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The hot air convective drying of blueberries (Vaccinium corymbosum) in a thin layer was performed using a laboratory-scale dryer. The experiments were carried out at drying air temperatures of 60, 70 and 80 o C, and drying air velocities of 0.5 and 1.5 m/s. At higher values of the drying air temperature and the drying air velocity, less time was required for the convective drying of blueberries, i.e. the drying time of blueberries decreased with increasing drying air temperatures and velocities. The experimental data obtained during the drying process were fitted to ten different mathematical models. The Midilli et al. model was found to be the most appropriate model for explaining the drying behavior of blueberries during convective drying. Effective moisture diffusion coefficients were calculated using the Fick's diffusion model, ranging from 9.66 x 10-12 m2 /s to 9.67 x 10-11 m2 /s. These values were found to increase proportionally with the increase in drying air temperatures and velocities. The lowest total color change and shrinkage of dried blueberries were recorded during freeze drying. A water activity less than 0.6 was measured at a blueberry moisture content of 0.235 kgw/kgd.m, a drying air temperature of 26 o C and a relative air humidity of 60 %.

In this paper, a procedure for the statistical verification and validation of a newly generated sorption isotherm M01 model is defined. A basic approach to the evaluation of a model for approximating experimental sorption data is presented. Based on the accuracy within an acceptable range, a model is considered valid for a set of experimental conditions conducive to its intended purpose. The matching of experimental data to the data obtained in the calculations was examined. Several statistical criteria, proposed in the literature, and indicators (the coefficient of determination (R2), the root mean squared error (RMSE) and the mean relative deviation (MRD)) were used for the quantitative verification of the newly generated sorption isotherm model. A qualitative statistical analysis was performed by the validation of statistical assumptions relative to the residuals obtained from the regression analysis. This was achieved by creating a normal quantile-quantile diagram with a normal residual distribution, and a Scatter plot diagram with a random residual distribution. Fitted with the newly generated three-parameter sorption isotherm model, the validation of the experimental data on the sorption isotherms of pear flesh tissue (determined at four temperatures 15˚C, 30˚C, 45˚C and 60˚C, and over a range of water activity from 0.110 to 0.920) was performed relative to the results of the Guggenheim, Anderson and De Boer (GAB) model. The success of the newly generated model was confirmed in relation to this reference model.

In this paper, a faster and easier way, in comparison with classical methods, to determine the equilibrium moisture content in food materials is shown. The equilibrium moisture content is determined only experimentally, with determination of sorption isotherms. However, the key issue that is a condition for application of certain experimental method for determining of sorption isotherms is the reliability of experimental data obtained for equilibrium moisture content, as well as the time required to determine specific sorption isotherm. Despite numerous advantages of the static gravimetric method, the long time to achieve equilibrium moisture content of the sample is its main drawback and reason why the researchers use other techniques and methods. Out of these reasons came the idea to apply relatively fast and simple method to determine equilibrium moisture content in food materials, based on the values of average material temperature change obtained from experiments including convective drying kinetics. Furthermore, the resulting temperature response from the conducted experiments can be successfully used to determine unknown parameters in the models for calculation of equilibrium moisture content, by applying of inverse approach method that is an essential tool in modeling of heat and mass transfer processes for different food materials.

Water activity is an important parameter that can be used to predict the stability and safety of food with respect to the most microbiological and biochemical reactions, conditioned by its value. In other words, it describes the degree of the bound level of water in the dry material, as well as the indicator of the ability of water to act as a solvent, participant in various biochemical reactions, or growth of different microorganisms. The determination of the minimum value of water activity that allows the growth of certain microorganisms and mechanical and thermal equilibrium of the material with the surroundings, are the most important parameters that characterize the stability of the material. The equilibrium moisture content has fundamental role in food industry and technology from the aspect of design and optimization of drying processes and equipment, design of packing materials for dried products, prediction of quality and stability, as well as for calculation of changes in the moisture content of dried material during its storage. Considering the relationship between these two physical parameters, their interdependence has been shown in this paper.

