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Fuzzy approach for the decision on disposable or returnable packaging

Peter Foldesi Péter Böröcz Kata Vöröskoi Ĺaszĺo T. Ḱoczy

Publication Name: Sustainability Switzerland

Publication Date: 2020-09-01

Volume: 12

Issue: 18

Page Range: Unknown

Description:

In modern logistics, companies and packaging engineers have to make decisions to find the optimal sustainable product-packaging system with adequate protection. The decision most often involves a decision option between disposable (single-trip) and reusable (returnable) packaging solutions. In practice, in most cases, this decision is based on historical data and traditions and only considers the packaging material and investment expenses. Although cost is an important factor, it is not the only one needed to find the optimal solution. Several other alternative factors further complicate the situation. Traditional (two-valued) logic is not able to model this problem. This study presents a novel technique to help the decision-making process using the application of fuzzy approach. The authors used three different fuzzy signatures connected by fuzzy rules to model the packaging decisions, which were based on logistics expert opinions. Practical examples are presented concerning both customer packaging (primary packaging) and industrial transport packaging (secondary packaging) as well.

Open Access: Yes

DOI: 10.3390/SU12187304

Effect of a five-week beta-alanine supplementation on the performance, cardio-respiratory system, and blood lactate level in well-trained rowing athletes: A double-blind randomized pre–post pilot study

Ferenc Ihász Erzsébet Mák Márta Veresné Bálint Dóra Nagy László Suszter Zsolt Szakály Zoltán Alföldi

Publication Name: Journal of Physical Education and Sport

Publication Date: 2020-09-01

Volume: 20

Issue: 5

Page Range: 2501-2507

Description:

Intense exercise by top-level athletes significantly lowers the pH of muscle and blood, which leads to fatigue. Beta-alanine (BA) supplementation can increase carnosine levels in skeletal muscle, which can delay a decrease in pH in the muscles. Previous studies have shown that multiple doses of BA supplementation were effective for people of different physical fitness and age. The purpose of this double-blind, randomized, controlled study is to investigate the effect of a five-week BA supplementation on well-trained, experienced rowing athletes at approximately the median dose of previous studies, which determined that 50 mg day−1 kg−1 of body weight was an effective daily dose. Two groups were formed in the spiroergometric study. One group received BA supplementation, while the control group did not. Five weeks after the first test (T1), the second test (T2) occurred, and the blood lactate levels were measured before and after the tests (Pre[La-]b; Post[La-]b). The maximum mean values of different physiological load parameters showed no significant difference. In the BA group, the mean lactate level was significantly lower after the T2 measurement (Post[La-]b) compared to those of T1 (P = 0.01) and the control group, i.e., T1 (P = 0,008), T2 (P = 0,028). The mean time and performance of the second measurement of the BA group increased [T1 = 582,7 ± 88,2 (s); T2 = 636,4 ± 106,6 (s)] but the result is not significant. In summary, the five-week dose of 50 mg day−1 kg−1 of body weight, which is 3.845 day−1 for the group average, lowers the blood lactate levels after the tests (Post[La-]b) but does not increase the athlete's performance. For well-trained athletes, during a five-week supplementation, it is not advisable to lover the value below 4–6 g day−1 with the dietary supplement to achieve an ergogenic effect.

Open Access: Yes

DOI: 10.7752/jpes.2020.05341

Mechanical property evaluation of closed and open-cell foam structures with finite element method

Ibolya Zsoldos K. Kulcsár J. Kónya

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2020-08-25

Volume: 903

Issue: 1

Page Range: Unknown

Description:

In this study, different lattice structures were examined with finite element method. Mechanical stress evaluations were performed on porous structured lattices that consisted simple cubic, face-centered cubic, body-centered cubic, and diamond unit cells. Finite element method simulations showed that structured foams with open and closed cells produced significantly different stress levels depending on their packing fraction. The aim of this study is to provide a basis for the design of an implant system that would promote the process of osseointegration.

Open Access: Yes

DOI: 10.1088/1757-899X/903/1/012010

Examination of welded joint of titanium alloy used in oral surgery

K. Kulcsár J. Kónya H. Hargitai

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2020-08-25

Volume: 903

Issue: 1

Page Range: Unknown

Description:

The additive manufacturing of customized Ti-6Al-4V (Grade 23) implants, which in the present research concerns the dental and maxillofacial surgical field, may require complex manufacturing technology due to their complexity and assembly. In practice, additively manufactured titanium implant elements are supplemented by threaded sleeves that allow disassembly. These turned elements made from Grade 5 material quality rolled preform are joined by laser micro-welding with Grade 1 material. This special process for implant production is still not widespread in current manufacturing practice, and there is no technical recommendation for the manufacturing parameters of these implants. The aim of our research is to explore the possibilities and limitations of additive process in the manufacture of custom-made implants and to provide guidelines for optimal manufacturing and welding parameters. In the initial phase of the research, preliminary experiments were conducted with the conventional and additive manufacturing of cylindrical test specimens and with the production of combined products by micro-welding. The specimens were subjected to tensile testing, the weld was examined by CT, and the fracture surfaces were studied by optical microscope and scanning electron microscope.

