bluuebunny/crossref_metadata_2025 huggingface dataset:
Do guests get their expected dishes or not? Evaluation of food & beverage services in hotel establishments: Case of Antalya
Misafir umduğunu mu yer bulduğunu mu? Otel işletmelerinde yiyecek – içecek hizmetlerinin değerlendirilmesi: Antalya örneği
Authors: Görkem Onur
Published: August 2015

Transportation, accomodation and food & beverage services are the basic components of the tourism industry. As well as these services mean the biggest amount of the total tourism expences, but at the same time these services are the main actors for tourist satisfaction. On the other side, food & beverage service has an extra importance for tourist satisfaction. Because it meets the vital and continuous necessities of the tourists. So, food & beverage service is one of the most important components of tourist satisfactin. The main subject of this study is to investigate the level of tourist satisfaction for food & beverage services and to note any differences in satisfaction levels between the dimensions of satisfaction. Within the aim of the study  research data gained from 25915 guests who reserved hotels in 2013 summer season  in Antalya and completed the online survey related to their holiday experiences. The study findings showed that, there was difference (p<0,05) between perception of satisfaction dimensions and the lowest perception was made for food & beverage services. The hightist perceptions were made for five star hotels in Belek region, and the lowest perceptions were made for tree star hotels in Kemer region for food & beverage services.

Özet

Ulaştırma, konaklama ve yiyecek içecek hizmetleri turizm sektörünün temel bileşenleridir.  Bu hizmetler, turistik harca-malarının en önemli kalemleri oldukları gibi, seyahate ilişkin memnuniyet düzeylerinin oluşmasında da en önemli faktörlerdir. Ancak yiyecek içecek hizmetleri, yaşamsal ve süreklilik gösteren bir gereksinimi karşılıyor olması nedeniyle memnuniyet algısının en önemli unsurlarındandır.  Araştırmanın temel amacı, Antalya’da hizmet sunan otellerin yiyecek içecek hizmetlerine ilişkin konuk değerlendirmelerinin tespiti ve ilgili değerlendirme düzeylerinin otel tiplerine ve konumlarına gore farklılık gösterip göster-mediğinin araştırılmasıdır. Söz konusu amaç doğrultusunda 2013 yaz sezonunda www.tatilsepeti.com çevrim içi seyahat acentesi aracılığıyla Antalya destinasyonu için rezervasyon yaptıran ve tatil sonrası online değerlendirme anketine katılan 25915 konu-ğun otel değerlendirmesi analiz edilmiştir. Çalışma bulgularına göre, yiyecek içecek hizmetlerine ilişkin değerlendirmelerin diğer hizmet boyutlarına göre p<0,05 düzeyinde anlamlı farklılık gösterdiği anlaşılmıştır. Yiyecek içecek hizmetlerine ilişkin değerlendirme düzeyinin ise diğer hizmet boyutlarına gore en düşük düzeyde kaldığı anlaşılmıştır. Yiyecek içecek hizmetlerine ilişkin en olumlu değerlendirmenin Belek bölgesi beş yıldızlı otelleri, en olumsuz değerlendirmenin ise Kemer bölgesi üç yıldızlı otelleri için söz konusu olduğu anlaşılmıştır.
Engaging Customers in Coproduction Processes: How Value-Enhancing and Intensity-Reducing Communication Strategies Mitigate the Negative Effects of Coproduction Intensity
Authors: Haumann Till , Güntürkün Pascal , Schons Laura Marie , Wieseke Jan
Published: August 2015

Coproduction offerings, in which customers engage in the production of goods and services, are ubiquitous (e.g., ready-to-assemble products, self-service technologies). However, although previous research has predominantly identified beneficial aspects of coproduction in contrast to traditional firm production, the pivotal role of coproduction intensity within coproduction processes has largely been neglected. Furthermore, little is known about strategies that firms can employ to positively influence customers’ perceptions of coproduction processes. Drawing on a large field experiment with 803 customers engaging in actual coproduction processes, the current study makes a first attempt to address these research voids. The results show that coproduction intensity negatively affects customers’ satisfaction with the coproduction process. Furthermore, the study offers first insights into how firms can mitigate these negative effects by employing corporate communication strategies that either emphasize specific coproduction value propositions (value-enhancing communication strategies) or highlight additional coproduction service supplements (intensity-reducing communication strategies).
Recovery Of Electrodic Powder From Spent Lithium Ion Batteries (LIBs)
Authors: Shin S.M. , Jung G.J. , Lee Woo-Jin , Kang C.Y. , Wang J.P.
Published: August 2015

This study was focused on recycling process newly proposed to recover electrodic powder enriched in cobalt (Co) and lithium (Li) from spent lithium ion battery. In addition, this new process was designed to prevent explosion of batteries during thermal treatment under inert atmosphere. Spent lithium ion batteries (LIBs) were heated over the range of 300°C to 600°C for 2 hours and each component was completely separated inside reactor after experiment. Electrodic powder was successfully recovered from bulk components containing several pieces of metals through sieving operation. The electrodic powder obtained was examined by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and atomic absorption spectroscopy (AA) and furthermore image of the powder was taken by scanning electron microscopy (SEM). It was finally found that cobalt and lithium were mainly recovered to about 49 wt.% and 4 wt.% in electrodic powder, respectively.
Design Of A Bi-Functional α-Fe2O3/Zn2SiO4:Mn2+ By Layer-By-Layer Assembly Method
Authors: Yu Ri , Yun Juyeon , Pee Jae-Hwan , Kim Yoojin
Published: August 2015

