Mohamad Y. Mustafa

Dielectric based sensing of atmospheric ice

Atmospheric ice is a naturally occurring mixture with lots of variations. It doesn’t only bind the chemistry of water, but also its physics. The variations of this complex mixture are directly associated with the surrounding dynamics. In this paper we are mainly concerned about the variations in the electrical properties of atmospheric ice due to variation in the surrounding temperature, conductivities, volumetric contents and relaxation time. All these variations are conveniently measured using the permittivity/dielectric sensing principles. Also these calculations can later be utilized to formulate the atmospheric ice type, icing rate and ice thickness.

Factors Influencing the Performance of Porous Wind Shields

Porosity, porosity distribution, porous shape, porous size, thickness of shield, shield height &width, and shield orientation are the factors that influence the performance of porous wind shields. Among them, porosity is the most important factor in determining the performance of porous shields. However shield height & width have major impacts on the performance of shields. The remaining factors play less significant influences on the performance of the shield, but they remain researching interests to be further studied.

Matching mother and calf reindeer using wireless sensor networks

The problem of matching newborn reindeer calves to their mothers, and hence to their owners, so that they are given proper identification tags, after the reindeers are gathered from the wild in September each year, is a painstaking task which is being undertaken using manpower which is very costly and time consuming, at the same time the manual techniques used are very stressful for the animals and farmers alike. In this paper, a method is proposed using wireless sensor networks based on WiFi enabled active RFID tags. It is proposed to hang WiFi enabled RFID tags to the necks of the calf and mother reindeers on a temporary basis, a procedure which should not consume much time nor cause stress on the animals, and to track the location of those tags using the WiFi network. Localization algorithms developed to monitor the location of the tags and to determine the correlation between any pairs of tags which indicate mother and her calf. A full description of the technology is presented together with description of well-known localization techniques. It is hoped that this paper will pave the way for the use of wireless sensor networks for the purpose of identification of semi-wild animals.

Challenges Facing Hydrogen Fuel Cell Technology to Replace Combustion Engines

In this paper; technological challenges and commercialization barriers for Proton Exchange Membrane (PEM) fuel cell are presented. Initially, the criteria that must be met by the energy source of the future is presented from the point of view of the authors. Sustainability, high energy content and combustion independence are recognized as the main decisive factor of future fuels, which are all met by hydrogen, consequently the application of fuel cells as combustion free direct energy converters of the future. Fuel cell technology as an alternative to heat engines is discussed in the context of the current status of fuel cells in various applications. Finally, the challenges facing fuel cell technology to replace heat engines from the commercial and research points of view are presented and discussed supported by current trends in the industry. It is concluded that there have been several advancements and breakthrough in materials, manufacturing and fabricating techniques of fuel cells since the eighties, many of these challenges which are associated with cost and durability still exist when compared with the already matured technology of internal combustion engines. Any effort to achieve these goals would be a significant contribution to the technology of the fuel cell.

Design of (PEM) fuel cell for optimized manufacturing and performance

The design of the fuel cell plays a major role in determining their cost. It is not only the cost of materials that increases the cost of the fuel cell, but also the manufacturing techniques and the need for skilled technicians for assembling and testing the fuel cell while manufacturing. The main aim of this work is to present a conceptual design of a fuel cell with the purpose of reducing the cost of production through using conventional materials and more effective production techniques, then testing the fuel cell to validate its performance. Small-scale intelligent manufacturing system (SIMS) can be associated with the proposed concept to reduce the cost of the fuel cell.

Design of water shock tube for testing shell materials

This paper presents design considerations for a shock tube experimental rig used to investigate the dynamic failure mechanisms of shell geometries subjected to water shock impact loading. In such setup, it is desirable that the drive pressure used within the tube can provide a wide range of impulsive loads on the test structures and some flexibility can be achieved on the applied pulse durations. With this aim a review of various existing shock tube experimental setup is presented and choices are made based on scientific merits. Finally design parameters are drawn for right set of conditions required for the experiments.

3D CFD Investigation of Air Flow Behind a Porous Fence Using Different Turbulence Models

Even after many years of the application of numerical CFD techniques to flow through porous fences, still there is disagreement between researchers regarding the best turbulence model to be implemented in this field. Moreover, different sources claim to have achieved good agreement between numerical results and experimental data; however, it is not always possible to compare numerical and experimental results due to the lack of information or variations in test conditions. In this paper, five different turbulence models namely; K-e models (standard, RNG and Realizable) and K-ω models (Standard and SST), have been applied through a 3D CFD model to investigate air flow behind a porous panel, under the same conditions (boundary conditions and numerical schemes). Results are compared with wind tunnel experiments. Comparison is based on the vertical velocity profile at a location 925 mm downstream of the fence along its center line. All models were capable of reproducing the velocity profile, however, some turbulence models over-predicted the reduction of velocity while it was under-predicted by other models, however, discrepancy between CFD modelling and experimental results was kept around 20%. Comprehensive description of the turbulence structure and the streamlines highlight the fact that the criterion for selecting the best turbulence model cannot rely only on the velocity comparison at one location, it must also include other variables.Copyright

Atmospheric Ice Accretion Measurement Techniques

Atmospheric icing on structures has proven to be an area of concern in many cold climate geographical regions like arctic and alpine. Difficulties encountered by the communication, construction and power industries in these areas are the subject of intense investigations for researchers from decades. Three main methods of investigation are generally employed by researchers to study atmospheric ice accretion on structures: a) continuous field measurements, b) lab based simulations using icing wind tunnel & c) numerical modelling. This paper presents a brief review study of various techniques to understand and measure the atmospheric ice accretion on structures, anti/de icing techniques and important parameters for numerical modelling of atmospheric ice accretion.

Multiphysics Based Design Study of an Atmospheric Icing Sensor

Partially funded by the Research Council of Norway, project no. 195153 and partially by the consortium of the project ColdTech - Sustainable Cold Climate Technology

Efficient Distributed Localization Algorithm for Ownership Identification of Reindeer Calf Using Wireless Sensor Networks

This paper presents a distributed algorithm for identifying the ownership of new-born reindeer calves using wireless sensor networks (WSNs). Reindeer are semi wild animals giving birth while in the wild. Although reindeer cows usually carry identification tags or signs of their owners, it is difficult to identify the ownership of the calves within a mixed herd. Currently, identification is performed in the traditional way which is stressful on both animals and herders and quite costly and time consuming. In this work, a localization algorithm implemented on a WSN is considered to get rid of matching mother reindeer to their calves in a fully automatic way. In particular, the proposed distributed localization algorithm is based on two phases where sensors nodes are attached to the reindeer in a confined space with the objective to identify the animals keeping close together the most of the time, which are reckoned to be the mother reindeer and her calf. At first, the initial estimated nodes’ positions are obtained from an existing biased-maximum likelihood estimator (B-MLE) based on the log-normal shadowing model (LNSM). Secondly, each sensor node seeks to estimate its local map (i.e., its own position and those from its neighbors) by using an on-line distributed stochastic approximation algorithm (DSA) such the identification mother-calves can be done. We present numerical are issued to the standard ZigBee IEEE 802.15.4 operating at 2:4 GHz by means of radio devices WSN430 (equipped with CC2420 chips).