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Abstract

Balance, thermodynamic and mainly kinetic approaches using methods of process engineering enable to determine conditions under which iron technology can actually work in limiting technological states, at the lowest reachable fuel consumption (reducing factor) and the highest reachable productivity accordingly. Kinetic simulation can be also used for variant prognostic calculations. The paper deals with thermodynamics and kinetics of iron making process. It presents a kinetic model of iron oxide reduction in a low temperature area. In the experimental part it deals with testing of iron ore feedstock properties. The theoretical and practical limits determined by heat conditions, feedstock reducibility and kinetics of processes are calculated.

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Authors and Affiliations

Pavlína Pustějovská
Simona Jursová
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Abstract

Iron-reducing bacteria (IRB) seek to unravel iron corrosion for oil and gas steel pipeline failure. IRB continued to be dominating the microbiological corrosion of iron structures in steel by deteriorating steel surface via Fe(III) reduction. The mechanisms by IRB mediate Fe(III) reduction into Fe(II) for bacterial respiration to contribute to iron steel corrosion. However, the complexity of corrosion is not fully comprehended. It remains controversial due to the corrosion mechanisms proposed by IRB that may induce or inhibit corrosion when engaged with microbial biofilm. In this brief review, understanding microbiological corrosion mechanisms associated with IRB interactions may better understand microbiological corrosion and derive corrosion control.
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Authors and Affiliations

N.A.A. Jamaluddin
1
ORCID: ORCID
M. Yusoff
1
ORCID: ORCID
S.K. Wee
1
ORCID: ORCID
M.N. Masri
1
ORCID: ORCID

  1. Universiti Malaysia Kelantan, Faculty of Bioengineering and Technology, 17600 Jeli Kelantan, Malaysia
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Abstract

In this work the effectiveness of the biotransformation of phosphogypsum in the cultures of sulphatereducing bacteria (SRB) was studied. SRB were isolated from soil contaminated with automobile fuel. The microorganisms were grown by two methods: the enrichment of the cultures and microcosms in: Postgate, minimal medium (with phenol, acetate or lactate) and Emerson medium. All media contained phosphogypsum as electron acceptors. The isolated microorganisms were passage in medium containing different carbon compounds: ethanol, lactate, phenol, acetate casein or lactose to test the effectiveness of biotransformation of phosphogypsum depending on the source of carbon used. In cultures in Postgate medium with lactate or casein there were found the maximal H2S concentration (654 and 540 mg HS-/dm3) and maximal decrease of phosphogypsum 84% and 64%, respectively. The isolated microorganisms utilised alcohol, sugar, protein and phenol.
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Authors and Affiliations

Dorota Wolicka
Włodzimierz Kowalski
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Abstract

Both shrinkage reducing admixtures (SRA) and expansive admixture (EXP) can be used to reduce the risk of cracking in concrete. Synergistic effect of using both of those admixtures simultaneously was a was found, however little information can be found on the effects of using both EXP and SRA on the properties of mortars and concrete other than shrinkage. Therefore in this paper, effect of adding both EXP and SRA on properties of mortars outside of their effect on shrinkage is researched. Mortars with Portland cement CEM I were modified by adding EXP and SRA in amount of full dose recommended by the producer, and half of the recommended dose. Research consisted of tests of properties of fresh mortars (consistency, initial setting time, hydration heat) and hardened mortars (compressive strength and drying shrinkage). It has been found that using both SRA and EXP admixtures leads to maintaining the same setting time which can be prolonged if only SRA is used, decreased compressive strength, possibility of increased consistency. Synergistic effect on shrinkage was also confirmed.
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Authors and Affiliations

Jacek Gołaszewski
1
ORCID: ORCID
Małgorzata Gołaszewska
1
ORCID: ORCID

  1. Silesian University of Technology, Faculty of Civil Engineering, ul. Akademicka 5, 44-100 Gliwice
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Abstract

