New mathematical approaches to the quantification of uncertainty affecting the measurement of U-value

This thesis describes the development and validation of a new computational procedure for the calculation of thermal transmittance (U-value) of existing building elements from the measurement of surface heat flux, and surface and nearby air temperatures. The U-value plays a key role in the determination of the final energy consumption of a dwelling, and, as in the current political scenario reducing carbon emissions is a growing concern, obtaining accurate and quick measurements of thermal transmittance is of particular relevance to the precise representation of the energy performance of the building sector. The calculation method developed is an extension of the RC network, a model based on the discretisation of building elements in resistors and capacitors in analogy with electrical circuits. The advances proposed in this work extend the discrete RC networks to a model based on the full heat equation, with continuous, spatially varying thermal prop- erties. The solution algorithm is inserted in a Bayesian framework that allows the reformulation of the problem in terms of probability distributions. Two solution schemes have been confronted: Markov Chain Monte Carlo and Ensemble Kalman Filters approximation. The model proposed has been validated on synthetic data, laboratory data collected in an environmental chamber on a solid and cavity wall, and in-situ data collected in 3 different locations (2 solid walls and 1 insulated steel frame construction). The results show that the model offers an improved characterisation of the heat transfer through the building elements, furthermore, the algorithm can be used to analyse different wall constructions without the necessity of changing the structure of the model, as opposed to the standard RC networks, and, finally, it offers the practical advantages of the uncertainty reduction on thermal transmittance (from 14-25% to 7-10%) and a diminution of the necessary monitoring period from a minimum of 3 days to 1 day or less. These advantages, in turn, benefit the building performance evaluation on different levels: in first instance, the practicality of measuring thermal transmittance in-situ is improved, thus making it easier to monitor the actual envelope performance and, secondly, the uncertainty reduction on the U-value leads to important reductions on the uncertainty surrounding the energy consumption predictions associated with a dwelling

New mathematical approaches to the quantification of uncertainty affecting the measurement of U-value

This thesis describes the development and validation of a new computational procedure for the calculation of thermal transmittance (U-value) of existing building elements from the measurement of surface heat flux, and surface and nearby air temperatures. The U-value plays a key role in the determination of the final energy consumption of a dwelling, and, as in the current political scenario reducing carbon emissions is a growing concern, obtaining accurate and quick measurements of thermal transmittance is of particular relevance to the precise representation of the energy performance of the building sector. The calculation method developed is an extension of the RC network, a model based on the discretisation of building elements in resistors and capacitors in analogy with electrical circuits. The advances proposed in this work extend the discrete RC networks to a model based on the full heat equation, with continuous, spatially varying thermal prop- erties. The solution algorithm is inserted in a Bayesian framework that allows the reformulation of the problem in terms of probability distributions. Two solution schemes have been confronted: Markov Chain Monte Carlo and Ensemble Kalman Filters approximation. The model proposed has been validated on synthetic data, laboratory data collected in an environmental chamber on a solid and cavity wall, and in-situ data collected in 3 different locations (2 solid walls and 1 insulated steel frame construction). The results show that the model offers an improved characterisation of the heat transfer through the building elements, furthermore, the algorithm can be used to analyse different wall constructions without the necessity of changing the structure of the model, as opposed to the standard RC networks, and, finally, it offers the practical advantages of the uncertainty reduction on thermal transmittance (from 14-25% to 7-10%) and a diminution of the necessary monitoring period from a minimum of 3 days to 1 day or less. These advantages, in turn, benefit the building performance evaluation on different levels: in first instance, the practicality of measuring thermal transmittance in-situ is improved, thus making it easier to monitor the actual envelope performance and, secondly, the uncertainty reduction on the U-value leads to important reductions on the uncertainty surrounding the energy consumption predictions associated with a dwelling

Cellulosic-crystals as a fumed-silica substitute in vacuum insulated panel technology used in building construction and retrofit applications

