A simple load sensor based on a bent single-mode–multimode–single-mode fiber structure

A load sensor is demonstrated using a single-mode-multimode-single-mode (SMS) fiber structure, which is sandwiched between two CR-39 plastic polymer plates. A larger effective transverse strain can be achieved when the distance, D2, between the stage and the edge of the multimode fiber is larger. A higher sensitivity is obtained when D2 = 7 cm with a value of −0.0102 nm/mN, as compared to −0.0027 nm/mN when D2 = 3 cm. In contrast, an FBG integrated in a similar manner has shown an indiscernible change in the wavelength shift as compared to that produced by the SMS device. The result indicates that the proposed SMS device is suitable for sensing a small load or transverse strain with a reasonably high sensitivity

Novel deep eutectic solvent-functionalized carbon nanotubes adsorbent for mercury removal from water

Due to the interestingly tolerated physicochemical properties of deep eutectic solvents (DESs), they are currently in the process of becoming widely used in many fields of science. Herein, we present a novel Hg2+ adsorbent that is based on carbon nanotubes (CNTs) functionalized by DESs. A DES formed from tetra-n-butyl ammonium bromide (TBAB) and glycerol (Gly) was used as a functionalization agent for CNTs. This novel adsorbent was characterized using Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, XRD, FESEM, EDX, BET surface area, and Zeta potential. Later, Hg2+ adsorption conditions were optimized using response surface methodology (RSM). A pseudo-second order model accurately described the adsorption of Hg2+. The Langmuir and Freundlich isotherms models described the absorption of Hg2+ on the novel adsorbent with acceptable accuracy. The maximum adsorption capacity was found to be 177.76 mg/g

Trendline and Monthly Variations of Nitrate in Water Supply Wells in Upper Egypt

Safe drinking water is among the most important environmental as well as health challenges facing Egypt. Groundwater from the aquifer of the Nile valley in Upper Egypt accounts for about 40% of the overall source of drinking water. Nearly, all rural residents rely on groundwater as the source of drinking water. Irrigation water is the main source of groundwater recharge in Nile Valley. Moreover, nitrate fertilizer utilization in Egypt has risen significantly due to the requirement for further agricultural production. Nitrate levels higher than the permissible limit (45 mg/L) for drinking water have been related to health issues. To determine the effect of agrochemical nitrate on the health of pumping water, municipal water wellfields established in Upper Egypt have been examined. Pumped water from those municipal wells (60 m depth and 2000 m3/day gross pumping rate) was evaluated from 2000 to 2018 to accomplish this objective. Monthly analysis of the quality of groundwater, in particular nitrate, has been conducted. Sulfate and nitrate concentrations as well as other consistency metrics were assessed. Water sampling findings show that the water already comes under the drinking-water limits. Nevertheless, increased nitrate and sulfate values are found beyond naturally existing levels in the aquifer. Consequently, to determine the possible future likelihood of nitrate contamination in such municipal wells, the trendline of nitrate level has been used. The observations suggest that the intensive utilization of nitrogen fertilizer in Upper Egypt in the last 30 years would endanger the quality of the groundwater supply. Resultantly, the usage of nitrogen fertilizers in Upper Egypt must be regulated and continuous groundwater monitoring must be implemented

Utilization of Water-Cooled and Air-Cooled Slag Aggregate in Concrete: A Solution to the Secular Economy

Aggregates are generally thought of as inert filler within a concrete mix, and a typical concrete mix is comprised of as much as 70–80% of them. They play an essential role in the properties of both fresh and hardened concrete. Nowadays, scientists are aiming to use waste materials, thereby replacing natural aggregates for economic and environmental considerations. This study investigates the effect of the utilization of steel slag by-product aggregates (air- and water-cooled slag) as concrete aggregates on the behavior characteristics of concrete. Various concrete mixtures, with different levels of replacement of slag aggregate (50, 75, and 100%), were conducted in order to find the optimum percentages to improve the microstructure and different properties of concrete (fresh and hardened). The results showed that increasing the fine aggregate replacement percentage led to a decrease in compressive strength values, in contrast with coarse aggregate replaced with slag aggregate. The steel slag aggregates showed potential to be used as replacement for natural aggregate with comparable compressive strength and acceptable workability

