<abstract>
<title style='display:none'>Abstract</title>
Regional economic activities and developments are measured through various techniques where Location Quotient (LQ) is one of the most reliable techniques. This paper classifies the settlements by economic potentials in the southern region of Niger state using the LQ. A structured questionnaire was administered to 1.040 in the 37 rural communities selected from 37 districts in 8 LGAs in the Niger South Federal constituency in Niger State. The data collected was analysed using LQ. Findings of the study in terms of economic potentials of the region, reveals that communities are mainly engaged in basic economic activities; including the cultivation of food crops (rice, maize, beans, millet and yam); cultivation of cash crops (benisead, ground nut, vegetable, cassava and melon), plantation agriculture (palm, kola nut, cashew and sugar cane). Findings in terms of basic economy revealed that Egbako has the highest LQ with an average score of 0.06, and is closely followed by Takuma, Batako, Kusoyaba, Mukugi and Kalmo, with an average LQ score of 0.04 each, while in terms of non-basic economy, the findings indicates that both Egbako and Kuchita have the highest non-basic LQ with an average score of 0.07, which were closely followed by Katcha, Mukugi and Gayankpa settlements with non-basic economic LQ and average scores of 0.04 each. The study concludes that LQ is one of the best techniques in measuring economic potentials of regions. It also recommends LQ for regional economic assessments.
</abstract>

Classification of Settlements by Economic Potentials in the Southern Region of Niger State: A Location Quotient Approach

<abstract>
<title style='display:none'>Abstract</title>
Carbonation of concrete is a complex phenomenon, depending on many factors, including the heterogeneity of concrete, which results in an uneven carbonation front. The assessment of the depth of the carbonation front depends on the measurement technique adopted. The article summarizes the standard techniques for measuring the depth of carbonation and proposes an alternative measurement technique based on the measurement of the fields of the carbonated and noncarbonated surfaces, and then converting to the averaged depth of carbonation. For an example sample, the results obtained with different standard techniques and the proposed off-standard technique were compared.
</abstract>

Methodology for Measuring the Carbonation Depth of Concrete – Standard and Non-Standard Aspects

<abstract>
<title style='display:none'>Abstract</title>
Turbidity is an important indicator of water quality in rivers, lakes, and coastal areas. Research on turbidity issues in these areas is significant not only for the development and utilization of water resources for aquaculture, tourism, and other purposes but also for assessing the level of silt (sand) in the river, allowing sediment alluvial to build up a bank of the river, and monitoring the degree of water corrosion in the bridge substructure. This allows for the building of an effective maintenance and conservation program for the bridge in response to climate change.
Traditional methods have defined the turbidity of water in a local area, on a small scale. Interpolation errors of traditional methods for large areas may exceed over 20%. The use of remote sensing technology as Landsat-8 satellite images with a high geometric resolution of 30-meter multispectral channels allows us to estimate and distribute the water turbidity in a 30 × 30 m grid in detail.
Using multi-temporal Landsat-8 data in 2014 and 2015 for modeling water turbidity of Tien and Hau rivers and coastal areas in South Vietnam, the obtained mean absolute error is approximately 20%, the Root Mean Square Error (RMSE) does not exceed 10 NTU. The models have a high coefficient of efficiency ME, approximately 90% (ME = 0.862), and the correlation coefficient R stronger than 90%. This allows an overall assessment of changes in water flow velocity concerning the amount of sediment in the river.
</abstract>

Using Satellite Images to Retrieve the River Turbidity and Water Flow Velocity for Monitoring their Influences on Bridge

<abstract>
<title style='display:none'>Abstract</title>
Use of de-icing agents is necessary in winter to maintain appropriate quality of road and airport surfaces. Formate or acetate de-icing agents are safer for aircraft and the environment than the commonly used sodium chloride, but may cause an alkali-silica reaction in concrete. The study investigated the influence of sodium formate and potassium formate on the occurrence of ASR (alkali-silica reaction) in mortars with granite aggregate. Accelerated mortar-bar tests at 80°C using various de-icing agents were performed and detailed studies of the SEM-EDS microstructure were carried out.
</abstract>

Influence of Sodium and Potassium Formate on the ASR Reactivity of Granite Aggregate

