Mössbauer, X-ray and Magnetic Studies of Black Sand from the Italian Mediterranean Sea

The study of natural magnetic sands is instrumental to investigate the geological aspects of their formation and of the origin of their territory. In particular, Mössbauer spectroscopy provides unique information on their iron content and on the oxidation state of iron in their mineral composition. The Italian coast on the Mediterranean Sea near Rome is known for the presence of highly magnetic black sands of volcanic origin. A study of the room temperature Mössbauer spec- trum, powder X-ray diffraction, energy dispersive X-ray spectroscopy, and magnetic measurements of a sample of black magnetic sand collected on the seashore of the town of Ladispoli is performed. This study reveals magnetite as main constituent with iron in both tetrahedral and octahedral sites. Minor constituents are the iron minerals hematite and ilmenite, the iron containing minerals diopsite, gossular, and allanite, as well as ubiquitous sanidine, quartz, and calcite.

Chiral Templating Activity of Tris(bipyridine)ruthenium(II) Cation in the Design of Three-Dimensional (3D) Optically Active Oxalate-Bridged {[Ru(bpy) 3 ][Cu 2 x Ni 2(1 - x ) (C 2 O 4 ) 3 ]} n (0 ≤ x ≤ 1; bpy = 2,2‘-bipyridine): Structural, Optical, and Magnetic Studies

Three-dimensional oxalate-based {[Ru(bpy)3][Cu2xNi2(1-x)(ox)3]}n (0≤ x ≤ 1, ox = C2O42-, bpy = 2,2‘bipyridine) were synthesized. The structure was determined for x = 1 by X-ray diffraction on single crystal. The compound crystallizes in the cubic space group P4132. It shows a three-dimensional 10-gon 3-connected (10,3) anionic network where copper(II) has an unusual tris(bischelated) environment. X-ray powder diffraction patterns and their Rietveld refinement show that all the compounds along the series are isostructural and single-phased. According to X-ray absorption spectroscopy, copper(II) and nickel(II) have an octahedral environment, respectively elongated and trigonally distorted. As shown by natural circular dichroism, the optically active forms of {[Ru(bpy)3][CuxNi2(1-x)(ox)3]}n are obtained starting from resolved Δ- or Λ-[Ru(bpy)3]2+. The Curie−Weiss temperatures range between −55 (x = 1) and −150 K (x = 0). The antiferromagnetic exchange interaction thus decreases when the copper contents increases in agreement with the crystallographic structure of the compounds and the electronic structure of the metal ions. At low temperature, the compounds exhibit complex long-range ordered magnetic behavior.

Bedouin in the Negev and Environmental Studies: Current and Future Research Prospects

Environmental aspects are increasingly being integrated in Negev Bedouin studies by both, NGO activists and scholars. We will present these recent works and discuss new concepts and methodologies of environmental studies with potential relevance in the field of Negev Bedouin studies. We will then identify research areas where environmental and development approaches converge or diverge with mainstream social sciences on this specific field of research. While most of the Bedouin population in southern Israel lives in urban centers in the Northern Negev, a large part of Bedouin people live in unrecognized clusters of houses in remote areas. Extensive livestock rearing is an important source of livelihood at least for non-urbanized Bedouin, the latter forming the lowest economic strata of the Israeli spectrum of incomes. Numerous stressors affect this Bedouin community enduring uncertain livelihood and access to land. The erratic precipitations from year to year and long-term changes in precipitation trends are a source of great uncertainty. With a significant price increase for feeding supplements to compensate for dry years, livestock rearing has become a harsher source of livelihood. Land scarcity for grazing adds to the difficulty in ensuring enough income for living. Studies in the last 15 years have described several livelihood strategies based on a livestock rearing semi-nomadic economy in the Negev. A number of other analyses have shown how Bedouin herders and governmental agencies have found agreements at the advantage of both, the agencies and the herders. New concepts such as transformability, resilience and adaptation strategies are important tools to analyze the capacity of vulnerable communities to cope with an ever increasing livelihood uncertainty. Such research concepts can assist in better understanding how Bedouin herders in the Negev may adapt to climate and political risks.

Liberalism and racism: an ‘elective affinity’?

This appraisal of David Scott FitzGerald and David Cook-Martín's Culling the Masses: The Democratic Origins of Racist Immigration Policy in the Americas argues that there is no ‘elective affinity’ between liberalism and racism, which is the core argument of the book. The notion of ‘elective affinity’, which the authors borrow from Max Weber, requires a structural homology between the ‘electively’ related elements that just does not exist in this case. The relationship between both is entirely contingent, ‘racism’ being a doctrine of inter-group relations while ‘liberalism’ is a doctrine of intra-group relations, with no consideration of how the boundaries of the group are constituted.