Radix Entomolaris in Mandibular First Molars: Report of 3 Cases

The radix entomolaris is an anatomical variation characterized by the presence of an additional root located in the distal-lingual region of mandibular molars. An accurate diagnosis is necessary to plan and institute effective endodontic therapy for teeth with this condition. The aim of this report was to present three cases of endodontic management in permanent mandibular first molars with radix entomolaris using contemporary technical resources. For diagnosis, periapical radiographs indicated the possibility of morphological alterations, which were confirmed in two cases by cone beam computed tomography (CBCT). Ultrasonic tips and magnification with operative microscopy were the auxiliary resources used for locating the root canals, which were prepared with NiTi rotary instrument systems and filled with gutta-percha by using the lateral condensation technique and AH Plus sealer. Resources such as periapical radiography, CBCT, magnification with operative microscopy, ultrasonic devices and NiTi instruments can be extremely valuable for use in the diagnosis and clinical approach to endodontic treatment of mandibular first molars with radix entomolaris.

Obudowy dźwiękochłonno-izolacyjne urządzeń ultradźwiękowych, ograniczające poziom hałasu przenikającego do środowiska. Wyniki badań własnych

The article discusses the technical solutions of sound-absorbing and sound-insulating enclosures for devices that are sources of ultrasonic noise (sound frequencies range of 10-40 kHz). Due to the high health risk of employees operating ultrasonic technological devices and the fact that they are in close proximity to these devices, it is necessary to use an effective measure to reduce this risk, i.e. sound-insulating enclosures. So far, however, the rules for the use of such casings and the sound-insulating and sound-absorbing properties of their materials (in this frequency range) have not been defined. The article presents the results of own research on the impact of the materials used to make enclosures, linings of casings and the presence of openings (hole) in casings on the level of noise emitted by ultrasonic devices that penetrates into the environment.

Applying Ultrasound Detection Devices to Examine Pгореrties of Concrete Structures

The article considers the problems of diagnostics of reinforced concrete structures and creation the generalized calibration dependence for the use of ultrasonic devices. The results of the study of the influence of some factors on the results of measuring the dissemination time of ultrasonic vibrations are presented. The study was conducted using devices "Pulsar 1.1" and "Novotest IPSM-U" in compliance with regulatory requirements. Statistical processing of the obtained results (with visualization) was performed using the software package EXEL. Processing of the obtained data confirmed the multifactorial dependence of ultrasonic measurements on the concrete surface. The lack of clearly defined conditions for measurements reduces the reliability of the results. The use of ultrasonic measurements to obtain absolute values of the properties of concrete is not adequate. It is proposed to make changes to the regulations regarding the limits of application of ultrasonic measurements.

Review of Research on the Rare-Earth Doped Piezoelectric Materials

The piezoelectric materials, such as ceramics, crystals, and films, have wide applications in the mechanical industry, medical imaging, electronic information, and ultrasonic devices, etc. Generally, adding oxide dopants, or introducing new solid solutions to form the morphotropic phase boundary of the piezoelectric materials were common strategies to enhance the electric properties. In recent decades, rare-earth elements doped piezoelectric materials have attracted much attention due to their multifunctional performances combining piezoelectric and photoluminescence properties, which has potential applications in ultrasonics, electronics, automatic control, machinery and optoelectronic fields. An overview of the recent investigations and perspectives on rare-earth doped piezoelectric ceramics, single crystals, and films were presented.

EXPERT SYSTEM FOR THE ADJUSTER OF ULTRASONIC DEVICES

В статье представлены результаты разработки экспертной системы аккумулирующей знания настройщиков ультразвуковых технологических аппаратов и позволяющая выработать рекомендации по аппаратному и программному обеспечению для ультразвукового аппарата, предназначенного для решения нестандартной или новой задачи. Приводятся результаты анализа внутреннего устройства ультразвуковых аппаратов, в результате которого были выделены параметры, которые будут содержаться в базе данных, а также в итоговом отчете в качестве выходных параметров. Описаны технологии, используемые при разработке пользовательского интерфейса. Предложен и описан способ подбора комплектующих для ультразвукового аппарата, основанный на методе анализа иерархий, а также представлены результаты подбора состава аппарата на основе требований пользователя. The article presents the results of the development of an expert system that accumulates the knowledge of the adjusters of ultrasonic technological devices and allows us to develop recommendations on hardware and software for an ultrasound device designed to solve a non-standard or new task. The results of the analysis of the internal structure of ultrasound devices are presented, as a result of which the parameters that will be contained in the database, as well as in the final report as output parameters, were selected. The technologies used in the development of the user interface are described. A method for selecting components for an ultrasound device based on the hierarchy analysis method is proposed and described, and the results of selecting the composition of the device based on user requirements are also presented.

The Efficacy of Ultrasonic Pest Repellent Devices against the Australian Paralysis Tick, Ixodes holocyclus (Acari: Ixodidae)

Ultrasonic pest repellers are often promoted as a means of protecting people and pets from the bites of hematophagous arthropods, such as ticks. However, to date, there has been no published research on the effectiveness of these devices against the Australian paralysis tick, Ixodes holocyclus Neumann. The purpose of this study was to test the effectiveness of nine ultrasonic devices against female I. holocyclus. Two arenas were constructed, one for the test (with the ultrasonic device) and one for the control (no device). Each arena had a test and an escape chamber, connected by a corridor. Twenty ticks were placed in each test chamber. After the ultrasonic device was operated for 1 h, the number of ticks in both chambers was recorded. Ten replicates were conducted for each device. The average number of ticks that moved from the test to the escape chamber was greater in all the test arenas, with three devices being statistically different from the control. However, the highest percent of ticks that escaped was only 19.5%. This amount is insufficient to offer adequate protection against tick bites and this study adds further weight to previous investigations that ultrasonic devices should not be employed in pest management.

Research on Ultrasonic Transducers to Accurately Determine Distances in a Coal Mine Conditions

Determining the location of objects, for example roadheader in a hard coal mine, is a task that should be automated in the conditions of state-of-the-art mining. Current solutions do not meet the user’s expectations due to the lack of the possibility of automation, maladjustment to the environment of a hard coal mine or not meeting the legal requirements. The article describes the initial stage of work on an automatic system for determining the position of machines in difficult underground conditions, including the analysis of requirements and constraints, an overview of available solutions, technologies and algorithms, as a result of which devices were selected for further tests. To determine the location, it is necessary to take distance measurements with high accuracy, despite the disturbances resulting from the working environment. Ultrasonic devices were selected and then tested under various operating conditions, including different distances between the transmitter and receiver as well as different directions and intensities of air movement that could distort the measurement results. During tests, sufficient accuracy, as well as other parameters, of the ultrasonic transducers were confirmed, allowing for distance measurements in the required range, suitable for use in the real-time locating system (RTLS) being developed.