An experimental study of acid gas absorption by method hybrid nanofluid spraying in the presence of continuous and alternating magnetic fields

Face-centered cubic structure of nickel oxide (NiO) nanoparticles with 30 nm average size was synthesized by co-precipitation method with some modification in synthesis, calcination time period and temperature. The morphology, particle size, surface area and pore size of NiO nanoparticles were determined by TEM, XRD and BET. FTIR and UV–visible analysis confirmed the formation of NiO nanoparticles. NiO nanoparticles have been used as photocatalyst for Congo red (CR) degradation from aqueous solution. The photocatalytic degradation of CR dye was analyzed by four parameters such as the concentration of CR dye, the effect of contact time, the effect of pH and dose of NiO nanoparticle catalyst. The maximum degradation of CR dye (84%) by NiO nanoparticles was determined with respect to contact time. Antioxidant activity increases as the NiO nanoparticle concentration increases. The concentration of NiO nanoparticles efficiently enhances the bacterial inhibition against gram-positive and gram-negative bacteria. The bacterial strains such as K. pneumonia 700603 and B. subtilis 5902 showed maximum zone of inhibition (15 mm) at 40 mg/ml concentration, and minimum inhibitory concentration 62.5 μg/ml by NiO nanoparticles, respectively. The photocatalytic degradation of CR and antibacterial study acknowledge that the NiO nanoparticles are efficient photocatalysts for degradation of CR dye and inhibition against different bacterial strains. NiO nanoparticles will be used to provide clean and low-cost drinking water without harmful dyes and pathogenic microbes generated in industrial wastewater.

RETROPERITONEOSCOPIC SURGERY IS NOT ASSOCIATED WITH INCREASED CARBON DIOXIDE ABSORPTION

Carbon dioxide output in laparoscopic cholecystectomy

Carbon dioxide absorption with aqueous amine solutions promoted by piperazine and 1-methylpiperazine in a rotating zigzag bed

In this paper, nickel oxide (NiO) nanoparticles have been fabricated using wet method and deposited on the surface of multi-walled carbon nanotube (MWCNT). To do so, functional groups were introduced on the surface of MWCNTs by treating with concentrated nitric acid. Nickel oxide nanoparticles were formed on the surface of functionalized MWCNTs by incipient wetness impregnation of nickel nitrate, and the resultant product was calcinated in air atmosphere. Characteristics of the NiO/MWCNT were examined by various techniques, for example, Fourier transform spectroscopy (FTIR), X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), thermogravimetric analyzer (TGA), and nitrogen adsorption–desorption isothermal as well as vibrating sample magnetometer (VSM). The FTIR spectra showed that carboxyl and hydroxyl functional groups existed on the surface of MWNTs after modification by concentrated nitric acid. The pattern of XRD indicated that MWNTs and nickel oxide nanoparticles coexisted in the NiO/MWCNT sample. The TEM images revealed that the NiO nanoparticles were distributed on the surface of the MWNTs, with the size ranging from 5 to 60 nm. Thermogravimetric analysis proved that NiO content decorated on MWCNTs was 80 and 15 wt%. The results of the Brunauer–Emmett–Teller (BET) data showed that the slight increment in the specific surface areas and porosities in the presence of the NiO nanoparticles on the surface of CNT.

Investigation of the visible-light-driven catalytic activity of nickel oxide-doped carbon nanotubes/polyvinylpyrrolidone nanocomposites towards methylene blue dye

Prevention of asphaltene formation in reservoir rocks can result in resolving a severe long-lasting issue in petroleum production. The present research addresses the issue in the context of exploring the potential effect of nickel oxide (NiO) nanoparticles in destabilizing asphaltene deposition in porous media, in the presence of carbon dioxide. To ensure proper distribution within the system and to retain future field-scale applicability, the NiO nanoparticles were exposed to the in situ oil via injection gas stream, in which they had been uniformly dispersed using polydimethylsiloxane (PDMS). The experimental results, established under miscible CO2 state, indicate a considerable improvement in permeability/porosity reduction of core, as well as less asphaltene accumulation in porous media and increased oil recovery factor after applying NiO nanoparticles.

