scholarly journals Color Measurement and Analysis of Fruit with a Battery-Less NFC Sensor

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1741 ◽  
Author(s):  
Antonio Lazaro ◽  
Marti Boada ◽  
Ramon Villarino ◽  
David Girbau
Keyword(s):  
Low Cost ◽  
Near Field ◽  
Color Space ◽  
Cloud Service ◽  
Color Measurement ◽  
Classification Algorithms ◽  
Measurement And Analysis ◽  
Hue Angle ◽  
Color Data ◽  
The Magnetic Field

This paper presents a color-based classification system for grading the ripeness of fruit using a battery-less Near Field Communication (NFC) tag. The tag consists of a color sensor connected to a low-power microcontroller that is connected to an NFC chip. The tag is powered by the energy harvested from the magnetic field generated by a commercial smartphone used as a reader. The raw RGB color data measured by the colorimeter is converted to HSV (hue, saturation, value) color space. The hue angle and saturation are used as features for classification. Different classification algorithms are compared for classifying the ripeness of different fruits in order to show the robustness of the system. The low cost of NFC chips means that tags with sensing capability can be manufactured economically. In addition, nowadays, most commercial smartphones have NFC capability and thus a specific reader is not necessary. The measurement of different samples obtained on different days is used to train the classification algorithms. The results of training the classifiers have been saved to the cloud. A mobile application has been developed for the prediction based on a table-based method, where the boundary decision is downloaded from a cloud service for each product. High accuracy, between 80 and 93%, is obtained depending on the kind of fruit and the algorithm used.

Determination of Ultrasonic Welding Optimal Parameters for Thermoplastic Material of Manufacturing Products

2013 ◽  
Vol 64 (1) ◽  
Author(s):  
Rashiqah Rashli ◽  
Elmi Abu Bakar ◽  
Shahrul Kamaruddin
Keyword(s):  
Electronic Device ◽  
Low Cost ◽  
Near Field ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Field Configuration ◽  
Welding Parameters ◽  
Optimal Parameters ◽  
Thermoplastic Material

Ultrasonic welding had been widely used in various manufacturing industries such as aviation, medical, electronic device and many more. It offers a continued safe operation, faster and also low cost as it able to join weld part less than one second and also simple to maintain the tooling devices. Though ultrasonic welding brings a lot of advantages in assembly especially in thermoplastic material of manufacturing product, it also has a dominant problem to be deal with. The problem in ultrasonic welding is poor weld quality due to improper selection of ultrasonic welding parameters especially in near field configuration. Thus, an optimal combination of parameters is crucial in order to produce good quality weld assembly for this configuration. In this paper, ultrasonic welding process, ultrasonic weld joint defects and determination of optimal parameters for thermoplastic material had been discussed thoroughly. 

scholarly journals A Survey of NFC Sensors Based on Energy Harvesting for IoT Applications

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3746 ◽  
Author(s):  
Antonio Lazaro ◽  
Ramon Villarino ◽  
David Girbau
Keyword(s):  
Energy Harvesting ◽  
Integrated Circuits ◽  
Radio Frequency Identification ◽  
Low Cost ◽  
Near Field ◽  
Wearable Sensors ◽  
Cold Chain ◽  
Iot Applications ◽  
Wide Range ◽  
Frequency Identification

In this article, an overview of recent advances in the field of battery-less near-field communication (NFC) sensors is provided, along with a brief comparison of other short-range radio-frequency identification (RFID) technologies. After reviewing power transfer using NFC, recommendations are made for the practical design of NFC-based tags and NFC readers. A list of commercial NFC integrated circuits with energy-harvesting capabilities is also provided. Finally, a survey of the state of the art in NFC-based sensors is presented, which demonstrates that a wide range of sensors (both chemical and physical) can be used with this technology. Particular interest arose in wearable sensors and cold-chain traceability applications. The availability of low-cost devices and the incorporation of NFC readers into most current mobile phones make NFC technology key to the development of green Internet of Things (IoT) applications.

