7,739 research outputs found
Exchange bias effect in the phase separated Nd_{1-x}Sr_{x}CoO_3 at the spontaneous ferromagnetic/ferrimagnetic interface
We report the new results of exchange bias effect in Nd_{1-x}Sr_{x}CoO_3 for
x = 0.20 and 0.40, where the exchange bias phenomenon is involved with the
ferrimagnetic (FI) state in a spontaneously phase separated system. The
zero-field cooled magnetization exhibits the FI (T_{FI}) and ferromagnetic
(T_C) transitions at ~ 23 and \sim 70 K, respectively for x = 0.20. The
negative horizontal and positive vertical shifts of the magnetic hysteresis
loops are observed when the system is cooled through T_{FI} in presence of a
positive static magnetic field. Training effect is observed for x = 0.20, which
could be interpreted by a spin configurational relaxation model. The
unidirectional shifts of the hysteresis loops as a function of temperature
exhibit the absence of exchange bias above T_{FI} for x = 0.20. The analysis of
the cooling field dependence of exchange bias field and magnetization indicates
that the ferromagnetic (FM) clusters consist of single magnetic domain with
average size around \sim 20 and ~ 40 \AA ~ for x = 0.20 and 0.40, respectively.
The sizes of the FM clusters are close to the percolation threshold for x =
0.20, which grow and coalesce to form the bigger size for x = 0.40 resulting in
a weak exchange bias effect.Comment: 9 pages, 9 figure
On the optical properties of Ag^{+15} ion-beam irradiated TiO_{2} and SnO_{2} thin films
The effects of 200-MeV Ag^{+15} ion irradiation on the optical properties of
TiO_{2} and SnO_{2} thin films prepared by using the RF magnetron sputtering
technique were investigated. These films were characterized by using UV-vis
spectroscopy, and with increasing irradiation fluence, the transmittance for
the TiO_{2} films was observed to increase systematically while that for
SnO_{2} was observed to decrease. Absorption spectra of the irradiated samples
showed minor changes in the indirect bandgap from 3.44 to 3.59 eV with
increasing irradiation fluence for TiO_{2} while significant changes in the
direct bandgap from 3.92 to 3.6 eV were observed for SnO_{2}. The observed
modifications in the optical properties of both the TiO_{2} and the SnO_{2}
systems with irradiation can be attributed to controlled structural
disorder/defects in the system.Comment: 6 pages, ICAMD-201
DEM simulation of effect of confining pressure on ballast behaviour
In this paper, an attempt has been made to investigate the influence of confining pressure on deformation and degradation behaviourof railway ballast using the Discrete Element Method (DEM). A novel approach has been employed to model the two dimensionalprojection of field size ballast particles as cluster of bonded particles. Bonded particles are held together by a bond, and debonding isconsidered as particle breakage. A series of cyclic loading simulations using DEM were carried out on an assembly of angular ballast particles at different confining pressures (10 kPa to 240 kPa). The results highlight that the development of axial strain during cyclicloading as a function of initial confining pressure and number of cycles. Very high axial strain and breakage of particles have been observed at low confining pressure (\u3c 30 kPa) owing to dilative volumetric strain behaviour. In terms of particle breakage, there existsan optimum range of confining pressures where breakage is minimal. In addition, the evolution of particle displacement vectors explains the breakage mechanism and associated deformations during cyclic loading
6-[(DimethylÂamino)methylÂeneÂamino]-1,3-dimethylÂpyrimidine-2,4(1H,3H)-dione dihydrate
Uracil, the pyrimidine nucleobase, which combined with adenine forms one of the major motifs present in the biopolymer RNA, is also involved in the self-assembly of RNA. In the title compound, C9H14N4O2·2H2O, the asymmetric unit contains one dimethylÂaminoÂuracil group and two water molÂecules. The plane of the N=C—NMe2 side chain is inclined at 27.6 (5)° to the plane of the uracil ring. Both water molÂecules form O—H⋯O hydrogen bonds with the carbonyl O atoms of the uracil group. Additional water–water hydrogen-bond interÂactions are also observed in the crystal structure. The O—H⋯O hydrogen bonds lead to the formation of a two-dimensional hydrogen-bonded network cage consisting of two dimethylÂaminoÂuracil groups and six water molÂecules
The Integration of Lean and Human Resource Management Practices as an Enabler for Lean Deployment- A Systematic Literature Review
Purpose – The current research aims to map and investigate how Human Resource Management and Lean practices can be integrated. This investigation will help identify the Human Resource Management aspects critical in the success of Lean initiatives while exploring the research gaps in the existing literature. The review also aims to delineate the benefits and challenges of integrating Lean with Human Resource Management systems to discuss further research and practice areas.
Design/methodology/approach – This study utilizes a Systematic Literature Review method to identify and synthesize the existing literature. As part of the process, a protocol that provided a plan for the review was followed, including the research questions and the data to be extracted.
Findings– The study results indicate that aspects of Human Resources Management practice and policies such as Training & Development, Teamwork, Motivation, Communication, Leadership, are key enablers of Lean initiative deployment and success. The benefits of the integration of Human Resources with Lean
15 can help in Lean training and development, communication of Lean initiatives and successes, allocating and hiring continuous improvement personnel, and supporting leadership in Lean deployment. Challenges to integrating Lean and HRM practices included lack of integration and collaboration between disciplines. Further exploration areas in successful Lean deployment would be practical longitudinal case studies on Lean deployments with HR partnerships and involvement.
