Water clarity is the most common indicator of water quality. The purpose of the study was to develop an instrument which can automatically measure water clarity in place of manual measurement by Secchi disk. The instrument is suspended by buoys at the water surface and uses solar energy to measure the light intensity of LED bulbs after passing through a water column; the result is then converted to Secchi depth by using a regression function. Measurement data are stored in a cloud server so that mobile users can access via an Internet connection. Three experiments were conducted to examine the instrument performance: (i) to ensure light intensity of the LED bulbs is strong enough to pass through the water column; (ii) to determine the regression relationship between the measured light intensity of the instrument and Secchi depth; and (iii) to evaluate the coefficient of variation (CV) of the measured water clarity when using our instrument and a conventional Secchi disk. Experiment results show that the measured values of light intensity are stable with the average CV = 5.25%. Moreover, although there are slight differences between the Secchi depth measured by our instrument and those measured by Secchi disk, the measurements by our instrument can efficiently replace the measurements by conventional Secchi disk, which can be affected by weather conditions as well as by human subjectivity.

In recent years, 3D printed arm casts can replace traditional arm casts to treat bones fractures. 3D printed arm cast modelling often uses professional 3D scanning systems to capture 3D data of the arm. These systems are very expensive and may not be available in many hospitals. In order to overcome this disadvantage, inexpensive methods should be developed. This paper introduces a new data collection method based on smartphones. The photos of an arm were taken with a smartphone camera using some special techniques that could facilitate the process of image processing and 3D modelling in Agisoft Metashape and CATIA. To validate the proposed method, the photogrammetric model was compared with the scanned model (obtained by a low cost scanner) in GOM Inspect. Besides, a fit check of real 3D printed arm casts attached on the volunteer's forearm was also performed. The test results indicate that the photogrammetric model could be used as raw data for 3D arm modelling.

This article deals with the comparative wear of CNMG-coated sintered carbide indexable cutting inserts by several manufacturers when turning 1.6582 steel hardened to 40–44 HRC. The main goal will be to demonstrate the different course of wear by testing seemingly identical inserts for engineering companies, showing the connection between the course of wear and the production of waste in the form of chips. The monitored type of wear was the flank wear VB_max of a cutting tool depending on the length of the machining time. Additionally, the effect of cutting tool wear on chip production, i.e., their quantity, shape and size, was monitored. For the purpose of mutual comparison, uniform cutting conditions were chosen on the basis of previous experiments, ensuring the stability of the given cutting process. For flank wear analysis, optical and electron microscopes were used. Meanwhile, a portable roughness tester was used to analyze the roughness of the machined surface. It was found that the quality of the interconnected coating layers has a perceptible influence on wear rate of the evaluated cutting inserts. The relation between the degree and characteristics of wear on the one hand, and the properties of the produced chips that identify the effect of the difference in the deposition layers using EDX/SEM analysis on the other, foreshadows the importance of choose between products with similarly declared properties was found. The current assessment of cutting tool wear and the evaluation of the chip produced has significant economic potential for manufacturing companies seeking to minimize costs.

Today, 3D printed wrist-hand orthoses can be used to immobilize the arms instead of plaster or fiberglass casts. Typically, 3D arm models for modelling wrist-hand orthoses can be created using a 3D scanning system. Our previous study shows that smartphone cameras and photogrammetry techniques can be used instead of professional 3D scanning systems, but the accuracy of the photogrammetric models has not yet been fully investigated. This paper presents the results of accuracy verification of arm models reconstructed from 2D images captured with a smartphone camera. The forearm and wrist-hand parts of a photogrammetric model were subjected to a virtual inspection by comparing them with the corresponding parts of an arm model created with a 3D scanner. In addition, a physical verification was carried out by assessing the contact between the arm of interest and an actual 3D printed wrist-hand orthosis that was created with reference to the photogrammetric model. The test results show that the photogrammetric models achieve the necessary accuracy to serve as reference models for the construction of 3D printed wrist-hand orthoses.

Using of cutting inserts is currently a normal part of the manufacturing process. The article deals with the tool wear evaluation of selected inserts for turning by electron microscopy. Use of electron microscopy helps on closer analysis of ma...