Characterization of a Hygro-Regulated Wall Base Ventilation System for Treatment of Rising Damp

2012 ◽  
Vol 326-328 ◽  
pp. 54-59 ◽  
Author(s):  
A.S. Guimarães ◽  
João M.P.Q. Delgado ◽  
V.P. de Freitas
Keyword(s):  
Experimental Research ◽  
Ventilation System ◽  
Experimental Studies ◽  
Salt Crystallization ◽  
Historical Buildings ◽  
New Approach ◽  
Physics Laboratory ◽  
Building Physics ◽  
Rising Damp

The treatment of rising damp in the walls of historical buildings is very complex, due to the thickness and heterogeneity of the walls. The techniques traditionally used for dealing with this problem (such as watertight barriers, injection of hydrofuge products, etc.) have sometimes proved ineffective, and that is why it is necessary to find a new approach. In recent years, the Building Physics Laboratory at the Faculty of Engineering, University of Porto has been conducting experimental research on the effectiveness of the wall base ventilation system, using natural or mechanical higro-regulate systems to reduce the level of the damp area. This experimental research and the simulations that were performed, clearly show that wall base ventilation is a system with potential. This paper presents the characterization of the hygro-regulated systems operation based on experimental studies developed in laboratory, which allowed the influence of the velocity of the air, condensation risk and the possibility of salt crystallization.

scholarly journals Degradation Control of Walls with Rising Damp Problems

2013 ◽  
Vol 334-335 ◽  
pp. 31-36 ◽  
Author(s):  
A.S. Guimarães ◽  
João M.P.Q. Delgado ◽  
V.P. de Freitas
Keyword(s):  
Moisture Transfer ◽  
Ventilation System ◽  
Experimental Studies ◽  
Complex Problem ◽  
Treatment Technique ◽  
Historical Building ◽  
Treatment Techniques ◽  
New Treatment ◽  
Building Physics ◽  
Rising Damp

Degradation in walls of Historical Building with rising damp is a complex problem to solve, due to the thickness and heterogeneity of those walls. The traditionally treatment techniques used (such as watertight barriers, injection of hydrofuge products, etc.) show, sometimes, to be ineffective or too expensive, justifying the need to find a new approach. Experimental studies validate the effectiveness of a new treatment technique applied to the walls of old buildings wall base ventilation system. Building Physics Laboratory (LFC) is developing a model of this technique. The sizing of the treatment system is based on knowledge of the characteristics of the wall, of the geometry of the ventilation system and of the building being dealt with. In this work it is described the moisture transfer process between the moving air flux, inside the system, and the wall. Experimental results were used to validate the mathematical solution and the values obtained are very similar.

scholarly journals Tratamento da humidade ascensional no património histórico

2014 ◽  
Vol 4 (1) ◽  
pp. 1-12 ◽  
Author(s):  
V. P. De Freitas ◽  
A. S. Guimarães
Keyword(s):  
Experimental Research ◽  
Treatment System ◽  
Historical Building ◽  
Physics Laboratory ◽  
Advantages And Disadvantages ◽  
Treatment Techniques ◽  
Building Physics ◽  
The University ◽  
Rising Damp

RESUMOA humidade ascensional associada aos sais é um fator de degradação das paredes dos edifícios antigos, pelo que se exige o conhecimento do seu comportamento higrotérmico, bem como o conhecimento das técnicas de tratamento e da sua eficácia. O tratamento, face à humidade ascensional, é muito complexo e muitas das técnicas para solucionar o problema não apresentem a eficácia desejável. O Laboratório de Física das Construções da Faculdade de Engenharia da Universidade do Porto tem desenvolvido investigação numérica e experimental que permitiu validar uma tecnologia baseada na ventilação higroregulável da base das paredes para tratar a humidade ascensional, patenteando o sistema – HUMIVENT. Nesta comunicação descrevem-se as patologias associadas à humidade ascensional; as vantagens e inconvenientes das tecnologias disponíveis no mercado para o seu tratamento; caracteriza-se o sistema – HUMIVENT, a sua implementação em edifícios em Portugal e a análise dos resultados obtidos.Palavras chave: humidade ascensional; património histórico; sistema higroregulável.ABSTRACTRising damp linked with the salts is a factor in old buildings walls degradation, which requires knowledge of its higrothermal behavior, as well as the treatment techniques and its effectiveness knowledge. The rising damp treatment is very complex and many of the techniques to solve the problem do not show the desirable effectiveness. The Building Physics Laboratory of the Faculty of Engineering of the University of Porto has developed numerical and experimental research that allowed the validation of a technology based on the wall base hygroregulated ventilation to treat rising damp, patent the system-HUMIVENT. This paper aims to describe the pathologies associated to rising damp; the advantages and disadvantages of the most common available technologies for its treatment; characterize the rising damp treatment system-HUMIVENT, their implementation in Portuguese buildings and the analysis of the obtained results.Keywords: rising damp; historical building; hygroregulated system.

