Crystal-chemistry of sulfates from the Apuan Alps, Tuscany, Italy. VIII. New data on khademite, Al(SO 4)F(H 2 O) 5

Khademite, ideally Al(SO4)F(H2O)5, from the Monte Arsiccio mine, Apuan Alps, Tuscany, Italy, has been characterised through quantitative electron microprobe analysis, micro-Raman spectroscopy and single-crystal X-ray diffraction. Khademite occurs as colourless to whitish tabular crystals, up to 5 mm. Electron microprobe analysis (in wt.%, average of 20 spot analyses) gave: SO3 35.43, Al2O3 21.27, F 6.92, H2Ocalc 39.73, sum 103.35, -O = F 2.92, total 100.43. On the basis of 10 anions per formula unit, assuming the occurrence of 5 H2O groups and 1 (F+OH) atom per formula unit, its chemical formula can be written as Al0.96S1.02O4[F0.84(OH)0.16]Σ1.00·5H2O. The Raman spectrum of khademite is characterised by the occurrence of vibrational modes of SO4 groups and by broad and strong bands due to the O-H stretching modes. Khademite is orthorhombic, space group Pcab, with unit-cell parameters a = 11.1713(2), b = 13.0432(3), c = 10.8815(2) Å, V = 1585.54(5) Å3 and Z = 8. The crystal structure refinement converged to R1 = 0.0293 on the basis of 2359 unique reflections with Fo > 4σ(Fo) and 152 refined parameters. The crystal structure of khademite is characterised by the alternation, along b, of two distinct kinds of {010} layers, one formed by [001] rows of isolated Al-centred octahedra, connected to each other through H bonds, and the other showing isolated SO4 groups. Along b, oxygen atoms belonging to SO4 groups act as acceptor of H bonds from H2O groups coordinating Al atoms. The new data improved the description of the H bonds in khademite and led us to discuss about the possible existence of its (OH)-analogue, rostite. In addition, Raman spectroscopic data were collected on the same crystal used for the crystal-chemical characterisation, allowing a comparison with previous results

Tetrahedrite-(Hg), a new 'old' member of the tetrahedrite group

Tetrahedrite-(Hg), Cu6(Cu4Hg2)Sb4S13, has been approved as a new mineral species using samples from Buca della Vena mine (hereafter BdV), Italy, Jedová hora (Jh), Czech Republic and RoŽÅ 1/2ava (R), Slovakia. It occurs as anhedral grains or as tetrahedral crystals, black in colour, with metallic lustre. At BdV it is associated with cinnabar and chalcostibite in dolomite veins. At Jh, tetrahedrite-(Hg) is associated with baryte and chalcopyrite in quartz-siderite-dolomite veins; at R it is associated with quartz in siderite-quartz veins. Tetrahedrite-(Hg) is isotropic, greyish-white in colour, with creamy tints. Minimum and maximum reflectance data for Commission on Ore Mineralogy wavelengths in air (BdV sample), R in %) are 32.5 at 420 nm; 32.9 at 546 nm; 33.2 at 589 nm; and 30.9 at 650 nm. Chemical formulae of the samples studied, recalculated on the basis of 4 (As + Sb + Bi) atoms per formula unit, are: (Cu9.44Ag0.07)Σ9.51(Hg1.64Zn0.36Fe0.06)Σ2.06Sb4(S12.69Se0.01)Σ12.70 (BdV), Cu9.69(Hg1.75Fe0.25Zn0.06)Σ2.06(Sb3.94As0.06)S12.87 (Jh) and (Cu9.76Ag0.04) Σ9.80(Hg1.83Fe0.15Zn0.10)Σ2.08(Sb3.17As0.58Bi0.25)S13.01 (R). Tetrahedrite-(Hg) is cubic, I3m, with a = 10.5057(8) Å, V = 1159.5(3) Å3 and Z = 2 (BdV). Unit-cell parameters for the other two samples are a = 10.4939(1) Å and V = 1155.61(5) Å3 (Jh) and a = 10.4725(1) Å and V = 1148.55(6) Å3 (R). The crystal structure of tetrahedrite-(Hg) has been refined by single-crystal X-ray diffraction data to a final R1 = 0.019 on the basis of 335 reflections with Fo > 4σ(Fo) and 20 refined parameters. Tetrahedrite-(Hg) is isotypic with other members of the tetrahedrite group. Mercury is hosted at the tetrahedrally coordinated M(1) site, along with minor Zn and Fe. The occurrence of Hg at this position agrees both with the relatively large M(1)-S(1) bond distance (2.393 Å) and the refined site scattering. Previous occurrences of Hg-rich tetrahedrite and tetrahedrite-(Hg) are reviewed, and its relations with other Hg sulfosalts are discussed

