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Pilot Test (pilot + test)

Distribution by Scientific Domains

Medical Sciences	33%
Business, Economics, Finance and Accounting	9%

Selected Abstracts

DRYING EFFECTS OF TWO AIR-DRYING SHELTERS IN A PILOT TEST ON SULTANA GRAPES

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2010
LINGLING LI
ABSTRACT The drying effects of sultana grapes in two different air-drying shelters were tested and analyzed. Ten different thin-layer drying mathematical models were compared according to their coefficients of determination and,2test. The Wang and Singh model was found to be the most suitable for describing the air-drying curves of sultana grapes. As compared with the local traditional shelter, the reformed shelter with a greenhouse can reduce about 12,18% of air-drying time, increase about 23% in green-grade rate of raisins and increase 33% in the effective moisture diffusivity of sultana grapes. PRACTICAL APPLICATIONS Grapes are one of the most popular and palatable fruits in the world. The preservation of grapes by drying is a major industry in many parts of the world where grapes are grown. Drying grapes, either by open sun drying, shade drying or mechanical drying, produces raisins. Air-drying of solar energy has been demonstrated to be cost-effective and could be an effective alternative to traditional and mechanical drying systems, especially in locations with good sunshine during the harvest season. The traditional air-drying shelter of grapes has been used for thousands of years in Asia and other places around the world. However, less investigation was done about the drying characteristics and the optimization of the shelter. The work of this manuscript provides interesting information that is useful for design of the drying shelter of raisins and for the improvement of raisin quality, especially using air-drying of solar energy. [source]

Pilot Test of an Attribution Retraining Intervention to Raise Walking Levels in Sedentary Older Adults

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 11 2007
Catherine A. Sarkisian MD
OBJECTIVES: To pilot test a new behavioral intervention to increase walking in sedentary older adults. DESIGN: Pre,post community-based pilot study. SETTING: Three senior centers in greater Los Angeles. PARTICIPANTS: Forty-six sedentary adults aged 65 and older. INTERVENTION: At four weekly 1-hour group sessions held at the senior centers, a trained health educator applied a theoretically grounded, standardized "attribution retraining" curriculum developed by a multidisciplinary team of investigators. Participants were taught that becoming sedentary is not inevitable with aging and that older adults should attribute being sedentary to modifiable attributes rather than to old age. A 1-hour exercise class including strength, endurance, and flexibility training followed each weekly attribution retraining session. MEASUREMENTS: Change from baseline in steps per week recorded using a digital pedometer was measured after 7 weeks. Age expectations (measured using the Expectations Regarding Aging-38 survey, a previously tested instrument on which higher scores indicate that the participant expects high functioning with aging and lower scores indicate that the participant expects physical and mental decline) and health-related quality of life were measured using in-person interviews. RESULTS: Mean steps per week increased from 24,749 to 30,707, a 24% increase,equivalent to 2.5 miles (2-sided t -test P=.002). Age expectation scores increased 30% (P<.001), and the changes in age expectations and steps per week correlated (correlation coefficient=0.39, P=.01). Participants experienced improved mental health,related quality of life (P=.049) and reported less difficulty with activities of daily living (P=.04). More than 50% of participants reported improvements in pain, energy level, and sleep quality. CONCLUSION: In this small pre,post community-based pilot study, a structured attribution retraining curriculum accompanied by a weekly exercise class was associated with increased walking levels and improved quality of life in sedentary older adults. Attribution retraining deserves further investigation as a potential means of increasing physical activity in sedentary older adults. [source]

