bluuebunny/crossref_metadata_2025_split huggingface dataset:
Façade–integrated photovoltaics: a life cycle and performance assessment case study
Authors: Perez Marc J. R. , Fthenakis Vasilis , Kim Hyung‐Chul , Pereira Anthony O. 
Published: January 2012

ABSTRACTThe Solaire Building has the first façade building‐integrated photovoltaic (BIPV) array in New York City. This paper presents the life cycle impacts of the Solaire BIPV and extrapolates its performance to other façade systems. Engineering diagrams, detailed material inventories and 5 years of irradiation and actual performance data in 15‐min intervals offer insights into current BIPV construction and performance. The Solaire BIPV employs waste‐stream monocrystalline silicon wafers. Correspondingly, zero energy input was allocated to this BIPV from wafer production, resulting to a very low energy payback time (EPBT) and global warming potential burden (0.8 years and −10.2 g CO2/kWh, respectively). A negative EPBT results from subtracting the impact of the thermally and structurally equivalent concrete and brick wall that the BIPV array replaced. Data from current photovoltaic‐dedicated Si wafer supply were also used; these resulted with an EPBT of 3.8 years and a global warming potential of 61 g CO2/kWh. The performance ratio and EPBT of the Solaire system were compared with those in the International Energy Agency Photovoltaic Power Systems Task 2 inventory database. The drawback of façade BIPV is its vertical orientation, receiving lower incident irradiation than rooftop and ground installations. Nevertheless, BIPV offers two main advantages over such installations: it does not require any ‘virgin’ land for its operation, and it replaces structural units, thus avoiding the cost, embodied energy and corresponding emissions related to those. We detail herein how the replacement of traditional cladding materials can offset the performance drawback of BIPV, in terms of environmental burden and EPBT. Copyright © 2012 John Wiley & Sons, Ltd.
Broadband scattering of the solar spectrum by spherical metal nanoparticles
Authors: Temple Tristan L. , Bagnall Darren M. 
Published: January 2012

ABSTRACTMetal nanoparticles offer the possibility of improved light trapping in solar cells, but careful design is required to maximise scattering and minimise parasitic absorption across the wavelength range of interest. We present an analysis of the broadband scattering and absorption characteristics of spherical metal nanoparticles, optimized for either crystalline silicon (c‐Si) or amorphous silicon (a‐Si:H) solar cells. A random two‐dimensional array of optimally sized Ag spheres can scatter over 97% of the AM1.5 spectrum from 400 to 1100 nm. Larger particles are required for c‐Si devices than a‐Si:H due to the increased spectral range, with optimum particle sizes ranging from 60 nm for a‐Si:H to 116 nm for c‐Si. Positioning the particles at the rear of the solar cell decreases absorption losses because these principally occur at short wavelengths. Increasing the refractive index of the surrounding medium beyond the optimum value, which is 1.0 for a‐Si:H and 1.6 for c‐Si, shifts absorption to longer wavelengths and decreases scattering at short wavelengths. Ag nanoparticles scatter more of the solar spectrum than Au, Cu or Al nanoparticles. Of these other metals, Al can only be considered for a‐Si:H applications due to high absorption in the near‐infrared, whereas Au and Cu can only be considered for the rear of c‐Si devices due to high absorption in the ultraviolet (UV) and visible. In general, we demonstrate the importance of considering the broadband optical properties of metal nanoparticles for photovoltaic applications. Copyright © 2012 John Wiley & Sons, Ltd.
Promotion and support of physical activity among cancer survivors: a service provider perspective
Authors: Robertson Lindsay , Richards Rosalina , Egan Richard , Szymlek‐Gay Ewa A. 
Published: January 2012

