Average Cr Research Articles

Functional Outcomes of the Renal Transplants Obtained from Controlled Donation Following Cardiopulmonary Death (DCD) with Compartmental Normothermic Extracorporeal Membrane Oxygenation Support (NECMO)

Introduction Since the implementation of the DCD protocol at our institution in 2012, some modifications have taken place in order to improve the organ viability. As for this, the NECMO has proven to be an effective method and to help reduce the ischemic organ damages. Objectives To analyse the functional outcomes of the transplanted kidneys (TK) obtained from DCD using NECMO. Methods We have reviewed the results from 15 kidney transplants (KT), whose organs where obtained from 9 DCD using NECMO as the preservation method, from 2015 to 2017 at our institution. Currently, in our protocol, arterial and venous femoral canulae and the aortic occlusion balloon catheter are placed in the operating room, on a premortem and setup. We have assessed the donors and recipient characteristics and also the TK outcomes, using a descriptive method from all our data available. Results From the 9 DCD, we have obtained 15 valid kidney grafts, who were transplanted at our institution, just one was not suitable due to anatomic alterations. The other 2 allografts were offered to other Hospitals. Donor age averaged 52 years and allografts recipients averaged 48 years. Four patients (26%) underwent previous kidney transplant, with an overall kidney allograft survival of 13.4 years. Prior to KT, 13% were on a pre-dyalisis basis and the remaining 86% were on renal replacement therapy for an average of 14 months. Cardiopulmonary death occurred within an average of 12.2 minutes following withdrawal of life support. From the 15 KT, 13 (83%) continue to function, 1 had arterial thrombosis which led to transplantectomy and the other suffered acute rejection. The 6 month average Cr was 1.6mg/dL. Delayed graft function, defined as at least one postoperative episode of dialysis, occurred in 40% of kidneys (6/15). Conclusion 1- The organ quality from DCD is comparable to brain death donors. 2- ECMO supported DCD is feasible and easily implemented if necessary resources are available 3- Helps optimizing the donation-renal transplant process as the medical team responsible is involved.

Allograft and Patient Outcomes of a Tumourectomized Kidney Transplant Program

Background There is an increased utilization of marginal donor kidneys for transplantation due to the shortage of donor kidneys. Patients with a small renal cell cancer occasionally undergo radical nephrectomy, which represents an opportunity to consider the utilization of these kidneys for transplantation that would otherwise be discarded. We report the long-term outcome of kidney transplant recipients who have received kidneys from live-unrelated donors with resected small renal cell cancers of less than 3 cm. Materials & Methods The potential recipients were informed and consent was obtained before they were listed for kidney transplantation by using a kidney graft, in which a small tumor was excised. The referral was sent from urologists to transplant team when a radical nephrectomy was decided as an option for treating a renal tumor. As such, the patient was offered an option of kidney donation after radical nephrectomy and the informed consent was signed. In our structured program, the decision for partial or radical nephrectomy for management of a small renal mass was purely made between the discussion of a patient and his or her treating urologist. The selection criteria for the potential donor and recipient have been established prior to implementation. The frozen section was performed after tumor excision on bench table to ensure the margin was clear prior to transplantation. The recipients were selected as age over 60 years or age 55 with urgent need for transplantation. Results From Feb 2007 to Aug 2017, 28 patients with a small renal mass chose radical nephrectomy and were considered suitable for kidney donation after tumor excision. The tumor size was from 1 cm to 4 cm, average 2.7 cm. There were 24 malignant tumors; with most of them were Fuhrman grade I-II; and 4 benign tumors. The recipients age were from 52-80 years old; average 63 year old at the time for kidney transplantation M:F=15:13. The average warm ischemic time was 5 minutes; cold ischemic time was from 155 minutes to 340 minutes (average 275). In our cohort the follow up period was from 2-10 years, median 7 years. There was no tumor recurrence. Of recipients, 68% are alive with average age 70 years old at follow up. The average Cr level was136 mmol/L. At early phase 3 patients developed urine leakage from the tumor excision area and one patient developed pseudoaneurysm, but all recoved well after interventional management. Conclusion Transplantation of tumourectomized kidneys from patients with small renal cell cancer is associated with comparable allograft and patient outcomes. The decision of utilizing these kidneys for transplantation needs careful informed consent process, balancing the benefit of kidney transplantation and the small but potential risk of tumour recurrence. The absence of tumor recurrence in this cohort may be associated with cold perfusion, which inhibits tumor cell proliferation and clear excision of tumor on bench table.

