bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intrinsic remediation of trichloroethene driven by tetraalkoxysilanes as co‐contaminants: Results of microcosm and field studies
Authors: Vancheeswaran Sanjay , Yu Seungho , Daley Paul , Halden Rolf U. , Williamson Kenneth J. , Ingle James D. , Semprini Lewis 
Published: April 2003

AbstractBiological reduction of trichloroethene (TCE), driven by the transformation
products of tetraalkoxysilanes, was investigated in seasonal field monitorings and anaerobic groundwater
microcosms. Under anaerobic conditions, tetraalkoxysilanes such as tetrabutoxysilane (TBOS) and
tetrakis(2‐ethylbutoxy)silane (TKEBS) are abiotically hydrolyzed to their
corresponding alcohols, 1‐butanol and 2‐ethylbutanol, respectively, and silicic acid. These
alcohols are then fermented by subsurface microorganisms to their corresponding acids and hydrogen, which likely
serves as the ultimate electron donor facilitating reductive dechlorination of TCE. At Site 300, Lawrence
Livermore National Laboratory (LLNL), California, tetraalkoxysilanes are present along with TCE as
subsurface contaminants. Intrinsic transformation of TCE to cis‐dichloroethene (c‐DCE)
was observed at this site, and this was promoted by the transformation products of these tetraalkoxysilanes.
Efficient transformation of high concentrations of TCE (150–300 mg/l aqueous concentration)
was observed in anaerobic microcosms constructed with groundwater from this site. The lack of transformation of
c‐DCE to vinyl chloride (VC) and ethene in the microcosms is consistent with studies of the
microbial community in the site groundwater reported by Lowe et al. (2002).
© 2003 Wiley Periodicals, Inc.
A systematic approach to in situ bioremediation in groundwater
Authors: Faris Bart , Vlassopoulos Dimitri 
Published: April 2003

AbstractIn situ bioremediation (ISB) melds an understanding of microbiology, chemistry, hydrogeology, and
engineering into a strategy for planned and controlled microbial degradation of specific contaminants. ISB creates
subsurface environmental conditions, typically through reduction oxidation manipulation, which induce the
degradation of contaminants via microbial catalyzed biochemical reactions. In turn, the microbes produce enzymes
that are utilized to derive energy and that are instrumental in the degradation of target chemicals. To accomplish
this chain of events, the type of microorganisms, contaminant, and the geological conditions at the site must be
considered. Since in situ conditions are manipulated by engineered means, the most important consideration is the
ability to transmit and mix liquids in the subsurface. The Interstate Technology Regulatory Council
(ITRC)–ISB Team has recently completed a guidance document that describes a systematic approach to
ISB in groundwater. ITRC is a state‐led coalition of more than 40 states working together with industry and
stakeholders to achieve regulatory acceptance of environmental technologies. © 2003 Wiley Periodicals,
Inc.
Development of a procedure for sustainable in situ aquifer denitrification
Authors: Khan Imtiyaz A. , Spalding Roy F. 
Published: April 2003

AbstractDenitrification experiments have provided data showing the pitfalls and successes in developing a sustainable
injection/extraction system in a sand and gravel aquifer. Experiments increase in complexity from continuous
injection at one well to automated‐pulsed eight well injections. In both continuous and pulsed injection of
organic carbon, 40 mg NO3‐N l−1 was reduced below the detection limit of <
0.1 mg NO3‐N l−1 in the denitrification zones. Under continuous injection,
accumulation of bacterial exudates in the vicinity of the injection well resulted in injection well clogging
within ten days. Periodic cleaning of the injection well and the adjacent gravel matrix was accomplished by using
a tool developed to circulate a cleaning solution composed of 5 percent H2O2 and 0.02
percent NaOCl; but, biofouling could not be eliminated. In the later experiments, acetate became the carbon
amendment because ethanol promoted more biomass development. A specialized pulse injection procedure was developed
to separate nitrate from acetate‐C and was successful in alleviating the proliferation of bacterial
exudates without affecting the performance of the denitrification system. Using pulsed injection, a maximum of 72
percent nitrate reduction was accomplished in the extraction well water, and denitrification was sustained for
three months without clogging. © 2003 Wiley Periodicals, Inc.
Isotope applications in environmental investigations part II: Groundwater age dating and recharge processes, and provenance of sulfur and methane
Authors: Sueker Julie K. 
Published: April 2003

