Search results for: temperature profile

Authors: Yongde Dai

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The recent Chinese military action blockbusters, notably known as, Wolf Warrior/Zhan Lang (2015), Operation Mekong/Mei gong he xing dong (2016), Warrior 2/Zhan Lang 2 (2017) and Operation Red Sea/Hong hai xing dong (2018), have achieved phenomenal box-office successes and in particular, Wolf Warrior 2 became China’s highest-grossing film of all time. However, their yearly presence tends to show a paradigmic shift from China’s primacy of wen manliness (soft) to wu masculinity (hard). With the increasing cinematic exposure of a more muscular image manifesting in both the Chinese heroic soldiers and China itself as a rising global power, the backlash of the Chinese public against the proliferation of the feminized masculinity influenced by the ‘pretty-boy’ pop-culture and China’s harder approach to the current Sino-US tensions have correspondingly emerged and continued to brew. Chinese masculinity imagined in these films is one of the key factors that enable a gendered interpretation of the correlation between the Chinese on-screen fantasy and off-screen reality, that is, China’s public and official discourse about the hegemonic masculinity and non-hegemonic masculinity as well as China’s international profile on cinematic appearance and in today’s Sino-US relation. By reading closely at the four megahits as visual-audio texts with Chinese masculinity studies by Kam Louie and Geng Song, this paper attempts to examine the Chinese construction of manliness with historical accounts and argue why and how the recurrent emphasis of hard/military masculinity (wu) on screen are viewed as China’s contemporary rewriting of the ‘sick-man’ history in the film form. Through this investigation, the paper finds that the rewriting of the ‘sick-man’ history in the cinematic world through heroic brawny soldiers comes to resonate a collective anxiety of China in countering the real-life increasing feminized masculinity on the public appearance, particularly on the male celebrities. In addition, the superpower fantasy about China illuminates a hypermasculine imaginary of China as a global rising power and this coincidently echoes China’s current tougher diplomatic strategy tackling the Sino-US trade war, South China sea dispute and Huawei-US lawsuits.

Keywords: Chinese masculinity, Chinese military action film, feminized masculinity, manhood and nationhood, sick man of Asia

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Authors: Ehsan Ahmadifar, Mohammad Ali Yousefi, Zahra Roohi

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In this study, the effects of different levels of Ergosan (control group (0), 2, 4 and 6 gr Ergosan per Kg diet) as a nutritional supplement were investigated on growth indices and stress in Zebrafish for 3 months. Larvae (4-day-old after hatching) were fed with experimental diet from the beginning of feeding until adult (adolescence) (average weight: 69.3 g, length: 5.1 cm). Different levels of Ergosan had no significant effect on rate survival (P < 0.05). The results showed that diet containing 6 gr Ergosan significantly caused the best FCR in Zebrafish (P < 0.05). By increasing the Ergosan diet, specific growth rate increased. Body weight gain and condition factor had significant differences (P < 0.05) as the highest and the lowest were observed in treatment 3 gr of Ergosan and control, respectively. The results showed that fish fed with experimental diet, had the highest resistance to environmental stresses compared to control, and the test temperature, oxygen, salinity and alkalinity samples containing 6 gr/kg, was significantly more resistance compared to the other treatments (P < 0.05). Overall, to achieve high resistance to environmental stress and increase final biomass using 6 gr/kg Ergosan in diet fish Zebrafish.

Keywords: Ergosan, stress, growth performance, Danio rerio

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Authors: I. Sterbova, E. Oberhofnerova, M. Panek, M. Pavelek

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With growing popularity, wood of European larch (Larix decidua, Mill.) is being more often applied into the exterior, usually as facade elements, also without surface treatment. The aim of this work was to compare two laboratory tests of artificial accelerated weathering of wood with two ways of natural weathering in the exterior. To assess changes in selected surface characteristics of larch wood, accelerated weathering methods in the Xenotest and UV chamber were used, both in combination with temperature cycling, for 6 weeks. They were compared with natural weathering results at exposition under 45° and 90° in the exterior for 12 months. The changes of colour, gloss, contact angle of water and also changes in visual characteristics were evaluated. The results of wood surfaces changes after 6 weeks of accelerated weathering in Xenotest are closer to 12 months of natural weathering in the exterior at an angle of 90° compared to the UV chamber testing. The results, especially the colour changes, of the samples exposed at an angle of 45° in the exterior were significantly different. Testing in Xenotest more closely simulates the weathering of façade elements in the exterior compared to the UV chamber testing.

Keywords: larch wood, wooden facade, wood accelerated weathering, weathering methods

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Authors: Ashti Morovati, Hushyar Azari, Bahram Pourghassem Gargari

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Objectives and goals: The prevalence of metabolic syndrome (MetS), as a major health burden for societies, is increasing. This clinical trial was conducted to evaluate the effects of CuEO supplementation on anthropometric indices, systolic and diastolic blood pressure, blood glucose level, insulin resistance and serum lipid level in patients suffering from MetS. Methods: This was a randomized, triple‐blind, placebo‐controlled clinical trial in which 56 patients with MetS aged 18–60 years who fulfilled the eligibility criteria were randomly allocated to an intervention or a control group. Inclusion criteria for the study were comprised of diagnosis of MetS according to the new International Federation of Diabetes. The exclusion criteria were defined as: taking herbal supplements, use of drugs having evident interaction with cumin such as anti‐depressant drugs, vitamin D, omega 3, selenium, zinc, smoking, pregnancy, or breastfeeding, suffering from cancer, having any history of gastrointestinal and hepatic, cardiovascular, thyroid and kidney disorders, and menopause. 75 mg CuEO or placebo soft gels were administered three times daily to the participants for eight weeks. The soft gel consumption was checked by asking the participants to bring the medication containers in the follow‐up visits at the 4th and the 8th weeks of the study. Data pertaining to blood pressure, height, weight, waist circumference, hip circumference and BMI, as well as food consumption were collected at the beginning and end of the study. Fasting blood samples ( glucose, triglyceride, total cholesterol, HDL-cholesterol and LDL-cholesterol) were obtained and biochemical measurements were assessed at the beginning and end of the study. Results: At eight weeks, a total of 44 patients completed this study. Except for diastolic blood pressure (DBP), the other assessed variables were not significantly different between the two groups. In intra group analysis, placebo and CuEO groups both had insignificant decrements in DBP (mean difference [MD] with 95% CI: −3.31 [−7.11, 0.47] and −1.77 [−5.95, 2.40] mmHg, respectively). However, DBP was significantly lower in CuEO compared with the placebo group at the end of study (81.41 ± 5.88 vs. 84.09 ± 5.54 mmHg, MD with 95% CI: −3.98 [−7.60, −0.35] mmHg, p < .05). Conclusions: The results of this study indicated that CuEO does not have any effect on MetS components, except for DBP in patients with MetS.

