The article considered the elements of the resource-saving technology for the production of vegetable peas with the use of low doses of synthetic fertilizers by stimulating the action of nitrogen-fixing nodule bacteria. They are symbionts of vegetable peas, with the help of bacteria and microfertilizers. They are much cheaper than mineral fertilizers and are not harmful for the environment and, thanks to microdoses, are absolutely safe for people. During the research, it was established that, in addition to increasing the yield of agricultural crops, such agro-techniques contribute to increasing soil fertility (due to the accumulation of a greater amount of biologically pure nitrogen in it after harvesting vegetable peas, compared to existing technologies) and make it possible to extend the period of technical maturity of seeds and the period of their processing. This is a very important and urgent problem in southern Ukraine. It was also determined that the treatment of seeds with boron, molybdenum and Rizotorfin affects the timing of the onset of the main phases of development and the duration of the growing season of vegetable peas, extending it by several days, and this, in turn, allows farmers to harvest on time without economic losses. For the first time, for the conditions of the south of Ukraine, an opportunity was found to significantly extend the term of receipt of raw materials for processing without deterioration of quality indicators and dietary properties. The proposed techniques allow, in addition to the existing technology, to accumulate up to 40–60 kg/ha of biological nitrogen in the soil. It was recorded that the highest yield of the vegetable pea crop was formed during the first sowing period, when the seeds were treated with boron and molybdenum and amounted to 9.21 t/ha, which is 2.32 t/ha higher than the control. Based on the generalization of research results, a mathematical model of vegetable pea crop programming was built based on the principle of relationships between individual factors that affect the culture and the formation of its plant productivity.
A pure molybdenum (Mo) coating layer was manufactured by using the atmospheric plasma spray (APS) process and its wear and corrosion characteristics were investigated in this study. A Mo coating layer was prepared to a thickness of approximately 480 μm, and it had sound physical properties with a porosity of 2.9% and hardness of 434 Hv. Room temperature dry wear characteristics were measured through a ball-on-disk test under load conditions of 5 N, 10 N and 15 N. Based on the coefficient of friction graph at 5 N and 10 N, the oxides formed during wear functioned as a wear lubricant, thereby confirming an increase in wear resistance. However, at 15 N, wear behavior changed, and wear occurred due to splat pulling out. A potentiodynamic polarization test was conducted under an artificial seawater atmosphere, and Ecorr and Icorr measured 0.717 V and 7.2E-5 A/cm2, respectively. Corrosion mainly occurred at the splat boundary and pores that were present in the initial state. Based on the findings above, the potential application of APS Mo coating material was also discussed.
The subject of the presented research is the influence of molybdenum on selected properties of alloys that are based on the Al-Cu system. It could be observed that the introduction of molybdenum to the multi-component alloy at levels of up to 0.5 wt.% showed increases in the degrees of undercooling ΔT along with the increasing contents of the introduced element. The addition of molybdenum contributed to the reduction of the size of the primary grains of the α(Al) phase. Molybdenum improved the strength of the alloy while achieving elongation at a significant level. This is an element that occurs in the alloy – both in the iron-manganese phases and in the segregates inside the grains. Most of the iron-manganese phases occurred in a more spheroidal form. Additionally, tests were carried out on higher molybdenum content in the alloy. The addition of the tested chemical element at a level of 1 wt.% caused the precipitation of the phases that contained molybdenum, which did not dissolve after heat treatment.
