Accurately predicting the elastic modulus of polymer-nanoparticle composites presents a critical challenge, as conventional micromechanical models rely on idealized assumptions that are fundamentally invalid at the nanoscale. In this study, we demonstrate this significant discrepancy in a system of electrospun polyvinylidene fluoride (PVDF) nanofibers reinforced with iron oxide (Fe₃O₄) nanoparticles. Our experimental measurements reveal a substantial 23% increase in the composite's elastic modulus, confirming significant nanoparticle reinforcement and the material's enhanced performance. However, we show that established predictive frameworks—including the rule of mixtures, Kerner’s model, and the Guth model— fail to predict this experimental outcome. The failure of these models is largely attributed to their flawed foundational assumptions, such as ideal interfacial bonding between the polymer and nanoparticle, uniform particle dispersion, and the inapplicability of bulk-scale mechanics to nanoscale phenomena. To address this predictive gap, we propose a new, more sophisticated predictive model that moves beyond these idealizations. Our framework successfully incorporates critical nanoscale parameters that govern composite behavior, including quantified nanoparticle dispersion characteristics and the properties of the crucial polymer-nanoparticle interfacial zone. The resulting model provides a far more accurate description of the elastic modulus in PVDF/Fe₃O₄ systems, establishing a robust foundation for the future rational design of advanced materials with precisely tunable mechanical properties.

The optimization of cooling systems and temperature management in data centers has been widely researched; however, this focus has been overly concentrated on large enterprises, leading to an oversight of small-scale ones. This study aimed to develop a validated Computational Fluid Dynamics (CFD) model and assess airflow and temperature distribution under varying heat loads and cooling systems in steady-state conditions. The study utilized CFD simulations and validated these through experimentation at the Digital Innovation Center data center of the University of the Philippines Los Baños. Three cases were analyzed: (1) the current server load and main cooling system, (2) the operation of a backup cooling system, and (3) a scenario of a maximized server load while using the main cooling system. Our results showed that all cases maintained compliance within the ASHRAE Thermal Guidelines, with rack inlet temperatures of 22.52ºC, 26.93ºC, and 16.31ºC. On the other hand, the airflow performance metrics of the Rack Temperature Index (RTI), Supply Heat Index (SHI), and Return Heat Index (RHI) reflected that there was recirculation of air in the server room. Specifically, the mixing that was interpreted based on the SHI, with values of 0.85, 0.98, and 0.60. Using a wall fan was recommended in these cases of recirculation for small-scale data centers. In conclusion, the thermal distribution inside the room is adequate for the heat loads, while the airflow distribution requires improvement. This study offers practical recommendations to enhance energy efficiency and reliability in small-scale data center operations.

A canned motor pump is a turbopump with a non-seal structure that integrates the pump and the motor into a single unit. A feature of the structure is that the pumped liquid also serves as the cooling liquid for the motor and the lubricating liquid for the sliding surfaces. In canned motor pumps, helical grooved plain bearings are typically used to provide adequate cooling of the motor. The flow rate of the influent flow to this bearing varies with the internal flow of the pump. Therefore, pumps that operate under a variety of conditions require suitable design for the tribological effects of this change in the flow rate of the influent flow, but the details of this design have not yet been clarified. This study focuses on the film pressure, which is important for the design of helical grooved plain bearings for canned motor pumps. The purpose of the study is to determine the effect of this influent flow on the film pressure through numerical analysis using Computational Fluid Dynamics (CFD). The CFD software used was OpenFOAM. Calculations under different conditions were performed to analyze the changes in film pressure that occur in the helical grooved plain bearing. Since the influent flow into the bearing affects the film pressure, it is concluded that the design must take into account the pump internal circulation of the pumped liquid, even from a tribological perspective.

Fertilizers with slow release and water retention have received a lot of attention lately because of their importance in agriculture and horticultural applications. In this study, a novel controlled release fertilizer system based on carboxymethyl cellulose (CMC) and chitosan (CH) was developed to boost biomass usage efficiency while reducing pollution. The bio-based CMC and CH were made from sugarcane bagasse and golden apple snail shell, respectively. The produced materials were analyzed using a Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), and moisture absorption techniques. The behaviors of nutrient release in slow release fertilizer (SRF) were examined thoroughly. SEM images reveal that a fertilizer coated with 5 wt% CMC exhibits an effective distribution of CMC across its surface, providing a comprehensive coverage of the fertilizer. However, if the quantity is elevated, the CMC becomes aggregate, leading to a comparatively inadequate coverage of the fertilizer surface. The experimental data revealed that the fertilizer utilizing CMC and CH as coating substances exhibits advantageous slow-release characteristics. The uncoated fertilizer exhibits a water absorption value of 53.3%, while the one-coating layer fertilizer shows a value of 154.0%, and the two-coating layers fertilizer reaches 223.2%. Therefore, incorporating natural polymers can enhance the efficiency of biomass utilization, minimize nutrient loss, and optimize water use efficiency.

