Mechanistic Insight into the Stability of HfO2‐Coated MoS2 Nanosheet Anodes for Sodium Ion Batteries

It is demonstrated for the first time that surface passivation of 2D nanosheets of MoS₂ by an ultrathin and uniform layer of HfO₂ can significantly improve the cyclic performance of sodium ion batteries. After 50 charge/discharge cycles, bare MoS₂ and HfO₂ coated MoS₂ electrodes deliver the specific capacity of 435 and 636 mAh g^?1, respectively, at current density of 100 mA g^?1. These results imply that batteries using HfO₂ coated MoS₂ anodes retain 91% of the initial capacity; in contrast, bare MoS₂ anodes retain only 63%. Also, HfO₂ coated MoS₂ anodes show one of the highest reported capacity values for MoS₂. Cyclic voltammetry and X‐ray photoelectron spectroscopy results suggest that HfO₂ does not take part in electrochemical reaction. The mechanism of capacity retention with HfO₂ coating is explained by ex situ transmission electron microscope imaging and electrical impedance spectroscopy. It is illustrated that HfO₂ acts as a passivation layer at the anode/electrolyte interface and prevents structural degradation during charge/discharge process. Moreover, the amorphous nature of HfO₂ allows facile diffusion of Na ions. These results clearly show the potential of HfO₂ coated MoS₂ anodes, which performance is significantly higher than previous reports where bulk MoS₂ or composites of MoS₂ with carbonaceous materials are used.     

Fatty acids,mineral composition ond functional (bread and chapati) properties of high protein and high lysine barley lines

Six barley lines derived from corsses involving Hiproly (SV 73608×Mona⁵) and Riso 1508 with higher yield recipients V 43-42 and V 5681, along with the four parents, were analyzed for faty acids and mineral composition. Dough properties, bread and chapaties were charcterized by blending barley line (B82503) at 2.5-25% with bread wheat flour (pak 81). Fatty acid contents were myristic acid, 0.60-1.16%; palmitic acid, 16.68-20.84%; stearic acid, 1.30-3.33% and degree of unsaturation 1.40-1.50%. The derived lines contained similar amounts of essential fatty acids. Significant variation for magnesium, copper, zinc, phosphorus and potassium was observed but overlapped among the lines and parents. The calciu, iron, and manganese showed non-significant differences among lines and parents. Blending up to 10% barley flour with bread wheat flour gave farinograph characteristics comparable to those of pure wheat flour, but increasing the proportion of barley beyond this decreased the mix time and dough stability. Breadbaking tests verfied that up to 10% barley could be mixed with wheat without adversely affecting loaf volume and other quality attributes. For chapati making up to 20% barley could be blended into the wheat, yet yield acceptable quality.     

Bandwidth allocation under end‐to‐end percentile delay bounds

We describe an efficient and accurate approximation method for calculating the bandwidth that should be allocated on each link along the path of a point‐to‐point Multiprotocol Label Switching connection, so that the end‐to‐end delay D is less than or equal to a given value T with a probability γ, that is, P(D ≤ T) = γ. We model a connection by a tandem queuing network of infinite capacity queues. The arrival process of packets to the connection is assumed to be bursty and correlated and it is depicted by a two‐stage Markov‐Modulated Poisson Process. The service times are exponentially distributed. The proposed method uses only the first queue of the tandem queuing network to construct an upper and lower bound of the required bandwidth so that P(D ≤ T) = γ. Subsequently, we estimate the required bandwidth using a simple interpolation function between the two bounds. Extensive comparisons with simulation showed that the results obtained have an average relative error of 1.25%. Copyright © 2011 John Wiley & Sons, Ltd.     

Influence of partial substitution of wheat flour with vetch (Lathyrus sativus L) flour on quality characteristics of doughnuts

Partial substitution of wheat flour (Triticum aestivum) with vetch flour (Lathyrus sativus L) at the levels of 5, 10, 15 and 20 g/100 g was carried out to determine its influence on physico-chemical, rheological, nutritional and sensory characteristics of composite flour doughnuts. Commercial wheat variety, Inqlab-91 was found suitable for the preparation of doughnuts. Sensory and objective evaluations (weight, volume and specific volume) of doughnuts were carried out to evaluate the acceptability of doughnuts. Protein, lysine and trypsin inhibitor contents increased significantly (P<0.05) from 12.10 to 13.84 g/100 g, 2.46-3.58 g/100 g protein and 173 to 187 TIU/g on increasing the level of vetch flour from 0 to 15 g/100 g in the doughnuts, respectively. In vitro protein digestibility of doughnuts was also found to increase (71.8-76.3 g/100 g). It was inferred that doughnuts supplemented with vetch flour up to the level of 15 g/100 g were sensorily acceptable.     