Case Studies of Rising Damp Treatment in Historical Buildings

2017 ◽  
Vol 10 ◽  
pp. 107-119
Author(s):  
A.S. Guimarães ◽  
J.M.P.Q. Delgado ◽  
V.P. de Freitas
Keyword(s):  
Building Materials ◽  
Ventilation System ◽  
Technical Specification ◽  
Residential Building ◽  
Ventilation Rate ◽  
Building Structures ◽  
Practical Application ◽  
Salt Damage ◽  
Building Physics ◽  
Rising Damp

Salt damage can affect the service life of numerous building structures, both historical and contemporary, in a significant way. Therefore, various conservation methods have been developed for the consolidation and protection of porous building materials exposed to the salt attack. As any successful treatment of salt damage requires a multidisciplinary attitude, many different factors such as salt solution transport and crystallization, presence and origin of salts in masonry, and salt-induced deterioration are to be taken into account. The importance of pre-treatment investigations is discussed as well; in a combination with the knowledge of salt and moisture transport mechanisms they can give useful indications regarding treatment options.Another important cause of building pathologies in buildings is the rising damp and this phenomenon it is particularly more severe with the presence of salts in water. The treatment of rising damp in historic building walls is a very complex procedure. At Laboratory of Building Physics (LFC-FEUP) a wall base hygro-regulated ventilation system was developed. This system patented, HUMIVENT, has been submitted to laboratorial monitoring and to in situ validation and a numerical simplified model was developed to facilitate the practical application. Having in mind the practical application of scientific and technological knowledge from Building Physics to practice, this paper presents the design of the system (geometry, ventilation rate and hygrothermal device), the detailing and technical specification of its different components and information about the implementation in three types of buildings: a church, a museum and a residential building.

scholarly journals Salt Damage and Rising Damp Treatment in Building Structures

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
J. M. P. Q. Delgado ◽  
A. S. Guimarães ◽  
V. P. de Freitas ◽  
Iñigo Antepara ◽  
Václav Kočí ◽  
...  
Keyword(s):  
Building Materials ◽  
Environmental Control ◽  
Treatment Options ◽  
Ventilation System ◽  
Mineral Wool ◽  
Building Structures ◽  
Salt Damage ◽  
Complex Procedure ◽  
Building Physics ◽  
Rising Damp

Salt damage can affect the service life of numerous building structures, both historical and contemporary, in a significant way. In this review, various damage mechanisms to porous building materials induced by salt action are analyzed. The importance of pretreatment investigations is discussed as well; in combination with the knowledge of salt and moisture transport mechanisms they can give useful indications regarding treatment options. The methods of salt damage treatment are assessed then, including both passive techniques based on environmental control, reduction of water transport, or conversion to less soluble salts and active procedures resulting in the removal of salts from deterioration zones. It is concluded that cellulose can still be considered as the favorite material presently used in desalination poultices but hydrophilic mineral wool can serve as its prospective alternative in future applications. Another important cause of building pathologies is the rising damp and, in this phenomenon, it is particularly severe considering the presence of salts in water. The treatment of rising damp in historic building walls is a very complex procedure and at Laboratory of Building Physics (LFC-FEUP) a wall base hygroregulated ventilation system was developed and patented.