AbstractObjectiveCancer survivors are a population group at higher risk of a number of adverse health outcomes. Physical activity during and post‐treatment is beneficial, yet participation in physical activity tends to be low amongst cancer survivors. There is still much to be learnt about how service providers can successfully translate research evidence about the benefits of physical activity for cancer survivors into effective and widely available interventions to support physical activity participation. The aim of this qualitative study is to describe some of the current approaches used by the Cancer Society of New Zealand (CSNZ) to supporting physical activity among survivors and the opportunities and challenges associated with this.MethodsParticipants were Supportive Care Managers and representatives of the CSNZ. A generic qualitative approach included semi‐structured interviews, transcription, member checking and analysis via thematic coding by two of the research team.ResultsFour major themes frame the discussion of the results: (i) existing physical activity programmes and resources for cancer survivors; (ii) gaps and needs in the provision of physical activity programmes for cancer survivors; (iii) barriers, facilitators and preferences in relation to physical activity participation; and (iv) considerations for service providers involved in developing physical activity programmes for cancer survivors.ConclusionsThe implications for future research and for service provision of physical activity programmes for cancer survivors are discussed. Potential strategies to increase physical activity participation among cancer survivors are put forward. Copyright © 2012 John Wiley & Sons, Ltd.
Validity of Measuring the Sit to Walk Movement with an Inertial Sensor
Authors: Kerr A. , Rafferty D. , Dall P. , Muhaidat J. 
Published: January 2012

AbstractBackgroundMoving from sitting to walking (STW) is a functional movement that is sufficiently demanding to reveal early mobility problems that may be masked in other tests (Kerr et al., 2007). Research to date has confirmed the inherent difficulty of the STW movement (Magnan et al., 1996); however, the technology used is limited to laboratory settings. Accelerometers may provide a suitable alternative.AimThis study aimed to test the concurrent validity of an accelerometer for measuring temporal parameters of the STW movement.MethodFollowing ethical approval, 15 healthy participants were instructed to stand up and walk from a chair while a motion analysis system tracked the 3D trajectory of reflective markers located on anatomical landmarks on the trunk and lower limbs. Concurrently, the acceleration signals of both thighs were recorded by two tri‐axial accelerometers (DelSys, Boston, MA, USA). Participants performed three STW movements at self‐selected speeds: slow, normal and fast. Time events for the STW movement (seat off, swing off and swing down) were identified from changes in the marker trajectories, as described in the literature, and points of inflection in the acceleration signals.ResultsAcross all speeds, there was an absolute difference of 0.064 seconds ± 0.05 seconds for seat off, 0.072 ± 0.063 seconds for swing off and 0.063 seconds ± 0.039 seconds for swing down. Agreement for the events was excellent with intraclass correlation coefficient values between 0.96 and 0.99. Agreement for the whole movement duration was 0.99.ConclusionsThis study demonstrated excellent agreement between a motion analysis system and inertial sensors for recording time events during the STW movement, suggesting clear potential for this technique. Copyright © 2012 John Wiley & Sons, Ltd.
Thermodynamic basis of selectivity in guide‐target‐mismatched rna interference
Authors: Joseph Thomas T. , Osman Roman 
Published: January 2012

AbstractSilencing in RNAi is strongly affected by guide‐strand/target‐mRNA mismatches. Target nucleation is thought to occur at positions 2–8 of the guide (“seed region”); successful hybridization in this region is the primary determinant of target‐binding affinity and hence target cleavage. To define a molecular basis for the target sequence selectivity in RNAi, we studied all possible distinct single mismatches in seven positions of the seed region—a total of 21 substitutions. We report results from soft‐core thermodynamic integration simulations to determine changes in targeting binding‐free energies to Argonaute due to single mismatches in the guide strand, which arise during binding of an imperfectly matched target mRNA. In agreement with experiment, most mismatches impair target binding, consistent with a prominent role for binding affinity changes in RNAi sequence selectivity. Individual Argonaute residues located near the mismatched base pair are found to contribute significantly to binding affinity changes. We also use this methodology to analyze the mismatch‐dependent free energy changes for dissociation of a DNA•RNA hybrid from Argonaute, as a model for the escape of miRNAs from the silencing pathway. Several mismatched sequences of the miRNA have increased affinity to Argonaute, implying that some mismatches may reduce the probability for escape. Furthermore, calculations of base‐substitution‐dependent free energy changes for binding ssDNA reveal mild sequence sensitivity as expected for guide strand binding to Argonaute. Our findings give a thermodynamic basis for RNAi target sequence selectivity and suggest that miRNA mismatches may increase silencing effectiveness and thus could be evolutionarily advantageous. Proteins 2012; © 2011 Wiley Periodicals, Inc.
Engineering proteins with enhanced mechanical stability by force‐specific sequence motifs
Authors: Lu Wenzhe , Negi Surendra S. , Oberhauser Andres F. , Braun Werner 
Published: January 2012