Removal of heavy metals and nutrients from wastewater using Salvinia molesta and Lemna gibba

As a result of industrialization and population growth, wastewater generation is increased worldwide. Heavy metals and excessive Nitrogen and Phosphates in industrial and municipal wastewater impose detrimental effects on environment and human health. The treatment of wastewater prior to release to water bodies is a vital necessity. Phytoremediation is an economically viable and eco-friendly plant based technique used to clean up contaminated water. The potential of aquatic macrophytes in removal of nutrients and heavy metals in wastewater is revealed by several studies. Eicchornia spp., Pistia spp., Salvinia spp., Azolla spp. and Duckweeds have shown their capacities in the removal of nutrients and heavy metals from wastewater in many studies. The aim of this study was to investigate the heavy metal (Cr, Cu and Fe) and nutrient removal efficiencies of Salvinia molesta and Duckweeds (Lemna gibba) from industrial wastewater in an operational period of seven days. The samples were analyzed for Nitrates, Nitrites, ammonia Nitrogen, Phosphates and heavy metals at 24 hour intervals. Biological oxygen demand, Chemical oxygen demand and total kjeldhal Nitrogen were analyzed at 7 day intervals. According to the results, the average Total Nitrogen removal efficiencies of S. molesta and L. gibba are 73.34% and 62.18% respectively. The average Total Phosphate removal efficiencies of S. molesta and L. gibba are 72.63% and 77.28% respectively. The average Cr, Cu,Fe, Ni and Pb removal efficiencies of S. molesta are 81.66%, 69.81%,65.26%,66.39% and 74.85% respectively. The average Cr, Cu, Fe, Ni and Pb removal efficiencies shown by L. gibba are 86.99%, 69.77%, 73.10%, 61.87% and 85.74% respectively. The results show that these two species are suitable candidates for polishing wastewater prior to release to water bodies. Key words: Phytoremediation, lemna gibba, Salvinia molesta

The Effects of Injected Vitamin D on Prognosis of Patients with Urosepsis.

The aim of this study was to evaluate the effect of prescribing vitamin D on improving the symptoms of patients diagnosed with urosepsis. The participants were randomly divided into two equal groups (each consisting of 50 patients). The patients in the first group received standard treatment with 300 000 units of injected vitamin with a volume of 1 cc. As for the patients in the second group, they received standard treatment along with 1 cc normal saline injected to them as placebo. Vital signs of the patients were checked every 6 h, while their CBC, EXR, CRP, creatinine, urea, and uric acid were checked 0, 24, 48, and 72 h following the interventions. Calcium, phosphorus, and vitamin D levels were measured 72 h following injection of the medicine. A significant difference was observed between the two groups in terms of the number of WBC's in 24th, 48th, and 72nd hours. A similarly significant difference was reported between the case and control group in terms of the average BUN within 24th, 48th, and 72nd hours. The difference observed between the two groups in terms of average Cr within the 0th, 24th, 48th, and 72nd hours and in terms of days of hospitalization was also significant. Considering these results and keeping in mind the fact that no particular side effects were reported as a result of utilizing muscular injections of vitamin D and the easy and cheap use of this medicine, it can be used in auxiliary treatment of patients with urosepsis.

