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Birds are implicated in spoiling and decay of buildings, especially through their droppings. Pigeons are considered the main culprits, and several studies have examined the effects and chemistry of accumulations of droppings without evidence to the exact origins of the source of the excreta. The paper aims to discuss these issues.

This study reviews and summarises the state of knowledge with regard to the impact of bird excreta on buildings. It experimentally assesses the acidity of fresh pigeon excreta with different diets and examines the development of the acidity of the excreta after voiding.

Feral pigeons in urban settings are known to be fed by a range of foods. Urban food scraps-derived diets produce more acidic excreta than more natural diets such as seeds. This is a first study of its kind to examine the impact of a bird’s diet on the pH and thus the resulting (potential) decay of masonry.

This study showed that from a management’s perspective, pigeons that subsist entirely on human provided foods will be depositing more initially acidic faeces. If faecal accumulation occurs; then, mould and other bacteria quickly alter the chemistry from acidic towards basic, but the damage may already be done.

This paper is the first study of its kind to examine the effects of fresh pigeon droppings of known origin and age once voided from the intestine. This allows the authors to assess the impact during the first few days.

The purpose of this paper is to study the influence of rhamnolipid biosurfactant complex on the corrosion and the repassivation of a freshly cut Al-Cu-Mg aluminium alloy surface.

The electrochemical methods, supported by quantum-chemical calculations and scanning electron microscopy data, were used.

It was established that the rhamnolipid biosurfactant effectively inhibits corrosion of the alloy in synthetic acid rainwater. The efficiency of inhibition becomes stronger with the increase of biosurfactant concentration; however, above the critical micelle concentration, the further improvement in inhibition is minor. It is believed that the mechanism of corrosion inhibition is related to the adsorption of the biosurfactant molecule on the aluminium alloy surface and the formation of a barrier film; however, the formation of a complex compound (salt film) between aluminium ions and rhamnolipid on anodic sites of the alloy is not ruled out. In case of surface mechanical activation of the alloy, the biosurfactant molecule effectively prevents corrosion. Furthermore, addition of the biosurfactant to the corrosion environment increases the repassivation kinetics of the alloy by two to four times as compared with an uninhibited environment.

The commercial impact of the study consists in the possibility of obtaining of environmentally safe corrosion inhibitors of aluminium alloys by biosynthesis from renewable agricultural raw materials.

The originality of this paper is to study the effectiveness of “green” corrosion inhibitor based on biogenic product on freshly generated surface of aluminium alloy.

This paper aims to estimate the level of histamine in fish and fish products, as it is very important because of their implication in fish poisoning in humans; hence, ascertaining histamine levels in the aforementioned serves as a chemical index for spoilage.

A technique was developed to immobilize an ordered multilayer of diamine oxidase (DAO) by means of chemical cross-linking on the biconical taper surface stepwisely alternating between chitosan, glutaraldehyde and the enzyme. A spectrophotometric signal results from horseradish peroxidase catalyzed reduction of H₂O₂, a secondary product of the oxidative deamination of histamine monitored at 450 nm.

The biosensor showed a linear response range up to 1.5 mM, a good sensitivity of 0.64 mM-1 with detection and quantification limits towards histamine of 0.086 mM (15.8 ppm) and 0.204 mM (37.7 ppm) and a linear response range of 0-1.5 mM. It showed a response and recovery time of 14 sec and operational stability up to 40 repeated analyses without significant loss of sensitivity.

The developed biosensor has a good potential for use in the quantitative determination of histamine in seafood.

The paper described an outcome of an experimental work on tapered fibre optics (taper)-based biosensor coated with DAO embedded into a chitosan membrane to measure histamine.

This study aims to develop multifunctional, namely, superhydrophobic, flame-retardant and antibacterial, coatings over cotton fabric, using casein as green-based flame-retardant and silver nanoparticles as antibacterial agent by solution immersion method.

The cotton fabric is first coated with casein to make it flame-retardant. AgNPs synthesized using Cinnamomum zeylanicum bark extract is coated over the casein layer. Finally, stearic acid is used to coat the cotton to make it superhydrophobic. X-ray diffraction, transmission electron microscopy analysis and ultraviolet-visible spectroscopy are used to investigate the produced AgNPs. The as-prepared multifunctional cotton is characterized by scanning electron microscopy, energy dispersive X-ray analysis and attenuated total reflection-infrared studies. Flame test, limiting oxygen index test and thermogravimetric analyzer studies have also been performed to study the flame-retardant ability and thermal stability of treated fabric, respectively. The antibacterial effect of the coatings is evaluated by disc-diffusion technique. Water contact angle is determined to confirm the superhydrophobic nature of cotton fabric.

The outcomes of this study showed that the prepared multifunctional cotton fabric had maximum contact angle of greater than 150° with good flame retardancy, high thermal stability, greater washing durability and high antibacterial activity against the growth of Pseudomonas aeruginosa and Acinetobacter indicus. Additionally, the as-prepared superhydrophobic cotton showed an excellent oil–water separation efficiency.

The trilayered multifunctional cotton fabric has limiting washing durability up to 20 washing cycles. Treated functional fabric can be used as an antibacterial, therapeutic, water repellent and experimental protective clothing for medical, health care, home curtains and industrial and laboratory purposes.

The study brings out the robustness of this method in the development of multifunctional cotton fabrics.

