Plant-specific Characteristics Research Articles

The cost of day-ahead solar forecasting errors in the United States

As solar energy contributes an increasing share of total electricity generation, solar forecasting errors become important relative to overall load uncertainty and can add costs to electricity systems. We investigated the costs of day-ahead solar forecast errors across 667 existing solar power plants in the United States (years 2012 through 2019). Our analysis was based on hourly real-time and day-ahead nodal prices. We analyzed two types of solar forecasts: persistence forecasts, a simple approach to forecasting, and a numerical weather prediction forecast, the North American Mesoscale Model (NAM), an improvement over persistence forecasts based on public data and modelling software. We modeled hourly energy forecasts using meteorological forecasts and plant specific characteristics. Hourly plant generation was modeled and debiased with multiple sources of generation records. NAM forecast errors had relatively low costs on average, at no more than $1/MWh in all years except 2016, when costs rose to $1.5/MWh. Even after these error costs, the value of solar was marginally higher when simulating solar participation in day-ahead markets versus participation only in real-time markets. On average, the premium for participating in the day-ahead market, based on NAM forecasts, ranged from −0.5 to 5.2 $/MWh across years. Average error costs were higher in regions with higher solar penetration (i.e., California and New England) compared to regions with low solar penetration. However, California and New England had similar error costs despite higher solar penetration in California, indicating that error costs to date have been only loosely correlated with solar penetration levels.

Comparison of Technologies for CO2 Capture from Cement Production—Part 2: Cost Analysis

This paper presents an assessment of the cost performance of CO2 capture technologies when retrofitted to a cement plant: MEA-based absorption, oxyfuel, chilled ammonia-based absorption (Chilled Ammonia Process), membrane-assisted CO2 liquefaction, and calcium looping. While the technical basis for this study is presented in Part 1 of this paper series, this work presents a comprehensive techno-economic analysis of these CO2 capture technologies based on a capital and operating costs evaluation for retrofit in a cement plant. The cost of the cement plant product, clinker, is shown to increase with 49 to 92% compared to the cost of clinker without capture. The cost of CO2 avoided is between 42 €/tCO2 (for the oxyfuel-based capture process) and 84 €/tCO2 (for the membrane-based assisted liquefaction capture process), while the reference MEA-based absorption capture technology has a cost of 80 €/tCO2. Notably, the cost figures depend strongly on factors such as steam source, electricity mix, electricity price, fuel price and plant-specific characteristics. Hence, this confirms the conclusion of the technical evaluation in Part 1 that for final selection of CO2 capture technology at a specific plant, a plant-specific techno-economic evaluation should be performed, also considering more practical considerations.

Fix-and-optimize procedures for solving the long-term unit commitment problem with pumped storages

In this paper, we consider a long-term unit commitment problem with thermal and renewable energy sources, where system operating costs have to be minimized. The problem is enhanced by adding pumped storages, where water is stored in reservoirs, being turbinated or pumped up if it is beneficial in terms of reducing the operating costs. We present a tight mixed-integer linear programming model with a redefinition of decision variables and a reformulation of constraints, e.g., for the spinning reserve. The model serves as a basis for a new decomposition method, where fix-and-optimize schemes are used. In particular, a time-oriented, a unit-oriented, and a generic fix-and-optimize procedure are presented. A computational performance analysis shows that the mixed-integer linear model is efficient in supporting the solution process for small- and medium-scale instances. Furthermore, the fix-and-optimize procedures are able to tackle even large-scale instances. Particularly, problem instances with real-world energy demands, power plant-specific characteristics, and a one-year planning horizon with hourly time steps are solved to near-optimality in reasonable time.

Soil microbial communities as potential regulators of in situ N2O fluxes in annual and perennial cropping systems

