Metal Blade Research Articles

Vortex structure for reducing tip leakage flow of linear turbine cascade using dielectric barrier discharge plasma actuator

An axial-flow turbine is one of the main components of aircraft jet engines. It is important to suppress the leakage flow at the blade tip to improve the aerodynamic performance of the turbine blades. To achieve this, a unique ring-type plasma actuator was developed as an active flow control device. This plasma actuator consists of a high-frequency−high-voltage electrode installed in the outer casing of the turbine rotor. The metallic turbine rotor blades act as the grounded electrode. Dielectric barrier discharge (DBD) plasma is generated between the outer casing and tip of the turbine blade; this plasma interrupts the leakage flow. In this study, the effect of the plasma actuator in reducing the tip leakage flow of a linear turbine cascade was demonstrated using particle image velocimetry (PIV) to obtain velocity measurements at two planes, namely, the blade mid-passage and blade exit. The turbulence intensity and vorticity were also analyzed. The blade mid-passage measurements showed that the low-velocity region caused by the tip leakage flow was reduced by the plasma actuator and the blade exit measurements clarified the vortex structure. The operation of the plasma actuator successfully reduced or eradicated the tip leakage vortex. Contrarily, the passage vortex at the tip side became clearer and stronger. The plasma actuator reduced the tip leakage vortex even when the Reynolds number was changed.

Anti-Toothbreaker: A Novel Low-Budget Device Enabling Contactless Dental Protection and a Forbidden Technique during Direct Laryngoscopy for Endotracheal Intubation

Iatrogenic dental injury is the most common complication of conventional laryngoscopy during orotracheal intubation. The main cause is unintended pressure and leverage forces from the hard metal blade of the laryngoscope. The aim of this pilot study was to introduce and test a novel, reusable low-budget device not only providing contactless dental protection during direct laryngoscopy for endotracheal intubation, but also enabling, in contrast to established tooth protectors, active levering with conventional laryngoscopes for easier visualization of the glottis. A constructed prototype for intrahospital usage was evaluated by seven participants on a simulation manikin for airway management. Endotracheal intubation was performed with and without the device using a conventional Macintosh laryngoscope (blade size 4) and a 7.5 mm endotracheal tube (Teleflex Medical GmbH, Fellbach, Germany). Necessary time and success of first pass were determined. Degree of visualization of the glottis with and without the device was stated by the participants according to the Cormack and Lehane (CL) classification system and the Percentage of Glottic Opening (POGO) scoring system. In addition, subjective physical effort, feeling of safety regarding successful intubation, and risk for dental injury were queried on a numeric scale between 1 and 10. All participants except one stated that the intubation procedure was easier with usage of the device than without it. On average, this was subjectively perceived as being approximately 42% (range, 15-65%) easier. In addition, time to first pass success, as well as degree of glottis visualization, subjective physical effort, and feeling of safety regarding risk for dental injury, were clearly better with usage of the device. Concerning feeling of safety regarding successful intubation, there was only a minor advantage. No difference in first pass success rate and number of total attempts could be observed. The Anti-Toothbreaker is a novel, reusable low-budget device which might not only provide contactless dental protection during direct laryngoscopy for endotracheal intubation, but also enables, in contrast to established tooth protectors, active levering with conventional laryngoscopes for easier visualization of the glottis. Future human cadaveric studies are needed to investigate whether these advantages also prove themselves there.

