Outdoor Walls Research Articles

NOx Abatement by a TiO2-Based Coating under Real-Life Conditions and Laboratory-Scale Durability Assessment

In urban environments, various pollutants generated by road traffic, human, and industrial activities degrade outdoor and indoor air quality. Among these pollutants, nitrogen oxides (NOx) are subject to air quality regulations designed to protect human health and the environment. It is therefore crucial to keep their concentration as low as possible. Advanced oxidation processes are a practical choice for the degradation of NOx; among them, heterogeneous photocatalysis has proven to be a viable route. However, while the efficiency of this process has been widely demonstrated on a laboratory scale, it is still the subject of debate for real-life applications. The purpose of this study was to present a new field experiment on the application of a photocatalytic coating to outdoor walls. Air quality monitoring stations were used to evaluate the NOx concentration reduction instead of the chemiluminescent analyzer, in order to increase the number of sampling points. Statistical analysis was carried out to interpret the results. Density probability functions were plotted and showed a positive impact of the coating, leading to lower NOx concentrations. This work was completed by a laboratory-scale assessment of the coating’s durability using abrasion, QUV, and immersion/drying tests. The air depollution capacity of the chosen coating was significantly reduced after QUV testing.

A review of the use of infrared thermography in building envelope thermal property characterization studies

International standards used to carry out building envelope energy audits such as ISO 9869 rely on using heat flux meters (HFM) and temperature sensors on indoor and outdoor walls in-situ as inputs in calculations to determine thermal properties. Obtaining these measurements may be restrictive, expensive, and time-consuming. By contrast, obtaining temperature measurements using infrared thermography (IRT) is accessible, inexpensive, and quick. For these reasons, an auditing methodology which could solely use IRT to perform most building audits would be beneficial on many fronts. However, this practice is unfavored as it is viewed as being unprecise and involves considering numerous environmental factors which may be inaccurate and difficult to model. The present review article serves as a critical analysis of measurement techniques and models currently used in energy auditing research, detailing their advantages, drawbacks, and accuracy, and examines how, with improvements in methodology and with proper environmental modeling, IRT imagery could be used in place of HFM in building envelope auditing standards such as ISO 9869, potentially saving time, effort, and costs in related research and commercial activities.

Potential Beneficiation of Readily Available Gold Tailings and Paper Wastes: Development of a New Building Material

Gold mine tailings (GMT) generated from gold mining processes are readily available in South Africa. The generated GMT is disposed to the environment by land filling. This occupies considerable land area, which subsequently results into environmental pollution. Numerous industries use paper for a number of applications on daily basis and its generation is inevitable. Unrecycled paper ends up in the landfill, which has a negative impact on the environment, as it is not degradable. This study investigated the blending of GMT and waste paper for the production of building bricks (papercrete). The chemical composition of GMT in terms of elemental, mineralogy and micrograph before and after paper stabilization was examined. Developed composites were cured for 7, 14, 21, 28 days, and the unconfined compressive strength (UCS) and absorption tests were conducted. The results obtained showed an improvement in both the UCS and the water absorption of the bricks with the increment in curing period. The brick cured for 28 days had the highest UCS of 7.76 MPa and the lowest water absorption of 80.43% when compared to the bricks cured for 7,14 and 21 days. The developed papercrete was relatively light in weight; however, they proved not to be suitable for outdoor walls and water logging areas due to their high capability to absorb water.

