16168 research outputs found
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Zero-day ransomware attack detection using static portable executable header features /
No full textRansomware is one of the types of malware attacks that most severely affects financial institutions, since they cannot afford to lose their data or experience long-term disruptions. It is crucial for financial institutions to protect themselves from ransomware attacks. To fight zero-day ransomware attacks that are previously unseen attacks, we have presented a method that uses the static header features of portable executables. The method forms a comprehensive static feature set that includes the header fields of portable executables, count of dynamic link libraries (DLLs), DLL average, DLL list, function call average, and a measure of section content randomness. In order to make a compact feature set, a threshold was applied to three feature sets: portable executable header, DLL features, and section randomness. To determine the DLL average usage, the Tanimoto coefficient was applied to measure DLL similarity. The same procedure was applied to determine the function call average. The Chi-square test was applied to measure the section content randomness of portable executables. A stacking classifier was applied to measure the performance of the developed feature set. A publicly available dataset was used for the experiments. The results for the detection of zero-day attacks demonstrated averages of 97.15% accuracy, 98.06% recall, and 92.74% F-measure. When compared with other methods using the same dataset, our proposed method provided slightly better performance for many ransomware families
Framework for the verification of geometric digital twins: application in a university environment /
No full textDigital Twins rely on accurate geometric models to ensure reliable representation, yet maintaining and updating these models remains a persistent challenge. This paper addresses one aspect of this challenge by focusing on the verification of photogrammetrybased models. It introduces a verification framework that defines measurable data quality elements and establishes conditions to assess whether model quality is maintained, improved, or degraded. Validation through a university building case study demonstrates the framework’s ability to detect quality differences between visually similar models. Meeting only one of the three verification conditions, the new model shows quality degradation, primarily due to reduced positional accuracy and resolution, making it unsuitable to replace the previous version used in the Digital Twin. Additionally, the developed web tool prototype enables the automated calculation of the framework’s verification scores. This study contributes to the growing discussion on Digital Twin maintenance by providing practical insights for improving the reliability of geometric models
Temperature effect analysis of PVDF-based piezoelectric energy harvester /
No full textThis study presents a comprehensive investigation into the temperature-dependent performance of polyvinylidene fluoride (PVDF)-based piezoelectric energy harvesters (PEHs), integrating both experimental analysis and finite element modeling. The primary objective is to elucidate the influence of temperature variations on the electrical output and resonant frequency of PVDF-based PEHs, thereby enhancing the reliability and efficiency of energy harvesting systems in diverse thermal environments. Recognizing that environmental conditions play a significant role in the degradation and failure of electronic devices, this research evaluates the electrical output and resonant frequency of PEHs across a temperature range of −20 °C to 50 °C. Four identical PEH prototypes were fabricated and subjected to controlled temperature conditions, revealing a nonlinear increase in output voltage and power with rising temperature, while the resonant frequency remained relatively stable. A new, flexible test rig was set up to easily check how PEH devices perform in different temperatures, and it can also be scaled up for testing many devices in large production. To accurately simulate the observed behavior, finite element models incorporating experimentally derived Rayleigh damping coefficients were developed using COMSOL Multiphysics. The simulations closely matched the experimental data, validating the effectiveness of the damping parameters in capturing the dynamic response of the PEHs under varying thermal conditions. The proposed methodology provides a strong basis for future research into thermal aging effects, long-term durability, and performance optimization of polymer-based energy harvesters. The findings underscore the suitability of PVDF as a piezoelectric material with a steel substrate for energy harvesting applications
