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Number of results: 36
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Abstract

A novel laser diode based length measuring interferometer for scientific and industrial metrology is presented. Wavelength the stabilization system applied in the interferometer is based on the optical wedge interferometer. Main components of the interferometer such as: laser diode stabilization assembly, photodetection system, measuring software, air parameters compensator and base optical assemblies are described. Metrological properties of the device such as resolution, measuring range, repeatability and accuracy are characterized.

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Authors and Affiliations

Marek Dobosz
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Abstract

In the paper I try to demonstrate that interactive concept of metaphor, in particular, that proposed by Ricoeur – contrary to what Wrzosek preaches – has a very limited use in the study of thought processes leading to the formulation of the metaphors used by the science.
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Authors and Affiliations

Artur Dobosz
1

  1. Politechnika Poznańska (emeritus)
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Abstract

Magnetic properties of Fe nanowire arrays (NWs) electrodeposited in anodic alumina membranes have been studied. The influence of nanowire geometry (length, pore diameter) and an external magnetic field applied during electrodeposition process on the magnetic properties of nanowire arrays was investigated. With the use of the X-ray diffraction analysis the structure of iron wires was determined. The iron wires have the regular Body Centered Cubic structure. Magnetic measurements show that shape anisotropy aligns the preferential magnetization axis along the wire axis. It was found that the application of an external magnetic field in a parallel direction to the sample surface induces magnetic anisotropy with an easy axis of magnetization following the nanowire axis. The dependence of the height of Fe wires on the electrodeposition time was determined.

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Authors and Affiliations

I. Dobosz
W. Gumowska
M. Czapkiewicz
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Abstract

Ditylenchus destructor is a serious pest of numerous economically important plants worldwide. The population of this nematode species was isolated from the root zone of Ammophila arenaria on a Baltic Sea sand dune. This population’s morphological and morphometrical characteristics corresponded to D. destructor data provided so far, except for the stylet knobs’ height (2.1–2.9 vs 1.3–1.8) and their arrangement (laterally vs slightly posteriorly sloping), the length of a hyaline part on the tail end (0.8–1.8 vs 1–2.9), the pharyngeal gland arrangement in relation to the intestine (dorsal or ventral vs dorsal, ventral or lateral) and the appearance of vulval lips (smooth vs annulated). Ribosomal DNA sequence analysis confirmed the identity of D. destructor from a coastal dune.

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Authors and Affiliations

Renata Dobosz
ORCID: ORCID
Katarzyna Rybarczyk-Mydłowska
Grażyna Winiszewska
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Abstract

Globodera artemisiae (Eroshenko et Kazachenko, 1972) was found in Poland in autumn of 2004. The nematodes developed on Artemisia vulgaris L. Morphological and morphometric characteristics of the Polish population correspond to earlier known populations from Far East of Russia, Armenia, China, Germany and Sweden. The traditional identification was confirmed by molecular methods. On the basic of rDNA sequences of G. artemisiae, deposited in GenBank the product of expected size was obtained. Subsequently, the results were confirmed by sequencing analysis.

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Authors and Affiliations

Renata Dobosz
Aleksandra Obrępalska-Stęplowska
Stefan Kornobis
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Abstract

Growing emission requirements are forcing the foundry industry to seek new, more environmentally friendly solutions. One of the

solutions may be the technologies of preparing moulding and core sands using organic biodegradable materials

as binders. However, not only environmental requirements grow but also those related to the technological properties

of moulding sand. Advancing automation and mechanization of the foundry industry brings new challenges related to the moulding sands.

Low elasticity may cause defects during assembly of cores or moulds by the manipulators.

The paper presents the study of flexibility in the room temperature according to new method and resistance to thermal deformation of selfhardening

moulding sands with furfuryl resin, containing biodegradable material PCL. The task of the new additive is to reduce the

moulding sands harmfulness to the environment and increase its flexibility in the room temperature. The impact of the additive and the

effect of the amount of binder on the properties of mentioned moulding sands were analysed. Studies have shown that the use of 5% of

PCL does not change the nature of the thermal deformation curve, improves the bending strength of tested moulding mixtures and

increases their flexibility at room temperature.

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Authors and Affiliations

A. Grabarczyk
K. Major-Gabryś
St.M. Dobosz
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Abstract

The article shows the influence of environment requirements on changes in different foundry moulding sands technologies such as cold

box, self-hardening moulding sands and green sands. The aim of the article is to show the possibility of using the biodegradable materials

as binders (or parts of binders’ compositions) for foundry moulding and core sands. The authors concentrated on the possibility of

preparing new binders consisting of typical synthetic resins - commonly used in foundry practice - and biodegradable materials. According

to own research it is presumed that using biodegradable materials as a part of new binders’ compositions may cause not only lower toxicity

and better ability to reclaim, but may also accelerate the biodegradation rate of used binders. What’s more, using some kinds of

biodegradable materials may improve flexibility of moulding sands with polymeric binder. The conducted research was introductory and

took into account bending strength and thermal properties of furan moulding sands with biodegradable material (PCL). The research

proved that new biodegradable additive did not decrease the tested properties.

