One of the advantages provided by fused deposition modelling (FDM) 3D printing technology is the manufacturing of product materials with infill structure, which provides advantages such as reduced production time, product weight and even the final price. In this paper, the tensile mechanical properties, tensile strength and elastic modulus, of PLA, Tough PLA and PC FDM 3D printed materials with the infill structure were analysed and compared. Also, the influence of infill pattern on tensile properties was analysed. Material testing were performed according to ISO 527-2 standard. All results are statistically analysed and results showed that infill pattern have influence on tensile mechanical properties for all three materials.

Abstract Male infertility is caused by spermatogenetic failure, clinically noted as oligoor azoospermia. Approximately 20% of infertile patients carry a genetic defect. The most frequent genetic defect leading to azoospermia (or severe oligozoospermia) is Klinefelter syndrome (47, XXY), which is numerical chromosomal abnormality and Y- structural chromosome aberration. The human X chromosome is the most stable of all human chromosomes. The X chromosome is loaded with regions of acquired, rapidly evolving genes. The X chromosome may actually play an essential role in male infertility and sperm production. Here we will describe X chromosome aberrations, which are associated with male infertility.

In the second half of the 20th century, the industrialisation and deagrarization of Bosnia and Herzegovina had a strong impact on the dynamics of urban development and economic growth of the post-war Sarajevo, which intensified immigration from its relatively underdeveloped regional environment. This was accompanied by accelerated housing construction, and it encouraged the spatial expansion of the city. Planning guidelines were set by the city administration and were based on the long-term development plans. They identified the disposition of urban functions necessary for housing, work, recreation and traffic, and the policy of building multi-residential buildings was aimed general social interest. At the same time, the planning activities neglected the actual socio-economic status of immigrants who had lesser opportunities for housing through the social distribution system of apartments, began the process of self-organized unregulated settlement construction with single-family houses on the city's slopes. This began an era of two parallel but controversial actions within town space: planned and unregulated housing construction. Spontaneous possession of the city's territory with unregulated construction today is characterised by: complex property-legal relations, high degree of construction, absence of public space, pedestrian communications and service functions, low quality of the infrastructure network, and that settlements are formed on unstable terrains and on active landslides. Since the consequences of the complexity of the situation cannot be addressed through radical urban transformation, we see an alternative in the idea of partial spatial interventions – transformation by method of sanation. Starting with the thesis that construction is always deeply connected to society's understanding of the function of space and the place of man in it, we have opened up a central question, and searching for answers is the basic goal of this paper: Is it possible to solve problems accumulated by decades within Sarajevo's unregulated residential settlements through means of transformation by method of sanation? Or: Can partial spatial interventions improve the overall quality of individual and social life? For the purpose of finding answers, we conducted an analysis of the causes of the formation and genesis of these settlements, as well as a series of problems produced by the accumulation of separate spatial interventions without elementary professional guidance. The results of this analysis showed that the answer to the questions asked can be positive, by establishing a critical relationship with the potential of the space of specific settlement sites, in terms of the degree of functional usability, correlation with utilities and user interactions with the environments they inhabit. We have concluded that it is precisely the potential of individual sites, by logically applying the transformation by method of sanation, will enable dual achievement – the merging the solution within the technical and structural aspect of potential landslides with the articulation of the public on new pedestrian communications. Also, it has been shown that the application of this method enables the typification of technical solutions, functions, contents, activities, urban design, and even the public itself. And this means that the conclusions on the characteristics of individual Sarajevo unregulated residential settlements, endangered by landslides, can offer general guidelines for design concepts, within them, an overall improvement of individual and social life.

Particleboards are used in the manufacture of furniture, as well as the furnishing of structures and prefabricated homes. Their quality dictates where they can be used and how long they can last. The boards’ characteristics deteriorate as they are used. To examine the change-degradation of the properties of the boards are exposed to the effects of the external climate (rain, snow, wind, sun) or regimes of accelerated aging. For this purpose, a degradation test of the properties of wood-based panels was performed, which aims to create a model that will describe the change in bending strength of the mentioned panels. The paper presents the results of bending strength and thickness swelling tests of 16 mm thick particleboards that were exposed to accelerated aging regimes, and the basic model of property degradation.

Determination of tensile shear strength of lap joints is carried out according to three standards: BAS EN 205:2018 for adhesives used for non–load–bearing structures, and according to BAS EN 302-1:2014 for adhesives used for the manufacture of load-bearing structures and according to EN 14257:2019 for lap joints who are exposed to elevated temperatures. The paper presents the results of tensile shear strength of lap joints made of solid fir/spruce (Abies alba ssp./Picea abies spp). Tensile shear strength was tested in 4 groups of tests samples. The Group 1 consisted the samples were 7 days in standard atmosphere [20/65]. The Group 2 consisted the samples were previously soaked in water at (20 ± 5) °C, then recondition in standard atmosphere [20/65]. The Group 3 consisted the samples were previously 6 h soaked in boiling water 2 h, then soaked in water at (20 ± 5) °C; the samples tested in the wet state. The Group 4 consisted the samples were previously exposed to heat in a preheated fan oven, at (80 ± 2) °C, for (60 ± 2) min. The test results can be applied for gluing windows, doors, stairs, high-frequency gluing, veneering panels, etc.

