The diatoms test in veterinary medicine: a pilot study on cetaceans and sea turtles

Fishing activities are considered one of the most relevant threats for cetaceans and sea turtles con- servation since these animals are sometimes found dead entangled in fishing gears. Currently, postmortem diagnosis is based mainly on the presence of nets and lines on the body and the related marks and injuries evident at gross examination. A more detailed and objective evidence is needed to clarify doubts cases and the diatoms technique, used in forensic human medicine, could support drowning diagnosis also in this field. Diatoms\u2019 investigation was implemented to be applied in ma- rine vertebrate on 8 striped (Stenella coeruleoalba) and 1 bottlenose (Tursiops truncatus) dolphins and 5 sea turtles (Caretta caretta) stranded along the Italian coastlines with a likely cause of death hypothized on necropsies carried out by veterinary pathologists. Diatoms were microscopically searched in the bone marrow collected from long bones implementing protocols used in human medicine and their presence was observed in 4 cetaceans and 2 sea turtles. Despite a clear relation between diatoms\u2019 presence and amount and the likely cause of death was not proved due to the poor number of samples, the higher burden of diatoms was found in 3 animals deemed to be death for the interaction with human activity. Despite more studied are necessary to identify the possible relation between the cause of death and diatoms\u2019 findings, the present study implemented this technique to be adapted to marine animals, confirming its possible application also in veterinary forensic medi- cine

A review of gerotor technology in hydraulic machines

Over the years, numerous investigations have established the gerotor fundamentals. This work aims to provide a complete review of the literature from the last decade, focusing on the articles published in the past five years on gerotor technology in hydraulic machines. The report gives a catalogue of guidelines based on the trochoidal-envelope definition, a background analysis, the worldwide distribution of articles in each continent and country and the most frequently used keywords in the field. The paper identifies state-of-the-art research, and reports on current mainstream ideas. From the historical background, this literature review reports the current approaches in gerotor pumps (geometry and performance approaches, modeling and numerical simulations), orbital motors and new concepts. The report will serve as a guide and a directory for novel engineers working with gerotor technology in hydraulic machines. Another intention of this paper is to disseminate the works of the researchers who use this technology around the world, and to provide a scenario for future international collaboration. The paper gives an account of the disparity between academia and engineering applications. There is currently very little published literature on design and production methodologies for gerotor pumps and orbital motors. Hence, the future goal is to collect recommendations that combine academia and industry expertise to make better use of these extensive studies in the fieldPostprint (published version

Utilization of advanced self-diagnostic functions implemented in frequency inverters for the purpose of the computer-aided identification of operating …

The article is a continuation of papers published in previous publications referred to the development of the Computer Control and Diagnostic System of Distributed Drives [1, 2, 3]. Authors of the paper focused on the group of frequency inverters coupled by the ProfiBus DP network, elaborated expert system and integrated control and diagnostic blocks placed in the PLC memory, at an angle of possibility of utilization of integrated selfdiagnostic algorithms of frequency inverters to the implementation in the Computer Control and Diagnosis System of Distributed Drives (CCaDSoDD) system. The article includes also an analysis of potential possibilities of utilization of embedded functions and restrictions connected with accepted assumptions