scholarly journals Distance scaling method for accurate prediction of slowly varying magnetic fields in satellite missions

2016 ◽  
Vol 5 (2) ◽  
pp. 281-288 ◽  
Author(s):  
Panagiotis P. Zacharias ◽  
Elpida G. Chatzineofytou ◽  
Sotirios T. Spantideas ◽  
Christos N. Capsalis
Keyword(s):  
Signal To Noise Ratio ◽  
Near Field ◽  
Magnetic Behavior ◽  
Field Measurements ◽  
High Signal ◽  
Signal To Noise ◽  
Scaling Method ◽  
Magnetic Signature ◽  
The Magnetic Field

Abstract. In the present work, the determination of the magnetic behavior of localized magnetic sources from near-field measurements is examined. The distance power law of the magnetic field fall-off is used in various cases to accurately predict the magnetic signature of an equipment under test (EUT) consisting of multiple alternating current (AC) magnetic sources. Therefore, parameters concerning the location of the observation points (magnetometers) are studied towards this scope. The results clearly show that these parameters are independent of the EUT's size and layout. Additionally, the techniques developed in the present study enable the placing of the magnetometers close to the EUT, thus achieving high signal-to-noise ratio (SNR). Finally, the proposed method is verified by real measurements, using a mobile phone as an EUT.

Fabrication of Low Cost 1D CdSe Nanowires using Near-field Electrospinning

2011 ◽  
Vol 1302 ◽  
Author(s):  
Leroy Magwood ◽  
Binil Starly
Keyword(s):  
Quantum Dots ◽  
Fluorescence Microscopy ◽  
Fiber Diameter ◽  
Low Cost ◽  
Near Field ◽  
Light Attenuation ◽  
Dimethyl Formamide ◽  
Cdse Quantum Dot ◽  
The Matrix ◽  
Cdse Nanowires

ABSTRACTWell-aligned, 1D CdSe quantum dot (QD) fibers (0.3μm to 2.5μm) containing up to 20wt% fluorescent quantum dots (QDs) were prepared by near-field electrospinning (NFES) process. Electrospun solutions were prepared using PVAc as the matrix polymer, dimethyl formamide (DMF) solvent and colloidal QDs in chloroform (CHCl3). The diameter of the fibers decreased as the ratio of DMF/CHCl3 is varied. QDs showed good dispersion and a linear relationship between QD loading and fiber diameter, as determined by the morphology measurements taken using TEM and SEM, respectively. Fluorescence microscopy shows that there is light attenuation throughout the fibers. Results also show that the NFES process may be used as a method to create aligned, 1D fibers of QDs and potentially other nanofibers.

Unraveling near-field and far-field relationships for 3D SERS substrates – a combined experimental and theoretical analysis

The Analyst ◽  
2016 ◽  
Vol 141 (5) ◽  
pp. 1779-1788 ◽  
Author(s):  
Dmitry Kurouski ◽  
Nicolas Large ◽  
Naihao Chiang ◽  
Nathan Greeneltch ◽  
Keith T. Carron ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Low Cost ◽  
Near Field ◽  
Far Field ◽  
Sers Substrates

Simplicity and low cost has positioned inkjet 3D substrates as the most commonly used SERS platforms for the detection and the identification of analytes down to the nanogram and femtogram levels.

scholarly journals Six-Month Color Stability Assessment of Two Calcium Silicate-Based Cements Used in Regenerative Endodontic Procedures

2019 ◽  
Vol 10 (1) ◽  
pp. 14 ◽  
Author(s):  
Paulo Palma ◽  
Joana Marques ◽  
Rui Falacho ◽  
Eder Correia ◽  
Alexandra Vinagre ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
Saline Solution ◽  
Color Space ◽  
Mineral Trioxide Aggregate ◽  
Color Stability ◽  
Color Variation ◽  
Color Measurement ◽  
Suitable Alternative ◽  
Significance Level ◽  
Over Time

