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Architectural heritage nowadays includes concrete structures constructed in the 20th century. These buildings are usually under-detailed, since the actual behavior of reinforced concrete at the time of their construction was not clearly understood, whilst building codes incorporating seismic resistance design, especially in seismic prone areas, did not exist. This inevitably led to inefficient design and consequently to severe damages in many historic concrete buildings during past seismic events. This paper explores the use of novel Engineered (Fiber Reinforced) Cementitious Composites (ECCs), with strain hardening abilities in tension, for the repair and strengthening of old sub-standard reinforced concrete columns, focusing on their confining and shear strengthening potentials. The experimental results show that, when replacing the reinforcement cover with fiber reinforced ECCs, the fibers bridge tensile cracks, limiting their opening and increasing their resistance against volumetric expansion, ultimately leading to increased amounts of energy dissipation. ECCs may thus by used in the repair of historic concrete structural elements.

PurposeOnly recently have historic concrete buildings received attention and the need for their protection has been understood. Their listing as architectural heritage in most countries is ruled by legislations. The research carried out within the framework of the CONSECH20 JPI project on the conservation of historic concrete buildings in the Czech Republic, Cyprus, Italy and the Netherlands has allowed to study the legislations in the four aforementioned countries and how these are brought to practice. This paper aims at the evaluation of these legislations and of their function in practice.Design/methodology/approachThe legislations have been examined focussing on the protection of historic buildings and the guidelines to achieve a correct technical conservation. These were assessed in practical situations. The situations of the four countries were studied and the parameters used allowed comparisons.FindingsConcrete buildings are at risk and the guidelines should be further developed to meet actual conservation needs, including historical and aesthetical compatibility. The re-use of listed concrete buildings often means transforming and adapting these to a variety of modern needs and norms: the complexity of this assignment asks for a multidisciplinary teamwork. The bottom-up Dutch programme for quality in conservation, striving to bring ethical and technological principles to practice, could be a sound basis for developing respectful conservation strategies of heritage concrete buildings.Research limitations/implicationsThe research concerns the four countries involved in the CONSECH30 project and could be extended to include more countries.Practical implicationsMore stakeholders have to be involved in the process of conservation and transformation of heritage concrete buildings. This should be directed by the legislation.Social implicationsNo direct social implications are foreseen from the outcome of the research. However, the suggestion is made that social involvement is essential in planning concrete building transformations.Originality/valueThe study focussed on the application of theory (the legislation) to practice (thus showing the limits of the legislation), which is an innovative way of contributing to the conservation of historic concrete buildings.

Purpose ECMO is an escalation treatment for hypoxic respiratory failure in patients with CDH. Open repair has been advocated after ECMO indicating that physiological changes associated to thoracoscopic repair were not well tolerated. Methods We have performed a retrospective review of all patients who underwent ECMO prior CDH repair over a 7 year period (2015–2021). Outcome measures were intra-operative Ph, PCO2, PO2 and FiO2 at 30 min, 1 h 30 min, and 2 h 30 min of surgery, operative time and recurrence rate. Data are shown in median (range). Results Eleven patients required ECMO prior CDH repair. Six of eleven (55%) were done thoracoscopically (Group A) and five of eleven (45%) via laparotomy (Group B). Two of six (33%) patients (Group A) were converted to a laparotomy, one of six (16%) patient developed a recurrence, and there was no recurrence in Group B. Two of five (40%) patients died within the first 60 days of life, whilst there was no death in Group A. Intra-operative values are shown below. Conclusion Whilst this is a preliminary report of a limited number of patients, there is no obvious difference of intra-operative blood gas parameters during surgical repair in patients after ECMO. Thoracoscopic CDH repair may be considered in patients after ECMO.

Iron-sulfur (FeS) proteins are ancient and fundamental to life, being involved in electron transfer and CO2 fixation. FeS clusters have structures similar to the unit-cell of FeS minerals such as greigite, found in hydrothermal systems linked with the origin of life. However, the prebiotic pathway from mineral surfaces to biological clusters is unknown. Here we show that FeS clusters form spontaneously through interactions of inorganic Fe2+/Fe3+ and S2− with micromolar concentrations of the amino acid cysteine in water at alkaline pH. Bicarbonate ions stabilize the clusters and even promote cluster formation alone at concentrations >10 mM, probably through salting-out effects. We demonstrate robust, concentration-dependent formation of [4Fe4S], [2Fe2S] and mononuclear iron clusters using UV-Vis spectroscopy, 57Fe-Mössbauer spectroscopy and 1H-NMR. Cyclic voltammetry shows that the clusters are redox-active. Our findings reveal that the structures responsible for biological electron transfer and CO2 reduction could have formed spontaneously from monomers at the origin of life., Iron-sulfur (FeS) proteins are involved in electron transfer and CO2 fixation. Here, the authors show that FeS clusters can form spontaneously in the presence of the amino acid cysteine, in conditions similar those expected in Hadean alkaline hydrothermal vents, suggesting a plausible mechanism of their emergence at the origin of life.