This article investigates impact of substituting fumed silica with a cellulosic-crystal innovation in a commercial Vacuum Insulated Panel (VIP) core. High building performance demands have attracted VIP technology investment to increase production capacity and reduce cost. In building retrofit VIPs resolve practical problems on space saving that conventional insulations are unsuitable for. Three challenges exists in fumed silica: cost, low sustainability properties, and manufacture technical maturity. Cellulosic nano-crystal (CNC) technology is in its infancy and was identified as a possible alternative due to a similar physical nano-structure, and biodegradability. The study aim was to determine a performance starting point and establish how this compares with the current benchmarks. Laboratory cellulosic-crystal samples were produced and supplied for incorporation into commercial VIP manufacture. A selection of cellulosic-panels with core densities ranging 127–170 kg/m3 were produced. Thermal conductivities were tested at a pressure of 1 Pa (0.01 mBar), with the results compared against a selection of fumed silica-VIPs with core densities ranging 144–180 kg/m3. Conductivity tests were then done on a cellulosic-VIP with 140 kg/m3 density, under variable pressures ranging 1–100,000 Pa (0.01–1000 mBar). This investigated panel lifespan performance, with comparisons made to a fumed silica-VIP of similar core density. Manufactured cellulosic-samples were found unsuitable as a commercial substitute, with performance below current standards. Areas for cellulosic nano-material technology development were identified that show large scope for improvement. Pursuit could create a new generation of insulation materials that resolve problems associated with current commercial versions. This is most applicable in building retrofit where large ranges of domestic and commercial cases are marginalised from their construction markets due to impracticalities and high upgrade costs. This being a problem in multiple economies globally

Quantifying uncertainty in thermophysical properties of walls by means of Bayesian inversion

We introduce a computational framework to statistically infer thermophysical properties of any given wall from in-situ measurements of air temperature and surface heat fluxes. The proposed framework uses these measurements, within a Bayesian calibration approach, to sequentially infer input parameters of a one-dimensional heat diffusion model that describes the thermal performance of the wall. These inputs include spatially-variable functions that characterise the thermal conductivity and the volumetric heat capacity of the wall. We encode our computational framework in an algorithm that sequentially updates our probabilistic knowledge of the thermophysical properties as new measurements become available, and thus enables an on-the-fly uncertainty quantification of these properties. In addition, the proposed algorithm enables us to investigate the effect of the discretisation of the underlying heat diffusion model on the accuracy of estimates of thermophysical properties and the corresponding predictive distributions of heat flux. By means of virtual/synthetic and real experiments we show the capabilities of the proposed approach to (i) characterise heterogenous thermophysical properties associated with, for example, unknown cavities and insulators; (ii) obtain rapid and accurate uncertainty estimates of effective thermal properties (e.g. thermal transmittance); and (iii) accurately compute an statistical description of the thermal performance of the wall which is, in turn, crucial in evaluating possible retrofit measures

Quantifying uncertainty in thermophysical properties of walls by means of Bayesian inversion

We introduce a computational framework to statistically infer thermophysical properties of any given wall from in-situ measurements of air temperature and surface heat fluxes. The proposed framework uses these measurements, within a Bayesian calibration approach, to sequentially infer input parameters of a one-dimensional heat diffusion model that describes the thermal performance of the wall. These inputs include spatially-variable functions that characterise the thermal conductivity and the volumetric heat capacity of the wall. We encode our computational framework in an algorithm that sequentially updates our probabilistic knowledge of the thermophysical properties as new measurements become available, and thus enables an on-the-fly uncertainty quantification of these properties. In addition, the proposed algorithm enables us to investigate the effect of the discretisation of the underlying heat diffusion model on the accuracy of estimates of thermophysical properties and the corresponding predictive distributions of heat flux. By means of virtual/synthetic and real experiments we show the capabilities of the proposed approach to (i) characterise heterogenous thermophysical properties associated with, for example, unknown cavities and insulators; (ii) obtain rapid and accurate uncertainty estimates of effective thermal properties (e.g. thermal transmittance); and (iii) accurately compute an statistical description of the thermal performance of the wall which is, in turn, crucial in evaluating possible retrofit measures

