Liquid Immersion Method Research Articles

Obtaining Highly Efficient Radon Adsorbents by Adjusting the Pore Structure of Bamboo Charcoal with Particle Size Fractionated Activation.

To achieve highly efficient adsorbents for radon (Rn), this study prepared bamboo activated carbon (BAC) using bamboo charcoal as the precursor and KOH and NaOH as activators and employed a method of activation by adjusting the pore structure through particle size fractionation. Under the same activation conditions, KOH was consumed less and showed better Rn adsorption performance than NaOH, and the solid milling method saved more activator dosage compared to the liquid immersion method. After carbonizing the bamboo, the highest Rn adsorption coefficients of the bamboo charcoal activated with particle size fractionation (0.43-0.85, 0.25-0.43, 0.18-0.25, and <0.18 mm) were 8.41 ± 0.05, 10.03 ± 0.24, 9.31 ± 0.01, and 8.15 ± 0.21 L/g, respectively under N2 conditions (at a temperature of 25 °C and humidity of 35%), which were significantly greater than those of bamboo charcoal with overall activation (7.05 ± 0.23 L/g). After optimization, all of the bamboo charcoals with different particle sizes had the highest volume ratio for pores with a diameter of 0.77 nm. BC0.43-0.85K1.25 and BC0.25-0.43K0.75 maintained 95.74 and 92.36%, respectively, of the original adsorption coefficient after 5 cycles of regeneration under nitrogen. As the bamboo charcoal particle size decreased, the optimal mass ratio of alkali/carbon also decreased. This indicates that particle-size-fractionated activation can reduce the raw material and activator waste. The optimized BAC has a significantly higher Rn adsorption coefficient than the currently used coconut shell activated carbon (4.13 ± 0.51 L/g), making it an efficient and economical adsorbent with excellent application value for radon removal.

Comparison between Liquid Immersion, Laser Diffraction, PDPA, and Shadowgraphy in Assessing Droplet Size from Agricultural Nozzles

Spray droplet diameters play a key role in the field of liquid plant protection product (PPP) application technology. However, the availability of various measurement techniques, each with its unique operating principles for evaluating droplet size spectra, can lead to different interpretations of spray characteristics. Therefore, in this study, four measurement techniques—Liquid Immersion (LI), Laser Diffraction (LD), Phase Doppler Particle Analysis (PDPA), and Shadowgraphy (SG)—were utilized to evaluate the droplet size distribution of agricultural spray nozzles. Additionally, PDPA and SG were used to assess the average velocity of spray droplets. Experiments were conducted in three different laboratories with the main aim of comparing results obtained with various types of equipment utilized under ordinary practical conditions. Spraying tests were carried out using three flat fan nozzles and an air-induction flat fan nozzle. As a general trend, the lowest values for droplet diameters were measured using the Laser Diffraction technique, followed by Shadowgraphy. The PDPA technique provided the highest values for mean diameters (D10, D20, and D30) and the numeric median diameter (Dn0.5), whereas the Liquid Immersion method yielded the highest values for the Sauter mean diameter (D32) and volumetric diameters (Dv0.1, Dv0.5, and Dv0.9). Importantly, all measurement techniques were able to discriminate the four nozzles based on their Dv0.5 diameter. Average droplet velocities showed a similar pattern across the four nozzles with the PDPA and the SG measurement techniques. The differences in diameter values observed with the four measurement techniques underline the necessity of always including reference nozzles in spray quality assessments to base classifications on relative rather than absolute values.

Carbon nanotube reinforced nanohybrid urea-hydroxyapatite fertilizer for an improved nutrients utilization efficiency and reducing environmental pollution