In the years 1996-2002 evaluation of herbicides' efficacy used in low doses was tested. For investigations several herbicides recommended for weed control in cereals were selected. The results of experiments indicate on possibility of reducing of herbicides' doses by about 25 to 3 7.5%, and still obtaining good effects ofweed control without significant decrease of yielding of cultivation plants. The dose is depended upon sensitivity of weed species, growth stage of weeds and their infestation, density of crop and the weather conditions. Low doses of herbicide can be applied where weeds are in early growth stage, where there is low infestation ofweeds, and weeds show susceptibility to used herbicides, moreover under correct crop density and good weather conditions.
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Authors and Affiliations

Krzysztof Domaradzki
Henryka Rola
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Abstract

In the years 2000-2002 the evaluation of herbicides' efficacy used in lowered doses was conducted. Six herbicides recommended for weed control in spring cereals were used for investigation. The majority of species of weeds occurring in spring wheat and spring barely reacted with a strong (above 90%) decrease of the fresh weight to the treatment with the herbicides applied in the doses reduced by 25%-50% in relation to the recommended ones. Polygonum convolvulus L., Polygonum persicaria L. and Thlaspi arvense L. were very sensitive species as they were very good controlled by tested herbicides in the doses decreased by 50%-75%. Veronica hederifolia L. and Viola arvensis Murr. were characterised by a low level of sensitivity and were controlled only by full recommended doses of tested herbicides. The significant statistical decrease on yield of spring wheat on the objects treated with the herbicides Aurora Super 61,5 SG (mecoprop-P+carfentrazone-ethyl), Granstar 75 DF (tribenuron-methyl) and Grody! 75 WG (amidosulfuron) in the doses lowered by 50% in relation to the recommended ones and Starane 250 EC (fluroxypyr) and Chwastox Trio 540 SL (mecoprop+MCPA+dicamba) in the dose lowered by 50%-7 5% was not observed. In the case of the herbicide Aminopielik D 450 SL (2,4-D+dicamba) the reduction of the dose by 25%-50% also did not cause decrease on yield of spring wheat. In the spring barley, the significant statistical decrease of yielding was not observed on all treatments with tested herbicides applied in the doses reduced by 50%-75%.
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Authors and Affiliations

Krzysztof Domaradzki
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Abstract

In the paper, problem of proper tuning of second-order Reduced Active Disturbance Rejection Controller (RADRC2) is considered in application for industrial processes with significant (but not dominant) delay time. For First-Order plus Delay Time (FOPDT) and Second-Order plus Delay Time (SOPDT) processes, tuning rules are derived to provide minimal Integral Absolute Error (IAE) assuming robustness defined by gain and phase margins. Derivation was made using optimization procedure based on D-partition method. The paper also shows results of comprehensive simulation validation based on examplary benchmark processes of more complex dynamics as well as final practical validation. Comparison with PID controller shows that RADRC2 tuned by the proposed rules can be practical alternative for industrial control applications.

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Authors and Affiliations

Paweł Nowak
ORCID: ORCID
Jacek Czeczot
Patryk Grelewicz
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Abstract

