Tactile perceptual dimensions: a study with light-weight wool fabrics

Volume 5024 of the series Lecture Notes in Computer Science.The aim of this study was to identify the tactile dimensions in the discrimination of light-weight wool fabrics. The participants judged the overall similarity between 21 light-weight wool fabrics using free sorting tasks. The fabrics were evaluated using active touch with limited exploratory procedure. Multidimensional scaling (MDS) was used to generate the perceptual space, revealing one dimension of tactile perception. Finally, through regression analysis we were able to interpret this dimension, using verbal attributes and physical properties of the fabrics. We discuss the relevance of the stimuli properties and the associations between verbal attributes and between physical properties, on the evaluation of the fabrics, considering its theoretical implications

Determinação de atributos verbais para a análise sensorial: estudo para a avaliação táctil de tecidos finos de lã.

Através das tarefas apresentadas neste trabalho, procurou-se definir um conjunto de adjectivos que permitissem uma descrição consistente das propriedades tácteis de um conjunto de tecidos, durante provas de análise sensorial. Os atributos foram seleccionados recorrendo a participantes não – especialistas, uma estratégia distinta da habitual em estudos de análise sensorial. Procurou-se ainda definir rigorosamente os adjectivos utilizados previamente à introdução dos produtos a avaliar. Desta forma, as primeiras tarefas realizadas exploram os adjectivos de forma puramente conceptual, sendo introduzidos os tecidos a avaliar apenas na fase final do estudo de vocabulário, procurando validar os atributos seleccionados na ausência dos tecidos. Através de quatro tarefas – identificação categorial, caracterização do produto, clarificação de significado e eliminação de conceitos sobrepostos – foi possível isolar 8 atributos, bons descritores dos tecidos finos de lã, referentes a propriedades diferenciadas: delicado, grosso, leve, liso, macio, maleável, quente e resistente.The purpose of this work was to define adjectives for a consistent description of the tactile properties of fabrics in sensory analysis tasks. The attributes were selected recurring to non-expert participants, an unusual strategy in sensory analysis procedures. The adjectives were strictly defined before the target product was presented to the participants. The initial tasks consisted in the exploration of the concepts associated with the attributes, in the absence of the product, which was introduced only in the final phases as a way to confirm and consolidate the attribute selection. Through four tasks – categorical identification, product characterization, clarification of meaning, and elimination of similar concepts – it was possible to isolate 8 attributes, shown to be good descriptors of light-weight wool fabrics, and related to different tactile properties: delicate, thick, light, smooth, soft, flexible, warm, and resistant

Haptic working memory: performance in interference tasks and span tasks with everyday objects