Income Insurance in European Agriculture

EUROCHOICES, Issue 1 2003
Miranda P. M. Meuwissen
Summary Income Insurance in EuropeanAgriculture The agricultural risk environment in Europe is changing, for example because of WTO agreements and governments increasingly withdrawing from disaster assistance in case of catastrophic events. In this context, some form of income insurance may be a useful risk management tool for farmers. Insuring farmers' incomes, however, is rather problematical for reasons of asymmetric information and high correlation of the risks amongst the would-be insured, for example risks due to price fluctuations, floods, droughts and livestock epidemics. It is concluded that the most aggregated forms of income insurance that are likely to be feasible include revenue insurance for field crops, especially if there are relevant futures markets and area yield data, and business interruption insurance for livestock commodities. In Europe, only a few such schemes currendy exist; some are purely private, others are subsidised. A somewhat larger involvement of the public sector, for example through public-private partnerships for reinsurance, could extend the availability of income insurance schemes throughout Europe. Governments, however, should tread warily in entering the field of subsidised agricultural insurance, which experience shows is beset with pitfalls. Pilot tests are useful in establishing the attractiveness of income insurance schemes and other income stabilising tools for the various parties involved. Le contexte du risque agncoie est en train de changer en Europe, en raison notamment des accords de 'OMC et d'un retrait croissant des gouvernements de , assistance sinistre en cas de catastrophes. Dans ce contexte, une certaine forme ? assurance sur le revenu peut être un outil utile de gestion des risques pour les agriculteurs. Assurer les revenus des agriculteurs, cependant, est une activitécute; assez délicate pour des raisons ? information asymétrique et de forte corrélation des risques chez les assurés potentiels, avec , exemple des risques dus aux fluctuations de prix, aux inondations, aux sécheresses et aux épidémies animales. On en conclut que les formes ? assurance revenu les plus complètes et les plus plausibles comprennent ľ assurance-revenu pour les récoltes, notamment s'il existe des marchés a terme appropriés et des données sur le rendement par région, et ,,assurance pour cessation ?'activite pour les produits de ,élevage;. En Europe, seuls quelques projets similaires existent; certains sont purement privés, ? autres sont subventionés. Une implication un peu plus importante du secteur public, par exemple par le biais de partenariats public-privé pour la réassurance, permettrait ?élargir la disponibilité des plans ? assurance-revenu dans toute , Europe. Les gouvernements, cependant, doivent aborder avec prudence le domaine de , assurance agricole subventionée qui, , expérience le montre, est semée ? embûches. Des expériences pilotes sont utiles pour définir , intérêt des projets ? assurance-revenu et des autres outils permettant de stabiliser les revenus pour les différentes parties impliquées. In Europa ändern sich zur Zeit die _ Rahmenbedingungen für die Landwirtschaft hinsichtlich des Risikos. Dies liegt zum Beispiel an WTO-Abkommen und Regierungen, die ihre Hilfsleistungen im Schadensfall zunehmend verweigern. In diesem Zusammenhang könnte irgendeine Form von Einkommenversicherung im Bereich des Risikomanagements für Landwirte von Nutzen sein. Eine solche Versicherung wirft jedoch Probleme auf, da asymmetrische Information und eine hohe Risikokorrelation bei den potenziellen Versicherungsnehmem vorliegen, wie beispielsweise Risiken, die auf Preisschwankungen, Flut- und Dürrekatastrophen oder Tierseuchen beruhen. Hieraus wird gefolgert, dass zu den umfassendsten realisierbaren Formen von Einkommenversicherungen die Erlösversicherung im Ackerbau - insbesondere bei Vorliegen von relevanten Warenterminmärkten und Flächenertragsdaten - und die Betriebsausfallversicherung für tieriscbe Erzeugnisse gehören. In Europa sind zur Zeit nur wenige solcher Programme vorhanden; bei einigen handelt es sich um ausschließlich private Versicherungen, andere werden subventioniert. Würde der öffentliche Sektor stärker mit eingebunden, zum Beispiel mit Hilfe von öffendich-privaten Rückversicherungsgesellschaften, könnten in ganz Europa weitere Programme zur Einkommenversicherung zur Verfügung gestellt werden. Für die Regierungen jedoch ist beim Etablieren subventionierter Versicherungen im Bereich der Landwirtschaft größte Vorsicht geboten, da dies erfahrungs-gemäß Schwierigkeiten aufwirft. Zunächst sollten Pilotprojekte durchgeführt werden, mit deren Hilfe die Attraktivität von Programmen zur Einkommen-aversicherung und von weiteren einkommensstabilisierendenMaßnahmen fÜr die verschiedenen beteiligten Parteien sicher gestellt wird. [source]