Aggregates constitute the largest proportion of the raw materials used for the production of mortars. Therefore, their quality significantly influences the in-use performance of the aforementioned composite building materials. This paper investigates the influence of ophiolitic crushed fine aggregate, quarried in Cyprus, on the performance of cement mortars. The experimental results vividly show that the mineralogical composition and physicomechanical properties of the fine aggregate materials under study highly affect the properties of the hardened cement mortars. More specifically, cement mortars prepared with “poor quality” aggregates, exhibiting high methylene blue and Micro-Deval loss values, showed inferior physicomechanical properties, compared to composites prepared with “better quality” aggregates. Sound correlations were also found between the mineralogy of aggregates and the physicomechanical properties of the hardened composites. This suggests that the combination of standardized aggregate characterization tests and mineralogical analyses may prove useful in assessing the quality of aggregates, prior to their use in mortar production.

Lime-based composites have been extensively used throughout the years as plasters/renders and jointing mortars in building construction. However, the low flexural strength and tensile ductility of these composite building materials, that are currently still used in the structural and thermal upgrading of existing structures of high cultural and architectural significance, have been a significant drawback. Therefore, researchers have been focusing on the development of novel composites involving the use of additives to enhance the tensile and flexural capacity of lime-based materials. For the first time in this study, naturally-derived polymer fibers produced by electrospinning have been successfully introduced as additives in lime pastes aiming to investigate their effect on the mechanical performance of the end composites. More precisely, the introduction of electrospun cellulose acetate (CA) microfibers within lime pastes resulted to a tremendous improvement of the mechanical properties of the latter. Consequently, the present study paves the pathway towards the use of electrospun fibrous additives in the development of advanced composite lime-based building materials, which is currently an unexplored area.

The article is focusing on aspects related to technology acceptance of LA in the context of school education. A survey that was based on the Technology Acceptance Model was distributed to 98 participants who work as schoolteachers and/or local educational policymakers and are geographically dispersed across two different European countries. The survey comprised of questions that span across four broad categories: a) actual usage of LA in schools, b) intention to use LA, c) perceived usefulness, and d) attitudes towards use. Regarding (a), most of the participants were aware that their educational institutions retain and use digital formats of student data as well as other data relevant to the learning process. Also, the participants could verify the existence of a respective privacy policy in their educational institutions. With respect to the perceived usefulness aspect, the participants were asked to opinionate concerning four promising types of LA usage, namely 1) real-time feedback, 2) prediction of at-risk students, 3) learning activities recommendation, and 4) student groups recommendation. All four types were well-received, but the perceived usefulness of prediction of at-risk students scored lower than the other three types of activities, while the learning activities recommendation scored higher in terms of perceived usefulness. The participants’ intention to use LA was examined in conjunction with their professionalism and that prospect was also well-received. The results are partially controversial, since the participants’ attitudes were not particularly favorable: they are moderate with respect to how much sceptic, willing and ready they feel about embarking on a LA endeavor.

Earth based building materials having low or negligible carbon footprint are looked upon as a sustainable alternative building material in the construction sector. The confidence of using any building material is augmented with through understanding of its mechanical properties. A brief review on the mechanical properties of the building materials such as Rammed Earth, Earth Blocks (Adobe, Compressed Earth Block, and Extruded Blocks) and Cob, which are manufactured using raw earth or by adding very little additives are presented in this chapter. The mechanical behaviour of earth based building material is highly dependent on raw material, manufacturing technique and testing conditions. Therefore it is highly recommended to conduct through experimental campaign for every soil mix. This chapter also presents various experiments recommended to study the mechanical properties of the materials.

Earth-based building materials have been used since antiquity for the construction of various structures. The main drawback of these materials is their vulnerability to direct contact with liquid water, such as rising damp. To protect earthen structures from rising damp, a stone foundation was used, resulting in composite masonry. In the current study, an experimental investigation of the capillary absorption of non-stabilized CEBs produced with soils sourced from different areas of Cyprus, as well as of 2-layer composite building materials comprising of natural stone and CEBs was carried out. The tests on CEBs indicated that the use of water as the wetting liquid led to the disintegration of the specimens and consequently to non-linear response. Thus, a non-reactive liquid was used instead to measure the capillary absorption coefficient of the materials. The test results showed that the capillary absorption coefficient of CEBs varied between 140-260 gr/m2sec1/2. In the case of the composites, capillary absorption with water as the wetting liquid showed perfectly linear response, following the t1/2 law, with no disintegration of the specimens. The results showed that there are two distinct capillary absorption branches with different gradients, in line with the theory of capillary absorption into 2-layer composite materials.