An upgraded technology is needed in the agricultural sector in order to adopt sustainable practice to maintain high yield as well as reducing environmental pollution due to ammonia emissions attributed to mineral nitrogen fertilization. This study reports a modified urea-hydroxyapatite nanohybrids fertilizers incorporated with carbon nanotube for more efficient sustainable nutrients utilization and reduction of ammonia emissions from fertilizers application. The urea-hydroxyapatite fertilizer was mixed with carbon nanotube at varying ratio by mass percentage (Sample A = 1:0.5. B = 1:1, C = 1:2, and D = 1:3) using simple liquid immersion method. The assessment of all the samples and the control specimen (sample E) was conducted by subjecting them to the analysis of thermogravimetric at intervals of 20 min to 200 min, to determine their nitrogen release behaviour activities. The morphological properties of urea-hydroxyapatite fertilizer with and without carbon nanotubes were compared using spectroscopic analysis (SEM, FTIR and XRD). The mechanical tests were conducted to examine the tensile and compressive strengths of the urea-hydroxyapatite fertilizer with carbon nanotubes using diametral tensile strength technique. The data obtained reveals that the control sample (urea-hydroxyapatite fertilizer) released 70 to 80 % urea within first 50minutes while the samples with carbon nanotubes retained urea for longer and 76 to 90 % amount of nitrogen release was recorded in the first 150minutes. It is revealed that the sample C with mixing ratio 1:2 exhibited best slow-release nitrogen properties. The sample C displayed a moderately large amount of nitrogen in form of urea in the initial phase and followed by slow-release even until the last minutes (200minutes). In the contrary, urea-hydroxyapatite fertilizer (control sample) which released heavily in the initial phase followed by the release of low and non-uniform quantities until its last drop towards 150minutes. SEM result demonstrated that chemical reaction occurred between urea-hydroxyapatites particles and carbon nanotubes. XRD patterns of urea-hydroxyapatites nanohybrid structures with carbon nanotubes demonstrate that the samples show the hydroxyapatite properties with monocrystalline structure. It is confirmed from the FTIR spectra that chemical functionalization cropped up between urea-hydroxyapatites nanohybrid and carbon nanotubes particles. A remarkable increase in the mechanical strength (150 % for the tensile strength and 100 % for the compressive strength) of the sample C structures confirms that introduction of carbon nanotubes improved its strength properties for the purpose of prolong stability while discharging its role as a nutrients slow-release fertilizer. Thus, the designed nano-fertilizer formulation of sample C mixing ratio can therefore be used as alternative way of improving the nutrients usage efficiency for the plants growth as well as to reduce the ammonia emission to the environment as pollutant.

Drop Size Measurement Techniques for Agricultural Sprays:A State-of-The-Art Review

Plant protection control based on the spray application of plant protection products is a very complex task depending on a series of factors, among which droplet size is the most influential for deposition and pesticide effectiveness. In fact, the adoption of the correct droplet size can ensure that the required dose reaches the target area and is not wasted, minimizes the off-target losses due to evaporation, drift and run-off and, at the same time, enhances the operator’s safety in terms of inhalation, ingestion and dermal exposure. In this paper, after defining some mean characteristic diameters helpful for a description of a drop population and focusing on the main drop size distribution functions for the statistical characterization of sprays, a critical analysis of known methods, both intrusive and non-intrusive, for drop size measurement is carried out by reviewing the literature. Among intrusive methods, the liquid immersion method and the use of water-sensitive papers are discussed, whereas, among non-intrusive methods, laser-based systems (laser diffraction, phase Doppler particle analysis) and high-speed imaging (shadowgrapy) are presented. Both types of method, intrusive and non-intrusive, can be used in machine-learning-based approaches exploiting regression techniques and neural network analysis.

Effect of Image Segmentation Thresholding on Droplet Size Measurement

Droplet size spectrum is a key factor in pesticide application because it affects the biological efficacy of a treatment in terms of target coverage, environmental impact in terms of evaporation, drift and run-off, and operator’s safety in terms of inhalation and dermal exposure. Droplet measurement methods based upon image analysis have to face the “binarization” or “segmentation” process, by which the objects of interest (the droplets) are extracted from the background. Segmentation is carried out by choosing appropriate threshold values, mostly based on the operator’s experience. In this study, images of droplets of an air induction nozzle TVI 8002 at four pressures (0.3, 0.5, 1.0, and 1.5 MPa) were obtained using the liquid immersion method. Each image was processed multiple times, firstly by using a “reference” threshold value based on the operator’s experience and then by using 11 different threshold values, chosen in the range of around ±5% of the reference threshold and based upon the average gray level of the image. For each threshold value, the corresponding spray parameters (volumetric diameters, mean diameters, Sauter diameters, and numeric diameters) were analyzed. The results showed that spray parameters had a statistically significant linear trend with respect to the threshold values in most cases. However, in absolute terms, variations were almost always less than 1.0% of reference values. This result allows considering the image acquisition system used in the present study as an automatic tool able to select the threshold according to the gray level of the image, making the whole segmentation process faster, more objective, and less dependent on the operator’s experience.