AbstractUse of atomic force microscopy (AFM) has recently led to a better understanding of the molecular mechanisms of the unfolding process by mechanical forces; however, the rational design of novel proteins with specific mechanical strength remains challenging. We have approached this problem from a new perspective that generates linear physical–chemical properties (PCP) motifs from a limited AFM data set. Guided by our linear sequence analysis, we designed and analyzed four new mutants of the titin I1 domain with the goal of increasing the domain's mechanical strength. All four mutants could be cloned and expressed as soluble proteins. AFM data indicate that at least two of the mutants have increased molecular mechanical strength. This observation suggests that the PCP method is useful to graft sequences specific for high mechanical stability to weak proteins to increase their mechanical stability, and represents an additional tool in the design of novel proteins besides steered molecular dynamics calculations, coarse grained simulations, and ϕ‐value analysis of the transition state. Proteins 2012; © 2011 Wiley Periodicals, Inc.
Signaling pathway of a photoactivable Rac1‐GTPase in the early stages
Authors: Peter Emanuel , Dick Bernhard , Baeurle Stephan A. 
Published: January 2012

AbstractIn modern life‐ and medical‐sciences major efforts are currently concentrated on creating artificial photoenzymes, consisting of light‐ oxygen‐voltage‐sensitive (LOV) domains fused to a target enzyme. Such protein constructs possess great potential for controlling the cell metabolism as well as gene function upon light stimulus. This has recently been impressively demonstrated by designing a novel artificial fusion protein, connecting the AsLOV2‐Jα‐photosensor from Avena sativa with the Rac1‐GTPase (AsLOV2‐Jα‐Rac1), and by using it, to control the motility of cancer cells from the HeLa‐line. Although tremendous progress has been achieved on the generation of such protein constructs, a detailed understanding of their signaling pathway after photoexcitation is still in its infancy. Here, we show through computer simulations of the AsLOV2‐Jα‐Rac1‐photoenzyme that the early processes after formation of the Cys450‐FMN‐adduct involve the breakage of a H‐bond between the carbonyl oxygen FMN‐C4O and the amino group of Gln513, followed by a rotational reorientation of its sidechain. This initial event is followed by successive events including β‐sheet tightening and transmission of torsional stress along the Iβ‐sheet, which leads to the disruption of the Jα‐helix from the N‐terminal end. Finally, this process triggers the detachment of the AsLOV2‐Jα‐photosensor from the Rac1‐GTPase, ultimately enabling the activation of Rac1 via binding of the effector protein PAK1. Proteins 2012; © 2012 Wiley Periodicals, Inc.
Evaluation of organically acceptable insecticides as stand‐alone treatments and in rotation for managing yellowmargined leaf beetle, Microtheca ochroloma (Coleoptera: Chrysomelidae), in organic crucifer production
Authors: Balusu Rammohan R , Fadamiro Henry Y 
Published: January 2012

AbstractBACKGROUND: Yellowmargined leaf beetle, Microtheca ochroloma, is the most damaging pest of organic crucifer crops in the southern United States. Experiments were conducted over four growing seasons (2007–2010) in Alabama to evaluate some botanical and microbial insecticides approved by the Organic Materials Review Institute (OMRI) against M. ochroloma in organically grown crucifer crops. Insecticides evaluated included PyGanic® (pyrethrum), Aza‐Direct® (azadiractin), Entrust® (spinosad), Mycotrol O® (Beauveria bassiana strain GHA) and NOFLY® [Isaria ( = Paecilomyces) fumosoroseus strain FE 9901]. Two experimental organic formulations, Tick‐Ex (Metarhizium anisopliae strain F52) and MBI‐203 (Chromobacterium subtsugae), and one non‐OMRI‐listed formulation, Novodor® (Bacillus thuringiensis subspecies tenebrionis), were also evaluated. The insecticides were applied as stand‐alone treatments at recommended field rates on a weekly schedule. In 2010, some of the treatments were also evaluated in rotation/alternation with Entrust®. Insecticide efficacy was determined by comparing densities of M. ochroloma larvae and adults and crop damage ratings in treated versus untreated turnip plots.RESULTS: Entrust® consistently performed well in suppressing M. ochroloma adults, larvae and crop damage. PyGanic® was the second best treatment. PyGanic® or NOFLY™ can be applied in rotation with Entrust® for effective management of M. ochroloma.CONCLUSION: Entrust® applied weekly or in alternation with PyGanic® or NOFLY™ provided acceptable control of M. ochroloma in organic crucifer production. Copyright © 2012 Society of Chemical Industry
Rationale for a natural products approach to herbicide discovery
Authors: Dayan Franck E , Owens Daniel K , Duke Stephen O 
Published: January 2012

