Morphological exploration of chemical vapor–deposited P-doped ZnO nanorods for efficient photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting is beneficial and has received attractive attention due to a greater potential to generate hydrogen and oxygen from water by using plentiful solar light to solve the problem of energy crisis. Various active semiconductor materials are used in PEC water splitting applications. Nevertheless, in past decades, most of the researchers suggested that titanium oxide (TiO₂) is the best photoanode for this type of applications. Now, Zinc oxide (ZnO) is considered a perfect substitution to TiO₂ due to its comparable energy band structure and superior photogenerated electron transfer rate. In this study, bare and phosphorous-doped ZnO nanorods were successfully developed on fluorine-doped tin oxide-coated glass (FTO) substrate by chemical vapor deposition. X-ray diffraction (XRD) pattern authenticated hexagonal structure formation with strong diffraction peak of (101), which showed that ZnO nanorods were perfectly developed along c axis. The optical and morphological properties were analyzed by UV–Vis and scanning electron microscopy images. The energy-dispersive X-ray spectra demonstrated that doping agent phosphorous was present in ZnO nanorods. The PEC properties of the developed ZnO nanorods were further investigated and obtained results suggested that a small amount of phosphorous-doped ZnO nanorods enhances their PEC performance.     

SUPERCRITICAL EXTRACTION OF STUART OIL SHALE

ABSTRACT

This paper describes the recovery of oil from Stuart oil shale using a supercritical extraction technique employing carbon dioxide as solvent. This supercritical technique provides yields superior to comparable retorting techniques. The importance of extraction temperature, pressure, and time has been investigated. In addition, the chemical composition of the oil extracted from the shale is presented. Simulated distillation has been employed to assess the effect of extraction conditions on the quality of the shale oil extracted.     

CHEMICAL COMPOSITION OF SHALE OIL I. DEPENDENCE ON OIL SHALE ORIGIN

ABSTRACT

Shale oils obtained by nitrogen retorting of North Carolina, Cleveland, Ohio, Colorado, Rundle, Stuart, and Condor oil shales have been chemically characterized by g.c.-m.s. techniques. After species identification, chemical compositions of the shale oils have been related to the geological origins of the parent shales. Based on the characteristics observed in the chromatograms, eight semi-quantitative parameters have been used to describe the chromatograms. Six of these parameters describe the relative abundance and distribution of straight chain alkanes and alkenes in the chromatograms. The other two parameters represent the abundance, relative to the total amount of volatiles in the oil, of alkylbenzenes and alkylphenols.     

Correlating the phenotypic and molecular diversity in Jatropha curcas L.

Thirty four Jatropha germplasm accessions, selected based on unique phenotypic traits from 180 accessions collected from diverse geographical regions were subjected to field evaluation and molecular analysis. The field evaluation using eight quantitative traits showed significant variation among the germplasm. The molecular analysis using 56 RAPD and 40 ISSR primers resulted in 7 and 8 clusters, respectively. The accession IC541633 from Bastar (Chattisgarh) emerged as the most diverse accession. An attempt has been made to correlate the clustering based on molecular data with the quantitative traits. There was partial correlation between the quantitative traits and molecular data. Interestingly, the diverse accessions according to molecular diversity were characterized by unique phenotypes. Time of flowering, inflorescence type and number, leaf colour and texture were the traits contributing to variation. These traits may be used in identification of diverse accessions during germplasm exploration surveys or short listing of accessions for crossing in Jatropha improvement programmes.     

RE in India: What does 2004 have in store?

How will the year 2004 progress for renewable energy (RE) in India? Will the long overdue national renewable policy become a reality during the year? Will this year's Budget provide some special sops for renewable development? Will the budgetary allocation increase incrementally? Will we see more states come up with favourable policies towards RE? Or will the sector see another year of mediocre progress? Sunil Puri, Refocus correspondent India, tried to gauge the mood of the industry and its expectations at the onset of the year.     

Impact of Variable Packet Length on the Performance of Heterogeneous Multimedia Wireless Sensor Networks

Wireless Personal Communications - Performance valuation of wireless sensor network (WSN) routing protocols calls for realistic data traffic models because of their application specific nature....     

