Tafel der viertel-quadrate aller ganzen zahlen von 1 bis 200 000, welche die ausführung von multiplikationen, quadrirungen und das ausziehen der quadratwurzel bedeutend erleichtert und durch vorzügliche correctheit fehlerlose resultate verbürgt.

"Gratis-beilage zur Tafel der viertel-quadrate. Napiertafel enthaltend die 8 vielfachen aller zahlen vermittels zusammensetzen der dazu erforderlichen stäbchen, zur bequemeren und rascheren ausführung von multiplicationen und divisionen vielstelliger zahlen laut gebrauchsanweisung, herausgegeben nach angabe des herren A. Steinhauser" (4 p. (23 cm.) and tab. (22 x 19 cm.) laid in.

Jerome de la Lande's logarithmisch-trigonometrische Tafeln durch die Tafel der Gaussschen Logarithmen und andere Tafeln und Formeln vermehrt.

Added t.-p. in French.

Das grosse buch der tafel-lieder ...

Mode of access: Internet.

Zur agrargeschichte Lübecks und Ostholsteins; studien nach archivalischen quellen, mit einer flurkarte und einer tafel,

Mode of access: Internet.

Tafel-lieder für die im jahre 1827 gestiftete schach-gesellschaft, verfasst von einigen wohlgesinnten mitgliedern.

Mode of access: Internet.

Adversaria in libros Veteris Testamenti e chirographo ejus in Bibliotheca Regiae Academiae Holmiensis asservato nunc primum edidit Jo. Fr. Im. Tafel.

Pt. V, vol.1 and 2 are also entitled: - "Diarii spiritualis partis Vae, volumen, 1, 2."

Die theilung Polens in den jahren 1773, 1793, 1796 und 1815 nebst einer dynastien-tafel der könige von Polen und der Wiener kongress im jahre 1815 /

Mode of access: Internet.

Der Einfluss der Versicherungsdauer auf die Sterblichkeit in der Lebensversicherung : nach dem Material der Tafel MI der 23 deutschen Gesellschaften.

Thesis (doctoral)--Georg Augusts-Universitat zu Gottingen.

Die höhere Backkunst für den Hausbedarf, oder gründliche Anweisungen zur Bereitung der vorzüglichsten Kuchen, - Pfefferkuchen und der beliebtesten Torten, - der Dessert-Backwerke, welche bei Tafel, Bällen und Kaffee-Gesellschaften in Anwendung kommen ... : ein Buch für Hausfrauen, Gastwirthe und Bäcker : nach Angabe eines Hofconditors

von C.F.G. Thon

Blocking layer optimisation of poly(3-hexylthiopene)based solid state dye sensitized solar cells

The optimisation study of the fabrication of a compact TiO2 blocking layer (via Spray Pyrolysis Deposition) for poly (3-hexylthiopene) (P3HT) for Solid State Dye Sensitized Solar Cells (SDSCs) is reported. We used a novel spray TiO2 precursor solution composition obtained by adding acetylacetone to a conventional formulation (Diisopropoxytitanium bis (acetylacetonate) in ethanol). By Scanning Electron Microscopy a TiO2 layer with compact morphology and thickness of around 100 nmis shown. Through a Tafel plot analysis an enhancement of the device diode-like behaviour induced by the acetylacetone blocking layer respect to the conventional one is observed. Significantly, the device fabricatedwith the acetylacetone blocking layer shows an overall increment of the cell performance with respect to the cellwith the conventional one (DJsc/Jsc = +13.8%, DFF/FF = +39.7%, DPCE/PCE = +55.6%). A conversion efficiency optimumis found for 15 successive spray cycles where the diode-like behaviour of the acetylacetone blocking layer is more effective. Over three batches of cells (fabricated with P3HT and dye D35) an average conversion efficiency value of 3.9% (under a class A sun simulator with 1 sun A.M. 1.5 illumination conditions) was measured. From the best cell we fabricated a conversion efficiency value of 4.5% was extracted. This represents a significant increment with respect to previously reported values for P3HT/dye D35 based SDSCs.

