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A regular feature giving news and comment on events and productions in the field of visual aids for technical and scientific teaching and training

ALTHOUGH the radioactive tracer technique has been known for many years, it is only recently that the production of a wide variety of artificially produced radioactive isotopes has opened up this field of research to all industries. Many firms may be prejudiced against adopting this new technique, because of possible dangers to personnel, lack of trained staff or an inadequate knowledge of the subject, but in many cases the advantages over ordinary methods are so great that it is worth while overcoming these prejudices.

Dutch power companies recently have become aware of a hazard due to the presence of radioactive ²¹⁰Pb in their boilers. In an investigation conducted by KEMA in The Netherlands it was discovered that ²¹⁰Pb isotope accumulates within fire‐side deposit layers that form on membrane waterwall tubes. Because the measured levels of total radioactivity exceeded the governmental regulation limit of 100 Bq/g, refurbishment activities in the boiler are subject to governmental authorization and must be conducted under the supervision of authorised radiation protection officers. The ²¹⁰Pb material originates from decay of ²³⁸U, which is present in small amounts in coal. During combustion of the coal, heavy metals such as Pb evaporate and are present in the flue gas in the form of Pb, PbCl, PbCl₂, PbS, PbS₂ or PbSO₄, dependent on the gas environment and temperature. These volatile products subsequently will condense at lower temperatures on the waterwall tubes in the boiler.

The study proposed a human–robot interaction (HRI) framework to enable operators to communicate remotely with robots in a simple and intuitive way. The study focused on the situation when operators with no programming skills have to accomplish teleoperated tasks dealing with randomly localized different-sized objects in an unstructured environment. The purpose of this study is to reduce stress on operators, increase accuracy and reduce the time of task accomplishment. The special application of the proposed system is in the radioactive isotope production factories. The following approach combined the reactivity of the operator’s direct control with the powerful tools of vision-based object classification and localization.

Perceptive real-time gesture control predicated on a Kinect sensor is formulated by information fusion between human intuitiveness and an augmented reality-based vision algorithm. Objects are localized using a developed feature-based vision algorithm, where the homography is estimated and Perspective-n-Point problem is solved. The 3D object position and orientation are stored in the robot end-effector memory for the last mission adjusting and waiting for a gesture control signal to autonomously pick/place an object. Object classification process is done using a one-shot Siamese neural network (NN) to train a proposed deep NN; other well-known models are also used in a comparison. The system was contextualized in one of the nuclear industry applications: radioactive isotope production and its validation were performed through a user study where 10 participants of different backgrounds are involved.

The system was contextualized in one of the nuclear industry applications: radioactive isotope production and its validation were performed through a user study where 10 participants of different backgrounds are involved. The results revealed the effectiveness of the proposed teleoperation system and demonstrate its potential for use by robotics non-experienced users to effectively accomplish remote robot tasks.

The proposed system reduces risk and increases level of safety when applied in hazardous environment such as the nuclear one.

The contribution and uniqueness of the presented study are represented in the development of a well-integrated HRI system that can tackle the four aforementioned circumstances in an effective and user-friendly way. High operator–robot reactivity is kept by using the direct control method, while a lot of cognitive stress is removed using elective/flapped autonomous mode to manipulate randomly localized different configuration objects. This necessitates building an effective deep learning algorithm (in comparison to well-known methods) to recognize objects in different conditions: illumination levels, shadows and different postures.

The nuclear battery technology depends on the spontaneous decay of the atomic nuclei of radioactive isotopes to generate electricity. One of the merits of a nuclear battery is its high-energy density, which can be around ten times higher than that of hydrogen fuel cells and a thousand times more than that of an electrochemical battery. A nuclear battery has an extremely long life and low maintenance and running costs coupled with applications in remote and hostile environmental environments. The rise of silicon technology has intensified research activities in the area of nuclear batteries. The paper aims to present a general overview of a nuclear battery.