Significant reductions in nitrous oxide (N2O) fluxes have been observed with perennial cropping systems compared to annual crops. However, it is unclear if this reduction in N2O flux is linked to soil microbial communities due to plant-specific characteristics stimulating changes in microbial community structure. The response of microbial communities involved in N2O production to liquid dairy manure (LDM) application and tillage in annual and perennial systems has also not been assessed. Our objectives were to contrast changes in the population sizes and community structures of ammonia oxidizer (represented by amoA and crenamoA gene targets) and denitrifier (nirK, nirS, and nosZ gene targets) communities in differently managed annual and perennial fields, and to determine if differences in these microbial communities were related to observed variation in N2O fluxes. Soil was sampled in 2012 and in 2014 in a 4-ha spring-applied LDM grass-legume (perennial) field and two 4-ha corn (annual) fields under fall or spring LDM application. Soil DNA was extracted and used to target N-cycling genes via qPCR (n = 6) and for next-generation sequencing (Illumina Miseq) (n = 3). Significantly higher field-scale N2O fluxes were observed in the annual fields compared to the perennial system; however N2O fluxes increased 10-fold after plough down of the perennial field. Nonmetric multidimensional scaling (NMS) and multi-response permutation procedure (MRPP) indicated statistical differences in N-cycling communities between annual and perennial cropping systems, and in some cases, communities became indistinct in ordination space between annual and perennial fields after ploughing. Indicator species analysis was used to identify sequences clustered into operational taxonomic units (OTUs) most responsible for community shifts related to management. The abundance of N2O-reducing soil microbial communities (nosZ gene copies) and specific nirK, nirS and nosZ OTUs were proposed as important with respect to the production and consumption of N2O in these soils. Our results illustrate that ammonia oxidizer and denitrifier soil bacterial communities are sensitive to agricultural management (annual or perennial crop type, LDM management, and ploughing), highlighting their significance for the development of effective N2O mitigation strategies.

The Impact of Spatial Externalities: Skills, Education and Plant Productivity

Wixe S. The impact of spatial externalities: skills, education and plant productivity, Regional Studies. This paper analyses the role of a broad range of spatial externalities in explaining average labour productivity of Swedish manufacturing plants. The main findings show positive effects from general urbanization economies and labour market matching, as well as a negative effect from within-industry diversity. These results confirm previous research despite methodological differences, which implies wider generalizability. Additionally, the empirical findings support Marshall–Arrow–Romer (MAR) and Porter externalities, i.e. positive effects from specialization and competition. No evidence is found of Jacobs externalities, neither when measured as between-industry diversity nor as within-industry diversity. Finally, plant-specific characteristics play a key role in explaining plant-level productivity.

The Importance of Geographic and Biological Variables in Predicting the Naturalization of Non-Native Woody Plants in the Upper Midwest

The selection, introduction, and cultivation of non-native woody plants beyond their native ranges can have great benefits, but also unintended consequences. Among these consequences is the tendency for some species to naturalize and become invasive pests in new environments to which they were introduced. In lieu of lengthy and costly field trials, risk-assessment models can be used to predict the likelihood of naturalization. We compared the relative performance of five established risk-assessment models on species datasets from two previously untested areas: southern Minnesota and northern Missouri. Model classification rates ranged from 64.2 to 90.5%, biologically significant errors ranged from 4.4 to 9.3%, and horticulturally limiting errors ranged from 6.6 to 30.4%. For the random forest model, we investigated the importance of variables used to predict naturalization by examining datasets for five distinct study areas across the Upper Midwest. Geographic-risk ratios were the most important predictors of species' tendency to naturalize. Other factors, such as quick maturity, record of invading elsewhere, and production of fleshy, bird-dispersed fruit were also important in the random forest models. Although some models tested need additional refinement, the random forest models maintain robustness and provide additional information on plant-specific characteristics that contribute to naturalization.

3C Technologies in plants

Chromosome conformation capture (3C) and 3C-based technology have revolutionized studies on chromosomal interactions and their role in gene regulation and chromosome organization. 3C allows the in vivo identification of physical interactions between chromosomal regions. Such interactions are shown to play a role in various aspects of gene regulation, for example transcriptional activation of genes by remote enhancer sequences, or the silencing by Polycomb-group complexes. The last few years the number of publications involving chromosomal interactions increased significantly. Until now, however, the vast majority of the studies reported are performed in yeast or animal systems. So far, studies on plant systems are extremely limited, possibly due to the plant-specific characteristics that hamper the implementation of the 3C technique. In this paper we provide a plant-specific 3C protocol, optimized for maize tissue, and an extensive discussion on (i) plant-specific adjustments to the protocol, and (ii) solutions to problems that may arise when optimizing the protocol for the tissue or plant of interest. Together, this paper should facilitate the application of 3C technology to plant tissue and stimulate studies on the 3D conformation of chromosomal regions and chromosomes in plants.