Photodynamic Inhibition of Biofilm Forming Microorganisms on Surfaces

Microorganisms play an important role in our everyday life and in an ecological context. While a great number of species provide a benefit to humans, some of them can be terribly harmful due to the diseases they trigger. To remove or hinder those unwanted microorganisms has been a goal since their discovery. There are classical approaches to accomplish that, but the adaptability of microorganisms – especially the alarming development of antibiotic resistant strains - always calls for new methods. Once microorganisms grow in biofilms they are hard to come by and inadvertently spread infections are a fatal risk for immunodeficient people. Photodynamic Inactivation (PDI) has good potential as antimicrobial agent, which avoids most of aforementioned problems. Singlet oxygen is a highly reactive molecule against which there has been no development of countermeasures in biological systems besides provision of quenching molecules inside the cells. Therefore there is also little to no risk of resistance development when using PDI against microorganisms. Easy availability of light and oxygen in many of the potential target sites are just some advantages of PDI. Even though much less often associated with maladies, fungi can be similarly harmful. Due to their asexual life cycle and sporulation they are more robust against changes in environmental conditions. Their high robustness requires highly toxic biocides which in turn come with the risk of damaging the environment. Even seemingly, harmless microorganisms like algae and cyanobacteria show increasing tendencies to harm humans directly or indirectly and in symbiosis with fungi, they form even more resistant lichen, which pose new challenges concerning their removal. Biofilms on outdoor walls cause aesthetic problems and economic damage. Therefore, wall colors are often mixed with conventional biocides. However, biocides are increasingly designed towards higher efficacy while remaining environmentally persistent. This combination implies serious toxicity problems for all living organisms and whole ecosystems. Thus, an eco-friendly and non-harmful to human health alternative to conventional biocides in wall color is strongly recommended. The well-known photosensitizer TMPyP was used as an additive in commercially available facade paint. The generation of singlet molecular oxygen was shown using time resolved 2D measurements of the singlet oxygen luminescence. The photodynamic activity of the photosensitizer in the facade paint was demonstrated by phototoxicity tests with defined mold fungi and a mixture of microorganisms harvested from native outdoor biofilms as model organisms. Phototrophic biofilms are an important factor in biofouling and biodeterioration of building materials. The aim of this study was to examine the potential of PDI through generation of singlet oxygen as a possible alternative to biocides preventing the growth and formation of biofilms of these phototrophic organisms. Four photosensitizers were investigated according to their photoinhibitive effect on two strains of green algae using visible light for photoexcitation. The two anionic photosensitizers showed no significant phototoxicity whereas the two cationic photosensitizers caused a drastic reduction of biomass on a short time scale and also displayed long term inhibition of algae growth. Furthermore, to investigate the intrinsic mechanisms of PDI we studied the singlet oxygen luminescence kinetics - a method that proved to be a very effective approach towards understanding mechanisms on a cellular level. Here we present the first two-dimensional measurement of singlet oxygen kinetics in phototrophic microorganisms on surfaces during PDI. We established a system of reproducible algae samples on surfaces, incubated with two different cationic, antimicrobial potent photosensitizers. Fluorescence microscopy images indicate that one photosensitizer localizes inside the green algae while the other accumulates along the outer algae cell wall. A newly developed setup allows for the measurement of singlet oxygen luminescence on the green algae sample surfaces over several days. The kinetics of the singlet oxygen luminescence of both photosensitizers show different developments and a distinct change over time, corresponding with the differences in their localization as well as their photosensitization potential. While the complexity of the signal reveals a challenge for the future, this study incontrovertibly marks a crucial, inevitable step in the investigation of photodynamic inactivation of biofilms: it shows the feasibility of using the singlet oxygen luminescence kinetics to investigate photodynamic effects on surfaces and thus opens a field for numerous investigations. Figure 1

A City of Walls. A Photo Essay on Writing on Walls in Alexandria, 2011-2017

Outdoor walls of Alexandria are full of writings. Stencil graffiti, sprayed messages, painted advertisements, ball-pen notes, stickers and billboards create a mostly anonymous conversation of different messages struggling for space, mostly transient and at times poetic. Especially political graffiti during and after the 2011 revolution became the site of an often uncivil debate made up of deletions, crossings-out and changes to graffiti by others. But also love messages, religious phrases and advertisement have important messages to tell.The writings on the cityʼs three-dimensional walls often mingle with the metaphorical walls of social media feeds as inhabitants of the city are engaged in poetic, transient conversations and commentary on their phones while they move through their city. Sometimes the different poetics and materialities of wall-writing also converge when social media mimes reproduce or simulate photos of graffiti.In Alexandria today, both ways to write on walls are common and productive of spaces and social relations in the city. These forms of everyday textual conversation and presence push the limits of conventional understandings of literary vs. ordinary language. They also tell important stories of the coexistence of different visions and ways of life in a plural but not pluralistic city.

Thermal Improvement in Residential Buildings in View of the Indoor Air Quality – Case Study for Polish Dwelling

Abstract The widespread thermal improvement in residential buildings involves not only the insulation of outdoor walls but also window replacement. In Poland it is the residents of individual premises who manage the replacement and in order to keep their heating bills low, they seek airtight solutions to minimize the cooling of premises due to air infiltration. In this situation the indoor air quality is not considered at all and no exchange of used air and fresh air occurs. Unawareness on the part of residents and the increased costs of replacing the windows which need additional devices to ensure the inflow of air are the main reason for the deteriorating microclimate conditions in residential dwellings. The present paper demonstrates the measurement of indoor air quality, the building leakage test and the measurement of air flow in exhaust opening a four-bedroom dwelling located in Gliwice, Poland. In order to evaluate the air exchange within a longer period and in different outdoor climate conditions, the measurements were supplemented with numerical simulation of ventilating airflows. Modifications to improve the indoor air quality in the examined flat were also suggested.

