scholarly journals Formation of drop-shaped inclusions based on Pt, Pd, Au, Ag, Bi, Sb, Te, As during crystallization of the intermediate solid solution in the Cu-Fe-Ni-S system

2019 ◽  
Vol 489 (1) ◽  
pp. 70-74
Author(s):  
E. F. Sinyakova ◽  
V. I. Kosyakov ◽  
N. A. Goryachev

The phase and chemical composition of drop-shaped inclusions in directionally crystallized intermediate solid solution was studied. The initial melt contained (in mol.%): Fe 31,79; Cu 15,94; Ni 1,70; S 50,20; Sn 0,05; As 0,04; Pt, Pd, Rh, Ru, Ag, Au, Se, Te, Bi, Sb 0,03. Experimental data indicate the simultaneous crystallization of two types of liquids upon cooling of the initial sulfide melt. One of them is formed in the subsystem (Pd, Au, Ag)-(Bi, Sb, Te), and the second - in the subsystem Cu-(S, Bi, Sb, Te). When these liquids solidified, inclusions formed, which we divided into four classes. Class I has a eutectic-like structure with a matrix of Pd(Bi,Sb)xTe1-x solid solution and Au crystallites with Ag, Cu, and Pd impurities. Class II is formed from sulfosalts with inclusions of Bi and Au. Class III includes inclusions of sperrylite Pt(As,S)2. Class IV forms compound inclusions from fragments of classes I-III. The experiment described in the work showed a more complex behavior of noble metals and metalloid impurities during the crystallization of complex sulfide-metalloid melts compared with the previously described data of isothermal experiments.

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 531 ◽  
Author(s):  
Elena Sinyakova ◽  
Victor Kosyakov ◽  
Galina Palyanova ◽  
Nikolay Karmanov

We carried out a directed crystallization of a melt of the following composition (in mol. %): Fe 31.79, Cu 15.94, Ni 1.70, S 50.20, Sn 0.05, As 0.04, Pt, Pd, Rh, Ru, Ag, Au, Se, Te, Bi, and Sb by 0.03. The obtained cylindrical sample consisted of monosulfide solid solution (mss), nonstoichometric isocubanite (icb*), and three modifications of intermediate solid solution (iss1, iss2, iss3) crystallized from the melt. The simultaneous formation of two types of liquids separated during cooling of the parent sulfide melt was revealed. In the first, concentrations of noble metals associated with Bi, Sb, and Te were found. The second is related to Cu and was found to contain a large amount of S in addition to Bi and Sb. We established the main types of inclusions formed during fractional crystallization of Pt-bearing sulfide melt. It was shown that noble metals are concentrated in inclusions in the form of RuS2, PdTe2, (Pt,Pd)Te2, PtRhAsS, and Ag2Se, doped with Ag, Cu, and Pd, in mss and in the form of PtAs2; Au-doped with Ag, Cu, and Pd; Ag2Te; and Pd(Bi,Sb)xTe1−x in icb* and iss. As solid solutions in the base metal sulfides, Rh is present in mss, Sn in iss.


2020 ◽  
Vol 105 (3) ◽  
pp. 344-352 ◽  
Author(s):  
Hassan M. Helmy ◽  
Roman Botcharnikov