The hypoeutectic aluminum alloy AlSi5Cu2Mg is used for the production of high-strength automotive components such as cylinder head castings. AlSi5Cu2Mg alloy is characterized by a specific chemical composition (low permitted Si and Ti content) determined by the supplier. Due to the low permitted Ti content it is impossible to refine the grain structure of this aluminum alloy using standard grain refiners based on Al-Ti-B. Al-Si-Cu-Mg alloys are thermal stable up to the temperature 200°C, due to the presence of strengthening precipitates. Due to the downsizing, the operating temperature exceeds the temperature of 200°C, which leads to a decrease in the mechanical and physical properties of Al-Si-Cu-Mg alloys. The aim of this study is to analyse influence the alloying elements and heat treatment on the selected properties of AlSi5Cu2Mg alloys that are crucial for cylinder head castings. The paper focuces on the evaluation of the influence of selected alloying elements Sr, Zr and Mo on mechanical and physical properties. The present work also analysis the effect of heat treatment T6 on selected properties and structure of AlSi5Cu2Mg alloy modified by Sr, Zr or Mo. Sr, Zr and Mo were added into the AlSi5Cu2Mg alloy in the form of master alloys AlMo10, AlSr10 or AlZr20. According to the findings, the incorporation of the chosen alloying elements did not result in a substantial improvement in the mechanical and physical characteristics of AlSi5Cu2Mg alloy, which would be critical for its practical application. Physical and mechanical properties noted positive increase due to the effect of thermal processing T6.
Given the significant consumption and future demand for water resources, this paper intends to find the conditions for using a flotation process with different water quality. One of the alternatives is using water under secondary treatment with industrial water mixtures to partly recycle domestic wastewater and maximize metallurgical benefits. Results show that using wastewater (only with secondary treatment) in flotation is detrimental to copper recovery. However, molybdenum recovery is significantly improved. For mixtures with 50 [%] wastewater, 50 [ppm] frother, 20 [ppm] collector, and pH 10, copper recovery decrease amounts to 0.4 [%], while molybdenum shows a 2.4 [%] recovery increase. In addition, copper concentrate grade decreases by 1.4 [%], while molybdenum grade remains. Therefore, using wastewater is viable, particularly in the case of molybdenum. So, this study proposes using of water mixtures in the copper depression stage to improve molybdenum recovery.
The latest research work in the field of electric power systems focuses on the development of new wire materials which will allow the increase of the transmission capacity of power lines currently in use. The reason for this research was the often limited possibilities of continuous and failure-free transmission of electricity. In this paper, the authors present research on a new aluminium-based alloy dedicated for use as a conductive braid in the HTLS cable group. There are many technical solutions for this group of cables on the market, although they are solutions with a number of disadvantages, ranging from their high price, various operational shortcomings, complicated installation techniques, and ending with the risk of monopolistic practices, which is related to the inability to attract several competitive suppliers. The main aim of the research was to develop a new alloy based on aluminium with the addition of silver and molybdenum dedicated for use in special overhead power cables. Experimental research on new materials focused on obtaining the necessary knowledge to produce an overhead wire from these alloys with higher current carrying capacity in relation to the currently used conventional wire materials based on aluminium.
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The elements are present in the environment. Moreover, they are used in pharmacy and the production of new materials used in medical applications. They are often as environmental pollutants. They can accumulate in organisms and induce toxic effects on the cellular level. HepG2, L929 and Caco-2 cell lines were exposed to known concentrations of chromium chloride, iron chloride, nickel chloride, molybdenum trioxide and cobalt chloride (200 or 1000 μ M used alone and in combinations). Concentrations of chromium, iron, nickel, molybdenum and cobalt in the cell lysate and the culture medium were determined by ICP-MS. Moreover, sodium, potassium, calcium and magnesium concentrations were also measured. What is more, cells were observed under light and scanning electron microscope. The dose-dependent increase in the concentration of chromium, iron, nickel, molybdenum and cobalt in all cell lines after incubation with elements was observed. Potassium concentration decreases while sodium calcium and magnesium increase after incubation of cells with of mentioned elements. The incubation of cells with microelements induces cell morphology changes. The presented study shows the crucial role of tested microelements in the induction of cell death as a result of an imbalance of sodium, potassium, calcium and magnesium concentration inside the cell.