To the Editor: Three cases of carbon dioxide rebreathing without a significant color change in the appearance of the canisters were experienced during general anesthesia with the same model anesthesia machines; Aestiva/5 (Datex Ohmeda, Wisconsin, USA) with a fresh gas flow of 1–2 l/min. Carbon dioxide rebreathing was recognized because the inspiratory carbon dioxide baseline of the capnogram trace gradually rose. The inhalational carbon dioxide concentration decreased immediately after increasing the fresh gas flow, and rose again with decreasing the fresh gas flow. This indicates that carbon dioxide rebreathing was due to carbon dioxide accumulation in the semi-closed circuit system of the anesthesia machines. A color change in the appearance of the carbon dioxide absorbent was recognized only in the upper part of the canister (Fig. 1a). The top surface of the canister showed a significant color change limited to the middle part of it (Fig. 1b). The section image of the canister showed a significant columnar color change of the carbon dioxide absorbent along the full length of the center part of it (Fig. 1c). The observation of the canister bottom of Aestiva/5 revealed that only the center part of it had the mesh part for the exhaled gas, and the color change of the carbon dioxide absorbent seemed to accord with the mesh part of the bottom (Fig. 1d). As an experiment, when a transparent plastic partition wall was settled in the canister before filling with carbon dioxide absorbent, the columnar color change was no longer visible. This indicated that the flow of the exhaled gas was influenced by the wall in the canister. Considering these results, it is supposed that the structural characteristic of the canister bottom of the anesthesia machine; Aestiva/5, caused channeling and the inhomogeneity of the current of inhaled gas in the canister led to the columnar color change of the carbon dioxide absorbent. The role of the carbon dioxide absorbent canister becomes more important as the fresh gas flow quantity decreases. A technique of using a fresh gas flow of 1 l/min was reported first in 1952 [1]. The technique with the fresh gas flow less than 1 l/min subsequently became known as ‘‘low-flow anesthesia’’. Afterwards, a technique using a fresh gas flow of 500 ml/min was reported as ‘‘minimal flow anesthesia’’ [2]. These cases of carbon dioxide rebreathing without significant color change in the appearance of the canisters provide very important information not only for anesthesiologists, but also for all persons using anesthesia machines. When carbon dioxide rebreathing is recognized, carbon dioxide accumulation in the circuit system of the anesthesia machines should be suspected and exhaustion of the carbon dioxide absorbent should be immediately T. Yamamoto (&) Department of Pediatric Anesthesiology and Critical Care Medicine, Children’s Hospital Asklepios Klinik Sankt Augustin, Arnold-Janssen-Str. 29, 53757 Sankt Augustin, Germany e-mail: yamatomo270@hotmail.com; t.yamamoto@asklepios.com

Ionic liquid crystals/nano-nickel oxide-decorated carbon nanotubes composite for electrocatalytic treatment of urea-contaminated water

Methane hydrate exists in huge amounts in certain locations, in sea sediments and the geological structures below them, at low temperature and high pressure. Production methods are in development to produce the methane to a floating platform. There it can be reformed to produce hydrogen and carbon dioxide, in an endothermic process. Some of the methane can be burned to provide heat energy to develop all needed power on the platform and to support the reforming process. After separation, the hydrogen is the valuable and transportable product. All carbon dioxide produced on the platform can be separated from other gases and then sequestered in the sea as carbon dioxide hydrate. In this way, hydrogen is made available without the release of carbon dioxide to the atmosphere, and the hydrogen could be an enabling step toward a world hydrogen economy.

In the present study, multi-spectroscopic methods were applied to investigate the effect of NiO nanoparticles on the structure, activity, and stability of proteinase K. To this aim, UV–Vis spectroscopy, circular dichroism photometry, and spectrofluorometry were conducted. UV absorption spectroscopy results revealed that with the addition of NiO nanoparticles, the maximum absorption of the enzyme showed hyperchromism. The regular decrement in the intrinsic fluorescence intensity of the enzyme was obtained with the increase in NiO nanoparticles concentrations. Far-circular dichroism also demonstrated a reduction in the β-sheet and β-turn and an increase in the α-helix content. Furthermore, the results obtained from this investigation revealed that the catalytic activity and thermal unfolding of the enzyme were improved in the presence of NiO nanoparticles in a concentration-dependent manner. Thus, NiO nanoparticles acted as an activator and stabilizer of proteinase K. Finally, the thermodynamic parameters showed that the enzyme–NiO nanoparticles combination was spontaneous and that the hydrophobic interactions and electrostatic forces played a key role in the interaction of the nanoparticles with the enzyme.

