Radiological impact of natural radioactivity in Egyptian phosphate rocks, phosphogypsum and phosphate fertilizers

International Nuclear Information System (INIS)

El-Bahi, S.M.; Sroor, A.; Mohamed, Gehan Y.; El-Gendy, N.S.

2017-01-01

In this study, the activity concentrations of the natural radionuclides in phosphate rocks and its products were measured using a high- purity germanium detector (HPGe). The obtained activity results show remarkable wide variation in the radioactive contents for the different phosphate samples. The average activity concentration of "2"3"5U, "2"3"8U, "2"2"6Ra, "2"3"2Th and "4"0K was found as (45, 1031, 786, 85 and 765 Bq/kg) for phosphate rocks, (28, 1234, 457, 123 and 819 Bq/kg) for phosphate fertilizers, (47, 663, 550, 79 and 870 Bq/kg) for phosphogypsum and (25, 543, 409, 54 and 897 Bq/kg) for single super phosphate respectively. Based on the measured activities, the radiological parameters (activity concentration index, absorbed gamma dose rate in outdoor and indoor and the corresponding annual effective dose rates and total excess lifetime cancer risk) were estimated to assess the radiological hazards. The total excess lifetime cancer risk (ELCR) has been calculated and found to be high in all samples, which related to high radioactivity, representing radiological risk for the health of the population. - Highlights: • Level of radioactivity of phosphate rocks and by-products samples. • The radiological health hazard parameters. • Radiological risk to the health of the population. • The excess lifetime cancer risk factor.

Phosphate additives in food--a health risk.

Science.gov (United States)

Ritz, Eberhard; Hahn, Kai; Ketteler, Markus; Kuhlmann, Martin K; Mann, Johannes

2012-01-01

Hyperphosphatemia has been identified in the past decade as a strong predictor of mortality in advanced chronic kidney disease (CKD). For example, a study of patients in stage CKD 5 (with an annual mortality of about 20%) revealed that 12% of all deaths in this group were attributable to an elevated serum phosphate concentration. Recently, a high-normal serum phosphate concentration has also been found to be an independent predictor of cardiovascular events and mortality in the general population. Therefore, phosphate additives in food are a matter of concern, and their potential impact on health may well have been underappreciated. We reviewed pertinent literature retrieved by a selective search of the PubMed and EU databases (www.zusatzstoffe-online.de, www.codexalimentarius.de), with the search terms "phosphate additives" and "hyperphosphatemia." There is no need to lower the content of natural phosphate, i.e. organic esters, in food, because this type of phosphate is incompletely absorbed; restricting its intake might even lead to protein malnutrition. On the other hand, inorganic phosphate in food additives is effectively absorbed and can measurably elevate the serum phosphate concentration in patients with advanced CKD. Foods with added phosphate tend to be eaten by persons at the lower end of the socioeconomic scale, who consume more processed and "fast" food. The main pathophysiological effect of phosphate is vascular damage, e.g. endothelial dysfunction and vascular calcification. Aside from the quality of phosphate in the diet (which also requires attention), the quantity of phosphate consumed by patients with advanced renal failure should not exceed 1000 mg per day, according to the guidelines. Prospective controlled trials are currently unavailable. In view of the high prevalence of CKD and the potential harm caused by phosphate additives to food, the public should be informed that added phosphate is damaging to health. Furthermore, calls for labeling

Neutron activation analysis of alternative phosphate rocks used in animal nutrition

International Nuclear Information System (INIS)

Canella, Artur A.; Ferreira, Walter M.

2005-01-01

Since 1980's, Bovine Sponghiform Encephalophaty has insidiously created a fierce battleground between farmers, scientists, environmentalists and consumers. The use of meat and bone meals is currently prohibited in ruminant feeds throughout the world. Some inorganic sources offer the combination of high phosphorus content and acceptable animal digestibility make them options as supplemental phosphorus, for instance phosphate rocks, general term applied to minerals valued chiefly for their phosphorus content. However, phosphate rocks are long been known containing hazardous elements, make them sometimes unsuitable for animal nutrition. Neutron Activation Analysis has been supportive to the mineral evaluation of alternative phosphate rocks. This evaluation is subject of on-going doctoral thesis which has been carried-out by the main author. The NAA method has been very efficient due to its highly sensitive and multi-elemental nature. In this paper results of Vanadium content from three different phosphate rocks are presented. Their values have been pointed out that Brazilian phosphate rocks present hazardous elements at the same levels of phosphate rocks from some countries of Africa, North America and Middle East, data from our study (Brazilian data) and FAO - Food and Agriculture Organization (others countries). (author)

Study on the relation between uranium content and total phosphorus in some sudanese phosphate ore samples

International Nuclear Information System (INIS)

Eltayeb, M. A. H.; Mohammed, A. A.

2003-01-01

In the present work uranium content and total phosphorus were determined in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba Mountains in Sudan. Spectrophotometry technique was used for this purpose. Uranium analysis is based on the use of nitrogen (V) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (Vi) is kept in solution as its carbonate complex. The ion exchange technique was used for the recovery of uranium. Uranium was eluted from the resin with 1 M hydrochloric acid. In the elute, uranium was determined spectrophotometrically by measurement of absorbance of the yellow uranium (Vi)-8-hydroxyquinolate complex at λ 400 nm. The total phosphorus was measured as (P 2 O 5 %) by treatment of the total liquor with ammonium molybdate solution. The absorbance of the blue complex was measured at λ 880 nm. The results show that a limited relation is existed between uranium content and total phosphorus in phosphate samples from kurun area, which contain 58.8 ppm uranium in average, where there are no relation is existed in phosphate samples from uro area, which contain 200 ppm uranium in average. (Author)

Study on the relation between uranium content and total phosphorus in some sudanese phosphate ore samples

International Nuclear Information System (INIS)

Mohammed, A.A.; Eltayeb, M.A.H.

2003-01-01

In the present work uranium content and total phosphorous were determined in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba mountains in sudan. Spectrophotometry technique was used for this purpose. Uranium analysis is based on the use of nitrogen (V) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (VI) is kept in solution as its carbonate complex. The ion-exchange technique was used for the recovery of uranium. Uranium was eluted from the resin with 1 M hydrochloric acid. In the elute, uranium was determined spectrophotometrically by measurement of the absorbance of the yellow uranium (VI) - 8- hydroxyquinolate complex at λ 400 nm. The total phosphorus was measured as (P 2 O 5 %) by treatment of the leach liquor with ammonium molybdate solution. The absorbance of the blue complex was measured at λ 880 nm. The results show that a limited relation is existed between uranium content and total phosphorus in phosphate samples from Kurun area, which contain 58.8 ppm uranium in average, where there are no relation is existed in phosphate samples samples from Uro area, which contain 200 ppm uranium in average

Effects of some organic materials on bicarbonate extractable phosphate content of soils having different pH

Directory of Open Access Journals (Sweden)

Nutullah Özdemir

2016-10-01

Full Text Available This study was carried out to determine the effects of rice husk compost (RC, town waste compost (TW and tobacco waste (TB on bicarbonate extractable phosphate content (P in soils having different pH levels under greenhouse conditions. Soil samples used in this study were taken from surfaces (0-20 cm of agricultural fields around Samsun, Northern Anatolia. The experiment was conducted according to split plot design with four doses of organic matterials (0, 2.5, 5.0 and 7.5, %. After a month of mixing organic matterials into soils, lettuce were grown in the medias. According to the results, RC, TW and TB applications into acidic (Tepecik, neutral (Kampüs and alkaline (Çetinkaya soils increased extractable P content. It was observed that effectiveness of organic matterials changed depend on soil reaction, type and dose of organic matterials. All organic wastes were more effective on increment of bicarbonate extractable phosphate content in neutral soil pH when compared the other soil pH levels.

Evaluation of natural radioactivity and heavy metals content in Sudanese phosphate rocks used as low cost fertilizer

International Nuclear Information System (INIS)

Elkhangi, F.A.; Aamhed, M.M.O.; Abdalla, I.A.

1997-01-01

This study was carried out to determine the level of natural radioactivity and heavy metals content of Sudanese rock phosphate used as low cost fertilizer. Thirty samples collected from two types of local phosphate rocks from the Nuba mountains (Uro and Kurun) were used in this study and the activity concentrations of natural radioactivity determined using gamma spectroscopy were compared to those found in samples of imported phosphorous fertilizers Single Super phosphate (SSP) and Triple Super phosphate (TSP). The results showed that the ' Ra activity concentration was 0.6 - 0.8 Bq/g for Uro and 0.3 - 0.5 Bq/g for Kurun. As for the most commonly used imported fertilizer TSP, the result was found to be greater than that of Uro (around 1.0 Bq/g). The heavy metals content of Uro and Kurun rocks measured using X-ray Fluorescence Technique showed their levels were below the toxic levels reported by Christina (1991). It is evident that the environmental hazard is comparable in the local and imported fertilizers and is acceptable in both cases by international standards. The determine factor therefore in optioning for the use of a local or an imported brand should then be the fertilizing efficiency of the brand used against other economic consideration rather than the fertilizers environmental impact

Most consumed processed foods by patients on hemodialysis: Alert for phosphate-containing additives and the phosphate-to-protein ratio.

Science.gov (United States)

Watanabe, Marcela T; Araujo, Raphael M; Vogt, Barbara P; Barretti, Pasqual; Caramori, Jacqueline C T

2016-08-01

Hyperphosphatemia is common in patients with chronic kidney disease (CKD) stages IV and V because of decreased phosphorus excretion. Phosphatemia is closely related to dietary intake. Thus, a better understanding of sources of dietary phosphate consumption, absorption and restriction, particularly inorganic phosphate found in food additives, is key to prevent consequences of this complication. Our aims were to investigate the most commonly consumed processed foods by patients with CKD on hemodialysis, to analyze phosphate and protein content of these foods using chemical analysis and to compare these processed foods with fresh foods. We performed a cross-sectional descriptive analytical study using food frequency questionnaires to rank the most consumed industrialized foods and beverages. Total phosphate content was determined by metavanadate colorimetry, and nitrogen content was determined by the Kjeldahl method. Protein amounts were estimated from nitrogen content. The phosphate-to-protein ratio (mg/g) was then calculated. Processed meat protein and phosphate content were compared with the nutritional composition of fresh foods using the Brazilian Food Composition Table. Phosphate measurement results were compared with data from the Food Composition Table - Support for Nutritional Decisions. An α level of 5% was considered significant. Food frequency questionnaires were performed on 100 patients (mean age, 59 ± 14 years; 57% male). Phosphate additives were mentioned on 70% of the product labels analyzed. Proteins with phosphate-containing additives provided approximately twice as much phosphate per gram of protein compared with that of fresh foods (p processed foods are higher than those of fresh foods, as well as phosphate-to-protein ratio. A better understanding of phosphate content in foods, particularly processed foods, may contribute to better control of phosphatemia in patients with CKD. Copyright © 2016 European Society for Clinical Nutrition and

Uranium abundance in some sudanese phosphate ores

International Nuclear Information System (INIS)

Adam, A.A.; Eltayeb, M.A.H.

2009-01-01

This work was carried out mainly to analysis of some Sudanese phosphate ores, for their uranium abundance and total phosphorus content measured as P 2 O 5 %. For this purpose, 30 samples of two types of phosphate ore from Eastern Nuba Mountains, in Sudan namely, Kurun and Uro areas were examined. In addition, the relationship between uranium and major, and trace elements were obtained, also, the natural radioactivity of the phosphate samples was measured, in order to characterize and differentiate between the two types of phosphate ores. The uranium abundance in Uro phosphate with 20.3% P 2 O 5 is five time higher than in Kurun phosphate with 26.7% P 2 O 5 . The average of uranium content was found to be 56.6 and 310 mg/kg for Kurun and Uro phosphate ore, respectively. The main elements in Kurun and Uro phosphate ore are silicon, aluminum, and phosphorus, while the most abundant trace elements in these two ores are titanium, strontium and barium. Pearson correlation coefficient revealed that uranium in Kurun phosphate shows strong positive correlation with P 2 O 5 , and its distribution is essentially controlled by the variations of P2O5 concentration, whereas uranium in Uro phosphate shows strong positive correlation with strontium, and its distribution is controlled by the variations of Sr concentration. Uranium behaves in different ways in Kurun phosphate and in Uro phosphate. Uro phosphate shows higher concentrations of all the estimated radionuclides than Kurun phosphate. According to the obtained results, it can be concluded that Uro phosphate is consider as secondary uranium source, and is more suitable for uranium recovery, because it has high uranium abundance and low P 2 O 5 %, than Kurun phosphate. (authors) [es

Engineering potato starch with a higher phosphate content

NARCIS (Netherlands)

Xu, Xuan; Huang, Xing Feng; Visser, Richard G.F.; Trindade, Luisa M.

2017-01-01

Phosphate esters are responsible for valuable and unique functionalities of starch for industrial applications. Also in the cell phosphate esters play a role in starch metabolism, which so far has not been well characterized in storage starch. Laforin, a human enzyme composed of a

Availability of rock phosphate with low P content in some Albanian soil: use of /sup 32/PO/sub 4/

Energy Technology Data Exchange (ETDEWEB)

Fardeau, J C; Migadel, F; Gjermani, A; Malja, S

1983-10-01

The availability of a calcareous low P content rock phosphate (4,3% P) was measured. This Albanian ore was used, in pot experiments, on various local soils whose pH is situated between 4,9 to 7,5. This phosphate was labelled with /sup 32/P and /sup 45/Ca in a reactor. The residual effect of this fertilizer was deduced from the results of isotopic dilution kinetics of phosphate ions realized in soil-solution systems. The main results can be summarized as follows: 1. When the soil-water pH was higher than 6,1, the utilization coefficient of phosphorus was minus than 1%, even with 5,5 months. 2. The ratio of P and Ca derived from fertilizer and taken up by the crop is most generally different of those measured in the fertilizer. It depends on the soil constitution. 3. The analysis of isotopic dilution kinetics of phosphate ions shows that in the major part of these soils, whose fixing capacity is very high, the rock phosphate and also superphosphate at 230 kg P/sub 2/O/sub 5/.ha/sup -1/ rate does not increase available soil phosphorus; it is only with rates over 800 kg P/sub 2/O/sub 5/.ha/sup -1/ that this objective can be reached. These results explain again that the fixing capacity of soil for phosphorus is a characteristic more useful for fertilization technique than the available phosphorus quantity.

Nitrate and Phosphate Contents on Sediments Related to The Density Levels of Mangrove Rhizophora Sp. in Mangrove Park Waters of Pekalongan, Central Java

Science.gov (United States)

Supriyantini, E.; Santoso, A.; Soenardjo, N.

2018-02-01

Mangrove Park waters area of Pekalongan City, Central Java, used to be an aquaculture field, now turning the function into a restoration-based mangrove area, and now it has undergone rehabilitation. The conditions may affect the distribution of nitrate and phosphate content. The objective of this study was to determine the content of nitrates and phosphates in sediments related to the density levels of mangrove Rhizophora sp. The method used in this research was a descriptive method, and sampling was done by purposive sampling method. Water and sediment sampling were conducted at three stations respectively, representing: no mangrove area but used as a residential and tourist area (station 1); less dense mangrove (station 2); and, the previously aquaculture field - or medium dense mangrove (station 3). The results showed that the content of nitrate and phosphate in the whole sediment showed a low fertility rate. Average nitrate content for station 1, station 2 and station 3 were 0.86 mg/100 g, 0.94 mg/100 g and 0.81 mg/100 g, respectively. The average phosphate content at each station were 1.14 mg/100 g, 0.04 mg/100 g and 0.05 mg/100 g, respectively. Except to the station 1 that was no vegetation anymore, the mangrove density levels at two other stations at study sites were relatively low to medium; at station 2 was 0.8 ind/10 m2 and at station 3 was 1.2 ind/10 m2. The role of nitrate and phosphate were for mangrove growth at the site.

Phosphate fertilizer influence on 238 U content in vegetables

International Nuclear Information System (INIS)

Lauria D, C.; Rodrigues S, J.I.; Ribeiro, F.C.A.

2006-01-01

Uranium is a naturally radioactive element, which is usually found in soils, superficial and ground water, vegetables and animals. After ingestion by human beings, most is excreted in few days by feces and urine, without reaching the bloodstream. However, a small part circulates through the body, being accumulated in the soft tissues, as kidneys. A minor fraction can remain in bones per some years, being able through the radioactive decay to irradiate adjacent tissues. Phosphate fertilizers used in conventional crop management can present variable amounts of uranium. In accordance with origin and use, the fertilizer can raise the content of this element in vegetables, and consequently to increase the human exposure for radiation due the consumption of vegetables. It is estimated that the use of phosphate fertilizer has at least doubled the prolonged exposure of humans from ingestion of food. This work aims to evaluate the contribution of organic and chemical fertilizer on the concentration of 238 U in vegetable samples. An experiment with black beans (a very important vegetable for Brazilian people) was conducted in a field which soil has never been fertilized with any sort of fertilizer, located near to the Rio de Janeiro city. On the organic management, bovine manure was used, while on conventional management urea, potassium chloride and superphosphate were used. Simultaneously, black bean samples from not fertilized management were collected. In addition, lettuce and carrot samples from organic and conventional managements were collected in Nova Friburgo farms (the most important vegetable supplier of Rio de Janeiro city market). The analyses of 238 U have been carried out by conventional fluorimetric method. The geometric mean of 238 U concentrations in the carrot and lettuce samples from conventional management were similar with those from organic management, while for beans the conventional samples had higher values than those ones found in organic management

Effect of exogenous phytase on degradation of inositol phosphate in dairy cows

DEFF Research Database (Denmark)

Brask-Pedersen, Dorte Buus; Glitsø, Lene Vibe; Skov, L.K.

2013-01-01

The effect of exogenous phytase on inositol phosphate degradation in the rumen of dairy cows was investigated in a 4 × 4 Latin square design. Four lactating Danish Holstein cows fitted with ruminal, duodenal, and ileal cannulas were offered a total mixed ration (TMR) with a high content of inositol...... phosphate and supplemented with 1 of 4 concentrations of phytase [none, low, medium, or high, corresponding to 23, 2,023, 3,982, and 6,015 phytase units/kg of dry matter (DM)]. Exogenous phytase lead to a higher rumen pool of phytase. Inositol phosphate content in digesta samples from rumen, duodenum, ileum...... and in samples of the TMR revealed that the exogenous phytase started degrading the inositol phosphate when feeds and phytase were mixed, and thus the InsP6 phosphorus (InsP6-P) content in the TMR was found to decrease with higher doses of phytase (1.69, 1.51, 1.39, and 1.25 g/kg of DM for the none, low, medium...

Formulation of single super phosphate fertilizer from rock phosphate of Hazara, Pakistan

Directory of Open Access Journals (Sweden)

Matiullah Khan

2012-05-01

Full Text Available Phosphorus deficiency is wide spread in soils of Pakistan. It is imperative to explore the potential and economics of indigenous Hazara rock phosphate for preparation of single super phosphate fertilizer. For the subject study rock phosphate was collected from Hazara area ground at 160 mesh level with 26% total P2O5 content for manual preparation of single super phosphate fertilizer. The rock phosphate was treated with various concentrations of sulfuric acid (98.9%, diluted or pure in the field. The treatments comprised of 20 and 35% pure acid and diluted with acid-water ratios of 1:5, 1:2, 1:1 and 2:1 v/v for acidulation at the rate of 60 liters 100 kg-1 rock phosphate. The amount was prior calculated in the laboratory for complete wetting of rock phosphate. A quantity of 150 kg rock phosphate was taken as treatment. The respective amount of acid was applied with the spray pump of stainless steel or poured with bucket. After proper processing, chemical analysis of the products showed a range of available P2O5 content from 9.56 to 19.24% depending upon the amount of acid and its dilution. The results reveal at that 1:1 dilutions gave the highest P2O5 content (19.24%, lowest free acid (6 % and 32% weight increase. The application of acid beyond or below this combination either pure or diluted gave hygroscopic product and higher free acids. The cost incurred upon the manual processing was almost half the prevailing rates in the market. These results lead to conclude that application of sulfuric acid at the rate of 60 liters 100 kg-1 with the dilution of 50% (v/v can yield better kind of SSP from Hazara rock phosphate at lower prices.

Extremely High Phosphate Sorption Capacity in Cu-Pb-Zn Mine Tailings.

Science.gov (United States)

Huang, Longbin; Li, Xiaofang; Nguyen, Tuan A H

2015-01-01

Elevated inorganic phosphate (Pi) concentrations in pore water of amended tailings under direct revegetation may cause toxicity in some native woody species but not native forbs or herb species, all of which are key constituents in target native plant communities for phytostabilizing base metal mine tailings. As a result, Pi sorption capacity has been quantified by a conventional batch procedure in three types of base metal mine tailings sampled from two copper (Cu)-lead (Pb)-zinc (Zn) mines, as the basis for Pi-fertiliser addition. It was found that the Pi-sorption capacity in the tailings and local soil was extremely high, far higher than highly weathered agricultural soils in literature, but similar to those of volcanic ash soils. The Langmuir P-sorption maximum was up to 7.72, 4.12, 4.02 and 3.62 mg P g-1 tailings, in the fresh tailings of mixed Cu-Pb-Zn streams (MIMTD7), the weathered tailings of mixed Cu-Pb-Zn streams (MIMTD5), EHM-TD (fresh Cu-stream, high magnetite content) and local soil (weathered shale and schist), respectively. Physicochemical factors highly correlated with the high Pi-sorption in the tailings were fine particle distribution, oxalate and dithionite-citrate-bicarbonate extractable Fe (FeO and Fed), oxalate-extractable Al and Mn, and the levels of soluble Cd and Zn, and total S and Fe. Large amounts of amorphous Fe oxides and oxyhydroxides may have been formed from the oxidation of pyritic materials and redox cycles of Fe-minerals (such as pyrite (FeS2), ankerite (Ca(Fe Mg)(CO3)2 and siderite (FeCO3), as indicated by the extractable FeO values. The likely formation of sparingly soluble Zn-phosphate in the Pb-Zn tailings containing high levels of Zn (from sphalerite ((Zn,Fe)S, ZnS, (Zn,Cd)S)) may substantially lower soluble Zn levels in the tailings through high rates of Pi-fertiliser addition. As a result, the possibility of P-toxicity in native plant species caused by the addition of soluble phosphate fertilizers would be minimal.

Spectroscopic properties of highly Nd-doped lead phosphate glass

Energy Technology Data Exchange (ETDEWEB)

Novais, A.L.F. [Instituto de Física, Universidade Federal de Alagoas, Grupo de Fotônica e Fluidos Complexos, 57072-970 Maceió, AL (Brazil); Dantas, N.O. [Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia, 38400-902 Uberlândia, MG (Brazil); Guedes, I. [Departamento de Física, Universidade Federal do Ceará, Campus do PICI, Caixa Postal 6030, 60455-760 Fortaleza, CE (Brazil); Vermelho, M.V.D., E-mail: vermelho@fis.ufal.br [Instituto de Física, Universidade Federal de Alagoas, Grupo de Fotônica e Fluidos Complexos, 57072-970 Maceió, AL (Brazil)

2015-11-05

The spectroscopic characteristics of highly Nd{sup 3+}-doped lead phosphate glasses (xNd:Pb{sub 3}(PO{sub 4}){sub 2}) have been investigated. The X-ray spectra show that the matrices are glassy up to 25 wt% of Nd{sup 3+} doping. From the Judd–Ofelt analysis we observe that while the Ω{sub (2)} parameter remains constant indicating that the 4f{sup N} and 4f{sup N−1}5 d{sup 1} configurations are not affected by the Nd{sup 3+} doping, the behavior of both Ω{sub (4)} and Ω{sub (6)} changes for 15 wt% of Nd{sup 3+} doping. The reduction of the Ω{sub (6)} parameter is related to the increase of the covalence bonding between the ligands and the Nd{sup 3+} ions. At this particular concentration, the radiative lifetime has a four-fold enhancement. Such behaviors are likely to be related to a modification in the glass structure for high Nd{sup 3+} concentrations. - Graphical abstract: Highly doped lead-phosphate glass matrix, with nominal concentration of up to 25 wt%, maintain the spectroscopic properties without deterioration. The analysis concerning the point of view of Nd{sup 3+} ions showed that high concentrations only affects the rare earth electronic charge density distribution. - Highlights: • Spectroscopic characterization of Nd{sub 2}O{sub 3} highly doped lead phosphate glasses. • Phosphate glass doped with Nd{sup 3+} for applications in photonic devices. • Judd–Ofelt analysis in phosphate glasses doped with Neodymium.

Phosphate fertilizer influence on {sup 238} U content in vegetables

Energy Technology Data Exchange (ETDEWEB)

Lauria D, C.; Rodrigues S, J.I. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN), Av. Salvador Allende s/n, Rio de Janeiro-RJ (Brazil); Ribeiro, F.C.A. [Centro Regional de Ciencias Nucleares (CRCN/CNEN) Av. Prof. Luiz Freire 200 Cidade Universitaria Recife-PE (Brazil)]. e-mail: dejanira@ird.gov.br

2006-07-01

Uranium is a naturally radioactive element, which is usually found in soils, superficial and ground water, vegetables and animals. After ingestion by human beings, most is excreted in few days by feces and urine, without reaching the bloodstream. However, a small part circulates through the body, being accumulated in the soft tissues, as kidneys. A minor fraction can remain in bones per some years, being able through the radioactive decay to irradiate adjacent tissues. Phosphate fertilizers used in conventional crop management can present variable amounts of uranium. In accordance with origin and use, the fertilizer can raise the content of this element in vegetables, and consequently to increase the human exposure for radiation due the consumption of vegetables. It is estimated that the use of phosphate fertilizer has at least doubled the prolonged exposure of humans from ingestion of food. This work aims to evaluate the contribution of organic and chemical fertilizer on the concentration of {sup 238} U in vegetable samples. An experiment with black beans (a very important vegetable for Brazilian people) was conducted in a field which soil has never been fertilized with any sort of fertilizer, located near to the Rio de Janeiro city. On the organic management, bovine manure was used, while on conventional management urea, potassium chloride and superphosphate were used. Simultaneously, black bean samples from not fertilized management were collected. In addition, lettuce and carrot samples from organic and conventional managements were collected in Nova Friburgo farms (the most important vegetable supplier of Rio de Janeiro city market). The analyses of {sup 238} U have been carried out by conventional fluorimetric method. The geometric mean of {sup 238} U concentrations in the carrot and lettuce samples from conventional management were similar with those from organic management, while for beans the conventional samples had higher values than those ones found in

Extremely High Phosphate Sorption Capacity in Cu-Pb-Zn Mine Tailings.

Directory of Open Access Journals (Sweden)

Longbin Huang

Full Text Available Elevated inorganic phosphate (Pi concentrations in pore water of amended tailings under direct revegetation may cause toxicity in some native woody species but not native forbs or herb species, all of which are key constituents in target native plant communities for phytostabilizing base metal mine tailings. As a result, Pi sorption capacity has been quantified by a conventional batch procedure in three types of base metal mine tailings sampled from two copper (Cu-lead (Pb-zinc (Zn mines, as the basis for Pi-fertiliser addition. It was found that the Pi-sorption capacity in the tailings and local soil was extremely high, far higher than highly weathered agricultural soils in literature, but similar to those of volcanic ash soils. The Langmuir P-sorption maximum was up to 7.72, 4.12, 4.02 and 3.62 mg P g-1 tailings, in the fresh tailings of mixed Cu-Pb-Zn streams (MIMTD7, the weathered tailings of mixed Cu-Pb-Zn streams (MIMTD5, EHM-TD (fresh Cu-stream, high magnetite content and local soil (weathered shale and schist, respectively. Physicochemical factors highly correlated with the high Pi-sorption in the tailings were fine particle distribution, oxalate and dithionite-citrate-bicarbonate extractable Fe (FeO and Fed, oxalate-extractable Al and Mn, and the levels of soluble Cd and Zn, and total S and Fe. Large amounts of amorphous Fe oxides and oxyhydroxides may have been formed from the oxidation of pyritic materials and redox cycles of Fe-minerals (such as pyrite (FeS2, ankerite (Ca(Fe Mg(CO32 and siderite (FeCO3, as indicated by the extractable FeO values. The likely formation of sparingly soluble Zn-phosphate in the Pb-Zn tailings containing high levels of Zn (from sphalerite ((Zn,FeS, ZnS, (Zn,CdS may substantially lower soluble Zn levels in the tailings through high rates of Pi-fertiliser addition. As a result, the possibility of P-toxicity in native plant species caused by the addition of soluble phosphate fertilizers would be minimal.

Isolation of phosphate solubiliser fungi from Araza rhizosphere

International Nuclear Information System (INIS)

Vera, Diana Fernanda; Perez, Hernando; Valencia Hernando

2002-01-01

Araza is an eatable plant, original from the Amazon region, which has been described as a promising species for commercialization (Quevedo 1995). This plant has high productivity even in low content phosphate soil but the presence of phosphate solubilizing microorganisms may contribute to increase this element availability. In this study we report the isolation and characterization of solubilizing fungi processed using the soil washing method, from soil samples were araza is cultivated at two regions in Guaviare, Colombia. Eighteen isolates of fungi capable of solubilizing phosphate were obtained from 2 different sources. The most important species that solubilized phosphate from calcium were Trichoderma aureoviride, Aspergillus aculeatus, Trichoderma strain 1 y Trichoderma strain 2 and for phosphate from iron: Aspergillus oryzae, Paecilomyces strain 3, Gongronella butleri and Fusarium oxysporum

Minimalistic Liquid-Assisted Route to Highly Crystalline α-Zirconium Phosphate.

Science.gov (United States)

Cheng, Yu; Wang, Xiaodong Tony; Jaenicke, Stephan; Chuah, Gaik-Khuan

2017-08-24

Zirconium phosphates have potential applications in areas of ion exchange, catalysis, photochemistry, and biotechnology. However, synthesis methodologies to form crystalline α-zirconium phosphate (Zr(HPO 4 ) 2 ⋅H 2 O) typically involve the use of excess phosphoric acid, addition of HF or oxalic acid and long reflux times or hydrothermal conditions. A minimalistic sustainable route to its synthesis has been developed by using only zirconium oxychloride and concentrated phosphoric acid to form highly crystalline α-zirconium phosphate within hours. The morphology can be changed from platelets to rod-shaped particles by fluoride addition. By varying the temperature and time, α-zirconium phosphate with particle sizes from nanometers to microns can be obtained. Key features of this minimal solvent synthesis are the excellent yields obtained with high atom economy under mild conditions and ease of scalability. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phosphate acquisition efficiency and phosphate starvation tolerance ...

Indian Academy of Sciences (India)

3Department of Genetics and Plant Breeding, College of Agriculture, Lembucherra, Tripura 799 ... vated in soil like red and lateritic or acid, with low soluble phosphate content. ..... activation of genes involved in the adaptation of Arabidopsis to.

Effect of phosphate supplementation on oxygen delivery at high altitude

Science.gov (United States)

Jain, S. C.; Singh, M. V.; Rawal, S. B.; Sharma, V. M.; Divekar, H. M.; Tyagi, A. K.; Panwar, M. R.; Swamy, Y. V.

1987-09-01

In the present communication, effect of low doses of phosphate supplementation on short-term high altitude adaptation has been examined. Studies were carried out in 36 healthy, male, sea-level residents divided in a double blind fashion into drug and placebo treated groups. 3.2 mmol of phosphate were given orally to each subject of the drug treated group once a day for 4 days on arrival at an altitude of 3,500 m. Sequential studies were done in the subjects in both groups on the 3rd, 7th, 14th and 21st day of their altitude stay. Haemoglobin, haematocrit, erythrocyte and reticulocyte counts increased to the similar extent in both groups. Blood pH, pO2 and adenosine tri-phosphate (ATP) did not differ between the two groups. On 3rd day of the altitude stay, inorganic phosphate and 2,3-diphosphoglycerate (2,3 DPG) levels in the drug treated group increased significantly as compared to the placebo group. No significant difference in inorganic phosphate and 2,3 DPG was observed later on in the two groups. Psychological and clinical tests also indicated that the drug treated subjects felt better as compared to the placebo treated subjects. The present study suggests that low doses of phosphate increases circulating 2,3-DPG concentration which in turn brings about beneficial effect towards short term high altitude adaptation.

Structural features of silver-doped phosphate glasses in zone of femtosecond laser-induced modification

Science.gov (United States)

Vasileva, A. A.; Nazarov, I. A.; Olshin, P. K.; Povolotskiy, A. V.; Sokolov, I. A.; Manshina, A. A.

2015-10-01

Femtosecond (fs) laser writing of two-dimensional microstructures (waveguides) is demonstrated in bulk phosphate glasses doped with silver ions. Silver-content phosphate and silver-content niobium-phosphate glasses with high concentration of silver oxide 55 mol% were used as samples for fs laser writing. The chemical network structure of the synthesized samples is analyzed through Raman spectroscopy and was found to be strongly sensitive to Nb incorporation. It was found that the direct laser writing process enables not only reorganization of glass network, but also formation of color centers and silver nanoparticles that are revealed in appearance of luminescence signal and plasmon absorption. The process of NPs' formation is more efficient for Nb-phosphate glass, while color centers are preferably formed in phosphate glass.

High inorganic phosphate causes DNMT1 phosphorylation and subsequent fibrotic fibroblast activation

Energy Technology Data Exchange (ETDEWEB)

Tan, Xiaoying [Department of Nephrology and Rheumatology, Göttingen University Medical Center, Georg August University, Göttingen (Germany); Department of Cardiology and Pneumology, Göttingen University Medical Center, Georg August University, Göttingen (Germany); Xu, Xingbo [Department of Cardiology and Pneumology, Göttingen University Medical Center, Georg August University, Göttingen (Germany); Zeisberg, Elisabeth M. [Department of Cardiology and Pneumology, Göttingen University Medical Center, Georg August University, Göttingen (Germany); German Center for Cardiovascular Research (DZHK), Göttingen (Germany); Zeisberg, Michael, E-mail: mzeisberg@med.uni-goettingen.de [Department of Nephrology and Rheumatology, Göttingen University Medical Center, Georg August University, Göttingen (Germany); German Center for Cardiovascular Research (DZHK), Göttingen (Germany)

2016-04-08

Phosphate is an essential constituent of critical cellular functions including energy metabolism, nucleic acid synthesis and phosphorylation-dependent cell signaling. Increased plasma phosphate levels are an independent risk factor for lowered life-expectancy as well as for heart and kidney failure. Nevertheless, direct cellular effects of elevated phosphate concentrations within the microenvironment are poorly understood and have been largely neglected in favor of phosphor-regulatory hormones. Because interstitial fibrosis is the common determinant of chronic progressive kidney disease, and because fibroblasts are major mediators of fibrogenesis, we here explored the effect of high extracellular phosphate levels on renal fibroblasts. We demonstrate that high inorganic phosphate directly induces fibrotic fibroblast activation associated with increased proliferative activity, increased expression of α-smooth muscle actin and increased synthesis of type I collagen. We further demonstrate that such fibroblast activation is dependent on phosphate influx, aberrant phosphorylation of DNA methyltransferase DNMT1 and aberrant CpG island promoter methylation. In summary, our studies demonstrate that elevated phosphate concentrations induce pro-fibrotic fibroblast activation independent of phospho-regulatory hormones. - Highlights: • We exposed human kidney fibroblasts to media containing 1 mM or 3 mM phosphate. • Increased phosphate influx causes phosphorylation of DNA methyltransferase Dnmt1. • Phosphorylated Dnmt1 causes promoter methylation and transcriptional silencing of RASAL1. • Depletion of RASAL1 causes increased intrinsic Ras-GTP activity and fibroblast activation. • Inorganic phosphate causes fibroblast activation independent of phospho-regulatory hormones.

Dietary calcium phosphate content and oat β-glucan influence gastrointestinal microbiota, butyrate-producing bacteria and butyrate fermentation in weaned pigs.

Science.gov (United States)

Metzler-Zebeli, Barbara U; Zijlstra, Ruurd T; Mosenthin, Rainer; Gänzle, Michael G

2011-03-01

This study aimed to evaluate the effects of oat β-glucan in combination with low- and high-dietary calcium phosphate (CaP) content on gastrointestinal bacterial microbiota, prevalence of butyrate-production pathway genes and fermentation end-products in 32 weaned pigs allocated to four diets: a cornstarch-casein-based diet with low [65% of the calcium (Ca) and phosphorous (P) requirement] and high CaP content (125% and 115% of the Ca and P requirement, respectively); and low and high CaP diets supplemented with 8.95% of oat β-glucan concentrate. Pigs were slaughtered after 14 days, and digesta were collected for quantitative PCR analysis, and quantification of short-chain fatty acids and lactate. The high CaP content reduced gastric lactate and streptococci and propionate in the large intestine. Oat β-glucan distinctly raised gastric bacterial numbers, and colonic lactobacilli and bifidobacteria. Although not reflected by gene copies of butyrate-production pathway genes, oat β-glucan also increased gastric, caecal and colonic butyrate concentrations, which may be favourable for intestinal development in weaned pigs. Thus, a high CaP content negatively affected the intestinal abundance of certain fermentation end-products, whereas oat β-glucan generally enhanced bacterial numbers and activity. The results emphasize the importance of the stomach for bacterial metabolism of oat β-glucan in weaned pigs. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Modeling of excimer laser radiation induced defect generation in fluoride phosphate glasses

International Nuclear Information System (INIS)

Natura, U.; Ehrt, D.

2001-01-01

Fluoride phosphate (FP) glasses with low phosphate content are high-transparent in the deep ultraviolet (UV) range and attractive candidates for UV-optics. Their optical properties are complementary to fluoride crystals. The anomalous partial dispersion makes them desirable for optical lens designs to reduce the secondary spectrum. Their UV transmission is limited by trace impurities introduced by raw materials and decreases when exposed to UV-radiation (lamps, lasers). The experiments of the paper published previously in this journal were used in order to separate radiation induced absorption bands in the fluoride phosphate glass FP10. In this paper the generation mechanism of the phosphorus-oxygen related hole center POHC 2 is investigated in detail in glasses of various compositions (various phosphate and impurity contents) in order to predict the transmission loss in case of long-time irradiation. Experiments were carried out using ArF- and KrF-excimer lasers (ns-pulses). POHC 2 generation strongly depends on the phosphate content and on the content of Pb 2+ . A model was developed on these terms. Rate equations are formulated, incorporating the influence of the Pb 2+ -content on the defect generation, a two-step creation term including an energy transfer process and a one-photon bleaching term. This results in a set of coupled nonlinear differential equations. Absorption coefficients and lifetimes of the excited states were calculated as well. Experimental results compared well with the numerical analysis of the theoretical rate equations

Role of magnesium on the biomimetic deposition of calcium phosphate

Science.gov (United States)

Sarma, Bimal K.; Sarma, Bikash

2016-10-01

Biomimetic depositions of calcium phosphate (CaP) are carried out using simulated body fluid (SBF), calcifying solution and newly developed magnesium containing calcifying solution. Calcium phosphate has a rich phase diagram and is well known for its excellent biocompatibility and bioactivity. The most common phase is hydroxyapatite (HAp), an integral component of human bone and tooth, widely used in orthopedic and dental applications. In addition, calcium phosphate nanoparticles show promise for the targeted drug delivery. The doping of calcium phosphate by magnesium, zinc, strontium etc. can change the protein uptake by CaP nanocrystals. This work describes the role of magnesium on the nucleation and growth of CaP on Ti and its oxide substrates. X-ray diffraction studies confirm formation of HAp nanocrystals which closely resemble the structure of bone apatite when grown using SBF and calcifying solution. It has been observed that magnesium plays crucial role in the nucleation and growth of calcium phosphate. A low magnesium level enhances the crystallinity of HAp while higher magnesium content leads to the formation of amorphous calcium phosphate (ACP) phase. Interestingly, the deposition of ACP phase is rapid when magnesium ion concentration in the solution is 40% of calcium plus magnesium ions concentration. Moreover, high magnesium content alters the morphology of CaP films.

Conditions promoting and restraining agronomic effectiveness of water-insoluble phosphate sources, in particular phosphate rock (PR): I. Indices of phosphate rock use opportunity (PRUOIS) and of phosphate rock suitability for direct use (PRSIDU)

International Nuclear Information System (INIS)

Borlan, Z.; Gavriluta, I.; Soare, M.; Stefanescu, D.; Alexandrescu, A.

2002-01-01

Several issues of phosphate rock (PR) use are discussed in this paper. Maize for green fodder (Zea mays L) and ryegrass (Lolium multiflorum Lam.) were grown in 7 kg of dry soil and in small pots of 1.25 kg dry soil capacity, respectively, on several base unsaturated soils belonging to Hapludoll and Hapludalf soil groups. The amount of phosphate rock (PR) to apply was based on experimental data considering soil adsorbed acidity (Ah), humus content (H 2 ), cation exchange capacity (T), sum of exchangeable bases (SEB) and mobile (easily soluble) phosphate content (P A L) in the soil. The factors were combined in a rock phosphate use, opportunity index of the soil (PRUOIS): PRUOIS=(A h *H 2 *100)/SEB*10 0.0245*P AL Rock phosphate suitability for direct use was evaluated by means of the rate of PR-P dissolution (PRPRS) in a 0.6% ammonium heptamolybdate in 0.01M calcium chloride solution (ppm P) and by carbonate content (%CaCO 3 ) in PR. Both of these parameters combined provided a phosphate rock suitability index for direct use (PRSIDU): PRSIDU [ppmP/min]=PRPRS*(1-0.03*CaCO 3 ) Water insoluble P sources studied were PR from Kola-Russia, Morocco, Kneifiss-Siria, El Hassa-Jordan, Gafsa- Tunisia, North-Carolina (USA), and Arad-Israel. All PRs were compared with TSP applied at the same rate of P. Neither PRUOIS or PRSIDU considered separately could satisfactorily explain the variance of PR efficiency. An index obtained by multiplicative combination of PRUOIS x PRSIDU did correlate significantly with indices on the agronomic efficiency of PR. (author)

Investigation the Effects of Different Doses Organic Fertilizers and Phosphate Solubilizing Bacterias on Yield and Nutrient Contents in Chickpea (Cicer arietinum L.

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Ferit SÖNMEZ

2015-07-01

Full Text Available The study was conducted to determine the effect of phosphate solubilizing bacteria (N2; Bacillus megaterium M-3, TV-6I; Cellulosimicrobium cellulans, TV-34A; Hafnia Alve, TV-69E; Acetobacter pasteurianus and TV-83F; Bacillus cereus and organic fertilizer (0, 10 and 20 ton / ha on the seed yield and nutrient content of chickpea under field conditions in 2010 and 2011 growing seasons. Phosphate solubilizing bacteria used in this study were determined by the separate investigation conducted in chamber room by using ten phosphate solubilizing bacteria and organic fertilizer (control, %5,%10. The tiral were laid out with a factorial design in randomized complete block with three replications. In this study, plant height, primary branches, secondary branches and number of pods per plant, number of seeds per pod, grain yield and biological yield and nutrient content of stem and seed were determined. According to the results of the study bacteria applications increased significantly biological and seed yield. Bacteria applications without organic fertilizer increased nutrient contents of seed and steed except cupper content. In case of inoculation with organic fertilizer provided more increases in biological and seed yields. The highest seed yield were obtained from application of 20 ton/ha + N2 (Bacillus megaterium M-3 with 1020 kg/ha and 1793 kg/ha in 2010 and 2011 years, respectively. Bacteria without organic fertilizer application were more active in terms of phosphorus uptake in both years. 

Phosphate sensing by fluorecent reporter proteins embedded in poly-acrylamide nanoparticles

DEFF Research Database (Denmark)

Sun, Honghao; Scharff-Poulsen, Anne Marie; Gu, Hong

2008-01-01

Phosphate sensors were developed by embedding fluorescent reporter proteins (FLIPPi) in polyacrylamide nanoparticles; with diameters from 40 to 120 nm. The sensor activity and protein loading efficiency varied according to nanoparticle composition, that is, the total monomer content (% T) and the......, in nanoparticles for, for example, sensing, biological catalysis, and gene delivery.......Phosphate sensors were developed by embedding fluorescent reporter proteins (FLIPPi) in polyacrylamide nanoparticles; with diameters from 40 to 120 nm. The sensor activity and protein loading efficiency varied according to nanoparticle composition, that is, the total monomer content (% T......) and the cross-linker content (% C). Nanoparticles with 28% T and 20% C were considered optimal as a result of relatively high loading efficiency (50.6%) as well as high protein activity (50%). The experimental results prove that the cross-linked polyacrylamide matrix could protect FLIPPi from degradation...

Characterization, Leaching, and Filtration Testing for Bismuth Phosphate Sludge (Group 1) and Bismuth Phosphate Saltcake (Group 2) Actual Waste Sample Composites

International Nuclear Information System (INIS)

Lumetta, Gregg J.; Buck, Edgar C.; Daniel, Richard C.; Draper, Kathryn; Edwards, Matthew K.; Fiskum, Sandra K.; Hallen, Richard T.; Jagoda, Lynette K.; Jenson, Evan D.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Shimskey, Rick W.; Sinkov, Sergey I.; Snow, Lanee A.

2009-01-01

A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan.() The test program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. The actual waste-testing program included homogenizing the samples by group, characterizing the solids and aqueous phases, and performing parametric leaching tests. Two of the eight defined groups - bismuth phosphate sludge (Group 1) and bismuth phosphate saltcake (Group 2) - are the subjects of this report. The Group 1 waste was anticipated to be high in phosphorus and was implicitly assumed to be present as BiPO4 (however, results presented here indicate that the phosphate in Group 1 is actually present as amorphous iron(III) phosphate). The Group 2 waste was also anticipated to be high in phosphorus, but because of the relatively low bismuth content and higher aluminum content, it was anticipated that the Group 2 waste would contain a mixture of gibbsite, sodium phosphate, and aluminum phosphate. Thus, the focus of the Group 1 testing was on determining the behavior of P removal during caustic leaching, and the focus of the Group 2 testing was on the removal of both P and Al. The waste-type definition, archived sample conditions, homogenization activities, characterization (physical, chemical, radioisotope, and crystal habit), and caustic leaching behavior as functions of time, temperature, and hydroxide concentration are discussed in this report. Testing was conducted according to TP-RPP-WTP-467

Thermo-tolerant phosphate-solubilizing microbes for multi-functional biofertilizer preparation.

Science.gov (United States)

Chang, Cheng-Hsiung; Yang, Shang-Shyng

2009-02-01

In order to prepare the multi-functional biofertilizer, thermo-tolerant phosphate-solubilizing microbes including bacteria, actinomycetes, and fungi were isolated from different compost plants and biofertilizers. Except Streptomycesthermophilus J57 which lacked pectinase, all isolates possessed amylase, CMCase, chitinase, pectinase, protease, lipase, and nitrogenase activities. All isolates could solubilize calcium phosphate and Israel rock phosphate; various isolates could solubilize aluminum phosphate, iron phosphate, and hydroxyapatite. During composting, biofertilizers inoculated with the tested microbes had a significantly higher temperature, ash content, pH, total nitrogen, soluble phosphorus content, and germination rate than non-inoculated biofertilizer; total organic carbon and carbon-to-nitrogen ratio showed the opposite pattern. Adding these microbes can shorten the period of maturity, improve the quality, increase the soluble phosphorus content, and enhance the populations of phosphate-solubilizing and proteolytic microbes in biofertilizers. Therefore, inoculating thermo-tolerant phosphate-solubilizing microbes into agricultural and animal wastes represents a practical strategy for preparing multi-functional biofertilizer.

Meal phosphate variability does not support fixed dose phosphate binder schedules for patients treated with peritoneal dialysis: a prospective cohort study.

Science.gov (United States)

Leung, Simon; McCormick, Brendan; Wagner, Jessica; Biyani, Mohan; Lavoie, Susan; Imtiaz, Rameez; Zimmerman, Deborah

2015-12-09

Removal of phosphate by peritoneal dialysis is insufficient to maintain normal serum phosphate levels such that most patients must take phosphate binders with their meals. However, phosphate 'counting' is complicated and many patients are simply prescribed a specific dose of phosphate binders with each meal. Therefore, our primary objective was to assess the variability in meal phosphate content to determine the appropriateness of this approach. In this prospective cohort study, adult patients with ESRD treated with peritoneal dialysis and prescribed phosphate binder therapy were eligible to participate. Participants were excluded from the study if they were unable to give consent, had hypercalcemia, were visually or hearing impaired or were expected to receive a renal transplant during the time of the study. After providing informed consent, patients kept a 3-day diet diary that included all foods and beverages consumed in addition to portion sizes. At the same time, patients documented the amount of phosphate binders taken with each meal. The phosphate content of the each meal was estimated using ESHA Food Processor SQL Software by a registered dietitian. Meal phosphate and binder variability were estimated by the Intra Class Correlation Coefficient (ICC) where 0 indicates maximal variability and 1 indicates no variability. Seventy-eight patients consented to participate in the study; 18 did not complete the study protocol. The patients were 60 (± 17) years, predominately male (38/60) and Caucasian (51/60). Diabetic nephropathy was the most common cause of end stage kidney disease. The daily phosphate intake including snacks ranged from 959 ± 249 to 1144 ± 362 mg. The phosphate ICC by meal: breakfast 0.63, lunch 0.16; supper 0.27. The phosphate binder ICC by meal: breakfast 0.68, lunch 0.73, supper 0.67. The standard prescription of a set number of phosphate binders with each meal is not supported by the data; patients do not appear to be adjusting their

Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

International Nuclear Information System (INIS)

Boatner, L.A.; Sales, B.C.

1989-01-01

This patent describes lead-iron phosphate glasses containing a high level of Fe 2 O 3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90 0 C, with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10 2 to 10 3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe 2 O 3 in forming the lead-iron phosphate glass is critical. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms

Separating and stabilizing phosphate from high-level radioactive waste: process development and spectroscopic monitoring.

Science.gov (United States)

Lumetta, Gregg J; Braley, Jenifer C; Peterson, James M; Bryan, Samuel A; Levitskaia, Tatiana G

2012-06-05

Removing phosphate from alkaline high-level waste sludges at the Department of Energy's Hanford Site in Washington State is necessary to increase the waste loading in the borosilicate glass waste form that will be used to immobilize the highly radioactive fraction of these wastes. We are developing a process which first leaches phosphate from the high-level waste solids with aqueous sodium hydroxide, and then isolates the phosphate by precipitation with calcium oxide. Tests with actual tank waste confirmed that this process is an effective method of phosphate removal from the sludge and offers an additional option for managing the phosphorus in the Hanford tank waste solids. The presence of vibrationally active species, such as nitrate and phosphate ions, in the tank waste processing streams makes the phosphate removal process an ideal candidate for monitoring by Raman or infrared spectroscopic means. As a proof-of-principle demonstration, Raman and Fourier transform infrared (FTIR) spectra were acquired for all phases during a test of the process with actual tank waste. Quantitative determination of phosphate, nitrate, and sulfate in the liquid phases was achieved by Raman spectroscopy, demonstrating the applicability of Raman spectroscopy for the monitoring of these species in the tank waste process streams.

Performance of pineapple slips inoculated with diazotrophic phosphate-solubilizing bacteria and rock phosphate

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Lílian Estrela Borges Baldotto

2014-06-01

Full Text Available Besides fixing N2, some diazotrophic bacteria or diazotrophs, also synthesize organic acids and are able to solubilize rock phosphates, increasing the availability of P for plants. The application of these bacteria to pineapple leaf axils in combination with rock phosphate could increase N and P availability for the crop, due to the bacterial activity of biological nitrogen fixation and phosphate solubilization. The objectives of this study were: (i to select and characterize diazotrophs able to solubilize phosphates in vitro and (ii evaluate the initial performance of the pineapple cultivars Imperial and Pérola in response to inoculation with selected bacteria in combination with rock phosphate. The experiments were conducted at Universidade Estadual do Norte Fluminense Darcy Ribeiro, in 2009. In the treatments with bacteria the leaf contents of N, P and K were higher than those of the controls, followed by an increase in plant growth. These results indicate that the combined application of diazotrophic phosphate-solubilizing bacteria Burkholderia together with Araxá rock phosphate can be used to improve the initial performance of pineapple slips.

Occupational radiation risks in conveyance of bulk phosphate and potash

International Nuclear Information System (INIS)

Grof, Y.; Even, O.; Schlesinger, T.; Margaliot, M.

1996-01-01

The issue of occupational ionizing radiation risks encountered in the conveyance and storage of Phosphates and Potash as loose cargo got very minor attention from the national health and occupational safety authorities in the world. In Israel, the Phosphates include an average 100- 150 ppm of Uranium in equilibrium with its daughters, while in Phosphates produced in most other countries the inaction reaches regularly only few ppm up to 50 ppm. Because of the high content of the Uranium in the Phosphate in Israel we must take into consideration the radiological implications involved in the handling of this mineral. The radiological implications of handling Potash are less significant but can not be neglected as we demonstrate bellow In this presentation we will estimate the occupational radiological risks involved in the storing and transportation of Phosphate and Potash. Note, that the main risk in working with Phosphate and Potash is the risk from the dust itself (authors)

Occupational radiation risks in conveyance of bulk phosphate and potash

Energy Technology Data Exchange (ETDEWEB)

Grof, Y; Even, O; Schlesinger, T; Margaliot, M [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center

1996-12-01

The issue of occupational ionizing radiation risks encountered in the conveyance and storage of Phosphates and Potash as loose cargo got very minor attention from the national health and occupational safety authorities in the world. In Israel, the Phosphates include an average 100- 150 ppm of Uranium in equilibrium with its daughters, while in Phosphates produced in most other countries the inaction reaches regularly only few ppm up to 50 ppm. Because of the high content of the Uranium in the Phosphate in Israel we must take into consideration the radiological implications involved in the handling of this mineral. The radiological implications of handling Potash are less significant but can not be neglected as we demonstrate bellow In this presentation we will estimate the occupational radiological risks involved in the storing and transportation of Phosphate and Potash. Note, that the main risk in working with Phosphate and Potash is the risk from the dust itself (authors).

Intracellular pH and inorganic phosphate content of heart in vivo: A 31P-NMR study

International Nuclear Information System (INIS)

Katz, L.A.; Swain, J.A.; Portman, M.A.; Balaban, R.S.

1988-01-01

Studies were performed to determine the contribution of red blood cells to the 31 P-nuclear magnetic resonance (NMR) spectrum of the canine heart in vivo and the feasibility of measuring myocardial intracellular phosphate and pH. This was accomplished by replacing whole blood with a perfluorochemical perfusion emulsion blood substitute, Oxypherol, and noting the difference in the 31 P-NMR spectrum of the heart. NMR data were collected with a NMR transmitter-receiver coil on the surface of the distal portion of the left ventricle. These studies demonstrated that a small contribution from 2,3-diphosphoglycerate (2,3-DPG) and phosphodiesters in the blood could be detected. The magnitude and shift of these blood-borne signals permitted the relative quantification of intracellular inorganic phosphate (P i ) content as well as intracellular pH. Under resting conditions, the intracellular ATP/P i was 7.0 ± 0.08. This corresponds to a free intracellular P 1 content of ∼ 0.8 μmol./g wet wt. The intracellular pH was 7.10 ± 0.01. Acute respiratory alkalosis and acidosis, with the arterial pH ranging from ∼7.0 to 7.7, resulted in only small changes in the intracellular pH. These latter results demonstrate an effective myocardial intracellular proton-buffering mechanism in vivo

Properties and structure of high erbium doped phosphate glass for short optical fibers amplifiers

International Nuclear Information System (INIS)

Seneschal, Karine; Smektala, Frederic; Bureau, Bruno; Floch, Marie Le; Jiang Shibin; Luo, Tao; Lucas, Jacques; Peyghambarian, Nasser

2005-01-01

New phosphate glasses have been developed in order to incorporate high rare-earth ions concentrations. These glasses present a great chemical stability and a high optical quality. The phosphate glass network is open, very flexible, with a linkage of the tetrahedrons very disordered and contains a larger number of non-bridging oxygens (66%). The great stability and resistance against crystallization associated with the possibility to incorporate high doping concentration of rare-earth ions in these phosphate glasses make them very good candidates for the realization of ultra short single mode amplifiers with a high gain at 1.55 μm

How do arbuscular mycorrhizal fungi handle phosphate? New insight into fine-tuning of phosphate metabolism.