Lime-based renders have been used since the earliest periods of antiquity. Amongst them, hydrated lime renders set and harden almost entirely through carbonation; this is a slow chemical reaction, ...

Capillary pressure as a function of moisture content is an essential element in the modelling of multiphase flow in porous media, such as rocks. The constitutive relationship predicting the capillary pressure as a function of fluid saturation in these materials has been the focus of many studies in the literature, as the direct experimental determination of the former is usually time-consuming and not quite straightforward, owing to the topologically complicated pore structure of rocks. In this paper, we perform a systematic analysis of the interrelation between capillary pressure curves (CPC) and the corresponding imbibition curves to evaluate the parameters influencing the entire diffusive process. The aim is the reconstruction of the wetting CPC from sorptivity test data through back analysis, within the framework of the Van Genuchten model. We perform numerical simulations with finite elements, using as input synthetic models of CPC with one, two and three degrees of freedom, the latter being the widely accepted Van Genuchten model. The effectiveness and the limitations of the different models used and the sensitivity of the imbibition curves to each degree of freedom are investigated and critically evaluated. The whole investigation is assisted by theoretical estimations of the sorptivity coefficient, as a function of the model parameters and the measured quantities. The results of our analysis provide not only a clarification of the aforementioned interrelation, but also a relatively simple procedure for reconstructing synthetically the wetting CPC.

We develop a conceptual understanding of when and how organizations respond to normative pressures. More precisely, we examine two main factors underlying the willingness and ability of organizatio...

This study investigates how companies adjusted their investments in key strategic resources—i.e., their workforce, capital expenditures, R&D, and CSR—in response to the sharp increase in the cost of credit (the “credit crunch”) during the financial crisis of 2007-2009. We compare companies whose long-term debt matured shortly before versus after the credit crunch to obtain (quasi-)random variation in the extent to which companies were hit by the higher borrowing costs. We find that companies that were adversely affected followed a “two-pronged” approach of curtailing their workforce and capital expenditures, while maintaining their investments in R&D and CSR. We further document that firms that followed this two-pronged approach performed better post-crisis.

The mechanical characterization of adobe bricks is an important first step in the study of the behaviour of adobe masonry. For this reason, in the last decades, different authors have conducted research on the mechanical behaviour of adobes from various regions of the world. Despite the importance of mechanical characterization, there are still only a few standards and normative documents with clear indications for the mechanical testing of earthen materials and, in general, these indications are not thorough and vary among different countries. Consequently, authors tend to adopt different types of test specimens and procedures in their experimental work, thus obtaining results that are not directly comparable. The fact that the materials and procedures traditionally used are also not standardized, varying greatly from region to region, also contributes to the difficulty of comparing results from different studies. This chapter presents a review of the indications provided by codes, standards and other technical recommendations for the mechanical testing of adobe bricks, as well as a detailed review of procedures adopted, and results obtained by different authors regarding the mechanical characterization of traditional adobe bricks. This chapter focuses, in particular, on the behaviour of adobe bricks when subjected to simple compression. It provides an overview of the existing knowledge and identifies needs for future research and development.

The RILEM TC ASC-271 is developing a new laboratory test to assess the durability of porous building materials to salt crystallisation. The test encompasses two phases: salt accumulation and damage propagation. This paper focuses on designing a procedure for the accumulation phase; this is considered successful when salts crystallise at the material's evaporative surface (common situation observed on site) without the occurrence of damage. Two procedures were developed and tested on two limestones with different porosity: (1) capillary absorption of a salt solution followed by drying, and (2) continuous capillary absorption. Sodium chloride or sodium sulphate solutions were used. Several methods for assessing the salt distribution were employed: ultrasonic pulse velocity, drilling/scratching resistance, hygroscopic moisture content, ion chromatography, scanning electron microscopy, and micro X-ray fluorescence. The results enabled the selection of the most effective protocol for the salt accumulation phase. ISSN:0950-0618