Nanocomposites of poly(vinyl cinnamate) (PVCin) with various concentration of nickel oxide (NiO) nanoparticles were prepared by in situ polymerization method. The effect of metal oxide particles on the structural, magnetic and thermal stability was analyzed by a high resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and thermogravimetric analysis (TGA) measurements. The electrical properties such as room temperature DC conductivity and temperature dependent AC conductivity were investigated with respect to different loading of NiO nanoparticles. XRD and HRTEM images showed the uniform arrangement of nanoparticles inside the macromolecular chain of PVCin. The VSM studies of nanocomposites indicated the hysteresis loops of the ferromagnetic behavior. The saturation of magnetization and coercivity values were varied with the content of NiO nanoparticles. From TGA analysis the composite attain better thermal stability than polyvinyl cinnamate and the thermal stability increases with increase in concentration of nanoparticles. The electrical conductivity of nanocomposite was increased with increase in temperature and also with the loading of nanoparticles. The activation energy values calculated from the AC conductivity was found to be decreases with increase in temperature in all compositions. AC and DC conductivity of nanocomposites were much greater than pure PVCin and the maximum conductivity values were obtained for 10 wt% of composite. Different theoretical equations based on Scarisbrick, McCullough and Bueche model were used to compare the experimentally determined conductivity with theoretical conductivities.

Lately, absorption of carbon dioxide using nanofluids has gained more attention as this acidic gas creates global warming effect. The absorption test was conducted in a custom designed high-pressure vessel made up of stainless steel 316 L, where CO2 and nanofluid are in direct contact at static state. The type of nanoparticles and influence of its concentration on absorption of carbon dioxide are analyzed. TiO2 and Al2O3 nanofluids at 0.02–0.14[Formula: see text]wt.% concentrations are prepared by dispersing in DI water. The CO2 absorption tests were carried out for the above-mentioned nanofluids at said concentrations with operating conditions being an initial pressure of 3 bar and initial temperature of 302[Formula: see text]K. The results show that relative absorption index (RAI) of CO2 absorption has increased to a maximum and then decreased with increase in nanoparticle concentration. The aqueous-based TiO2, Al2O3 nanofluids are found to be most effective at 0.1 and 0.14[Formula: see text]wt.%, respectively, with RAI showing 39.81% and 22.3% increase in CO2 absorption as compared to basefluid, respectively. The absorption test has also been conducted for saline-based TiO2 and Al2O3 nanofluids at 1, 2, 3 and 3.1[Formula: see text]wt.% of salt concentration. The stability of saline-based nanofluids was analyzed using turbidity meter. It was found that increase in salt concentration decreases the stability of nanofluids and also decreases the CO2 absorption rate because of unstability of nanoparticles in salt solutions. Absorption decreased by 11.93% for TiO2, and 5.68% for Al2O3, when salt concentration was increased from 1 to 3.1[Formula: see text]wt.%.

The number of pollutants released into freshwater and marine environments has increased due to the widespread use of nanoparticles. Nickel oxide nanoparticles (NiO-NPs) were tested for genotoxicity in fish fingerlings of the species Ctenopharyngodon idella. For 7, 14, and 21days, fingerlings were exposed to NiO-NPs with each increasing concentrations of 2.25mg/L, 4.50mg/L, and 6.75mg/L, respectively. The micronuclei assay and comet assay were used to evaluate the DNA damage. The experiment revealed that with the increase in nanoparticle concentration and exposure duration, the level of DNA damage also increased. The experiment resulted to be time and dose dependent, and the damage was found as follows: 6.75mg/L > 4.50mg/L > 2.25mg/L against each exposure period. In terms of comet assay, the results showed that after 7days, the level of DNA damage in all the concentrations was highly significant (P < 0.001). Increased DNA damage was calculated at the higher administered dose of 6.75mg/L for 21days of exposition, followed by 14 and 7days, respectively. The second high toxic effect was observed in the fish blood at the exposure concentration of 4.50mg/L for 21days, followed by 14 and 7days, respectively. The micronuclei induction in the nanoparticle's administered blood could be detected only for a 7-day exposition period. Whereas for the exposed duration of 14 and 21days, the entire red blood cells of the grass carp were completely destroyed demonstrating the ability of the nanoparticles to cause anomalies in aquatic life.

Modification of structural and physical properties of samarium doped zinc phosphate glasses due to the inclusion of nickel oxide nanoparticles