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Abstract

The objective of the paper is to evaluate the implications of trade liberalization under the Transatlantic Trade and Investment Partnership (TTIP) for the Polish economy. We analyze the level of tariffs and non-tariff protection in the US and in the EU and identify products particularly “sensitive” from the point of view of TTIP liberalization. With the help of a partial equilibrium model, we simulate the trade implications of the TTIP for Poland’s trade with the US at the detailed product level. We analyze trade creation and diversion effects of tariff elimination and partial removal of non-tariff barriers. We found that the TTIP can increase Poland’s trade with the US by around 45 percent with a limited impact on its trade with the European Union (EU) members. Subsequent general equilibrium simulations show that trade diversion effects of the TTIP are substantial, while the welfare benefits of the agreement are limited.
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Authors and Affiliations

Jan Hagemejer
1 2
ORCID: ORCID
Jan Jakub Michałek
1
ORCID: ORCID
Karolina Pawlak
3
ORCID: ORCID

  1. University of Warsaw, Poland
  2. CASE Center for Economic and Social Research, Warsaw, Poland
  3. Poznan University of Life Sciences, Poland
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Abstract

In this paper, we propose a robust estimation of the conditional variance of the GARCH(1,1) model with respect to the non-negativity constraint against parameter sign. Conditions of second order stationary as well as the existence of moments are given for the new relaxed GARCH(1,1) model whose conditional variance is estimated deriving firstly the unconstrained estimation of the conditional variance from the GARCH(1,1) state space model, then, the robustification is implemented by the Kalman filter outcomes via density function truncation method. The GARCH(1,1) parameters are subsequently estimated by the quasi-maximum likelihood, using the simultaneous perturbation stochastic approximation, based, first, on the Gaussian distribution and, second, on the Student-t distribution. The proposed approach seems to be efficient in improving the accuracy of the quasi-maximum likelihood estimation of GARCH model parameters, in particular, with a prior boundedness information on volatility.
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Authors and Affiliations

Abdeljalil Settar
1
ORCID: ORCID
Nadia Idrissi Fatmi
1
ORCID: ORCID
Mohammed Badaoui
1 2
ORCID: ORCID

  1. LIPIM, École Nationale des Sciences Appliquées (ENSA), Khouribga, Morocco
  2. LaMSD, École Supérieure de Technologie (EST), Oujda, Morocco
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Abstract

The educational expansion in many advanced economies in the past few decades has triggered a debate on overeducation. The aim of the study is to provide an empirical evaluation of the wage effects of overeducation in different occupational groups. We also analyse whether these effects differ between genders. In order to achieve this, we use individual data from the Structure of Wages and Salaries by Occupations database of firms with 10 or more employees in Poland. We use data from the 2006-2014 waves of the survey. We calculate the impact of overeducation on wages using a Mincer-type wage regression model. We show that on average workers are rewarded for being overeducated, but the size of wage effects of overeducation differs among particular occupational groups. We show also that the choice of the method of measurement of overeducation affects the results.
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Authors and Affiliations