In this study, a thin - layer drying of pear slices as a function of drying conditions were examined. The experimental data set of thin - layer drying kinetics at five drying air temperatures 30, 40, 50, 60 and 70°C, and three drying air velocities 1, 1.5 and 2 m s-1 were obtained on the experimental setup, designed to imitate industrial convective dryer. Five well known thin - layer drying models from scientific literature were used to approximate the experimental data in terms of moisture ratio. In order to find which model gives the best results, numerical experiments were made. For each model and data set, the statistical performance index, (φ), and chi-squared, (χ2), value were calculated and models were ranked afterwards. The performed statistical analysis shows that the model of Midilli gives the best statistical results. Because the effect of drying air temperature and drying air velocity on the empirical parameters was not included in the base Midilli model, in this study the generalized form of this model was developed. With this model, the drying kinetic data of pear slices can be approximated with high accuracy. The effective moisture diffusivity was determined by using Fick’s second laws. The obtained values of the effective moisture diffusivity, (Deff), during drying ranged between 6.49 x 10-9 and 3.29 x 10-8 m2 s-1, while the values of activation energy (E0) varied between 28.15 to 30.51 kJ mol-1.

In this paper the thin-layer drying of quince slices as a function of drying conditions were examined. The experimental data set of thin-layer drying kinetics of quince at five drying air temperatures 30, 40, 50, 60 and 70 oC, and three drying air velocities 1, 1.5 and 2 m s-1 were obtained on the experimental setup, designed to imitate an industrial convective dryer. Ten well known thin layer drying models from scientific literature were used to approximate the experimental data in terms of moisture ratio. In order to find which model gives the best results, the numerical experiments were made. For each model and data set, the statistical performance index (φ) and chi-squared (x2) value were calculated and models were ranked afterwards. The performed statistical analysis shows that the model of Hii gives the best results for approximation of experimental drying data of quince.

This paper describes the experimental results on the drying of the apple slices by infrared radiation under vacuum condition. The investigation of vacuum far-infrared drying processes was conducted on the experimental set-up that is designed to imitate industrial batch dryer. The experimental conditions have been chosen such that heaters temperature and absolute chamber pressure have been in the range used on the industrial dryer. Apple slices were dried at four vacuum pressures 20, 40, 60 and 80 kP and five temperature of heatres, 120, 140, 160, 180 and 200ºC which were kept constant during the single experiments. Based on experimental drying data, it was found that the drying time decreased with an increase of temperature of heaters and the decrease in the absolute chamber pressure. It was also concluded that the influence of the temperature of heaters has more significant effect on reducing of the drying time than the vacuum pressure.

The main idea of this paper is to review and present the papers in which sorption isotherms of different types of materials were determined. For this purpose, the number of publications, references, etc., in the most frequently used journals for publications of sorption isotherms papers were studied. In order to obtain clear picture what is realistic to expect from the scientific investigation in fields of determination of sorption isotherms for different materials in the near future and where future research should be focused, some statistical analysis were made. The papers have been classified into nine categories: I. Papers in which determination of sorption isotherms of fruits are performed; II. Vegetables; III. Tea, Herbs, Coffee and Tobacco; IV. Pistachio nuts, Almond, Soybeans and Cereals; V. Flour, Pasta and Powder milk; VI. Meat and Fish; VII. Foodstuffs; VIII. Wood, Paper and Clay and IX. Pharmaceutical materials. From the performed analysis it was concluded that the categories of papers 'Foodstuffs ', 'Fruits ', 'Pistachio nuts, Almond, Soybean and Cereals ', 'Vegetables ' and 'Flour, Pasta and Powder milk' comprise 75.6% of the published referent papers. The remaining categories of papers for 'Tea, Herbs, Coffee and Tobacco', 'Meat and Fish', Wood, Paper and Clay ' and 'Pharmaceutical materials ', are 24.4% of the referent papers. For this reason, future research should be focused of determination of sorption isotherms of these materials.

