2,821 research outputs found

    First-Principles Simulations of Lithium Melting: Stability of the bcc Phase Close to Melting

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    We report large-scale first-principles simulations of melting of four different phases of Li at pressures ranging from 0 to 50 GPa. We find excellent agreement with existing experimental data at low pressures, and confirm that above 10 GPa the melting line develops a negative slope, in parallel to what occurs for Na at 30 GPa. Surprisingly, our results indicate that the melting temperature of the bcc phase is always higher than that of fcc Li, suggesting the intriguing possibility of the existence of a narrow field of bcc stability separating the fcc and liquid phases, as predicted by Alexander and McTague [Phys. Rev. Lett. 41, 702 (1978)]

    Effects of Slag-Based Fertilizer to Mitigate Salinity Stress on Greenhouse Durum Wheat (Triticum Durum Desf.) Cultivars

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    For a modern agricultural, the search for sustainable practices to increase productivity is fundamental. Steel slag have been studied for their potential use in agriculture. These substances present a great possibility of agricultural applications since they are rich in nutrients, which enhance plant uptake. In this regard, the effect of steel slag based-fertilizer was investigated in the greenhouse durum wheat cultivation in pots under salt-stress conditions. Two slag doses: 10 g slag/ kg soil (D1) and 20 g slag/ kg soil (D2) were evaluated under no salt-stress (0 mM NaCl) and salt-stress conditions (100 mM NaCl) for salinity stress mitigation. Morpho-physiological and biochemical parameters of wheat were measured and compared to the different treatments. Wheat exposure to salinity decreased its biomass, stomatal conductance, efficiency of photosystem II, protein content and increased total soluble sugars, hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents. Amended plants with 10 g slag/ kg soil (D1), led to a significant improve in biomass with an increase of shoot and root dry weights (133% and 400% respectively), stomatal conductance (22 %), soluble sugars (14 %) and protein content (158%) under salinity conditions as compared to the control treatment 0 g slag/ kg soil (C), indicating a positive influence on durum wheat plants. However, soil enrichment with 20 g slag/ kg soil (D2) decreased plant growth parameters and presented the highest levels of H2O2 and MDA contents compared to the control and treatment D1 after three months of cultivation under salt-stress. This study supports the hypothesis of the application of slag at lower dose improve productivity of durum wheat and mitigate salinity stress

    Effects of Slag Applications and Salinity Stress on Greenhouse Durum Wheat (Triticum durum Desf.) Plants

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    The search for sustainable practices to increase productivity is a fundamental need in current agriculture. Steel slag has been studied for its potential use in agriculture. These substances present a great ability of agricultural applications since they are rich in nutrients. The effect of steel slag-based fertilizer was investigated on greenhouse durum wheat cultivar under salt-stress conditions. Two doses of slag: 10 g slag/ kg soil (D1) and 20 g slag/ kg soil (D2) were evaluated under no salt-stress (0 mM NaCl) and salt-stress conditions (100 mM NaCl) for salinity stress mitigation. Morpho-physiological and biochemical parameters of wheat were measured and compared to the different treatments. Exposure of wheat to salinity decreased its biomass, stomatal conductance, efficiency of photosystem II, and protein content, but it increased total soluble sugars, hydrogen peroxide (H2O2), and malondialdehyde (MDA) contents. Amended plants with 10 g slag/ kg soil (D1) led to a significant improvement in biomass with an increase of shoot and root dry weights (133% and 400% respectively), stomatal conductance (22 %), soluble sugars (14 %), and protein content (158%) under saline conditions compared to the control treatment with 0 g slag/ kg soil (C), thus indicating a positive influence on durum wheat plants. Soil enrichment with 20 g slag/kg soil (D2) decreased plant growth parameters and presented the highest levels of H2O2 and MDA contents compared to the control and treatment (D1) after three months of cultivation under salt stress. This study supports the hypothesis of the application of slag at lower dose, which improves productivity of durum wheat and mitigate salinity stress

    Effects of Slag-Based Fertilizer to Mitigate Salinity Stress on Greenhouse Durum Wheat (Triticum Durum Desf.) Cultivars

    Get PDF
    For a modern agricultural, the search for sustainable practices to increase productivity is fundamental. Steel slag have been studied for their potential use in agriculture. These substances present a great possibility of agricultural applications since they are rich in nutrients, which enhance plant uptake. In this regard, the effect of steel slag based-fertilizer was investigated in the greenhouse durum wheat cultivation in pots under salt-stress conditions. Two slag doses: 10 g slag/ kg soil (D1) and 20 g slag/ kg soil (D2) were evaluated under no salt-stress (0 mM NaCl) and salt-stress conditions (100 mM NaCl) for salinity stress mitigation. Morpho-physiological and biochemical parameters of wheat were measured and compared to the different treatments. Wheat exposure to salinity decreased its biomass, stomatal conductance, efficiency of photosystem II, protein content and increased total soluble sugars, hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents. Amended plants with 10 g slag/ kg soil (D1), led to a significant improve in biomass with an increase of shoot and root dry weights (133% and 400% respectively), stomatal conductance (22 %), soluble sugars (14 %) and protein content (158%) under salinity conditions as compared to the control treatment 0 g slag/ kg soil (C), indicating a positive influence on durum wheat plants. However, soil enrichment with 20 g slag/ kg soil (D2) decreased plant growth parameters and presented the highest levels of H2O2 and MDA contents compared to the control and treatment D1 after three months of cultivation under salt-stress. This study supports the hypothesis of the application of slag at lower dose improve productivity of durum wheat and mitigate salinity stress

    Manganite charge and orbitally ordered and disordered states probed by Fe substitution into Mn site in LnBaMn1.96Fe0.04O5, LnBaMn1.96Fe0.04O6 and LnBaMn1.96Fe0.04O5.5 (Ln=Y, Gd, Sm, Nd, Pr, La)