Accumulation of semivolatile organic compounds in Antarctic vegetation: A case study of polybrominated diphenyl ethers

Antarctic plant communities are dominated by lichens and mosses which accumulate semivolatile organic compounds (SOCs) such as polybrominated diphenyl ethers (PBDEs) directly from the atmosphere. Differences in the levels of PBDEs observed in lichens and mosses collected at King George Island in the austral summers 2004–05 and 2005–06 are probably explained by environmental and/or plant parameters. Contamination of lichens showed a positive correlation with local precipitation, suggesting that wet deposition processes are a major mechanism controlling the uptake of most PBDE congeners. These findings are in agreement with physical–chemical data supporting that tetra- through hepta-BDEs in the Antarctic atmosphere are basically bound to aerosols. Conversely, accumulation of PBDEs in mosses appears to be controlled by other environmental factors and/or plant-specific characteristics. Model simulations demonstrated that an ocean–atmosphere coupling may have played a role in the long-range transport of less volatile SOCs such as PBDEs to Antarctica. According to simulations, the atmosphere is the most important transport medium for PBDEs while the surface ocean serves as a temporary storage compartment, boosting the deposition/volatilization “hopping” effect similarly to vegetation on continents.

The Spatial Patterns of Networks, Hierarchies and Subsidiaries

This article reviews evidence and arguments linking the networking behaviour of firms with geographic distance, before examining the spatial relationships of electronics firms in the three major electronics centres in Spain. The focus is on the spatial pattern and extent of different types of inter-firm relations. Based on the analysis of 184 surveyed establishments, displaying different ownership and organization characteristics, the results show that while regional linkages are important, significant extra-regional linkages are also maintained by firms in regional clusters. The spatial extent of linkages depends on the mode of relations; arm's length, network and hierarchy relations show different spatial patterns, as do different types of cooperation. The importance of extra-regional linkages also varies with firm- and plant-specific characteristics. Extra-regional linkages are more common among larger and more R&D-intensive firms, firms with greater presence in the rest of the country and firms with more experience of cooperation and more stable relationships.

Application of the Genetic Programming for Increasing the Soft Annealing Productivity in Steel Industry

The optimal thermomechanical processing in steel industry is difficult because of the multiconstituent and multiphase character of the commercial steels, variety of the possible processing paths, and plant specific equipment characteristics. This article shows successful implementation of the genetic programming approach for increasing the furnace conveyor speed and consequently productivity of the heat treatment furnace in the soft annealing process. The data (222 samples covering 24 different steel grades) on a furnace conveyor speed, chemical composition of steel (weight percent of C, Cr, Mo, Ni, and V) and Brinell hardness, before and after the soft annealing, were collected during daily production. On the basis of the monitored data a mathematical model for the hardness after the soft annealing was developed by genetic programming. According to the modeled influences on the hardness, the higher furnace conveyor speed was attempted in practice. The experimental results of the hardness after the soft annealing with the increased conveyor speed and the predictions of the mathematical model were compared within the agreement of 3.24%. The genetic model was also compared and verified with linear regression model. The productivity of the soft annealing process increased (from the furnace conveyor speed 3.2 m/h to 7 m/h) as a consequence of the used computational intelligence approach.

Direct heat transfer considerations for improving energy efficiency in pulp and paper Kraft mills

The success of any process improvement study depends on the quality of the available data and the way in which the plant-specific characteristics are incorporated in the applied conceptual models; in the context of process integration studies these issues are directly related to the rules followed during the data extraction stage. Improving energy efficiency in a pulp and paper Kraft mill requires the identification of the most promising heat recovery network retrofit projects. In a retrofit analysis using pinch technology/process integration methods, only the process streams associated to the existing heat exchangers and some outlet streams (such as wastewater/effluent streams and vents) with high potential for heat recovery are usually included, while the energy exchanged through non-isothermal stream mixing (NIM) or direct heat transfer (DHT) is often assumed fixed and is not considered in the analysis. Relaxing this assumption requires extracting more data to represent the DHT design configuration that exists in the plant. However, different data extraction options can be considered to represent the DHT configuration depending on the associated process/operation constraints. This work describes a systematic procedure to extract and analyse the impacts of DHT on the overall energy efficiency of a Kraft process with a specific focus on mixing along the pulp line and in water tanks.