Practice nurses' role and knowledge about diabetes management within rural and remote Australian general practices

EUROPEAN DIABETES NURSING, Issue 2 2010
District Nurse, MRCNA, R Livingston RN
Abstract Background: The increasing prevalence of diabetes and obesity represents a significant disease burden in Australia. Practice nurses (PNs) play an important role in diabetes education and management. Aim: To explore PNs' roles, knowledge and beliefs about diabetes education and management in rural and remote general practice in Australia. Method: Exploratory study undertaken in three phases: 1) Pilot study to test the performance of the questionnaire; 2) One-shot cross-sectional survey using self-complete questionnaires; 3) Individual interviews. Results: Ten PNs completed the pilot test; the draft questionnaire was deemed appropriate to the study purpose. Then, 65 questionnaires were distributed to PNs and 21 responded. Fourteen respondents had worked in the role <5 years, and most PNs attended diabetes education programmes in their workplace. A minority (40%) used diabetes management guidelines regularly. Most knew obesity to be the most common risk factor for diabetes but only 50% knew that glycosylated haemoglobin indicates blood glucose levels over the preceding three months. Self-reported competency to assess patients' self-care practices and medication management practices varied. Conclusion: PNs' diabetes management was self-reported; their knowledge varied and their perceived benefits of diabetes education differed from those of patients. Copyright © 2010 FEND [source]

Development and preliminary testing of a Paediatric Version of the Haemophilia Activities List (pedhal)

HAEMOPHILIA, Issue 2 2010
W. G. GROEN
Summary., Worldwide, children with haemophilia suffer from limitations in performing activities of daily living. To measure such limitations in adults a disease-specific instrument, the Haemophilia Activities List (HAL), was created in 2004. The aim of this study was to adapt the HAL for children with haemophilia and to assess its psychometric properties. The structure and the main content were derived from the HAL. Additionally, items of the Childhood Health Assessment Questionnaire and the Activity Scale for Kids were considered for inclusion. This version was evaluated by health professionals (n = 6), patients (n = 4), and parents (n = 3). A pilot test in a sample of 32 Dutch children was performed to assess score distribution, construct validity (Spearman's rho) and reproducibility. Administration of the pedhal was feasible for children from the age of 4 years onwards. The pedhal scores of the Dutch children were in the high end of the scale, reflecting a good functional status. Most subscales showed moderate associations with the joint examination (rho = 0.42,0.63) and moderate-to-good associations with the physical function subscale of the CHQ-50 (rho = 0.48,0.74). No significant associations were found for the pedhal and the subscales mental health and behaviour, except for the subscales leisure and sport and mental health (rho = 0.47). Test,retest agreement was good. The pedhal is a promising tool, but further testing in populations with a higher level of disability is warranted to study the full range of its psychometric properties. [source]

Measuring Hospital Care from the Patients' Perspective: An Overview of the CAHPS® Hospital Survey Development Process

HEALTH SERVICES RESEARCH, Issue 6p2 2005
Elizabeth Goldstein
Objective. To describe the developmental process for the CAHPS® Hospital Survey. Study Design. A pilot was conducted in three states with 19,720 hospital discharges. Methods of Analysis. A rigorous, multi-step process was used to develop the CAHPS Hospital Survey. It included a public call for measures, multiple Federal Register notices soliciting public input, a review of the relevant literature, meetings with hospitals, consumers and survey vendors, cognitive interviews with consumer, a large-scale pilot test in three states and consumer testing and numerous small-scale field tests. Findings. The current version of the CAHPS Hospital Survey has survey items in seven domains, two overall ratings of the hospital and five items used for adjusting for the mix of patients across hospitals and for analytical purposes. Conclusions. The CAHPS Hospital Survey is a core set of questions that can be administered as a stand-alone questionnaire or combined with a broader set of hospital specific items. [source]

