bluuebunny/crossref_metadata_2025_split huggingface dataset:
Critical issues in the design of polycrystalline, thin‐film tandem solar cells
Authors: Coutts Timothy J. , Ward J. Scott , Young David L. , Emery Keith A. , Gessert Timothy A. , Noufi Rommel 
Published: September 2003

AbstractWe use an empirical technique for modeling the efficiency of thin‐film tandem solar cells and calculate an approximate upper limit on the range of performance of these hypothetical devices. This is shown to be approximately 28.2%, without losses due to inactive layers at the front of the device, or other parasitic sources. Reduction of the value of the reverse saturation current density by a factor of ten, increases the lossless efficiency by approximately 4% absolute. This change also greatly broadens the range of top and bottom cell bandgaps that would lead to efficiencies greater than 25%, the project goal. These observations emphasize the critical importance of focusing future research on gaining a thorough understanding of recombination losses.We then calculate daily energy density outputs for various direct spectra, computed from meteorological data, and show that the optimum bandgap pairs are relatively insensitive to the detail of the spectral irradiance. We also show that the use of daily energy density output may be a more useful criterion than efficiency in designing tandem thin‐film solar cells. We compute contours of equal daily energy density output and show that the range of potentially suitable bandgap pairs is much larger than simple maximization of efficiency implies.The simple parametric approach enables us to investigate the effect of partial loss of photons with energies less than that of the bandgap of the top cell, but greater than that of the bottom cell. These photons are essential to the project goal of 25% efficiency, which emphasizes the need to evaluate the optical properties in this wavelength range very carefully. We also discuss the reduction of the thickness, or the area, of the top cell. When the top subcell generates a greater current than the bottom subcell, either of these parameters may be reduced to enable current‐matching, and increased efficiencies, to be achieved. Again, this approach greatly extends the range of bandgaps that could lead to a 25% tandem thin‐film cell.Next, we consider the case of concentrated sunlight and show that the optimum bandgap pairs decrease with concentration ratio. This is due to the atmospheric absorption bands. The efficiency increases by approximately 4% absolute per decade increase in concentration ratio.Finally, we comment on some of the practical difficulties that can already be anticipated in constructing these devices. Published in 2003 by John Wiley & Sons, Ltd.
Corrosion effects in thin‐film photovoltaic modules
Authors: Carlson D. E. , Romero R. , Willing F. , Meakin D. , Gonzalez L. , Murphy R. , Moutinho H. R. , Al‐Jassim M. 
Published: September 2003

AbstractElectrochemical corrosion effects can occur in thin‐film photovoltaic (PV) modules that are fabricated on tin‐oxide‐coated glass when operating at high voltages and at elevated temperatures in a humid climate. The current study shows that this corrosion is associated with a delamination of the tin oxide layer from the glass, which is caused by sodium accumulation near the interface between the tin oxide and the glass and by the ingression of moisture into the PV module from the edges. This corrosion in thin‐film PV modules can be significantly reduced by altering the growth conditions of the tin oxide or by using zinc oxide as a transparent conductive oxide electrode. Copyright © 2003 John Wiley & Sons, Ltd.
Characterization of optical collectors for concentration photovoltaic applications
Authors: Antón I. , Pachón D. , Sala G. 
Published: September 2003

AbstractThe design and characterization of the collector of a photovoltaic concentrator system is commonly carried out for a given receiver, the optical parameters of the collector being linked to it. This paper, which has substantial tutorial content, deals with the characterization of collectors for concentrator photovoltaic systems, independently of any receiver, and providing the necessary parameters for the design of a system. This strategy allows the parameters related to the collector and the receiver, which are usually manufactured by different industries, to be totally separated. It also allows the optical collectors coming from non‐photovoltaic industries to be evaluated. The information that the mirror and lens manufacturers should provide for a photovoltaic concentrator application can be summarized under three characteristics: overall optical efficiency; light distribution; and acceptance angle. Theory, equipment, and procedures to carry out the optical characterization of the collectors are explained. Copyright © 2003 John Wiley & Sons, Ltd.
International harmonization of grid connection guidelines: adequate requirements for the prevention of unintentional islanding
Authors: Woyte Achim , De Brabandere Karel , Van Dommelen Daniel , Belmans Ronnie , Nijs Johan 
Published: September 2003