Fabrication and characterization of zeolite bulk body containing mesopores and macropores using starch as pore-forming agent

Zeolite bulk bodies containing macropores, mesopores, and micropores were prepared and characterized using ZSM-5 raw powder as the starting material. Starch powder was selected as a pore-forming agent and the internal porous structure was controlled by using the property that starch particles form a network structure by heat treatment. The presence of mesopores was characterized by N2 gas adsorption/desorption measurement, and the macroporous structure was observed by the 3D-image analysis of hundreds of cross-sectional images in the depth direction by a confocal laser fluorescent microscope using the liquid immersion method. The observation method demonstrated that it is possible to observe structures of several microns size in the three dimensions. The compressive strength and N2 gas permeability of the bulk samples depended on the sample structure; bulk bodies with a compressive strength comparable to that of general concrete were created. The network structure of the starch pore-forming agent was effective in creating a continuous macroporous structure. The bulks could be used in applications such as novel catalyst carriers and filters, and combining functional nanoparticles.

Modelling Spray Pressure Effects on Droplet Size Distribution from Agricultural Nozzles

For spray applications, drop size is the most important feature as it affects all aspects of a phytosanitary treatment: biological efficacy, environmental pollution, and operator safety. In turn, drop size distribution depends on nozzle type, liquid properties, and working pressure. In this research, three nozzles were studied under ordinary working conditions and the effect of pressure on drop size distribution was assessed. The nozzles under test, all from Albuz (France), were an orange hollow cone nozzle ATR 80 (European color code), an air induction flat spray nozzle AVI 11003, and an air induction hollow cone nozzle TVI 8002. The ATR 80 and the TVI 8002 nozzles were tested at four pressure values: 0.3, 0.5, 1.0, and 1.5 MPa; the AVI 11003 nozzle was tested at 0.3 and 0.5 MPa. The drop size measurement technique was based on the liquid immersion method by using a custom-made test bench; spray quality parameters were computed by means of suitable functions written in R language. Results showed that an increase in working pressure caused an increase in drop pulverization regardless of the type of nozzle, and drop pulverization was higher for the turbulence nozzle than for the two air induction nozzles. Based on skewness and kurtosis values, the theoretical gamma distribution was the most adapt to fit the experimental data. The scale parameter showed a decreasing trend with the increase in the pressure, a clear index of higher drop pulverization.

Analysis of Overcurrent Performance of YBCO Tape Considering Different Heat Exchange Conductions

The performance degradation of High Temperature Superconducting (HTS) tape, which may be influenced by various heat exchange conditions due to different cooling methods, is of significant for HTS devices under repeated overcurrent. In this article, considering different heat exchange conditions, a series of repeated overcurrent experiments were carried on YBCO tapes under 50Hz sinusoidal alternating current. The degradation of critical current of YBCO tapes after repeated overcurrent was recorded. the resistance characteristics of YBCO tapes under different cooling conditions were analyzed. Through finite element simulation, the temperature and current distribution of YBCO tape under different heat exchange conditions were simulated. The experimental results show that the overcurrent capability of the conductor under conduction cooling is far inferior to the liquid nitrogen immersion method.

Kaplama Yapılmış Enjektör Gövde Millerinin Fiziksel Özelliklerinin Araştırılması

Diesel engines have an important place in today's internal combustion engines. Although use of the engines has decreased due to exhaust emissions, the engines continue to be used in different fields such as marine vehicles, generators, rail system and water vehicles. One of the most important equipment of diesel engines is the fuel system, especially such as common rail system with wide usage area. High pressure pump and injectors parts are manufactured very precisely in diesel fuel systems. Common-Rail injectors operate under very high pressure (1400-2000bar). This can cause easy damage injector parts such as nozzle, needle, shaft and valve. In this study, the effects of coating the common rail injector were investigated. For this purpose, different coatings were made on 3 diesel injectors which used in commercial vehicle engines and then fuel injection values and wear on the shaft surface after operation were compared with the standard injector. Body shafts covered with ALTiN and TiN are coated using the PVD arc method. Three injector body shafts were coated with Cr, TiN, ALTiN, respectively and working tests were performed with standard injectors. Cr coated shaft is coated using liquid immersion method. After the coating, the shaft roughness values were measured. The injectors were continuously tested by creating a cycle for 90 hours. As a result, it was determined that the coated shafts provided the original injector catalogue values, the spray quantities were within the ± tolerance range and the coating was suitable for use in injectors.

Determination of the Refractive Index of Particles Through the Immersion Solid Matching Method

We describe a new measurement technique to determine the refractive index (RI) of solid particles by monitoring the simultaneous scattering of light from suspension with a camera and the value of the RI with a refractometer. Our immersion solid matching method is based on the solidification process of the liquid continuously changing the RI as a function of time. The principle of the determination is based on finding the RI matching point of the particle and the liquid during the solidification. The traditional liquid immersion method is based on a set of immersion liquids with different refractive indices, while the proposed method requires only a small amount of a single immersion liquid. The method was tested using calcium fluoride (CaF2) particles with a varnish immersion liquid. The RI value of CaF2 was obtained to be consistent with the literature values, thus indicating the proper functioning of the proposed procedure.

