Beyond Gross-Pitaevskii equation for 1D gas: Quasiparticles and solitons

Describing properties of a strongly interacting quantum many-body system poses a serious challenge both for theory and experiment. In this work, we study excitations of one-dimensional repulsive Bose gas for arbitrary interaction strength using a hydrodynamic approach. We use linearization to study particle (type-I) excitations and numerical minimization to study hole (type-II) excitations. We observe a good agreement between our approach and exact solutions of the Lieb-Liniger model for the particle modes and discrepancies for the hole modes. Therefore, the hydrodynamical equations find to be useful for long-wave structures like phonons and of a limited range of applicability for short-wave ones like narrow solitons. We discuss potential further applications of the method.Comment: 27 pages, 11 figures. Submission to SciPos

Wpływ dodatku proszku żelaza oraz rozdrobnionego złomu stalowego na krystalizację żeliwa

The study proves that by introducing the iron powder and disintegrated steel scrap to low-sulphur cast iron still before the inoculation carried out with a conventional graphitising inoculant, the mechanical properties similar to those obtained during the inoculation treatment carried out on cast iron with the recommended high sulphur content are achieved. The said operation increases the number of crystallisation nuclei for dendrites of the primary austenite. In this case, the iron particles act as substrates for the nucleation of primary austenite gp due to a similar crystallographic behaviour of the regular face centered cubic lattice The more numerous are the dendrites of primary austenite, the less free space is available in the interdendritic spaces for the formation of graphite eutectic grains, which makes the structure more refined (more eutectic grains) and the mechanical properties higher.W pracy wykazano, że wprowadzenie do żeliwa o niskiej zawartości siarki, jeszcze przed zabiegiem modyfikowania tradycyjnym modyfikatorem grafityzującym, proszku żelaza i/lub złomu stalowego w postaci rozdrobnionej, prowadzi do otrzymania podobnych właściwości wytrzymałościowych jak przy zabiegu modyfikowania dla żeliwa o zalecanej wyższej zawartości siarki. Zabieg ten zwiększa liczbę zarodków krystalizacji dendrytów austenitu pierwotnego. W tym przypadku cząstki żelaza spełniają rolę podkładek do zarodkowania austenitu pierwotnego ϒp wskutek podobieństwa krystalograficznego sieci regularnej (ściennie centrowanej). Im większa liczba dendrytów austenitu pierwotnego, tym mniej miejsca w przestrzeniach międzydendrytycznych na kształtowanie się ziaren eutektyki grafitowej, a w efekcie nieco drobniejsza struktura (większa liczba ziaren eutektycznych) oraz większe wartości właściwości wytrzymałościowych

A R C H I V E S of F O U N D R Y E N G I N E E R I N G Forming of primary austenite in low-sulphur cast iron

Abstract The study proves that by introducing the disintegrated steel scrap to low-sulphur cast iron still before the inoculation carried out with a conventional graphitising inoculant, the mechanical properties similar to those obtained during the inoculation treatment carried out on cast iron with the recommended high sulphur content are achieved. The said operation increases the number of crystallisation nuclei for dendrites of the primary austenite. In this case, the iron particles act as substrates for the nucleation of primary austenite p due to a similar crystallographic behaviour of the regular face centered cubic lattice The more numerous are the dendrites of primary austenite, the less free space is available in the interdendritic spaces for the formation of graphite eutectic grains, which makes the structure more refined (mor e eutectic grains) and the mechanical properties higher

A R C H I V E S of F O U N D R Y E N G I N E E R I N G Analysis of Structure and Abrasion Resistance of the Metal Composite Based on an Intermetallic FeAl Phase with VC and TiC Precipitates

Abstract Metal alloys with matrix based on an Fe-Al system are generally considered materials for high-temperature applications. Their main advantages are compact crystallographic structure, long-range ordering and structural stability at high temperatures. These materials are based on an intermetallic phase of FeAl or Fe 3 Al, which is stable in the range from room temperature up to the melting point of 1240°C. Their application at high temperatures is also beneficial because of the low cost of production, very good resistance to oxidation and corrosion, and high mechanical strength. The casting alloy the structure of which includes the FeAl phase is, among others, highaluminium cast iron. This study has been devoted to the determination of the effect of vanadium and titanium on the transformation of the high-aluminium cast iron structure into an in-situ FeAl-VC composite

Analysis of structure and abrasion resistance of the metal composite based on an intermetallic FeAl phase with VC and TiC precipitates

Metal alloys with matrix based on an Fe-Al system are generally considered materials for high-temperature applications. Their main advantages are compact crystallographic structure, long-range ordering and structural stability at high temperatures. These materials are based on an intermetallic phase of FeAl or Fe3Al, which is stable in the range from room temperature up to the melting point of 1240°C. Their application at high temperatures is also beneficial because of the low cost of production, very good resistance to oxidation and corrosion, and high mechanical strength. The casting alloy the structure of which includes the FeAl phase is, among others, high-aluminium cast iron. This study has been devoted to the determination of the effect of vanadium and titanium on the transformation of the high-aluminium cast iron structure into an in-situ FeAl-VC composite

Analysis of Structure and Abrasion Resistance of the Metal Composite Based on an Intermetallic FeAl Phase with VC and TiC Precipitates

Metal alloys with matrix based on an Fe-Al system are generally considered materials for high-temperature applications. Their main advantages are compact crystallographic structure, long-range ordering and structural stability at high temperatures. These materials are based on an intermetallic phase of FeAl or Fe3Al, which is stable in the range from room temperature up to the melting point of 1240°C. Their application at high temperatures is also beneficial because of the low cost of production, very good resistance to oxidation and corrosion, and high mechanical strength. The casting alloy the structure of which includes the FeAl phase is, among others, high-aluminium cast iron. This study has been devoted to the determination of the effect of vanadium and titanium on the transformation of the high-aluminium cast iron structure into an in-situ FeAl-VC composite

Inoculation of Austenite Primary Grains in Cast Iron

The modification is a widespread method of improving the strength properties of cast iron. The impact in terms of increasing amounts of eutectic grains has been thoroughly studied while the issue of the impact on the mechanical properties of primary austenite grains has not been studied in depth yet. The paper presents the study of both aspects. The methodology was to conduct the melting cast iron with flake graphite, then modifying the alloy by two sets of modifiers: the commercial modifier, and a mixture of iron powder with a commercial inoculant. The DAAS test was carried out to identify the primary austenite grains. The degree of supercooling was determined and the UTS test was performed as well. Additionally carried out the metallographic specimen allowing for counting grains. It can be concluded that the introduction of the iron powder significantly improved the number of austenite primary grains which resulted in an increase in tensile strength UTS

Inoculation of Austenite Primary Grains in Cast Iron

The modification is a widespread method of improving the strength properties of cast iron. The impact in terms of increasing amounts of eutectic grains has been thoroughly studied while the issue of the impact on the mechanical properties of primary austenite grains has not been studied in depth yet. The paper presents the study of both aspects. The methodology was to conduct the melting cast iron with flake graphite, then modifying the alloy by two sets of modifiers: the commercial modifier, and a mixture of iron powder with a commercial inoculant. The DAAS test was carried out to identify the primary austenite grains. The degree of supercooling was determined and the UTS test was performed as well. Additionally carried out the metallographic specimen allowing for counting grains. It can be concluded that the introduction of the iron powder significantly improved the number of austenite primary grains which resulted in an increase in tensile strength UTS