This work describes the design of bi-functional α-Fe2O3/Zn2SiO4:Mn2+ using a two-step coating process. We propose a combination of pigments (α-Fe2O3) and phosphor (Zn2SiO4:Mn2+) glaze which is assembled using a layer-by-layer method. A silica-coated α-Fe2O3 pigment was obtained by a sol-gel method and a Zn2+ precursor was then added to the silica-coated α-Fe2O3 to create a ZnO layer. Finally, the Zn2SiO4:Mn2+ layer was prepared with the addition of Mn2+ ions to serve as a phosphor precursor in the multi-coated α-Fe2O3, followed by annealing at a temperature above 1000°C. Details of the phase structure, color and optical properties of the multi-functional α-Fe2O3/Zn2SiO4:Mn2+ were characterized by transmission electron microscopy and X-ray diffraction analyses.
Alumina Coating To Realize Desired Pore Characteristics Of Sintered Diatomite Membrane
Authors: Ha J.-H. , Park Y.-H. , Song I.-H.
Published: August 2015

Porous ceramic membranes prepared from natural materials such as diatomite, have lately attracted great interest in industrial applications due to their cost-effectiveness. In this study, we attempted to prepare an alumina coating to be deposited over a sintered diatomite-kaolin composite support layer in order to reduce the largest pore size to below 0.4 μm; such a coating could be potentially used in water treatment applications for bacterial removal.
Characterization Of Cladding Hull Wastes From Used Nuclear Fuels
Authors: Kang K.H. , Lee C.H. , Jeon M.K. , Han S.Y. , Park G.I. , Hwang S.-M.
Published: August 2015

Used cladding hulls from pressurized water reactor (PWR) are characterized to provide useful information for the treatment and disposal of cladding hull wastes. The radioactivity and the mass of gamma emitting nuclides increases with an increase in the fuel burn-up and their removal ratios are found to be more than 99 wt.% except Co-60 and Cs-137. In the result of measuring the concentrations of U and Pu included in the cladding hull wastes, most of the residues are remained on the surface and the removal ratio of U and Pu are revealed to be over 99.98 wt.% for the fuel burn-up of 35,000 MWd/tU. An electron probe micro-analyzer (EPMA) line scanning shows that radioactive fission products are penetrated into the Zr oxide layer, which is proportional to the fuel burn-up. The oxidative decladding process exhibits more efficient removal ratio of radionuclides.
Compositional Dependence Of Hardness Of Ge-Sb-Se Glass For Molded Lens Applications
Authors: Park J.K. , Lee J.H. , Shin S.Y. , Yi J.H. , Lee W.H. , Park B.J. , Choi J.H. , Kim N.Y. , Choi Y.G.
Published: August 2015

Chalcogenide glass in the ternary Ge-Sb-Se system is inherently moldable, thus being considered as a strong candidate material for use in infrared-transmitting lens applications from the viewpoint of thermal and mechanical stability. In an effort to experimentally determine compositional region suitable for the molded lens applications, we evaluate its compositional dependence of hardness. Among the constituent atoms, Ge content turns out to exert a most conspicuous correlation with hardness. This phenomenological behavior is then explained in connection with the structural evolution that Ge brings about.
Microstructure And Thermoelectric Properties Of Tags-90 Compounds Fabricated By Mechanical Milling Process
Authors: Kim H.-S , Babu M. , Hong S.-J.
Published: August 2015

TAGS-90 compound powder was directly prepared from the elements by high-energy ball milling (HEBM) and subsequently consolidated by a spark plasma sintering (SPS). Effect of milling time on the microstructure and thermoelectric properties of the samples were investigated. The particle size of fabricated powders were decreased with increasing milling time, finally fine particles with ~1μm size was obtained at 90 min. The SPS samples exhibited higher relative densities (>99%) with fine grain size. X-ray diffraction analysis (XRD) and energy dispersion analysis (EDS) results revealed that all the samples were single phase of GeTe with exact composition. The electrical conductivity of samples were decreased with milling time, whereas Seebeck coefficient increased over the temperature range of RT~450°C. The highest power factor was 1.12×10−3W/mK2 obtained for the sample with 90 min milling at 450°C.
Graphite Nanosheet Exfoliation From Graphite Flakes Through Functionalization Using Phthalic Acid
Authors: Kim J.H. , Lee J.-H.
Published: August 2015

In order to fabricate graphite nanosheets from graphite flakes, edge-functionalized graphite nanosheets were prepared by a functionalization method using phthalic acid as the molecule to be grafted. A polyphosphoric acid/P2O5solution containing graphite and phthalic acid were heated at different temperatures for 72 h in a nitrogen atmosphere. It was confirmed by transmission electron microscopy and atomic force microscopy that the resultant phthalic acid-functionalized graphite nanosheets had a large surface area of 20.69μm2in average and an average thickness of 1.39 nm. It was also found by X-ray diffractometry and Fourier transform infrared spectroscopy (FT-IR) analysis that the functionalization caused the formation of C=O bonds at the edges of the graphite nanosheets. The yield from this functionalization method was found to be dependent on the reaction temperature, only when it is between 70 and 130°C, because of the dehydration of phthalic acid at higher temperatures. This was confirmed by FT-IR analysis and the observation of low thermal energies at low temperatures.
Formation And Stabilization Of Silver Nanoparticles In Ethanol By Phosphinic Acid
Authors: Kim J.-K. , Shim H.M. , Park M.-J. , Koo K.-K.
Published: August 2015