Science.gov (United States)

Ezawa, Tatsuhiro; Saito, Katsuharu

2018-04-27

Contents Summary I. Introduction II. Foraging for phosphate III. Fine-tuning of phosphate homeostasis IV. The frontiers: phosphate translocation and export V. Conclusions and outlook Acknowledgements References SUMMARY: Arbuscular mycorrhizal fungi form symbiotic associations with most land plants and deliver mineral nutrients, in particular phosphate, to the host. Therefore, understanding the mechanisms of phosphate acquisition and delivery in the fungi is critical for full appreciation of the mutualism in this association. Here, we provide updates on physical, chemical, and biological strategies of the fungi for phosphate acquisition, including interactions with phosphate-solubilizing bacteria, and those on the regulatory mechanisms of phosphate homeostasis based on resurveys of published genome sequences and a transcriptome with reference to the latest findings in a model fungus. For the mechanisms underlying phosphate translocation and export to the host, which are major research frontiers in this field, not only recent advances but also testable hypotheses are proposed. Lastly, we briefly discuss applicability of the latest tools to gene silencing in the fungi, which will be breakthrough techniques for comprehensive understanding of the molecular basis of fungal phosphate metabolism. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

Science.gov (United States)

Boatner, Lynn A.; Sales, Brian C.

1989-01-01

Lead-iron phosphate glasses containing a high level of Fe.sub.2 O.sub.3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90.degree. C., with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10.sup.2 to 10.sup.3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe.sub.2 O.sub.3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800.degree. C., since they exhibit very low melt viscosities in the 800.degree. to 1050.degree. C. temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550.degree. C. and are not adversely affected by large doses of gamma radiation in H.sub.2 O at 135.degree. C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms.

Glucose-6-phosphate dehydrogenase protects Escherichia coli from tellurite-mediated oxidative stress.

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Juan M Sandoval

Full Text Available The tellurium oxyanion tellurite induces oxidative stress in most microorganisms. In Escherichia coli, tellurite exposure results in high levels of oxidized proteins and membrane lipid peroxides, inactivation of oxidation-sensitive enzymes and reduced glutathione content. In this work, we show that tellurite-exposed E. coli exhibits transcriptional activation of the zwf gene, encoding glucose 6-phosphate dehydrogenase (G6PDH, which in turn results in augmented synthesis of reduced nicotinamide adenine dinucleotide phosphate (NADPH. Increased zwf transcription under tellurite stress results mainly from reactive oxygen species (ROS generation and not from a depletion of cellular glutathione. In addition, the observed increase of G6PDH activity was paralleled by accumulation of glucose-6-phosphate (G6P, suggesting a metabolic flux shift toward the pentose phosphate shunt. Upon zwf overexpression, bacterial cells also show increased levels of antioxidant molecules (NADPH, GSH, better-protected oxidation-sensitive enzymes and decreased amounts of oxidized proteins and membrane lipids. These results suggest that by increasing NADPH content, G6PDH plays an important role in E. coli survival under tellurite stress.

Heat- and exercise-induced hyperthermia: effects on high-energy phosphates.

Science.gov (United States)

Francesconi, R; Mager, M

1979-08-01

To assess the role of high-energy phosphate compounds in the etiology of heat injury with respect to the release of intracellular constituents, the susceptibility of selected tissues to heat injury, and the shock-like demise of the animals, rats were exercised on a treadmill (9.14 m/min) in a hot environment (34.5-35 degrees C) to a rectal temperature (Tre) of 42.5-43 degrees C. In the heart, kidney, left lateral lobe of the liver, and gastrocnemius muscle extricated from animals immediately upon termination of the treadmill run, levels of glucose-6-phosphate (G-6-P), adenosine triphosphate (ATP), and creatine phosphate (CP) were unchanged when compared with sedentary controls. In animals which had been resuscitated by infusion of isotonic saline into a jugular catheter, levels of CP were significantly (p less than 0.025) elevated in gastrocnemius muscle. In rats which were unconscious and succumbing to the effects of hyperthermic injury, levels of hepatic G-6-P and ATP were significantly reduced (p less than 0.05, p less than 0.02, respectively). These results indicate that the combination of exhaustive excercise/heat injury had the most deleterious effects upon hepatic metabolism. However, while resuscitation with physiological saline may be accompanied by an increased synthesis of CP, hyperthermic exhaustion and the concomitant efflux of cellular constituents cannot be attributed to a depletion or even a decrement of high-energy phosphates in vital tissues.

PHOSPHATE CRYSTALLURIA IN VARIOUS FORMS OF UROLITHIASIS AND POSSIBILITIES OF ITS PROGNOSTICATION IN PATIENTS WITH PHOSPHATE STONES

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O. V. Konstantinova

2017-01-01

Full Text Available Purpose. Definition of types of crystalluria in various forms of urolithiasis and biochemical signs of phosphate crystals in the urine, while phosphate urolithiasis (infectious origin.Patients and methods. The study involved 144 patients with recurrent urolithiasis — 75 women and 69 men. Of these, 46 — diagnosed calculi with uric acid, 44 — calcium oxalate or mixed with a prevalence of calcium oxalate, in 54 — phosphate rocks (carbonate-apatite and/or struvite. The age of patients ranged from 21 to 74 years. 93 people have been under long-term, within 2–15 years, outpatient observation. The examination included the collection of anamnesis, general and microbiological analysis of urine, biochemical blood serum and urine on 10 indicators, reflecting renal function, state of the protein, water and electrolyte metabolism, uric acid metabolism, the chemical composition of the stone analysis.Results. It was found that in patients with calcium oxalate stones phosphaturia has been diagnosed in 2% of cases. And, along with calcium phosphate crystals they had oxalate crystals. In patients with phosphate urolithiasis phosphaturia observed in 96% of patients, in two patients (4% they determined except phosphates also oxalate salt in urine sediment. Patients with phosphate urolithiasis at occurrence of phosphate crystalluria have metabolic state changes: increased serum uric acid concentration from 0.322 ± 0.009 to 0.367 ± 0.018 mmol/l daily renal excretion of inorganic phosphate 23.94 ± 2.93 mmol/day to 32.12 ± 4.39 mmol/day, and reduced total calcium content in urine 6.61 ± 0.94 mmol/day to 3.37 ± 0.89 mmol/day. The results led to the following conclusion.Conclusion. Biochemical signs of occurrence of phosphate crystalluria in patients with stones of infectious origin can be: the approaching level of excretion in the urine of inorganic phosphates to 32,12 ± 4,39 mmol/day, serum uric acid concentration to 0,367 ± 0,018 mmol/l, and the

Ammonia-nitrogen and phosphates sorption from simulated reclaimed waters by modified clinoptilolite

International Nuclear Information System (INIS)

Huo, Hanxin; Lin, Hai; Dong, Yingbo; Cheng, Huang; Wang, Han; Cao, Lixia

2012-01-01

Highlights: ► The salt and thermally modified clinoptilolite can effectively sorb NH 3 -N and phosphates. ► The phosphorus and nitrogen removal was consistent with Langmuir isotherm model. ► The modified clinoptilolite possesses rapid adsorption and slow balance characteristics. ► The adsorption is more in line with the Elovich adsorption dynamics equation. ► The entropy effect plays the role of the main driving force in the adsorption. - Abstract: This paper presents the investigation of the ammonia-nitrogen and phosphates sorption from simulated reclaimed wastewater by modified clinoptilolite. The results showed that the modified clinoptilolite has a high sorption efficiency and removal performance. The ammonia-nitrogen and phosphates removal rate of the modified clinoptilolite reached to 98.46% and 99.80%, respectively. The surface of modified clinoptilolite became loose and some pores appeared, which enlarged the specific surface area; the contents of Na and Fe increased, and the contents of Ca and Mg decreased. The modified clinoptilolite possesses rapid sorption and slow balance characteristics and ammonia-nitrogen and phosphates sorption is more consistent with the Langmuir isotherm model. The adsorption kinetics of ammonia-nitrogen and phosphates follows the Elovich adsorption dynamics equation, which describes the sorption of ammonia-nitrogen and phosphates in aqueous solution as mainly a chemical sorption. Results from the thermodynamics experiment involving ammonia-nitrogen and phosphates sorption reveal that the process is a spontaneous and endothermic process, and is mainly driven by entropy effect.

Efficiency of phosphate fertilization to maize crop in high phosphorus content soil, evaluated by 32P tracer

International Nuclear Information System (INIS)

Trevizam, Anderson R.; Alvarez Villanueva, Felipe C.; Silva, Maria Ligia de S.; Muraoka, Takashi

2007-01-01

Application of high dosis of phosphorus (P) in agricultural soils is justified by its intense fixation by the soil clays, which reduce availability to crops. The objective of this research was to evaluate the response of maize crops to five rates of triple superphosphate in a soil with high available phosphorus content. Portions of 2 dm 3 of soil (Typic Quartzipisamment) with 75 mg kg -1 of available phosphorus and pH 7.00, collected from the upper 0-20 cm layer, were placed in plastic pots, received solution containing 5.55 MBq (150 μCi) of 32 P and incubated for 7 days. Then 0, 250, 500, 1000 and 4000 mg P kg -1 as triple superphosphate was added to soil in the respective pots and incubated for 15 days keeping the soil moisture to 60 % of the field capacity. Maize (Zea mays L.) plants, single hybrid P30F80, were grown for 50 days (after germination), collected, oven dried, weighed and ground in a Wiley mill for analysis of total P content and 32 P radioactivity. The maize dry matter increased with triple superphosphate rates. The phosphorus content and accumulation in the maize plants increased with triple superphosphate rate up to 4000 mg kg -1 . The percentage of phosphorus derived from the fertilizer ranged from 79 to 97% and consequently the phosphorus derived from soil decreased with increasing application of triple superphosphate. In spite of soil high P available content, maize plants responded to applied phosphorus rates. (author)

Can the isotopic exchange kinetic method be used in soils with a very low water extractable phosphate content and a high sorbing capacity for phosphate ions?

Czech Academy of Sciences Publication Activity Database

Randriamanantsoa, L.; Morel, Ch.; Rabeharisoa, L.; Douzet, J.-M.; Jansa, Jan; Frossard, E.

2013-01-01

Roč. 200, JUN 2013 (2013), s. 120-129 ISSN 0016-7061 Institutional support: RVO:61388971 Keywords : Ferralsol * Andosol * Phosphate ion sorption Subject RIV: EE - Microbiology, Virology Impact factor: 2.509, year: 2013

Cyclic-2,3-diphosphoglycerate levels in Methanobacterium thermoautotrophicum reflect inorganic phosphate availability.

Science.gov (United States)

Seely, R J; Krueger, R D; Fahrney, D E

1983-11-15

Methanobacterium thermoautotrophicum was grown in phosphate-limited chemostat cultures at a dilution rate corresponding to a doubling time of 13.2 h. The cyclic-2,3-diphospho-D-glycerate content of these cells was 8 to 10-fold lower than that of cells grown in batch cultures having a doubling time of 11.5 h. This metabolite accounted for 5% of cell dry weight during batch growth on 2 mM phosphate. In the chemostat the steady-state concentration of phosphate was 4 microM, showing that this methanogen is adapted to highly efficient growth at low phosphate concentrations. Since growth rates were similar in both cultures, the growth rate clearly does not depend on intracellular levels of cyclic-2,3-diphosphoglycerate.

Rare earth elements in sedimentary phosphate deposits: Solution to the global REE crisis?

Science.gov (United States)

Emsbo, Poul; McLaughlin, Patrick I.; Breit, George N.; du Bray, Edward A.; Koenig, Alan E.

2015-01-01

The critical role of rare earth elements (REEs), particularly heavy REEs (HREEs), in high-tech industries has created a surge in demand that is quickly outstripping known global supply and has triggered a worldwide scramble to discover new sources. The chemical analysis of 23 sedimentary phosphate deposits (phosphorites) in the United States demonstrates that they are significantly enriched in REEs. Leaching experiments using dilute H2SO4 and HCl, extracted nearly 100% of their total REE content and show that the extraction of REEs from phosphorites is not subject to the many technological and environmental challenges that vex the exploitation of many identified REE deposits. Our data suggest that phosphate rock currently mined in the United States has the potential to produce a significant proportion of the world's REE demand as a byproduct. Importantly, the size and concentration of HREEs in some unmined phosphorites dwarf the world's richest REE deposits. Secular variation in phosphate REE contents identifies geologic time periods favorable for the formation of currently unrecognized high-REE phosphates. The extraordinary endowment, combined with the ease of REE extraction, indicates that such phosphorites might be considered as a primary source of REEs with the potential to resolve the global REE (particularly for HREE) supply shortage.

PHOSPHATES REMOVAL FROM REJECT WATER FROM DIGESTION OF SLUDGE

Directory of Open Access Journals (Sweden)

Elżbieta Sperczyńska

2016-06-01

Full Text Available The aim of the research work was to evaluate if coagulants used on technical scale are useful in phosphates removal from reject water. Effectiveness of phosphorus compounds removal from reject water from digestion of sewage sludge was examined. Selected prehydrolysed alkaline aluminium polychlorides were used. The results were compared to the ones obtained with aluminium sulphate. Reject water from digestion of sewage sludge form WWTP of 100 000 PE were examined. Commercial agents – prehydrolysed PAX 18, PAX XL10, PAX-XL1905 as well as aluminium sulphate were used. Various doses of coagulants: 0.7; 1.0; 1.5 – time higher than stoichiometric dose were applied. Stoichiometric dose was calculated based on chemical reaction of insoluble aluminium phosphate formation. Concentrations of Kiejdahl nitrogen (891 mgNKj/dm3, phosphates (125 mgPO43-/dm3 and organic compounds - COD (592 mgO2/dm3 in reject water were very high. The effectiveness of coagulation process increased as the doses of chemical agents increased. The most effective doses were the highest ones used during the experiment. The most effective agent was PAX 18 (96% removal efficiency. As the phosphates concentration decreased COD content declined simultaneously. Maximum COD removal (47% was obtained when highly alkaline PAX XL 1905 was used. Use of the lowest dose of Al2(SO43 allowed for 50% phosphates removal, whereas the lowest dose of PAX 18 decreased phosphates concentration by 83%.

Enhancement of carotenoid and chlorophyll content of an edible freshwater alga (Kai: Cladophora sp. by supplementary inorganic phosphate and investigation of its biomass production

Directory of Open Access Journals (Sweden)

Siripen Traichaiyaporn

2012-01-01

Full Text Available Enhancement of the carotenoid and chlorophyll content of an edible freshwater alga (Kai:Cladophora sp. by supplementary inorganic phosphate in canteen wastewater was investigated. Themass cultivation of the alga was conducted at ambient temperature and light intensity in dilutedcanteen wastewater enhanced with dipotassium hydrogen phosphate at 5-20 mg L-1. An increase intotal carotenoid and chlorophyll was observed. However, it had no effect on biomass production. Asa result of the algal cultivation, there was a dramatic improvement in the quality of canteen wastewater.

Calcium phosphate bioceramics prepared from wet chemically precipitated powders

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Kristine Salma

2010-03-01

Full Text Available In this work calcium phosphates were synthesized by modified wet chemical precipitation route. Contrary to the conventional chemical precipitation route calcium hydroxide was homogenized with planetary mill. Milling calcium oxide and water in planetary ball mill as a first step of synthesis provides a highly dispersed calcium hydroxide suspension. The aim of this work was to study the influence of main processing parameters of wet chemical precipitation synthesis product and to control the morphology, phase and functional group composition and, consequently, thermal stability and microstructure of calcium phosphate bioceramics after thermal treatment. The results showed that it is possible to obtain calcium phosphates with different and reproducible phase compositions after thermal processing (hydroxyapatite [HAp], β-tricalcium phosphate [β-TCP] and HAp/β-TCP by modified wet-chemical precipitation route. The β-TCP phase content in sintered bioceramics samples is found to be highly dependent on the changes in technological parameters and it can be controlled with ending pH, synthesis temperature and thermal treatment. Pure, crystalline and highly thermally stable (up to 1300°C HAp bioceramics with homogenous grainy microstructure, grain size up to 200–250 nm and high open porosity can be successfully obtained by powder synthesized at elevated synthesis temperature of 70°C and stabilizing ending pH at 9.

Structural Isosteres of Phosphate Groups in the Protein Data Bank.

Science.gov (United States)

Zhang, Yuezhou; Borrel, Alexandre; Ghemtio, Leo; Regad, Leslie; Boije Af Gennäs, Gustav; Camproux, Anne-Claude; Yli-Kauhaluoma, Jari; Xhaard, Henri

2017-03-27

We developed a computational workflow to mine the Protein Data Bank for isosteric replacements that exist in different binding site environments but have not necessarily been identified and exploited in compound design. Taking phosphate groups as examples, the workflow was used to construct 157 data sets, each composed of a reference protein complexed with AMP, ADP, ATP, or pyrophosphate as well other ligands. Phosphate binding sites appear to have a high hydration content and large size, resulting in U-shaped bioactive conformations recurrently found across unrelated protein families. A total of 16 413 replacements were extracted, filtered for a significant structural overlap on phosphate groups, and sorted according to their SMILES codes. In addition to the classical isosteres of phosphate, such as carboxylate, sulfone, or sulfonamide, unexpected replacements that do not conserve charge or polarity, such as aryl, aliphatic, or positively charged groups, were found.

Zirconium-based metal organic frameworks: Highly selective adsorbents for removal of phosphate from water and urine

Energy Technology Data Exchange (ETDEWEB)

Lin, Kun-Yi Andrew, E-mail: linky@nchu.edu.tw [Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan (China); Chen, Shen-Yi [Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan (China); Jochems, Andrew P. [New Mexico Bureau of Geology & Mineral Resources and New Mexico Institute of Mining & Technology, Socorro, NM (United States)

2015-06-15

Phosphate is one of the most concerning compounds in wastewater streams and a main nutrient that causes eutrophication. To eliminate the phosphate pollution, Metal Organic Frameworks (MOFs) are proposed in this study as adsorbents to remove phosphate from water. The zirconium-based MOF, UiO-66, was selected as representative MOF given its exceptional stability in water. To investigate the effect of an amine functional group, UiO-66-NH2 was also prepared using an amine-substituted ligand. The adsorption kinetics and isotherm reveal that UiO-66-NH2 exhibited higher adsorption capacities than UiO-66 possibly due to the amine group. However, the interaction between phosphate and zirconium sites of UiO MOFs might be the primary factor accounting for the phosphate adsorption to UiO MOFs. UiO MOFs also exhibited a high selectivity towards phosphate over other anions such as bromate, nitrite and nitrate. Furthermore, UiO MOFs were found to adsorb phosphate and to completely remove diluted phosphate in urine. We also found that UiO MOFs could be easily regenerated and re-used for phosphate adsorption. These findings suggest that UiO MOFs can be effective and selective adsorbents to remove phosphate from water as well as urine. - Highlights: • UiO-66 as the first type of MOFs was used to remove phosphate from water and urine. • The amine group in UiO MOFs was found to enhance the phosphate adsorption. • UiO-66 exhibited a high adsorption selectivity towards phosphate over other anions. • UiO-66 could be easily regenerated and re-used with 85% regeneration efficiency.

Lead-iron phosphate glass: a stable storage medium for high-level nuclear waste

International Nuclear Information System (INIS)

Sales, B.C.; Boatner, L.A.

1984-01-01

Results are presented which show that lead-iron phosphate glasses are a promising new waste form for the safe immobilization of both high-level defense and high-level commercial radioactive waste. Relative to the borosilicate nuclear waste glasses that are currently the ''reference'' waste form for the long-term disposal of nuclear waste, lead-iron phosphate glasses have several distinct advantages: (1) an aqueous corrosion rate that is about 1000 times lower, (2) a processing temperature that is 100 0 to 250 0 C lower and, (3) a much lower melt viscosity in the temperature range from 800 0 to 1000 0 C. Most significantly, the lead-iron phosphate waste form can be processed using a technology similar to that developed for borosilicate nuclear waste glasses

Lead-iron phosphate glass as a containment medium for the disposal of high-level nuclear wastes

Science.gov (United States)

Boatner, L.A.; Sales, B.C.

1984-04-11

Disclosed are lead-iron phosphate glasses containing a high level of Fe/sub 2/O/sub 3/ for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste

Neutron activation analysis of alternative phosphate rocks used in animal nutrition; Analise por ativacao neutronica por fontes alternativas de fosforo para a nutricao animal

Energy Technology Data Exchange (ETDEWEB)

Canella, Artur A.; Ferreira, Walter M. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Escola de Veterinaria]. E-mail: avelara@ufmg.br; Menezes, Maria Angela de B.C. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)]. E-mail: menezes@cdtn.br

2005-07-01

Since 1980's, Bovine Sponghiform Encephalophaty has insidiously created a fierce battleground between farmers, scientists, environmentalists and consumers. The use of meat and bone meals is currently prohibited in ruminant feeds throughout the world. Some inorganic sources offer the combination of high phosphorus content and acceptable animal digestibility make them options as supplemental phosphorus, for instance phosphate rocks, general term applied to minerals valued chiefly for their phosphorus content. However, phosphate rocks are long been known containing hazardous elements, make them sometimes unsuitable for animal nutrition. Neutron Activation Analysis has been supportive to the mineral evaluation of alternative phosphate rocks. This evaluation is subject of on-going doctoral thesis which has been carried-out by the main author. The NAA method has been very efficient due to its highly sensitive and multi-elemental nature. In this paper results of Vanadium content from three different phosphate rocks are presented. Their values have been pointed out that Brazilian phosphate rocks present hazardous elements at the same levels of phosphate rocks from some countries of Africa, North America and Middle East, data from our study (Brazilian data) and FAO - Food and Agriculture Organization (others countries). (author)

Effect of heavy store dressing with rock phosphate on a fine sand soil

Directory of Open Access Journals (Sweden)

Armi Kaila

1969-05-01

Full Text Available Results are reported of a long-term field trial on acid fine sand soil in which the effects of store dressing with rock phosphate in amounts of 0, 4000, 8000, or 12000 kg/ha was studied comparing them with an annual application of 200 kg/ha of superphosphate using the split plot technique. In the first four years, more thoroughly studied, the response to the store dressing with rock phosphate was distinct both in the dry matter yields and the phosphorus content of the cereal and the red clover-timothy hay. The differences between the various rates of rock phosphate treatments were not statistically significant, though there was some tendency to higher results with larger amounts of rock phosphate. The annual applications of superphosphate as surface dressing to the ley did not brought about any significant increase in the dry matter yield of the rock phosphate plots, and although they tended to increase the phosphorus content of hay, the increase was statistically significant only in a few cases. No effect was found on the phosphorus content of barley grain and straw in the ninth experimental year. No differences were found in the calcium, magnesium, or potassium content of the plant samples from the variously treated plots. Nitrogen content of clover and timothy was increased by both rock phosphate and superphosphate, particularly in the first year ley. In this soil, 4000 kg/ha of rock phosphate was effective enough to produce higher dry matter yields of hay, with equal phosphorus content, than the annual application of 200 kg/ha of superphosphate. Soil analyses indicated that this soil represented the extreme pattern of phosphorus retention in which applied phosphate is almost completely retained as aluminium bound forms of the fluoride soluble fraction supposed to be fairly available. It was suggested that in soils which retain the slowly dissolving rock phosphate phosphorus mainly as less available iron bound forms, heavy applications of

Effect of sucrose, erythrose-4-phosphate and phenylalanine on biomassa and flavonoid content of callus culture from leaves of Gynura procumbens Merr.

Science.gov (United States)

Nurisa, Aryana; Kristanti, Alfinda Novi; Manuhara, Yosephine Sri Wulan

2017-08-01

The aims of this study were to know the effect of concentration of sucrose, erythrose-4-phosphate and phenylalanine on biomass and flavonoid content of callus cultures from leaves of sambung nyawa (Gynura procumbens Merr.). This study was experimental research with complete randomized design. Callus induction was treated in MS medium supplemented with NAA 2 mg/L, BAP 1 mg/L and sucrose concentration (10 g/L, 30 g/L and 50 g/L) respectively were combined with erythrose-4-phosphate (0 µM, 2,5 µM and 5 µM) and phenylalanine (0 mg/L, 2 mg/L and 3 mg/L), each treatment were repeated four times. After six weeks of culture, fresh and dry weight of calli were measured and extracted with ethanol absolut. Crude extract ethanolic of callus was analyzed used by a modified colorimetric with spectrophotometer method. The best yield of calli biomass (0,672 ± 0,112 gram of fresh weight and 0,033 ± 0,009 gram of dry weight) was obtained in treatment of 30 g/L sucrose of and 5 µM erythrose-4-phosphate. The highest total flavonoid content was obtained of calli treated with 30 g/L of sucrose and 3 mg/L of phenylalanine (3633,4 ppm quercetin/gram dry weight and 15777,8 ppm kaempferol/gram dry weight).

Phosphate-bonded composite electrodes for hydrogen evolution

Energy Technology Data Exchange (ETDEWEB)

Potvin, E.; Menard, H.; Lalancette, J.M. (Sherbrooke Univ., PQ (Canada). Dept. de Chimie); Brossard, L. (Institut de Recherche d' Hydro-Quebec, Varennes, PQ (Canada))

1990-03-01

A new process of cementing metallic powders to produce high surface area cathodes for alkaline water electrolysis is described. The binding compound is a tridimensional polymer of aluminium phosphate (AlPO{sub 4}). Phosphate-bonded composite electrodes give a low-polarization performance for hydrogen evolution in 1 M KOH aqueous solution in the case of 95wt% Pt and 98wt%Ni. When electrode materials are prepared with nickel powder, the electrocatalytic activity for the hydrogen evolution reaction, the chemical stability and the electrical conductivity depend on the Ni content and morphology of the electrode. The best performance and chemical stability with Ni as the starting material are obtained for spiky filamentary particles produced by the decomposition of nickel carbonyl. (author).

Phosphate-rich sedimentary rocks: significance for organic facies and petroleum exploration

Energy Technology Data Exchange (ETDEWEB)

Waples, D W

1982-03-01

Phosphorus-bearing rocks and sediments can be divided into two genetically distinct classes: phosphatic shales or limestones and phosphorites. Phosphatic shales are primary sediments in which phosphate nodules or micronodules have formed diagenetically by precipitation of calcium phosphates derived mainly from organic phosphorus. The nodules form in reducing environments at shallow depths within the sediments, where loss of phosphate by diffusion to the overlying water column is minimized. Highly biogenic sediments containing large amounts of organic matter and some fine clastic debris provide ideal environments for the formation of phosphate nodules. Phosphorites, in contrast, represent concentrated accumulations of reworked phosphate nodules which originated in phosphatic shales or limestones. Currents, wave action, recrystallization, and erosion and resedimentation are important mechanisms in the concentration process. Phosphatic shales and limestones may become excellent oil source rocks if thermal maturity is achieved. They are useful facies indicators for anoxic or nearly anoxic depositional environments, and are often associated with restricted basins, or, during certain geologic periods, with broad shelves developed during transgressions. Phosphorites, in contrast, are often correlated with sea-level regressions or uplifts. They are modest source rocks because of their low organic carbon contents and the fact that they were reworked under oxidizing conditions. Nevertheless, because phosphorites are derived from, and often grade into, phosphatic shales, they also are of potential utility in the search for oil source beds.

Iron environment in ferritin with large amounts of phosphate, from Azotobacter vinelandii and horse spleen, analyzed using Extended X-ray Absorption fine Structure (EXAFS)

International Nuclear Information System (INIS)

Rohrer, J.S.; Islam, Q.T.; Sayes, D.E.; Theil, E.C.; Watt, G.D.

1990-01-01

The iron core of proteins in the ferritin family displays structural variations that includes phosphate content was well as the number and the degree of ordering of the iron atoms. Earlier studies had shown that ferritin iron cores naturally high in phosphate, e.g., Azotobacter vinelandii (AV) ferritin had decreased long-range order. Here, the influence of phosphate on the local structure around iron in ferritin cores is reported, comparing the EXAFS of AV ferritin, reconstituted ferritin and native horse spleen ferritin. In contrast, when the phosphate content was high in AV ferritin and horse spleen ferritin reconstituted with phosphate, the average iron atom had five to six phosphorus neighbors at 3.17 angstrom. Moreover, the number of detectable iron neighbors was lower when phosphate was high or present during reconstitution and the interatomic distance was longer indicating that some phosphate bridges neighboring iron atoms. However, the decrease in the number of detectable iron-iron neighbors compared to HSF and the higher number of Fe-P interactions relative to Fe-Fe interactions suggest that some phosphate ligands were chain termini, or blocked crystal growth, and/or introduced defects which contributed both to the long-range disorder and to altered redox properties previously observed in AV ferritin

Effect of altitude on oxygen binding by hemoglobin and on organic phosphate levels

Science.gov (United States)

Lenfant, Claude; Torrance, John; English, Eugenia; Finch, Clement A.; Reynafarje, Cesar; Ramos, Jose; Faura, Jose

1968-01-01

The relationship between oxygen dissociation and 2,3-diphosphoglycerate (2,3-DPG) in the red cell has been studied in subjects moving from low to high altitude and vice versa. Within 24 hr following the change in altitude there was a change in hemoglobin affinity for oxygen; this modification therefore represents an important rapid adaptive mechanism to anoxia. A parallel change occurred in the organic phosphate content of the red cell. While this study does not provide direct evidence of a cause-effect relationship, the data strongly suggest that with anoxia, the observed rise in organic phosphate content of the red cell is responsible for increased availability of oxygen to tissues. Images PMID:5725278

The effect of pH on bromelain partition from Ananas comosus by PEG4000/phosphate ATPS

Directory of Open Access Journals (Sweden)

Juliana Ferrari Ferreira

2011-02-01

Full Text Available In this work, the thermodynamic equilibrium and applying of PEG4000/Phosphate ATPS on the purification of bromelain extracted from pineapple was studied. A rigorous study of the equilibrium curves and tie-line length from PEG4000/phosphate ATPS were done for the pH 6-11 at 25ºC. Results showed that there was augment in the PEG and salt contents with the high pH value from PEG4000/Phosphate ATPS and two-phase formation needed only increasing the PEG content. Two tie-line length at pH 11 from PEG4000/Phosphate ATPS were optimal condition for bromelain purification, one on composition of 14% PEG and 13% salt and other at 12.6% PEG and 12.2% salt, while a 25-62 folds of enzyme was found. SDS-PAGE electrophoreses had one band only, which showed that bromelain was purified. Optimum conditions of bromelain use were found at pH 7 and between 30-40ºC.

Efficiency of phosphate fertilization to maize crop in high phosphorus content soil, evaluated by {sup 32}P tracer

Energy Technology Data Exchange (ETDEWEB)

Trevizam, Anderson R.; Alvarez Villanueva, Felipe C.; Silva, Maria Ligia de S.; Muraoka, Takashi [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Fertilidade do Solo]. E-mails: trevizam@cena.usp.br; falvarez@cena.usp.br; mlsousi@hotmail.com; muraoka@cena.usp.br

2007-07-01

Application of high dosis of phosphorus (P) in agricultural soils is justified by its intense fixation by the soil clays, which reduce availability to crops. The objective of this research was to evaluate the response of maize crops to five rates of triple superphosphate in a soil with high available phosphorus content. Portions of 2 dm{sup 3} of soil (Typic Quartzipisamment) with 75 mg kg{sup -1} of available phosphorus and pH 7.00, collected from the upper 0-20 cm layer, were placed in plastic pots, received solution containing 5.55 MBq (150 {mu}Ci) of {sup 32}P and incubated for 7 days. Then 0, 250, 500, 1000 and 4000 mg P kg{sup -1} as triple superphosphate was added to soil in the respective pots and incubated for 15 days keeping the soil moisture to 60 % of the field capacity. Maize (Zea mays L.) plants, single hybrid P30F80, were grown for 50 days (after germination), collected, oven dried, weighed and ground in a Wiley mill for analysis of total P content and {sup 32}P radioactivity. The maize dry matter increased with triple superphosphate rates. The phosphorus content and accumulation in the maize plants increased with triple superphosphate rate up to 4000 mg kg{sup -1}. The percentage of phosphorus derived from the fertilizer ranged from 79 to 97% and consequently the phosphorus derived from soil decreased with increasing application of triple superphosphate. In spite of soil high P available content, maize plants responded to applied phosphorus rates. (author)

On the mechanism of ion exchange in zirconium phosphates

International Nuclear Information System (INIS)

Clearfield, A.; Frianeza, T.N.

1978-01-01

α-titanium phosphate, Ti(HPO 4 ) 2 .H 2 O, was found to form two sodium ion exchanged phases. A half exchanged phase of ideal composition TiNaH(PO 4 ) 2 .4H 2 O formed first. However, before all of the titanium phosphate was converted to this phase a second phase of higher Na + content formed. Thus, a three phase solid existed until sufficient sodium ion uptake (approximately 5.5 meq/g) produced only the two exchanged phases. Finally, the half exchanged phase was converted to the more highly loaded one and this latter phase existed from 6 to 8 meq/g of Na + uptake. Severe disordering of the crystal lattice during exchange is proposed to explain this unusual exchange behavior. A broad range of titanium phosphate-zirconium phosphate solid solutions was found to form. Their behavior towards Na + -H + exchange was determined and interpreted on the basis of the known behavior of the pure phases. Mixed Ti-Zr solid solutions of their pyrophosphates were obtained at elevated temperatures. (author)

Iron phosphate glasses: Bulk properties and atomic scale structure

Energy Technology Data Exchange (ETDEWEB)

Joseph, Kitheri; Stennett, Martin C.; Hyatt, Neil C.; Asuvathraman, R.; Dube, Charu L.; Gandy, Amy S.; Govindan Kutty, K. V.; Jolley, Kenny; Vasudeva Rao, P. R.; Smith, Roger

2017-10-01

Bulk properties such as glass transition temperature, density and thermal expansion of iron phosphate glass compositions, with replacement of Cs by Ba, are investigated as a surrogate for the transmutation of 137Cs to 137Ba, relevant to the immobilisation of Cs in glass. These studies are required to establish the appropriate incorporation rate of 137Cs in iron phosphate glass. Density and glass transition temperature increases with the addition of BaO indicating the shrinkage and reticulation of the iron phosphate glass network. The average thermal expansion coefficient reduces from 19.8 × 10-6 K-1 to 13.4 × 10-6 K-1, when 25 wt. % of Cs2O was replaced by 25 wt. % of BaO in caesium loaded iron phosphate glass. In addition to the above bulk properties, the role of Ba as a network modifier in the structure of iron phosphate glass is examined using various spectroscopic techniques. The FeII content and average coordination number of iron in the glass network was estimated using Mössbauer spectroscopy. The FeII content in the un-doped iron phosphate glass and barium doped iron phosphate glasses was 20, 21 and 22 ± 1% respectively and the average Fe coordination varied from 5.3 ± 0.2 to 5.7 ± 0.2 with increasing Ba content. The atomic scale structure was further probed by Fe K-edge X-ray absorption spectroscopy. The average coordination number provided by extended X-ray absorption fine structure spectroscopy and X-ray absorption near edge structure was in good agreement with that given by the Mössbauer data.

High-Strength / High Alkaline Resistant Fe-Phosphate Glass Fibers as Concrete Reinforcement

Energy Technology Data Exchange (ETDEWEB)

Mariano Velez

2008-03-31

Calcium-iron-phosphate glasses were developed whose chemical durabilities in alkaline solutions (pH 13) were comparable or superior to those of commercial alkaline-resistant (AR) silica-based glasses. However, the tensile strength of Ca-Fe-phosphate fibers, after being exposed to alkaline environments, including wet Portland cement pastes, is lower than that of current AR silicate fibers. Another series of Ca-Fe-phosphate glasses were developed with excellent chemical durability in strong acidic solutions (H2SO4, HF), indicating potential applications where silica-based fibers degrade very quickly, including E-glass. The new Ca-Fe-phosphate glasses can be melted and processed 300 to 500°C lower than silica-based glasses. This offers the possibility of manufacturing glass fibers with lower energy costs by 40-60% and the potential to reduce manufacturing waste and lower gas emissions. It was found that Ca-Fe-phosphate melts can be continuously pulled into fibers depending on the slope of the viscosity-temperature curve and with viscosity ~100 poise, using multi-hole Pt/Rh bushings.

Transfer of Some Major and Trace Elements From Phosphate Rock to Super-Phosphate Fertilizers

International Nuclear Information System (INIS)

El-Reefya, H.I.; Bin-Jaz, A.A.; Zaied, M.E.; Badran, H.M.; Badran, H.M.

2014-01-01

This study assesses the transfer of some major and trace elements from phosphate rock (PR) to single (SSP) and triple (TSP) superphosphate fertilizers. Samples from a fertilizer plant and local market were collected and analyzed using inductively coupled plasma spectrometer. Cluster analysis indicated that the inner-relationship among the concentration of the elements in PR, SSP, and TSP are different. Only one element (Mo) has concentration in SSP higher than phosphate rock. The production process of these two types of superphosphate leads to transfer higher portion of Mn, B, Cu, Mo, Sr, and V present in the phosphate rock to SSP than TSP. The potentially hazardous element Cd is also transmitted more to SSP than TSP, and Cr is equally transferred to both types. The mean elemental concentrations normalized to the percentage of P 2 O 5 demonstrate that for most elements they are the higher concentrations in SSP are linked to the phosphate contents

Global radiological impact of the phosphate fertilizers

International Nuclear Information System (INIS)

Morales, Rudnei Karam; Alves, Rex Nazare

1996-01-01

About ninety percent of the products obtained in the phosphate industry are directly used in agriculture as fertilizers. The uranium, thorium and radium content in phosphate fertilizers pollute the soil, water and air, creating risks due to associated natural radiation. This work shows the concentration of radionuclides present in various products of the national and American phosphate fertilizers industry, and compared them with worldwide mean values. The radiological impact of the products on the environment is evaluated and suggestions are presented in order to minimize the risks due to radioactivity. (author)

Contribution to the geochemical study of Phosphates in Gafsa-Metlaoui basin: Example of Gisement Oum EL Khecheb

International Nuclear Information System (INIS)

Khelifi, Lobna

2012-01-01

This study is devoted to the distribution of uranium in the phosphates of Oum Al Khashab deposit, located South of Tunisia. The analysis were conducted by XRF, HPGe/ γ-ray and ICP-OES. The results showed that high Sr, Zn and Cd concentrations are correlated with high phosphorus contents at the top of the series. The concentration of uranium in the phosphate series is bracketed between 29.5 and 58.8 mg/kg, the highest contents being located at the base of the series. Two types of correlations are highlighted between uranium and phosphorus, one testifying that part of uranium is included in apatite, and the other showing that part of it is independent from apatite

Highly Doped Phosphate Glass Fibers for Compact Lasers and Amplifiers: A Review

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Nadia Giovanna Boetti

2017-12-01

Full Text Available In recent years, the exploitation of compact laser sources and amplifiers in fiber form has found extensive applications in industrial and scientific fields. The fiber format offers compactness, high beam quality through single-mode regime and excellent heat dissipation, thus leading to high laser reliability and long-term stability. The realization of devices based on this technology requires an active medium with high optical gain over a short length to increase efficiency while mitigating nonlinear optical effects. Multicomponent phosphate glasses meet these requirements thanks to the high solubility of rare-earth ions in their glass matrix, alongside with high emission cross-sections, chemical stability and high optical damage threshold. In this paper, we review recent advances in the field thanks to the combination of highly-doped phosphate glasses and innovative fiber drawing techniques. We also present the main performance achievements and outlook both in continuous wave (CW and pulsed mode regimes.

Magnesium prevents phosphate-induced vascular calcification via TRPM7 and Pit-1 in an aortic tissue culture model.

Science.gov (United States)

Sonou, Tomohiro; Ohya, Masaki; Yashiro, Mitsuru; Masumoto, Asuka; Nakashima, Yuri; Ito, Teppei; Mima, Toru; Negi, Shigeo; Kimura-Suda, Hiromi; Shigematsu, Takashi

2017-06-01

Previous clinical and experimental studies have indicated that magnesium may prevent vascular calcification (VC), but mechanistic characterization has not been reported. This study investigated the influence of increasing magnesium concentrations on VC in a rat aortic tissue culture model. Aortic segments from male Sprague-Dawley rats were incubated in serum-supplemented high-phosphate medium for 10 days. The magnesium concentration in this medium was increased to demonstrate its role in preventing VC, which was assessed by imaging and spectroscopy. The mineral composition of the calcification was analyzed using Fourier transform infrared (FTIR) spectroscopic imaging, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) mapping. Magnesium supplementation of high-phosphate medium dose-dependently suppressed VC (quantified as aortic calcium content), and almost ablated it at 2.4 mm magnesium. The FTIR images and SEM-EDX maps indicated that the distribution of phosphate (as hydroxyapatite), phosphorus and Mg corresponded with calcium content in the aortic ring and VC. The inhibitory effect of magnesium supplementation on VC was partially reduced by 2-aminoethoxy-diphenylborate, an inhibitor of TRPM7. Furthermore, phosphate transporter-1 (Pit-1) protein expression was increased in tissues cultured in HP medium and was gradually-and dose dependently-decreased by magnesium. We conclude that a mechanism involving TRPM7 and Pit-1 underpins the magnesium-mediated reversal of high-phosphate-associated VC.

Purification of Sodium Phosphates as by Product of Rirang Ore Decomposition Process

International Nuclear Information System (INIS)

Sugeng-Walujo; Hafni-LN; Susilaningtyas; Mukhlis; Budi-Sarono; Widowati

2004-01-01

The aim of this experiment is to get purification condition of sodium phosphates from the filtration result of mixing mother liquor and filtrate of washing residue from Rirang monazite decomposition by alkaline. The method of purification which has been used is dissolved the precipitation of sodium phosphates into agitated water 5 minutes and solution settling for 12 hours until appear of sodium phosphate crystals. The variable of experiment included dissolution time and ratio of the amount precipitate sodium phosphate volume of water to solvent. Experimental data shown that the good temperature of dissolution is 70 o C with the ratio of precipitate sodium phosphate is 80 gram/ 40 ml to water. The recovery of sodium phosphate crystallisation is 87.4314 % with 54.0105 % pure of Na 3 PO 4 , U content is 0.0004%, NaOH content and other impurities is 45.9889%. (author)

Radioactivity Content in Phosphoric Acid Used for Fertilizer Production

International Nuclear Information System (INIS)

Ibrahiem, N.M.; Hamed, A.A.

2003-01-01

Uranium content in phosphoric acid used fertilizer production was measured by alpha spectrometry, laser fluorimetry high resolution gamma spectrometry. Also, polonium-210 content was determined in phosphoric acid by alpha spectrometry. Uranium-234 and uranium-238 concentrations, measured by alpha spectroscopy, were found to be 601 and 507 Bq I -1 , respectively. Total uranium content obtained by laser fluorimetry was about 545 BqI - (45.4ppm). Gamma spectroscopy analysis gave the concentrations of 40 K, 238 U, 235 U, 214 Pb, 214 Bi and 208 TI, as 17,644,19.5, 1.2,1.3 and 9.4 Bq I -1 , respectively. Polonium-210 concentration was found to be about 3.1 Bq I -1 . Uranium-232 and polonium-208 were used as yield tracers, for alpha measurements of uranium and polonium, respectively. Samples of the tri-super phosphate (TSP) and single-super phosphate (SSP) fertilizers and the phosphogypsum produced were also analyzed by gamma spectroscopy. Uranium content in both phosphate fertilizers was 3205 and 1440 Bq Kg -1 for 238 U and 83 and 35 Bq Kg -1 for, 235 U respectively

Studies on the synthesis and characterization of cesium-containing iron phosphate glasses

Science.gov (United States)

Joseph, Kitheri; Govindan Kutty, K. V.; Chandramohan, P.; Vasudeva Rao, P. R.

2009-02-01

Isotopes of cesium and strontium can be utilized as radiation source for various industrial and medical applications after their separation from high level nuclear waste. However, these elements need to be immobilized in a suitable matrix. In the present work, a systematic approach has been made to immobilize inactive cesium into iron phosphate glass. Up to 36 mol% of Cs 2O has been loaded successfully without crystallization. The glass transition temperature of the cesium loaded glass was found to increase initially and then decrease as a function of Cs 2O content. Mössbauer studies show that the concentration of Fe 3+ ions in the cesium loaded glasses is >95%. Volatilization experiments at 1263 K show that the weight loss is >0.5% for a period of 4 h. The 36 mol% of Cs 2O loaded iron phosphate glass with high Fe 3+ content described in this paper is reported for the first time.

P Status In Andisol And P Content In Arabica Coffee Seedling Leaves Due To The Application Of Phosphate Providing Microorganisms And Organic Matters In Bener Meriah District

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Hifnalisa

2017-09-01

Full Text Available Bener Meriah district is one of the arabica coffee producing regions in Indonesia. Most of arabica coffee in Bener Meriah district grown on Andisol. Generally the availability of P in Andisol is very low. Phosphate providing microorganisms and organic matters can be used to increase Andisol P availability. The objective of this study was to examine the effect of the application of phosphate providing microorganisms and organic matters on P status in Andisol and P content in arabica coffee seedlings leaves in Bener Meriah district. The experiment used a randomized block design that consisted of two factors. Factor I was the application of phosphate providing microorganisms consisting of without microorganisms Glomus sp. Kurthia sp. Corynebacterium sp. and Listeria sp. Factor II was the application of organic matters consisting of T. diversifolia and coffee bean skins. The results of the study showed that Glomus sp. Kurthia sp. Corynebacterium sp. and Listeria sp. decreased soil P-retention by 2.38 5.12 7.48 9.17 respectively increased soil P-available by 24.85 36.03 52.79 77.33 respectively and increased P-content in the arabica coffee seedling leaves by 22.22 33.33 37.0372.27 respectively compared to without the application of microorganisms. The application of coffee bean skins resulted in lower soil P-retention higher soil P-available and P-content in arabica coffee seedling leaves than T. diversifolia. The application of Listeria sp.-coffee bean skins resulted in the lowest soil P-retention the highest soil P-available and P-content in arabica coffee seedlings leaves.

Preparation of Edible Corn Starch Phosphate with Highly Reactive ...

African Journals Online (AJOL)

1Food & Bioengineering Department, Henan University of Science and Technology, Luoyang, Henan 471003 ... Purpose: To prepare edible corn starch phosphate under optimized experimental conditions. ... In food industry, starch phosphate.

Effect of phosphate ion on filtration characteristics of solids generated in simulated high level liquid waste

International Nuclear Information System (INIS)

Kondo, Y.

1998-01-01

The effect of phosphate ion on the filtration characteristics of solids generated in a high level liquid waste was experimentally examined. Addition of phosphate ion into the simulated HLLW induced the formation of phosphate such as zirconium phosphate and phosphomolybdic acid. The filtration rate of zirconium phosphate abruptly dropped in the midst of filtration because of a gel-cake formation on the filter surface. The denitration of the simulated HLLW contained zirconium phosphate improved the filterability of this gelatinous solid. The filtration rates of denitrated HLLW decreased with increase of the phosphate ion concentration, since the solids formed by denitration had irregular particle size and configuration in the simulated HLLW with phosphate ion. To increase the filtration rate of denitrated HLLW, a solid suspension filtration tester was designed. The solid-suspension accelerated the filtration rate only in the simulated HLLW with more than 1500 ppm phosphate ion concentration. Under this condition, the simple agitation can easily suspend the constituent solids of filter cake in the solution and a much higher filtration rate can be obtained because the filter cake is continuously swept from the filter surface by rotation of propellers. (authors)

Bone mineralisation in premature infants cannot be predicted from serum alkaline phosphatase or serum phosphate

DEFF Research Database (Denmark)

Faerk, J; Peitersen, Birgit; Petersen, S

2002-01-01

BACKGROUND: The bone mineral content of premature infants at term is lower than in mature infants at the same postconceptional age. Serum alkaline phosphatase and serum phosphate are often used as indicators of bone mineralisation. OBJECTIVE: To analyse the association between bone mineral content...... content was measured at term (mean gestational age 41 weeks) by dual energy x ray absorptiometry and corrected for body size. RESULTS: Serum alkaline phosphatase was significantly negatively associated with serum phosphate (p mineral content was not associated with mean serum alkaline...... and serum alkaline phosphatase and serum phosphate. METHODS: Serum alkaline phosphatase and phosphate were measured at weekly intervals during admission in 108 premature infants of gestational age below 32 weeks (mean (SD) gestational age 29 (2) weeks; mean (SD) birth weight 1129 (279) g). Bone mineral...

Lithium-Ion Mobility in Quaternary Boro-Germano-Phosphate Glasses.

Science.gov (United States)

Moguš-Milanković, Andrea; Sklepić, Kristina; Mošner, Petr; Koudelka, Ladislav; Kalenda, Petr

2016-04-28

Effect of the structural changes, electrical conductivity, and dielectric properties on the addition of a third glass-former, GeO2, to the borophosphate glasses, 40Li2O-10B2O3-(50 - x)P2O5-xGeO2, x = 0-25 mol %, has been studied. Introduction of GeO2 causes the structural modifications in the glass network, which results in a continuous increase in electrical conductivity. Glasses with low GeO2 content, up to 10 mol %, show a rapid increase in dc conductivity as a result of the interlinkage of slightly depolymerized phosphate chains and negatively charged [GeO4](-) units, which enhances the migration of Li(+) ions. The Li(+) ions compensate these delocalized charges connecting both phosphate and germanium units, which results in reduction of both bond effectiveness and binding energy of Li(+) ions and therefore enables their hop to the next charge-compensating site. For higher GeO2 content, the dc conductivity increases slightly, tending to approach a maximum in Li(+) ion mobility caused by the incorporation of GeO2 units into phosphate network combined with conversion of GeO4 to GeO6 units. The strong cross-linkage of germanium and phosphate units creates heteroatomic P-O-Ge bonds responsible for more effectively trapped Li(+) ions. A close correspondence between dielectric and conductivity parameters at high frequencies indicates that the increase in conductivity indeed is controlled by the modification of structure as a function of GeO2 addition.

Co-precipitation of phosphate and iron limits mitochondrial phosphate availability in Saccharomyces cerevisiae lacking the yeast frataxin homologue (YFH1).

Science.gov (United States)

Seguin, Alexandra; Santos, Renata; Pain, Debkumar; Dancis, Andrew; Camadro, Jean-Michel; Lesuisse, Emmanuel

2011-02-25

Saccharomyces cerevisiae cells lacking the yeast frataxin homologue (Δyfh1) accumulate iron in the mitochondria in the form of nanoparticles of ferric phosphate. The phosphate content of Δyfh1 mitochondria was higher than that of wild-type mitochondria, but the proportion of mitochondrial phosphate that was soluble was much lower in Δyfh1 cells. The rates of phosphate and iron uptake in vitro by isolated mitochondria were higher for Δyfh1 than wild-type mitochondria, and a significant proportion of the phosphate and iron rapidly became insoluble in the mitochondrial matrix, suggesting co-precipitation of these species after oxidation of iron by oxygen. Increasing the amount of phosphate in the medium decreased the amount of iron accumulated by Δyfh1 cells and improved their growth in an iron-dependent manner, and this effect was mostly transcriptional. Overexpressing the major mitochondrial phosphate carrier, MIR1, slightly increased the concentration of soluble mitochondrial phosphate and significantly improved various mitochondrial functions (cytochromes, [Fe-S] clusters, and respiration) in Δyfh1 cells. We conclude that in Δyfh1 cells, soluble phosphate is limiting, due to its co-precipitation with iron.

Sucrose Phosphate Synthase and Sucrose Accumulation at Low Temperature 1

Science.gov (United States)

Guy, Charles L.; Huber, Joan L. A.; Huber, Steven C.

1992-01-01

The influence of growth temperature on the free sugar and sucrose phosphate synthase content and activity of spinach (Spinacia oleracea) leaf tissue was studied. When plants were grown at 25°C for 3 weeks and then transferred to a constant 5°C, sucrose, glucose, and fructose accumulated to high levels during a 14-d period. Predawn sugar levels increased from 14- to 20-fold over the levels present at the outset of the low-temperature treatment. Sucrose was the most abundant free sugar before, during, and after exposure to 5°C. Leaf sucrose phosphate synthase activity was significantly increased by the low-temperature treatment, whereas sucrose synthase and invertases were not. Synthesis of the sucrose phosphate synthase subunit was increased during and after low-temperature exposure and paralleled an increase in the steady-state level of the subunit. The increases in sucrose and its primary biosynthetic enzyme, sucrose phosphate synthase, are discussed in relation to adjustment of metabolism to low nonfreezing temperature and freezing stress tolerance. Images Figure 1 Figure 2 Figure 3 PMID:16652990

Effect of Various Feed Phosphates on Biochemical Indices of Blood and Mineral Composition of Bones in Finishing Pigs

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Zbigniew Dobrzański

2010-01-01

Full Text Available The aim of this study was to evaluate the effect of three different chemical feed phosphates on the blood biochemical indicators and the content of main minerals of bones in finishing pigs. Over a period of 85 days of fattening, monocalcium (MCP, Finnish product, dicalcium (DCP, Polish product and calcium-sodium (CSP, Russian product phosphates were used in fattener feeding. The feeding was based on standard mixtures of starter, grower and finisher type. Dicalcium phosphate was produced according to the new, pro-ecological technology based on phosphoric acid. The content of Ca, Na, P, solubility of P in citric acid, and the concentration of undesirable substances (As, Cd, F, Hg and Pb were determined in feed phosphates. At the end of the fattening period, blood was collected from 36 finishing pigs (12 from each group and the following biochemical indicators were determined in the serum: enzymatic activity of aspartate aminotransferase (AST, alanine aminotransferase (ALT, γ-glutamyltransferase (GGT, creatine kinase (CK, lactic dehydrogenase (LDH, lactic acid (LA; the concentration of total protein, albumins, glucose, urea, creatinine, content of triglycerides, cholesterol and its high density lipoproteins (HDL and low density lipoproteins (LDL fractions, and mineral components concentration (Ca, Cl, Cu, Fe, K, Mg, Na, P, Zn. Basic macroelement content (Ca, Mg, P was determined in the thigh bones from 30 pigs (10 from each group. Significant differences (p < 0.05 between groups were observed only in some biochemical indicators, i.e. CK, LDH and LA. The highest content of Ca, Mg and P was found in the bones of pigs fed mixtures supplemented with DCP which indicates improved bioavailability of main macroelements from that phosphate.

Radiation exposure due to agricultural uses of phosphate fertilizers

International Nuclear Information System (INIS)

Khater, Ashraf E.M.; AL-Sewaidan, H.A.

2008-01-01

Radiological impacts of phosphate rocks mining and manufacture could be significant due to the elevated radioactivity contents of the naturally occurring radioactive materials (NORM), such as 238 U series, 232 Th series and 40 K, in some phosphate deposits. Over the last decades, the land reclamation and agriculture activities in Saudi Arabia and other countries have been widely expanded. Therefore, the usage of chemical fertilizers is increased. Selected phosphate fertilizers samples were collected and the specific activities of NORM were measured using a gamma ray spectrometer based on a hyper pure germanium detector and alpha spectrometer based on surface barrier detector. The obtained results show remarkable wide variations in the radioactivity contents of the different phosphate fertilizer samples. The mean (ranges) of specific activities for 226 Ra, 210 Po, 232 Th and 40 K, and radium equivalent activity are 75 (3-283), 25 (0.5-110), 23 (2-74), 2818 (9-6501) Bq/kg and 283 (7-589) Bq/kg, respectively. Based on dose calculations, the increment of the public radiation exposure due to the regular agricultural usage of phosphate fertilizers is negligible. Its average value 1 m above the ground is about 0.12 nGy/h where the world average value due to the NORM in soil is 51 nGy/h. Direct radiation exposures of the farmers due to phosphate fertilizers application was not considered in our study

Niobium phosphates as an intermediate temperature proton conducting electrolyte for fuel cells

DEFF Research Database (Denmark)

Huang, Yunjie; Li, Qingfeng; Jensen, Annemette Hindhede

2012-01-01

A new proton conductor based on niobium phosphates was synthesized using niobium pentoxide and phosphoric acid as precursors. The existence of hydroxyl groups in the phosphates was confirmed and found to be preserved after heat treatment at 500 °C or higher, contributing to an anhydrous proton co...... are of high interest as potential proton conducting electrolytes for fuel cells operational in an intermediate temperature range....... conductivity of 1.6 × 10−2 S cm−1 at 250 °C. The conductivity increased with water content in the atmosphere and reached 5.8 × 10−2 S cm−1 under pure water vapour at the same temperature. The conductivity showed good stability in the low water partial pressure range of up to 0.05 atm. The metal phosphates...