Abstract The stability relations of Pt and Pd antimonides and bismuthinides in the Sb- and Bi-bearing Fe-Ni-Cu sulfide systems have been experimentally determined at temperatures between 1100 and 700 °C in evacuated silica tubes. Both PtSb and PdSb are stable as immiscible liquids at temperatures above 1100 and 1000 °C, respectively. The Fe-Ni-Cu-sulfide melt that coexists with the immiscible antimonide melt can dissolve up to 3.8 wt% Sb at 1100 °C, whereas monosulfide solid solution (mss) dissolves very low amounts of Sb over the entire 1100–700 °C temperature range. The liquidus of Pt-antimonides and Pdantimonides are above 980 and 750 °C, respectively. Bismuth does not form immiscible melt at 1100 °C but may partially partition into a vapor phase at 1050 °C. The Pt- and Pd-bismuthinides crystallize directly from immiscible bismuthinide melt only after crystallization of the sulfide melt into intermediate solid solution (iss). Insizwaite (PtBi2) and froodite (PdBi2) are stable at 780 and 700 °C, respectively. At the last stage of evolution of Sb-bearing magmatic Fe-Ni-Cu sulfide melts, Sb will form immiscible antimonide melt that will extract Pt and Pd from the sulfide melt. During cooling, Pt and Pd-antimonides will crystallize directly from the immiscible antimonide melt, and Pt-phases will form at higher temperatures relative to Pd-phases. Bismuth will partition into vapor phase and concentrate into a low-temperature melt in hydrothermal and porphyry systems that scavenge precious metals. The Sb and Bi (like Te) will be highly incompatible at moderate degrees of mantle partial melting.


Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 942
Author(s):  
Maria Shapovalova ◽  
Nadezhda Tolstykh ◽  
Roman Shelepaev ◽  
Valery Kalugin

The mafic-ultramafic massifs with the PGE-Cu-Ni mineralization located in North-Central Mongolia: Oortsog, Dulaan, Mankhan, Yamat, and Nomgon were investigated. For the first time we consider these massifs as a single magmatic association and as fragments of Khangai batholith caused by the action of the plume responsible for the formation Permian Khangai LIP. The massifs fractionated from peridotite to gabbro have a similar typomorphic ore mineralogical and geochemical features, which change depending on the degrees of fractionation of magma and evolution of the sulfide melt. The least fractionated Oortsog massif originated from Ni-rich high-Mg basaltic magma. It is characterized by predominance of pyrrhotite mineralization due to exsolution of monosulfide solid solution (MSS). The most fractionated is the Nomgon massif originated from Cu-rich basaltic magma with bornite-chalcopyrite mineralization, formed as an exsolution of intermediate solid solution (ISS). The rest of the massifs have a medium characteristics between these two. The compositions of sulfides in the studied massifs change in accordance with the increase in sulfur fugacity from peridotite to gabbro: enrichment of pentlandite in Ni and pyrrhotite in S. The composition of PGM changes from Pt minerals in Oortsog massif to Pd minerals in Nomgon massif in the same direction. These massifs can be considered as potential for the PGE.


2020 ◽  
Vol 41 (S1) ◽  
pp. s69-s70
Author(s):  
Angie Dains ◽  
Michael Edmond ◽  
Daniel Diekema ◽  
Stephanie Holley ◽  
Oluchi Abosi ◽  
...  

Background: Including infection preventionists (IPs) in hospital design, construction, and renovation projects is important. According to the Joint Commission, “Infection control oversights during building design or renovations commonly result in regulatory problems, millions lost and even patient deaths.” We evaluated the number of active major construction projects at our 800-bed hospital with 6.0 IP FTEs and the IP time required for oversight. Methods: We reviewed construction records from October 2018 through October 2019. We classified projects as active if any construction occurred during the study period. We describe the types of projects: inpatient, outpatient, non–patient care, and the potential impact to patient health through infection control risk assessments (ICRA). ICRAs were classified as class I (non–patient-care area and minimal construction activity), class II (patients are not likely to be in the area and work is small scale), class III (patient care area and work requires demolition that generates dust), and class IV (any area requiring environmental precautions). We calculated the time spent visiting construction sites and in design meetings. Results: During October 2018–October 2019, there were 51 active construction projects with an average of 15 active sites per week. These sites included a wide range of projects from a new bone marrow transplant unit, labor and delivery expansion and renovation, space conversion to an inpatient unit to a project for multiple air handler replacements. All 51 projects were classified as class III or class IV. We visited, on average, 4 construction sites each week for 30 minutes per site, leaving 11 sites unobserved due to time constraints. We spent an average of 120 minutes weekly, but 450 minutes would have been required to observe all 15 sites. Yearly, the required hours to observe these active construction sites once weekly would be 390 hours. In addition to the observational hours, 124 hours were spent in design meetings alone, not considering the preparation time and follow-up required for these meetings. Conclusions: In a large academic medical center, IPs had time available to visit only a quarter of active projects on an ongoing basis. Increasing dedicated IP time in construction projects is essential to mitigating infection control risks in large hospitals.Funding: NoneDisclosures: None