Investigation of the Influence of Sublayer Thickness on Pairing of Metallic MEMS Shutter Blades

For the 3D self-assembly of microstructures, the net intrinsic stress within a hybrid metal layer stack is utilised to study the dynamics of the pairing of metallic MEMS shutter blades with dimensions of 150 × 400 µm2, representing a highly nonlinear Casimir system. The study focuses on two main geometries: (i) unpaired (freestanding) and (ii) paired metallic Micro-Electro-Mechanical Systems (MEMS) shutter blades. The hybrid metal stack comprises three metal layers that are under intrinsic stress, which enables the curling of the freestanding shutter blades. The top aluminum layer thickness is varied systematically, creating tailored stress in the shutter blades, resulting in the freestanding blades curling differently, as well as geometrical changes in the paired shutter blades. Concerning the thickness variations, a large technological processing window has been identified, during which the pairing of the neighbouring shutter blades occurs (the top aluminum layer thickness ranges between 70 and 88 nm). Circles and ellipses have been fitted to micrographs obtained by scanning electron microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). We observed a trend of the reduction of the radius of curvature RoC (ranging between 17 and 79 µm) for the unpaired shutters, and eccentricity (0.36 < ε < 0.67) occurs throughout the system for the paired shutters. Concerning the specific shape of the overlapping region of the two blades of the paired shutters, three pairing scenarios (I, II, and III) have been identified, classified, evaluated, and reported. The overlapping length lo between the paired shutter blades ranges between 31 and 8 µm. These scenarios also reveal nonlinearities in the pairing process.

TO OBSERVE EFFECTS OF MELATONIN PREMEDICATION ON HAEMODYNAMIC RESPONSES TO LARYNGOSCOPY AND INTUBATION

Laryngoscopy using rigid metal blade produces noxious stimuli that causes stimulation of sensory receptors which in turn causes release of endogenous catecholamines, which in turn provokes hemodynamic changes called stress response. Due to its inhibitory action on CNS which causes sedation and anxiolysis as well as suppression of catecholamine release, we hypothesized that oral melatonin tablet 10 mg, administered orally about 120 minutes before the procedure should provide hemodynamic stability and blunt this response. The primary objective of the study was to observe magnitude and duration of changes in vital parameters before, during and after laryngoscopy and intubation, in a group of patients who were premedicated with 10 mg mouth dispersible tablet melatonin 120 min anesthesia. Continuous numeric data on pulse rate, blood pressure, SPO2 were analyzed as mean and standard deviation. Signicance of observation was derived by applying student's t-test. Non parametric data on complication of study drug was reported as number of patients exhibiting the complication and also as percentage. One group of 35 patients received 10 mg of oral melatonin as mouth dispersible tablet 120 minutes before conduct of anesthesia and other group did not received the study drug and acted as control group for comparison. Pre induction hemodynamic parameters after 120 minutes of oral melatonin administration were recorded and after induction of anesthesia and intubation hemodynamic parameters were recorded. In group of patients who received melatonin the magnitude of rise of heart rate, systolic, diastolic and mean arterial pressure was less returning to pre induction value within 3 minutes. .In control group patients we observed a statistically signicant rise in magnitude of heart rate and blood pressure that remained elevated till 10 minutes after laryngoscopy and intubation. The rate pressure product, an indicator of myocardial oxygen demand and consumption was signicantly higher in control group and lasted for longer time. While in melatonin treated patients insignicant rise of RPP occurred. The clinical observations made in the present study allow us to conclude that oral melatonin administered 120 minutes before induction of anesthesia effectively controlled the stress response to laryngoscopy and endotracheal intubation and shown cardio-protective effect.

Effect of Strength and Porosity of Tablets on the Magnitudes of Subdivision Forces

: In this study, a hardness tester was modified by attaching a metal blade to its testing area to obtain the minimum forces required to subdivide tablets along their diameters (F’). Moreover, the tensile strengths of subdividing tablets (TS’) were calculated. Tablets of microcrystalline cellulose (MCC) weighing 0.5 g were produced at applied compression pressures of 21, 31, 41, 50, and 60 MPa. In addition, tablets of Ludipress®, and a 5:2 mixture of paracetamol to MCC weighing 0.7 g were produced at applied compression pressures of 77, 116, 154, 193, and 232 MPa. It was found that F’ increased as the applied compression pressure used to produce the tablets increased until a maximum value was reached. This maximum value was at around 100 N for MCC and Ludipress® tablets and at around 76 N for paracetamol/MCC tablets. Moreover, a maximum value of TS’ was reached at a porosity of 0.37 for MCC, 0.15 for Ludipress®, and 0.11 for paracetamol/MCC tablets. The maximum TS’ values were at around 1.5 MPa for MCC and Ludipress® tablets and at around 0.9 MPa for paracetamol/MCC tablets. Therefore, both interparticulate bonding (tablet strength) and porosity (packing) affected the magnitudes of F’ and TS’.