This paper presents a general overview of a nuclear battery and will significantly reduce reliance on non-renewable energy source. The requirement for long-lived power supplies have necessitated the pragmatic shift toward the realization of cleaner, safer and renewable energy sources.

Nuclear battery is a safe enabling technology for many applications including military and commercial applications. They have very long operating life under harsh environmental conditions. These cells demonstrate high potential for use in low power applications under a broad range of temperatures.

The nuclear battery technology has been receiving considerable in-depth research for applications that require long-life power sources.

This paper aims to investigate the wear behaviour of different materials for cylinder liners and piston rings in a linear reciprocating tribometer with special focus on the wear of the cylinder liner in the boundary lubrication regime.

Conventional nitrided steel, as well as diamond-like carbon and chromium nitride-coated piston rings, were tested against cast iron, AlSi and Fe-coated AlSi cylinder liners. The experiments were carried out with samples produced from original engine parts to have the original surface topography available. Radioactive tracer isotopes were used to measure cylinder liner wear continuously, enabling separation of running-in and steady-state wear.

A ranking of the material pairings with respect to wear behaviour of the cylinder liner was found. Post-test inspection of the cylinder samples by scanning electron microscopy (SEM) revealed differences in the wear mechanisms for the different material combinations. The results show that the running-in and steady-state wear of the liners can be reduced by choosing the appropriate material for the piston ring.

The use of original engine parts in a closely controlled tribometer environment under realistic loading conditions, in conjunction with continuous and highly sensitive wear measurement methods and a detailed SEM analysis of the wear mechanisms, forms an intermediate step between engine testing and laboratory environment testing.

In the search for on or off‐line methods for condition monitoring of wear sensitive components, Thin Layer Activation (TLA) has much to offer. It is possible to measure very small surface losses directly, and by the use of double layer, or direct, or indirect sentinel layer modifications, wear of material to any depth can be measured. The technique can be applied to most materials and extended to virtually all materials and components by the use of treated plugs or inserts. Material loss can often be measured under operating conditions without dismantling equipment. The technique is reliable and of known useful life, ie there can be no electrical or mechanical failures of the implanted layer. The total radioactivity is very low and no modification of material surface properties is likely. The use of TLA in condition monitoring will speed up the identification of incipient faults.

The object of this paper is to know what are the artificial radioactive nucliides in marine environment, where and what are the sources of their products, what are their effects to the health of marine and land populations. With this view in mind we shall discuss the large‐scale production of man‐made artificial nucliides that have been poured into the oceans since about the middle of the present century. The first significant release of radioactive nucliides to the marine environment began in late 1944 in USA with the discharge of effluent from her reactors at Hanford Atomic Plant to the North East Pacific Ocean via Columbia River. In the following year, July 1945, an atom bomb was tested successfully and the detonation of two more tests of atom bombs at Bikini Atoll (Pritchard et al, 1971; Seymour, 1971) introduced enough amount of radioactive nucliides into the North Equatorial Current System of the Pacific Ocean.

With the drastically changed pattern of the retail food trade in recent years in which the retailer's role has become little more than that of a provider of shelves for commodities, processed, prepared, packed and weighed by manufacturers, the defence afforded by the provisions of Section 113, Food and Drugs Act, 1955 has really come into its own. Nowadays it is undoubtedly the most commonly pleaded statutory defence. Because this pattern of trade would seem to offer scope for the use of the warranty defence (Sect. 115) in food prosecutions it is a little strange that this defence is not used more often.

Russia represents one of the world's most dangerous ecological risk zones. Yet, the risk is not evenly distributed within the country. Certain areas of Russia show a disproportionately heavy concentration of pollution and present an even higher ecological risk than the country as a whole. Making a major contribution to the list of areas at greatest risk are the “ZATO.” These unique “Closed Administrative Territorial Establishments” are Russian settlements or cities containing large nuclear enterprises; they are held in a state of extreme secrecy and security. Despite the end of the cold war, ZATO persist and their production activities continue to cause terrible damage to the environment and to the health of their residents. Additionally, the sites of closed former ZATO represent lasting ecological and health threats.