2017 ◽  
Vol 52 (4) ◽  
pp. 270
Author(s):  
Okti Setyowati ◽  
Endang Kusdarjanti

The making of removable denture is performed by a dental laboratory. To facilitate the identification, according to Kennedy classification, classes are divided onto groups, the Kennedy class I, II, III and IV. To suit with the needs of the dental laboratory tasks commonly done, priority are necessary for common cases and should to be taught to students of Dental Health Technology Diploma. In Surabaya, research of various cases of removable partial denture with the various Kennedy classifications has never been done before. This study was to analyze the pattern of service for the removable partial denture manufacture in dental laboratory at Surabaya (2011 – 2013). The research is an observatory analytic. The population is all dental laboratories located around the campus of the Faculty of Dentistry Airlangga University Surabaya. The sample was the whole population is willing to become respondents. Sampling by total sampling. The method of collecting data using secondary data from a dental laboratory in Surabaya from 2011 until 2013. The note is cases removable denture according to the classification of Kennedy that Kennedy Class I, II, III and IV. Also of note kinds of materials used to make the denture base that is heat cured acrylic resins, thermoplastic resins and metals coherent. The data is a compilation table charting the frequency until needed, then analyzed using cross tabulation. Mostly denture type is flexible type and the least is metal framework. Most cases by classification Kennedy is followed by class II class III and class II and more recently is the fourth. In conclusion, in 2011 and 2013 the manufacture of removable partial dentures according to the classification of Kennedy Class III is the most common in both the upper arch and lower jaw, followed by Class II, Class I and Class IV. In 2012 which is the highest grade III followed by class II, class IV and class I. The denture type most used is a flexible denture, followed acrylic denture and the last is the metal framework.


2019 ◽  
Vol 100 (3) ◽  
pp. 500-504
Author(s):  
D G Tarasov ◽  
I I Chernov ◽  
A V Molochkov ◽  
A V Pavlov

Aim. To evaluate the results of surgical treatment of post-infarction left ventricular aneurysms with on-pump beating heart technique. Methods. In our center from April, 2009 to January, 2014 169 patients had reconstruction of the left ventricle with on-pump beating heart technique. Among the patients 159 were males (94.1%) and 10 of them were females (5.9%), average age 53.8±8.9 years (39 to 72 years). Angina pectoris class I (according to the classification of Canadian Heart Association) was established in 7 (4.1%) patients, class II - in 49 (29.0%), class III - in 107 (63.3%), class IV - in 4 (2.4%), unstable angina in 2 (1.2%) patients. Chronic heart failure class I (according to New York Heart association functional classification) was diagnosed in 5 (3.0%) patients, class II in 37 (21.9%), class III in 124 (73.4%), class IV in 3 (1.8%) patients. Average ejection fraction of the left ventricle was 38.6±7.9% (25 to 67%). Mitral valve insufficiency stage 2-3 was revealed in 23 (13.6%) patients. Results. Endoventriculoplasty of the left ventricle by Dor's technique was performed in 49 (29.0%) patients, auto-septoplasty of the left ventricle - 59 (34.9%) patients, linear repair in 40 (23.7%) patients. Combined surgical interventions were performed in 21 (12.4%) patients. In-hospital lethality was 2.4% (n=4). Conclusion. Left ventricular reconstruction with on-pump beating heart technique without cardioplegic arest is effective and safe; the method allows performing remodelling of the left ventricle and reaching the target volume parameters.


2014 ◽  
Vol 8 (1) ◽  
pp. 91-94 ◽  
Author(s):  
Pablo Chandra ◽  
Bageshri Gogate ◽  
Parikshit Gogate ◽  
Nilesh Thite ◽  
Abhay Mutha ◽  
...  