Formation of calcium phosphates by vapour diffusion in highly concentrated ionic micro-droplets

Energy Technology Data Exchange (ETDEWEB)

Iafisco, M. [Alma Mater Studiorum Universita di Bologna, Dipartimento di Chimica ' ' G. Ciamician' ' , Via Selmi 2, 40126 Bologna (Italy); Universita del Piemonte Orientale, Dipartimento di Scienze Mediche, Via Solaroli 4, 28100 Novara (Italy); Delgado-Lopez, J.M.; Gomez-Morales, J.; Hernandez-Hernandez, M.A.; Rodriguez-Ruiz, I. [Laboratorio de Estudios Cristalograficos, IACT CSIC-UGR, Edificio Lopez Neyra, Avenida del Conocimiento, s/n 18100 Armilla (Spain); Roveri, N. [Alma Mater Studiorum Universita di Bologna, Dipartimento di Chimica ' ' G. Ciamician' ' , Via Selmi 2, 40126 Bologna (Italy)

2011-08-15

In this work we have used the sitting drop vapour diffusion technique, employing the ''crystallization mushroom '' to analyze the evolution of calcium phosphate crystallization in micro-droplets containing high initial concentrations of Ca{sup 2+} and HPO{sub 4}{sup 2-}. The decomposition of NH{sub 4}HCO{sub 3} solution produces vapours of NH{sub 3} and CO{sub 2} which diffuse through the droplets containing an aqueous solution of Ca(CH{sub 3}COO){sub 2} and (NH{sub 4}){sub 2}HPO{sub 4}. The result is the increase of pH by means of the diffusion of NH{sub 3} gas and the doping of the calcium phosphate with CO{sub 3}{sup 2-} ions by means of the diffusion of CO{sub 2} gas. The pH of the crystallization process is monitored and the precipitates at different times are characterized by XRD, FTIR, TGA, SEM and TEM techniques. The slow increase of pH and the high concentration of Ca{sup 2+} and HPO{sub 4}{sup 2-} in the droplets induce the crystallization of three calcium phosphate phases: dicalcium phosphate dihydrate (DCPD, brushite), octacalcium phosphate (OCP) and carbonate-hydroxyapatite (HA). The amount of HA nanocrystals with needle-like morphology and dimensions of about 100 nm, closely resembling the inorganic phase of bones, gradually increases, with the precipitation time up to 7 days, whereas the amount of DCPD, growing along the b axis, increases up to 3 days. Then, DCDP crystals start to hydrolyze yielding OCP nanoribbons and HA nanocrystals. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Evaluation of intestinal phosphate binding to improve the safety profile of oral sodium phosphate bowel cleansing.

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Stef Robijn

Full Text Available Prior to colonoscopy, bowel cleansing is performed for which frequently oral sodium phosphate (OSP is used. OSP results in significant hyperphosphatemia and cases of acute kidney injury (AKI referred to as acute phosphate nephropathy (APN; characterized by nephrocalcinosis are reported after OSP use, which led to a US-FDA warning. To improve the safety profile of OSP, it was evaluated whether the side-effects of OSP could be prevented with intestinal phosphate binders. Hereto a Wistar rat model of APN was developed. OSP administration (2 times 1.2 g phosphate by gavage with a 12h time interval induced bowel cleansing (severe diarrhea and significant hyperphosphatemia (21.79 ± 5.07 mg/dl 6h after the second OSP dose versus 8.44 ± 0.97 mg/dl at baseline. Concomitantly, serum PTH levels increased fivefold and FGF-23 levels showed a threefold increase, while serum calcium levels significantly decreased from 11.29 ± 0.53 mg/dl at baseline to 8.68 ± 0.79 mg/dl after OSP. OSP administration induced weaker NaPi-2a staining along the apical proximal tubular membrane. APN was induced: serum creatinine increased (1.5 times baseline and nephrocalcinosis developed (increased renal calcium and phosphate content and calcium phosphate deposits on Von Kossa stained kidney sections. Intestinal phosphate binding (lanthanum carbonate or aluminum hydroxide was not able to attenuate the OSP induced side-effects. In conclusion, a clinically relevant rat model of APN was developed. Animals showed increased serum phosphate levels similar to those reported in humans and developed APN. No evidence was found for an improved safety profile of OSP by using intestinal phosphate binders.

Vanadate influence on metabolism of sugar phosphates in fungus Phycomyces blakesleeanus.

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Milan Žižić

Full Text Available The biological and chemical basis of vanadium action in fungi is relatively poorly understood. In the present study, we investigate the influence of vanadate (V5+ on phosphate metabolism of Phycomyces blakesleeanus. Addition of V5+ caused increase of sugar phosphates signal intensities in 31P NMR spectra in vivo. HPLC analysis of mycelial phosphate extracts demonstrated increased concentrations of glucose 6 phosphate, fructose 6 phosphate, fructose 1, 6 phosphate and glucose 1 phosphate after V5+ treatment. Influence of V5+ on the levels of fructose 2, 6 phosphate, glucosamine 6 phosphate and glucose 1, 6 phosphate (HPLC, and polyphosphates, UDPG and ATP (31P NMR was also established. Increase of sugar phosphates content was not observed after addition of vanadyl (V4+, indicating that only vanadate influences its metabolism. Obtained results from in vivo experiments indicate catalytic/inhibitory vanadate action on enzymes involved in reactions of glycolysis and glycogenesis i.e., phosphoglucomutase, phosphofructokinase and glycogen phosphorylase in filamentous fungi.

Issues of natural radioactivity in phosphates

International Nuclear Information System (INIS)

Schnug, E.; Haneklaus, S.; Schnier, C.; Scholten, L.C.

1996-01-01

The fertilization of phosphorus (P) fertilizers is essential in agricultural production, but phosphates contain in dependence on their origin different amounts of trace elements. The problem of cadmium (Cd) loads and other heavy metals is well known. However, only a limited number of investigations examined the contamination of phosphates with the two heaviest metals, uranium (U) and thorium (Th), which are radioactive. Also potassium (K) is lightly radioactive. Measurements are done n the radioactivity content of phosphates, P fertilizers and soils. The radiation doses to workers and public as well as possible contamination of soils from phosphate rock or fertilizer caused by these elements or their daughter products is of interest with regard to radiation protection. The use of P fertilizers is necessary for a sustainable agriculture, but it involves radioactive contamination of soils. The consequences of the use of P fertilizers is discussed, also with regard to existing and proposed legislation. 11 refs., 2 figs., 7 tabs

Highly selective and sensitive phosphate anion sensors based on AlGaN/GaN high electron mobility transistors functionalized by ion imprinted polymer.

Science.gov (United States)

Jia, Xiuling; Chen, Dunjun; Bin, Liu; Lu, Hai; Zhang, Rong; Zheng, Youdou

2016-06-09

A novel ion-imprinted electrochemical sensor based on AlGaN/GaN high electron mobility transistors (HEMTs) was developed to detect trace amounts of phosphate anion. This sensor combined the advantages of the ion sensitivity of AlGaN/GaN HEMTs and specific recognition of ion imprinted polymers. The current response showed that the fabricated sensor is highly sensitive and selective to phosphate anions. The current change exhibited approximate linear dependence for phosphate concentration from 0.02 mg L(-1) to 2 mg L(-1), the sensitivity and detection limit of the sensor is 3.191 μA/mg L(-1) and 1.97 μg L(-1), respectively. The results indicated that this AlGaN/GaN HEMT-based electrochemical sensor has the potential applications on phosphate anion detection.

Dimensional stability under wet curing of mortars containing high amounts of nitrates and phosphates

International Nuclear Information System (INIS)

Benard, P.; Cau Dit Coumes, C.; Garrault, S.; Nonat, A.; Courtois, S.

2008-01-01

Investigations were carried out in order to solidify in cement some aqueous streams resulting from nuclear decommissioning processes and characterized by a high salinity (300 g/L), as well as important concentrations of nitrate (150-210 g/L) and phosphate ions (0-50 g/L). Special attention was paid to the influence of these compounds on the dimensional variations under wet curing of simulated solidified waste forms. The length changes of mortars containing nitrate salts only (KNO 3 , NaNO 3 ) were shown to be governed by a concentration effect which involved osmosis: the higher their concentration in the mixing solution, the higher the swelling. The expansion of mortars containing high amounts of phosphates (≥ 30 g/L in the mixing solution) was preceded by a shrinkage which increased with the phosphate concentration, and which could be suppressed by seeding the cement used with hydroxyapatite crystals. This transitory shrinkage was attributed to the conversion into hydroxyapatite of a precursor readily precipitated in the cement paste after mixing

An alternative approach to recovering valuable metals from zinc phosphating sludge.

Science.gov (United States)

Kuo, Yi-Ming

2012-01-30

This study used a vitrification process (with good potential for commercialization) to recover valuable metals from Zn phosphating sludge. The involved vitrification process achieves two major goals: it transformed hazardous Zn phosphating sludge into inert slag and it concentrated Fe (83.5%) and Zn (92.8%) into ingot and fine particulate-phase material, respectively. The Fe content in the ingot was 278,000 mg/kg, making the ingot a potential raw material for iron making. The fine particulate-phase material (collected from flue gas) contained abundant Zn (544,000 mg/kg) in the form of ZnO. The content (67.7%) of ZnO was high, so it can be directly sold to refineries. The recovered coarse particulate-phase material, with insufficient amount of ZnO, can be recycled as a feeding material for Zn re-concentration. Therefore, the vitrification process can not only treat hazardous materials but also effectively recover valuable metals. Copyright © 2011 Elsevier B.V. All rights reserved.

Rare-earth elements and uranium in phosphatic nodules from the continental margins of India

Digital Repository Service at National Institute of Oceanography (India)

Nath, B.N.; Rao, B.R.; Rao, K.M.; Rao, Ch.M.

of Pleistocene age. They are less than 1-5 cm in size, have carbonate flourapatite (CFA) as a single authigenic mineral phase, are free of detrital inclusions, and have very high P sub(2) O sub(5) contents (> 30%). In addition, soft and hard phosphatic nodules...

Recovery of uranium and of rare earths from Moroccan phosphates

International Nuclear Information System (INIS)

Ezahr, I.; El Houari, A.; Smani, S.M.

1984-01-01

The contents of uranium and of rare earths in Moroccan phosphates vary from 75 to 250 ppm and from 900 to 1500 ppm, respectively. The phosphates produced in Morocco contain therefore about 2500 t of uranium and 25 000 t of rare earths, compared with annual productions of uranium and of rare earths of 43 000 t and 33 000 t, respectively. During the sulphuric leaching of the phosphate ores, uranium is found to 80-90% in the phosphoric acid. Research into the extraction of uranium has shown that for the phosphoric acids produced at Safi the coefficient of extraction: is not very sensitive to the P 2 O 5 concentration on the 28-30% region; is not affected by the sulphur level up to the concentration of 4%; is very sensitive to the fluorine content beyond 1%. On the level of the first cycle of the process in Depa-Topo, four extraction stages permit a yield of between 92 and 98% to be reached. The addition of an oxidizing agent to the phosphoric acids under examination was not necessary, as their potential level is high. The purity of the yellow-cakes obtained varies from 94 to 99%. The overall recovery efficiency lies between 67 and 71%. In a second part, this paper deals with the recovery of the rare earths [fr

Structural features of silver-doped phosphate glasses in zone of femtosecond laser-induced modification

International Nuclear Information System (INIS)

Vasileva, A.A.; Nazarov, I.A.; Olshin, P.K.; Povolotskiy, A.V.; Sokolov, I.A.; Manshina, A.A.

2015-01-01

Femtosecond (fs) laser writing of two-dimensional microstructures (waveguides) is demonstrated in bulk phosphate glasses doped with silver ions. Silver-content phosphate and silver-content niobium–phosphate glasses with high concentration of silver oxide 55 mol% were used as samples for fs laser writing. The chemical network structure of the synthesized samples is analyzed through Raman spectroscopy and was found to be strongly sensitive to Nb incorporation. It was found that the direct laser writing process enables not only reorganization of glass network, but also formation of color centers and silver nanoparticles that are revealed in appearance of luminescence signal and plasmon absorption. The process of NPs' formation is more efficient for Nb-phosphate glass, while color centers are preferably formed in phosphate glass. - Graphical abstract: Formation of silver NPs on the surface of 0.5Ag 2 O–0.4P 2 O 5 –0,1Nb 2 O 5 glass induced by CW laser irradiation. - Highlights: • The structure of 0.5Ag 2 O–0.1Nb 2 O 5 –0.4P 2 O 5 and 0.55Ag 2 O–0.45P 2 O 5 glasses was investigated by Raman spectroscopy. • Fs laser writing induces formation of silver NPs in investigated glasses. • Surface plasmon resonance in the absorption spectra confirms the formation of NP. • The possibility of CW laser induced formation of silver NPs on the surface of sample with niobium is shown

Biomimetic fabrication of antibacterial calcium phosphates mediated by polydopamine.

Science.gov (United States)

Forte, Lucia; Torricelli, Paola; Bonvicini, Francesca; Boanini, Elisa; Gentilomi, Giovanna Angela; Lusvardi, Gigliola; Della Bella, Elena; Fini, Milena; Vecchio Nepita, Edoardo; Bigi, Adriana

2018-01-01

In this work we developed new antibacterial composite materials using polydopamine (PDA) to trigger the deposition of silver nanoparticles (AgNPs) onto calcium phosphates, namely octacalcium phosphate (OCP) and α-tricalcium phosphate (αTCP). Functionalization of OCP and αTCP with a self-polymerized polydopamine layer was obtained by soaking the calcium phosphates in dopamine solution. The PDA surface of functionalized calcium phosphates (OCPd and αTCPd) promoted the deposition of AgNPs by reducing silver ions when soaked in a silver nitrate solution. The amount of deposited AgNPs can be modulated by varying the concentration of silver nitrate solution and the type of substrate. The results of in vitro tests carried out with osteoblast-like MG63 cells indicate that the combination of AgNPs with OCP provides more biocompatible materials than those obtained using αTCP as substrate. In particular, the study of osteoblast activity and differentiation was focused on the samples OCPdAg5 (silver content=8.2wt%) and αTCPdAg5 (silver content=4.7wt%), which did not show any cytotoxicity, and compared with those obtained on pure OCP and αTCP. The results demonstrate that the AgNPs loaded materials support osteoblast viability and differentiation, whereas they significantly inhibit the growth of relevant antibiotic-resistant pathogenic bacteria. Copyright © 2017 Elsevier Inc. All rights reserved.

Spectrophotometric determination of trace uranium in phosphate ore samples from kurum and uro areas, Nuba mountains, Sudan

International Nuclear Information System (INIS)

Mohamed, A. A.; Ali, A. H.; Altayeb, M. A. H.

2004-01-01

A method was proposed for the spectrophotometric determination of uranium content in phosphate ores. the method is based on the use of nitrogen (v) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (Vi) is kept in solution as its carbonate complex. The ion-exchange technique was used for the recovery of uranium. Uranium was determined spectrophotometrically by measurement of the absorbance of the yellow uranium (Vi)-8-hydroxyquinolate complex at λ 425 nm. The procedure was used for the determination of trace uranium content in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba mountains in Sudan. X-ray fluorescence technique was employed for the assessment of the method used. The spectrophotometric method results show a high similarity with those obtained by XRF technique. This agreement indicates that the procedure proposed here has been successfully applied for the determination of uranium in phosphate ores. (Author)

Method of stripping plutonium from tributyl phosphate solution which contains dibutyl phosphate-plutonium stable complexes

International Nuclear Information System (INIS)

Ochsenfeld, W.; Schmieder, H.

1976-01-01

Fast breeder fuel elements which have been highly burnt-up are reprocessed by extracting uranium and plutonium into an organic solution containing tributyl phosphate. The tributyl phosphate degenerates at least partially into dibutyl phosphate and monobutyl phosphate, which form stable complexes with tetravalent plutonium in the organic solution. This tetravalent plutonium is released from its complexed state and stripped into aqueous phase by contacting the organic solution with an aqueous phase containing tetravalent uranium. 6 claims, 1 drawing figure

Leucine-Enriched Essential Amino Acids Augment Muscle Glycogen Content in Rats Seven Days after Eccentric Contraction

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Hiroyuki Kato

2017-10-01

Full Text Available Eccentric contractions induce muscle damage, which impairs recovery of glycogen and adenosine tri-phosphate (ATP content over several days. Leucine-enriched essential amino acids (LEAAs enhance the recovery in muscles that are damaged after eccentric contractions. However, the role of LEAAs in this process remains unclear. We evaluated the content in glycogen and high energy phosphates molecules (phosphocreatine (PCr, adenosine di-phosphate (ADP and ATP in rats that were following electrically stimulated eccentric contractions. Muscle glycogen content decreased immediately after the contraction and remained low for the first three days after the stimulation, but increased seven days after the eccentric contraction. LEAAs administration did not change muscle glycogen content during the first three days after the contraction. Interestingly, however, it induced a further increase in muscle glycogen seven days after the stimulation. Contrarily, ATP content decreased immediately after the eccentric contraction, and remained lower for up to seven days after. Additionally, LEAAs administration did not affect the ATP content over the experimental period. Finally, ADP and PCr levels did not significantly change after the contractions or LEAA administration. LEAAs modulate the recovery of glycogen content in muscle after damage-inducing exercise.

A model for phosphate glass topology considering the modifying ion sub-network

DEFF Research Database (Denmark)

Hermansen, Christian; Mauro, J.C.; Yue, Yuanzheng

2014-01-01

In the present paper we establish a temperature dependent constraint model of alkali phosphate glasses considering the structural and topological role of the modifying ion sub-network constituted by alkali ions and their non-bonding oxygen coordination spheres. The model is consistent with availa......In the present paper we establish a temperature dependent constraint model of alkali phosphate glasses considering the structural and topological role of the modifying ion sub-network constituted by alkali ions and their non-bonding oxygen coordination spheres. The model is consistent...... with available structural data by NMR and molecular dynamics simulation and dynamic data such glass transition temperature (Tg) and liquid fragility (m). Alkali phosphate glasses are exemplary systems for developing constraint model since the modifying cation network plays an important role besides the primary...... phosphate network. The proposed topological model predicts the changing trend of the Tg and m with increasing alkali oxide content for alkali phosphate glasses, including an anomalous minimum at around 20 mol% alkali oxide content. We find that the minimum in Tg and m is caused by increased connectivity...

Some peculiarities of the relationship between uranium and phosphate of nodular phosphorites of the Russian Platform

Energy Technology Data Exchange (ETDEWEB)

Kozlov, A A [Vsesoyuznyj Nauchno-Issledovatel' skij Inst. Yadernoj Geofiziki i Geokhimii, Moscow (USSR)

1976-02-01

In nodular phosphorites of the Cenomanian stage of the central regions of the Russian platform the uranium content of phosphate ranges within 20 to 50x10/sup -4/%. The maximum concentrations of uranium are found in amorphous phosphates, the richest in humic colloid. Uranium found in the bone phosphate of fossil reptiles is uniformly distributed throughout the bone tissue area, its content amounting to 30 to 40x10/sup -4/%. As bone phosphate reaches its holocrystalline modification, the uranium compounds are substituted and the uranium concentration decreases to 0.2x10/sup -4/%, i.e. it becomes 200 times lower. The most intensive sorption of uranium by phosphate occurs under the reducing conditions of diagenesis which is characterized by the most comprehensive combination of uranium-sorption factors: the existence of various uranium compounds in solution, isomorphic substitutions of all kinds, adsorption of uranium compounds and organic matter on the surfaces of submicron crystalline phosphate compounds. A decrease in the intensity of sorption factors leads to a decrease in the uranium content of phosphate. Under the oxidative conditions prevailed during the formation of Khoperian silicophosphorites, uranium has been sorbed by the phosphate only in negligible amounts (0.1x10/sup -4/%) due to the lack of organic colloids and uranium compounds capable of isomorphic substitution.

Phosphate content influence on structural, spectroscopic, and lasing properties of Er,Yb-doped potassium-lanthanum phosphate glasses

Czech Academy of Sciences Publication Activity Database

Šulc, J.; Švejkar, R.; Jelínková, H.; Nejezchleb, K.; Nitsch, Karel; Cihlář, Antonín; Král, Robert; Ledinský, Martin; Fejfar, Antonín; Rodová, Miroslava; Zemenová, Petra; Nikl, Martin

2016-01-01

Roč. 55, č. 4 (2016), 1-10, č. článku 047102. ISSN 0091-3286 R&D Projects: GA ČR GAP204/12/0805 Institutional support: RVO:68378271 Keywords : erbium laser s * infrared laser s * laser materials modification * phosphate glass * diode -pumped eye-safe solid state laser Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.082, year: 2016

RF magnetron-sputtered coatings deposited from biphasic calcium phosphate targets for biomedical implant applications

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K.A. Prosolov

2017-09-01

Full Text Available Bioactive calcium phosphate coatings were deposited by radio-frequency magnetron sputtering from biphasic targets of hydroxyapatite and tricalcium phosphate, sintered at different mass % ratios. According to Raman scattering and X-ray diffraction data, the deposited hydroxyapatite coatings have a disordered structure. High-temperature treatment of the coatings in air leads to a transformation of the quasi-amorphous structure into a crystalline one. A correlation has been observed between the increase in the Ca content in the coatings and a subsequent decrease in Ca in the biphasic targets after a series of deposition processes. It was proposed that the addition of tricalcium phosphate to the targets would led to a finer coating's surface topography with the average size of 78 nm for the structural elements.

Development of Antibiotics Impregnated Nanosized Silver Phosphate-Doped Hydroxyapatite Bone Graft

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Waraporn Suvannapruk

2013-01-01

Full Text Available Nanosized Ag3PO4 loaded hydroxyapatite which was prepared by a novel low temperature phosphorization of 3D printed calcium sulfate dihydrate at the nominal silver concentration of 0.001 M and 0.005 M was impregnated by two antibiotics including gentamicin and vancomycin. Phase composition, microstructure, antibiotics loading, silver content, antimicrobial performance, and cytotoxic potential of the prepared samples were characterized. It was found that the fabricated sample consisted of hydroxyapatite as a main phase and spherical-shaped silver phosphate nanoparticles distributing within the cluster of hydroxyapatite crystals. Antibacterial activity of the samples against two bacterial strains (gram negative P. aeruginosa and gram positive S. aureus was carried out. It was found that the combination of antibiotics and nanosized Ag3PO4 in hydroxyapatite could enhance the antibacterial performance of the samples by increasing the duration in which the materials exhibited antibacterial property and the size of the inhibition zone depending on the type of antibiotics and bacterial strains compared to those contained antibiotics or nanosilver phosphate alone. Cytotoxic potential against osteoblasts of antibiotics impregnated nanosilver phosphate hydroxyapatite was found to depend on the combination of antibiotics content, type of antibiotics, and nanosilver phosphate content.

Liming effect on P availability from Maardu phosphate rock

International Nuclear Information System (INIS)

Sidlauskas, G.; Masauskas, S.; Ezerinskas, V.

2002-01-01

Thirty years ago phosphate rock from the Maardu deposit was intensively used for soil fertilization in Lithuania. However, the application of finely ground product caused an undesirable dusty operation. Afterwards, a super-phosphate production plant was built in Kedainiai and the use of phosphate rock was completely abandoned. Field experiments with fodder beets and barley were carried out to evaluate the P availability of granulated superphosphate and Maardu phosphate rock. The comparison was made at three acidity levels: a) unlimed acid soil with a high content of Al (pH kcl 4.3-4.4, hydrolytic acidity was 41-44 meq/kg soil), b) soil limed with 0.5n rate CaCO 3 powder limestone based on hydrolytic acidity, and c) soil limed with 1.0n rate CaCO 3 . Two field experiments were carried out with fodder beets. In 1997 the yield increased significantly due to liming. However, no significant yield increases were found due to the application of phosphorus fertilizers. Differences between the effect of superphosphate and phosphate rock were also not observed. This might have been caused by a severe drought during the vegetative growth of plants. In the following year, 1998, a soil with similar acidity was chosen, however it contained even lower amounts of available phosphorus in the arable soil (about 50 mg/kg soil A-L method). In the unlimed soil the yield was low, the effect of superphosphate was better than that of phosphate rock. A good fodder beet yield of 32 to 35 t/ha was obtained and the effect of phosphate rock was better than that of superphosphate at 0.5n CaCO 3 rate. When liming with at the high rate (1.0n CaCO 3 rate according to hydrolytic acidity) the action of phosphate rock declined, and a better yield was obtained with superphosphate. Barley was grown after fodder beets in the 1997 experimental field and the residual effect of superphosphate and phosphate rock was investigated. Weather conditions were favorable for barley growth. Therefore a normal yield

Effect of boron and phosphate compounds on physical, mechanical, and fire properties of wood-polypropylene composites

Science.gov (United States)

Nadir Ayrilmis; Turgay Akbulut; Turker Dundar; Robert H. White; Fatih Mengeloglu; Umit Buyuksari; Zeki Candan; Erkan Avci

2012-01-01

Physical, mechanical, and fire properties of the injection-molded wood flour/polypropylene composites incorporated with different contents of boron compounds; borax/boric acid and zinc borate, and phosphate compounds; mono and diammonium phosphates were investigated. The effect of the coupling agent content, maleic anhydride-grafted polypropylene, on the properties of...

One-step synthesis of magnetite core/zirconia shell nanocomposite for high efficiency removal of phosphate from water

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhe; Xing, Mingchao; Fang, Wenkan; Wu, Deyi, E-mail: dywu@sjtu.edu.cn

2016-03-15

Graphical abstract: - Highlights: • Magnetite core/zirconia shell nanocomposite was prepared by one-step method. • Fe/Zr molar ratio of 4/1 allowed high magnetization and high adsorption capacity. • The nanocomposite had good selectivity towards phosphate. • Ligand exchange was the adsorption mechanism of phosphate. • Desorption of adsorbed phosphate could be achieved by NaOH treatment. - Abstract: A self-assembled magnetite core/zirconia shell (Fe{sub 3}O{sub 4}@ZrO{sub 2}) nanoparticle material was fabricated by the one-step co-precipitation method to capture phosphate from water. Fe{sub 3}O{sub 4}@ZrO{sub 2} with different Fe/Zr molar ratios were obtained and characterized by XRD, TEM, BET surface area and magnetization. It was shown that, with the decreasing of Fe/Zr molar ratio, magnetization decreased whereas surface area and adsorption capacity of phosphate increased. Fe{sub 3}O{sub 4}@ZrO{sub 2} with the ratio of higher than 4:1 had satisfactory magnetization property (>23.65 emu/g), enabling rapid magnetic separation from water and recycle of the spent adsorbent. The Langmuir adsorption capacity of Fe{sub 3}O{sub 4}@ZrO{sub 2} reached 27.93–69.44 mg/g, and the adsorption was fast (90% of phosphate removal within 20 min). The adsorption decreases with increasing pH, and higher ionic strength caused slight increase in adsorption at pH > about 5.5. The presence of chloride, nitrate and sulfate anions did not bring about significant changes in adsorption. As a result, Fe{sub 3}O{sub 4}@ZrO{sub 2} performed well to remove phosphate from real wastewater. These results were interpreted by the ligand exchange mechanism, i.e., the direct coordination of phosphate onto zirconium by replacement of hydroxyl groups. Results suggested that phosphate reacted mainly with surface hydroxyl groups but diffusion into interior of zirconia phase also contributed to adsorption. The adsorbed phosphate could be desorbed with a NaOH treatment and the regenerated Fe

Structural features of silver-doped phosphate glasses in zone of femtosecond laser-induced modification

Energy Technology Data Exchange (ETDEWEB)

Vasileva, A.A., E-mail: anvsilv@gmail.com [Saint-Petersburg State University, Institute of Chemistry, Saint-Petersburg (Russian Federation); Nazarov, I.A. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg (Russian Federation); Olshin, P.K.; Povolotskiy, A.V. [Saint-Petersburg State University, Institute of Chemistry, Saint-Petersburg (Russian Federation); Sokolov, I.A. [St.Petersburg State Polytechnical University, St.Petersburg (Russian Federation); LTD “AtomTjazhMash”, St.Petersburg (Russian Federation); Manshina, A.A. [Saint-Petersburg State University, Institute of Chemistry, Saint-Petersburg (Russian Federation)

2015-10-15

Femtosecond (fs) laser writing of two-dimensional microstructures (waveguides) is demonstrated in bulk phosphate glasses doped with silver ions. Silver-content phosphate and silver-content niobium–phosphate glasses with high concentration of silver oxide 55 mol% were used as samples for fs laser writing. The chemical network structure of the synthesized samples is analyzed through Raman spectroscopy and was found to be strongly sensitive to Nb incorporation. It was found that the direct laser writing process enables not only reorganization of glass network, but also formation of color centers and silver nanoparticles that are revealed in appearance of luminescence signal and plasmon absorption. The process of NPs' formation is more efficient for Nb-phosphate glass, while color centers are preferably formed in phosphate glass. - Graphical abstract: Formation of silver NPs on the surface of 0.5Ag{sub 2}O–0.4P{sub 2}O{sub 5}–0,1Nb{sub 2}O{sub 5} glass induced by CW laser irradiation. - Highlights: • The structure of 0.5Ag{sub 2}O–0.1Nb{sub 2}O{sub 5}–0.4P{sub 2}O{sub 5} and 0.55Ag{sub 2}O–0.45P{sub 2}O{sub 5} glasses was investigated by Raman spectroscopy. • Fs laser writing induces formation of silver NPs in investigated glasses. • Surface plasmon resonance in the absorption spectra confirms the formation of NP. • The possibility of CW laser induced formation of silver NPs on the surface of sample with niobium is shown.

Removal of phosphate from solution by adsorption and precipitation of calcium phosphate onto monohydrocalcite.

Science.gov (United States)

Yagi, Shintaro; Fukushi, Keisuke

2012-10-15

The sorption behavior and mechanism of phosphate on monohydrocalcite (CaCO(3)·H(2)O: MHC) were examined using batch sorption experiments as a function of phosphate concentrations, ionic strengths, temperatures, and reaction times. The mode of PO(4) sorption is divisible into three processes depending on the phosphate loading. At low phosphate concentrations, phosphate is removed by coprecipitation of phosphate during the transformation of MHC to calcite. The sorption mode at the low-to-moderate phosphate concentrations is most likely an adsorption process because the sorption isotherm at the conditions can be fitted reasonably with the Langmuir equation. The rapid sorption kinetics at the conditions is also consistent with the adsorption reaction. The adsorption of phosphate on MHC depends strongly on ionic strength, but slightly on temperature. The maximum adsorption capacities of MHC obtained from the regression of the experimental data to the Langmuir equation are higher than those reported for stable calcium carbonate (calcite or aragonite) in any conditions. At high phosphate concentrations, the amount of sorption deviates from the Langmuir isotherm, which can fit the low-to-moderate phosphate concentrations. Speciation-saturation analyses of the reacted solutions at the conditions indicated that the solution compositions which deviate from the Langmuir equation are supersaturated with respect to a certain calcium phosphate. The obtained calcium phosphate is most likely amorphous calcium phosphate (Ca(3)(PO(4))(2)·xH(2)O). The formation of the calcium phosphate depends strongly on ionic strength, temperature, and reaction times. The solubility of MHC is higher than calcite and aragonite because of its metastability. Therefore, the higher solubility of MHC facilitates the formation of the calcium phosphates more than with calcite and aragonite. Copyright © 2012 Elsevier Inc. All rights reserved.

High-precision determination of 18O/16O ratios of silver phosphate by EA-pyrolysis-IRMS continuous flow technique.

Science.gov (United States)

Lécuyer, Christophe; Fourel, François; Martineau, François; Amiot, Romain; Bernard, Aurélien; Daux, Valérie; Escarguel, Gilles; Morrison, John

2007-01-01

A high-precision, and rapid on-line method for oxygen isotope analysis of silver phosphate is presented. The technique uses high-temperature elemental analyzer (EA)-pyrolysis interfaced in continuous flow (CF) mode to an isotopic ratio mass spectrometer (IRMS). Calibration curves were generated by synthesizing silver phosphate with a 13 per thousand spread in delta(18)O values. Calibration materials were obtained by reacting dissolved potassium dihydrogen phosphate (KH(2)PO(4)) with water samples of various oxygen isotope compositions at 373 K. Validity of the method was tested by comparing the on-line results with those obtained by classical off-line sample preparation and dual inlet isotope measurement. In addition, silver phosphate precipitates were prepared from a collection of biogenic apatites with known delta(18)O values ranging from 12.8 to 29.9 per thousand (V-SMOW). Reproducibility of +/- 0.2 per thousand was obtained by the EA-Py-CF-IRMS method for sample sizes in the range 400-500 microg. Both natural and synthetic samples are remarkably well correlated with conventional (18)O/(16)O determinations. Silver phosphate is a very stable material and easy to degas and, thus, could be considered as a good candidate to become a reference material for the determination of (18)O/(16)O ratios of phosphate by high-temperature pyrolysis. Copyright 2006 John Wiley & Sons, Ltd.

The analysis of impurities in the diuranate-determination of phosphate by phosphomolybdate blue spectrophotometric method

International Nuclear Information System (INIS)

Sun Haobo

2014-01-01

Phosphomolybdenum blue spectrophotometric method was used for determination of phosphate in the diuranate. Diuranate was dissolved in nitric acid solution, in which formed a soluble heteropolyacid complex (namely phosphomolybdenum yellow) due to interaction of phosphate and ammonium molybdate. Then phosphomolybdenum yellow was reduced to phosphomolybdenum blue with Bismuth nitrate as catalyst. Colour intensity at 700 nm is in proportion to the content of phosphate determined by spectrophotometric method. This experiment presents good linearity at the range of 30 μg to 245 μg phosphate, and the relative standard deviation of the experimental result is 2.4%, and the recovery rate is from 95% to 105%. The determination result of phosphate content will not be effected under conditions of 4 mg of SiO 2 , 6 mg of Fe, 400 mg of Cl - and 4.5 mg of Ge in the solution. (author)

The antimicrobial activity of as-prepared silver-loaded phosphate glasses and zirconium phosphate

International Nuclear Information System (INIS)

Jing, Wang; Jiang, Ji Zhi; Yang, Yang; Yan, Zhao Chun; Yan, Wang Xiao; He, Shui Zhong

2016-01-01

The antimicrobial activities of silver-loaded zirconium phosphate (JDG) and silver-loaded phosphate glasses (ZZB) against Escherichia coli were studied. Although the silver content in JDG was higher than that in ZZB, ZZB suspensions showed better antimicrobial property than JDG suspensions, especially at low concentrations. The antimicrobial activity was analyzed using minimum inhibitory concentrations, bacterial inhibition ring tests, and detection of silver ions in the suspensions. Furthermore, the amounts of silver ions in suspensions with/without bacterial cells were analyzed. Results revealed that only a portion of released silver ions could be adsorbed by E. coli cells, which are critical to cell death. The damaged microstructures of E. coli cells observed by transmission electron microscopy may further prove that the adsorbed silver ions play an important role in the antimicrobial process.

Removal mechanism of phosphate from aqueous solution by fly ash.

Science.gov (United States)

Lu, S G; Bai, S Q; Zhu, L; Shan, H D

2009-01-15

This work studied the effectiveness of fly ash in removing phosphate from aqueous solution and its related removal mechanism. The adsorption and precipitation of phosphate by fly ash were investigated separately in order to evaluate their role in the removal of phosphate. Results showed that the removal of phosphate by fly ash was rapid. The removal percentage of phosphate in the first 5min reached 68-96% of the maximum removal of phosphate by fly ash. The removal processes of phosphate by fly ash included a fast and large removal representing precipitation, then a slower and longer removal due to adsorption. The adsorption of phosphate on fly ash could be described well by Freundlich isotherm equation. The pH and Ca2+ concentration of fly ash suspension were decreased with the addition of phosphate, which suggests that calcium phosphate precipitation is a major mechanism of the phosphate removal. Comparison of the relative contribution of the adsorption and precipitation to the total removal of phosphate by fly ash showed that the adsorption accounted for 30-34% of the total removal of phosphate, depending on the content of CaO in fly ash. XRD patterns of the fly ash before and after phosphate adsorption revealed that phosphate salt (CaHPO4 x 2H2O) was formed in the adsorption process. Therefore, the removal of phosphate by fly ash can be attributed to the formation of phosphate precipitation as a brushite and the adsorption on hydroxylated oxides. The results suggested that the use of fly ash could be a promising solution to the removal of phosphate in the wastewater treatment and pollution control.

Characterization and in vitro evaluation of biphasic α-tricalcium phosphate/β-tricalcium phosphate cement

Energy Technology Data Exchange (ETDEWEB)

Arahira, Takaaki; Maruta, Michito, E-mail: maruta@college.fdcnet.ac.jp; Matsuya, Shigeki

2017-05-01

Biphasic calcium phosphate consisting of hydroxyapatite (HA) and β-tricalcium phosphate(β-TCP) is an excellent bone substitute with controllable bioresorbability. Fabrication of biphasic calcium phosphate with self-setting ability is expected to enhance its potential application as bone substitute. In this study, mixtures of α-TCP and β-TCP with various compositions were prepared through α-β phase transition of α-TCP powder at 1000 °C for various periods. These powders were mixed with 0.25 M Na{sub 2}HPO{sub 4} at a P/L ratio of 2, and then hardened at 37 °C at 100% RH for up to 24 h. Material properties of biphasic HA/β-TCP cement with different α-TCP/β-TCP composition were characterized. These cements were also evaluated with respect to cell response in vitro using MC3T3-E1 cell lines. In conclusion, mechanical and biological properties of HA/β-TCP cement could be controlled by changing the heat treatment time of α-TCP powder at 1000 °C. In vitro results indicated that cell proliferation and ALP activity increased with increase β-TCP content. - Highlights: • We could fabricate biphasic HA/β-TCP cements using heat treated α-TCP powder. • It is easy to control the ratio of α-TCP to β-TCP changing the heat treatment time up to 48 h. • Both cell number and ALP activity increased with increase in β-TCP content. • In vitro results showed that β-TCP has superior cell affinity to HA.

Preferable removal of phosphate from water using hydrous zirconium oxide-based nanocomposite of high stability.

Science.gov (United States)

Chen, Liang; Zhao, Xin; Pan, Bingcai; Zhang, Weixian; Hua, Ming; Lv, Lu; Zhang, Weiming

2015-03-02

In this study, we employed a new nanocomposite adsorbent HZO-201, which featured high stability under varying solution chemistry, for preferable removal of phosphate from synthetic solution and a real effluent. An anion exchange resin (D-201) was employed as the host of HZO-201, where nano-hydrous zirconium oxide (HZO) was encapsulated as the active species. D-201 binds phosphate through nonspecific electrostatic affinity, whereas the loaded HZO nanoparticles capture phosphate through formation of the inner-sphere complexes. Quantitative contribution of both species to phosphate adsorption was predicted based on the double-Langmuir model. Preferable removal of phosphate by HZO-201 was observed in the presence of the competing anions at higher levels (Cl(-), NO3(-), SO4(2-), HCO3(-)). Fixed-bed adsorption indicated that the effective volume capacity of a synthetic water (2.0 mg P-PO4(3-)/L) by using HZO-201 was ∼1600 BV in the first run (<0.5mg P-PO4(3-)/L), comparable to Fe(III)-based nanocomposite HFO-201 (∼1500 BV) and much larger than D-201 (<250 BV). The exhausted HZO-201 can be in situ regenerated by using a binary NaOH-NaCl solution for cyclic runs, whether fed with the synthetic solution or real effluent. In general, HZO-201 is a promising alternative to Fe(III)-based adsorbents for trace phosphate removal from effluent particularly at acidic pH. Copyright © 2014 Elsevier B.V. All rights reserved.

Biological phosphate removal using a degradable carbon source produced by hydrothermal treatment of excess sludge

Directory of Open Access Journals (Sweden)

L. H. Haraguchi

2006-03-01

Full Text Available The possibility of reusing excess sludge treated by hydrothermal reaction for the purpose of improving the efficiency of the enhanced biological phosphate removal (EBPR process was investigated. Excess sludge from a fish-processing industry located in Japan was treated in high-temperature and high-pressure water, at a reaction temperature ranging from 200 to 400ºC, a pressure of 1.8 to 30MPa and a constant reaction time of 7 min. For the conditions tested, the results showed that when the reaction temperature was increased the content of readily biodegradable substrate in the total COD Cr increased. In addition, the amount of some volatile fatty acids (VFAs produced by the hydrothermal reaction increased as reaction temperature increased. From the phosphate release tests under anaerobic conditions, it was possible to demonstrate that not only the VFAs, but also the readily and slowly biodegradable substrates are used as potential carbon source by the phosphate-accumulating organisms (PAOs.

Role of Phosphate Transport System Component PstB1 in Phosphate Internalization by Nostoc punctiforme.

Science.gov (United States)

Hudek, L; Premachandra, D; Webster, W A J; Bräu, L

2016-11-01

In bacteria, limited phosphate availability promotes the synthesis of active uptake systems, such as the Pst phosphate transport system. To understand the mechanisms that facilitate phosphate accumulation in the cyanobacterium Nostoc punctiforme, phosphate transport systems were identified, revealing a redundancy of Pst phosphate uptake systems that exists across three distinct operons. Four separate PstB system components were identified. pstB1 was determined to be a suitable target for creating phenotypic mutations that could result in the accumulation of excessive levels of phosphate through its overexpression or in a reduction of the capacity to accumulate phosphate through its deletion. Using quantitative real-time PCR (qPCR), it was determined that pstB1 mRNA levels increased significantly over 64 h in cells cultured in 0 mM added phosphate and decreased significantly in cells exposed to high (12.8 mM) phosphate concentrations compared to the level in cells cultured under normal (0.8 mM) conditions. Possible compensation for the loss of PstB1 was observed when pstB2, pstB3, and pstB4 mRNA levels increased, particularly in cells starved of phosphate. The overexpression of pstB1 increased phosphate uptake by N. punctiforme and was shown to functionally complement the loss of PstB in E. coli PstB knockout (PstB - ) mutants. The knockout of pstB1 in N. punctiforme did not have a significant effect on cellular phosphate accumulation or growth for the most part, which is attributed to the compensation for the loss of PstB1 by alterations in the pstB2, pstB3, and pstB4 mRNA levels. This study provides novel in vivo evidence that PstB1 plays a functional role in phosphate uptake in N. punctiforme IMPORTANCE: Cyanobacteria have been evolving over 3.5 billion years and have become highly adept at growing under limiting nutrient levels. Phosphate is crucial for the survival and prosperity of all organisms. In bacteria, limited phosphate availability promotes the

Sol-Gel Synthesis of Phosphate-Based Glasses for Hydrophilic Enamel Applications

International Nuclear Information System (INIS)

Kim, Dae-Sung; Ryu, Bong-ki

2017-01-01

In this study, quaternary phosphate-based sol-gel derived glasses were synthesized from a P 2 O 5 -CaO-Na 2 O-TiO 2 system with a high TiO 2 content of up to 50 mol%. The sol-gel method was chosen because incorporating a high percentage of titanium into a phosphate network via traditional melt-quench methods is non-trivial. The structure and thermal properties of the obtained stabilized sol-gel glasses were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC). The XRD results confirmed the amorphous nature of all of the stabilized sol–gel derived glasses. The FTIR results revealed that added TiO 2 enters the network as (TiO 6 ), which likely acts as a modifier oxide. Consequently, the number of terminal oxygen atoms increases, leading to an increase in the number of P-OH bonds. In addition, DSC results confirmed a decrease in glass transition and crystallization temperatures with increasing TiO 2 content. This is the first report of a sol-gel synthesis strategy combined with enameling to prepare glass at low processing temperatures and the first use of such a system for both hydrophilic and chemical resistance purposes.

Sol-Gel Synthesis of Phosphate-Based Glasses for Hydrophilic Enamel Applications

Energy Technology Data Exchange (ETDEWEB)

Kim, Dae-Sung; Ryu, Bong-ki [Pusan National University, Busan (Korea, Republic of)

2017-04-15

In this study, quaternary phosphate-based sol-gel derived glasses were synthesized from a P{sub 2}O{sub 5}-CaO-Na{sub 2}O-TiO{sub 2} system with a high TiO{sub 2} content of up to 50 mol%. The sol-gel method was chosen because incorporating a high percentage of titanium into a phosphate network via traditional melt-quench methods is non-trivial. The structure and thermal properties of the obtained stabilized sol-gel glasses were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC). The XRD results confirmed the amorphous nature of all of the stabilized sol–gel derived glasses. The FTIR results revealed that added TiO{sub 2} enters the network as (TiO{sub 6}), which likely acts as a modifier oxide. Consequently, the number of terminal oxygen atoms increases, leading to an increase in the number of P-OH bonds. In addition, DSC results confirmed a decrease in glass transition and crystallization temperatures with increasing TiO{sub 2} content. This is the first report of a sol-gel synthesis strategy combined with enameling to prepare glass at low processing temperatures and the first use of such a system for both hydrophilic and chemical resistance purposes.

Novel selenium containing boro-phosphate glasses: preparation and structural study.

Science.gov (United States)

Ciceo-Lucacel, R; Radu, T; Ponta, O; Simon, V

2014-06-01

We synthesized a new boro-phosphate glass system with different %mol SeO2 content by conventional melt quenching technique. All samples were obtained in a glassy state with the vitreous structure confirmed by X-ray diffraction analysis. Scanning electron microscopy (SEM) revealed some non-homogeneous domains on the glasses surface, and their tendency to link each other once the selenium oxide content increases. Energy-dispersive X-ray analysis (EDAX) indicated similar elemental composition in different regions of each sample. X-ray photoelectron spectroscopy (XPS) was used to determine the nature of chemical bonding and the elemental composition at the sample surfaces, and Fourier transform infrared (FT-IR) spectroscopy was used to determine the structural groups in the obtained glass structure. Based on FT-IR results, the glass structure at short range order consists mainly of small phosphate units such as pyrophosphate (i.e. P2O7(4-) dimmers or terminating groups at the end of phosphate chains) and some metaphosphate (i.e. PO3(-) middle groups in the phosphate chains) units. The boron atoms are mainly placed in three-coordinated sites in BØ3 or BØ2O(-) units. A small contribution of BØ4(-) units was also detected from the FT-IR spectra of glasses. For SeO2 content higher than 5mol%, the modifier role of selenium ions is strongly reflected on the local structure dominated in this case by pyrophosphate units. Copyright © 2014 Elsevier B.V. All rights reserved.

Economical and environmental impact of using of Nuba Mountain Rock Phosphate that contain uranium as a fertilizer without any treatment

International Nuclear Information System (INIS)

Hassan, Abdelrahman Khidir

1994-01-01

This study investigates the possible use of ground rock phosphate in Nuba Mountain for fertilization of arable land. Geological and chemical component of untreated ground rock phosphate has been compared with other ground rock phosphate from different geographical regions worldwide. The data show that economic exploitation of this rock phosphate as fertilizer is not feasible because of low solubility and low phosphorus content (12% on average). In addition, the high concentration of some elements in the rock phosphate could adversely affect the growth of the plant when it is applied on the soil by changing the chemical composition of the soil.As regards the environmental impact that could be result from the use of the rock phosphate as fertilizer is that it will unnecessarily increase the concentration of uranium which amount to 0.3% in the soil. The study recommends the use of this rock phosphate as a raw material for production of phosphoric acid and extraction of uranium and some elements as a bi-product of phosphate industry.(Author)

High-energy phosphate transfer in human muscle: diffusion of phosphocreatine

OpenAIRE

Gabr, Refaat E.; El-Sharkawy, AbdEl-Monem M.; Schär, Michael; Weiss, Robert G.; Bottomley, Paul A.

2011-01-01

The creatine kinase (CK) reaction is central to muscle energetics, buffering ATP levels during periods of intense activity via consumption of phosphocreatine (PCr). PCr is believed to serve as a spatial shuttle of high-energy phosphate between sites of energy production in the mitochondria and sites of energy utilization in the myofibrils via diffusion. Knowledge of the diffusion coefficient of PCr (DPCr) is thus critical for modeling and understanding energy transport in the myocyte, but DPC...

Recent advances in phosphate laser glasses for high power applications

International Nuclear Information System (INIS)

Campbell, J.H.

1996-01-01

Recent advances in Nd-doped phosphate laser glasses for high-peak-power and high-average-power applications are reviewed. Compositional studies have progressed to the point that glasses can be tailored to have specific properties for specific applications. Non-radiative relaxation effects can be accurately modeled and empirical expressions have been developed to evaluate both intrinsic (structural) and extrinsic (contamination induced) relaxation effects. Losses due to surface scattering and bulk glass absorption have been carefully measured and can be accurately predicted. Improvements in processing have lead to high damage threshold (e.g. Pt inclusion free) and high thermal shock resistant glasses with improved edge claddings. High optical quality pieces up to 79 x 45 x 4cm 3 have been made and methods for continuous melting laser glass are under development

Determination of inositol phosphate ester in lake sediments

International Nuclear Information System (INIS)

Weimer, W.C.; Armstrong, D.E.

1977-01-01

A procedure for the determination of the total inositol polyphosphate content of lake sediments is presented and evaluated. This technique involves extraction with NaOH, cleanup of the extract, and isolation and identification of two groups of inositol phosphate esters by ion-exchange chromatography. Radioisotope dilution is employed to correct for losses during the extraction, cleanup and isolation steps. Recoveries of the radiotracer inositol phosphates have averaged 85% during the analysis of approximately 40 calcareous and non-calcareous sediment samples and more than 20 soil samples

Isolation of phosphate solubilizer fungi from Araza rhizosphere

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Diana Fernanda Vera

2002-01-01

Full Text Available Araza is an eatable plant, original from the Amazon region which has been describedas a promising species for commercialization (Quevedo 1995. This plant has highproductivity even in low content phosphate soil but the presence of phosphatesolubilizazing microorganisms may contribute to increase this element availability.In this study we report the isolation and characterization of solubilizing fungiprocessed using the soil washing method, from soil samples were Araza is cultivated attwo regions in Guaviare, Colombia. Eighteen isolates of fungi capable of solubilizingphosphate were obtained from 2 different sources. The most importat species that solubilized phosphate from calcium were Trichodermaaureoviride, Aspergillus aculeatus,Trichodermastrain 1 y Trichodermastrain 2 and for phosphate from iron: Aspergillus oryzae,Paecilomycesstrain 3, Gongronella butleri& Fusarium oxysporum

Preferable removal of phosphate from water using hydrous zirconium oxide-based nanocomposite of high stability

International Nuclear Information System (INIS)

Chen, Liang; Zhao, Xin; Pan, Bingcai; Zhang, Weixian; Hua, Ming; Lv, Lu; Zhang, Weiming

2015-01-01

Highlights: • The nanocomposite HZO-201 was stable under varying solution chemistry. • HZO-201 exhibited preferable phosphate removal over other ubiquitous anions. • Selective sorption mechanism was probed and discussed. • HZO-201 could be regenerated for cyclic use with constant efficiency. - Abstract: In this study, we employed a new nanocomposite adsorbent HZO-201, which featured high stability under varying solution chemistry, for preferable removal of phosphate from synthetic solution and a real effluent. An anion exchange resin (D-201) was employed as the host of HZO-201, where nano-hydrous zirconium oxide (HZO) was encapsulated as the active species. D-201 binds phosphate through nonspecific electrostatic affinity, whereas the loaded HZO nanoparticles capture phosphate through formation of the inner-sphere complexes. Quantitative contribution of both species to phosphate adsorption was predicted based on the double-Langmuir model. Preferable removal of phosphate by HZO-201 was observed in the presence of the competing anions at higher levels (Cl − , NO 3 − , SO 4 2− , HCO 3 − ). Fixed-bed adsorption indicated that the effective volume capacity of a synthetic water (2.0 mg P-PO 4 3− /L) by using HZO-201 was ∼1600 BV in the first run (<0.5 mg P-PO 4 3− /L), comparable to Fe(III)-based nanocomposite HFO-201 (∼1500 BV) and much larger than D-201 (<250 BV). The exhausted HZO-201 can be in situ regenerated by using a binary NaOH–NaCl solution for cyclic runs, whether fed with the synthetic solution or real effluent. In general, HZO-201 is a promising alternative to Fe(III)-based adsorbents for trace phosphate removal from effluent particularly at acidic pH

Are Polyphosphates or Phosphate Esters Prebiotic Reagents?

Science.gov (United States)

Keefe, Anthony D.; Miller, Stanley L.

1995-01-01

It is widely held that there was a phosphate compound in prebiotic chemistry that played the role of adenosine triphosphate and that the first living organisms had ribose-phosphate in the backbone of their genetic material. However, there are no known efficient prebiotic synthesis of high-energy phosphates or phosphate esters. We review the occurrence of phosphates in nature, the efficiency of the volcanic synthesis of P4O10, the efficiency of polyphosphate synthesis by heating phosphate minerals under geological conditions, and the use of high-energy organic compounds such as cyanamide or hydrogen cyanide. These are shown to be inefficient processes especially when the hydrolysis of the polyphosphates is taken into account. For example, if a whole atmosphere of methane or carbon monoxide were converted to cyanide which somehow synthesized polyphosphates quantitatively, the polyphosphate concentration in the ocean would still have been insignificant. We also attempted to find more efficient high-energy polymerizing agents by spark discharge syntheses, but without success. There may still be undiscovered robust prebiotic syntheses of polyphosphates, or mechanisms for concentrating them, but we conclude that phosphate esters may not have been constituents of the first genetic material. Phosphoanhydrides are also unlikely as prebiotic energy sources.

Phosphate control in dialysis

Directory of Open Access Journals (Sweden)

Cupisti A

2013-10-01

Full Text Available Adamasco Cupisti,1 Maurizio Gallieni,2 Maria Antonietta Rizzo,2 Stefania Caria,3 Mario Meola,4 Piergiorgio Bolasco31Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy; 2Nephrology and Dialysis Unit, San Carlo Borromeo Hospital, Milan, Italy; 3Territorial Department of Nephrology and Dialysis, ASL Cagliari, Italy; 4Sant'Anna School of Advanced Studies, University of Pisa, Pisa, ItalyAbstract: Prevention and correction of hyperphosphatemia is a major goal of chronic kidney disease–mineral and bone disorder (CKD–MBD management, achievable through avoidance of a positive phosphate balance. To this aim, optimal dialysis removal, careful use of phosphate binders, and dietary phosphate control are needed to optimize the control of phosphate balance in well-nourished patients on a standard three-times-a-week hemodialysis schedule. Using a mixed diffusive–convective hemodialysis tecniques, and increasing the number and/or the duration of dialysis tecniques are all measures able to enhance phosphorus (P mass removal through dialysis. However, dialytic removal does not equal the high P intake linked to the high dietary protein requirement of dialysis patients; hence, the use of intestinal P binders is mandatory to reduce P net intestinal absorption. Unfortunately, even a large dose of P binders is able to bind approximately 200–300 mg of P on a daily basis, so it is evident that their efficacy is limited in the case of an uncontrolled dietary P load. Hence, limitation of dietary P intake is needed to reach the goal of neutral phosphate balance in dialysis, coupled to an adequate protein intake. To this aim, patients should be informed and educated to avoid foods that are naturally rich in phosphate and also processed food with P-containing preservatives. In addition, patients should preferentially choose food with a low P-to-protein ratio. For example, patients could choose egg white or protein from a vegetable source

A high-performance liquid chromatography-based radiometric assay for sucrose-phosphate synthase and other UDP-glucose requiring enzymes

International Nuclear Information System (INIS)

Salvucci, M.E.; Crafts-Brandner, S.J.

1991-01-01

A method for product analysis that eliminates a problematic step in the radiometric sucrose-phosphate synthase assay is described. The method uses chromatography on a boronate-derivatized high-performance liquid chromatography column to separate the labeled product, [14C]sucrose phosphate, from unreacted uridine 5'-diphosphate-[14C]glucose (UDP-Glc). Direct separation of these compounds eliminates the need for treatment of the reaction mixtures with alkaline phosphatase, thereby avoiding the problem of high background caused by contaminating phosphodiesterase activity in alkaline phosphatase preparations. The method presented in this paper can be applied to many UDP-Glc requiring enzymes; here the authors show its use for determining the activities of sucrose-phosphate synthase, sucrose synthase, and uridine diphosphate-glucose pyrophosphorylase in plant extracts

Simultaneous quantification of porcine myocardial adenine nucleotides and creatine phosphate by ion-pair reverse-phase high-performance liquid chromatography

International Nuclear Information System (INIS)

Cordis, G.A.; Das, D.K.

