Assessment Of Plant Performance Research Articles

Adaptability and variation in Isatis tinctoria L.: a new crop for Europe

Isatis tinctoria L. was cultivated until the 19th century to produce indigo, a natural blue pigment used principally for dyestuffs. The current search for alternative crops and interest in natural products has led to reconsidering I. tinctoria as a crop to be grown in marginal areas to produce natural indigo. To reintroduce I. tinctoria into cultivation, its behaviour under different climatic conditions as well as its morpho-physiological and genetic diversity must be assessed in order to evaluate the possibilities of future breeding work. To do this, a Eurasian collection of 15 accessions was studied in a 2-year experiment. The study was carried out in four locations in order to assess plant performance at altitudes ranging from 380 to 1,700 m a.s.l. A second experiment evaluated the morpho-physiological diversity of several traits (some related to agronomic performances) of the collection. In a third experiment the genetic traits of the collection were characterised by using eight AFLP and eight SAMPL markers. The species showed a wide adaptability to different mountainous conditions and the populations showed high morphologic and genetic variability and differed according to their origins. Both morpho-physiological and molecular characterisation allowed the accessions to be distinguished into groups of European and Asian origin. Future breeding work is recommended because some accessions have good agronomic potential.

Reproductive constraints for the long-term persistence of fragmented Acacia dealbata (Mimosaceae) populations in southeast Australia

Fragmented and degraded vegetation characterises agricultural landscapes across southern Australian. Remnant vegetation within these regions performs a number of vital ecological and hydrological roles, but little is known about whether or how fragmentation is affecting the long-term persistence of these critical landscape elements. Acacias are a significant component of many remnant vegetation communities across Australia, forming numerous integral faunal and floral relationships. Here, reproductive output of 11 fragmented Acacia dealbata (Mimosaceae) populations from across the southern tablelands of New South Wales was assessed over 2 years to identify reproductive constraints associated with increasing vegetation fragmentation. Fertilization success is the major reproductive constraint, particularly in small populations, and probably reflects a self-incompatible reproductive strategy. During 2002 larger and more dense populations produced more legumes ( p = 0.014 and <0.001, respectively) while in 2003 these two variables were associated with increased fertilization success ( p = 0.004 and 0.017, respectively). There was also some suggestion that populations with fewer exotic species also experienced increased fertilization success ( p = 0.055). Assessment of plant performance within populations suggests that consistent reproductive output of particular individuals within small populations may limit reproductive compatibility within these populations over time. The long-term persistence of many small A. dealbata populations may be jeopardised by low seed set, and limited recruitment and aging stands. Immediate steps are now required to ensure that these populations continue contributing to landscape function by augmenting populations, improving connectivity, and allowing disturbance events that will stimulate recruitment.

Extension of the IWA/COST simulation benchmark to include expert reasoning for system performance evaluation

In this paper the development of an extension module to the IWA/COST simulation benchmark to include expert reasoning is presented. This module enables the detection of suitable conditions for the development of settling problems of biological origin (filamentous bulking, foaming and rising sludge) when applying activated sludge control strategies to the simulation benchmark. Firstly, a flow diagram is proposed for each settling problem, and secondly, the outcome of its application is shown. Results of the benchmark for two evaluated control strategies illustrate that, once applied to the simulation outputs, this module provides supplementary criteria for plant performance assessment. Therefore, simulated control strategies can be evaluated in a more realistic framework, and results can be recognised as more realistic and satisfactory from the point of view of operators and real facilities.

Community level engineering effects of Triglochin maritima (seaside arrowgrass) in a salt marsh in northern New England, USA

Summary 1 Ecosystem engineers can influence other organisms indirectly by modifying their physical habitat and are common in all natural communities. We examined the mechanisms underlying the effects of engineering by seaside arrowgrass, Triglochin maritima (Juncaginaceae), in a northern New England forb panne. Within these waterlogged areas, T. maritima creates elevated rings that support high plant cover compared with nearly bare adjacent substrate. 2 The influence on vegetation patterns of ring height and facilitation by neighbouring vegetation were examined in the field with T. maritima rings (elevation + vegetation), experimentally lowered rings (vegetation only), artificially raised mud (elevation only) and bare mud. Transplants of four perennial species, along with naturally occurring seedlings, were followed to assess plant performance. We also monitored edaphic conditions, seed dispersal and plant cover in experimental plots over two growing seasons. 3 All transplanted species showed increased success in raised treatments (in which the substrate showed an increase in reductive potential and a decrease in waterlogging) while there was no significant relationship to the presence of neighbouring vegetation. Seed supply, however, was enhanced by both ring elevation and the presence of neighbours. 4 A glasshouse experiment to test the response of T. maritima to waterlogging showed an increased production of shallow roots, suggesting a mechanism that may contribute to ring formation. 5 Our results indicate that community consequences of engineering by T. maritima are predominantly due to raised ring formation that ameliorates waterlogging stress and thereby promotes increased species diversity. Consequently, T. maritima may be an important target species for conservation, as sea level rise is expected to increase waterlogging stress in marshes.