Paulina Broniatowska
1
ORCID: ORCID

  1. University of Warsaw
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Abstract

There are reasons researchers may be interested in accounting for spatial heterogeneity of preferences, including avoiding model misspecification and the resulting bias, and deriving spatial maps of willingness-to-pay (WTP), which are relevant for policy-making and environmental management. We employ a Monte Carlo simulation of three econometric approaches to account for spatial preference heterogeneity in discrete choice models. The first is based on the analysis of individual-specific estimates of the mixed logit model. The second extends this model to explicitly account for spatial autocorrelation of random parameters, instead of simply conditioning individual-specific estimates on population-level distributions and individuals’ choices. The third is the geographically weighted multinomial logit model, which incorporates spatial dimensions using geographical weights to estimate location-specific choice models. We analyze the performance of these methods in recovering population-, region- and individual-level preference parameter estimates and implied WTP in the case of spatial preference heterogeneity. We find that, although ignoring spatial preference heterogeneity did not significantly bias population-level results of the simple mixed logit model, neither individual-specific estimates nor the geographically weighted multinomial logit model was able to reliably recover the true region- and individual-specific parameters. We show that the spatial mixed logit proposed in this study is promising and outline possibilities for future development.
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[23] McFadden D., (1974), Conditional Logit Analysis of Qualititative Choice Behaviour, [in]: Frontiers in Econometrics, [ed.:] Zarembka P., Academic Press, New York, NY, 105–142.
[24] Smith T. E., LeSage J. P., (2004), A bayesian probit model with spatial dependencies, Spatial and Spatiotemporal Econometrics 18(18), 127–160.
[25] Train K., Sonnier G., (2005), Mixed Logit with Bounded Distributions of Correlated Partworths, [in:] Applications of Simulation Methods in Environmental and Resource Economics, [eds.:] Scarpa R., Alberini A., Springer Netherlands, 117–134.
[26] Train K. E., (2009), Discrete Choice Methods with Simulation, 2 Ed., Cambridge University Press, New York.
[27] Yao R. T., Scarpa R., Turner J. A., Barnard T. D., Rose J. M., Palma J. H. N., Harrison D. R., (2014), Valuing biodiversity enhancement in New Zealand’s planted forests: Socioeconomic and spatial determinants of willingness-to-pay, Ecological Economics 98(0), 90–101.


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Authors and Affiliations

Wiktor Budziński
1
ORCID: ORCID
Mikołaj Czajkowski
1
ORCID: ORCID

  1. University of Warsaw
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Abstract

The olive psyllid Euphyllura straminea Loginova (Hemiptera: Aphalaridae) is one of the most important pests of olive trees in Iran. To determine this pest’s economic injury level (EIL) and to evaluate the relationship between density of nymphs (DON) and yield loss, different densities of olive psyllid nymphs were maintained on olive trees by different insecticide concentrations. Counting nymphs on olive terminal shoots was done to determine nymph abundance at the end of nymphal stage. Different densities of olive psyllid nymphs resulted in significantly different yield losses of olive trees. Regression analysis was used to determine the relationship between nymph density and yield loss. Considering pest management costs, the market value of olive, and insecticide efficiency, economic injury levels were evaluated from 4.08 to 7.14 nymphal days. The olive psyllid EIL values could be used to plan a pest control program in Zanjan and Guilan provinces.
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Authors and Affiliations

Aref Marouf
1
Mohammadreza Abbasi Mojdehi
2
Shamsollah Najafi
1

  1. Plant Protection Department, Agricultural and Natural Resources Research Center of Zanjan Province (AREEO), Iran
  2. Plant Protection Department, Agricultural and Natural Resources Research Center of Guilan Province, Rasht, Iran
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Abstract

The high sensitivity of beans to herbicides is one of the limiting factors regarding the management of dicot weeds in bean crops. Protoporphyrinogen oxidase (PPO) inhibition is an important mechanism of action that has unregistered molecules with potential use in bean crops. The objectives of this study were to investigate the tolerance of Brazilian bean cultivars to distinct PPO inhibitors and to determine the existence of cross-tolerance in cultivars to the different PPO inhibitor chemical groups. In the first and second experiments, the BRSMG Talismã, Jalo Precoce, BRS Esplendor, and IPR 81 cultivars were subjected to saflufenacil doses pre- (0, 9.6, 14.1, 20.5, 30.0, and 43.8 g a.i. ‧ ha–1) and post-emergence (0, 0.7, 1.0, 1.5, 2.1, and 3.1 g a.i. ‧ ha–1). In the third experiment, the tolerance of 28 bean genotypes to saflufenacil (20.5 g a.i. ‧ ha–1) in pre-emergence was determined. In the fourth, fifth, sixth and seventh experiments, we investigated the cross-tolerance of bean to the fomesafen, flumioxazin, sulfentrazone, and saflufenacil herbicides, respectively. Even very low saflufenacil doses in post-emergence caused plants of all cultivars to die rapidly; therefore, the tolerance was much lower at this application time than in pre-emergence. There was high tolerance variability to saflufenacil among the 28 cultivars. The bean tolerance to fomesafen, flumioxazin, sulfentrazone, and saflufenacil applied pre-emergence depended on the cultivar and dose. Fomesafen was highlighted owing to its higher selectivity in relation to the different cultivars. No cross-tolerance pattern to the PPO inhibitor chemical groups applied in pre-emergence was observed among the evaluated bean cultivars. The results of this study could be of significance to farmers and technical assistance personnel, as well as for future research on cultivar breeding and the elucidation of biochemical and genetic mechanisms involved in herbicide tolerance.
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Authors and Affiliations