Morphological assessment of the surface profile, mesiodistal diameter, and contact tightness of Class II composite restorations using three matrix systems: An in vitro study.

Sectional matrices and contact rings are valuable aids to establish proximal contact tightness in Class II composite restorations. This study aims to evaluate the proximal contact area in Class II composite restorations using three matrix systems based on morphological analysis, mesiodistal (M-D) diameter and contact tightness. A standardized DO cavity was prepared in 30 plastic molar teeth. They were randomly divided into three groups (n = 10) and restored using Tetric N-Ceram composite material and three matrix systems - Saddle matrix, Palodent system, and Palodent Plus system. The quality of proximal contacts was assessed by measuring the maximum M-D diameter of the restored teeth using a digital caliper; the tightness of the proximal contact area using Unifloss and a standardized metal blade (30 μm). Qualitative assessment of contact morphology was done by visual means while quantitative assessment of contour was done using Medit scanner superimposing method and ExoCAD software. One-way ANOVA test was used to compare the mean M-D diameter (in mm) in the occlusal third, middle third, and the proximal contact area between the three groups. Chi-square test was used to compare the proximal contact area tightness using the passage of Unifloss. The buccolingual and occluso-gingival morphology was also compared among the three groups. The level of significance (P value) was set at P < 0.05. For the occlusal and middle third, significantly larger diameters were achieved with the Palodent Plus system than with the Saddle matrix. More flat contours were seen in the case of the Saddle matrix than in the case of the Palodent system while the Palodent Plus system exhibited a minimal depth of concavity as determined by three-dimensional imaging of the contact morphology. Palodent Plus and Palodent matrix systems established superior contacts and contours than the Saddle matrix.

Thermoplastic micro-forming process of bulk metallic glass surgical blades using drawing velocity regulation

Drawing velocity is essential in the manufacturing of the multi-facet bulk metallic glass (BMG) knife edges used in corneal surgery since it is one of the factors that can determine good blade profiles in the thermoplastic forming process. The goal of this article is to determine and regulate drawing velocity based on the viscoelastic filament stretching and knowledge of the thermoplastic forming map of BMG. The generation of drawing velocity profile is done in two stages: the initial transient stage before the extensional viscosity stage is fully developed, and the extensional viscosity stage. The controller based on the system identification of the testbed is then optimized from the requirements of the drawing velocity and its implementation feasibility. The control objectives of regulation performance and robustness to modeling uncertainties are posed and solved in an optimal control ( H∞) framework. The proposed controller shows an improvement over other controllers including proportional-integral-derivative controllers in terms of robustness to uncertainties and tracking performance. BMG samples processed from this study result in good quality with improvement of 20% and 54% in X–Y ([Formula: see text] µm) and X–Z ([Formula: see text]µm) straightness and 25% more consistent edge radii ([Formula: see text] nm).

Analyzing Reliability and Maintainability of Crawler Dozer BD155 Transmission Failure Using Markov Method and Total Productive Maintenance: A Novel Case Study for Improvement Productivity

Surface mining is the world’s most costly industry due to its enormous expenses. Reduced production is forcing mining companies to automate their equipment, predominantly heavy earth mining machinery (HEMMs), for example, dump trucks, shovels, and dozers. The backbone of pit mining is the crawler dozer, commonly known as a dozer. Crawler dozers are tracked earth-moving machines with metal blades positioned in front for pushing materials such as rocks, soil, etc. In order to survive the harsh competition, dozers must be durable and adequately maintained. Crawler dozers work under challenging conditions to avoid production delays that result in losses such as breakdowns, transmission failures, and other issues in mining operations. Transmission failures, among other issues with dozers, are one of the hardest to resolve. This study evaluates the reliability, availability, and maintainability (RAM) of a BD155 crawler dozer transmission using failure and repair data and the Markov method. A realistic case study on (BD155) transmission failure and associated subsystems has been performed. Potential approaches and alternatives are also identified to increase dependability and performance. This article also discusses best maintenance practices for minimizing transmission failures and boosting productivity. The availability of the BD155 increases to 71% from 62% using proper planning and maintenance.