<abstract>
<title style='display:none'>Abstract</title>
Ensuring the accessibility of buildings and spaces is a common contemporary challenge, in particular for historic buildings and spaces as well as the heritage of contemporary culture. It involves all activities aimed at adapting facilities and space to the needs of people with various disabilities, including seniors. The problem of aging societies and increasing life expectancy forces extensive changes both in the approach to architectural and urban design as well as in the practice of making historic buildings accessible through architectural solutions. Particularly in existing public buildings, it becomes very important to pay attention to the specific needs and reduced psychophysical abilities of various groups of architecture recipients due to their age. For this reason, the article analyzes the accessibility of selected examples of historical objects (case studies) functioning in the structures of the modern city of Kielce – for several dozen years. In order to get acquainted with the functioning and architectural solutions of buildings, which are among the most frequented by the general public, in situ research was carried out, the multi-criteria method was used, enabling comparative analyzes and being an effective tool in making a precise assessment. The research was focused on the location of the city of Kielce, taking into account current reports and statistics indicating the largest increase in the number of people over 65 in the Świętokrzyskie Voivodeship. It was found that it is important to revise the approach and generally accepted functional and spatial solutions regarding the accessibility of this type of facilities.
</abstract>

Accessibility Study of Historic Buildings and Contemporary Heritage – On the Example of Kielce’s Public Utility Buildings

<abstract>
<title style='display:none'>Abstract</title>
The article presents an assessment of the possibility of using the existing reinforced concrete foundations as foundations for a new battery of steel silos for storing rape and soybean in the factory of fats. Visual tests of the reinforced concrete mantle were performed, as well as destructive and non-destructive tests of concrete strength, tests of the location of reinforcement, concrete carbonation and the degree of steel corrosion. On the basis of the conducted analyzes, final conclusions and recommendations concerning the conditions of further operation were formulated.
</abstract>

Assessment of the Possibility of Using the Existing Foundations for the Construction of a Steel Silos

<abstract>
<title style='display:none'>Abstract</title>
Boiling is a phase-change phenomenon, which is of significant practical application potential due to large heat flux values exchanged in the process. The paper provides an overview of calculation methods that enable to determine the values of pool boiling heat flux on smooth surfaces. The most commonly used correlations were analysed and the boiling phenomenon occurring on smooth surfaces has been discussed based on the experimental data. A modification of the Rohsenow model has been proposed with the values of the constants determined experimentally.
</abstract>

Determination Methods of Boiling Heat Flux

<abstract>
<title style='display:none'>Abstract</title>
The current trend of conservation of immovable monuments is – in addition to ongoing maintenance and protection – adaptation. Simply taking care of a monument is not an effective way to keep it in good repair if it is not used. Utility is the primary function of architecture, as buildings are erected for this purpose only. No building can survive without function, especially a centuries-old one. This is because the lack of a user condemns any monument to destruction, which leads to ruin and, ultimately, to demolition. Therefore, proper adaptation to new functions and current technical conditions is necessary. In the process of adaptation, all the heritage values of the object should be brought out and only then should new ones be introduced, taking into account the integrity of the monument and ensuring authenticity. Sacred architecture has special cultural and historical values, both tangible and intangible, i.e. spiritual. Continually discussed adaptations of religious buildings in the case of Judaic religious buildings destroyed and abandoned after World War II proved to be the best way to reclaim synagogues. The Kielce synagogue is one of the early examples of adaptation to another function. The building, destroyed during World War II, was rebuilt in the 1950s in a different form than the original one, for use as an archive. This historic building, however, has been standing useless for more than a decade now, and this fact has a destructive effect on its heritage value, therefore it is necessary to take action as soon as possible. Numerous concepts for this building located in a prestigious area in Kielce can be produced, which will be presented and evaluated in terms of substantive potential of utilizing its value in a new incarnation.
</abstract>

New Proposal for the Former Synagogue in Kielce

<abstract>
<title style='display:none'>Abstract</title>
Superabsorbent polymers (SAP) allow for the introduction of changes to the pore network characteristics in cementitious composites and the course of binder hydration. Therefore, SAP addition contributes to significant changes in multiple properties of concrete. The effect of internal curing differs depending on its design process – the initial content of curing water in the concrete mix, polymer characteristics and water absorption properties, the state in which it’s added (non-saturated/hydrogel), and the design method regarding curing water content in the entire water content. The authors investigated those variables’ influence on selected concrete properties – compressive strength, water absorption, and shrinkage. All independent variables significantly influenced the studied properties of concrete. The increase in the total water-to-cement ratio led to a significant decrease in the mechanical properties of cementitious composites. Modification with the use of SAP added in the form of hydrogel had the most positive influence on the properties of concrete..
</abstract>

