Metal Blade Research Articles

In vitro inhibition of Xanthomonas vasicola pv. musacearum, the causal agent of banana Xanthomonas Wilt, using medicinal plant extracts from North Kivu, Eastern Democratic Republic of Congo

Banana Wilt caused by Xanthomonas vasicola pv. musacearum (Xvm), has emerged as a significant threat to food security in eastern Democratic Republic of Congo (Kivu). Currently, the only means of combatting this biotic constraint is through best agricultural practices. The aim of this study was to evaluate the effectiveness of medicinal plants used in the Kivu provinces in inhibiting Xvm. Three in vitro experiments were conducted at laboratories of Uganda's National Agriculture Research Organization (NARO) and the International Institute of Tropical Agriculture (IITA) in South Kivu. The bacterial samples were collected from infected field-grown banana plants in South Kivu and isolated on Yeast Extract Peptone Agar (YPGA). Pure Xvm colonies were used for identification via i) Polymerase Chain Reaction (PCR) with specific primers and, ii) greenhouse inoculation trials. A completely randomized design was used for the three inhibition tests (1) on Mueller Hinton Agar (MHA) using disc diffusion with 10 plant extracts; (2) in liquid YPG Broth using 10 plant extracts; and (3) on MHA using disc diffusion with 19 plant extracts. The first two trials used plant extracts diluted in petroleum ether, while the third trial used 19 plant extracts diluted in methanol. After maceration, filtration, and solvent evaporation, 10 mg of extract was diluted in 80 µl of distilled water + 10 µl of Dimethylsulfoxide (DMSO). Ten µl of this solution was impregnated on perforated discs of Whatman filter paper. Zingiber officinale (ginger) and Ricinus communis (castor) were the most effective plant extracts in suppressing Xvm. Of the thirteen plant species identified as effective against the pathogen, the Myrtaceae and Euphorbiaceae families were the most represented. Based on these results, evaluating the effectiveness of the most promising plant extracts in disinfecting the metal blades of garden tools is recommended. In addition, various phytochemical groups present in plant extracts could be evaluated for their effectiveness in suppressing Xvm, especially phenols and tannins.

Model-based dimensional NDE from few X-ray radiographs: Application to the evaluation of wall thickness in metallic turbine blades

The extraction of 3D dimensional measurements based on a limited number of 2D X-ray radiographs of a part would offer a significant speed-up of quality control procedures in industry. However, there are challenges with respect to both measurements and uncertainties. This work addresses these challenges by creating an estimated numerical model of the imaged part on which dimensional measurements can be made. The numerical model is chosen as a parametric deformable model that encodes the expected shape variability of the parts resulting from the manufacturing process. The parameters and uncertainties of the numerical model of the imaged part are estimated by the registration of the computed projections of the model and the observed radiographs without the need of any segmentation. The registration requires the model, the initial parameters, and the observed radiographs. The proposed approach is applied to the inspection of turbine blades manufactured by investment casting, and in particular to the measurement of their wall thickness, which is a critical control. The deformable model consists in partitioning the inner ceramic core into multiple subparts, which may undergo a rigid body motion with respect to the master die. Wall thickness measurements are determined from the estimation of these rigid body motions. To assess the reliability of the proposed procedure, a repeatability study is performed. In addition, wall thickness measurements were compared to corresponding measurements from the surface of the metal boundary obtained by X-ray computed tomography. This surface was determined from a reconstructed tomogram using commercial software. Both analyses show that such measurements are reliable and efficient. Furthermore, residual differences between captured and computed projections reveal localized shape deviations from the CAD model, meaning that despite localized model errors, the approach is operable.