Antonio Pedro Brusamarello
1
Michelangelo Muzell Trezzi
1
Fortunato de Bortoli Pagnoncelli Júnior
1
Paulo Henrique de Oliveira
1
Taciane Finatto
1
Marcos Vinícius Jaeger Barancelli
1
Bruno Alcides Hammes Schmalz
1
Patrícia Bortolanza Pereira
1

  1. Department of Agronomy, Federal Technological University of Paraná (UTFPR), Brazil
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Abstract

The present research employs the statistical tool of Response surface methodology (RSM) to evaluate the machining characteristics of carbon nanotubes (CNTs) coated high-speed steel (HSS) tools. The methodology used for depositing carbon nanotubes was Plasma-Enhanced Chemical Vapor Deposition (PECVD). Cutting speed, thickness of cut, and feed rate were chosen as machining factors, and cutting forces, cutting tooltip temperature, tool wear, and surface roughness were included as machining responses. Three-level of cutting conditions were followed. The face-centered, Central Composite Design (CCD) was followed to conduct twenty number of experiments. The speed of cutting and rate of feed have been identified as the most influential variables over the responses considered, followed by the thickness of cut. The model reveals the optimized level of cutting parameters to achieve the required objectives. The confirmation experiments were also carried out to validate the acceptable degree of variations between the experimental results and the predicted one.
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Authors and Affiliations

Chandru Manivannan
1
ORCID: ORCID
Selladurai Velappan
2
ORCID: ORCID
Venkatesh Chenrayan
3
ORCID: ORCID

  1. Dhirajlal Gandhi College of Technology, Salem – 636309, Tamilnadu, India
  2. Coimbatore Institute of Technology, Coimbatore – 641014, Tamilnadu, India
  3. Adama Science and Technology University, Adama, Ethiopia
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Abstract

In this investigation, Copper Matrix Surface Composites (CMSCs) were reinforced with various ceramic particles like Aluminum Nitrate (AlN), Titanium diboride (TiB2), and Rice Husk Ash (RHA) are used to increase the metallurgical and mechanical properties by Friction Stir Processing (FSP). The Design of the Experiment (DOE) Taguchi L9 orthogonal array method was used. The process parameters considered were groove width and various types of reinforcement particles. The fabrication of CMSCs was achieved by using optimized process parameters, such as the tool transverse speed of 40 mm/min, rotational tool speed of 1000 rpm, and an axial load of 10 kN with one pass. The influence of FSP process parameters on CMSCs in the stir zone is observed through Optical Microscope (OM), Field Emission Scanning Electron Microscope (FESEM), and Transmission Electron Microscope (TEM). Mechanical properties such as microhardness and wear rate are studied and compared. It reveals that good interfacial bonding was produced between ceramic particles in CMSCs. TiB2 reinforced with copper matrix surface composites enhance microhardness and had a lesser wear rate.
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Authors and Affiliations