Although phosphinic acid (H3PO2) has a powerful reduction potential, the reduction of silver ions by phosphinic acid salt has not yet been reported. In this work, colloidal silver has successfully synthesized by reducing silver ions in ethanol with phosphinic acid as a reducing agent. The effects of [AgNO3]/[H3PO2] ratios and reaction temperature were considered. Spherical silver nanoparticles with cubic structure were successfully prepared and their diameters were measured to be 8.5±0.9 nm − 11.3±0.2 nm. Half-life analysis showed that the reduction of silver ions proceeded with the reaction order of 1.30 on concentration of phosphinic acid and activation energy of 120.7 kJ/mol.
Comparison Of Mercury Distribution Between The Types Of Spent Fluorescent Lamp
Authors: Rhee S.W. , Park H.-S. , Choi H.H.
Published: August 2015

Spent fluorescent lamps(SFLs) such as linear type lamp, compact type lamp and U-type lamp are used to estimate mercury distribution in the components of lamps. Determination of mercury concentration in the components of spent fluorescent lamp is performed by the DMA method. Mercury concentration in the components of spent fluorescent lamp can be varied with the manufactures of lamp. Mercury portion in phosphor powder and glass from any types of spent fluorescent lamp is estimated to be higher than 99% by the analysis of mercury distribution. Through mercury distribution in the components for SFLs, the mercury concentration in phosphor powder is much higher than that in other components regardless of the type of lamp. Hence, it is desirable that phosphor powder of spent fluorescent lamps should be controlled separately and safely.
Novel Extraction Process Of Rare Earth Elements From NdFeB Powders Via Alkaline Treatment
Authors: Chung K.W. , Kim C.-J. , Yoon H.-S.
Published: August 2015

The alkaline treatment of NdFeB powders in NaOH solution at various equivalent amounts of NaOH at 100°C was performed. The resultant powders were then leached in 0.5M H2SO4 solution at 25°C for 2 minutes. At 5 equivalents of NaOH, neodymium in NdFeB powders was partially transformed to neodymium hydroxide. The transformation of neodymium to neodymium hydroxide actually occurred at 10 equivalents of NaOH and was facilitated by increasing the equivalent of NaOH from 10 to 30. In addition, iron was partially transformed to magnetite during the alkaline treatment, which was also promoted at a higher equivalent of NaOH. The leaching yield of neodymium from alkaline-treated powders was increased with an increasing equivalent of NaOH up to 10; however, it slightly decreased with the equivalent NaOH of over 10. The leaching yield of iron was inversely proportional to that of rare earth elements. NdFeB powders treated at 10 equivalents of NaOH showed a maximum leaching yield of neodymium and dysprosium of 91.6% and 94.6%, respectively, and the lowest leaching yield of iron of 24.2%, resulting in the highest selective leaching efficiency of 69.4%.
Analysis Of Drilling Of A Metal Plate With Pilot Hole
Authors: Kim K.S.
Published: August 2015

This paper performed a numerical analysis study of the cutting characteristics when drilling a taper hole whose upper and lower diameters are different, that is, a pilot hole. 3-dimensional drilling analysis was performed using a commercial code, and these results were used to determine analytically and compare the cutting temperature, the phenomenon of cutting chip formation, deformation and pressure, etc., for the tools, chips, and specimens during cutting. Also, cutting force and the required energy were calculated and compared. To verify the results of analysis, a cutting dynamometer was used to analyze 3-axis cutting force. Results of analysis showed that the specimen maintained a temperature of approximately 650°, with rapid cooling after chips were formed from the specimen. The tool reached a maximum of 700°, similarly to the chips. It is expected that these results will be utilized to optimize cutting processes and work conditions when drilling holes.
Effect Of Carbon Nanotubes On The Properties Of Spark Plasma Sintered ZrO2/CNT Composites
Authors: Shim D.H. , Jung S.S. , Kim H.S. , Cho H. , Kim J.K. , Kim T.G. , Yoon S.J.
Published: August 2015

Zirconia matrix ZrO2/CNT composite materials reinforced with multiwall carbon nanotubes were fabricated using a spark plasma sintering technique. The effects of the amount of CNTs addition, sintering temperature and sintering pressure on the properties of the resulting ZrO2/CNT composites were examined. 0 to 9 vol. % CNTs were dispersed in zirconia powder, and the resulting mixture was sintered. The electrical conductivity, hardness, flexural strength, and density were measured to characterize the composites. The friction and wear properties of the composites were also tested. The flexural strength and friction coefficient of the composites were improved with up to 6 vol.% of CNT addition and the flexural strength showed a close relationship with the relative density of the composite. The electrical conductivity increased with increasing proportion of the CNTs, but the efficiency was reduced at more than 6 vol.% CNTs.
Thermal Plasma Decomposition Of Nickel And Cobalt Compounds
Authors: Woch M. , Lis M. , Kołacz D. , Kamińska M. , Staszewski M.
Published: August 2015

The paper presents the study on manufacturing of nickel and cobalt powders by thermal plasma decomposition of the carbonates of these metals. It was shown the dependence of process parameters and grain size of initial powder on the composition of final product which was ether metal powder, collected in the container as well as the nanopowder with crystallite size of 70 - 90 nm, collected on the inner wall of the reaction chamber. The occurrence of metal oxides in the final products was confirmed and discussed.
Recovery Of Nickel From Spent Nickel-Cadmium Batteries Using A Direct Reduction Process
Authors: Shin D.J. , Joo S.-H. , Wang J.-P. , Shin S.-M.
Published: August 2015