Allyl triphenyl phosphonium bromide based DES-functionalized carbon nanotubes for the removal of mercury from water

Recently, deep eutectic solvents (DESs) have shown their new and interesting ability for chemistry through their involvement in variety of applications. This study introduces carbon nanotubes (CNTs) functionalized with DES as a novel adsorbent for Hg2+ from water. Allyl triphenyl phosphonium bromide (ATPB) was combined with glycerol as the hydrogen bond donor (HBD) to form DES, which can act as a novel CNTs functionalization agent. The novel adsorbent was characterized using Raman, FTIR, XRD, FESEM, EDX, BET surface area, TGA, TEM and Zeta potential. Response surface methodology was used to optimize the removal conditions for Hg2+. The optimum removal conditions were found to be pH 5.5, contact time 28 min, and an adsorbent dosage of 5 mg. Freundlich isotherm model described the adsorption isotherm of the novel adsorbent, and the maximum adsorption capacity obtained from the experimental data was 186.97 mg g−1. Pseudo-second order kinetics describes the adsorption rate order

Water wave gauge based on singlemode-multimode-singlemode fiber structure

A simple wave gauge that uses a single-mode-multimode-single-mode (SMS) fiber structure is investigated in this paper. The SMS interferometer is packaged with Cr-39 plastic polymer plates in order to gauge water waves in the laboratory flume. The working principle of the sensor is based on the linear uniform fiber bending mechanism, which, because of the wave frequency, changes the light interference pattern and output power. In the experiment, the intermediate depth wave of 0.18 < d/L < 0.25 was generated in the flume. The average power corresponded to the SMS at wave celerities ranging from 0.43–0.57 m/s, exhibiting almost perfect periodic manner. The results of the frequency spectrum showed that the proposed SMS fiber structure could be exploited in measuring water wave celerity and wavelength, yielding linear sensitivities of 2.0304 Hz/(m/s) and 1.5613 Hz/ m, respectively

Glycerol-based deep eutectic solvents: Physical properties

Deep eutectic solvents (DESs) have been used in many industrial applications. DES is a mixture of a salt and a hydrogen bond donor (HBD). In this study, 70 DESs were synthesized successfully based on glycerol (Gly) as the HBD with different phosphonium and ammonium salts, namely methyl triphenyl phosphonium bromide (MTPB), benzyl triphenyl phosphonium chloride (BTPC), allyl triphenyl phosphonium bromide (ATPB), choline chloride (ChCl), N,N-diethylethanolammonium chloride (DAC), and tetra-n-butylammonium bromide (TBAB). The DESs were prepared using different molar ratios of the HBD to the salts. The freezing point of each DES was determined using Differential Scanning Calorimetry (DSC). The physical properties of these DESs, including density, viscosity, conductivity, and surface tension, were investigated as functions of temperature. In addition, the functional groups were analyzed utilizing Fourier transform infrared (FTIR) spectroscopy. It is worth noting that these systems have a wide variety of physical properties, which implies that these DESs would be suitable for diverse applications

Functionalization of CNTs surface with phosphonuim based deep eutectic solvents for arsenic removal from water

Herein, we present the use of deep eutectic solvent (DES) as functionalization agents for carbon nanotubes (CNTs) to form novel adsorbents for removal of arsenic ions (As3+) from water. Two DESs systems were prepared using methyltriphenylphosphonium bromide (MTPB) and benzyltriphenylphosphonium chloride (BTPC) as salts, in conjugation with glycerol (Gly) as a hydrogen bond donor. The resulting novel adsorbents were characterized using thermogravimetric analysis (TGA), Zeta potential, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, XRD, EDX, FESEM, and BET surface area. Optimization studies were carried out utilizing RSM-CCD experimental design to estimate the optimum removal conditions for each adsorbent. The adsorption experimental data of both adsorbents were found to fit well with pseudo-second-order kinetics model, as well as with Langmuir and Freundlich adsorption isotherm models. The maximum adsorption capacity of a MTPB-DES-functionalized CNTs adsorbent was 23.4 mg/g