Insights into the structural,electronic, and magnetic properties of Fe2−x Ti x O3/Fe2O3 thin films with x = 0.44 grown on Al2O3 (0001)

The interface between hematite (α-Fe ₂ ^III O₃) and ilmenite (Fe^IITiO₃), a weak ferrimagnet and an antiferromagnet, respectively, has been suggested to be strongly ferrimagnetic due to the formation of a mixed valence layer of Fe²⁺/Fe³⁺ (1:1 ratio) caused by compensation of charge mismatch at the chemically abrupt boundary. Here, we report for the first time direct experimental evidence for a chemically distinct layer emerging at heterointerfaces in the hematite—Ti-doped-hematite system. Using molecular beam epitaxy, we have grown thin films (~25 nm thickness) of α-Fe₂O₃ on α-Al₂O₃ (0001) substrates, which were capped with a ~25 nm thick Fe_2?x Ti _x O₃ layer (x = 0.44). An additional 3 nm cap of α-Fe₂O₃ was deposited on top. The films were structurally characterized in situ with surface X-ray diffraction, which showed a partial low index orientation relationship between film and substrate in terms of the [0001] axis and revealed two predominant domains with \( (0001) _{{{\text{Fe}}_{2} {\text{O}}_{3} }} \;||\;(0001) _{{{\text{Al}}_{2} {\text{O}}_{3} }}, \) one with \( [10\bar{1}0]_{{{\text{Fe}}_{2} {\text{O}}_{3} }} \;||\;[10\bar{1}0]_{{{\text{Al}}_{2} {\text{O}}_{3} }}, \) and a twin domain with \( [01\bar{1}0]_{{{\text{Fe}}_{2} {\text{O}}_{3} }} \;||\;\;[10\bar{1}0]_{{{\text{Al}}_{2} {\text{O}}_{3} }}. \) Electron energy loss spectroscopy profiles across the Fe_2?x Ti _x O₃/Fe₂O₃ interface show that Fe²⁺/Fe³⁺ ratios peak right at the interface. This strongly suggests the formation of a chemically distinct interface layer, which might also be magnetically distinct as indicated by the observed magnetic enhancement in the Fe_2?x Ti _x O₃/α-Fe₂O₃/Al₂O₃ system compared to the pure α-Fe₂O₃/Al₂O₃ system.     

Karanja (Pongamia Pinnata) biodiesel production in Bangladesh, characterization of karanja biodiesel and its effect on diesel emissions

This paper presents production of biodiesel (BD) from non-edible renewable karanja (Pongamia Pinnata) oil, determination of BD properties and influence of BD on engine performance and emissions. Bangladesh imports 2.4 million metric ton (MT) DF each year [M.N. Nabi, M.S. Akhter, K.M.F. Islam, Prospect of biodiesel production from jatropha curcas, a promising non edible oil seed in Bangladesh, International Conference on Mechanical Engineering (ICME, Dhaka, Bangladesh) Proceedings 2007, paper no. ICME07-TH-06. [1]]. It has 0.32 million hectare of unused land [M.N. Nabi, S.M.N. Hoque, M.S. Uddin, Prospect of Jatropha curcas and pithraj cultivation in Bangladesh, Journal of Engineering and Technology, IUT, Dhaka, Bangladesh, 7 (1) (2009) 41–54. [2]]. It has been found that cultivating of karanja plant in such unused land; Bangladesh can reduce DF import by 28%. Karanja methyl ester (KME), which is termed as BD, has been produced by well-known transesterification process. The properties of B100 (B100) and its blends were determined mainly according to ASTM standard and some of them were as per EN14214 standard. The Fourier transform infrared (FTIR) analysis showed that the DF fuel contained mainly alkanes and alkens, while the B100 contained mainly esters. The gas chromatography (GC) of B100 revealed that a maximum of 97% methyl ester was produced from karanja oil. Engine experiment result showed that all BD blends reduced engine emissions including carbon monoxide (CO), smoke and engine noise, but increased oxides of nitrogen (NOx). Compared to DF, B100 reduced CO, and smoke emissions by 50 and 43%, while a 15% increase in NOx emission was observed with the B100. Compared to DF, engine noise with B100 was reduced by 2.5 dB.     

Does Misery Love Company? Exploring the Therapeutic Effects of TV Viewing on Regretted Experiences

Testing hypotheses derived from regret and mood management theories, this research explores how regretted experiences impact interest in viewing experience-relevant TV programming and such viewing's effects on program enjoyment and felt regret. One hundred and forty-four participants, half of whom had been unfaithful in romantic relationships, were asked first to rate their interest in viewing a series of storylines and then to provide their reactions to 1 of 2 versions of a TV program depicting cheating behavior. Largely consistent with hypotheses, results indicated that those who had both cheated and felt regret about their behavior were more likely than others to want to watch experience-related storylines, were no less likely to enjoy watching such programming, and particularly preferred viewing the program version in which the main character rationalized, rather than expressed regret for, her behavior. Both program versions, however, reduced regret equally. A survey of 206 city residents also offered evidence consistent with predictions based on regret theory. Overall, this research speaks to the value of integrating theories of emotion with media theory to enhance the latter's predictive ability.     