The use of biostimulants and cultivar selection play an important role in modern potato farming because they influence tuber yield and quality. The nutritional value and processing suitability of potato tubers are affected by their content of total protein, reducing sugars and sucrose. The aim of this study was to determine the effect of biostimulants on the content of total protein, glucose, fructose and sucrose in potato tubers (skin, flesh and whole tubers with skin), at harvest and after 5 months of storage. The experimental materials included tubers of five edible potato cultivars: Irga, Satina, Valfi, Blaue St. Galler and HB Red. During the growing season, potato plants were treated with the following biostimulants: Asahi SL, Bio-Algeen S-90, Kelpak SL and Trifender WP. Control plants were not treated with biostimulants. The total protein content of tubers was determined by the Kjeldahl method. Simple sugars and sucrose were determined by high-performance liquid chromatography. At harvest, total protein concentration was significantly higher in purple- and red-fleshed cultivars than in cream- and yellow-fleshed cultivars. An analysis of tuber parts revealed that flesh had the highest protein content. The total protein content of tubers increased during storage. Biostimulants had no significant effect on total protein concentration in tubers at harvest or after storage. The content of simple sugars and sucrose was higher in the skin, flesh and whole tubers of purple- and red-fleshed cultivars, than in cream- and yellow-fleshed cultivars. Potato tubers with colored flesh accumulated the highest amounts of total sugars. Biostimulants, in particular Bio-Algeen S-90 and Kelpak SL, contributed to the accumulation of monosaccharides and the disaccharide in potato tubers, and, in consequence, total sugars. Their concentrations in potato tubers increased during storage.
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Authors and Affiliations

Małgorzata Głosek-Sobieraj
1
Jadwiga Wierzbowska
2
ORCID: ORCID
Bożena Cwalina-Ambroziak
1
ORCID: ORCID
Agnieszka Waśkiewicz
3
ORCID: ORCID

  1. Department of Entomology, Phytopathology and Molecular Diagnostics, University of Warmia and Mazury, Olsztyn, Poland
  2. Department of Agricultural and Environmental Chemistry, University of Warmia and Mazury, Olsztyn, Poland
  3. Department of Chemistry, Poznań University of Life Sciences, Poznań, Poland
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Abstract

Entrapped gases, solidification shrinkage and non-metallic compound formation are main sources of porosity in aluminium alloy castings. Porosity is detrimental to the mechanical properties of these castings; therefore, its reduction is pursued. Rotary degassing is the method mostly employed in industry to remove dissolved gases from aluminium melts, reducing porosity formation during solidification of the cast part. Recently, ultrasonic degassing has emerged as a promising alternative thanks to a lower dross formation and higher energy efficiency. This work aims to evaluate the efficiency of the ultrasonic degasser and compare it to a conventional rotary degassing technique applied to an AlSi10Mg alloy. Degassing efficiency was evaluated employing the reduced pressure test (RPT), where samples solidified under reduced pressure conditions are analysed. Factors affecting RPT were considered and temperature parameters for the test were established. The influence of ultrasonic degassing process parameters, such as degassing treatment duration and purging gas flow rate were studied, as well as treated aluminium volume and oxide content. Finally, ultrasonic degassing process was contrasted to a conventional rotary degassing technique, comparing their efficiency.

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Authors and Affiliations

H. Galarraga
M.G. de Cortazar
E. Arregi
A. Artola
J.L. Oncala
M. Merchan
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Abstract

Recyclability is one of the great features of aluminium and its alloys. However, it has been typically considered that the secondary aluminium quality is low and bad. This is only because aluminium is so sensitive to turbulence. Uncontrolled transfer and handling of the liquid aluminium results in formation of double oxide defects known as bifilms. Bifilms are detrimental defects. They form porosity and deteriorate the properties. The detection and quantification of bifilms in liquid aluminium can be carried out by bifilm index measured in millimetres as an indication of melt cleanliness using Reduced Pressure Test (RPT). In this work, recycling efficiency and quality change of A356 alloy with various Ti additions have been investigated. The charge was recycled three times and change in bifilm index and bifilm number was evaluated. It was found that when high amount of Ti grain refiner was added, the melt quality was increased due to sedimentation of bifilms with Ti. When low amount of Ti is added, the melt quality was degraded.