In recent years, biochar has been regarded as an efficient adsorbent in potable water treatment owing to its low-cost, larger surface area, functional groups, and carbon-negative texture. However, biochar might not have higher pollutant adsorption capacity owing to its heterogeneous texture and some surface characteristics. Furthermore, biochar can include both positive and negative charges depending on the pyrolysis temperature, which might decrease the adsorption capacity of biochar in order to remove anionic pollutant substances such as fluoride. In this study, the modification of biochar (B) by bentonite, which is a type of nanoclay (NC) for the treatment of fluoride polluted groundwater, was achieved. The nanoclay-assisted biochar (NAB) process for groundwater treatment was also investigated. This research developed a novel modified malt-dust-derived biochar by bentonite for efficient potable water treatment, obtaining new insights into NAB adsorption performance. The water samples were provided from Sarım and Karataş villages located in an arid/semi-arid region in Türkiye. The mixing ratios (NC:B) were 1:1, 1:2 and 1:4, respectively. The results demonstrated that the highest fluoride removal efficiency was achieved by using 15 g/L-groundwater of bentonite and biochar (1:1). Bentonite addition promoted the fluoride removal from groundwater by 18.1% on average. A groundwater remediation index (GRI) was developed and validated by a sensitivity analysis as a result of the Monte Carlo simulation following the NAB process based on treatment efficiencies and water quality parameters. The highest GRI was reported in the range of 0.983-0.99 as a result of the NAB process.

Introduction. Dimethyl sulfoxide (DMSO) is a solvent widely used in biomedical research. It is known to interfere with cell signaling, but at a final concentration of 1% or lower is often deemed safe. One of the applications of DMSO is to dissolve hydrophobic compounds. During the characterization of a novel hydrophobic anti-inflammatory compound, we found that dilutions of 4 orders of magnitude of the compound diluted in DMSO, used at a 1% final concentration in cell culture media, strongly inhibited the lipopolysaccharide (LPS) induction of Interleukin (IL)-1b and Tumor Necrosis Factor (TNF)-a secretion without a dose-dependent effect (p<0.001 for all doses).

Hypothesis. We hypothesized that DMSO could inhibit LPS-dependent cytokine release.

Methods. We stimulated mouse macrophages (J774.1 cells) with LPS (1 µg/ml, 6h, to activate NF-kB-dependent gene expression) and administered ATP (5 mM, 30 min). LPS promotes TNF-a secretion and pro-IL-1b intracellular production, while ATP induces caspase-1-dependent IL-1 b maturation and release. Cells were exposed to increasing concentrations of DMSO (0.2, 0.5, 1.0%). We collected the cell supernatants and performed ELISA assays to measure IL-1b and TNF-a production.

Results. The 1% dose of DMSO significantly reduced IL-1β secretion (205±12 vs 709±7 pg/ml; p<0.0001); 0.5% and 0.2% DMSO had no effect. DMSO at concentrations of 1.0% and 0.5% reduced TNF-α (1348±37 and 2672±25 vs 3125±27 pg/ml; all p<0.0001); 0.2% DMSO had no effect on TNF-α release.

Conclusion. DMSO induces a dose-dependent inhibition of IL-1β and TNF-α by reducing LPS/NF-kB-dependent gene expression.