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Authors and Affiliations

St.M. Dobosz
A. Grabarczyk
K. Major-Gabryś
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Abstract

The paper presents the impact of biodegradable material - polycaprolactone (PCL) on selected properties of moulding sands. A self-hardening moulding sands with phenol-furfuryl resin, which is widely used in foundry practice, and an environmentally friendly self-hardening moulding sand with hydrated sodium silicate where chosen for testing. The purpose of the new additive in the case of synthetic resin moulding sands is to reduce their harmfulness to the environment and to increase their “elasticity” at ambient temperature. In the case of moulding sands with environmentally friendly hydrated sodium silicate binder, the task of the new additive is to increase the elasticity of the tested samples while preserving their ecological character. Studies have shown that the use of 5% PCL in moulding sand increases their flexibility at ambient temperature, both with organic and inorganic binders. The influence of the new additive on the deformation of the moulding sands at elevated temperatures has also been demonstrated.
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Authors and Affiliations

A. Grabarczyk
S.M. Dobosz
K. Major-Gabryś
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Abstract

This paper focuses on mechanical properties of self hardening moulding sands with furfuryl and alkyd binders. Elasticity as a new

parameter of moulding sands is investigated. With the use of presented testing equipment, it is possible to determine force kinetics and

deformation of moulding sand in real time. The need for this kind of study comes from the modern casting industry. New foundries can be

characterized with high intensity of production which is correlated with high level of mechanization and automatization of foundry

processes. The increasingly common use of manipulators in production of moulds and cores can lead to generation of new types of flaws,

caused by breakage in moulds and cores which could occur during mould assembly. Hence it is required that moulds and cores have high

resistance to those kinds of factors, attributing it with the phenomenon of elasticity. The article describes the theoretical basis of this

property, presents methods of measuring and continues earlier research.

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Authors and Affiliations

St.M. Dobosz
A. Grabarczyk
K. Major-Gabryś
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Abstract

A cast iron is gradient material. This means that depending on the cooling rate it is possible, at the same chemical composition and the physicochemical state of molten metal, to obtain material with a different structure. The connection between the wall thickness of the casting and the speed of its cooling expresses the casting module. Along with the module escalation a cooling rate of the casting is reducing what can cause changes of the microstructure and the increased tendency to the crystallization of distorted graphite forms. Inspections of experimental castings from nodular cast iron with different modules were conducted to the graphite form.

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Authors and Affiliations

M. Hosadyna
St.M. Dobosz
J. Kusiński
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Abstract

Due to the presence of harmful substances in resins those mould sands may be hazardous to the natural environment and workers. The general assessment of harmfulness of sands used for molds and cores encompasses 2 basic points: emission of hazardous substances during processes of preparing sands, pouring mold with liquid metals (high temperatures), cooling and shaking-out; possibility of washing out hazardous substances from used sands to the environment, during storage or economic use outside foundries. We present the results of research on the emission of BTEX compounds from mould sands with phenolic resins during pouring liquid metal of different temperature (cast iron and Al alloy). The research was conducted according to the original method prepared by the authors, which has been used for years in cooperation with various foundries (Poland, abroad).
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Authors and Affiliations

St.M. Dobosz
J. Jakubski
K. Major-Gabryś
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Abstract

The necessity of obtaining high quality castings forces both researchers and producers to undertake research in the field of moulding sands. The key is to obtain moulding and core sands which will ensure relevant technological parameters along with high environmental standards. The most important group in this research constitutes of moulding sands with hydrated sodium silicate. The aim of the article is to propose optimized parameters of hardening process of moulding sands with hydrated sodium silicate prepared in warm-box technology. This work focuses on mechanical and thermal deformation of moulding sands with hydrated sodium silicate and inorganic additives prepared in warm-box technology. Tested moulding sands were hardened in the temperature of 140oC for different time periods. Bending strength, thermal deformation and thermal degradation was tested. Chosen parameters were tested immediately after hardening and after 1h of cooling. Conducted research proved that it is possible to eliminate inorganic additives from moulding sands compositions. Moulding sands without additives have good enough strength properties and their economic and ecological character is improved.
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Authors and Affiliations

K.A. Major-Gabryś
S.M. Dobosz
A.P. Grabarczyk
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Abstract

The constantly developing and the broadly understood automation of production processes in foundry industry, creates both new working conditions - better working standards, faster and more accurate production - and new demands for previously used materials as well as opportunities to generate new foundry defects. Those high requirements create the need to develop further the existing elements of the casting production process. This work focuses on mechanical and thermal deformation of moulding sands prepared in hot-box technology. Moulding sands hardened in different time periods were tested immediately after hardening and after cooling. The obtained results showed that hardening time period in the range 30-120 sec does not influence the mechanical deformation of tested moulding sands significantly. Hot distortion tests proved that moulding sands prepared in hot-box technology can be characterized with stable thermal deformation up to the temperature of circa 320oC.