The development and resulting performance impact of positive psychological capital

HUMAN RESOURCE DEVELOPMENT QUARTERLY, Issue 1 2010
Fred Luthans
Recently, theory and research have supported psychological capital (PsyCap) as an emerging core construct linked to positive outcomes at the individual and organizational level. However, to date, little attention has been given to PsyCap development through training interventions; nor have there been attempts to determine empirically if such PsyCap development has a causal impact on participants' performance. To fill these gaps we first conducted a pilot test of the PsyCap intervention (PCI) model with a randomized control group design. Next, we conducted a follow-up study with a cross section of practicing managers to determine if following the training guidelines of the PCI caused the participants' performance to improve. Results provide beginning empirical evidence that short training interventions such as PCI not only may be used to develop participants' psychological capital, but can also lead to an improvement in their on-the-job performance. The implications these findings have for human resource development and performance management conclude the article. [source]

A model for quantitative evaluation of an end-to-end question-answering system

JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 8 2007
Nina Wacholder
We describe a procedure for quantitative evaluation of interactive question-answering systems and illustrate it with application to the High-Quality Interactive Question-Answering (HITIQA) system. Our objectives were (a) to design a method to realistically and reliably assess interactive question-answering systems by comparing the quality of reports produced using different systems, (b) to conduct a pilot test of this method, and (c) to perform a formative evaluation of the HITIQA system. Far more important than the specific information gathered from this pilot evaluation is the development of (a) a protocol for evaluating an emerging technology, (b) reusable assessment instruments, and (c) the knowledge gained in conducting the evaluation. We conclude that this method, which uses a surprisingly small number of subjects and does not rely on predetermined relevance judgments, measures the impact of system change on work produced by users. Therefore this method can be used to compare the product of interactive systems that use different underlying technologies. [source]

Setting school-level outcome standards

MEDICAL EDUCATION, Issue 2 2006
David T Stern
Background, To establish international standards for medical schools, an appropriate panel of experts must decide on performance standards. A pilot test of such standards was set in the context of a multidimensional (multiple-choice question examination, objective structured clinical examination, faculty observation) examination at 8 leading schools in China. Methods, A group of 16 medical education leaders from a broad array of countries met over a 3-day period. These individuals considered competency domains, examination items, and the percentage of students who could fall below a cut-off score if the school was still to be considered as meeting competencies. This 2-step process started with a discussion of the borderline school and the relative difficulty of a borderline school in achieving acceptable standards in a given competency domain. Committee members then estimated the percentage of students falling below the standard that is tolerable at a borderline school and were allowed to revise their ratings after viewing pilot data. Results, Tolerable failure rates ranged from 10% to 26% across competency domains and examination types. As with other standard-setting exercises, standard deviations from initial to final estimates of the tolerable failure rates fell, but the cut-off scores did not change significantly. Final, but not initial cut-off scores were correlated with student failure rates (r = 0.59, P = 0.03). Discussion, This paper describes a method to set school-level outcome standards at an international level based on prior established standard-setting methods. Further refinement of this process and validation using other examinations in other countries will be needed to achieve accurate international standards. [source]

Evaluating surgeons' informed decision making skills: pilot test using a videoconferenced standardised patient

