102,073 research outputs found
Chlorophyll-c from marine algae and its characterization as natural dye for dye-sensitized solar cells.
No full textMarine algae (seaweeds) have a broad range of applications in several productive sectors, from human consumption to pharmacology, cosmetics, agriculture and waste water treatments. Algal biomass are also employed in the field of renewable energies for the production of biogas. Marine algae are indeed a reserve of natural dyes (Chls a, b and c), being therefore potentially suitable in PV technology for their low cost and easy attainability, without potential environmental load in terms of land subtraction. Chlorophyll-c is a photosynthetic pigment, a porfirine molecule, presents only in brown algae. Undaria pinnatifida (known as Wakame) is largely present in Venice Lagoon and for it a disposal strategy is recommended.
In this study, a low cost and eco-friendly extraction protocol was developed to obtain chlorophyll-c from brown alga Undaria pinnatifida, for utilization in dye-sensitized solar cells (DSSCs), along with the characterization of optical absorption and spectroscopy of the dye. Photovoltaic performances of the chlorophyll-based devices were also tested by measuring current-voltage curves as well as the incident photon to current efficiency. Three different solvents were tested, whose polarity was modified with different dilution with water. Better chlorophyll-c was extracted using 60% of acetone, whereas Ritchie algorithms were used to determine chlorophyll concentrations. The UV absorbance spectrum of chlorophyll extract exhibits the characteristic absorption peaks at 630 nm, confirming the presence of chl-c. The DSSC has delivered a short-circuit photocurrent density (Jsc) of 1.739 mA/cm2, open circuit photo-voltage (Voc) of 0.407 V, fill factor (FF) of 0.67, an efficiency (η) of 0.49% and a maximum incident photon-to-current conversion efficiency (IPCEmax) of 16% atthe Soret peak. The data presented here, improving η and IPCEmax , exceed the prior art of our previous study.[1] Obtained data suggest that protocols developed are useful to get an optimum amount of chlorophyll-c and that the DSSC performance indicates the possible use of marine algae in sustainable energy technologies.[1] G. Calogero, I. Citro, G. Di Marco, S. Armeli Minicante, M. Morabito and G. Genovese, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 117 (2014) 702
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
No full textDieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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3346: Samuel G. Freedman, author, 2013
No full textPhotograph of author Samuel G. Freedman, at NT Daily Slash meeting in the Mayborn School of Journalism at UNT
The Right to Strike under the United States Constitution: Theory, Practice, and Possible Implications for Canada
No full textAnswering critics of the Canadian Supreme Court's judgment in B.C. Health, the author argues that the Court laid the foundation for a principled and durable doctrine protecting constitutional labour rights, one that goes directly to the heart of the matter — the inequality of workers’ power in the employment relation. In the author’s view, two paths could lead from B.C. Health to the recognition of Charter protec- tion for a right to strike: one that treats the right as an accessory to col- lective bargaining, and one that upholds the right directly on the basis of the Charter values of equality and participation. The author supports the latter approach, contending that constitutional rights should be defined in relation to fundamental values, in a way that is not contingent on time-bound or fact-sensitive assessments about the role of strikes within a particular collective bargaining regime. Although a Charter right to strike may involve the courts in difficult choices about when to defer to legislative policy decisions, and courts may lack the institutional capac- ity to deal effectively with labour law issues, the author points out that judges can look to ILO standards for expert guidance. Noting that the U.S. experience in this area might be of considerable use to Canadians, the author concludes by providing an overview of American case law concerning a constitutional right to strike.Peer reviewe
Bicalutamide monotherapy versus flutamide plus goserelin in prostate cancer: Updated results of a multicentric trial
No full textOBJECTIVES:
To compare the efficacy of bicalutamide monotherapy to maximal androgen blockade in advanced prostatic cancer.
PATIENTS AND METHODS:
Previously untreated patients with histologically proven stage C or D (American Urological Association Staging System) disease were randomly allocated to either bicalutamide (B) or goserelin plus flutamide (G+F). After disease progression, patients treated with B were assigned to castration. The primary endpoint for this trial was overall survival. Prostate cancer-specific survival and progression were included among secondary endpoints.
RESULTS:
In total 108 patients received B and 112 received G+F. At a median follow-up time of 54 months (range 1-89), 151 patients progressed and 113 died. There was no significant difference in the duration of either progression-free or overall survival. Hazards of progression, death and cancer-specific death, corrected by disease stage, tumor grade and baseline PSA level, showed that patients initially assigned to B had a higher risk of progression but a comparable risk of death and cancer-specific death with the exception of patients with G3 tumors who had an increased risk of death).
CONCLUSIONS:
In patients with well or moderately well differentiated tumors, B monotherapy followed by castration may offer the same survival chance as maximal androgen deprivation. In those patients it thus represents a reasonable choice that can avoid the side effects of androgen deprivation for considerable periods of time
ECONOMIC ANALYSIS IN DISPUTES OVER TRADE REMEDY AND RELATED MEASURES IN AGRICULTURE, WITH EXAMPLES FROM RECENT CASES
No full textInternational Relations/Trade,
Photoelectrochemical and spectrophotometric studies on dye-sensitized solar cells (DSCs) and stable modules (DSCMs) based on natural apocarotenoids pigments
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