In this research, graphene oxide was introduced as an efficient flotation reagent for the selective separation of molybdenite from chalcopyrite. The performance of graphene oxide and its adsorption mechanism on chalcopyrite were investigated by flotation tests, FTIR spectra, and XPS measurements. First, graphene oxide was synthesised, and then its performance was evaluated by SEM, XRD, and EDX. Flotation tests were carried out in a hallimond flotation cell with a volume of 300 ml. Optimum flotation values were achieved at pH = 9 by adding 250 g/t of PAX (Potassium Amyl Xanthate) as a collector and 50 g/t of A65 (Poly Propylene Glycol) as a frother. The results showed high recovery, around 80% for molybdenite, while chalcopyrite was depressed in high amounts by employing 11 kg/t of graphene oxide as a depressant. Compared to common chalcopyrite depressants such as NaHS, Na2S, and C2H3NaO2S, graphene oxide had a higher potency in depressing, which can be applied as a green-depressant in the separation of molybdenite from chalcopyrite by the flotation process. Also, the validity of the depressing effect on chalcopyrite was verified by XPS and FTIR spectra.
This paper examines the process and methodological aspects of implementing online X-ray fluorescence monitoring of ore in terms of its silver, cadmium, zinc, lead, molybdenum, and iron grade at the process conveyors at Balkhash and Karagaily Concentrators and the main conveyor of the Nurkazgan underground mine operated by Kazakhmys Corporation LLC. The research was complicated by the need to: a) ensure reliable measurement of silver and cadmium in the range of 1+ ppm, molybdenum in the range of 10+ ppm, as well as copper, zinc, lead, and iron in the ore size class –300 mm; b) implement monitoring of the grade of these elements (except molybdenum) at Balkhash Concentrator in the waste slag of Balkhash Copper Smelter, characterized by a very complex elemental matrix. A modification of the ore monitoring station RLP-21T (by Aspap Geo LLC, Alma-Ata) was developed, implemented, and thoroughly tested for online monitoring of low-grade silver ore flows. Energy dispersive X-ray fluorescence method was adopted for ore assays. Instrument spectra were measured every second. Silver, cadmium, and molybdenum grade was calculated based on 40 measurements, copper, zinc, lead, and iron grade – based on 20 measurements.
PL
W artykule przeanalizowano proces i aspekty metodologiczne wdrażania zdalnego monitorowania zawartości srebra, kadmu, cynku, ołowiu, molibdenu i żelaza w zakładach wzbogacania Balkhash i Karagaily oraz na głównym przenośniku w kopalni podziemnej Nurkazgan obsługiwana przez Kazakhmys Corporation LLC. Badania były skomplikowane ze względu na konieczność: a) zapewnienia niezawodnego pomiaru srebra i kadmu w zakresie 1+ ppm, molibdenu w zakresie 10+ ppm, a także miedzi, cynku, ołowiu i żelaza w klasie –300 mm; b) wdrożyć monitorowanie tych pierwiastków (z wyjątkiem molibdenu) w koncentracie Balkhash ,w żużlu odpadowym Huty Miedzi Balkhash, charakteryzującym się bardzo złożoną matrycą elementarną. Opracowano, wdrożono i dokładnie przetestowano modyfikację stacji monitorowania rudy RLP-21T (firmy Aspap Geo LLC, Alma-Ata) do monitorowania online przepływów rudy srebra o niskiej jakości. Do fluorescencji rentgenowskiej zastosowano dyspersyjną metodę rentgenowską. Widma mierzono co sekundę. Zawartość srebra, kadmu i molibdenu obliczono na podstawie 40 pomiarów, a miedzi, cynku, ołowiu i żelaza – na podstawie 20 pomiarów.