The Serine/Arginine-Rich Protein Family in Rice Plays Important Roles in Constitutive and Alternative Splicing of Pre-mRNA

Ser/Arg-rich (SR) proteins play important roles in the constitutive and alternative splicing of pre-mRNA. We isolated 20 rice (Oryza sativa) genes encoding SR proteins, of which six contain plant-specific characteristics. To determine whether SR proteins modulate splicing efficiency and alternative splicing of pre-mRNA in rice, we used transient assays in rice protoplasts by cotransformation of SR protein genes with the rice Waxy(b) (Wx(b))-beta-glucuronidase fusion gene. The results showed that plant-specific RSp29 and RSZp23, an SR protein homologous to human 9G8, enhanced splicing and altered the alternative 5' splice sites of Wx(b) intron 1. The resulting splicing pattern was unique to each SR protein; RSp29 stimulated splicing at the distal site, and RSZp23 enhanced splicing at the proximal site. Results of domain-swapping experiments between plant-specific RSp29 and SCL26, which is a homolog of human SC35, showed the importance of RNA recognition motif 1 and the Arg/Ser-rich (RS) domain for the enhancement of splicing efficiencies. Overexpression of plant-specific RSZ36 and SRp33b, a homolog of human ASF/SF2, in transgenic rice changed the alternative splicing patterns of their own pre-mRNAs and those of other SR proteins. These results show that SR proteins play important roles in constitutive and alternative splicing of rice pre-mRNA.

Protein localization in the plant Golgi apparatus and the trans-Golgi network.

This review presents plant-specific characteristics of the Golgi apparatus and discusses their impact on retention of membrane proteins in the Golgi or the trans-Golgi network (TGN). The plant Golgi consists of distinct stacks of cisternae that actively move throughout the cytoplasm. The Golgi apparatus is a very dynamic compartment and the site for maturation of N-linked glycans. It is also a factory for complex carbohydrates that are part of the cell wall. The TGN is believed to be the site from where vacuolar proteins are sorted by receptors towards each type of vacuole. To maintain the structure and specific features of the Golgi, resident proteins ought to be maintained in the proper Golgi cisternae or in the TGN. Two families of membrane proteins will be taken as examples for Golgi/TGN retention: (i) the enzymes involved in N-glycosylation processes and (ii) a vacuolar sorting receptor. Although the number of available plant proteins localized in Golgi/TGN is low, the basis of retention appears to be shared over all kingdoms and may result from pure retention and recycling mechanisms. In this review, we will summarize the characteristics of a plant Golgi and will discuss especially their consequences on on the study of this highly dynamic structure. We then choose membrane proteins with a single transmembrane domain to illustrate the signals and mechanisms involved in plants to localize and maintain proteins in the Golgi and the TGN.

PLANT‐LEVEL ENVIRONMENTAL MANAGEMENT ORIENTATION: THE INFLUENCE OF MANAGEMENT VIEWS AND PLANT CHARACTERISTICS

As customers, the public and other stakeholders are increasingly demanding that manufacturing firms improve their approach to environmental management, some plants have moved to develop an orientation that is increasingly proactive. Synthesizing earlier research, environmental management orientation is defined here to include system analysis and planning, organizational responsibility, and management controls. The relationship between a proactive orientation and two sets of internal factors, specifically the personal views of plant managers and plant‐specific characteristics, was tested using survey data from the furniture industry. The production outlook for the plant was critical, with a favorable outlook fostering a more proactive environmental management orientation. After controlling for plant‐specific factors, personal views also were influential; an increasing emphasis on short‐term economic value was related to a more reactive plant‐level orientation. Thus senior corporate management can foster strong plant‐level environmental management through a more balanced emphasis on economic and ethical values and continued investment in a plant's long‐term viability.