Keywords: blood pressure, fasting blood glucose, lipid profile, waist circumference

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Authors: Anton Trník, Lenka Scheinherrová, Robert Černý

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Silica fume is a by-product of the ferro-silicon and silicon metal industries. It is mainly in the form of amorphous silica. Silica fume belongs to pozzolanic active materials which can be used in concrete to improve its final properties. In this paper, the influence of silica fume on hydration of cement pastes is studied using differential scanning calorimetry (DSC) and thermogravimetry (TG) at various curing times (2, 7, 28, and 90 days) in the temperature range from 25 to 1000 °C in an argon atmosphere. Samples are prepared from Portland cement CEM I 42.5 R which is partially replaced with the silica fume of 4, 8, and 12 wt.%. The water/binder ratio is chosen as 0.5. It is identified and described the liberation of physically bound water, calcium–silicate–hydrates dehydration, portlandite and calcite decomposition in studied samples. Also, it is found out that an exothermic peak at 950 °C is observed without a significant mass change for samples with 12 wt.% of silica fume after two days of hydration. This peak is probably caused by the pozzolanic reaction between silica fume and Portland cement. Its size corresponds to the degree of crystallization between Ca and Si. The portlandite content is lower for the samples with a higher amount of silica fume.

Keywords: differential scanning calorimetry, hydration, silica fume, thermogravimetry

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Authors: Mamadou Diop, Florence Crick, Momadou Sow, Kate Elizabeth Gannon

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Understanding SME leaders’ responses to climate is essential to cope with ongoing changes in temperature and rainfall. This study analyzes the response of SME leaders to the adverse effects of climate change in semi-arid lands (SAL) in Senegal. Based on surveys administrated to 161 SME leaders, this research shows that 91% of economic units are affected by climatic conditions, although 70% do not have a plan to deal with climate risks. Economic actors have striven to take measures to adapt. However, their efforts are limited by various obstacles accentuated by a lack of support from public authorities. In doing so, substantial political, institutional and financial efforts at national and local levels are needed to promote an enabling environment for economic actors to adapt. This will focus on information and training about the threats and opportunities related to global warming, the creation of an adaptation support fund to support local initiatives and the improvement of the institutional, regulatory and political framework.

Keywords: small and medium-sized enterprises, climate change, adaptation, semi-arid lands

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Authors: Mohammad R. Irshidat, Rami H. Haddad, Hanadi Al-Mahmoud

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Reinforced concrete (RC) is the most common used material for construction in the world. In the past decades, fiber reinforced polymer (FRP) bars had been widely used to substitute the steel bars due to their high resistance to corrosion, high tensile capacity, and low weight in comparison with steel. Experimental studies on the behavior of FRP bar reinforced concrete beams had been carried out worldwide for a few decades. While the research on such structural members under elevated temperatures is still very limited. In this research, the flexural behavior of heat-damaged concrete beams reinforced with FRP bars is studied. Two types of FRP rebar namely, carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP), are used. The beams are subjected to four levels of temperature before tested to monitor their flexural behavior. The results are compared with other concrete beams reinforced with regular steel bars. The results show that the beams reinforced with CFRP bars and GFRP bars had higher flexural capacity than the beams reinforced with steel bars even if heated up to 400°C and 300°C, respectively. After that the beams reinforced with steel bars had the superiority.

Keywords: concrete beams, FRP rebar, flexural behavior, heat-damaged

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Authors: Reinaldo Biscaro, Luciano R. Ferreira, Leonardo C. Biscaro, Raphael C. Biscaro, Isabela S. Vasconcelos, Laura C. R. Ferreira, Cristiano M. Galhardi, Erica P. Baciuk

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Introduction: The present study had the objective to present the profile of workers with shoulder disorders related to labor lawsuits in Brazil. The study analyzed the association between the worker’s health and the actions performed by the companies related to injured professional. The research method performed a retrospective, cross-sectional and quantitative database analysis. The documents of labor lawsuits with shoulder injury registered at the Regional Labor Court in the 15^th region (Campinas - São Paulo) were submitted to the medical examination and evaluated during the period from 2012 until 2015. The data collected were age, gender, onset of symptoms, length of service, current occupation, type of shoulder injury, referred complaints, type of acromion, associated or related diseases, company actions as CAT (workplace accident communication), compliance of NR7 by the organization (Environmental Risk Prevention Program - PPRA and Medical Coordination Program in Occupational Health - PCMSO). Results: From the 93 workers evaluated, there was a prevalence of men (58.1%), with a mean age of 42.6 y-o, and 54.8% were included in the age group 35-49 years. Regarding the length of work time in the company, 66.7% have worked for more than 5 years. There was an association between gender and current occupational status (p < 0.005), with predominance of women in household occupation (13 vs. 2) and predominance of unemployed men in job search situation (24 vs. 10) and reintegrated to work by judicial decision (8 vs. 2). There was also a correlation between pain and functional limitation (p < 0.01). There was a positive association of PPRA with the complaint of functional limitation and negative association with pain (p < 0.04). There was also a correlation between the sedentary lifestyle and the presence of PCMSO and PPRA (p < 0.04), and the absence of CAT in the companies (p < 0.001). It was concluded that the appearance or aggravation of osseous and articular shoulder pathologies in workers who have undertaken labor law suits seem to be associated with individual habits or inadequate labor practices. These data can help preventing the occurrence of these lesions by implementing local health promotion policies at work.

