Analysis of Tribological and Cytotoxicity Assays of a Biocompatible Mg-Zn-Ca-Pr Alloy.

This work covers a Mg-Zn-Ca-Pr alloy fabricated by a novel method of mechanical alloying and spark plasma sintering (SPS). Currently, magnesium alloys used as biomaterials are mostly commercial alloys without consideration of cytotoxicity from the perspective of biosafety. So far, the tribological and cytotoxic properties of Mg-Zn-Ca-Pr alloys have not been investigated.

The Effect of Recycled Geogrid Fibres on Asphalt Concrete Performance: A Case Study from Poland.

This study articulates findings from research pertaining to the utilisation of recycled geogrid in asphalt concrete. The issue of contamination of reclaimed waste with geosynthetic materials persists as a significant concern that warrants attention. In Poland, the allowable quantity of geogrid contaminants within the mineral-asphalt composition is 0.

Influence of Selected Factors of Vibratory Work Hardening Machining on the Properties of CuZn30 Brass.

The purpose of this study was to determine the effect of selected vibratory strengthening machining factors on the properties of CuZn30 brass. Vibratory strengthening machining was carried out using metal media dedicated to polishing processes, which also contributed to strengthening the treated surfaces. The test samples were cut with an abrasive water jet and recrystallized to obtain a soft microstructure.

Using the Burning of Polymer Compounds to Determine the Applicability of the Acoustic Method in Fire Extinguishing.

In order to achieve the objective of the work-an experimental study of the capabilities of the acoustic method for extinguishing organic compounds and for ensuring environmental monitoring-the effect of the combustion of various polymers on the acoustic parameters of the medium is considered. The negative effect of the combustion of organic substances on the medium is noted. The features of the use of fire extinguishing agents are analyzed, and it is noted that the acoustic method is a promising, inexpensive, and environmentally friendly approach for use in extinguishing fires.

Evaluation of Wear Resistance in Tungsten-Doped Diamond-like Carbon Coatings (WC/C) on Coated and Uncoated Surfaces Under Starved Oil Lubrication with R452A Refrigerant.

This article assesses the potential of using a diamond-like carbon coating doped with tungsten, a-C:H:W (WC/C), on the sliding pairs of refrigeration compressors. The ability of WC/C coating to provide low wear and a low coefficient of friction was experimentally verified in a specific refrigeration compressor operating environment (lubrication with oil diluted with refrigerant) and under extreme operating conditions (starved lubrication with a small amount of oil). Conditions of starved lubrication with a substance of reduced lubricity promote a temperature increase and high mechanical (friction) stresses on the surface of the sliding pairs.

Multiscale Analysis of Surface Topography for Engineering Applications in the Casting Industry.

This paper presents the results of studies aimed at assessing the impact of the molding process on the variability of surface irregularities of casting models. This research was conducted using a selected multiscale method, i.e.

Effect of Laser on the Interface and Thermal Conductivity of Metallized Diamond/Cu Composite Coatings Deposited by Supersonic Laser Deposition.

To achieve the rapid heat dissipation of components in the industrial field, the heat dissipation coating is prepared on the surface, which is conducive to improving the service life of the parts and greatly reducing the industrial costs. In this paper, metallized diamond/Cu composite coatings were fabricated on 1060Al substrate by supersonic laser deposition. The composite coatings were prepared at a nitrogen pressure of 3.

The Possibility of Improving the Range and Quality of Air-to-Ground WebRTC-Based IoT Communication in Emergency Situations by Employing an External Transceiver.

The proliferation of new services, either interpersonal or machine-oriented, has generated new demands concerning the flexibility and efficiency of transmission. The ubiquity of multimedia communication in the current internet is seamlessly and successfully supported by the WebRTC concept. This paper reports on the study of the usage of a solution employing a proxy transmission unit for air-to-ground delivery of video streaming multiplexed with sensor data in the UAV-IoT system when using the WebRTC protocol stack.

Composite Materials Used for Dental Fillings.

This article explores the properties of composite materials employed in dental fillings. A traditional nano-hybrid composite containing nanofiller particles exceeding 82% by weight served as a benchmark. The remaining samples were fabricated from ormocer resin, maintaining an identical nanofiller content of 84%.

Mechanical Properties of Full-Scale Wooden Beams Strengthened with Carbon-Fibre-Reinforced Polymer Sheets.

The strengthening, rehabilitation and repair of wooden beams and beams made of wood-based materials are still important scientific and technical issues. This is reflected, among other things, in the number of scientific articles appearing and the involvement of research centres around the world. This is also related to society's growing belief in the importance of ecological and sustainable development.

Evaluation of the Influence of Technological Parameters of Selected 3D Printing Technologies on Tribological Properties.

The article presents the results of tribological research of sample models manufactured using three separate 3D printing technologies: selective laser sintering-SLS, photo-curing of liquid polymer resins-PolyJet Matrix (PJM) and fused deposition modeling-FDM. The impact of process parameters (printing direction, layer thickness, and energy density for SLS) on tribological properties was assessed through linear wear and coefficient of friction. The research was carried out to assess the possibility of using 3D printing for the quick manufacturing of casting models, which has a significant impact on shortening the time of implementation for mass production of the casting process.

Influence of Zinc Chloride Exposure on Microstructure and Mechanical Behavior of Age-Hardened AZ91 Magnesium Alloy.

The AZ91 magnesium alloy was subjected to a complex treatment involving age hardening (supersaturation and artificial aging) and simultaneous surface layer modification. The specimens were supersaturated in contact with a mixture containing varying concentrations of zinc chloride, followed by cooling either in air or water. After supersaturation, the specimens were subjected to artificial aging and then air-cooled.