The mouflon (Ovis gmelini ophion) is the largest wild terrestrial mammal of Cyprus. Regarded as the local flagship species, its population range is limited to the mountainous Paphos Forest and adjacent areas including part of Troodos National Forest Park (> 700 Km2). This species, protected by both national and international legislation, is classified as Endangered by the IUCN, with livestock intrusion, poaching and habitat loss as the main threatening factors. We determined the spatial genetic structure by investigating sexes separately and shed further light on the Cyprus mouflon placement among Ovis haplogroups (HGs) to enforce its protection within an adaptive conservation framework. We genotyped 108 samples collected across the entire species’ range at both14 loci of the microsatellite DNA and the mitochondrial DNA Control Region (CR). Microsatellite genotyping indicated that the wild population retained low genetic variability, which, however, was not associated with a level of inbreeding raising particular concern (FIS = 0.12). An overall weak spatial genetic structure was disclosed, consistently with the limited extension of the mouflon range, the lack of significant physical barriers to dispersal and the intense gene flow mostly occurring along a northeast-southwest axis across the forest. Nevertheless, evidences of structure were found for females in compliance with their philopatric behaviour. The disclosure of unique features compared to Mediterranean and Near East conspecifics, such as the occurrence of a six-fold 76 bp-long repeated motif in the Cyprus mouflon CR, along with the outcome of a phylogenetic reconstruction (based on a far higher number of Ovis GenBank records and Cyprus haplotypes than in previous studies) inspired the proposal of a new haplogroup (HGC2) which included the Anatolian mouflon (O. g. anatolica, former HGX) as sister taxon. While both high habitat heterogeneity and low human disturbance were the main drivers in determining the overall spatial structure, future conservation efforts to preserve this valuable genetic resource should focus on avoiding possible introgressive hybridisation with co-grazing livestock to the edge of its range.

The electric vehicle (EV) market has grown over the last few years and even though electric vehicles do not currently possess a high market segment, it is projected that they will do so by 2030. Currently, the electric vehicle industry is looking to resolve the issue of vehicle range, using higher battery capacities and fast charging. Energy consumption is a key issue which heavily effects charging frequency and infrastructure and, therefore, the widespread use of EVs. Although several factors that influence energy consumption of EVs have been identified, a key technology that can make electric vehicles more energy efficient is drivetrain design and development. Based on electric motors&rsquo, high torque capabilities, single-speed transmissions are preferred on many light and urban vehicles. In the context of this paper, a prototype electric vehicle is used as a test bed to evaluate energy consumption related to different gear ratio usage on single-speed transmission. For this purpose, real-time data are recorded from experimental road tests and a dynamic model of the vehicle is created and fine-tuned using dedicated software. Dynamic simulations are performed to compare and evaluate different gear ratio set-ups, providing valuable insights into their effect on energy consumption. The correlation of experimental and simulation data is used for the validation of the dynamic model and the evaluation of the results towards the selection of the optimal gear ratio. Based on the aforementioned data, we provide useful information from numerous experimental and simulation results that can be used to evaluate gear ratio effects on electric vehicles&rsquo, energy consumption and, at the same time, help to formulate evolving concepts of smart grid and EV integration.

Recent challenges faced by humanity in relation to the ongoing climatic changes around the globe, have led many practitioners and researchers search for new environmentally friendly materials to use in construction, such as earth-based materials. A specific form of an earth-based building material that nowadays receives particular attention is Compressed Earth Blocks (CEBs). CEBs comprise of soil mixed at low moisture content and are formed under high pressure in compression, without firing. The end-products can be non-stabilized, i.e., without any cement or lime added, or stabilized, whereby a small quantity of stabilizer (In Cyprus, CEBs were not used in the past, as the prevailing earth building technique on the island was adobe masonry. Recently, however, there appears to be an interest in the use of this material for contemporary construction. The work hereby presented is part of an ongoing research project that focuses on the design, production and characterization of a sustainable and eco-friendly prototype CEB masonry system that will be fabricated using raw materials originating from Cyprus. The project is funded by the European Regional Development Fund and the Republic of Cyprus, through the Cyprus Research and Innovation Foundation (Project ENTERPRISES/0618/0007).In the framework of the aforementioned project, various types of locally sourced soils, with different mineralogical/granular composition and plasticity characteristics have been selected and used for the production of non-stabilized CEBs. A series of tests, including particle-size analysis, Atterberg limits determination, shrinkage and compaction measurements, and X-ray diffraction analyses have been carried out to determine the characteristics of the raw materials selected. In addition, compression and 3-point bending tests, capillary absorption measurements and thermal conductivity analyses have been conducted to assess the physico-mechanical properties of the CEBs produced.XRD analyses have shown that the soils investigated are mainly composed of carbonates and silicates at different ratios. Preliminary capillary absorption tests have demonstrated that the use of a non-reactive liquid, such as acetone, is better over water in determining the sorptivity of non-stabilized CEBs. In addition, the thermal conductivity of all specimens ranged between 0.60-0.85 W/mK. Finally, the results suggest that, despite the different granular composition of the soils used, all soils demonstrated adequate mechanical properties in terms of compressive (over 5 MPa) and flexural (over 0.5 MPa) strength.