In this paper, a new approach for selection of a thin-layer drying model based on serial statistical criteria was proposed. The experimental data set of thin-layer drying kinetics of apple slices at five different drying air temperatures (40, 60, 80, 100 and 120 C) and three drying air velocities (1, 2 and 3 ms-1) were obtained on the experimental setup, designed to imitate an industrial convective dryer. The drying data were fitted with twenty-three published thin-layer drying models (Lewis, Page, Modified Page, Henderson and Pabis, Modified Henderson and Pabis, Logarithmic(Asymptotic), Two term, Two term exponential, Midilli, Diffusion approach, Wang and Singh, Weibull, Aghbashlo, Verma., Grigoriaş, Parabolic, Hll, Demir, Logarithmic,Logistic, Vega-Lemus, Jena-Das and Alibas). In order to find which model gives the best results, some numerical experiments were made. For each model and data set, the performance index was calculated and models were ranked afterwards. After that, several statistical rejection criteria were checked. The performed analysis shows that the Alibas model could satisfactory describe the drying curve of an apple.

In this paper, the results of comparative analysis between transcendental and cyclometric sorption isotherm models are presented. In order to find which model gives the best results, some numerical experiments were made. The experimental data set for equilibrium moisture content and the water activity for apple, pear, kiwi and banana at two different temperatures were used from the scientific literature. For each model and data set, several statistical parameters were calculated and models were ranked afterwards. The performed comparative analysis shows that the cyclometric models in many cases have higher values of the coefficient of determination, and lower values of the root mean squared error and the mean relative deviation than transcendental the isotherm models. All these results show that the cyclometric sorption isotherm models give the best overall fit to experimental data. After choosing the best transcendental and cyclometric model with the high value of statistical performance index, the residual plot was checked graphically.

In this paper the particle density of potato and carrot slices during convective drying was studied. Some experiments were conducted in a laboratory air-dryer. The experiment was repeated at different air temperatures and velocities. The drying air temperature was 40, 50, 60 and 70°C and the drying air velocity 1, 2 and 3 m/s. Some new mathematical models for correlating the dimensionless particle density with the dimensionless material moisture content are proposed. Regression analysis on the experimental data is made. High values of the correlation coefficients show that the differences between predicted and observed data are very small.

One of the main global problems related to the environment is air pollution which not only affects the environment and the ecosystem but also affects human health. Many countries of the world did research on how to reduce air pollution so that the concentrations do not exceed the permissible thresholds which are set at that level so that neither human health nor the environment are exposed to further damage. One of the issues regarding air pollution is the concentrations of PM particles 2.5 and 10, PM particles are a big problem in developing countries such as the Republic of North Macedonia. The research paper was focused in processing the data that has been collected for daily averages of PM 2,5 and PM10 particles that contribute in air pollution. All analyzes and processing of the results are done in compliance with the current laws of the Republic of North Macedonia and with Directive 2008/50/EC, all for µg/m3. In the city of Skopje, numerous exceedances of the permissible thresholds of PM particles 2.5 and 10 were recorded at the two measurement stations where the results were obtained for the months of January, February, March, April, May and June of 2023. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to examine the knowledge and level of awareness of Occupational Safety and Health (OSH) in North Macedonia, to improve the effectiveness of trainings and analyze how the choice of training type affects the quality of knowledge. In order to collect the necessary data, in the last 5 years (2019-2023), more than 90 trainings on safety at work in many companies from three different sectors in North Macedonia (construction, garment industry and public administration), were carried out. As part of these trainings, which are a legal obligation for every company, questionnaires were filled out to test knowledge about OSH. The conducted survey covers a sample of 180 respondents. Despite the fact that 89% of surveyed in construction know that they perform high-risk work, 52% do not think that they must constantly wear personal protective equipment (PPE) during work. As many as 94% don't know for the right to refuse the work if they are not trained. Employees in garment industry (46%) are not aware that the employer must provide them with not only functional, but also ergonomic equipment. Also, 17% of employees in the public sector did not consider about risks of injuries in administrative work. Creating guidelines for early detection of potential causes of injuries instead of remedying the consequences of accidents at work, is the essence of OSH concept. [ABSTRACT FROM AUTHOR]

