In this paper, the authors present an extended survey on the evolution and the modern approaches in the thermal analysis of electrical machines. The improvements and the new techniques proposed in the last decade are analyzed in depth and compared in order to highlight the qualities and defects of each. In particular, thermal analysis based on lumped-parameter thermal network, finite-element analysis, and computational fluid dynamics are considered in this paper. In addition, an overview of the problems linked to the thermal parameter determination and computation is proposed and discussed. Taking into account the aims of this paper, a detailed list of books and papers is reported in the references to help researchers interested in these topics.

/pdf/evolution-and-modern-approaches-for-thermal-analysis-of-1z8m24e02a.pdf

Evolution and Modern Approaches for Thermal Analysis of Electrical Machines

An automated irrigation system was developed to optimize water use for agricultural crops. The system has a distributed wireless network of soil-moisture and temperature sensors placed in the root zone of the plants. In addition, a gateway unit handles sensor information, triggers actuators, and transmits data to a web application. An algorithm was developed with threshold values of temperature and soil moisture that was programmed into a microcontroller-based gateway to control water quantity. The system was powered by photovoltaic panels and had a duplex communication link based on a cellular-Internet interface that allowed for data inspection and irrigation scheduling to be programmed through a web page. The automated system was tested in a sage crop field for 136 days and water savings of up to 90% compared with traditional irrigation practices of the agricultural zone were achieved. Three replicas of the automated system have been used successfully in other places for 18 months. Because of its energy autonomy and low cost, the system has the potential to be useful in water limited geographically isolated areas.

Automated Irrigation System Using a Wireless Sensor Network and GPRS Module

A natural carbohydrate biopolymer was extracted from the agricultural biomass waste (durian seed). Subsequently, the crude biopolymer was purified by using the saturated barium hydroxide to minimize the impurities. Finally, the effect of different drying techniques on the flow characteristics and functional properties of the purified biopolymer was investigated. The present study elucidated the main functional characteristics such as flow characteristics, water- and oil-holding capacity, solubility, and foaming capacity. In most cases except for oven drying, the bulk density decreased, thus increasing the porosity. This might be attributed to the increase in the inter-particle voids of smaller sized particles with larger contact surface areas per unit volume. The current study revealed that oven-dried gum and freeze-dried gum had the highest and lowest compressibility index, thus indicating the weakest and strongest flowability among all samples. In the present work, the freeze-dried gum showed the lowest angle of repose, bulk, tapped and true density. This indicates the highest porosity degree of freeze dried gum among dried seed gums. It also exhibited the highest solubility, and foaming capacity thus providing the most desirable functional properties and flow characteristics among all drying techniques. The present study revealed that freeze drying among all drying techniques provided the most desirable functional properties and flow characteristics for durian seed gum.

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Effect of different drying techniques on flowability characteristics and chemical properties of natural carbohydrate-protein Gum from durian fruit seed.

A joint initiative by the British Thoracic Society and the Society for Cardiothoracic Surgery in Great Britain and Ireland was undertaken to update the 2001 guidelines for the selection and assessment of patients with lung cancer who can potentially be managed by radical treatment.

https://thorax.bmj.com/content/thoraxjnl/65/Suppl_3/iii1.full.pdf

Guidelines on the radical management of patients with lung cancer

In this paper, we present four purely textile patch antennas for Bluetooth applications in wearable computing using the frequency range around 2.4 GHz. The textile materials and the planar antenna shape provide a smooth integration into clothing while preserving the typical properties of textiles. The four antennas differ in the deployed materials and in the antenna polarization, but all of them feature a microstrip line as antenna feed. We have developed a manufacturing process that guarantees unaffected electrical behavior of the individual materials when composed to an antenna. Thus, the conductive textiles possess a sheet resistance of less than 1Omega/squarein order to keep losses at a minimum. The process also satisfies our requirements in terms of accuracy meeting the Bluetooth specifications. Our investigations not only characterize the performance of the antennas in planar shape, but also under defined bending conditions that resemble those of a worn garment. We show that the antennas can withstand clothing bends down to a radius of 37.5 mm without violating specifications