1987-01-01

In order to follow the energy metabolism and the levels of high-energy phosphate compounds in porcine myocardium subjected to ischemic insult, it was necessary to develop a high-performance liquid chromatography (HPLC) method where creatine phosphate (CP) and the adenine nucleotides could be measured simultaneously in a single run. Currently available ion-pair reverse-phase HPLC methods require a separate injection with a change in wavelength and mobile phase in order to measure the creatine phosphate, while baseline separation of AMP is lacking. The ion-exchange HPLC method includes a simultaneous determination, but the baseline drifts due to the gradient and baseline separation of AMP is not achieved. In the following ion-pair reverse-phase HPLC method, simultaneous measurements of porcine myocardial adenine nucleotides and creatine phosphate were achieved along with a stable baseline and homogeneous baseline separation of each measured compound, allowing accurate quantification

Phosphate limitation induces sporulation in the chytridiomycete Blastocladiella emersonii.

Science.gov (United States)

Bongiorno, Vagner Alexandre; Ferreira da Cruz, Angela; Nunis da Silva, Antonio; Corrêa, Luiz Carlos

2012-09-01

The cell cycle is controlled by numerous mechanisms that ensure correct cell division. If growth is not possible, cells may eventually promote autophagy, differentiation, or apoptosis. Microorganisms interrupt their growth and differentiate under general nutrient limitation. We analyzed the effects of phosphate limitation on growth and sporulation in the chytridiomycete Blastocladiella emersonii using kinetic data, phase-contrast, and laser confocal microscopy. Under phosphate limitation, zoospores germinated and subsequently formed 2-4 spores, regardless of the nutritional content of the medium. The removal of phosphate at any time during growth induced sporulation of vegetative cells. If phosphate was later added to the same cultures, growth was restored if the cells were not yet committed to sporulation. The cycles of addition and withdrawal of phosphate from growth medium resulted in cycles of germination-growth, germination-sporulation, or germination-growth-sporulation. These results show that phosphate limitation is sufficient to interrupt cell growth and to induce complete sporulation in B. emersonii. We concluded that the determination of growth or sporulation in this microorganism is linked to phosphate availability when other nutrients are not limiting. This result provides a new tool for the dissection of nutrient-energy and signal pathways in cell growth and differentiation.

Methods of synthesis and performance improvement of lithium iron phosphate for high rate Li-ion batteries: A review

Directory of Open Access Journals (Sweden)

T.V.S.L. Satyavani

2016-03-01

Full Text Available Lithium ion battery technology has the potential to meet the requirements of high energy density and high power density applications. A continuous search for novel materials is pursued continually to exploit the latent potential of this technology. In this review paper, methods for preparation of Lithium Iron Phosphate are discussed which include solid state and solution based synthesis routes. The methods to improve the electrochemical performance of lithium iron phosphate are presented in detail.

High-resolution nonresonant x-ray Raman scattering study on rare earth phosphate nanoparticles

NARCIS (Netherlands)

Huotari, Simo; Suljoti, Edlira; Sahle, Christoph J.; Raedel, Stephanie; Monaco, Giulio; de Groot, Frank M. F.

2015-01-01

We report high-resolution x-ray Raman scattering studies of high-order multipole spectra of rare earth 4d -> 4f excitations (the N-4,N-5 absorption edge) in nanoparticles of the phosphates LaPO4, CePO4, PrPO4, and NdPO4. We also present corresponding data for La 5p -> 5d excitations (the O-2,O-3

Hydrous iron oxide modified diatomite as an active filtration medium for phosphate capture.

Science.gov (United States)

Wang, Zhe; Lin, Yan; Wu, Deyi; Kong, Hainan

2016-02-01

A simple method to functionalize diatomite with hydrous iron oxide was attempted and its performance as a new active filtration material to remove and recover phosphate from water was investigated under varying solution conditions. The Langmuir phosphate adsorption capacity increased from 0.6 mgP/g for raw diatomite to 4.89, 14.71, 25.02 mgP/g for hydrous iron oxide modified diatomite (HIOMD), depending on the amount of iron loaded. Loading of hydrous iron oxide caused the increase in true and bulk density and a decline in filtration rate, but to a lesser extent. It was shown that the HIOMD product with suitable iron content could retain a good filtration performance with a greatly increased adsorption capacity for phosphate. The phosphate adsorption increased by decreasing pH and by increasing ionic strength at high pH levels. The adsorption process was interpreted by ligand exchange. Coexisting oxyanions of sulfate, nitrate, citrate, carbonate, silicate and humic acid showed different effects on phosphate fixation but it was presumed that their influence at their concentrations and pH levels commonly encountered in effluent or natural waters was limited, i.e., HIOMD had a reasonably good selectivity. Results in repeated adsorption, desorption and regeneration experiment showed that the adsorbed phosphate could be recovered and the material could be reused after regeneration. The column test showed that HIOMD could be potentially utilized as an adsorption filtration medium for phosphate removal and recovery from water. Copyright © 2015 Elsevier Ltd. All rights reserved.

Trace elements in rock phosphates and P containing mineral and organo-mineral fertilizers sold in Germany

Energy Technology Data Exchange (ETDEWEB)

Kratz, Sylvia, E-mail: sylvia.kratz@jki.bund.de; Schick, Judith; Schnug, Ewald

2016-01-15

68 rock phosphates and 162 P containing (organo-)mineral fertilizers sold in Germany were evaluated with regard to trace element contents. While Al, As, B, Be, Cd, Cr, Mo, Ni, Pb, Sb, Se, Tl, U, and Zn were higher in sedimentary than in igneous rock phosphates, the opposite was true for Co, Cu, Sn, Mn, Ti, Fe, and Sr. Comparing element concentrations to the currently valid legal limit values defined by the German Fertilizer Ordinance, it was found that some PK and many straight P fertilizers (superphosphate, triple superphosphate, partly acidulated rock phosphates) exceeded the limit of 50 mg Cd/kg P{sub 2}O{sub 5}. Mean values for As, Ni, Pb, and Tl remained below legal limits in almost all cases. While no legal limit has been defined for U in Germany yet, the limit of 50 mg U/kg P{sub 2}O{sub 5} for P containing fertilizers proposed by the German Commission for the Protection of Soils was clearly exceeded by mean values for all fertilizer types analyzed. A large share of the samples evaluated in this work contained essential trace elements at high concentrations, with many of them not being declared as such. Furthermore, trace elements supplied with these fertilizers at a fertilization rate leveling P uptake would exceed trace element uptake by crops. This may become most relevant for B and Fe, since many crops are sensitive to an oversupply of B, and Fe loads exceeding plant uptake may immobilize P supplies for the crops by forming Fe phosphate salts. The sample set included two products made from thermochemically treated sewage sludge ash. The products displayed very high concentrations of Fe and Mn and exceeded the legal limit for Ni, emphasizing the necessity to continue research on heavy metal removal from recycled raw materials and the development of environmentally friendly and agriculturally efficient fertilizer products. - Highlights: • Mineral fertilizers (MF) sold in Germany often exceed legal limits for Cd • MF sold in Germany contain high

Study of the radionuclides contained in wastes produced by the phosphate industry and their impact on the environment

International Nuclear Information System (INIS)

Baetsle, L.H.

1991-01-01

This report reviews the present state of the management and disposal of waste associated with mining, milling and reprocessing of phosphate ores with regard to its content on naturally occurring radionuclides. The main areas of investigation are: phosphate ores and their characteristics and phosphate trade in the Member States of the European Community, production and processing methods of phosphoric acids and phosphates, interaction of phosphate products and wastes with the environment, standards and regulations for radioactivity released during processing in the phosphate industry

Ternary complex formation of lanthanides and radiolanthanides with phosphate and serum proteins

International Nuclear Information System (INIS)

Neumaier, B.; Roesch, F.

1999-01-01

Radioyttrium was recently reported to form ternary complexes with phosphate and serum proteins in blood. In the present work it was investigated whether the trivalent radiolanthanides react in a chemically similar way. In systematic binding studies using gel filtration a ternary complex formation between different lanthanides, phosphate and serum proteins could be identified. The tendency to build a ternary compound of the type Ln III - phosphate - serum protein, however, is dependent on the ionic radii of the lanthanides. Whereas the light and transition lanthanides have a strong inclination to build a ternary complex, this tendency is weaker for the heavier ones. Taking into account the high content of phosphate in human blood, the corresponding ternary complexes of radiolanthanides represent an important transport form of these elements in blood. This finding may contribute to an understanding of the nuclear medical observation on the biodistribution of radiolanthanides. The heavy radiolanthanides can be classified as bone seeking metals, whereas the light and transition lanthanide elements accumulate mainly in the liver and the spleen. For the lighter radiolanthanides the corresponding ternary complexes thus represent an important transport form in blood. This physicochemical form of lanthanides mainly results in reticulo endothelial accumulation; on the other hand, the lower tendency of heavier lanthanides leads to preferential skeletal deposition. (orig.)

Structure and properties of calcium iron phosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Qian, Bin [School of Science, Southwest University of Science and Technology, Mianyang 621010 (China); Liang, Xiaofeng, E-mail: xfliangswust@gmail.com [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); Wang, Cuiling; Yang, Shiyuan [School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China)

2013-11-15

The structural properties of xCaO–(100 − x) (0.4Fe{sub 2}O{sub 3}–0.6P{sub 2}O{sub 5}) (x = 0, 10, 20, 30, 40, 50 mol%) glasses have been investigated by XRD, DTA, IR and Raman spectroscopy. XRD analysis has confirmed that the majority of samples are X-ray amorphous, and EDS analysis indicates that the glass matrix can accommodate ≈30 mol% CaO. IR and Raman spectra show that the glass structure consists predominantly of pyrophosphate (Q{sup 1}) units. IR spectra indicate that the phosphate network is depolymerized with the addition of CaO content. The density and glass transition temperature (T{sub g}) increase with increasing CaO content for the glasses. This behavior indicates that the addition of CaO improves the strength of the cross-links between the phosphate chains of the glass.

A magnesium based phosphate binder reduces vascular calcification without affecting bone in chronic renal failure rats.

Directory of Open Access Journals (Sweden)

Ellen Neven

Full Text Available The alternative phosphate binder calcium acetate/magnesium carbonate (CaMg effectively reduces hyperphosphatemia, the most important inducer of vascular calcification, in chronic renal failure (CRF. In this study, the effect of low dose CaMg on vascular calcification and possible effects of CaMg on bone turnover, a persistent clinical controversy, were evaluated in chronic renal failure rats. Adenine-induced CRF rats were treated daily with 185 mg/kg CaMg or vehicle for 5 weeks. The aortic calcium content and area% calcification were measured to evaluate the effect of CaMg. To study the effect of CaMg on bone remodeling, rats underwent 5/6th nephrectomy combined with either a normal phosphorus diet or a high phosphorus diet to differentiate between possible bone effects resulting from either CaMg-induced phosphate deficiency or a direct effect of Mg. Vehicle or CaMg was administered at doses of 185 and 375 mg/kg/day for 8 weeks. Bone histomorphometry was performed. Aortic calcium content was significantly reduced by 185 mg/kg/day CaMg. CaMg ameliorated features of hyperparathyroid bone disease. In CRF rats on a normal phosphorus diet, the highest CaMg dose caused an increase in osteoid area due to phosphate depletion. The high phosphorus diet combined with the highest CaMg dose prevented the phosphate depletion and thus the rise in osteoid area. CaMg had no effect on osteoblast/osteoclast or dynamic bone parameters, and did not alter bone Mg levels. CaMg at doses that reduce vascular calcification did not show any harmful effect on bone turnover.

Yb-doped phosphate double-cladding optical fiber for high-power laser applications

Science.gov (United States)

Mura, E.; Scarpignato, G. C.; Lousteau, J.; Boetti, N. G.; Abrate, S.; Milanese, D.

2013-02-01

A Yb-doped phosphate glass double cladding optical fiber was prepared using a custom designed glass composition (P2O5 - Al2O3 - Li2O - B2O3 - BaO - PbO - La2O3) for high-power amplifier and laser applications. The preform drawing method was followed, with the preform being fabricated using the rotational casting technique. This technique, previously developed for tellurite, fluoride or chalcogenide glass preforms is reported for the first time using rare earth doped phosphate glasses. The main challenge was to design an adequate numerical aperture between first and second cladding while maintaining similar thermo-mechanical properties in view of the fiber drawing process. The preform used for the fiber drawing was produced by rod-in-tube technique at a rotation speed of 3000 rpm. The rotational casting technique allowed the manufacturing of an optical fiber featuring high quality interfaces between core and internal cladding and between the internal and external cladding, respectively. Loss attenuation was measured using the cut-back method and lasing was demonstrated at 1022 nm by core pumping with a fiber pigtailed laser diode at the wavelength of 976 nm.

Characterization of a calcium phosphate cement based on alpha-tricalcium phosphate obtained by wet precipitation process

International Nuclear Information System (INIS)

Thurmer, M.B.; Diehl, C.E.; Vieira, R.S.; Coelho, W.T.G.; Santos, L.A.

2012-01-01

There are several systems of calcium phosphate cements being studied. Those based on alpha-tricalcium phosphate are of particular interest. After setting they produce calcium deficient hydroxyapatite similar to bone like hydroxyapatite. This work aims to obtain alpha-tricalcium phosphate powders by the wet precipitation process, using calcium nitrate and phosphoric acid as reagents. This powder was characterized by infrared spectroscopy, X-ray diffraction and particle size distribution. In order to prepare the calcium phosphate cement, the powder was mixed with an accelerator in an aqueous solution. The mechanical properties of the cement were assessed and it was evaluated by means of apparent density, X-ray diffraction and scanning electron microscopy. The described method produced crystalline alpha-tricalcium phosphate as the major phase. The calcium phosphate cement showed high values of compression strength (50 MPa). The soaking of the cement in a simulated body fluid (SBF) formed a layer of hydroxyapatite like crystals in the surface of the samples. (author)

Aqueous phosphate removal using nanoscale zero-valent iron

International Nuclear Information System (INIS)

Almeelbi, Talal; Bezbaruah, Achintya

2012-01-01

Nanoscale zero-valent iron (NZVI) particles have been used for the remediation of a wide variety of contaminants. NZVI particles have high reactivity because of high reactive surface area. In this study, NZVI slurry was successfully used for phosphate removal and recovery. Batch studies conducted using different concentrations of phosphate (1, 5, and 10 mg PO 4 3− -P/L with 400 mg NZVI/L) removed ∼96 to 100 % phosphate in 30 min. Efficacy of the NZVI in phosphate removal was found to 13.9 times higher than micro-ZVI (MZVI) particles with same NZVI and MZVI surface area concentrations used in batch reactors. Ionic strength, sulfate, nitrate, and humic substances present in the water affected in phosphate removal by NZVI but they may not have any practical significance in phosphate removal in the field. Phosphate recovery batch study indicated that better recovery is achieved at higher pH and it decreased with lowering of the pH of the aqueous solution. Maximum phosphate recovery of ∼78 % was achieved in 30 min at pH 12. The successful rapid removal of phosphate by NZVI from aqueous solution is expected to have great ramification for cleaning up nutrient rich waters.

Measurement of 226Ra, 232Th and 40K radioactivity contents in by-product phosphogypsum from phosphate fertilizer industry using gamma ray spectrometric method

International Nuclear Information System (INIS)

Demirel, H.; Parmaksiz, A.; Vural, M.; Cakir, I.T.; Demircioglu, B.; Yucel, H.

2004-01-01

Full text: Phosphatic fertilizers are produced from the industrial processing of rock phosphate ores which are known to contain naturally occurring radionuclides such as 238 U and its daughter products. A high volume by-product known as phosphogypsum (PG) from the production of phosphoric acid and phosphate fertilizer causes serious storage and environmental problems in phosphoric acid industries. During the phosphoric acid production process, 226 Ra (t 1/2 =1600 y) ends up in PG which has chemical analogous to calcium element. Since the stockpiles of PG near the phosphatic fertilizer plants are huge amounts, the radioactivity contained in PG has measured in view of environmental radioactivity problem. In this work, the natural radioactivity in eighty PG samples taken from a stock near Samsun phosphoric fertilizer plant was measured by a high resolution gamma ray spectrometer. The mean activity of 226 Ra in PG samples has been found to be 546 Bq.kg -1 . However, the activities of 232 Th and 40 K measured in PG samples are negligibly small. In the presented paper, the gamma spectrometric method employed for this work is discussed and the radiological risk impact of radon gas emanation from 226 Ra mainly contained in PG, has been assessed

High-energy phosphate transfer in human muscle: diffusion of phosphocreatine.

Science.gov (United States)

Gabr, Refaat E; El-Sharkawy, Abdel-Monem M; Schär, Michael; Weiss, Robert G; Bottomley, Paul A

2011-07-01

The creatine kinase (CK) reaction is central to muscle energetics, buffering ATP levels during periods of intense activity via consumption of phosphocreatine (PCr). PCr is believed to serve as a spatial shuttle of high-energy phosphate between sites of energy production in the mitochondria and sites of energy utilization in the myofibrils via diffusion. Knowledge of the diffusion coefficient of PCr (D(PCr)) is thus critical for modeling and understanding energy transport in the myocyte, but D(PCr) has not been measured in humans. Using localized phosphorus magnetic resonance spectroscopy, we measured D(PCr) in the calf muscle of 11 adults as a function of direction and diffusion time. The results show that the diffusion of PCr is anisotropic, with significantly higher diffusion along the muscle fibers, and that the diffusion of PCr is restricted to a ∼28-μm pathlength assuming a cylindrical model, with an unbounded diffusion coefficient of ∼0.69 × 10(-3) mm(2)/s. This distance is comparable in size to the myofiber radius. On the basis of prior measures of CK reaction kinetics in human muscle, the expected diffusion distance of PCr during its half-life in the CK reaction is ∼66 μm. This distance is much greater than the average distances between mitochondria and myofibrils. Thus these first measurements of PCr diffusion in human muscle in vivo support the view that PCr diffusion is not a factor limiting high-energy phosphate transport between the mitochondria and the myofibrils in healthy resting myocytes.

The chemistry of high temperature phosphate solutions in relation to steam generation

International Nuclear Information System (INIS)

Broadbent, D.; Lewis, G.G.; Wetton, E.A.M.

1978-01-01

The problems associated with the use of phosphate for chemical treatment of the P.W.R. secondary circuit have prompted renewed interest in the physical chemistry of these solutions. Solubility and phase studies have been carried out at 250, 300 and 350 0 C with solutions having sodium to phosphate ratios from 1.0 to above 3.0. A solid phase of ratio about 2.8 exists in equilibrium with a wide range of saturated solution compositions at each temperature. Invariant points at which three phases are in equilibrium have been identified and at the two higher temperatures a region of liquid-liquid immiscibility occurs. Phase diagrams have been constructed for each temperature from which it is possible to predict the compositional changes occurring during the isothermal evaporation process. The corrosivity of these phosphate solutions to a range of steel alloys is being studied, the results reported in the present work, however, are confined to mild steel in the temperature and phosphate composition ranges of the phase studies. The corrosion of mild steel is generally considerably less than in sodium hydroxide solutions of equivalent concentration. The dependence of corrosion rate on sodium and phosphate concentrations in not readily explicable in terms of the solubility and phase studies and it is thought that the solubility of iron in the phosphate solutions is an important rate-determining factor since several complex compounds containing sodium, phosphorus and ferrous iron are present in the corrosion films. (author)

Impact of phosphate limitation on PHA production in a feast-famine process.

Science.gov (United States)

Korkakaki, Emmanouela; van Loosdrecht, Mark C M; Kleerebezem, Robbert

2017-12-01

Double-limitation systems have shown to induce polyhydroxyalkanoates (PHA) production in chemostat studies limited in e.g. carbon and phosphate. In this work the impact of double substrate limitation on the enrichment of a PHA producing community was studied in a sequencing batch process. Enrichments at different C/P concentration ratios in the influent were established and the effect on the PHA production capacity and the enrichment community structure was investigated. Experimental results demonstrated that when a double substrate limitation is imposed at a C/P ratio in the influent in a range of 150 (C-mol/mol), the P-content of the biomass and the specific substrate uptake rates decreased. Nonetheless, the PHA storage capacity remained high (with a maximum of 84 wt%). At a C/P ratio of 300, competition in the microbial community is based on phosphate uptake, and the PHA production capacity is lost. Biomass specific substrate uptake rates are a linear function of the cellular P-content, offering advantages for scaling-up the PHA production process due to lower oxygen requirements. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hierarchical one-dimensional ammonium nickel phosphate microrods for high-performance pseudocapacitors

CSIR Research Space (South Africa)

Raju, K

2015-12-01

Full Text Available :17629 | DOI: 10.1038/srep17629 www.nature.com/scientificreports Hierarchical One-Dimensional Ammonium Nickel Phosphate Microrods for High-Performance Pseudocapacitors Kumar Raju1 & Kenneth I. Ozoemena1,2 High-performance electrochemical capacitors... OPEN w w w . n a t u r e . c o m / s c i e n t i f i c r e p o r t s / 2S C I E N T I F I C REPORTS | 5:17629 | DOI: 10.1038/srep17629 Hierarchical 1-D and 2-D materials maximize the supercapacitive properties due to their unique ability to permit ion...

Calcium phosphates: what is the evidence?

Science.gov (United States)

Larsson, Sune

2010-03-01

A number of different calcium phosphate compounds such as calcium phosphate cements and solid beta-tricalcium phosphate products have been introduced during the last decade. The chemical composition mimics the mineral phase of bone and as a result of this likeness, the materials seem to be remodeled as for normal bone through a cell-mediated process that involves osteoclastic activity. This is a major difference when compared with, for instance, calcium sulphate compounds that after implantation dissolve irrespective of the new bone formation rate. Calcium phosphates are highly biocompatible and in addition, they act as synthetic osteoconductive scaffolds after implantation in bone. When placed adjacent to bone, osteoid is formed directly on the surface of the calcium phosphate with no soft tissue interposed. Remodeling is slow and incomplete, but by adding more and larger pores, like in ultraporous beta-tricalcium phosphate, complete or nearly complete resorption can be achieved. The indications explored so far include filling of metaphyseal fracture voids or bone cysts, a volume expander in conjunction with inductive products, and as a carrier for various growth factors and antibiotics. Calcium phosphate compounds such as calcium phosphate cement and beta-tricalcium phosphate will most certainly be part of the future armamentarium when dealing with fracture treatment. It is reasonable to believe that we have so far only seen the beginning when it comes to clinical applications.

Phosphate application to firing range soils for Pb immobilization: The unclear role of phosphate

International Nuclear Information System (INIS)

Chrysochoou, Maria; Dermatas, Dimitris; Grubb, Dennis G.

2007-01-01

Phosphate treatment has emerged as a widely accepted approach to immobilize Pb in contaminated soils and waste media, relying on the formation of the highly insoluble mineral pyromorphite as solubility-controlling phase for Pb. As such, phosphate treatment has been proposed as a Best Management Practice (BMP) for firing ranges where Pb occurs in its metallic forms and several other phases (carbonates, oxides). While pyromorphite thermodynamically has the potential to control Pb solubility at low levels, its formation is kinetically controlled by pH, the solubility of the phosphate source, and the solubility of Pb species. Treatability studies have shown that excess quantities of soluble and acidic phosphate sources, such as phosphoric acid, are necessary for successful in situ treatment. Even under these conditions, Extended X-ray Absorption Fine Structure (EXAFS), the only reliable method to identify and quantify Pb speciation, showed that Pb conversion to pyromorphite in in situ treated soils was less than 45% after 32 months. Furthermore, the use of lime (CaO) to restore soil pH in acidified soil treatments inhibited further conversion. Additionally, phosphate treatment is known to reduce bioavailability through pyromorphite formation in the intestinal tract, and the phytoaccumulation of Pb; both desirable effects for Pb-impacted areas. Given the costs of phosphate treatment, the use of biogenic phosphate sources, such as bone meal, may be a more environmentally sustainable approach toward this end. In the many studies focusing on phosphate treatment, the attendant P leaching and eutrophication have been largely overlooked, along with other issues such as the enhanced leaching of oxyanionic contaminants, such as Se, As and W. The success and sustainability of applying phosphate as a BMP in firing range soils therefore remain questionable

Microbial community changes in biological phosphate-removal systems on altering sludge phosphorus content

NARCIS (Netherlands)

Liu, WT; Linning, KD; Nakamura, K; Mino, T; Matsuo, T; Forney, LJ

Biomarkers (respiratory quinones and cellular fatty acids) and denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA genes were used to characterize the microbial community structure of lab-scale enhanced biological phosphate-removal (EBPR) systems in response to altering sludge

Phosphate fertilization changes the characteristics of 'Maçã' banana starch.

Science.gov (United States)

Mesquita, Camila de Barros; Garcia, Émerson Loli; Bolfarini, Ana Carolina Batista; Leonel, Sarita; Franco, Célia Maria L; Leonel, Magali

2018-06-01

The unripe banana has been studied as a potential source of starch for use in various applications. Considering the importance of phosphorus in the biosynthesis of the starch and also the interference of this mineral in starch properties, in this study it was evaluated the effect of rates of phosphate fertilizer applied in the cultivation of 'Maçã' banana on the characteristics of the starch. Starches extracted from fruits from different treatments were analyzed for morphological characteristics, X-ray diffraction pattern, relative crystallinity, granule size, amylose, resistant starch and phosphorus levels, as well as, for pasting and thermal properties. Results showed that the phosphate fertilization has interference on the characteristics of the banana starch led to increase of phosphorus content and size of the granules, reduction of crystallinity and resistant starch content, decrease of viscosity peak, breakdown, final viscosity, setback, transitions temperatures and enthalpy. These changes caused by phosphate fertilizer conditions can be increase the applications of the 'Maçã' banana starch. Copyright © 2018. Published by Elsevier B.V.

Ultraviolet optical absorptions of semiconducting copper phosphate glasses

Science.gov (United States)

Bae, Byeong-Soo; Weinberg, Michael C.

1993-01-01

Results are presented of a quantitative investigation of the change in UV optical absorption in semiconducting copper phosphate glasses with batch compositions of 40, 50, and 55 percent CuO, as a function of the Cu(2+)/Cu(total) ratio in the glasses for each glass composition. It was found that optical energy gap, E(opt), of copper phosphate glass is a function of both glass composition and Cu(2+)/Cu(total) ratio in the glass. E(opt) increases as the CuO content for fixed Cu(2+)/Cu(total) ratio and the Cu(2+)/Cu(total) ratio for fixed glass composition are reduced.

Silicon effect on the composition and structure of nanocalcium phosphates

Energy Technology Data Exchange (ETDEWEB)

Tomoaia, Gheorghe [Orthophedics and Traumatology Department, Iuliu Hatieganu University of Medicine and Pharmacy, 47 Traian Mosoiu Str., Cluj-Napoca 400132 (Romania); Mocanu, Aurora [Department of Chemical Engineering, Babes-Bolyai University of Cluj-Napoca, 11 Arany J. Str., Cluj-Napoca 400028 (Romania); Vida-Simiti, Ioan; Jumate, Nicolae [Department of Materials Science and Engineering, Technical University of Cluj-Napoca, 103-105 Muncii Bd., Cluj-Napoca 400641 (Romania); Bobos, Liviu-Dorel [Department of Chemical Engineering, Babes-Bolyai University of Cluj-Napoca, 11 Arany J. Str., Cluj-Napoca 400028 (Romania); Soritau, Olga [Oncology Institute of Cluj-Napoca, 34-36 Republicii Str., 400015 Cluj-Napoca (Romania); Tomoaia-Cotisel, Maria, E-mail: mtcotisel.ubbcluj@yahoo.ro [Department of Chemical Engineering, Babes-Bolyai University of Cluj-Napoca, 11 Arany J. Str., Cluj-Napoca 400028 (Romania)

2014-04-01

Nanostructured calcium phosphates, such as nanohydroxyapatite (HAP) and HAP with silicon content (HAP-Si) of 0.47 wt.% (1% SiO{sub 2}), 2.34 wt.% (5% SiO{sub 2}) and 4.67 wt.% (10% SiO{sub 2}) in the final product, were synthesized by aqueous precipitation, freeze dried and then calcined at 650, 950 and 1150 °C. The obtained materials were investigated by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometry, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) imaging. From the analysis of the XRD patterns, the HAP and β-tricalcium phosphate (β-TCP) phases were identified and their amounts in the samples were estimated. The size of HAP and β-TCP crystallites was estimated to be in the nanocrystalline domain. FTIR spectra showed the presence of characteristic vibrations for P–O, H–O and Si–O groups and their modification with Si content and calcination temperature. TEM, SEM and AFM images also revealed the morphology of the particles and of their aggregates. These materials have been used to manufacture scaffolds which were tested for their influence on adhesion and proliferation of cells, in human osteoblast culture, considering their further use in bone reconstruction. It was found that an appropriate addition of silicon in nanocalcium phosphate scaffolds leads to an enhanced adhesion and proliferation of cells in osteoblasts in vitro. - Highlights: • Nanostructured calcium phosphates with different silicon contents were synthesized. • Scaffolds made from hydroxyapatites with Si were used in human osteoblast cultures. • All scaffolds proved to be biocompatible to human osteoblasts in vitro. • Cell adhesion and proliferation were improved for scaffolds with 0.47 and 2.34% Si.

Novel selenium containing boro-phosphate glasses: Preparation and structural study

Energy Technology Data Exchange (ETDEWEB)

Ciceo-Lucacel, R.; Radu, T., E-mail: teodora.radu@phys.ubbcluj.ro; Ponta, O.; Simon, V.

2014-06-01

We synthesized a new boro-phosphate glass system with different %mol SeO{sub 2} content by conventional melt quenching technique. All samples were obtained in a glassy state with the vitreous structure confirmed by X-ray diffraction analysis. Scanning electron microscopy (SEM) revealed some non-homogeneous domains on the glasses surface, and their tendency to link each other once the selenium oxide content increases. Energy-dispersive X-ray analysis (EDAX) indicated similar elemental composition in different regions of each sample. X-ray photoelectron spectroscopy (XPS) was used to determine the nature of chemical bonding and the elemental composition at the sample surfaces, and Fourier transform infrared (FT-IR) spectroscopy was used to determine the structural groups in the obtained glass structure. Based on FT-IR results, the glass structure at short range order consists mainly of small phosphate units such as pyrophosphate (i.e. P{sub 2}O{sub 7}{sup 4−} dimmers or terminating groups at the end of phosphate chains) and some metaphosphate (i.e. PO{sub 3}{sup −} middle groups in the phosphate chains) units. The boron atoms are mainly placed in three-coordinated sites in BØ{sub 3} or BØ{sub 2}O{sup −} units. A small contribution of BØ{sub 4}{sup −} units was also detected from the FT-IR spectra of glasses. For SeO{sub 2} content higher than 5 mol%, the modifier role of selenium ions is strongly reflected on the local structure dominated in this case by pyrophosphate units. - Highlights: • New P{sub 2}O{sub 5}-CaO-B{sub 2}O{sub 3}-SeO{sub 2} glasses synthesized by conventional melt quenching method. • Evidences for the Se ions modifier role in the local structure by FT-IR and XPS. • Significant advances in understanding the structural properties of the new system.

Novel selenium containing boro-phosphate glasses: Preparation and structural study

International Nuclear Information System (INIS)

Ciceo-Lucacel, R.; Radu, T.; Ponta, O.; Simon, V.

2014-01-01

We synthesized a new boro-phosphate glass system with different %mol SeO 2 content by conventional melt quenching technique. All samples were obtained in a glassy state with the vitreous structure confirmed by X-ray diffraction analysis. Scanning electron microscopy (SEM) revealed some non-homogeneous domains on the glasses surface, and their tendency to link each other once the selenium oxide content increases. Energy-dispersive X-ray analysis (EDAX) indicated similar elemental composition in different regions of each sample. X-ray photoelectron spectroscopy (XPS) was used to determine the nature of chemical bonding and the elemental composition at the sample surfaces, and Fourier transform infrared (FT-IR) spectroscopy was used to determine the structural groups in the obtained glass structure. Based on FT-IR results, the glass structure at short range order consists mainly of small phosphate units such as pyrophosphate (i.e. P 2 O 7 4− dimmers or terminating groups at the end of phosphate chains) and some metaphosphate (i.e. PO 3 − middle groups in the phosphate chains) units. The boron atoms are mainly placed in three-coordinated sites in BØ 3 or BØ 2 O − units. A small contribution of BØ 4 − units was also detected from the FT-IR spectra of glasses. For SeO 2 content higher than 5 mol%, the modifier role of selenium ions is strongly reflected on the local structure dominated in this case by pyrophosphate units. - Highlights: • New P 2 O 5 -CaO-B 2 O 3 -SeO 2 glasses synthesized by conventional melt quenching method. • Evidences for the Se ions modifier role in the local structure by FT-IR and XPS. • Significant advances in understanding the structural properties of the new system

Phosphate and Cardiovascular Disease beyond Chronic Kidney Disease and Vascular Calcification

Directory of Open Access Journals (Sweden)

Sinee Disthabanchong

2018-01-01

Full Text Available Phosphate is essential for life but its accumulation can be detrimental. In end-stage renal disease, widespread vascular calcification occurs as a result of chronic phosphate load. The accumulation of phosphate is likely to occur long before the rise in serum phosphate above the normal range since several observational studies in both general population and early-stage CKD patients have identified the relationship between high-normal serum phosphate and adverse cardiovascular outcomes. Consumption of food high in phosphate increases both fasting and postprandial serum phosphate and habitual intake of high phosphate diet is associated with aging, cardiac hypertrophy, endothelial dysfunction, and subclinical atherosclerosis. The decline in renal function and dietary phosphate load can increase circulating fibroblast growth factor-23 (FGF-23 which may have a direct impact on cardiomyocytes. Increased FGF-23 levels in both CKD and general populations are associated with left ventricular hypertrophy, congestive heart failure, atrial fibrillation, and mortality. Increased extracellular phosphate directly affects endothelial cells causing cell apoptosis and vascular smooth muscle cells (VSMCs causing transformation to osteogenic phenotype. Excess of calcium and phosphate in the circulation can promote the formation of protein-mineral complex called calciprotein particles (CPPs. In CKD, these CPPs contain less calcification inhibitors, induce inflammation, and promote VSMC calcification.

Iron phosphate glass containing simulated fast reactor waste: Characterization and comparison with pristine iron phosphate glass

International Nuclear Information System (INIS)

Joseph, Kitheri; Asuvathraman, R.; Venkata Krishnan, R.; Ravindran, T.R.; Govindaraj, R.; Govindan Kutty, K.V.; Vasudeva Rao, P.R.

2014-01-01

Detailed characterization was carried out on an iron phosphate glass waste form containing 20 wt.% of a simulated nuclear waste. High temperature viscosity measurement was carried out by the rotating spindle method. The Fe 3+ /Fe ratio and structure of this waste loaded iron phosphate glass was investigated using Mössbauer and Raman spectroscopy respectively. Specific heat measurement was carried out in the temperature range of 300–700 K using differential scanning calorimeter. Isoconversional kinetic analysis was employed to understand the crystallization behavior of the waste loaded iron phosphate glass. The glass forming ability and glass stability of the waste loaded glass were also evaluated. All the measured properties of the waste loaded glass were compared with the characteristics of pristine iron phosphate glass

Properties and solubility of chrome in iron alumina phosphate glasses containing high level nuclear waste

International Nuclear Information System (INIS)

Huang, W.; Day, D.E.; Ray, C.S.; Kim, C.W.; Reis, S.T.D.

2004-01-01

Chemical durability, glass formation tendency, and other properties of iron alumina phosphate glasses containing 70 wt% of a simulated high level nuclear waste (HLW), doped with different amounts of Cr 2 O 3 , have been investigated. All of the iron alumina phosphate glasses had an outstanding chemical durability as measured by their small dissolution rate (1 . 10 -9 g/(cm 2 . min)) in deionized water at 90 C for 128 d, their low normalized mass release as determined by the product consistency test (PCT) and a barely measurable corrosion rate of 2 . d) after 7 d at 200 C by the vapor hydration test (VHT). The solubility limit for Cr 2 O 3 in the iron phosphate melts was estimated at 4.1 wt%, but all of the as-annealed melts contained a few percent of crystalline Cr 2 O 3 that had no apparent effect on the chemical durability. The chemical durability was unchanged after deliberate crystallization, 48 h at 650 C. These iron phosphate waste forms, with a waste loading of at least 70 wt%, can be readily melted in commercial refractory crucibles at 1250 C for 2 to 4 h, are resistant to crystallization, meet all current US Department of Energy requirements for chemical durability, and have a solubility limit for Cr 2 O 3 which is at least three times larger than that for borosilicate glasses. (orig.)

A novel 5-enolpyruvylshikimate-3-phosphate synthase shows high glyphosate tolerance in Escherichia coli and tobacco plants.

Directory of Open Access Journals (Sweden)

Gaoyi Cao

Full Text Available A key enzyme in the shikimate pathway, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS is the primary target of the broad-spectrum herbicide glyphosate. Identification of new aroA genes coding for EPSPS with a high level of glyphosate tolerance is essential for the development of glyphosate-tolerant crops. In the present study, the glyphosate tolerance of five bacterial aroA genes was evaluated in the E. coli aroA-defective strain ER2799 and in transgenic tobacco plants. All five aroA genes could complement the aroA-defective strain ER2799, and AM79 aroA showed the highest glyphosate tolerance. Although glyphosate treatment inhibited the growth of both WT and transgenic tobacco plants, transgenic plants expressing AM79 aroA tolerated higher concentration of glyphosate and had a higher fresh weight and survival rate than plants expressing other aroA genes. When treated with high concentration of glyphosate, lower shikimate content was detected in the leaves of transgenic plants expressing AM79 aroA than transgenic plants expressing other aroA genes. These results suggest that AM79 aroA could be a good candidate for the development of transgenic glyphosate-tolerant crops.

Variables affecting the acceptability of radappertized ground beef products. Effects of food grade phosphates, NaCl, fat level, and grinding methods

International Nuclear Information System (INIS)

Cohen, J.S.; Shults, G.W.; Mason, V.C.; Wierbicki, E.

1977-01-01

A series of experiments was conducted to determine the effect of different variables on the quality of an irradiated ground beef product. Factors studied included: different food-grade phosphates; NaCl content; fat content; and size of grind. The influence of these variables on the cooking loss (moisture retention), shear press values and sensory scores was studied. The addition of phosphates and NaCl was desirable in controlling cooking losses. The most effective phosphate was tetrasodium pyrophosphate. The addition of NaCl decreased the shear press force required to penetrate the beef patty, i.e., it tenderized the product. Phosphate addition did not affect the shear press force. Increased fat content increased the cooking losses, but did not affect the shear press force. Irradiation with sterilizing doses had a marked effect on decreasing the shear press force

Biocompatible Ni-free Zr-based bulk metallic glasses with high-Zr-content: compositional optimization for potential biomedical applications.

Science.gov (United States)

Hua, Nengbin; Huang, Lu; Chen, Wenzhe; He, Wei; Zhang, Tao

2014-11-01

The present study designs and prepares Ni-free Zr60+xTi2.5Al10Fe12.5-xCu10Ag5 (at.%, x=0, 2.5, 5) bulk metallic glasses (BMGs) by copper mold casting for potential biomedical application. The effects of Zr content on the in vitro biocompatibility of the Zr-based BMGs are evaluated by investigating mechanical properties, bio-corrosion behavior, and cellular responses. It is found that increasing the content of Zr is favorable for the mechanical compatibility with a combination of low Young's modulus, large plasticity, and high notch toughness. Electrochemical measurements demonstrate that the Zr-based BMGs are corrosion resistant in a phosphate buffered saline solution. The bio-corrosion resistance of BMGs is improved with the increase in Zr content, which is attributed to the enrichment in Zr and decrease in Al concentration in the surface passive film of alloys. Regular cell responses of mouse MC3T3-E1 cells, including cell adhesion and proliferation, are observed on the Zr-Ti-Al-Fe-Cu-Ag BMGs, which reveals their general biosafety. The high-Zr-based BMGs exhibit a higher cell proliferation activity in comparison with that of pure Zr and Ti-6Al-4V alloy. The effects of Zr content on the in vitro biocompatibility can be used to guide the future design of biocompatible Zr-based BMGs. Copyright © 2014 Elsevier B.V. All rights reserved.

Astroglial Pentose Phosphate Pathway Rates in Response to High-Glucose Environments

Directory of Open Access Journals (Sweden)

Shinichi Takahashi

2012-02-01

Full Text Available ROS (reactive oxygen species play an essential role in the pathophysiology of diabetes, stroke and neurodegenerative disorders. Hyperglycaemia associated with diabetes enhances ROS production and causes oxidative stress in vascular endothelial cells, but adverse effects of either acute or chronic high-glucose environments on brain parenchymal cells remain unclear. The PPP (pentose phosphate pathway and GSH participate in a major defence mechanism against ROS in brain, and we explored the role and regulation of the astroglial PPP in response to acute and chronic high-glucose environments. PPP activity was measured in cultured neurons and astroglia by determining the difference in rate of 14CO2 production from [1-14C]glucose and [6-14C]glucose. ROS production, mainly H2O2, and GSH were also assessed. Acutely elevated glucose concentrations in the culture media increased PPP activity and GSH level in astroglia, decreasing ROS production. Chronically elevated glucose environments also induced PPP activation. Immunohistochemical analyses revealed that chronic high-glucose environments induced ER (endoplasmic reticulum stress (presumably through increased hexosamine biosynthetic pathway flux. Nuclear translocation of Nrf2 (nuclear factor-erythroid 2 p45 subunit-related factor 2, which regulates G6PDH (glyceraldehyde-6-phosphate dehydrogenase by enhancing transcription, was also observed in association with BiP (immunoglobulin heavy-chain-binding protein expression. Acute and chronic high-glucose environments activated the PPP in astroglia, preventing ROS elevation. Therefore a rapid decrease in glucose level seems to enhance ROS toxicity, perhaps contributing to neural damage when insulin levels given to diabetic patients are not properly calibrated and plasma glucose levels are not adequately maintained. These findings may also explain the lack of evidence for clinical benefits from strict glycaemic control during the acute phase of stroke.

Astroglial pentose phosphate pathway rates in response to high-glucose environments

Science.gov (United States)

Takahashi, Shinichi; Izawa, Yoshikane; Suzuki, Norihiro

2012-01-01

ROS (reactive oxygen species) play an essential role in the pathophysiology of diabetes, stroke and neurodegenerative disorders. Hyperglycaemia associated with diabetes enhances ROS production and causes oxidative stress in vascular endothelial cells, but adverse effects of either acute or chronic high-glucose environments on brain parenchymal cells remain unclear. The PPP (pentose phosphate pathway) and GSH participate in a major defence mechanism against ROS in brain, and we explored the role and regulation of the astroglial PPP in response to acute and chronic high-glucose environments. PPP activity was measured in cultured neurons and astroglia by determining the difference in rate of 14CO2 production from [1-14C]glucose and [6-14C]glucose. ROS production, mainly H2O2, and GSH were also assessed. Acutely elevated glucose concentrations in the culture media increased PPP activity and GSH level in astroglia, decreasing ROS production. Chronically elevated glucose environments also induced PPP activation. Immunohistochemical analyses revealed that chronic high-glucose environments induced ER (endoplasmic reticulum) stress (presumably through increased hexosamine biosynthetic pathway flux). Nuclear translocation of Nrf2 (nuclear factor-erythroid 2 p45 subunit-related factor 2), which regulates G6PDH (glyceraldehyde-6-phosphate dehydrogenase) by enhancing transcription, was also observed in association with BiP (immunoglobulin heavy-chain-binding protein) expression. Acute and chronic high-glucose environments activated the PPP in astroglia, preventing ROS elevation. Therefore a rapid decrease in glucose level seems to enhance ROS toxicity, perhaps contributing to neural damage when insulin levels given to diabetic patients are not properly calibrated and plasma glucose levels are not adequately maintained. These findings may also explain the lack of evidence for clinical benefits from strict glycaemic control during the acute phase of stroke. PMID:22300409

Characterisation of phosphate rocks at kurun mountain, Sudan

International Nuclear Information System (INIS)

Abdelgader, G. A. M.

2014-08-01

This main objective of this study was to characterise some Sudanese phosphate raw materials collected from Jebel Kurun, located in the eastern part of Nuba Mountain, Western Sudan. The study also aimed to investigate the association between uranium and phosphate and to determine the concentration of some essential elements and trace elements in the phosphate rock. A total of 30 samples were collected from Karun's eastran mountains, near Abujibiha City and have been analyzed for the selected elements using x-ray fluorescence. The obtained results showed that the average concentration of elements was Ca (11.3) and Fe (1.7) as a percentage, while it was Cu (1617.7), Ni (258.4), Pb (185.9), Ti (27.62), V (3779.9), U (160.9), Zn (152.8) and Mn (776.3) in ppm. The average total phosphorus content (analyzed as P O5 %) using UV-visible spectrometer was found to be 30.54%. This could be considered is acceptable percentage for phosphate to be 30.54%. This could be considered is acceptable percentage for phosphate to be used in industrial fertilizers and phosphoric acid production. The average total calcium carbonate was 15.7%. For the elements distribution, uranium found to be more concentrated in the summit of Jebel Kurun, and it displayed a correlation with lead. Furthermore, four groups of association have been noticed, based on elements concentrations.(Author)

Visual and Plasmon Resonance Absorption Sensor for Adenosine Triphosphate Based on the High Affinity between Phosphate and Zr(IV)

OpenAIRE

Qi, Wenjing; Liu, Zhongyuan; Zhang, Wei; Halawa, Mohamed Ibrahim; Xu, Guobao

2016-01-01

Zr(IV) can form phosphate and Zr(IV) (?PO3 2??Zr4+?) complex owing to the high affinity between Zr(IV) with phosphate. Zr(IV) can induce the aggregation of gold nanoparticles (AuNPs), while adenosine triphosphate(ATP) can prevent Zr(IV)-induced aggregation of AuNPs. Herein, a visual and plasmon resonance absorption (PRA)sensor for ATP have been developed using AuNPs based on the high affinity between Zr(IV)with ATP. AuNPs get aggregated in the presence of certain concentrations of Zr(IV). Aft...

L-Myo-inositol 1-phosphate synthase in the aquatic fern Azolla filiculoides.

Science.gov (United States)

Benaroya, Rony Oren; Zamski, Eli; Tel-Or, Elisha

2004-02-01

L-Myo-inositol 1-phosphate synthase (INPS EC 5.5.1.4) catalyzes the conversion of D-glucose 6-phosphate to L-myo-inositol 1-phosphate. INPS is a key enzyme involved in the biosynthesis of phytate which is a common form of stored phosphates in higher plants. The present study monitored the increase of INPS expression in Azolla filiculoides resulting from exposure to inorganic phosphates, metals and salt stress. The expression of INPS was significantly higher in Azolla plants that were grown in rich mineral growth medium than those maintained on nutritional growth medium. The expression of INPS protein and corresponding mRNA increased in plants cultured in minimal nutritional growth medium when phosphate or Zn2+, Cd2+ and NaCl were added to the growth medium. When employing rich mineral growth medium, INPS protein content increased with the addition of Zn2+, but decreased in the presence of Cd2+ and NaCl. These results indicated that accumulation of phytate in Azolla is a result of the intensified expression of INPS protein and mRNA, and its regulation may be primarily derived by the uptake of inorganic phosphate, and Zn2+, Cd2+ or NaCl.

Pilot-scale incineration of wastes with high content of chlorinated and non-halogenated organophosphorus flame retardants used as alternatives for PBDEs.

Science.gov (United States)

Matsukami, Hidenori; Kose, Tomohiro; Watanabe, Mafumi; Takigami, Hidetaka

2014-09-15

Chlorinated and non-halogenated organophosphorus flame retardants (OPFRs) including tris(2-chloroisopropyl) phosphate (TCIPP), diethylene glycol bis(di(2-chloroisopropyl) phosphate) (DEG-BDCIPP), triphenyl phosphate (TPHP), and bisphenol A bis(diphenyl phosphate) (BPA-BDPP) have been used increasingly as alternatives to polybrominated diphenyl ethers and other brominated flame retardants. For this study, five batches of incineration experiments of wastes containing approximately 1% of TCIPP, DEG-BDCIPP, TPHP, and BPA-BDPP were conducted using a pilot-scale incinerator. Destruction and emission behaviors of OPFRs were investigated along with the effects on behaviors of unintentional persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (dl-PCBs), hexachlorobenzene (HCB), pentachlorobenzene (PeCB), and pentachlorophenol (PCP). Incineration conditions were chosen according to current regulations for waste incinerators in Japan and UNEP. The OPFRs in the input materials were mainly destroyed in the primary combustion with destruction efficiencies greater than 99.999%. Concentrations of the OPFRs in the exhaust gases and ash were, respectively, incineration. Inputs of chlorinated OPFRs did not affect the formation markedly. Destruction and emission behaviors of unintentional POPs were investigated. Emissions of such POPs in exhaust gases and the ash were lower than the Japanese and international standards. Results show that even in wastes with high contents of chlorinated and non-halogenated OPFRs, waste incineration by the current regulations for the waste incinerators can control environmental emissions of OPFRs and unintentional POPs. Incineration is regarded as a best available technology (BAT) for waste management systems. Copyright © 2014 Elsevier B.V. All rights reserved.

Geochemical exploration for phosphate in the State of Acre

International Nuclear Information System (INIS)

Costa, M.L. da; Melo Costa, W.A. de; Santos, A.J.M. dos

1989-01-01

The geochemical prospecting conducted for phosphates in Acre which could explain the good fertility of the region was charged to discover this material. The phosphates are strictly built of all the bone structures and coprolites of the several fragments of vertebrate fossils, which are widespread in the region. The phosphatic fossils are bedded in the Solimoes Formation, especially its basal to intermediary conglomeratic bed. The fossils are constituted of low crystallinity apatite, and their matrix sediments include quartz, feldspars, smectite, halloysite and calcite. The P 2 O 5 content reaches up to 5% in the sediments and up to 32% in the fragments. The fossils are enriched in U 3 O 8 and rare earth elements. There is no perspect of classic or mineral deposits but the geological knowlwdge will permit the improvement of the use of the soils in Acre. (author) [pt

Physicochemical characteristics and sorption capacities of heavy metal ions of activated carbons derived by activation with different alkyl phosphate triesters

Science.gov (United States)

Wang, Jing; Liu, Hai; Yang, Shaokun; Zhang, Jian; Zhang, Chenglu; Wu, Haiming

2014-10-01

Five alkyl phosphate triesters (APTEs), including trimethyl phosphate (TMP), triethyl phosphate (TEP), triisopropyl phosphate (TPP), tributyl phosphate (TBP) and trioctyl phosphate (TOP), were used as activating agents for preparing activated carbons (AC-APTEs) with high surface acidity and metal ion sorption capacity. N2 adsorption/desorption isotherms, surface morphologies, elemental compositions, results of Boehm's titration and sorption capacities of heavy metal ions of the carbons were investigated. AC-APTEs contained much more acidic groups and exhibited much less surface area (phosphoric acid activation. For the AC-APTEs, AC-TOP had the highest surface area (488 m2/g), AC-TMP showed the highest yield (41.1%), and AC-TBP possessed the highest acidic groups (2.695 mmol/g), oxygen content (47.0%) and metal ion sorption capacities (40.1 mg/g for Ni(II) and 53.5 mg/g for Cd(II)). For the carbons, AC-APTEs showed much larger Ni(II) and Cd(II) sorption capacities than AC-PPA, except AC-TPP. The differences of the carbons in the physicochemical and sorption properties suggested surface chemistry of the carbons was the main factor influencing their sorption capacities whereas the pore structure played a secondary role.

Method of decomposing treatment for radioactive organic phosphate wastes

International Nuclear Information System (INIS)

Uki, Kazuo; Ichihashi, Toshio; Hasegawa, Akira; Sato, Tatsuaki

1985-01-01

Purpose: To decompose the organic phosphoric-acid ester wastes containing radioactive material, which is produced from spent fuel reprocessing facilities, into inorganic materials using a simple device, under moderate conditions and at high decomposing ratio. Method: Radioactive organic phosphate wates are oxidatively decomposed by H 2 O 2 in an aqueous phosphoric-acid solution of metal phosphate salts. Copper phosphates are used as the metal phosphate salts and the decomposed solution of the radioactive organic phosphate wastes is used as the aqueous solution of the copper phosphate. The temperature used for the oxidizing decomposition ranges from 80 to 100 0 C. (Ikeda, J.)

Barley starch bioengineering for high phosphate and amylose

DEFF Research Database (Denmark)

Blennow, Per Gunnar Andreas; Carciofi, Massimiliano; Shaik, Shahnoor Sultana

2011-01-01

Starch is a biological polymer that can be industrially produced in massive amounts in a very pure form. Cereals is the main source for starch production and any improvement of the starch fraction can have a tremendous impact in food and feed applications. Barley ranks number four among cereal...... crops and barley is a genetically very well characterized. Aiming at producing new starch qualities in the cereal system, we used RNAi and overexpression strategies to produce pure amylose and high-phosphate starch, respectively, using the barley kernel as a polymer factory. By simultaneous silencing...... of the three genes encoding the starch-branching enzymes SBEI, SBEIIa, and SBEIIb using a triple RNAi chimeric hairpin construct we generated a virtually amylopectin-free barley. The grains of the transgenic lines were shrunken and had a yield of around 80% of the control line. The starch granules were...

Phosphine from rocks: mechanically driven phosphate reduction?

Science.gov (United States)

Glindemann, Dietmar; Edwards, Marc; Morgenstern, Peter

2005-11-01

Natural rock and mineral samples released trace amounts of phosphine during dissolution in mineral acid. An order of magnitude more phosphine (average 1982 ng PH3 kg rock and maximum 6673 ng PH3/kg rock) is released from pulverized rock samples (basalt, gneiss, granite, clay, quartzitic pebbles, or marble). Phosphine was correlated to hardness and mechanical pulverization energy of the rocks. The yield of PH3 ranged from 0 to 0.01% of the total P content of the dissolved rock. Strong circumstantial evidence was gathered for reduction of phosphate in the rock via mechanochemical or "tribochemical" weathering at quartz and calcite/marble inclusions. Artificial reproduction of this mechanism by rubbing quartz rods coated with apatite-phosphate to the point of visible triboluminescence, led to detection of more than 70 000 ng/kg PH3 in the apatite. This reaction pathway may be considered a mechano-chemical analogue of phosphate reduction from lightning or electrical discharges and may contribute to phosphine production via tectonic forces and processing of rocks.

Characterization of composite high density polyethylene and layered zirconium phosphate

International Nuclear Information System (INIS)

Lino, Adan S.; Silva, Daniela F.; Mendes, Luis C.

2011-01-01

Zirconium phosphate (ZrP) (2 w%), synthesized by direct precipitation method, was used in the preparation of composite with high density polyethylene (HDPE), through extrusion processing in the molten state. Wide angle x-ray diffraction (WAXD), stress-strain mechanical analysis and scanning electron microscopy (SEM) techniques were used for ZrP, neat polymer and composite mechanical and morphologic characterization. Although there was a slight increase in the Young modulus, WAXD and SEM analysis showed that the intercalation of the HDPE matrix in the filler galleries did not occur, probably due to the insufficient lamellae spacing to intercalate the polymer chains. Then, a microcomposite was achieved. (author)

Effect of Biofertilizers on Macro and Micro Nutrients Uptake and Essential Oil Content in Dracocephalum moldavica L.

Directory of Open Access Journals (Sweden)

S Rahimzadeh

2013-08-01

Full Text Available In order to investigation the effect of different fertilization treatments on nutrient and essential oil contents in dragonhead drug (Dracocephalum moldavica L., an experiment was conducted in the station of agricultural research in Urmia on 2008. Treatments (nitroxin, barvar phosphate biofertilizer, biosulfur, nitroxin+ barvar phosphate biofertilizer, barvar phosphate biofertilizer + biosulfur, nitroxin+ biosulfur, nitroxin+ barvar phosphate biofertilizer + biosulfur, chemical fertilizer, control were arranged based on randomized complete block design with 4 replications. Results indicated that uptake of Nitrogen, Phosphorus, Potassium, Iron, Copper, Manganese and essential oil content were affected by studied treatments significantly but uptake of zinc by plant was not affected. Means comparison showed the highest values of Nitrogen (3.55%, Potassium (3.47% and Iron (4.56 ppm in Nitroxin treatment, Phosphorus (0.26% and Copper (0.33 ppm in barvar phosphate biofertilizer + biosulfur treatment, Manganese (0.48 ppm in chemical origin of nitrogen+phosphorus+ potassium treatment and essential oil content (0.48% in nitroxin+ barvar phosphate biofertilizer + biosulfur treatment

Effect upon biocompatibility and biocorrosion properties of plasma electrolytic oxidation in trisodium phosphate electrolytes.

