Walking through architectural spaces: The impact of interior forms on human brain dynamics

© 2017 Banaei, Hatami, Yazdanfar and Gramann. Neuroarchitecture uses neuroscientific tools to better understand architectural design and its impact on human perception and subjective experience. The form or shape of the built environment is fundamental to architectural design, but not many studies have shown the impact of different forms on the inhabitants’ emotions. This study investigated the neurophysiological correlates of different interior forms on the perceivers’ affective state and the accompanying brain activity. To understand the impact of naturalistic three-dimensional (3D) architectural forms, it is essential to perceive forms from different perspectives. We computed clusters of form features extracted from pictures of residential interiors and constructed exemplary 3D room models based on and representing different formal clusters. To investigate human brain activity during 3D perception of architectural spaces, we used a mobile brain/body imaging (MoBI) approach recording the electroencephalogram (EEG) of participants while they naturally walk through different interior forms in virtual reality (VR). The results revealed a strong impact of curvature geometries on activity in the anterior cingulate cortex (ACC). Theta band activity in ACC correlated with specific feature types (rs (14) = 0.525, ρ = 0.037) and geometry (rs (14) = –0.579, ρ = 0.019), providing evidence for a role of this structure in processing architectural features beyond their emotional impact. The posterior cingulate cortex and the occipital lobe were involved in the perception of different room perspectives during the stroll through the rooms. This study sheds new light on the use of mobile EEG and VR in architectural studies and provides the opportunity to study human brain dynamics in participants that actively explore and realistically experience architectural spaces

Influence of Different Percentages of Copper on the Size and Optical Properties of Ag-Cu Nanoparticles Formed by Wet-Chemical Method

In this work, Ag-Cu nanoparticles (with different percentages of copper, 10%, 25%, 50%, 75% Cu) were synthesized by wet chemical method. Copper(II) sulfate and silver nitrate were taken as metal precursors, ascorbic acid as reducing agent and anhydride maleic (MA) as a modifier. The prepared nanoparticles were characterized by means of X-ray diffraction (XRD) technique and scanning electron microscopy (SEM-EDAX), Fourier transform infrared spectroscopy (FT-IR) and UV-Vis spectroscopy. SEM indicated the formation of uniform spherical crystalline nanoparticle in a well distributed size and morphology. It can be seen from these pictures that the particle siz

An Isolated Off-Line High Power Factor Electrolytic Capacitor-Less LED Driver with Pulsating Output Current

One of the most efficient lighting technology is based on light-emitting diodes (LEDs). Common LED drivers with AC-input (50-60Hz) usually require a bulk electrolytic capacitor to decrease low-frequency ripple in the output. However, the critical element that limits the lifespan of the LED driver is the electrolytic capacitor. An isolated off-line LED driver is proposed in this paper, in which the required output capacitance is reduced so that the electrolytic capacitor can be omitted from the driver structure. The driver’s configuration and controlling method provide a high input power factor. Just a single switch and therefore a single controlling IC have been used in the proposed structure. The input power factor correction is implemented utilizing a boost-based method, and a novel structure is introduced for dc/dc conversion section. Power factor correction and dc/dc conversion are performed employing a simplistic and single controlling system. The output current feeding the LEDs is a high frequency pulsating current. Calculations, simulations and experimental waveforms of a laboratory prototype are presented to confirm the validity of the proposed driver

Analysis of Switched Inductor Three-level DC/DC Converter

A non-isolated DC/DC converter with high transfer gain is proposed in this paper. The presented converter consists of the switched inductor and three-level converters. The DC/DC power converter is three-level boost converter to convert the output voltage of the DC source into two voltage sources. The main advantages of DC/DC converter are using low voltage semiconductors and high gain voltage. The steady-state operation of the suggested converter is analyzed. A prototype is developed and tested to verify the performance of the proposed converter. To sum up, the MATLAB simulation results and the experimental results have transparently approved high efficiency of proposed converter as well as its feasibility

Two-Stage Inverter Based on Combination of High Gain DC-DC Converter and Five-Level Inverter for PV-Battery Energy Conversion