S. Saravanakumar
1
ORCID: ORCID
S. Gopalakrishnan
2
ORCID: ORCID
K. Kalaiselvan
3
ORCID: ORCID

  1. Department of Mechanical Engineering, M. Kumarasamy College of Engineering, Karur, Tamilnadu, India
  2. Department of Mechanical Engineering, KS Rangasamy College of Technology, Tiruchengode, Tamilnadu, India
  3. Department of Mechanical Engineering, Dr. NGP Institute of Technology, Coimbatore, Tamilnadu, India
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Abstract

The aim of this work was to characterize the changes in microstructure and chemical composition of the austenitic overlays on a pressure vessel steel that occur in the vicinity of the interface between the overlay and the base material. The investigations were carried out on a 16Mo3 boiler pipes weld overlaid by 309 and 310 steels. The microstructural examinations were performed on longitudinal cross-sectioned samples. The qualitative and quantitative chemical composition analyses on metallographic samples were determined on Scanning Electron Microscopy (SEM) by means of Energy Dispersive Spectrometry (EDS). The article analyzes the influence of the solidification sequence in both types of steel on final microstructure.
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Authors and Affiliations

M. Rozmus-Górnikowska
1
S. Dymek
1
M. Blicharski
1
Ł. Cieniek
1
J. Kusiński
1

  1. AGH University of Science and Technology, Faculty of Metals Engineering and Industrial Computer Science, al. A. Mickiewicza 30, 30-059 Krakow, Poland
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Abstract

This paper deals with the subject of high temperature analysis of refining slags originating from a ladle from an actual/industrial secondary refining process. The objective of the conducted research was to learn about the rheological behaviour of the complex industrial slag systems analysed in conditions of variable rheological parameters and temperature, also analyses with a high-temperature microscope. The analysed system seems to be a Newtonian body (with viscosity between 0.1 and 0.8 Pa·s, depend on temperature value, and chemical composition).
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Authors and Affiliations

M. Ślęzak
1
ORCID: ORCID
M. Karbowniczek
1
ORCID: ORCID
P. Migas
1
ORCID: ORCID
W. Ślęzak
1
ORCID: ORCID

  1. AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Krakow, Poland
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Abstract

The methods of making diamond tools have undergone a remarkable development since the invention of synthetic diamond in the mid-1950s. The current review summarises key historical, recent and ongoing trends and developments in sintered diamond tools. The report concentrates on tools used within the stone and construction industries which, being the main consumers of metal-bonded diamond tools fabricated by powder metallurgy (P/M) technology, have always fuelled advances in tool design and production technologies.
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Authors and Affiliations

J. Konstanty
1
ORCID: ORCID

  1. AGH – University of Science & Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland
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Abstract

TiAl based intermetallics are widely used for structural applications in aviation, chemical engineering, automotive and sports equipment. In this study, the electrical resistance sintering (ERS) technology used in the production of gamma-TiAl intermetallics is based on the principle of applying pressure simultaneously with a high-density electric current. The purpose of this study was to investigate the cyclic oxidation resistance of Ti-44Al-3Mo and Ti-44Al-3Nb alloys (at.%) and the applicability of artificial neural network (ANN) modeling for the forecast of the oxidation behavior of these alloys. In order to obtain this aim, the alloys sintered by ERS were oxidized at 900°C for 360 h and then the oxidation behaviors of them are evaluated by plotting a graph between weight change as a function of time. The data collected after the oxidation experiments were used to construct the prediction models. The modelling results show that a good agreement between experimental results and prediction results was found. The oxidized alloys were characterized using XRD and SEM-EDS. The XRD patterns revealed the oxidation products are composed of TiO2 and Al2O3 oxides. SEM-EDS analysis indicated that the oxide scales of alloys are made up of a multilayered structure.
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Authors and Affiliations

