In this article, we present the design and operation process of the AssIuT-IoT testbed; an educational and remotely accessible testbed for Internet-of-Things (IoT) applications. The testbed adopts the experiment as a service (EaaS) model in which users are able to access the testbeds and reserve/use the available resources remotely over the Internet. Also, the testbed is federated with other ones distributed among different locations to allow the sharing of resources, user accounts, and policies. The federated testbeds form an educational consortium that facilitates students' access to hardware resources available at different locations. AssIuT-IoT testbed consists of a control server and a set of IoT nodes (hardware resources) supported with different wireless communication capabilities. We present the design, operation, and performance details of the testbed in terms of the hardware and software components. We describe the steps needed to complete experiments using our testbed and we provide some examples. Moreover, we evaluate the testbed and the IoT network's performance. Finally, we present the IoT students' competition as one of the activities where the testbed has been used.

Internet of Thins is a paradigm in which things (devices) communicate with each other and with a cloud platform to perform a set of tasks includes monitoring and controlling the device or the surrounding environment. In this paper, we introduce the basic architecture of AssIUT IoT a remotely accessible testbed designed for IoT applications. The testbed adopts Experiment as a Service (EaaS) model as it provides a suitable and easy way to remotely implement experiments related to IoT applications. We provide details about the testbed design and architecture from hardware and software point of views. Also, we provide some examples of the experiments which can be implemented using our testbed.

Large space buildings, such as airport terminal buildings, consume high energy due to the cooling demand; especially in hot arid climates; to achieve passenger thermal comfort. Evaluation of thermal environment and energy analysis inside airports is an important issue, in terms of reducing energy and controlling indoor environments. This work aims to analyze electrical energy consumption and the indoor environment of the terminal building at Assiut International Airport, Egypt as a case study. Indoor environmental conditions, and energy consumption with HVAC systems, were monitored inside five multiple functional zones within the terminal building (Departure hall, Public area, Duty-free hall, Gate, and Arrival hall) during summer (August 2017). The indoor environmental parameters monitored include: temperature, relative humidity, and illuminance. The results indicate the HVAC system consumed the largest …

The spread of the 5G technology in the telecom power applications increased the need to supply high power density with higher efficiency and higher power factor. Thus, in this paper, the performance of the different power factor correction ( PFC ) topologies implemented to work with high power density telecom power applications are investigated. Two topologies, namely the conventional and the bridge interleaved continues-current-conduction mode (CCM) PFC boost converters are designed. Selection methodology of the switching elements, the manufacturing of the boost inductors, and the optimal design for the voltage and current control circuits based on the proposed small signal stability modeling are presented. The printed circuit board (PCB) for the two different PFC topologies with a power rating of 2 kW were designed. PSIM simulation and the experiments are used to show the supply current total harmonic distortions (THD), voltage ripples, power efficiency, and the power factor for the different topologies with different loading conditions.

This paper presents an optimal design for the inner current-control loop of the continuous current conduction mode (CCM) power factor correction (PFC) stage, which can be used as the front stage of the two-stage AC/DC telecom power supply. The conventional single-phase CCM-PFC boost converter is implemented with proportional–integral (PI) controllers in both the voltage and current-control loops to regulate the output DC voltage to the specified value and to ensure the input current follows the input voltage, which offers a converter with a high-power factor (PF) and low current total harmonic distortion (THD). However, due to the slow dynamic response of the PI controller at the zero-crossing point of the input supply current, the input current cannot fully follow the input voltage, which leads to high THD. In this paper, we investigate a digitally controlled PFC converter with an optimally designed inner current-control loop using a doubly-fed control loops integral-proportional (IP) controller to reduce the THD and to offer an input current with a unity PF. For the economic design of a digitally controlled PFC converter, two isolated AC and DC voltage sensors are designed for interfacing with the microcontroller unit (MCU). PSIM software as well as experimental prototype was used to test the converter performance using the proposed designed current controllers and isolated voltage sensors. We achieved a high-power-density, digitally controlled, telecom PFC stage with a power factor more than 99% and THD of about 5.50%

This paper presents a complete mathematical design of the main components of the 2 kW, 54V direct current (DC)–DC converter stage, which can be used as the second stage of the two stages of alternating current (AC)–DC telecom power supply. In this paper, a simple inrush current controlling circuit to eliminate the high inrush current, which is generated due to a high input capacitor at the input side of the DC-DC converter, is proposed, designed, and briefly discussed. The proposed circuit is very easy to implement in the lab using a single metal–oxide–semiconductor field-effect transistor (MOSFET) switch and some small passive elements. PSIM simulation has been used to test the power supply performance using the value of the designed components. Furthermore, the experimental setup of the designed power supply with inrush current control is built in the lab to show the practical performance of the designed power supply and to test the reliability of the proposed inrush current mitigation circuit to eliminate the high inrush current at initial power application to the power supply circuit. DC–DC power supply with phase shift zero voltage switching (ZVS) technique is chosen and designed due to its availability to achieve ZVS over the full load range at the primary side of the power supply, which reduces switching losses and offers high conversion efficiency. High power density DC–DC converter stage with smooth current startup operation, full load efficiency over 95%, and better voltage regulation is achieved

This study aims to compare different historical predictive master curve techniques which model the rheological properties of asphalt binders in terms of dynamic shear modulus (G*). The investigated models are the Sigmoidal model, Generalized Logistic Sigmoidal model (GLS), Christensen-Anderson model (CA), and Christensen-Anderson and Marasteanu (CAM) model. These models are applied on virgin and sulfur-extended asphalts (SEA). Two types of recycled plastic waste; recycled high-density polyethylene (RHDPE) and recycled low-density polyethylene (RLDPE) are used to modify both the virgin asphalt and SEA. The investigated models are employed to describe the rheological viscoelastic characteristics of the different investigated binders at different aging conditions under the influence of different frequencies and temperatures based on dynamic mechanical analysis (DMA). The results of this study show that the performance of the investigated models is affected by binder modification and aging conditions. The G* of virgin and sulfur asphalts (either modified or virgin) can be satisfactorily represented by all models investigated in this study under original and aged conditions. The most accurate model is the generalized modified sigmoidal model followed by the Sigmoidal model, the CAM Model, and CA Model, respectively

This research evaluates the rheological properties of virgin asphalt and sulfur extended asphalt (SEA) modified with two types of recycled plastic waste (rPW). The investigated plastic wastes are the recycled low-density polyethylene (rLDPE) and recycled high-density polyethylene (rHDPE). It also assesses the environmental and economic benefits of recycling such materials. A total of 16 modified binder samples are produced by adding rLDPE and rHDPE modifiers to virgin asphalt and SEA in four different concentrations of 2%, 4%, 6%, and 8% by weight of asphalt. The basic and rheological properties of the virgin and modified asphalts are explored by conventional tests, and advanced rheological tests at different aging conditions. Finally, cost-effectiveness and environmental analyses are conducted. The environmental benefit analysis is performed by comparing carbon and non-methyl volatile organic compound (NMVOC) emission from the various recycled polyethylene (rPE) with the manufacturing process of the same quantities of virgin LDPE and HDPE when used to modify asphalt. The effect of incorporating sulfur into virgin asphalt on the environment is also determined. Results show that modification yields a higher binder complex shear modulus (G*) and a lower loss tangent (tan δ) at all traffic speeds meaning improved rut resistance behavior under heavy traffic loading and high temperature conditions. About 29% reduction in material cost occurs when rPE-modified SEA is used instead of virgin asphalt. The environmental and economic analyses show that using SEA modified with rPE for road construction is an economic, sustainable, and ecological alternative with better performance compared to virgin asphalt.