The purpose of this paper is to demonstrate the heterogeneous effects of gains and losses on the perception of new products. It seeks to argue that the heterogeneity in these effects (partly) stems from the price-perceived quality relationship which is more important for quality-seeking customers.

A multilevel logit model was applied to household panel data on purchases of new yoghurt and sausage products in Germany. The multilevel model allowed to estimate heterogeneous price effects and accounted for the nested structure in panel data.

Significant variation in the effects of gains, losses, and promotions were found. Internal reference prices (IRPs), which served as indicator of loss-averse vs quality-seeking customers, were found to moderate these effects. Monetary losses have less negative effects for customers with high IRPs. Negative interaction effects of IRPs with monetary gains and promotions indicate that quality-seeking customers are less attracted by gains and promotions.

The heterogeneity in the price effects confirms the strategic importance of new product prices to influence customers’ perception of value. The price-quality relationship is an explanatory approach for heterogeneous price effects and should not be neglected in price setting. The inclusion of customer-specific reference price information yields deeper insights into customers’ use of prices to evaluate new products.

This study is the first to estimate asymmetric gain and loss effects in the analysis of new product trial. A customer-specific view in price setting is emphasized by taking customer-specific reference prices into account.

Another Christmas month is upon us, following it seems quickly on others that have been. Such is the relativity of Time, it is not yesteryear, but could be yester‐month or even yester‐week. The seasons pass like youth, all too soon. Our minds return to other Christmas months of yore — “Memories are like Christmas roses!”, the old saying goes. The children, singing much‐loved hymns and carols, happy family settings, a birth, christening, so much to look forward to in the new year. There are not always such happy memories, but memories just the same — Christmas in war‐time, Earth's joys growing dimmer each year, change and decay, life drawing to a close for many a soul; old folk tend to see Christmas as a time of passing, of leaving the world behind.

The purpose of this paper is to provide an immediate image about the reality of the renewable energies as experienced by an Algerian company.

The adopted approach focused on assessment of renewable energies’ impact (especially the thermal solar power) on the environment and on the economic aspect of an Algerian company.

The perception of environmental dimension is highlighted by means of an evaluation study supported by the calculation of quantities of CO₂ emitted by two power stations (the new hybrid power station of Hassi R’mel (SPPI) and a conventional one (Sonelgaz)).

This research has limitations that the authors plan to study in perspective: assessing the impact of wind systems on the environmental and economic aspects.

The analysis of obtained results shows and puts emphasis on the importance of renewable energies, especially thermal solar power, by identifying and evaluating the environmental and economic aspects of the new hybrid power station of Hassi R’mel (SPPI) and a conventional one (Sonelgaz) and by comparing the importance of their atmospheric emissions.

The paper shows that this new technology represents in theory a solution for environmental problems and could also be economically competitive with conventional energies if wisely exploited.

A clean motor car that emits only water vapour – it makes great PR, but the hydrogen to fuel it still has to be produced and distributed. Production requires a lot of energy, generated by ordinary power plants, and distribution requires a new infrastructure. Nuclear power may be a bête noir for some environmentalists, but others now see it as the only way to make the 21st century truly “green”.

In addition to agriculture, energy production, and industries, potable water plays a significant role in many fields, further increasing the demand for potable water. Purification and desalination play a major role in meeting the need for clean drinking water. Clean water is necessary in different areas, such as agriculture, industry, food industries, energy generation and in everyday chores.

The authors have used the different search engines like Google Scholar, Web of Science, Scopus and PubMed to find the relevant articles and prepared this mini review.

The various stages of water purification include coagulation and flocculation, coagulation, sedimentation and disinfection, which have been discussed in this mini review. Using nanotechnology in wastewater purification plants can minimize the cost of wastewater treatment plants by combining several conventional procedures into a single package.

In society, we need to avail clean water to meet our everyday, industrial and agricultural needs. Purification of grey water can meet the clean water scarcity and make the environment sustainable.

This mini review will encourage the researchers to find out ways in water remediation to meet the need of pure water in our planet and maintain sustainability.

System dynamics is a whole-system modelling and learning approach, useful for tackling non-linear problems, such as sustainable urban development. The purpose of this paper is to review system dynamics applications in the simulation of sustainable urban development over a period from 2005 to 2017.

The analysis reveals that the number of applications of system dynamics modelling in the area of urban sustainable development increased in the analysed period. Research has changed its focus from the modelling of environmental problems to more complex models, portraying the multidimensional socio-economic processes that have an impact on the sustainability of urban development. Analysed case studies most often use the behaviour reproduction test for model validation, but without a unified approach. In most cases, modelling has been done in China, Germany and the USA, while urban development in the Eastern European countries, Africa and Latin America has not often been investigated. This paper indicates the knowledge gaps and suggests future research directions.

Papers that report the use of system dynamics modelling reveal a wide range of applications in urban sustainability. The analysis shows significant emphasis on environmental problems, while the interest for modelling social problems has been increasing during the last several years. Most of the modelled problems examine the sustainability of resources (land, water) and waste management, which are used for insights into the reasons for the system behaviour, forecasting future behaviour and policy testing.

The presented models were developed in most cases for the purpose of understanding the phenomena examined, as well as the future use of the models in policy planning. This brings us back to the need for greater stakeholder involvement, not only in the initial phase, but also during the whole modelling process, which could increase understanding, use and ownership of the models in the future, and thus increase their practical application.