New insights into secondary metabolite potential in hypericum perforatum, UPLC-ESI-MS/MS to novel phytochemical discovery with bioactivity assessment /
No full textDifferent anatomical components of Hypericum perforatum (H. perforatum) have been utilized by humans for generations as a natural remedy with pharmacological attributes. This work aimed to investigate the secondary metabolite potential of H. perforatum from algeria using LC-ESI-MS/MS to determine its phytochemical profile. LC-ESI-MS/MS analysis revealed 22 components, with isoquercitrin being the most abundant bioactive compound at a concentration of 4162 µg/g. The total phenolic and flavonoid contents were also quantified, with TPC equal 171.54 ± 0.79 mg GAE/g and TFC equal 144.26 ± 14.3 mg QE/g. The antioxidant capacity of the extract was evaluated using in vitro assays, showing strong activity with an ABTS IC50 of 0.173 mg/mL. The antiproliferative potential of the methanolic extract was assessed by the MTT assay on CAPAN-1, DLD-1, and the healthy L929 cell line. The extract exhibited significant antiproliferative effects on CAPAN-1 and DLD-1 cells, with IC50 values of 0.807 ± 0.06 mg/mL and 0.953 ± 0.03 mg/mL, respectively, whereas no cytotoxicity was observed on L929 cells. Furthermore, SwissADME was used to evaluate the pharmacokinetics and drug-likeness of the main compounds. These findings enhance the understanding of H. perforatum and may support its prospective applications in pharmaceutical and cosmetic industries
Identification and characterization of a small-molecule inhibitor of the pseudomonas aeruginosa SOS response /
No full textThe SOS response is among the most conserved pathways that promote antibiotic resistance onset in bacteria. This study aimed to identify and characterize small-molecule inhibitors of the SOS response in the opportunistic pathogen Pseudomonas aeruginosa. A library of 318 drug-like compounds was screened for inhibition of RecA-induced LexA autoproteolysis, a key step in SOS activation. One hit compound, 3-(2-sulfanylanilino)propanoic acid, showed dose-dependent inhibition with an IC50 in the mid-micromolar. Differential scanning fluorimetry and isothermal titration calorimetry revealed that A12 binds to both RecA and LexA with a low micromolar affinity. Mass spectrometry analysis demonstrated that A12 covalently modifies RecA via condensation, while it forms a disulfide bond with Cys104 of LexA. Inhibition was diminished under reducing conditions, confirming that disulfide formation is crucial for A12 activity. A12 did not impair LexA's ability to bind SOS box DNA sequences, which is needed to keep the SOS genes repressed. Antimicrobial susceptibility testing of A12 on P. aeruginosa PAO1 showed no additive effect with tested antibiotics, but it impaired P. aeruginosa colonization of A549 lung epithelial cells and survival in THP-1-derived macrophages. While A12's potency requires optimization, it represents a promising scaffold for developing anti-SOS compounds targeting P. aeruginosa
Towards sustainable construction: methodology for wood content assessment in buildings /
No full textGlobally, the construction sector is responsible for 34 % of global energy demand and 37 % of CO2 emissions from the construction and operation of buildings. In the EU, buildings account for approximately 40 % of energy consumption and one third of greenhouse gas emissions. The aim of the study is to develop a methodology for determining the use of wood and/or other organic materials made from renewable natural resources in construction products in buildings by proposing assessment criteria, thereby contributing to the promotion of sustainable building construction and the establishment of a circular economy in the construction sector (or supporting the implementation of circular economy principles in the construction sector). The study contains a structural analysis of the tensile, compressed and bending elements taking into account different strength classes and various cross-sections. It was found that relative values of volumes and masses of wooden, reinforced concrete and steel structures differ significantly and cannot be applied to assess of wood in buildings. Therefore, in the proposed methodology the wood amount is assessed not according to the ratio of the physical properties of structures, but according to stored and released CO2 of these structures. Moreover, the methodology takes into account not only the durability of different structures, but also the rational use of it
A review of theories and numerical methods in nanomechanics for the analysis of nanostructures /