AbstractIslanding is still one of the major controversial subjects in the international harmonization of grid connection requirements for distributed generation, and particularly photovoltaics. As long as islanding is not intended in order to back up a loss of mains, it should be avoided. The present study reviews the theory of unintentional islanding and assesses the probability of occurrence of the phenomenon, based on previous studies and theoretical considerations. While islanding is virtually impossible if only a small number of distributed generation units is connected to a distribution grid, with higher distributed generation densities, the possibility of islanding becomes realistic. The risk associated with unintentional islanding is estimated, and adequate requirements for functional safety of protection devices are determined in order to ensure the necessary additional degree of safety to be introduced by an islanding prevention device. Finally, a fundamental set of requirements with regard to islanding, to be included in an international grid connection guideline, is derived from the study. Copyright © 2003 John Wiley & Sons, Ltd.
The Devensian periglacial record on Thanet, Kent, UK
Authors: Murton J. B. , Bateman M. D. , Baker C. A. , Knox R. , Whiteman C. A. 
Published: September 2003

AbstractThe Devensian periglacial record on Thanet, Kent, is traced from c. 88 to 74 ka and from c. 24 to 12 ka by optical luminescence dating of aeolian sand and silt in the periglacial stratigraphy. The record commences before 88 ka with valley cutting at Pegwell Bay. Valley filling had begun by c. 88 ka and continued to at least 74 ka, coinciding with a major episode of loess deposition in Europe. Permafrost aggradation commenced before c. 21 ka, brecciating near‐surface chalk by ice segregation in permafrost and the overlying active layer. Deposition of aeolian sand (coversand) occurred at c. 24–21 ka, correlating with the Older Coversand I in mainland Europe. Permafrost degradation commenced at c. 21 ka, probably due to climate warming during Greenland Interstadial 2. The resulting active‐layer deepening through ice‐rich permafrost initiated soft‐sediment deformation and formation of large‐scale patterned ground in an active layer c. 2 m deep. Renewed permafrost aggradation between c. 21.25 and 18 ka coincided with climate cooling during Greenland Stadial 2c and led to cryoturbation in a thinner active layer. Final permafrost degradation commenced no later than c. 14.7 ka, that is, the start of Greenland Interstadial 1e, and may have occurred to some extent during the climate warming associated with Greenland Stadial 2b (c. 19.5–16.9 ka). Renewed deposition of aeolian sand took place at c. 15.5 ka, coincident with loess deposition on Thanet. A final episode of aeolian sand deposition occurred at 12 ka, correlating with the Younger Coversand deposits that are widespread in northwest Europe and formed during Greenland Stadial 1. Copyright © 2003 John Wiley & Sons, Ltd.
The rock glaciers on Prins Karls Forland: corrections of surface displacement rates
Authors: Berthling Ivar , Etzelmüller Bernd , Eiken Trond , Sollid Johan Ludvig 
Published: September 2003

AbstractThe results from new global positioning system (GPS) surveys in 1998 and 2000 show, that errors exist in the results from terrestrial surveys in 1996. The published displacement values of Berthling et al. (1998) are too large. This note corrects these displacement values. Copyright © 2003 John Wiley & Sons, Ltd.
Massive ground ice body of glacial origin at Yugorski Peninsula, arctic Russia
Authors: Ingólfsson Ólafur , Lokrantz Hanna 
Published: September 2003

AbstractA massive ground ice body at Cape Shpindler on Yugorski Peninsula, southern Kara Sea coast, Russia, was studied with regard to large‐scale internal structures, its stratigraphic context and contacts to surrounding sediments, in order to highlight its origin. The massive ground ice contains deformation structures and deformed sediment rafts that show a consistent direction of deforming force. It is bounded upwards with a sharp and unconformable thaw contact to overlying till. The stratigraphical and structural evidence suggests that the massive ground ice body is relict glacier ice. Examination of data from a separate study on ice crystallography and isotopic composition of the massive ice body does not contradict this conclusion. The isotope composition and profiles conform with what can be expected for deformed basal ice. The chronology for the Shpindler Cape sequence implies that the glacier ice might be older than 250 ka years. Consequently, permafrost has preserved the relict glacier ice for the duration of at least two interglacials (Eemian and Holocene), as well as several Saalian and Weichselian interstadials, illustrating the preservation potential of the permafrost. Copyright © 2003 John Wiley & Sons, Ltd.
Evidence for late‐Pleistocene permafrost in the New Jersey Pine Barrens (latitude 39°N), eastern USA
Authors: French Hugh M. , Demitroff Mark , Forman Steve L. 
Published: September 2003