AbstractMeasurement of the isotopic composition of solids, solutes, gases, and water complement standard
hydrogeological
investigation techniques by providing information that may not otherwise be obtainable. Groundwater age
estimates
determined from the decay of radio‐isotopes or from groundwater concentrations of anthropogenic gases
such
as chlorofluorocarbons (CFCs) and sulfur hexafluoride (SF6) are used to verify
flow
regimes and constrain or calibrate hydrologic flow models. Groundwater recharge rates are estimated by measuring
the concentrations or activities of a variety of isotopes including 2H, 3H,
18O,
and 36Cl. Excess sulfur causes salinization of water supplies and acidification of precipitation,
surface water, and groundwater. The wide range of sulfur isotopic compositions exhibited by different sulfur
species and sources allows the application of sulfur isotopes to trace sources and fate of sulfur in the
environment. Methane is a ubiquitous gas that has economic value when located in extractable reservoirs. Methane
is
also a greenhouse gas and is a potential explosion and health hazard when it accumulates in buildings and water
distribution systems. The carbon and hydrogen isotopic composition of methane can be used to determine the
provenance of methane, distinguishing between thermogenic and biogenic sources. The addition of isotopic
analyses
to environmental investigations can be a cost‐effective means of resolving intractable issues. ©
2003
Wiley Periodicals, Inc.
Improving decision quality: Making the case for adopting next‐generation site characterization practices
Authors: Crumbling Deana M. , Griffith Jennifer , Powell Dan M. 
Published: April 2003

AbstractBetter site characterization is critical for cheaper, faster, and more effective cleanup. This fact is especially
true as cleanup decisions increasingly include site redevelopment and reuse considerations. However, established
attitudes about what constitutes “data quality” create many barriers to exciting new tools capable of
achieving better characterization, slowing their dissemination into the mainstream. Traditional approaches to
environmental “data quality” rest on simplifying assumptions that are rarely acknowledged by the
environmental community. Data quality assessments focus on the quality of the analysis, while seldom asking what
impact matrix heterogeneity has had on analytical results. Assessments of data quality typically assume that
chemical contaminants are distributed nearly homogeneously throughout environmental matrices and that
contaminant‐matrix interactions are well behaved during analysis. Yet, these assumptions seldom hold true for
real‐world matrices and contaminants at scales relevant to accurate risk assessment and efficient remedial
design. For the site cleanup industry to continue technical advancement, over‐simplified paradigms must give
way to next‐generation models that are built on current scientific understanding. If reuse programs such as
Brownfields are to thrive, the scientific defensibility of individual projects must be maintained at the same time
as characterization and cleanup costs are lowered. The U.S. Environmental Protection Agency (EPA) offers
the Triad Approach as an alternative paradigm to foster highly defensible, yet extremely cost‐effective reuse
decisions. © 2003 Wiley Periodicals, Inc.
Facilitating brownfields transactions using Triad and environmental insurance
Authors: Woll Bryn , Mack James , Ellerbusch Fred , Vetter James R. 
Published: April 2003