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Authors and Affiliations

O. Gursoy
E. Erzi
K. Tur
D. Dispinar
ORCID: ORCID
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Abstract

The concepts of full-order and reduced-order observers are extended to the fractional linear continuous-time systems. Necessary and sufficient conditions for the existence of the observers for fractional linear systems are established. Procedures for designing of the observers are given and illustrated by examples.
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Authors and Affiliations

Tadeusz Kaczorek
1
ORCID: ORCID

  1. Białystok University of Technology, Faculty of Electrical Engineering, Wiejska 45D, 15-351 Białystok, Poland
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Abstract

The outdoor pot experiments on the influence of weeds' growth stage and climate conditions on herbicides' effect were carried out in the Danish Institute of Agriculture Science in 2000-2001. The experiment concerning growth stage took into consideration three phases of Galium aparine: l, 2 and 3 whorls. The influence of temperature was performed using climate simulator running at three temperatures: 8/2°C, l 6.5/8°C, 24/16°C. The rain was applied using rain simulator 1, 3 and 6 hours after herbicides' treatment. Herbicides: Grody! 75 WG (amidosulfuron 750 g*kg-1), Aurora Super 61,5 WG (mecoprop 600 g=kg' + carfentrazone-ethyl 15 g*kt1), Lintur 70 WG (dicamba 65.9 g=kg', triasulfuron 4.1 g=kg') and Chwastox Trio 540 SL (dicamba 40 g*r1, MCPA 200 g"l', mecoprop 300 g*r') were applied in four doses: full recommended, 1/2, 1/4 and 1/8 of full dose on G. aparine. Grody! 75 WG and Aurora Super 61,5 WG were the most efficient to the youngest plants of G. aparine. Differences in susceptibility among three growth stages (1, 2, 3 whorls) to Grody! 75 WG were higher than to Aurora Super 61,5 WG. Effectiveness of tested herbicides tended to increase as temperature rose. The addition of adjuvant improved activity of herbicide Lintur 70 WG that showed satisfactory weed control even at four time reduced dose independently from temperature. The rain treatment 1, 3 and 6 hours after spraying caused reduction of Aurora Super 61,5 WG activity at 1/4 and 1/8 doses. The half dose gave a good result only when rain was applied 6 hours after treatment. Herbicide Grody! 75 WG was efficient after rain application (1, 3, 6 HAT) only at full dose.
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Authors and Affiliations

Renata Kieloch
Krzysztof Domaradzki
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Abstract

While cycloid pin-wheel precision reducers (referred to as RV reducers) are widely used in industrial robots, a widely accepted design standard or verification method of their test platforms is not available. In this study, a comprehensive sliding-separation test platform of RV reducers was developed. The test platform can test various measurement items such as transmission error, static measurement of lost motion, dynamic measurement of lost motion, torsional rigidity, no-load running torque, starting torque, backdriving torque, and transmission efficiency of the RV reducer for robots. The principle and method of dynamic measurement of lost motion tests based on the two-way transmission error method were studied and this test function was successfully integrated with the comprehensive test platform in order to increase the test items of the dynamic performance parameters of RV reducers. The measurement results of the no-load running torque of the RV reducer were consistent with the Stribeck curve. Based on the concept of optimal measurement speed, a decomposition test method of the geometric component of the dynamic measurement of lost motion and the elastic component of the dynamic measurement of lost motion was proposed in the dynamic measurement test of lost motion. Through precision calibration, function test and repeatability test, the results were compared with the data of enterprise’s samples. The consistent results have proved that the test platform met engineering requirements and measurement accuracy requirements. Based on the new test principle, the developed platform can test more parameters of RV reducers with high precision and display the comprehensive test performance.
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Authors and Affiliations

Huijun Yue
1
Xiangkai Wu
1
Zhaoyao Shi
1
Yue Zhang
1
Yong Ye
1
Lintao Zhang
1
Ying Fu
1

  1. Beijing University of Technology, Beijing Engineering Research Center of Precision Measurement Technology and Instruments, 100, Ping Le Yuan, Chaoyang District, Beijing 100124, China
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Abstract

Presented article contain the teachers opinions of the perceived social expectations in relation to their own expectations of both the institutions of school and local educational authorities. The starting point is a thesis that asymmetrical and disproportionate expectations conducive to the construction of the reduced school reality a specified group of students. as reality shows school does not always reflect the social expectations, which is closely connected with the attitudes of teachers in mainstream schools. however, their expectations of working conditions and the same students with disabilities often remain inconsistent. To identify and interpret the reality that create the appearance of the school, the topic is examined in the context of the concept of the reduced space and the theory of games.