DESIGN AND ANALYSIS OF COMPOSITE PROPELLER BLADE FOR AIRCRAFT

The work in this paper primarily focuses on the modelling and analysis of a plane's propeller blade for strength. The geometry of a propeller blade is a sophisticated 3D model. CATIA V5 R20 is utilised to generate the blade model, which necessitates the usage of high-end modelling CAD software. This document provides a brief overview of Fiber Reinforced Plastic materials as well as the benefits of employing composite propellers over traditional metallic propeller blades. The purpose of this research is to use finite element analysis to analyse the metal and composite strength of the propeller blade. We conducted static and modal analysis for isotropic materials using ANSYS software, as well as linear layer analysis for orthotropic materials. FEA methods were used to investigate two distinct types of propellers, namely aluminium, E-glass, and carbon fibre.

Medium-entropy (Me,Ti)0.1(Zr,Hf,Ce)0.9O2 (Me = Y and Ta): Promising thermal barrier materials for high-temperature thermal radiation shielding and CMAS blocking

With continuous enhancement of gas-turbine inlet temperature and rapid increase of radiant heat transfer, thermal barrier coating (TBC) materials with a combination of low thermal conductivity and good high-temperature thermal radiation shielding performance play vital roles in ensuring the durability of metallic blades. However, yttria-stabilized zirconia (YSZ), as the state-of-the-art TBC and current industry standard, is unable to meet such demands since it is almost translucent to high-temperature thermal radiation. Besides, poor corrosion resistance of YSZ to molten calcia-magnesia-alumina-silicates (CMAS) also impedes its application in sand, dust, or volcanic ash laden environments. In order to improve the high-temperature thermal radiation shielding performance and CMAS resistance of YSZ and further reduce its thermal conductivity, two medium-entropy (ME) oxide ceramics, ME (Y, Ti)0.1(Zr, Hf, Ce)0.9O2 and ME (Ta, Ti)0.1(Zr, Hf, Ce)0.9O2, were designed and prepared by pressureless sintering of binary powder compacts in this work. ME (Y, Ti)0.1(Zr, Hf, Ce)0.9O2 presents cubic structure but a trace amount of secondary phase, while ME (Ta, Ti)0.1(Zr, Hf, Ce)0.9O2 displays a combination of tetragonal phase (81.6 wt.%) and cubic phase (18.4 wt.%). Both ME (Y, Ti)0.1(Zr, Hf, Ce)0.9O2 and ME (Ta, Ti)0.1(Zr, Hf, Ce)0.9O2 possess better high-temperature thermal radiation shielding performance than YSZ. Especially, the high-temperature thermal radiation shielding performance of ME (Ta, Ti)0.1(Zr, Hf, Ce)0.9O2 is superior to that of ME (Y, Ti)0.1(Zr, Hf, Ce)0.9O2 due to its narrower band gap and correspondingly higher infrared absorbance (above 0.7) at the waveband of 1 to 5 μm. The two ME oxides also display significantly lower thermal conductivity than YSZ and close thermal expansion coefficients (TECs) to YSZ and Ni-based superalloys. In addition, the two ME oxides possess excellent CMAS resistance. After attack by molten CMAS at 1250 °C for 4 h, merely ∼2 μm thick penetration layer has been formed and the structure below the penetration layer is still intact. These results demonstrate that ME (Me, Ti)0.1(Zr, Hf, Ce)0.9O2 (Me = Y and Ta), especially ME (Ta, Ti)0.1(Zr, Hf, Ce)0.9O2, are promising thermal barrier materials for high-temperature thermal radiation shielding and CMAS blocking.