Analysis of Head Movement in KPSIT Dummies and the Impact of Seats and Seat Belts during Low-Speed Collisions 20 km/h.

The aim of this study was to compare the head displacement of the KPSIT C50 dummy, representing a 50th percentile male, with the KPSIT C5 dummy, representing a 5th percentile female, during low-speed collisions. Low-speed collisions, such as those occurring in urban traffic jams, are increasingly common. The research was conducted on a dedicated educational workstation designed to measure forces in seat belts.

Classification of Unmanned Aerial Vehicles Based on Acoustic Signals Obtained in External Environmental Conditions.

Detection of unmanned aerial vehicles (UAVs) and their classification on the basis of acoustic signals recorded in the presence of UAVs is a very important source of information. Such information can be the basis of certain decisions. It can support the autonomy of drones and their decision-making system, enabling them to cooperate in a swarm.

The Phase Change Heat of Water in the Pore Space of Rocks Based on DSC Studies.

This research investigates the phase change behavior of water within the pore space of Devonian carbonate rock samples using Differential Scanning Calorimetry (DSC) across a temperature range of -80 to 0 °C. This study focuses on dolomite and limestone samples, all with porosities below 3%, an area not extensively covered in previous literature. Significant endothermic effects were observed at temperatures below -2 °C, challenging conventional understanding.

Strength and Fracture Toughness of TIG- and Laser-Welded Joints of Low Carbon Ferritic Steels.

This paper presents the results of experimental testing of joints welded using conventional TIG and laser methods. The welded components were sheets of the low-carbon steels 13CrMo4-5 and 16Mo3. Welded joints were made using different levels of linear welding energy.

Endolysin CHAP domain-carbosilane metallodendrimer complexes with triple action on Gram-negative bacteria: Membrane destabilization, reactive oxygen species production and peptidoglycan degradation.

Bacterial resistance to antibiotics is a significant challenge that is associated with increased morbidity and mortality. Gram-negative bacteria are particularly problematic due to an outer membrane (OM). Current alternatives to antibiotics include antimicrobial peptides or proteins and multifunctional systems such as dendrimers.

Geopolymer Materials from Fly Ash-A Sustainable Approach to Hazardous Waste Management.

This study explores the utilisation challenges of fly ash from municipal waste incineration, specifically focusing on ash from a dry desulphurisation plant (DDS), which is categorised as hazardous due to its high heavy metal content. The ash's low silicon and calcium contents restrict its standalone utility. Laboratory investigations initially revealed that geopolymers derived solely from fly ash after flue gas treatment (FGT), in combination with coal combustion fly ash, exhibited low compressive strength (below 0.

Evaluation of the Influence of Bolt Fastener Spacing on the Elastic Critical Load from the Lateral-Torsional Buckling Condition of Built-Up Bending Members.

In an experimental study of two-branched beams bent transversely about the major stiffness axis, the elastic critical load from the lateral-torsional buckling condition was determined. The tests were conducted on simply supported two-branch beam models with a built-up section consisting of two cold-formed channel members (2C) bolted back-to-back. The bolts were located at the mid-height of the built-up cross-section.

Exploring historical changes in mountain river hydrodynamics induced by human impact.

During the 20th-century many mountain rivers in Europe were subjected to intensive human impacts which substantially modified their channel morphology. How these changes affected river hydrodynamics and response to floods remains uncertain. In this work, we perform hydraulic modelling using data from archival aerial photos to explore relations between hydraulic parameters of floods and human-induced channel incision occurring on the Czarny Dunajec River (Polish Carpathians) between 1964 and 2012.

Novel extended hybrid tool for real time control and practically support decisions to reduce GHG emissions in full scale wastewater treatment plants.

In this paper, a novel methodology and extended hybrid model for the real time control, prediction and reduction of direct emissions of greenhouse gases (GHGs) from wastewater treatment plants (WWTPs) is proposed to overcome the lack of long-term data availability in several full-scale case studies. A mechanistic model (MCM) and a machine learning (ML) model are combined to real time control, predict the emissions of nitrous oxide (NO) and carbon dioxide (CO) as well as effluent quality (COD - chemical oxygen demand, NH-N - ammonia, NO-N - nitrate) in activated sludge method. For methane (CH), using the MCM model, predictions are performed on the input data (VFA, CODs for aerobic and anaerobic compartments) to the MLM model.

Numerical Analysis of Laminated Veneer Lumber Beams Strengthened with Various Carbon Composites.

Among the many benefits of implementing numerical analysis on real objects, economic and environmental considerations are likely the most important ones. Nonetheless, it is also crucial to constrain the duration and space necessary for conducting experimental investigations. Although these benefits are clear, the applicability of such models must be appropriately verified.

The Effect of Changing the Angle of the Passenger Car Seat Backrest on the Head Trajectories of the 50th Percentile Male Dummy.

The aim of the study is to compare the head displacement of the KPSIT C50 dummy during a frontal collision at a speed of 20 km/h, along with the change in the angle of the car seat backrest. Passenger car manufacturers recommend setting the backrest angle of the car seat between 100 and 125 degrees. It should be noted that the driver's position is of great importance in the event of a collision injury.

Mobility of Zn and Cu in Bentonites: Implications for Environmental Remediation.

The aim of this study was to evaluate the mobility of copper (Cu) and zinc (Zn) and their impact on the properties of bentonites and unfrozen water content. Limited research in this area necessitates further analysis to prevent the negative effects of metal interactions on bentonite effectiveness. Tests involved American (SWy-3, Stx-1b) and Slovak (BSvk) bentonite samples with Zn or Cu ion exchange.

New Advances in Strengthening of Structural Timber.

As one of the oldest building materials, wood is still widely used today [...