National Institute of Standards (Egypt)

Heavy metals exist in different water resources and can threaten human health, inducing several chronic illnesses such as cancer and renal diseases. Therefore, this work dealt with the fabrication of highly efficient nanomembranes based on silver nanoparticle (Ag NP)-doped hybrid polyvinyl chloride (PVC) by dapsone (DAP) using an in situ method. Fourier-transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) analysis were used to confirm the hybridization of PVC as well as the crystalline structure of hybrid PVC nanocomposites. Three varying proportions of Ag NPs (i.e., 0.1, 0.2, and 0.3%) were used to fabricate hybrid PVC-DAP nanomembranes. The Brunauer–Emmet–Teller (BET) method was used to estimate membrane surface area, porosity and distribution of pore volume. The mechanical strength and antibacterial properties of the cased films notably improved when Ag NPs were added depending on the NP ratio inside the matrix. Results obtained from adsorption experiments of PVC-DAP nanomembranes at 35 °C revealed that the optimum nanomembrane was achieved at 0.2% NPs and its percentage of removal effectiveness ranged from 71 to 95% depending on the ion type. The surface morphology of the PVC-DAP-0.2 Ag NPs before and after the adsorption process of the metal ions was analyzed using SEM-EDX. Moreover, the impact of other parameters such as the initial concentrations, pH media, temperature, and contacting time, on the adsorption efficiency of PVC-DAP-0.2 Ag NPs was also investigated. Furthermore, kinetic and adsorption isotherm models were suggested to describe the adsorption efficiency of the PVC-DAP-0.2 Ag NP membrane, and the uptake mechanism of metal ion removal was studied. The obtained outcomes for these fabricated nanomembranes demonstrated that they could be potential candidates for water purification and other potential purposes including biomedical areas.

The CNC (computerized numerically controlled) machines are widespread in use due to their high capability of precise manufacturing in industrial production. They have a wide range of designs depending on the working capacity in manufacturing. The associated form errors in large-capacity CNC machines during production shall be identified and corrected or eliminated. This study presents an investigation of one of the main form errors that may affect the manufacturing precision of these machines. This error type is a straightness error with both two kinds of horizontal and vertical errors. The study is carried out for a vertical turning center CNC machine type. The straightness errors are measured for the X axis at different latches in the Z direction and for the Z axis at three positions in the X direction with multi-displacement steps. Different algorithms are used in the determination of straightness errors. The X-axis has minimum horizontal straightness errors at latch Nr. 3 and minimum vertical straightness errors at latch Nr. 5. For the Z axis, the minimum values for horizontal and vertical straightness errors exist when the spindle is located 1200 mm away from the machining center to the right. The displacement steps have a significant impact on the determination of straightness errors.

Innovative and cost-effective paper sheets with superior fire safety and reinforcement properties have been developed. The paper sheets were fabricated via valorization of agricultural waste to paper and then coated with nanoparticles. Paper attained from rice straw was used to create the sheets. Afterward, bentonite sheets were incorporated in these sheets, and finally, PbO nanoparticles were coated on prepared paper nanocomposites. The mass ratio of bentonite sheets was altered. The flammability and mechanical properties of the developed paper nanocomposites were studied. The flame retardancy of developed paper nanocomposite was significantly improved achieving LOI value of 24% compared to 20% for bentonite and PbO nanoparticle-free sample. Additionally, the tensile strength was improved recording 44% enhancement compared to unmodified sample. Furthermore, the flame retardancy mechanism was proposed and studied.