Keywords: work-related accidents, cross-sectional study, shoulder lesions, labor lawsuits

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Authors: Xiaoxiao Zhao

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We report macroscopic evidence of the liquidlike nature of surface-tethered poly(dimethylsiloxane) (PDMS) brushes by studying their adhesion to ice. Whereas ice permanently detaches from solid surfaces when subjected to sufficient shear, commonly referred to as the material’s ice adhesion strength, adhered ice instead slides over PDMS brushes indefinitely. When additionally methylated, we observe a Couette-like flow of the PDMS brushes between the ice and silicon surface. PDMS brush ice adhesion displays shear-rate-dependent shear stress and rheological behavior reminiscent of liquids and is affected by ice velocity, temperature, and brush thickness, following scaling laws akin to liquid PDMS films. This liquidlike nature allows it to detach solely by self-weight, yielding an ice adhesion strength of 0.3 kPa, 1000 times less than low surface energy, perfluorinated monolayer. The methylated PDMS brushes also display omniphobicity, repelling all liquids essentially with vanishingly small contact angle hysteresis. Methylation results in significantly higher contact angles than previously reported, nonmethylated brushes, especially for polar liquids of both high and low surface tension.

Keywords: omniphobic, surface science, polymer brush, icephobic surface

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Authors: Alberto Mínguez-Martínez, Jesús De Vicente Y Oliva

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It seems that we live in a world in which the trend in industrial environments is the miniaturization of systems and materials and the fabrication of parts at the micro-and nano-scale. The problem arises when manufacturers want to study the quality of their production. This characteristic is becoming crucial due to the evolution of the industry and the development of Industry 4.0. As Industry 4.0 is based on digital models of production and processes, having accurate measurements becomes capital. At this point, the metrology field plays an important role as it is a powerful tool to ensure more stable production to reduce scrap and the cost of non-conformities. The most extended measuring instruments that allow us to carry out accurate measurements at these scales are optical microscopes, whether they are traditional, confocal, focus variation microscopes, profile projectors, or any other similar measurement system. However, the accuracy of measurements is connected to the traceability of them to the SI unit of length (the meter). The fact of providing adequate traceability to 2D and 3D dimensional measurements at micro-and nano-scale in industrial environments is a problem that is being studied, and it does not have a unique answer. In addition, if commercial material standards for micro-and nano-scale are considered, we can find that there are two main problems. On the one hand, those material standards that could be considered complete and very interesting do not give traceability of dimensional measurements and, on the other hand, their calibration is very expensive. This situation implies that these kinds of standards will not succeed in industrial environments and, as a result, they will work in the absence of traceability. To solve this problem in industrial environments, it becomes necessary to have material standards that are easy to use, agile, adaptive to different forms, cheap to manufacture and, of course, traceable to the definition of meter with simple methods. By using these ‘customized standards’, it would be possible to adapt and design measuring procedures for each application and manufacturers will work with some traceability. It is important to note that, despite the fact that this traceability is clearly incomplete, this situation is preferable to working in the absence of it. Recently, it has been demonstrated the versatility and the utility of using laser technology and other AM technologies to manufacture customized material standards. In this paper, the authors propose to manufacture a customized material standard using an ultraviolet laser system and a method to calibrate it. To conclude, the results of the calibration carried out in an accredited dimensional metrology laboratory are presented.

Keywords: industrial environment, material standards, optical measuring instrument, traceability

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Authors: Thomas Rowan, Mohammed Seaid

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A fast finite volume solver for multi-layered shallow water flows with mass exchange and an erodible bed is developed. This enables the user to solve a number of complex sediment-based problems including (but not limited to), dam-break over an erodible bed, recirculation currents and bed evolution as well as levy and dyke failure. This research develops methodologies crucial to the under-standing of multi-sediment fluvial mechanics and waterway design. In this model mass exchange between the layers is allowed and, in contrast to previous models, sediment and fluid are able to transfer between layers. In the current study we use a two-step finite volume method to avoid the solution of the Riemann problem. Entrainment and deposition rates are calculated for the first time in a model of this nature. In the first step the governing equations are rewritten in a non-conservative form and the intermediate solutions are calculated using the method of characteristics. In the second stage, the numerical fluxes are reconstructed in conservative form and are used to calculate a solution that satisfies the conservation property. This method is found to be considerably faster than other comparative finite volume methods, it also exhibits good shock capturing. For most entrainment and deposition equations a bed level concentration factor is used. This leads to inaccuracies in both near bed level concentration and total scour. To account for diffusion, as no vertical velocities are calculated, a capacity limited diffusion coefficient is used. The additional advantage of this multilayer approach is that there is a variation (from single layer models) in bottom layer fluid velocity: this dramatically reduces erosion, which is often overestimated in simulations of this nature using single layer flows. The model is used to simulate a standard dam break. In the dam break simulation, as expected, the number of fluid layers utilised creates variation in the resultant bed profile, with more layers offering a higher deviation in fluid velocity . These results showed a marked variation in erosion profiles from standard models. The overall the model provides new insight into the problems presented at minimal computational cost.

Keywords: erosion, finite volume method, sediment transport, shallow water equations

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Authors: Junaid Bin Aamir, Ma Fanhua

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Methanol is one of the most suitable alternative fuels for replacing gasoline in present and future spark-ignited engines. However, for pure methanol engines, cold start problems and misfires are observed under certain operating conditions. Hydrogen provides a solution for such problems. This paper experimentally investigated the effect of hydrogen on the performance of a pure methanol SI-engine at city driving conditions (1500 rpm speed and 1.18 excess air ratio). Hydrogen was used as a part of methanol reformed syngas (67% hydrogen by volume). 4% by mass of the total methanol converted to hydrogen and other constituent gases, was used in each cycle. Port fuel injection was used to inject methanol and hydrogen-rich syngas into the 4-cylinder engine. The results indicated an increase in brake thermal efficiency up to 5% with the addition of hydrogen, a decrease in brake specific fuel consumption up to 200 g/kWh, and a decrease in exhaust gas temperature by 100°C for all mean effective pressures. Hydrogen addition also decreased harmful exhaust emissions significantly. There was a reduction in THC emissions up to 95% and CO emissions up to 50%. NOx emissions were slightly increased (up to 15%), but they can be reduced to zero by lean burn strategy.