Regulatory basis for the Waste Isolation Pilot Plant performance assessment

The Waste Isolation Pilot Plant (WIPP) is the first operational repository designed for the safe disposal of transuranic (TRU) radioactive waste from the defense programs of the US Department of Energy (DOE). The US Environmental Protection Agency (EPA) is responsible for certifications and regulation of the WIPP facility for the radioactive components of the waste. The EPA has promulgated general radioactive waste disposal standards at 40 CFR Part 191. and WIPP-specific criteria to implement and interpret the generic disposal standards at 40 CFR Part 194. In October 1996. the DOE submitted its Compliance Certification Application (CCA) to the EPA to demonstrate compliance with the disposal standards at Subparts B and C of 40 CFR Part 191. This paper summarizes the development of the overall legal framework for radioactive waste disposal at the WIPP, the parallel development of the WIPP performance assessment (PA), and how the EPA disposal standards and implementing criteria formed the basis for the CCA WIPP PA. The CCA resulted in a certification in May 1998 by the EPA of the WIPP'S compliance with the EPA's disposal standard, thus enabling the WIPP to begin radioactive waste disposal.

Performance Monitoring and Measurement for Central Air Conditioning Chiller Plants in Buildings in Hong Kong

Space cooling for buildings in Hong Kong accounts for a significant part of the energy consumption in the building sector. Electricity consumption by a central air conditioning chiller plant may be up to 30% of the total energy consumed in a building. Detailed site surveys on several local chiller plants in the past revealed that there existed a number of problems relating to plant design and operation, which influenced the overall operating efficiency of the plants. Setting up a quality monitoring system for a chiller plant will help plant operators to diagnose problems and optimise plant performance. This paper summarises such problems and discusses the need for having a chiller plant monitored and assessed using quality instrumentation. The difficulties in assessing plant performance and accuracy requirements for carrying out an assessment are also discussed. A pilot study on carrying out detailed monitoring and measurement for a direct sea water cooled chiller plant using quality instrumentation is us...

Assessing plant performance using MPA

Knowledge of microbiotic particulate composition provides valuable information for assessing treatment plant performance and enhancing plant operation.Concentration of microbiota and total particulates in raw and finished water samples from 55 conventional treatment plants was compared. Analyses included (1) enumeration and identification of the microbiota, (2) direct measurement of the pellet volume of total particulates after laboratory centrifugation, (3) total particle counts, and (4) Giardia and Cryptosporidium detection. Organism reduction based on microscopic particulate analysis in the raw and finished waters ranged from –0.8 to 6.0 log. There was a significant correlation between reduction values generated by organism counts, centrifugate pellet measurements, and particle counts. However, only organism reduction values remained consistent regardless of influent turbidity or flocculent material present in the effluent. Because of low concentrations and intermittent occurrence, counts of Giardia and Cryptosporidium did not accurately reflect treatment plant performance.

ESTIMATION OF OPTIMUM OPERATING PARAMETERS OF UASB REACTOR TREATING FLAX RETYING WASTEWATER BY KINETIC MODEL

A laboratory study was used to develop a simplified kinetic model, to evaluate the kinetic parameters, and to provide rational design parameters for a pilot plant treating flax retting wastewater by means of the simulation of optimal operation of the UASB reactor. The results indicated that the developed model can be used predicatively for assessing plant performance and when the concentration of the influent is at the range of 5.5-7.3gCOD/l, the concentration of the hard-biodegradable materials is 0.46gCOD/l.

