Rotary Disk Research Articles

Development of a Disc Blade Cutting System for Sesame Harvesting: Determination of Operating Criteria and Energy Requirements

This study aimed to explore the use of rotary disc blades in cutting, since the mowing units used in sesame harvesting contain many parts, require frequent lubrication, and have vibration problems. An experimental setup with a disc blade working on a cut-mowing system based from harvesting methods of sesame plants was designed and fabricated. The most suitable cutting criteria which are blade edge types (30°-30°, 30°-Flat, 45°-45°, 45°-Flat) and disc blade diameters (150, 180, and 210 mm) were determined for shearing and disc cutting action. The lowest cutting energy was consumed by the disc blade with a 30°-wedge angle at all stem thicknesses and by the disc blade with a diameter of 180 mm for large stem thicknesses. In all pairs of edge, as the disc diameter increased, the energy spent for cutting the stems decreased. There was a significant difference between the two methods in terms of energy consumption only when cutting stems with a diameter of 10 mm. These results show that disc cutting can be recommended as a method for sesame harvesting.

Surprising Effects of Al2O3 Coating on Tribocatalytic Degradation of Organic Dyes by CdS Nanoparticles

With a band gap of 2.4 eV, CdS has been extensively explored for photocatalytic applications under visible light irradiation. In this study, CdS nanoparticles have been investigated for the tribocatalytic degradation of concentrated Rhodamine B (RhB) and methyl orange (MO) solutions. For CdS nanoparticles in a glass beaker, 78.9% of 50 mg/L RhB and 69.8% of 20 mg/L MO solutions were degraded after 8 h and 24 h of magnetic stirring using Teflon magnetic rotary disks, respectively. While for CdS nanoparticles in a beaker with Al2O3 coated on its bottom, 99.8% of the RhB solution was degraded after 8 h of magnetic stirring and 95.6% of the MO solution was degraded after 12 h of magnetic stirring. Moreover, another contrast was observed between the two beaker bottoms—a new peak at 250 nm in UV–visible absorption spectra was only observed for the MO degradation by CdS in the as-received glass beaker, which indicates that MO molecules were only broken into smaller organic molecules in that case. These findings are meaningful for expanding the catalytic applications of CdS and for achieving a better understanding of tribocatalysis as well.

Bacterial nanocellulose by static, static intermittent fed-batch and rotary disc bioreactor-based fermentation routes using economical black tea broth medium: A comparative account

Bacterial nanocellulose was produced here using static, static intermittent-fed batch (SIFB) and rotary disc bioreactor (RDB) mode. Economical black tea broth media with symbiotic consortia of bacteria and yeast (SCOBY) was used towards feasible BNC production (instead of commercial NCIM 2526 strain and conventional HS media). The physicochemical characterization of BNC produced in all three modes via FE-SEM, ATR-FTIR, XRD and TGA results showed a highly porous morphology, mostly Iα form, good crystallinity and thermal stability, respectively. BNC crystallinity lies in the range of 68 % (RDB) to 79.4 % (static and SIFB). Water retention value (86 to 93 %) and moisture content (85 to 93 %) are high for BNC produced in all three modes. Commendable difference in the BNC yield, sugar consumption, conversion yield and residual sugar was observed using different methods. Highest BNC yield 29.4 ± 0.66 gL−1 was obtained under SIFB method as compared to static mode (13.6 ± 0.32 g L−1). Under RDB, a negligible amount of BNC i.e., 1.0 ± 0.2 g L−1 was produced. SCOBY with BTB medium was found unsuitable for BNC production under RDB and needs further investigation. Thus, this comparative study offers a way to produce a commendable amount of low-priced BNC for various techno-industrial usage.

Experimental and Numerical Failure Analysis of a Rotary Vacuum Disc Lime Filter - Part 1: Fluid Flow Study of Filtration Process

Experimental and Numerical Failure Analysis of a Rotary Vacuum Disc Lime Filter - Part 1: Fluid Flow Study of Filtration Process

Surprising Effects of Ti and Al2O3 Coatings on Tribocatalytic Degradation of Organic Dyes by GaN Nanoparticles.