Chemical processing is among the significant keys to tackle agro-residues utilization field, aiming to obtain value-added materials. Extraction of cellulose nanocrystals (CNCs) is an emerging route to valorize lignocellulosic wastes into high value particles. In this investigation, effect of acidic hydrolysis duration was monitored on size and morphology of obtained crystals; namely: CNCs from Nile roses fibers (NRFs) (Eichhornia crassipes). Different acidic hydrolysis duration range or different characterization techniques set this article apart from relevant literature, including our group research articles. The grinded NRFs were firstly subjected to alkaline and bleaching pretreatments, then acid hydrolysis process was carried out with varied durations ranging from 5 to 30 min. Microcrystalline cellulose (MCC) was used as reference for comparison with NRFs based samples. The extracted CNCs samples were investigated using various techniques such as scanning electron microscopy (SEM), Atomic force microscopy (AFM), Raman spectroscopy, and thermogravimetric (TGA) analysis. The figures gotten from SEM and AFM depicted that NRFs based CNCs appeared as fibril-like shapes, with reduced average size when the NRFs underwent pulping and bleaching processes. This was indicated that the elimination of hemicellulose and lignin components got achieved successfully. This outcome was proven by chemical composition measurements and TGA/DTG curves. On the other hand, AFM-3D images indicated that CNCs topology and surface roughness were mostly affected by increasing hydrolysis durations, besides smooth and homogeneous surfaces were noticed. Moreover, Raman spectra demonstrated that the particle size and crystallinity degree of NRFs based CNCs can be affected by acidic hydrolysis durations and optimum extraction time was found to be 10 min. Thermal stability of extracted CNCs-NRFs and CNCs-MCC was measured by TGA/DTG and the kinetic models were suggested to identify the kinetic parameters of the thermal decomposition of CNCs for each acid hydrolysis duration. Increasing hydrolysis duration promoted thermal stability, particularly for NRFs based CNCs. Results showcased in this article add new perspective to Nile rose nanocellulose and pave down the way to fabricate NRFs based humidity nano-sensors.

New scalable synthesis approach has been developed for the production of nanoporous carbon nanoparticles derived from renewable sunflower seed shell, with an average size of 41 nm and spherical shape. Interestingly, the developed nanopo-rous carbon nanoparticles achieved mesopores feature with specific surface area and total pore volume of 442 m 2 g −1 and 0.21 cm 3 g −1 , respectively. Moreover, the newly attained adsorbent has mesopore size ranging from 2 to 10 nm as well as naturally doped with oxygenated functional groups. These features are precious and desirable for the removal of methylene blue (MB) dyes. Additionally, spherical porous carbon nanoparticles were facilely decorated with one-dimensional polyaniline nanofibers (PANI-NFs) producing hybrid nanocomposites. The porous carbon nanoparticles and their nanocomposites-based PANI-NFs were implemented individually as an efficient adsorbent for removal of MB from aqueous solution, recording superior maximum uptake capacity compared to reported. The as-developed sustainable nanoadsorbents were elucidated using different spectroscopic, microscopic, and thermogravimetric tools. The new hybrid nanoadsorbents achieved good removal efficiency of MB recording 81.4% with maximum uptake capacity of 140 mg g −1 compared to 67.7% and 110 mg g −1 for free-PANI-NF porous carbon adsorbent, respectively. Several adsorption parameters such as contact time, nanoadsor-bent dose, dye concentrations, pH, and temperature were also studied and optimized. The Freundlich and Langmuir models are used, and the Langmuir model was found to be effective and well suited to characterize the MB adsorption isotherms. Additionally, the commercial viability of produced adsorbents was assessed. Graphical abstract H N H N N

This paper presents the method of preparing (60 − x ) B 2 O 3 –20 K 2 O–20 PbO– x NiO, coded as (NiO x ), and x = (0–10 mol%) glass systems fabricated through the melt-quench technique. The prepared glass was characterized through X-ray diffraction spectra (XRD); the mechanical behavior of the glass samples was investigated using the ultrasonic technique, Fourier transform infrared (FTIR) spectra, the optical reflectance R ( λ ), refractive index ( n ), optical conductivity ( σ opt ), the dispersion parameters of the studied samples were deduced using Wemple and Di-Domenico models. The results obtained were reported in detail. One of the fundamental parameters used to evaluate the interaction of radiation with shielding material was the mass attenuation coefficient ( μ m ), which was obtained using Phy/X software and PHITS code program. It was used to calculate radiation interaction parameters, e.g., linear ( μ L ) attenuation coefficient, effective atomic number ( Z eff ), half value layer HVL, mean free path (MFP) and the average atomic cross section, σt . Comparing the shielding behavior of the glass samples revealed that (NiO 10) glass demonstrated the highest μ m and μ L compared to the other samples. The maximum μ m values equal 48.13, 48.73, 49.42, 50.59, and 51.08 cm ² /g for (NiO 0) to (NiO 10), recorded at 0.015 MeV, respectively. This study shows that increasing the amount of NiO in the preferred glass samples leads to achieving high-performance radiation shielding materials. Graphical abstract

