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Currently, photovoltaic (PV) installations target a maximization of annual energy yield. However, as the grid penetration of PV is increasing, PV electricity generation will need to match better with local load profiles. Especially the seasonal variabilities remain challenging. While wind and PV tend to have complementary seasonal variability, wind turbine installation faces limitations especially in densely populated areas. In this paper, we discuss how this challenge may be addressed with climateand consumption-specific PV module technology. In particular, we demonstrate how the temperature coefficient of a PV system can impact the energy yield throughout the year. In colder climates, higher temperature coefficients allow for a better energy balance, favoring production in colder seasons without a significant reduction of yearly energy yield. Simulations for locations at high latitude, and colder climates, indicate that higher temperature coefficients and improved low-light behavior not only enable a higher energy yield in cold seasons, but also negligible losses in the overall yearly energy yield compared to lower temperature coefficients and slightly better low-light behavior. Simulations show that these results can be obtained using commercial PV modules. More broadly, they indicate how PV module technology may be optimized depending on the location and climate. (C) 2020 Elsevier Ltd. All rights reserved. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 751159. The work in this paper was partially funded by the Kuwait Foundation for the Advancement of Sciences under project number CN18-15 EE-01. Govaerts, J (corresponding author), IMEC, Kapeldreef 75, Leuven, Belgium. Jonathan.Govaerts@imec.be

© 2018 Elsevier Ltd PV module testing under standard conditions is an important and well-established procedure, which plays a vital role in module rating. However, PV modules rarely operate at standard conditions therefore their field performance should be predicted based on long term outdoor monitoring or by means of models – so called energy yield models, which combine PV module characteristics with varying environmental conditions. The present work employs a bottom-up, physics-based energy yield modelling approach, which accounts to the interacting optical, thermal and electrical mechanisms in a detailed manner. Additionally, measured data is used for the accurate calibration of the models. Such an approach permits to explore the influence of cell- and module technology details on energy yield under any specific environmental conditions. The present work employs such a method to evaluate the influence of Silicon solar cell technology on energy yield under desert and moderate climates, where the interplay of different irradiance and ambient temperature levels result in a challenging PV performance prediction problem. The purpose of this work is to identify the best-suited solar cell technologies and to understand the underlying mechanisms, which lead to superior PV performance under specific climate conditions. The study is performed by means of physics-based exploratory energy yield simulations with detailed resolution of the thermal effects. Our comparison of four different cell technologies in monofacial modules highlights that superior illumination-dependent performance can contribute to annual energy yield enhancement under both moderate and desert climates amounting to 1.75% and 0.4%, respectively; while a 0.04%/°C advantage in relative temperature coefficient increases annual energy yield (by 1.2%) only under a desert climate. ispartof: SOLAR ENERGY vol:173 pages:728-739 status: published

The phosphorus index (PI) is a field-scale assessment tool developed to identify fields most vulnerable to phosphorus (P) loss. The USDA Natural Resource Conservation Service (NRCS) recently revised its 590 Nutrient Management Standard and Title 190 National Instruction requiring that all NRCS-approved PI tools meet certain criteria. A recent study evaluating the Kentucky PI showed that it did not meet several of the criteria established by NRCS. This paper describes the development and evaluation of a revised PI for Kentucky in response to the revised 590 Standard. Important revisions to the Kentucky PI include (1) use of a component formulation, (2) incorporation of erosion and P application rates, (3) use of continuous variables, and (4) use of empirically based weighting factors. The revised Kentucky PI was evaluated against measured P loss data reported in the literature. Output from the revised PI was well correlated (Spearman9s ρ = 0.86; p