GaN is more stable than most metal oxide semiconductors for the photocatalytic degradation of organic pollutants in harsh conditions, while its catalytic efficiency has been difficult to be substantially improved. In this study, the tribocatalytic degradation of organic dyes by GaN nanoparticles has been investigated. Stimulated through magnetic stirring using homemade Teflon magnetic rotary disks in glass beakers, the GaN nanoparticles were found to induce negligible degradation in rhodamine B (RhB) and methyl orange (MO) solutions. Surprisingly, the degradation was greatly enhanced in beakers with Ti and Al2O3 coatings on their bottoms: 99.2% and 99.8% of the 20 mg/L RhB solutions were degraded in 3 h for the Ti and Al2O3 coatings, respectively, and 56% and 60.2% of the 20 mg/L MO solutions were degraded in 24 h for the Ti and Al2O3 coatings, respectively. Moreover, the MO molecules were only broken into smaller organic molecules for the Ti coating, while they were completely degraded for the Al2O3 coating. These findings are important for the catalytic degradation of organic pollutants by GaN in harsh environments and for achieving a better understanding of tribocatalysis as well.

Antibacterial Efficacy of Graphene Nanoparticles against Enterococcus faecalis: In Vitro Study.

This study compared the antimicrobial efficacy of nanographene (NG) particles with chlorhexidine (CHX) and calcium hydroxide (Ca(OH)2) against Enterococcus faecalis. Forty extracted human mandibular premolar teeth were cleaned using a scaler, and the middle-third of the root (6 mm) was decoronated using a rotary diamond disk. The inner diameter of the teeth was made consistent using Gates Glidden Drills #3, treated with ethylene diamine tetra-acetic acid and sodium hypochlorite before sterilization. The samples were then contaminated with E. faecalis grown in Tryptic soy broth for 21 days. Tooth samples were then randomly divided into four groups: Group I (Control), untreated saline; Group II, Ca(OH)2; Group III, CHX; and Group IV, NG. The assessment of bacterial growth was carried out by harvesting dentin chips at the end of 1, 3, and 7 days. The colonies were physically counted and tabulated after 24 hours from seeding. Statistical analysis of the collected data was performed with analysis of variance and Tukey's post hoc test using SPSS Version 20.0. The contaminated dentine blocks irrigated with NG (0.5 µg) and CHX (0 ± 0; p < 0.001) had no growth of E. faecalis colonies compared to blocks of Ca(OH)2 (10 ± 21) and saline (927 ± 455). All concentrations of NG (0.5 and 1.0 µg) showed effectiveness higher (p < 0.001) than 2% CHX when measured by the zone of inhibition against E. faecalis. CONCLUSION: It may be concluded that NG is effective against growth of E. faecalis and may be used as a promising antimicrobial agent during root canal treatment. However, further studies should be done to investigate the effect of NG against other dental pathogens.

Bacterial nanocellulose: A versatile biopolymer production using a cost-effective wooden disc based rotary reactor.

Bacterial nanocellulose (BNC) has various unique qualities, including high mechanical strength, crystallinity, and high water-holding capacity, which makes it appropriate for a wide range of industrial applications. But its lower yield coupled with its high production cost creates a barrier to its usage. In this study, we have demonstrated the better yield of BNC from an indigenous strain Komagataeibacter rhaeticus MCC-0157 using a rotary disc bioreactor (RDB) having a wooden disc. The RDB was optimized based on the type of disc material, distance between the disc, and rotation speed to get the highest yield of 13.0 g/L dry material using Hestrin-Schramm (H-S) medium. Further, the bioreactor was compared for the BNC production using reported medium, which is used for static condition; the RDB showed up to fivefold increase in comparison with the static condition reported. Komagataeibacter rhaeticus MCC-0157 was previously reported to be one of the highest BNC producing stains, with 8.37 g/L of dry yield in static condition in 15 days incubation. The designed RDB demonstrated 13.0 g/L dry yield of BNC in just 5 days. Other characteristics of BNC remain same as compared with static BNC production, although the difference in the crystallinity index was observed in RDB (84.44%) in comparison with static (89.74%). For the first time, wooden disc was used for rotary bioreactor approach, which demonstrated higher yield of BNC in lesser time and can be further used for sustainable production of BNC at the industrial level.