AbstractRelict sand wedges, up to 2.5 m deep and 0.4 m wide, are present in the Pine Barrens of southern New Jersey. They indicate the previous existence of permafrost. The wedges are composed predominantly of sand that shows evidence of wind transport and abrasion. Optically‐stimulated‐luminescence dating of infill material indicates that thermal‐contraction‐cracking and emplacement of the sand infill must have occurred during two separate periods during the Late Pleistocene. The most recent was in Late Wisconsinan times,∼15–18 ka. An earlier period of permafrost conditions is indicated by dates >55–65 ka. On both occasions, the Late‐Pleistocene ice sheets would have advanced as far south as northern New Jersey and strong winds would have occurred in the lower mid‐latitudes. The sandy soils of the Pine Barrens would have allowed the ice‐marginal periglacial zone to extend southwards into southern New Jersey. The sparse tundra vegetation on the sandy substrate, with its relatively high thermal conductivity, would have permitted deep frost penetration because the ‘thermal offset’ would have been minimized. A mean annual air temperature of between −3.0°C and −4.0°C is inferred. Permafrost was probably discontinuous and less than 10–15 m in thickness. Episodes of permafrost thaw are indicated by the widespread occurrence of deformed sediments (‘thermokarst involutions’) and by various small‐scale non‐diastrophic structures associated with bog ironstone beds. The presence of soil (ground) wedges in southern New Jersey and adjacent Delaware also suggest conditions of deep seasonal frost, probably when the most recent permafrost degraded. Copyright © 2003 John Wiley & Sons, Ltd.
Prediction of formation temperatures in permafrost regions from temperature logs in deep wells—field cases
Authors: Kutasov I. M. , Eppelbaum L. V. 
Published: September 2003

AbstractImportant data on the thermal regime of the Earth's interior come from temperature measurements in deep boreholes. Drilling greatly alters the temperature field of earth materials surrounding the wellbore. In permafrost regions, due to thawing of adjacent strata during drilling, representative data can be obtained only by repeated observations over a long period of time. In this paper we predict undisturbed formation temperatures (and geothermal gradients) from shut‐in temperature logs in deep wells. The main features of the method are: (1) in the permafrost section of the well, the starting point in the well thermal recovery is moved from the end of well completion to the moment of time when the refreezing of enclosing strata was completed; it takes into account the refreezing of thawed material in a temperature interval; and (2) below the permafrost base, the starting point in the well thermal recovery is moved from the end of well completion to the moment of time when the first shut‐in temperature log was taken. A generalized formula to process field data (for the well sections below and above the permafrost base) is presented. Temperature logs conducted in five wells verify the method. Copyright © 2003 John Wiley & Sons, Ltd.
Ground ice and soluble cations in near‐surface permafrost, Inuvik, Northwest Territories, Canada
Authors: Kokelj S. V. , Burn C. R. 
Published: September 2003

AbstractThe distribution of segregated ice and soluble ions in near‐surface permafrost were investigated in hummocky terrain near Inuvik, Northwest Territories. Soil water content profiles from analyses of drill cores indicate that ice‐poor permafrost developed beneath a permafrost table aggrading at approximately 4 cm/a, but an ice‐rich zone, 10 to 20 cm thick, was observed beneath a permafrost table that had remained stable for about a decade. Ice‐rich intervals 10 to 30 cm thick were observed immediately beneath both a thaw unconformity formed in 1981 and an older, deeper unconformity. In profile, the correspondence between zones of cation and ice enrichment suggests soluble materials were incorporated into permafrost during development of near‐surface aggradational ice. Moisture enrichment below an experimentally degrading permafrost table was negligible. Similar ice contents beneath the present permafrost table and the deep thaw unconformity, and the preservation of ice‐poor intervals immediately above the 1981 and deep thaw unconformities indicate limited vertical ice enrichment. The estimated rates of ice accumulation in two‐decade‐old permafrost are on the order of mm/a, but ice accumulation above older unconformities indicates that, in aggregate, these initial rates decrease with time. The ground ice and soluble cations sequestered in near‐surface permafrost comprise an important pool of water and nutrients that may be released into the active layer during periods of deeper thaw. Copyright © 2003 John Wiley & Sons, Ltd.
Capacity of model biobeds to retain and degrade mecoprop and isoproturon
Authors: Henriksen Vibeke V , Helweg Arne , Spliid Niels Henrik , Felding Gitte , Stenvang Lars 
Published: September 2003