Tuning the microstructure and mechanical properties of magnetron sputtered Cu-Cr thin films: The optimal Cr addition

Grain boundary (GB) engineering via alloying opens a pathway to design the interfaces in alloys for tuning their mechanical properties, thus it is quite critical to determine the optimum addition of alloying element. Here, we prepared immiscible Cu-Cr alloyed thin films by non-equilibrium magnetron sputtering deposition to study Cr alloying effects on the microstructure and mechanical properties of Cu thin films. It is found that Cr doping can notably refine the grains and promote the formation of fully nanotwinned columnar grains at low Cr volume concentrations (≤∼3.7 at.%) associated with the average GB Cr concentrations ≤ ∼15 at.%, beyond which the formation of nanotwins is significantly suppressed. The role of Cr atoms/clusters played in the twinning process is rationalized in terms of dislocation rebound-promotion mechanism. Importantly, a maximum hardness is discovered at the optimum Cr addition of ∼2.0 at.%. The Cr concentration-dependent hardness of Cu-Cr alloyed films was quantified by a combined strengthening model. The achievement of the maximum hardness was related to the greatest GB solute segregation-induced strength contribution. It is further uncovered that the Cu-Cr system exhibits strain rate sensitivity (SRS, m) monotonically reduced with increasing the Cr concentration, ranging from a positive m of 0.0314 (for pure Cu) to a negative m of −0.0245, which is attributed to a competition between the dislocation-boundary interactions (increasing m) and the dislocation-solute atoms interactions (decreasing m). These findings provide valuable insights into tuning the composition of alloyed thin films to achieve optimized mechanical performance.

Losses of Cr content in plant samples using digestion procedures with acids

In the WEPAL IPE 2009.2 proficiency test, Jožef Stefan Institute (JSI) participated by measuring Cr by k0-INAA; it was the only laboratory providing data by an instrumental technique. The JSI Cr result was about 38% higher than the assigned value in plant sample 124 (Lucerne/Medicago sativum). The same sample was again studied in 2012. This time, more labs, including JSI, used instrumental techniques and the average Cr result was higher and consistent with the 2009 and 2012 JSI results. From the results obtained in the present study, involving four INAA labs, it is confirmed that Cr losses in this sample occurred during the chemical digestion required by the techniques applied by other laboratories, illustrating the inherent advantage of nuclear techniques to be almost matrix independent and independent of the chemical state of the element under study.

Concept of Aided Phytostabilization of Contaminated Soils in Postindustrial Areas.

The experiment was carried out in order to evaluate the effects of trace element immobilizing soil amendments, i.e., chalcedonite, dolomite, halloysite, and diatomite on the chemical characteristics of soil contaminated with Cr and the uptake of metals by plants. The study utilized analysis of variance (ANOVA), principal component analysis (PCA) and Factor Analysis (FA). The content of trace elements in plants, pseudo-total and extracted by 0.01 M CaCl2, were determined using the method of spectrophotometry. All of the investigated element contents in the tested parts of Indian mustard (Brassica juncea L.) differed significantly in the case of applying amendments to the soil, as well as Cr contamination. The greatest average above-ground biomass was observed when halloysite and dolomite were amended to the soil. Halloysite caused significant increases of Cr concentrations in the roots. The obtained values of bioconcentration and translocation factors observed for halloysite treatment indicate the effectiveness of using Indian mustard in phytostabilization techniques. The addition of diatomite significantly increased soil pH. Halloysite and chalcedonite were shown to be the most effective and decreased the average Cr, Cu and Zn contents in soil.

Environmental radiation and potential ecological risk levels in the intertidal zone of southern region of Tamil Nadu coast (HBRAs), India

Natural radioactivity content and heavy metal concentration in the intertidal zone sand samples from the southern region of Tamil Nadu coast, India, have been analyzed using gamma ray spectrometer and ICP-OES, respectively. From gamma spectral analysis, the average radioactivity contents of 238U, 232Th, and 40K in the intertidal zone sand samples are 12.13±4.21, 59.03±4.26, and 197.03±26.24Bq/kg, respectively. The average radioactivity content of 232Th alone is higher than the world average value. From the heavy metal analysis, the average Cd, Cr, Cu, Ni, Pb, and Zn concentrations are 3.1, 80.24, 82.84, 23.66, 91.67, and 137.07ppm, respectively. The average Cr and Ni concentrations are lower, whereas other four metal (Cd, Cu, Pb, and Zn) concentrations are higher than world surface rock average values. From pollution assessment parameter values, the pollution level is “uncontaminated to moderately contaminated” in the study area.