Crystal-chemistry of sulfates from the apuan alps (tuscany, italy). VI. Tl-bearing alum-(k) and voltaite from the fornovolasco mining complex

Thallium-bearing samples of alum-(K) and voltaite from the Fornovolasco mining complex (Apuan Alps, Tuscany, Italy) have been characterized through X‑ray diffraction, chemical analyses, micro-Raman, infrared (FTIR), Mössbauer, and X-ray absorption spectroscopy (XAS). Alum-(K) occurs as anhedral colorless grains or rarely as octahedral crystals, up to 5 mm. Electron-microprobe analysis points to the chemical formula (K0.74Tl0.10)ς0.84(Al0.84Fe0.14)ς0.98S2.03O8·12H2O. The occurrence of minor NH4+ $ext{NH}_{4}^{+}$ was detected through FTIR spectroscopy. Its unit-cell parameter is a = 12.2030(2) Å, V = 1817.19(9) Å3, space group Pa3¯. $Paar{3}.$Its crystal structure has been refined down to R1 = 0.0351 for 648 reflections with F o > 4σ(Fo) and 61 refined parameters. The crystal structure refinement agrees with the partial substitution of K by 12 mol% Tl. This substitution is confirmed by XAS data, showing the presence of Tl+ having a first coordination shell mainly formed by 6 O atoms at 2.84(2) Å. Voltaite occurs as dark green cubic crystals, up to 1 mm in size. Voltaite is chemically zoned, with distinct domains having chemical formula (K1.94Tl0.28)σ2.22(Fe2+3.57Mg0.94Mn0.55)σ5.06Fe3+3.06Al0.98S11.92O4818H2O and (K2.04Tl0.32)σ2.36(Fe2+3.83Mg0.91Mn0.29)σ5.03Fe3+3.05Al0.97S11.92O48 18H2O, respectively. Infrared spectroscopy confirmed the occurrence of minor NH4+ also in voltaite. Its unit-cell parameter is a = 27.2635 Å, V = 20265(4) Å3, space group Fd3c. The crystal structure was refined down to R1 = 0.0434 for 817 reflections with Fo > 4σ(Fo) and 87 refined parameters. The partial replacement of K by Tl is confirmed by the structural refinement. XAS spectroscopy showed that Tl+ is bonded to six O atoms, at 2.89(2) Å. The multi-technique characterization of thallium-bearing alum-(K) and voltaite improves our understanding of the role of K-bearing sulfates in immobilizing Tl in acid mine drainage systems, temporarily avoiding its dispersion in the environment

Loving work: drawing attention to pleasure and pain in the body of the cultural worker

In this article, we present our current research into the body and mind at work, with a particular focus on experiences and implications of enjoyment and love of work within the culture sector. This research is developed through the project Manual Labours that explores the historical conditioning between the body and mind in the so-called immaterial labour conditions. The project aims to identify positive and negative affective labour and the role that physical relationships to work can have in helping conceptualise current working conditions. The enjoyment of work leads to complex differentiations between work and life. This article explores the implications of exploitative labour conditions as self-employed or salaried passionate workers are internalising and developing a sense of ‘un-alienated’ ownership over their wage labour

Candidemia after cardiac surgery in the intensive care unit: an observational study

