Vitor Sousa

Anomalies in Wall Renders: Overview of the Main Causes of Degradation

The assessment of historical buildings is usually focused on: 1) structural features related to brick or stone walls, wooden floors and other structural elements, or 2) highly valued decorative features, such as frescoes, stuccos, and facade details. During the last quarter of the 20th century, some “secondary” elements also started to receive their share of attention from researchers and practitioners. Wall renders are one of the most important of such elements because of their role as a sacrificial protective layer and the numerous problems that were encountered in the past as a result of incompatibility issues in rehabilitation works. This article discusses the main causes of the deterioration of wall renders, with emphasis on lime-based renders; these renders thoroughly reviewed and their relative weight in the overall degradation is addressed.

Engineering risk management in performance-based building environments

AbstractNowadays, a wide range of stakeholders seek explicit performance and risk information on construction projects. These stakeholders include end-users, authorities, insurance companies and financial institutions, among others. They look for proof that engineering risks are being properly managed and that specified performance-based requirements are fulfilled throughout all stages of the project (e.g. technical requirements related to the building such as structural safety, structural serviceability, structural durability, fire safety, energy efficiency, or others). Such demonstration can be conveyed through statements of technical conformity, such as technical risk reports or engineering performance certificates. Statements of conformity are particularly valuable to make informed decisions associated with contractual or other legal warranties against building nonconformities. This paper describes the conceptual background and the methodologies undertaken to design and develop a management framework ...

Managing the technical risk of performance-based building structures

AbstractDuring the past decades, the construction industry has been gradually adhering to major conceptual approaches such as those of quality, performance and risk. This paper proposes a management framework that enables the joint application of these conceptual approaches throughout the various phases of building projects – a Risk-Managed Performance- Based Building (RM-PBB) framework. This framework is based on the policies, procedures and practices of initiatives that gather international consensus, including performance-based model codes and standards, internationally recognized management principles and guidelines, standardized requirements for different types of management systems and also agreed principles of conformity assessment and auditing. This paper presents a summary of the strategic and operational components of this RM-PBB management framework. It also shows the practical outreach of the proposed framework by providing an example of application of each component of the management framewor...

Comparison of the inspector and rating protocol uncertainty influence in the condition rating of sewers

Wastewater drainage systems asset management decisions, in particular regarding rehabilitation interventions, are largely dependent on close-circuit television (CCTV) inspection results. However, the results of CCTV inspections are affected by several sources of uncertainty. Within the present communication, the inspectors uncertainty is quantified by comparing periodic inspection reports from three trunk sewers of a Portuguese sewer system. The inspections were carried out by the same experienced inspector using the same equipment. Therefore, the uncertainties from the lack of experience and the difference of the inspector and equipment were ruled out. The protocol uncertainty is also quantified comparing the results obtained with the Water Research Center (WRc) and the National Research Council of Canada (NRC) protocols condition ratings. Both operational and structural condition rating were analysed, but emphasis was given to the later since it dictates the repair and replacement interventions.

Rosai-Dorfman disease manifesting as a mediastinal mass with calcifications.

Sinus histiocytosis with massive lymphadenopathy, also known as Rosai-Dorfman disease, is a rare entity predominantly affecting children and young adults, characterized in 95% of patients by painless bilateral cervical limphadenopathy. We report the case of a 30-year-old female with an anterior mediastinal mass due to lymph node enlargement, which showed calcifications on computed tomography. To our knowledge, calcification in lymphadenopathy, as is present in this case, has never been described in Rosai-Dorfman disease.