Keywords: alternative fuels, hydrogen, methanol, performance, spark ignition engines

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Authors: Gopal Ji, Priyanka Dwivedi, Shanthi Sundaram, Rajiv Prakash

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Inhibition effect of aqueous Argemone Mexicana root extract (AMRE) on mild steel corrosion in 1 M HCl has been studied by weight loss, Tafel polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. Results indicate that inhibition ability of AMRE increases with the increasing amount of the extract. A maximum corrosion inhibition of 94% is acknowledged at the extract concentration of 400 mg L-1. Polarization curves and impedance spectra reveal that both cathodic and anodic reactions are suppressed due to passive layer formation at metal-acid interface. It is also confirmed by SEM micro graphs and FTIR studies. Furthermore, the effects of acid concentration (1-5 M), immersion time (120 hours) and temperature (30-60˚C) on inhibition potential of AMRE have been investigated by weight loss method and electrochemical techniques. Adsorption mechanism is also proposed on the basis of weight loss results, which shows good agreement with Langmuir isotherm.

Keywords: mild steel, polarization, SEM, acid corrosion, EIS, green inhibition

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Authors: Fulya Ozbey, Ecehan Ozmehmet

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Health and living in a healthy environment are important for all the living creatures. Healthy buildings are the part of the healthy environment and the ones that people and sometimes the animals spend most of their times in it. Therefore, healthy buildings are important subject for everybody. There are many elements of the healthy buildings from material choice to the thermal comfort including indoor air quality. The aim of this study is, to simulate two natural ventilation strategies which are used as a cooling method in Mediterranean climate, by applying to a residential building and compare the results for Asian climate. Fulltime natural and night-time ventilation strategies are simulated for three days during the summertime in Mediterranean climate. The results show that one of the chosen passive cooling strategies worked on both climates good enough without using additional shading element and cooling device, however, the other ventilation strategy did not provide comfortable indoor temperature enough. Finally, both of the ventilation strategies worked better on the Asian climate than the Mediterranean in terms of the total overheating hours during the chosen period of year.

Keywords: Asian climate, indoor air quality, Mediterranean climate, natural ventilation simulation, thermal comfort

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Authors: L. Nevrivova, K. Lang, M. Kotoucek, D. Vsiansky

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This entry concerned with dense silica microstructure was produced as a part of a project within the Technology Agency of the Czech Republic which is being implemented in cooperation of the biggest producer of refractories the P-D Refractories CZ company with the research organisation Brno University of Technology. The paper is focused on the influence of mixture homogenisation and the influence of grain size of the mineraliser on the resulting utility properties of the material as well as its microstructure. It has a decisive influence on the durability of the material in a building structure. This paper is a continuation of a previously published study dealing with the suitability of various types of mineralising agents in terms of density, strength and mineral composition of silica. The entry describes the influence of the method of mixture homogenisation and the influence of granulometry of the applied Fe-mineralising agent on the resulting silica microstructure. Porosity, density, phase composition and microstructure of the experimentally prepared silica samples were examined and the results were discussed in context with the technology of homogenisation and firing temperature used. The properties of silica brick samples were compared to the sample without any Fe-mineraliser.

Keywords: silica bricks, Fe-mineraliser, mineralogical composition, new developed silica material

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Authors: Zeyu Zhou, Ziyu Zhao, Xiaochen Yang, Ling AI, Heng Zhai, Stuart Holmes

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As a promising sustainable alternative to traditional fossil fuels, fuel cell technology is highly favoured due to its enhanced working efficiency and reduced emissions. In the context of high-temperature fuel cells (operating above 100 °C), the most commonly used proton exchange membrane (PEM) is the Polybenzimidazole (PBI) doped phosphoric acid (PA) membrane. Grafting is a promising strategy to advance PA-doped PBI PEM technology. The existing grafting modification on PBI PEMs mainly focuses on grafting phosphate-containing or alkaline groups onto the PBI molecular chains. However, quaternary ammonium-based grafting approaches face a common challenge. To initiate the N-alkylation reaction, deacidifying agents such as NaH, NaOH, KOH, K2CO3, etc., can lead to ionic crosslinking between the quaternary ammonium group and PBI. Polyvinylpyrrolidone (PVP) is another widely used polymer, the N-heterocycle groups within PVP endow it with a significant ability to absorb PA. Recently, PVP has attracted substantial attention in the field of fuel cells due to its reduced environmental impact and impressive fuel cell performance. However, due to the the poor compatibility of PVP in PBI, few research apply PVP in PA-doped PBI PEMs. This work introduces an innovative strategy to graft PVP onto PBI to form a network-like polymer. Due to the absence of quaternary ammonium groups, PVP does not pose issues related to crosslinking with PBI. Moreover, the nitrogen-containing functional groups on PVP provide PBI with a robust phosphoric acid retention ability. The nuclear magnetic resonance (NMR) hydrogen spectrum analysis results indicate the successful completion of the grafting reaction where N-alkylation reactions happen on both sides of the grafting agent 1,4-bis(chloromethyl)benzene. On one side, the reaction takes place with the hydrogen atoms on the imidazole groups of PBI, while on the other side, it reacts with the terminal amino group of PVP. The XPS results provide additional evidence from the perspective of the element. On synthesized PBI-g-PVP surfaces, there is an absence of chlorine (chlorine in grafting agent 1,4-bis(chloromethyl)benzene is substituted) element but a presence of sulfur element (sulfur element in terminal amino PVP appears in PBI), which demonstrates the occurrence of the grafting reaction and PVP is successfully grafted onto PBI. Prepare these modified membranes into MEA. It was found that during the fuel cell operation, all the grafted membranes showed substantial improvement in maximum current density and peak power density compared to unmodified one. For PBI-g-PVP 30, with a grafting degree of 22.4%, the peak power density reaches 1312 mW cm⁻², marking a 59.6% enhancement compared to the pristine PBI membrane. The improvement is caused by the improved PA binding ability of the membrane after grafting. The AST test result shows that the grafting membranes have better long-term durability and performance than unmodified membranes attributed to the presence of added PA binding sites, which can effectively prevent the PA leaching caused by proton migration. In conclusion, the test results indicate that grafting PVP onto PBI is a promising strategy which can effectively improve the fuel cell performance.