This paper aims to describe the idea and approach to innovate the curricula and syllabuses at the Faculty of Technical Sciences at University "Mother Tereza" towards taking its part of responsibility to contribute to the UN goals of Sustainable Development. In last improvement of the curricula od different studying programs, the Faculty of Technical Sciences introduced a course "Sustainable development in technology" as basic tool to make sure the students, further engineers, become familiar with one of the most important awareness of humanity regarding periods to come, all shaped in UN Sustainable Development strategy. Due to the fact that Sustainable Development is a mixture of environmental, economic and social aspects of contemporary life, and all of them have deep connections with the technology, no gap between purely technical, economic and social views are allowed any more. Therefore, in front of teaching staff at the Faculty of Technical Sciences is a very important and complex duty to make students aware of the core meaning of Sustainable Development, its relation to their further profession and bring knowledge and skills how to deal with all new challenges. This task, opposite to some basic courses in engineering is much more complex in terms of multidisciplinary and put some new challenges in front of the teaching staff. This comes from the fact that nowadays, and in the future, the role of the engineer has been widened and become more complex, and more interdisciplinary adding more environmental, economic and social aspects. It is important that including of sustainable development knowledge, competences and skills, in engineer portfolio should not be taken as a burden, but chance to contribute to everyone's future. The Faculty of Technical Sciences already takes the first steps in this direction and first experiences are described here. [ABSTRACT FROM AUTHOR]

This paper is a result of a project that aims to raise the awareness and enrich the knowledge of high school students regarding sustainable development. In order to build an appropriate program structure it was necessary to assess the current level of awareness and knowledge about sustainable development. Therefore the main intent of this research is to establish a clear picture of the degree of information students have about sustainable development, including its definition and goals, as well as their knowledge of the different types of renewable energy sources, the basic principles of their functioning, their benefits and shortcomings, how much they are present in our country. The research was also focused on analyzing whether there is a connection between areas of living and gender with the comprehension of sustainable development. [ABSTRACT FROM AUTHOR]

This paper is focused on identifying and analyzing the challenges and opportunities that North Macedonian companies faced while migrating from OHSAS 18001 to ISO 45001. The most common challenges identified were the lack of expertise, corporate culture, cost, low top management support and the redefinition of health. These challenges were pretty similar to the ones companies in other countries faced. On the other hand, there were opportunities that arose during this transition such as proactive approach and the redefinition of health, but there were some companies that didn't recognize any opportunities. The proactive approach is one of the differencing elements between OHSAS 18001 and ISO 45001, which results in implementing preventive measures that lower the number of work-relatedinjuries, which is the main goal of any Occupational Health and Safety Management System. [ABSTRACT FROM AUTHOR]

This paper describes goals, process, and results in the effort to introduce new curricula at The Faculty of Technical Sciences of University Mother Theresa - Skopje fully devoted to teach students in the direction of sustainable development. The idea was born in the process of reaccreditation of the old curricula named "Mechanical Engineering and management" at The Faculty of Technical Sciences. The authors of this paper, and the idea for reconstruction were fully aware of the direction Mechanical Engineering needs to go to contribute to the sustainable development of the country and wider. Therefore, that idea led the developing process into new curricula titled: "Sustainable Design in Mechanical Engineering". From total of 40 courses, 15-20 are fully related to sustainable development goals and the curricula includes also a number of projects and diploma work by which students will additionally have an opportunity to add to their understanding and knowledge of sustainable development tools. The new curricula successfully passed the process of accreditation and it is now a part of this University offer. Based on this curricula, a number of courses for lifelong learning will be developed. It is expected that this curricula will attract attention both of the new students, but also of the professionals at different companies, state and municipality institutions. [ABSTRACT FROM AUTHOR]

