LEATCH -L: Low Energy Adaptive Tier Clustering Hierarchy for Large scale WSNs

Spin-devices are switched by flipping spins without moving charge in space and this can lead to ultra-low-energy switching replacing traditional transistors in beyond Moore’s law era. In particular, the electric field-induced magnetization switching has emerged to be an energy-efficient paradigm. Here, we review the recent developments on ultra-low-energy, area-efficient, and fast spin-devices using multiferroic magnetoelectric composites. It is shown that both digital logic gates and analog computing with transistor-like high-gain region in the input-output characteristics of multiferroic composites are feasible. We also review the equivalent spin-circuit representation of spin-devices by considering spin potential and spin current similar to the charge-based counterparts using Kirchhoff’s voltage/current laws, which is necessary for the development of large-scale circuits. We review the spin-circuit representation of spin pumping, which happens anyway when there is a material adjacent to a rotating magnetization and therefore it is particularly necessary to be incorporated in device modeling. Such representation is also useful for understanding and proposing experiments. In spin-circuit representation, spin diffusion length is an important parameter and it is shown that a thickness-dependent spin diffusion length reflecting Elliott–Yafet spin relaxation mechanism in platinum is necessary to match the experimental results.

Download Full-text

Current research on Internet of Things (IoT) in Agriculture

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.g5904.069820 ◽

2020 ◽

Vol 9 (8) ◽

pp. 882-886

Keyword(s):

Power Supply ◽

Precision Agriculture ◽

Large Scale ◽

Low Cost ◽

Low Energy ◽

Sensor Nodes ◽

Wireless Sensor ◽

Energy Usage ◽

Major Application ◽

Sensing Time

IoT, a sensation in modern-day technology, has a major impact on the rapidly growing technological aspects. It’s making people’s life easier and also enabling us to do things that were previously seen as miracles. It helps in solving many complex real-time problems. One such major application in the field of agriculture can turn out to be productive and profitable. This paper explains a variety of techniques infusing IoT in agriculture, that helps in productive and predictive results in that field, thereby leading towards precision agriculture. A low-cost power supply and unambiguous farming can be possible with using IoT system. Wireless Sensor Networks (WSN) in which sensor nodes learn and adopt over the sensing time, gives simplicity, low energy usage. This is aimed to be deployed on a large scale by predicting using big data techniques from centralized data analysis.

Download Full-text

Building Information Modeling-Based Building Energy Modeling: Investigation of Interoperability and Simulation Results

Frontiers in Built Environment ◽

10.3389/fbuil.2020.573971 ◽

2020 ◽

Vol 6 ◽

Author(s):

Mohamed H. Elnabawi

Keyword(s):

Large Scale ◽

Building Information Modeling ◽

Data Transfer ◽

Building Design ◽

Building Energy ◽

Energy Modeling ◽

Low Energy ◽

Information Modeling ◽

Building Energy Modeling ◽

Building Information

There is increasing need to apply building information modeling (BIM) to low energy buildings, this includes building energy modeling (BEM). If a building energy model can be flawlessly generated from a BIM model, the energy simulation process can be better integrated within the design, can be more competent, and timesaving. However, concerns about both the reliability and integrity of the data transfer process and the interoperability between the BIM and BEM prevent any implementation of BIM-based energy modeling on a large scale. This study addresses the accuracy and integrity of BIM-based energy modeling by investigating how well Autodesk's Revit (BIM), in conjunction with two of the most used energy modeling programs (BEM) known as DesignBuilder and Virtual Environment (IES-ve), were integrated in terms of interoperability, including location and weather files, geometry, construction and materials, thermal zones, occupancy operating schedules, and HVAC systems. All misrepresented data during the interoperability process were identified, followed by benchmarking between the BIM-based energy modeling simulation outcomes and the actual energy consumption of the case study, to assess the reliability of the process. The investigation has revealed a number of interoperability issues regarding the BIM data input and BEM data interpretation. Overall, BIM-based energy modeling proved to be a promising tool for sustainable and low energy building design, however, the BIM to BEM process is a non-standardized method of producing building energy models as it varies from one modeler to another, and the BIM to BEM process. All these might slow down any possible application for the process and might cause some uncertainties for the professionals in the field applying it.

Download Full-text

Efficient Communication Scheme for Bluetooth Low Energy in Large Scale Applications

Sensors ◽

10.3390/s20216371 ◽

2020 ◽

Vol 20 (21) ◽

pp. 6371

Author(s):

Maciej Nikodem ◽

Mariusz Slabicki ◽

Marek Bawiec

Keyword(s):

Energy Efficiency ◽

Large Scale ◽

Real Life ◽

Low Energy ◽

Typical Application ◽

Bluetooth Low Energy ◽

Iot Applications ◽

Communication Scheme ◽

Improve Device ◽

The Internet Of Things

The use of Bluetooth Low Energy (BLE) in the Internet-of-Things (IoT) applications has become widespread and popular. This has resulted in the increased number of deployed BLE devices. To ensure energy efficiency, applications use connectionless communication where nodes broadcast information using advertisement messages. As the BLE devices compete for access to spectrum, collisions are inevitable and methods that improve device coexistence are required. This paper proposes a connectionless communication scheme for BLE that improves communication efficiency in IoT applications where a large number of BLE nodes operate in the same area and communicate simultaneously to a central server. The proposed scheme is based on an active scanning mode and is compared with a typical application where passive scanning mode is used. The evaluation is based on numerical simulations and real-life evaluation of a network containing 150 devices. The presented scheme significantly reduces the number of messages transmitted by each node and decreases packet loss ratio. It also improves the energy efficiency and preserves the battery of BLE nodes as they transmit fewer radio messages and effectively spent less time actively communicating. The proposed connectionless BLE communication scheme can be applied to a large variety of IoT applications improving their performance and coexistence with other devices operating in the 2.4 GHz band. Additionally, the implementation complexity and costs of the proposed communication scheme are negligible.

Download Full-text

The structure of a red-shifted photosystem I reveals a red site in the core antenna

Nature Communications ◽

10.1038/s41467-020-18884-w ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Hila Toporik ◽

Anton Khmelnitskiy ◽

Zachary Dobson ◽

Reece Riddle ◽

Dewight Williams ◽

...

Keyword(s):

Photosystem I ◽

Large Scale ◽

Structural Heterogeneity ◽

Low Energy ◽

Structural Elements ◽

Precise Location ◽

Enhanced Absorption ◽

Harvesting Efficiency ◽

Function Relationship ◽

Photosystem I Complex

AbstractPhotosystem I coordinates more than 90 chlorophylls in its core antenna while achieving near perfect quantum efficiency. Low energy chlorophylls (also known as red chlorophylls) residing in the antenna are important for energy transfer dynamics and yield, however, their precise location remained elusive. Here, we construct a chimeric Photosystem I complex in Synechocystis PCC 6803 that shows enhanced absorption in the red spectral region. We combine Cryo-EM and spectroscopy to determine the structure−function relationship in this red-shifted Photosystem I complex. Determining the structure of this complex reveals the precise architecture of the low energy site as well as large scale structural heterogeneity which is probably universal to all trimeric Photosystem I complexes. Identifying the structural elements that constitute red sites can expand the absorption spectrum of oxygenic photosynthetic and potentially modulate light harvesting efficiency.

Download Full-text