Candidemia is a well-recognized complication of hospital stay, especially in critically ill patients. There is not a general consensus that predictors for candidemia in cardiosurgical intensive care unit (cICU) are different from a general ICU and it has been reported that cardiopulmonary bypass time is a specific risk factor in the cICU. We performed a prospective study to evaluate the main predictors for candidemia in patients admitted to the cICU. Included patients were adults admitted between July 2005 and December 2007 with an ICU-length of stay (ICU-LOS) ≥48 hours after cardiac surgery. Exclusion criteria were solid organ or bone marrow transplants, previous diagnosis of candidemia or other invasive infections and ICU stay before surgery. A multiple regression analysis was performed to identify the risk factors. Among 1955 patients admitted to the cICU, 345 were enrolled. Only 26 patients (1.3%) had candidemia after an ICU-LOS of 20 days (inter-quartile range, IQR 8-49 days). Total parenteral nutrition [odds ratio (OR) = 9.56; confidence interval (CI) = 1.741-52.534], severe sepsis (OR = 4.20; CI = 1.292-13.667), simplified acute physiology score II (OR = 1.16; CI = 1.052-1.278) and ICU-LOS >20 days (OR=6.38; CI = 1.971-20.660) were independent predictors of candidemia. Patients undergoing cardiac surgery developed candidemia late after cICU admission and the independent predictors were similar to the general ICU. © 2011 Published by European Association for Cardio-Thoracic Surgery

Estudio y desarrollo de un secadero de adobes de ladrillos macizos

Se presenta el estudio y desarrollo de un secadero de adobes de una fábrica de ladrillosmacizos de la zona de Makalle (Chaco). Se obtuvieron curvas representativas del proceso de secado para una capacidad de 5000 adobes en el interior del secadero. Se logró determinar para una temperatura aproximada de 50ºC del aire que ingresa al secadero, la cantidad de agua extraída de los adobes es de 6265 kg y el tiempo final del proceso de secado es de aproximadamente 60 horas. Además se seleccionaron los diferentes componentes del secadero como ser: ventiladores, economizador y bomba de calor.

Accuracy of Plateau Pressure and Stress Index to Identify Injurious Ventilation in Patients with Acute Respiratory Distress Syndrome.

BACKGROUND: Guidelines suggest a plateau pressure (PPLAT) of 30 cm H(2)O or less for patients with acute respiratory distress syndrome, but ventilation may still be injurious despite adhering to this guideline. The shape of the curve plotting airway pressure versus time (STRESS INDEX) may identify injurious ventilation. The authors assessed accuracy of PPLAT and STRESS INDEX to identify morphological indexes of injurious ventilation. METHODS: Indexes of lung aeration (computerized tomography) associated with injurious ventilation were used as a "reference standard." Threshold values of PPLAT and STRESS INDEX were determined assessing the receiver-operating characteristics ("training set," N = 30). Accuracy of these values was assessed in a second group of patients ("validation set," N = 20). PPLAT and STRESS INDEX were partitioned between respiratory system (Pplat,Rs and STRESS INDEX,RS) and lung (PPLAT,L and STRESS INDEX,L; esophageal pressure; "physiological set," N = 50). RESULTS: Sensitivity and specificity of PPLAT of greater than 30 cm H(2)O were 0.06 (95% CI, 0.002-0.30) and 1.0 (95% CI, 0.87-1.00). PPLAT of greater than 25 cm H(2)O and a STRESS INDEX of greater than 1.05 best identified morphological markers of injurious ventilation. Sensitivity and specificity of these values were 0.75 (95% CI, 0.35-0.97) and 0.75 (95% CI, 0.43-0.95) for PPLAT greater than 25 cm H(2)O versus 0.88 (95% CI, 0.47-1.00) and 0.50 (95% CI, 0.21-0.79) for STRESS INDEX greater than 1.05. Pplat,Rs did not correlate with PPLAT,L (R(2) = 0.0099); STRESS INDEX,RS and STRESS INDEX,L were correlated (R(2) = 0.762). CONCLUSIONS: The best threshold values for discriminating morphological indexes associated with injurious ventilation were Pplat,Rs greater than 25 cm H(2)O and STRESS INDEX,RS greater than 1.05. Although a substantial discrepancy between Pplat,Rs and PPLAT,L occurs, STRESS INDEX,RS reflects STRESS INDEX,L