Keywords: fuel cell, grafting modification, PA doping ability, PVP

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Authors: Felix U. Asoiro, Meshack I. Simeon, Chinenye E. Azuka, Harami Solomon, Chukwuemeka J. Ohagwu

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The drying kinetics, specific energy consumed (SEC), effective moisture diffusivity (EMD), flavonoid, phenolic, and vitamin C contents of onion slices dried under convective oven drying (COD) were compared with microwave drying (MD). Drying was performed with onion slice thicknesses of 2, 4, 6, and 8 mm; air drying temperatures of 60, 80, and 100°C for COD, and microwave power of 450 W for MD. A decrease in slice thickness and an increase in drying air temperature led to a drop in the drying time. As thickness increased from 2 – 8 mm, EMD rose from 1.1-4.35 x 10⁻⁸ at 60°C, 1.1-5.6 x 10⁻⁸ at 80°C, and 1.25-6.12 x 10⁻⁸ at 100°C with MD treatments yielding the highest mean value (6.65 x 10⁻⁸ m² s⁻¹) at 8 mm. Maximum SEC for onion slices in COD was 238.27 kWh/kg H₂O (2 mm thickness), and the minimum was 39.4 kWh/kg H₂O (8 mm thickness) whereas maximum during MD was 25.33 kWh/kg H₂O (8 mm thickness) and minimum, 18.7 kWh/kg H₂O (2 mm thickness). MD treatment gave a significant (p 0.05) increase in the flavonoid (39.42 – 64.4%), phenolic (38.0 – 46.84%), and vitamin C (3.7 – 4.23 mg 100 g⁻¹) contents, while COD treatment at 60°C and 100°C had positive effects on only vitamin C and phenolic contents, respectively. In comparison, the Weibull model gave the overall best fit (highest R²=0.999; lowest SSE=0.0002, RSME=0.0123, and χ²= 0.0004) when drying 2 mm onion slices at 100°C.

Keywords: allium cepa, drying kinetics, specific energy consumption, flavonoid, vitamin C, microwave oven drying

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Authors: Karthick Gopalan, Selvamohan Thankiah

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Biosurfactants are lipid compounds produced by microbes, which are amphipathic molecules consisting of hydrophophic and hydrophilic domains. In the present investigation, ten bacterial strains were isolated from petroleum oil contaminated sites near petrol bunk. Oil collapsing test, haemolytic activity were used as a criteria for primary isolation of biosurfactant producing bacteria. In this study, all the bacterial strains gave positive results. Among the ten strains, two were observed as good biosurfactant producers, they utilize the diesel as a sole carbon source. Optimization of biosurfactant producing bacteria isolated from petroleum oil contaminated sites was carried out using different parameters such as, temperature (20ºC, 25ºC, 30ºC, 37ºC and 45ºC), pH (5,6,7,8 & 9) and nitrogen sources (ammonium chloride, ammonium carbonate and sodium nitrate). Biosurfactants produced by bacteria were extracted, dried and quantified. As a result of optimization of parameters the suitable values for the production of more amount of biosurfactant by the isolated bacterial species was observed as 30ºC (0.543 gm/lt) in the pH 7 (0.537 gm/lt) with ammonium nitrate (0.431 gm/lt) as sole carbon source.

Keywords: isolation and identification, biosurfactant, microorganism, bioaugmentation

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Authors: Amir Moslehi, Gholamreza Raisali

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Microdosimetric detectors based on multiple-thick gas electron multiplier (multiple-THGEM) configurations are being used in various fields of radiation protection and dosimetry. In the present work, microdosimetric response of these detectors to fast neutrons has been investigated by Monte Carlo method. Three similar microdosimeters made of A-150 and rexolite as the wall materials are designed; the first based on single-THGEM, the second based on double-THGEM and the third is based on triple-THGEM. Sensitive volume of the three microdosimeters is a right cylinder of 5 mm height and diameter which is filled with the propane-based tissue-equivalent (TE) gas. The TE gas with 0.11 atm pressure at the room temperature simulates 1 µm of tissue. Lineal energy distributions for several neutron energies from 10 keV to 14 MeV including 241Am-Be neutrons are calculated by the Geant4 simulation toolkit. Also, mean quality factor and dose-equivalent value for any neutron energy has been determined by these distributions. Obtained data derived from the three microdosimeters are in agreement. Therefore, we conclude that the multiple-THGEM structures present similar microdosimetric responses to fast neutrons.

Keywords: fast neutrons, geant4, multiple-thick gas electron multiplier, microdosimeter

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Authors: Mojtaba Valinejadshoubi, Ashutosh Bagchi, Osama Moselhi

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Structures such as buildings, bridges, dams, wind turbines etc. need to be maintained against various factors such as deterioration, excessive loads, environment, temperature, etc. Choosing an appropriate monitoring system is important for determining any critical damage to a structure and address that to avoid any adverse consequence. Structural Health Monitoring (SHM) has emerged as an effective technique to monitor the health of the structures. SHM refers to an ongoing structural performance assessment using different kinds of sensors attached to or embedded in the structures to evaluate their integrity and safety to help engineers decide on rehabilitation measures. Ability of SHM in identifying the location and severity of structural damages by considering any changes in characteristics of the structures such as their frequency, stiffness and mode shapes helps engineers to monitor the structures and take the most effective corrective actions to maintain their safety and extend their service life. The main objective of this study is to review the overall SHM process specifically determining the natural frequency of an instrumented simply-supported concrete beam using modal testing and finite element model updating.

