Human-Machine Interface-Based Robotic Wheel Chair Control

This chapter presents the P300-based human machine interference (HMI) systems control robotic wheel chair (RWC) prototype in right, left, forward, backward, and stop positions. Four different targets letters are used to elicit the P300 waves, flickering in the low frequency region, by using oddball paradigms and displayed on a liquid crystal display (LCD) screen by Lab-VIEW. After the pre-processing and taking one second time window, feature is extracted by using discrete wavelet transform (DWT). Three different classifiers—two based on ANNs pattern recognition neural network (PRNN) and feed forward neural network (FFNN) and the and other one based on support vector machine (SVM)—are used. Those three techniques are designed and compared with the different accuracies among them.

ADDITIVE MANUFACTURING OF HOLLOW MICRONEEDLES FOR INSULIN DELIVERY

Microneedles (MN) are miniature devices capable of perforating painlessly stratum corneum and delivering active ingredients in the inner epidermal layers. Hollow microneedles (HMNs) are highly detailed objects due to their internal microchannels and thus, their fabrication with Additive Manufacturing (AM) is a challenging task. Vat polymerization techniques provide a sufficient accuracy for such microstructures. Differentiated from other approaches where stereolithography and 2-photon polymerization were adopted, this paper presents the 3D-printing of HMNs purposed for insulin delivery, using the more economic Liquid Crystal Display (LCD) method. First, different geometries (hexagon, square pyramid, beveled) were 3D printed with constant height and varying curing time, printing angle and layer resolution. Quality features in each case were captured with optical and scanning electron microscopy (SEM). The most promising geometry was found to be the beveled one due to the more refined tip area and the feasibility of non-clogged microchannel formation. Among printing parameters, printing angle proved to be the most influential, as it affects resin flow phenomenon during printing process. Lastly, optimized HMN geometry was the beveled configuration, where the average height was measured 900μm, 3D printing angle was set at -45°, the curing time was 10s per layer and the optimal layer height was 30μm.

Blue Light Intensity in Organic Light-Emitting Diode and Liquid-Crystal Display Televisions

Exposure to artificial blue light from screens, especially at evening or nighttime hours, can suppress melatonin production, throw the circadian rhythm off balance, and lead to general difficulty falling asleep. This study sought to investigate the difference in blue light intensity in organic light-emitting diode (OLED) and liquid-crystal display (LCD) screens, specifically in the form of televisions. An observational and quasi-experimental method was used, using a photometer to measure light intensity and a longpass optical filter to block out light ranging from 415 to 515 nanometers, serving as the wavelength of blue light for this study. Two televisions—one OLED and one LCD—were used, with five colors being displayed on each one, one at a time. The LCD television contained more relative blue light than the OLED television for four out of the five colors displayed. On average for all colors, the LCD television emitted 24.92% more blue light than the OLED television, relative to their overall brightnesses. Limitations in scope and the potential of confounding variables interfering with data prevent any definitive conclusions from being drawn, however this study still contributes to the current body of knowledge with evidence towards a trend of lessened blue light intensity in OLED screens compared to LCD screens, which correlates with speculation by other researchers. This study sets the ground for future research investigating the potential of OLED technology in lowering exposure to blue light, thus lessening the negative impacts it can have on individuals.

Frequency-tunable wide-angle polarization selection with a graphene-based anisotropic epsilon-near-zero metamaterial

In this paper, we achieve frequency-tunable wide-angle polarization selection based on an anisotropic epsilon-near-zero (AENZ) metamaterial mimicked by a subwavelength graphene/SiO2 multilayer. The physical mechanism of wide-angle polarization selection can be explained by the analysis of the iso-frequency curve (IFC). Under transverse electric polarization, only the incident lights which are close to normal incidence can transmit through the designed multilayer since the IFC of the AENZ metamaterial is an extremely small circle. However, under transverse magnetic polarization, all the incident lights can transmit through the designed multilayer since the IFC of the AENZ metamaterial is a flat ellipse. Therefore, polarization selection can work in a broad angular width. By changing the gate voltage applying to the graphene, the operating frequency of polarization selection can be flexibly tuned. The optimal operating angular width of high-performance polarization selection where the polarization selection ratio is larger than 102 reaches 54.9 degrees. This frequency-tunable wide-angle polarization selector would possess potential applications in liquid crystal display, read-write magneto-optical data storage, Q-switched lasing, and chiral molecule detection.