Transporting viscous oils through pipelines is usually challenging due to their very high viscosity. Significant friction reduction in the transportation of viscous oils through pipelines using an ecologically friendly way is the most appealing feature of the core annular Flow (CAF) technique. An experimental study has been conducted to investigate the flow patterns and pressure gradient of viscous oil-water two-phase flow in a horizontal acrylic pipe with a 50 mm inner diameter. The test section was equipped with a fluid lubrication injector element to artificially provide CAF. The pressure gradient measurements were focused on the CAF pattern. The prediction models of the CAF pressure gradient were reviewed and evaluated. An empirical prediction model of CAF pressure gradient was developed, relying on both the present and previously published experimental results. The flow patterns were classified into five patterns. It was observed that the CAF occupied a large region in the constructed flow pattern map and its frictional pressure gradient closely resembles that of water flowing alone. It was found that the developed empirical model provided quite good predictions of the experimental pressure gradients and significantly outperformed the original model. The reviewed prediction models in this area for CAF either overpredicted or underpredicted the experimental pressure gradients. Some of these models considered the extensive effect of viscous oil adhered to the inner wall of the pipe, while others neglected the effect entirely.

The capability to emulate skin‐like temperature and pressure sensing is fundamental for next‐generation artificial intelligence products. However, detecting temperature and pressure simultaneously with a single sensor without signal interference is challenging. Herein, a novel PCC aerogel sensor composed of PEDOT:PSS, CNTs, and CNF via directional freezing technology is developed. The PCC sensor can decouple temperature and pressure stimuli into individual voltage and resistance signals. It exhibits high‐precision temperature sensing capabilities, boasting an exceptionally high Seebeck coefficient of 30.4 µV K‐1 and the ability to detect temperature variations as low as 0.1 K. PCC sensors show excellent sensitivity and fast response times for detecting static and dynamic pressures, as well as high stability after 1000 cycles. Its maximum pressure sensitivity can reach 159.1% kPa ⁻¹ , and the lowest detection limit is 10 Pa. Additionally, its excellent thermoelectric properties also enable to generating thermopower from human skin for self‐powered pressure sensing. A 3×3 PCC sensor array has been proposed to simulate the unique features of human skin in temperature and pressure recognition. This work provides a scalable manufacturing strategy for multi‐functional tactile sensors.

Here in, we are reporting the effect of the catalyst particle size on the catalytic activity and product selectivity by understanding the strength of the interaction between the active catalyst and the reactants (CO2 and H2). In this regard, two catalytic systems having different active catalyst particle sizes and support surface areas were synthesized using metal–organic frameworks (MOF) (MIL-100(Fe)) having two crystal size ranges as sacrificial templates. The active catalyst having smaller nanoparticles exhibited greater chemisorption of hydrogen (Fe–H bond), resulting in heightened selectivity for paraffin due to hydrogenation of re-adsorbed olefins. Conversely, larger nanoparticles showed enhanced chemisorption of CO2 (Fe–C bond), leading to increased selectivity for olefins (O/P = 0.15). Additionally, a reduction in particle size boosts activity from 24% to 38.7% at 340 °C/20 bar. While, higher particle size enhances the selectivity towards C5+ from 11.1 to 45.6% at (300 °C/10 bar) and 9.6 to 21.3% at (340 °C/20 bar).