The Influence of Total Water-To-Cement Ratio on the Mechanical Properties of Cementitious Composites Internally Cured with Polyacrylic Superabsorbent Polymers (SAP)

<abstract>
<title style='display:none'>Abstract</title>
The article analyzes the accessibility of selected examples of public utility buildings, implemented at the end of the 20th century and at the beginning of the 21st century, in the structures of the conteporary city of Kielce. In order to learn about the functioning and architectural solutions of buildings that are among the most frequented by the general public, an in situ study was conducted, using a multi-criteria method that allows comparative analysis and is an effective tool in making an accurate assessment. The selection of the most relevant evaluation criteria was based on the actual needs and psychophysical condition of today’s society. The research was locationally focused on the Kielce city area, taking into account current reports and statistics indicating the largest increase in the number of people over 65 in the Świętokrzyskie voivodeship. The studies carried out have led to conclusions and recommendations to help in the design and management of facility spaces.
</abstract>

Multi-Criteria Evaluation of Accessibility of Conteporary Public Utility Buildings – On the Example of Kielce

<abstract>
<title style='display:none'>Abstract</title>
The remarkable feature of rapid urbanisation, which has fundamentally altered the distribution of land cover and land use (LULC), is what sets the contemporary era apart. The impact of these modifications on the resilience of Abuja’s metropolitan infrastructure from 2017 to 2022 is examined in this study. Our study examined the dynamic changes in LULC using information from remote sensing, geospatial analysis software, and land cover categorization techniques. The findings indicate major changes in Abuja’s topography, including a decrease in the number of water bodies, a decrease in the number of trees, the expansion of urban areas, changes in agricultural land use, and fluctuations in the amount of grazing land. The previously mentioned changes have significant consequences for urban infrastructure resilience, affecting various sectors such as water supply, transportation, housing, utilities, and food distribution systems. The infrastructure supporting water supply and sanitation may be severely stretched as the number of water bodies decreases, affecting the quantity and quality of accessible water supplies. As metropolitan areas expand, greater strain is placed on transportation infrastructure, exacerbating traffic congestion and complicating road maintenance difficulties. Changes in agricultural land use can have an impact on food production and distribution, hence affecting food security. Deforestation can cause ecological deterioration, affecting a variety of aspects such as temperature regulation, biological diversity, and atmospheric purity. Adaptive approaches, green infrastructure, and adopting sustainable urban design can all strengthen the resilience of urban infrastructure, according to this study. The significance of renewable energy adoption, community participation, green building laws, the establishment of public-private partnerships, integrated water resource management, and data-driven decision-making is emphasised. Improving legal frameworks that prioritise resilience and sustainability is critical. It is critical to have a complete grasp of the complicated links between changes in LULC, and the resilience of urban infrastructure in order to enable educated urban design and decision-making processes. Policymakers and urban planners may address and minimise the negative consequences of climate change while improving the overall quality of life in cities by using sustainable development practises. The findings of this study have the potential to dramatically improve Abuja’s people’s well-being and sustainability, especially given the variety of urban difficulties they encounter.
</abstract>

Assessing the Impact of Land Cover and Land Use Change on Urban Infrastructure Resilience in Abuja, Nigeria: A Case Study from 2017 to 2022

<abstract>
<title style='display:none'>Abstract</title>
The article presents the influence of pumice, trass and chalcedonite powder on rheological properties of cement pastes. Cement was being replaced both of additions 10% or 20% by mass and combination of pumice or trass and chalcedonite powder in the amount 5% or 10% of each of them. The main purpose of the publication was to assess the effects of chalcedonite powder with selected mineral additions in terms of rheological properties and compare them with the results obtained for pastes modified with only one of the additions. In each case, the additive or combination of additives introduced into the paste reduced the flow, compared to the result of paste without additive(s). Rheological properties varied depending on type and amount of additive(s).
</abstract>