Mobile information services enabled by mobile publishing (MIS-MP)

Mobile users and devices want to discover and share a growing range of information as the processing and storage capabilities of mobile devices grow. For example, users want to discover nearby networks, and location-based or time-sensitive user information contents. A mobile device may want to discover neighboring networks and the parameters required to access these networks so that it can intelligently decide which networks to use next, and use its existing network connection to authenticate with selected neighboring networks before it moves into the coverage areas of the selected networks. This can significantly reduce handoff delays. Existing service discovery frameworks are not effective for such neighboring network discovery or for discovering dynamic, location- or time-sensitive user information contents. This paper describes and evaluates a new approach—Mobile Information Services enabled by Mobile Publishing (MIS-MP)—for real time collection, discovery, and sharing of network and user information. With MIS-MP, mobiles take full advantage of the wealth of information they can accumulate during their routine mobility and use of networks to help each other to discover the information they want when and where they want it. This is accomplished by mobiles publishing the information they collect about the networks they visited, and the user information contents they learned or used, to make the information available to other mobiles. This paper presents analytical models and simulation results to evaluate the feasibility and performance of MIS-MP. It also describes a testbed implementation of MIS-MP and some of the lessons we learned. Tao Zhang is Director of Mobile Networking Research Group at Telcordia Technologies, Piscataway, New Jersey, USA. He develops and directs research and advanced development programs in mobile networking and applications, including mobility and applications across heterogeneous radio networks, mobile information services, vehicular networking, mobile peer-to-peer applications, sensor networking and applications, and collaborative networking .Dr. Zhang’s work has led to several new commercial products. He co-authored the book “IP-Based Next Generation Wireless Networks” published by John Wiley & Sons in 2004. He initiated the International Conference on Collaborative Computing: Networking, Applications, and Worksharing (CollaborateCom), and has been serving in various roles for it. Dr. Zhang holds 4 U.S. patents, with over 25 more pending. He received the 2000 Telcordia CEO Award (for most exceptional teams and individuals who have achieved a significant business success) and 2002 SAIC’s Executive Science and Technology Council Publication Prize. Eric van den Berg received his Ph.D. in Applied Mathematics from Cornell University in 1999. After obtaining his degree, he joined Telcordia Technologies, where he is a Research Scientist in Applied Research Department. His research interests include traffic modeling and performance analysis of IP- and wireless networks. He received the 2000 Telcordia CEO Award (for most exceptional individuals and teams who have achieved a significant business success) and the 2002 SAIC Executive Science and Technology Council Publication Prize. Sunil Madhani is a Distinguished MTS with Motorola where he manages the IP Realization team in Mobile Device Technology Office. He aims at working on unconventional and disruptive IP technologies. His current research focus is on convergent networks, dynamic mobility management and fast handoff in secured/seamless wireless LAN/WAN roaming. His past research includes registration/configuration protocols in wireless environment, application layer mobility management, secured Mobile IP, managed DOS attack sensor and TCP/IP boosters. Sunil Madhani holds MS (2002) in Engineering Management & System from Columbia University and MS (1997) in Computer Science from State University of New York.     

Phenomena of reverse momentum pulse and fluid leak after poison injection in the shut down system of PHWR

The primary function of the shut down system in a nuclear reactor is to terminate any reactivity transient occurring in the core during its entire design life. Normally there is more than one system, which are independent and diverse in its mode of operation. They consist of quick acting mechanisms like dropping of safety rods by gravity, poison injection, etc. Typically in liquid poison injection system wherein high flow velocities are involved, there is significant fluid structure interaction associated with cyclic shock transients in the system. One such phenomenon has been captured and analyzed to understand the dynamics involved in the loop. The trends of loop pressure and vibration indicated presence of more than two pressure transients after complete injection of poison. The first transient arrived after 1.44 s and the second after 0.75 s. The reverse pressure pulses that manifested in the loop as a result of fast injection of fluid has been mathematically characterized by solving basic fluid balance equations. Possibility of ball lifting due to momentum pulse is also discussed.     

Relations and functions in multiset context

A multiset is a collection of objects in which repetition of elements is significant. In this paper an attempt is made to generalize the concepts of relation, function, composition and equivalence in the multiset context. As a pre-requisite a brief survey of the axiomatic approach to the multiset theory is also presented.     

Dynamic Loads in the Fan Containment Structure of a Turbofan Engine

In accordance with the FAA certification requirements, all modern commercial turbofan engines must successfully demonstrate its ability to withstand a fan blade-out (FBO) event through actual test. Possibility of losing a rotating fan blade from a running engine is a flight safety consideration, which must be addressed during the design phase of the engine. A typical fan blade-out event involves very complex nonlinear transient dynamics with large deflection of the release blade and rigid body rotation of the trailing blade as well as progressive failure and fragmentation of various components. Due to the nature of the impact type loading, the solution to the problem should also address dependence of the material behavior such as yield strength as a function of strain rates. In short, the transient dynamic analysis of a fan blade-out event highlights the complexity of the numerical technique, which includes all the nonlinearities of structural dynamics: plastic behavior of the materials, large displacements, and contact interaction between structural elements. In this paper, we present the results of a LS-DYNA simulation of a FBO event on a full-engine analytical model, which covers both the primary as well as secondary damages.