<abstract><title style='display:none'>ABSTRACT</title><italic>The article introduces the concept and content of facilities management (FM) services. The</italic><italic>paper presents the concept of customer satisfaction and discusses the key factors which</italic><italic>influence the opinions of customers and their satisfaction or dissatisfaction with the</italic><italic>services provided. The article presents two studies: a brief survey of several FM service</italic><italic>providers and a survey of customer satisfaction with FM services in Lithuania. The</italic><italic>conclusions are given at the end of the article.</italic></abstract>

Department of Construction Economics and Property Management Vilnius Gediminas Technical University, Sauletekio ave. 11, LT–10223 Vilnius, Lithuania

Study on Customer Satisfaction with Facilities Management Services in Lithuania

<abstract xml:lang="en"><title style='display:none'>On the use of the Muskingum method for the simulation of flood wave movements</title>The Muskingum method is a hydrological flow routing model with lumped parameters, which describes the transformation of discharge waves in a river bed using two equations. The first one is the continuity equation (conservation of mass) and the second equation is the relationship between the storage, inflow, and outflow of the reach (the discharge storage equation). These equations are applied within a river reach between two cross sections of a river. The parameters of the model can be estimated by several methods. Here the classical graphic method is compared with two new methods where a genetic algorithm and harmony search was used for optimization. The discrete state space formulation of the Muskingum method was applied on the lower Morava reach between Moravský Svätý Ján and Záhorská Ves. The results showed a good degree of accuracy of all three methods, which were assessed by the Nash-Sutcliffe efficiency coefficient.</abstract>

On the use of the Muskingum method for the simulation of flood wave movements

<abstract><title style='display:none'>Abstract</title> This study focuses on the soft-storey behavior of RC structures with lead core rubber bearing (LRB) isolation systems under near and far-fault motions. Under near-fault ground motions, seismic isolation devices might perform poorly because of large isolator displacements caused by large velocity and displacement pulses associated with such strong motions. In this study, four different structural models have been designed to study the effect of soft-storey behavior under near-fault and far-fault motions. The seismic analysis for isolated reinforced concrete buildings is carried out using a nonlinear time history analysis method. Inter-story drifts, absolute acceleration, displacement, base shear forces, hysteretic loops and the distribution of plastic hinges are examined as a result of the analysis. These results show that the performance of a base isolated RC structure is more affected by increasing the height of a story under nearfault motion than under far-fault motion.</abstract>

Effect of a Near Fault on the Seismic Response of a Base-Isolated Structure with a Soft Storey

<abstract><title style='display:none'>Abstract</title>The structural integrity of precast concrete structures mainly depends on the connections between the precast structural elements. The purpose of a connection is to transfer loads, restrain movement, and/or to provide stability to a component or an entire structure. Therefore, the design of connections is one of the most important aspects in the design of precast concrete structures. All the connections should be designed according to the valid codes. All precasters have developed connection details over the years that suit their particular production and erection preferences. It is common that the structural engineer shows the internal forces and connection locations, and the manufacturer’s engineering department provides the final design and details of the connections. This paper describes basic types of connections and joints used in precast concrete structures</abstract>

Connections and Joints in Precast Concrete Structures

<abstract xml:lang="en"><title style='display:none'>Improvement performance of secondary clarifiers by a computational fluid dynamics model</title>Secondary clarifier is one of the most commonly used unit operations in wastewater treatment plants. It is customarily designed to achieve the separation of solids from biologically treated effluents through the clarification of biological solids and the thickening of sludge. As treatment plants receive increasingly high wastewater flows, conventional sedimentation tanks suffer from overloading problems, which result in poor performance. Modification of inlet baffles through the use of an energy dissipating inlet (EDI) was proposed to enhance the performance in the circular clarifiers at the Al-Dewanyia wastewater treatment plant. A 3-dimensional fully mass conservative clarifier model, based on modern computational fluid dynamics theory, was applied to evaluate the proposed tank modification and to estimate the maximum capacity of the existing and modified clarifiers. A Computational Fluid Dynamics (CFD) model was formulated to describe the tank is performance, and design parameters were obtained based on the experimental results. The study revealed that velocity and (suspended solids) SS is a better parameter than TS (total solids), (Biochemical Oxygen Demand) BOD, (Chemical Oxygen Demand) COD to evaluate the performance of sedimentation tanks and that the removal efficiencies of the suspended solids, biochemical oxygen demand, and chemical oxygen demand were higher in the baffle.</abstract>

Department of civil Engineering, Faculty of civil Engineering, AL-Qadisyia University, Iraq

Department of Sanitary and Environmental Engineering, Faculty of Civil Engineering, Slovak University of Technology, Radlinského 13, 813 68, Bratislava, Slovakia