Tese de doutoramento em Psicologia Especialidade em Psicologia Experimental e Ciências CognitivasIn this work, human haptic working memory is analysed in interference and span tasks, aiming to systematically study memory for touch in natural conditions, and to examine how haptic information is encoded and processed in human memory. The first part of this thesis consists in a literature review of data on haptic perception and haptic memory. Our approach to this review implied a systematisation of the main variables manipulated in tactile and haptic studies, followed by a critical review of studies on memory for touch. The first group of experiments, evaluating the impact of interference tasks in haptic recognition is described in Part II. Participants were required to sequentially touch lists of 50 common (e.g., comb) or uncommon (e.g., plastic onion) everyday objects, either in single task or interference task conditions, and then were asked to perform an immediate incidental haptic recognition memory task, by touching a new list of 50 objects (25 presented and 25 non-presented objects) and to indicate if each object had been touched before. The interference tasks were always performed at encoding and could be haptic (evaluating paper samples), motor (performing a concurrent movement), verbal (evaluating pseudo-word pairs), or visuospatial (evaluating three-dimensional stimuli images). Results showed that participants were able to perform these tasks with a high accuracy rate, either for common or uncommon objects. For common objects, only haptic interference impaired haptic recognition. For uncommon objects, haptic recognition was affected by haptic, verbal and visual interference tasks, but not by motor interference. A final analysis, considering direct comparisons between object types for each interference condition revealed that common objects systematically present higher recognition rates, and are less affected by interference than uncommon objects. Overall, these studies suggest a haptic specificity in working memory, and an object familiarity mediation of the participant’s performance. The third part of this thesis reports a group of exploratory studies on haptic span, recurring to immediate serial recall and reconstruction of order tasks. Considering the relevance of verbal representations for everyday objects, the participant’s performance was studied in single task and articulatory suppression conditions. In immediate serial recall tasks participants were asked to touch lists of common objects (e.g., ball), starting with a list extension of two objects, and going up to ten objects, according to the participant’s performance. Results revealed an haptic span of approximately five items in single task and of four items in articulatory suppression conditions. In reconstruction of order tasks, after the list presentation, all touched objects were available again, and the participants had to order them according to the initial presentation. This task, not implying item identification (naming), allowed a comparison between common and uncommon object’s span. Results showed that similar spans exist for both conditions, with about six items being recalled in single task, and about five items in the articulatory suppression conditions. The present work is a contribute to the field of haptic cognition, specifically haptic memory, by presenting a first attempt to systematically study working memory for touch by adapting classical paradigms in the study of human memory to the haptic sensory modality. Throughout this work, empirical and theoretical topics regarding touch experiments are discussed and future research paths in this field are suggested.Neste trabalho analisa-se a memória de trabalho háptica em humanos, procurando estudá-la de forma sistemática e em condições naturais, explorando a forma como a informação háptica é codificada e processada na memória humana. A primeira parte desta tese consiste numa revisão da literatura existente nas áreas de percepção e memória táctil e háptica. A abordagem à revisão teórica passou pela sistematização das variáveis centrais nos estudos sobre tacto, seguida de uma revisão crítica do estudo da memória táctil. O primeiro grupo de experiências avalia o impacto de tarefas de interferência no reconhecimento háptico e é descrito na Parte II. Os participantes tocaram sequencialmente uma lista de 50 objectos quotidianos comuns (e.g., pente) ou incomuns (e.g., cebola de plástico), em condições de tarefa simples ou em condições de interferência. De seguida foi-lhes solicitada a realização de uma tarefa de reconhecimento háptico imediata e incidental, tocando uma nova lista de 50 objectos (25 apresentados previamente e 25 não apresentados) e indicando para cada objecto se este havia sido tocado anteriormente. A tarefa de interferência foi realizada durante a fase de codificação dos objectos e poderia ser de natureza háptica (avaliação de amostras de papel), motora (realizar um movimento específico), verbal (avaliação de pseudo-palavras), ou visuo-espacial (avaliação de imagens de estímulos tridimensionais). Os resultados demonstram que os participantes foram capazes de realizar a tarefa de reconhecimento háptico com elevadas taxas de acerto, quer para objectos comuns, quer para objectos incomuns. Para os objectos comuns, apenas a interferência háptica prejudicou o reconhecimento háptico. Para os objectos incomuns, o reconhecimento háptico foi prejudicado pela interferência háptica, verbal e visuo-espacial, mas não pela interferência motora. Uma última análise, comparando directamente o desempenho para objectos comuns e incomuns para cada tipo de interferência, revelou que os objectos comuns produzem sistematicamente melhores taxas de reconhecimento e são menos prejudicados pela interferência do que os objectos incomuns. De uma forma geral, os estudos apresentados na segunda parte deste trabalho sugerem a existência de especificidade háptica na memória de trabalho, assim como um efeito mediador da familiaridade dos estímulos no desempenho dos participantes. A terceira parte desta tese descreve um conjunto de estudos exploratórios sobre tarefas de capacidade de memória háptica, recorrendo a tarefas de evocação serial imediata e a tarefas de ordenação. Considerando a relevância das representações verbais para os objectos quotidianos, os participantes nestes estudos realizaram as tarefas de capacidade em condições de tarefa simples e com supressão articulatória Nas tarefas de evocação serial imediata, os participantes tocaram listas de objectos comuns (e.g., bola), começando a tarefa com listas com a extensão de dois objectos, que podiam ser aumentadas até um máximo de 10 objectos, dependendo do desempenho individual. Os resultados demonstram que a capacidade háptica é de aproximadamente cinco itens em condições de tarefa simples, e de quatro itens em condições de supressão articulatória. Nas tarefas de ordenação, após a apresentação das listas, todos os objectos tocados estão disponíveis para o participante, que deverá ordená-los de acordo com a apresentação inicial. Nesta tarefa, uma vez que não é necessária a identificação dos itens, foi possível comparar o desempenho com objectos comuns e incomuns. Os resultados mostram que o número de itens correctamente ordenados é idêntico para objectos comuns e incomuns e corresponde a aproximadamente seis itens em condições de tarefa simples e a cinco itens em condições de supressão articulatória. Este trabalho apresenta-se como um contributo para o campo da cognição háptica, especificamente da memória háptica, apresentando uma primeira tentativa de estudar sistematicamente a memória para o tacto, adaptando paradigmas clássicos no estudo da memória humana à modalidade sensorial háptica. Ao longo deste trabalho, tópicos empíricos e teóricos acerca das experiências com tacto serão discutidos e serão sugeridos caminhos de investigação futura nesta área