Science.gov (United States)

Kim, Yu-Kyoung; Park, Il-Song; Lee, Kwang-Bok; Bae, Tae-Sung; Jang, Yong-Seok; Oh, Young-Min; Lee, Min-Ho

2016-03-01

Surface modification to improve the corrosion resistance and biocompatibility of the Mg-Al-Zn-Ca alloy was conducted via plasma electrolytic oxidation (PEO) in an electrolyte that included phosphate. Calcium phosphate can be easily induced on the surface of a PEO coating that includes phosphate in a physiological environment because Ca(2+) ions in body fluids can be combined with PO4 (3-). Cytotoxicity of the PEO coating formed in electrolytes with various amounts of Na3PO4 was identified. In particular, the effects that PEO films have upon oxidative stress and differentiation of osteoblast activity were studied. As the concentration of Na3PO4 in the electrolyte increased, the oxide layer was found to become thicker, which increased corrosion resistance. However, the PEO coating formed in electrolytes with over 0.2 M of added Na3PO4 exhibited more microcracks and larger pores than those formed in smaller Na3PO4 concentrations owing to a large spark discharge. A nonuniform oxide film that included more phosphate caused more cytotoxicity and oxidative stress, and overabundant phosphate content in the oxide layer interrupted the differentiation of osteoblasts. The corrosion resistance of the magnesium alloy and the thickness of the oxide layer were increased by the addition of Na3PO4 in the electrolyte for PEO treatment. However, excessive phosphate content in the oxide layer led to oxidative stress, which resulted in reduced cell viability and activity.

Natural phosphate-supported palladium: A highly efficient and recyclable catalyst for the suzuki-miyaura coupling under microwave irradiation

KAUST Repository

Hassine, Ayoub; Bouhrara, Mohamed; Sebti, Said; Solhy, Abderrahim; Mahfouz, Remi; Luart, Denis; Lene, Christophe; Fihri, Aziz

2015-01-01

This report explores Suzuki-Miyaura coupling under microwave irradiation, using a new generation of catalyst that is based on natural phosphate (NP) impregnated by palladium. This catalyst was prepared by the treatment of natural phosphate with bis(benzonitrile)palladium(II) chloride in acetone at room temperature. The catalyst displayed high catalytic activity for the Suzuki-Miyaura coupling of aryl bromides and chlorides with aryl boronic acids in pure water and with the use of microwave irradiation. The low-cost and availability of the solid support, mild reaction conditions, high yields of desired products, recyclability of the catalyst and short reaction times are the notable features of these methods.

Natural phosphate-supported palladium: A highly efficient and recyclable catalyst for the suzuki-miyaura coupling under microwave irradiation

KAUST Repository

Hassine, Ayoub

2015-01-19

This report explores Suzuki-Miyaura coupling under microwave irradiation, using a new generation of catalyst that is based on natural phosphate (NP) impregnated by palladium. This catalyst was prepared by the treatment of natural phosphate with bis(benzonitrile)palladium(II) chloride in acetone at room temperature. The catalyst displayed high catalytic activity for the Suzuki-Miyaura coupling of aryl bromides and chlorides with aryl boronic acids in pure water and with the use of microwave irradiation. The low-cost and availability of the solid support, mild reaction conditions, high yields of desired products, recyclability of the catalyst and short reaction times are the notable features of these methods.

Biocompatible Ni-free Zr-based bulk metallic glasses with high-Zr-content: Compositional optimization for potential biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Hua, Nengbin, E-mail: flower1982cn@126.com [Department of Materials Science and Engineering, Fujian University of Technology, 350118 Fuzhou (China); Department of Materials Science and Engineering, Fuzhou University, 350116 Fuzhou (China); Huang, Lu [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996-2100 (United States); Chen, Wenzhe [Department of Materials Science and Engineering, Fujian University of Technology, 350118 Fuzhou (China); Department of Materials Science and Engineering, Fuzhou University, 350116 Fuzhou (China); He, Wei [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996-2100 (United States); Department of Mechanical, Aerospace and Biomedical Engineering, The University of Tennessee, Knoxville, TN 37996-2200 (United States); Zhang, Tao [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, 100191 Beijing (China)

2014-11-01

The present study designs and prepares Ni-free Zr{sub 60+x}Ti{sub 2.5}Al{sub 10}Fe{sub 12.5−x}Cu{sub 10}Ag{sub 5} (at.%, x = 0, 2.5, 5) bulk metallic glasses (BMGs) by copper mold casting for potential biomedical application. The effects of Zr content on the in vitro biocompatibility of the Zr-based BMGs are evaluated by investigating mechanical properties, bio-corrosion behavior, and cellular responses. It is found that increasing the content of Zr is favorable for the mechanical compatibility with a combination of low Young's modulus, large plasticity, and high notch toughness. Electrochemical measurements demonstrate that the Zr-based BMGs are corrosion resistant in a phosphate buffered saline solution. The bio-corrosion resistance of BMGs is improved with the increase in Zr content, which is attributed to the enrichment in Zr and decrease in Al concentration in the surface passive film of alloys. Regular cell responses of mouse MC3T3-E1 cells, including cell adhesion and proliferation, are observed on the Zr–Ti–Al–Fe–Cu–Ag BMGs, which reveals their general biosafety. The high-Zr-based BMGs exhibit a higher cell proliferation activity in comparison with that of pure Zr and Ti-6Al-4V alloy. The effects of Zr content on the in vitro biocompatibility can be used to guide the future design of biocompatible Zr-based BMGs. - Highlights: • Ni-free Zr{sub 60+x}Ti{sub 2.5}Al{sub 10}Fe{sub 12.5−x}Cu{sub 10}Ag{sub 5} (at.%, x = 0, 2.5, 5) BMGs were fabricated. • Plasticity and notch toughness of BMGs are enhanced by high-Zr-content. • The high-Zr-based BMGs exhibit excellent bio-corrosion resistance in PBS solution. • The biosafety of BMGs is revealed by regular cell adhesion and proliferation. • High-Zr-bearing BMGs are favorable for potential applications as biomaterials.

Theoretical evaluation of high-energy lithium metal phosphate cathode materials in Li-ion batteries

Science.gov (United States)

Howard, Wilmont F.; Spotnitz, Robert M.

Lithium metal phosphates (olivines) are emerging as long-lived, safe cathode materials in Li-ion batteries. Nano-LiFePO 4 already appears in high-power applications, and LiMnPO 4 development is underway. Current and emerging Fe- and Mn-based intercalants, however, are low-energy producers compared to Ni and Co compounds. LiNiPO 4, a high voltage olivine, has the potential for superior energy output (>10.7 Wh in 18650 batteries), compared with commercial Li(Co,Ni)O 2 derivatives (up to 9.9 Wh). Speculative Co and Ni olivine cathode materials charged to above 4.5 V will require significant advances in electrolyte compositions and nanotechnology before commercialization. The major drivers toward 5 V battery chemistries are the inherent abuse tolerance of phosphates and the economic benefit of LiNiPO 4: it can produce 34% greater energy per dollar of cell material cost than LiAl 0.05Co 0.15Ni 0.8O 2, today's "standard" cathode intercalant in Li-ion batteries.

Environmental considerations on uranium and radium from phosphate fertilizers

International Nuclear Information System (INIS)

Cioroianu, T.M.; Bunus, F.; Filip, D.; Filip, Gh.

2001-01-01

In the process of fertilizer production from natural phosphates of sedimentary origin, most of the existing radioactivity will be found in the final product. The phosphates exploited for fertilizer production at about 150 mill. tons/year are processed by two chemical methods: sulphuric and nitric acid attack. In the process of sulphuric acid attack of the phosphate rock, phosphoric acid and phosphogypsum are produced. The first product is used for fertilizer production, either as triplesuperphosphate (TSP) or diammonium phosphate (DAP). The phosphogypsum waste is deposited on stacks thus becoming a source of concern. In the case of nitric acid attack, the result is a phosphonitric (PN) solution, which is used to produce a complex fertilizer NPK. Uranium and 226Ra (usually in secular equilibrium) are dissolved and distributed between the intermediary products. Thus the average concentration of 100 mg/kg U in the phosphate rock is dissolved in 90-95 % in phosphoric acid while the 226Ra of initial 1000 / 2000 Bq/kg concentration is completely precipitated together with phosphogypsum. Therefore phosphogypsum waste has 1000-1500 Bq/kg 226Ra. The TSP fertilizer being produced by partial neutralization of phosphoric acid with phosphate rock with 100-150 mg/kg U, while 226Ra is only introduced in the neutralization process i.e. 500-800 Bq/kg. In the case of DAP, the uranium content is 140-170 mg/kg without the present of 226Ra. The complex fertilizer obtained through the process of nitric acid attack will have the whole uranium and radium of the phosphate rock (both are dissolved in nitric acid) with uranium and radium contents of 120-160 mg/kg, 1000-1500 Bq/kg respectively. The radioactivities of fertilizers produced may be a source of concern since both uranium and radium are exceeding the present accepted limits for their disposal in the environment. About 10,000-15,000 tons/yr. of uranium is spread every year on the agricultural lands worldwide by the use of phosphate

Final Report - Assessment of Potential Phosphate Ion-Cementitious Materials Interactions

International Nuclear Information System (INIS)

Naus, Dan J.; Mattus, Catherine H.; Dole, Leslie Robert

2007-01-01

The objectives of this limited study were to: (1) review the potential for degradation of cementitious materials due to exposure to high concentrations of phosphate ions; (2) provide an improved understanding of any significant factors that may lead to a requirement to establish exposure limits for concrete structures exposed to soils or ground waters containing high levels of phosphate ions; (3) recommend, as appropriate, whether a limitation on phosphate ion concentration in soils or ground water is required to avoid degradation of concrete structures; and (4) provide a 'primer' on factors that can affect the durability of concrete materials and structures in nuclear power plants. An assessment of the potential effects of phosphate ions on cementitious materials was made through a review of the literature, contacts with concrete research personnel, and conduct of a 'bench-scale' laboratory investigation. Results of these activities indicate that: no harmful interactions occur between phosphates and cementitious materials unless phosphates are present in the form of phosphoric acid; phosphates have been incorporated into concrete as set retarders, and phosphate cements have been used for infrastructure repair; no standards or guidelines exist pertaining to applications of reinforced concrete structures in high-phosphate environments; interactions of phosphate ions and cementitious materials has not been a concern of the research community; and laboratory results indicate similar performance of specimens cured in phosphate solutions and those cured in a calcium hydroxide solution after exposure periods of up to eighteen months. Relative to the 'primer,' a separate NUREG report has been prepared that provides a review of pertinent factors that can affect the durability of nuclear power plant reinforced concrete structures

Final Report - Assessment of Potential Phosphate Ion-Cementitious Materials Interactions

Energy Technology Data Exchange (ETDEWEB)

Naus, Dan J [ORNL; Mattus, Catherine H [ORNL; Dole, Leslie Robert [ORNL

2007-06-01

The objectives of this limited study were to: (1) review the potential for degradation of cementitious materials due to exposure to high concentrations of phosphate ions; (2) provide an improved understanding of any significant factors that may lead to a requirement to establish exposure limits for concrete structures exposed to soils or ground waters containing high levels of phosphate ions; (3) recommend, as appropriate, whether a limitation on phosphate ion concentration in soils or ground water is required to avoid degradation of concrete structures; and (4) provide a "primer" on factors that can affect the durability of concrete materials and structures in nuclear power plants. An assessment of the potential effects of phosphate ions on cementitious materials was made through a review of the literature, contacts with concrete research personnel, and conduct of a "bench-scale" laboratory investigation. Results of these activities indicate that: no harmful interactions occur between phosphates and cementitious materials unless phosphates are present in the form of phosphoric acid; phosphates have been incorporated into concrete as set retarders, and phosphate cements have been used for infrastructure repair; no standards or guidelines exist pertaining to applications of reinforced concrete structures in high-phosphate environments; interactions of phosphate ions and cementitious materials has not been a concern of the research community; and laboratory results indicate similar performance of specimens cured in phosphate solutions and those cured in a calcium hydroxide solution after exposure periods of up to eighteen months. Relative to the "primer," a separate NUREG report has been prepared that provides a review of pertinent factors that can affect the durability of nuclear power plant reinforced concrete structures.

Natural radionuclides in phosphatic fertilizer and their behaviour of absoption and accumulation in soils and crops

International Nuclear Information System (INIS)

Chen Jingjian; Zhu Yongyi; Yang Juncheng; Gu Baming

1990-06-01

The systematic data on the radioactivity of U, Th, Ra and 40 K in phosphate rocks, phosphatic fertilizers and soil are given. The radioactive composition and radioactivity in phosphatic fertilizers vary with different kinds of phosphatic fertilizers. The radioactive compositions in the phosphatic fertilizers made from phosphate rock are the same as that in the original phosphate rock, but the radioactivity is only 50∼60% of the original. The natural uranium in the compound fertilizer made from phosphoric acid is several times higher than that in the phosphate rock, and the other radionuclides were separated during the process of forming phosphoric acid. In soil, the radioactivity varies with the soil types. The U content is slightly higher in the south region with red earth and the 40 K is higher in the north region with black earth, but all are in normal level. Usually, the radioactivity of phosphate rock and phosphatic fertilizer is between the natural background of soil and the limitation of radioactive protection, but the radioactivity of 226 Ra in some phosphate rocks and phosphatic fertilizers in Guizhou and Hunan is higher than the permitted limitation set by the government

Development of a new biofertilizer with a high capacity for N2 fixation, phosphate and potassium solubilization and auxin production.

Science.gov (United States)

Leaungvutiviroj, Chaveevan; Ruangphisarn, Pimtida; Hansanimitkul, Pikul; Shinkawa, Hidenori; Sasaki, Ken

2010-01-01

Biofertilizers that possess a high capacity for N(2) fixation (Azotobacter tropicalis), and consist of phosphate solubilizing bacteria (Burkhoderia unamae), and potassium solubilizing bacteria (Bacillus subtilis) and produce auxin (KJB9/2 strain), have a high potential for growth and yield enhancement of corn and vegetables (Chinese kale). For vegetables, the addition of biofertilizer alone enhanced growth 4 times. Moreover, an enhancement of growth by 7 times was observed due to the addition of rock phosphate and K-feldspar, natural mineral fertilizers, in combination with the biofertilizer.

Long term field evaluation of phosphate rock and superphosphate in acid soils of Hungary; Incubation and pot experiments

International Nuclear Information System (INIS)

Nemeth, T.; Osztoics, E.; Csatho, P.; Radimszky, L.; Baczo, G.Y.

2002-01-01

A series of experiments was conducted to compare the agronomic effectiveness of phosphate rock (from Algeria) and of single superphosphate (from Russia, Kola) on a moderately acidic pseudogley brown forest soil (Szentgyoergyvoelgy) and on a slightly acidic chernozem brown forest soil (Kompolt). Dynamics of water-soluble and ammonium lactate-soluble P-contents (AL-P) and soil pH-H 2 O changes were studied in a half-year long incubation experiment. A follow-up pot experiment with the same soils was carried out with winter rape as test plants. Both experiments were set up with similar P fertilizer sources and P rates (100, 200, and 400 mg mineral acid soluble P 2 O 5 per kg soil). At the beginning of incubation experiment, the water-soluble P content of the pseudogley brown forest soil was influenced by both the sources of P and the experimental conditions. The water-soluble P content decreased with time. After the 15 th to 20 th day of incubation, when the fast binding process of the water-soluble P ended, the effects of the P forms decreased. In this stage, the effects of environmental conditions depended on the form of the P fertilizer. The water-soluble P content of the phosphate rock-treated samples was affected to a great extent by soil water content, while the incubation temperature had a greater effect in soils treated with superphosphate. The AL-P content of soils was increased similarly by addition of equal rates of phosphate rock and super-phosphate at the beginning of incubation. The AL-P content of phosphate rock-treated soils was higher throughout the incubation period than of the superphosphate-treated soils -treated. Temperature had a greater effect on the AL-P content of soils than soil water content. As the AL-extraction may dissolve a substantial amount of the undecomposed phosphate rock, this method is not applicable to soil testing of available P forms from phosphate rock-treated soils. Initial soil pH decreased on average by 0.5 units in the

Hanford phosphate precipitation filtration process evaluation

International Nuclear Information System (INIS)

Walker, B.W.; McCabe, D.J.

1997-01-01

The purpose of this filter study was to evaluate cross-flow filtration as effective solid-liquid separation technology for treating Hanford wastes, outline operating conditions for equipment, examine the expected filter flow rates, and determine proper cleaning. A proposed Hanford waste pre-treatment process uses sodium hydroxide at high temperature to remove aluminum from sludge. This process also dissolves phosphates. Upon cooling to 40 degrees centigrade the phosphates form a Na7(PO4)2F9H2O precipitate which must be removed prior to further treatment. Filter studies were conducted with a phosphate slurry simulant to evaluate whether 0.5 micron cross-flow sintered metal Mott filters can separate the phosphate precipitate from the wash solutions. The simulant was recirculated through the filters at room temperature and filtration performance data was collected

Acid-base properties and surface complexation modeling of phosphate anion adsorption by wasted low grade iron ore with high phosphorus.

Science.gov (United States)

Yuan, Xiaoli; Bai, Chenguang; Xia, Wentang; An, Juan

2014-08-15

The adsorption phenomena and specific reaction processes of phosphate onto wasted low grade iron ore with high phosphorus (WLGIOWHP) were studied in this work. Zeta potential and Fourier transform infrared spectroscopy (FTIR) analyses were used to elucidate the interaction mechanism between WLGIOWHP and aqueous solution. The results implied that the main adsorption mechanism was the replacement of surface hydroxyl groups by phosphate via the formation of inner-sphere complex. The adsorption process was characterized by chemical adsorption onto WLGIOWHP. The non-electrostatic model (NEM) was used to simulate the surface adsorption of phosphate onto WLGIOWHP. The total surface site density and protonation constants for NEM (N(T)=1.6×10(-4) mol/g, K(a1)=2.2×10(-4), K(a2)=6.82×10(-9)) were obtained by non-linear data fitting of acid-base titrations. In addition, the NEM was used to establish the surface adsorption complexation modeling of phosphate onto WLGIOWHP. The model successfully predicted the adsorption of phosphate onto WLGIOWHP from municipal wastewater. Copyright © 2014 Elsevier Inc. All rights reserved.

Biotemplate synthesis of monodispersed iron phosphate hollow microspheres

International Nuclear Information System (INIS)

Cao Feng; Li Dongxu

2010-01-01

Monodispersed iron phosphate hollow microspheres with a high degree of crystallization were prepared through a facile in situ deposition method using rape pollen grains as a biotemplate. The functional group on the surface of the pollen grains could adsorb Fe 3+ , which provided the nucleation sites for growth of iron phosphate nanoparticles. After being sintered at 600 deg. C for 10 h, the pollen grains were removed and iron phosphate hollow microspheres were obtained. A scanning electron microscope and x-ray diffraction were applied to characterize the morphology and crystalline structure of the pollen grains, iron phosphate-coated pollen grains and iron phosphate hollow microspheres. Differential scanning calorimetry and thermogravity analyses were performed to investigate the thermal behavior of the iron phosphate-coated pollen grains during the calcinations. Energy dispersive spectroscopy and Fourier transform infrared spectroscopy were utilized to investigate the interaction between the pollen grains and iron phosphate. The effect of the pollen wall on the surface morphology of these iron phosphate hollow microspheres was also proven in this work.

Biotemplate synthesis of monodispersed iron phosphate hollow microspheres

Energy Technology Data Exchange (ETDEWEB)

Cao Feng; Li Dongxu, E-mail: dongxuli@njut.edu.c [College of Materials Science and Engineering, Nanjing University of Technology, Jiangsu Nanjing 210009 (China)

2010-03-15

Monodispersed iron phosphate hollow microspheres with a high degree of crystallization were prepared through a facile in situ deposition method using rape pollen grains as a biotemplate. The functional group on the surface of the pollen grains could adsorb Fe{sup 3+}, which provided the nucleation sites for growth of iron phosphate nanoparticles. After being sintered at 600 deg. C for 10 h, the pollen grains were removed and iron phosphate hollow microspheres were obtained. A scanning electron microscope and x-ray diffraction were applied to characterize the morphology and crystalline structure of the pollen grains, iron phosphate-coated pollen grains and iron phosphate hollow microspheres. Differential scanning calorimetry and thermogravity analyses were performed to investigate the thermal behavior of the iron phosphate-coated pollen grains during the calcinations. Energy dispersive spectroscopy and Fourier transform infrared spectroscopy were utilized to investigate the interaction between the pollen grains and iron phosphate. The effect of the pollen wall on the surface morphology of these iron phosphate hollow microspheres was also proven in this work.

The benchmark of P-31 NMR parameters in phosphate: a case study on structurally constrained and flexible phosphate

Czech Academy of Sciences Publication Activity Database

Fukal, Jiří; Páv, Ondřej; Buděšínský, Miloš; Šebera, Jakub; Sychrovský, Vladimír

2017-01-01

Roč. 19, č. 47 (2017), s. 31830-31841 ISSN 1463-9076 R&D Projects: GA ČR(CZ) GA16-00270S; GA ČR GA13-26526S Institutional support: RVO:61388963 Keywords : phosphate * MD * DFT * NMR Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 4.123, year: 2016 http://pubs.rsc.org/en/content/articlepdf/2017/cp/c7cp06969c

Radiometric analysis of Hazara phosphate rock and fertilizers in Pakistan

International Nuclear Information System (INIS)

Khan, K.; Khan, H.M.; Tufail, M.; Khatibeh, A.J.A.H.; Ahmad, N.

1998-01-01

Natural radioactivity due to 40 K, 226 Ra and 232 Th has been measured in phosphate rock samples, collected from various localities of Hazara division of Pakistan, and in locally prepared and imported fertilizer. For data acquisition and analysis, a high-purity germanium (HPGe) detector and a PC-based MCA were used. The 226 Ra content was very high and was found to vary from 307.7 Bq kg -1 to 617.5 Bq kg -1 . This can result in a significant radiation exposure if the rock and fertilizer are handled in places with poor ventilation that could lead to radon accumulation. These data can be used to determine the radioactivity being spread along with fertilizer on agricultural lands. (author)

The variable charge of andisols as affected by nanoparticles of rock phosphate and phosphate solubilizing bacteria

Science.gov (United States)

Arifin, M.; Nurlaeny, N.; Devnita, R.; Fitriatin, B. N.; Sandrawati, A.; Supriatna, Y.

2018-02-01

Andisols has a great potential as agriculture land, however, it has a high phosphorus retention, variable charge characteristics and high value of zero net charge or pH0. The research is aimed to study the effects of nanoparticles of rock phosphate (NPRP) and biofertilizer (phosphate solubilizing bacteria/PSB) on soil pH, pHo (zero point of charge, ZPC) and organic-C in one subgroup of Andisols, namely Acrudoxic Durudands, Ciater Region West Java. The research was conducted from October 2016 to February 2017 in Soil Physics Laboratory and Laboratory of Soil Chemistry and Fertility, Soil Science Department, Faculty of Agriculture, Universitas Padjadjaran. This experiment used a completely randomized factorial design, consisting of two factors and three replications. The first factor was nanoparticles of rock phosphate consist of 4 doses 0; 25; 50 and 75 g/1 kg soil and the second factor was biofertilizer dose consist of g/1 kg soil and without biofertilizer. Total treatment combinations were 8 with 3 replications, so there were 24 experimental plots. The results showed that in general NPRR and biofertilizer will decrease the value of soil pH throughout the incubation periods. There is an interaction between nanoparticles of rock phosphate and biofertilizer in decreasing pHo in the first month of incubation, but after 4-month incubation period, NPRP increased. Interaction between 75 g nanoparticles of rock phosphate with 1 g biofertilizer/1 kg soil in fourth months of incubation decreased soil organic-C to 3.35%.

TRANSFORMAÇÃO DO FOSFATO MONOCÁLCICO EM FOSFATO BICÁLCICO TRANSFORMATION OF MONOCALCIC PHOSPHATE IN BICALCIC PHOSPHATE

Directory of Open Access Journals (Sweden)

Terezinha de H. B. O. Tocantins

2007-09-01

Full Text Available

O Estado de Goiás é rico em fosfato monocálcico (de baixo preço, o qual é usado como adubo. Com a finalidade de transformá-1o em fosfato bicálcico (de preço elevado e utilizá-lo na alimentação de bovinos, desenvolveu-se nova técnica de obtenção do bicálcico, à partir do monocálcico, e não a partir da rocha fosfático ou da reação do óxido de cálcio com ácido sulfúrico. A metodologia aplicada foi a seguinte: preparo das amostras visando a obtê-las com teores de acidez livre variando de 1 a 6 em função do ácido sulfúrico (amostras estas chamadas de T1, T2, ..... T6 respectivamente. Após obtidos os graus de acidez desejados, iniciaram-se os tratamentos térmicos das mesmas, ou seja, as amostras foram submetidas às temperaturas de 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 260, 280 e 300 graus centígrados durante tempos de exposição de 20, 30 e 40 minutos. Finalmente, as amostras foram analisadas a fim de se obter os teores de P205 solúvel em água e em ácido cítrico a 2%. Pelas aná1ises desses teores, concluiu-se o seguinte: dos tratamentos efetivados, o que apresentou maior eficiência de transformação do fosfato monocálcico para bicálcico foi o denominado de T1 com tempo de exposição de 40 minutos sob a temperatura de 280°C.

The state of Goiás is rich in monocalcic phosphate, which is used as fertilizer and has low price, in order to change it to bicalcic phosphate, which has high price and is used for cattle feeding. A new technique of bicalcic obtention was developed from the monocalcic, and not from the phosphatic rocks or from the calcium oxide reaction with sulphuric acid. The methodology applied was the following: Preparation of the samples trying to obtain them with contents of free acidity varying from one to six in function of sulphuric acid (samples

Chemical Synthesis, Characterization, and Biocompatibility Study of Hydroxyapatite/Chitosan Phosphate Nanocomposite for Bone Tissue Engineering Applications

Directory of Open Access Journals (Sweden)

Nabakumar Pramanik

2009-01-01

Full Text Available A novel bioanalogue hydroxyapatite (HAp/chitosan phosphate (CSP nanocomposite has been synthesized by a solution-based chemical methodology with varying HAp contents from 10 to 60% (w/w. The interfacial bonding interaction between HAp and CSP has been investigated through Fourier transform infrared absorption spectra (FTIR and x-ray diffraction (XRD. The surface morphology of the composite and the homogeneous dispersion of nanoparticles in the polymer matrix have been investigated through scanning electron microscopy (SEM and transmission electron microscopy (TEM, respectively. The mechanical properties of the composite are found to be improved significantly with increase in nanoparticle contents. Cytotoxicity test using murine L929 fibroblast confirms that the nanocomposite is cytocompatible. Primary murine osteoblast cell culture study proves that the nanocomposite is osteocompatible and highly in vitro osteogenic. The use of CSP promotes the homogeneous distribution of particles in the polymer matrix through its pendant phosphate groups along with particle-polymer interfacial interactions. The prepared HAp/CSP nanocomposite with uniform microstructure may be used in bone tissue engineering applications.

Radioactivity distribution in phosphate products, by-products, effluents, and wastes

International Nuclear Information System (INIS)

Guimond, R.J.; Windham, S.T.

1975-08-01

Phosphate rock throughout the world contains uranium in concentrations ranging from a few ppM to a few hundred ppM. In the United States, phosphate rock normally contains between 100 to 150 ppM uranium. Mining and processing of these ores redistributes much of the uranium daughters among the various products, by-products, and wastes. These materials are then widely dispersed throughout the environment. This redistribution may lead to increased exposure of the public to these naturally-occurring radionuclides. In determining the magnitude of the population exposure caused by this redistribution and in developing environmental standards and controls to prevent contamination of the biosphere from these naturally-occurring radionuclides it is necessary to determine the concentrations and total quantities of these radionuclides in the products, by-products, effluents and wastes of phosphate mining and manufacturing. Samples of phosphate ores, products, by-products, effluents, and wastes were obtained and analyzed for their radioactivity content. Quantities of radioactivity entering the environment through various products, by-products, effluents, and wastes were estimated

Immobilization of fission products in phosphate ceramic waste forms

Energy Technology Data Exchange (ETDEWEB)

Singh, D.; Wagh, A. [Argonne National Lab., IL (United States)

1997-10-01

Chemically bonded phosphate ceramics (CBPCs) have several advantages that make them ideal candidates for containing radioactive and hazardous wastes. In general, phosphates have high solid-solution capacities for incorporating radionuclides, as evidenced by several phosphates (e.g., monazites and apatites) that are natural analogs of radioactive and rare-earth elements. The phosphates have high radiation stability, are refractory, and will not degrade in the presence of internal heating by fission products. Dense and hard CBPCs can be fabricated inexpensively and at low temperature by acid-base reactions between an inorganic oxide/hydroxide powder and either phosphoric acid or an acid-phosphate solution. The resulting phosphates are extremely insoluble in aqueous media and have excellent long-term durability. CBPCs offer the dual stabilization mechanisms of chemical fixation and physical encapsulation, resulting in superior waste forms. The goal of this task is develop and demonstrate the feasibility of CBPCs for S/S of wastes containing fission products. The focus of this work is to develop a low-temperature CBPC immobilization system for eluted {sup 99}Tc wastes from sorption processes.

High strength, biodegradable and cytocompatible alpha tricalcium phosphate-iron composites for temporal reduction of bone fractures.

Science.gov (United States)

Montufar, E B; Casas-Luna, M; Horynová, M; Tkachenko, S; Fohlerová, Z; Diaz-de-la-Torre, S; Dvořák, K; Čelko, L; Kaiser, J

2018-04-01

In this work alpha tricalcium phosphate (α-TCP)/iron (Fe) composites were developed as a new family of biodegradable, load-bearing and cytocompatible materials. The composites with composition from pure ceramic to pure metallic samples were consolidated by pulsed electric current assisted sintering to minimise processing time and temperature while improving their mechanical performance. The mechanical strength of the composites was increased and controlled with the Fe content, passing from brittle to ductile failure. In particular, the addition of 25 vol% of Fe produced a ceramic matrix composite with elastic modulus much closer to cortical bone than that of titanium or biodegradable magnesium alloys and specific compressive strength above that of stainless steel, chromium-cobalt alloys and pure titanium, currently used in clinic for internal fracture fixation. All the composites studied exhibited higher degradation rate than their individual components, presenting values around 200 μm/year, but also their compressive strength did not show a significant reduction in the period required for bone fracture consolidation. Composites showed preferential degradation of α-TCP areas rather than β-TCP areas, suggesting that α-TCP can produce composites with higher degradation rate. The composites were cytocompatible both in indirect and direct contact with bone cells. Osteoblast-like cells attached and spread on the surface of the composites, presenting proliferation rate similar to cells on tissue culture-grade polystyrene and they showed alkaline phosphatase activity. Therefore, this new family of composites is a potential alternative to produce implants for temporal reduction of bone fractures. Biodegradable alpha-tricalcium phosphate/iron (α-TCP/Fe) composites are promising candidates for the fabrication of temporal osteosynthesis devices. Similar to biodegradable metals, these composites can avoid implant removal after bone fracture healing, particularly in

Electrical properties of phosphate glasses

International Nuclear Information System (INIS)

Mogus-Milankovic, A; Santic, A; Reis, S T; Day, D E

2009-01-01

Investigation of the electrical properties of phosphate glasses where transition metal oxide such as iron oxide is the network former and network modifier is presented. Phosphate glasses containing iron are electronically conducting glasses where the polaronic conduction is due to the electron hopping from low to high iron valence state. The identification of structural defects caused by ion/polaron migration, the analysis of dipolar states and electrical conductivity in iron phosphate glasses containing various alkali and mixed alkali ions was performed on the basis of the impedance spectroscopy (IS). The changes in electrical conductivity from as-quenched phosphate glass to fully crystallized glass (glass-ceramics) by IS are analyzed. A change in the characteristic features of IS follows the changes in glass and crystallized glass network. Using IS, the contribution of glass matrix, crystallized grains and grain boundary to the total electrical conductivity for iron phosphate glasses was analyzed. It was shown that decrease in conductivity is caused by discontinuities in the conduction pathways as a result of the disruption of crystalline network where two or more crystalline phases are formed. Also, phosphate-based glasses offer a unique range of biomaterials, as they form direct chemical bonding with hard/soft tissue. The surface charges of bioactive glasses are recognized to be the most important factors in determining biological responses. The improved bioactivity of the bioactive glasses as a result of the effects of the surface charges generated by electrical polarization is discussed.

High-resolution angle-resolved photoemission investigation of potassium and phosphate tungsten bronzes

International Nuclear Information System (INIS)

Paul, Sanhita; Kumari, Spriha; Raj, Satyabrata

2016-01-01

Highlights: • Electronic structure of potassium and phosphate tungsten bronzes. • Origin of transport anomalies in bronzes. • Flat segments of Fermi surfaces are connected by a nesting vector, q. • Nesting driven charge-density wave is responsible for the anomalies. - Abstract: We have performed high-resolution angle-resolved photoemission spectroscopy (ARPES) and density functional ab initio theoretical calculation to study the electronic structure of potassium (K_0_._2_5WO_3) and phosphate (P_4W_1_2O_4_4) tungsten bronzes. We have experimentally determined the band dispersions and Fermi surface topology of these bronzes and compared with our theoretical calculations and a fair agreement has been seen between them. Our experimental as well as theoretical investigation elucidates the origin of transport anomalies in these bronzes. The Fermi surfaces of these bronzes consist of flat patches, which can be connected with each other by a constant nesting wave vector, q. The scattering wave vectors found from diffraction measurements match with these nesting vectors and the anomalies in the transport properties of these bronzes can be well explained by the evolution of charge-density wave with a partial nesting between the flat segments of the Fermi surfaces.

Different effects of copper (II), cadmium (II) and phosphate on the sorption of phenanthrene on the biomass of cyanobacteria.

Science.gov (United States)

Tao, Yuqiang; Li, Wei; Xue, Bin; Zhong, Jicheng; Yao, Shuchun; Wu, Qinglong

2013-10-15

Due to the large surface area and high organic carbon content of cyanobacteria, organic contaminants can be readily sorbed on cyanobacteria during algal blooms, and then be transferred to the food web. This process is likely to be affected by the coexisting metals and nutrients, however, the possible impacts remain unclear. Effects of Cu(2+), Cd(2+), and phosphate on the sorption of phenanthrene on cyanobacterial biomass collected from an algal bloom were therefore studied. Continuous decrease in phenanthrene sorption was observed in the presence of low concentrations of Cu(2+), and Cd(2+) (phosphate concentration. Phosphate blocked the binding sites, modified the cell morphology, and increased the negative charge as well as the hydrophilicity of the cyanobacterial surface, thereby suppressing phenanthrene sorption. This study indicates that sorption of aromatic organic compounds by cyanobacteria could be significantly alerted by concentrations and properties of the coexisting transition metals and phosphates, which may subsequently affect their transfer to the food web in eutrophic waters. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Evaluation of lead-iron-phosphate glass as a high-level waste form

International Nuclear Information System (INIS)

Chick, L.A.; Bunnell, L.R.; Strachan, D.M.; Kissinger, H.E.; Hodges, F.N.

1986-01-01

The lead-iron-phosphate nuclear waste glass developed at Oak Ridge National Laboratory (ORNL) was evaluated for its potential as an improvement over the current reference waste form, borosilicate glass. Vitreous lead-iron-phosphate glass appears to have substantially better chemical durability than borosilicate glass. However, severe crystallization leading to deteriorated chemical durability would result if this glass were poured into large canisters as is presently done with borosilicate glass. Cesium leach rates from this crystallized material are orders of magnitude greater than those from borosilicate glass. Therefore, in order to realize the performance advantages of the lead-iron-phosphate material in a nuclear waste form, it would be necessary to process it so that it is rapidly cooled, thus retaining its vitreous structure. 22 refs., 4 figs., 4 tabs

Fabrication of Phosphate Cement with High Integrity

International Nuclear Information System (INIS)

Yang, Jae Hwan; Lee, Chang Hwa; Heo, Cheol Min; Jeon, Min Ku; Kang, Kweon Ho

2011-01-01

As the development of industrial society has accelerated, hazardous wastes are generated as well. According to the 1986 statistics of U.S.A, each person made 40 tons of waste in America that year. Treatment of radioactive waste is one of the most important and serious problems related to waste treatments, because its radioactivity and decaying heat have harmful effects to human and environment for a long time. Nuclear developed countries have used conventional method of treatment such as vitrification or cementation in order to stabilize and solidify radioactive waste. Although the former guarantees the formation of high leaching resistant and durable waste form, it requires several hundred (or even more than one thousand) temperature to melt glass frit. This process generates secondary waste volatilized, as well as being non-economical. Cement technology played a role of immobilizing low and middle class wastes. It has advantages of low temperature setting, low cost, easy process, etc. The alkalinity of ordinary cement, however, constrains the utility of cement to the solidification of alkaline waste. In addition, leachability and mechanical strength of cements are not quite appropriate for the stabilization of high level waste. In this regard, chemically bonded phosphate cement(CBPC), which sets by an acid-base reaction, is a potentially expectable material for immobilization of radioactive waste. CBPC not only sets at room temperature, but also encapsulates various isotopes chemically. The performance of CBPC can be enhanced by the addition of fly ash, sand, wollastonite, etc. This study aims at fabricating the CBPC containing fly ash with high integrity. Morphology, microstructure, and compressive strength are evaluated using SEM, and digital compressing machine

Preparation and Characterization of Porous Calcium Phosphate Bioceramics

Institute of Scientific and Technical Information of China (English)

Honglian Dai; Xinyu Wang; Yinchao Han; Xin Jiang; Shipu Li

2011-01-01

β-tricalcium phosphate (β-TCP) powder and Na2O-CaO-MgO-P2O5 glass binder were synthesized and mixed, and then the biodegradable porous calcium phosphate ceramics were successfully prepared by foaming and sintering at 850℃. The as-prepared ceramics possess a high porosity with partial three-dimension interconnected macro- and micro-pores. As in vitro experiment testified, the calcium phosphate ceramics (CPCs) has good degradability.

Method of preparing highly active and thermostable preparations of liver uridin-kinase usable for enzymic synthesis of radioactive nucleoside-5'-phosphates

International Nuclear Information System (INIS)

Cihak, A.; Vesely, J.

1975-01-01

A method is described of preparing a high-activity uridine kinase for the enzymic synthesis of radioactive nucleoside-5m-phosphates of the pyrimidine series. The preparation is separated from male rat liver after intraperitoneal application of 5'-azacytidine. Examples are given showing detailed procedures for the conversion of uridine and 6-azauridine to the corresponding 5'-phosphates. (L.K.)

Mechanisms of postradiation transformations in alkaline-phosphate glasses activated by copper

International Nuclear Information System (INIS)

Vil'chinskaya, N.N.; Dmitryuk, A.V.; Ignat'ev, E.G.; Karapetyan, G.O.; Petrovskij, G.T.

1984-01-01

Lithium aluminophosphate glasses activated by copper served as the object under investigation. Copper content varied from 0 up to 0.13 mass.%. It is shown that pole redistribution among PO 4 2- and Cu(2) centers takes place in alkaline -phosphate glasses activated by Cu(1). This process prevails for copper content of above 0.1%. Therefore the possibility appears to evaluate the quantum yield of colour center formation

Mechanisms of postradiation transformations in alkaline-phosphate glasses activated by copper

Energy Technology Data Exchange (ETDEWEB)

Vil' chinskaya, N.N.; Dmitryuk, A.V.; Ignat' ev, E.G.; Karapetyan, G.O.; Petrovskij, G.T. (Gosudarstvennyj Opticheskij Inst., Leningrad (USSR))

1984-01-01

Lithium aluminophosphate glasses activated by copper served as the object under investigation. Copper content varied from 0 up to 0.13 mass.%. It is shown that pole redistribution among PO/sub 4//sup 2 -/ and Cu(2) centers takes place in alkaline -phosphate glasses activated by Cu(1). This process prevails for copper content of above 0.1%. Therefore the possibility appears to evaluate the quantum yield of colour center formation.

40 CFR 422.40 - Applicability; description of the defluorinated phosphate rock subcategory.

Science.gov (United States)

2010-07-01

... defluorinated phosphate rock subcategory. 422.40 Section 422.40 Protection of Environment ENVIRONMENTAL... Defluorinated Phosphate Rock Subcategory § 422.40 Applicability; description of the defluorinated phosphate rock... phosphate rock by application of high temperature treatment along with wet process phosphoric acid, silica...

Mixed zirconia calcium phosphate coatings for dental implants: Tailoring coating stability and bioactivity potential

International Nuclear Information System (INIS)

Pardun, Karoline; Treccani, Laura; Volkmann, Eike; Streckbein, Philipp; Heiss, Christian; Destri, Giovanni Li; Marletta, Giovanni; Rezwan, Kurosch

2015-01-01

Enhanced coating stability and adhesion are essential for long-term success of orthopedic and dental implants. In this study, the effect of coating composition on mechanical, physico-chemical and biological properties of coated zirconia specimens is investigated. Zirconia discs and dental screw implants are coated using the wet powder spraying (WPS) technique. The coatings are obtained by mixing yttria-stabilized zirconia (TZ) and hydroxyapatite (HA) in various ratios while a pure HA coating served as reference material. Scanning electron microscopy (SEM) and optical profilometer analysis confirm a similar coating morphology and roughness for all studied coatings, whereas the coating stability can be tailored with composition and is probed by insertion and dissections experiments in bovine bone with coated zirconia screw implants. An increasing content of calcium phosphate (CP) resulted in a decrease of mechanical and chemical stability, while the bioactivity increased in simulated body fluid (SBF). In vitro experiments with human osteoblast cells (HOB) revealed that the cells grew well on all samples but are affected by dissolution behavior of the studied coatings. This work demonstrates the overall good mechanical strength, the excellent interfacial bonding and the bioactivity potential of coatings with higher TZ contents, which provide a highly interesting coating for dental implants. - Highlights: • Different ratios of zirconia (TZ) and calcium phosphate (CP) were deposited on zirconia substrates. • Enhancement of TZ content in mixed coatings increased coating stability. • Enhancement of CP content in mixed coatings increased bioactivity. • All tested coating compositions were non-toxic

Mixed zirconia calcium phosphate coatings for dental implants: Tailoring coating stability and bioactivity potential

Energy Technology Data Exchange (ETDEWEB)

Pardun, Karoline [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Treccani, Laura, E-mail: treccani@uni-bremen.de [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Volkmann, Eike [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Streckbein, Philipp [University Hospital, Justus-Liebig-University Giessen, Department of Cranio-Maxillo-Facial Surgery, Klinikstrasse 33, 35385 Giessen (Germany); Heiss, Christian [University Hospital of Giessen-Marburg, Department of Trauma Surgery, Rudolf-Buchheim-Strasse 7, 35385 Giessen, Germany, (Germany); Laboratory of Experimental Surgery, Kerkraderstrasse 9, 35392 Giessen (Germany); Destri, Giovanni Li; Marletta, Giovanni [Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN), Department of Chemistry, University of Catania and CSGI, Viale A. Doria 6, 95125 Catania (Italy); Rezwan, Kurosch [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany)

2015-03-01

Enhanced coating stability and adhesion are essential for long-term success of orthopedic and dental implants. In this study, the effect of coating composition on mechanical, physico-chemical and biological properties of coated zirconia specimens is investigated. Zirconia discs and dental screw implants are coated using the wet powder spraying (WPS) technique. The coatings are obtained by mixing yttria-stabilized zirconia (TZ) and hydroxyapatite (HA) in various ratios while a pure HA coating served as reference material. Scanning electron microscopy (SEM) and optical profilometer analysis confirm a similar coating morphology and roughness for all studied coatings, whereas the coating stability can be tailored with composition and is probed by insertion and dissections experiments in bovine bone with coated zirconia screw implants. An increasing content of calcium phosphate (CP) resulted in a decrease of mechanical and chemical stability, while the bioactivity increased in simulated body fluid (SBF). In vitro experiments with human osteoblast cells (HOB) revealed that the cells grew well on all samples but are affected by dissolution behavior of the studied coatings. This work demonstrates the overall good mechanical strength, the excellent interfacial bonding and the bioactivity potential of coatings with higher TZ contents, which provide a highly interesting coating for dental implants. - Highlights: • Different ratios of zirconia (TZ) and calcium phosphate (CP) were deposited on zirconia substrates. • Enhancement of TZ content in mixed coatings increased coating stability. • Enhancement of CP content in mixed coatings increased bioactivity. • All tested coating compositions were non-toxic.

Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids.

Science.gov (United States)

Xu, Ren-kou; Zhu, Yong-guan; Chittleborough, David

2004-01-01

Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids. Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubilization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the pKa values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was notcorrelated with pKa. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.

Optimization of Liquid Medium for High Phosphate Solubilization by Serratia Marcescens Strain AGKT4

Directory of Open Access Journals (Sweden)

Mohd Yusoff Abd. Samad

2017-12-01

Full Text Available This study is on the optimization of the medium for solubilization of phosphate based on the Box-Behnken design and response surface methodology. Optimization of the liquid medium for phosphate solubilization using Serratia marcescens strain AGKT4 was carried out by varying the concentrations of 3 ingredients; the fructose, peptone and inoculum size of bacteria. A mathematical model derived from the response surface methodology was then validated statistically for the target test variables. The highest phosphate solubilization in the medium was achieved at the optimal concentrations of fructose and peptone at 6% (w/v and 0.6% (w/v, respectively. The maximum phosphate solubilization at these concentrations was 239.12 µg/mL. Under the same conditions, the bacterial growth in the medium was 9 log10 CFU.

Eu{sup 3+} emission in phosphate glasses with high UV transparency

Energy Technology Data Exchange (ETDEWEB)

Silva, G.H. [Laboratório de Espectroscopia de Materiais (LEM), Departamento de Física, Universidade Federal de Juiz de Fora, CEP 36036-900 Juiz de Fora, MG (Brazil); Anjos, V., E-mail: virgilio@fisica.ufjf.br [Laboratório de Espectroscopia de Materiais (LEM), Departamento de Física, Universidade Federal de Juiz de Fora, CEP 36036-900 Juiz de Fora, MG (Brazil); Bell, M.J.V. [Laboratório de Espectroscopia de Materiais (LEM), Departamento de Física, Universidade Federal de Juiz de Fora, CEP 36036-900 Juiz de Fora, MG (Brazil); Carmo, A.P. [Instituto Federal Fluminense-Campus Cabo Frio, CP 112015, CEP 28909-971 Cabo Frio, RJ (Brazil); Pinheiro, A.S.; Dantas, N.O. [Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia, CP 593, CEP 38400-902 Uberlândia, MG (Brazil)

2014-10-15

We report a study of the phosphate glass PZABP (P{sub 2}O{sub 5}–ZnO–Al{sub 2}O{sub 3}–BaO–PbO) doped with europium (Eu{sup 3+}) in different concentrations. Absorption, photoluminescence and time resolved photoluminescence were used to investigate the influence of increasing Eu{sup 3+} concentrations. The present glass exhibits Eu{sup 3+} absorption bands in the ultraviolet region (about 300 nm) due to the high transparency of the system compared to other phosphate glasses. In this way, it was possible to obtain the Judd–Ofelt parameters from the emission and absorption spectra. Moreover, a strong red emission attributed to the transition {sup 5}D{sub 0}→{sup 7}F{sub 2} of Eu{sup 3+} (611 nm) was observed. It was found that the radiative lifetime and the quantum efficiency of the Eu{sup 3+} level, {sup 5}D{sub 0}, do not suffer a significant change as the concentration of Eu{sup 3+} ions increases. - Highlights: • UV transparent glass matrix is used for Eu{sup 3+} doping. • Judd–Ofelt parameters from the emission and absorption spectra were obtained. • Red emission attributed to the transition {sup 5}D{sub 0}→{sup 7}F{sub 2} of Eu{sup 3+} (611 nm) was observed.

Thermochemical investigations on uranyl phosphates and arsenates

International Nuclear Information System (INIS)

Barten, H.

1986-01-01

Results are described of a study of the thermochemical stability of anhydrous phosphates and arsenates. The results of phase studies deal with compound formation and characterization, coexisting phases and limiting physical or chemical properties. The uranyl phosphates evolve oxygen at higher temperatures and the arsenates lose arsenic oxide vapour. These phenomena give the possibility to describe their thermodynamic stabilities. Thus oxygen pressures of uranyl phosphates have been measured using a static, non-isothermal method. Having made available the pure anhydrous compounds in the course of this investigation, molar thermodynamic quantities have been measured as well. These include standard enthalpies of formation from solution calorimetry and high-temperature heat-capacity functions derived from enthalpy increments measured. Some attention is given to compounds with uranium in valencies lower than six which have been met during the investigation. An evaluation is made of the thermodynamics of the compounds studied, to result in tabulized high-temperature thermodynamic functions. Relative stabilities within the systems are discussed and comparisons of the uranyl phosphates and the arsenates are made. (Auth.)

Structural and thermochemical properties of sodium magnesium phosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Oueslati Omrani, Refka [Université de Tunis El Manar, Faculté des Sciences de Tunis, Chemistry Department, LR01SE10 Applied Thermodynamics Laboratory, 2092 Tunis (Tunisia); Kaoutar, Abdeltif; El Jazouli, Abdelaziz [LCMS, URAC 17, Faculté des Sciences Ben M’Sik, UH2MC, Casablanca (Morocco); Krimi, Saida [LPCMI, Faculté des Sciences Aïn Chok, UH2C, Casablanca (Morocco); Khattech, Ismail, E-mail: ismail.khattech@fst.rnu.tn [Université de Tunis El Manar, Faculté des Sciences de Tunis, Chemistry Department, LR01SE10 Applied Thermodynamics Laboratory, 2092 Tunis (Tunisia); Jemal, Mohamed [Université de Tunis El Manar, Faculté des Sciences de Tunis, Chemistry Department, LR01SE10 Applied Thermodynamics Laboratory, 2092 Tunis (Tunisia); Videau, Jean-Jacques [ICMCB, Institut de Chimie de la matière condensée, Université de Bordeaux 1 (France); Couzi, Michel [Institut des Sciences Moléculaires, CNRS-Université de Bordeaux 1 (France)

2015-05-25

Highlights: • Phosphate glasses were prepared by met quenching technique. • Structural study is investigated using FTIR, Raman and {sup 31}PNMR spectroscopy. • A 4.5% weight of H{sub 3}PO{sub 4} solution has use for glass dissolution. • Dissolution is endothermic for lower MgO content and becomes exothermic when x rises. - Abstract: Ternary phosphate based glasses with the general formula (50−x/2)Na{sub 2}O–xMgO–(50−x/2)P{sub 2}O{sub 5} (0 ⩽ x ⩽ 42.8 mol%), where the O/P ratio was varied from 3 to 3.75, have been prepared using a conventional melt quenching technique. Samples were investigated by means of density measurements, Fourier-transformed infrared (FTIR), Raman and {sup 31}P solid state magic angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopies, differential scanning calorimetry (DSC), inductively coupled plasma atomic emission spectroscopy (ICP/AES) analysis and calorimetric dissolution. The depolymerization of metaphosphate chains are described by the decrease of Q{sup 2} tetrahedral sites allowing the formation of pyrophosphate groups (Q{sup 1}) revealed by spectroscopic investigations. As a result, the increase of density and glass transition temperature when x rises. Calorimetric study shows that the dissolution phenomenon is endothermic for a lower MgO content and becomes exothermic when magnesium oxide is gradually incorporated, suggesting the disruption of phosphate chains with increasing O/P ratio.

Analysis of di-calcic phosphate from the Erkimia plant in Flix, Catalonia (Spain)

International Nuclear Information System (INIS)

2006-01-01

As an investigation showed that solid wastes released in the Ebra River between 1978 and 1988 from the Erkimia factory displayed high natural radionuclides contents, this document reports analysis performed on the di-calcic phosphate produced by this factory (from Moroccan phosphorite). It indicates and comments the results obtained by gamma spectrometry for some radionuclides belonging to the U 238 and U 235 chains (uranium 238, thorium 230 and 234, radium 226, lead 210, Uranium 235). It comments the associated potential radiological risks, and gives some recommendations to limit these risks

Evaluation of growth of calcium phosphate ceramics on sintered Ti-Ca-P composites

Energy Technology Data Exchange (ETDEWEB)

Karanjai, Malobika [Centre for Nano Materials, International Advanced Research Centre for Powder Metallurgy and New Materials, Balapur P.O, Hyderabad - 500 005, Andhra Pradesh (India)], E-mail: malobika_k@rediffmail.com; Sundaresan, Ranganathan [Centre for Nano Materials, International Advanced Research Centre for Powder Metallurgy and New Materials, Balapur P.O, Hyderabad - 500 005, Andhra Pradesh (India); Mohan, Tallapragada Raja Rama; Kashyap, Bhagwati Prasad [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai - 400 076, Maharashtra (India)

2008-12-01

Sintered Ti-Ca-P composites having in situ formed calcium phosphate phases developed by powder metallurgy processing were soaked for 28 days in simulated body fluid (SBF) with a pH of 7.4 at 37 deg. C and evaluated for the growth of calcium phosphate ceramics onto its surface. The composites were taken out once every 7 days and characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) for evaluating the Ca-P growth. Based on the change in chemistry of the SBF and phase contents, a model has been proposed for mechanism of growth of calcium phosphate compounds on sintered Ti-Ca-P composites immersed in SBF.

Environmental implications of element emissions from phosphate-processing operations in southeastern Idaho

Science.gov (United States)

Severson, R.C.; Gough, L.P.

1979-01-01

In order to assess the contribution to plants and soils of certain elements emitted by phosphate processing, we sampled sagebrush, grasses, and A- and C-horizon soils along upwind and downwind transects at Pocatello and Soda Springs, Idaho. Analyses for 70 elements in plants showed that, statistically, the concentration of 7 environmentally important elements, cadmium, chromium, fluorine, selenium, uranium, vanadium, and zinc, were related to emissions from phosphate-processing operations. Two additional elements, lithium and nickel, show probable relationships. The literature on the effects of these elements on plant and animal health is briefly surveyed. Relations between element content in plants and distance from the phosphate-processing operations were stronger at Soda Springs than at Pocatello and, in general, stronger in sagebrush than in the grasses. Analyses for 58 elements in soils showed that, statistically, beryllium, fluorine, iron, lead, lithium, potassium, rubidium, thorium, and zinc were related to emissions only at Pocatello and only in the A horizon. Moreover, six additional elements, copper, mercury, nickel, titanium, uranium, and vanadium, probably are similarly related along the same transect. The approximate amounts of elements added to the soils by the emissions are estimated. In C-horizon soils, no statistically significant relations were observed between element concentrations and distance from the processing sites. At Soda Springs, the nonuniformity of soils at the sampling locations may have obscured the relationship between soil-element content and emissions from phosphate processing.

Control of morphology and surface wettability of anodic niobium oxide microcones formed in hot phosphate-glycerol electrolytes

International Nuclear Information System (INIS)

Yang, Shu; Habazaki, Hiroki; Fujii, Takashi; Aoki, Yoshitaka; Skeldon, Peter; Thompson, George E.

2011-01-01

Highlights: → Anodic niobium oxide microcones with nanofiber morphology are formed simply by anodizing. → The cone size and its tip angle are controlled by anodizing condition. → The surface shows extremely high contact angle for water after coating with a fluoroalkyl layer. - Abstract: We report the fabrication of superhydrophobic surfaces with a hierarchical morphology by self-organized anodizing process. Simply by anodizing of niobium metal in hot phosphate-glycerol electrolyte, niobium oxide microcones, consisting of highly branched oxide nanofibers, develop on the surface. The size of the microcones and their tip angles are controlled by changing the applied potential difference in anodizing and the water content in the electrolyte. Reduction of the water content increases the size of the microcones, with the nanofibers changing to nanoparticles. The size of microcones is also reduced by increasing the applied potential difference, without influencing the tip angle. The hierarchical oxide surfaces are superhydrophilic, with static contact angles close to 0 o . Coating of the anodic oxide films with a monolayer of fluoroalkyl phosphate makes the surfaces superhydrophobic with a contact angle for water as high as 175 o and a very small contact angle hysteresis of only 2 o . The present results indicate that the larger microcones with smaller tip angles show the higher contact angle for water.