Aim: The purpose of the present study is to assess the color stability of two calcium silicate-based cements (CSCs) used in regenerative endodontic procedures (REPs). Methods: A total of 40 acrylic single-rooted transparent teeth, with immature apex, were used. Root canals were filled up to 3 mm below the level of the cementoenamel junction, with either saline solution (Mineral Trioxide Aggregate (MTA)/saline and Biodentine/saline) or blood (MTA/blood and Biodentine/blood). Subsequently, ProRoot MTA® or BiodentineTM was placed in the root canal to create a cervical barrier. Color measurement was carried out at four different evaluation periods (3 h, 72 h, 7 days, and 6 months). Shade analysis within the L* a* b* color space was performed and color variation (∆E) calculated. The significance level for statistical analysis was set at p < 0.05. Results: The four groups showed a significant decrease in L* values over time. The ΔE value increased over time for all groups but was not statistically significant for the Biodentine/blood group. Two-way ANOVA showed no interaction between the CSC and treatment (contact with saline solution or blood). CSC used was the factor responsible for ΔE over time, inducing statistically significant color variations from T3H to T7D (p = 0.04) and T3H to T6M (p < 0.01). After 6 months, MTA/saline had 5.08 (p = 0.001) higher ΔE than Biodentine/Saline and the MTA/blood had 3.65 (p = 0.009) higher than Biodentine/blood. Conclusions: After 6 months, regardless of blood exposure, Biodentine exhibits superior color stability compared to MTA. Biodentine might be a suitable alternative to MTA as a cervical barrier material in REPs.

scholarly journals Near-Field Communication Sensors

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3947 ◽  
Author(s):  
Zhonglin Cao ◽  
Ping Chen ◽  
Zhong Ma ◽  
Sheng Li ◽  
Xingxun Gao ◽  
...  
Keyword(s):  
Communication Technology ◽  
Low Cost ◽  
Near Field ◽  
Near Field Communication ◽  
Daily Life Activities ◽  
Quality Detection ◽  
Communication Device ◽  
Real World Applications ◽  
Wireless Signal ◽  
Communication Devices

Near-field communication is a new kind of low-cost wireless communication technology developed in recent years, which brings great convenience to daily life activities such as medical care, food quality detection, and commerce. The integration of near-field communication devices and sensors exhibits great potential for these real-world applications by endowing sensors with new features of powerless and wireless signal transferring and conferring near field communication device with sensing function. In this review, we summarize recent progress in near field communication sensors, including the development of materials and device design and their applications in wearable personal healthcare devices. The opportunities and challenges in near-field communication sensors are discussed in the end.

Integrated Bidirectional Inductive-Array Design for Power Transfer in Implantable BioMEMS

Proceedings ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 10 ◽  
Author(s):  
Natiely Hernández-Sebastián ◽  
Francisco Javier Renero-Carrillo ◽  
Daniela Díaz-Alonso ◽  
Wilfrido Calleja-Arriaga
Keyword(s):  
Continuous Monitoring ◽  
Electromagnetic Coupling ◽  
Low Cost ◽  
Near Field ◽  
Power Transfer ◽  
Inductive Power Transfer ◽  
Thin Film Fabrication ◽  
Novel Approach ◽  
Power Transfer Efficiency ◽  
Novel Design

This work presents a novel design of a bidirectional Inductive Power Transfer (IPT) system capable of continuous monitoring of cardiac pressure. The proposed system results from a robust electromagnetic coupling between an external reading coil and an implanted two-level (3D approach) inductor array. In this design, each coupling module follows a 13.56 MHz operating frequency, where both passive RCL networks are near field tuned. Among our main results, we obtained a Power Transfer Efficiency (PTE) of 94.1% across the 3.5 cm-thick composed biological tissue whereas the implanted coil array is about 50% of its conventional size. Since the resulting PTE efficiency is 40% higher, based on the optimized L and Q parameters, this novel approach could be used in other medical applications. This IPT system design is based on a low-cost thin film fabrication technology.

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