Khatt Islāmi: Sacred Scripts from Islamic Africa

Khatt Islāmi: Sacred Scripts from Islamic Africa

Direction Finding Using a Single Antenna With Blade Modulation

A single top-hat antenna using blade modulation is presented for direction finding (DF). Unlike conventional DF techniques requiring an antenna array with multiple elements, the fixed single antenna is utilized to receive incoming signals. To enhance radiation pattern diversity and perform direction of arrival estimation, four rotating blades are placed around four corners of the antenna. The antenna is designed to operate at the frequency where the incoming wave is in resonance with the metallic blades. The incoming signals are recorded as blades rotating with an angle from 0 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ $</tex-math></inline-formula> to 180 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ $</tex-math></inline-formula> . To validate the radiation pattern diversity at the resonant frequency and out of the operational frequency band, correlation coefficients of amplitude and phase of complex radiation patterns between the antennas with different blade rotation angles are investigated. DF accuracy in azimuth directions of the proposed single antenna with blade modulation is demonstrated by Cramer–Rao bound using the complex radiation patterns at different frequencies.

Development of an Economical Solar Powered Lawn Mover

Abstract: Common lawn- knife machines are operated by energy and electrical energy, which are precious, and need high conservation. To keep terrain clean and reduce use of energy a solar powered lawn trimmer has been designed in this exploration work. The purpose of this study is to design and fabricate a solar- powered lawn trimmer which is affordable, easy to operate and environment friendly. The lawn trimmer uses a 12V, 100AH battery to power a12V DC motor of 180W. A solar panel 1 000V system voltage is used tocharge the battery. A solar charge regulator of 20A is used to control the energy into the battery. The machine uses distance metal blade to cut the lawn. It can run for nearly two hours when completely chargedand there's no sun. It's easy to tell if the battery is completely charged or flat. This paper summarizes and reviews technological development for making effective and cost effective lawnknife. Our end is to study the colorful developments in the lawn knife machines and their performance. Current technology generally used for cutting the lawn by the manually handled device From the check weplant that colorful types of lawn knife available in request which are run by means of solar, electric and internal combustion machine. Lawn knives are available in request having some limit to cut lawn at some height. We're trying to make the new innovative conception substantially used in agrarian field. We're going to fabricate the lawn cutting machine for the use of agrarian field, to cut the crops in the field as wellas to cut the lawn. Index Terms: Components

Integrated interval Mahalanobis classification system for the quality classification of turbine blades based on vibrational data incorporating measurement uncertainty

Measurements are not exactly accurate, and measurement errors could lead to a biased trained classifier, and finally to a wrong classification of the parts. This paper extends the recently proposed (Integrated) Mahalanobis Classification System with the concept of Interval Mahalanobis distance (IMD) in order to account for measurement uncertainty. This novel Integrated Interval Mahalanobis Classification System (IIMCS) is applied to an experimental case study of complex shaped metallic turbine blades with various damage types. The turbine blades have been vibrationally tested in a wide frequency range. The IIMCS selects a subset of optimal features that contribute the most to the system under the framework of Binary Particle Swarm Optimization, and determines the optimal decision threshold based on Particle Swarm Optimizer. A Monte Carlo method (MCM) is implemented to account for measurement uncertainty, and as such yields an indicator of reliability, implying the confidence level of the classification results. The obtained results illustrate a high performance of the IIMCS for classifying turbine blades based on vibrational response data with measurement uncertainty.