Rheological Properties of Cement Pastes Modified with Pumice, Trass and Chalcedonite Powder

<abstract>
<title style='display:none'>Abstract</title>
The article presents the results of the assessment of the possibility of using chalcedonite powder as a partial replacement for cement in mortars. Portland cement CEM I 42.5 R was used as a binder, which was replaced in the amount of 5%, 20%, 35% and 50% with chalcedonite powder. The experimental tests concerned the determination of the technological and mechanical properties of mortars: consistency, air content, compressive and bending strength, supplemented by X-ray diffraction analysis and calorimetric measurements of the pastes. The research results indicate that chalcedonite powder can be used in the production of mortars. The best mechanical properties of tested mortars were obtained in the case of replacing cement with the addition of powder in the amount of 5% and 20%.
</abstract>

Assessment of the Possibility of Using Chalcedonite Powder as a Component of Mortars

<abstract>
<title style='display:none'>Abstract</title>
The issue of thermal comfort and its subjective feelings inside a building is becoming more and more important in the modern world. It is caused by the desire to create optimal conditions in places where people stay. The article presents two methods, indirect and direct, which are typically used in the research projects. These methods enable to assess the thermal sensations of people and compare the feelings of the respondents with the value of PMV (the value of human thermal sensations) calculated using the formula from the ISO 7730 standard and the questionnaire surveys.
</abstract>

Modern Methods of Thermal Comfort Measurements

<abstract>
<title style='display:none'>Abstract</title>
Windows are an essential part of building envelopes since they enhance the appearance of the building, allow daylight and solar heat to come in, and allow people to observe outside. However, conventional windows tend to have poor U-values, which cause significant heat losses during the winter season and undesired heat gain in summer. Modern glazing technologies are therefore required to improve thermal resistance and comfort of the occupants, whilst mitigating the energy consumption of buildings. In the present work, a comprehensive review of the numerical investigations of the thermal properties of window systems and glazed buildings partitions is presented. However, the proposed models to predict the thermal performance most often concern only specific cases of window systems related to geometry and used material solutions, focused on specific physical processes, thus they contain a lot of simplifications, such as omitting the influence of radiation, temperature changes or velocity profiles.
</abstract>

Numerical Investigations of the Thermal Properties of Window Systems: A Review

<abstract>
<title style='display:none'>Abstract</title>
This work aims to characterize the microstructure of mortars derived from the walls of sacred buildings from the 17th century. The tests were carried out using the X-ray diffraction method, differential thermal analysis and scanning microscopy combined with the analysis of the elemental composition in the micro area. The results of this study show that the materials bonding the elements of the wall in historic buildings are porous sand-lime mortars with an increased binder-to-aggregate ratio, also containing limestone crumbs, flints and feldspars, and fragments of bricks larger than sand particles. The binder is fully carbonated calcium hydroxide, with no pozzolanic additives. The results of the microstructure and phase composition tests of mortars used for bonding wall elements in buildings constructed at the end of the 16th and early 17th centuries can be used to select the composition of mortars used in the renovation and repair of historic buildings.
</abstract>

The Microstructure and Phase Composition of Mortars from the 17th Century Sacred Buildings

<abstract>
<title style='display:none'>Abstract</title>
Effectiveness of selected chemical admixtures and mineral additives to mitigate alkali-silica reaction was compared based on reactive gravel aggregate. Lithium compounds in the form of nitrate and lithium polysilicate were used as chemical admixtures. Natural pozzolans containing zeolite were used as mineral additive. Efficiency of the additive was enhanced by modification with ammonium ions. Linear changes of mortars with crushed gravel aggregates were studied with the accelerated and long-term methods. Additionally, scanning electron microscopy was used for microstructural observations. It was demonstrated that at elevated temperatures the application of lithium compounds provided better protection. Under conditions similar to those in the field, 20-30% of natural pozzolans proved to be more effective in inhibiting the expansion. Regardless of the method of protection applied, the presence of alkali-silica reaction products was detected in the microstructure of the mortars.
</abstract>

Methods of Mitigating Alkali Reactivity of Gravel Aggregate

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Structure and Environment

ABOUT THE JOURNAL   Structure and Environment, a quarterly journal, has been published by the Kielce University of...