AbstractA significant hindrance to reuse of brownfields properties is the risk associated with redevelopment,specifically the uncertainty associated with environmental cleanup. This article explores an approach tomanaging environmental risk through a combination of risk quantification, environmental insurance, and theTriad Approach to site sampling and data interpretation. The expected costs of environmental liabilities areestimated using the Marsh Peer ReviewSM risk quantification process that employs statistical techniques andhighly experienced technical staff. The outputs of the process indicate premiums and attachment points forinsurance products, but they also point to “critical uncertainties” that drive the insurancepremiums. Insurance premiums are often linked to site delineation deficiencies, such as the magnitude ofimpacted soil or the size of a groundwater plume. The Triad Approach is an integrated site characterizationprocess developed by the Environmental Protection Agency that combines systematic planning, dynamic or adaptivefield decision making and field analytical methods (FAMs). The real‐time data produced by FAMsallow for in‐field resolution of uncertainty about sample location, which in turn provides morerepresentative delineation of contaminant distribution. The trade‐off of using slightly less accuratebut substantially lower cost FAMs is an increase in sampling frequency or density, thereby reducing the risk ofincomplete detection or delineation while yielding a “data set” that is more powerful than fewerindividual data points analyzed through traditional methods. Employing the Triad Approach to analyze the“critical uncertainties” identified in the Peer Review Process can impact insurance premiums andallow for better terms of coverage. The combination of using the Triad Approach and environmental insuranceproducts can lead to more predictable and profitable Brownfield transactions. © 2003 Wiley Peridicals,Inc.
A study of treatment options to remediate explosives and perchlorate in soils and groundwater at Camp Edwards, Massachusetts
Authors: Weeks Katherine R. , Veenstra Scott C. , Hill David L. , Gregson Benjamin P. 
Published: April 2003

AbstractThe Army National Guard initiated an Innovative Technology Evaluation (ITE) Program in March 2000
to study potential remedial technologies for the cleanup of explosives‐contaminated soil and groundwater
at the Camp Edwards site on the Massachusetts Military Reservation. The soil technologies chosen for the ITE
program were: soil washing, chemical oxidation, chemical reduction, thermal desorption/destruction
(LTTD), bioslurry, composting, and solid phase bioremediation. The technologies were evaluated based
on their ability to treat both washed and untreated soil. A major factor considered was the ability to degrade
explosives, such as RDX, found in particulate form in the soils. The heterogeneous nature of explosives in soils
dictates that the preferred technology must be able to treat explosives in all forms, including the particulate
form. Groundwater remediation technologies considered include: in situ cometabolic reduction, two forms of in
situ chemical oxidation, Fenton‐like oxidation and potassium permanganate. This article presents the
results of each of the remedial technologies evaluated and discusses which technologies met the established ITE
performance goals. © 2003 Wiley Periodicals, Inc.
The use of zero‐valent iron injection to remediate groundwater: Results of a pilot test at the Marshall Space Flight Center
Authors: McElroy Bill , Keith Amy , Glasgow Jason , Dasappa Srini 
Published: April 2003

AbstractIn situ treatability studies are being conducted to evaluate various in situ technologies to manage
groundwater contamination at the NASA Marshall Space Flight Center in Huntsville, Alabama. The focus of these
studies is to evaluate remediation options for contaminated (mostly aerobic) groundwater occurring
within the basal portion of a clayey residuum called the rubble zone. The tension‐saturated media and
unsaturated media lying above the rubble zone are also being treated where they make up a significant component
of the contaminant mass. An in situ chemical reduction field pilot test was implemented (following
bench‐scale tests) during July and August 2000. The test involved the injection of zero‐valent
iron powder in slurry form, using the FeroxSM process patented by ARS Technologies, Inc. The pilot
test focused on trichloroethene (TCE)‐contaminated groundwater within the rubble zone. Maximum
pre‐injection concentrations of about 72,800 micrograms per liter (μg/l) were observed
and no secondary sources are believed to exist beneath the area. The potential presence of unexploded ordnance
forced an implementation strategy where source area injections were completed, as feasible, followed by
overlapping injections in a down gradient alignment to create a permeable reactive zone for groundwater
migration. Eight post‐injection rounds of groundwater performance monitoring were completed. The results
are encouraging, in terms of predicted responses and decreasing trends in contaminant levels. © 2003 Wiley
Periodicals, Inc.
Dynamic Analysis of Tendon Driven Robotic Mechanisms
Authors: Lee Jyh‐Jone , Lee Yueh‐Hua 
Published: April 2003