Self-lubricating epoxy-based composite abradable seal coating eliminating adhesive transfer via hierarchical design

Aluminum-based composite abradable seal coatings are pivotal to improving the efficiency of aero engines or gas turbines. However, the adhesive transfer frequently occurs between metallic blade tips and aluminum-based composite coatings, resulting in engine vibration and even jam. Many past studies had tried to solve this problem by reducing coating hardness, improving lubrication, or strengthening blade tips, but all had failed. In this paper, we proposed a novel epoxy-based composite abradable seal coating, eliminating adhesive transfer by changing metal-to-metal scraping pair to metal-to-polymer scraping pair. The coating was developed via a hierarchical structure design. Large spherical pores were uniformly distributed in the continuous epoxy matrix with fine graphite dispersion. By adding 20 vol.% graphite and 50 vol.% hollow microspheres, a self-lubricating epoxy-based coating of 0.26 friction coefficient with thermal conductivity of 0.28 W/(m·K), coating HR15Y hardness at 54.8, and bonding strength at 18.7 MPa can be reached. When the metallic blades scrape the epoxy-based composite coating, no adhesive transfer occurs. Besides, a smooth scraped surface is formed by pseudoplastic deformation. This epoxy-based composite abradable seal coating opens a new way to improve the efficiency and reliable operations of air engine compressors.

Archaeology of Calumat Open Site: Dating the Burial and its Archaeological Implication

The Calumat Open Site (COS) is in the Municipality of Alubijid, Province of Misamis Oriental, Philippines. The site, situated on top of a hill, was considered the first settlement of the people in Alubijid. The 2019 archaeological excavation conducted by the University of the Philippines – Archaeological Studies Program addressed the chronology of the site’s antiquity. Relative dating indicated that the area may have been occupied as early as the Neolithic period (ca. 3000 BC) until the coming of the European Recollect missionary in 1622. One of the interesting archaeological finds was the discovery of the human burial in Trench 2. Grave goods (celadon bowl, metal blade and worked shell artifact) were found associated with the burial along with dental modification. These grave furniture or “pabaon” were thought to accompany the deceased into the afterlife and ensure the safety of their spiritual journey. In this study, collagen samples were extracted from the bones, found in the burial, by gelatinization. Bones were subjected to radiocarbon dating using accelerator mass spectroscopy. The result suggested that burial may be dated between 774 and 1030 AD with reference to the relative dating of the funerary goods and dental modification, which are significant in interpreting and understanding the socioeconomic activities in the first millennium AD. The findings from the COS contribute to the knowledge of the archaeology of the island of Mindanao and the archipelago in general.

Opaque Gd2Zr2O7/GdMnO3 thermal barrier materials for thermal radiation shielding: The effect of polaron excitation

Opaque thermal barrier materials play a pivotal role in thermal radiation shielding of turbine blades, since the intensity of thermal radiation rapidly increases with the increase of operating temperature of gas turbines and has become a new and major concern for the durability of metallic blades. The conventional thermal barrier coating (TBC) materials such as YSZ and Gd2Zr2O7, however, are almost translucent to thermal radiation and are unable to protect the blades at such harsh environment. Although searching for new thermal barrier materials is significant, it is still a challenge to make the current TBC materials opaque without significantly modifying the composition or other physical properties. To cope with this challenge, GdMnO3 is incorporated as an absorptive second phase into Gd2Zr2O7 in this work, which is originally translucent (absorption coefficient 101–102 m−1) in the near-infrared wavelengths. Intriguingly, with less than 5 wt.% GdMnO3, the Gd2Zr2O7/GdMnO3 becomes opaque to thermal radiation and successfully refrains the rise of thermal conductivity at high temperatures. Meanwhile, the lattice thermal conductivity and mechanical properties are almost unchanged. The small polaron mechanism is confirmed for GdMnO3, leading to a high absorption coefficient (> 106 m−1) for near-infrared radiation. To understand the underling mechanism, a theoretical model is built to estimate the absorption coefficient of the Gd2Zr2O7/GdMnO3 composites (> 104 m−1). This paper proposes a powerful strategy to design thermal-radiation-shielding TBCs through incorporating minor second-phase particles with high-absorption mechanism, such as polaron excitation.