Investigation on the structure and property of a gradient nanostructure CuCr25 with high hardness and high electrical conductivity

Surface mechanical attrition treatment (SMAT) was used to produce gradient nanostructure in CuCr25 alloy. A gradient structure up to 200 μm thick in its surface layer with grain size from nano-scale to micro-scale was obtained. The microstructural features of the surface layer produced by SMAT were systematically characterized. The average Cr and Cu grain size of the top surface layer was about 10 nm. The hardness of the SMATed surface layer after annealing treatment reached 475 HV which was three times higher than that of the original sample. The electrical conductivity of annealing sample was 46.5% IACS which was better than that of other nanocrystalline CuCr alloys. The SMAT treatment provides a new approach for preparation of CuCr alloy vacuum interrupters with high surface hardness and high electrical conductivity.

Atomic Scale Structural Characterization of Epitaxial (Cd,Cr)Te Magnetic Semiconductor

A detailed knowledge of the atomic structure of magnetic semiconductors is crucial to understanding their electronic and magnetic properties, which could enable spintronic applications. Energy-dispersive X-ray spectrometry (EDX) in the scanning transmission electron microscope and atom probe tomography (APT) experiments reveal the formation of Cr-rich regions in Cd1-x Cr x Te layers grown by molecular beam epitaxy. These Cr-rich regions occur on a length scale of 6-10 nm at a nominal Cr composition of x=0.034 and evolve toward an ellipsoidal shape oriented along directions at a composition of x=0.083. Statistical analysis of the APT reconstructed volume reveals that the Cr aggregation increases with the average Cr composition. The correlation with the magnetic properties of such (Cd,Cr)Te layers is discussed within the framework of strongly inhomogeneous materials. Finally, difficulties in accurately quantifying the Cr distribution in the CdTe matrix on an atomic scale by EDX and APT are discussed.

LSM/YSZ Button Cell Tests in Cathode Air with Measured Cr Concentrations

A test fixture and methodology was developed for testing anode-supported SOFC button cells downstream from a chromia pellet at a prescribed temperature for qualitative control of Cr volatility. An alumina foam coated with Cr-gettering Na2CO3 was placed downstream from the cell to capture Cr species from the cathode air by reacting to form Na2CrO4. The coating and reaction product are both water soluble, facilitating dissolution from the porous substrate for subsequent ICP analysis to determine the Cr concentration in the resulting solution. The mass of collected Cr is used to calculate the average Cr concentration in the known volume of air used during the test. Cells with LSM/YSZ cathodes were electrochemically tested for 600 to 1000 hours with chromia pellets at varying conditions of temperature and humidity to elicit varying levels of Cr volatility. Molar Cr concentrations of only 40 to 170 ppt caused ~4%/kh degradation.

A Forearc (Guleman, Elaziğreve;) Ophiolite: Evidence from Peridotite Mineral Geochemistry