Most nickel is produced as Ferro-Nickel through a smelting process from Ni-bearing ore. However, these days, there have been some problems in nickel production due to exhaustion and the low-grade of Ni-bearing ore. Moreover, the smelting process results in a large amount of wastewater, slag and environmental risk. Therefore, in this research, spent Ni-Cd batteries were used as a base material instead of Ni-bearing ore for the recovery of Fe-Ni alloy through a direct reduction process. Spent Ni-Cd batteries contain 24wt% Ni, 18.5wt% Cd, 12.1% C and 27.5wt% polymers such as KOH. For pre-treatment, Cd was vaporized at 1024K. In order to evaluate the reduction conditions of nickel oxide and iron oxide, pre-treated spent Ni-Cd batteries were experimented on under various temperatures, gas-atmospheres and crucible materials. By a series of process, alloys containing 75 wt% Ni and 20 wt% Fe were produced. From the results, the reduction mechanism of nickel oxide and iron oxide were investigated.
Large-Area Sodium Titanate Nanorods Formed On Titanium Surface Via NaOH Alkali Treatment
Authors: Lee K. , Yoo D.
Published: August 2015

Ti surfaces covered with large sodium titanate nanorods act as efficient electrodes for energy conversion and environmental applications. In this study, sodium titanate nanorod films were prepared on a Ti substrate in a 5M NaOH aqueous solution followed by heat treatment. The morphological characterization and the crystal structures of the sodium titanate nanorods were investigated via scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS). Thin amorphous sodium titanate layers formed during the alkali-treatment, and sodium titanate nanorods were obtained after heat treatment at a temperature of 700°C. The sodium titanate nanorods obtained at this temperature had a thickness of about 80 nm and a length of 1μm. The crystal structure of the sodium titanate was identified with the use of Na2Ti5O11. The nanorods were agglomerated at a temperature above 900°C, and large-scale nanorods formed on the Ti surface, which may be used for electrodes for energy conversion applications.
An Analysis Of Stress Intensity Factor Due To Normal Stress For A Cracked Plate Reinforced With A Sheet By Seam Welding
Authors: Kim O-H. , Kim Y.C.
Published: August 2015

It is essential in damage tolerance design to determine the stress intensity factor theoretically. The stress intensity factor for a cracked plate that is reinforced with a sheet by seam welding is determined theoretically and plotted as function of the seam welding location and stiffness ratio. The singular integral equation is derived based on the compatibility condition between the cracked plate and the reinforcement plate, and it is solved by means of Erdogan and Gupta‘s method. The theory is verified by comparing the results of the present analysis with those of a numerical analysis. The results from the present analysis show that the reinforcement effect improves as the welding line is situated closer to the crack and as the stiffness ratio of the cracked plate and the reinforcement plate increases.
Synthesis Of Magnesium-Aluminum Layered Double Hydroxides By Mechanochemical Method And Its Solid State Reaction Kinetics
Authors: Hongbo Y. , Meiling C. , Xiuhui W. , Hong G.
Published: August 2015

A mechanochemical method is developed in preparing magnesium-aluminum-layered double hydroxides (MgAl-LDHs). This approach includes activation process and diffusion process. In order to verify the LDHs structure and study the reaction kinetics, X-ray diffraction (XRD) patterns, inductively coupled plasma(ICP) and physical adsorption instrument were characterized. The results show that activation time can change the surface of particles and affect the reaction grade. During the diffusion process, reaction time is the most important factor. The reaction energy (ΔQ) was calculated that is 6kJ/mol.
Analysis Of The Extrusion Process Of A Square Tube Multi-Channel Heat Pipe
Authors: Kim K.S. , Kim J.Y.
Published: August 2015

Heat pipes have been recently in use for cooling purposes in various fields, including electronic circuit boards and vehicle parts that generate large amounts of heat. In order to minimize the loss of heat transferred, there is a need to maximize the contact area of the working fluid. This study produced a square tube multi-channel heat pipe to replace the existing circular pipe type to maximize the internal surface area thereof. This expands the surface, allowing the working fluid to come into contact with a wider area and enhancing thermal radiation performance. A mold for the production for such a product was designed, and finite element simulation was performed to determine whether production is possible.
Improved Light Conversion Efficiency Of Dye-Sensitized Solar Cell By Dispersing Submicron-Sized Granules Into The Nano-Sized TiO2 Layer
Authors: Song S.A. , Lim M.J. , Jung K.Y. , So W.-W. , Moon S.-J.
Published: August 2015

In this work, TiO2 nanoparticles and submicron-sized granules were synthesized by a hydrothermal method and spray pyrolysis, respectively. Submicron-sized granules were dispersed into the nano-sized TiO2 layer to improve the light conversion efficiency. Granules showed better light scattering, but lower in terms of the dye-loading quantity and recombination resistance compared with nanoparticles. Consequently, the nano-sized TiO2 layer had higher cell efficiency than the granulized TiO2 layer. When dispersed granules into the nanoparticle layer, the light scattering was enhanced without the loss of dye-loading quantities. The dispersion of granulized TiO2 led to increase the cell efficiency up to 6.51%, which was about 5.2 % higher than that of the electrode consisting of only TiO2 nanoparticles. Finally, the optimal hydrothermal temperature and dispersing quantity of granules were found to be 200°C and 20 wt%, respectively.
A Study On The Metal Carbide Composite Diffusion Bonding For Mechanical Seal
Authors: Kim D.-K. , Shon I.-J. , Song J. , Ryu W.-J. , Shin H.-Ch. , Kwon E.-Y. , Shin H. , Kang S.-J.
Published: August 2015

Mechanical Seal use highly efficient alternative water having a great quantity of an aqueous solution and has an advantage no corrosion brine. Metal Carbide composites have been investigated as potential materials for high temperature structural applications and for application in the processing industry. The existing Mechanical seal material is a highly expensive carbide alloy, and it is difficult to take a price advantage. Therefore the study of replacing body area with inexpensive steel material excluding O-ring and contact area which demands high characteristics is needed.

