Magnetic properties of the oceanic igneous rocks (Table 1)

Hysteresis measurements have been carried out on a suite of ocean-floor basalts with ages ranging from Quaternary to Cretaceous. Approximately linear, yet separate, relationships between coercivity (Bc) and the ratio of saturation remanence/saturation magnetization (Mrs/Ms) are observed for massive doleritic basalts with low-Ti magnetite and for pillow basalts with multi-domain titanomagnetites (with x= 0.6). Even when the MORB has undergone lowtemperature oxidation resulting in titanomaghemite, the parameters are still distinguishable, although offset from the trend for unoxidized multidomain titanomagnetite. The parameters for these iron oxides with different titanium content reveal contrasting trends that can be explained by the different saturation magnetizations of the mineral types. This plot provides a previously underutilized and non-destructive method to detect the presence of low-titanium magnetite in igneous rocks, notably MORB.

The Amplifier - v. 14, no. 1

In this issue...Mineral Club, Enrollment, Naval Shipyard, Mill Building, New Faculty, VISTA, Homecoming, American Chemical Society, Computer Courses

La progresividad del artículo 1° de la Declaración Americana de los Derechos y Deberes: el aporte del desarrollo de los derechos reproductivos en América Latina

 Resumen  El desarrollo progresivo del derecho a la vida, la libertad y la seguridad personal se han visto enriquecidos con la lucha y posterior positivación de los derechos reproductivos, en tanto estos han generado una ampliación de los criterios sobre los cuales se basa la obligación del Estado respecto de los derechos humanos en general, y en particular de aquellos consagrados en el primer artículo de la Declaración Americana de Derechos y Deberes. Los países de América Latina, en el marco de dicha obligación, han adoptado posturas diversas frente a los derechos reproductivos, específicamente en lo que refiere a la despenalización del aborto consolidando tres grandes tendencias regionales que muestran aciertos y desaciertos. El presente artículo que surge como reflexión personal propuesta como aporte académico en el marco de los debates jurídicos llevados a cabo durante el I Congreso Latinoamericano Jurídico sobre Derechos Reproductivos, tiene como objetivo realizar una mirada a dichas tendencias con el fin de dar un panorama general de la situación de América Latina y su deuda frente a los derechos reproductivos y de esta manera pensar propuestas más holísticas para alcanzar la realización de dichos derechos, y consecuentemente seguir promoviendo progresivamente el desarrollo del derecho a la vida, la libertad y la seguridad personal.Palabras clave: derechos reproductivos, vida, libertad personal, progresividad.AbstractThe progressive development of the right to life, liberty and personal security has been enriched by the struggle for and subsequent onset of reproductive rights, in as much as they have widened the State’s obligations towards the respect of human rights and in particular those enumerated in the first article of the American Declaration of the Rights and Duties. Latin American countries, within these requirements, have taken diverse stances towards reproductive rights, specifically with regards to the decriminalization of abortion, which can be reduced into three major trends representing successes as well as errors. This article comes as a personal reflection, and proposed as an academic contribution, in the context of legal debates held during the First Latin American Congress on Reproductive Rights Law. It is aimed at taking a look at these trends in order to give an overview on the situation in Latin America and its debt to reproductive rights, and, in this way, to ponder about more holistic proposals to achieve their fulfillment, hence progressively promoting the development of the right to life, to liberty and to personal security. Keywords: Reproductive rights, life, personal liberty, progressiveness.

The'cave' mineral oxammite: a high resolution thermogravimetry and Raman spectroscopic study

The thermal decomposition of natural ammonium oxalate known as oxammite has been studied using a combination of high resolution thermogravimetry coupled to an evolved gas mass spectrometer and Raman spectroscopy coupled to a thermal stage. Three mass loss steps were found at 57, 175 and 188°C attributed to dehydration, ammonia evolution and carbon dioxide evolution respectively. Raman spectroscopy shows two bands at 3235 and 3030 cm-1 attributed to the OH stretching vibrations and three bands at 2995, 2900 and 2879 cm-1, attributed to the NH vibrational modes. The thermal degradation of oxammite may be followed by the loss of intensity of these bands. No intensity remains in the OH stretching bands at 100°C and the NH stretching bands show no intensity at 200°C. Multiple CO symmetric stretching bands are observed at 1473, 1454, 1447 and 1431cm-1, suggesting that the mineral oxammite is composed of a mixture of chemicals including ammonium oxalate dihydrate, ammonium oxalate monohydrate and anhydrous ammonium oxalate.

Towards a single crystal Raman spectrum of kaolinite at 77 K

The Raman spectra at 77 K of the hydroxyl stretching of kaolinite were obtained along the three axes perpendicular to the crystal faces. Raman bands were observed at 3616, 3658 and 3677 cm−1 together with a distinct band observed at 3691 cm−1 and a broad profile between 3695 and 3715 cm−1. The band at 3616 cm−1 is assigned to the inner hydroxyl. The bands at 3658 and 3677 cm−1 are attributed to the out-of-phase vibrations of the inner surface hydroxyls. The Raman spectra of the in-phase vibrations of the inner-surface hydroxyl-stretching region are described in terms of transverse and longitudinal optic splitting. The band at 3691 cm−1 is assigned to the transverse optic and the broad profile to the longitudinal optic mode. This splitting remained even at liquid nitrogen temperature. The transverse optic vibration may be curve resolved into two or three bands, which are attributed to different types of hydroxyl groups in the kaolinite.