Preparation of dense/spherical fine particle by spray dryer

Fine particle granulation using a spray dryer was performed to prepare with a high drug content, a spherical shape, and a smooth surface. Since the target particle size was less than 200 μm, a rotary disk atomizer was adopted and a slurry was chosen as the spray liquid. When 5-aminosalicylic acid used as a model drug, hydroxypropyl cellulose, and sodium chloride were added in the slurry and was spray dried, the desired size of particles were obtained. Then, the obtained particles were coated with an enteric polymer, no dissolution of the drug in the 1st solution was observed, indicating no disruption occurred during coating.

Comparative evaluation of antimicrobial efficacy of different combinations of calcium hydroxide against Enterococcus faecalis

BackgroundThe study aims to compare the synergistic antibacterial efficacy of different combinations of calcium hydroxide as an intracanal medicament against E. faecalis.Material and methodsThe current study included four hundred extracted human permanent mandibular premolar teeth. After complete chemo-mechanical preparation, the middle third of the root was sectioned using a rotary diamond disc and a total of 400 samples were obtained. The specimens were inoculated with E. faecalis for 21 days. After that, specimens were divided into five groups (n = 80) based on materials used for the disinfection of samples: Group I, calcium hydroxide alone; Group II, calcium hydroxide + 2% chlorhexidine gel; Group III, calcium hydroxide + 2% chitosan gel; Group IV, calcium hydroxide + 0.02% silver nanoparticle gel; Group V, calcium hydroxide + Bioactive glass S53P4. Dentin shavings from the apical third were obtained from the inner third of dentin were obtained using gates glidden no.1 to the apical depth, followed by no.2, 3, 4 and 5 analyzed for E. faecalis using the culture method. One-way analysis of variance (ANOVA) was used for data analysis, followed by post-hoc Tukey's test for multiple comparisons of means to check the difference in bacterial inhibition between the groups.ResultsANOVA results revealed a significant reduction of bacterial counts in all the groups compared (p < 0.001). Intergroup comparison showed maximum bacterial reduction (p < 0.001) with calcium hydroxide + bioactive glass S53P4 compared with other groups.ConclusionSynergistic effect of calcium hydroxide showed better bacterial reduction compared to calcium hydroxide alone. Among the combinations evaluated, calcium hydroxide with bioactive glass, found to be most effective compared to other groups.

Morphological characteristics of spray dried cellulose nanofibers produced using various wood pulp feedstocks and their effects on polypropylene composite properties

Bleached Kraft pulp (BKP), unbleached Kraft pulp (UKP), and old corrugated cardboard pulp (OCC) are excellent feedstock sources for producing CNF suspensions manufactured by a mechanical disk refining process. The CNF drying operation should be performed to produce dry powders that can be compounded into thermoplastic matrices, and spray drying is fast, simple, cost-effective, and scalable. Among several spray-drying techniques, the pilot scale-rotary disk atomizer has many advantages, including large capacities, drying efficiency, and less feed blockage. In this study, BKP, UKP, and OCC pulps fibrillated to 90 % and 100 % fines levels were spray-dried using a pilot-scale rotary disk atomizer. The high-quality micrometer scale, round-shaped powders were produced from all feedstock sources, and a smaller particle size powder was produced with the higher fibrillated pulps. The spray-dried cellulose nanofibrils (SDCNFs) were compounded into a polypropylene (PP) matrix as a reinforcing material, and maleic anhydride-grafted polypropylene (MAPP) was used as a coupling agent. A masterbatch was used for the optimal dispersion and distribution of SDCNFs and MAPP in the PP matrix. It was concluded that the tensile and flexural properties increased as the particle size of SDCNFs increased, and the impact strength increased as the particle size decreased. The tensile strength, tensile modulus, flexural strength, flexural modulus, and impact strength increased by up to 29 %, 66 %, 15 %, 27 %, and 11 % respectively, compared to the neat PP after adding 10 wt% of SDCNFs with MAPP to the PP matrix.