AbstractIn this paper, a systematic methodology for the dynamic analysis of tendon‐driven robotic mechanisms is presented. The approach utilizes the recursive Newton‐Euler equations to compute the kinematic and dynamic equations of all links that locate on the transmission line of a tendon‐driven robotic mechanism. The inertias of the intermediate links in the mechanism are taken into account. It is shown that the dynamic equations can be established in a recursive manner from the end‐effector links toward the proximal links and can be solved at the proximal end without the need of solving the simultaneous system equations. The joint reaction forces and the tension in each segment of tendon can be also obtained. The methodology can be applied to both endless and open‐ended tendon drives. © 2003 Wiley Periodicals, Inc.
Pose Optimization of Serial Manipulators Using Knowledge of Their Velocity‐Degenerate (Singular) Configurations
Authors: Nokleby Scott B. , Podhorodeski Ron P. 
Published: April 2003

AbstractThis work investigates the exploitation of velocity‐degenerate configurations to optimize the pose of either nonredundant or redundant serial manipulators to sustain desired wrenches. An algorithm is developed that determines a desirable start point for the optimization of a serial manipulator's pose. The start‐point algorithm (SPA) uses analytical expressions of the velocity‐degenerate (singular) configurations of a serial manipulator to determine a pose that would be best suitable to sustain a desired wrench. Results for an example redundant serial manipulator are presented. The example results show that by using the SPA with the optimization routine, the resulting poses obtained require less effort from the actuators when compared to the poses obtained without using the SPA. It is shown that when no constraint is imposed on the position of the end‐effector, the SPA excels at providing a better solution with less iterations than running the optimization without the SPA. © 2003 Wiley Periodicals, Inc.
Geometric Motion Control for a Kinematically Redundant Robotic Chain: Application to a Holonomic Mobile Manipulator
Authors: Altafini Claudio 
Published: April 2003

AbstractFor kinematically redundant robotic manipulators, the extra degrees of freedom available allows freedom in the generation of the trajectories of the end‐effector. In this paper, for this scope, we use techniques for motion control of rigid bodies on Riemannian manifolds (and Lie groups in particular) to design workspace control algorithms for the end‐effector of the robotic chain and then to pull them back to joint space, all respecting the different geometric structures of the two underlying model spaces. The trajectory planner makes use of geometric splines. Examples of the different kinds of curves that are obtained via the De Casteljau algorithm in correspondence of different metric structures in SE(3) are reported. The feedback module, instead, consists of a Lyapunov based PD controller defined from a suitable notion of error distance on the Lie group. The motivating application of our work is a holonomic mobile manipulator for which simulation results are described in detail. © 2003 Wiley Periodicals, Inc.
Dynamic Feedback Control of XYnR̄ Planar Robots withnRotational Passive Joints
Authors: Iannitti Stefano , De Luca Alessandro 
Published: April 2003

AbstractWe consider the problem of trajectory planning and control for an XYnR̄ Planar robot with the first two joints (rotational or prismatic) actuated andnrotational passive joints, moving both in the presence and the absence of gravity. Under the assumption that each passive link is attached at the center of percussion of the previous passive link, dynamics of the system can be expressed through the behavior ofnspecial points of the plane. These points are called link‐related acceleration points (LRAP) since their instantaneous acceleration is oriented as the axis of the related passive links. Moreover, LRAP dynamics present a backward recursive form which can be exploited to recursively design a dynamic feedback that completely linearizes the system equations. We use this approach to solve trajectory planning and tracking problems and report simulation results obtained for an RR2R̄ robot having the first two rotational joints actuated. © 2003 Wiley Periodicals, Inc.
TCRA: a time‐based channel reservation scheme for handover requests in LEO satellite systems
Authors: Boukhatem L. , Beylot A. L. , Gaïti D. , Pujolle G. 
Published: April 2003

AbstractIn this paper, we propose a time‐based channel reservation algorithm (TCRA) suitable for handover and call admission control procedures in future mobile satellite systems. These systems are characterized by a high rate of handover attempts which can degrade significantly their performance. Therefore, we propose TCRA, a scheme which guarantees a null handover failure probability by using a channel reservation strategy in the cells to be crossed by the user. The performance of TCRA has been compared to the guaranteed handover (GH) scheme. The TCRA reservation method has the advantage of a better channel utilization by locking the resources only for their expected time of use. A mathematical model has been developed for both schemes, and its results have been validated through simulations. Copyright © 2003 John Wiley & Sons, Ltd.
On ACK filtering on a slow reverse channel
Authors: Barakat Chadi , Altman Eitan 
Published: April 2003