Keywords: structural health monitoring, natural frequency, modal analysis, finite element model updating

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Authors: Sonia Pajaron, Flaviano Sentina, Ranulfo Etulle

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Learning a second language calls for a total commitment from the learner whose response is necessary to successfully send and receive linguistic messages. It is relevant to virtually every aspect of human behaviour which is even more challenging when the components on -affective domains- are involved in second language learning. This study investigated the association between the identified affective attributes and second language performance of the one hundred seventeen (117) randomly selected third year maritime students. A descriptive-correlational method was utilized to generate data on their affective attributes while composition writing (2 series) and IELTS-based interview was done for speaking test. Additionally, to establish the respondents’ English language profile, data on their high school grades (GPA), entrance exam results in English subject (written) as well as in the interview was extracted as baseline information. Data were subjected to various statistical treatment (average means, percentages and pearson-r moment coefficient correlation) and found out that, Nautical Science and Marine Engineering students were found to have average high school grade, entrance test results, both written and in the interview turned out to be very satisfactory at 50% passing percentage. Varied results were manifested in their affective attributes towards learning the second language. On attitude, nautical science students had true positive attitude while marine engineering had only a moderate positive one. Secondly, the former were positively motivated to learn English while the latter were just moderately motivated. As regards anxiety, both groups embodied a moderate level of anxiety in the English language. Finally, data showed that nautical science students exuded real confidence while the marine engineering group had only moderate confidence with the second language. Respondents’ English academic achievement (GWA) was significantly correlated with confidence and speaking with anxiety towards the second language among the students from the nautical science group with moderate positive and low negative degree of correlation, respectively. On the other hand, the marine engineering students’ speaking test result was significantly correlated with anxiety and self-confidence with a moderate negative and low positive degree of correlation, respectively while writing was significantly correlated with motivation bearing a low positive degree of correlation.

Keywords: affective attributes, second language, second language performance, anxiety, attitude, self-confidence and motivation

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Authors: A. Sharma, S. S. Sandhu, A. Shahi, A. Kumar

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The aim of present investigation was to carry out Finite element modeling of distortion in the case of butt weld. 12mm thick AISI 304L plates were butt welded using three different combinations of groove design namely Double U, Double V and Composite. A full simulation of shielded metal arc welding (SMAW) of nonlinear heat transfer is carried out. Aspects like, temperature-dependent thermal properties of AISI stainless steel above liquid phase, the effect of thermal boundary conditions, were included in the model. Since welding heat dissipation characteristics changed due to variable groove design significant changes in the microhardness tensile strength and impact toughness of the joints were observed. The cumulative distortion was found to be least in double V joint followed by the Composite and Double U-joints. All the joints have joint efficiency more than 100%. CVN value of the Double V-groove weld metal was highest. The experimental results and the FEM results were compared and reveal a very good correlation for distortion and weld groove design for a multipass joint with a standard analogy of 83%.

Keywords: AISI 304 L, Butt joint, distortion, FEM, groove design, SMAW

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Authors: María de los Ángeles Cerda González, Itzel Arriaga Hurtado, Pascacio José Martínez Pichardo

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In México, the recognition of refugee condition is a fundamental right which, as host State, has the obligation of respect, protect, and fulfill to the foreigners – where we can find the figure of immigrants in irregular situation-, that cannot return to their country of origin for humanitarian reasons. The recognition of the refugee condition as a fundamental right in the Mexican law system proceeds under these situations: 1. The immigrant applies for the refugee condition, even without the necessary proving elements to accredit the humanitarian character of his departure from his country of origin. 2. The immigrant does not apply for the recognition of refugee because he does not know he has the right to, even if he has the profile to apply for. 3. The immigrant who applies fulfills the requirements of the administrative procedure and has access to the refugee recognition. Of the three situations above, only the last one is contemplated for the national indexes of the status refugee; and the first two prove the inefficiency of the governmental system viewed from its lack of sensibility consequence of the no education in human rights matter and which results in the legal vulnerability of the immigrants in irregular situation because they do not have access to the procuration and administration of justice. In the aim of determining the causes and consequences of the no recognition of the refugee status, this investigation was structured from a systemic analysis which objective is to show the advances in Central American humanitarian emergency investigation, the Mexican States actions to protect, respect and fulfil the fundamental right of refugee of immigrants in irregular situation and the social and legal vulnerabilities suffered by Central Americans in Mexico. Therefore, to achieve the deduction of the legal nature of the humanitarian emergency from the Human Rights as a branch of the International Public Law, a conceptual framework is structured using the inductive deductive method. The problem statement is made from a legal framework to approach a theoretical scheme under the theory of social systems, from the analysis of the lack of communication of the governmental and normative subsystems of the Mexican legal system relative to the process undertaken by the Central American immigrants to achieve the recognition of the refugee status as a human right. Accordingly, is determined that fulfilling the obligations of the State referent to grant the right of the recognition of the refugee condition, would mean a guideline for a new stage in Mexican Law, because it would enlarge the constitutional benefits to everyone whose right to the recognition of refugee has been denied an as consequence, a great advance in human rights matter would be achieved.