No full textNanostructures, such as carbon nanotubes (CNTs), graphene, nanoplates, etc., show behaviors that classical continuum theories cannot capture. At the nanoscale, size effects, surface stresses, and nonlocal interactions become important, so new models are needed to study nanostructures. The main nanomechanics theories that are used in recently published papers include nonlocal elasticity theory (NET), couple stress theory (CST), and nonlocal strain gradient theories (NSGTs). To solve these models, methods such as finite elements, isogeometric analysis, mesh-free approaches, molecular dynamics (MD), etc., are used. Also, this review categorizes and summarizes the major theories and numerical methods used in nanomechanics for the analysis of nanostructures in recently published papers. Recently, machine learning methods have enabled faster and more accurate prediction of nanoscale behaviors, offering efficient alternatives to traditional methods. Studying these theories, numerical models and data driven approaches provide an important foundation for future research and the design of next generation nanomaterials and devices
Empowering sustainable development through social mobility: insights from Lithuania /
No full textThis article examines intergenerational social mobility as a driver of sustainable development on the case of Lithuania, a country in Eastern Europe. Using data from the European Social Survey (2020), the analysis explores how parental education and occupation shape individual educational and occupational outcomes. Descriptive, correlational, and regression analyses reveal that while structural mobility has been facilitated by Lithuania’s transition from Soviet rule to a market economy and subsequent European integration, family background remains a decisive factor. The study also highlights the key factors that promote or constrain social mobility in contemporary Lithuania. The interaction between mothers’ and fathers’ education fosters the attainment of higher levels of education, whereas mothers’ occupational status and respondents’ gender (male) appear to limit it. Similarly, the achievement of a higher occupational level is positively influenced by the interaction between parental education and the respondent’s own highest educational attainment, while negatively influenced by gender. These findings demonstrate that education not only determines social mobility but also supports the broader objectives of sustainable development by reducing inequality, fostering human capital, and advancing gender equality. The results underscore the importance of inclusive social policies that ensure equitable access to quality education and align educational opportunities with labor market demands, thereby reinforcing social mobility as a foundation for long-term social resilience and sustainability
The auxiliary equation method for the construction of deformed solitary solutions to the model of tumor-immune system interaction /
No full textThe auxiliary equation method for the construction of deformed solitary solutions to the mathematical model of tumor-immune system interaction is presented in this paper. The investigated model does not admit classical solitary solutions. Special techniques based on symbolic computations are used to construct deformed solitary solutions by simultaneously avoiding the inherent additional constraints to the model parameters. It is demonstrated that the introduction of the auxiliary equation does not drop any solutions from the original system. Also, deformed solitary solutions do not depend on the parameters of the auxiliary equations. Analytical and computations experiments are used to demonstrate the efficacy of the proposed method
Rheological evaluation of xanthan gum and carboxymethyl cellulose for enhanced oil recovery: effects of concentration, salinity, and temperature /
No full textGlobal energy demand continues to rise and is projected to increase by 50%–60% in the next decade. To meet this demand, enhanced oil recovery (EOR) techniques are being employed to maximize extraction from existing reservoirs. Polymer flooding is a promising EOR method, where water-soluble polymers improve sweep efficiency by increasing the viscosity of the displacing fluid. However, successful polymer flooding relies on careful polymer selection and a thorough understanding of rheological behavior. This study presents a systematic rheological evaluation of two polymers, Xanthan Gum (XG, C35H49O29) and Carboxymethyl Cellulose (CMC), at varying concentrations (0.25, 0.50, 0.75, and 1 wt%) for EOR applications. Steady-shear rheology, thermal stability, and salinity effects were investigated to assess polymer performance under different conditions. The Herschel-Bulkley and Cross models were used to characterize the non-Newtonian behavior of the polymers. Results indicate that higher polymer concentrations enhance viscosity and shear-thinning behavior. However, salinity (NaCl and MgCl2) reduces solution viscosity, while increasing temperature (25 °C, 50 °C, and 75 °C) further diminishes viscosity. These findings provide critical insights into polymer selection and optimization for efficient EOR processes