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Authors and Affiliations

A. Grabarczyk
K. Major-Gabryś
S.M. Dobosz
J. Jakubski
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Abstract

Modern techniques of castings production, including moulding sands production, require a strict technological regime and high quality

materials. In the case of self-hardening moulding sands with synthetic binders those requirements apply mainly to sand, which adds to

more than 98% of the whole moulding sand mixture. The factors that affect the quality of the moulding sands are both chemical (SiO2

,

Fe2O3 and carbonates content) and physical. Among these factors somewhat less attention is paid to the granulometric composition of the

sands. As a part of this study, the effect of sand quality on bending strength Rgu

and thermal deformation of self-hardening moulding sands

with furfural and alkyd resin was assessed. Moulding sands with furfural resin are known [1] to be the most susceptible to the sand quality.

A negative effect on its properties has, among others, high content of clay binder and so-called subgrains (fraction smaller than 0,1mm),

which can lead to neutralization of acidic hardeners (in the case of moulding sands with furfuryl resin) and also increase the specific

surface, what forces greater amount of binding agents. The research used 5 different quartz sands originating from different sources and

characterized with different grain composition and different clay binder content.

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Authors and Affiliations

St.M. Dobosz
A. Grabarczyk
J. Jakubski
K. Major-Gabryś
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Abstract

The paper presents possibility of using biodegradable materials as parts of moulding sands’ binders based on commonly used in foundry

practice resins. The authors focus on thermal destruction of binding materials and thermal deformation of moulding sands with tested

materials. All the research is conducted for the biodegradable material and two typical resins separately. The point of the article is to show

if tested materials are compatible from thermal destruction and thermal deformation points of view. It was proved that tested materials

characterized with similar thermal destruction but thermal deformation of moulding sands with those binders was different.

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Authors and Affiliations

St.M. Dobosz
J. Jakubski
K. Major-Gabryś
D. Drożyński
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Abstract

This paper presents a new perspective on the issue of reclamation of moulding and core sands. Taking as a premise that the reclamation process must remain on the surface of grains some not separated binding materials rests, it should be chosen the proper moulding sand’s composition that will be least harmful for the reclaim quality. There are two different moulding and core sands taken into examinations. The researches prove that a small correction of their compositions (hardener type) improves the quality of the received reclaims. Carried out in this article studies have shown that such an approach to the problem of reclamation of the moulding and core sands is needed and reasonable.

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Authors and Affiliations

S.M. Dobosz
K. Major-Gabryś
M. Hosadyna
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Abstract

Artificial neural networks are one of the modern methods of the production optimisation. An attempt to apply neural networks for controlling the quality of bentonite moulding sands is presented in this paper. This is the assessment method of sands suitability by means of detecting correlations between their individual parameters. The presented investigations were aimed at the selection of the neural network able to predict the active bentonite content in the moulding sand on the basis of this sand properties such as: permeability, compactibility and the compressive strength. Then, the data of selected parameters of new moulding sand were set to selected artificial neural network models. This was made to test the universality of the model in relation to other moulding sands. An application of the Statistica program allowed to select automatically the type of network proper for the representation of dependencies occurring in between the proposed moulding sand parameters. The most advantageous conditions were obtained for the uni-directional multi-layer perception (MLP) network. Knowledge of the neural network sensitivity to individual moulding sand parameters, allowed to eliminate not essential ones.
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Authors and Affiliations

St.M. Dobosz
J. Jakubski
K. Major-Gabryś
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Abstract

The constant growth of foundry modernization, mechanization and automation is followed with growing requirements for the quality and parameters of both moulding and core sands. Due to this changes it is necessary to widen the requirements for the parameters used for their quality evaluation by widening the testing of the moulding and core sands with the measurement of their resistance to mechanical deformation (further called elasticity). Following article covers measurements of this parameter in chosen moulding and core sands with different types of binders. It focuses on the differences in elasticity, bending strength and type of bond destruction (adhesive/cohesive) between different mixtures, and its connection to the applied bonding agent. Moulding and cores sands on which the most focus is placed on are primarily the self-hardening moulding sands with organic and inorganic binders, belonging to the group of universal applications (used as both moulding and core sands) and mixtures used in cold-box technology.

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Authors and Affiliations

St.M. Dobosz
A. Grabarczyk
K. Major-Gabryś
J. Kusiński

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