Web Monitoring Temperature Ruangan berbasis Arduino Uno R3 dengan Fuzzy Logic

This study aims to develop a prototype system of control and monitoring of temperature, humidity and light automatic room with fuzzy logic-based Arduino Uno Rev. 3. The prototype built will be able to perform the function of monitoring the temperature of the room, light and moisture. This function can be accessed through the web pages and the internet, simultaneously displayed on the outdoor walls of the data center with 20x2 LCD size.

Photodynamic inactivation of biofilm building microorganisms by photoactive facade paints

This study was performed as a proof of concept for singlet oxygen generating facade paint as an alternative to conventional biocide containing facade paint for the prevention of biofilm growth on outdoor walls.Biofilms on outdoor walls cause esthetic problems and economic damage. Therefore facade paints often contain biocides. However commercially available biocides may have a series of adverse effects on living organisms as well as harmful environmental effects. Furthermore, biocides are increasingly designed to be more effective and are environmentally persistent. Thus, an eco-friendly and non-harmful to human health alternative to conventional biocides in wall color is strongly recommended.The well-known photosensitizer 5,10,15,20-tetrakis(N-methyl-4-pyridyl)-21H,23H-porphine (TMPyP) was used as an additive in a commercially available facade paint. The generation of singlet molecular oxygen was shown using time resolved 2D measurements of the singlet oxygen luminescence. The photodynamic activity of the photosensitizer in the facade paint was demonstrated by phototoxicity tests with defined mold fungi and a mixture of microorganisms harvested from native outdoor biofilms as model organisms.It was proven in general that it is possible to inhibit the growth of biofilm forming microorganisms growing on solid wall paint surfaces by the cationic photosensitizer TMPyP added to the facade paint using daylight conditions for illumination in 12h light and dark cycles.

(Invited) Photodynamic Inactivation of Natural Environmental Biofilm Forming Microorganisms on Surfaces

Biofilms on outdoor walls cause aesthetic problems and economic damage. Therefore, facade paints often-containing biocides. However, commercial available biocides may have a series of adverse effects on living organisms as well as harmful environmental effects. Furthermore, biocides are increasingly designed to be more effective and are environmentally persistent. Thus, an eco-friendly and non-harmful to human health alternative to conventional biocides in wall color is strongly recommended. This study was performed as a proof of concept for singlet oxygen generating facade paint as an alternative to conventional biocide containing facade paint for the prevention of biofilm growth on outdoor walls. The well-known photosensitizer 5,10,15,20-tetrakis(N-methyl-4-pyridyl)-21H,23H-porphine (TMPyP) was used as an additive in a commercially available facade paint. The generation of singlet molecular oxygen was shown using time resolved 2D measurements of the singlet oxygen luminescence. Using phototoxicity tests, we demonstrated the photodynamic activity of the photosensitizer against defined mold fungi and a mixture of microorganisms harvested from native outdoor biofilms on surfaces. It was proven in general that it is possible to inhibit the growth of biofilm forming microorganisms growing on solid wall paint surfaces by the cationic photosensitizer TMPyP added to the facade paint using daylight conditions for illumination in 12 hours light and dark cycles. Figure: Singlet oxygen luminescence scan of microorganisms incubated with the PS with TMPyP. The intensity plot, which is overlayed with the picture of the sample, shows the amplitude of singlet oxygen luminescence Figure 1

Messages of allegiance and defiance: the murals of Gaza

Behind the iron grip which Israel maintains on the Gaza Strip, there exists a vibrant tradition of painting murals and graffiti on outdoor walls. The origins and contemporary form of this tradition are considered in this article. The painting of murals and graffiti in the West Bank and the Gaza Strip has its roots in the first intifada which began in 1987. As part of the resistance to Israeli occupation and repression, young people, at great personal risk, mobilised popular support through their clandestine artwork. The second intifada, beginning in 2000, saw the rise of Hamas as a force to be reckoned with, not least in terms of the increasing sophistication of its murals and graffiti, which paid special attention to calligraphy. Finally, with the departure of Israeli soldiers and settlers in 2005 and the takeover of Hamas in the Gaza Strip in 2007 this organisation came to dominate the walls. Murals in Gaza today cover a number of themes: Israeli oppression, Palestinian resistance, martyrs, prisoners and Palestinian aspirations – in particular, freedom and statehood, and the right to return.