One of the crucial assessments for electricity meters involves the solar radiation test, typically conducted using solar simulators. This work focuses on the modification of the climatic chamber (MKF-240) at the Egyptian National Institute of Standards (NIS) to serve as a solar simulator. To replicate solar test conditions, enhancements such as an aluminum plate and quartz tungsten halogen (QTH) lamps have been integrated into the MKF-240 climatic chamber. Several experimental trials were undertaken to ascertain the optimal number of lamps required to meet testing standards and achieve optimal uniformity within the test area. The solar simulator, designed for irradiance levels up to 1066 W/m2, allows for control of output radiation by adjusting the number of illuminated lamps and the distances between lamps and the unit under examination. At maximum irradiance, the simulator demonstrates a remarkable 91.5% uniformity of radiation. To validate its functionality, the solar radiation test was executed on an outdoor electricity meter, exposing it to different loads and varying radiation values. The accuracy of the meter was precisely recorded and analyzed as an essential component of the overall assessment process.

Reusing industrial waste is one of the new tactics being used to fight the dumping of solid waste for environmental protection. In the current work, the waste polyurethane (WPU) was ground to a fine powder and used for reinforcement of devulcanized waste rubber/styrene butadiene rubber (DWR/SBR) blends. DWR/SBR/WPU composites were prepared using (0, 3, 6, 9, 15, 30) phr (parts per hundred of rubber) of WPU. It was hypothesized that the treatment of WPU with trimethylolpropane triacrylate (TMPTMA) and irradiated at 10 kGy would improve its compatibility with the DWR/SBR blend and, consequently, its reinforcement efficacy. The incorporation of 30 phr of treated WPU (TWPU) improved the tensile strength (TS) by 47.7% and 8.6% compared to neat DWR/SBR and composites containing 30 phr of untreated WPU (UWPU). In addition, the incorporation of TWPU improved other mechanical characteristics such as tear strength, hardness, and abrasion resistance. As a result of increasing polarity and cross‐link density within the DWR/SBR blend after the addition of polar WPU, the resistance to motor oil was improved. The outcomes are encouraging from the standpoint of the circular economy and help produce high‐performing, reasonably priced DWR/SBR composites for a range of industrial uses, especially in the floor tiles application. Highlights Waste polyurethane (WPU) was activated using gamma irradiation in the presence of TMPTMA. The treatment of WPU improved its compatibility with DWR/SBR blend. The impact of WPU treatment on the properties of DWR/SBR blend was investigated. TWPU improved the mechanical properties of DWR/SBR blend more than UWPU. TWPU increased the motor oil resistance of DWR/SBR blend more than UWPU.

A certified reference material (CRM, KRISS 108-01-002) for zearalenone in corn flour was developed to assure reliable and accurate measurements in testing laboratories. Commercially available corn flour underwent freeze-drying, pulverization, sieving, and homogenization. The final product was packed in amber bottles, approximately 14 g per unit, and preserved at –70 °C. 13C18-Zearalenone was used as an internal standard (IS) for the certification of zearalenone by isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC‒MS/MS) and for the analysis of α-zearalenol, β-zearalenol, and zearalanone by LC‒MS/MS. The prepared CRM was sufficiently homogeneous, as the among-unit relative standard deviation for each mycotoxin ranged from 2.2 to 5.7 %. Additionally, the stability of the mycotoxins in the CRM was evaluated under different temperature conditions and scheduled test periods, including storage at −70°C, −20°C, and 4°C and room temperature for up to 12 months, 6 months, and 1 month, respectively. The content of each target mycotoxin in the CRM remained stable throughout the monitoring period at each temperature. Zearalenone content (153.6 ± 8.0 µg/kg) was assigned as the certified value. Meanwhile, the contents of α-zearalenol (1.30 ± 0.17 µg/kg), β-zearalenol (4.75 ± 0.33 µg/kg), and zearalanone (2.09 ± 0.16 µg/kg) were provided as informative values.