Y. Garip
1
ORCID: ORCID
Z. Garip
2
ORCID: ORCID
O. Ozdemir
1
ORCID: ORCID

  1. Sakarya Applied Science University, Technology Faculty , Department of Metallurgy and Materials Engineering, Esentepe Campus, 54187, Sakarya -Turkey
  2. Sakarya Applied Science University, Technology Faculty, Department of Computer Engineering, Esentepe Campus, 54187, Sakarya -Turkey
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Abstract

Growing awareness for occupational safety in the welding environment needs a sustainable welding system. Welding gases releases toxic tiny particles and gases that inflict severe health consequences in the weld zone are unsolicited. Some of the other main adverse effects are lung disease, hemoptysis, pulmonary inflammation, pneumoconiosis, etc. GMAW procedure has been used for welding 316L stainless steel plates of 3 mm, 5 mm, and 6 mm. Various current configurations with gas flow rate of 5 LPM, 10 LPM and 15 LPM were also used to achieve optimum butt joint performance and to reduce the production rate of fume contributing to cost-effectiveness. In this research a cost-effective fume extraction hood was fabricated for measuring Emission factor produced during welding. Various shielding gas compositions including Pure Argon, Pure CO2, 92% Ar+8% CO2 and 88% Ar+12% CO2 were used to determine the best operating parameters in the GMAW method. To satisfy the latest Permissible Exposure Limit (PEL) legislation, optimum technical parameters for efficient welding were acknowledged with the lowest emission factor. A maximum reduction of Emission factor can be achieved by using Pure Argon. The inclusion of CO2 as a shielding gas mixture gives higher emission factor when compared to Pure Argon. Very low emission factor were witnessed in this research when compared to previous investigations. Lower emission factor of 2941.17 mg /kg of electrode, 4411.76 mg/kg of electrode and 7352.94 mg/kg of electrode were obtained for pure argon as shielding gas with 150 A welding current.
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Authors and Affiliations

K.V. Satheesh Kumar
1
ORCID: ORCID
P. Selvakumar
2
ORCID: ORCID
K.R. Uvanshankar
1
ORCID: ORCID
S. Thirunavukarasu
1
ORCID: ORCID
V. Vijay Anand
1
ORCID: ORCID
D. Vishal
1
ORCID: ORCID

  1. Department of Mechanical Engineering, Kongu Engineering College, Erode- 638060, Tamilnadu, India
  2. Department of Chemistry, Vivekanandha College of Arts & Sciences for Women, Tiruchengode- 637205, Tamilnadu, India
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Abstract

The analysis of the development of the microstructure of deep drawn automotive B pillar, as well as the analysis of deformation based on numerical simulation and experiment, was performed. The microstructure of steel sheet as well as Al-Si coating after various stages of B pillar production was investigated. It was found that the obtained microstructure of the B pillar was significantly different from that described in many studies as a proper one. The microstructure of the investigated material consisted of martensite, bainite, and a small amount of ferrite. Al-Si coating, despite its morphological changes, remained on the surface of B pillar and, in spite of this, did not fully eliminate oxidation and decarburization of B pillar material. The analysis of the state of strain allowed to evaluate the deformation safety of the process, as well as to verify the simulation results through measurements of sheet thickness variations.
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Authors and Affiliations

M. Paćko
1
ORCID: ORCID
J. Krawczyk
1
ORCID: ORCID
T. Śleboda
1
ORCID: ORCID
T. Frocisz
1
ORCID: ORCID
Maciej Rumiński
ORCID: ORCID
O. Lypchanskyi
1
T. Tokarski
1
ORCID: ORCID
P. Piasecki
2

  1. AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland
  2. Kirchhoff Automotive, Mielec, Poland
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Abstract

Heat consumption and steel loss for scale determine the costs of a heating process. The heating rate influences both. This paper evaluates the heating rate of a long charge made of three various materials, depending on the changes of the furnace atmosphere on the rotary furnace circumference. Numerical computing was performed based on a formulated heat transfer model in the rotary furnace chamber, while considering the growth of the scale layer. One heating curve was selected, which has allowed the heating time to be reduced by 36% while limiting the scale loss by 40%. It was also shown that the thermal stresses and strains should not lead to fractures of the charge heated.
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Authors and Affiliations