Performance and kinetics of an upflow anaerobic sludge blanket (UASB) reactor treating slaughterhouse wastewater

Abstract A laboratory study was devised to verify the use of Monod kinetics for the modelling of a continuous upflow anaerobic sludge blanket (UASB) reactor treating slaughterhouse wastewater. Eight different hydraulic retention times (4.0–0.3 day) were investigated at an average influent COD concentration of 5.1 g.l‐1. The maximum substrate utilization rate, k, and half saturation coefficient, KL, were determined to be 1.47 kg CODremoved. .kg‐1 VSS‐day‐1 and 1.23 kg COD.kg‐1 VSS‐day1. The yield coefficient, Y, and sludge decay rate coefficient, Kd, were also determined to be 0.17 kg VSS.kg‐1 CODremoved and 0.029 day‐1, respectively. The lose relationship between biomass loading rate and specific substrate utilization rate supported the use of Monod equations and allowed the model to be used predictively for assessing plant performance.

Kinetics of an upflow anaerobic sludge blanket reactor treating ice‐cream wastewater

Abstract A laboratory study was devised to verify the use of Monod kinetics for the modelling of continuous upflow anaerobic sludge blanket (UASB) reactors treating ice‐cream wastewater. Eight different hydraulic retention times (5.0–0.4 day) were investigated at an average influent COD concentration of 5.2 g.1‐1). The maximum substrate utilization rate, k, and half saturation coefficient, KL, were determined to be 1.39 kg CODremoved.kg‐1 VSS.day‐1 and 0.29 kg COD.kg‐1 VSS.day‐1. The yield coefficient, Y, and sludge decay rate coefficient, Kd, were also determined to be 0.16 kg VSS.kg‐1 CODremoved and 0.028 day‐1, respectively. The close relationship between biomass loading rate and specific substrate utilization rate supported the use of Monod equations and allowed the model to be used predictively for assessing plant performance.

Assessing Treatment Plant Performance

Many utilities are concerned about the performance of their treatment systems as a result of recent Cryptosporidium outbreaks in the United States and Canada. The most responsive course of action a utility can take at this time is to ensure that its treatment facilities are operating at as close to optimum efficiency for pathogen removal and disinfection as possible. Currently, the best measure of efficiency for removal of parasites such as Cryptosporidium is assessing plant performance for turbidity and particle removal. This article reviews a number of performance evaluation procedures as well as results derived from evaluation and process improvement programs initiated by water utilities. A thorough treatment plant evaluation and improvement program is the best way to ensure pathogen‐free drinking water.

Biological treatment of waste with high ash content using a hydrolytically assisted extended aeration process

AbstractIn previous reports from this laboratory it has been shown that the extended aeration process for biological treatment of organically laden municipal and/or industrial waste could be successfully employed for concurrent purification and sludge disposal. Also results using a modified process in which autodigestion was aided and controlled by periodic partial hydrolysis of small portions of the recycle sludge showed that operational control was feasible. There was some question regarding the success of such a process if the original waste contained a large portion of inorganic solids. Accordingly, a 1½ year pilot plant study was made using a waste (hydrolyzed trickling filter sludge) of exceptionally high ash content (50–60%). It was found that the ash content of activated sludge grown on this substrate did not continually increase nor did the high ash content of the waste interfere in any way with the efficiency of removal of organic matter. In general it exceeded 90 percent. Also a highly nitrified effluent was produced. A variety of analyses were performed: COD, BOD, TOC, suspended solids, NH3‐N, organic‐N, NO3‐N, etc. Interrelationships between these important monitoring parameters for assessing plant performance offered useful insight into operational control for hydrolytically assisted extended aeration processes.

Availability of Power Stations and Their Equipment

Comprehensive and self-consistent data relating to plant availability and outage rates are essential for the assessment of plant performance, thereby enabling standby requirements to be estimated, plant extensions planned and the performance of different types of plant compared. The present paper deals with the essential requirements that must be met to ensure the comparability and adequacy of the statistical data. Five main points are emphasized in the paper: the assessment of plant performance is best given by outage rates, stated in terms of time; three classes of outage are described; namely forced, deferable and planned. Shortfall is considered separately; since the practical consequences of the three kinds of outage will in general be very different, and since one may affect another the record must always include the three outage rates shown as separate items; to permit the assessment and comparison of statistics from different sources the record should also include an output factor—(total output of item during period/rated capacity x total hours in period), a service factor—(total hours of item in service during period/total hours in period) and the number of starts during the period under review; statistics from plants of very dissimilar properties and design and with widely different operating regimes should be compared cautiously.