Construction and qualification of the pre-series MQM superconducting quadrupoles for the LHC insertions

The LHC insertions will be equipped with individually powered MQM superconducting quadrupoles, produced in three versions with magnetic lengths of 2.4 m, 3.4 m, and 4.8 m. The quadrupoles feature a 56 mm aperture coil, designed on the basis of an 8.8 mm wide Rutherford-type NbTi cable for a nominal gradient of 200 T/m at 1.9 K and 5390 A. A total of 96 quadrupoles are in production in Tesla Engineering, UK. In this report we describe the construction of the pre-series MQM quadrupoles and present the results of the qualification tests.     

Potentiation of tumour necrosis factor-mediated cell killing by VP16 on human ovarian cancer cell lines. In vitro results and clinical implications

Synergism between recombinant human tumour necrosis factor (rHuTNF) and DNA topoisomerase II inhibitor VP16 during the killing of cells has been studied in six human ovarian cancer cell lines (A2774, A2780, SW626, IGROV-1, SKOV3, Pa1) and a cervical carcinoma cell line (Me180). Studies were performed using an assay of colony formation inhibition (drug treatment for 1 h) and a growth inhibition assay (continuous exposure for 20 h). Concomitant treatment of cells with VP16+rHuTNF enhanced cell killing in all the cell lines tested--an effect observed in both short- and long-term cytotoxicity assays. This study suggests that the activity of VP16 in ovarian cancer cell lines might be enhanced by rHuTNF in in vitro models.     

Analysis of thin walled structures using the boundary element method

In this article the direct boundary element formulations of stretching and bending plate problems are combined together to solve thin walled structures and other similar frames. The final system is obtained by assuming each individual plane structural element as a subregion. After the necessary transforms of these equations they can be combined together taking into account the displacement compatibility and equilibrium conditions.     

De nouveaux stannures ternaires de rhodium et d'elements des terres rares: TR1+xRh2Sn4−x, 0 ⩽ x ⩽ 0,5, TR = La - SmNew ternary stannides: TR1+xRh2Sn4−x, 0≦x≦0.5, TR = La - Sm

New ternary stannides are reported: RE_1+xRh₂Sn_4?x, 0 ? x ? 0,5 (RE = La ? Sm). NdRh₂Sn₄ has been characterized by single - crystal X-ray diffraction analysis. Its structure is of a new type with space group Pnma and Z = 4: a = 18,535(3), b = 4,463(1), $\text{c}\text{= 7,229(1)}\text{A}\text{?}$, D_x = 9,16 g.cm^?1, μ(AgKα) = 13,6 mm^?1, F(000) = 1300, R = 0,040 for 496 independent reflexions (R_w = 0,047). One of the tin sites can be partly occupied by rare earths atoms. The structure types of NdRh₂Sn₄ and Y₂Rh₃Sn₅ are closely related. LaRh₂Sn₄ does not exhibit superconductivity above 1.4 K.     

Neutron diffraction studies of CaMn2Ge2 and BaMn2Ge2 compounds: first examples of antiferromagnetic Mn planes in ThCr2Si2-type structure compounds

The magnetic properties of ThCr₂Si₂-type structure CaMn₂Ge₂ and BaMn₂Ge₂ compounds have been investigated by neutron diffraction experiments. In the whole temperature range studied (2–270 K), both compounds are purely collinear antiferromagnets (not detected by bulk magnetometric measurements) characterized by a stacking of antiferromagnetic (001) Mn planes. This peculiar Mn-sublattice magnetic behaviour seems to be related to the valency of the large metal. At 2 K, the total Mn moments are about 2.7 μ_B and 3.6 μ_B for CaMn₂Ge₂ and BaMn₂Ge₂, respectively. The results are compared with those of closely related RMnSi and RMnGe compounds and the isotypic alkali-metal manganese pnictides. The magnetic properties of the ThCr₂Si₂-type structure RMn₂X₂ (XSi, Ge) compounds are discussed.     

Magnetic properties of RCoSi (R La—Sm, Gd, Tb) compounds from susceptibility measurements and neutron diffraction studies

Investigations made by powder X-ray diffraction, susceptibility measurements and neutron diffraction experiments on the ternary silicide TbMnSi are reported. This compound crystallizes in the tetragonal structure of the CeFeSi-type (space group, P4/nmm). It exhibits a ferrimagnetic behaviour below T_c = 260 K. The magnetization value and the coercive field are 2.7 μ_B and 6 kOe, respectively, at 4.2 K. Neutron diffraction study confirms that both Mn and Tb sublattices order simultaneously at 260 K. The magnetic structure consists of Mn and Tb ferromagnetic (001) layers coupled antiferromagnetically (μ_Mn = 2.2 μ_B and μ_Tb = 8.45 μ_B at 2 K). The occurrence of a ferromagnetic Mn(001) layer in this CeFeSi-type structure compound is discussed.     

A new short-path distillation system applied to the reduction of cholesterol in butter and lard

A molecular distillation plant, built particularly to increase the separation efficiency and to obtain safer working conditions, was tested to remove cholesterol from anhydrous butter and lard. A preliminary experiment was carried out with butter to evaluate the fractionation obtained at temperatures between 190 and 250°C and residual pressures between 10⁻³ and 10⁻⁴ torr. A second experiment was carried out at 185°C and at the maximum operational vacuum, evaluating the fractionation achieved within a time scale between 30 and 180 min. Cholesterol was almost completely removed during the second hour with minimal loss of low-molecular weight triglycerides. An experiment was carried out with lard at 250°C and maximum achievable operational vacuum (10⁻⁴ Torr), lasting approximately 6 h, and cholesterol was removed almost completely during the second hour without significant modifications in the triglyceride composition. This situation remained constant throughout the duration of the test.     

Slicing the metric space to provide quick indexing of complex data in the main memory

Searching in a dataset for elements that are similar to a given query element is a core problem in applications that manage complex data, and has been aided by metric access methods (MAMs). A growing number of applications require indices that must be built faster and repeatedly, also providing faster response for similarity queries. The increase in the main memory capacity and its lowering costs also motivate using memory-based MAMs. In this paper, we propose the Onion-tree, a new and robust dynamic memory-based MAM that slices the metric space into disjoint subspaces to provide quick indexing of complex data. It introduces three major characteristics: (i) a partitioning method that controls the number of disjoint subspaces generated at each node; (ii) a replacement technique that can change the leaf node pivots in insertion operations; and (iii) range and k-NN extended query algorithms to support the new partitioning method, including a new visit order of the subspaces in k-NN queries. Performance tests with both real-world and synthetic datasets showed that the Onion-tree is very compact. Comparisons of the Onion-tree with the MM-tree and a memory-based version of the Slim-tree showed that the Onion-tree was always faster to build the index. The experiments also showed that the Onion-tree significantly improved range and k-NN query processing performance and was the most efficient MAM, followed by the MM-tree, which in turn outperformed the Slim-tree in almost all the tests.