Field trialling of a pulse airtightness tester in a range of UK homes

A new low pressure ‘quasi-steady’ pulse technique for determining the airtightness of buildings has been developed further and compared with the standard blower-door technique for field-testing a range of typical UK homes. The reported low pressure air pulse unit (APU) has gone through several development stages related to optimizing the algorithm, pressure reference and system construction. The technique, which is compact, portable and easy to use, has been tested alongside the standard blower-door technique to measure the airtightness of a range of typical UK home types. Representative of the UK housing stock, the homes mostly have low levels of airtightness, resulting in poor energy performance, poor indoor air quality and poor thermal comfort. Some of these homes have been targeted for retrofitting and a quick, low cost and simple method for accurately determining their airtightness has clear advantages for correctly predicting the benefits of any improvements. A comparison between the results given by the two techniques is presented and the field trials indicate that the latest version of the pulse technique is reliable for determining building leakage at low pressure. Repeatability of multiple APU tests in the same house is found to be within +/-5% of the mean. A test where the leakage is increased by a known amount shows the APU is able to measure the change more accurately than the blower-door test. The APU also gives convenience in practical applications, due to being more compact and portable, plus it doesn’t need to penetrate the building envelope. The field trials demonstrate the pulse test has the potential to be a feasible alternative to the standard blower-door test

Why are we not flooded by involuntary thoughts about the past and future? Testing the cognitive inhibition dependency hypothesis

© The Author(s) 2018In everyday life, involuntary thoughts about future plans and events occur as often as involuntary thoughts about the past. However, compared to involuntary autobiographical memories (IAMs), such episodic involuntary future thoughts (IFTs) have become a focus of study only recently. The aim of the present investigation was to examine why we are not constantly flooded by IFTs and IAMs given that they are often triggered by incidental cues while performing undemanding activities. One possibility is that activated thoughts are suppressed by the inhibitory control mechanism, and therefore depleting inhibitory control should enhance the frequency of both IFTs and IAMs. We report an experiment with a between-subjects design, in which participants in the depleted inhibition condition performed a 60-min high-conflict Stroop task before completing a laboratory vigilance task measuring the frequency of IFTs and IAMs. Participants in the intact inhibition condition performed a version of the Stroop task that did not deplete inhibitory control. To control for physical and mental fatigue resulting from performing the 60-min Stroop tasks in experimental conditions, participants in the control condition completed only the vigilance task. Contrary to predictions, the number of IFTs and IAMs reported during the vigilance task, using the probe-caught method, did not differ across conditions. However, manipulation checks showed that participants’ inhibitory resources were reduced in the depleted inhibition condition, and participants were more tired in the experimental than in the control conditions. These initial findings suggest that neither inhibitory control nor physical and mental fatigue affect the frequency of IFTs and IAMs.Peer reviewedFinal Published versio

Multidrug resistant pulmonary tuberculosis treatment regimens and patient outcomes: an individual patient data meta-analysis of 9,153 patients.

Treatment of multidrug resistant tuberculosis (MDR-TB) is lengthy, toxic, expensive, and has generally poor outcomes. We undertook an individual patient data meta-analysis to assess the impact on outcomes of the type, number, and duration of drugs used to treat MDR-TB