MEDICAL EDUCATION, Issue 12 2003
Sarah L Clever
Background, Standardised patients (SPs) are effective in evaluating communication skills, but not every training site may have the resources to develop and maintain SP programmes. Objectives, To test whether videoconferencing technology (VT) could enable an interaction between an SP and an orthopaedic surgeon that would allow the SP to accurately evaluate the surgeon's informed decision making (IDM) skills. We also assessed whether this sort of interaction was acceptable to orthopaedic surgeons as a means of learning IDM skills. Methods, We trained an SP to represent a 75-year-old woman considering hip replacement surgery. Orthopaedic surgeons in Chicago individually consulted with the SP in Philadelphia; each participant could see and hear the other on large television screens. The SP evaluated the surgeons' advice using a 23-item checklist of IDM elements, and gave each surgeon verbal and written feedback on his IDM skills. The surgeons then gave their evaluations of the exercise. Results, Twenty-two surgeons completed the project. The SP was ,,80% accurate in classifying 20 of the 23 IDM skills when compared to a clinician rater. Although 12 (55%) of the orthopaedic surgeons felt that some aspects of the technology were distracting, most were pleased with it, and 19 of 22 (86%) would recommend the videoconferenced SP interaction to their colleagues as a means of learning IDM skills. Conclusions, These results suggest that VT allows accurate evaluation of IDM skills in a format that is acceptable to orthopaedic surgeons. Videoconferencing technology may be useful in long-distance SP communication assessment for a variety of learners. [source]

Over- and underreporting of energy intake by patients with metabolic syndrome using an automated dietary assessment website

NUTRITION & DIETETICS, Issue 4 2007
Yasmine PROBST
Abstract Under- and overreporting of dietary intake in a face-to-face context is related to age, gender and body mass index. The use of computer technology in dietetic practice is restricted to analysis of nutrient data rather than assessment of the diet. DietAdvice, a website developed to allow patients with metabolic syndrome to self-report their dietary intake, has been developed in the Illawarra region of New South Wales, Australia. Patients are recruited by their general practitioner, and use the website, and the data are electronically fed to a dietitian for an individualised dietary prescription. The aim of the present study is to describe the reporting status of patients using a pilot test of the website from November 2004 to October 2005, and determine relationships to body mass index, gender and age. Reported energy intake (EI) was compared with predicted basal metabolic rate (BMR). Patients were classified as underreporting if EI : BMR <1.35 and overreporting if EI : BMR >2.4. Chi-square and ordinal regression analyses were used to determine relationships to patient characteristics. Two hundred patients were recruited, of whom 57 had missing data or did not complete the assessment. Of the remaining 143 patients, 32.3% underreported their intakes, 21.7% overreported their intakes, and 46.2% were on target with their reporting. No relationships were found for age, gender or body mass index. Findings suggest that computerised dietary assessment may encourage patients to report with less bias than in a verbal dietary assessment when compared with the literature. [source]

Successful unsaturated zone treatment of PCE with sodium permanganate

REMEDIATION, Issue 2 2009
John R. Hesemann
In situ chemical oxidation (ISCO) with permanganate has been widely used for soil and groundwater treatment in the saturated zone. Due to the challenges associated with achieving effective distribution and retention in the unsaturated zone, there is a great interest in developing alternative injection technologies that increase the success of vadose-zone treatment. The subject site is an active dry cleaner located in Topeka, Kansas. A relatively small area of residual contamination adjacent to the active facility building has been identified as the source of a large sitewide groundwater contamination plume with off-site receptors. The Kansas Department of Health and Environment (KDHE) currently manages site remedial efforts and chose to pilot-test ISCO with permanganate for the reduction of perchloroethene (PCE) soil concentrations within the source area. KDHE subsequently contracted Burns & McDonnell to design and implement an ISCO pilot test. A treatability study was performed by Carus Corporation to determine permanganate-soil-oxidant-demand (PSOD) and the required oxidant dosing for the site. The pilot-test design included an ISCO injection approach that consisted of injecting aqueous sodium permanganate using direct-push technology with a sealed borehole. During the pilot test, approximately 12,500 pounds of sodium permanganate were injected at a concentration of approximately 3 percent (by weight) using the methods described above. Confirmation soil sampling conducted after the injection event indicated PCE reductions ranging from approximately 79 to more than 99 percent. A follow-up treatment, consisting of the injection of an additional 6,200 pounds of sodium permanganate, was implemented to address residual soil impacts remaining in the soil source zone. Confirmation soil sampling conducted after the treatment indicated a PCE reduction of greater than 90 percent at the most heavily impacted sample location and additional reductions in four of the six samples collected. © 2009 Wiley Periodicals, Inc. [source]