Nickel-based alloys have fabrication issues such as requiring more fabrication time than general-purpose metal materials due to their hardness. However, because it is a high-strength material, it is an appropriate material when designing thinner components. This conflicting relationship between manufacturing and design makes it difficult to apply nickel-based alloys as a general-purpose material for industrial components. One way to solve this issue is to creat multi-materials by wire arc additive manufacturing (WAAM). Since the strength required for a component is not necessarily uniform throughout the component, an appropriate balance between manufacturing and design can be achieved if nickel-base alloys can be applied only to areas subjected to high stress. Several studies have conducted fundamental evaluations of the mechanical properties and other aspects of multi-materialization of nickel-base alloys and general-purpose stainless steels by WAAM. However, the study of manufacturing multi-materialized industrial components by the combination of these materials has not progressed. In this study, an experimental investigation was conducted to fabricate an axial-flow impeller with multi-material blades by WAAM and machining. The materials used were Inconel 718 and SST 316L. A 3D scan of the fabricated axial-flow impeller confirmed that it was finished according to the design dimensions. Furthermore, observation of the multi-materialized blades by X-ray CT revealed the presence of several small internal defects. Although the reduction in these internal defects is an issue for the future works, the possibility of applying multilateralization by WAAM to the manufacturing of industrial components was experimentally demonstrated.

The ultra-low detection of substances of interest in atto-molar concentration ranges can be exploited to detect the analyte in real-world scenarios via simple dilution steps. The high sensitivity of several plasmonic-based biosensors is utilized to detect biomarkers or pollutants at an atto-molar level. This goal can be achieved via low-cost and simple equipment in small-sized setups combined with sensor chips based on ultra-high-sensitive plasmonic probes or ultra-efficient receptor layers. More specifically, extrinsic and intrinsic optical fiber sensing schemes can be achieved using plastic optical fiber (POF) characteristics combined with cheap equipment. The reported sensing strategy is simply implemented using a white light source and spectrometers. For instance, this work recalls atto-plasmonic sensors achieved via hybrid plasmonic probes combined with several receptors or ultra-efficient receptors and integrated into conventional plasmonic probes. These atto-plasmonic sensors, which utilize simple setups, can be useful for detecting substances of interest via Point-of-Care Tests (PoCTs) in various application fields. The sensor systems enable on-site measurement of the substance of interest in just a few minutes, with the results transmitted via an Internet connection. Moreover, via the Internet connection, remote control of sensor systems for on-site measurement can be carried out, combining the sensors with mechatronics and robotics.

The beam–column connection is the main element in frame structures. It is particularly vulnerable to cyclic lateral loads such as earthquakes. The main reason for this is the occurrence of shear forces. The main components of this force are the forces that are transmitted from the beam to the column. A good knowledge of these forces will allow for the safe and accurate dimensioning of frame joints. In current codes of differently countries, as well as in Eurocode, beam forces are determined capacitively, based on the longitudinal reinforcing bars passing through the beam–column connection. However, this method does not take into account the involvement of the concrete section. Furthermore, this method does not allow the forces transmitted from the beam to the column to be determined on the basis of the applied load. Experimental studies conducted over the past few decades have shown the significant contribution of these two factors, concrete strength and applied load, to the shear force. Analytical solutions of beams of frame construction subjected to different types of loads provide an explanation to the issue of the significant influence of load and strength of concrete [1-2]. In this paper, numerical results obtained from the analytical studies will be shown and conclusions will be drawn supporting experimental observations from the literature.

References:

[1] A. Doicheva, Distribution of Forces in RC Interior Beam–Column Connections, Eng. Proc., 56(1), 114, 2023.

[2] A. Doicheva, Shear Force of Interior Beam–Column Joints under Symmetrical Loading with Two Transverse Forces on the Beam, Buildings, 14(9), 3028, 2024.

This research is about controlling the altitude of the Unmanned Ariel Vehicle (UAV) through the elevator. Elevators are flight control surfaces, which control lateral altitude by changing the pitch balance. The elevators are usually hinged to a fixed or adjustable rear surface, making as a whole, a tailplane or horizontal stabilizer. The elevator is used to control the altitude by its movement which gives lift to the UAV. It consists of two loops: an inner-loop controller to achieve stability and robustness to expected parameter uncertainty and an outer loop for tracking reference performances. In the past, people have done work on its longitudinal maneuver using elevator control input and in this research, we are going to control vertical height using elevator control input of the Unmanned Ariel Vehicle. This work eyes on altitude maintenance of UAV through a dual laser and ultra-sonic deflection, for graphing the surrounding and maintaining the minimum maintained altitude. The angle deflection along with the thrust from propulsion system is matched and guided by the system for the gain or loss of altitude over desired range of distance. The significance of the system would be efficient increase and decrease of altitude of UAV along with easier piloted drone; and in military aspects the stealth enhancements for low chances of being detected. The expected result increases efficiency of any Unmanned Aerial Vehicle along with low fuel consumption because of achieving desired altitude over short range.