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    The layered manganese oxides LnBaMn1.96Fe0.04Oy (Ln=Y, Gd, Sm, Nd, Pr, La) have been synthesized for y=5, 5.5 and 6. In the oxygen-saturated state (y=6) they exhibit the charge and orbital order at ambient temperature for Ln=Y, Gd, Sm, but unordered eg-electronic system for Ln=La,Pr,Nd. Fourfold increase of quadrupole splitting was observed owing to the charge and orbital ordering. This is in agreement with the jumplike increase in distortion of the reduced perovskite-like cell for the charge and orbitally ordered manganites compared to the unordered ones. Substitution of 2 percents of Mn by Fe suppresses the temperatures of structural and magnetic transitions by 20 to 50 K. Parameters of the crystal lattices and the room-temperature M\"{o}ssbauer spectra were studied on forty samples whose structures were refined within five symmetry groups: P4/mmm, P4/nmm, Pm-3m, Icma and P2/m. Overwhelming majority of the Fe species are undifferentiated in the M\"{o}ssbauer spectra for most of the samples. Such the single-component spectra in the two-site structures are explained by the preference of Fe towards the site of Mn(III) and by the segmentation of the charge and orbitally ordered domains.Comment: 8 figures; figures 2 and 3 were revise

    A knowledge-based design advisory system for collaborative design for micromanufacturing

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    The manufacture of microproducts differs from that of conventional products in many ways, not only in the sizes, but also in issues concerning the effects of material properties, tools, and manufacturing equipment. There was a need for a new design methodology and associated design tools to aid designers in assessing the design of their microproducts by considering new micromanufacturing capabilities and constraints. A knowledge-based design advisory system (DAS) was, therefore, developed in MASMICRO in which the knowledge-based system with dedicated assessment modules and knowledge representatives based on the ontology was created to implement the distributed design and manufacturing assessment for micromanufacturing. The modules address the assessment on geometrical features relating to manufacturability, manufacturing processes, selection of materials, tools, and machines, as well as manufacturing cost. The Microsoft C# programming language, ASP.NET web technology, Prolog, and Microsoft Access database were used to develop the DAS. The test on the DAS prototype system was found to provide an increase of design efficiency due to more efficient use of design and manufacturing knowledge and afforded a web-based collaborative design environment

    Coexistence between renal cell cancer and Hodgkin's lymphoma: A rare coincidence

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    BACKGROUND: Renal cell carcinoma is the most common kidney tumor in adults and accounts for approximately 3% of adult malignancies. An increased incidence of second malignancies has been well documented in a number of different disorders, such as head and neck tumors, and hairy cell leukemia. In addition, treatment associated second malignancies (usually leukemias and lymphomas but also solid tumors) have been described in long term survivors of Hodgkin's lymphoma (HL), Non Hodgkin's lymphoma and in various pediatric tumors. CASE PRESENTATION: We present the case of a 66 year-old woman with abdominal pain and dyspnea. We performed a thorax CT scan that showed lymph nodes enlargement and subsequently by presence of abdominal pain was performed an abdominal and pelvis CT scan that showed a right kidney tumor of 4 × 5 cms besides of abdominal lymph nodes enlargement. A radical right nephrectomy was designed and Hodgkin's lymphoma was diagnosed in the abdominal lymph nodes while renal cell tumor exhibited a renal cell cancer. Patient received EVA protocol achieving complete response. CONCLUSION: We described the first case reported in the medical literature of the coexistence between Hodgkin's lymphoma and renal cell cancer. Previous reports have shown the relationship of lymphoid neoplasms with solid tumors, but they have usually described secondary forms of cancer related to chemotherapy

    Comparative efficacy of ultrasound-guided and stimulating popliteal-sciatic perineural catheters for postoperative analgesia

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    Perineural catheter insertion using ultrasound guidance alone is a relatively new approach. Previous studies have shown that ultrasound-guided catheters take less time to place with high placement success rates, but the analgesic efficacy compared with the established stimulating catheter technique remains unknown. We tested the hypothesis that popliteal-sciatic perineural catheter insertion relying exclusively on ultrasound guidance results in superior postoperative analgesia compared with stimulating catheters. Preoperatively, subjects receiving a popliteal-sciatic perineural catheter for foot or ankle surgery were assigned randomly to either ultrasound guidance (bolus via needle with non-stimulating catheter insertion) or electrical stimulation (bolus via catheter). We used 1.5% mepivacaine 40 mL for the primary surgical nerve block and 0.2% ropivacaine (basal 8 mL·hr−1; bolus 4 mL; 30 min lockout) was infused postoperatively. The primary outcome was average surgical pain on postoperative day one. Forty of the 80 subjects enrolled were randomized to each treatment group. One of 40 subjects (2.5%) in the ultrasound group failed catheter placement per protocol vs nine of 40 (22.5%) in the stimulating catheter group (P = 0.014). The difference in procedural duration (mean [95% confidence interval (CI)]) was −6.48 (−9.90 - −3.05) min, with ultrasound requiring 7.0 (4.0-14.1) min vs stimulation requiring 11.0 (5.0-30.0) min (P < 0.001). The average pain scores of subjects who provided data on postoperative day one were somewhat higher for the 33 ultrasound subjects than for the 26 stimulation subjects (5.0 [1.0-7.8] vs 3.0 [0.0-6.5], respectively; P = 0.032), a difference (mean [95%CI]) of 1.37 (0.03-2.71). For popliteal-sciatic perineural catheters, ultrasound guidance takes less time and results in fewer placement failures compared with stimulating catheters. However, analgesia may be mildly improved with successfully placed stimulating catheters. Clinical trial registration number NCT00876681
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