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Przedstawiono pełną procedurę otrzymywania syntetycznych nanocząstek disiarczku molibdenu za pomocą metody mokrej. W tym celu zastosowano roztwory heptamolibdenianu amonu, siarczku amonu oraz kwasu cytrynowego jako katalizatora reakcji. Proces prowadzono w sposób ciągły, stosując reaktory zderzeniowe. Podano metodę separacji MoS₂ z mieszaniny poreakcyjnej oraz jego krystalizacji. Przeprowadzono również badania nad potencjalnymi zastosowaniami uzyskanego produktu.
EN
(NH₄)₆Mo7O₂₄, (NH₄)₂S and citric acid solns. were introduced into the impinging jet reactor with coaxial and tangential type inlets to obtain MoS₂ nanoparticles. The resulting ppt. was washed with water, dried at 50oC for 24 h and calcined in a furnace under Ar for 1 h. The particle size distribution was detd. by using a laser diffraction particle size analyzer. Sepd. particles smaller than 300 nm were dispersed in engine oil and their effect on rheol. and tribol. properties was examd.
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We demonstrated a tunable Q-switched ytterbium-doped fiber laser (YDFL) using MWS₂/rGO nanocomposite as passive saturable absorber. Further, the Mo₁₋xWxS₂/rGO nanosheets, with x proportion of 0.2, are synthesized using hydrothermal exfoliation technique. The proposed nanocomposite-PVA based thin film is fabricated by mixing the MoWS₂/rGO nanosheets with polyvinyl alcohol (PVA). The fabricated thin film is sandwiched between two fiber ferrules to realize the proposed saturable absorber (SA). Further, the proposed MoWS₂/rGO-PVA based thin film SA exhibits a fast relaxation time and a high damage threshold which are suitable to realize a Q-switched pulsed laser with a tunable wavelength range of 10 nm that extends from 1028 nm to 1038 nm. For the highest pump power of 267.4 mW, the generated Q-switched pulses exhibit a narrow pulse width of 1.22 μs, the pulse repetition rate of 90.4 kHz, the highest pulse energy of 2.13 nJ and its corresponding average power of 0.193 mW. To the best of author’s knowledge, this is the first realization of a tunable Q-switching fiber laser in a 1 μm wavelength using MoWS₂/rGO nanocomposite saturable absorber.
The influence of the electrode geometry on the microstructure and corrosion behaviour of Co-Mo nano-crystalline coatings elaborated by electrodeposition is studied. The corrosion behaviour was determined in the Ringer’s solution at 25°C. Electrodeposition mechanisms are also discussed as a function of the electrode geometry. The electrode geometry was found to affect the growth rate and, under certain conditions, the microstructure (existence of channels and pores). It does not have influence on the corrosion behaviour.
The influence on the corrosion behaviour of Co-Mo nano-crystalline coatings of dissolved oxygen is studied in the Ringer’s solution and artificial saliva at 25°C. This was done by means of potentiodynamic tests and surface observations. It was shown that dissolved oxygen has no influence on passivity, oxidation of the coating and selective dissolution of cobalt. By contrast, dissolved oxygen affects corrosion. General corrosion was observed in the Ringer’s solution whereas pitting corrosion was found in artificial saliva.
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Wydzielano struwit w sposób ciągły z wodnych roztworów fosforanów zawierających także charakterystyczne składniki obecne w gnojowicy: bor, kobalt, mangan i molibden. Wykazano, że bor, kobalt i molibden, w przeciwieństwie do manganu, sprzyjały otrzymywaniu dobrze wykształconych kryształów struwitu. Kobalt i molibden nie zmieniały standardowego pokroju kryształów struwitu (La/Lb ok. 6), ale mangan i bor (obecne w układzie procesowym) zwiększały te proporcje geometryczne odpowiednio do 7,7, a nawet do 9,1. Krystalizacja struwitu przebiegała najlepiej w obecności boru. Liniowa szybkość wzrostu wyniosła ponad 2·10-8 m/s, a szybkość zarodkowania była mniejsza niż 2·108 1/(s·m3). Kobalt i mangan wydzieliły się jako wodorotlenki, a ich zawartość w fazie stałej wynosiła odpowiednio 393 mg/kg i 749 mg/kg.