Triazinylamino-alkylphosphonate reactive dyes for cellulosic fibres

A bifunctional reactive bis-phosphonoalkylaminotriazine dye was synthesised by condensing 2 mol of aminoethylphosphonic acid with the commercially available bis-monochloro- s -triazinyl dye, CI Reactive Red 120. A similar but much lower molecular weight dye was prepared by condensing the commercially available dichloro- s -triazine dye, Procion Red MX 8B, with aminomethylphosphonate. A model aryl-phosphonate dye was also prepared by diazotising m -aminobenzene-phosphonic acid and coupling the diazonium salt to R-salt. These dyes were isolated as their free acids and then converted to their ammonium salts. Pad liquors containing dye, cyanamide and ammonium dihydrogen phosphate were applied to cotton fabric. In the case of the bis-phosphonoethylamino- s -triazine dye, very high dye–fibre fixation values (>90%) were achieved using a pad–batch–bake procedure; for the Procion T model dye, the comparative maximum fixation was only modest. In the absence of cyanamide, no fixation could be obtained for the arylphosphonate dye but both bis-phosphonoalkylaminotriazine dyes gave significant fixation.     

Hydrogen storage and PL properties of novel Cd/CdO shelled hollow microspheres prepared under NH3 gas environment

Here we report the first ever fabrication of metal/semiconductor Cd/CdO shelled hollow microspheres with average diameter of 20–30 μm via heating cadmium metal powder inside horizontal tube furnace at 500 °C for 40 min under ammonia gas flow of 150 sccm. Vapor-solid (VS) based growth mechanism was proposed for the formation of Cd/CdO shelled hollow microspheres (CCOSHMs). The as-prepared product was characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Room temperature photoluminescence (PL) studies exhibited a UV emission band at 395 nm (E = 3.13 eV) which may be ascribed to combined effect of near band edge emission of CdO and Cd related radiative recombination of electrons in s, p conduction band near Fermi surface and the holes in the d bands generated by Xe light excitation. The hydrogen absorption properties of CCOSHMs were investigated at three different temperatures 373, 473, and 573 K. The maximum hydrogen absorption of 1.30 wt% was observed at 573 K which is better than many other materials. This indicates the potential of Cd/CdO shelled hollow microspheres for applications in light emitting devices as well as an interesting material for hydrogen storage research.     

Improved FEM model for defect-shape construction from MFL signal by using genetic algorithm

In-line inspection of ferromagnetic gas or oil pipe lines having pipe wall defects is typically accomplished using magnetic flux leakage (MFL) technique. An efficient modelling and computational scheme for forward model, during the process of solving inverse problems in magnetostatic non-destructive evaluation using finite-element method is presented. The shape, size and place of defect are determined considering the nonlinearity of the pipe material using genetic algorithm as the optimisation technique. It is shown that the reduced model improves the FE computations significantly. The methodology for construction of defect shapes from particular MFL signals has been explained     

PSO-RDAL: particle swarm optimization-based resource- and deadline-aware dynamic load balancer for deadline constrained cloud tasks

The Journal of Supercomputing - Cloud computing is an Internet-provisioned computing paradigm that provides scalable resources for the execution of the end user’s tasks. The cloud users lease...     

RADL: a resource and deadline-aware dynamic load-balancer for cloud tasks

The Journal of Supercomputing - Cloud service providers acquire the computing resources and allocate them to their clients. To effectively utilize the resources and achieve higher user...     

Reconfigurable bow tie‐based filtering antenna for cognitive radio applications

This article presents the design and implementation of an 88 × 85 mm reconfigurable filtering bow‐tie antenna with four operating states. Two PIN diodes are deployed to reconfigure the transmission zeros to realize ultra‐wide band (UWB), 3.5/5.5 GHz with independent switching. This switching prevents the interference of the primary user into the secondary user thereby making the filtenna suitable for cognitive radio applications. The proposed filtenna consists of a UWB bow‐tie antenna integrated with a band‐pass filter with reconfigurable property enabled using two PIN diodes. The prototype‐filtering antenna is fabricated and the simulated results are validated using measurements. The presented results show that the antenna exhibits good impedance and radiation characteristics.     

Polarization diversity enabled flexible directional UWB monopole antenna for WBAN communications

This article presents the design of an ultra‐wideband (UWB) quasi‐circular monopole antenna with directional characteristics for use in wireless body area network (WBAN) applications. The proposed antenna has hybrid geometry and it is constructed using a semicircular and square patch on a very thin substrate of thickness 0.2 mm. The antenna has a compact geometry with a footprint of 30 × 20 mm. The proposed antenna covers 3.1 to 10.6 GHz with a measured peak gain of 5.37 dBi at 6 GHz. The proximity effect of the human body is resolved by incorporating the reflector behind the antenna. The antenna with reflector provides a directional pattern with a measured peak gain of 8.84 dBi at 6 GHz. Further to improve the link reliability between the sensor and the cluster head in WBAN, polarization diversity technique is adopted and the performance metrics are evaluated. The proposed flexible antenna simultaneously offers large gain and high impedance bandwidth. The prototype antenna is fabricated and the simulation results are validated using experimental measurements. The measurement results are in good agreement with the simulation results.