AbstractWeeds continue to evolve resistance to all the known modes of herbicidal action, but no herbicide with a new target site has been commercialized in nearly 20 years. The so‐called ‘new chemistries’ are simply molecules belonging to new chemical classes that have the same mechanisms of action as older herbicides (e.g. the protoporphyrinogen‐oxidase‐inhibiting pyrimidinedione saflufenacil or the very‐long‐chain fatty acid elongase targeting sulfonylisoxazoline herbicide pyroxasulfone). Therefore, the number of tools to manage weeds, and in particular those that can control herbicide‐resistant weeds, is diminishing rapidly. There is an imminent need for truly innovative classes of herbicides that explore chemical spaces and interact with target sites not previously exploited by older active ingredients. This review proposes a rationale for a natural‐products‐centered approach to herbicide discovery that capitalizes on the structural diversity and ingenuity afforded by these biologically active compounds. The natural process of extended‐throughput screening (high number of compounds tested on many potential target sites over long periods of times) that has shaped the evolution of natural products tends to generate molecules tailored to interact with specific target sites. As this review shows, there is generally little overlap between the mode of action of natural and synthetic phytotoxins, and more emphasis should be placed on applying methods that have proved beneficial to the pharmaceutical industry to solve problems in the agrochemical industry. Published 2012 by John Wiley & Sons, Ltd.
Efficacy of two insecticides for protecting loblolly pines (Pinus taeda L.) from subcortical beetles (Coleoptera: Curculionidae and Cerambycidae)
Authors: Burke Jordan L , Hanula James L , Horn Scott , Audley Jackson P , Gandhi Kamal JK 
Published: January 2012

AbstractBACKGROUND: Tests were conducted on two insecticides (carbaryl and bifenthrin) for excluding subcortical beetles (Coleoptera: Curculionidae and Cerambycidae) from loblolly pine trees (Pinus taeda L.). Two trap designs (single‐ and double‐pane windows) and two trapping heights (1.5 and 4 m) were also evaluated for maximizing beetle catches.RESULTS: In July 2009, 15 loblolly pine trees were double girdled and were either left unsprayed or sprayed with carbaryl or bifenthrin. A total of 28 473 bark beetles were caught in window traps, including Ips avulsus Eichoff, I. grandicollis (Eichhoff), I. calligraphus (Germar) and Dendroctonus terebrans (Olivier). Both insecticides significantly reduced colonization of the trees by bark and woodboring beetles by 300–400%, with no differences in efficacy observed between the two insecticides. About 59% more I. avulsus were caught in double‐ than in single‐pane window traps, with no differences for any other species. Traps at 4 m caught more I. avulsus and I. grandicollis (290 and 153% respectively), while traps at 1.5 m caught more D. terebrans (215%).CONCLUSIONS: Either bifenthrin or carbaryl can be used to exclude subcortical beetles from loblolly pine trees. Trapping data reflect known vertical partitioning on the bole by these insects. Double‐pane traps were slightly more effective than single‐pane traps in catching subcortical beetles. Copyright © 2012 Society of Chemical Industry
Non‐target‐site‐based resistance to ALS‐inhibiting herbicides in six Bromus rigidus populations from Western Australian cropping fields
Authors: Owen Mechelle J , Goggin Danica E , Powles Stephen B 
Published: January 2012

AbstractBACKGROUND: Bromus rigidus is a common weed species that has increased in cropping fields owing to limited control options. During a random field survey in Western Australia, six B. rigidus populations that had survived in‐crop weed control programmes were collected. The study aimed to determine the resistance profile of these six populations.RESULTS: Based on dose–response studies, all six B. rigidus populations had a low‐level resistance to sulfosulfuron and sulfometuron (both sulfonylurea herbicides) while remaining susceptible to herbicides with other modes of action. ALS in vitro activity assays revealed no differences in enzyme sensitivity between susceptible and resistant populations, while the use of malathion (a cytochrome P450 inhibitor) in combination with sulfosulfuron caused the resistant populations to behave like the susceptible population.CONCLUSION: This study established that these six B. rigidus populations have a low‐level resistance to the ALS‐inhibiting sulfonylurea herbicides, but are able to be controlled by other herbicide modes of action. The low‐level, malathion‐reversible resistance, together with a sensitive ALS, strongly suggest that a non‐target‐site enhanced metabolism is the mechanism of resistance. Copyright © 2012 Society of Chemical Industry
Effect of indium on the conductivity of poly‐crystalline GaN grown on high purity fused silica
Authors: Keller Stacia , Lu Jing , Mishra Umesh K. , DenBaars Steven P. , Speck James S. 
Published: January 2012