A practical approach to steam-enhanced dual-phase extraction: A case study

REMEDIATION, Issue 3 2003
David P. Bouchard
This article presents the results of a pilot test that was conducted to determine the effectiveness of using steam-enhanced dual-phase extraction (DPE) at a former industrial site in New York. The pilot test proved that steam-enhanced DPE was very effective at removing significant contaminant mass from the subsurface in a relatively short time period. Concentrations of volatile organic compounds and semivolatile organic compounds in the vapor stream and groundwater were successfully reduced, in some cases by orders of magnitude. Based on the results of the steam-enhanced DPE pilot test, the final remedy for the site includes implementing this technology at selected areas as an alternative to DPE alone or other remedial alternatives, such as excavation or groundwater pump and treat. © 2003 Wiley Periodicals, Inc. [source]

Perspective-driven text comprehension

APPLIED COGNITIVE PSYCHOLOGY, Issue 3 2008
Johanna K. Kaakinen
The present article reports results of an eye-tracking experiment, which examines whether the perspective-driven text comprehension framework applies to comprehension of narrative text. Sixty-four participants were instructed to adopt either a burglar's or an interior designer's perspective. A pilot test showed that readers have more overlapping prior knowledge with the burglar-relevant than with the interior designer-relevant information of the experimental text. Participants read either a transparent text version where the (ir)relevance of text segments to the perspective was made apparent, or an opaque text version where no direct mention of the perspective was made. After reading participants wrote a free recall of the text. The results showed that perspective-related prior knowledge modulates the perspective effects observed in on-line text processing and that signalling of (ir)relevance helps in encoding relevant information to memory. It is concluded that the proposed framework generalizes to the on-line comprehension of narrative texts. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Trichlorofluoroethene: A reactive tracer for evaluating reductive dechlorination in large-diameter permeable columns

GROUND WATER MONITORING & REMEDIATION, Issue 2 2005
Jennifer A. Field
Trichlorofluoroethene (TCFE) was used as a reactive tracer to determine the in situ rate of reductive dechlorination in treatment zones impacted by three large-diameter permeable columns (LDPCs) that were installed at a trichloroethene (TCE),contaminated site. The LDPCs were part of a pilot study to evaluate the effectiveness of hydrogen, lactate, and zero-valent iron for remediating TCE-contaminated ground water. The rate of TCFE reductive dechlorination was determined for each LDPC by means of push-pull tests conducted in each treatment layer. In addition, the distribution of TCFE's lesser chlorinated transformation products was determined. The rates of TCFE reductive dechlorination ranged from 0.05/d to 0.20/d and corresponded to half-lives ranging from 3.5 to 13.9 d. cis -Dichlorofluoroethene was the dominant transformation product detected in all the tests, which is consistent with the findings from pilot tests conducted in the LDPCs prior to the TCFE push-pull tests. cis -Chlorofluoroethene (CFE) and 1,1-CFE also were detected and indicate the potential for vinyl chloride to form under all treatment regimes. Significant production of fluoroethene (FE), the analog of ethene, was observed for only one of the hydrogen treatments. Unambiguous and sensitive detection of the lesser chlorinated products, such as CFE and FE, is possible because TCFE and its transformation products are not found in the background ground water at contaminated sites. Good agreement between the rates and transformation product profiles for TCFE and TCE in both field and laboratory experiments indicates the suitability of TCFE as a surrogate for predicting the rates of TCE reductive dechlorination. [source]