Photocatalytic hydrogen production using noble and transition metals surface modified titania [Resumo]

ABSTRACT: A large number of photocatalytic materials have been studied for water splitting since the seminal work of Fujishima and Honda1, showing great potential for solar energy conversion, including H2 production. The irradiation of a suspension of semiconductor oxides, as is the case of TiO2, presents attracting features but also stringent requirements regarding materials properties, including the tailoring of the electronic structure. Furthermore, efficient charge transport is necessary, as well as effective charge separation and prevention of electron-hole pair recombination, before the redox reactions can proceed2,3. In this work, the catalytic activity under UV excitation of TiO2-Au photocatalyst for H2 production was undertaken using glycerol and ethanol as sacrificial agents. Furthermore, substitution of Au by transition metal Cu was attempted with good results. Comparison is made with results obtained using TiO2-rGO-Pt catalyst under analogous loading conditions.N/

Accommodative and binocular vision dysfunctions in a Portuguese clinical population

Article in Press, Available online 28 November 2021Background: Several studies have suggested that accommodative and non-strabismic binocular dysfunctions are commonly encountered in optometric practice. This study aims to verify whether these findings apply to a Portuguese clinical population. Methods: This study included consecutive nonpresbyopic subjects that came to two Portuguese optometric clinics over a period of six months. A complete visual exam was conducted and included the measurement of visual acuity (VA), refraction, near point of convergence (NPC), distance and near phoria, near and distance fusional vergences, amplitude of accommodation (AA), monocular accommodative facility (MAF), relative accommodation and lag of accommodation. Results: 156 subjects with a mean age of 24.9 ± 5.3 years (from 18 to 35 years old) participated in the study. Of all subjects, 32 % presented binocular vision and/or accommodative disorders accompanied or not by refractive errors. Moreover, 21.1 % had accommodative disorders, and 10.9 % had a binocular vision dysfunction. Accommodative insufficiency (11.5 %) was the most prevalent disorder, followed by convergence insufficiency (7.1 %) and accommodative infacility (5. 8 %). Conclusions: Clinicians should be aware that about one third of the optometric clinical population could have accommodative and/or non-strabismic binocular disorders. Accommodative insufficiency was the most prevalent dysfunction presented in the studied population, followed by accommodative infacility and convergence insufficiency.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2019

Generation of hydrogen from chemical hydrides under pressure up to 70 Bar

Hydrogen production by sodium borohydride through hydrolysis in alkaline solutions has been extensively studied as a production/storage option. The potential application of this option is dependent on an easily controllable catalysed hydrolysis reaction at significant rates to comply with fuel cell feeding but also on the increase of the gravimetric density being of paramount importance, the design and implementation of compact and efficient reactors and the reaction characterization under pressure. In this work, hydrogen generation by the catalyzed hydrolysis of sodium borohydride was studied under pressure up to 70 bar with excellent result