AbstractA significant resistivity reduction was observed for GaN:Si films grown on high purity fused silica by metal organic vapour deposition when an InGaN:Si sacrificial layer was inserted beneath or within the GaN:Si layers. Thereby at least part of the GaN:Si layer on top of the sacrificial layer was grown at high temperature. Using this technique, a film resistance of 0.8 Ω cm was obtained, compared to a resistance of 60 Ω cm measured for the same layer stack without InGaN sacrificial layer.
Green light‐emitting diodes fabricated on semipolar (11–22) GaN on r‐plane patterned sapphire substrate
Authors: Okada Narihito , Uchida Katsumi , Miyoshi Seita , Tadatomo Kazuyuki 
Published: January 2012

AbstractWe have succeeded in the growth of a high‐quality semipolar (11–22) GaN layer on an r‐plane patterned sapphire substrate (r‐PSS). In this study, we report on green‐light‐emitting diodes (LEDs) fabricated on the (11–22) GaN layer on the r‐PSS. The optical property of (11–22) MQWs on the r‐PSS improved from that of the same MQWs on an m‐plane sapphire substrate. The green light emission from the LED on the r‐PSS was confirmed, which exhibited scattered light emission. The effect of the r‐PSS on the improvement of light extraction was evaluated by ray tracing simulation, which is higher than that of a conventional LED on a c‐PSS. This improvement is derived from the air void structure in the LED fabricated on the r‐PSS. It was also confirmed that the LED had a small blue shift compared with that on the conventional green LED, and that the quantum confined Stark effect can be reduced using the semipolar (11–22) GaN layer on the r‐PSS.
Study of defects and lifetime of green InGaN laser diodes
Authors: Strauss Uwe , Lermer Teresa , Müller Jens , Hager Thomas , Brüderl Georg , Avramescu Adrian , Lell Alfred , Eichler Christoph 
Published: January 2012

AbstractInGaN quantum wells for direct green lasers with indium concentrations of about 30% are studied in respect to defect structure and influence of defects on device lifetime. A new test structure enables us to determine strain relaxation in In‐rich layers by X‐ray diffraction even at typical well thicknesses of few nanometers. We show that there is a high risk to generate screw and edge dislocations in the In‐rich quantum wells in non‐optimized structures as verified by transition electron microscopy. Such defects strongly influence the device lifetimes of green lasers. Non‐optimized devices have a drop of output power on a time scale of 100 h. The threshold current increases proportional to the square root of time. Additionally, a linear correlation of slope efficiency versus one over laser threshold current is observed. The degradation process is explained as reduced carrier injection efficiencies related to the generation of additional charged defects in the active layers. Optimized active layers already enable stable operation over a period of more than 1000 h at 50 mW constant power at 517 nm emission wavelength with an extrapolated increase of operation current by <30% within this time.
Influence of film thickness on structural and optical properties of ZnS thin films obtained by SILAR method and analysis of Zn/ZnS/n‐GaAs/In sandwich structure
Authors: Özakın Oğuzhan , Güzeldir Betül , Yıldırım M. Ali , Sağlam Mustafa , Ateş Aytunç 
Published: January 2012

AbstractZnS thin films were deposited on glass substrates using SILAR method at room temperature and ambient pressure. The relationship between refractive index and energy bandgap was investigated. The film thickness effect on the structural, morphological and optical properties of ZnS thin films was investigated. The crystalline and surface properties of the films improved with increasing film thickness. The energy bandgap values changed from 3.87 to 3.58 eV with increasing film thickness. The refractive index (n), high frequency dielectric constant (ε∞) values were calculated by using the energy bandgap values as a function of the film thickness. Also, ZnS thin film was deposited directly on n‐GaAs substrate for obtaining the Zn/ZnS/n‐GaAs/In sandwich structure at room temperature. The sandwich structure demonstrated clearly rectifying behaviour by the current–voltage (I–V) curves at room temperature. From I–V characteristics n and Φb values were calculated as 1.894 and 0.632 eV at room temperature, respectively.