A Prototype of an Electronic Pegboard Test to Measure Hand-Time Dexterity with Impaired Hand Functionality

This paper proposes an electronic prototype of the Grooved Pegboard Test (GPT), which is normally used to test the presence of hand dexterity. The prototype imitates the geometrical dimensions of an on-the-market GPT device, but it is electronic, not manual like the one available now for users. The suggested electronic GPT device makes automated time calculation between placing the first and the last peg in their designated locations, instead of manually observing a stopwatch normally used during the GPT. The electronic GPT prototype consists of a fabricated wooden box, electronics (switches and microcontroller), and liquid crystal display (LCD). A set of 40 normal volunteers, 20 females and 20 males, tested the designed prototype. A set of six volunteers with chronic medical conditions also participated in evaluating the proposed model. The results on normal volunteers showed that the proposed electronic GPT device yielded time calculations that match the population mean value of similar calculations by the GPT device. The one-sample t-test showed no significant difference in calculations between the new electronic GPT and the manual GPT device. The p-value was much higher than 0.05, indicating the possible use of the suggested electronic GPT device.

Development of Stand-Alone DC Energy Datalogger for Off- Grid PV System Application Based on Microcontroller

This article presents a microcontroller-based direct current (DC) energy data logger developed by adapting low-cost ATmega328 by measuring the PV system DC and voltage characteristics while simultaneously recording the measured value over time to compute the energy production Watt-hour (Wh). The prototype logger has been tested on a live 1 kW standalone PV system where the voltage sensor detects PV series array output voltage ranging between 0–50 VDC by a voltage divider sensing circuit. For accurate sensing of the current output measurement from the PV array, 50A ACS756 hall effect IC was integrated as the current sensor. The data was measured and saved in text format with comma-separated values (CSV) in an SD card, read using Microsoft Excel software. The liquid crystal display (LCD) showed the actual value of the recording process’s current, voltage, power, and duration in minutes. The recorded data has been compared to the standard laboratory digital multimeter for calibration manually to justify the measurement value. The error is minimized to 0.6% average by varying the constant float value in the programming code. The advantage of developing this logger is that the development cost is much cheaper than the standard commercial PV energy meter, can be reproduced for other DC application energy measurements, and easily modify the voltage and current range to suit the application. Apart from that, this logger also provides high accuracy performance, and its independent characteristic is practical for off-grid or off-site PV system use.

Design and prototyping of GSM-bluetooth based solar energy remote monitoring system

Purpose The purpose of this study is to monitor the surface cooling of the photovoltaic (PV) panel and the effect of the dust accumulated on the panel surface on the electrical efficiency remotely and instantaneously. Design/methodology/approach An autonomous system has been designed that can measure and record the PV surface temperature, the amount of dust on the surface, current, voltage and power values at certain intervals. It can also perform surface cooling and cleaning with water cycle when the temperature and dust amount reach certain threshold values and transmit these values to the user via global system for mobile communications module, Bluetooth module and graphically with a touchscreen liquid crystal display panel. Thus, it is aimed to benefit from PV at the maximum level, and it was installed in Kahramanmaras Sütçü Imam University Faculty of Engineering and Architecture. Findings An increase in power was observed for PV surface cooling and surface dust removal by 3.78% and 45.99%, respectively. Originality/value This system is of vital importance in terms of time and energy-saving, especially for solar plants far from the city center, which are difficult to access because of climatic conditions. In other hand for future studies, it is foreseen that more efficiency gains can be achieved by using artificial intelligence and image processing techniques.

Microcontroller based Multifunctional Automated Weather Monitoring and Logging System

This paper describes a microcontroller-based prototype Automated Weather Monitoring and Logging System that can col- lect meteorological data such as air temperature, relative humidity, atmospheric pressure, light intensity, and rain detection from any distant location. The Weather Monitoring and Logging System is entirely automated, and measured weather data is transferred to a public server while showing immediate data on a liquid crystal display (LCD) and stored to a Secure Digital (SD) card. For private viewers, Android-based smart phones may be interfaced with the weather station and operated via the android application. The weather station is supplied by a direct current (DC) source, with a backup rechargeable battery. In the event of an emergency power outage, the system will immediately switch to battery power. Two Atmega 328p and Two ESP 8266 microcontrollers are utilized as the core of the control and coordination of the relative multitude of exercises of the singular modules. All of the sensors in the systems have been calibrated, ensuring that the system’s accuracy seems to be exceptional. This system will benefit all users, and it will benefit the meteorological industry because it will allow them to work from a remote location. Keywords: Automated Weather Station; Microcontroller; Sensor; Meteorological Instrument