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Authors and Affiliations

Dorota Prysak
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Abstract

The aim of the work is to present the method for designing sparse FIR filters with very low group delay and approximately linear-phase in the passband. Significant reduction of the group delay, e.g. several times in relation to the linear phase filter, may cause the occurrence of undesirable overshoot in the magnitude frequency response. The method proposed in this work consists of two stages. In the first stage, FIR filter with low group delay is designed using minimax constrained optimization that provides overshoot elimination. In the second stage, the same process is applied iteratively to reach sparse solution. Design examples demonstrate the effectiveness of the proposed method.
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Authors and Affiliations

Jacek Konopacki
1

  1. Faculty of Automatic Control, Electronics and Computer Sciences, Silesian University of Technology
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Abstract

Increasing development in information and communication technology leads to the generation of large amount of data from various sources. These collected data from multiple sources grows exponentially and may not be structurally uniform. In general, these are heterogeneous and distributed in multiple databases. Because of large volume, high velocity and variety of data mining knowledge in this environment becomes a big data challenge. Distributed Association Rule Mining(DARM) in these circumstances becomes a tedious task for an effective global Decision Support System(DSS). The DARM algorithms generate a large number of association rules and frequent itemset in the big data environment. In this situation synthesizing highfrequency rules from the big database becomes more challenging. Many algorithms for synthesizing association rule have been proposed in multiple database mining environments. These are facing enormous challenges in terms of high availability, scalability, efficiency, high cost for the storage and processing of large intermediate results and multiple redundant rules. In this paper, we have proposed a model to collect data from multiple sources into a big data storage framework based on HDFS. Secondly, a weighted multi-partitioned method for synthesizing high-frequency rules using MapReduce programming paradigm has been proposed. Experiments have been conducted in a parallel and distributed environment by using commodity hardware. We ensure the efficiency, scalability, high availability and costeffectiveness of our proposed method.
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Authors and Affiliations

Sudhanshu Shekhar Bisoyi
1
Pragnyaban Mishra
2
Saroja Nanda Mishra
3

  1. Department of Computer Science and Information Technology, Siksha ’O’ Anusandhan Deemed to be University (SOA), Institute of Technical Education and Research (ITER), Bhubaneswar, Odisha, India
  2. Dept. of Computer Science and Engineering, Koneru Lakshmaiah Education Foundation, Vaddeswaram, Guntur, AP, India
  3. Dept. of CSE&A, IGIT, Sarang, Dhenkanal, Odisha, India
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Abstract

The analysis of subsonic stall flutter in turbomachinery blade cascade is carried out using a medium-fidelity reduced-order aeroelastic numerical model. The model is a type of field mesh-free approach and based on a hybrid boundary element method. The medium-fidelity flow solver is developed on the principle of viscous-inviscid two-way weak-coupling approach. The hybrid flow solver is employed to model separated flow and stall flutter in the 3D blade cascade at subsonic speed. The aerodynamic damping coefficient w.r.t. inter blade phase angle in traveling-wave mode is estimated along with other parameters. The same stability parameter is used to analyze the cascade flutter resistance regime. The estimated results are validated against experimental measurements as well as Navier-Stokes based high fidelity CFD model. The simulated results show good agreement with experimental data. Furthermore, the hybrid flow solver has managed to bring down the computational cost significantly as compared to mesh-based CFD models. Therefore, all the prime objectives of the research have been successfully achieved.
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Authors and Affiliations

Chandra Shekhar Prasad
1
Pavel Šnábl
1
Luděk Pešek
1
ORCID: ORCID

  1. Institute of Thermomechanics of the CAS, Prague, Czech Republic
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Abstract