Dispersion-free characterization of terahertz slab–waveguide modal confinement based on a metal Bragg grating structure

Photonic waveguide structures that use periodic metal grooves and periodically perforated metal slits (PPMSs) can laterally confine Sommerfeld and Zenneck surface waves of metals with the electric field accumulation among metal interspaces in the terahertz (THz) region, instead of the total internal reflection principle of dielectric slab media. For the efficiency enhancements of THz-wave coupling and slab–waveguide confinement, specific integrators with high refractive indices or specified for input angles of transverse magnetic polarized waves, such as prisms, metal blades, and waveguides, are requested to excite spoof surface plasmons in the THz region. However, the integrator-assembled slab–waveguides encounter challenges of THz pulse-wave communication in compact and low-distortion systems. A resonant waveguide grating structure based on PPMSs is experimentally demonstrated to confine THz lateral waves from the plane-wave radiation in free space. The open frame and periodic metal cavities of PPMSs can work as a slab–waveguide to transmit structural confined waveguide modes with forwarding evanescent waves of Fabry–Pérot resonance. For 0.1–1 THz waves, the short wavelengths that are both less than half the metal slit width and 3.75 times the metal thickness can lead to zero dispersion and the highest confinement factor in a slab–waveguide for PPMS-confined THz waves. This behavior is opposite to the high structural dispersion in confined THz waves of surface plasmonic devices.

Comparison of proximal contact and contours of class II restoration in premolars and molars restored with three different matrix systems using FDI criteria: An in vivo study.

Sectional matrix systems, namely, Garrison and Bioclear with contact rings, are valuable aids to establish proximal contact tightness and contours in Class II composite restorations when compared with the circumferential matrix system Tofflemire. This study aimed to compare the proximal contact and contours of Class II restoration in premolars and molars restored with Tofflemire, Garrison, and Bioclear matrix system by FDI criteria of approximal anatomical form using floss or 25-µm metal blade and radiographic examination. Sixty Class II patients were selected, and a preoperative bitewing radiograph was taken. Initially, caries removal was done by round diamond bur, followed by 245 carbide bur. Samples were divided randomly into three groups based on the type of matrix system used for restoration. Group 1 (n = 20): Tofflemire, Group 2 (n = 20): Garrison matrix system, and Group 3 (n = 20): Bioclear matrix system. Matrix systems were applied according to the manufacturer's instructions, and composite restoration was done. The clinical evaluation of proximal contact and contour was done by a blinded observer immediately after placement of composite restoration using FDI criteria by passing dental floss or 25-µm metal blade, whereas marginal gaps and overhangs were checked using a radiograph. Results were statistically analyzed. The statistical analysis was done using the Statistical Package for the Social Sciences (SPSS for Windows, Version 19.0). Descriptive statistics was calculated as frequency and percentage. The comparison of characteristics of the contact points, contour, and radiographic examination was carried out using the Chi-square test. Multiple comparisons were done by comparing column proportions with Bonferroni adjustments. The level of significance for the present study was fixed at P < 0.05. There were significantly higher proportions of normal contacts in Garrison (60%) and Bioclear (70%) compared to that in the Tofflemire (20%) matrix system (Bioclear > Garrison > Tofflemire). Comparison of contours showed normal contours with Garrison (50%), Bioclear (50%), and Tofflemire (15%) matrix system (Bioclear = Garrison > Tofflemire). In radiographic examination, harmonious transitions between the restoration and the tooth were similar in Garrison (30%) and Bioclear (30%) compared to the Tofflemire (15%) matrix system (Bioclear = Garrison > Tofflemire). Garrison and Bioclear sectional matrix systems established superior contacts and contours than the Tofflemire circumferential system.