Model for the separate collection of packaging waste in Portuguese low-performing recycling regions

Separate collection of packaging waste (glass; plastic/metals; paper/cardboard), is currently a widespread practice throughout Europe. It enables the recovery of good quality recyclable materials. However, separate collection performance are quite heterogeneous, with some countries reaching higher levels than others. In the present work, separate collection of packaging waste has been evaluated in a low-performance recycling region in Portugal in order to investigate which factors are most affecting the performance in bring-bank collection system. The variability of separate collection yields (kg per inhabitant per year) among 42 municipalities was scrutinized for the year 2015 against possible explanatory factors. A total of 14 possible explanatory factors were analysed, falling into two groups: socio-economic/demographic and waste collection service related. Regression models were built in an attempt to evaluate the individual effect of each factor on separate collection yields and predict changes on the collection yields by acting on those factors. The best model obtained is capable to explain 73% of the variation found in the separate collection yields. The model includes the following statistically significant indicators affecting the success of separate collection yields: i) inhabitants per bring-bank; ii) relative accessibility to bring-banks; iii) degree of urbanization; iv) number of school years attended; and v) area. The model presented in this work was developed specifically for the bring-bank system, has an explanatory power and quantifies the impact of each factor on separate collection yields. It can therefore be used as a support tool by local and regional waste management authorities in the definition of future strategies to increase collection of recyclables of good quality and to achieve national and regional targets.

The Influence of the Construction Technology in Time-Cost Relationships of Sewerage Projects

Time-cost models have been developed in various contexts to assist in forecasting the duration of different types of projects. The present research explores the influence of the construction technology on the time-cost relationship. For that purpose, the data from 21 sewerage projects using trenchless technology and from 49 sewerage projects using the traditional open-cut method was analyzed. The 70 sewerage projects analyzed were completed in Chicago, U.S., between 1994 and 2002. The influence of the construction technology in the time-cost relationship was found to be statistically significant and time-relationships were determined for sewerage projects using trenchless technology and the traditional open-cut method. Furthermore, along with the Bromilow type models an alternative approach was tested using the time normalized by the project cost as dependent variable, allowing additional insight into the time performance of the open-cut and lining technology used (cured in place).

Heterogeneity in Lung Cancer

Lung cancer diagnosis is a challenge since it is also one of the most frequently diagnosed cancers. Diagnostic challenges are deeply related to the development of personalized therapy and molecular and precise histological characterizations of lung cancer. When addressing these features, it is very important to acknowledge the issue of tumour heterogeneity, as it imposes several questions. First of all, lung cancer is a very heterogeneous disease, at a cellular and histological level. Cellular and histological heterogeneity are addressed with emphasis on the diagnosis, pre-neoplastic lesions, and cell origin, trying to contribute to a better knowledge of carcinogenesis. Molecular intra-tumour and inter-tumour heterogeneity are also addressed as temporal heterogeneity. Lung cancer heterogeneity has implications in pathogenesis understanding, diagnosis, selection of tissue for molecular diagnosis, as well as therapeutic decision. The understanding of tumour heterogeneity is crucial and we must be aware of the implications and future developments regarding this field.

Modeling the Degradation Rate of the Wood Frame Doors and Windows of the National Palace of Sintra, Portugal

AbstractModeling the service life of building components is a key requirement for several purposes, including the implementation of an effective and efficient asset-management system, life-cycle assessments, or life-cycle cost calculations. Because the phenomena underlying the degradation of building components is highly complex, it is common to use statistical approaches for modeling purposes. This paper is focused on the statistical modeling of the service life of the wood frame doors and windows of the National Palace of Sintra. A review of the main factors of degradation of traditional linseed-based painted wood frame doors and windows and of the approaches that have been used to model the service life of building materials and components is presented. The influence of the exposure to weather agents on the degradation rate of external wood frame doors and windows is investigated and a model to estimate the average condition level is proposed. The proposed model takes into account radiation and wind-dr...

Risk assessment of sewer condition using artificial intelligence tools: application to the SANEST sewer system

Operation, maintenance and rehabilitation comprise the main concerns of wastewater infrastructure asset management. Given the nature of the service provided by a wastewater system and the characteristics of the supporting infrastructure, technical issues are relevant to support asset management decisions. In particular, in densely urbanized areas served by large, complex and aging sewer networks, the sustainability of the infrastructures largely depends on the implementation of an efficient asset management system. The efficiency of such a system may be enhanced with technical decision support tools. This paper describes the role of artificial intelligence tools such as artificial neural networks and support vector machines for assisting the planning of operation and maintenance activities of wastewater infrastructures. A case study of the application of this type of tool to the wastewater infrastructures of Sistema de Saneamento da Costa do Estoril is presented.