Agriculture is one of the most important economic components of a society, unfortunately accompanied by many casualties related to occupational risks and hazards. The main object of this research is to present the current state of knowledge regarding safety and health at work in agriculture among farmers in the city of Debar. Research is done through questionnaires, observation and interviewing of farmers, in order to interpret a part of the safety and health at work is presented to people who deal with agriculture, based on the basic knowledge of safety and health for agriculture. There are many dangers found on farms. Most of them are ignored, which can cause the farmer to suffer later in terms of ill health, possible injury or death. [ABSTRACT FROM AUTHOR]

Supporting the participation of institutions in social dialogue advances policy making, but at the same time encourages the practice of regular consultations of Economic-Social Councils (ESC) at the national and local level. This paper aims, through several indicators, to determine the importance of social inclusion for strengthening the capacities for Occupational Safety and Health (OSH) in the Union of Defense and Security (SOB), followed by social dialogue between stakeholders. Through the realized trainings for SOB members, the especially low value of only 22.2% for the OSH awareness among the employee's indicator, increased to a value of about 48.6%. Also, the educational workshops contributed to the increase in the value of the Education of SOB members on OSH indicator, from 11.2% to 56.4%. Important progress has also been achieved in the education of future OSH trainers, where the value of 4.3% for this indicator was increased to 81.5%. Also, the initially measured value of 2.8% for the indicator of legal awareness of the participants, notices progress up to 41.2% for availability of information, after using the services of the legal clinic. The results analyzed and the progress achieved in all indicators show that social dialogue creates more transparent conditions for social partners, followed by better education for giving quality advice and delivering services based on the demand for creating more and better workplaces. [ABSTRACT FROM AUTHOR]

The goal of this study was to find the link between workplace accidents and the lack of Occupational Safety and Health education and training on the woodworking industry workforce. The focus of research was to determine the level of the understanding of the importance of personal protective equipment in preventing injuries as well as the amount of information the employees have received about the hazards they can and will face on their workplace and the ways they can prevent or minimize the risks before and during their employment. The research aims to give a clearer insight about how much the alertness of workers needs to be adjusted along with the changes necessary in the degree and type of education needed. [ABSTRACT FROM AUTHOR]

The occupational environment and work procedures of automobile technicians are closely tied with chemicals, which often have fundamental roles in many procedures during daily activities. Automobile technicians can be exposed to different chemicals on a daily basis, which can lead to health deterioration and a lower quality of life with prolonged long-term exposure. The key challenge that health and safety now faces are to engage and influence the huge variety of businesses, particularly small businesses, and to help them manage health and safety more effectively. As a result of insufficient implementation of appropriate safety rules or management procedures, as well as lack of training for the employees to carry out these practices, the majority of exposure occurred especially on projects undertaken by small companies. The main objective of this paper is to assess the occupational exposure frequency to chemicals as well as the level of the awareness among the employees in order to build a more insightful database of issues related to Occupational Health and Safety. [ABSTRACT FROM AUTHOR]

The main objective in this paper is to analyze several quality indicators for the working environment in the Defense and Security Trade Union (SOB) and to examine serious problems that contradict the concept of sustainability and human capital conservation. The research aims to present the real situation for the workplace’s quality, but also to obtain data on the level of awareness and education on Occupational Safety and Health (OSH) among SOB members, which does not meet international standards for a NATO member such as the Republic of North Macedonia. Due to collecting ofthe necessary data, educational trainings for the members of SOB, and trainings for the future trainers for presidents in SOB were realized during 2020/2021. For the same purpose, an anonymous survey was conducted and ten quality indicators were developed. Although the quality indicator for accidents at work was only 13 (on a 0 to 100 scale), the value of 53 belonged to the indicator for the importance of level of protection at work from physical injury. A total value of 69 was registered for the personal protective equipment (PPE) indicator, which is one of the biggest problems in terms of requiring adequate safety working conditions. During trainings and operations, most of the military personnel include intense combat training and extremely dangerous situations, so the stress they are exposed to is a much bigger problem than physical exertion. [ABSTRACT FROM AUTHOR]