EN
Struvite was continuously pptd. from aq. solns. of phosphates in presence of B, Co, Mn and Mo salts contained in liq. manure. The B, Co and Mo compds. (in contrast to Mn compds.) favored well-formed struvite crystals. Neither Co nor Mo changed the std. geometrical proportions of struvite crystals, while Mn and B increased the proportions. Struvite crystn. run well in the presence of B. The linear growth rate was more than 2·10-8 m/s, and the nucleation rate was less than 2·108 1/(s·m3). Co and Mn were sepd. as hydroxides and their content in solid phase was 393 mg/kg and 749 mg/kg Mn, resp.
The article presents the results of hydrochemical studies of water objects, located in the impact zone of one of the largest mining enterprises in the Russian Federation – JSC “Apatite”. According to the monitoring studies, the source of surface water pollution with molybdenum was determined, geochemical assessment of the molybdenum transformation in the system “ore-bearing rocks – mine water – surface water” was performed. In order to reduce the technogenic load on the surface water located in the considered area, the way of large-tonnage mine waters purification from molybdenum was proposed. The method involves using the chemical sorbent based on waste metals. The method of sewage purification will allow solving one of the key environmental problems of the considered enterprise and, in addition, to improve the environmental situation in the considered area as well as the quality of the local population life.
Molibden jest biopierwiastkiem, którego niedobór w organizmie człowieka może prowadzić do poważnych schorzeń. Z drugiej strony narażenie na nadmierne ilości tego pierwiastka może powodować szereg negatywnych skutków zdrowotnych. Dane literaturowe dotyczące pobrania molibdenu ze spożywaną wodą w Polsce nie były do tej pory opublikowane. W ramach niniejszej pracy przeprowadzono oznaczenia molibdenu w próbkach wody przeznaczonej do spożycia pobranych z trzech obszarów problemowych województwa dolnośląskiego za pomocą metody losowego pobierania próbek wody – zalecanej w monitorowaniu stężeń metali. Wyznaczone średnie tygodniowe stężenia molibdenu w wodzie przeznaczonej do spożycia dostarczanej na terenach stref zaopatrzenia Wrocławia, Kłodzka i Janowic Wielkich wynosiły odpowiednio 0,868 μg/l, 0,185 μg/l i 1,96 μg/l. Ponieważ obliczone na tej podstawie współczynniki zagrożenia są niskie (HQ<<1), można stwierdzić, że narażenie na ten metal pobierany z wodą jest znikome. Dodatkowo, spożywana woda na terenie ww. miejscowości wnosi niewielki wkład do całkowitego średniego dobowego pobrania tego metalu (0,31-3,3%) oszacowanego na poziomie 120 μg/dobę. Na terenach, na których eksploatowano rudy metali, średnie dobowe pobranie molibdenu wraz z wodą przeznaczoną do spożycia jest nieznacznie wyższe i może dochodzić do 8,7% zalecanego dziennego spożycia w przypadku osób dorosłych.
EN
Molybdenum is a bioelement whose deficiency in the human body can lead to serious illness. On the other hand, exposure to excessive amounts of this element can cause a number of adverse health effects. Literature data on the intake of molybdenum with water intended for human consumption in Poland has not been published so far. In this work molybdenum was determined in samples of drinking water collected from three problem areas of the Lower Silesian Voivodeship using the Random Daytime sampling method – recommended for monitoring of metal concentrations. The average weekly concentrations of molybdenum in drinking water supplied in the supply areas of Wroclaw, Klodzko and Janowice Wielkie were 0.868 μg/l, 0.185 μg/l and 1.96 μg/l, respectively. Because the hazard indexes calculated on this basis are low (HQ<<1), it can be concluded that the exposure to this metal taken from water is negligible. In addition, consumed water in the individual supply zones contributes little to the total daily average metal intake (0.31-3.3%) estimated at the level of 120 μg/day. In areas where metal ores are mined, the average daily intake of molybdenum with drinking water is slightly higher and may reach 8.7% of the Recommended Dietary Allowance for adults.