High-valent vanadium ions were substituted into the synthetic cryptomelane manganese oxide (K-OMS-2) framework through a simple and low-cost reflux method and investigated for total and preferential catalytic oxidation of carbon monoxide. Substitutional doping of V5+ resulted in materials with modified composition, morphology, thermal stability; and textural, redox, and catalytic properties. The catalytic activity increased with V concentration until an optimum amount (≈10 % V incorporated) was reached, beyond that a structural “crash point” was observed, resulting in a material with low crystallinity, nanosphere morphology, and reduced catalytic activity. An increase in O2 concentration in the feed gas resulted in an increase in conversion over 10% V K-OMS-2. This most active catalyst was deactivated by moisture only at low temperatures and showed better tolerance than undoped K-OMS-2. This catalyst also preferentially oxidized CO to CO2 from 25 °C to 120 °C in large amounts of H2 under dry conditions, without significantly affecting CO conversion. The doped catalyst also showed stable activity and selectivity in long-run experiments. The mobility and lability of surface oxygen, formation of hydroxyl groups, and enhanced surface redox properties promoted by V doping were strongly correlated with the enhancement of catalytic activities of K-OMS-2 nanomaterials.

The effects of visible and UV light on the characteristics and properties of Prudhoe Bay (PB) and South Louisiana (SL) emulsions were investigated to better understand the role of sunlight on the fate of spilled crude oils that form emulsions with a dispersant in the aquatic environment. Before irradiation, crude oil emulsions showed the presence of dispersed crude oil micelles in a continuous water phase and crude oil components floating on the surface. The crude oil micelles decreased in size with irradiation, but emulsions retained their high degree of polydispersity. UV irradiation reduced the stability of emulsions more effectively than visible light. The reduction of micelles size caused the viscosity of emulsions to increase and melting point to decrease. Further, irradiation increased acid concentrations and induced ion formation which lowered the pH and increased the conductivity of emulsions, respectively. Ni and Fe in PB emulsions were extracted from crude oil with UV irradiation, which may provide an efficient process for metal removal. The emulsions were stable toward freeze/thaw cycles and their melting temperatures generally decreased with irradiation. Evidence of ˙OH production existed when emulsions were exposed to UV but not to visible light. The presence of H(2)O(2) enhanced the photodegradation of crude oil. Overall, the changes in emulsion properties were attributed to direct photodegradation and photooxidation of crude oil components.

Mesoporous copper manganese oxides with high surface areas (>268 m 2 /g) were prepared using the redox method and tested in the preferential oxidation of CO. These materials were highly active and selective under typical operating conditions of a proton-exchange membrane fuel cell. The synthesized catalysts preferentially oxidized CO with a stoichiometric amount of oxygen in the feed gas. The presence of CO 2 and H 2 O in the feed gas retarded catalytic activity significantly at low ( 2 oxidation.

Those plastics that have been used by food industry as packaging (especially in sweet industry) have strict requirements. Most of these plastic constructions are primary or secondary packaging with direct or indirect contact with foodstuff. Over the appropriate mechanical properties, these packagings need to be safe enough to be used as direct contact material without any dangerous material migration or transfer. Recently the polyethylene-terephthalate (PET) is that material which is widely used for this kind of purpose and application. To substitute the PET, only that kind of alternative material which are fulfilling the requirements of applications and compliant to the relevant regulations can be applied.The cost-efficient application of plastics strongly depends on the mechanical properties of the material. In light of these facts, both types of polylactic-acid (PDLLA, PLLA) and the PET were tested. Comparing their mechanical properties PLA could be used as a real alternative of PET.

The tensile and fracture properties of cross-linked paper were investigated at low and high relative humidity by cross-linking the joints formed between fibers. Cationic acetal dextran served as a model cross-linking agent, as it can be prepared to adsorb specifically to the fiber surface. Thus, cross-linking occurs only in the joints between fibers. The kinetics of hydrolysis was investigated to optimize the stock preparation, such that the resulting aldehyde groups react as the paper is dried. The effect of the cross-link density on the tensile and fracture properties was studied by varying the amount of acetal groups adsorbed to the pulp fibers. At low humidity, cross-linking improved the tensile and fracture properties of paper, although lower cross-link densities yielded better properties. Cross-linking was not effective at high relative humidty, as the tensile strength and stiffness were not improved. However, the fracture properties were significantly improved.

