The comparative tensile flow and work-hardening behavior of P9 steel in two different product forms, normalized and tempered plate and thick section tube plate forging, and P91 steel were ...investigated in the framework of the dislocation dynamics based Estrin–Mecking (E–M) one-internal-variable approach. The analysis indicated that the flow behavior of P9 and P91 steels was adequately described by the E–M approach in a wide range of temperatures. It was suggested that dislocation dense martensite lath/cell boundaries and precipitates together act as effective barriers to dislocation motion in P9 and P91 steels. At room and intermediate temperatures, the evolution of the internal-state variable,
i.e
., the dislocation density with plastic strain, exhibited insignificant variations with respect to temperature. At high temperatures, a rapid evolution of dislocation density with plastic strain toward saturation with increasing temperature was observed. The softer P9 steel tube plate forging exhibited higher work hardening in terms of larger gains in the dislocation density and flow stress contribution from dislocations than the P9 steel plate and P91 steel at temperatures ranging from 300 K to 873 K (27 °C to 600 °C). The evaluation of activation energy suggests that the deformation is controlled by cross-slip of dislocations at room and intermediate temperatures, and climb of dislocations at high temperatures. The relative influence of initial microstructure on flow and work-hardening parameters associated with the E–M approach was discussed in the three temperature regimes displayed by P9 and P91 steels.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
42.
Recommender system for personalised travel itinerary B, Tanuja Choudhary; B, Tulasi
International journal of electrical and computer engineering (Malacca, Malacca),
10/2019, Volume:
9, Issue:
5
Journal Article
A recommender system is an approach to give an appropriate solu-tion to a particular problem. This helps in recognising the pattern or behaviour of a user to suggest future possible likes of the ...user. Nowa-days people like to travel during their spare time, it has become a rigid task to decide where to go. This paper represents a customised recommender system to help users in destining their itinerary. A model is designed to suggest the best places to visit in Rome. A questionnaire was prepared to get information about users interest during their travel. The model generates the best five places to visit with respect to the choice picked by the user. The top five places for each category will be displayed to the user and the user was asked to pick a starting point for the itinerary. Then the model generates another set off a filtered list of places to enhance their travel experi-ence. It includes displaying the top 5 restaurants to visit during their travel.
The relationship among the composition, structure and selected properties for five series of silver phosphate glasses containing 0, 5, 10, 15 and 20 wt% Fe
2
O
3
has been investigated. The ...synthesized glasses have been characterized using different experimental techniques. X-ray diffraction studies revealed that the glasses are amorphous in nature. IR spectral studies have shown the presence of characteristic P–O–P linkages of linear phosphate chains, presence of O–P–O units in the phosphate tetrahedral and the formation of P–O–Fe bonds in the doped glass. It is also confirmed that due to doping of Fe
2
O
3
, loosening of glassy structure occurred and the glass became more disordered. Differential scanning calorimetric (DSC) studies revealed that glass transition temperature increased with Fe
2
O
3
concentration. Scanning electron microscopic studies have shown that Fe
2
O
3
doping modifies the microstructures of the glass and at lower concentration of dopant, a nanostructure is obtained. Electrical conductivity measurements from 303 to 373 K in a frequency range from 100 Hz to 5 MHz have indicated that all glasses are ionic conductors with Ag
+
ions as the charge carrier. Fe
2
O
3
doping in silver phosphate glass increased the electrical conductivities. Results have shown that dielectric constants increased with the increase of temperature at all the frequencies; a.c. and d.c. conductivities have been separated and a Cole–Cole plot is also drawn. Dielectric losses in all the glasses decreased with frequency at a particular temperature. It is found that Ag
2
O–P
2
O
5
glass doped with 5 wt% Fe
2
O
3
gives high OCV value and the doped glass can be used as an electrolyte for solid-state batteries.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Density functional theory-based first-principles investigation is performed on pristine and mono vacancy induced GaAs nanoribbons to detect the presence of three volatile organic compounds (VOCs), ...aniline, isoprene and o-toluidine, which will aid in sensing lung cancer. The study has shown that pristine nanoribbon senses all three analytes. For the pristine structure, we observe decent adsorbing parameters and the bandgap widens after the adsorption of analytes. However, the introduction of the carrier traps induced by defect causes deep energy wells that vary the electrical properties as indicated in the bandgap analysis of GaAs, wherein adsorption of aniline and o-toluidine reduces the bandgap to 0 eV, making the structure highly conductive in nature. The adsorption energies of defect-induced nanoribbon are more as compared with the pristine counterpart. Nonetheless, the introduction of defects has improved the sensitivity further.