Badania zawartości molibdenu i manganu w powierzchniowej warstwie gleb i roślinach przeprowadzono w okolicy Jabłonek w Beskidach Wschodnich w rejonie występowania łupków menilitowych i piaskowców z Otrytu. Pracę wykonano w celu zbadania zawartości molibdenu i manganu w roślinach oraz określenia wskaźnika bioakumulacji tych pierwiastków w dwóch gatunkach roślin (Trifolium hybridum L. i Plantago major L.). Oznaczenia Mo wykonano metodą ICP-MS, a Mn analizowano metodą ICP-OES. Stwierdzono wyższe zawartości Mo w Trifolium hybridum L. na terenie występowania łupków menilitowych (w liściach – 14 mg/kg) niż na terenie piaskowców z Otrytu (w liściach – 0,30 mg/kg). Najwięcej Mn gromadzi się w liściach (86–257 mg/kg). Wskaźnik bioakumulacji Mo poszczególnych gatunków roślin jest różny, jego wartości zmieniają się w zakresie 0,13–1,13. Najwyższym wskaźnikiem bioakumulacji molibdenu (1,13) cechuje się Trifolium hybridum L., występująca na terenach łupków menilitowych.
EN
Studies of molybdenum and manganese content in topsoil and plants were carried out in the Eastern Beskids (Carpathians) in area of occurrence of menilite shales and the Otryt sandstones. The aim of the study was to evaluate the content of molybdenum and manganese in plants and the determination of a bioaccumulation of these two chemical elements in two species of plants (Trifolium hybridum L. and Plantago major L.). Mo symbols were performed by means of ICP-MS method, and Mn were analyzed by means of ICP-OES method. Result of studies in the Trifolium hybridum L. have shown higher content of Mo in the area of occurence of menilite shales (in leaves – 14 mg/kg) than in the Otryt sandstones (in leaves – 0.30 mg/kg). Most Mn accumulates in leaves (86–257 mg/kg). The bioaccumulate indicator of Mo in individual plant species is different and ranges from 0.13 to 1.13. The highest rate of bioaccumulation of molybdenum (1.13) can be observed in Trifolium hybridum L., which inhabits areas of menilite shales.
Titanium β-type alloys are a class of interesting biomaterials that can exhibit a unique combination of mechanical as well as physicochemical and biological properties. The aim of this study is to develop a titanium-molybdenum alloys (Ti-x at % Mo, x = 15 and 23). These materials were prepared by the combination of mechanical alloying and powder metallurgical process. The details of the processing method were presented. The samples were characterized by X-ray diffraction, scanning electron micros-copy, chemical composition determination as well as density and Vickers microhardness measurements. The corrosion behaviour in Ringer solution was investigated, too. The crystallization of the obtained material upon annealing led to the formation of a near single β type alloys. The molybdenum content in titanium and heat treatment parameters of a nearly amorphous phase allow to synthesize Ti(β)-type alloys. The present study has demonstrated that Ti23Mo alloy can be the next generation of biomaterial for bone tissue engineering.
Large demand for bulk of sapphire optical products, which are widely used as illuminators, optical windows in aviation and aeronautics etc., generates the inquiry of effective production of high quality industrial crystals. The technology of crystal growth with the horizontal single crystal sapphire crystallization method is based on putting the crystal seed into the front of the crucible resistant to temperatures up to 2150°C. Without encompassment of the production technology of this special container made from thin molybdenum sheet is not realistic to consider the productive exploitation of horizontal crystallization systems in engineering practice. This paper presents the analysis of the possibility of the local resistance of molybdenum sheet heating by its deep drawing to obtain better drawing properties by increased blank temperature.
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