Purpose : To find out the average economic burden of medical care on a patient with diabetes in Pune, India Methods : A semi-open ended questionnaire followed by interview was conducted with patients attending diabetes and ophthalmic out-patient departments. They were asked regarding the duration of diabetes, methods undertaken for blood sugar control and the amount they spend on consultations, laboratory tests, medicines and procedures if any within past year. Expenditure was classified as direct cost (cost of medicines, doctor’s fees, investigations, lasers and surgery) and indirect cost (travel, diet control, health classes and loss of wages). Data was collected regarding the socioeconomic status according to Kuppaswamy classification. Results : 219 patients participated of whom 129 were males (58.9%). Average annual direct cost of diabetes treatment was Rs 8,822 of which 52.1% was spend on medicines, 3.2% was spend on lasers, 12.6% was spend on surgical procedures, 11.6% spent on investigations and 10.4% was spend on clinician fees. Average annual indirect cost was Rs. 3949 of which 3.4% was spend on travelling purpose, 0.4% was spent on health classes, 4.9% was spent on diet control and 91.3% was loss of wages. Average expenditure done by lower middle class was 23.7% of their income. Average percentage of income for direct and indirect cost was 3.6% and 1.4% respectively. The cost of the treatment formed1.3% of the annual income for those in Socio-economic class I, 1.7% in class II, 3.7% in class III and 23.7% in class IV. Conclusion : The cost of managing diabetes was a significant proportion of the patients’ income, especially for those on lower socio-economic scale (class IV).


2018 ◽  
Vol 200 (15) ◽  
Author(s):  
Mylea A. Echazarreta ◽  
Johnathan L. Kepple ◽  
Li-Hua Yen ◽  
Yue Chen ◽  
Karl E. Klose

ABSTRACTVibrio choleraeis a Gram-negative bacterium with a monotrichous flagellum that causes the human disease cholera. Flagellum-mediated motility is an integral part of the bacterial life cycle inside the host and in the aquatic environment. TheV. choleraeflagellar filament is composed of five flagellin subunits (FlaA, FlaB, FlaC, FlaD, and FlaE); however, only FlaA is necessary and sufficient for filament synthesis.flaAis transcribed from a class III flagellar promoter, whereas the other four flagellins are transcribed from class IV promoters. However, expressingflaAfrom a class IV promoter still facilitated motility in a strain that was otherwise lacking all five flagellins (ΔflaA-E). Furthermore, FlaA fromV. parahaemolyticus(FlaAVP; 77% identity) supported motility of theV. choleraeΔflaA-Estrain, whereas FlaA fromV. vulnificus(FlaAVV; 75% identity) did not, indicating that FlaA amino acid sequence is responsible for its critical role in flagellar synthesis. Chimeric proteins composed of different domains of FlaAVCand FlaD or FlaAVVrevealed that the N-terminal D1domain (D1N) contains an important region required for FlaA function. Further analyses of chimeric FlaAVC-FlaD proteins identified a lysine residue present at position 145 of the other flagellins but absent from FlaAVCthat can prevent monofilament formation. Moreover, the D1Nregion of amino acids 87 to 153 of FlaAVVinserted into FlaAVCallows monofilament formation but not motility, apparently due to the lack of filament curvature. These results identify residues within the D1Ndomain that allow FlaAVCto fold into a functional filament structure and suggest that FlaAVCassists correct folding of the other flagellins.IMPORTANCEV. choleraecauses the severe diarrheal disease cholera. Its ability to swim is mediated by rotation of a polar flagellum, and this motility is integral to its ability to cause disease and persist in the environment. The current studies illuminate how one specific flagellin (FlaA) within a multiflagellin structure mediates formation of the flagellar filament, thus allowingV. choleraeto swim. This knowledge can lead to safer vaccines and potential therapeutics to inhibit cholera.


Author(s):  
N. Clavier ◽  
F. Crétaz ◽  
S. Szenknect ◽  
A. Mesbah ◽  
C. Poinssot ◽  
...  

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