ALBERT

Description: Questions Do composition and richness of woody plants differ between gaps and closed canopy in subtropical forests, and does this difference vary across life stages of tree species? Is tree species richness in gaps a function of regeneration density? Location Subtropical Shorea robusta Gaertn (Sal) forest, central Nepal. Methods We collected vegetation data from two old-growth S. robusta forest stands. We sampled 128 plots of 100 m 2 equally spread between the two habitats: gap and closed canopy. In each plot, we recorded the total number of woody species, number of individuals of seedlings and saplings of tree species and measured the DBH of all saplings. We compared species richness and composition of total woody species, seedlings and saplings between the two habitats. We used ordination to analyse species composition, and an individual-based species accumulation curves to illustrate the effect of density on species richness. Results The species composition of total woody species and seedlings was similar in both habitats, but species composition of saplings differed between habitats. Total woody and seedling richness were similar between habitats at one site, but were richer under closed canopy at the other site. Sapling richness was higher in gaps at both sites and was a function of stem density at one site, but not at the other site. Conclusions Gaps are not always areas of higher woody species richness and therefore may be less important than expected for the overall species richness of woody plants. Instead, they are potentially important for enhancing local tree richness by increasing sapling richness. Gap disturbance is the primary driver of structural heterogeneity in forests where topographic and edaphic gradients are negligible. We compare richness and composition of woody species between gaps and closed canopy patches in subtropical Shorea robusta forest. We did not find that gaps enhance overall woody species richness, but gaps maintain tree richness by supporting seedling to sapling transition. Higher sapling richness and occurrence of some gap-specific saplings suggest that gap provide important regeneration niches for some tree species.

Description: Nickel is a silvery-white metal mostly used to enhance the value, utility, and lifespan of industrial equipment and components by protecting them from corrosion. Nickel is commonly used in the chemical and food processing industries to prevent iron from contamination. Since the properties of nickel can be controlled and varied over broad ranges, nickel plating finds numerous applications in industries. In the present investigation, pulse current electro-deposition technique has been used to deposit nickel on a high strength low alloy (HSLA) steel substrate.Coating of nickel is confirmed by X-ray diffraction (XRD) and EDAX analysis. Optical microscopy and SEM is used to assess the coating characteristics. Electrochemical polarization study has been carried out to study the corrosion behaviour of nickel coating and the polarisation curves have revealed that current density used during pulse electro-deposition plays a vital role on characteristics of nickel coating.

Description: We explore seasonal variability and spatiotemporal patterns in characteristic drainage timescale ( K ) estimated from river discharge records across the Kilombero Valley in central Tanzania. K values were determined using streamflow recession analysis with a Brutsaert-Nieber solution to the linearized Boussinesq equation. Estimated K values were variable comparing between wet and dry seasons for the relatively small catchments draining upland positions. For the larger catchments draining through valley bottoms, K values were typically longer and relatively more consistent across seasons. Variations in K were compared with long-term averaged, MODIS-derived monthly evapotranspiration. While the variations in K were potentially related to evapotranspiration, the influence of data quality and analysis procedure could not be discounted. As such, even though recession analysis offers a potential approach to explore aquifer release timescales and thereby gain insight a region's hydrology to inform water resources management, care must be taken when interpreting spatiotemporal shifts in K in connection with process representation in regions like Kilombero Valley. This article is protected by copyright. All rights reserved.

Description: Communications connect the flight deck to the ground and the flight deck to the passengers. On-board communications are provided by public-address systems and aircraft intercoms. Inefficient communication may lead to a catastrophe risking lives and resources. SKYVOIX, an intelligent system on board that enhances safety and improves the communication of the aircraft by reducing human error and increasing the awareness. The system is intended to be centralized and installed in addition to the current systems. With high air traffic and busy airspace, the transmissions are often misheard causing communication failure which is undesirable. A backup for enabling communication with the ground in emergencies is required which ensures active transmissions and is intelligent enough to handle the gravity of situation. The passengers who are often unaware about the routine and emergency protocols, busy with their electronics, listening to music cutting them off with the environment shall be...

Description: In this paper, the free vibration behavior of functionally graded ceramic-metal sandwich flat panels is investigated. The sandwich panels are considered to be composed of metal rich face layers with varying composition and a homogenous isotropic ceramic core layer. The kinematics of the panels is modeled using ANSYS commercial package. The convergence and the validity of the present model have been established by comparing the present results with the benchmark results available in published literature. Subsequently, the influence of power index, symmetry type and the support conditions on the non-dimensional fundamental frequency is investigated. The fundamental frequency is found to decrease with increasing power index value and increase with number of constraints at the support. The stiffness of the panels is affected by core thickness and the panels with higher core-to-face thickness ratio are observed to have lower fundamental frequency.