Food fortification strategy--preventing iron deficiency anemia: a review

Iron deficiency anemia (IDA) is a significant challenge in developing countries. It increases the risk of premature delivery and low birth weight. In children, IDA retards growth, impairs cognitive performance, and reduces physical activity. It also accelerates the mortality and morbidity rate in women. The key factors responsible include dietary elevated iron demand, socioeconomic, and disease status. To overcome IDA, disease control measures, dietary diversification, supplementation and iron fortification in food have been adopted. Iron fortification in food is considered a long term and sustainable strategy in the present scenario. For an efficient fortification program, the combination of iron fortificants and food vehicle must be safe, acceptable, and consumed by the target population. Moreover, it should not adversely affect acceptability and stability of the end product.     

Effect of Ag Content and the Minor Alloying Element Fe on the Mechanical Properties and Microstructural Stability of Sn-Ag-Cu Solder Alloy Under High-Temperature Annealing

This study compares the high-Ag-content Sn-3Ag-0.5Cu with the low- Ag-content Sn-1Ag-0.5Cu solder alloy and the three quaternary solder alloys Sn-1Ag-0.5Cu-0.1Fe, Sn-1Ag-0.5Cu-0.3Fe, and Sn-1Ag-0.5Cu-0.5Fe to understand the beneficial effects of Fe on the microstructural stability, mechanical properties, and thermal behavior of the low-Ag-content Sn-1Ag-0.5Cu solder alloy. The results indicate that the Sn-3Ag-0.5Cu solder alloy possesses small primary β-Sn dendrites and wide interdendritic regions consisting of a large number of fine Ag₃Sn intermetallic compound (IMC) particles. However, the Sn-1Ag-0.5Cu solder alloy possesses large primary β-Sn dendrites and narrow interdendritic regions of sparsely distributed Ag₃Sn IMC particles. The Fe-bearing SAC105 solder alloys possess large primary β-Sn dendrites and narrow interdendritic regions of sparsely distributed Ag₃Sn IMC particles containing a small amount of Fe. Moreover, the addition of Fe leads to the formation of large circular FeSn₂ IMC particles located in the interdendritic regions. On the one hand, tensile tests indicate that the elastic modulus, yield strength, and ultimate tensile strength (UTS) increase with increasing Ag content. On the other hand, increasing the Ag content reduces the total elongation. The addition of Fe decreases the elastic modulus, yield strength, and UTS, while the total elongation is still maintained at the Sn-1Ag-0.5Cu level. The effect of aging on the mechanical behavior was studied. After 720 h and 24 h of aging at 100°C and 180°C, respectively, the Sn-1Ag-0.5Cu solder alloy experienced a large degradation in its mechanical properties after both of the aging conditions, whereas the mechanical properties of the Sn-3Ag-0.5Cu solder alloy degraded more dramatically after 24 h of aging at 180°C. However, the Fe-bearing SAC105 solder alloys exhibited only slight changes in their mechanical properties after both aging procedures. The inclusion of Fe in the Ag₃Sn IMC particles suppresses their IMC coarsening, which stabilizes the mechanical properties of the Fe-bearing SAC105 solder alloys after aging. The results from differential scanning calorimetry (DSC) tests indicate that the addition of Fe has a negligible effect on the melting behavior. However, the addition of Fe significantly reduces the solidification onset temperature and consequently increases the degree of undercooling. In addition, fracture surface analysis indicates that the addition of Fe to the Sn-1Ag-0.5Cu alloy does not affect the mode of fracture, and all tested alloys exhibited large ductile dimples on the fracture surface.     

On the phenomenon of large photoluminescence red shift in GaN nanoparticles

We report on the observation of broad photoluminescence wavelength tunability from n-type gallium nitride nanoparticles (GaN NPs) fabricated using the ultraviolet metal-assisted electroless etching method. Transmission and scanning electron microscopy measurements performed on the nanoparticles revealed large size dispersion ranging from 10 to 100 nm. Nanoparticles with broad tunable emission wavelength from 362 to 440 nm have been achieved by exciting the samples using the excitation power-dependent method. We attribute this large wavelength tunability to the localized potential fluctuations present within the GaN matrix and to vacancy-related surface states. Our results show that GaN NPs fabricated using this technique are promising for tunable-color-temperature white light-emitting diode applications.