The purpose of the research study is analyses and preventing pollution that is a compelling strategy for many reasons. The huge dependence on ecosystem management services resulting in depletion of natural resources and biodiversity is one of the major challenges in efforts to mitigate and adapt to climate change and improve the quality of life. The research aims to approach the analysis of the possibilities for reducing pollution as well as its reporting by the citizens themselves. Raising public awareness among citizens and encouraging a sense of responsibility in the protection and promotion of the environment, by animating the young population in taking measures to prevent or reduce environmental pollution. The expected findings and arguments of the work provides sufficient information on sources of pollution and how to address them especially by firstly focusing on increasing the awareness to these factor and damages that pollution is causing to health in general. For the realization of the research, development of a software portal is envisaged. The research methodology used is triangulation technique which combines qualitative and quantitative methodology. As research method used questionnaire and focus groups. [ABSTRACT FROM AUTHOR]

The purpose of the research in this study is to analyze the impact of early prediction of hazards to prevent workplace injuries and improve employees' safety. The tremendous advances in technology in recent decades have created new hazards in machine handling, which has led to the development of new techniques for a higher degree of protection that society expects from employers to provide to their employees. The analyses show that regardless of the type of method used for risk assessment, the highest risks for machine operators are generated by mechanical hazards. This research aims to approach the analysis of risks caused by mechanical hazards and propose measures to prevent them before occurrence. A risk assessment for a mechanic was done and all factors that generate a high level of risk were analyzed. The methodology used for risk assessment is a tabular technique that combines qualitative and quantitative methodology. The Kinney method was used as the research method. Raising awareness of occupational safety among employers and encouraging a sense of responsibility for workers' health will be a major benefit that will provide better working conditions in any business, both human and economically. [ABSTRACT FROM AUTHOR]

In this study, a power series which can generate different families of new water sorption isotherm models were presented. Experimentally obtained values for equilibrium moisture content of pear for three different temperatures, 15, 30 and 45 C, and water activities, from 0.112 to 0.920, as well as literature experimental values for equilibrium moisture content of potato for three different temperatures, 30, 45 and 60 C, and water activities, from 0.112 to 0.900, were fitted with the newly generated sorption isotherm models plus the referent Anderson model known in the literature as Guggenheim- Anderson-de Boer ( GAB) model. In order to find which model gives the best results for approximation of experimental sorption data, several statistical criteria proposed in scientific literature were used. For each model and experimental data set, the average performance index was calculated and models were ranked afterwards. After that, some statistical rejection criteria were checked ( D' Agostino- Pearson test of normality, single-sample run test, confidence intervals of estimated parameters, significance and precision of the model parameters). The performed statistical analysis shows that the two newly generated three-parameter models, M32 and M34, give the better fit to the sorption data of pear than the referent three-parameter Anderson model, while M32 gives the best fit to the sorption data of potato. Practical Applications The sorption isotherms of food materials are of great importance in the food industry and technology, especially for the design and optimization of the drying equipment and in the approach to the prediction of shelf life stability of material. The new generated three-parameter models, M32 and M34, can be successfully used in practical calculations of the equilibrium moisture content, which is an important parameter in storage conditions of dry food materials. With the incorporation of M32 or M34 in the drying model, more accurate values of transient moisture and temperature profiles on the dried materials will be obtained. [ABSTRACT FROM AUTHOR]

In this paper, some of the statistical indicators which refer to serious and fatal accidents at work in the European Union (EU-28) and in the Republic Macedonia are presented. The performed statistical analysis shows that the number of serious and fatal accidents at work in EU-28 and in the Republic Macedonia, in 2012 was decreased in comparison with 2008. Nevertheless, the Republic of Macedonia has high incidence rate for fatal accidents at work compared to highly develop European countries. The activities of public administration and defense, construction, manufacturing, transportation and storage sector and the activities of households as employers are the economic sectors in which it is possible to prevent injuries caused by serious accidents at work. The activities of households as employers, construction sector, transportation and storage sector and agriculture, forestry and fishing are the economic sectors in where prevention of injuries at work caused by fatal accidents must be addressed. [ABSTRACT FROM AUTHOR]