Practical implications – This review paper has crucial implications for practice relating to, integration of Lean with Human resource management structures and tailoring Human resource management initiatives to ensure the success of Lean deployment and reduce risks of failure.
Originality/value – The Systematic literature review study conducted in this paper is the first of its kind to integrate and map the human resource management concepts that can be integrated with Lean to deploy the initiative successfully. This mapping is critical for ensuring the success of Lean methodologies within an organization and paves the way for future research. In addition, managers and organizations can find support and guidance from this study to focus on vital areas of partnership between their Lean and HR programs
Low temperature specific heat of La_{3}Pd_{4}Ge_{4} with U_{3}Ni_{4}Si_{4}-type structure
Low temperature specific heat has been investigated in a novel ternary
superconductor La_{3}Pd_{4}Ge_{4} with an U_{3}Ni_{4}Si_{4}-type structure
consisting of the alternating BaAl_{4} (ThCr_{2}Si_{2})- and AlB-type
layers. A comparative study with the related ThCr_{2}Si_{2}-type superconductor
LaPd_{2}Ge_{2}, one of the layers in La_{3}Pd_{4}Ge_{4}, is also presented.
From the normal state specific heat, the Sommerfeld coefficient mJ/mol K^2 and the Debye temperature = 256 K are derived
for the La_{3}Pd_{4}Ge_{4}, while those for the LaPd_{2}Ge_{2} are mJ/mol K^2 and = 291 K. The La_{3}Pd_{4}Ge_{4} has
moderately high electronic density of state at the Fermi level. Electronic
contribution on the specific heat, , in each compound is well
described by the BCS behavior, suggesting that both of the La_{3}Pd_{4}Ge_{4}
and the LaPd_{2}Ge_{2} have fully opened isotropic gap in the superconducting
state
Manufacturing and characterization of sustainable and recyclable wood-polypropylene biocomposites:Multiprocessing-properties-structure relationships
In this study, sustainable polymeric materials with a polypropylene matrix reinforced with wood waste were developed for structural applications. The new polymer biocomposites (WPCs) were evaluated for their mechanical and structural properties regarding their susceptibility to multiple processing. As thermo-mechanical degradation processes are associated with the repeated processing of plastics, which causes changes in the properties and structure of these materials. Therefore, to determine the extent to which the composites can be used under operating conditions, the composites were examined by DMA. As a result of the study observed some effects caused by the repeated effects of shear stress and temperature on the rheological and mechanical properties of polymer composites. The first of these is related to a decrease in viscosity of WPC composites subjected to the six times processing and changes in flow conditions during extrusion and injection moulding due to the degradation of the polypropylene matrix. As the viscosity of the composites decreased, a reduction in tensile strength and other mechanical properties of the polypropylene matrix was noted. On the other hand, the second effect observed leads to the conclusion that, as the composites' processing cycles increase, the WPC composite's mechanical properties increase due to an increase in the degree of homogenization of the individual components of the WPC composition. This study aims to describe the relationship between these two primary processes and to determine the relationship between the properties and the structure of the new WPCs.</p
Efectos de la tecnologÃa de procesos sobre las propiedades fisicoquÃmicas del aceite de peonÃa
Peony seed oils (PSOs) were prepared using supercritical CO2 (SC) and compared with soxhlet extraction (SE) and mechanical screw press extraction (SPE) methods. The fatty acid compositions of the oils were determined, and the physicochemical properties of the oils, including free radical-scavenging activity, α-amylase and α-glucosidase inhibition, thermal and rheological properties were evaluated. The unsaturated fatty acids in the SE oils were higher than SC and SPE oils due to the higher percentage of olefinic, allylic methylene and allylic methine protons in the SE oils. The SPE oils also displayed the highest DPPH and ABTS+ radical scavenging activity at the tested concentrations. However, the SE oils showed stronger inhibitory effects on α-amylase and α-glucosidase enzymes under in vitro conditions when compared with the other oil samples. The three oils had similar melting and crystalline point due to similar contents of fatty acids (FAs). The SC oils had a lower Ea than the others.Se prepararon aceites de semillas de peonia (PSOs) utilizando CO2 supercrÃtico (SC) y se compararon con los métodos de extracción en soxhlet (SE) y de extracción mecánica de tornillos (SPE). Se determinaron las composiciones en ácidos grasos y se evaluaron las propiedades fisicoquÃmicas de los aceites incluyendo la actividad de eliminación de radicales libres, la inhibición de α-amilasa y α-glucosidasa, las propiedades térmicas y reológicas. Los ácidos grasos insaturados en los aceites SE fueron más altos que los aceites SC y SPE debido al mayor porcentaje de protones olefÃnicos, metileno alÃlico y metino alÃlico en los aceites SE. Los aceites SPE también mostraron una actividad de eliminación de radicales DPPH y ABTS+ más alta a las concentraciones ensayadas. Sin embargo, los aceites SE mostraron efectos inhibidores más fuertes sobre las enzimas α-amilasa y α-glucosidasa bajo condiciones in vitro cuando se compararon con las otras muestras de aceite. Los aceites tenÃan puntos de fusión y cristalinos similares debido a un contenido similar de ácidos grasos (FAs). Los aceites SC tenÃan un Ea más bajo que los demás
- …