The study examines various approaches oriented towards conceptual and numerical reduction of first-principle models, data-driven methodologies for surrogate (black box) and hybrid (grey box) modeling, and addresses the prospect of using digital twins in chemical and process engineering. In the case of numerical reduction of mechanistic models, special attention is paid to methodologies in which simulation data are used to construct light but robust numerical models while preserving all the physics of the problem, yielding reduced-order datadriven but still white-box models. In addition to reviewing various methodologies and identifying their applications in chemical engineering, including industrial process engineering, as well as fundamental research, the study outlines associated problems and challenges, as well as the risks posed by the era of big data.
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Authors and Affiliations

Katarzyna Bizon
1
ORCID: ORCID

  1. Cracow University of Technology, Faculty of Chemical Engineering and Technology,Warszawska 24, 31-155 Kraków, Poland
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Abstract

Admixtures are commonly used nowadays in the mix composition of concrete. These additions affect concrete properties and performance especially creep deformations. This paper shows the effect of admixtures on creep of concrete. In fact, creep deformations have prejudicial consequences on concrete behaviour; an incorrect or inaccurate prediction leads to undesirable consequences in structures. Therefore, an accurate estimation of these deformations is mandatory. Moreover, design codes do not consider admixtures’ effect while predicting creep deformations, thus it is necessary to develop models that predict accurately creep deformations and consider the effect of admixtures. Using a large experimental database coming from international laboratories and research centres, this study aims to update the Eurocode 2 creep model by considering the type and percentage of admixtures using Bayesian Linear Regression method. The effect of two types of admixtures is presented in this paper; the water reducer and silica fume.

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Authors and Affiliations

E. Zgheib
W. Raphael
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Abstract

Sand drifting on road networks in the region of the Lower Algerian Sahara is one of the main problems for the sector. Machines are repeatedly deployed to overcome this phenomenon. The long experience acquired while dealing with the removal of sand from roads pushed us to focus on obstacles called "Draas". The purpose of this study is to perform an optimization of these special protective structures called “Draas”, using a reduced physical model. Model tests were performed in flow channel. The principle of modeling the wind transport using a reduced model is to simulate the wind using a liquid stream while respecting the laws of hydraulic and sedimentological similarity. The results obtained are extrapolated to make a normal size prototype.

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Authors and Affiliations

A.K. Sebaa
M. Belhamra
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Abstract

With the steady increase in the incidence of breast cancer in women, treatment that includes not only tumor removal but also breast reconstruction is becoming a more relevant issue for oncologic and plastic surgeons. Mastectomy recently evolved as a form of primary prevention of hereditary breast cancer, commonly performed in combination with simultaneous reconstruction. A case of 44-year-old woman who underwent right mastectomy with adjuvant radiotherapy is presented. Due to the patient’s positivity for BRCA1 mutation and her wishes, a risk-reducing mastectomy with nipple-areola complex preservation and bilateral deep inferior epigastric artery perforator flap reconstruction were performed in one-stage. In selected cases this method appears to be the best possible procedure for simultaneous preventative and reconstructive management in patients with genetically determined breast cancer who have undergone mastectomy with radiotherapy.
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Bibliography

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Authors and Affiliations

Łukasz Ulatowski
1
Piotr Gierej
1
Maria Molska
1

  1. Department of Plastic Surgery, Medical Centre for Postgraduate Education, Professor W. Orlowski Memorial Hospital, 231st Czerniakowska Street, 00-416 Warsaw, Poland
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Abstract