Improvement performance of secondary clarifiers by a computational fluid dynamics model

<abstract><title style='display:none'>Abstract</title>The Pulicat Lake is the second largest brackish water lake after Chilika Lake in India. The average area of the water spread is 461 sq km. During the monsoon Pulicat Lake receives freshwater through three major rivers, namely, the Swarnamukhi, the Kalangi and the Arani. The Pulicat lagoon system, which is a storehouse of rich biological resources, is under great threat because of the anthropogenic influences. The Pulicat Lake ecosystem is degraded by siltation, bar mouth dynamics, shell mining and processing and population pressure due to the resettlement of villagers from Sriharikota Island. It has been determined that the extent of the lake, including its water spread area, is decreasing. Therefore, it is essential to assess the land use / land cover changes taking place in and around Pulicat Lake using remote sensing and GIS. Studies on its sediment characteristics are also vital. The grain size content reveals that most of the sediments contain clay and silt in enormous amounts. This lake has been the prime source of a livelihood through fishing for a large section of the population living in the surrounding villages. It is the most important refuge for water birds in south India. The fishing community who lives in and around Pulicat Lake follows the Padu system for fishing in the lake. In this study, apart from studies on configuration changes and sediment analysis, a study of the flora and fauna of the lake and the socio-economic conditions of the local community were also carried out. Finally, mitigation measures for the sustainable protection of the lake’s ecosystem were identified.</abstract>

Assistant Professor, Department of Civil Engineering, Tagore Engineering College Rathinamangalam, Chennai, Tamil Nadu. PIN: 600127

Professor in Civil Engineering and Principal, Karpaga Vinayaga College of Engineering and Technology, Padalam – 603308, Kancheepuram District, Tamil Nadu.

Pulicat Lake: A Fragile Ecosystem Under Threat

<abstract><title style='display:none'>Abstract</title>
In countries that are big producers of olive oil such as Spain, Italy, or Greece, large amounts of olive husk remain as waste from processing olives and pose a serious environmental issue. One of the solutions could be to use this waste to partially replace sand in cement mortar to preserve the environment, decrease the consumption of cement, and improve economic benefits. This work presents our initial results which show the viability of using olive waste as an aggregate in cementitious mortars, indicating that the organic materials studied can be promising for this purpose.
</abstract>

Properties of Olive Stones with a View to Their use as Lightweight Aggregate in Construction Mortars

<abstract><title style='display:none'>Abstract</title>
This study presents a numerical approach to an analysis of the mechanical behavior of double-layered tensegrity grids. We present a comparative study on the behavior of tensegrity grids through geometric nonlinear analysis (GNA) and combined nonlinear analysis (CNLA) (geometric and material), considering the possible effect of evolution in the elasto-plastic domain of the cable elements. The effect of the relaxation of cable on the amplification of the displacement of these grids was taken into account. The updated Lagrangian formulation, which modifies the Newton-Raphson iterative scheme with incremental loading, was adopted. We have developed a numerical computational model specific to tensegrity structures that simulates the geometric and material nonlinear behavior. The reliability of the calculation tool developed has been validated. Additionally, the results of the application of the numerical model on a grid, which was generated based on demi-cuboctahedral tensegrity cells, are presented.
</abstract>

Non-Linear Behavior of Double-Layered Grids

<abstract>
<title style='display:none'>Abstract</title>
Faced with the increasingly growing need for construction material resources and the strict requirements and conditions for preserving the environment, it has become necessary and relevant to study all possibilities and opportunities for the recycling and valorization of industrial waste and by-products in the construction field. Strapping straps is a product used to bundle and transport goods and construction materials. After its use, it is considered as waste. The objective of this experimental work is to study the possibility of reusing the strapping strap waste as fibers in the production of fiber-reinforced concrete. For this purpose, three families of concrete were composed using strapping strap fibers, steel fibers, and polypropylene fibers, which were introduced into a concrete composition by volumetric substitution (0.4%, 0.8% and 1.2%) of aggregates. The fresh properties were evaluated through slump, density and air content tests. Hardened properties were investigated using the compressive and flexural strengths, pulse velocity, dynamic elastic modulus, and water absorption tests. The results obtained showed that strapping strap waste fibers significantly improve the mechanical properties of fiber-reinforced concrete and have a behavior similar to that of steel fibers. The optimum rates of strapping strap fibers were 0.4% and 1.2% for compressive and flexural strengths respectively. Compared to polypropylene fibers, the strapping strap fibers were found to be more efficient and led to a gradual increase in flexural strength with an increase in the strapping strap fibers. The results obtained also showed that the increase in strapping strap fiber content gradually increased the water absorption of fiber-reinforced concrete.
</abstract>