The penetration of cationic polyelectrolytes into anionic cellulosic fibers was evaluated with fluorescent imaging techniques in order to clarify the mechanism and time scales for the diffusion process. The bulk charge of the cellulosic fibers indirectly creates a driving force for diffusion into the porous fiber wall, which is entropic in nature due to a release of counterions as the polyelectrolyte adsorbs. The individual bulk charges in the fiber cell wall also interact with the diffusing polyelectrolyte, such that the polyelectrolyte diffuses to the first available charge and consequently adsorbs and remains fixed. Thus, subsequent polyelectrolyte chains must first diffuse through the adsorbed polyelectrolyte layer before adsorbing to the next available bulk charges. This behavior differs from earlier suggested diffusion mechanisms, by which polyelectrolytes were assumed to first adsorb to the outermost surface and then reptate into the pore structure. The time scales for polyelectrolyte diffusion were highly dependent on the flexibility of the chain, which was estimated from calculations of the persistence length. The persistence length ultimately depended on the charge density and electrolyte concentration. The charge density of the polyelectrolyte had a greater influence on the time scales for diffusion. High charge density polyelectrolytes were observed to diffuse on a time scale of months, whereas the diffusion of low charge density polyelectrolytes was measured on the order of hours. An influence of the chain length, that is, steric interactions due the persistence length of the polyelectrolyte and to the tortuosity of the porous structure of the fiber wall, could only be noted for low charge density polyelectrolytes. Increasing the electrolyte concentration increased the chain flexibility by screening the electrostatic contribution to the persistence length, in turn inducing a faster diffusion process. However, a significant change in the diffusion behavior was observed at high electrolyte concentrations, at which the interaction between the polyelectrolyte charges and the fiber charges was almost completely screened.

The adsorption behavior of a low charge density cationic polyelectrolyte to cellulosic fibers has been studied. Cationic dextran served as a model polyelectrolyte, as it can be prepared over a range in molecular mass and charge density. The adsorption behavior of the cationic dextran was measured in electrolyte-free conditions using polyelectrolyte titration techniques. By fluorescent labeling the cationic dextran, the extent to which adsorption occurs inside the porous structure was further determined by fluorescent confocal laser scanning microscopy. Cationic dextran having a sufficiently low charge density adsorbed into the pores, although the extent the cationic dextran adsorbed was governed by the molecular mass. The adsorption behavior of the cationic dextran was also studied in various electrolyte concentrations. The adsorbed mass monotonically decreased with increasing electrolyte, as the electrostatic interaction with the substrate was more effectively screened. This behavior also suggests that the interactions between adsorbed polyelectrolyte chains, i.e. lateral correlation effects, are negligible for low charge density polyelectrolytes. Finally, the effect of having a preadsorbed layer of cationic dextran on the adsorption behavior was determined in electrolyte-free conditions using fluorescent double staining techniques. The preadsorbed cationic dextran had almost no effect on the adsorption of low molecular mass fractions. Low molecular mass fractions directly adsorbed into the pore structure, as opposed to adsorbing to a free surface and diffusing into the pores. It was also shown that cationic dextran can be selectively adsorbed to different locations, such that the surface of a porous substrate can be treated uniquely from the bulk.

Cationic polyallylamine (PAH) and cationic starch were adsorbed to unbleached softwood kraft pulp fibres in order to study the effect of these additives on the creep properties of the resulting pap ...