Mechanical behaviour of degradable phosphate glass fibres and composites-a review.

Science.gov (United States)

Colquhoun, R; Tanner, K E

2015-12-23

Biodegradable materials are potentially an advantageous alternative to the traditional metallic fracture fixation devices used in the reconstruction of bone tissue defects. This is due to the occurrence of stress shielding in the surrounding bone tissue that arises from the absence of mechanical stimulus to the regenerating bone due to the mismatch between the elastic modulus of bone and the metal implant. However although degradable polymers may alleviate such issues, these inert materials possess insufficient mechanical properties to be considered as a suitable alternative to current metallic devices at sites of sufficient mechanical loading. Phosphate based glasses are an advantageous group of materials for tissue regenerative applications due to their ability to completely degrade in vivo at highly controllable rates based on the specific glass composition. Furthermore the release of the glass's constituent ions can evoke a therapeutic stimulus in vivo (i.e. osteoinduction) whilst also generating a bioactive response. The processing of these materials into fibres subsequently allows them to act as reinforcing agents in degradable polymers to simultaneously increase its mechanical properties and enhance its in vivo response. However despite the various review articles relating to the compositional influences of different phosphate glass systems, there has been limited work summarising the mechanical properties of different phosphate based glass fibres and their subsequent incorporation as a reinforcing agent in degradable composite materials. As a result, this review article examines the compositional influences behind the development of different phosphate based glass fibre compositions intended as composite reinforcing agents along with an analysis of different potential composite configurations. This includes variations in the fibre content, matrix material and fibre architecture as well as other novel composites designs.

Meningococcal X polysaccharide quantification by high-performance anion-exchange chromatography using synthetic N-acetylglucosamine-4-phosphate as standard.

Science.gov (United States)

Micoli, F; Adamo, R; Proietti, D; Gavini, M; Romano, M R; MacLennan, C A; Costantino, P; Berti, F

2013-11-15

A method for meningococcal X (MenX) polysaccharide quantification by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) is described. The polysaccharide is hydrolyzed by strong acidic treatment, and the peak of glucosamine-4-phosphate (4P-GlcN) is detected and measured after chromatography. In the selected conditions of hydrolysis, 4P-GlcN is the prevalent species formed, with GlcN detected for less than 5% in moles. As standard for the analysis, the monomeric unit of MenX polysaccharide, N-acetylglucosamine-4-phosphate (4P-GlcNAc), was used. This method for MenX quantification is highly selective and sensitive, and it constitutes an important analytical tool for the development of a conjugate vaccine against MenX. Copyright © 2013 Elsevier Inc. All rights reserved.

Evaluating agronomic effectiveness of phosphate rocks using nuclear and related techniques: Results from an FAO/IAEA co-ordinated research project

International Nuclear Information System (INIS)

Zapata, F.

2000-01-01

An FAO/IAEA Co-ordinated Research Project, 'The use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphatic fertilisers, in particular rock phosphates', was in operation during the period 1993-98. The research network comprised twenty-three scientists, of whom seventeen were in developing countries, with six in industrialized nations. Conventional and 32 P-isotope techniques were utilized to assess the bioavailability of P in soils amended with phosphate rock (PR) and water-soluble fertilisers, and to evaluate the agronomic effectiveness of PR products. No single chemical extraction method was found to be suitable for all soils and fertilisers. The Pi strip method showed promising results, but more testing is needed with tropical acid soils. The 32 P-phosphate-exchange kinetics method allowed a complete characterization of P dynamics, and provided basic information for estimating the kinetic pools of soil P. The agronomic effectiveness (AE) of PRs depends on their solubility (reactivity), which is related to the degree of carbonate substitution for phosphate in the apatite structure. Rock phosphates of low reactivity were unsuitable for direct application to annual crops. Research in Venezuela, China, Cuba, Brazil, and Thailand demonstrated that AE can be increased by partial acidulation, or by mixing with organic materials or a water-soluble source. The AE can be enhanced also through inoculation with mycorrhizal fungi and rhizobacteria. The AE, which depends on species, is particularly high in crops such as canola and lupin that exude organic acids from the roots. Agronomic effectiveness of PR is higher on soils with low pH, low available P, low exchangeable Ca, high cation exchange capacity and high organic-matter content. The 32 P-techniques are powerful tools for studying the factors that affect AE. Information from field trials was used to create a database for validating a model for providing recommendations for PR

Prevention of radioactive contamination in the manufacture of phosphate fertilizers

International Nuclear Information System (INIS)

Romero G, E.T.

1995-01-01

In this work was studied the separation of uranium from the phosphate rock to decrease the level of radioactivity in the phosphate fertilizers, this prevents the redistribution of uranium in the environment. The uranium leaching conditions from phosphate rock were estimated using alkaline solutions. The changes in the natural phosphate rock after leaching were studied. The amenability to separate the uranium from phosphate rock with ammonium carbonate / bicarbonate solution was determined. The uranium extraction was approximately 40%. The leaching conditions showed high selectivity for uranium without changes in the ore structure. The bulk ore was not dissolved. (Author)

Metabolism of 32P-phosphate in guinea pig cerebrum and cerebellum in experimental allergic encephalomyelitis

International Nuclear Information System (INIS)

Mezes, V.; Bukovsky, V.; Drgova, A.; Mezesova, V.

1984-01-01

The metabolism of intraventricularly administered 32 P-phosphate in the cerebral and cerebellar tissue of guinea pigs was analyzed in the acute state of experimental allergic encephalomyelitis. One and six hours following administration of 32 P-phosphate into the right lateral ventricle of the brain no differences were found in the specific activity of phosphates of the acid-soluble fraction of the brain tissue in the compared series of guinea pigs. The cerebellar tissue in experimental allergic encephalomyelitis displayed the specific activity of the total phosphorus of the acid-soluble fraction reduced by 27% one hour after administration and by 37% after six hours, and the specific activity of inorganic phosphates was reduced by 40% and by 45%, respectively. Experimental allergic encephalomyelitis does not affect the content of total phosphorus in the acid-soluble fraction and in the fraction of inorganic phosphates in the cerebrum and cerebellum of guinea pigs. (author)

Lack of awareness among future medical professionals about the risk of consuming hidden phosphate-containing processed food and drinks.

Directory of Open Access Journals (Sweden)

Yoshiko Shutto

Full Text Available Phosphate toxicity is an important determinant of mortality in patients with chronic kidney disease (CKD, particularly those undergoing hemodialysis treatments. CKD patients are advised to take a low phosphate-containing diet, and are additionally prescribed with phosphate-lowering drugs. Since these patients usually seek guidance from their physicians and nurses for their dietary options, we conducted a survey to determine the levels of awareness regarding the high phosphate content in commercially processed food and drinks among medical and nursing students at the Hirosaki University School of Medicine in Japan. For this survey, 190 medical and nursing students (average age 21.7±3 years were randomly selected, and provided with a list of questions aimed at evaluating their awareness of food and drinks containing artificially added phosphate ingredients. While 98.9% of these students were aware of the presence of sugar in commercially available soda drinks, only 6.9% were aware of the presence of phosphate (phosphoric acid. Similarly, only 11.6% of these students were aware of the presence of phosphate in commercially processed food, such as hamburgers and pizza. Moreover, around two thirds of the surveyed students (67.7% were unaware of the harmful effects of unrestricted consumption of phosphate-containing food and drinks. About 28% of the surveyed students consume such "fast food" once a week, while 40% drink at least 1∼5 cans of soda drinks/week. After realizing the potential long-term risks of consuming excessive phosphate-containing food and drinks, 40.5% of the survey participants considered reducing their phosphate intake by minimizing the consumption of commercially processed "fast food" items and soda drinks. Moreover, another 48.4% of students showed interest in obtaining more information on the negative health effects of consuming excessive amounts of phosphate. This survey emphasizes the need for educational initiative to raise

Structural and electrical properties of iron molybdenum phosphate glasses

International Nuclear Information System (INIS)

De Oliveira, R.S.; Quixada-Ceara, Univ. Estadual do Ceara; De Paiva, J.A.C.; De Araujo, M.A.B.; Sombra, A. S.B.

1998-01-01

iron molybdenum phosphate glasses (xMoO 3 ·(0.6 - x)P 2 O 5 ·0.4Li 2 O) : yFe 2 O 2 with 0≤x≤ 0.6 and y = 0.03 (mol%) prepared in ambient atmosphere using the melt quenching technique were studied by using DC electrical conductivity, 57 Fe Moessbauer and infrared spectroscopies. The Dc conductivity depends on the MoO 3 concentration x. It was observed that, with increasing x, the ratio Fe 2+ /(Fe 3+ + Fe 2+ ) and the Dc conductivity increase. Infrared spectroscopy and X-ray powder diffraction indicate that a Li 2 MoO 4 crystalline phase is present for high MoO 3 content samples (x = 0.5, 0.6)

Uranium recovery from phosphate fertilizer in the form of a high purity compound

International Nuclear Information System (INIS)

Bunus, F.; Coroianu, T.; Filip, G.; Filip, D.

2001-01-01

Uranium recovery from phosphate fertilizer industry is based on a one cycle extraction-stripping process. The process was experimented on both sulfuric and nitric acid attack of phosphate rock when uranium is dissolved in phosphoric acid (WPA) or phosphonitric (PN) solution respectively. The WPA and PN solution must be clarified. In the first alternative by ageing and settling and in the second by settling in the presence of flocculant. The organic components must be removed on active carbon for WPA only since in the case of nitric attack calcined phosphates are used. In both alternatives uranium is extracted from aqueous acidic solutions in the same time with the rare earths (REE), by di(2-ethylhexyl) phosphate (DEPA) as basic extractants, eventually in the presence of octylphosphine oxide (TOPO) as synergic agent. The stripping process is carried out in two stages: in the first stage REE are stripped and precipitated by HF or NH 4 F + H 2 S0 4 and in the second stage uranium as U(VI) is stripped by the same reagents but in the presence of Fe(II) as reductant for U(VI) to U(IV) inextractible species. Tetravalent uranium is also precipitated as green cake either UF 4 xH 2 0 or (NH 4 ) 7 U 6 F 31 as dependent on reagents HF or NH 4 F + H 2 S0 4 . Uranium stripping is possible for PN solution only if HNO 3 partially extracted is previously washed out by a urea solution. The green cake washed and filtered is dissolved in nitric acid in presence of Al(OH)3 as complexant for F. The filtered nitric solution is adjusted to 3-5 mol/L HNO 3 and extracted by 20% TBP when uranium is transferred to the organic phase which after scrubbing is stripped in the classic way with acidulated (HN0 3 ) demineralized water. Uranium is precipitated as diuranate of high purity. Rare earths left in the aqueous raffinate are extracted by pure TBP from 8-10 mol/L HNO 3 medium. The stripping process takes place with acidulated water. Rare earths are precipitated as hydroxides. (author)

Phosphate Recovery From Sewage Sludge Containing Iron Phosphate

NARCIS (Netherlands)

Wilfert, P.K.

2018-01-01

The scope of this thesis was to lay the basis for a phosphate recovery technology that can be applied on sewage sludge containing iron phosphate. Such a technology should come with minimal changes to the existing sludge treatment configuration while keeping the use of chemicals or energy as small as

Synthesis and Characterization of Metal Phosphates for Photocatalytic Applications

KAUST Repository

Al-Sabban, Bedour

2012-07-01

Solar energy is the most abundant efficient and important source of renewable energy. The objective of this study is to develop highly efficient visible light responsive photocatalysts for overall water splitting. This is done by using silver or copper containing materials. Phosphate compounds have caught much attention due to their rigid structure, thermal stability and resistance to chemical attacks. Solid phosphates can be prepared by direct solid-state reaction between metal cations and phosphate anions at high temperatures. Double metal phosphates of the Nasion-type structure had shown further technological importance. It has been reported that well-crystallized double metal phosphate particles have excellent ordering and cationic conduction channels in the Nasicon framework. In this study, several Nasion-type structured materials have been synthesized by solid-state method (e.g. CuTi2(PO4)3 and AgTi2(PO4)3) heated up under different temperatures (400–1100C) in N2 or air atmosphere. These materials were characterized by XRD, SEM, DR-UV-Vis spectroscopy and tested for photocatalytic applications. A new method for direct synthesis of photoelectrode on Ti Plate had been demonstrated. Further investigations on controlling the size and morphology for better performance of single and double metal phosphates will be done.

Concentration and distribution of elements in plants and soils near phosphate processing factories, Pocatello, Idaho

International Nuclear Information System (INIS)

Severson, R.C.; Gough, L.P.

1976-01-01

The processing of phosphatic shale near Pocatello, Idaho has a direct influence on the element content of local vegetation and soil. Samples of big sagebrush (Artemisia tridentata Nutt. subsp. tridentata) and cheatgrass (Bromus tectorum L.) show important negative relations between the concentration of certain elements (Cd, Cr, F, Ni, P, Se, U, V, and Zn) and distance from phosphate processing factories. Plant tissues within 3 km of the processing factories contain unusually high amounts of these elements except Ni and Se. Important negative relations with distance were also found for certain elements (Be, F, Fe, K, Li, Pb, Rb, Th, and Zn) in A-horizon soil. Amounts of seven elements (Be, F, Li, Pb, Rb, Th, and Zn) being contributed to the upper 5 cm of the soil by phosphate processing, as well as two additional elements (U and V) suspected as being contributed to soil, were estimated, with F showing the greatest increase (about 300 kg/ha) added to soils as far as 4 km downwind from the factories. The greatest number of important relations for both plants and soils was found downwind (northeast) of the processing factories

U.S. phosphate industry as a source of U3O8 to the year 2000

International Nuclear Information System (INIS)

Borg, I.Y.

1976-01-01

U 3 O 8 recovered as a by-product of the phosphate fertilizer industry may equal 3600-5200 tons by 1985 and represent 7-10 percent of the anticipated annual U.S. demand. If the enormous U.S. phosphate reserves and resources are mined primarily for their uranium content they appear sufficient to fill more than twice the projected cumulative U.S. demand to the year 2000

Ultrasonic and Thermal Properties of Borate and Phosphate Glasses Containing Bismuth and Lead

International Nuclear Information System (INIS)

Aziz, Sidek Hj. Abd.; Ahmad, Hamezan; Wahab, Zaidan A.; Sulaiman, Zainal Abidin; Talib, Zainal Abidin; Shaari, A. Halim; Senin, H. B.

2007-01-01

Systematic series of (B2O3,P2O5)-Bi2O3-PbO glasses have been successfully prepared by using the rapid quenching technique in which each oxide content changes for every series on the basis of its weight percentage. Their amorphous natures were confirmed earlier by the x-ray diffraction technique. The experimental results show that the density of both glasses, determined by using the Archimedes principle, increases with the glass modifier content. This is due to the replacement of Bi2O3 and PbO in the borate and phosphate glassy networks. The molar volume for borate glass increases with the addition of bismuth and lead oxides, but a reverse trend occurs for the phosphate glass. The longitudinal and shear ultrasound velocities, determined by the MBS 8000 system, of both lead bismuth borate and phosphate glasses show a decreasing trend as more PbO and Bi2O3 are added to the glass system. The increase in PbO/Bi2O3 content was probably related to the progressive increase in the concentration of non-bridging oxygen (NBOs). Thermal studies of the glass, using the Labsys DTA-Setaram machine, show that the value of the glass transition temperature (Tg) is closely related to the chemical bond in the system. In lead bismuth borate glasses, the addition of more Pb2+ and Bi3+ results in a more dominant ionic bond character in the system and hence decreases Tg of the sample. However, in lead bismuth phosphate glasses, the addition of Pb2+ and Bi3+ not only failed to weaken the covalent character in P-O-P bonds, but strengthened it further, leading to an increment in the values of Tg

The Effect On the Bones of Condensed Phosphate When Used as Food Additives : Its Importance in Relation to Preventive Medicine

OpenAIRE

Miyako, OMOTO; Tsunehiko, IMAI; Kumiko, SEKI; Ryoji, NOMURA; Yumi, OTAHARA; Department of Environmental and Occupational Health, Toho University, School of Medicine; Department of Environmental and Occupational Health, Toho University, School of Medicine; Department of Environmental and Occupational Health, Toho University, School of Medicine; Department of Environmental and Occupational Health, Toho University, School of Medicine; Department of Environmental and Occupational Health, Toho University, School of Medicine

1997-01-01

Based on the fact that chemical products such as binding agents are produced by mixing three kinds of phosphates with different ratios, we mixed metaphosphate, polyphosphate and pyrophosphate. Each was made to Na-phosphate, K-phosphate, and Ca-phosphate and each was mixed with commercial feeds so that the content of P would be approximately 0.1, 0.15, 0.3, 0.4, 0.6 and 1.0%. The prepared pellets were given to ICR, CF # 1 and AKR strains of mice at 29 days of age for 680 days and observations ...

Structure and properties of gadolinium loaded calcium phosphate glasses

International Nuclear Information System (INIS)

Wang, Cuiling; Liang, Xiaofeng; Li, Haijian; Yu, Huijun; Li, Zhen; Yang, Shiyuan

2014-01-01

The glass samples with composition xGd 2 O 3 –(50 − x)CaO–50P 2 O 5 (0 ⩽ x ⩽ 9 mol%) were prepared by the conventional melt quench method. The structure and properties of gadolinium loaded in calcium phosphate glasses were investigated using XRD, SEM, DTA, IR and Raman spectroscopy. The XRD and SEM analysis for the samples show that the majority of samples are amorphous, and crystallization occurs when the content of Gd 2 O 3 containing is up to 6 mol%. Two main crystalline phases, Ca 2 P 2 O 7 and Gd 3 (P 2 O 7 ) 3 , are embedded in an amorphous matrix. IR and Raman data indicate that glass structure consists of predominantly metaphosphate (Q 2 ) units and the depolymerization of phosphate network with the addition of Gd 2 O 3 . Both the chemical durability and the glass transition temperature (T g ) are improved with the increase of Gd 2 O 3 , which suggests that the Gd acts a role of strengthening the cross-links between the phosphate chains of the glass

Phosphate Framework Electrode Materials for Sodium Ion Batteries.

Science.gov (United States)

Fang, Yongjin; Zhang, Jiexin; Xiao, Lifen; Ai, Xinping; Cao, Yuliang; Yang, Hanxi

2017-05-01

Sodium ion batteries (SIBs) have been considered as a promising alternative for the next generation of electric storage systems due to their similar electrochemistry to Li-ion batteries and the low cost of sodium resources. Exploring appropriate electrode materials with decent electrochemical performance is the key issue for development of sodium ion batteries. Due to the high structural stability, facile reaction mechanism and rich structural diversity, phosphate framework materials have attracted increasing attention as promising electrode materials for sodium ion batteries. Herein, we review the latest advances and progresses in the exploration of phosphate framework materials especially related to single-phosphates, pyrophosphates and mixed-phosphates. We provide the detailed and comprehensive understanding of structure-composition-performance relationship of materials and try to show the advantages and disadvantages of the materials for use in SIBs. In addition, some new perspectives about phosphate framework materials for SIBs are also discussed. Phosphate framework materials will be a competitive and attractive choice for use as electrodes in the next-generation of energy storage devices.

Comparisons Study of Phosphate Removal in Unaerated and Aerated High Calcium Steel Slag Filter System of Different pH Feed

Directory of Open Access Journals (Sweden)

Ahmad Siti Zu Nurain

2017-01-01

Full Text Available Excess phosphorus in water body will lead to eutrophication. This study investigated the phosphate removal efficiencies of unaerated and aerated filter systems using high composition of Calcium (Ca steel slag as the filter media at different pH values of the wastewater influents. Lab-scale filters were developed using 25 mg/L synthetic wastewater and weekly sampling was done to monitor the phosphate removal efficiencies together with the concentration of metals (Calcium (Ca and Magnesium (Mg. The results show that both unaerated and aerated systems have excellent phosphate removal efficiency at all acidic, neutral and alkaline pH feed, though unaerated systems removed slightly better compared to aerated systems; 76-98% and 69-97% respectively. The dominant phosphate removal mechanism for aerated systems was adsorption, meanwhilefor unaerated systems; both adsorption and precipitation for acidic and neutral pH, whileprecipitation was more dominant at basic pH. The performance of unaerated systems are slightly better compared to aerated systems, however, aerated systems are recommended to be applied when simultaneous removal of nutrients (phosphorus and nitrogen are concerned.

Novel routes in flame retardancy of bisphenol A polycarbonate/impact modifier/aryl phosphate blends

Energy Technology Data Exchange (ETDEWEB)

Wawrzyn, Eliza

2013-07-01

The massive use of electronic engineering products accompanied by high demands on fire safety has led to increasing interest in environmentally friendly flame retardancy of bisphenol A polycarbonate (PC) based materials. In this work, novel routes for enhancing the flame retardancy of PC/Impact Modifier/Aryl phosphate were studied with respect to pyrolysis (TG, TG-FTIR, ATR-FTIR, NMR), flammability (LOI and UL 94) and fire behavior (cone calorimeter at different irradiations). To improve charring of PC/ABS{sub PTFE}+Aryl phosphate, the exchange of bisphenol A bis(diphenyl phosphate) (BDP) with novel aryl phosphates was proposed. Two novel flame retardants were synthesized: 3,3,5-trimethylcyclohexylbisphenol-bis(diphenyl phosphate) (TMC-BDP) and bisphenol A-bis(diethylphosphate) (BEP). TMC-BDP was more stable than BDP, thus gave a potential to increase the chemical reactions between the components of the PC/ABS{sub PTFE}+Aryl phosphate, whereas more reactive BEP was expected to increase the cross linking activity with the polymer matrix. Nevertheless, the corresponding blends did not enhance the flame retardancy compared to PC/ABS{sub PTFE}+BDP. BEP in PC/ABS{sub PTFE} preferred to cross-link with itself instead of with PC, thus it showed poor fire protection performance. TMC-BDP gave as good results as BDP in PC/ABS PTFE material. The results delivered evidence that BDP possesses a high degree of optimization in PC/ABS{sub PTFE} system. To provide a novel impact modifier improving not only mechanical properties but also the fire retardancy of PC/BDP material, the replacement of highly flammable acrylonitrile-butadiene-styrene (ABS) with silicon acrylate rubber (SiR) with high content of polydimethylsiloxane (PDMS) was studied. In PC/SiR{sub PTFE}/BDP the replacement of ABS is beneficial, but PDMS worsened the BDP gas phase and condensed phase action. PDMS reacted also with PC during combustion. PDMS-PC and PDMS-BDP interactions led to silicon dioxide. In fact, the

Magnesium-phosphate-glass cements with ceramic-type properties

Science.gov (United States)

Sugama, T.; Kukacka, L.E.

1982-09-23

Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate, exhibits rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

Magnesium phosphate glass cements with ceramic-type properties

Science.gov (United States)

Sugama, Toshifumi; Kukacka, Lawrence E.

1984-03-13

Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate exhibiting rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

A Phosphate Starvation-Inducible Ribonuclease of Bacillus licheniformis.

Science.gov (United States)

Nguyen, Thanh Trung; Nguyen, Minh Hung; Nguyen, Huy Thuan; Nguyen, Hoang Anh; Le, Thi Hoi; Schweder, Thomas; Jürgen, Britta

2016-08-28

The BLi03719 protein of Bacillus licheniformis DSM13 belongs to the most abundant extracellular proteins under phosphate starvation conditions. In this study, the function of this phosphate starvation inducible protein was determined. An amino-acid sequence analysis of the BLi03719-encoding gene showed a high similarity with genes encoding the barnase of Bacillus amyloliquefaciens FZB42 and binase-like RNase of Bacillus pumilus SARF-032. The comparison of the control strain and a BLi03719-deficient strain revealed a strongly reduced extracellular ribonuclease activity of the mutant. Furthermore, this knockout mutant exhibited delayed growth with yeast RNA as an alternative phosphate and carbon source. These results suggest that BLi03719 is an extracellular ribonuclease expressed in B. licheniformis under phosphate starvation conditions. Finally, a BLi03719 mutant showed an advantageous effect on the overexpression of the heterologous amyE gene under phosphate-limited growth conditions.

Effect of Biofertilizers on Macro and Micro Nutrients Uptake and Essential Oil Content in Dracocephalum moldavica L.

OpenAIRE

S Rahimzadeh; Y Sohrabi; Gh.R Heidari; A.R Eivazi; S.M.T Hoseini

2013-01-01

In order to investigation the effect of different fertilization treatments on nutrient and essential oil contents in dragonhead drug (Dracocephalum moldavica L.), an experiment was conducted in the station of agricultural research in Urmia on 2008. Treatments (nitroxin, barvar phosphate biofertilizer, biosulfur, nitroxin+ barvar phosphate biofertilizer, barvar phosphate biofertilizer + biosulfur, nitroxin+ biosulfur, nitroxin+ barvar phosphate biofertilizer + biosulfur, chemical fertilizer, c...

Ferric oxide quantum dots in stable phosphate glass system and their magneto-optical study

Energy Technology Data Exchange (ETDEWEB)

Garaje, Sunil N.; Apte, Sanjay K. [Nanocomposite Group, Centre for Materials for Electronics Technology (C-MET), Department of Electronics and Information Technology (DeitY), Government of India, Panchawati, Off Pashan Road, Pune 411008 (India); Kumar, Ganpathy [Department of Electrical and Computer Engineering, Tennessee Technological University, 1 William L. Jones Drive, Cookeville, TN 38505 (United States); Panmand, Rajendra P.; Naik, Sonali D. [Nanocomposite Group, Centre for Materials for Electronics Technology (C-MET), Department of Electronics and Information Technology (DeitY), Government of India, Panchawati, Off Pashan Road, Pune 411008 (India); Mahajan, Satish M., E-mail: smahajan@tntech.edu [Department of Electrical and Computer Engineering, Tennessee Technological University, 1 William L. Jones Drive, Cookeville, TN 38505 (United States); Chand, Ramesh [Ministry of Communications and Information Technology, Department of Electronics and Information Technology (DeitY), Electronics Niketan, 6, CGO Complex, New Delhi 110003 (India); Kale, Bharat B., E-mail: bbkale@cmet.gov.in [Nanocomposite Group, Centre for Materials for Electronics Technology (C-MET), Department of Electronics and Information Technology (DeitY), Government of India, Panchawati, Off Pashan Road, Pune 411008 (India)

2013-02-15

Graphical abstract: We report synthesis of ferric oxide embedded low melting phosphate glass nanocomposite and also the effect of ferric oxide nanoparticles (NCs) content on the optical and magneto-optical properties of the glasses. Faraday rotation of the glass nanocomposites was measured and showed variation in Verdet constant with concentration of ferric oxide. Interestingly, the host glass itself showed fairly good Verdet constant (11.5°/T cm) and there is a threefold enhancement in the Verdet constant of ferric oxide quantum dot-glass nanocomposite. Highlights: ► We synthesize ferric oxide embedded low melting stable phosphate glass nanocomposite. ► Glasses doped with 0.25 and 2% ferric oxide show particle size in the range of 4–12 nm. ► The host phosphate glass itself shows fairly good Verdet constant (11.5°/T cm). ► Glasses doped with 0.25% ferric oxide show high Verdet constant (30.525°/T cm). ► The as synthesis glasses may have potential application in magneto optical devices. -- Abstract: Herein, we report the synthesis of ferric oxide embedded low melting phosphate glass nanocomposite and also the effect of ferric oxide nanoparticles content on the optical and magneto-optical properties of the glasses. The optical study clearly showed red shift in optical cut off with increasing ferric oxide concentration. The band gap of the host glass was observed to be 3.48 eV and it shifted to 3.14 eV after doping with ferric oxide. The glasses doped with 0.25 and 2% ferric oxide showed particle size of 4–6 nm and 8–12 nm, respectively. Faraday rotation of the glass nanocomposites was measured and showed variation in the Verdet constant as per increasing concentration of ferric oxide. Interestingly, the host glass itself showed fairly good Verdet constant (11.5°/T cm) and threefold enhancement was observed in the Verdet constant of ferric oxide quantum dot-glass nanocomposite.

Decontamination of liquid radioactive waste by thorium phosphate

International Nuclear Information System (INIS)

Rousselle, J.; Grandjean, S.; Dacheux, N.; Genet, M.

2004-01-01

In the field of the complete reexamination of the chemistry of thorium phosphate and of the improvement of the homogeneity of Thorium Phosphate Diphosphate (TPD, Th 4 (PO 4 ) 4 P 2 O 7 ) prepared at high temperature, several crystallized compounds were prepared as initial powdered precursors. Due to the very low solubility products associated to these phases, their use in the field of the efficient decontamination of high-level radioactive liquid waste containing actinides (An) was carefully considered. Two main processes (called 'oxalate' and 'hydrothermal' chemical routes) were developed through a new concept combining the decontamination of liquid waste and the immobilization of the actinides in a ceramic matrix (TPD). In phosphoric media ('hydrothermal route'), the key-precursor was the Thorium Phosphate Hydrogen Phosphate hydrate (Th 2 (PO 4 ) 2 (HPO 4 ). H 2 O, TPHP, solubility product log(K S,0 0 ) ∼ - 67). The replacement of thorium by other tetravalent actinides (U, Np, Pu) in the structure, leading to the preparation of Th 2-x/2 An x/2 (PO 4 ) 2 (HPO 4 ). H 2 O solid solutions, was examined. A second method was also considered in parallel to illustrate this concept using the more well-known precipitation of oxalate as the initial decontamination step. For this method, the final transformation to single phase TPD containing actinides was purchased by heating a mixture of phosphate ions with the oxalate precipitate at high temperature. (authors)

Phosphate-a poison for humans?

Science.gov (United States)

Komaba, Hirotaka; Fukagawa, Masafumi

2016-10-01

Maintenance of phosphate balance is essential for life, and mammals have developed a sophisticated system to regulate phosphate homeostasis over the course of evolution. However, due to the dependence of phosphate elimination on the kidney, humans with decreased kidney function are likely to be in a positive phosphate balance. Phosphate excess has been well recognized as a critical factor in the pathogenesis of mineral and bone disorders associated with chronic kidney disease, but recent investigations have also uncovered toxic effects of phosphate on the cardiovascular system and the aging process. Compelling evidence also suggests that increased fibroblastic growth factor 23 and parathyroid hormone levels in response to a positive phosphate balance contribute to adverse clinical outcomes. These insights support the current practice of managing serum phosphate in patients with advanced chronic kidney disease, although definitive evidence of these effects is lacking. Given the potential toxicity of excess phosphate, the general population may also be viewed as a target for phosphate management. However, the widespread implementation of dietary phosphate intervention in the general population may not be warranted due to the limited impact of increased phosphate intake on mineral metabolism and clinical outcomes. Nonetheless, the increasing incidence of kidney disease or injury in our aging society emphasizes the potential importance of this issue. Further work is needed to more completely characterize phosphate toxicity and to establish the optimal therapeutic strategy for managing phosphate in patients with chronic kidney disease and in the general population. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

In situ synchrotron X-ray powder diffraction study of the early hydration of α-tricalcium phosphate/tricalcium silicate composite bone cement

Energy Technology Data Exchange (ETDEWEB)

Morejon-Alonso, Loreley; Correa, Jose Raul, E-mail: lmorejon@fq.uh.cu [Departamento de Quimica General, Facultad de Quimica, Universidad de La Habana, UH (Cuba); Motisuke, Mariana [Universidade Federal de Sao Paulo (UNIFESP), Sao Jose dos Campos, SP (Brazil); Carrodeguas, Raul Garcia [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Laboratorio de Avaliacao e Desenvolvimento de Biomateriais do Nordeste; Santos, Luis Alberto dos [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Escola de Engenharia. Departamento de Materiais

2015-01-15

Bioactivity, osteogenicity and mechanical properties of α-tricalcium phosphate (α-TCP) based phosphates cements can be improved by adding tricalcium silicate (C{sub 3}S); however, the addition of C{sub 3}S delays the precipitation and growth of calcium deficient hydroxyapatite (CDHA). Thus, the aim of this work was the study of in situ setting reaction of α-TCP/C{sub 3}S composite bone cement under high energy X-ray generated by a synchrotron source within the first 72h. The results showed that the addition of C{sub 3}S induces the precipitation of nanosized CDHA at early times depending on the added content. Calculated crystallite sizes showed that the higher the content of C{sub 3}S, the smaller the crystal size at the beginning of the precipitation. These results are different from those obtained by conventional XRD method, suggesting that the proposed technique is a powerful tool in determining the composition and extent of reaction of CPCs surfaces in real time. (author)

Uranium extraction from Uro area phosphate ore, Nuba mountains, Sudan

International Nuclear Information System (INIS)

Mohammed, A. A.; Eltayeb, M. A. H.

2003-01-01

This study was carried out mainly to extract uranium from Uro area phosphate ore in the eastern part of Nuba mountains near Abu Gibiha town in southern Kurdufan state. For this purpose first, the phosphate ore samples were decomposed with sulphuric acid. the resulting phosphoric acid was filtered off, and pretreated with pyrite and activated charcoal. the chemical analysis of the obtained grain phosphoric acid showed that about 98% of uranium content of the phosphate ore was rendered soluble in the phosphoric acid. The clear green phosphoric acid was introduced to uranium extraction by 25% tributylphosphate (Tbp) in kerosene. The effect of several factors on the extraction and stripping processes namely, interference's effect, the suitable strip solution, the required number of extraction and stripping stages, the optimum phase ratio have been studied in details. A three stage extraction at a phase ratio (aqueous/organic) of 1:2, followed by two stages stripping using 0.5 M sodium carbonate solution at a phase ratio (A/O) of 1:4 were found to be the optimum conditions to report more than 98% of uranium content in green phosphoric acid to the aqueous phase as uranyl tricarbonate complex (UO 2 (CO 3 ) 3 ) 4- . By applying sodica decomposition upon the stripping carbonate solution using 50% sodium hydroxide, about 98% of uranium content was precipitated as sodium diuranate concentrate (Na 2 U 2 O 7 ). The chemical analysis using atomic absorption spectrometry (Aas) showed a good agreement between the specification of the obtained uranium concentrate with the standard commercial specification of sodium diuranate concentrate. Further purification was achieved for the yellow cake by selective precipitation of uranium from the solution as uranium peroxide (UO 4 .2H 2 O) using 30% hydrogen peroxide. Finally the uranium peroxide precipitated was calcined at 450 degree C to obtain the orange powder uranium trioxide (UO 3 ). The chemical analysis of the final uranium trioxide

Synthesis and characterization of ferrous phosphate (vivianite) and its behavior in aqueous media

International Nuclear Information System (INIS)

Diaz F, J.C.

2003-01-01

The synthesis and characterization of materials that can be useful in Environmental Chemistry is very important because their characteristics are exposed and its behavior in chemical phenomena as the sorption in aqueous media is understand to use it in the human being benefit. With the object of using, in a future, the octa hydrated ferrous phosphate (vivianite) as a potential candidate for matrix confinement in contention walls for the storage of radioactive waste of long half life, it was synthesized and it characterized physico chemically and their properties of surface of this compound were evaluated. Presently work was carried out the synthesis and structural characterization of the iron phosphate II by infrared spectroscopy with having Fourier transform, high vacuum scanning electron microscopy, X-ray diffraction, thermal gravimetric analysis, the BET multipoint surface area and Moessbauer spectroscopy; as well as, the determination between aqueous media of the isoelectric point and the density of sites of surface of the compound. The octa hydrated ferrous phosphate was obtained pure. The results indicate that the product corresponds to the prospective mineral, the vivianite. The thermal gravimetric analysis demonstrated that the ferrous phosphate is a stable salt after the lost of water. The isoelectric point is since an important parameter because allows to know the behavior of the surface of the material in aqueous systems, in this case the isoelectric point, of the octa hydrated ferrous phosphate, in distilled water is of pH 4.20 and in solution of potassium nitrate 0.5 M is of pH = 3.75. This indicates that the material has an amphoteric surface depending on the pH. On the other hand, the density of active sites of surface obtained by titrations acid-base is of 20 sites by nm 2 . (Author)

Triphenyl phosphate allergy from spectacle frames

DEFF Research Database (Denmark)

Carlsen, L; Andersen, K E; Egsgaard, Helge

1986-01-01

A case of triphenyl phosphate allergy from spectacle frames is reported. Patch tests with analytical grade triphenyl phosphate, tri-m-cresyl phosphate, and tri-p-cresyl phosphate in the concentrations 5%, 0.5% and 0.05% pet. showed positive reactions to 0.05% triphenyl phosphate and 0.5% tri......-m-cresyl phosphate, but no reaction to tri-p-cresyl phosphate. Gas chromatography of the tricresyl phosphate 5% pet. patch test material supplied from Trolab showed that it contained a mixture of a wide range of triaryl phosphates, including 0.08% triphenyl phosphate which is above the threshold for detecting...

Glucose and phosphate modulation of intracellular 45Ca incorporated into pancreatic islets during culture in the absence and presence of serum

International Nuclear Information System (INIS)

Bergsten, P.

1985-01-01

The effects of glucose and phosphate on the intracellular 45 Ca content were measured in β cell-rich pancreatic islets cultured in media containing or lacking serum. Irrespective of the glucose and serum concentrations there were no or very small increments of 45 Ca contents when phosphate was raised from 0.8 to 5.8 mM during culture for 1 day. However, after 7 days of culture in serum-free medium there was a massive accumulation of 45 Ca in the islets in response to the higher phosphate concentration. Glucose markedly reduced, and serum eliminated, the extensive accumulation probably due to increased cell viability. In the cells cultured in the presence of serum, raising the glucose concentration from 1.0 to 5.5 mM resulted in an increased incorporation of 45 Ca. This effect was particularly pronounced after culture for 7 days in 5.8 mM phosphate. A further increase of glucose to 20 mM reduced the 45 Ca content. The results are consistent with the concept that glucose both stimulates 45 Ca uptake into different β-cell pools and degranulates the cell with associated loss of intracellular calcium from the granular calcium pool. (author)

Phosphate retention by soil in relation to waste disposal

NARCIS (Netherlands)

Beek, J.

1979-01-01

The disposal of large amounts of domestic sewage water and liquid manure, both containing dissolved phosphates, is often problematic. Discharge of these into (shallow and standing) surface waters is highly undesirable, as phosphate is considered to be one of the prime causes of eutrophication. If,

The effects of uranium oxide high-level waste on the structure of iron phosphate glasses

International Nuclear Information System (INIS)

Badyal, Y.

1998-01-01

Because of their unusually good chemical durability, iron phosphate glasses are a natural candidate for a nuclear waste disposal glass. We have studied the effects of UO 2 high-level waste on the structure of iron phosphate glasses with both neutron and high-energy x-ray diffraction using the GLAD instrument of the Intense Pulsed Neutron Source and the 1-BM bending magnet beamline of the Advanced Photon Source, respectively. The results of neutron scattering, which is mostly sensitive to correlations involving light atoms i.e. O-O, Fe-O and P-O, suggest the main structural features of the base glass are largely unaffected by the addition of UO 2 . The nearest-neighbor P-O, Fe-O and O-O peaks remain at the same position in real space and their intensities scale approximately with concentration. These findings are consistent with the earlier results of Raman scattering and EXAFS on the Fe-K edge wherein both cases the spectra remain similar to the base glass. High-energy x-ray scattering which is sensitive to correlations involving the heavier atoms and thus complements the neutron measurements, is also consistent with uranium occupying interstitial sites in the relatively undisturbed base glass structure. However, important questions remain as to the precise local structure and oxidation state of uranium in these glasses

Prerequisite for highly efficient isoprenoid production by cyanobacteria discovered through the over-expression of 1-deoxy-d-xylulose 5-phosphate synthase and carbon allocation analysis.

Science.gov (United States)

Kudoh, Kai; Kawano, Yusuke; Hotta, Shingo; Sekine, Midori; Watanabe, Takafumi; Ihara, Masaki

2014-07-01

Cyanobacteria have recently been receiving considerable attention owing to their potential as photosynthetic producers of biofuels and biomaterials. Here, we focused on the production of isoprenoids by cyanobacteria, and aimed to provide insight into metabolic engineering design. To this end, we examined the over-expression of a key enzyme in 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway, 1-deoxy-d-xylulose 5-phosphate synthase (DXS) in the cyanobacterium Synechocystis sp. PCC6803. In the DXS-over-expression strain (Dxs_ox), the mRNA and protein levels of DXS were 4-times and 1.5-times the levels in the wild-type (WT) strain, respectively. The carotenoid content of the Dxs_ox strain (8.4 mg/g dry cell weight [DCW]) was also up to 1.5-times higher than that in the WT strain (5.6 mg/g DCW), whereas the glycogen content dramatically decreased to an undetectable level. These observations suggested that the carotenoid content in the Dxs_ox strain was increased by consuming glycogen, which is a C-storage compound in cyanobacteria. We also quantified the total sugar (145 and 104 mg/g DCW), total fatty acids (31 and 24 mg/g DCW) and total protein (200 and 240 mg/g DCW) content in the WT and Dxs_ox strains, respectively, which were much higher than the carotenoid content. In particular, approximately 54% of the proteins were phycobiliproteins. This study demonstrated the major destinations of carbon flux in cyanobacteria, and provided important insights into metabolic engineering. Target yield can be improved through optimization of gene expression, the DXS protein stabilization, cell propagation depression and restriction of storage compound synthesis. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Enhanced proton conductivity of niobium phosphates by interfacing crystal grains with an amorphous functional phase

DEFF Research Database (Denmark)

Huang, Yunjie; Yu, Lele; Li, Haiyan

2016-01-01

Niobium phosphate is an interesting proton conductor operational in the intermediate temperature range. In the present work two forms of phosphates were prepared: an amorphous one with high specific area and a crystalline one with low specific surface area. Both phosphates exhibited very low prot...... the high surface area amorphous phosphate was used as the precursor. At 250 °C thus obtained niobium phosphate showed a high and stable conductivity of 0.03 S cm−1 under dry atmosphere and of 0.06 S cm−1 at a water partial pressure of 0.12 atm....... conductivities. An activation process was developed to convert the phosphates into crystal grains with a phosphorus rich amorphous phase along the grain boundaries. As a result, the obtained niobium phosphates showed considerably enhanced and stable proton conductivities. The activation effect was prominent when...

Application of Potential Phosphate-Solubilizing Bacteria and Organic Acids on Phosphate Solubilization from Phosphate Rock in Aerobic Rice

Directory of Open Access Journals (Sweden)

Qurban Ali Panhwar

2013-01-01

Full Text Available A study was conducted at Universiti Putra Malaysia to determine the effect of phosphate-solubilizing bacteria (PSB and organic acids (oxalic & malic on phosphate (P solubilization from phosphate rock (PR and growth of aerobic rice. Four rates of each organic acid (0, 10, 20, and 30 mM, and PSB strain (Bacillus sp. were applied to aerobic rice. Total bacterial populations, amount of P solubilization, P uptake, soil pH, and root morphology were determined. The results of the study showed significantly high P solubilization in PSB with organic acid treatments. Among the two organic acids, oxalic acid was found more effective compared to malic acid. Application of oxalic acid at 20 mM along with PSB16 significantly increased soluble soil P (28.39 mg kg−1, plant P uptake (0.78 P pot−1, and plant biomass (33.26 mg. Addition of organic acids with PSB and PR had no influence on soil pH during the planting period. A higher bacterial population was found in rhizosphere (8.78 log10 cfu g−1 compared to the nonrhizosphere and endosphere regions. The application of organic acids along with PSB enhanced soluble P in the soil solution, improved root growth, and increased plant biomass of aerobic rice seedlings without affecting soil pH.

Infrared and Raman Spectra of Magnesium Ammonium Phosphate Hexahydrate (Struvite) and its Isomorphous Analogues. VIII. Spectra of Protiated and Partially Deuterated Magnesium Rubidium Phosphate Hexahydrate and Magnesium Thallium Phosphate Hexahydrate.

Science.gov (United States)

Soptrajanov, Bojan; Cahil, Adnan; Najdoski, Metodija; Koleva, Violeta; Stefov, Viktor

2011-09-01

The infrared and Raman spectra of magnesium rubidium phosphate hexahydrate MgRbPO4 • 6H2O and magnesium thallium phosphate hexahydrate, MgTlPO4 • 6H2O were recorded at room temperature (RT) and the boiling temperature of liquid nitrogen (LNT). To facilitate their analysis, also recorded were the spectra of partially deuterated analogues with varying content of deuterium. The effects of deuteration and those of lowering the temperature were the basis of the conclusions drawn regarding the origin of the observed bands which were assigned to vibrations which are predominantly localized in the water molecules (four crystallographically different types of such molecules exist in the structures) and those with PO43- character. It was concluded that in some cases coupling of phosphate and water vibrations is likely to take place. The appearance of the infrared spectra in the O-H stretching regions of the infrared spectra is explained as being the result of an extensive overlap of bands due to components of the fundamental stretching modes of the H2O units with a possible participation of bands due to second-order transitions. A broad band reminiscent of the B band of the well-known ABC trio characteristic of spectra of substances containing strong hydrogen bonds in their structure was found around 2400 cm-1 in the infrared spectra of the two studied compounds.

Compatibility and stability of aloxi (palonosetron hydrochloride) admixed with dexamethasone sodium phosphate.

Science.gov (United States)

Trissel, Lawrence A; Zhang, Yanping

2004-01-01

The purpose of this study was to evaluate the physical and chemical stability of palonosetron hydrochloride 0.25 mg admixed with dexamethasone (as sodium phophate) 10 mg or 20 mg in 5% dextrose injection or 0.9% sodium chloride injection in polyvinylchloride minibags, and also admixed with dexamethasone (as sodium phosphate) 3.3 mg in 5% dextrose injection or 0.9% sodium chloride injection in polypropylene syringes, at 4 deg C stored in the dark for 14 days, and at 23 deg C exposed to normal laboratory fluorescent light over 48 hours. Test samples of palonosetron hydrochloride 5 micrograms/mL with dexamethasone (as sodium phosphate) 0.2 mg/mL and also 0.4 mg/mL were prepared in polyvinylchloride minibags of each infusion solution. Additionally, palonosetron hydrochloride 25 micrograms/mL with dexamethasone (as sodium phosphate) 0.33 mg/mL in each infusion solution were prepared as 10 mL of test solution in 20-mL polypropylene syringes. Evaluations for physical and chemical stability were performed on samples taken initially and after 1, 3, 7 and 14 days of storage at 4 deg C and after 1, 4, 24 and 48 hours at 23 deg C. Physical stability was assessed using visual observation in normal room light and using a high-intensity monodirectional light beam. In addition, turbidity and particle content were measured electronically. Chemical stability of the drug was evaluated by using a stability-indicating high-performance liquid chromatographic analytical technique. All samples were physically compatible throughout the study. The solutions remained clear and showed little or no change in particulate burden and haze level. Additionally, little or no loss of palonosetron hydrochloride and dexamethasone occurred in any of the samples at either temperature throughout the entire study period. Admixtures of palonosetron hydrochloride with dexamethasone sodium phosphate in 5% dextrose injection or in 0.9% sodium chloride injection packaged in polyvinylchloride minibags or in

(13)C metabolic flux analysis in neurons utilizing a model that accounts for hexose phosphate recycling within the pentose phosphate pathway.

Science.gov (United States)

Gebril, Hoda M; Avula, Bharathi; Wang, Yan-Hong; Khan, Ikhlas A; Jekabsons, Mika B

2016-02-01

Glycolysis, mitochondrial substrate oxidation, and the pentose phosphate pathway (PPP) are critical for neuronal bioenergetics and oxidation-reduction homeostasis, but quantitating their fluxes remains challenging, especially when processes such as hexose phosphate (i.e., glucose/fructose-6-phosphate) recycling in the PPP are considered. A hexose phosphate recycling model was developed which exploited the rates of glucose consumption, lactate production, and mitochondrial respiration to infer fluxes through the major glucose consuming pathways of adherent cerebellar granule neurons by replicating [(13)C]lactate labeling from metabolism of [1,2-(13)C2]glucose. Flux calculations were predicated on a steady-state system with reactions having known stoichiometries and carbon atom transitions. Non-oxidative PPP activity and consequent hexose phosphate recycling, as well as pyruvate production by cytoplasmic malic enzyme, were optimized by the model and found to account for 28 ± 2% and 7.7 ± 0.2% of hexose phosphate and pyruvate labeling, respectively. From the resulting fluxes, 52 ± 6% of glucose was metabolized by glycolysis, compared to 19 ± 2% by the combined oxidative/non-oxidative pentose cycle that allows for hexose phosphate recycling, and 29 ± 8% by the combined oxidative PPP/de novo nucleotide synthesis reactions. By extension, 62 ± 6% of glucose was converted to pyruvate, the metabolism of which resulted in 16 ± 1% of glucose oxidized by mitochondria and 46 ± 6% exported as lactate. The results indicate a surprisingly high proportion of glucose utilized by the pentose cycle and the reactions synthesizing nucleotides, and exported as lactate. While the in vitro conditions to which the neurons were exposed (high glucose, no lactate or other exogenous substrates) limit extrapolating these results to the in vivo state, the approach provides a means of assessing a number of metabolic fluxes within the context of hexose phosphate recycling in the PPP from a

Fourier transform Raman spectroscopy of synthetic and biological calcium phosphates.

Science.gov (United States)

Sauer, G R; Zunic, W B; Durig, J R; Wuthier, R E

1994-05-01

Fourier-transform (FT) Raman spectroscopy was used to characterize the organic and mineral components of biological and synthetic calcium phosphate minerals. Raman spectroscopy provides information on biological minerals that is complimentary to more widely used infrared methodologies as some infrared-inactive vibrational modes are Raman-active. The application of FT-Raman technology has, for the first time, enabled the problems of high sample fluorescence and low signal-to-noise that are inherent in calcified tissues to be overcome. Raman spectra of calcium phosphates are dominated by a very strong band near 960 cm-1 that arises from the symmetric stretching mode (v1) of the phosphate group. Other Raman-active phosphate vibrational bands are seen at approximately 1075 (v3), 590 (v4), and 435 cm-1 (v2). Minerals containing acidic phosphate groups show additional vibrational modes. The different calcium phosphate mineral phases can be distinguished from one another by the relative positions and shapes of these bands in the Raman spectra. FT-Raman spectra of nascent, nonmineralized matrix vesicles (MV) show a distinct absence of the phosphate v1 band even though these structures are rich in calcium and phosphate. Similar results were seen with milk casein and synthetic Ca-phosphatidyl-serine-PO4 complexes. Hence, the phosphate and/or acidic phosphate ions in these noncrystalline biological calcium phosphates is in a molecular environment that differs from that in synthetic amorphous calcium phosphate. In MV, the first distinct mineral phase to form contained acidic phosphate bands similar to those seen in octacalcium phosphate. The mineral phase present in fully mineralized MV was much more apatitic, resembling that found in bones and teeth.(ABSTRACT TRUNCATED AT 250 WORDS)

n-Alkylamine-assisted preparation of a high surface area vanadyl phosphate/tetraethylorthosilicate nanocomposite

Energy Technology Data Exchange (ETDEWEB)

Ferreira, João Paulo L., E-mail: billbrujah@yahoo.com.br [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14040-901 (Brazil); Zampronio, Elaine C.; Oliveira, Herenilton P. [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14040-901 (Brazil)

2013-02-15

Graphical abstract: CuK{sub α} X-ray diffraction patterns of the VP, VPOc, VPOcT, VPOcT200 and VPOcT500. Highlights: ► TEOS and octylamine incorporation into the VP was achieved by expanding the lamellar. ► The specific surface area increased from 15 m{sup 2} g{sup −1} in VP to 237 m{sup 2} g{sup −1} in VPOcT. ► The VPOcT exhibited thermal resistance up to 200 °C in air. ► Upon thermal treatment up to 500 °C, the surface area increased to 838 m{sup 2} g{sup −1}. -- Abstract: We have developed a vanadyl phosphate/tetraethylorthosilicate (VPO/TEOS) nanocomposite comprised of silicate chains interleaved with VPO layers, prepared by using an n-alkylamines such as octylamine as the structure directing agent. The nanocomposites were synthesized by reacting amine-intercalated vanadyl phosphate with tetraethylorthosilicate via the soft chemistry approach. The synthetic procedure encompassed the exfoliation of the layered vanadyl phosphate as well as the reorganization of this exfoliated solid into a mesostructured lamellar phase with the same V–P–O connectivity as in the original matrix. TEOS incorporation into the vanadyl phosphate was achieved by expanding the lamellar structure with n-alkylamine (Δd = 13 Å with n-octylamine). The specific surface area increased from 15 m{sup 2} g{sup −1} in the vanadyl phosphate matrix to 237 m{sup 2} g{sup −1} in VPOcT, and the isotherm curves revealed the characteristic hysteresis of mesoporous materials. Upon thermal treatment up to 500 °C, the surface area increased to 837 m{sup 2} g{sup −1}, which is suitable for catalytic purposes.

Integrated assessment of the phosphate industry

International Nuclear Information System (INIS)

Ryan, M.T.; Cotter, S.J.

1980-05-01

The phosphate industry in the United States includes three major activities, namely, mining and milling of phosphate rock, phosphate product manufacture, and phosphate product use. Phosphatic materials contain uranium, thorium, and their decay products in greater than background amounts. This assessment of the radiological impacts associated with the redistribution of radioactive components of phosphate materials may provide insight into the effects of uranium extraction from phosphate materials for use in the nuclear fuel cycle

Uranium from phosphates to rabbit bones: Predicting dietary contribution to uranium deposition in animal bones

International Nuclear Information System (INIS)

Canella Avelar, A.; Motta Ferreira, W.; Menezes, M.

2014-01-01

Uranium is a hazardous element, both for radioactivity and metallotoxicity. Health implications of human overexposure to uranium are well documented: from reproduction impairment, liver and kidney diseases to some types of cancer. There are limited data in the modern literature concerning the levels of uranium in animal tissues and foods, as well the dietary daily intake of uranium is not fully known both for man and livestock. On the other hand, practically every phosphate and its products contain uranium in its structure. The average U content in agricultural phosphate may vary from 10 up to 390 ppm. In this particular feature, uranium can reach animal and man food chain by ingestion of feed and food grade phosphate containing U.

Overexpressing Exogenous 5-Enolpyruvylshikimate-3-Phosphate Synthase (EPSPS Genes Increases Fecundity and Auxin Content of Transgenic Arabidopsis Plants

Directory of Open Access Journals (Sweden)

Jia Fang

2018-02-01

Full Text Available Transgenic glyphosate-tolerant plants overproducing EPSPS (5-enolpyruvylshikimate-3-phosphate synthase may exhibit enhanced fitness in glyphosate-free environments. If so, introgression of transgenes overexpressing EPSPS into wild relative species may lead to increased competitiveness of crop-wild hybrids, resulting in unpredicted environmental impact. Assessing fitness effects of transgenes overexpressing EPSPS in a model plant species can help address this question, while elucidating how overproducing EPSPS affects the fitness-related traits of plants. We produced segregating T2 and T3Arabidopsis thaliana lineages with or without a transgene overexpressing EPSPS isolated from rice or Agrobacterium (CP4. For each of the three transgenes, we compared glyphosate tolerance, some fitness-related traits, and auxin (indole-3-acetic acid content in transgene-present, transgene-absent, empty vector (EV, and parental lineages in a common-garden experiment. We detected substantially increased glyphosate tolerance in T2 plants of transgene-present lineages that overproduced EPSPS. We also documented significant increases in fecundity, which was associated with increased auxin content in T3 transgene-present lineages containing rice EPSPS genes, compared with their segregating transgene-absent lineages, EV, and parental controls. Our results from Arabidopsis with nine transgenic events provide a strong support to the hypothesis that transgenic plants overproducing EPSPS can benefit from a fecundity advantage in glyphosate-free environments. Stimulated biosynthesis of auxin, an important plant growth hormone, by overproducing EPSPS may play a role in enhanced fecundity of the transgenic Arabidopsis plants. The obtained knowledge is useful for assessing environmental impact caused by introgression of transgenes overproducing EPSPS from any GE crop into populations of its wild relatives.