Noncontact Rotational Speed Measurement with Near-Field Microwave of Open-Ended Waveguide

Rotational speed measurement is important for many applications. Here, a noncontact rotational speed test method based on the detection of the periodically perturbed near-field microwave of an open-ended waveguide is proposed. Both simulations and experiments were conducted to verify the near-field microwave rotational speed sensor. The constructed rotation speed sensing system was composed of a standard open-ended WR-42 waveguide (in our measurements, a waveguide-to-coaxial adapter was used to represent an open-ended waveguide) working at ~18 GHz, a radio frequency (RF) circulator, a signal generator, a, RF detector and an oscilloscope. A rotating fan to be measured was placed close to the waveguide’s mouth and, thus, the waveguide’s reflection coefficient was periodically modulated by the rotating fan blades. Then, the RF detector converted this varying reflection coefficient into a direct current (DC) voltage, namely, a periodical waveform. Finally, the rotational speed of the fan could be extracted from this waveform. Measurements using both the proposed near-field microwave method and conventional optical transmission/reflection methods were conducted for verification. The effect of the rotating fan’s location relative to the waveguide’s mouth was also studied. The results show the following: 1. The proposed method works well with a rotational speed of up to ~5000 RPM (rounds per minute), and an accuracy of 1.7% can be achieved. 2. Metallic or non-metallic fan blades are all suitable for this method. Compared with the existing radar method, the proposed method may be advantageous for rotation detection in a constrained space.

Proton Beam APerture MoniTor instrument design and overview for the Commissioning and Operation of ESS High Power Beam on Target

This paper presents a detector developed to protect the ESS spallation target. The detector is installed to receive a proton beam that has a peak current of 62.5 mA, an average power of 5 MW, and energy up to 2 GeV. It is designed to detect any part of the proton beam that goes outside a defined aperture, which is deemed as an errant beam condition. This detector is mainly used for machine protection. The detector works based on two physical processes. The first process is the generation of current in metallic blades, which is proportional to the intercepting beam. The second process is heat load from the beam energy deposition in interacting thermocouples. The combination of these two signals allows the detection of events ranging from microseconds to several minutes. This paper also presents the design of the instrument, its efficiency, and its range of operation.

The Influence of Discontinuity‐Induced Fringing Effect on the Output Performance of Contact‐Separation Mode Triboelectric Nanogenerators: Experiment and Modeling Studies

Triboelectric nanogenerators (TENGs) are promising self‐powering supplies for various intelligent sensing and monitoring devices, especially because they can harvest electric energy from low frequency and small‐scale mechanical motions. Despite the fact that contact‐separation mode TENGs with smaller contact areas harvest higher electrical outputs due to fringing effect, the impact of fringing effect on TENGs’ electrical outputs is rarely investigated quantitatively. Herein, in this study, the influence of fringing effect on the electrical outputs of contact‐separation mode TENGs by introducing discontinuity on the tribo‐negative side manually is investigated. In the results, it is revealed that the TENGs with more discontinuities show higher overall electric performance. Compared to pristine TENGs, the TENGs with discontinuity increased significantly, improving the surface charge by 50% and the power density by 114% when cross discontinuities are applied. However, one should generate discontinuities on tribo‐negative side of TENGs using ceramic blade instead of metal blade within a positive‐ion atmosphere due to the neutralization through the electrically conductive metal blade. The computational simulation validates that the TENGs with discontinuities obtain higher electrical outputs, and further investigates the effect of discontinuity gap size and array distance on TENGs performance. In this study, a promising method is provided for the future design of TENGs using discontinuous structures.

Numerical Investigation of the Effect of Trailing Edge Thickness of Simulated Ceramic Matrix Composite Blades on Loss Profiles

Abstract Ceramic matrix composite (CMC) is an enabling material allowing higher turbine inlet temperatures and possibly resulting in better thermal efficiency of gas turbine engines. This is because CMC layers with environmental barrier coating have significantly higher thermal limits (∼1755 K) compared with the more conventional alloyed metallic blades. CMCs possess a complex fabrication process resulting in different geometrical characteristics than metallic blades (e.g., larger trailing edge thickness, large leading-edge curvature, etc.). It is therefore desirable to assess the aerodynamic performance of the CMC blades using experimental and numerical simulations. To investigate, three different CMC blades with varying trailing edge thicknesses were numerically simulated. Both large-eddy simulation with the dynamic subgrid closure as well a recently implemented Reynolds-averaged Navier–Stokes coupled with an intermittency function-based transition model were utilized. Two sets of experimental test points with different Reynolds numbers at a given high-freestream turbulence range (Tu = ∼10–13%) were considered. The predicted pressure loading profiles, total loss distributions, and integrated loss of the three different CMC blades were computed and comparisons against the experimental data are presented herein. It was found that the mixing loss forms a larger proportion of the overall loss as the trailing edge thickness increases.