Impact of documented land use changes on the surface albedo and evapotranspiration in a plain watershed

Agricultural land use series are investigated in a plain catchment area of the Tisza River, almost identically represented by six administrative counties. Each county, commonly covering 34,000 km2, is characterised by high percentage (70–80 %) of managed vegetation. Effects of area coverage variations between the different plants are computed for the period 1951–1993 by applying results of a literature-based syntheses, specified for Hungary. The latter studies estimate surface-albedo values and proportion between real and potential evapotranspiration for the great majority of the plants grown in the region. Potential evapotranspiration and relative soil moisture content are estimated from the monthly meteorological series of temperature, precipitation and atmospheric water vapour pressure. Product of these plant-specific characteristics and the relative area coverage yield in monthly series of surface albedo and real evapotranspiration. Furthermore, these values are related to the energy balance of the surface-atmosphere system by using a radiative-convective model adjusted for the given location. Two questions are investigated:i) Are there monotonous trends in the given terms of the energy and water budget?ii) Are these changes comparable to the effects caused by other external forcings?Our computations give positive answer to both questions.

Geographic differences and the location of new manufacturing facilities

This paper introduces two innovations to the empirical study of plant location: (1) division of the decision into stages, and (2) use of plant-specific characteristics to either magnify or temper factors defined at the state level. The plant-specific characteristics derive from a study of Fortune 500 plants that were opened in the 1970s. A number of relationships are derived from considerations of expected profitability that relate site selection to state and firm characteristics. These are tested through a series of multinomial logit models. The results confirm that the plant location decision can be usefully approached as a staged process and that geographically defined differences are not sufficient, by themselves, to explain why some states do better than others in attracting new plants. When plant-specific characteristics are used to modify the state-based factors, the explanation becomes much richer and more powerful.

Vessel behavior following a through-wall crack

A fracture mechanics model has been developed to predict the behavior of a reactor pressure vessel following the occurrence of a through-wall crack during a pressurized thermal shock event. This study has been coordinated with the Integrated Pressurized Thermal Shock (IPTS) Program at Oak Ridge National Laboratory. The fracture mechanics model uses as inputs the critical transients and probabilities of through-wall cracks from the IPTS Program. The model has been applied to predict the modes of failure for plant specific vessel characteristics. A Monte Carlo type of computer code has been written to predict the probabilities of alternate failure modes. This code treats the fracture mechanics properties of the various welds and plates of a vessel as random variables. The computer code also calculates the crack driving force as a function of the crack length and the internal pressure for critical times during the transient. The fracture mechanics model has been applied in calculations that simulate the Oconee-1 reactor pressure vessel. The model predicted that about 50% of the through-wall axial cracks will turn and follow a circumferential weld giving a potential for missiles. Missile arrest calculations predict that vertical as well as all potential horizontal missiles will be arrested and will be confined to the vessel enclosure cavity. In future work, plant specific analyses will be continued with calculations that simulate Calvert Cliff-1 and H.B. Robinson-2 reactor vessels.

Autökologische Studien an Moorpflanzen 1. Charakterisierung der wichtigsten Pflanzensippen oligotroph-saurer Moore auf Grund ihrer Kationengehalte

Summary 692 leave samples from mire plants (28 species, 9 families) were analyzed with regard to their contents in K, Ca, Mg, Mn and Fe to find out, if it is possible to characterize plant families by their cation-design according to the concepts of D uvigneaud & D enaeyer -D e Smet (1968, 1970) and H orak & K inzel (1971). The plant material used was earned in 4 collections, 2 in Sept. 1977 and 1978 to get values from the autumn-situation with the highest ion concentrations, one collection was done during investigations on a mirecomplex in the Limestone Alps in June 1979 and the fourth is from an investigation on the annual fluctuation of macronutrients in the genus Vaccinium from 1977–1979 (E der 1980). The first 2 collections were from 20 mire-sites situated all over Austria and each one site in Bavaria and Slovenia. Samples were taken too from mineral soil habitats in the neighbourhood of the mires and from Subalpine dwarf-shrub heaths in the Central Alps. This diversity of the sample localities should guarantee, that the results show really plant specific characteristics and not values depending on habitat conditions. For the interpretation of the results the BMDP5D-PROGRAM in the version of 1982, the univariate scatter plot was used showing diagrams with the distributions of the ions. This distributions were found to be characteristic for the following 5 family-groups: Coniferae , Ericaceae and Empetraceae , Cyperaceae , Poaceae and Scheuchzeriaceae , dicotyle herbs as a whole and mosses. Moreover, the results could also be used for interpretations in connection with the autecological behaviour of families, genera or single species, e.g. the role of Manganese in the distribution of Vaccinium myrtillus and Vaccinium uliginosum in the gradient mire expanse, mire margin, Lagg and!neighboured spruce forest.