Overexpressing Exogenous 5-Enolpyruvylshikimate-3-Phosphate Synthase (EPSPS) Genes Increases Fecundity and Auxin Content of Transgenic Arabidopsis Plants.

Science.gov (United States)

Fang, Jia; Nan, Peng; Gu, Zongying; Ge, Xiaochun; Feng, Yu-Qi; Lu, Bao-Rong

2018-01-01

Transgenic glyphosate-tolerant plants overproducing EPSPS (5-enolpyruvylshikimate-3-phosphate synthase) may exhibit enhanced fitness in glyphosate-free environments. If so, introgression of transgenes overexpressing EPSPS into wild relative species may lead to increased competitiveness of crop-wild hybrids, resulting in unpredicted environmental impact. Assessing fitness effects of transgenes overexpressing EPSPS in a model plant species can help address this question, while elucidating how overproducing EPSPS affects the fitness-related traits of plants. We produced segregating T 2 and T 3 Arabidopsis thaliana lineages with or without a transgene overexpressing EPSPS isolated from rice or Agrobacterium ( CP4 ). For each of the three transgenes, we compared glyphosate tolerance, some fitness-related traits, and auxin (indole-3-acetic acid) content in transgene-present, transgene-absent, empty vector (EV), and parental lineages in a common-garden experiment. We detected substantially increased glyphosate tolerance in T 2 plants of transgene-present lineages that overproduced EPSPS. We also documented significant increases in fecundity, which was associated with increased auxin content in T 3 transgene-present lineages containing rice EPSPS genes, compared with their segregating transgene-absent lineages, EV, and parental controls. Our results from Arabidopsis with nine transgenic events provide a strong support to the hypothesis that transgenic plants overproducing EPSPS can benefit from a fecundity advantage in glyphosate-free environments. Stimulated biosynthesis of auxin, an important plant growth hormone, by overproducing EPSPS may play a role in enhanced fecundity of the transgenic Arabidopsis plants. The obtained knowledge is useful for assessing environmental impact caused by introgression of transgenes overproducing EPSPS from any GE crop into populations of its wild relatives.

Polyaspartic Acid Concentration Controls the Rate of Calcium Phosphate Nanorod Formation in High Concentration Systems

Energy Technology Data Exchange (ETDEWEB)

Krogstad, Daniel V. [Biosystems and; Wang, Dongbo [Biosystems and; Lin-Gibson, Sheng [Biosystems and

2017-08-31

Polyelectrolytes are known to greatly affect calcium phosphate (CaP) mineralization. The reaction kinetics as well as the CaP phase, morphology and aggregation state depend on the relative concentrations of the polyelectrolyte and the inorganic ions in a complex, nonlinear manner. This study examines the structural evolution and kinetics of polyaspartic acid (pAsp) directed CaP mineralization at high concentrations of polyelectrolytes, calcium, and total phosphate (19–30 mg/mL pAsp, 50–100 mM Ca2+, Ca/P = 2). Using a novel combination of characterization techniques including cryogenic transmission electron microscopy (cryo-TEM), spectrophotometry, X-ray total scattering pair distribution function analysis, and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), it was determined that the CaP mineralization occurred over four transition steps. The steps include the formation of aggregates of pAsp stabilized CaP spherical nanoparticles (sNP), crystallization of sNP, oriented attachment of the sNP into nanorods, and further crystallization of the nanorods. The intermediate aggregate sizes and the reaction kinetics were found to be highly polymer concentration dependent while the sizes of the particles were not concentration dependent. This study demonstrates the complex role of pAsp in controlling the mechanism as well as the kinetics of CaP mineralization.

Radioelement migration in natural and mined phosphate terrains. Final report

International Nuclear Information System (INIS)

Osmond, J.K.; Cowart, J.B.; Humphreys, C.L.; Wagner, B.E.

1984-06-01

The phosphatic strata of the Central Florida Phosphate District are enriched in uranium, along with all of its daughters, including thorium-230 and radium-226. Some of the surface and shallow aquifer waters have higher than average concentrations of radium, this being especially pronounced in the down-flow direction of aquifer water movement. However, most of the shallow and deep aquifer waters of the mining district, as well as surface waters, are within normal range in terms of the radioelement content. In the course of mining operations, it appears that the natural pattern is not greatly altered, except in the immediate pit and spoil areas. As a result of mining and processing operation, most of the radioelements accumulate in the waste clays

Lanthanum-modified bentonite: potential for efficient removal of phosphates from fishpond effluents.

Science.gov (United States)

Kurzbaum, Eyal; Raizner, Yasmin; Cohen, Oded; Rubinstein, Guy; Bar Shalom, Oded

2017-06-01

Adsorption has been suggested as an effective method for removing phosphates from agricultural wastewater effluents that contain relatively high phosphate concentrations. The present study focused on the use of a bentonite-lanthanum clay (Phoslock ® ) for reducing the dissolved phosphate concentration in fishpond effluents. Batch experiments with synthetic phosphate-spiked solutions and with fishpond effluents were performed in order to determine adsorption equilibrium isotherms and kinetics as well as to determine the efficiency of Phoslock ® in removing phosphate from these solutions. In the synthetic phosphate-spiked solution, the mean maximum phosphate adsorption capacity was 92 mg Phoslock ® /mg phosphate removal. A ratio of 50, 100, and 200 mg Phoslock ® /mg phosphate removal was found for complete phosphate removal from the fishpond effluents, where higher doses of Phoslock ® led to a faster removal rate (94% removal within the first 150 min). These results show that bentonite-lanthanum clay can be employed for designing a treatment process for efficient phosphate removal from fishpond effluents.

Effects of education on low-phosphate diet and phosphate binder intake to control serum phosphate among maintenance hemodialysis patients: A randomized controlled trial

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Eunsoo Lim

2018-03-01

Full Text Available Background : For phosphate control, patient education is essential due to the limited clearance of phosphate by dialysis. However, well-designed randomized controlled trials about dietary and phosphate binder education have been scarce. Methods : We enrolled maintenance hemodialysis patients and randomized them into an education group (n = 48 or a control group (n = 22. We assessed the patients' drug compliance and their knowledge about the phosphate binder using a questionnaire. Results : The primary goal was to increase the number of patients who reached a calcium-phosphorus product of lower than 55. In the education group, 36 (75.0% patients achieved the primary goal, as compared with 16 (72.7% in the control group (P = 0.430. The education increased the proportion of patients who properly took the phosphate binder (22.9% vs. 3.5%, P = 0.087, but not to statistical significance. Education did not affect the amount of dietary phosphate intake per body weight (education vs. control: -1.18 ± 3.54 vs. -0.88 ± 2.04 mg/kg, P = 0.851. However, the dietary phosphate-to-protein ratio tended to be lower in the education group (-0.64 ± 2.04 vs. 0.65 ± 3.55, P = 0.193. The education on phosphate restriction affected neither the Patient-Generated Subjective Global Assessment score (0.17 ± 4.58 vs. -0.86 ± 3.86, P = 0.363 nor the level of dietary protein intake (-0.03 ± 0.33 vs. -0.09 ± 0.18, P = 0.569. Conclusion : Education did not affect the calcium-phosphate product. Education on the proper timing of phosphate binder intake and the dietary phosphate-to-protein ratio showed marginal efficacy.

Extra-phosphate load from food additives in commonly eaten foods: a real and insidious danger for renal patients.

Science.gov (United States)

Benini, Omar; D'Alessandro, Claudia; Gianfaldoni, Daniela; Cupisti, Adamasco

2011-07-01

Restriction of dietary phosphorus is a major aspect of patient care in those with renal disease. Restriction of dietary phosphorus is necessary to control for phosphate balance during both conservative therapy and dialysis treatment. The extra amount of phosphorus which is consumed as a result of phosphate-containing food additives is a real challenge for patients with renal disease and for dieticians because it represents a "hidden" phosphate load. The objective of this study was to measure phosphorus content in foods, common protein sources in particular, and comprised both those which included a listing of phosphate additives and those which did not. Determinations of dry matter, nitrogen, total and soluble phosphate ions were carried out in 60 samples of foods, namely cooked ham, roast breast turkey, and roast breast chicken, of which, 30 were with declared phosphate additives and the other 30 similar items were without additives. Total phosphorus (290 ± 40 mg/100 g vs. 185 ± 23 mg/100 g, P additives than in foods without additives. No difference was detected between the 2 groups regarding dry matter (27.2 ± 2.0 g/100 g vs. 26.7 ± 1.9 g/100 g) or total nitrogen (3.15 ± 0.40 g/100 g vs. 3.19 ± 0.40 g/100 g). Consequently, phosphorus intake per gram of protein was much greater in the foods containing phosphorus additives (15.0 ± 3.1 mg/g vs. 9.3 ± 0.7 mg/g, P foods which contain phosphate additives have a phosphorus content nearly 70% higher than the samples which did not contain additives. This creates a special concern because this extra amount of phosphorus is almost completely absorbed by the intestinal tract. These hidden phosphates worsen phosphate balance control and increase the need for phosphate binders and related costs. Information and educational programs are essential to make patients with renal disease aware of the existence of foods with phosphate additives. Moreover, these facts highlight the need for national and international

High-beam quality, high-efficiency laser based on fiber with heavily Yb(3+)-doped phosphate core and silica cladding.

Science.gov (United States)

Egorova, O N; Semjonov, S L; Medvedkov, O I; Astapovich, M S; Okhrimchuk, A G; Galagan, B I; Denker, B I; Sverchkov, S E; Dianov, E M

2015-08-15

We have fabricated and tested a composite fiber with an Yb(3+)-doped phosphate glass core and silica cladding. Oscillation with a slope efficiency of 74% was achieved using core pumping at 976 nm with fiber lengths of 48-90 mm in a simple laser configuration, where the cavity was formed by a high-reflectivity Bragg grating and the cleaved fiber end. The measured M(2) factors were as low as 1.05-1.22 even though the fiber was multimode at the lasing wavelength.

SINTESIS PATI SAGU IKATAN SILANG FOSFAT BERDERAJAT SUBSTITUSI FOSFAT TINGGI DALAM SUASANA ASAM [Synthesis of Cross-Linked Sago Starch Phosphate with the Highest Degree of Substitution of Phosphate Under Acidic Condition

Directory of Open Access Journals (Sweden)

Jorion Romengga*

2011-12-01

Full Text Available Cross-linked sago starch phosphate (SgP with high phosphorus contents was successfully synthesized by reacting sago with a mixture of primary and secondary sodium phosphates under acidic condition. The experimental variables investigated include pH, temperature, reaction time, and mixture rate. The physicochemical properties evaluated were moisture, swelling power, water binding capacity, transmittance (%T and percent amylose (%Am, while the pasting properties examined were pasting time, pasting temperature, viscosity at peak, final, and setback. The granule structure was observed by scanning electron microscope and X-ray diffraction. The results showed that the maximum degree of phosphate substitution was obtained at pH of 6.50, 40°C, 20 minutes of reaction time and 300 rpm of mixing rate. The physicochemical (%T and %Am and pasting (viscosity at peak, final, and setback properties of SgP were significantly different (P<0.01 from Sg. Structure of SgP was characterized by FT-IR and the results indicated a new absorption peak at 2362.87 cm-1 which was characterized as the phospho-diester (RO-PO3-R’ stretching vibration. In the fingerprint area, there were two new absorption peaks at 1242.05 and 989.79 cm-1 which were characterized as the P=O and C-O-P vibration, respectively. Sago granules were substantially altered after cross-linking.

FTIR and Mössbauer spectroscopic study of sodium–aluminum–iron phosphate glassy materials for high level waste immobilization

Energy Technology Data Exchange (ETDEWEB)

Stefanovsky, S.V., E-mail: serge.stefanovsky@yandex.ru [Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Laboratory of Radioecology and Radiation Problems, Moscow (Russian Federation); Stefanovsky, O.I. [Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Laboratory of Radioecology and Radiation Problems, Moscow (Russian Federation); Remizov, M.B.; Belanova, E.A.; Kozlov, P.V. [FSUE PA Mayak, Central Plant Laboratory, Ozersk, Chelyabinsk Reg. (Russian Federation); Glazkova, Ya.S.; Sobolev, A.V.; Presniakov, I.A. [Lomonosov Moscow State University, Department of Radiochemistry (Russian Federation); Kalmykov, S.N. [Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Laboratory of Radioecology and Radiation Problems, Moscow (Russian Federation); Lomonosov Moscow State University, Department of Radiochemistry (Russian Federation); Vernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences, Laboratory of Radiochemistry, Moscow (Russian Federation); Myasoedov, B.F. [Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Laboratory of Radioecology and Radiation Problems, Moscow (Russian Federation); Vernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences, Laboratory of Radiochemistry, Moscow (Russian Federation)

2015-11-15

Complex sodium-aluminum-iron phosphate glassy materials with various Al{sub 2}O{sub 3} to Fe{sub 2}O{sub 3} ratio containing high level waste (HLW) surrogate were characterized by X-ray diffraction and scanning electron microscopy and studied in details by Fourier transform infrared (FTIR) spectroscopy. The samples with high Al{sub 2}O{sub 3} content and not containing Fe{sub 2}O{sub 3} were predominantly amorphous but subjected to devitrification under annealing. Addition of B{sub 2}O{sub 3} and partial Fe{sub 2}O{sub 3} substitution for Al{sub 2}O{sub 3} in the materials increases their resistance to devitrification whereas further substitution and NiO incorporation significantly increase the tendency to devitrification. FTIR spectra demonstrate changes in the structure of glassy materials caused by both structural variations in the anionic motif and occurrence of crystalline phases in the materials. According to Mössbauer spectroscopy data, iron in the glassy samples is present as octahedrally coordinated Fe{sup 3+} ions while in the partly devitrified samples iron is partitioned among vitreous and crystalline phases entering the vitreous phase mainly as Fe{sup 3+}O{sub 6} units and crystalline phases as major Fe{sup 3+} and minor Fe{sup 2+} ions in a magnetically ordered state and participating in a “fast” electronic exchange.

Three-step preparation and purification of phosphorus-33-labeled creatine phosphate of high specific activity

International Nuclear Information System (INIS)

Savabi, F.; Geiger, P.J.; Bessman, S.P.

1984-01-01

Rabbit heart mitochondria were used as a source of enzymes for the synthesis of phosphorus-labeled creatine phosphate. This method is based on the coupled reaction between mitochondrial oxidative phosphorylation and mitochondrial-bound creatine kinase. It is possible to convert more than 90% of the inorganic phosphate (P/sub i/) to creatine phosphate. The method used only small amounts of adenine nucleotides which led to a product with only slight nucleotide contamination. This could be removed by activated charcoal extraction. For further purification, a method for the removal of residual P/sub i/ is described. 20 references

Potentially Prebiotic Syntheses of Condensed Phosphates

Science.gov (United States)

Keefe, Anthony D.; Miller, Stanley L.

1996-01-01

In view of the importance of a prebiotic source of high energy phosphates, we have investigated a number of potentially prebiotic processes to produce condensed phosphates from orthophosphate and cyclic trimetaphosphate from tripolyphosphate. The reagents investigated include polymerizing nitriles, acid anhydrides, lactones, hexamethylene tetramine and carbon suboxide. A number of these processes give substantial yields of pyrophosphate from orthophosphate and trimetaphosphate from tripolyphosphate. Although these reactions may have been applicable in local areas, they are not sufficiently robust to have been of importance in the prebiotic open ocean.

Zinc phosphate conversion coatings

Science.gov (United States)

Sugama, Toshifumi

1997-01-01

Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

Determination of adenosine phosphates in rat gastrocnemius at various postmortem intervals using high performance liquid chromatography.

Science.gov (United States)

Huang, Hong; Yan, Youyi; Zuo, Zhong; Yang, Lin; Li, Bin; Song, Yu; Liao, Linchuan

2010-09-01

Although the change in adenosine phosphate levels in muscles may contribute to the development of rigor mortis, the relationship between their levels and the onset and development of rigor mortis has not been well elucidated. In the current study, levels of the adenosine phosphates including adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) in gastrocnemius at various postmortem intervals of 180 rats from different death modes were detected by high performance liquid chromatography. The results showed that the levels of ATP and ADP significantly decreased along with the postmortem period of rats from different death mode whereas the AMP level remained the same. In addition, it was found that changes in the ATP levels in muscles after death correlated well with the development of rigor mortis. Therefore, the ATP level could serve as a reference parameter for the deduction of rigor mortis in forensic science.

Structural studies of calcium phosphate doped with titanium and zirconium obtained by high-energy mechanical alloying

Energy Technology Data Exchange (ETDEWEB)

Silva, C C; Sombra, A S B [Telecommunications and Materials Science and Engineering Laboratory (LOCEM), Physics Department, Federal University of Ceara, Campus do Pii, Postal Code 6030, 60455-760, Fortaleza-Ceara (Brazil)], E-mail: sombra@fisica.ufc.br

2009-12-15

In this paper, we present a new variation of the solid-state procedure on the synthesis of bioceramics with titanium (CapTi) and zirconium (CapZr), considering that zirconium (ZrO{sub 2}) and titanium oxide (TiO{sub 2}) are strengthening agents, due to their superb force and fracture toughness. The high efficiency of the calcination process opens a new way of producing commercial amounts of nanocrystalline bioceramics. In this work, a new variation of the solid-state procedure method was used to produce nanocrystalline powders of titanium and zirconium, using two different experimental chemical routes: CapTi: Ca(H{sub 2}PO{sub 4}){sub 2}+TiO{sub 2} and CapZr: Ca(H{sub 2}PO{sub 4}){sub 2}+ZrO{sub 2}. The powders were submitted to calcination processes (CapTic and CapZrc) at 800, 900 and 1000 deg. C. The calcium titanium phosphate phase, CaTi{sub 4}P{sub 6}O{sub 24}, was obtained in the CapTic reaction and the calcium zirconium phosphate, CaZr{sub 4}P{sub 6}O{sub 24}, was obtained in the CapZrc reaction. The obtained ceramics were characterized by x-ray powder diffraction (XRD), infrared (IR) spectroscopy, Raman scattering spectroscopy (RSS) and scanning electron microscopy (SEM) analysis. This method was compared with the milling process (CapTim and CapZrm), where in the last process the melting is not necessary and the powder obtained is nanocrystalline. The calcium titanium phosphate phase, CaTi{sub 4}P{sub 6}O{sub 24}, was obtained in the reaction CapTim, but in CapZrm the formation of any calcium phosphate phase even after 15 h of dry mechanical alloying was not observed.

Comprehensive thermal and structural characterization of antimony-phosphate glass

Science.gov (United States)

Moustafa, S. Y.; Sahar, M. R.; Ghoshal, S. K.

For the first time, we prepare new ternary glass systems of composition (95-x)Sb2O3-xP2O5-5MgO, where x = 45, 40, 35 mol%; (85-x)Sb2O3-xP2O5-15MgO, where x = 55, 35, 25 mol%; (75-x)Sb2O3-xP2O5-25MgO, where x = 45, 35, 25 mol%; and 60Sb2O3-(40-x)P2O5-xMgO, where x = 10, 20 mol% via melt-quenching method. Synthesized glasses are characterized using XRD, FESEM, EDX, and TG/DTA measurements. The influence of varying modifier concentrations on their thermal properties is evaluated. The XRD patterns confirmed the amorphous nature of samples. SEM images demonstrated interesting phase formation with ribbons-like texture. Five crystalline phases are evidenced in the ternary diagram which are antimony phosphate and antimony orthophosphate as major phases as well as magnesium phosphate, magnesium cyclo-tetraphosphate and cervantite as minor phases. EDX spectra detected the right elemental traces. Detailed thermal analysis of these glasses revealed their high-molecular polymer character for Sb2O3 content greater than 50 mol%. Three different glass transition temperatures are achieved around 276, 380-381 and 422-470 °C depending on the composition. Furthermore, the solidus and liquidus temperature are found to decrease with increasing Sb2O3 and increases for MgO contents till 15 mol% and then decrease, where the lowest recorded solidus temperature is 426 °C. This observation may open up new research avenues for antimony based ternary glasses and an exploitation of the derived results for optoelectronics applications, photonic devices and non-linear optical devices.

A novel biphasic calcium phosphate derived from fish otoliths

Science.gov (United States)

Montañez-Supelano, N. D.; Sandoval-Amador, A.; Estupiñan-Durán, H. A.; Y Peña-Ballesteros, D.

2017-12-01

Calcium phosphates are bioceramics that have been widely used as bone substitutes because they encourage the formation of bone on their surface and can improve the healing of the bone. Hydroxyapatite HA (calcium/phosphorus ratio of 1.67) and tricalcium phosphate TCP (calcium/phosphorus ratio of 1.50) are the most common calcium phosphates. Natural materials have begun to be tested to make HA or TCP such as shells of cardiidae (family of mollusks) and eggshells. The calcium phosphate obtained has a high ability to precipitate apatite. In this work, the mixed phase ceramic of beta-Tri-calcium phosphate / hydroxyapatite (β-TCP/HA) was synthesized by aqueous precipitation from fish otoliths, which are monomineralic species composed of aragonite. Otoliths of the specie Plagioscion squamosissimus, commonly called the river croaker, were used. Techniques such as DRX, Raman spectroscopy and SEM-EDS were used to characterize the raw material and the obtained material. X-ray diffraction analysis revealed the presence of two crystalline phases of calcium phosphates with 86.2% crystallinity. SEM micrographs showed agglomeration of particles with porous structure and submicron particle sizes.

TGF-β prevents phosphate-induced osteogenesis through inhibition of BMP and Wnt/β-catenin pathways.

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Fátima Guerrero

Full Text Available BACKGROUND: Transforming growth factor-β (TGF-β is a key cytokine during differentiation of mesenchymal stem cells (MSC into vascular smooth muscle cells (VSMC. High phosphate induces a phenotypic transformation of vascular smooth muscle cells (VSMC into osteogenic-like cells. This study was aimed to evaluate signaling pathways involved during VSMC differentiation of MSC in presence or not of high phosphate. RESULTS: Our results showed that TGF-β induced nuclear translocation of Smad3 as well as the expression of vascular smooth muscle markers, such as smooth muscle alpha actin, SM22α, myocardin, and smooth muscle-myosin heavy chain. The addition of high phosphate to MSC promoted nuclear translocation of Smad1/5/8 and the activation of canonical Wnt/β-catenin in addition to an increase in BMP-2 expression, calcium deposition and alkaline phosphatase activity. The administration of TGF-β to MSC treated with high phosphate abolished all these effects by inhibiting canonical Wnt, BMP and TGF-β pathways. A similar outcome was observed in high phosphate-treated cells after the inhibition of canonical Wnt signaling with Dkk-1. Conversely, addition of both Wnt/β-catenin activators CHIR98014 and lithium chloride enhanced the effect of high phosphate on BMP-2, calcium deposition and alkaline phosphatase activity. CONCLUSIONS: Full VSMC differentiation induced by TGF-β may not be achieved when extracellular phosphate levels are high. Moreover, TGF-β prevents high phosphate-induced osteogenesis by decreasing the nuclear translocation of Smad 1/5/8 and avoiding the activation of Wnt/β-catenin pathway.

Crude oil degradation by phosphate-solubilizing bacteria

Digital Repository Service at National Institute of Oceanography (India)

DeSouza, M.J.B.D.; Nair, S.; David, J.J.; Chandramohan, D.

Phosphate-solubilizing bacteria were isolated from tropical areas around the Indian peninsula. Two of the isolates showed high phosphatase activity. The isolates were identified as Klebsiella pneumoniae and Bacillus pumilus, and they showed high...

Radioactivity in groundwater associated with uranium and phosphate mining and processing

International Nuclear Information System (INIS)

Kaufmann, R.F.

1981-01-01

From 1975 to 1980 USEPA investigations of the uranium and phosphate mining and milling industries addressed associated changes in the radionuclide content of nearby water resources. Available data for 226 Ra in central Florida aquifers show no significant difference in phosphate mineralized vs. nonmineralized areas. Apparently neither mineralization nor the industry cause significant increase in the Ra content of groundwater. Uranium mining and milling in a number of Western States (e.g. New Mexico, Wyoming, Colorado, Washington) cause locally increased levels of U, Ra and Th in shallow groundwater, but potable water supplies have not been adversely affected. Contamination of deep aquifers does not appear to occur, although elevated levels of Ra and U are present in many mine water discharges as a result of ore body oxidation and leaching. Model underground and surface U mines were used to evaluate chemical loading of 238 U, 226 Ra, 210 Pb and 210 Po to local and regional hydrographic units. Infiltration of mine water to potable groundwater and suspension/solution of contaminants in flood water constitute the principal elements of the aqueous pathway

Hemodialysis for near-fatal sodium phosphate toxicity in a child receiving sodium phosphate enemas.

Science.gov (United States)

Becknell, Brian; Smoyer, William E; O'Brien, Nicole F

2014-11-01

This study aimed to demonstrate the importance of considering hemodialysis as a treatment option in the management of sodium phosphate toxicity. This is a case report of a 4-year-old who presented to the emergency department with shock, decreased mental status, seizures, and tetany due to sodium phosphate toxicity from sodium phosphate enemas. Traditional management of hyperphosphatemia with aggressive hydration and diuretics was insufficient to reverse the hemodynamic and neurological abnormalities in this child. This is the first report of the use of hemodialysis in a child without preexisting renal failure for the successful management of near-fatal sodium phosphate toxicity. Hemodialysis can safely be used as an adjunctive therapy in sodium phosphate toxicity to rapidly reduce serum phosphate levels and increase serum calcium levels in children not responding to conventional management.

Evaluating agronomic effectiveness of phosphate rocks using nuclear and related techniques: Results from an FAO/IAEA co-ordinated research project

Energy Technology Data Exchange (ETDEWEB)

Zapata, F [International Atomic Energy Agency, Vienna (Austria)

2000-06-01

An FAO/IAEA Co-ordinated Research Project, 'The use of nuclear and related techniques for evaluating the agronomic effectiveness of phosphatic fertilisers, in particular rock phosphates', was in operation during the period 1993-98. The research network comprised twenty-three scientists, of whom seventeen were in developing countries, with six in industrialized nations. Conventional and {sup 32}P-isotope techniques were utilized to assess the bioavailability of P in soils amended with phosphate rock (PR) and water-soluble fertilisers, and to evaluate the agronomic effectiveness of PR products. No single chemical extraction method was found to be suitable for all soils and fertilisers. The Pi strip method showed promising results, but more testing is needed with tropical acid soils. The {sup 32}P-phosphate-exchange kinetics method allowed a complete characterization of P dynamics, and provided basic information for estimating the kinetic pools of soil P. The agronomic effectiveness (AE) of PRs depends on their solubility (reactivity), which is related to the degree of carbonate substitution for phosphate in the apatite structure. Rock phosphates of low reactivity were unsuitable for direct application to annual crops. Research in Venezuela, China, Cuba, Brazil, and Thailand demonstrated that AE can be increased by partial acidulation, or by mixing with organic materials or a water-soluble source. The AE can be enhanced also through inoculation with mycorrhizal fungi and rhizobacteria. The AE, which depends on species, is particularly high in crops such as canola and lupin that exude organic acids from the roots. Agronomic effectiveness of PR is higher on soils with low pH, low available P, low exchangeable Ca, high cation exchange capacity and high organic-matter content. The {sup 32}P-techniques are powerful tools for studying the factors that affect AE. Information from field trials was used to create a database for validating a model for providing recommendations

Kinetics of strontium sorption in calcium phosphate

International Nuclear Information System (INIS)

Bacic, S.; Komarov, V.F.; Vukovic, Z.

1989-01-01

Kinetics of strontium sorption by highly dispersed solids: tricalcium phosphate (Ca 3 (PO 4 ) 2 , TCP) and hydroxyapatite (Ca 5 (PO 4 ) 3 )H, HAP) were investigated. Analysis of sorption data was made taking into consideration composition and morphology of ultra micro particles. Conclusion is that the isomorphous strontium impurity is structurally sensitive element for calcium phosphate. It was determined that the beginning of strontium desorption corresponds to the beginning of transformation of the TCP - HAP (author)

Phosphate transporter mediated lipid accumulation in Saccharomyces cerevisiae under phosphate starvation conditions.

Science.gov (United States)

James, Antoni W; Nachiappan, Vasanthi

2014-01-01

In the current study, when phosphate transporters pho88 and pho86 were knocked out they resulted in significant accumulation (84% and 43%) of triacylglycerol (TAG) during phosphate starvation. However in the presence of phosphate, TAG accumulation was only around 45% in both pho88 and pho86 mutant cells. These observations were confirmed by radio-labeling, fluorescent microscope and RT-PCR studies. The TAG synthesizing genes encoding for acyltransferases namely LRO1 and DGA1 were up regulated. This is the first report for accumulation of TAG in pho88Δ and pho86Δ cells under phosphate starvation conditions. Copyright © 2013. Published by Elsevier Ltd.

Structure of cesium loaded iron phosphate glasses: An infrared and Raman spectroscopy study

International Nuclear Information System (INIS)

Joseph, Kitheri; Premila, M.; Amarendra, G.; Govindan Kutty, K.V.; Sundar, C.S.; Vasudeva Rao, P.R.

2012-01-01

The structure of cesium loaded iron phosphate glasses (IPG) was investigated using infrared and Raman spectroscopy. The spectra of the cesium doped samples revealed a structural modification of the parent glass owing to the incorporation of cesium. The structural changes could be correlated with the variation observed in the glass transition temperature of these glasses. Increased Cs-mediated cationic cross linking appears to be the reason for the initial rise in glass transition temperature up to 21 mol% Cs 2 O in IPG; while, breakdown of the phosphate network with increasing cesium content, brings down the glass transition temperature.

Zinc in calcium phosphate mediates bone induction: in vitro and in vivo model

NARCIS (Netherlands)

Luo, Xiaoman; Barbieri, D.; Davison, N.; Yan, Y.; de Bruijn, Joost Dick; Yuan, Huipin

2014-01-01

Zinc-containing tricalcium phosphate (Zn-TCP) was synthesized to investigate the role of zinc in osteoblastogenesis, osteoclastogenesis and in vivo bone induction in an ectopic implantation model. Zinc ions were readily released in the culture medium. Zn-TCP with the highest zinc content enhanced

Conversion of spent mushroom substrate to biofertilizer using a stress-tolerant phosphate-solubilizing Pichia farinose FL7.

Science.gov (United States)

Zhu, Hong-Ji; Sun, Li-Fan; Zhang, Yan-Fei; Zhang, Xiao-Li; Qiao, Jian-Jun

2012-05-01

To develop high-efficient biofertilizer, an environmental stress-tolerant phosphate-solubilizing microorganism (PSM) was isolated from agricultural wastes compost, and then applied to spent mushroom substrate (SMS). The isolate FL7 was identified as Pichia farinose with resistance against multiple environmental stresses, including 5-45°C temperature, 3-10 pH range, 0-23% (w/v) NaCl and 0-6M ammonium ion. Under the optimized cultivation condition, 852.8 mg/l total organic acids can be produced and pH can be reduced to 3.8 after 60 h, meanwhile, the soluble phosphate content reached 816.16 mg/l. The P. farinose was used to convert SMS to a phosphate biofertilizer through a semi-solid fermentation (SSF) process. After fermentation of 10 days, cell density can be increased to 5.6 × 10(8)CFU/g in biomass and pH in this medium can be decreased to 4.0. SMS biofertilizer produced by P. farinose significantly improved the growth of soybean in pot experiments, demonstrating a tremendous potential in agricultural application. Copyright © 2012 Elsevier Ltd. All rights reserved.

Study of hMSC proliferation and differentiation on Mg and Mg–Sr containing biphasic β-tricalcium phosphate and amorphous calcium phosphate ceramics

International Nuclear Information System (INIS)

Singh, Satish S.; Roy, Abhijit; Lee, Boeun; Kumta, Prashant N.

2016-01-01

Biphasic mixtures of either Mg"2"+ or combined Mg"2"+ and Sr"2"+ cation substituted β-tricalcium phosphate (β-TCP) and amorphous calcium phosphate (ACP) were prepared using a low temperature chemical phosphatizing and hydrolysis reaction approach. Scaffolds prepared using the cation substituted calcium phosphates were capable of supporting similar levels of human mesenchymal stem cell proliferation in comparison to commercially available β-TCP. The concentrations of Mg"2"+, Sr"2"+, and PO_4"3"− released from these scaffolds were also within the ranges desired from previous reports to support both hMSC proliferation and osteogenic differentiation. Interestingly, hMSCs cultured directly on scaffolds prepared with only Mg"2"+ substituted β-TCP were capable of supporting statistically significantly increased alkaline phosphatase activity, osteopontin, and osteoprotegerin expression in comparison to all compositions containing both Mg"2"+ and Sr"2"+, and commercially available β-TCP. hMSCs cultured in the presence of scaffold extracts also exhibited similar trends in the expression of osteogenic markers as was observed during direct culture. Therefore, it was concluded that the enhanced differentiation observed was due to the release of bioactive ions rather than the surface microstructure. The role of these ions on transforming growth factor-β and bone morphogenic protein signaling was also evaluated using a PCR array. It was concluded that the release of these ions may support enhanced differentiation through SMAD dependent TGF-β and BMP signaling. - Highlights: • Synthesis of Mg and Mg-Sr containing biphasic beta tricalcium phosphate ceramics • Magnesium substitution influences ALP activity compared to strontium content. • Solution extract plays a more dominant role on hMSC differentiation. • Direct and indirect Mg and Mg-Sr TCP culture show similar OPG and OPN expression.

Study of hMSC proliferation and differentiation on Mg and Mg–Sr containing biphasic β-tricalcium phosphate and amorphous calcium phosphate ceramics

Energy Technology Data Exchange (ETDEWEB)

Singh, Satish S., E-mail: sss42@pitt.edu [Department of Chemical & Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Roy, Abhijit, E-mail: abr20@pitt.edu [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Lee, Boeun [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Kumta, Prashant N., E-mail: pkumta@pitt.edu [Department of Chemical & Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Center for Craniofacial Regeneration, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Mechanical Engineering and Materials Science, University of Pittsburgh, PA 15261 (United States)

2016-07-01

Biphasic mixtures of either Mg{sup 2+} or combined Mg{sup 2+} and Sr{sup 2+} cation substituted β-tricalcium phosphate (β-TCP) and amorphous calcium phosphate (ACP) were prepared using a low temperature chemical phosphatizing and hydrolysis reaction approach. Scaffolds prepared using the cation substituted calcium phosphates were capable of supporting similar levels of human mesenchymal stem cell proliferation in comparison to commercially available β-TCP. The concentrations of Mg{sup 2+}, Sr{sup 2+}, and PO{sub 4}{sup 3−} released from these scaffolds were also within the ranges desired from previous reports to support both hMSC proliferation and osteogenic differentiation. Interestingly, hMSCs cultured directly on scaffolds prepared with only Mg{sup 2+} substituted β-TCP were capable of supporting statistically significantly increased alkaline phosphatase activity, osteopontin, and osteoprotegerin expression in comparison to all compositions containing both Mg{sup 2+} and Sr{sup 2+}, and commercially available β-TCP. hMSCs cultured in the presence of scaffold extracts also exhibited similar trends in the expression of osteogenic markers as was observed during direct culture. Therefore, it was concluded that the enhanced differentiation observed was due to the release of bioactive ions rather than the surface microstructure. The role of these ions on transforming growth factor-β and bone morphogenic protein signaling was also evaluated using a PCR array. It was concluded that the release of these ions may support enhanced differentiation through SMAD dependent TGF-β and BMP signaling. - Highlights: • Synthesis of Mg and Mg-Sr containing biphasic beta tricalcium phosphate ceramics • Magnesium substitution influences ALP activity compared to strontium content. • Solution extract plays a more dominant role on hMSC differentiation. • Direct and indirect Mg and Mg-Sr TCP culture show similar OPG and OPN expression.

Effect of phosphate additive on the nitrogen transformation during pig manure composting.

Science.gov (United States)

Wu, Juan; He, Shengzhou; Liang, Ying; Li, Guoxue; Li, Song; Chen, Shili; Nadeem, Faisal; Hu, Jingwei

2017-07-01

Previous studies revealed that phosphate, as an additive to composting, could significantly reduce NH 3 emission and nitrogen loss through change of pH and nitrogen fixation to form ammonium phosphate. However, few studies have explored the influence of pH change and phosphate additive on NO x - -N, NH 4 + -N, NH 3 , and N 2 O, which are dominate forms of nitrogen in composting. In this study, the equimolar H 3 PO 4 , H 2 SO 4 , and K 2 HPO 4 were added into pig manure composting to evaluate the effect of H + and PO 4 3- on nitrogen transformation. As a result, we reached the conclusion that pH displays significant influence on adsorption from PO 4 3- to NH 4 + . The NH 4 + -N concentration in H 3 PO 4 treatment kept over 3 g kg -1 DM (dry matter) which is obviously higher than that in H 2 SO 4 treatment, and NH 4 + -N concentration in K 2 HPO 4 treatment (pH>8.5) is lower than 0.5 g kg -1 DM because adsorption capacity of PO 4 3- is greatly weakened and NH 4 + -N rapidly transformed to NH 3 -N influenced by high pH value. The N 2 O emission of composting is significantly correlated with incomplete denitrification of NO x - -N, and PO 4 3- addition could raise NO x - -N contents to restrict denitrification and further to promote N 2 O emission. The study reveals the influence mechanism of phosphate additive to nitrogen transformation during composting, presents theoretical basis for additive selection in nitrogen fixation, and lays foundation for study about nitrogen circulation mechanism during composting.

Immobilization of Uranium Silicide in Sintered Iron-Phosphate Glass

International Nuclear Information System (INIS)

Mateos, Patricia; Russo, Diego; Rodriguez, Diego; Heredia, A; Sanfilippo, M.; Sterba, Mario

2003-01-01

This work is a continuation of a previous one performed in vitrification of uranium silicide in borosilicate and iron-silicate glasses, by sintering.We present the results obtained with an iron-phosphate glass developed at our laboratory and we compare this results with those obtained with the above mentioned glasses. The main objective was to develop a method as simple as possible, so as to get a monolithic glass block with the appropriate properties to be disposed in a deep geological repository.The thermal transformation of the uranium silicide was characterized by DTA/TG analysis and X-ray diffraction.We determined the evolution of the crystalline phases and the change in weight.Calcined uranium silicide was mixed with natural U 3 O 8 , the amount of U 3 O 8 was calculated to simulate an isotopic dilution of 4%.This material was mixed with powdered iron-phosphate glass (in wt.%: 64,9 P 2 O 5 ; 22,7 Fe 2 O 3 ; 8,1 Al 2 O 3 ; 4,3 Na 2 O) in different proportions (in wt%): 7%, 10% y 15%.The powders were pressed and sintered at temperatures between 585 y 670 °C. Samples of the sintered pellet were prepared for the lixiviation tests (MCC-1P: monolithic samples; deionised water; 90° C; 7, 14 and 28 days).The samples showed a quite good durability (0,6 g.m -2 .day -1 ), similar to borosilicate glasses.The microstructure of the glass samples showed that the uranium particles are much better integrated to the glass matrix in the iron-phosphate glasses than in the borosilicate or iron-silicate glasses.We can conclude that the sintered product obtained could be a good alternative for the immobilization of nuclear wastes with high content of uranium, as the ones arising from the conditioning of research reactors spent fuels

Bentonite surface modification and characterization for high selective phosphate adsorption from aqueous media and its application for wastewater treatments

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S. Yaghoobi-Rahni

2017-06-01

Full Text Available Raw and modified bentonite has been used to develop effective sorbents to remove phosphate from aqueous solution. Acid thermoactivation, Rewoquate, Irasoft, calcium, Fe and Al were employed to treat the bentonite. Results show that samples adsorption capacity for phosphate is in the order of, unmodified bentonite = acid thermoactivation < Rewoquate < calcium ≅ Irasoft < Fe < Al ≅ Fe-Al. The phosphate adsorption with Fe-Al-bentonite (FAB modification was more than 99% and the phosphate removal reached the peak value in the initial 30 min. The phosphate adsorption of FAB was pH independent in the range of 2–10. The common coexisting ions in wastewater have no effect on the phosphate adsorption. The phosphate adsorption results were very well fitted in the Freundlich and Langmuir isotherm model and the maximum adsorption capacity was 8.33 mg P/g at pH 6.5 for 1 hour, which was better than similar modified bentonite with low time and Fe-Al consumption. FAB was characterized by scanning electron microscopy, X-ray diffraction, X-ray fluorescence and Fourier transform infrared. Therefore, the results confirm that FAB is a selective phosphate sorbent and environmentally friendly for its potential application for phosphate removal from wastewater.

Evaluation of phosphate fertilizers for the stabilization of cadmium in highly contaminated soils

International Nuclear Information System (INIS)

Thawornchaisit, Usarat; Polprasert, Chongrak

2009-01-01

The efficiency of three phosphate fertilizers including triple superphosphate (TSP), diammonium phosphate (DAP), and phosphate rock (PR) as stabilizing agents of cadmium-contaminated soils has been assessed in this study. Two types of assessment criteria, (a) the reduction of leachable cadmium concentration; and (b) the changes in Cd association with specific operational soil fraction based on the sequential extraction data, are used in the evaluation of stabilization performance of each fertilizer. Results of the study showed that after the 60-day stabilization, the leachable concentrations of Cd in PR-, DAP- and TSP- treated soils reduced from 306 mg/kg (the control) to 140, 34, and 12 mg/kg with the stabilization efficiency as TSP>DAP>PR. Results from the assessment of Cd speciation via sequential extraction procedure revealed that the soluble-exchangeable fraction and the surface adsorption fraction of Cd in the soils treated with PO 4 fertilizers, especially with TSP, have been reduced considerably. In addition, it is found that the reduction was correspondingly related with the increase of more stable forms of cadmium: the metal bound to manganese oxides and the metal bound to crystalline iron oxides. Treatment efficiency increased as the phosphate dose (based on the molar ratio of PO 4 /Cd) increased. In addition, it was observed that stabilization was most effective when using the molar ratio of PO 4 /Cd at 2:1 and at least 21-day and 28-day stabilization time for TSP and DAP, respectively.

21 CFR 137.175 - Phosphated flour.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Phosphated flour. 137.175 Section 137.175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Related Products § 137.175 Phosphated flour. Phosphated flour, phosphated white flour, and phosphated...

Polypyrrole electrodeposited on copper from an aqueous phosphate solution: Corrosion protection properties

OpenAIRE

Redondo, Clara; Breslin, Carmel B.

2007-01-01

Highly adherent and homogenous polypyrrole films were electrodeposited at copper from a dihydrogen phosphate solution. The polypyrrole films were electrosynthesized in the overoxidized state by cycling the copper electrode from –0.4 to 1.8 V (SCE) in a pyrrole-containing phosphate solution. The growth of the polypyrrole films was facilitated by the initial oxidation of the copper electrode in the phosphate solution to generate a mixed copper–phosphate, copper oxide or hydroxide layer. This la...

Over-expression of Arabidopsis thaliana SFD1/GLY1, the gene encoding plastid localized glycerol-3-phosphate dehydrogenase, increases plastidic lipid content in transgenic rice plants.

Science.gov (United States)

Singh, Vijayata; Singh, Praveen Kumar; Siddiqui, Adnan; Singh, Subaran; Banday, Zeeshan Zahoor; Nandi, Ashis Kumar

2016-03-01

Lipids are the major constituents of all membranous structures in plants. Plants possess two pathways for lipid biosynthesis: the prokaryotic pathway (i.e., plastidic pathway) and the eukaryotic pathway (i.e., endoplasmic-reticulum (ER) pathway). Whereas some plants synthesize galactolipids from diacylglycerol assembled in the plastid, others, including rice, derive their galactolipids from diacylglycerols assembled by the eukaryotic pathway. Arabidopsis thaliana glycerol-3-phosphate dehydrogenase (G3pDH), coded by SUPPRESSOR OF FATTY ACID DESATURASE 1 (SFD1; alias GLY1) gene, catalyzes the formation of glycerol 3-phosphate (G3p), the backbone of many membrane lipids. Here SFD1 was introduced to rice as a transgene. Arabidopsis SFD1 localizes in rice plastids and its over-expression increases plastidic membrane lipid content in transgenic rice plants without any major impact on ER lipids. The results suggest that over-expression of plastidic G3pDH enhances biosynthesis of plastid-localized lipids in rice. Lipid composition in the transgenic plants is consistent with increased phosphatidylglycerol synthesis in the plastid and increased galactolipid synthesis from diacylglycerol produced via the ER pathway. The transgenic plants show a higher photosynthetic assimilation rate, suggesting a possible application of this finding in crop improvement.

Hydrophobic and Metallophobic Surfaces: Highly Stable Non-wetting Inorganic Surfaces Based on Lanthanum Phosphate Nanorods.

Science.gov (United States)

Sankar, Sasidharan; Nair, Balagopal N; Suzuki, Takehiro; Anilkumar, Gopinathan M; Padmanabhan, Moothetty; Hareesh, Unnikrishnan Nair S; Warrier, Krishna G

2016-03-09

Metal oxides, in general, are known to exhibit significant wettability towards water molecules because of the high feasibility of synergetic hydrogen-bonding interactions possible at the solid-water interface. Here we show that the nano sized phosphates of rare earth materials (Rare Earth Phosphates, REPs), LaPO4 in particular, exhibit without any chemical modification, unique combination of intrinsic properties including remarkable hydrophobicity that could be retained even after exposure to extreme temperatures and harsh hydrothermal conditions. Transparent nanocoatings of LaPO4 as well as mixture of other REPs on glass surfaces are shown to display notable hydrophobicity with water contact angle (WCA) value of 120° while sintered and polished monoliths manifested WCA greater than 105°. Significantly, these materials in the form of coatings and monoliths also exhibit complete non-wettability and inertness towards molten metals like Ag, Zn, and Al well above their melting points. These properties, coupled with their excellent chemical and thermal stability, ease of processing, machinability and their versatile photo-physical and emission properties, render LaPO4 and other REP ceramics utility in diverse applications.

Water-Soluble Cellulose Derivatives Are Sustainable Additives for Biomimetic Calcium Phosphate Mineralization

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Andreas Taubert

2016-10-01

Full Text Available The effect of cellulose-based polyelectrolytes on biomimetic calcium phosphate mineralization is described. Three cellulose derivatives, a polyanion, a polycation, and a polyzwitterion were used as additives. Scanning electron microscopy, X-ray diffraction, IR and Raman spectroscopy show that, depending on the composition of the starting solution, hydroxyapatite or brushite precipitates form. Infrared and Raman spectroscopy also show that significant amounts of nitrate ions are incorporated in the precipitates. Energy dispersive X-ray spectroscopy shows that the Ca/P ratio varies throughout the samples and resembles that of other bioinspired calcium phosphate hybrid materials. Elemental analysis shows that the carbon (i.e., polymer contents reach 10% in some samples, clearly illustrating the formation of a true hybrid material. Overall, the data indicate that a higher polymer concentration in the reaction mixture favors the formation of polymer-enriched materials, while lower polymer concentrations or high precursor concentrations favor the formation of products that are closely related to the control samples precipitated in the absence of polymer. The results thus highlight the potential of (water-soluble cellulose derivatives for the synthesis and design of bioinspired and bio-based hybrid materials.

Phosphate-mediated electrochemical adsorption of cisplatin on gold electrodes

International Nuclear Information System (INIS)

Kolodziej, Adam; Figueiredo, Marta C.; Koper, Marc T.M.; Fernandez-Trillo, Francisco; Rodriguez, Paramaconi

2017-01-01

Highlights: •The potential-dependent adsorption and deposition of cisplatin on polycrystalline gold electrode is mediated by the adsorption of phosphate anions on gold electrode. •Quantitative analysis suggests that the stoichiometry of the phosphate species and the cisplatin adsorbed was 1:1. •Upon reduction of the phosphate-mediated cisplatin adsorption, the platinum deposits are formed by 3D nanoclusters -- Abstract: This manuscript reports the potential-dependent adsorption and deposition of cisplatin on polycrystalline gold electrode. It was found that this process is mediated by the adsorption of phosphate anions on the gold electrode and that the maximum coverage of Pt adsorbed is given by the maximum coverage of phosphate adsorbed at a given potential. The interaction of cisplatin with the phosphate groups was confirmed by in situ FTIR spectroscopy under external reflexion configuration. Quantitative analysis suggests that the stoichiometry of the phosphate species and the cisplatin adsorbed was 1:1. Moreover, the relationship between the charge of the Pt deposited and the charge of the electrochemical surface area of the Pt deposited on the gold electrodes indicates that 3D nanoclusters of a few atoms of Pt were formed over the gold electrode upon the electrochemical reduction of the adsorbed cisplatin. The Pt nanoclusters formed under these conditions were later evaluated for the oxidation of a monolayer of carbon monoxide. The Pt nanoclusters showed a high overpotential for the oxidation of the carbon monoxide monolayer and the high oxidation overpotential was attributed to the absence of adsorption sites for OH species on the Pt clusters: only at potentials where the OH species are adsorbed at the edge between the Pt nanocluster and the gold support, the oxidation of the carbon monoxide on the Pt nanoparticles takes place.

Highly stable CsPbBr3 quantum dots coated with alkyl phosphate for white light-emitting diodes.

Science.gov (United States)

Xuan, Tongtong; Yang, Xianfeng; Lou, Sunqi; Huang, Junjian; Liu, Yong; Yu, Jinbo; Li, Huili; Wong, Ka-Leung; Wang, Chengxin; Wang, Jing

2017-10-19

Inorganic halide perovskite quantum dots (QDs) suffer from problems related to poor water stability and poor thermal stability. Here we developed a simple strategy to synthesize alkyl phosphate (TDPA) coated CsPbBr 3 QDs by using 1-tetradecylphosphonic acid both as the ligand for the CsPbBr 3 QDs and as the precursor for the formation of alkyl phosphate. These QDs not only retain a high photoluminescence quantum yield (PLQY, 68%) and narrow band emission (FHWM ∼ 22 nm) but also exhibit high stability against water and heat. The relative PL intensity of the QDs was maintained at 75% or 59% after being dispersed in water for 5 h or heated to 375 K (100 °C), respectively. Finally, white light-emitting diodes (WLEDs) with a high luminous efficiency of 63 lm W -1 and a wide color gamut (122% of NTSC) were fabricated by using green-emitting CsPbBr 3 /TDPA QDs and red-emitting K 2 SiF 6 :Mn 4+ phosphors as color converters. The luminous efficiency of the WLEDs remained at 90% after working under a relative humidity (RH) of 60% for 15 h, thereby showing promise for use as backlight devices in LCDs.

Advances in process technology for eco-friendly phosphates by separation of radionuclides

Energy Technology Data Exchange (ETDEWEB)

Singh, H; Mukherjee, T K [Uranium and Rare Earths Extraction Division, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

Phosphates are used in the industry for fertilizers, industrial chemicals (detergents, water-treatment chemicals) and food-additives. The source of phosphates for the industry is rock-phosphate. Over 90% of phosphate rocks of the world are associated with uranium and its radioactive daughter products. Processing and use of phosphates is accompanied by radiation hazards. The concentration of radionuclides is low, but in view of large number of persons exposed to the hazards, the cumulative societal pollution load is high, and a matter of concern for international organisations. Chemical engineering techniques have been developed for the reduction of societal radiation hazard from the phosphates. In this paper, brief details of the process and developmental efforts in India are described. (author). 4 refs., 1 fig.

Phosphate binding therapy in dialysis patients: focus on lanthanum carbonate

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Ismail A Mohammed

2008-11-01

Full Text Available Ismail A Mohammed, Alastair J HutchisonManchester Institute of Nephrology and Transplantation, Manchester Royal Infirmary, Oxford Road, Manchester, UKAbstract: Hyperphosphatemia is an inevitable consequence of end stage chronic kidney disease and is present in the majority of dialysis patients. Recent observational data has associated hyperphosphatemia with increased cardiovascular mortality among dialysis patients. Dietary restriction of phosphate and current dialysis prescription practices are not enough to maintain serum phosphate levels within the recommended range so that the majority of dialysis patients require oral phosphate binders. Unfortunately, conventional phosphate binders are not reliably effective and are associated with a range of limitations and side effects. Aluminium-containing agents are highly efficient but no longer widely used because of well established and proven toxicity. Calcium based salts are inexpensive, effective and most widely used but there is now concern about their association with hypercalcemia and vascular calcification. Sevelamer hydrochloride is associated with fewer adverse effects, but a large pill burden and high cost are limiting factors to its wider use. In addition, the efficacy of sevelamer as a monotherapy in lowering phosphate to target levels in severe hyperphosphatemia remains debatable. Lanthanum carbonate is a promising new non-aluminium, calcium-free phosphate binder. Preclinical and clinical studies have demonstrated a good safety profile, and it appears well tolerated and effective in reducing phosphate levels in dialysis patients. Its identified adverse events are apparently mild to moderate in severity and mostly GI related. It appears to be effective as a monotherapy, with a reduced pill burden, but like sevelamer, it is significantly more expensive than calcium-based binders. Data on its safety profile over 6 years of treatment are now available.Keywords: hyperphosphatemia, lanthanum

Comparative efficiency of high (trip super phosphate) and low (rock phosphate) grade p nutrition source enriched with organic amendment in maize crop

International Nuclear Information System (INIS)

Sabah, N.U.; Sarwar, G.; Tahir, M.A.

2016-01-01

Pakistan falls under arid to semi-arid climate and therefore, Pakistani soils are sufferer of phosphorus deficiency. Costly phosphatic commercial fertilizers and their unavailability at the time of crop demand is the burning issue in Pakistan. Under such circumstances, use of locally available rock phosphate (RP) grasps the interest of researchers now a day. Pakistan has blessed with considerable quantity of cheaper low grade RP in Abbottabad and Hazara districts of KPK province. Due to this scenario, a pot experiment was carried out to evaluate growth efficiency of maize crop by adding organic manure fortified with RP in comparison with TSP in normal soil (pHs= 8.15, ECe= 1.28 dSm-1, SAR = 4.77 mmol L-1, saturation percentage = 29% and sandy clay loam texture). The study was comprised of 7 treatments replicated three times including: T1 = Control (0 P); T2 = Recommended NK + organic material; T3 = Recommended NK + RRP; T4 = Recommended NK + RRP + OM; T5 = Recommended NK + TSP; T6 = Recommended NK + TSP + OM and T7 = N + K + TSP + 0.5 Organic manure. It was concluded that integrated use of organic amendment with RP (Local Hazara Red Rock Phosphate) and TSP proved superior as compared to their sole use on maize crop growth. A significant increase in available P concentration of the growth medium was observed due to addition of organic material along with TSP as a source of P. Addition of organic material also enhanced the soil carbon level as compared to control. It can be concluded that rock phosphate (RP) could be an effective and economic substitution for TSP when it is integrated with suitable organic amendment with specific size. (author)

Impact of phosphate-solubilizing bacteria inoculation methods on phosphorus transformation and long-term utilization in composting.

Science.gov (United States)

Wei, Yuquan; Zhao, Yue; Fan, Yuying; Lu, Qian; Li, Mingxiao; Wei, Qingbin; Zhao, Yi; Cao, Zhenyu; Wei, Zimin

2017-10-01

This study aimed to assess the effect of phosphate-solubilizing bacteria (PSB) application and inoculation methods on rock phosphate (RP) solubilization and bacterial community during composting. The results showed that PSB inoculation in different stages of composting, especially both in the beginning and cooling stages, not only improved the diversity and abundance of PSB and bacterial community, but also distinctly increased the content of potential available phosphorus. Redundancy analysis indicated that the combined inoculation of PSB in the initial stage with higher inoculation amount and in the cooling stage with lower inoculation amount was the best way to improve the inoculation effect and increase the solubilization and utilization of RP during composting. Besides, we suggested three methods to improve phosphorus transformation and long-term utilization efficiency in composts based on biological fixation of phosphates by humic substance and phosphate-accumulating organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Quantitative determination of glass content in monazite glass-ceramics by IR technique].

Science.gov (United States)

He, Yong; Zhang, Bao-min

2003-04-01

Monazite glass-ceramics consist of both monazite and metaphoshate glass phases. The absorption bands of both phases do not overlap each other, and the absorption intensities of bands 1,275 and 616 cm-1 vary with the glass contents. The correlation coefficient between logarithmic absorbance ratio of the two bands and glass contents was r = 0.9975 and its regression equation was y = 48.356 + 25.93x. The absorbance ratio of bands 952 and 616 cm-1 also varied with different ratios of Ce2O3/La2O3 in synthetic monazites, with r = 0.9917 and a regression equation y = 0.2211 exp (0.0221x). High correlation coefficients show that the IR technique could find new application in the quantitative analysis of glass content in phosphate glass-ceramics.