Due to the excellent catalytic performance of manganese oxide (K-OMS-2) in a wide range of applications, incorporation of various dopants has been commonly applied for K-OMS-2 to acquire additional functionality or activities. However, the understanding of its substitution mechanism with respect to the catalytic performance of doped K-OMS-2 materials remains unclear. Here we present the structural distortion (from tetragonal to monoclinic cell) and morphological evolution in K-OMS-2 materials by doping hexavalent molybdenum. With a Mo-to-Mn ratio of 1:20 (R-1:20) in the preparation, the resultant monoclinic K-OMS-2 shows a small equidimensional particle size (∼15 nm), a high surface area of 213 m(2) g(-1), and greatly improved catalytic activity toward CO oxidation with lower onset temperatures (40 °C) than that of pristine K-OMS-2 (above 130 °C). HR-TEM analyses reveal direct evidence of structural distortion on the cross-section of 2 × 2 tunnels with the absence of 4-fold rotation symmetry expected for a tetragonal cell, which are indexed using a monoclinic cell. Our results suggest that substitution of Mo(6+) for Mn(3+) (rather than Mn(4+)) coupled with the vacancy generation results in a distorted structure and unique morphology. The weakened Mn-O bonds and Mn vacancies associated with the structural distortion may be mainly responsible for the enhanced catalytic activity of monoclinic K-OMS-2 instead of dopant species.

[1-14C]N-methylneodecanamide (MNDA), a potent insect-repellent, was synthesized from [1-12C]neodecanoic acid (NDA) by an exchange variant of the Koch reaction, followed by conversion to the acyl halide and methylamination. The product had all the characteristics of authentic commercial MNDA, and the radiocarbon was distributed among the isomers in the same proportions as the isomers were among the mass. Copyright © 2000 John Wiley & Sons, Ltd.

Suspensions of iron particles in media with yield stresses were investigated to determine the effect of the continuous phase yield stress on the magnetorheological (MR) response. The steady-shear MR response was independent of the continuous phase yield stress for yield stresses in the range 0.9–37 Pa. The field-induced suspension yield stress increased sub-quadratically with the flux density. The small amplitude oscillatory shear response exhibited history dependence. The storage modulus depended not only on the magnitude of the applied magnetic field, but also on its history. This history dependence can be explained in terms of the field-dependent evolution of the suspension microstructure.

Introduction by the column editor Any health care system that provides care to individuals in the context of a budget for a population must establish priorities for allocating resources. Establishing priorities is ultimately a process of questioning our values; it is, in other words, a process of ethics. A severe weakness of the U.S. market-based system is that to date it lacks any guiding ethical vision (1). In this column, Robert Rosenheck, M.D., and his colleagues report on an important effort by the Department of Veterans Affairs to articulate an ethical vision for a VA resource allocation policy. Future columns will present other efforts in the managed care arena to make ethical considerations an active force in shaping policy and practice.

Cet article s'interesse a la reconstruction des reseaux sociaux reliant les pionners de l'informatique domestique afin d'identifier les representations sociales et politiques ainsi que les images qu'ils se sont faites de ces reseaux sociaux. A partir d'interviews realisees aupres de personnes cles, et orientees par la theorie du reseau social, les AA. decrivent le lien entre le developpement technique et les representations culturelles, particulierement celles de l'utilisateur, dans le cas des ordinateurs personnels. L'ordinateur personnel, dans cette perspective, peut etre vu a la fois comme une machine et comme une culture, permettant ainsi d'analyser la maniere dont notre activite, en tant qu'utilisateurs d'ordinateurs aujourd'hui, a ete construite socialement. L'etude est centree sur deux institutions majeures qui ont joue un role important dans le developpement des reseaux pour l'ordinateur personnel, le Standford Research Institute (SRI) et le Xerox Palo Alto Research Center (PARC) dans les annees 1970 afin de transposer les idees de ces deux centres de recherche sur les progres realises par les AA. dans la reconstruction de ces reseaux et les representations qu'ils contenaient

Guidelines are presented for treating the patient with both addictive behavior (AB) and mental disorder (MD) who refuses referral to specialized AB treatment. These guidelines are based on a cognitive-behavioral therapy (CBT) model of AB. The CBT model avoids conflicts associated with providing a psychological treatment for MD and a disease model treatment for AB. Many CBT AB interventions can be provided by a psychotherapist who does not specialize in AB. These interventions may be sufficient treatment, or may motivate the patient to obtain specialized AB treatment.

