Coin test

Today the coin-tap test is a widely used technique on wind turbine rotor blades for inspection of thin GFRP laminates for disbonded and delaminated areas. However, since the sensitivity of this technique depends not only on the operator but also on the thickness of the inspected component, the coin-tap testing technique is most sensitive to defects positioned near the surface of the laminate. Therefore, there has been an increasing demand for alternative non-destmctive testing techniques which is less operator dependent and also more sensitive to delaminations and disbonded areas situated beyond thicker GFRP-laminates. 

Statistical considerations make it possible to test the assumption of independent additions. Let us approach this topic by considering an easier problem coin tossing. Under conditions where two events are purely random-as in tossing a fair coin-the probability of a specific sequence of outcomes is given by the product of the probabilities of the individual events. The probability of tossing a head followed by a head-indicated HH-is given by... 

If we were testing whether a coin were biased or not, we would use ideas like these as the basis for a test. We could count, for example, HHH and HH sequences and divide them according to Eq. (7.48). If Ph/hh Ph would be suspicious ... 

Freshly assembled lithium/carbon coin cells typically have voltages between 2.8 and 3.4 volts. The cells are in their fully charged state which means that no lithium is inserted in the carbon anode. Then the coin cells are tested with computer-controlled constant-current cyclers having currents stable to 1%. The cells are placed in thermostats at a particular set temperature v/hich is stable to 0.1°C during the test. Most of our cells were tested at 30°C. 

The term annulene was coined to refer to the completely conjugated monocyclic polyenes. The synthesis of annulenes has been extended well beyond the first two members of the series [4]annulene (cyclobutadiene) and [6]annulene (benzene). The generality of the Hiickel rule can be tested by considering the properties of members of the annulene series. 

Radium, the last element in the group, was isolated in trace amounts as the chloride by P. and M. Curie in 1898 after their historic processing of tonnes of pitchblende. It was named by Mme Curie in allusion to its radioactivity, a word also coined by her (Latin radius, a ray) the element itself was isolated electrolytically via an amalgam by M. Curie and A. Debieme in 1910 and its compounds give a carmine-red flame test. 

Probe-munze,/. proof coin, -muster, n. sample for testing. 

Of historical interest may be the use of a half dollar coin (the lighter weight 250 not as efficient). During the early 1940s the coin tap test was used very successfully in evaluating the performances of plastics, particularly RP primary aircraft structures. With a good ear (human hearing ear) there was (and is) a definite different sound between a satisfactory and unsatisfactory RP product. The unsatisfactory product would contain voids, delaminations, defects in fiber distribution, etc. In... 

Self-Test E.2A The mass of a copper coin is 3.20 g. Suppose it were pure copper. 

A specific feature of the CEMS technique is the possibility for nondestructive testing of the surface composition of paintings, ancient coins, and pottery or other valuable objects. Wagner et al. [445] have investigated Celtic gold coins (from the time period 480-15 b.c.) and have shown that the surface of the coins consist of two phases, one of which is strongly eiuiched in gold compared to the bulk composition. 

This splendid medal in alchemic gold was coined in 1609 in order to test the success of an Adept. . In Les Clefs Secretes De La Chimie Des Anciens, Fabrice Bardeau, First Image, Robert Laffont, Paris, 1975. Coll. part. ph. Suark International... 

Coin-type cells (size CR2032, Hohsen Co.) with a lithium foil counter electrode (FMC Corporation) and a polypropylene separator (Celgard 3501) were assembled inside a helium-filled glovebox (<5ppm, H20 and 02). Laboratory made cell fixtures were also used for the HPPC test at room temperature. 

In the next paper by Y. Illin et al., capabilities of Sn anodes are considered as a possible alternative to carbon. Thin films of Sn were deposited onto current collector in vacuum, and tested in the coin cells. Authors were able to obtain reversible alloying reaction, which stabilized at 100 mAh/g between cycle number 100 and 400. The stability of Sn and its characteristics upon cycling was seen to be a function of the current collector material. The best results were achieved with non-copper-based substrates. 

Figure 1. Typical galvanostatic charge (1) - discharge (2) curves of the lithium-ion battery grade graphite, SL-20 (Superior Graphite Co., USA), as tested at C/20 rate in 2016 coin cells having Li metalfoil as counter electrode and electrolyte EC.DMC + lMLiPFf,.

All samples were galvanostatically tested in coin cell 2016 semielements and special Teflon T-type testing cells in the potential window 0.03 - 0.80 V versus lithium foil in different modes from C/2 to C/40. We used standard electrolyte LP 71 (Merck). 

Both carbon materials were tested for their initial electrochemical performance in the 2-electrode electrochemical cells with Li metal as a counter electrode. Our findings have shown that with both types of carbon materials, achieving near theoretical reversible capacity upon Li+ deintercalation was possible. Thus, in a typical half cell environment (a CR2016 type coin cell with graphite and Li metal electrodes, a 1M LiPF6,... 

Carbon coated Si-based anode materials were successfully synthesized by chemical vapor deposition methods. Coated materials performed well during the coin cell testing. Future work on this section... 

Further on, the Co-Ni complexes were used for modification of Hohsen Carbon type (10-10) and Hohsen Graphite type (10-28) anode materials for Li-ion batteries applying similar procedure. These anode materials were tested in 2016 size lithium coin cells with a configuration Li/electrolyte (LP-30)/(modified anode material). The coin cells were assembled by standard technology in dry atmosphere of a glove box and then... 

In the fifth paper of this chapter on cathodes, an investigation of thin-film oxide-hydroxide electrodes containing Cr, Ni, and Co compounds was authored by N. Vlasenko et al. The thin-films were produced by electrochemical deposition from transition metal aqueous fluorine-containing electrolytes onto steel substrates. These thin-films were tested in Li coin cells. Electrochemical activity appears to scale with the amount of fluoride used in the deposition the larger concentration of fluoride in the bath, the greater the capacity. One Ni oxide-hydroxide film electrode showed greater than 175 mAh/g reversible capacity on the 50th cycle with excellent coulombic efficiency. 

Preliminary electrochemical tests of materials obtained have been performed in two types of cells. Primary discharge measurements have been executed in standard 2325 coin-type cells (23 mm diameter and 2.5 mm height) with an electrolyte based on propylene carbonate - dimethoxyethane solution of LiC104. Cathode materials have been prepared from thermally treated amorphous manganese oxide in question (0.70 0.02g, 85wt%.) mixed with a conductive additive (10 % wt.) and a binder (5wt%). Lithium anodes of 0.45 mm thickness have been of slightly excess mass if compared to the stoichiometric amount, so as to ensure maximal possible capacity of a cell and full consumption of the cathode material. 

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