Graphical abstract
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Uniaxial tensile flow and work hardening behavior of type 316L(N) austenitic stainless steel have been examined in the framework of two-internal-variable approach based on the evolution of forest ...dislocation density and mean free path with plastic strain in the temperature range from 300 K to 1023 K (27 °C to 750 °C) and strain rates ranging from 3.16 × 10
−5
to 3.16 × 10
−3
s
−1
. The steel exhibited three-stage work hardening behavior in the variations of
θσ
d
with
σ
d
, where
θσ
d
is the product of instantaneous work hardening rate,
θ
(
θ
= d
σ
d
/d
ε
p
) and flow stress contribution from dislocation (
σ
d
), and
ε
p
is the true plastic strain. The three-stage work hardening was characterized by a gradual increase in
θσ
d
at low stresses (transient stage) followed by a linear increase in
θσ
d
in stage-II and inverted parabolic hardening at high
σ
d
in stage-III. At all the strain rate and temperature conditions, the flow and work hardening behavior was appropriately described by the two-internal-variable model. The work hardening parameters such as dynamic recovery parameter and final mean free path, and the predicted forest, mobile, and total dislocation densities at uniform plastic strain exhibited three distinct temperature regimes. Anomalous variations in the work hardening parameters with respect to temperature and strain rate observed at intermediate temperatures have been ascribed to the occurrence of dynamic strain aging. At high temperatures, dominance of dynamic recovery has been observed.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This article reports on the RIXS (Resonant inelastic X-ray scattering), XES (X-ray emission spectroscopy), and XAS (X-ray absorption spectroscopy) of the LaSr2Mn2O7, La0.95Ba0.05MnO3, and ...La1.2(BaCa)1.8Mn2O7 at 40 K, 100 K and 300 K. The RIXS spectra of these samples show the presence of Mn in different valence states (Mn2+, Mn3+, and Mn4+) which is associated with the Jahn-Teller distortion due to overlapping between O2− and the unpaired electrons of transition metal Mn. It has also been noticed that the distortion observed in different valence states of Mn with O2− is found to be suppressed with dropping and the temperature. So, based on aforementioned studies, the Manganites have been considered as a strongly correlated magnetic system which would be useful in magnetic device applications.
•Studies on the RIXS, XES, XAS of single crystal LaSr2Mn2O7, La0.95Ba0.05MnO3, and La1.2(BaCa)1.8Mn2O7.•Different valence states of Mn have been probed under different temperatures.•Jahn-Teller distortion have been observed in Mn-O bonds due to overlapping of 3d and 2p states, respectively.•Studies of different electronic structure reflect manganites as strongly correlated magnetic system.•Suitable and potential candidates for magneto-caloric, magnetoresistance and magnetic device applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A constitutive model describing stress-relaxation behaviour of P91 steel at 873 K has been presented. In the model, the equations defining the evolution of internal stress and relaxation stress with ...time have been coupled with the sine hyperbolic rate law to predict the relaxation stress as a function of hold time as well as the stress dependence of inelastic strain rate. The evolution of internal stress with time has been derived from the power law dependence of internal stress on relaxation stress. The predicted evolution of internal and effective stresses with time exhibited an initial rapid decrease followed by stress plateaus at longer durations. The applicability of the model has been demonstrated for two different strain holds of 1.3 and 2.5% in P91 steel. It has been shown that the present model can be used to predict the evolution of inter-barrier spacing and activation volume with time for both the strain holds at 873 K. Further, the observed increase in activation volume and inter-barrier spacing with hold time in P91 steel has been presented.
•A constitutive model has been developed to describe stress-relaxation behaviour.•Interrelationship between internal stress and relaxation stress has been derived.•Model accurately described the relaxation stress vs. hold time data of P91 steel at 873 K.•Model can predict the variations in activation volume and inter-barrier spacing with hold time.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
► Tensile
σ–
ɛ behaviour is adequately described by Voce strain hardening relation. ► Temperature dependence of work hardening parameters exhibited three distinct regimes. ► Voce parameters are well ...correlated with tensile properties at all temperatures. ► Instantaneous work hardening rate vs. stress exhibited two-stage behaviour. ► Influence of DSA and dynamic recovery are highlighted.
Tensile stress–strain and work hardening behaviour of 9Cr–1Mo steel, containing three levels of silicon content (i.e., 0.24, 0.42 and 0.60
wt.%) have been examined in the temperature range 300–873
K in the framework of strain hardening law proposed by Voce. True stress–true plastic strain data for all test conditions were adequately described by Voce equation. The variations of work hardening parameters with temperature exhibited three different temperature regimes and displayed good correlations with the respective tensile properties of the steel. The variations of instantaneous work hardening rate with stress exhibited two-stage behaviour characterised by a rapid decrease in work hardening rate (transient stage) at low stresses followed by a gradual decrease (stage-III) at high stresses. Both work hardening parameters and instantaneous work hardening rate exhibited signatures of dynamic strain ageing at intermediate temperatures and dominance of dynamic recovery at high temperatures.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Tensile tests were performed at strain rates ranging from 3.16 × 10
−5
to 1.26 × 10
−3
s
−1
over a temperature range of 300 K to 923 K (27 °C to 650 °C) to examine the effects of temperature and ...strain rate on tensile deformation and fracture behavior of P92 ferritic steel. The variations of flow stress/strength values, work hardening rate, and tensile ductility with respect to temperature exhibited distinct three temperature regimes. The fracture mode remained transgranular. The steel exhibited serrated flow, an important manifestation of dynamic strain aging, along with anomalous variations in tensile properties in terms of peaks in flow stress/strength and work hardening rate, negative strain rate sensitivity, and ductility minima at intermediate temperatures. At high temperatures, the rapid decrease in flow stress/strength values and work hardening rate, and increase in ductility with increase in temperature and decrease in strain rate, indicated the dominance of dynamic recovery.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Detailed analysis indicated that true stress (σ)-true plastic strain (ε) and work hardening behaviour of 9Cr–1Mo steel in two different forms, i.e. 20mm plate and thick section tubeplate forging can ...be adequately described by Voce equation and Kocks–Mecking approach in the temperature range 300–873K. The steel exhibited two-stage work hardening in the variations of instantaneous work hardening rate (θ=dσ/dε) and θσ with stress. The variations in σ–ε, work hardening parameters, θ–σ and θσ–σ with temperature exhibited three distinct temperature regimes. Good correlations between the predicted tensile properties using Voce equation and the respective experimental values along with analogy between Voce equation and Kocks–Mecking approach have been demonstrated for the steel. The differences in σ–ε, work hardening parameters, θ–σ and θσ–σ observed between plate and tubeplate forging have been ascribed to the effects associated with initial microstructures for the two product forms of the steel.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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