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Adherent electroactive films of poly͑o-phenylenediamine͒ ͑PPD͒ were obtained by electropolymerization of o-phenylenediamine ͑o-PD͒ on 304 stainless steel under potentiostatic conditions. The in situ Fourier transform infrared reflectance spectroscopy study suggests a phenazine ring ladder-structure polymer. Open circuit potential and potentiodynamic studies of PPD-coated steel electrodes, in chloride aqueous solution show a positive shift of the corrosion potential.

SUMMARYThe frequency of stereotyped abnormal behaviour i.e. windsucking/crib-biting, weaving and stall-walking were studied in 100 Chilean horses of both sex, stabled in individual boxes either all day long or during a certain period of time. All horses were tamed and older than 2 years old, and belonging to 16 studs of the Comuna de Chillán (Chile). The horses were observed between 7:00 and 19:00 hours during one day, and its owner or carer was asked whether the horse presented some stereotyped abnormal behaviour or not. Horses were separated according to age into 2 groups: 2 to 5 years old and older than 5 years, and also according to sex: stallions, geldings or mares. Data was analysed using the Microsoft® Excel Worksheet to establish frequencies. Differences between groups were analysed by Exact Fisher's Test. Significance level was P < 0.05. The results showed that 50% of the studs had one or more horses with some stereotyped abnormal behaviour. Ten porcent of the horses presented stereotyped abnormal behaviour. Stall-walking was the most frequent stereotyped abnormal behaviour (8%), then windsucking/crib-biting (2%), and finally weaving (1%). According to sex, statistic differences were observed only for stall-walking between stallions and mares (P = 0.012). According to age no statistic differences were observed.Palabras claves: comportamiento anormal, estereotipias, equinos, caballo Chileno.

RESUMENEn Chile se han realizado dos estudios de estereotipias clásicas en caballos de raza chileno, ambos con resultados diferentes respecto a la prevalencia total y estereotipia más frecuente en esta raza. El objetivo de este estudio fue determinar la prevalencia total y de cada una de las estereotipias clásicas en caballos chilenos estabulados de las comunas de Pinto y Coihueco, Región del Biobío, Chile, y su asociación con el sexo y edad. Se estudió la totalidad de los caballos chilenos inscritos y estabulados en ambas comunas (n = 103). Se determinó la presencia o ausencia de aerofagia, balanceo y/o paseo circular en pesebrera en cada caballo mediante observación directa, 20 min por hora, durante 4 horas. Para analizar los datos, los equinos fueron divididos de acuerdo al sexo en 3 grupos: machos enteros (n = 36), machos castrados (n = 33) y hembras (n = 34). De acuerdo a la edad se dividieron en 3 grupos: 3-5 años (n = 14), 5-15 años (n = 83) y >15 años (n = 6). Los resultados son expresados como porcentajes simples. El efecto de las variables sexo y edad fue analizado mediante la prueba exacta de Fisher con un nivel de significancia de p < 0,05. La prevalencia total de estereotipias clásicas fue 6,8% (1,94% aerofagia, 0,98% balanceo y 3,88% paseo circular en pesebrera). No se encontró diferencias estadísticas asociadas a la edad y sexo. Los resultados sugieren que los caballos chilenos presentan una prevalencia normal de estereotipias clásicas y que el paseo circular en pesebrera es la más frecuente en caballos de esta raza.Palabras clave: aerofagia, balanceo, paseo circular en pesebrera, equino, conducta estereotipada. ABSTRACTIn Chile, there have been two studies on classic stereotypic behavior in Chilean horses breed. The objective of the study was to determine the prevalence of classic stereotypies in Chilean horses stabled of the counties of Pinto and Coihueco, Biobío Region, Chile, and its association with sex and age. All Chilean horses registered and stabled in both counties were studied (n=103). Presence or absence of classic stereotypies (crib-biting, weaving and box-walking) was determined by direct observation of 20 min per hour for 4 hours. Data were analyzed dividing horses by sex into three groups: stallions (n = 36), geldings (n = 33) and mares (n = 34). Based on their age, they were divided into three groups: 3-5 years old (n = 14), 5-15 years old (n = 83) and >15 years old (n = 6). Results were expressed as simple percentages. The effects of age and sex were analyzed statistically by Fisher's exact test with a significance level at 0.05. Total prevalence of classic stereotypies was 6.8% (1.94%