The Role of Stress–Strain State of Gas Turbine Engine Metal Parts in Predicting Their Safe Life

The influence of various factors on the workability of critical metallic parts of a gas turbine engine (GTE) is analysed and systematized. As shown, compressor blades fail as a result of foreign-objects’ damage, gas corrosion, and erosion. Compressor blade roots in most cases fail due to fretting wear caused by vibrations, while the fir-tree rim of turbine discs fails due to low-cycle fatigue (LCF) damage and creep. An increase in the radial gaps between the rotor and stator of the turbine reduces the thrust force and causes changes in the gas-dynamic loading of the engine components. Additional oxidation of metal parts is observed under the action of hot gases from the combustion chamber. The principles of material selection for manufacturing turbine blades and disks, concepts of alloying heat-resistant alloys, and modern methods of surface engineering due to applying protective oxidation-resistant coatings, in particular, chemical vapour deposition (CDV), physical vapour deposition (PVD), air plasma spraying (APS), etc., are also described. To predict the lifetime of turbine disks, it is proposed to use the modified Walker model and Miner’s rule. To specify the time before the failure of the metal blades of the turbine, it is proposed to use the finite element method. To monitor the working-surfaces’ deformations of the gas turbine engine, it is recommended to use optical-digital methods.

Development of Biomedical Dynamometer for Measurement of Grip Strength in Mice Modeled with Cerebral Palsy

This research aimed to develop a biomedical dynamometer capable of measuring the grip strength of the forepaws of laboratory mices to verify the posterior phase, the effect of modeled cerebral palsy in the animal. The equipment was developed using a stainless steel blade, two double strain gages, a signal conditioning circuit that was connected to a software for acquisition, processing and plotting of graphs and tables in Excel. The metal blade has a length of 18.5 cm, a width of 1.5 cm and a thickness of 2 mm and a double strain gage model pa-09-125ha-350-l8 from Excel Sensors (Brazil), was glued to each face. The two double strain gages were connected in a Wheatstone bridge, which produces an analog response due to mechanical deformation of the blade, with force applied by the mice. This response was submitted to a signal conditioning circuit developed with Arduino that modulated the input wave, generated 10000 times amplification and performed filtering 4th order using Butterworth filter. Finally, a software developed in Labview 2019 of National Instruments (USA) was used for acquisition, processing and plotting of graphs and tables in Excel of the measurements performed. In the next step, the dynamometer was calibrated for sequential loading of masses of 0, 15.48 g, 31.53 g, 46.88 g to 62.47 g and also for sequential unloading of the same masses. For this, the masses were hung on a nylon string that was attached to the free end of the metal sheet. The final test was to measure the response time of the dynamometer with a stopwatch, when hanging a mass of 62.47 g on the nylon thread that was cut abruptly with scissors. Some of the main results of the calibration were as follows: 15.48 g generated 3.70 V, 31.53 g generated 7.48 V and 62.47 g gene rated 14.80 V and the response time was 0.3 s. These answers show that the dynamometer can be used to measure the grip strength of mice and can be modified for use in humans.

Development of a manual garden shovel with the ability to quickly clean the working surface

Manual garden shovels have various shapes and sizes, are used to perform a large number of works with soil. A common problem for all garden shovels is the sticking of soil on the working part – the blade. Constant sticking of soil on the blade reduces labor productivity, requires considerable effort and time for cleaning, even the presence of special devices. There are constant attempts to solve the problem of quick cleaning of the blade of manual shovels. Many technical solutions to this problem are patented and are actively used in practice. The design of the self-cleaning shovel consists of a handle and a metal blade with a sharpened cutting edge fixed at one end of the handle, a tubular clamp and footrests, as well as a cleaning plate that is fixed to the movable handle, and a compression spring located under the movable handle around the tubular clamp of the shovel. Cleaning of a metal blade is performed by the cleaning plate, which moves along the metal blade from the footrests to the cutting edge and back. To do this, the user moves the movable handle towards the metal blade, providing compression of the spring.