B. Hadała
1
ORCID: ORCID
M. Rywotycki
1
ORCID: ORCID
Z. Malinowski
1
ORCID: ORCID
Sz. Kajpust
2
S. Misiowiec
2

  1. AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059 Krakow, Poland
  2. Zarmen FPA Sp. z o.o., 39 Filarskiego Str., 47-330, Zdzieszowice, Poland
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Abstract

The presented article concerns the issue of supporting the ADI cast iron product manufacturing process and presents an IT system dedicated mainly to designers and technologists. Designers can be supported at the stage of selecting types of materials and technologies (including ADI cast iron) to produce products with required properties. Technologists can obtain support in determining the parameters (temperature and chemical) of the ADI cast iron manufacturing process in order to obtain products with specific properties. The system also contains an information resources (standards, documentation, examples) concerning ADI cast iron and products made of it. Examples of use by individual system users are presented as a case study.
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Authors and Affiliations

A. Opaliński
1
ORCID: ORCID
D. Wilk-Kołodziejczyk
1 2
ORCID: ORCID

  1. AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059 Krakow, Poland
  2. Łukasiewicz Research Network – Krakow Institute of Technology, 73 Zakopiańska Str., 30-418 Kraków, Poland
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Abstract

In this work, the influence of plastic injection molding conditions, mainly plasticizing conditions: plasticizing pressure (back pressure) and decompression (suck-back) after dosing on weight, thickness, mechanical properties and structure of HDPE parts obtained by injection molding with the addition of chemical blowing agent was done. In order to enable the manufacturing of correctly made molded parts under given plasticizing conditions, other parameters (hold time and hold pressure, injection velocity and injection time) were also changed. It was found that making correct molded parts using decompression requires increased hold pressure and hold time. The share of the porous structure in the parts is inversely proportional to the decompression as well as the hold pressure and hold time, while the plasticizing pressure has little effect on thickness, mass, tensile strength and elongation at maximum force, however, it affects the structure of the molded parts to some extent.
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Authors and Affiliations

P. Palutkiewicz
1
ORCID: ORCID
P. Postawa
1
ORCID: ORCID
J. Wawrzyniak
1
ORCID: ORCID

  1. Czestochowa University of Technology, Faculty of Mechanical Engineering and Computer Science, Department of Technology and Automation, 21 Armii Krajowej Av., 42-201 Czestochowa, Poland
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Abstract

Knowledge about complex physical phenomena used in the casting process simulation requires continuous complementary research and improvement in mathematical modeling. The basic mathematical model taking into account only thermal phenomena often becomes insufficient to analyze the process of metal solidification, therefore more complex models are formulated, which include coupled heat-flow phenomena, mechanical or shrinkage phenomena. However, such models significantly complicate and lengthen numerical simulations; therefore the work is limited only to the analysis of coupled thermal and flow phenomena. The mathematical description consists then of a system of Navier-Stokes differential equations, flow continuity and energy. The finite element method was used to numerically modeling this problem. In computer simulations, the impact of liquid metal movements on the alloy solidification process in the casting-riser system was assessed, which was the purpose of this work, and the locations of possible shrinkage defects were pointed out, trying to ensure the right supply conditions for the casting to be free from these defects.
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Authors and Affiliations

L. Sowa
1
ORCID: ORCID
T. Skrzypczak
1
ORCID: ORCID
P. Kwiatoń
1
ORCID: ORCID

  1. Czestochowa University of Technology, Department of Mechanics and Machine Design Fundamentals, 73 Dąbrowskiego Str., 42-200 Częstochowa, Poland
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Abstract

