Sensors for Quality Control in Welding

The classical inspection methods used for detecting and finding disturbances in welding process are based on direct measurement of its parameters as arc voltage, welding current, wire feed speed, etc. Using these inspection methods implies sensors insertion around the welding process and its presence could alter the metallic transference behavior and consequently an uneven quality as well as it can increase the production cost. For reducing these implications is necessary using a non intrusive inspection method. In this paper we will show nonintrusive methods to the weld quality inspection. These methods are based on sensor fusion, the extraction of global information coming from the interrelation data given by each sensor that, for example, sensing the spectroscopy radiation emission, the acoustic sensing of the electrical arc, the infrared emissions indicating the heat content of the weld. Finally, the fusion data will be applied to a statistical control for detecting and finding welding disturbances. The results will show that sensor fusion could be used as a tool to measure indirectly the weld quality in the GMAW process

Trends, challenges and processes in conversational agent design: exploring practitioners’ views through semi-structured interviews

The aim of this study is to explore the challenges and experiences of conversational agent (CA) practitioners in order to highlight their practical needs and bring them into consideration within the scholarly sphere. A range of data scientists, conversational designers, executive managers and researchers shared their opinions and experiences through semi-structured interviews. They were asked about emerging trends, the challenges they face, and the design processes they follow when creating CAs. In terms of trends, findings included mixed feelings regarding no-code solutions and a desire for a separation of roles. The challenges mentioned included a lack of socio-technical tools and conversational archetypes. Finally, practitioners followed different design processes and did not use the design processes described in the academic literature. These findings were analyzed to establish links between practitioners’ insights and discussions in related literature. The goal of this analysis is to highlight research-practice gaps by synthesising five practitioner needs that are not currently being met. By highlighting these research-practice gaps and foregrounding the challenges and experiences of CA practitioners, we can begin to understand the extent to which emerging literature is influencing industrial settings and where more research is needed to better support CA practitioners in their work

Wiring Nanoscale Biosensors with Piezoelectric Nanomechanical Resonators

Nanoscale integrated circuits and sensors will require methods for unobtrusive interconnection with the macroscopic world to fully realize their potential. We report on a nanoelectromechanical system that may present a solution to the wiring problem by enabling information from multisite sensors to be multiplexed onto a single output line. The basis for this method is a mechanical Fourier transform mediated by piezoelectrically coupled nanoscale resonators. Our technique allows sensitive, linear, and real-time measurement of electrical potentials from conceivably any voltage-sensitive device. With this method, we demonstrate the direct transduction of neuronal action potentials from an extracellular microelectrode. This approach to wiring nanoscale devices could lead to minimally invasive implantable sensors with thousands of channels for in vivo neuronal recording, medical diagnostics, and electrochemical sensing

Doped and dedoped polyaniline nanofiber based conductometric hydrogen gas sensors

Template-free, rapid polymerisation was employed to synthesize polyaniline nanofibers using chemical oxidative polymerisation of aniline, with HCl as a dopant. The doped and dedoped nanofibers were deposited onto conductometric sapphire transducers for gas sensing applications. The sensors were exposed to various concentrations of hydrogen (H2) gas at room temperature. The sensitivity was measured to be 1.11 for doped and 1.07 for dedoped polyaniline nanofiber sensors upon exposure to 1% H2. Fast response times of 28 seconds and 32 seconds were observed for dedoped and doped sensors respectively. The dedoped nanofiber sensor outperforms the doped sensor in terms of baseline stability and repeatability. Due to its room temperature operation, the gas sensor is promising for environmental applications

PSSA doped polyaniline nanofiber based ZnO/64° YX LiNbO3 SAW H2 gas sensor

A polyaniline (PANI) nanofiber based surface acoustic wave (SAW) gas sensor, has been developed and investigated towards hydrogen (H<sub>2</sub>) gas. A template-free, rapidly-mixed reaction approach was employed to synthesize polyaniline nanofibers, which utilized chemical oxidative polymerization of aniline. Hydrochloric acid (HCl) was used as the dopant acid in the synthesis of the polyaniline nanofibers. Polystyrene sulfonic acid (PSSA) was used to re-dope PANI nanofibers after dialyzing with ammonium hydroxide. Then PSSA doped nanofibers were deposited onto a ZnO/64 YX LiNbO<sub>3</sub> SAW transducer. The sensor was exposed to various concentrations of H<sub>2</sub> gas in an ambient of synthetic air, and operated at room temperature