A wideband multi-bit reflectarray antenna with low cross-polarization based on nonradiative dielectric waveguide

This paper presents a wideband reflectarray antenna (RA) based on a nonradiative dielectric (NRD) waveguide with an inserted metal blade for muti-bit phase quantization. The proposed design eliminates the need of resonant components that typically exist in traditional RAs. Additionally, low cross-polarization is achieved by exciting the appropriate propagation mode in NRD waveguide. The beam scanning performance based on multi-bit phase quantization is verified by a series of static prototypes. Compared to traditional rectangular waveguide RAs, the proposed design possesses collimated beam scanning up to 60° without grating lobes, due to the compact unit cell dimensions. At a collimation beam angle of 20°, a 1-dB gain bandwidth of 18 % is achieved with an aperture efficiency of over 40 % and a cross-polarization level of below −40 dB.

Additive manufacturing and performance research of aluminum-based ceramic cores

As a ceramic core for forming the cooling structure of the intrinsic cavern of turbine blades, the quality of tubular turbine blades is directly affected by their accuracy and performance. In this paper, based on the DLP photocuring technology, the 50% by volume alumina porcelain suspensions with low viscosity were successfully prepared. Secondly, the effects of printing parameters on the curing characteristics were explored to obtain the best printing parameters. The alumina porcelain properties were analyzed for the heating treatment process effect. As the temperature increases, its mechanical properties increase. In addition, the porosity of the patulous orifice reached 48%. The flexural strength of the alumina porcelain component was 26 MPa, which met the requirements of a high-temperature compound metal blade for the porcelain core.

Blade emitters for atmospheric ionic thrusters

In the field of atmospheric ionic thrusters, the objective of this work is to evaluate the possibility of an alternative ionic emitter to the traditional thin wire emitter, in order to overcome the technical issues of the EHD technology related to the fragility of the wires and to make it more suitable to applications outside the laboratory. For the presented experiments, emitters in the form of metallic blades have been produced. These were tested while varying the geometric parameters of both the emitters themselves and of the thruster configuration. Through this measurement campaign, the electrical characteristics, as well as the feasibility and the performances of the new proposed solutions have been evaluated and compared with wire emitters. Results indicate that the blade emitters can work as alternative emitters, however the performance of the present prototypes does not reach that of wire emitters and therefore further research is needed in order to make them a valid alternative.

Coated Blade Spray Ion Mobility Spectrometry.

Coated blade spray (CBS) is a microextraction technology with blades that serve as both the extraction device and the electrospray ionization (ESI) emitter. CBS is designed for easy and rapid extraction of analytes in complex matrices as well as ESI directly from the blade. The technology selectively enriches the components of interest on a coated metal blade. The coating consists of a selective polymer. So far, CBS has only been coupled with mass spectrometry but never with ion mobility spectrometry (IMS), where ions are separated and detected based on their ion mobility in a drift gas under the influence of an electric field, while instrumentation is compact and easy to operate so that the advantages of CBS can be particularly well exploited. Therefore, this work focuses on coupling CBS with our previously described ESI-IMS. The ion mobility spectrometer has a drift length of only 75 mm and provides a high resolving power of RP = 100. In this work, preliminary measurements of CBS-IMS are presented. In particular, the detection of benzodiazepines and ketamine in drinks and the pesticide isoproturon in water samples is shown to demonstrate the feasibility of CBS-IMS.