The article has been devoted to issues connected with socket fusion welding, which is next to welding one of the methods of thermoplastic polymers joining. In this paper, the research was presented, which the aim was analysis of quality of joints obtained as a result of resistance welding of polypropylene pipes with diameter ø20 in the temperature range of 200÷230°C. To that end a Testo thermal imaging camera was used, flexural strength of the combined components was tested as well as the received weld was observed under a stereoscopic microscope. Conducted studies showed that the best results of joint are obtained during welding at 220°C and 230°C, while lower temperatures did not fully perform their function during the process of joining the pipe elements.
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Authors and Affiliations

A. Kalwik
1
ORCID: ORCID
K. Mordal
1
ORCID: ORCID
J. Redutko
1
ORCID: ORCID

  1. Czestochowa University of Technology, Faculty of Mechanical Engineering and Computer Science, Department of Technology and Automation,21 Armii Krajowej Av., 42-201 Czestochowa, Poland
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Abstract

The study examined the impact of the angle of incidence of mechanical waves on various types of quasi one-dimensional superlattice. Binary periodic structure, quasi-periodic distribution of Thue-Morse layers and Severin’s aperiodic multilayer were used. Using the concatenation and recursive rules, the distribution of layers was determined for individual structure types for generation numbers equal to 3, 4 and 5. The structures were selected so that the thickness of the composite was the same for each type of distribution for a given generation number value. Transfer Matrix Method algorithm was used to determine reflectance. The band structure of reflectance has been demonstrated for incidence angles up to 90 degrees at mechanical wave frequencies up to 50 kHz. The existence of wide bands of high reflectance above the acoustic frequencies was demonstrated for the analyzed structures. Increasing the layer thickness caused an inhomogeneous shifts of transmission peaks towards lower frequencies.
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Authors and Affiliations

S. Garus
1
ORCID: ORCID
W. Sochacki
1
ORCID: ORCID

  1. Czestochowa University of Technology, Department of Mechanics and Fundamentals of Machinery Design, Faculty of Mechanical Engineering and Computer Science, 73 Dąbrowskiego Str., 42-201 Częstochowa, Poland
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Abstract

The goal of this paper is to measure the non-wetting to wetting transition temperatures of liquid tin on surfaces of different steel samples in vacuum with residual pressure of 10–8 bar. The experiments were conducted on four steels (C45, S103, CK60 and EN1.4034) of varying compositions using pure tin (99.99%) by the sessile drop method. Non-wetting to wetting transition (contact angle decreasing below 90°) by liquid tin was observed as function of increasing temperature in the range of 820-940 K for low alloyed steels C45, S103 and CK60, while it was considerably higher (around 1130 K) for high chromium EN1.4034 steel. It is concluded that at about the same temperatures, the surfaces of the steel samples are spontaneously deoxidized due to the combined effect of high temperature, low vacuum and C-content of steels. After the oxide layer is removed, the contact angles of liquid tin on steel surfaces were found in the range of 45-80° for low alloyed C45, S103 and CK60 steels and around 20° for high chromium EN1.4034 steel. These relatively high contact angle values compared to other metal/metal couples (such as liquid Cu on steels) are due to the formation of not fully metallic intermetallic compounds (FeSn and FeSn2) at the interface (such do not form in the Cu/Fe system).
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Authors and Affiliations

D. Varanasi
1
K.E. Aldawoudi
1
P. Baumli
1
D. Koncz-Horvath
1
G. Kaptay
1

  1. University of Miskolc, Institute of Physical Metallurgy, Metal Forming and Nanotechnology, 3515 Miskolc-Egyetemvaros, Hungary
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Abstract