AÇÕES EXTENSIONISTAS INTERDISCIPLINARES DESENVOLVIDAS COM MULHERES PRIVADAS DE LIBERDADE

Objective: this paper aims to report the health and feeding activities developed by project Accessibility and Health: Interdisciplinarity in Action and Food and Health subproject of the National Program for Professional Reorientation in Health with women deprived of liberty. Method: this is an interdisciplinary extensionist experience report, of qualitative - quantitative nature, carried out in the Women's State Prison in Rio Pardo, Rio Grande do Sul, from July to September 2022. The team works one morning a week with the women in situation of deprivation of freedom. An initial evaluation was carried out mapping socio-demographic data and health conditions by means of instruments: smoking addiction level (Fagerström Questionnaire), sleep quality (Pittsburgh Questionnaire), urinary incontinence (ICIQ-SF), and dietary assessment. Kinesiotherapy, mechanotherapy, nutrition and cooking workshops are held. Results: forty-seven women participated in the kinesiotherapy, with a mean age of 33.4 years, time of confinement between 7 days and 5 years, more than 70% were smokers, with a prevalence of high nicotine dependence, low education and overweight, 44.6% reported some clinical diagnosis, 59.5% reported pain, 65.5% reported use of medication, and 53.1% reported some treatment. The quality of sleep was predominantly good; however, 53.1% made continuous use of sleep inducers. In addition, 12 women reported urinary loss, 34 were pregnant, 50% had a cesarean section. Regarding food, 27 women answered, 81.48% reported liking the food prepared and served, however 59.25% reported post feeding discomfort and 37.03% constipation. Conclusion: Brazil has the fourth largest female prison population in the world. The legislation provides that the reintegration of women deprived of freedom into society must begin at the prison system, so that they can have opportunities for reintegration into society, thus, extensionist actions of this magnitude, in this reality and context are very important, because in addition to the benefits to the public, provides qualification and humanization in academic training. Keywords: Health; Penitentiary; Quality of life; Vulnerability.Objetivo: relatar as atividades de saúde e alimentação desenvolvidas pelo Projeto Acessibilidade e Saúde: Interdisciplinaridade em Ação e subprojeto Alimentação e Saúde do Programa Nacional de Reorientação Profissional em Saúde com mulheres privadas de liberdade. Método: trata-se de um relato de experiência extensionista interdisciplinar, de caráter quali-quantitativo, realizado no Presídio Estadual Feminino em Rio Pardo, Rio Grande do Sul, de julho a setembro de 2022. A equipe atua uma manhã por semana, junto às mulheres em situação de privação de liberdade. Foi realizada avaliação inicial mapeando dados sociodemográficos e condições de saúde por meio de instrumentos: nível de dependência tabágica (Questionário de Fagerström), qualidade do sono (Questionário de Pittsburgh), incontinência urinária (ICIQ-SF) e avaliação alimentar. São realizadas oficinas de cinesioterapia, mecanoterapia, nutrição e culinária. Resultados: participaram da cinesioterapia 47 mulheres com idade média de 33,4 anos e tempo de reclusão entre 7 dias e 5 anos, mais de 70% tabagistas com prevalência de alta dependência de nicotina, baixa escolaridade e sobrepeso, 44,6% relatou algum diagnóstico clínico, 59,5% quadro álgico, 65,5% uso de medicação e 53,1% algum tratamento. A qualidade do sono teve predominância em bom, entretanto 53,1% faz uso contínuo de indutores de sono. Além disso, 12 mulheres referiram perda urinária, 34 já estiveram grávidas, destas 50% realizaram cesariana. Quanto à alimentação, 27 mulheres responderam, destas 81,48% informou gostar da comida preparada e servida, todavia 59,25% referiu desconforto pós alimentação e 37,03% constipação. Conclusão: o Brasil apresenta a quarta maior população carcerária feminina mundial. A legislação prevê que a reintegração de mulheres privadas de liberdade na sociedade deve começar no sistema prisional, para que possam ter oportunidades de reinserção ao convívio social, sendo assim, ações extensionistas desta magnitude, nesta realidade e contexto são muito importantes, pois além dos benefícios ao público, propicia qualificação e humanização na formação acadêmica. Palavras-Chave: Saúde; Penitenciária; Qualidade de vida; Vulnerabilidade