AbstractBiobeds are used to increase the adsorption and degradation of pesticide spillage on sites used for mixing and loading and for cleaning of sprayers. The adsorption and the rate of degradation of 14C‐labelled isoproturon and mecoprop (MCPP) at concentrations from 0.0005 to 25 000 mg kg−1 were determined in biobed soil. Further leaching of the two herbicides was determined in a model biobed with a surface area of 2 m2. The biobed material showed enhanced ability to adsorb the two herbicides. Kd was 5.2 litre kg−1 for isoproturon and 1.6 litre kg−1 for MCPP in biobed material, which is higher than in natural soil. In different experiments with natural soil, Kd ranges from 0.07 to 0.6 litre kg−1 for MCPP and from 1.5 to 4.6 litre kg−1 for isoproturon in soils with varying organic carbon content. Degradation of MCPP was rapid at concentrations from 0.0005 to 500 mg kg−1, delayed at 5000 mg kg−1, and very slow at 25 000 mg kg−1. For isoproturon, the relative degradation was most rapid at the lowest concentration and decreasing with increasing concentrations. After 120 days, between 55% and 8% 14C was evolved as 14CO2 at concentrations between 0.0005 and 25 000 mg kg−1. The rate of evolution of 14CO2 indicated that degradation rates at low concentrations were of first‐order and at higher concentrations of zero‐order. Leaching of MCPP and isoproturon was determined in a newly established model biobed during a 2‐year period. About 13% of applied MCPP and 1.4% of applied isoproturon leached out during the winter following the first autumn application (worst‐case scenario). Leaching was completely prevented when the biobed had a well‐developed grass cover and was covered during the winter. Copyright © 2003 Society of Chemical Industry
Effects of fludioxonil and pyrimethanil, two fungicides used against Botrytis cinerea, on carbohydrate physiology in Vitis vinifera L
Authors: Saladin Gaëlle , Magné Christian , Clément Christophe 
Published: September 2003

AbstractIn Vitis vinifera L, photosynthesis and photosynthate partitioning are affected in the presence of fludioxonil and pyrimethanil, two fungicides commonly used in vineyards against Botrytis cinerea Pers. However, the effects were found to be different according to the model studied: plantlets (cv Chardonnay) grown in vitro, fruiting cuttings (cv Chardonnay) and plants grown in vineyards (cvs Chardonnay, Pinot noir and Pinot Meunier). In the plantlets grown in vitro, both fungicides decreased gas exchanges, photosynthetic pigment and starch concentrations in the leaves, whereas soluble carbohydrates transiently accumulated, suggesting that plantlets mobilised starch in response to photosynthesis inhibition caused by fungicides. In the fruiting cuttings, the fungicides did not affect photosynthesis, although fludioxonil caused starch decrease in parallel with sucrose accumulation, suggesting that the fungicide effects were of lower intensity than in vitro. Conversely, in vineyard, the two fungicides stimulated photosynthesis and increased pigment concentrations in the three vine cultivars tested. In the meantime, glucose, fructose and starch levels of the leaves declined after fungicide exposure, whereas sucrose accumulated, indicating that sucrose synthesis increased in the leaves following the fungicide treatment. Among the three varieties, Chardonnay was the most sensitive to the fungicides as revealed by the intensity of the responses and the longer period for recovery. In vineyard, the results suggested that the two fungicides, in addition to inhibiting B cinerea development, had a beneficial effect on vine physiology through the stimulation of leaf carbon nutrition, which may further enable the plant to rapidly make use of its defence reactions. Copyright © 2003 Society of Chemical Industry
Insecticidal activity and nicotinic acetylcholine receptor binding of dinotefuran and its analogues in the housefly, Musca domestica
Authors: Kiriyama Kazuhisa , Nishiwaki Hisashi , Nakagawa Yoshiaki , Nishimura Keiichiro 
Published: September 2003