The development of WC-Ni base carbide alloy optimal bonding composition technique was accomplished in this study. To check out the influence of bonding temperature and time, bonding characteristics of sintering temperature was experimented. The bonding statuses of this test specimen were excellent. The hardness of specimen and bonding rate were measured using ultrasound equipment.

In this work, Powder of WC (involved VC, Cr), Co and Mo2C mixed by attrition milling for 24hours. Nanostructured WC-27.6wt.%Ni-1.5wt.%Si-0.11wt.%VC-1.1wt.%B4C composite were fabricated at 1190°C by high temperature vacuum furnace. To check out the influence of bonding temperature and time, bonding characteristics of sintering temperature was experimented. Its relative density was about 99.7%. The mechanical properties (hardness and fracture toughness) were 87.2 HRA and 4.2 M·Pam1/2, respectively. The bonding status of this test specimen was excellent and the thickness of bonding layer was 20 ~30§ at 1050 and 1060°C bonding temperature.
Effect Of The Desorption-Recombination Temperature On The Microstructure And Magnetic Properties Of HDDR Processed Nd-Fe-B Powders
Authors: Lee J.-G. , Cha H.-R. , Liu S. , Yu J.-H. , Baek Y.-K. , Kwon H.-W.
Published: August 2015

The effect of the desorption-recombination temperature on the microstructure and magnetic properties of hydrogenation-disproportionation-desorption-recombination (HDDR) processed Nd-Fe-B powders was studied. The NdxB6.4Ga0.3Nb0.2Febal (x=12.5-13.5, at.%) casting alloys were pulverized after homogenizing annealing, and then subjected to HDDR treatment. During the HDDR process, desorption-recombination (DR) reaction was induced at two different temperature, 810°C and 820°C. The higher Nd content resulted in enhanced coercivity of the HDDR powder, and which was attributed to the thicker and more uniform Nd-rich phase along grain boundaries. But this uniform Nd-rich phase induced faster grain growth. The remanence of the powder DR-treated at 820°C is higher than that DR-treated at 810°C. In addition, it was also confirmed that higher DR temperature is much more effective to improve squareness.
Aluminum Oxide Formation On Fecral Catalyst Support By Electro-Chemical Coating
Authors: Yang H.S. , Jang D.H. , Lee K.J.
Published: August 2015

FeCrAl is comprised essentially of Fe, Cr, Al and generally considered as metallic substrates for catalyst support because of its advantage in the high-temperature corrosion resistance, high mechanical strength, and ductility. Oxidation film and its adhesion on FeCrAl surface with aluminum are important for catalyst life. Therefore various appropriate surface treatments such as thermal oxidation, Sol, PVD, CVD has studied. In this research, PEO (plasma electrolytic oxidation) process was applied to form the aluminum oxide on FeCrAl surface, and the formed oxide particle according to process conditions such as electric energy and oxidation time were investigated. Microstructure and aluminum oxide particle on FeCrAl surface after PEO process was observed by FE-SEM and EDS with element mapping analysis. The study presents possibility of aluminum oxide formation by electro-chemical coating process without any pretreatment of FeCrAl.
Microstructure And Mechanical Properties Of Al-WC Composites
Authors: Simon A. , Lipusz D. , Baumli P. , Balint P. , Kaptay G. , Gergely G. , Sfikas A. , Lekatou A. , Karantzalis A. , Gacsi Z.
Published: August 2015

The scope of the research work is the production and characterization of Al matrix composites reinforced with WC ceramic nanoparticles. The synthesis process was powder metallurgy. The produced composites were examined as far as their microstructure and mechanical properties (resistance to wear, micro/macrohardness). Intermetallic phases (Al12W and Al2Cu) were identified in the microstrucutre. Al4C3 was not detected in the composites. Adding more than 5 wt% WC to the aluminum, microhardness and wear resistance exceed the values of Al alloy. Composites having weak interface bond performed the highest wear rate.
Purification And Separation Of Rare Earth Elements From CCFL With Extraction Chromatography
Authors: Kim J.-G.
Published: August 2015

In this study, Amberite XAD-7HP was used as the solvent-impregnated resin to separate each REE from the standard solution, which was mixed with the REEs (e.g., La Eu, Tb, Y and Ba). About 100 ppm of each of the REEs was separated from DI water using extraction chromatography. REEs were separated by extraction chromatography using Amberite XAD-7HP resin, the changes in the pH values of the HCl and HClO4 were between 0.2 N and 5 N, and the extraction rate of the solution was between 0.5 and 3 ml/min. The La solution with the separated REEs was leached. The solid-state REEs were annealed between 1083K. The extraction result was analyzed with ICP-AES and an X-ray diffractometer. Each REE was successfully separated with HCl and HClO4 with pH values between 0.1 N and 3 N and with extraction rate between 1.0 m/min and 3.0 m/min.
Biodegradable Poly(Lactic Acid)/Multiwalled Carbon Nanotube Nanocomposite Fabrication Using Casting And Hot Press Techniques
Authors: Park S.G. , Abdal-Hay A. , Lim J.K.
Published: August 2015