Challenges arising from the use of TiO2/rGO/Pt photocatalysts to produce hydrogen from crude glycerol compared to synthetic glycerol

ABSTRACT: Photoreforming has emerged as a novel technology expected to obtain chemical energy through solar energy transformation. In this way, sustainable valorization of glycerol, a biodiesel by-product, to clean fuels is a promising alternative to help meet the world's growing energy demand. In this work, TiO2/rGO(x)/Pt(y) photocatalysts have been developed for hydrogen production from synthetic and crude glycerol solutions. The effect of several key operating parameters (including vol% of glycerol, pH, catalyst loading, wt% of GO, wt% of Pt, temperature, and light source) on hydrogen production rate has been studied. The results indicated different optimal operating parameters depending on glycerol origin, achieving up to 70.8 and 12.7 mmol h(-1) g(-1) of hydrogen using synthetic glycerol and crude glycerol, respectively. Additionally, GO nanosheets and Pt nanoparticles strongly influenced the hydrogen production rate but not the overall reaction mechanism. Impurities contented in crude glycerol are key factors in developing realistic hydrogen production processes.info:eu-repo/semantics/publishedVersio

Photocatalytic hydrogen production using ethanol as sacrificial agent from gas and liquid phases on reduced graphene oxide-TiO2- Pt nanocomposites

ABSTRACT: Various strategies such as heterostructuring, crystal/textural modifications and band gap engineering, have been applied to the improvement of the photocatalytic activity of Titania for hydrogen production from water splitting. In this work deposited Pt on TiO2 is used as electron trap to suppress charge recombination. To reinforce this effect, composites with graphene oxide (GO) have been prepared, exhibiting promising photocatalytic performance for both hydrogen generation and the degradation of ethanol added as hole scavenger. Photocatalytic reactions were conducted in gas and liquid phases.N/

A Metabolomics-Inspired Strategy for the Identification of Protein Covalent Modifications

This work was supported by Fundação para a Ciência e a Tecnologia (FCT), Portugal, through projects UID/QUI/00100/2019, IF/01091/2013/CP1163/CT0001 and PTDC/QUIQAN/32242/2017 as well as doctoral fellowships SFRH/BD/102846/2014 (to CC) and SFRH/BD/140157/2018 (to JN);joint funding from FCT and the COMPETE Program is also acknowledge through RNEM-LISBOA-01-0145-FEDER-022125-funded postdoctoral fellowship (to JM).Identification of protein covalent modifications (adducts) is a challenging task mainly due to the lack of data processing approaches for adductomics studies. Despite the huge technological advances in mass spectrometry (MS) instrumentation and bioinformatics tools for proteomics studies, these methodologies have very limited success on the identification of low abundant protein adducts. Herein we report a novel strategy inspired on the metabolomics workflows for the identification of covalently-modified peptides that consists on LC-MS data preprocessing followed by statistical analysis. The usefulness of this strategy was evaluated using experimental LC-MS data of histones isolated from HepG2 and THLE2 cells exposed to the chemical carcinogen glycidamide. LC-MS data was preprocessed using the open-source software MZmine and potential adducts were selected based on the m/z increments corresponding to glycidamide incorporation. Then, statistical analysis was applied to reveal the potential adducts as those ions are differently present in cells exposed and not exposed to glycidamide. The results were compared with the ones obtained upon the standard proteomics methodology, which relies on producing comprehensive MS/MS data by data dependent acquisition and analysis with proteomics data search engines. Our novel strategy was able to differentiate HepG2 and THLE2 and to identify adducts that were not detected by the standard methodology of adductomics. Thus, this metabolomics driven approach in adductomics will not only open new opportunities for the identification of protein epigenetic modifications, but also adducts formed by endogenous and exogenous exposure to chemical agents.publishersversionpublishe