Keywords: central American immigrants in irregular situation, humanitarian emergency, human rights, refugee

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Authors: Deepak Jugran, Rajesh Gill

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Purpose: To study the demographic, sociological, gender and clinical profile of the children presented for childhood cataract at a public sector tertiary eye care centre in India. Methodology: The design of the study is retrospective, and hospital-based data is available with the Central Registration Department of the PGIMER, Chandigarh. The majority of the childhood cataract cases are being reported in this hospital, yet not each and every case of childhood cataract approaches PGI, Chandigarh. Nevertheless, this study is going to be pioneering research in India, covering five-year data of the childhood cataract patients who visited the Advanced Eye Centre, PGIMER, Chandigarh, from 1.1.2015 to 31.12.2019. The SPSS version 23 was used for all statistical calculations. Results: A Total of 354 children were presented for childhood cataract from 1.1.2015 to 31.12.2019. Out of 354 children, 248 (70%) were male, and 106 (30%) were female. In-spite of 2 flagship programmes, namely the National Programme for Control of Blindness (NPCB) and Aayushman Bharat (PM JAY) for eradication of cataract, no children received any financial assistance from these two programmes. A whopping 99% of these children belong to the poor families. In most of these families, the mothers were house-wives and did not employ anywhere. These interim results will soon be conveyed to the Govt. of India so that a suitable mechanism can be evolved to address this pertinent issue. Further, the disproportionate ratio of male and female children in this study is an area of concern as we don’t know whether the prevalence of childhood cataract is lower in female children or they are not being presented on time in the hospital by the families. Conclusion: The World Health Organization (WHO) has categorized Childhood blindness resulting from cataract as a priority area and urged all member countries to develop institutionalized mechanisms for its early detection, diagnosis and management. The childhood cataract is an emerging and major cause of preventable and avoidable childhood blindness, especially in low and middle-income countries. In the formative years, the children require a sound physical, mental and emotional state, and in the absence of either one of them, it can severely dent their future growth. The recent estimate suggests that India could suffer an economic loss of US$12 billion (Rs. 88,000 Crores) due to blindness, and almost 35% of cases of blindness are preventable and avoidable if detected at an early age. Besides reporting these results to the policy makers, synchronized efforts are needed for early detection and management of avoidable causes of childhood blindness such as childhood cataract.

Keywords: childhood blindness, cataract, Who, Npcb

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Authors: Raghvendra Singh Yadav, Ivo Kuřitka, Jarmila Vilcakova, Pavel Urbanek, Michal Machovsky, Milan Masař, Martin Holek

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ZnFe2O4 spinel ferrite nanoparticles were synthesized by sol-gel auto-combustion method. The synthesized spinel ferrite nanoparticles were annealed at different higher temperature to achieve different size nanoparticles. The as synthesized and annealed samples were characterized by powder X-ray Diffraction Spectroscopy, Raman Spectroscopy, Fourier Transform Infrared Spectroscopy, UV-Vis absorption Spectroscopy and Scanning Electron Microscopy. The magnetic properties were studied by vibrating sample magnetometer. The variation in magnetic parameters was noticed with variation in grain size. The dielectric constant and dielectric loss with variation of frequency shows normal behaviour of spinel ferrite. The variation in conductivity with variation in grain size is noticed. Modulus and Impedance Spectroscopy shows the role of grain and grain boundary on the electrical resistance and capacitance of different grain sized spinel ferrite nanoparticles. Acknowledgment: This work was supported by the Ministry of Education, Youth and Sports of the Czech Republic – Program NPU I (LO1504).

Keywords: spinel ferrite, nanoparticles, magnetic properties, dielectric properties

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Authors: S. Rashidi, L. C. Abdullah, R. Walvekar, K. Mohammad, F-R. Ahmadun, M. Y. Faizah

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In this research, stability and rheology behavior of Multi-walled carbon nanotube (MWCNT) nanofluids by using Xanthan Gum as a dispersant were measured. This paper addresses the effects of Xanthan Gum (XG) concentration and nanoparticle loading on stability and viscosity of nanofluids. The stability of nanofluids is measured by Zeta Sizer Nano-ZS (Malvern Instruments, ZEN 3600). The zeta potential of the stable samples was analyzed. The rheological behavior of carbon nanotube CNT nanofluids was analyzed using rheometer (Model AR G2, TA Instrument). Both stability and viscosity of the nanofluids increased with increasing CNT and XG concentration. The experimental results indicated that the zeta potential of nanofluid samples is stable. The results demonstrated that the zeta potential was affected by the CNT concentration and is augmented in parallel with increasing CNT concentration. The rheology results showed that the viscosity of CNT/XG nanofluid was increased. The escalated viscosity of CNT/XG nanofluid is owing to the higher van der Waals interaction between the CNT nanoparticles. On the other hand, the viscosity of the CNT/XG nanofluid decreases with increasing temperature. In summary, this research provides useful insight into the behavior of CNT nanofluids.

Keywords: nanofluid, carbon nanotube, stability, rheology

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Authors: T. H. N. Nguyen, A. Khodan, M. Amamra, J-V. Vignes, A. Kanaev

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The ultraporous nanofibrous alumina (NOA, Al2O3·nH2O) was synthesized by oxidation of laminated aluminium plates through a liquid mercury-silver layer in a humid atmosphere ~80% at 25°C. The material has an extremely high purity (99%), porosity (90%) and specific area (300 m2/g). The subsequent annealing of raw NOA permits obtaining pure transition phase (γ and θ) nanostructured materials. In this combination, we report on chemical, structural and phase transformations of pure and modified NOA by an impregnation of trimethylethoxysilane (TMES) and tetraethoxysilane (TEOS) during thermal annealing in the temperature range between 20 and 1650°C. The mass density, specific area, average diameter and specific area are analysed. The 3D model of pure NOA monoliths and silica modified NOA is proposed, which successfully describes the evolution of specific area, mass density and phase transformations. Activation energies of the mass transport in two regimes of surface diffusion and bulk sintering were obtained based on this model. We conclude about a common origin of modifications of the NOA morphology, chemical composition and phase transition.

