Correction to: Investigating Energy Flow in Water-Energy Storage for Hydropower Generation in Water Distribution Systems

Water Resources Management - The original version of this article unfortunately contains mistake introduced during the publishing process. The author name “M. Fayzul” should be deleted...     

Structural variability and its relation to edaphic attributes of mangroves in the south‐west coast of India

We estimated the tree structural variables (density, frequency and basal area) of true mangroves and soil variables like particle size distribution, carbon, available nitrogen and phosphorus, sulphur, nutrient cations (K, Na, Ca, Mg) of Cochin mangroves and examined the relationship between vegetation and environment. The study sites were classified as seaward fringe, riverine and interior. Of the thirteen true mangrove species present, Avicennia officinalis, Sonneratia caseolaris and Excoecaria agallocha showed higher Importance Value Index. The mean stem density varied from 80 to 25,000 no./ha and basal area from 0.1 to 39.68 m²/ha. Seaward mangroves showed maximum stand basal area and biomass production while riverine exhibited maximum density. Maturity Index value of Cochin mangroves revealed a very low degree of structural maturity. Interior mangroves were characterized by silty soil with higher nutrient concentrations. Principal component analysis of soil data revealed that the major factors influencing mangrove vegetation were soil texture, nutrients, salinity and oxidation–reduction potential. The stem density and basal area of different species correlated highly with soil nutrients and texture (p < .001) while salinity showed negative correlations with vegetation characteristics. The data generated in the study would be fundamental in site‐specific management and conservation efforts of these degrading mangroves.     

Characterisation and tribological evaluation of nitrogen-containing molybdenum–copper PVD metallic nanocomposite films

This paper reports on the structural, mechanical and tribological properties of molybdenum–copper nanocomposite films ‘doped’ with small amounts of nitrogen, which contain either no nitride phase (i.e. the nitrogen is held in interstitial solid solution, mainly in molybdenum) or small amounts of lower nitrides (i.e. Mo₂N). All films were deposited on Si wafers, AISI M2 high speed steel and AISI 316 stainless steel by reactive sputtering using a hot-filament-enhanced dc unbalanced magnetron system. A systematic approach was adopted to investigate the evolution of metal/metal and ceramic/metal phase combinations with increasing nitrogen content (up to 40 at.% N) in the film. Coating composition and microstructure were determined by cross-sectional TEM, SEM and XPS. XRD was used to identify (where possible) metallic and metal-nitride phases. Mechanical properties such as hardness and elastic modulus were determined by low load Knoop and instrumented Vickers indentation measurements. Reciprocating sliding, micro-abrasion and impact tests were performed to assess tribological performance.

It was found that increasing the nitrogen gas flow rate from 0 to 15 sccm (and therefore nitrogen content in the film from 0 to 24 at.% N), refined significantly the coating microstructure from columnar to a dense and more equiaxed morphology, increasing the hardness whilst maintaining (almost constant) elastic modulus values, close to that of molybdenum metal. Further increases in the nitrogen gas flow rate resulted in films that appeared to contain significant fractions of the Mo₂N ceramic phase. SEM and cross-sectional TEM analyses of the film deposited at a nitrogen flow rate of 20 sccm (containing 36 at.% N) demonstrated a microstructure consisting of 50–100 nm wide columns, which contain small regions of contrast in dark-field images, of the order of 3–5 nm wide. A maximum hardness of 32 GPa and the highest hardness/modulus ratio was however found in the (predominantly metallic) film deposited at a nitrogen gas flow rate of 15 sccm. This film also performed best in both micro-abrasion and impact wear tests; in contrast, the ‘ceramic’ film (deposited at 20 sccm nitrogen flow rate) performed better in reciprocating sliding wear.     

Characterizing the deformation of cold-rolled copper sheet

An advanced x-ray diffraction technique allows the development of texture components to be monitored and provides supplementary information about the cold work and residual stresses in cold-rolled copper sheet. The new technique confirms the results of an ultrasonic test, except for the ultrasonic test’s sensitivity to grain size. The new x-ray diffraction technique could be adapted to provide in-process, nondestructive evaluation of thin copper sheet, even for material moving at high speeds.     

Sustainable end-of-life vehicle recycling: R&;D collaboration between industry and the U.S. DOE

Approximately 15 million cars and trucks reach the end of their useful life in the United States each year. More than 75% of the materials from end-of-life vehicles are profitably recovered and recycled by the private sector; automotive materials recycling is a success story. To achieve greater fuel efficiency and safety, today’s cars incorporate an increasing share of innovative light-weight materials. While these materials greatly enhance efficiency during vehicle use, they can present special challenges for recycling. These challenges will persist as automotive designs and the mix of materials used in vehicles continue evolving to further improve safety and performance. To meet the challenges of automotive materials recycling, the U.S. Department of Energy has recently expanded its collaborative research with industry in this area. This article discusses this collaborative government/industry approach to sustainable end-of-life vehicle recycling. For more information, contact Edward J. Daniels, Argonne National Laboratory, 9700 S. Cass Avenue, Building 362, Room C393, Argonne, IL 60439-4815; (630) 252-5279; fax (630) 252-1342; e-mail edaniels@anl.gov.     