A straightforward and green coating is prepared from graphene sheets decorated with MnO2@Polypyrrole for obtaining multifunctional lyocell textiles. A facile ultrasonication approach was developed for the preparation of effectively exfoliated graphene sheets using sodium casein salt (mGRP). A dipping and drying method was used for applying graphene onto the textile. Further, MnO2@Polypyrrole was then prepared on the graphene-modified textile using a new vapor polymerization approach to obtain ternary-coated textiles (LC@mGRP@MOPpy). Different spectroscopic and microscopic analysis techniques were exploited for approving the chemical structure and surface morphology of mGRP, and the various obtained textiles. The thermal, mechanical, electrical resistance, UPF, and flame retardancy behaviors of the fabricated fabrics were evaluated. The electrical resistance of the composite modified textiles was estimated as 10.6 MΩ, which is relatively lower than the pure lyocell fabric (178.9 MΩ). A highly improved ultraviolet protection factor was recorded also for the coated textile (33.74) compared to the pure one (7). Moreover, the flammability tests stated that the rate of burning of coated textile was measured as 0 mm/min compared to the virgin lyocell fabric (125 mm/min). In addition, the afterflame, and glow times were noted as 0 s, and 300 s compared to 17, and 10 s for the uncoated textiles assuring an efficient retardation performance against flame spread.

Improving eco‐friendly coating‐based materials for wool artifacts, such as kilim fabric can inspire new‐fashion design avenues for conserving ancient cultural heritage. Thus, this research addresses an efficient treatment agent from natural rosin acids (R) and dapsone (D) with variable sublethal proportions of synthesized titanium dioxide nanoparticles (TiO 2 NPs) (i.e., 0.1%, 0.3%, and 0.6%) for modifying kilim fabric (KF) using a dip‐coating method. The nanostructure of prepared TiO 2 nanoparticles and their particle size were examined by x‐ray diffraction (XRD) and Zetasizer analyzer. The data showed that the majority of prepared TiO 2 oriented to a rutile‐type structure with an average hydrodynamic diameter of 48.30–49.65 nm. The KF‐R/D‐0.3% TiO 2 NPs specimen provided the best tensile properties reached ~3192 N compared with the untreated KF (i.e., 1125 N). This finding confirmed by SEM observations. Whereas, the specimen containing decorated TiO 2 NPs (i.e., 0.6%) possessed higher flammability resistance property compared with other specimens. Moreover, XRD and FTIR results for treated KF specimens demonstrated the significant role of TiO 2 NPs, which react with KF keratin either by new linkages or through chelating geometry to form a compact KF matrix. This contributed to enhance the tensile and flammability properties. Additionally, a great achievement in antibacterial properties occurred when TiO 2 NPs used and their inhibitory zones were 18–36 mm, depending on the bacteria and specimen type. Highlights Novel treatment of KF fabric‐based bioagents with sublethal contents of TiO 2 NPs was successfully prepared by dip‐coating route. The tensile force and flammability of treated KF fabric were greatly enhanced. A great achievement in antibacterial activity was noticed when TiO 2 added. These treated fabrics have excellent possibility for use in conserving cultural heritage.

The purpose of this study is to evaluate the effect of the number of diffusers placed in the same room, as well as the effect of diffusers with a flat area (8.4, 13.2, and 18 m ² ) on the calculated sound absorption coefficient in a reverberation room, when an iterative procedure based on the evaluation of the sound power level is applied (this is done by using the sound power equation and substituting with different values of equivalent absorption area on both sides of the transformed equation to reach the correct value for absorption area, which achieves equality on both sides of the equation in order to achieve the goal). The sound absorption coefficient at random incident of three materials having different degrees of absorption—has been measured in a reverberation room according to ISO 345: a highly absorbent material (sponge) a medium absorbent material (rubber) and a low absorbent material (wood).There is a noticeable convergence between the calculated and measured sound absorption coefficient from the usual ISO 354 procedure and from the sound power level equation from ISO 3741,when diffusers are present. The difference in sound power level is close to 1.0 dB depending on the position of the source with the diffuser area. Thanks to the diffusers effect, the difference between the measured and the calculated sound absorption coefficient can be considerably reduced.