Keywords: nanostructured materials, alumina (Al₂O₃), morphology, phase transitions

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Authors: Ankit Khurana

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The sufficient heat storage capacity or ability to dissipate heat is the most decisive parameter to have an effective and efficient functioning of Friction-based Brake Disc systems. The primary aim of the research was to analyse the effect of multiple coatings on lightweight disk rotors surface which not only alleviates the mass of vehicle & also, augments heat transfer. This research is projected to aid the automobile fraternity with an enunciated view over the thermal aspects in a braking system. The results of the project indicate that with the advent of modern coating technologies a brake system’s thermal curtailments can be removed and together with forced convection, heat transfer processes can see a drastic improvement leading to increased lifetime of the brake rotor. Other advantages of modifying the surface of a lightweight rotor substrate will be to reduce the overall weight of the vehicle, decrease the risk of thermal brake failure (brake fade and fluid vaporization), longer component life, as well as lower noise and vibration characteristics. A mathematical model was constructed in MATLAB which encompassing the various thermal characteristics of the proposed coatings and substrate materials required to approximate the heat flux values in a free and forced convection environment; resembling to a real-time braking phenomenon which could easily be modelled into a full cum scaled version of the alloy brake rotor part in ABAQUS. The finite element of a brake rotor was modelled in a constrained environment such that the nodal temperature between the contact surfaces of the coatings and substrate (Wrought Aluminum alloy) resemble an amalgamated solid brake rotor element. The initial results obtained were for a Plasma Electrolytic Oxidized (PEO) substrate wherein the Aluminum alloy gets a hard ceramic oxide layer grown on its transitional phase. The rotor was modelled and then evaluated in real-time for a constant ‘g’ braking event (based upon the mathematical heat flux input and convective surroundings), which reflected the necessity to deposit a conducting coat (sacrificial) above the PEO layer in order to inhibit thermal degradation of the barrier coating prematurely. Taguchi study was then used to bring out certain critical factors which may influence the maximum operating temperature of a multi-coated brake disc by simulating brake tests: a) an Alpine descent lasting 50 seconds; b) an Autobahn stop lasting 3.53 seconds; c) a Six–high speed repeated stop in accordance to FMVSS 135 lasting 46.25 seconds. Thermal Barrier coating thickness and Vane heat transfer coefficient were the two most influential factors and owing to their design and manufacturing constraints a final optimized model was obtained which survived the 6-high speed stop test as per the FMVSS -135 specifications. The simulation data highlighted the merits for preferring Wrought Aluminum alloy 7068 over Grey Cast Iron and Aluminum Metal Matrix Composite in coherence with the multiple coating depositions.

Keywords: lightweight brakes, surface modification, simulated braking, PEO, aluminum

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Authors: Lina Lauciene, Vaida Andruleviciute, Ingrida Sinkeviciene, Mindaugas Malakauskas, Loreta Serniene

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Dairy product manufacturers constantly are looking for new markets for their production. And in most cases, the problem of product compliance with the composition requirements of foreign products is highlighted. This is especially true of the composition of milk fat in dairy products. It is well known that there are many factors such as feeding ratio, season, cow breed, stage of lactation that affect the fatty acid composition in milk. However, there is less evidence on the impact of the technological process on the composition of fatty acids in raw milk and products made from it. In this study the influence of the technological process on fat composition in 82% fat butter, 15% fat curd, 3.6% fat yogurt and 2.5% fat UHT milk was determined. The samples were collected at each stage of production, starting with raw milk and ending with the final product in the Lithuanian milk-processing company. Fatty acids methyl esters were quantified using a GC (Clarus 680, Perkin Elmer) equipped with flame ionization detector (FID) and a capillary column SP-2560, 100 m x 0.25 mm id x 0.20 µm. Fatty acids peaks were identified using Supelco® 37 Component FAME Mix. The concentration of each fatty acid was expressed in percent of the total fatty acid amount. In the case of UHT milk production, it was compared raw milk, cream, milk mixture, and UHT milk but significant differences were not estimated between these stages. Analyzing stages of the yogurt production (raw milk, pasteurized milk, and milk with a starter culture and yogurt), no significant changes were detected between stages as well. A slight difference was observed with C4:0 - a percentage of this fatty acid was less (p=0.053) in the final stage than in milk with the starter culture. During butter production, the composition of fatty acids in raw cream, buttermilk, and butter did not change significantly. Only C14:0 decreased in the butter then compared to buttermilk. The curd fatty acid analysis showed the increase of C6:0, C8:0, C10:0, C11:0, C12:0 C14:0 and C17:0 at the final stage when compared to raw milk, cream, milk mixture, and whey. Meantime the increase of C18:1n9c (in comparison with milk mixture and curd) and C18:2n6c (in comparison with raw milk, milk mixture, and curd) was estimated in cream. The results of this study suggest that the technological process did not affect the composition of fatty acids in UHT milk, yogurt, butter, and curd but had the impact on the concentration of individual fatty acids. In general, all of the fatty acids from the raw milk were converted into the final product, only some of them slightly changed the concentration. Therefore, in order to ensure an appropriate composition of certain fatty acids in the final product, producers must carefully choose the raw milk. Acknowledgment: This research was funded by Lithuanian Ministry of Agriculture (No. MT-17-13).

Keywords: dairy products, fat composition, fatty acids, technological process

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Authors: Strahinja Kovačević, Jelena Vladić, Senka Vidović, Zoran Zeković, Lidija Jevrić, Sanja Podunavac Kuzmanović

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Supercritical extracts of highly valuated medicinal plant Satureja montana were prepared by application of supercritical carbon dioxide extraction in the carbon dioxide pressure range from 125 to 350 bar and temperature range from 40 to 60°C. Using GC/MS method of analysis chemical profiles (aromatic constituents) of S. montana extracts were obtained. Self-training artificial neural networks were applied to predict the retention time of the analyzed terpenes in GC/MS system. The best ANN model obtained was multilayer perceptron (MLP 11-11-1). Hidden activation was tanh and output activation was identity with Broyden–Fletcher–Goldfarb–Shanno training algorithm. Correlation measures of the obtained network were the following: R(training) = 0.9975, R(test) = 0.9971 and R(validation) = 0.9999. The comparison of the experimental and predicted retention times of the analyzed compounds showed very high correlation (R = 0.9913) and significant predictive power of the established neural network.

Keywords: ANN regression, GC/MS, Satureja montana, terpenes

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