Hydrogen evolution by a metal-free electrocatalyst

Electrocatalytic reduction of water to molecular hydrogen via the hydrogen evolution reaction may provide a sustainable energy supply for the future, but its commercial application is hampered by the use of precious platinum catalysts. All alternatives to platinum thus far are based on nonprecious metals, and, to our knowledge, there is no report about a catalyst for electrocatalytic hydrogen evolution beyond metals. Here we couple graphitic-carbon nitride with nitrogen-doped graphene to produce a metal-free hybrid catalyst, which shows an unexpected hydrogen evolution reaction activity with comparable overpotential and Tafel slope to some of well-developed metallic catalysts. Experimental observations in combination with density functional theory calculations reveal that its unusual electrocatalytic properties originate from an intrinsic chemical and electronic coupling that synergistically promotes the proton adsorption and reduction kinetics.

Simplified Mathematical Model for Effects of Freezing on the Low-Temperature Performance of the Lead-Acid Battery

Discharge periods of lead-acid batteries are significantly reduced at subzero centigrade temperatures. The reduction is more than what can he expected due to decreased rates of various processes caused by a lowering of temperature and occurs despite the fact that active materials are available for discharge. It is proposed that the major cause for this is the freezing of the electrolyte. The concentration of acid decreases during battery discharge with a consequent increase in the freezing temperature. A battery freezes when the discharge temperature falls below the freezing temperature. A mathematical model is developed for conditions where charge-transfer reaction is the rate-limiting step. and Tafel kinetics are applicable. It is argued that freezing begins from the midplanes of electrodes and proceeds toward the reservoir in-between. Ionic conduction stops when one of the electrodes freezes fully and the time taken to reach that point, namely the discharge period, is calculated. The predictions of the model compare well to observations made at low current density (C/5) and at -20 and -40 degrees C. At higher current densities, however, diffusional resistances become important and a more complicated moving boundary problem needs to be solved to predict the discharge periods. (C) 2009 The Electrochemical Society.

Direct electrochemical formation of nanostructured amorphous Co(OH)2 on gold electrodes with enhanced activity for the oxygen evolution reaction.

The oxides of cobalt have recently been shown to be highly effective electrocatalysts for the oxygen evolution reaction (OER) under alkaline conditions. In general species such as Co3O4 and CoOOH have been investigated that often require an elevated temperature step during their synthesis to create crystalline materials. In this work we investigate the rapid and direct electrochemical formation of amorphous nanostructured Co(OH)2 on gold electrodes under room temperture conditions which is a highly active precursor for the OER. During the OER some conversion to crystalline Co3O4 occurs at the surface, but the bulk of the material remains amorphous. It is found that the underlying gold electrode is crucial to the materials enhanced performance and provides higher current density than can be achieved using carbon, palladium or copper support electrodes. This catalyst exhibits excellent activity with a current density of 10 mA cm-2 at an overpotential of 360 mV with a high turnover frequency of 2.1 s-1 in 1 M NaOH. A Tafel slope of 56 mV dec-1 at low overpotentials and a slope of 122 mV dec-1 at high overpotentials is consistent with the dual barrier model for the electrocatalytic evolution of oxygen. Significantly, the catalyst maintains excellent activity for up to 24 hr of continuous operation and this approach offers a facile way to create a highly effective and stable material.

Insoluble anode of porous lead dioxide for electrosynthesis: preparation and characterization

Preparation of a novel type of titanium-substrate lead dioxide anode with enhanced electrocatalytic activity for electrosynthesis is described. It has been demonstrated that in the presence of a suitable surfactant in the coating solution, an adherent and mainly tetragonal form of lead dioxide is deposited on a platinized titanium surface such that the solution side of the coating is porous while the substrate side is compact. By an analysis of anodic charging curves and steady-state Tafel plots with such porous electrodes in contact with sodium sulphate solution, it has been proved that the electrochemically active area of these anodes is higher by more than an order of magnitude when compared to the area of conventional titanium-substrate lead dioxide anodes. The electrocatalytic activity is also thereby enhanced to a significant degree.

Kinetics of hydrogen evolution on a stainless steel electrode

The kinetic parameters for the hydrogen evolution reaction on a stainless steel substrate have been obtained from a study of the steady-state polarization curves as well as the galvanostatic transients. The high Tafel slope obtained in the steady-state polarization measurements was ascribed to the presence of an oxide film present on the surface of the stainless steel electrode.