Growth of a highly colored insoluble material on a platinum electrode by the oxidative reaction of 1,2-dimethoxybenzene (veratrole) in acetonitrile is observed when tetrabutylammonium tetrafluoroborate is used as supporting electrolyte. The organic yield of the deposit reaches 98% when short-timed electrolyses are performed. The main product has been characterized by several electrochemical and spectroscopic methods.Electrochemical oxidation of methoxybenzenes has been studied since 1964.1 The same year, Eberson 2 and Ross 3 proposed a radical ion as the intermediate species involved. Theoretical models were developed in order to explain the electrochemical behavior of the substrates. 41~ A rule was suggested 14 for the electrochemical reaction of aromatic compounds: side chain substitution would follow a mechanism via free radical, while ring substitution would be explained via a carbonium ion mechanism. Bechgaard and Parker 16 synthesized mono-triphenylene, di-triphenylene, and tri-triphenylene cations from the anodic oxidation of 1,2-dimethoxybenzene in trifluoroacetic acid (TFA). The extraordinary stability of organic cationic radicals in TFA allowed the reaction to be stopped at the radical cation stage, thus enabling the study of the effect of electrochemical variables on it.

The electrooxidation of methanol on an iridium disk in the pH range 0−14 was studied by Fourier transform infrared (FTIR) spectroscopy. The following solutions were used:  1 M H2SO4, 0.1 M HClO4, 1 M H3PO4, and 1 M Na2SO4 whose pH had been adjusted to 2 with H2SO4, 0.5 M phosphate buffer of pH 7, 0.1 M borax buffer, and 1 M NaOH. Linear potential sweep (LPS) FTIR spectroscopy showed that the products of 0.1−1.0 M methanol electrooxidation on smooth Ir were CO2 and formic acid in acidic media and bicarbonate/carbonate and formate ions in alkaline media. Only at pH 7 and 9.2 neither formic acid nor formate ion was detected. The activity of Ir for methanol electrooxidation was very low. At all pH values dissociative chemisorption of methanol yielded chemisorbed CO, always in the linear form. At pH 14 this chemisorbed CO was completely electrooxidized by 0.6 V vs RHE, a value 0.4 V less positive than in perchloric and phosphoric acids of pH 1. This behavior is parallel to that of the appearance of formate/formic:  at pH 14 formate is detected already at 0.4 V, while in perchloric and phosphoric acids of pH 1 formic acid is first detected at 0.9 V. This dependence on pH of the electrocatalytic activity of Ir both for the electrooxidation of chemisorbed CO and for that of methanol to formate/formic is in perfect agreement with the fact that the peak of the main Ir surface oxidation process occurs at 0.6 V vs RHE at pH 14, but at a rather more positive potential, 0.9−1.0 V vs RHE, in acidic media (super-Nernstian pH dependence). This agreement lends support to the hypothesis that the electrooxidation of organic compounds requires the presence of oxide, hydroxide, and/or oxyhydroxide groups on the Ir surface, which provide the O atoms necessary for the formation of CO2 and formic/formate. However, in sulfuric acid, both at pH 0 and 2, formic acid was already observed at 0.7 V, possibly because in sulfuric acid a prepeak of Ir oxidation at 0.6 V that precedes the main peak at 1.0 V is better defined. The stretching frequency of linear CO increased by up to 60 cm-1 with increasing coverage and at the same coverage was higher in HClO4 than in H3PO4 solutions. The Stark shift varied over the range 39−45 cm-1 V-1 with pH, CO coverage, and nature of the anion in the case of acids.

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