/pdf/design-and-characterization-of-purely-textile-patch-antennas-2nanw0dxzs.pdf

Design and Characterization of Purely Textile Patch Antennas

Optimization of thin film deposition is often the limiting step in the discovery of new materials and device development. Over the years, high-throughput combinatorial methods were developed for the deposition of thin films from the gas phase. However, very few reports focused on combinatorial thin film deposition from solution. Here, we introduce a combinatorial approach for the deposition of thin films from solution. The flow deposition setup allows for simultaneously studying the effect of two critical parameters, deposition time and deposition temperature, on a single sample. As a proof of concept, we demonstrate the solution deposition of PbS thin films, which resulted in a library of 25 deposition condition combinations on a single GaAs (100) substrate. X-ray diffraction and scanning electron microscopy combined with focused ion beam cross-sectional sample preparation confirmed the formation of high-quality PbS films and showed the morphology evolution as a function of these two deposition parameters. This method can be easily adapted for cost-effective and rapid combinatorial studies of a large variety of solution-deposited thin film materials. 

A Combinatorial Approach for the Solution Deposition of Thin Films

A procedure for the estimation of digital-wattmeter sensitivity with respect to the presence of spurious components in the acquired signals is proposed in this paper The procedure allows an analytical estimation of such a sensitivity to be obtained if the spectral-analysis algorithm of the wattmeter under investigation is completely known; otherwise, an experimental estimation is required Two different procedures are proposed: one approach can be used if the wattmeter is used on an FFT algorithm, while another longer procedure is able to characterize any kind of wattmeters Both experimental procedures can be performed by employing a simple test-set, which is based on two commercial signal generators and on a Personal Computer

Measurement of spurious-related errors on commercial wattmeters

Noise in work places is a critical problem and inter-national regulations are becoming more restrictive on this aspect. The normal a-priori’ way of stating the workers’ exposure to the noise is becoming not enough to warrant that the worker is not exposed to a too high noise thus personal measuring systems are often required. In this paper one of these systems is described that is, not only capable of logging the noise the worker is subjected to, but also to raise an alarm if the noise seems to exceed the maximum allowed level. The system employs a 1$ microphone and off-the-shelf components and has a cost lower than 100$ so that any worker can be provided with a measuring system. The described solution connects to a central system via LoRa protocol without the necessity for the measuring system to be connected to the receiver or to be put close to it.

A Wearable System for Noise Assessment in Workplaces

Conservation of precious metallic works of art requires an in situ monitoring of the conditions of the objects and of the protecting coatings employed for their restoration. In this paper a simple diagnostic tool based on digital photography and 2D-FFT imaging processing is proposed that is used for monitoring the corrosion process occurring on metal surfaces. The proposed approach has been tested in laboratory on a set of silver reference samples which have been coated with SiO x thin films deposited via plasma and submitted to a tarnishing test. The obtained results show that the proposed technique permits to overcome most of the problems usually encountered when using conventional image processing based on amplitude and colors that require maintaining standard lighting and artifacts conditions, that are not easily achievable in museums. Although the proposed solution is not able to provide details about protective coating failure and the corrosion mechanism, its results can be correlated to the tarnishing susceptibility and, therefore, this technique can be use to assess the stability of the artifacts and to put in evidence the beginning of dangerous localized corrosion phenomena, that require immediate restoration.

FFT-based imaging processing for cultural heritage monitoring

Painted walls represent a great heritage of cultural and artistic value. Unfortunately, these works of art, especially the frescos, are constantly attacked by moisture and salt content in the wall plaster, thus, particular attention has to be paid on their conservation state. Nevertheless, there are no many instruments that permit to detect the wall state without causing damages to the paintings. For these reasons, a non-invasive measuring system, which is based on resistivity measurements, is proposed to investigate the moisture content in painted walls and ceilings. The method is able to provide information not only at the wall surface but also at few centimeters beneath the painting, thus allowing one to detect dangerous situations before the deteriorating effects take place. Despite the attention has been focused on the conservation of work of arts, the proposed system can be employed in many other fields including the building sector in general.

Marco Parvis

Papers

A Combinatorial Approach for the Solution Deposition of Thin Films

Measurement of spurious-related errors on commercial wattmeters

A Wearable System for Noise Assessment in Workplaces

FFT-based imaging processing for cultural heritage monitoring

Electrical tomography for the monitoring of water moisture in painted walls and ceilings