Description: This article presents the vibro-acoustic modeling and analysis of un-baffled laminated composite conical shell panels with varying thickness subjected to harmonic point load. The variation of thickness is considered to be unidirectional. A simulation model for the vibrating panel is developed using the commercial finite element package (ABAQUS). The natural frequencies are computed and compared with available published values for validation purpose. Then, the modal values are exported to LMS Virtual.Lab environment where an indirect boundary element approach has been adopted to extract the coupled vibro-acoustic responses. The sound power radiated by the vibrating structure computed using the present scheme is compared with the results available in the published literature. A comprehensive study has been performed to highlight the effect of thickness variation, excitation location, lamination scheme and support conditions on the acoustic radiation responses of the laminated coni...

Description: The objective of this work is to develop a finite element model of active human skeletal muscle, which can mimic its contraction behaviour. The model is then used to analyse the effects of active muscle contraction into occupant kinematics and injuries during rear-end collision. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)

Description: Multi-walled Carbon nanotubes–copper (MWCNT/Cu) composite powders with variable MWCNT content were synthesized by modified electro-co-deposition method. The electro-co-deposited MWCNT/Cu powders were consolidated by conventional compaction and sintering process. The consolidated products were then hot rolled and cold drawn to fine wires. The MWCNT/Cu composite wire samples were characterized for electrical and mechanical properties. We have been able to achieve an increase of around 8% in electrical conductivity of the form wires repeatedly. It has been observed that there was gradual improvement in the properties with reinforcement of MWCNT in the copper matrix. The betterment of electrical property has been achieved with simultaneous improvement in mechanical properties of the wire. The yield strength of MWCNT/Cu composite wire was found to be four times and the tensile strength two times greater than that of pure copper. The improved properties are attributed to the proper di...

Description: The energy harnessing is a process of obtaining energy from the surrounding environment and converting into electrical energy. In the last two decades, there has been a plenteous study in energy harnessing. Now a day, energy harnessing using piezoelectric materials has drawn attention of researchers due to low cost, flexibility and light weight. The benefits of piezoelectric material can be utilized by designing a self-powered device for artificial nanoswimmer. Some of the ceramics which displays the piezoelectric effect are lead-zirconate-titanate (PZT), lead-titanate (PbTiO 2 ), lead-zirconate (PbZrO 3 ) and Barium Titanate (BaTiO 3 ). PZT is most extensively used piezoelectric material in the field of energy harnessing but it is brittle in nature. Lead based piezoelectric materials are toxic in nature and may not suitable for in-vivo biomedical applications. To eradicate this problem, researchers are interested in synthesizing lead free piezoelectri...

Description: Catchment hydrology has become replete with flow pathway characterizations obtained via combinations of physical hydrologic measurements (e.g., streamflow hydrographs) and natural tracer signals (e.g., stable water isotopes, geochemistry). In this study we explored how our understanding of hydrologic flow pathways can be improved and expanded in both space and time by the simultaneous application of engineered synthetic DNA tracers. In this study, we compared the advective-dispersive transport properties and mass recovery rates of two types of synthetic DNA tracers, one consisting of synthetic DNA strands encapsulated into biodegradable microspheres and another consisting of ‘free’ DNA, i.e., not encapsulated. The DNA tracers were also compared with a conservative fluorescent dye. All tracers were injected into a small (3.2 km 2 ) valley glacier, Storglaciären, in northern Sweden. Seven of the nine DNA tracers showed clear recovery during the sampling period and similar peak arrival times and dispersion coefficients as the conservative fluorescent dye. However, recovered DNA tracer mass ranged only from 1% to 66% while recovered fluorescent dye mass was 99%. Resulting from the cold and opaque subglacial environment provided by the glacier, mass loss associated with microbial activity and photochemical degradation of the DNA is likely negligible, leaving sorption of DNA tracers onto suspended particles and loss of microtracer particles to sediment storage as probable explanations. Despite the difference in mass recovery, the advection and dispersion information derived from the DNA tracer breakthrough curves provided spatially explicit information that allowed inferring a theoretical model of the flow pathways that water takes through the glacier. This article is protected by copyright. All rights reserved.