Wireless capsule endoscope for targeted drug delivery

The diagnosis and treatment of pathologies of the gastrointestinal (GI) tract are performed routinely by gastroenterologists using endoscopes and colonoscopes, however the small intestinal tract is beyond the reach of these conventional systems. Attempts have been made to access the small intestines with wireless capsule endoscopes (WCE). These pill-sized cameras take pictures of the intestinal wall and then relay them back for evaluation. This practice enables the detection and diagnosis of pathologies of the GI tract such as Crohn's disease, small intestinal tumours such as lymphoma and small intestinal cancer. The problems with these systems are that they have limited diagnostic capabilities and they do not offer the ability to perform therapy to the affected areas leaving only the options of administering large quantities of drugs or surgical intervention. To address the issue of administering therapy in the small intestinal tract this thesis presents an active swallowable microrobotic platform which has novel functionality enabling the microrobot to treat pathologies through a targeted drug delivery system. This thesis first reviews the state-of-the-art in WCE through the evaluation of current and past literature. A review of current practises such as flexible sigmoidoscopy, virtual colonoscopy and wireless capsule endoscopy are presented. The following sections review the state-of-the-art in methods of resisting peristalsis, drug targeting systems and drug delivery. A review of actuators is presented, in the context of WCE, with a view to evaluate their acceptability in adding functionality to current WCEs. The thesis presents a novel biologically-inspired holding mechanism which overcomes the issue of resisting natural peristalsis in the GI tract. An analysis of the two components of peristaltic force, circumferential and longitudinal peristaltic contractions, are presented to ensure correct functionality of the holding mechanism. A detailed analysis of the motorised method employed to deploy the expanding mechanism is described and a 5:1 scale prototype is presented which characterises the gearbox and validates the holding mechanism. The functionality of WCE is further extended by the inclusion of a novel targeting mechanism capable of delivering a metered dose of medication to a target site of interest in the GI tract. A solution to the problem of positioning a needle within a 360 degree envelope, operating the needle and safely retracting the needle in the GI tract is discussed. A comprehensive analysis of the mechanism to manoeuvre the needle is presented and validation of the mechanism is demonstrated through the evaluation of scale prototypes. Finally a drug delivery system is presented which can expel a 1 ml dose of medication, stored onboard the capsule, into the subcutaneous tissue of the GI tract wall. An analysis of the force required to expel the medication in a set period of time is presented and the design and analysis of a variable pitch conical compression spring which will be used to deliver the medication is discussed. A thermo mechanical trigger mechanism is presented which will be employed to release the compressed conical spring. Experimental results using 1:1 scale prototype parts validate the performance of the mechanisms.Open Acces

Application of vibration signal in the diagnosis of IC engine valve clearance

The article describes a concept of a non-invasive method for diagnosing the size of valve clearance in internal combustion engines, based on the analysis of engine surface vibration signals using artificial neural networks. The applicability of the method was tested on a single-cylinder compression-ignition engine with a low power rating, which had an OHV timing gear, acting indirectly on the valves, and manual adjustment of valve clearance. The method uses as diagnostic signals the readings of vibration sensors, which record the acceleration of engine head movement as a function of the angle of rotation of the crankshaft, with pre-set valve clearance values measured in a cold condition. From among the signals recorded, components corresponding to the impact of rocker arms against valve stems were identified and low-pass filtered in order to eliminate measurement interference. A classifier of selected features of the signals processed was constructed using artificial neural networks. This classifier recognizes signals generated by engines with correct valve clearance as well as those with too much and too little valve clearance

Movement and force

How – and why – do things move? How do we describe how they move? This chapter looks at ideas and activities concerning movement and force. It deals with two major issues: firstly, ideas children have about motion and the strategies for teaching about motion in the primary school program. This will include some discussion of the different contexts in which movement and force can be studied. Secondly, it looks at the wider context of studying movement and force, linking it with technology and science as a human endeavour

MODEL-BASED DIAGNOSTICS OF SIMULTANEOUS TOOTH CRACKS IN SPUR GEARS

This study aims at developing a numerical model that could be used to simulate the effect of tooth cracks on the vibration behavior of spur gears. Gears are a key component that is widely used in various rotating equipment in order to transmit power and change speed. Any failure of this vital component may cause severe disturbance to production and incur heavy financial losses. The tooth fatigue crack is amongst the most common causes of gear failure. Early detection of tooth cracks is crucial for effective condition-based monitoring and decision making. The scope of this work was widened to include the influence of multiple simultaneous tooth cracks on the time and frequency domain responses at various locations and with different severity levels. As cracks significantly alter the gear mesh stiffness, a finite element analysis was performed to determine the stiffness variation with respect to the angular position for different combinations of crack lengths. A simplified six degrees of freedom nonlinear lumped parameter model of a one-stage gearbox was developed to simulate the vibration response of faulty spur gears with the consideration of inter-tooth friction. Four different multiple crack scenarios were proposed and studied. The performances of various statistical fault detection indicators were investigated. The vibration simulation results of the gearbox obtained using MATLAB were verified with those stated in the published research articles. It was observed that as the severity of a single crack increased, the values of the time-domain statistical indicators increased, with different rates. However, the number of cracks had an adverse effect on the values of all the performance indicators, except the RMS indicator. The number and amplitude of the sidebands in the frequency spectrum were also utilized to detect the severity of the faults in each scenario. It was observed that, in the case of consecutive tooth cracks, the number of spectrum peaks and the number of cracks were well consistent in the frequency range of 4 to 5 kHz. The main finding of this study was that the peak spectral amplitude is the most sensitive indicator to the number and severity of cracks