Durability considerations of refurbished external walls

The paper present results of the European project Sustainable Refurbishment of Building Facades and External Walls. The objective of the research was to analyse the durability of refurbished outdoor walls on the bases of building-physical analyses and estimate the benefits of refurbishment on concrete façade. All analyses were made for concrete walls in Nordic conditions when an exterior insulation layer is added. The major part of building envelope failures was caused by excessive moisture content of building materials. This topic has a high industrial relevance and the results can be utilised as recommendations for refurbishment projects.

Optimisation of Raman analysis of walnut oil used as protective coating of Galician granite monuments

AbstractIn the middle of last century, many valuable monuments of the Galician cultural heritage showed disintegration of the granite in the outdoor walls due to chemical erosion. To repair and conserve the stone from further deterioration, restorers decided to apply protective coatings that might act as consolidants and as hydrofugants. It is important to study these coatings in order to understand the processes that affect their conservation and deterioration and to design protocols for any future restoration action that might be necessary. Raman spectroscopy presents several advantages for this kind of application since it is a versatile technique, does not need sample preparation and provides a non‐destructive method. In this work, different types of walnut oil are analysed. A comparative study was performed using five different laser excitation wavelengths, and 532 and 488 nm turned out to be the most appropriate wavelengths for oil detection on aluminium substrates. Additionally, Raman spectroscopy allows the study of the evolution of the treatment once applied, as well as the determination of the curing times and chemical transformation. Raman analysis of walnut oil over Roan granite using excitation at both 532 and 488 nm are viable for in situ testing, but 532 nm offers higher sensitivity. Copyright © 2010 John Wiley & Sons, Ltd.

폐기물 재활용성 향상을 위한 리모델링 철거공사의 시공성 평가 및 사례적용

From now on, the aged apartment or house is expected to increase rapidly. So, we have to build a process of remodeling and develop the new technique. Demolition work is needed for systematic plan and management. However, contractors of the remodeling project established a rough plan and did not consider recycling wastes, safety of workers and structural stability of building. Therefore, we need a step to develop a assessment system, verify and make specified. This paper evaluated how much improve on construction speed, work efficiency, intensity of work and influence with another process comparing the existing method with the new demolition method. The qualitative and quantitative assessment system are developed with these output. The case study was carried out experimental group and control group, based on developed assessment system, which have the same condition. The existing method was made up of 3 steps- 1)Demolish windows, doors and iron goods, 2)Demolish indoor and outdoor walls, 3)Drop the waste. The new demolition method was made up of 5 steps- 1)Demolish windows, doors and iron goods, 2)Demolish the ceiling and wall`s finishing materials, 3)Demolish the floor`s finishing materials, 4)Demolish indoor and outdoor walls, 5)Drop the waste. Work time, idle time, the character of a work unit are analyzed by mock-up test. This study`s output is expected to establish a systematic process of new demolition method and based on the maximizing waste recycling work in our construction industry.

Spiders (Araneae) of the selected synanthropic environments in Lublin City

Material collected in the area of Lublin City in typical synanthropic environments were worked out.Collected species, depending on the level of attachment, were classified to 3 ecological groups: eusynanthropic species, hemisynanthropic and asynanthropic ones. The difference in frequency of occurring and numbers of many species were noticed, depending on the type of synanthropic environment. It was observed that outdoor walls of buildings were eagerly inhabited by species, which are associated with bark in natural conditions. This suggests that those species may supply the groups of synanthropic spiders in the future. Among 97 spiders recorded, the occurrence of Dipoena torva (TH.) and Leptorchestes berolinensis (C.L.K.) – very rare species in Poland and Central Europe – was worth mentioning. It was also found, that Achaearanea tabulata LEVI is a stable and common element of Polish arachnofauna.

Durability Improvement of Ancient Bricks by Cementation of Porous Media

The physicomechanical properties of historic bricks in Toledo (Spain) that have undergone a time-dependent self-healing by natural weathering processes have been improved by porous infill with gypsum, ettringite, and, mainly, calcite. Both these bricks and their experimental replica bricks, made from the original calcareous clays fired at the appropriate historical temperatures (700°–900°C), have been analyzed by X-ray diffraction, optical and scanning electron microscopy, mercury intrusion porosimetry, and ultrasound velocities to compare pore structure and strength evolution by mineral cementation. The resultant microstructure and mineral fillings depend on the brick calcareous composition and firing temperature, the brick location environment, burial, indoor or outdoor walls, the lime-based joint mortars and coat plasters, and infiltration waters.