This paper proposes a new two-stage inverter based on transformer-less high gain DC-DC converter for energy conversion of a photovoltaic system. The designed system consists of a high gain DC-DC converter cascaded with a three-phase inverter. The proposed DC-DC converter has a simple structure, and it has one switch in its structure. The output voltage of the DC-DC converter supplies DC source for the inverter part of the multi-stage inverter. The advanced two-stage inverter sample was fabricated, then the findings of the acquired simulation and hardware warranted the configuration applicability. Finally, the MATLAB/SIMULINK is employed for the simulation of PV-battery system. The obtained results revel that the proposed power conversion system effectively chases the load and generation fluctuations and also properly handles the power mismatches in PV-battery system

Two Inputs Five-Level Quasi-Z-Source Inverter

This paper combines quasi-Z-source into a typical five-level inverter, which includes two dc voltage sources, two quasi-Z-sources and five switching devices. In this structure, the output voltage amplitude is not limited to dc voltage source and it can be increased by quasi-Z-source. Besides, due to nature of Z-source families, this new structure is reliable and higher efficiency. Also, in this inverter, two quasi-Z-networks can be controlled independently. This paper also proposes new switching algorithms for proposed five-level dual quasi-Z-Source inverter based on pulse width modulation (PWM) and selective harmonic elimination method (SHEM) algorithms .The performance of proposed inverter and switching algorithm are validated with simulation results using MATLAB/SIMULINK software and experimental results based PCI-1716 data acquisition system

Dosimetric Comparison of Four Different Techniques for Supraclavicular Irradiation in 3D-conformal Radiotherapy of Breast Cancer

This study aimed to compare and evaluated the dosimetric characteristics of esophagus, spinal cord, carotid artery, lungs, and brachial plexus in patients with breast cancer undergoing four various techniques of supraclavicular irradiation. By keeping unchanged the breast tangential radiotherapy fields, four different treatment field arrangements were created to irradiate the supraclavicular region as follows: (1) four field (4F; 1 anterior-posterior and 1 posterior-anterior), (2) six field (6F; 2 anterior-posterior and 2 posterior-anterior), (3) five field-1 (5F-1; 2 anterior-posterior and 1 posterior-anterior), and (4) five field-2 (5F-2; 1 anterior-posterior and 2 posterior-anterior). Then, the dosimetric parameters for the above-mentioned organs were evaluated. The mean dose (Dmean) of the esophagus had significant difference between 6F and 5F-2 techniques. For the spinal cord, the Dmean dosimetric parameter demonstrated significant difference between the 4F and 6F techniques, and between the 4F and 5F-1 techniques, with lower values for the 4F technique. There was no significant difference between the different irradiation techniques in all the dosimetric parameters for the carotid artery. The Dmean of the left lung significantly differed between the 4F and 5F-2 techniques, with lower values for the 5F-2 technique. Furthermore, the V20Gy dosimetric parameter had significant difference between the 4F and 6F, and also 4F and 5F-2, techniques with lower values for 5F-2. The maximum dose (Dmax) of the brachial plexus showed significant difference between the two techniques of 5F. The V45Gy dosimetric parameter of the brachial plexus revealed significant difference between the 4F and 6F techniques, and also between the 4F and 5F-1 techniques, with lower values for 5F-1. In general, these techniques had similar dosimetric results, with little differences. The dosimetric parameters for the esophagus and lung showed better results with the 5F-2 technique in comparison with other techniques. Dosimetric results for the brachial plexus and spinal cord improved with the 5F-1 and 4F techniques, respectively, against other techniques. Dose distribution for the carotid artery did not differ in the four irradiation techniques

Predicting tuberculosis drug resistance with machine learning-assisted Raman spectroscopy

Tuberculosis (TB) is the world's deadliest infectious disease, with 1.5 million annual deaths and half a million annual infections. Rapid TB diagnosis and antibiotic susceptibility testing (AST) are critical to improve patient treatment and to reduce the rise of new drug resistance. Here, we develop a rapid, label-free approach to identify Mycobacterium tuberculosis (Mtb) strains and antibiotic-resistant mutants. We collect over 20,000 single-cell Raman spectra from isogenic mycobacterial strains each resistant to one of the four mainstay anti-TB drugs (isoniazid, rifampicin, moxifloxacin and amikacin) and train a machine-learning model on these spectra. On dried TB samples, we achieve > 98% classification accuracy of the antibiotic resistance profile, without the need for antibiotic co-incubation; in dried patient sputum, we achieve average classification accuracies of ~ 79%. We also develop a low-cost, portable Raman microscope suitable for field-deployment of this method in TB-endemic regions