A single-mode tunable plasmonic sensor based on an 8-shaped resonator for cancer cell detection

In this paper, a novel 8-shaped resonator coupled to metal–insulator–metal waveguides is used for designing plasmonic filters and sensors. The resonator supports two resonance modes, which result in peaks in the transmission spectrum of the structure. A Q-factor of 247.4 which can reach up to 270 at the wavelength of 1187.5 nm is observed. By placing vertical and horizontal metal blades in the resonator, two tunable single-mode plasmonic filters are obtained at the first and second resonance modes, respectively. The effect of structural parameters on the transmission spectrum is investigated using the finite-difference time-domain (FDTD) method. Based on the obtained results, the proposed plasmonic structure can be used for biosensing applications such as the detection of basal cancer cells with a sensitivity of 1200 nm/RIU. It is of great significance that both the sensitivity and Q-factor values for the proposed structure are higher than most recent sensors reported in the literature. Therefore, the proposed structure is a potentially promising candidate for filtering and sensing applications.

Gamelan Selonding as Part of an Essential Instrument in the Sustainment of the Sacred Art Activities of the Batur Indigenous People in Kintamani, Bali

Objective: The purpose of this study is to analyze the gamelan selonding, which has become an important part of the structure of the sacred arts of the people in the Batur customary environment, Bali. In general, gamelan selonding is not an essential instrument in Balinese sacred art activities. In contrast to the sacred art activities of the Batur indigenous people, gamelan selonding seems to be something essential.&#x0D; &#x0D; Method: Both of the problems have been resolved by using qualitative methods. All primary data was successfully collected through observation, FGD, and interviews with informants in Kintamani, Bali. Some of the data classified as secondary was successfully collected through literature studies on Balinese culture. All data were analysed qualitatively using practise theory, symbol theory, and reception theory. Practical theory with the help of symbol theory and reception theory is used in analysing the contribution of gamelan selonding to the sacred art activities of the Batur customary villager, while symbol theory and reception theory with the help of practical theory are used in analysing the form of gamelan selonding.&#x0D; &#x0D; Results: Gamelan selonding is an essential part of the continuation of the sacred arts of the Batur indigenous people due to the existence of religious benefits, social benefits, artistic benefits, and cultural capital. As an essential instrument, the gamelan selonding is often used by the indigenous people of Batur for artistic activities in the sacred area of Kintamani, Bali. The gamelan selonding is a type of traditional Balinese musical instrument with a seven-tone pelog barrel. The shape of this gamelan physically consists of two pelvises and a wide blade made of iron, which is placed on a pelawah wooden.&#x0D; &#x0D; Conclusion: The gamelan selonding holds significant importance among the sacred arts of the indigenous Batur community, since it encompasses various dimensions including religious, social, aesthetic, and cultural aspects. This gamelan ensemble under consideration comprises two resonating chambers and a broad metallic blade positioned above a hardwood resonator.

How Can Wind Turn Into Electricity?

Wind generators, also known as wind turbines, turn wind into electricity. A wind turbine consists of several metal blades mounted on a metal pole and connected to an electrical generator. The wind rotates the blades, which turn a gear shaft connected to the generator, causing a coil of wires in the generator to move around a magnetic core. This generates an electric current that can be used for all our electrical needs, such as lights. Wind turbines should be placed in areas with strong winds, such as beaches, high mountain peaks, and wide-open mountain valleys. Wind turbines do not consume fuel, and therefore they are environmentally friendly because they do not emit the greenhouse gases that cause global warming.

State-Of-The-Art Developments in Soil Lifting Hand Tool : A Review

Shovel is commonly used for soil lifting, weed removal,ormation, lifting straw, etc. Due to soil packing, unequal height, and other factors, the standardized spade size is not suitable for every worker and every field situation. As a result, the standard shovel lacked flexibility and was unsuitable for all of the labours need to work productively. So a shovel should be introduced that can quickly change the shovel metal head or blade angle to carry out the task effectively, and the wooden handle should be replaced with a suitable alternative.The authors have undertaken several studies looking which aims to research on shovel that increases overall yield while also immediately lowering time consumption and protection.