Tribo-Catalytic Degradation of Methyl Orange Solutions Enhanced by Silicon Single Crystals

Coating materials on the bottoms of reactors/beakers has emerged as an effective method to regulate tribo-catalytic reactions. In this study, silicon single crystals were coated on the bottoms of glass beakers, in which 30 mg/L methyl orange (MO) solutions suspended with alumina nanoparticles were subjected to magnetic stirring using Teflon magnetic rotary disks. With a gentle rotating speed of 400 rpm for the Teflon disks, the MO solutions were changed from yellow to colorless and the characteristic absorption peak of MO at 450 nm in the UV-Vis spectrum disappeared entirely within 120 min. Mass spectrometry tests were further performed to gain insights into the degradation process, which suggested that the degradation was initiated with the cleavage of the nitrogen-nitrogen double bond in ionized MO molecules by the attack of •OH radicals. Through comparison experiments, we established that the observed degradation was related to the friction between alumina and silicon during magnetic stirring, and hydroxyl and superoxide radicals were formed from the friction, according to electron paramagnetic resonance analysis. It is proposed that electron-hole pairs are excited in silicon single crystals through friction with alumina, which diffuse to the surface of the single crystals and result in the degradation.

Flow characteristics of radial inflow in impeller rear cavity with baffle plate

The research purpose of this paper is to explore the influence of the baffle plate on the airflow in the rear cavity of the centrifugal impeller and optimize the performance of the secondary air system's air bleed section. In this paper, a comprehensive experimental study was carried out on the flow characteristics in the impeller rear cavity with baffle plate. The windage torque, flow structure and pressure drop between inlet and outlet were measured respectively. The experiment was carried out with the condition that the range of rotational Reynolds number was from 8.33 × 105 to 22.2 × 105 and the range of mass flow rate coefficient was from 0.92 × 104 to 2.92 × 104. The results show that the static cavity and the narrow stator-rotor cavity formed by the baffle plate effectively suppress the overall swirl coefficient in the cavity. Thus, the static pressure and total pressure drop in the rotor–stator cavity were reduced. The influence of the baffle plate on the windage torque of the rotary disk is related to the turbulence parameters. Under large turbulence parameters, the windage torque would be reduced with baffle plate, while under small turbulence parameters, the baffle plate would increase with baffle plate. In general, the baffle plate can improve the flow capacity and optimize the bleed air performance with proper structure and operation conditions.

Submersible rotor disc mixers

The article presents the most common varieties of low-volume rotary disc mixers. The features of their design are described, the main advantages and disadvantages are identified. A description of a new design of a submersible rotor-disk mixer is given. It is shown that a mixer of this type can be used to create high-quality emulsions and maintain them. The mixer can be installed in overall tanks and in the reactor.

REALISATION OF MPC ALGORITHM FOR QUANSER QUBE-SERVO

This paper offers an in-depth look into the design and implementation of a Model Predictive Control (MPC) algorithm for the QUANSER QUBE-SERVO system. The QUBE-SERVO is a sophisticated laboratory experimental setup consisting of a servo motor, an encoder, and a rotary module. This combination provides a robust platform for investigating and testing various control strategies. In particular, the central focus of this study is the usage of the MPC algorithm for controlling the position of the QUBE-SERVO’s rotary disc load module. The MPC algorithm plays a pivotal role in this application by predicting the future behaviors of the system, and controlling the system by minimizing an objective function over a defined finite horizon. This makes it a versatile and effective tool for controlling complex systems. One of the key challenges in practical control applications is maintaining system stability in the presence of disturbances and uncertainties. To this end, we propose a MPC algorithm designed specifically to stabilize the QUBE-SERVO under such conditions. The functionality of this algorithm is not limited to the QUBE-SERVO system alone, and can be extended to other control systems exhibiting similar characteristics. The effectiveness of the proposed MPC algorithm is rigorously tested through simulation studies. These studies involve subjecting the QUBE-SERVO to various reference signals and disturbances. The results of the simulations provide strong evidence of the algorithm’s capability to effectively track reference signals, while also rejecting disturbances and uncertainties, thereby corroborating its efficacy for the QUBE-SERVO application. Moreover, the original MPC algorithm was enhanced to improve its performance for trajectory tracking tasks. We also discuss the integration of the MPC algorithm within the MatLAB and LabVIEW programming environments, which served as the base platforms for designing and running the simulations in this project. This paper, therefore, presents a comprehensive and practical approach for the successful implementation of the MPC algorithm in the QUANSER QUBE-SERVO system, and demonstrates its potential for wider application in similar control systems.