Background: Despite advanced research and great progress in understanding the chronic pancreatitis (CP) pathogenesis, no current causal treatment for the condition is available. For preclinical studies, the existence of a well-characterized CP animal model is essential.
The aim of the study was to assess the impact of chronic pancreatitis on the antioxidant enzymes activity in rat blood serum and on the level of glutathione (intracellular antioxidant) in rat pancreas.
Methods: The experiments were carried out on the Wistar Kyoto rats in two groups: control and study group (CP), in which chemical induction of pancreatitis with dibutyl dichloride was performed. Serum enzyme activities of amylase, lipase, catalase and superoxide dismutase were analyzed. The levels of the following biochemical parameters were also investigated: total protein, albumin, calcium, magnesium, and triglycerides. Levels of low-molecular-weight thiols: reduced (GSH) and oxidized (GSSG) glutathione, were determined in pancreatic homogenates.
Results: Histopathological imaging of rat pancreatic parenchyma with induced inflammation confirmed focal lymphocytic interstitial chronic pancreatitis with fibrosis features and mild parenchymal atrophy, as well as pancreatic islets degeneration. In the CP group, we observed a statistically significant decrease in serum amylase and lipase activities and in total protein/albumin levels. Also, the elevated catalase activity was registered. In CP rats’ tissues, we observed a 15-fold reduction in GSH levels. The other examined parameters remained unchanged. Clinically relevant are hypoalbuminemia and a moderate decrease in lipase activity. The described changes are most probably indicative of the impaired exocrine pancreas function, however without organ failure features.
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Authors and Affiliations

Patrycja Bronowicka-Adamska
1
Tomasz Hutsch
2
Dominika Szlęzak
1
Anna Bentke-Imiolek
1
Kinga Kaszuba
1
Piotr Ceranowicz
3
Beata Kuśnierz-Cabala
1

  1. Chair of Medical Biochemistry, Faculty of Medicine, Jagiellonian University Medical College, Kraków, Poland
  2. Department of Pathology and Veterinary Diagnostics, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
  3. Department of Physiology, Faculty of Medicine, Jagiellonian University Medical College, Kraków, Poland
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Abstract

The aim of trials was to determine the efficacy of three doses of herbicides in different weather conditions. There were tested two herbicide groups: hormon type herbicides and sulfonylurea herbicides. Each of the herbicide (Aminopielik Gold 530 EW, MCPA 750 SL, Duplosan Super 600 SL, Granstar 75 WG, Grody! 75 WG, Lintur 70 WG) was applied in three doses: recommended dose, 1/2 of recommended dose and 1/4 of recommended dose. The herbicides were applied in the tillering stage of spring wheat. In some cases it is possible reducing doses of herbicides but decision about choice of herbicide type and dose should be considered in connection with weather conditions before application.
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Authors and Affiliations

Kinga Matysiak
Stanisław Stachecki
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Abstract

Recently, some major changes have occurred in the structure of the European foundry industry, such as a rapid development in the production of castings from compacted graphite iron and light alloys at the expense of limiting the production of steel castings. This created a significant gap in the production of heavy steel castings (exceeding the weight of 30 Mg) for the metallurgical, cement and energy industries. The problem is proper moulding technology for such heavy castings, whose solidification and cooling time may take even several days, exposing the moulding material to a long-term thermal and mechanical load. Owing to their technological properties, sands with organic binders (synthetic resins) are the compositions used most often in industrial practice. Their main advantages include high strength, good collapsibility and knocking out properties, as well as easy mechanical reclamation. The main disadvantage of these sands is their harmful effect on the environment, manifesting itself at various stages of the casting process, especially during mould pouring. This is why new solutions are sought for sands based on organic binders to ensure their high technological properties but at the same time less harmfulness for the environment. This paper discusses the possibility of reducing the harmful effect of sands with furfuryl binders owing to the use of resins with reduced content of free furfuryl alcohol and hardeners with reduced sulphur content. The use of alkyd binder as an alternative to furfuryl binder has also been proposed and possible application of phenol-formaldehyde resins was considered.

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Authors and Affiliations

K. Major-Gabryś
ORCID: ORCID
M. Hosadyna-Kondracka
ORCID: ORCID

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