A Detailed Study on Various Sources of Cabin Noise and Vibration in Crawler Dozers and Methodology Followed to Reduce the Noise

The major environmental concern in the field of opencast mining industries are the means of controlling and mitigating noise generated from different Heavy earth moving machineries (HEMM) like Excavators, Dozers, Dumpers, Loaders, Graders, etc. Continuous exposure of the operators to excess noise shall result in hearing impairment and other related health issues. Also, for the HEMM manufacturers, it is important to meet the statutory requirement and mine safety norms to qualify for the tenders. Crawler tractors also called Dozers are heavy earth-moving equipment used in open cast mines with metal blades attached in front of it for pushing or dozing of materials. Dozers being one of the major sources of such noise, in this paper we focus on noise control in dozers. The DGMS (Director General of Mine Safety) regulatory requirement specifies the noise generated inside the cabin should be less than 85dB. We present a detailed analysis of major sources of noise generation in dozers, including Structure borne, Air borne and Rattling noise. We also discuss the various stages and methodologies followed to mitigate the noise at different sources and inside the cabin to ensure that the noise level are within the accepted limits. Our study provides a comprehensive understanding of the noise control measures that can be implemented in dozers to reduce noise exposure and ensure safety and well-being of operators in open cast mining industries.

Kitchen knife blade made from ceramic

The kitchen knife blades currently on the market are divided into metal blades and ceramic blades, and the performance of ceramic blades is better than that of metal blades. According to the performance of the blade, Yttria-steaded zirconia ceramic material is the most suitable to be made into ceramic blade. Zirconia ceramics have good mechanical properties, anti-corrosion, not easy to leave odor and light weight. The only disadvantage of zirconia ceramics is its high cost, but it can be recycled and reused later to reduce costs.

Near-Infrared Trapping by Surface Plasmons in Randomized Platinum-Ceramic Metamaterial for Thermal Barrier Coatings.

As the operation temperature of next generation gas turbine is targeted to be 1800°C toward a higher efficiency and lower carbon emission, the near-infrared (NIR) thermal radiation becomes a major concern for the durability of the metallic turbine blades. Although thermal barrier coatings (TBCs) are applied to provide thermal insulations, they are translucent to the NIR radiation. It is a major challenge for TBCs to achieve optically thick with limited physical thickness (usually < 1mm) for effectively shielding the NIR radiation damage. Here, an NIR metamaterial is reported, where a Gd2 Zr2 O7 ceramic matrix is randomly dispersed with microscale Pt (0.53 vol%) nanoparticles with a size of 100-500nm. Attenuated by the Gd2 Zr2 O7 matrix, a broadband NIR extinction is achieved through the red-shifted plasmon resonance frequencies and higher-order multipole resonances of the Pt nanoparticles. A very high absorption coefficient of ≈3 × 104 m-1 , approaching the Rosseland diffusion limit for a typical coating thickness, minimizes the radiative thermal conductivity to ≈10-2 W m-1 K-1 and successfully shields the radiative heat transfer. This work suggests that constructing a conductor/ceramic metamaterial with tunable plasmonics could be a strategy to shield NIR thermal radiation for high temperature applications.

Dual Functional Roof Ventilator

Abstract: The world is facing a huge energy crisis due to resources depletion. The renewable energies play a vital role in energy generation sector. Fossil fuels such as coal and oil cause enormous environmental pollution. Wind energy is a major renewable source of energy and can replace this fossil energy. This paper aims to study the energy generation methods using roof ventilators. A wind driven, having metallic construction and blades on its periphery is a roof top ventilator. It is installed on the roof of industries as well as machine shops, warehouse and it provide effective ventilation. Hot air becomes lighter and goes upward on the top of industries and is expelled out through ventilator. At the same time fresh air also suck inside due to free spinning of roof ventilator. This free spinning can be converted into electrical energy using different electrical components. This technique is low in cost and feasible because of the minimum quantity of transferring elements and electric systems.