Biodegradable advanced polymer composites have recently received a large amount of attention. The present study aimed to design poly(lactic acid) multiwalled carbon nanotube nanocomposites (PLA/MWCNTs) using a simple fabrication technique. A PLA sheet was first dissolved in dichloromethane, and MWCNTs were subsequently added at various concentrations (0.5, 1.5 and 5%) while applying shear strain stirring to achieve dispersion of carbon nanotubes (CNTs). These solutions were then molded and a hot press was used to generate sheets free of voids with entrapped solvent. The prepared samples were characterized using field emission scanning electron microscopy (FE-SEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Our data showed composite samples free of defects and voids, indicating that the hot press is capable of generating sufficiently compact polymer matrices. Additionally, TGA and FTIR showed significant bonding interactions between the PLA matrix and the nano-fillers. Collectively, our results suggest that incorporation of CNTs as nano-fillers into biodegradable polymers may have multiple applications in many different sectors.
Contacts Erosion Modelling Using Ansys Computer Software And Experimental Research
Authors: Borkowski P. , Sienicki A.
Published: August 2015

The paper presents a method of contacts’ erosion modelling by using computer simulation and analyzing heating, melting and evaporation processes, which cause contact erosion due to application of electric arc. Calculations have been conducted using professional ANSYS software which allows for thermal processes simulation and includes phase transitions for Ag, Cu, W metals and Ag-W50 composite.
Study On Nanohardness Of Phases Occurring In ZnAl22Cu3 And ZnAl40Cu3 Alloys
Authors: Michalik R. , Chmiela B.
Published: August 2015

Zn-Al alloys are mainly used due to their high tribological and damping properties. A very important issue is determination of the hardness of the phases present in the Zn-Al-Cu alloys. Unfortunately, in literature there is lack of studies on the hardness of the phases present in the alloys Zn-Al-Cu. The aim of this research was to determine the hardness of the phases present in the ZnAl22Cu3Si and ZnAl40Cu3Si alloys. The scope of the research included examination of the structure, chemical composition of selected micro-regions and hardness of phases present in the examined alloys. The research carried out has shown, that CuZn4 phase is characterized by a similar hardness as the hardness of the interdendritic areas. The phases present in the structure of ZnAl40Cu3 and ZnAl22Cu3 alloys after soaking at the temperature of 185 °C are characterized by lower hardness than the phase present in the structure of the as-cast alloys.
Effect Of The T6 Heat Treatment On Change Of Mechanical Properties Of The AlSi12CuNiMg Alloy Modified With Strontium
Authors: Pezda J.
Published: August 2015

The paper presents test results concerning an effect of the heat treatment on microstructure and mechanical properties of eutectic EN AC-AlSi12CuNiMg (EN AC-48000) alloy according to the EN 1706:2010 (tensile strength –Rm, hardness –HB10/1000/30) modified with strontium. Solution heat treatment and ageing treatment temperature ranges were selected on base of heating (melting) curves recorded with use of the ATD method. Temperatures of the solution heat treatment were 500, 520, and 535°C ±5°C, while the solution time ranged from 0.5 to 3 h (0.5; 1.5 and 3 h). Temperature of the solution heat treatment amounted to 180, 235 and 310°C, while the ageing time ranged from 2 to 8 h (2, 5 and 8 h).

Obtained results have enabled determination of optimal parameters of the T6 heat treatment in aspect of improvement of tensile strengthRmand hardnessHBof the alloy, with reduced time of individual treatments and determination of mathematical relationships enabling prediction of these mechanical properties.
Nitrogen And Oxygen Amount In Weld After Welding With Micro-Jet Cooling
Authors: Węgrzyn T. , Piwnik J.
Published: August 2015

Micro-jet cooling after welding was tested only for MIG welding process with argon, helium and nitrogen as a shielded gases. A paper presents a piece of information about nitrogen and oxygen in weld after micro-jet cooling. There are put down information about gases that could be chosen both for MIG/MAG welding and for micro-jet process. There were given main information about influence of various micro-jet gases on metallographic structure of steel welds. Mechanical properties of weld was presented in terms of nitrogen and oxygen amount in WMD (weld metal deposit).
Influence Of Cooling Rate On Phase Composition And Magnetic Properties Of Sm12.5Co66.5Fe8Cu11Si2 Alloy In The Form Of Ribbon In As-Quenched State
Authors: Dośpiał M. , Nabiałek M. , Błoch K.
Published: August 2015

The fabrication method and magnetic properties of Sm12.5Co66.5Fe8Cu11Si2 alloy are presented in this article. The samples were produced by rapid quenching of the liquid alloy onto a rotating, copper wheel (the so-called ‘melt-spinning’ method) and they had a thin ribbon shape. The microstructure of the samples was investigated by measurements of diffraction patterns for powdered samples, in order to obtain data from the entire volume of the sample. It was found, that samples were composed of different amounts of Sm2Co17, SmCo5 and SmCo7 phases, depending on the linear velocity of the copper wheel used during the fabrication process. The magnetic measurements were performed using a vibrating sample magnetometer (LakeShore VSM) working with an external magnetic field of up to 2 T. It was found that the obtained ribbons displayed relatively good hard magnetic properties, such as remanence μ0MR, and high resistance to demagnetization fields JHC.
The Optimization And Diagnostics Of Combustion Process With Numerical Modelling Application
Authors: Zajemska M. , Radomiak H. , Poskart A.
Published: August 2015