The Guleman ophiolite, one of the most important ophiolitic massifs of the Southeast Anatolian Ophiolitic Belt, consists of a core of serpentinized mantle rocks overlain by an ultramafic sequence, layered and isotropic gabbro, and sheeted dykes. The ophiolite structurally overlies the Lower Miocene Lice Formation and is overlain by young sandstones and shales of the Upper Maashtrichtian‐Lower Eocene Hazar Complex and Middle Eocene Maden Complex. The Guleman ophiolite tectonically overlain by Precambrian to Upper Triassic Bitlis metamorphic massif.The mantle peridotites compose mainly of fresh and in place serpentinized harzburgite tectonite with local bands and lenses of dunites with large‐sized chromitite pods. The Guleman peridotites commonly show porphyroclastic texture, high‐temperature fabrics such as kink‐bands in olivines.According to microprobe analyses, the harzburgite and dunite have low CaO and Al2O3 abundance similar to Mariana forearc, and their average Cr‐ (=Cr/(Cr+Al) atomic) ratio of Cr‐spinelsis surprisingly high (>0.63) besides Fo content of olivine is between 90.9 to 92.3 in peridotites. According to Mg# (Mg/(Mg+Fe2+)) versus Cr# in spinel diagram, the degree of partial melting is higher than 35% and spinel values plot in the forearc peridotites field. The Gulemanharzburgites have low CaO, Al2O3 and TiO2 contents in orthopyroxene and clinopyroxene lammelles, resembling those of depleted harzburgites from modern forearcs and different from moderately depleted abyssal peridotites.Consequently, we propose that the Guleman peridotites form in a forearc setting during the subduction initiation that developed as a result of northward subduction of the southern branch of the Neo‐Tethys in response to the convergence between Arabian and Anatolian plates.

Crystal structure of bis-[(oxalato-κ2O1,O2)(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ4N)chromium(III)] dichromate octa-hydrate from synchrotron X-ray data.

The asymmetric unit of the title compound, [Cr(C2O4)(C10H24N4)]2[Cr2O7]·8H2O (C10H24N4 = 1,4,8,11-tetra-aza-cyclo-tetra-decane, cyclam; C2O4 = oxalate, ox) contains one [Cr(ox)(cyclam)]+ cation, one half of a dichromate anion that lies about an inversion centre so that the bridging O atom is equally disordered over two positions, and four water mol-ecules. The terminal O atoms of the dichromate anion are also disordered over two positions with a refined occupancy ratio 0.586 (6):0.414 (6). The CrIII ion is coordinated by the four N atoms of the cyclam ligand and one bidentate oxalato ligand in a cis arrangement, resulting in a distorted octa-hedral geometry. The Cr-N(cyclam) bond lengths are in the range 2.069 (2)-2.086 (2) Å, while the average Cr-O(ox) bond length is 1.936 Å. The macrocyclic cyclam moiety adopts the cis-V conformation. The dichromate anion has a staggered conformation. The crystal structure is stabilized by inter-molecular hydrogen bonds involving the cyclam N-H groups and water O-H groups as donors, and the O atoms of oxalate ligand, water mol-ecules and the Cr2O72- anion as acceptors, giving rise to a three-dimensional network.

Removal of Cr(VI) from groundwater by Fe(0)

This research was conducted to investigate the treatment of hexavalent chromium (Cr(VI)) by iron powder (Fe(0)) columns of simulated permeable reactive barriers with and without calcium carbonate (CaCO3). Two columns filled with Fe(0) were used as Cr(VI) removal equipment running at a flow velocity of 10 ml/min at room temperature. After 200 days running of the two columns, the results showed that Fe(0) was an effective material for Cr(VI) reduction with an average removal rate of above 84.6%. The performance of Column 2 with CaCO3 was better than Column 1 without CaCO3 in terms of average Cr(VI) removal rate. The presence of CaCO3 buffered the increasing pH caused by Fe(0) corrosion in Column 2 and enhanced the removal rate of Column 2. Scanning Electron Microscopy (SEM) images of Fe(0) in the three stages of running of the two columns illustrated that the coat layer of Column 1 was a little thicker than that of Column 2. Energy-dispersive spectrometry (EDS) results showed that the surface of Fe(0) of Column 2 contained more chromium elements. Raman spectroscopy found that all iron oxide was generated on the Fe(0) surface of Column 1 and Column 2 and chromium class objects were only detected on Fe(0) surface in Column 2.