Natural disasters that cause tremendous material harm and threaten human lives, infrastructure, and economic and social activities become more frequent. While most material and human casualties are the effects of sudden and brief natural disasters, it is not possible to disregard long-term disasters, most frequently triggered by climate change. Damage from long-term disasters is quite significant and hampers the sustainability of the economy and life in densely populated cities. Following climate change, it is concluded that special attention should be paid to coastal cities, cities along rivers and the potential risks of possible disasters should be reduced before they materialize. The reduction of disaster risk is an endeavor involving various professional fields, viewpoints, and stakeholders. An integrated approach that brings together all the necessary elements is therefore required. The planning for protection against natural disasters and in the very moments when it occurs, it is necessary to quickly obtain reliable data to coordinate activities in the field well. However, there are problems in the field with the availability, access, and spatial data use. In this sense, the Spatial Data Infrastructure (SDI) can provide an appropriate framework for sharing spatial data through the cooperation of administration, public, and private institutions and citizens.

The paper presents the engineering practice, which the company “Regeneracija” Ltd. Velika Kladuša – Bosnia and Herzegovina uses to perform preliminary experimental testing and measurements, followed by mathematical modeling of critical pressure of these vessels, in order to obtain the projected quality of pressure vessels made of composite materials. The paper will confirm the hypothesis that it is possible to relate mathematical connection and dependence of the critical pressure of vessels of composite materials (Pkr) with mechanical characteristics of vessel material (σM), vessel diameter (D), and vessel wall thickness (s). In this way, by varying the mentioned parameters, it is possible to achieve the desired product quality in the production of composite material containers by achieving the projected critical and thus working pressure. Generally speaking, the mathematical model of critical pressure obtained in this way will be a good indicator for design engineers to know how much critical pressure a given vessel can withstand, and based on that to take quick control of working or projected pressure, but also for designing completely new vessels made of composite materials as a substitute for the expensive experimental testing.

This paper investigates the local and global character of the unique positive equilibrium of a mixed monotone fractional second-order difference equation with quadratic terms. The corresponding associated map of the equation decreases in the first variable, and it can be either decreasing or increasing in the second variable depending on the corresponding parametric values. We use the theory of monotone maps to study global dynamics. For local stability, we use the center manifold theory in the case of the non-hyperbolic equilibrium point. We show that the observed equation exhibits three types of global behavior characterized by the existence of the unique positive equilibrium, which can be locally stable, non-hyperbolic when there also exist infinitely many non-hyperbolic and stable minimal period-two solutions, and a saddle. Numerical simulations are carried out to better illustrate the results.

UDK: 630*52:519.233.5]:582.475(497.6) As the result of sporadic afforestation of not-grown forest land in the past, today in B&H we have significant areas of even-aged forest plants of Scots pine of different ages. Estimate of yield capabilities of habitats/sites of these stands is one of very real issues in even-aged management planning for this tree species. In order to get the clear idea on the value of yield of even-aged stands, it is necessary to conduct long-term researches on permanent experimental plots. Considering that for the results of those researches it is necessary to wait approximately for the duration of production periods for specific tree species, to gain orientation solutions of the problem we can apply short-term researches – using temporary experimental plots set in stands of different ages. Members of the Forest Management Department of Forestry Faculty in Sarajevo in a period from 1985 to 1990 gathered data on temporary experimental plots in existing even-aged forest plantations of spruce, Scots pine and black pine in order to research their growth, structural and production characteristics. Part of those data for Scots pine is used for making of this document. Objective of this research was, based on data on measurement of 77 experimental plots positioned in even-aged not-tended plantations of Scots pine Bosnia-wide, to reach relevant information on the value of wood volume depending on their age and site quality, and to create the most favourable regression model for assessment of volume of large wood value based on known values of the stand taxation elements that could be easily and quickly determined. Besides this, in this document by comparing gained results with appropriate data from other authors we have evaluated productivity of even-aged not-tended forest plantations of Scots pine in B&H.