The authors present the case of a male patient misdiagnosed with right upper lobe tuberculosis and repeatedly treated for this in the last two years, without response. In our institution, the source of the hemoptysis proved to be a pulmonary carcinoma, which in its evolution involved the carina and the last tracheal ring. Right carenal pneumonectomy with two tracheal ring resection is performed, with reconstruction of the airway by anastomosing the main left bronchus to trachea. The resection involved also the azygos vein and the lateral wall of the superior vena cava (angioplastic resection), the vagus nerve and the pericardium, the last are being reconstructed with synthetic mesh. Histopatologic diagnosis is squamous cell carcinoma moderately differentiated. The right tracheal sleeve pneumonectomy was the therapeutically choice for a middle-aged patient with recurrent hemoptysis and retrostenotic lung destruction.

The adsorption behavior of highly charged cationic polyelectrolytes onto porous substrates is electrostatic in nature and has been shown to be highly dependent on the polyelectrolyte properties. Copolymers of acrylamide (AM) and diallyldimethylammonium chloride (DADMAC) were synthesized to have a range of macromolecular properties (i.e., charge density and molecular mass). Traditional titration methods have been complemented by fluorescence labeling techniques that were developed to directly observe the extent that fluorescently labeled poly(AM- co-DADMAC) adsorbs into the pore structure of a cellulosic substrate. Although contributing to the electrostatic driving force, the charge density acts to limit adsorption to the outermost surface under electrolyte-free conditions. However, adsorption into the pores can occur if both the molecular mass and charge density of poly(AM- co-DADMAC) are sufficiently low. Adsorption initially increases as the electrolyte concentration is increased. However, the electrostatic persistence length of poly(AM- co-DADMAC) restricts the polyelectrolyte from entering the pores. Therefore, changes in the adsorption behavior at moderate electrolyte concentrations have been attributed to swelling of the polyelectrolyte layer at the fiber exterior. The adsorption behavior changes again at high electrolyte concentrations such that poly(AM- co-DADMAC) could adsorb into the pore structure. This occurred when the electrolyte concentration was sufficient to screen the electrostatic persistence length of poly(AM- co-DADMAC), provided that the entropic driving force for adsorption still existed. It is suggested that adsorption into the pore structure is a kinetic process that is governed by localized electrostatic interactions between poly(AM- co-DADMAC) and the charges located within the pores.

We analyze challenges in the current approaches to digital video surveillance solutions, both technically and financially. We propose a Cell Processor based digital video surveillance platform to overcome those challenges and address ever growing needs in enterprise class surveillance solutions capable of addressing multiple thousands camera installations. To improve the compression efficiency we have chosen H.264 video compression algorithm which outperforms all standard video compression schemes as of today.

Given the present operational tempo of the Marine Corps, it is important to get the most out of all of its assets. The Marine Corps Recruiting Command's (MCRC) current operating practice has proven inefficient, as demonstrated by the recruiter shortfall. MCRC has begun to increase the number of recruiters on the streets and has taken steps to maintain a clear personnel picture to accurately place recruiters where they are needed most. With additional tweaks, such as placing recruiters on production the month after PAR training and not allowing Marines to go back on leave immediately after checking in, MCRC can lessen the need for additional Marines from the fleet and allow those Marines to continue serving of the front lines in the war against terrorism.

The human immunodeficiency virus-1 (HIV-1) preferentially infects CD4+ cells, leading to their destruction. In contrast to other viral infections, the immune system is unable to keep the HIV infection under permanent control in most cases. This failure ultimatively results in immunodeficiency with occurrence of AIDS-defining diseases. In recent years, highly active antiretroviral therapy (HAART) has become available, and the number of AIDS cases and deaths have decreased dramatically. However, limitations of HAART become more apparent, demanding greater emphasis on search for alternative approaches. Stimulation and modulation of the immune response to HIV are new and promising strategies. A prerequisite, however, is the knowledge about immunologic defense mechanisms against HIV. In this article, the major factors of innate and acquired immune responses to HIV are described.