Effects of process parameters on the spreading morphology of disc surface and aluminium powder produced by centrifugal atomisation

ABSTRACT An apparatus was developed to study the effects of operating parameters on liquid spreading and particle size in centrifugal atomisation. Different areas of aluminium spreading on the surface of the rotary disc were observed, in which the diameter of the ‘Plane area’ showed a linear relationship with the rotational speed. The microscopic morphology of the aluminium powder samples was analysed by scanning electron microscopy (SEM). The variation of particle size distribution curve with rotational speed was explored, and the shape of the curve was changed from ‘Single-peak’ to ‘Double-peak’ when the rotating speed increased to a certain value. The effect of the fragmentation mode on the particle size distribution and median diameter was analysed. The variation of the median diameter of the powder with the rotating speed was obtained. The effect of different disc configurations on the particle size was obtained.

Enhanced mechanical and water resistance properties of cassava starch-PVA composites with TiO2 nanofillers for triboelectric nanogenerators films

The utilization of biopolymers for energy applications continues to attract researchers, due to the unique properties of biopolymers that are easily modified, such as cassava starch (CS) biopolymer that has hydroxyl molecular chains. However, the brittle, and non-waterproof nature of starch films is an obstacle to their use in triboelectric nanogenerator (TENG) solid-solid films. This study aims to improve the physicochemical properties of cassava starch films by modifying them into nanocomposite films. The nanocomposite film was made from 70:30 CS/polyvinyl alcohol (PVA) composite and variation of TiO2 nanoparticles addition using solvent casting method. The results showed that the mechanical properties of cassava starch film increased with the addition of PVA. Meanwhile, the addition of TiO2 above 1 wt % of the mechanical properties of the film tends to decrease. The film has low wettability properties with a contact angle of 83.6°. The performance of the nanocomposite film as a Rotary disc freestanding film (RDF-TENG) produces 4.4-fold the output voltage and 2.8-fold the current compared to the film without TiO2. This is a new finding that the CS/PVA-TiO2 nanocomposite film has the potential for TENG films in high-humidity environmental conditions

Surprising Tribo‐catalytic Conversion of H2O and CO2 into Flammable Gases utilizing Frictions of Copper in Water

AbstractCopper rotary disks were fabricated through mounting copper disks and magnets on opposite surfaces of Teflon disks separately, and quartz glass reactors (150 mL) were modified through covering their bottoms with Al2O3, copper, and titanium disks separately. For a glass‐bottomed reactor placed with a copper rotary disk and filled with 50 mL water and 1 atm CO2, flammable gases of 670.96 ppm H2, 22.21 ppm CO, 3.98 ppm CH4, 0.96 ppm C2H4, and 0.66 ppm C2H6 were surprisingly produced after the copper rotary disk was driven to rotate for 5 h; flammable gases were obtained in comparable amounts for reactors with Al2O3, copper, and titanium bottoms separately. A tribo‐catalytic mechanism has been proposed, in which water at micro‐holes in friction surfaces is squeezed by elastically deformed copper of rotating copper disks, and under increased pressure CO2 and H2O are catalyzed to react to form flammable gases by copper.