Effect of Strapping Straps Waste Fibers on Fresh and Hardened Properties of Concrete

<abstract><title style='display:none'>Abstract</title>
As part of a change in the division of transport work, bicycle transport has made the most progress in recent years. As the largest city in Slovakia Bratislava, is trying to keep up with foreign cities. In recent years, it has developed projects that have made it possible to increase the development of cycling in the city. The last major cycling survey was conducted in 2011 by Cyklokoalicia. This survey aims at determining the momentum of bicycle traffic by identifying its greatest shortcomings or, conversely, the most positives. The data from the analysis given will also be used to develop a concept for the development of bicycle transport in the city of Bratislava.
</abstract>

The Effect of the Development of Bicycle Transport from the Point of View of the Inhabitants of the City of Bratislava

<abstract><title style='display:none'>Abstract</title>
The concept of smart cities is gaining momentum with efforts to go greener and be more sustainable along with the growing demand for data-driven policies. The European Union (EU) is highly committed to fostering sustainable urban development through targeted funding programs that encourage innovation, collaboration, and practical solutions for climate-neutral and smart cities. We have used data mining on the data of the Community Research and Development Information Service (CORDIS) and Eurostat during 2014 – 2022, to analyze such projects. Firstly, we can report that in absolute measures, Germany, Spain, France, Sweden and Lithuania have obtained the largest amounts of money fromthe EU Horizon program to support the development of smart cities. Secondly, we have found that when accounting for the size of funding per capita, Estonia leads in terms of funds invested in smart cities followed by Luxembourg, the Netherlands, Finland, and Cyprus. Focusing our attention on the cost of outcomes, i.e., the efficiency of spending funds on smart cities, we can see that the leading countries in the EU are Romania, Switzerland, Norway, and Luxembourg. The authors have compared the success of European projects in their different phases, while considering the overall results as most relevant for our evaluation.
</abstract>

On Relative Success in Obtaining Grants for Smart Cities in the European Union and on the Cost of the Outcome

<abstract><title style='display:none'>Abstract</title>
The relationship between stress and strain tensors in soil is described by the soil constitutive equation, which depends on the soil type and deformation conditions. The development of various constitutive models has enabled a better understanding of the macromechanical properties of soil. One such model is hypoplasticity, which was discovered more than three decades ago. The purpose of this study is to determine whether hypoplasticity could accurately represent the behavior of Danube sand, a specific type of sand. The researchers conducted laboratory measurements to obtain the eight basic hypoplastic parameters of Danube sand and employed the intergranular strain concept as an extension of hypoplasticity to achieve a more precise material behavior. All the parameters were then utilized to simulate the cyclic triaxial test using the SoilTest Module of PLAXIS. The results showed that the hypoplastic constitutive simulation model for Danube sand was capable of making relatively accurate predictions for accumulative settlement.
</abstract>

Calibration of Hypoplastic Parameters for Danube Sand

<abstract><title style='display:none'>Abstract</title> Engineering properties such as compaction, unconfined compressive strength, consistency limits, percentage swell, free swell index, the California bearing ratio and the consolidation of bentonite stabilized with lime and phosphogypsum are presented in this paper. The content of the lime and phosphogypsum varied from 0 to 10 %. The results reveal that the dry unit weight and optimum moisture content of bentonite + 8 % lime increased with the addition of 8 % phosphogypsum. The percentage of swell increased and the free swell index decreased with the addition of 8 % phosphogypsum to the bentonite + 8 % lime mix. The unconfined compressive strength of the bentonite + 8 % lime increased with the addition of 8 % phosphogypsum as well as an increase in the curing period up to 14 days. The liquid limit and plastic limit of the bentonite + 8 % lime increased, whereas the plasticity index remained constant with the addition of 8 % phosphogypsum. The California bearing ratio, modulus of subgrade reaction, and secant modulus increased for the bentonite stabilized with lime and phosphogypsum. The coefficient of the consolidation of the bentonite increased with the addition of 8 % lime and no change with the addition of 8 % phosphogypsum.</abstract>

Department of Civil Engineering, National Institute of Technology, Hamirpur – 177005, Himachal Pradesh, India

Department of Civil Engineering, National Institute of Technology, Hamirpur - 177005, Himachal Pradesh, India