Coupled effects of carbonation and bio-deposition in concrete surface treatment

This paper reports the coupled effects of carbonation and microbially induced carbonate precipitation (MICP) on behaviors in relation to the durability of concrete. Liquid immersion and semi-solid immobilization methods were compared for their effectiveness in bio-deposition treatment. After bio-deposition, the reduction ratio of water sorptivity coefficient for carbonated concrete was higher than that for untreated concrete; In contrast, the reduction ratio of water permeability coefficient for carbonated concrete was lower than that for untreated one. An analysis based on a simple model helps to explain this phenomenon. It shows that the water absorption was related to both the pore structure and the wettability of concrete surface, while the water permeability depended solely on the pore structure of concrete. Similar effectiveness of bio-treatment were obtained from liquid immersion and semi-solid immobilization methods, whereas the latter appears more promising in field application.

Determining the complex refractive index of cellulose nanocrystals by combination of Beer-Lambert and immersion matching methods

Nanocelluloses have received significant interest due to their unique structural, mechanical, and optical properties. Nanocellulose refractive indices can be used to indicate many crucial characteristics, such as crystallinity, transparency, and purity. Thus, accurate measurement is important. This study describes a new method to determine the wavelength dependent complex refractive index of cellulose nanocrystals (CNCs) by the measurement of light transmittance with a spectrophotometer. The data analysis is based on a combination of the Beer-Lambert and immersion liquid matching equations. The immersion liquid method's main advantage is that it is independent of particle shape and size. Moreover, the measurement is easy and relatively quick to perform. The present procedure is not restricted to the nanocellulose and could potentially be applied to other nanomaterials, such as hyphenate nanoparticle-based, lignin nanoparticles, nanopigments, biological entities, structural elements of dielectric metamaterials, and nanoparticle-based composites.

Recycling and separation of rare earth resources lutetium from LYSO scraps using the diglycol amic acid functional XAD-type resin

• Diglycol amic acid functional XAD-type resins were prepared using the ionic liquid (IL) immersion method.

On the Immersion Liquid Evaporation Method Based on the Dynamic Sweep of Magnitude of the Refractive Index of a Binary Liquid Mixture: A Case Study on Determining Mineral Particle Light Dispersion.

This is a feasibility study of a modified immersion liquid technique for determining the refractive index of micro-sized particles. The practical challenge of the traditional liquid immersion method is to find or produce a suitable host liquid whose refractive index equals that of a solid particle. Usually, the immersion liquid method uses a set of immersion liquids with different refractive indices or continuously mixes two liquids with different refractive indices, e.g., using a pumping system. Here, the phenomenon of liquid evaporation has been utilized in defining the time-dependent refractive index variation of the host liquid. From the spectral transmittance data measured during the evaporation process, the refractive index of a solid particle in the host liquid can be determined as a function of the wavelength. The method was tested using calcium fluoride (CaF2) particles with an immersion liquid mixed from diethyl ether and diffusion pump fluid. The dispersion data obtained were consistent with the literature values thus indicating the proper functioning of the proposed procedure.

Effect of the air to water ratio on the performance of internal mixing two-fluid atomiser

Abstract One of the important parameters describing pneumatic liquid atomisation is the air to liquid mass ratio (ALR). Along with the atomiser design and properties of the liquid it has extremely important influence on parameters of atomised liquid such as: mean droplet diameter, jet range and angle. Knowledge about real characteristics of an atomiser in this respect is necessary to correctly choose its operating parameters in industrial applications. The paper presents results of experimental research of two-fluid atomisers with internal mixing built according to custom design. Investigated atomizers were designed for spraying a urea aqueous solution inside the power boiler combustion chamber. They are an important element of SNCR (selective non-catalytic reduction) installation which is used to reduce nitrogen oxides in a flue gas boiler. Obtained results were used by authors in further research, among others to determine the boundary conditions in the SNCR installation modeling. The research included determining mean droplet diameter as a function of ALR. It has been based on the immersion liquid method and on the use of specialised instrumentation for determining distribution of droplet diameters in a spray – Spraytec by Malvern. Results obtained with both methods were later compared. The measurements were performed at a laboratory stand located at the Institute of Heat Engineering, Warsaw University of Technology. The stand enables extensive investigation of the water atomisation process.

