), and reaction temperature (30-70^oC). Numeral optimisation was performed, and an optimum yield of 94.024% was obtained at a 9.6 mol ratio, 0.96 wt. % catalyst ratio, 63 min reaction time, 52 ^o C reaction temperature, and a low standard error yield of 0.576 %. Analysis of variance (ANOVA) showed that the methanol-to-oil ratio had the highest influence on the biodiesel yield, followed by the catalyst ratio, and reaction time had the least impact after temperature. The kinetics study describes that the reaction is controlled by pseudo-first order, and the activation energy was found to be 62.41 kJ/mol. It was concluded that biodiesel could be produced using waste margarine oil as a cost-effective feedstock optimised by RSM.