A room temperature polyaniline nanofibre hydrogen gas sensor

Electro-conductive polyaniline (PANI) nanofiber based surface acoustic wave (SAW) gas sensors have been investigated with hydrogen (H 2) gas. A template-free, rapidly mixed method was employed to synthesize polyaniline nanofibers using chemical oxidative polymerization of aniline. The nanofibers were deposited onto a layered ZnO/64° YX LiNbO3 SAW transducer for gas sensing applications. The novel sensor was exposed to various concentrations of H2 gas at room temperature. The sensor response, defined as the relative variation in operating frequency of oscillation due to the introduction of the gas, was 3.04 kHz towards a 1% H2 concentration. A relatively fast response time of 8 sec and a recovery time of 60 sec with good repeatability were observed at room temperature. Due to room temperature operation, the novel gas sensor is promising for environmental and industrial applications

AMPA receptors and seizures mediate hippocampal radial glia-like stem cell proliferation.

Neurogenesis is sustained throughout life in the mammalian brain, supporting hippocampus-dependent learning and memory. Its permanent alteration by status epilepticus (SE) is associated with learning and cognitive impairments. The mechanisms underlying the initiation of altered neurogenesis after SE are not understood. Glial fibrillary acidic protein-positive radial glia (RG)-like cells proliferate early after SE, but their proliferation dynamics and signaling are largely unclear. We have previously reported a polarized distribution of AMPA receptors (AMPARs) on RG-like cells in vivo and postulated that these may signal their proliferation. Here, we examined the acute effects of kainate on hippocampal precursor cells in vitro and in kainate-induced SE on proliferating and quiescent clones of 5-bromo-2-deoxyuridine prelabeled hippocampal precursors in vivo. In vitro, we found that 5 μM kainate shortened the cell cycle time of RG-like cells via AMPAR activation and accelerated cell cycle re-entry of their progeny. It also shifted their fate choice expanding the population of RG-like cells and reducing the population of downstream amplifying neural progenitors. Kainate enhanced the survival of all precursor cell subtypes. Pharmacologically, kainate's proliferative and survival effects were abolished by AMPAR blockade. Functional AMPAR expression was confirmed on RG-like cells in vitro. In agreement with these observations, kainate/seizures enhanced the proliferation and expansion predominantly of constitutively cycling RG-like cell clones in vivo. Our results identify AMPARs as key potential players in initiating the proliferation of dentate RG-like cells and unravel a possible receptor target for modifying the radial glia-like cell response to SE

Triangular Textures for Quark Mass Matrices

The hierarchical quark masses and small mixing angles are shown to lead to a simple triangular form for the U- and D-type quark mass matrices. In the basis where one of the matrices is diagonal, each matrix element of the other is, to a good approximation, the product of a quark mass and a CKM matrix element. The physical content of a general mass matrix can be easily deciphered in its triangular form. This parameterization could serve as a useful starting point for model building. Examples of mass textures are analyzed using this method.Comment: 10 pages, no figure

A room temperature polyaniline nanofiber hydrogen gas sensor

Abstract—Electro-conductive polyaniline (PANI) nanofiber based Surface Acoustic Wave (SAW) gas sensors have been investigated with hydrogen (H2) gas. A template-free, rapidly mixed method was employed to synthesize polyaniline nanofibers using chemical oxidative polymerization of aniline. The nanofibers were deposited onto a layered ZnO/64º YX LiNbO3 SAW transducer for gas sensing applications. The novel sensor was exposed to various concentrations of H2 gas at room temperature. The sensor response, defined as the relative variation in operating frequency of oscillation due to the introduction of the gas, was 3.04 kHz towards a 1 % H2 concentration. A relatively fast response time of 8 sec and a recovery time of 60 sec with good repeatability were observed at room temperature. Due to room temperature operation, the novel gas sensor is promising for environmental and industrial applications. I