Assessment of Bioavailability of Chromium (Cr), Vanadium (V) and Uranium (U) in Wild Plants in Siwaqa Area, Central Jordan

Surficial soil enriched with U-rich encrustations and green Cr-rich smectite covers large areas of Siwaqa, Central Jordan. The wide distribution of redox-sensitive elements (RSE) as chromium (Cr), vanadium (V) and uranium (U) in the top soil are related to the weathering action of alkaline surface and groundwater on the parent rocks. The bioavailability, distribution, sorption, and ecotoxicity of Cr, V, and U of the wild plants and top soils in the study area were investigated. A total number of 23 surface soil samples and 23 plant samples were collected and analyzed for the most toxic elements (Cr, V and U) by using Induced Coupled Plasma-Mass Spectrometry (ICP- MS). The average Cr, V and U values in the soil was 59, 6.6 and 67 mg/kg respectively. The transfer factors (TFs) of these elements have indicated that the highest Cr and V values (0.6 and 0.26 respectively) were in the wild plants and particularly in Bellevalia sp. The highest TF for U (0.25) was recorded in Onopordum transjordanicum. The uptake of elements by plants was dependent on the plant species and the concentration of elements in the soil. Differences between TFs values of these elements in the various plant species are related to the different characteristics of the plants. The comparative uptake of the studied RSE was affected by the numerous physical, chemical and biological conditions of the soil. The results of this work provide a valuable knowledge for understanding the bioavailability of some toxic elements in the soil and plants of Central Jordan. The results are expected to be of great help for the Jordanian Uranium Mining Company during their environmental risk assessments.

Metal ion levels in ceramic-on-ceramic THR with cobalt-chrome modular necks: analysis of cobalt and chromium serum levels in 23 healthy hip patients.

Modular necks in total hip replacement (THR) can be a source of metal ion release. We measured the level of cobalt (Co) and chromium (Cr) ions in the serum of 23 healthy volunteers with a well-functioning ceramic-on-ceramic THR of a particular design, containing a cobalt-chrome (Co-Cr) stem and a Co-Cr modular neck. Average Co in serum was 1,71 µg/l; median Co was 1.50 µg/l. No patient had Co levels higher than 3.70 µg/l. Average Cr level was 0.49 µg/l; in all but one patient Cr was below the detection limit (<0.50 µg/l). Co was higher for varus necks compared to all other subtypes: 2.14 µg/l vs 1.58 µg/l (p<0.05). The same system with Titanium modular necks shows lower Co serum levels: 1.26 µg/l (p<0.01 ). In conclusion, the hybrid THR Profemur Xm® - Procotyle L® with a Co-Cr modular neck on a Co-Cr stem design shows very low Cr ion serum levels in a randomly selected group of well-functioning hip patients. Co ion serum levels are low, but significantly higher for 8° varus necks, and Co levels are significantly higher than values of this system with a Titanium modular neck.

Serologic and radiographic outcome of total hip arthroplasty with CoCr modular neck at mid-term follow-up

The aim of this study is a radiographic evaluation and to determine serologic values of chromium and cobalt in the blood and urine of patients who have been implanted with a Stryker® ABG II Modular Neck and see if there is correlation with the features of prosthesis and patients. The study involves the collection of data from patients operated on for total hip model with the ABG II Modular Neck with a minimum follow-up of 1year. We evaluated 22 patients who underwent implantation of a hip prosthesis with modular neck in CoCr. Of these, the average Cr in the blood was 0.63μgL-1 (range 0.1-2.15μgL-1), the average of Co in the blood was 3.50μgL-1 (range 0.62-7.78μgL-1), the average Cr in the urine was 1.24μgL-1 (range 0.48-2.21μgL-1), and the average Co in urine was 14.22μgL-1 (range 3.3-31.2μgL-1). None of these patients had undergone revision surgery. Our study seems to indicate that the restoration of offset and age are correlated with the release of metal ions, although the correlation is weak and needs better methodological studies and a greater number of patients to confirm this hypothesis. Case series Level of Evidence 4.