The progressing development of industry and the associated rising environmental pollution create the need for the intensification of combustion processes and the implementation of increasingly stringent environmental protection standards. Therefore, an intensive progress in scientific and research work that is lately observed and studies with the use of numerical methods, are becoming an indispensable element of experimental research. This allows for: optimization of combustion processes, development of new designs of burners and technologies of low-emission combustion, as well as prediction of ecological effects. This article presents the possibilities of numerical modelling in combustion processes in heat furnaces. The chemistry of the combustion process was modelled in CHEMKIN software, while the dynamics of flue gas flow in the combustion chamber was modelled with the use of FLUENT software. Numerical computations were performed for both, the experimental chamber and the real objects, i.e. a pusher furnace and a sheet hardening furnace. The results of obtained measurements and numerical calculations clearly show that the use of hot air affects the growth of emissions, in particular NOx. Furthermore, it has also been proved that the design and the appropriate location of the lance supplying the secondary air result in the reduction of emissions of nitrogen oxides.
High-Temperatures Rheometric Analysis Of Selected Heterogeneous Slag Systems
Authors: Migas P.
Published: August 2015

It is known that the dynamic viscosity coefficient of slag – with an increased titanium compounds content in the reducing conditions of the blast furnace - may rapidly change. The products of the reduction reaction, precipitation and separation of titanium compounds are responsible for the thickening effect of the slag and the problems of permeability of blast furnace, causing anomalies in the dipping zone. The presence of solid components (particles) in the melts determines the rheological character of the entire system. Identifying the rheological character of semi-solid slag systems provides opportunities for the development of mathematical modeling of liquid phase flows in a dripping zone of the blast furnace, allowing e.g to indentify the unstable parts of a metallurgical aggregate.

Author have performed study of synthetic aluminosilicates slag concentration of TiO2 in the range up to 30%, systems were doped solids TiN also, it was made in order to assess the impact of the type forming areas/units of the SRO nature on the rheological identification mentioned systems. The high-temp rheometric measurements were performed at temperatures in the range between 1310-1490°C. The obtained results made it possible to carry out the rheological characteristics of analyzed liquid and semi-solid slag systems.
The Use Of Multifrequency Induction Heating For Temperature Distribution Control
Authors: Smalcerz A.
Published: August 2015

The paper presents possibilities of controlling temperature field distribution in inductively heated charge. The change of its distribution was obtained using the sequential one-, two-, and three-frequency heating. The study was conducted as a multi-variant computer simulation of hard coupled electromagnetic and temperature fields. For the analysis, a professional calculation software package utilizing the finite element method, Flux 3D, was used. The problem of obtaining an appropriate temperature distribution in the heated charge of a complex shape is very important in many practical applications. A typical example is hardening of gear wheels. For such an application, it is necessary to obtain (on the surface and at a desired depth) an uniform temperature distribution on the tooth face, top land and bottom land of the gear. The obtained temperature should have proper distribution and value. Such a distribution is very difficult to achieve.
The Study Of The Impact Of Surface Preparation Methods Of Inconel 625 And 718 Nickel-Base Alloys On Wettability By BNi-2 And BNi-3 Brazing Filler Metals
Authors: Lankiewicz K. , Baranowski M. , Babul T. , Kowalski S.
Published: August 2015

The article discusses the impact of surface preparation method of Inconel 625 and 718 nickel-base alloys in the form of sheets on wettability of the surface. The results of the investigations of surface preparation method (such as nicro-blasting, nickel plating, etching, degreasing, abrasive blasting with grit 120 and 220 and manually grinding with grit 120 and 240) on spreading of BNi-2 and BNi-3 brazing filler metals, widely used in the aerospace industry in high temperature vacuum brazing processes, are presented. Technological parameters of vacuum brazing process are shown. The macro- and microscopic analysis have shown that nicro-blasting does not bring any benefits of wettability of the alloys investigated.
Nitrogen Availability Of Nitriding Atmosphere In Controlled Gas Nitriding Processes
Authors: Michalski J. , Burdyński K. , Wach P. , Łataś Z.
Published: August 2015

Parameters which characterize the nitriding atmosphere in the gas nitriding process of steel are: the nitriding potential KN, ammonia dissociation rate α and nitrogen availabilitymN2. The article discusses the possibilities of utilization of the nitriding atmosphere’s nitrogen availability in the design of gas nitriding processes of alloyed steels in atmospheres derived from raw ammonia, raw ammonia diluted with pre-dissociated ammonia, with nitrogen, as well as with both nitrogen and pre-dissociated ammonia. The nitriding processes were accomplished in four series. The parameters selected in the particular processes were: process temperature (T), time (t), value of nitriding potential (KN), corresponding to known dissociation rate of the ammonia which dissociates during the nitriding process (α). Variable parameters were: nitrogen availability (mN2), composition of the ingoing atmosphere and flow rate of the ingoing atmosphere (FIn).
Microstructure And Properties Of WC-Co HVAF Coatings Obtained From Standard, Superfine And Modified By Sub-Micrometric Carbide Powders
Authors: Myalska H. , Szymański K. , Moskal G.
Published: August 2015

In this paper, microstructure and some properties of various coatings based on WC-Co obtained by the High Velocity Air Fuel technique are discussed. Initially, two WC-Co 83-17 powders of standard and superfine size were examined as a feedstock for a coatings deposition on a steel substrate. A standard Amperit 526.074 powder and an Inframat superfine powder were applied. Then three different sub-micrometric powders, WC, Cr3C2 and TiC were applied to modify the microstructure of WC-Co (Amperit 526.074). The aim of the investigations was to compare the microstructure and basic properties of coatings deposited from different components. The influence of sub-micrometric additions on mechanical properties of basic coatings was analyzed. Microstructure characterization of powders by using SEM and characterization of their technological properties as well, are presented. For all manufactured coatings obtained by a High Velocity Air Fuel method, the microhardness, porosity, adhesion to a substrate, and fracture toughness were determined. An improvement in WC-Co coating properties, as a result of sub-micrometric carbides addition, was revealed.
Estimation Of Cooling Rates In Suction Casting And Copper-Mould Casting Processes
Authors: Kozieł T.
Published: August 2015