Investigation of the anti-adhesion layers for nanoimprint molding

To realize the anti-adhesion issue between silicon mold and nanostructures of hard polydimethylsiloxane (H-PDMS), anti-adhesion layers were coated on molds to improve the H-PDMS grating structure with half-pitch below 200 nm. Various deposition methods such as liquid immersion method, vapor deposition method, and plasma-enhanced chemical vapor deposition were used to coat various anti-adhesion layers, respectively. Three anti-adhesion layers including diamond-like carbon (DLC) film, fluorine-doped diamond-like carbon (F-DLC) film, and perfluorooctyl-trichlorosilane (PFOTCS) were investigated. PFOTCS was functioned as a mold-releasing agent using the liquid immersion and vapor deposition methods, respectively. The effect of those anti-adhesion layers on the molding process was characterized. The results show that the PFOTCS anti-adhesion layer coated by vapor deposition method exhibits the best separability among all of the anti-adhesion layers. The maximum contact angle using PFOTCS is about 115° under 0.5 h of heating time. Compared to DLC, the F-DLC anti-adhesion layer shows good separability when the line width exceeds 100 nm, and does not require recoating again after each use. In addition, atomic force microscopy (AFM) was adopted to measure the adhesion force between the H-PDMS and the anti-adhesion layers.

Fabrication of asymmetric and symmetric membranes based on PES/PEG/DMAc

Phase inversion is one of the main techniques for fabrication of asymmetric structural membranes and occasionally for the formation of a symmetric structure. Microporous membrane has been utilized for size-selective filtration in sample pre- or post-treatment applications. In this study, symmetrical or sponge-like membrane with highly interconnected pores based on polyethersulfone (PES) was fabricated via a combination of phase inversion techniques. The membrane pore sizes and distributions were controlled in the microfiltration range and the effects of humidity and polyethylene glycol (PEG) as a pore-forming agent on membrane morphology were investigated. Scanning electron microscopy (SEM) used to evaluate membrane cross section morphology, the porosity was calculated through the liquid immersion method, and pure water flux (PWF) was measured in a dead-end apparatus. We found that the humidity and pore-forming agent have a great impact on the formation of fully sponge-like structure in PES-based membrane. The results confirmed that by introducing PEG as pore-forming agent the sponge-like structure forms and molecular weight of additives as well as humidity alters the membrane morphology. Being located in a moist environment before immersion in non-solvent bath and after addition of PEG with different molecular weight (MW) will change the morphological structure of PES-based membrane, flux and retention properties. For nominal sample, the water permeability and porosity were 490.57 L/m2h and 90.39 %, respectively. Eventually the application of this membrane was investigated to determine the optimal potential in microorganisms filtration.

ChemInform Abstract: Immersion Liquid Techniques in Solid Particle Characterization: A Review

AbstractReview: 120 refs.

Study on Anti-Adhesion Layers Using AFM for Nanoimprint Process

This study investigates how to improve the anti-adhesion issues between Silicon mold and nanostructures of hard polydimethylsiloxane (H-PDMS). A Silicon mold with different depths and widths was made using a focused ion beam (FIB). During the soft-lithography molding process, anti-adhesion layers were needed between the Silicon mold and H-PDMS samples to prevent the de-molding failure caused by the adhesion issues between the interfaces. This study adopts three methods to deposit anti-adhesion layers, such as liquid immersion, vapor deposition, and fluorine-doped diamond-like carbon (F-DLC) film. Perfluorooctyl-trichlorosilane (PFOTCS) was used as a mold-releasing agent for the liquid immersion and vapor deposition methods. The contact angles between each film were measured to determine the effect of anti-adhesion on the molding process. In addition, atomic force microscopy (AFM) was used to measure the adhesion force between the H-PDMS and anti-adhesion layers. The results show that the coatings of anti-adhesion layers are an effective approach to improve the formability of molding.

Use of light dispersion for monitoring particle purity

The purity evaluation of materials plays an important role in many manufacturing processes. For example, in the pigment industry the desire for high chemical purity is obvious. In this study, a practical spectroscopic method capable of such purity estimation is presented. The method relies on the characteristic light dispersion of materials and it also falls into the range of liquid immersion methods. The method was tested using CaF2 particles with traces of different material as impurities. Our results show that the monitoring of sub ‰-level contamination can be readily achieved. The experimental results are supported by simulations. The light dispersion method can be used for on-site testing purposes where the speed, simplicity and cost of measuring are an issue.