Numerical Simulation of Rising Damp Phenomenon

2012 ◽  
Vol 326-328 ◽  
pp. 48-53 ◽  
Author(s):  
A.S. Guimarães ◽  
João M.P.Q. Delgado ◽  
V.P. de Freitas
Keyword(s):  
Numerical Simulation ◽  
Boundary Conditions ◽  
Direct Contact ◽  
Moisture Transfer ◽  
Historical Buildings ◽  
Soluble Salts ◽  
Water Absorption Coefficient ◽  
Fraunhofer Institute ◽  
Building Physics ◽  
Rising Damp

The treatment of rising damp in historical buildings walls is very complex. Moisture transfer in walls of old buildings, which are in direct contact with the ground, leads to a migration of soluble salts responsible for many building pathologies. The present work describes an extensive numerical analyse of rising damp phenomenon, using the software WUFI-2D, developed by Fraunhofer Institute for Building Physics. The results show that the numerical simulation describes very well the rising damp front for different boundary conditions and materials. The influence of the wall thickness, boundary conditions, composition of walls and material properties, such as, porosity and water absorption coefficient were analysed in detail.

A new approach to treatment of stomatitis in experiments on white rats (experimental research)

2018 ◽  
pp. 168-173
Author(s):  
Е.Б. Ганина ◽  
Ю.В. Червинец ◽  
Н.В. Грудинин ◽  
В.Г. Шестакова ◽  
В.М. Червинец ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Oral Cavity ◽  
Experimental Research ◽  
Quantitative Composition ◽  
Oral Diseases ◽  
New Approach ◽  
Highly Active ◽  
White Rats ◽  
Before And After ◽  
Intact Rats

Цель исследования - охарактеризовать микробиологическую картину стоматита до и после его лечения высокоактивными культурами лактобацилл, дать оценку эффективности их применения при экспериментальном стоматите. Методика. Опыты проводились на 32 самках беспородных белых крыс массой 230 г. Моделирование стоматита включало 2 этапа: моделирование травматического стоматита и воспроизведение бактериального стоматита на базе травматического. У крыс контрольной и опытных серий на всех этапах эксперимента брали мазки с поверхности десен для характеристики микробиоценоза ротовой полости. Результаты. После обработки слизистой оболочки полости рта (СОПР) культурой патогенного штамма Staphylococcus aureus существенно снизились частота встречаемости и количество условно-патогенных микроорганизмов. Лечение стоматита у крыс культурами лактобацилл ( Lactobacillus 11 зв., Lactobacillus 2 п.рта, Lactobacillus 24 д.ст.) и их комбинацией приводило к снижению распространенности S. aureus вплоть до его исчезновения, а также к нормализации количества условно-патогенной микробиоты. Заключение. Исследования показали эффективность использования отдельных высокоактивных штаммов лактобацилл или их комбинации при лечении заболеваний СОПР, в частности бактериального стоматита. Aim. To characterize the microbiological picture of stomatitis in intact rats before and after the treatment with highly active cultured lactobacilli and to evaluate the effectiveness of this treatment in experiments on white rats. Methods. Experiments were carried out on 32 mongrel female white rats weighing 230 g. Smears were taken from the gum surface of control and experimental rats at all stages of the experiment to characterize the oral cavity microbiocenosis. Results. After treatment of the oral cavity with cultured Staphylococcus aureus , the occurrence and quantity of opportunistic microorganisms significantly decreased. The treatment of stomatitis in rats with cultured lactobacillus ( Lactobacillus 11 zv., Lactobacillus 2 p.r., Lactobacillus 24 d.st. and their combination) led to a decrease in S. aureus prevalence up to its extinction and to normalization of the quantitative composition of opportunistic microbiota. Conclusions. The study showed the effieacy of highly active lactobacillus strains individually or their combinations in the treatment of oral diseases, in particular, bacterial stomatitis.

scholarly journals Sustainability Investigation of Vehicles’ CO2 Emission in Hungary

2021 ◽  
Vol 13 (15) ◽  
pp. 8237
Author(s):  
István Árpád ◽  
Judit T. Kiss ◽  
Gábor Bellér ◽  
Dénes Kocsis
Keyword(s):  
Energy Efficiency ◽  
Co2 Emissions ◽  
Energy Supply ◽  
Internal Combustion Engines ◽  
Combustion Engines ◽  
The European Union ◽  
New Approach ◽  
Technology System ◽  
Low Co2