AbstractAcknowledgement (ACK) filtering has been proposed as a technique to alleviate the congestion at the input of a slow channel located on the reverse path of a TCP connection. Old ACKs waiting at the input of the slow channel are erased when new ACKs are to be queued. In the literature the case of one‐ACK per connection at a time has been studied. In this paper we show that this is too aggressive for short transfers where ACKs arrive in bursts due to the slow start phase, and where the TCP source needs to receive the maximum number of ACKs to increase fast its window. We study first static filtering where a certain ACK queue length is allowed. We show analytically how this length needs to be chosen. We present then some algorithms that adapt the filtering of ACKs as a function of the slow channel utilization rather than the ACK queue length. These algorithms provide a good compromise between reducing the ACK queueing delay and passing a large number of ACKs that guarantee a fast window increase. Copyright © 2003 John Wiley & Sons, Ltd.
Capacity provisioning and failure recovery for Low Earth Orbit satellite constellation
Authors: Sun Jun , Modiano Eytan 
Published: April 2003

AbstractThis paper considers the link capacity requirement for an LEO satellite constellation. We model the constellation as an N×N mesh‐torus topology under a uniform all‐to‐all traffic model. Both primary capacity and spare capacity for recovering from a link or node failure are examined. In both cases, we use a method of ‘cuts on a graph’ to obtain lower bounds on capacity requirements and subsequently find algorithms for routing and failure recovery that meet these bounds. Finally, we quantify the benefits of path‐based restoration over that of link‐based restoration; specifically, we find that the spare capacity requirement for a link‐based restoration scheme is nearly N times that for a path‐based scheme. Copyright © 2003 John Wiley & Sons, Ltd.
BPSK and QPSK non‐linear satellite communication system performance in the presence of cochannel interference
Authors: Stefanovic Mihajlo C. , Djordjevic Goran T. 
Published: April 2003

AbstractTaking the uplink and downlink cochannel interference and noise into account, the analytical expressions are derived for determining the bit error probability in detecting a binary phase‐shift‐keying (BPSK) and a quaternary phase‐shift‐keying (QPSK) Gray coded signal, transmitted over a satellite system exhibiting amplitude modulation‐to‐amplitude modulation (AM/AM) conversion effects and amplitude modulation‐to‐phase modulation (AM/PM) conversion effects. On the basis on the derived theoretic formulae, using real‐life system parameters, numerical results are obtained and presented. We point out the explicit comparisons of satellite communication system performance obtained when a satellite transponder amplifier is modelled by a hard‐limiter and those obtained when both AM/AM and AM/PM non‐linearities of the satellite transponder amplifier are taken into consideration. Copyright © 2003 John Wiley & Sons, Ltd.
Development of an information retrieval system suitable for large‐scale scholarly databases
Authors: Oyama Keizo , Kageura Kyo , Kando Noriko , Kimura Masaru , Maruyama Katsumi , Yoshioka Masaharu , Takahashi Kazumichi 
Published: April 2003

AbstractThe demand for full‐fledged information retrieval services via the World Wide Web has grown as the Internet has evolved. However, existing information retrieval systems for the World Wide Web have various limitations in the search functions, and in structure and scale of databases. The information retrieval system described in this paper has been operating for a real information retrieval service, providing high‐level search functions via a command line and a Web interface for large‐scale scholarly databases in text form with complex structures. In this paper, the authors first describe an outline of and the design of the information retrieval functions, in particular the characteristic functions including set operations, thesaurus searches, hierarchical structure searches, and unified searches of multiple databases. Next, they describe the implementation technologies of the system focusing on the features of the search engine, the session control method, the handling of large‐scale databases, and the structure of servers and processes. Then, the authors evaluate the current system based on the real operation, and finally discuss the future issues and the related researches. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(6): 44–58, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10015