Architectural space of the 21st century confirms, for the umpteenth time that, architecture is a personified image of society: The products of architectural interventions are the final creations in time and space. The whims of the market, the linear economy model, and users' pluralistic needs generated by cultural preferences mutually develop "white elephants" - inert material, useless and expensive to deconstruct. In response to social, environmental, climate, and economic changes, the construction sector needs to revalue existing construction techniques. The lack of broader application of the circular economy model, the use of inorganic materials and chemical bonds in architectural structures, due to the loss of cultural significance or the appearance of natural disasters, are deprived of their function and produce a large amount of waste. Therefore, the reuse of organic materials derived from renewable energy sources is becoming essential for pushing further the boundaries of reversible design and energy efficiency in architectural interventions. Limits of use of the old – new materials - compressed straw are defined by comparing the results of thermal properties of the building envelope elements - U and R values and levels of reversibility through two opposite approaches to construction, on the example of the conceptual design of a housing unit affected by natural disasters. Analysing the three levels of reversibility that 21st century buildings should possess, given the existing research, the material level limit is shifted in terms of returning to nature with potentially zero environmental waste. Comparing the results of the R values of prefabricated straw structures with the R values of materials predominantly used in architectural interventions raises awareness of the importance and benefits of using compressed straw in architectural envelopes. Existing design parameters of straw structures are optimized by valorising the importance of local climate and materials used. The interaction of native - cellulosic materials breaks down dogmas related to this material and generates the architectural language of reversible and energy-efficient architectural straw products.

The Travelling Salesman Problem is categorized as NP-complete problems called combinatorial optimization problems. For the growing number of cities it is unsolvable with the use of exact methods in a reasonable time. Genetic algorithms are evolutionary techniques used for optimization purposes according to survival of the fittest idea. These methods do not ensure optimal solutions, however they give good approximation usually in time. Studies have shown that the proposed genetic algorithm can find a shorter route in real time, compared with the existing manipulator model of path selection. The genetic algorithm depends on the selection criteria, crosses, and mutation operators described in detail in this paper. Possible settings of the genetic algorithm are listed and described, as well as the influence of mutation and crossing operators on the efficiency of the genetic algorithm. The optimization results are presented graphically in the MATLAB software package for different cases, after which a comparison of the efficiency of the genetic algorithm with respect to the given parameters is performed.

UDK: 574.5(282.249 Bunica) Research into the benthic diatoms in the Bunica River was performed during the period from 5th May 2013 to 9th January 2014 on three different sites, from the headwaters to the mouth. The Bunica River is located in the south-eastern part of the Mostar valley, in the south of Bosnia and Herzegovina. The aim of this research was to test the use of benthic diatoms as indicators and the use of diatom indices as a tool for estimating water quality in an example of a small karstic river. For that purpose, diatom indices were calculated using OMNIDIA GB 5.3 software. This was the first testing of diatom indices for a small karstic river. Diatom indices showed different results and huge variations between sites on the Bunica River. According to the results, the indices in the OMNIDIA software are not applicable for karstic rivers in Bosnia and Herzegovina and they must be modified for this purpose. This paper can be the first step towards calibration indices for karstic region. Also, it can be useful for the development of biomonitoring tool for karstic rivers in Bosnia and Herzegovina.

UDK: 574:502(497.6) With the geographical position and climate conditions it has, Bosnia and Herzegovinais a countryof unique life forms and biodiversity. The flora, fauna and fungi of Bosnia and Herzegovina are among the most diverse in Europe, and the high level of endemism and relict species provide for the country’s significance at the global biodiversity level (UNCBD, 2019). Since 2002, Bosnia and Herzegovina, as a party to the United Nations Convention on Biological Diversity (UNCBD), has been following global trends of conservation and sustainable use of biodiversity. Followingthe Convention, among others, six national reports were developed, as well as the Strategy and Action Plan for Protection of Biological Diversity in Bosnia and Herzegovina (NBSAP) by 2020. These documents seek to ensure that protection and sustainable use of biodiversity become inevitable principles when relevant sectoral policies, strategies and legislation at all governmental levels of Bosnia and Herzegovina are being developed. In 2013, the Bosnian-Herzegovina Clearing House Mechanism (CHM) portal for sharing information on biodiversity was established within the global network CBD CHM. As a member country of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), Bosnia and Herzegovina actively represents and advocates for the interests of Eastern Europe. Bosnia and Herzegovina has made significant contribution to the preparation of a Regional and Sub-Regional Assessment for Biodiversity and Ecosystem Services for Europe and Central Asia, which was adopted at the Sixth Plenary Session of IPBES (Medellin, Colombia, March 2018). In the context of regional and global cooperation, Bosnia and Herzegovina significantly contributes  to the organization of the workshop and the preparation of an Eastern European Action Document on Pollinators, Food Security and Rural Development, within BES-Net Trialogue. Bosnia and Herzegovina reaffirmed its commitment to the status of pollinators by accessing to the global Coalition of the Willing on Pollinators at the 6th IPBES Plenary Session.

Recurrent Respiratory Papillomatosis (RRP) is a rare but severe manifestation of human papillomavirus (HPV). As our knowledge about HPV infections has expanded, it has become possible to understand the course of RRP disease and unravel plausible efficient methods to manage the disease. However, the surge in reports on HPV has not been accompanied by a similar increase in research about RRP specifically. In this paper, we review the clinical manifestation and typical presentation of the illness. In addition, the pathogenesis and progression of the disease are described. On the other hand, we discuss the types of treatments currently available and future treatment strategies. The role of vaccination in both the prevention and treatment of RRP will also be reviewed. We believe this review is essential to update the general knowledge on RRP with the latest information available to date to enhance our understanding of RRP and its management.