Enhancing the Heat Transfer Due to Hybrid Nanofluid Flow Induced by a Porous Rotary Disk with Hall and Heat Generation Effects

A study of hybrid-nanofluid flow induced by the uniform rotation of a circular porous disk is presented for the purpose of facilitating the heat transfer rate. The Hall and Ohmic heating effects resulting from an applied magnetic field and the source of heat generation/absorption are also considered to see their impact on flow behavior and enhancing the heat transfer rate. The physical problem under the given configuration is reduced to a set of nonlinear partial differential equations using the conservation laws. Similarity transformations are adopted to obtain a system of ordinary differential equations which are further solved using the Shooting Method. Results are presented via graphs and tables thereby analyzing the heat transfer mechanism against different variations of physical parameters. Outcomes indicate that the wall suction plays a vital role in determining the behavior of different parameters on the velocity components. It is notable that the wall suction results in a considerable reduction in all the velocity components. The enhanced Hartman number yields a growth in the radial velocity and a decay in the axial velocity. Moreover, consequences of all parametric effects on the temperature largely depend upon the heat generation/absorption.

Tribo-Catalytic Conversions of H2O and CO2 by NiO Particles in Reactors with Plastic and Metallic Coatings

NiO has been found to be highly outstanding in producing H2 and O2 from H2O through magnetic stirring, while its capability for the reduction of CO2 through mechanical stimulation has not been investigated. Presently, NiO particles have been employed to promote the conversion of H2O and CO2 enclosed in reactors into flammable gases through magnetic stirring. For a 150 mL glass reactor filled with 50 mL water, 1.00 g of NiO particles, and 1 atm of CO2, 24 h of magnetic stirring using a home-made Teflon magnetic rotary disk resulted in the formation of 33.80 ppm CO, 10.10 ppm CH4, and 12,868.80 ppm H2. More importantly, the reduction of CO2 was found to be substantially enhanced through coating some polymers and metals on the reactor bottoms, including 25.64 ppm CO and 70.97 ppm CH4 obtained for a PVC-coated reactor and 30.68 ppm CO, 52.78 ppm CH4, 3.82 ppm C2H6, and 2.18 ppm C2H4 obtained for a stainless steel-coated reactor. Hydroxyl radicals were detected using fluorescence spectroscopy for NiO particles under magnetic stirring in water. A tribo-catalytic mechanism has been proposed for the conversion of H2O and CO2 into flammable gases by NiO particles under magnetic stirring that is based on the excitation of electron-hole pairs in NiO by mechanical energy absorbed through friction. These findings not only reveal a great potential for mechanical energy to be utilized for CO2 conversion but are also valuable for fundamental studies.

The use of spherical notched and needle-shaped rotary discs for soil cultivation in the aisles of garden plantings

Relevance. Soil cultivation in the aisles of perennial plantations has its own characteristics. In this connection, there is a constant improvement of units for tillage. Methods. The present research in the direction of no-till maintenance of row spacings was carried out in the conditions of fruit-bearing apple orchards of the varieties Renet Simirenko, Idared, located in AO “KSP “Svetlogorskoe””, Krasnodar region. Modification of the existing units for tillage was carried out on our own in the conditions of the farm's workshops. Long-term studies of the quality of work of the units and the advantages obtained through their operation have been carried out. Results. А constructive scheme of a double-row discator with cut-out discs in conjunction with needle rotary discs for surface tillage in the aisles of apple orchards was proposed, which makes it possible to improve the qualitative performance of the discator, reduce specific, energy and labor costs, change the intensity of seam turnover, and create a multifunctional tillage unit in the future, capable of carrying out not only surface tillage, but also (after replacing the working organs) to cut rows, ridges, and apply physiologically active substances. Optimized modes of operation of the modernized double-row discator BDM 2.5 x 2 in the spacing of garden plantings have been developed: at the working speed of the discator BDM 2.5 x 2 7–8 km/h, the productivity was 2–2.3 ha/h, the tillage depth was 7–15 cm, the soil was crumbled into fractions up to 50 mm in size, weeds were cut to 98 %, the ridging of the soil was 5–17 cm, the fuelconsumption was 6–6.5 kg/ha, the traction resistance did not exceed 980 kg.