The electronic, optical and thermoelectric properties of MoS2 nano-sheet in presence of the Ru impurity have been calculated by density functional theory framework with Generalized Gradient approximation. The MoRuS2 nano-sheet electronic structure was changed to the n-type semiconductor by 1.3 eV energy gap. The optical coefficients were shown that the loosing optical energy occurred in the higher ultraviolet region, so this compound is a promising candidate for optical sensing in the infrared and visible range. The thermoelectric behaviors were implied to the good merit parameter in the 100K range and room temperatures and also has high amount of power factor in 600K which made it for power generators applications.
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Authors and Affiliations

Firouzeh Motamad Dezfuli
1
ORCID: ORCID
Arash Boochani
2
ORCID: ORCID
Sara Sadat Parhizgar
1
ORCID: ORCID
Elham Darabi
1
ORCID: ORCID

  1. Department of Physics, Faculty of Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
  2. Department of Physics, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran
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Abstract

The aim of this study was to present the results of the examinations of the structure and thermomechanical properties of PA6/NanoBent composite. NanoBent composites composed of minerals from the smectite group (mainly montmorillonite) were used for modification of polyamide 6. PA6 composite with content of 1, 3, 5% of NanoBent was prepared in a Theysohn TSK 75-N twin screw extruder. The samples were prepared using the injection technology by means of a Krauss-Maffei KM65-160 C1 injection molding machine. The samples of composites obtained at different injection temperatures and injection mold temperatures were used for the examinations. Degree of crystallinity was examined using the DSC method whereas the material structure was examined with an optical microscope. DSC studies showed a reduction in the value of the degree of crystallinity with the increasing content of nanofiller in the polymer material. The narrowing of the peak was recorded in the DSC thermograms for nanocomposites with greater percentage of the nanofiller. Dynamical properties of polyamide 6 nanocomposite were also determined in relation to temperature and frequency. The samples were bended at frequencies of 1 Hz and 10 Hz over the temperature range from –100°C to 180°C and the heating rate of 2K/min. A significant increase in storage modulus was observed for PA6 samples with the content of 5% of NanoBent obtained at the injection temperature of 270°C and mold temperature of 70°C. Smaller size of spherulites and arrangement of structural elements in clusters along the line of polymeric material flow in the mold cavity at higher contents of NanoBent were observed during structural examinations of the composites.
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Authors and Affiliations

A. Gnatowski
1
ORCID: ORCID
R. Gołębski
1
ORCID: ORCID
K. Stachowiak
1
ORCID: ORCID

  1. Czestochowa University of Technology, Department of Technology and Automation, 19c Armii Krajowej Ave, 42-201 Czestochowa, Poland
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Abstract

Prolonged exposure to UV radiation, and ever-increasing life expectancy, mean that an increasing proportion of the population suffers from clouding of the intraocular lens. Nowadays, the performance of intraocular implantation procedures is commonplace. Unfortunately, with the increasing number of operations, the number of postoperative complications is also increasing. One way to avoid complications may be to use an intraocular implant that has been immersed in a solution containing silver nanoparticles. As part of the study, four selected intraocular implants – that are available on the ophthalmic market – were tested. In order to investigate the effect of silver particles on the optical properties of the implants, tests were carried out using a UV-VIS spectrophotometer. Two series of implants were tested: before and after immersion in a silver solution. The implants were immersed for a period of 7 days. It was found that the presence of silver particles does not have a negative impact on the translucency of the implants.
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Authors and Affiliations

K. Jeż
1
ORCID: ORCID
M. Gacek
1
ORCID: ORCID
M. Nabiałek
1
ORCID: ORCID
L. Toth
2
ORCID: ORCID
M. Pike-Biegunski
3

  1. Czestochowa University of Technology, Faculty of Production Engineering and Materials Technology, Department of Physics, 19 Armii Krajowej Str., 42-200 Częstochowa, Poland
  2. Óbuda University, Bánki Donát Faculty of Mechanical and Safety Engineering, Material Science Department, 1081, Népszínház 8, Budapest, Hungary
  3. Nano Koloid sp. z o. o, Hoża 62/37, 00-682 Warszawa, Poland

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