Engineering Properties of Bentonite Stabilized with Lime and Phosphogypsum

<abstract><title style='display:none'>Abstract</title>A detailed analysis of concrete structures requires knowledge of the mechanical properties of the materials used. In the case of a non-linear analysis, the scope of the information needed is even greater. In particular, the tensile strength and fracture-mechanical parameters are required for the concrete. Prospective approaches that could increase the informative value of detailed analyses include the use of stochastic modelling. It particularly enables the definition of the effects of individual input parameters on the load capacity, failure mode, and general behaviour of the structure. The presented paper aims at a detailed analysis of a reinforced-concrete beam without shear reinforcement, which is based on a complex set of laboratory tests and non-linear analyses with a sensitivity study. The laboratory program includes different types of laboratory tests. Selected and missing material parameters of the concrete are calculated according to recommendations in scientific papers and the valid standards. The results are compared and discussed.</abstract>

Non-Linear Analysis of an RC Beam Without Shear Reinforcement with a Sensitivity Study of the Material Properties of Concrete

<abstract><title style='display:none'>Abstract</title>In the 21st century, global climate change and the high level of fossil energy consumption have introduced changes affecting all sectors of the economy, including the building industry. Reducing energy consumption has become an important task for engineers because 30% of the total energy consumption is used for heating our buildings. Recycling the huge amount of industrial and agricultural by-products has also become urgent because due to their CO2 emissions, their combustion is not a state-of-the-art alternative. Besides rediscovering some long-known, nature-based insulating materials, there are also several research projects that have resulted in new products. In the last century it was relatively easy to review this product range, but nowadays there are so many kinds of nature-based thermal insulating products, there is a need for systematization, and more in-depth knowledge about them is required. The purpose of this paper is to develop a new systematization of nature-based thermal insulation materials, summarize the main knowledge about them, and indicate the direction of recent research and development.</abstract>

Nature-Based Thermal Insulation Materials From Renewable Resources – A State-Of-The-Art Review

<abstract><title style='display:none'>Abstract</title>Climate variability, particularly, that of the annual air temperature and precipitation, has received a great deal of attention worldwide. The magnitude of the variability of the factors changes according to the locations. The present study focuses on detecting the trends and variability in the annual temperature and rainfall for the district of Mandi in Himachal Pradesh, India. This study used annual and monsoon time series data for the time period 1981-2010 and modified the Mann-Kendall test and Sen's slope estimator in analyzing the problem. The results of the analysis indicate that the annual maximum temperature (TMX) and annual minimum temperature (TMN) for the period of 30 years have shown an increasing trend, whereas the monsoon’s maximum and minimum temperatures have shown a decreasing trend, although it is statistically not significant. The amount of annual rainfall does not show any significant trend, but the monsoonal rainfall has shown an increasing trend that is also statistically not significant. The resulting Mann-Kendall test statistic (Z) and Sen’s slope estimate (Q) of all the parameters studied indicate that changes are occurring in the magnitude and timing of the precipitation and temperature events at the Mandi station.</abstract>

Assessment of Trends and Variability of Rainfall and Temperature for the District of Mandi in Himachal Pradesh, India

<abstract><title style='display:none'>Abstract</title>The paper presents an analysis of changes in the structure of the average annual discharges, average annual air temperature, and average annual precipitation time series in Slovakia. Three time series with lengths of observation from 1961 to 2006 were analyzed. An introduction to spectral analysis with Fourier analysis (FA) is given. This method is used to determine significant periods of a time series. Later in this article a description of a wavelet transform (WT) is reviewed. This method is able to work with non-stationary time series and detect when significant periods are presented. Subsequently, models for the detection of potential changes in the structure of the time series analyzed were created with the aim of capturing changes in the cyclical components and the multiannual variability of the time series selected for Slovakia. Finally, some of the comparisons of the time series analyzed are discussed. The aim of the paper is to show the advantages of time series analysis using WT compared with FT. The results were processed in the R software environment.</abstract>

Advantages Of A Time Series Analysis Using Wavelet Transform As Compared With A Fourier Analysis

<abstract><title style='display:none'>Abstract</title>The article presents the results of a study of the properties of flax straw as a raw material and as a lightweight, environmentally-friendly insulation made of a two-component mixture of flax straw and liquid glass. The flax is considered to be renewable and is a 100% natural waste product of the agriculture industry, which may be widely used as sustainable building insulation after light modifications. The ratio mixes of the two-component eco-insulation of flax straw and liquid glass (Na2O(SiO2)) have been developed in terms of sustainability principles such as environmental friendliness and energy efficiency. We used thermal analysis to compare flax straw as a raw material, and a complex insulation made of flax straw demonstrated a slower decomposition of the composite and shorter peaks, which supports the concept of the transformation of flax straw with liquid glass to increase its fire resistance properties. The peaks of the loss of mass with the exothermal process were defined for both flax samples. The thermal conductivity coefficient of the material is around 0.085 W/m K, which permits its use as an effective insulation material for sustainable buildings.</abstract>

Study of Thermal Properties of Lightweight Insulation Made of Flax Straw

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