Open Access: Yes

DOI: 10.1088/1757-899X/903/1/012016

Characterisation of Inhomogeneous Plastic Deformation of AlMg Sheet Metals during Tensile Tests

Szabolcs Szalai Dóra Harangozó Imre Czinege

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2020-08-25

Volume: 903

Issue: 1

Page Range: Unknown

Description:

The Portrevin-Le-Chatelier (PLC) effect was analysed quantitatively in the selected AlMg alloys with Mg-content between 2,8-4,6%. The propagation and characteristics of PLC bands were detected by digital image correlation (DIC) technique and the parameters of the bands were evaluated from strain distributions of tensile test specimens. In parallel, stress-strain curves were analysed evaluating stress serrations. The numerically defined parameters of changes in stress and strain were used for characterising the PLC effect on the behaviour of different sheet metals. General statements of literature were numerically proven for the tested materials and the effect of magnesium content on stress amplitude was analysed in detail.

Open Access: Yes

DOI: 10.1088/1757-899X/903/1/012023

Preparation of soft magnetic composite from Fe-6.9wt%Si by different heat treatment strategies.

Ibolya Zsoldos L. K. Varga B. Kocsis

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2020-08-25

Volume: 903

Issue: 1

Page Range: Unknown

Description:

Present study investigated the effect of isothermal heat treatment strategies between 800 °C and 1150 °C on the magnetic properties of toroidal samples made from Fe-6.9wt%Si powder. The samples were prepared by classical powder metallurgy method since the classical sheet forming methods no longer work with the high silicon content. Our results presented here are part of a series of comparative experiments where we study the effectiveness of the insulating layers created during and before the compacting of soft magnetic composites (SMCs). Our goal was to create a soft magnetic composite made of ferromagnetic and inorganic insulating material with a frequency limit already in the megahertz range and a Snoek limit of few gigahertz. In the case of samples made from Fe-6.9wt%Si powder, the computed tomography results showed that significant porosity is to be expected after pressing. Its positive effect occurred during the heat treatment in the atmospheric agent, where silicon is precipitated and deposited on the surface of the particle. This coating is an electrically insulating layer at the grain boundaries. Depending on the heat treatment strategy, 1 or 2 ferromagnetic phases were observed. The frequency limit approached the target values, but due to the low value of static permeability, the Snoek limit did not reach the gigahertz range. However, there is a significant improvement in magnetic properties compared to the heat-treated samples in a protective gas.

Open Access: Yes

DOI: 10.1088/1757-899X/903/1/012042

Flame retardancy of recycled PET foam

V. A. Szabó Gabor Dogossy

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2020-08-25

Volume: 903

Issue: 1

Page Range: Unknown

Description:

Although significant marketing efforts have been made in recent years to reduce polymer use, the number of plastic bottles being discarded is increasing worldwide. The global environmental-socio-economic problem posed by polyethylene terephthalate (PET) bottles can only be solved by expanding large-scale recycling opportunities, while reducing the use of pure raw materials. In this article on the large quantities product of PET was upcycled with chemical foaming. During the experiments 2 m% chain extender and 4 m% chemical blowing agent and different amount of brominated flame retardant was used. The invested materials were examined with standard mechanical tests, scanning electron microscopy and UL-94 standard flammability test. After the investigation it was found that the crystallized blue PET bottle re-granulate can be used forming a flame retardant closed cell foam structure.

Open Access: Yes

DOI: 10.1088/1757-899X/903/1/012048

Determining the optimum heating time of small sized test specimen made from weldable mild steel

Tamás Ibriksz F. Tancsics

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2020-08-25

Volume: 903

Issue: 1

Page Range: Unknown

Description:

The usage of CHT (Continuous Heating Transformations) diagrams for a given steel or equivalent grade, requires knowledge of heating temperature, average heating rate, and the heating time. Definition of these technological parameters are primarily based on the complex relationship system between the geometric, thermal parameters and the heating device. In our research, we mainly focused on those physical key parameters that can mostly influence the heating and transformation rate. These parameters provide realistic, usable data for analysing the process of thermal diffusion and FEA (Finite Element Analysis) tests. During analysis, an easy-to-use function relationship was determined for approaching the heating rate more precisely. This method allows handling the CHT charts easily, within a selected range, regarding weldable mild steels.

Open Access: Yes

DOI: 10.1088/1757-899X/903/1/012033

Investigation of the tribological properties of nano-scaled ZrO2 and CuO additive in automotive lubricants

Jan Knaup D. Tóth

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2020-08-25

Volume: 903

Issue: 1

Page Range: Unknown

Description:

To improve the fuel efficiency and the lifetime of the internal combustion engines, the lubricants and their additives have to be developed further. One of the possible future engines lubricants can be the nano-sized ceramic particles, which can provide positive tribological properties also in the presence of non-metallic surface materials. This paper presents the results of investigations with the help of ZrO2 and CuO nano-sized ceramic particles. To define the tribological properties of these additives, lubricant samples with different additive-concentrations were prepared and tribologically analysed. The frictional losses of these lubricant samples were analysed by a ball-on-disk sliding friction machine. The worn surface on the test specimens was analysed by different high-resolution microscopes. To define the functional mechanisms of the nano-additives, the worn surfaces were investigated by high resolution scanning electron microscopes. The ZrO2 additive has experimentally shown an excellent wear reduction property (over 40% wear reduction compared with the neat Group 3 base oil) at the optimum mixing concentration of 0.4wt%. Both frictional and wear reduction properties could be determined at the application of CuO additive (15-15% friction coefficient and wear scar diameter reduction) at its optimum concentration (0.5wt%). A copper-yellow layer can be seen on the worn surface of the disc specimens with CuO, which indicates the mechanism of chemical transformation to elementary copper from the cupric-oxide nanoparticle and this elementary copper can be melted on the surface, because of the applied high temperature and high loads during the experiments.

Open Access: Yes

DOI: 10.1088/1757-899X/903/1/012015