Heavy metal deposition through rainfall in Chinese natural terrestrial ecosystems: Evidences from national-scale network monitoring

Industrialization and urbanization have led to increasingly serious levels of atmospheric heavy metal pollution, which is one of the main sources of heavy metals to terrestrial ecosystems. Therefore, it is essential to quantify atmospheric fluxes and explore their potential effects on natural ecosystems and human welfare. We monitored water-soluble heavy metals (lead (Pb), cadmium (Cd), and chromium (Cr)) in rainfalls on a monthly basis in 2013 and 2014, at 31 field stations located in typical natural Chinese ecosystems. The average soluble Pb, Cd, and Cr deposition was 1.90 ± 1.54, 0.28 ± 0.25, and 0.96 ± 0.48 mg m−2 yr−1, respectively, with a large variation among the different sites. Generally, the atmospheric deposition of soluble Pb, Cd, and Cr was higher in the southwest, central, south, and north China than in the northwest and northeast China, Inner Mongolia, and Qinghai-Tibet. As expected, the atmospheric heavy soluble metal deposition fluxes were significantly correlated with the number of vehicles (Ps < 0.1). The wet deposition of soluble Pb and Cr was positively correlated with oil and coal consumption, unlike Cd deposition. Moreover, soluble Pb and Cd in atmospheric wet deposition were positively correlated with the contents of Pb and Cd in soil at different regions. In this study, atmospheric heavy metal deposition through rainfall in typical natural ecosystems in China is assessed at the national scale, alerting potential ecological hazards resulting from an increasing atmospheric heavy metal deposition and providing a basis for future studies.

Approximate Riemann solvers for the cosmic ray magnetohydrodynamical equations

We analyze the cosmic-ray magnetohydrodynamic (CR MHD) equations to improve the numerical simulations. We propose to solve them in the fully conservation form, which is equivalent to the conventional CR MHD equations. In the fully conservation form, the CR energy equation is replaced with the CR "number" conservation, where the CR number density is defined as the three fourths power of the CR energy density. The former contains an extra source term, while latter does not. An approximate Riemann solver is derived from the CR MHD equations in the fully conservation form. Based on the analysis, we propose a numerical scheme of which solutions satisfy the Rankine-Hugoniot relation at any shock. We demonstrate that it reproduces the Riemann solution derived by Pfrommer et al. (2006) for a 1D CR hydrodynamic shock tube problem. We compare the solution with those obtained by solving the CR energy equation. The latter solutions deviate from the Riemann solution seriously, when the CR pressure dominates over the gas pressure in the post-shocked gas. The former solutions converge to the Riemann solution and are of the second order accuracy in space and time. Our numerical examples include an expansion of high pressure sphere in an magnetized medium. Fast and slow shocks are sharply resolved in the example. We also discuss possible extension of the CR MHD equations to evaluate the average CR energy.

Mineral chemistry and petrology of mantle peridotites from the Guleman ophiolite (SE Anatolia, Turkey): Evidence of a forearc setting

The mantle section of Guleman ophiolite, southeast (SE) Turkey consists mainly of harzburgites and dunite lenses and large chromitite pods. The average Cr ratio = [100 × Cr/(Cr + Al) atomic ratio] of Cr-spinels in harzburgites and dunites is remarkably high (>63). The forsterite (Fo) content of olivine is between 90.9 and 92.3 in harzburgites and dunites. These features indicate that the harzburgites and dunites resulted from >35% of partial melting of a depleted mantle source. Discriminant geochemical diagrams based on the mineral chemistry of harzburgites indicate a supra-subduction zone (SSZ) origin. Orthopyroxene and clinopyroxene from the Guleman harzburgites have low CaO, Al2O3 and TiO2 contents, resembling those of depleted harzburgites from modern forearcs and contrasting with moderately depleted abyssal peridotites. Consequently, we propose that the Guleman peridotites formed in a forearc setting during the subduction initiation that developed as a result of northward subduction of the southern branch of the Neo-Tethys in response to the convergence between the Arabian and Anatolian plates.