Tracking Evolution of Stator-based Fault in Induction Machines using the Growing Curvilinear Component Analysis Neural Network

Stator-based faults are one of the most common faults among induction motors (IMs). The conventional approach to IM control and protection employs current sensors installed on the motor. Recently, most studies have focused on fault detection by means of stator current. This paper presents an application of the Growing Curvilinear Component Analysis (GCCA) neural network aided by the Extended Park Vector Approach (EPVA) for the purpose of transforming the three-phase current signals. The GCCA is a growing neural based technique specifically designed to detect and follow changes in the input distribution, e.g. stator faults. In particular, the GCCA has proven its capability of correctly identifying and tracking stator inter-turn fault in IMs. To this purpose, the three-phase stator currents have been acquired from IMs, which start at healthy operating state and, evolve to different fault severities (up to 10%) under different loading conditions. Data has been transformed using the EPVA and pre-processed to extract statistical time domain features. To calibrate the GCCA neural network, a topological manifold analysis has been carried out to study the input features. The efficacy of the proposed method has been verified experimentally using IM with l.lkW rating and has potential for IMs with different manufacturing conditions

A social constructed human beeing : a (bio)technological approach

As a social construction, (bio)technology1 should not be studied out of the social field. From a Social Imaginaries approach, (bio)technology can be considered as a contemporary social magma formed by biological, technical, psychological, sociological and axiological factors. Orbiting around the the cyborg metaphor, in this article we intend to build a multidisciplinary approach of this polycontextureComo una construcción social, la (bio)tecnología no debe ser estudiada fuera del campo social. Desde una perspectiva analítica sobre los imaginarios sociales, la (bio)tecnología puede ser considerada como un magma social formado por factores biológicos, técnicos, psicológicos, sociológicos y axiológicos. Orbitando alrededor de la metáfora del cyborg, en este artículo nos proponemos construir un enfoque multidisciplinar de esta polycontextura

Gap in Techno-Scientific Activity: The Iberoamerican Context

The aim of this paper is to apply the hermeneutic approach to social imaginaries of science and technology. Special attention will be given to discuss how the techno-scientific system intends to face poverty, although the system focuses to a different direction, which is a growing inter-penetration with the economic system. The techno-scientific system, as well as its politics, sets aside poor people. In such a context, the scientific-technologic gap continues to grow, generating gradually two different paces of international development. Factors like the cyborgization, robotization, the development of ITCs, etc., have an impact into the poorest regions, ending up into situations of technologic-scientific neo-colonialism. In spite of peripheral states efforts, the possible development of these regions is an always faced and never overcome challenge. Transformations of the scientific-technologic system, which are more and more scientifically and technologically dependent every day, constitute as a gap. Key words: Science; technology; poverty; scientific-technologic ga

Experimental investigation and modelling of diffusion dialysis process for regeneration of acidic pickling solutions

Pickling is one of the key steps in metal finishing industries, where HCl solutions are largely used thus generating significant amounts of spent waste solutions containing high concentrations of metals and acid. The recovery of acid from such waste solutions is thus one of the most beneficial steps for reducing the environmental and economical impact of these processes. Among several separation methods, diffusion dialysis (DD) is becoming more and more attractive thanks to the recent important advances in ion exchange membranes (IEMs) field and because of its clean nature and operational simplicity, low installation and operating costs and low energy consumption [1,2]. In the present work, a single-cell diffusion dialysis module equipped with a FumaTech Anion Exchange Membrane (AEM), operated in a batch mode, has been employed in order to study the effect of some parameters on the efficiency of HCl recovery from waste pickling acidic solutions. In addition, a mathematical model, capable of simulate and predict this process, has been also developed and validated with experimental information. The laboratory test-rig and procedures have been first evaluated and optimised by measuring salt and water fluxes with artificial NaCl solutions with different types of AEMs. Then, experiments with HCl solutions were carried out, at different compositions of diffusate and retentate streams, varying HCl concentration values in the range of 0.1-3 M. HCl and water osmotic fluxes were measured and their dependence on operating conditions was identified. Also the effect of the presence of selected iron salts were investigated in order to simulate the operation of the system when treating actual pickling solutions. In particular, the acid diffusion permeability as well as the water osmotic permeability tend to increase when increasing the solution concentration. In addition, an increasing HCl recovery is detected in the presence of iron chloride. References [1] Luo et al., Diffusion dialysis processes of inorganic acids and their salts: the permeability of different acidic anions, Separation and Purification Technology 78 (2011), 97-102 [2] Xu et al., Recovery of hydrochloric acid from the waste acid solution by diffusion dialysis, Journal of Hazardous Materials 165 (2009), 832-83

Elevated Levels of DNA Strand Breaks Induced by a Base Analog in the Human Cell Line with the P32T ITPA Variant