In situ remediation of PCE at a site with clayey lithology and a significant smear zone

REMEDIATION, Issue 3 2010
Josephine Molin
Groundwater at the former Serry's Dry Cleaning site in Corvallis, Oregon, was impacted by chlorinated volatile organic compounds (CVOCs). The primary CVOCs impacting the site include tetrachloroethene, trichloroethene, dichloroethene, and vinyl chloride, which were detected at concentrations up to 22,000, 1,700, 3,100, and 7 ,g/L, respectively, prior to treatment. Large seasonal fluctuations in groundwater CVOC concentrations indicated that a significant fraction of the CVOC mass was present in the smear zone. Field-scale pilot tests were performed for the Oregon Department of Environmental Quality's Dry Cleaner Program to evaluate the performance of EHC® in situ chemical reduction (ISCR) technology. The pilot study involved evaluating field performance and physical distribution into low-permeability soil using basic Geoprobe® injection tooling. The testing results confirmed that bioremediation enhanced by ISCR supported long-term treatment at the site. This article describes the implementation and results of the tests. Performance data are available from a three-year period following the injections, allowing for a discussion about sustained performance and reagent longevity. © 2010 Wiley Periodicals, Inc. [source]

Remediation of chlorinated ethenes, ethanes, and methanes in groundwater using carbon- and iron-based electron donor

REMEDIATION, Issue 4 2009
Nanjun Shetty
Field-scale pilot tests were performed to evaluate enhanced reductive dechlorination (ERD) of dissolved chlorinated solvents at a former manufacturing facility located in western North Carolina (the site). Results of the site assessment indicated the presence of two separate chlorinated solvent,contaminated groundwater plumes, located in the northern and southern portions of the site. The key chlorinated solvents found at the site include 1,1,2,2-tetrachloroethane, trichloroethene, and chloroform. A special form of EHC® manufactured by Adventus Americas was used as an electron donor at this site. In this case, EHC is a pH-buffering electron donor containing controlled release carbon and ZV Iron MicroSphere 200, a micronscale zero-valent iron (ZVI) manufactured by BASF. Approximately 3,000 pounds of EHC were injected in two Geoprobe® boreholes in the saprolite zone (southern plume), and 3,500 pounds of EHC were injected at two locations in the partially weathered rock (PWR) zone (northern plume) using hydraulic fracturing techniques. Strong reducing conditions were established immediately after the EHC injection in nearby monitoring wells likely due to the reducing effects of ZV Microsphere 200. After approximately 26 months, the key chlorinated VOCs were reduced over 98 percent in one PWR well. Similarly, the key chlorinated solvent concentrations in the saprolite monitoring wells decreased 86 to 99 percent after initial increases in concentrations of the parent chlorinated solvents. The total organic carbon and metabolic acid concentrations indicated that the electron donor lasted over 26 months after injection in the saprolite aquifer. © 2009 Wiley Periodicals, Inc. [source]

Nanotechnology and groundwater remediation: A step forward in technology understanding

REMEDIATION, Issue 2 2006
Christian Macé
Nanotechnology application to contaminated site remediation, and especially the use of nanoscale zero-valent iron particles to treat volatile organic compound (VOC)-impacted groundwater, is now recognized as a promising solution for cost-effective in situ treatment. Results obtained during numerous pilot tests undertaken by Golder Associates between 2003 and 2005 in North America (United States and Canada) and Europe have been used to present a synthetic cross-comparison of technology dynamics. The importance of a comprehensive understanding of the site-specific geological, hydrogeological, and geochemical conditions, the selection of appropriate nanoscale particles, the importance of monitoring geochemical parameters during technology application, and the potential of nanoparticle impact on microbial activity are discussed in this article. The variable technology dynamics obtained during six pilot tests (selected among numerous other tests) are then presented and discussed. © 2006 Wiley Periodicals, Inc. [source]