The cooling rates associated with suction and copper-mould casting of ø2, ø3 and ø5 mm rods made in Fe-25wt%Ni and Al-33wt%Cu alloys were determined based on their cellular and lamellar spacings, respectively. The work showed that the temperature profile in cylindrical samples can not be determined merely by microstructural examination of eutectic sample alloys. A concave solidification front, as a result of eutectic transformation, caused decrease of a lamellar spacing while approaching to the rod centre. The minimum axial cooling rates, estimated based on the cellular spacing in the Fe-25wt%Ni alloy, were evaluated to be about 200 K/s for both ø2 and ø3 mm and only 30 K/s for the ø5 mm suction cast rods. The corresponding values were slightly lower for the copper-mould cast rods.
Sinteraustempering Of Two Mo-(Cu)-(Cr)-(Ni)-(Mn)-C Steels In A Semi-Closed Container In Flowing Nitrogen
Authors: Fiał Ch. , Dudrova E. , Kabatova M. , Kupkova M. , Selecka M. , Sułowski M. , Ciaś A.
Published: August 2015

Three types of heat treatment, sinteraustempering in 500°C, 400°C and 350°C; sinterhardening and sintering with cooling at the rate 10K/min) as the final operation, on steels sintered semi-closed container were investigated. Results of mechanical properties, microstructure investigations and fracture and EDX analyses are reported. The study involved two PM steels: DH-1 (Fe-2%Cu-1.5%Mo-0.5%C) and 34HNM (Fe-0.2%Mo-0.8%Mn-1.5%Cr-1.5Ni-0.4%C). Prealloyed Höganäs DH (Direct Hardening) iron powder and graphite powder (grade C-UF) were used to produce DH-1 steel. Prealloyed Astaloy CrL iron powder, low carbon ferromanganese, elemental nickel and graphite grade C-UF powder were the starting powders of 34HNM steel. Pressing was in rigid dies at 660MPa according to PN-EN ISO 2740 standard. After compaction, green compacts were sintered in a specially designed semi-closed container at 1120°C for 60 minutes in a nitrogen atmosphere. The chemical composition of the sintering atmosphere was modified by adding ferromanganese and/or activator into the container.

All specimens were tested for tensile strength (UTS), elongation (A), yield offset strength (R0,2), TRS, apparent surface and cross section hardness (HV 30). The best combination of strength and plasticity for both steels was achieved after sinteraustempering at 500°C. The results show that, using the specially designed semi-closed container, sinteraustempering in N2 atmosphere offers the same or even better mechanical properties in comparison with sinteraustempering in vacuum. It means that sinteraustempering in N2 atmosphere is a very interesting process in terms of cost in comparison with vacuum sinteraustempering.
Numerical And Experimental Analysis Of Fracture Of Athrombogenic Coatings Deposited On Ventricular Assist Device In Micro-Shear Test
Authors: Kopernik M. , Milenin A. , Kąc S.
Published: August 2015

The Polish left ventricular assist device (LVAD – RELIGA_EXT) will be made of thermoplastic polycarbonate-urethane (Bionate II) with deposited athrombogenic nano-coatings: gold (Au) and titanium nitride (TiN). Referring to the physical model, the two-scale model of LVAD developed in the previous works in the authors’ finite element code is composed of a macro-model of blood chamber and a micro-model of wall: TiN, Au and Bionate II. The numerical analysis of stress and strain states confirmed the possibility of fracture based on localization of zones of the biggest values of triaxiality factor. The introduction of Au interlayer between TiN and polymer improved the toughness of the connection, and increased the compressive residual stress in the coating what resulted in reduction of stress and strain close to the boundary between substrate and coating.

However, the proper design of multilayer wall of the medical device requires the introduction of the real stress and strain states in the deposited coatings. The characteristics of TiN nano-coating such as residual stress, material model and fracture model were determined in the previously completed studies such as experimental and numercial nanoindentation tests, profilometry studies and in situ SEM’s micro-tension tests.

The experimental in situ SEM’s micro-shear test was performed in the present paper and the corresponding numerical model of the test was also developed, and then, interpreted. The critical strains taken from experiment and considered as the effective strains in the model of test are the values which are the function of triaxiality factors for the tested samples. The developed in the authors’ FE code model of multilayer wall of VAD enriched with critical strain determined in the present paper enables prediction of fracture.
Analysis Of Rolls Wear During The Ribbed Bars Multi-Slit Rolling Process
Authors: Szota P. , Strycharska D. , Mróz S. , Stefanik A.
Published: August 2015

An analysis of the roll wear in the multi-strand rolling of reinforced concrete ribbed bars has been made in the study. In the technology under consideration, the longitudinal partition of the band takes place in special slitting passes, while the separation of individual strands – in idle separating rollers. During rolling, the slitting passes undergo fast wear compared to the remaining passes of the rolling line. The paper reports the results of theoretical and experimental examinations, on the basis of which the wear of the slitting passes in the 16 mm-diameter ribbed bar three-strand rolling process has been determined. The theoretical examination was done using the Forge2011® software program, while experimental tests were carried out in a D350 medium-size continuous rolling mill. Based on the analysis of the investigation results, the wear coefficient was established for the slitting passes, which allowed the determination of their quantitative wear.