Water quality prediction capabilities of WASP model for a tropical lake system

Water quality modelling facilitates our better understanding of the processes taking place in a lake system, and conservation plans to address them. The water quality analysis simulation programme (WASP) was used in this study to predict daily variations in water quality parameters, namely dissolved oxygen, nitrate, phosphate and chlorophyll‐a and biochemical oxygen demand concentrations in a tropical lake system. The lake was divided into eight segments with the respective morphological, environmental and flow details being model inputs. The monthly concentration of each water quality parameter also comprised model input. The model output was daily spatiotemporal variation in these parameters over a period of 476 days. This study also indicated that the occurrence of precipitation plays a major role in defining the water quality of a tropical lake. The heavy precipitation after a long gap, especially during the summer season, results in a large quantity of organic matter entering the lake through drains, thereby increasing the organic matter and phosphate in the water body, and subsequently resulting in high chlorophyll‐a concentrations in the lake. A reduced chlorophyll‐a concentration was observed during the heavy rains. The water quality fluctuations are more pronounced with precipitation, especially where polluted drains enter the lake. An improved water quality can be observed downstream, including increased dissolved oxygen and nitrate concentrations. Improved water quality was observed during the postmonsoon period, with increased salinity and dissolved oxygen concentrations, a finding that confirms generalized and specific conclusions can be achieved with the use of the WASP model.     

Subroutine based detection of APT malware

Statistical detection of mass malware has been shown to be highly successful. However, this type of malware is less interesting to cyber security officers of larger organizations, who are more concerned with detecting malware indicative of a targeted attack. Here we investigate the potential of statistically based approaches to detect such malware using a malware family associated with a large number of targeted network intrusions. Our approach is complementary to the bulk of statistical based malware classifiers, which are typically based on measures of overall similarity between executable files. One problem with this approach is that a malicious executable that shares some, but limited, functionality with known malware is likely to be misclassified as benign. Here a new approach to malware classification is introduced that classifies programs based on their similarity with known malware subroutines. It is illustrated that malware and benign programs can share a substantial amount of code, implying that classification should be based on malicious subroutines that occur infrequently, or not at all in benign programs. Various approaches to accomplishing this task are investigated, and a particularly simple approach appears the most effective. This approach simply computes the fraction of subroutines of a program that are similar to malware subroutines whose likes have not been found in a larger benign set. If this fraction exceeds around 1.5 %, the corresponding program can be classified as malicious at a 1 in 1000 false alarm rate. It is further shown that combining a local and overall similarity based approach can lead to considerably better prediction due to the relatively low correlation of their predictions.     

Virtual reflected-light microscopy

Research on better methods to digitally represent microscopic specimens has increased over recent decades. Opaque specimens, such as microfossils and metallurgic specimens, are often viewed using reflected light microscopy. Existing 3D surface estimation techniques for reflected light microscopy do not model reflectance, restricting the representation to only one illumination condition and making them an imperfect recreation of the experience of using an actual microscope. This paper introduces a virtual reflected-light microscopy (VRLM) system that estimates both shape and reflectance from a set of specimen images. When coupled with anaglyph creation, the system can depict both depth information and illumination cues under any desired lighting configuration. Digital representations are compact and easily viewed in an online setting. A prototype used to construct VRLM representations is comprised only of a microscope, a digital camera, a motorized stage and software. Such a system automatically acquires VRLM representations of large batches of specimens. VRLM representations are then disseminated in an interactive online environment, which allows users to change the virtual light source direction and type. Experiments demonstrate high quality VRLM representations of 500 microfossils.     

Non-encapsulated thermo-liquid crystals for digital particle tracking thermography/velocimetry in microfluidics

The ever accelerating state of technology has powered an increasing interest in heat transfer solutions and process engineering innovations in the microfluidics domain. In order to carry out such developments, reliable heat transfer diagnostic techniques are necessary. Thermo-liquid crystal (TLC) thermography, in combination with particle image velocimetry, has been a widely accepted and commonly used technique for the simultaneous measurement and characterization of temperature and velocity fields in macroscopic fluid flows for several decades. However, low seeding density, volume illumination, and low TLC particle image quality at high magnifications present unsurpassed challenges to its application to three-dimensional flows with microscopic dimensions. In this work, a measurement technique to evaluate the color response of individual non-encapsulated TLC particles is presented. A Shirasu porous glass membrane emulsification approach was used to produce the non-encapsulated TLC particles with a narrow size distribution and a multi-variable calibration procedure, making use of all three RGB and HSI color components, as well as the proper orthogonally decomposed RGB components, was used to achieve unprecedented low uncertainty levels in the temperature estimation of individual particles, opening the door to simultaneous temperature and velocity tracking using 3D velocimetry techniques.