AbstractThe insecticidal activity of dinotefuran and 23 related compounds against the housefly, Musca domestica (L) was measured by injection with metabolic inhibitors. Dinotefuran was less active than imidacloprid and clothianidin by a factor of 10 in molar concentrations. Their binding activities to the fly‐head membrane preparation were measured by using [125I]α‐bungarotoxin ([125I]α‐BGTX) and [3H]imidacloprid ([3H]IMI) as radioligands. The activity of some selected compounds measured with [3H]IMI was 104‐fold higher than that measured with [125I]α‐BGTX. With [3H]IMI as a radioligand, dinotefuran was 13‐fold less active than imidacloprid. The inhibitory effect of dinotefuran on the binding of [3H]IMI to the membrane preparation was in a competitive manner. Quantitative analysis of the insecticidal activity of the test compounds with the binding activity measured with [3H]IMI showed that the higher the binding activity, the higher was the insecticidal activity. Copyright © 2003 Society of Chemical Industry
Inhibitors of 3‐hydroxy‐3‐methylglutaryl‐CoA reductase lower fecundity in the German cockroach: correlation between the effects on fecundity in vivo with the inhibition of enzymatic activity in embryo cells
Authors: Zapata Rafael , Piulachs Maria‐Dolors , Bellés Xavier 
Published: September 2003

AbstractThe enzyme 3‐hydroxy‐3‐methylglutaryl‐CoA (HMG‐CoA) reductase is crucial to insect development and reproduction, as revealed by the sterilising properties of some specific inhibitors of it. In the present paper, we study the sterilising effects of a number of HMG‐CoA reductase inhibitors on the German cockroach, Blattella germanica (L). The inhibitors tested were naringenin, lovastatin, mevastatin, simvastatin, atorvastatin and fluvastatin. The first two compounds were ineffective or scarcely effective as HMG‐CoA reductase inhibitors. The most active compounds in vivo were fluvastatin and atorvastatin, followed by simvastatin and mevastatin. They were equally ranked when tested as HMG‐CoA reductase inhibitors in the B germanica embryonic derived cell line UM‐BGE‐1. This suggests that this cell line may be an appropriate tool for testing HMG‐CoA reductase inhibitors and so to predict their properties as insect sterilising agents with insecticide potential. Copyright © 2003 Society of Chemical Industry
Rapid mineralisation of the herbicide isoproturon in soil from a previously treated Danish agricultural field
Authors: Sørensen Sebastian R , Aamand Jens 
Published: September 2003

AbstractMineralisation of the phenylurea herbicide isoproturon (3‐(4‐isopropylphenyl)‐1,1‐dimethylurea) and two of its known metabolites, 3‐(4‐isopropylphenyl)‐1‐methylurea (monodesmethyl‐isoproturon) and 4‐isopropylaniline, was studied in Danish agricultural soils with or without previous exposure to isoproturon. A potential for rapid mineralisation of isoproturon and the two metabolites was present in soils sampled from three plots within an agricultural field previously treated regularly with the herbicide, with 34–45%, 51–58% and 33–36% of the added [phenyl‐U‐14C]isoproturon, [phenyl‐U‐14C]monodesmethyl‐isoproturon and [phenyl‐U‐14C]4‐isopropylaniline metabolised to [14C]carbon dioxide within 30 days at 20 °C. In contrast, such extensive mineralisation of these three compounds was not observed within this period in soils sampled from two other agricultural fields without previous treatment with isoproturon. The mineralisation patterns indicated growth‐linked metabolism of the three compounds in the previously exposed soils, and doubling times for [14C]carbon dioxide production ranged from 1.6 to 3.2, 1.0 to 2.1 and 1.3 to 1.7 days for isoproturon, monodesmethyl‐isoproturon and 4‐isopropylaniline, respectively. The ability to mineralise [phenyl‐U‐14C]isoproturon to [14C]carbon dioxide was successfully sub‐cultured to a fresh mineral medium which provided isoproturon as sole source of carbon and nitrogen. One of the soils sampled from an agricultural field not previously treated with isoproturon showed accelerated mineralisation of [phenyl‐U‐14C]4‐isopropylaniline toward the end of the experiment, with a doubling time for [14C]carbon dioxide production of 7.4 days. This study indicates that the occurrence of rapid mineralisation of the phenyl ring of isoproturon to carbon dioxide is related to previous exposure to the herbicide, which suggests that microbial adaptation upon repeated isoproturon use may occur within agricultural fields. Copyright © 2003 Society of Chemical Industry