The regulation of vehicular CO2 emissions determines the permissible emissions of vehicles in units of g CO2/km. However, these values only partially provide adequate information because they characterize only the vehicle but not the emission of the associated energy supply technology system. The energy needed for the motion of vehicles is generated in several ways by the energy industry, depending on how the vehicles are driven. These methods of energy generation consist of different series of energy source conversions, where the last technological step is the vehicle itself, and the result is the motion. In addition, sustainability characterization of vehicles cannot be determined by the vehicle’s CO2 emissions alone because it is a more complex notion. The new approach investigates the entire energy technology system associated with the generation of motion, which of course includes the vehicle. The total CO2 emissions and the resulting energy efficiency have been determined. For this, it was necessary to systematize (collect) the energy supply technology lines of the vehicles. The emission results are not given in g CO2/km but in g CO2/J, which is defined in the paper. This new method is complementary to the European Union regulative one, but it allows more complex evaluations of sustainability. The calculations were performed based on Hungarian data. Finally, using the resulting energy efficiency values, the emission results were evaluated by constructing a sustainability matrix similar to the risk matrix. If only the vehicle is investigated, low CO2 emissions can be achieved with vehicles using internal combustion engines. However, taking into consideration present technologies, in terms of sustainability, the spread of electric-only vehicles using renewable energies can result in improvement in the future. This proposal was supported by the combined analysis of the energy-specific CO2 emissions and the energy efficiency of vehicles with different power-driven systems.

scholarly journals BIM for Existing Construction: A Different Logic Scheme and an Alternative Semantic to Enhance the Interoperabilty

2021 ◽  
Vol 11 (4) ◽  
pp. 1855
Author(s):  
Franco Guzzetti ◽  
Karen Lara Ngozi Anyabolu ◽  
Francesca Biolo ◽  
Lara D’Ambrosio
Keyword(s):  
Project Management ◽  
Building Information Modeling ◽  
Information Modeling ◽  
Historical Buildings ◽  
Architectural Heritage ◽  
New Approach ◽  
Building Information ◽  
Heritage Building ◽  
New Construction

In the construction field, the Building Information Modeling (BIM) methodology is becoming increasingly predominant and the standardization of its use is now an essential operation. This method has become widespread in recent years, thanks to the advantages provided in the framework of project management and interoperability. Hoping for its complete dissemination, it is unthinkable to use it only for new construction interventions. Many are experiencing what happens with the so-called Heritage Building Information Modeling (HBIM); that is, how BIM interfaces with Architectural Heritage or simply with historical buildings. This article aims to deal with the principles and working methodologies behind BIM/HBIM and modeling. The aim is to outline the themes on which to base a new approach to the instrument. In this way, it can be adapted to the needs and characteristics of each type of building. Going into the detail of standards, the text also contains a first study regarding the classification of moldable elements. This proposal is based on current regulations and it can provide flexible, expandable, and unambiguous language. Therefore, the content of the article focuses on a revision of the thinking underlying the process, also providing a more practical track on communication and interoperability.

Synthesis and characterization of L-threonine ammonium bromide: grown on single crystal with experimental studies on NLO

2021 ◽  
Vol 44 (3) ◽  
Author(s):  
T KALAIARASI ◽  
M SENTHILKUMAR ◽  
S SHANMUGAN ◽  
T JARIN ◽  
V CHITHAMBARAM ◽  
...  
Keyword(s):  
Single Crystal ◽  
Experimental Studies ◽  
Synthesis And Characterization ◽  
Ammonium Bromide

scholarly journals An Intrinsic Characterization of Five Points in a CAT(0) Space

2020 ◽  
Vol 8 (1) ◽  
pp. 114-165
Author(s):  
Tetsu Toyoda
Keyword(s):  
Metric Space ◽  
Isometric Embedding ◽  
Metric Spaces ◽  
Necessary Conditions ◽  
New Approach ◽  
Intrinsic Characterization ◽  
New Family

AbstractGromov (2001) and Sturm (2003) proved that any four points in a CAT(0) space satisfy a certain family of inequalities. We call those inequalities the ⊠-inequalities, following the notation used by Gromov. In this paper, we prove that a metric space X containing at most five points admits an isometric embedding into a CAT(0) space if and only if any four points in X satisfy the ⊠-inequalities. To prove this, we introduce a new family of necessary conditions for a metric space to admit an isometric embedding into a CAT(0) space by modifying and generalizing Gromov’s cycle conditions. Furthermore, we prove that if a metric space satisfies all those necessary conditions, then it admits an isometric embedding into a CAT(0) space. This work presents a new approach to characterizing those metric spaces that admit an isometric embedding into a CAT(0) space.

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