Base analogs are powerful antimetabolites and dangerous mutagens generated endogenously by oxidative stress, inflammation, and aberrant nucleotide biosynthesis. Human inosine triphosphate pyrophosphatase (ITPA) hydrolyzes triphosphates of noncanonical purine bases (i.e., ITP, dITP, XTP, dXTP, or their mimic: 6-hydroxyaminopurine (HAP) deoxynucleoside triphosphate) and thus regulates nucleotide pools and protects cells from DNA damage. We demonstrate that the model purine base analog HAP induces DNA breaks in human cells and leads to elevation of levels of ITPA. A human polymorphic allele of the ITPA, 94C->A encodes for the enzyme with a P32T amino-acid change and leads to accumulation of nonhydrolyzed ITP. The polymorphism has been associated with adverse reaction to purine base-analog drugs. The level of both spontaneous and HAP-induced DNA breaks is elevated in the cell line with the ITPA P32T variant. The results suggested that human ITPA plays a pivotal role in the protection of DNA from noncanonical purine base analogs

Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) for the prevention of migraine in adults

Background: This is an updated version of the original Cochrane review published in 2005 on selective serotonin re-uptake inhibitors (SSRIs) for preventing migraine and tension-type headache. The original review has been split in two parts and this review now only regards migraine prevention. Another updated review is under development to cover tension-type headache. Migraine is a common disorder. The chronic forms are associated with disability and have a high economic impact. In view of discoveries about the role of serotonin and other neurotransmitters in pain mechanisms, selective serotonin re-uptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) have been evaluated for the prevention of migraine. Objectives: To determine the efficacy and tolerability of SSRIs and SNRIs compared to placebo and other active interventions in the prevention of episodic and chronic migraine in adults. Search strategy: For the original review, we searched MEDLINE (1966 to January 2004), EMBASE (1994 to May 2003), the Cochrane Central Register of Controlled Trials (CENTRAL 2003, Issue 4), and Headache Quarterly (1990 to 2003). For this update, we applied a revised search strategy to reflect the broader type of intervention (SSRIs and SNRIs). We searched CENTRAL (2014, Issue 10), MEDLINE (1946 to November 2014), EMBASE (1980 to November 2014), and PsycINFO (1987 to November 2014). We also checked the reference lists of retrieved articles and searched trial registries for ongoing trials. Selection criteria: We included randomised controlled trials comparing SSRIs or SNRIs with any type of control intervention in participants 18 years and older of either sex with migraine. Data collection and analysis: Two authors independently extracted data (migraine frequency, index, intensity, and duration; use of symptomatic/analgesic medication; days off work; quality of life; mood improvement; cost-effectiveness; and adverse events) and assessed the risk of bias of trials. The primary outcome of this updated review is migraine frequency. Main results: The original review included eight studies on migraine. Overall, we now include 11 studies on five SSRIs and one SNRI with a total of 585 participants. Six studies were placebo-controlled, four compared a SSRI or SNRI to amitriptyline, and one was a head-to-head comparison (escitalopram versus venlafaxine). Most studies had methodological or reporting shortcomings (or both): all studies were at unclear risk of selection and reporting bias. Follow-up rarely extended beyond three months. The lack of adequate power of most of the studies is also a major concern. Few studies explored the effect of SSRIs or SNRIs on migraine frequency, the primary endpoint. Two studies with unclear reporting compared SSRIs and SNRIs to placebo, suggesting a lack of evidence for a difference. Two studies compared SSRIs or SNRIs versus amitriptyline and found no evidence for a difference in terms of migraine frequency (standardised mean difference (SMD) 0.04, 95% confidence interval (CI) -0.72 to 0.80; I2 = 72%), or other secondary outcomes such as migraine intensity and duration. SSRIs or SNRIs were generally more tolerable than tricyclics. However, the two groups did not differ in terms of the number of participants who withdrew due to adverse advents or for other reasons (one study, odds ratio (OR) 0.39, 95% CI 0.10 to 1.50 and OR 0.42, 95% CI 0.13 to 1.34). We did not find studies comparing SSRIs or SNRIs with pharmacological treatments other than antidepressants (e.g. antiepileptics and anti-hypertensives)

Direction of Arrival Estimation Based on Support Vector Regression: Experimental Validation and Comparison with MUSIC

In this letter, the problem of estimating the directions of arrival (DOAs) of coherent electromagnetic waves impinging upon a uniform linear array (ULA) is considered. In particular, an efficient DOA estimation approach based on the support vector regression is assessed using experimental measurements. Moreover, the obtained results are compared with those yielded by the multiple signal classification (MUSIC) algorithm

Pneumatic tools for vitreoretinal surgery

One of the difficulties of microsurgery is learning how to control physiological tremors. The pneumatic tool eliminates the physiological tremor, but no tactile feedback is provided. The manual tremor when closing the forceps is completely eliminated and the exact target can be more easily grabbed. Forceps closure pressure can rise up to 50 psi, whereas the scissors can be used in two modes: multicut and proportional. When performing bimanual surgery the pedal range is divided into two steps: in the first step, the forceps are controlled, and in the second step, the forceps remain closed. At the same time the scissors start to work in the preselected mode. No adverse events occurred and no iatrogenic retinal breaks were produced. Precision and control sensation were a grateful surprise