Infrared spectra of phosphate sorbed on iron hydroxide gel and the sorption products

International Nuclear Information System (INIS)

Nanzyo, M.

1986-01-01

Infrared absorption spectra of phosphate sorbed on iron hydroxide gel were obtained by applying the differential diffuse reflectance method. Absorption bands due to P-O stretching vibration were observed at 1,110 and 1,010 cm -1 at pH 12.3. With decreasing pH, these absorption bands gradually shifted to 1,100 and 1,020 cm -1 at pH 4.9. At pH 2.3, they became a broad single absorption band at 1,060 cm -1 . At pH 11 or above, the difference in the Na + adsorption between phosphated iron hydroxide gel and iron hydroxide gel was almost equal to the amount of phosphate sorption. This finding shows that phosphate was retained on the iron hydroxide gel surface as a bidentate ligand at a high pH. It was concluded that at a high pH phosphate was sorbed on iron hydroxide gel as a binuclear surface complex similar to that on goethite; the change in spectra for P-O stretching vibration with decreasing pH value was mainly caused by an increase in the fraction of amorphous iron phosphate; at pH 2.3, the phosphate sorption product consisted of amorphous iron phosphate. (author)

Spectroscopic studies of copper doped alkaline earth lead zinc phosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Sastry, S. Sreehari, E-mail: sreeharisastry@yahoo.com [Department of Physics, Acharya Nagarjuna University, Nagarjunanagar 522510 (India); Rao, B. Rupa Venkateswara [Department of Physics, Acharya Nagarjuna University, Nagarjunanagar 522510 (India); Department of Physics, V.R. Siddhartha Engineering College, Vijayawada 52007 (India)

2014-02-01

In this paper spectroscopic investigation of Cu{sup 2+} doped alkaline earth lead zinc phosphate glasses was done through the spectroscopic techniques like X-ray diffraction, Ultra Violet (UV) absorption Spectroscopy, Electron Paramagnetic Resonance (EPR – X band), Fourier Transform Infra Red (FTIR) and Raman Spectroscopy. Alkaline earth lead zinc phosphate glasses containing 0.1% copper oxide (CuO) were prepared by the melt quenching technique. Spectroscopic studies indicated that there is a greater possibility for the copper ions to exist in Cu{sup 2+} state in these glasses. The optical absorption spectra indicated that the absorption peak of Cu{sup 2+} is a function of composition. The maxima absorption peak was reported at 862 nm for strontium lead zinc phosphate glass. Bonding parameters were calculated for the optical and EPR data. All these spectral results indicated clearly that there are certain structural changes in the present glass system with different alkaline earth contents. The IR and Raman spectra noticed the breaking of the P–O–P bonds and creating more number of new P–O–Cu bonds.

Spectroscopic studies of copper doped alkaline earth lead zinc phosphate glasses

International Nuclear Information System (INIS)

Sastry, S. Sreehari; Rao, B. Rupa Venkateswara

2014-01-01

In this paper spectroscopic investigation of Cu 2+ doped alkaline earth lead zinc phosphate glasses was done through the spectroscopic techniques like X-ray diffraction, Ultra Violet (UV) absorption Spectroscopy, Electron Paramagnetic Resonance (EPR – X band), Fourier Transform Infra Red (FTIR) and Raman Spectroscopy. Alkaline earth lead zinc phosphate glasses containing 0.1% copper oxide (CuO) were prepared by the melt quenching technique. Spectroscopic studies indicated that there is a greater possibility for the copper ions to exist in Cu 2+ state in these glasses. The optical absorption spectra indicated that the absorption peak of Cu 2+ is a function of composition. The maxima absorption peak was reported at 862 nm for strontium lead zinc phosphate glass. Bonding parameters were calculated for the optical and EPR data. All these spectral results indicated clearly that there are certain structural changes in the present glass system with different alkaline earth contents. The IR and Raman spectra noticed the breaking of the P–O–P bonds and creating more number of new P–O–Cu bonds

Studies on phosphate use efficiency of wheat in Egypt

Energy Technology Data Exchange (ETDEWEB)

Abdou, M [Suez Canal Univ., Ismailia (Egypt). Soil and Water Dept.

1996-07-01

Genotypic differences in the efficiency of use of phosphorus and other nutrients in wheat was evaluated in a field study. The experiment was conducted during the 1991/92 and 1992/93 seasons on a virgin loamy sandy soil (pH 7.9) with low available phosphorus, in Ismailia, Suez Canal, Egypt. Because of arid climate, water was applied through sprinkler irrigation throughout the growing period (November to May). Shoot samples were taken at four developmental stages. Results show that there are substantial differences in phosphorus use efficiency of wheat. Biomass production, grain yield, straw yield, number of ears per m{sup 2}, and the number of grain per ear differed substantially at different phosphorus levels but there was no major difference in the 1000 grain weight. Wheat cultivars also showed significant differences in their P, K, Ca, and Mg contents. Eighteen local wheat cultivars (Triticum aestivum L.) were grown in the field to obtain information about root characteristics and vesicular-arbiscular mycorrhiza fungi infection that known to play a role in phosphate use efficiency of crops. Some root parameters such as root volume, root dry matter, root length and vesicular-arbiscular mycorrhiza infection rate were measured at three development stages. In addition, root diameter and root density were also measured. Wheat cultivars efficient in phosphorus use have a high root density in the sub soil region and this is accompanied with a high vesicular-arbiscular mycorrhiza infection rate. Cultivars showed differences in root morphology and vesicular-arbiscular mycorrhiza infection rate. Some cultivars had a low root density and vesicular-arbiscular mycorrhiza infection rate and these cultivars exhibited a high phosphorus use efficiency. This was particularly true with cultivars 14, 16, and 18. This information may be useful to plant breeders in their attempts to breed wheat cultivars efficient in phosphate uptake and use. 41 refs, 2 figs, 4 tabs.

Studies on phosphate use efficiency of wheat in Egypt

International Nuclear Information System (INIS)

Abdou, M.

1996-01-01

Genotypic differences in the efficiency of use of phosphorus and other nutrients in wheat was evaluated in a field study. The experiment was conducted during the 1991/92 and 1992/93 seasons on a virgin loamy sandy soil (pH 7.9) with low available phosphorus, in Ismailia, Suez Canal, Egypt. Because of arid climate, water was applied through sprinkler irrigation throughout the growing period (November to May). Shoot samples were taken at four developmental stages. Results show that there are substantial differences in phosphorus use efficiency of wheat. Biomass production, grain yield, straw yield, number of ears per m 2 , and the number of grain per ear differed substantially at different phosphorus levels but there was no major difference in the 1000 grain weight. Wheat cultivars also showed significant differences in their P, K, Ca, and Mg contents. Eighteen local wheat cultivars (Triticum aestivum L.) were grown in the field to obtain information about root characteristics and vesicular-arbiscular mycorrhiza fungi infection that known to play a role in phosphate use efficiency of crops. Some root parameters such as root volume, root dry matter, root length and vesicular-arbiscular mycorrhiza infection rate were measured at three development stages. In addition, root diameter and root density were also measured. Wheat cultivars efficient in phosphorus use have a high root density in the sub soil region and this is accompanied with a high vesicular-arbiscular mycorrhiza infection rate. Cultivars showed differences in root morphology and vesicular-arbiscular mycorrhiza infection rate. Some cultivars had a low root density and vesicular-arbiscular mycorrhiza infection rate and these cultivars exhibited a high phosphorus use efficiency. This was particularly true with cultivars 14, 16, and 18. This information may be useful to plant breeders in their attempts to breed wheat cultivars efficient in phosphate uptake and use. 41 refs, 2 figs, 4 tabs

Thermal decomposition of calcium aluminium phosphate of Thies. [Vaporization of uranium and phosphorus pentoxide

Energy Technology Data Exchange (ETDEWEB)

Allaf, K; Rouanet, A

1984-01-01

This study is related to the work on beneficiation of raw phosphates by thermal processing (selective vaporization). More precisely it deals with the ability of a calcium-aluminium phosphate (ores from Thies) to vaporize selectively as phosphorus pentoxide and uranium contents. Experiments are performed on liquid samples at Tsub(f)

Uranyl phosphate mineral in Gapyeong area

International Nuclear Information System (INIS)

Chung, S.J.

1980-01-01

An uranyl phosphate crystal from Gapeong area is studied by means of single crystal x-ray diffraction and electron microscopic qualitative analysis of chemical contents. The crystal is identified as meta-ankoleite which has a unit cell of super structure with a=b=6.99 A, c=17.69 A and space group P4 2 22. There exists some indication in the total fluorescent spectrum of the sample that potassium may be partially substituted by calcium. The chemical formula of this meta-ankoleite may be expressed by Ksub(1-2x)Casub(x)(UO 2 PO 4 ) (H 2 O)sub(3-x). (Author)

EPMA Study of the Interface of β-Tricalcium Phosphate Ceramics in Vivo

Institute of Scientific and Technical Information of China (English)

Honglian DAI; Xianying CAO; Haichen SHAO; Chunhua SHEN; Shipu LI

2004-01-01

Electron probe and X-ray energy spectrum were used to investigate the chemical composition of the interface between material and new bone after porous tricalcium phosphate ceramic implanted in tibia of rabbits. The element changes of the interface, the materials transformation and the situation of new bone formation at different implantation period were observed. The results showed that the carbon element content decreased gradually in new bone tissue, and the content of calcium and phosphor element increased by degrees with the implantation time. At the same time, calcium-phosphor ratio in the new bone kept a higher level. New bone grew into the materials interior, material dispersed and degraded simultaneously. Both composition of materials and new bone tended to be consentient. Finally, the materials were substituted by new bone. After implantation, not only the materials itself dissolved and degraded partially, but also new bone formed on the outer and pore surface of β-TCP porous bioceramics, which showed that the degradation products of lifeless calcium phosphate inorganic materials took part in constituting of new bone tissue.

Structure and properties of gadolinium loaded calcium phosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Wang, Cuiling [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Liang, Xiaofeng, E-mail: XFLiang@swust.edu.cn [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Li, Haijian; Yu, Huijun; Li, Zhen [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Yang, Shiyuan [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China)

2014-10-15

The glass samples with composition xGd{sub 2}O{sub 3}–(50 − x)CaO–50P{sub 2}O{sub 5} (0 ⩽ x ⩽ 9 mol%) were prepared by the conventional melt quench method. The structure and properties of gadolinium loaded in calcium phosphate glasses were investigated using XRD, SEM, DTA, IR and Raman spectroscopy. The XRD and SEM analysis for the samples show that the majority of samples are amorphous, and crystallization occurs when the content of Gd{sub 2}O{sub 3} containing is up to 6 mol%. Two main crystalline phases, Ca{sub 2}P{sub 2}O{sub 7} and Gd{sub 3}(P{sub 2}O{sub 7}){sub 3}, are embedded in an amorphous matrix. IR and Raman data indicate that glass structure consists of predominantly metaphosphate (Q{sup 2}) units and the depolymerization of phosphate network with the addition of Gd{sub 2}O{sub 3}. Both the chemical durability and the glass transition temperature (T{sub g}) are improved with the increase of Gd{sub 2}O{sub 3}, which suggests that the Gd acts a role of strengthening the cross-links between the phosphate chains of the glass.

A Review on New Technological Progress for Beneficiation of Refractory Phosphate Ore in China

Science.gov (United States)

Dong, Xu; Siqing, Liu; Yanqing, Yao; Hailin, Liu; Yi, Pei

2017-05-01

The world is rich in phosphate resources, but the vast majority of the resources are of middle and low grade ores, and it is difficult to obtain high grade concentrate at a high recovery by using traditional separation methods. In this paper, the distribution and flotation processes of typical phosphate ores in China are introduced. Considering the current situation in phosphate ore beneficiation both home and abroad, the new trend of processing technology and reagents in China are summarized. Flotation is still regarded as the main processing method in phosphate ore beneficiation for a certain time in near future.

Interference of different ionic species on the analysis of phosphate in HLW using spectrophotometer

International Nuclear Information System (INIS)

Mishra, P.K.; Ghongane, D.E.; Valsala, T.P.; Sonavane, M.S.; Kulkarni, Y.; Changrani, R.D.

2010-01-01

During reprocessing of spent nuclear fuel by PUREX process different categories of radioactive liquid wastes like High Level (HL), Intermediate Level (IL) and Low Level (LL) are generated. Different methodologies are adopted for management of these wastes. Since PUREX solvent (30% Tri butyl phosphate-70% Normal Paraffin Hydrocarbon) undergoes chemical degradation in the highly acidic medium of dissolver solution, presence of phosphate in the waste streams is inevitable. Since higher concentrations of phosphate in the HLW streams will affect its management by vitrification, knowledge about the concentration of phosphate in the waste is essential before finalising the glass composition. Since a large number of anionic and cationic species are present in the waste, these species may interfere phosphate analysis using spectrophotometer. In the present work, the interference of different anionic and cationic species on the analysis of phosphate in waste solutions using spectrophotometer was studied

In-situ high temperature XRD of calcium phosphate biomaterial using DEHPA as the starting material

International Nuclear Information System (INIS)

Meor Yusoff Meor Sulaiman; Masliana Muslim

2009-01-01

A process to produce calcium phosphate biomaterial was done using an organic based phosphoric acid (DEHPA) as its starting material. The gel obtained from this reaction was used to study calcium phosphate transformation using in-situ XRD with temperature ranges from room temperature to 1300 degree C. The results obtained from this analysis show the following phase transformation: Gel β-Ca 2 P 2 O 7 β-TCP + HA α-TCP + HA, β-Ca 2 P 2 O 7 forms at 400 degree C and as we heat the sample at 1000 degree C peaks belonging to β- TCP and HA appears showing the transformation of the β-Ca 2 P 2 O 7 phase. When the sample is heated up further to 1200 degree C, β-TCP is transform into α-TCP. In the cold in-situ study, XRD analysis was performed on the sample from room temperature to -140 degree C. At room the XRD diffractogram shows the sample as an amorphous material and as the temperature was further lowered sharp peaks begins to form indicating that the material had becomes crystalline. The peaks were identified to be that calcium hydrogen phosphate (Ca(H 2 PO 4 ) 2 ) and this indicates that there is no hydroxyl group removal during the cooling process. The relative crystallinity values obtained for the different cooling temperatures show a slow exponential increase on the initial cooling of 0 to -100 degree C and at further cooling temperatures resulted fast and linear process. Also unlike the in-situ XRD analysis performs at high temperature no phase transformation occurred at this low temperature. (Author)

Transformation of ceria nanoparticles in cucumber plants is influenced by phosphate

International Nuclear Information System (INIS)

Rui, Yukui; Zhang, Peng; Zhang, Yanbei; Ma, Yuhui; He, Xiao; Gui, Xin; Li, Yuanyuan; Zhang, Jing; Zheng, Lirong; Chu, Shengqi; Guo, Zhi; Chai, Zhifang; Zhao, Yuliang; Zhang, Zhiyong

2015-01-01

Transformation is a critical factor that affects the fate and toxicity of manufactured nanoparticles (NPs) in the environment and living organisms. This paper aims to investigate the effect of phosphate on the transformation of CeO 2 NPs in hydroponic plants. Cucumber seedlings were treated with 2000 mg/L CeO 2 NPs in nutrient solutions with or without adding phosphate (+P or –P) for 3 weeks. Large quantities of needle-like CePO 4 was found outside the epidermis in the +P group. While in the –P group, CePO 4 only existed in the intercellular spaces and vacuole of root cells. X-ray absorption near edge spectroscopy (XANES) indicates that content and percentage of Ce-carboxylates in the shoots of –P group (418 mg/kg, 67.5%) were much higher than those in the +P group (30.1 mg/kg, 21%). The results suggest that phosphate might influence the transformation process of CeO 2 NPs in plants and subsequently their ultimate fate in the ecosystem. - Highlights: • We compared the transformation of CeO 2 NPs in cucumber plants with and without phosphate in nutrient solutions. • Results of TEM and STXM show that CePO 4 located differently in roots between +P and –P group. • The chemical species distributions of Ce in shoots were different between +P and –P group by XANES. • Phosphate significantly affected the transformation of CeO 2 NPs in plants. - CeO 2 NPs can be partially transformed to CePO 4 and Ce carboxylates in hydroponic plants. Phosphate significantly affected the transformation of CeO 2 NPs and subsequent translocation of Ce species

Protective roles of DMP1 in high phosphate homeostasis.

Directory of Open Access Journals (Sweden)

Afsaneh Rangiani

Full Text Available Dmp1 (dentin matrix protein1 null mice (Dmp1(-/- display hypophosphatemic rickets with a sharp increase in fibroblast growth factor 23 (FGF23. Disruption of Klotho (the obligatory co-receptor of FGF23 results in hyperphosphatemia with ectopic calcifications formed in blood vessels and kidneys. To determine the role of DMP1 in both a hyperphosphatemic environment and within the ectopic calcifications, we created Dmp1/Klotho compound deficient (Dmp1(-/-kl/kl mice.A combination of TUNEL, immunohistochemistry, TRAP, von Kossa, micro CT, bone histomorphometry, serum biochemistry and Scanning Electron Microscopy techniques were used to analyze the changes in blood vessels, kidney and bone for wild type control, Dmp1(-/-, Klotho deficient (kl/kl and Dmp1(-/-kl/kl animals.Interestingly, Dmp1(-/-kl/kl mice show a dramatic improvement of rickets and an identical serum biochemical phenotype to kl/kl mice (extremely high FGF23, hyperphosphatemia and reduced parathyroid hormone (PTH levels. Unexpectedly, Dmp1(-/-kl/kl mice presented elevated levels of apoptosis in osteocytes, endothelial and vascular smooth muscle cells in small and large blood vessels, and within the kidney as well as dramatic increase in ectopic calcification in all these tissues, as compared to kl/kl.These findings suggest that DMP1 has an anti-apoptotic role in hyperphosphatemia. Discovering this novel protective role of DMP1 may have clinical relevance in protecting the cells from apoptosis in high-phosphate environments as observed in chronic kidney disease (CKD.

Rapid preparation of ceramic moulds for medium-sized superalloy castings with magnesia-phosphate-bonded bauxite-mullite investments

Directory of Open Access Journals (Sweden)

Li Tingzhong

2010-11-01

Full Text Available Phosphate-bonded investments have already been widely utilized in dental restoration and micro-casting of artistic products for its outstanding rapid setting and high strength. However, the rapid setting rate of investment slurry has up to now been a barrier to extend the use of such slurry in preparation of medium-sized ceramic moulds. This paper proposes a new process of rapid fabrication of magnesia-phosphate-bonded investment ceramic moulds for medium-sized superalloy castings utilizing bauxite and mullite as refractory aggregates. In order to determine the properties of magnesia-phosphate-bonded bauxite-mullite investments (MPBBMI, a series of experiments were conducted, including modification of the workable time of slurry by liquid(mL/powder(g(L/P ratio and addition of boric acid as retard agent and sodium tri-polyphosphate (STP as strengthening agent, and adjustment of bauxite (g/mullite(g(B/M ratio for mechanical strength. Mechanical vibration was applied to improve initial setting time and fluidity when pouring investment slurry; then an intermediate size ceramic mould for superalloy castings was manufactured by means of this rapid preparing process with MPBBMI material. The results showed that the MPBBMI slurry exhibits proper initial setting time and excellent fluidity when the L/P ratio is 0.64 and the boric acid content is 0.88wt.%. The fired specimens made from the MPBBMI material demonstrated adequate compression strength to withstand impact force of molten metal when the B/M ratio is 0.89 and the STP content is 0.92wt.%. The experimental results confirmed the feasibility of the proposed rapid fabricating process for medium-sized ceramic moulds with MPBBMI material by appropriate measures.

New sunflower seeds with high contents of phytosterols

Directory of Open Access Journals (Sweden)

Velasco Leonardo

2014-11-01

Full Text Available Dietary phytosterols have a positive nutritional impact because they contribute to reduce cholesterol levels in blood. Accordingly, foods rich in phytosterols are required in a healthy diet. Vegetable oils are the richest source of phytosterols in the diet, though sunflower oil has lower phytosterol content than other seed oils such as rapeseed and corn. Increasing phytosterol content in sunflower oil requires optimizing first selection procedures. In this way, the development of accurate methods for analyzing phytosterol content in seeds instead of oils has opened up recently the way for large-scale screening for this trait. Large variability for seed phytosterol content has been identified in sunflower germplasm, from which we have developed a line, IASP-18, with about twofold seed phytosterol content than conventional sunflower. The trait is expressed across environments. Genetic studies are underway to characterize its inheritance and assess the feasibility of introgressing genes for high phytosterol content into elite sunflower germplasm.

Sorption of phosphate onto calcite; results from batch experiments and surface complexation modeling

DEFF Research Database (Denmark)

Sø, Helle Ugilt; Postma, Dieke; Jakobsen, Rasmus

2011-01-01

The adsorption of phosphate onto calcite was studied in a series of batch experiments. To avoid the precipitation of phosphate-containing minerals the experiments were conducted using a short reaction time (3h) and low concentrations of phosphate (⩽50μM). Sorption of phosphate on calcite was stud......The adsorption of phosphate onto calcite was studied in a series of batch experiments. To avoid the precipitation of phosphate-containing minerals the experiments were conducted using a short reaction time (3h) and low concentrations of phosphate (⩽50μM). Sorption of phosphate on calcite...... of a high degree of super-saturation with respect to hydroxyapatite (SIHAP⩽7.83). The amount of phosphate adsorbed varied with the solution composition, in particular, adsorption increases as the CO32- activity decreases (at constant pH) and as pH increases (at constant CO32- activity). The primary effect...... of ionic strength on phosphate sorption onto calcite is its influence on the activity of the different aqueous phosphate species. The experimental results were modeled satisfactorily using the constant capacitance model with >CaPO4Ca0 and either >CaHPO4Ca+ or >CaHPO4- as the adsorbed surface species...

Estimation of readily-available phosphate in some English Lake District woodland soils

International Nuclear Information System (INIS)

Harrison, A.F.

1975-01-01

Four chemical extraction methods (2.5 percent acetic acid, Olsen, Truog and Egner) and 5 isotope dilution methods involving short exchange periods (1 inverse dilution, 2 carrier-free and 2 using phosphate carrier) were investigatd for reliability in measurement of readily-available phosphate in widely differing soils from some non-fertilized semi-natural Lake District woodlands. Correlation coefficients between values produced and phosphate uptake during a two-month period from 16 soils (pH range 3.85 to 7.85) by Urtica dioica L., a phosphate-sensitive plant, differed markedly. They were negative for all the extraction procedures, varying from r = -0.079 for the Truog method to -0.518 for the Olsen method. The isotope dilution methods, with the exception of one, all gave positive correlation coefficients, varying from r = -0.676 for the carrier-free method of Talibudeen to r = 0.798 for a modified Amer carrier method. When combined by multiple regression analysis, the results of the isotope dilution methods accounted for 86.4 percent of the variation in phosphate-uptake by the nettle plants, whereas the results of the four extraction methods accounted for only 32.2 percent. Multiple regression analysis of the data showed that there were strong and different interactions between all methods investigated and soil properties, particularly soil pH, organic matter content, extractable iron, C/P and C/N. This clearly indicates that methods must be evaluated for each series of soils to be compared. (author)

Copper tolerance mediated by polyphosphate degradation and low-affinity inorganic phosphate transport system in Escherichia coli.

Science.gov (United States)

Grillo-Puertas, Mariana; Schurig-Briccio, Lici Ariane; Rodríguez-Montelongo, Luisa; Rintoul, María Regina; Rapisarda, Viviana Andrea

2014-03-19

Metal tolerance in bacteria has been related to polyP in a model in which heavy metals stimulate the polymer hydrolysis, forming metal-phosphate complexes that are exported. As previously described in our laboratory, Escherichia coli cells grown in media containing a phosphate concentration >37 mM maintained an unusually high polyphosphate (polyP) level in stationary phase. The aim of the present work was to evaluate the influence of polyP levels as the involvement of low-affinity inorganic phosphate transport (Pit) system in E. coli copper tolerance. PolyP levels were modulated by the media phosphate concentration and/or using mutants in polyP metabolism. Stationary phase wild-type cells grown in high phosphate medium were significantly more tolerant to copper than those grown in sufficient phosphate medium. Copper addition to tolerant cells induced polyP degradation by PPX (an exopolyphosphatase), phosphate efflux and membrane polarization. ppk-ppx- (unable to synthesize/degrade polyP), ppx- (unable to degrade polyP) and Pit system mutants were highly sensitive to metal even in high phosphate media. In exponential phase, CopA and polyP-Pit system would act simultaneously to detoxify the metal or one could be sufficient to safeguard the absence of the other. Our results support a mechanism for copper detoxification in exponential and stationary phases of E. coli, involving Pit system and degradation of polyP. Data reflect the importance of the environmental phosphate concentration in the regulation of the microbial physiological state.

Effect of High-Dose Vitamin C Infusion in a Glucose-6-Phosphate Dehydrogenase-Deficient Patient

Science.gov (United States)

Gerber, Bryan; Kenyon, Katharine; Muthukanagaraj, Purushothaman

2017-01-01

Vitamin C supplementation is generally regarded as benign. There has been a resurgence of interest in the general medical community regarding the use of vitamin C most notably in the care of sepsis. Nonetheless, caution must be taken if supraphysiologic vitamin C supplementation is being administered as it should be considered a medication just like any other. We present a case of hemolysis in a glucose-6-phosphate dehydrogenase- (G6PD-) deficient patient receiving high-dose vitamin C infusions for his rheumatoid arthritis. PMID:29317868

The Effect of Iron Salt on Anaerobic Digestion and Phosphate Release to Sludge Liquor

Directory of Open Access Journals (Sweden)

Svetlana Ofverstrom

2011-12-01

Full Text Available Iron salts are used at wastewater treatment plants (WWTPs for several reasons: for removing chemical phosphorus, preventing from struvite formation and reducing the content of hydrogen sulfide (H2S in biogas. Anaerobic digestion is a common scheme for sludge treatment due to producing biogas that could be used as biofuel. Laboratory analysis has been carried out using anaerobic digestion model W8 (Armfield Ltd, UK to investigate any possible effect of adding FeCl3 on the anaerobic digestion of primary sludge (PS and waste activated sludge (WAS mixture as well as on releasing phosphates to digested sludge liquor. The obtained results showed that FeCl3 negatively impacted the anaerobic digestion process by reducing the volume of produced biogas. Fe-dosed sludge (max produced 30% less biogas. Biogas production from un-dosed and Fe-dosed sludge (min was similar to the average of 1.20 L/gVSfed. Biogas composition was not measured during the conducted experiments. Phosphorus content in sludge liquor increased at an average of 38% when digesting sludge without ferric chloride dosing. On the contrary, phosphate content in sludge liquor from digested Fe-dosed sludge decreased by approx. 80%.

Preferable adsorption of phosphate using lanthanum-incorporated porous zeolite: Characteristics and mechanism

Science.gov (United States)

He, Yinhai; Lin, Hai; Dong, Yingbo; Wang, Liang

2017-12-01

The adsorbent, where lanthanum oxide was incorporated onto porous zeolite (La-Z), of preferable adsorption towards phosphate was prepared by hydrothermal synthesis. Based on pH effect results, La-Z would effectively sequestrate phosphate over wider pH range of 3.0-7.0, alkaline conditions were unfavorable for phosphate. The adsorption of phosphate was not significantly influenced by ionic strength and by coexisting anions of chloride, nitrate and sulfate but bicarbonate showed slightly greater negative effects, indicating La-Z possessed highly selectivity to phosphate. Adsorption of phosphate could be well fitted by pseudo-second-order model and the process was mainly controlled by intra-particle diffusion. Equilibrium adsorption demonstrated that Langmuir model was more suitable than Freundlich model for description phosphate adsorption and the adsorption capacity was 17.2 mg P g-1, which exhibited 95% utilization of incorporated La. Over 95% phosphate was eliminated in real effluent treatment when the dose was 2 g L-1. The underlying mechanism for phosphate capture was probed with Zeta potential and X-ray photoelectron spectroscope analysis, and the formation of La-P inner-sphere complexation was testified to be the dominant pathway. All the results suggested that the porous zeolite-supported lanthanum oxide can serve as a promising adsorbent for phosphate removal in realistic application.

Nuclear waste immobilization in iron phosphate glasses

International Nuclear Information System (INIS)

Garcia, D.A.; Rodriguez, Diego A.; Menghini, Jorge E.; Bevilacqua, Arturo

2007-01-01

Iron-phosphate glasses have become important in the nuclear waste immobilization area because they have some advantages over silicate-based glasses, such as a lower processing temperature and a higher nuclear waste load without losing chemical and mechanical properties. Structure and chemical properties of iron-phosphate glasses are determined in terms of the main components, in this case, phosphate oxide along with the other oxides that are added to improve some of the characteristics of the glasses. For example, Iron oxide improves chemical durability, lead oxide lowers fusion temperature and sodium oxide reduces viscosity at high temperature. In this work a study based on the composition-property relations was made. We used different techniques to characterize a series of iron-lead-phosphate glasses with uranium and aluminium oxide as simulated nuclear waste. We used the Arquimedes method to determine the bulk density, differential temperature analysis (DTA) to determine both glass transition temperature and crystallization temperature, dilatometric analysis to calculate the linear thermal expansion coefficient, chemical durability (MCC-1 test) and X-ray diffraction (XRD). We also applied some theoretic models to calculate activation energies associated with the glass transition temperature and crystallization processes. (author)

Bone substitute material composition and morphology differentially modulate calcium and phosphate release through osteoclast-like cells.

Science.gov (United States)

Konermann, A; Staubwasser, M; Dirk, C; Keilig, L; Bourauel, C; Götz, W; Jäger, A; Reichert, C

2014-04-01

The aim of this study was to determine the material composition and cell-mediated remodelling of different calcium phosphate-based bone substitutes. Osteoclasts were cultivated on bone substitutes (Cerabone, Maxresorb, and NanoBone) for up to 5 days. Bafilomycin A1 addition served as the control. To determine cellular activity, the supernatant content of calcium and phosphate was measured by inductively coupled plasma optical emission spectrometry. Cells were visualized on the materials by scanning electron microscopy. Material composition and surface characteristics were assessed by energy-dispersive X-ray spectroscopy. Osteoclast-induced calcium and phosphate release was material-specific. Maxresorb exhibited the highest ion release to the medium (P = 0.034; calcium 40.25mg/l day 5, phosphate 102.08 mg/l day 5) and NanoBone the lowest (P = 0.021; calcium 8.43 mg/l day 5, phosphate 15.15 mg/l day 5); Cerabone was intermediate (P = 0.034; calcium 16.34 mg/l day 5, phosphate 30.6 mg/l day 5). All investigated materials showed unique resorption behaviours. The presented methodology provides a new perspective on the investigation of bone substitute biodegradation, maintaining the material-specific micro- and macrostructure. Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Structural and mechanical characterization of boron doped biphasic calcium phosphate produced by wet chemical method and subsequent thermal treatment

Energy Technology Data Exchange (ETDEWEB)

Albayrak, Onder, E-mail: albayrakonder@mersin.edu.tr

2016-03-15

In the current study, boron doped biphasic calcium phosphate bioceramics consisting of a mixture of boron doped hydroxyapatite (BHA) and beta tricalcium phosphate (β-TCP) of varying BHA/β-TCP ratios were obtained after sintering stage. The effects of varying boron contents and different sintering temperatures on the BHA/β-TCP ratios and on the sinterability of the final products were investigated. Particle sizes and morphologies of the obtained precipitates were determined using SEM. XRD and FTIR investigation were conducted to detect the boron formation in the structure of HA and quantitative analysis was performed to determine the BHA/β-TCP ratio before and after sintering stage. In order to determine the sinterability of the obtained powders, pellets were prepared and sintered; the rates of densification were calculated and obtained results were correlated by SEM images. Also Vickers microhardness values of the sintered samples were determined. The experimental results verified that boron doped hydroxyapatite powders were obtained after sintering stage and the structure consists of a mixture of BHA and β-TCP. As the boron content used in the precipitation stage increases, β-TCP content of the BHA/β-TCP ratio increases but sinterability, density and microhardness deteriorate. As the sintering temperature increases, β-TCP content, density and microhardness of the samples increase and sinterability improves. - Highlights: • This is the first paper about boron doped biphasic calcium phosphate bioceramics. • Boron doping affects the structural and mechanical properties. • BHA/β-TCP ratio can be adjustable with boron content and sintering temperature.

High-level expression of a novel chromoplast phosphate transporter ClPHT4;2 is required for flesh color development in watermelon.

Science.gov (United States)

Zhang, Jie; Guo, Shaogui; Ren, Yi; Zhang, Haiying; Gong, Guoyi; Zhou, Ming; Wang, Guizhang; Zong, Mei; He, Hongju; Liu, Fan; Xu, Yong

2017-02-01

Chromoplast development plays a crucial role in controlling carotenoid content in watermelon flesh. Modern cultivated watermelons with colorful flesh are believed to originate from pale-colored and no-sweet progenitors. But the molecular basis of flesh color formation and regulation is poorly understood. More chromoplasts and released carotenoid globules were observed in the red-fleshed fruit of the 97103 cultivar than in the pale-colored fruits of the PI296341-FR line. Transcriptome profiles of these two materials identified Cla017962, predicted as ClPHT4;2, was dramatically up-regulated during flesh color formation. High ClPHT4;2 expression levels were closely correlated with increased flesh carotenoid contents among 198 representative watermelon accessions. Down-regulation of ClPHT4;2 expression in transgenic watermelons reduced the fruit carotenoid accumulation. ClPHT4;2 as a function of chromoplast-localized phosophate transporter was tested by heterologous expression into a yeast phosphate-uptake-defective mutant, western blotting, subcellular localization, and immunogold electron microscopy analysis. Two transcription factors, ClbZIP1 and ClbZIP2, were identified, which responded to ABA and sugar signaling to regulate ClPHT4;2 transcription only in cultivated watermelon species. Our findings suggest that elevated ClPHT4;2 gene expression is necessary for carotenoid accumulation, and may help to characterize the co-development of flesh color and sweetness during watermelon development and domestication. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Performance of pineapple slips inoculated with diazotrophic phosphate-solubilizing bacteria and rock phosphate

OpenAIRE

Lílian Estrela Borges Baldotto; Marihus Altoé Baldotto; Fábio Lopes Olivares; Adriane Nunes de Souza

2014-01-01

Besides fixing N2, some diazotrophic bacteria or diazotrophs, also synthesize organic acids and are able to solubilize rock phosphates, increasing the availability of P for plants. The application of these bacteria to pineapple leaf axils in combination with rock phosphate could increase N and P availability for the crop, due to the bacterial activity of biological nitrogen fixation and phosphate solubilization. The objectives of this study were: (i) to select and characterize diazotrophs abl...

Uranium-phosphate relationship in phosphated chalks of the Mons and Picardie Bassins

Energy Technology Data Exchange (ETDEWEB)

Quinif, Y; Charlet, J M; Dupuis, C; Robaszynski, F [Faculte Polytechnique de Mons (Belgium)

1981-11-30

The lithological and geochemical conditions relative to the ''Senonian'' phosphatic chalks are relatively simple in the Basins of Mons (Belgium) and of Picardy (France). Their characteristics permit us to study chiefly the uranium-phosphate relation. It appears a very good linear correlation between the phosphate and the uranium. The coefficient U/P/sub 2/O/sub 5/ remains a constant from the bottom to the top of the same section, but changes in space for synchronic formations (lateral variation of geochemical facies) and in time for two separated basins.

Metal immobilization and phosphorus leaching after stabilization of pyrite ash contaminated soil by phosphate amendments.

Science.gov (United States)

Zupančič, Marija; Lavrič, Simona; Bukovec, Peter

2012-02-01

In this study we would like to show the importance of a holistic approach to evaluation of chemical stabilization using phosphate amendments. An extensive evaluation of metal stabilization in contaminated soil and an evaluation of the leaching of phosphorus induced after treatment were performed. The soil was highly contaminated with Cu (2894 mg kg(-1)), Zn (3884 mg kg(-1)), As (247 mg kg(-1)), Cd (12.6 mg kg(-1)) and Pb (3154 mg kg(-1)). To immobilize the metals, mixtures of soil with phosphate (from H(3)PO(4) and hydroxyapatite (HA) with varying ratios) were prepared with a constant Pb : P molar ratio of 1: 10. The acetic acid extractable concentration of Pb in the mixture with the highest amount of added phosphoric acid (n(H(3)PO(4)) : n(HA) = 3 : 1) was reduced to 1.9% (0.62 mg L(-1)) of the extractable Pb concentration in the untreated soil, but the content of water extractable phosphorus in the samples increased from 0.04 mg L(-1) in the untreated soil sample up to 14.3 mg L(-1) in the same n(H(3)PO(4)) : n(HA) = 3 : 1 mixture. The high increase in arsenic mobility was also observed after phosphate addition. The PBET test showed phosphate induced reduction in Pb bioavailability. In attempting to stabilize Pb in the soil with the minimum treatment-induced leaching of phosphorus, it was found that a mixture of soil with phosphate addition in the molar ratio of H(3)PO(4) : HA of 0.75 : 1 showed the most promising results, with an acetic acid extractable Pb concentration of 1.35 mg L(-1) and a water extractable phosphorus concentration of 1.76 mg L(-1). The time-dependent leaching characteristics of metals and phosphorus for this mixture were evaluated by a column experiment, where irrigation of the soil mixture with the average annual amount of precipitation in Slovenia (1000 mm) was simulated. The phosphorus concentration in the leachates decreased from 2.60 mg L(-1) at the beginning of irrigation to 1.00 mg L(-1) at the end.

Uranium from phosphate ores

International Nuclear Information System (INIS)

Hurst, F.J.

1983-01-01

The following topics are described briefly: the way phosphate fertilizers are made; how uranium is recovered in the phosphate industry; and how to detect covert uranium recovery operations in a phsophate plant

The structural response of gadolinium phosphate to pressure

International Nuclear Information System (INIS)

Heffernan, Karina M.; Ross, Nancy L.; Spencer, Elinor C.; Boatner, Lynn A.

2016-01-01

Accurate elastic constants for gadolinium phosphate (GdPO 4 ) have been measured by single-crystal high-pressure diffraction methods. The bulk modulus of GdPO 4 determined under hydrostatic conditions, 128.1(8) GPa (K′=5.8(2)), is markedly different from that obtained with GdPO 4 under non-hydrostatic conditions (160(2) GPa), which indicates the importance of shear stresses on the elastic response of this phosphate. High pressure Raman and diffraction analysis indicate that the PO 4 tetrahedra behave as rigid units in response to pressure and that contraction of the GdPO 4 structure is facilitated by bending/twisting of the Gd–O–P links that result in increased distortion in the GdO 9 polyhedra. - Graphical abstract: A high-pressure single crystal diffraction study of GdPO 4 with the monazite structure is presented. The elastic behaviour of rare-earth phosphates are believed to be sensitive to shear forces. The bulk modulus of GdPO 4 measured under hydrostatic conditions is 128.1(8) GPa. Compression of the structure is facilitated by bending/twisting of the Gd−O−P links that result in increased distortion in the GdO 9 polyhedra. Display Omitted - Highlights: • The elastic responses of rare-earth phosphates are sensitive to shear forces. • The bulk modulus of GdPO 4 measured under hydrostatic conditions is 128.1(8) GPa. • Twisting of the inter-polyhedral links allows compression of the GdPO 4 structure. • Changes to the GdO 9 polyhedra occur in response to pressure (<7.0 GPa).

Preparation and photocatalytic activity of chemically-bonded phosphate ceramics containing TiO2

Science.gov (United States)

Martins, Monize Aparecida; de Lima, Bruna de Oliveira; Ferreira, Leticia Patrício; Colonetti, Emerson; Feltrin, Jucilene; De Noni, Agenor

2017-05-01

Titanium dioxide was incorporated into chemically-bonded phosphate ceramic for use as photocatalytic inorganic coating. The coatings obtained were applied to unglazed ceramic tiles and cured at 350 °C. The surfaces were characterized by photocatalytic activity, determined in aqueous medium, based on the degradation of methylene blue dye. The effects of the percentage of TiO2 and the thickness of the layer on the photocatalytic efficiency were evaluated. The influence of the incorporation of TiO2 on the consolidation of the phosphate matrix coating was investigated using the wear resistance test. The crystalline phases of the coatings obtained were determined by XRD. The microstructure of the surfaces was analyzed by SEM. The thermal curing treatment did not cause a phase transition from anatase to rutile. An increase in the photocatalytic activity of the coating was observed with an increase in the TiO2 content. The dye degradation indices ranged from 14.9 to 44.0%. The photocatalytic efficiency was not correlated with the thickness of the coating layer deposited. The resistance to wear decreased with an increase in the TiO2 content. Comparison with a commercial photocatalytic ceramic coating indicated that there is a range of values for the TiO2 contents which offer potential for photocatalytic applications.

Biodegradation of tert-butylphenyl diphenyl phosphate

International Nuclear Information System (INIS)

Heitkamp, M.A.; Freeman, J.P.; Cerniglia, C.E.

1986-01-01

The biodegradation of tert-butylphenyl diphenyl phosphate (BPDP) was examined in microcosms containing sediment and water from five different ecosystems as part of studies to elucidate the environmental fate of phosphate ester flame retardants. Biodegradation of [ 14 C]BPDP was monitored in the environmental microcosms by measuring the evolution of 14 CO 2 . Over 37% of BPDP was mineralized after 8 weeks in microcosms from an ecosystem which had chronic exposure to agricultural chemicals. In contrast, only 1.7% of BPDP was degraded to 14 CO 2 in samples collected from a noncontaminated site. The exposure concentration of BPDP affected the percentage which was degraded to 14 CO 2 in microcosms from the two most active ecosystems. Mineralization was highest at a concentration of 0.1 mg of BPDP and was inhibited with 10- and 100-fold higher concentrations of BPDP. The authors observed adaptive increases in both microbial populations and phosphoesterase enzymes in some sediments acclimated to BPDP. Chemical analyses of the residues in the microcosms indicated undegraded BPDP and minor amounts of phenol, tert-butylphenol, diphenyl phosphate, and triphenyl phosphate as biodegradation products. These data suggest that the microbial degradation of BPDP results from at least three catabolic processes and is highest when low concentrations of BPDP are exposed to sediment microorganisms of eutrophic ecosystems which have high phosphotri- and diesterase activities and previous exposure to anthropogenic chemicals

Phosphate bonded ceramics as candidate final-waste-form materials

International Nuclear Information System (INIS)

Singh, D.; Wagh, A.S.; Cunnane, J.; Sutaria, M.; Kurokawa, S.; Mayberry, J.

1994-04-01

Room-temperature setting phosphate-bonded ceramics were studied as candidate materials for stabilization of DOE low-level problem mixed wastes which cannot be treated by other established stabilization techniques. Phosphates of Mg, Mg-Na, Al and Zr were studied to stabilize ash surrogate waste containing RCRA metals as nitrates and RCRA organics. We show that for a typical loading of 35 wt.% of the ash waste, the phosphate ceramics pass the TCLP test. The waste forms have high compression strength exceeding ASTM recommendations for final waste forms. Detailed X-ray diffraction studies and differential thermal analyses of the waste forms show evidence of chemical reaction of the waste with phosphoric acid and the host matrix. The SEM studies show evidence of physical bonding. The excellent performance in the leaching tests is attributed to a chemical solidification and physical as well as chemical bonding of ash wastes in these phosphate ceramics

Electrochemical Reduction of Zinc Phosphate

International Nuclear Information System (INIS)

Kim, Chang Hwan; Lee, Jung Hyun; Shin, Woon Sup

2010-01-01

We demonstrated first that the electrochemical reduction of zinc phosphate in neutral phosphate buffer is possible and potentially applicable to bio-compatible rechargeable battery. The actual redox component is Zn(s)/Zn phosphate(s) and the future research about the control of crystal formation for the better cyclability is required. In lead-acid battery, the electrochemical redox reaction of Pb (s) /PbSO 4(s) is used by reducing Pb(II) and oxidizing Pb(0) in sulfate rich solution. Since both reduced form and oxidized form are insoluble, they cannot diffuse to the opposite electrodes and react. It is a very common strategy to make a stable battery electrode that a metal element is reduced and oxidized in solution containing an abundance of anion readily precipitating with the metal ion. For the application of this strategy to construction of rechargeable battery using bio-compatible electrode materials and electrolytes, the use of phosphate ion can be considered as anion readily precipitating with metal ions. If phosphate buffer with neutral pH is used as electrolyte, the better bio-compatibility will be achieved than most of rechargeable battery using strong acid, strong base or organic solvent as electrolyte solution. There are many metal ions readily precipitating with phos-phate ion, and zinc is one of them

Information management for high content live cell imaging

Directory of Open Access Journals (Sweden)

White Michael RH

2009-07-01

Full Text Available Abstract Background High content live cell imaging experiments are able to track the cellular localisation of labelled proteins in multiple live cells over a time course. Experiments using high content live cell imaging will generate multiple large datasets that are often stored in an ad-hoc manner. This hinders identification of previously gathered data that may be relevant to current analyses. Whilst solutions exist for managing image data, they are primarily concerned with storage and retrieval of the images themselves and not the data derived from the images. There is therefore a requirement for an information management solution that facilitates the indexing of experimental metadata and results of high content live cell imaging experiments. Results We have designed and implemented a data model and information management solution for the data gathered through high content live cell imaging experiments. Many of the experiments to be stored measure the translocation of fluorescently labelled proteins from cytoplasm to nucleus in individual cells. The functionality of this database has been enhanced by the addition of an algorithm that automatically annotates results of these experiments with the timings of translocations and periods of any oscillatory translocations as they are uploaded to the repository. Testing has shown the algorithm to perform well with a variety of previously unseen data. Conclusion Our repository is a fully functional example of how high throughput imaging data may be effectively indexed and managed to address the requirements of end users. By implementing the automated analysis of experimental results, we have provided a clear impetus for individuals to ensure that their data forms part of that which is stored in the repository. Although focused on imaging, the solution provided is sufficiently generic to be applied to other functional proteomics and genomics experiments. The software is available from: fhttp://code.google.com/p/livecellim/

Unsymmetrical phosphate as extractant for the extraction of nitric acid

International Nuclear Information System (INIS)

Gaikwad, R.H.; Jayaram, R.V.

2016-01-01

Tri-n-butyl phosphate (TBP) was first used as an extractant in 1944, during Manhattan project for the separation of actinides and further explored by Warf in 1949 for the extraction of Ce(IV) from aqueous nitric acid. TBP was further used as an extractant in the Plutonium Uranium Recovery by Extraction (PUREX) process. To meet the stringent requirements of the nuclear industry TBP has been extensively investigated. In spite of its wide applicability, TBP suffers from various disadvantages such as high aqueous solubility, third phase formation, chemical and radiation degradation leading to the formation of undesired products. It also suffers from incomplete decontamination of the actinides from fission products. Various attempts have been made to overcome the problems associated with TBP by way of using higher homologues of TBP such as Tri-iso amyl phosphate (TiAP), Tri-secondary butyl phosphate (TsBP), Tri amyl phosphate (TAP). It was found that in some cases the results were considerably better than those obtained with TBP for uranium/thorium extraction. The extraction of nitric acid by TBP and its higher homologues which are symmetrical are well documented. However, no solvent has emerged clearly superior than TBP. Here in we report the extraction of nitric acid with neutral unsymmetrical phosphates and study them as extractants for the extraction of nitric acid. Dibutyl secbutyl phosphate, dibutyl pentyl phosphate and dibutyl heptyl phosphate were synthesised for this purpose and the extraction of nitric acid was studied in n-dodecane. The results indicate that the substitution of one of the alkyl groups of the symmetrical phosphate adjacent to the phosphoryl (P=O) group of the phosphate does not have any pronounced effect on the extraction capacity of nitric acid. (author)

Methyl phosphate formation as a major degradation mode of direct methanol fuel cells with phosphoric acid based electrolytes

DEFF Research Database (Denmark)

Aili, David; Vassiliev, Anton; Jensen, Jens Oluf

2015-01-01

Phosphoric acid and phosphoric acid doped polymer membranes are widely used as electrolytes in hydrogen based fuel cells operating at elevated temperatures. Such electrolytes have been explored for direct oxidation of methanol to further increase the versatility of the systems, however......, with demonstrated lifetimes of only a few days to weeks. In this work the methyl phosphate formation from the acid and methanol is identified and proposed to be a major mechanism for the cell degradation. Proton conductivity and fuel cell durability tests validate the mechanism at high methanol contents....

Injectable TEMPO-oxidized nanofibrillated cellulose/biphasic calcium phosphate hydrogel for bone regeneration.

Science.gov (United States)

Safwat, Engie; Hassan, Mohammad L; Saniour, Sayed; Zaki, Dalia Yehia; Eldeftar, Mervat; Saba, Dalia; Zazou, Mohamed

2018-05-01

Nanofibrillated cellulose, obtained from rice straw agricultural wastes was used as a substrate for the preparation of a new injectable and mineralized hydrogel for bone regeneration. Tetramethyl pyridine oxyl (TEMPO) oxidized nanofibrillated cellulose, was mineralized through the incorporation of a prepared and characterized biphasic calcium phosphate at a fixed ratio of 50 wt%. The TEMPO-oxidized rice straw nanofibrillated cellulose was characterized using transmission electron microscopy, Fourier transform infrared, and carboxylic content determination. The injectability and viscosity of the prepared hydrogel were evaluated using universal testing machine and rheometer testing, respectively. Cytotoxicity and alkaline phosphatase level tests on osteoblast like-cells for in vitro assessment of the biocompatibility were investigated. Results revealed that the isolated rice straw nanofibrillated cellulose is a nanocomposite of the cellulose nanofibers and silica nanoparticles. Rheological properties of the tested materials are suitable for use as injectable material and of nontoxic effect on osteoblast-like cells, as revealed by the positive alkaline phosphate assay. However, nanofibrillated cellulose/ biphasic calcium phosphate hydrogel showed higher cytotoxicity and lower bioactivity test results when compared to that of nanofibrillated cellulose.

Molecular analysis of phosphate limitation in Geobacteraceae during the bioremediation of a uranium-contaminated aquifer

Energy Technology Data Exchange (ETDEWEB)

N' Guessan, L.A.; Elifantz, H.; Nevin, K.P.; Mouser, P.J.; Methe, B.; Woodard, T. L.; Manley, K.; Williams, K. H.; Wilkins, M. J.; Larsen, J.T.; Long, P. E.; Lovley, D. R.

2009-09-01

Nutrient limitation is an environmental stress that may reduce the effectiveness of bioremediation strategies, especially when the contaminants are organic compounds or when organic compounds are added to promote microbial activities such as metal reduction. Genes indicative of phosphate-limitation were identified via microarray analysis of chemostat cultures of Geobacter sulfureducens. This analysis revealed that genes in the pst-pho operon, which is associated with a high affinity phosphate uptake system in other microorganisms, had significantly higher transcript abundance under phosphate-limiting conditions, with the genes pstB and phoU the most up-regulated. Quantitative PCR analysis of pstB and phoU transcript levels in G. sulfurreducens grown in chemostats demonstrated that the expression of these genes increased when phosphate was removed from the culture medium. Transcripts of pstB and phoU within the subsurface Geobacter species predominating during an in situ uranium bioremediation field experiment were more abundant than in chemostat cultures of G. sulfurreducens that were not limited for phosphate. Addition of phosphate to incubations of subsurface sediments did not stimulate dissimilatory metal reduction. The added phosphate was rapidly adsorbed onto the sediments. The results demonstrate that Geobacter species can effectively reduce U(VI) even when experiencing suboptimal phosphate concentrations and that increasing phosphate availability with phosphate additions is difficult to achieve due to the high reactivity of this compound. This transcript-based approach developed for diagnosing phosphate limitation should be applicable to assessing the potential need for additional phosphate in other bioremediation processes.

Crystal Analysis of Multi Phase Calcium Phosphate Nanoparticles Containing Different amount of Magnesium

Science.gov (United States)

Gozalian, Afsaneh; Behnamghader, Ali Asghar; Moshkforoush, Arash

In this study, Mg doped hydroxyapatite [(Ca, Mg)10(PO4)6(OH)2] and β-tricalcium phosphate nanoparticles were synthesized via sol gel method. Triethyl phosphite, calcium nitrate tetrahydrate and magnesium nitrate hexahydrate were used as P, Ca and Mg precursors. The ratio of (Ca+Mg)/P and the amount of magnesium (x) were kept constant at 1.67 and ranging x = 0 up to 3 in molecular formula of Ca10-xMgx (PO4)6(OH)2, respectively. Phase composition and chemical structure were performed using X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). Phase percentages, crystallite size, degree of crystallinity and lattice parameters were investigated. The presence of magnesium led to form the Mg doped tricalcium phosphate (β-TCMP) and Mg doped hydroxyapatite (Mg-HA). Based on the results of this study, lattice parameters, degree of crystallinity and crystallite size decreased with magnesium content. In addition, with increasing magnesium content, the amount of CaO phase decreased whereas the amount of MgO phase increased significantly. Obtained results can be used for new biomaterials design.

ION EXCHANGE SUBSTANCES BY SAPONIFICATION OF ALLYL PHOSPHATE POLYMERS

Science.gov (United States)

Kennedy, J.

1959-04-14

An ion exchange resin having a relatively high adsorption capacity tor uranyl ion as compared with many common cations is reported. The resin comprises an alphyl-allyl hydrogen phosphate polymer, the alphyl group being either allyl or a lower alkyl group having up to 5 carbon atoins. The resin is prepared by polymerizing compounds such as alkyl-diallyl phosphate and triallyl phosphate in the presence of a free radical generating substance and then partially hydrolyzing the resulting polymer to cause partial replacement of organic radicals by cations. A preferred free radical gencrating agent is dibenzoyl peroxide. The partial hydrolysis is brought about by refluxing the polymer with concentrated aqueous NaOH for three or four hours.

Advances in Predictive Toxicology for Discovery Safety through High Content Screening.

Science.gov (United States)

Persson, Mikael; Hornberg, Jorrit J

2016-12-19

High content screening enables parallel acquisition of multiple molecular and cellular readouts. In particular the predictive toxicology field has progressed from the advances in high content screening, as more refined end points that report on cellular health can be studied in combination, at the single cell level, and in relatively high throughput. Here, we discuss how high content screening has become an essential tool for Discovery Safety, the discipline that integrates safety and toxicology in the drug discovery process to identify and mitigate safety concerns with the aim to design drug candidates with a superior safety profile. In addition to customized mechanistic assays to evaluate target safety, routine screening assays can be applied to identify risk factors for frequently occurring organ toxicities. We discuss the current state of high content screening assays for hepatotoxicity, cardiotoxicity, neurotoxicity, nephrotoxicity, and genotoxicity, including recent developments and current advances.

iScreen: Image-Based High-Content RNAi Screening Analysis Tools.

Science.gov (United States)

Zhong, Rui; Dong, Xiaonan; Levine, Beth; Xie, Yang; Xiao, Guanghua

2015-09-01

High-throughput RNA interference (RNAi) screening has opened up a path to investigating functional genomics in a genome-wide pattern. However, such studies are often restricted to assays that have a single readout format. Recently, advanced image technologies have been coupled with high-throughput RNAi screening to develop high-content screening, in which one or more cell image(s), instead of a single readout, were generated from each well. This image-based high-content screening technology has led to genome-wide functional annotation in a wider spectrum of biological research studies, as well as in drug and target discovery, so that complex cellular phenotypes can be measured in a multiparametric format. Despite these advances, data analysis and visualization tools are still largely lacking for these types of experiments. Therefore, we developed iScreen (image-Based High-content RNAi Screening Analysis Tool), an R package for the statistical modeling and visualization of image-based high-content RNAi screening. Two case studies were used to demonstrate the capability and efficiency of the iScreen package. iScreen is available for download on CRAN (http://cran.cnr.berkeley.edu/web/packages/iScreen/index.html). The user manual is also available as a supplementary document. © 2014 Society for Laboratory Automation and Screening.

Developing porous carbon with dihydrogen phosphate groups as sulfur host for high performance lithium sulfur batteries

Science.gov (United States)

Cui, Yanhui; Zhang, Qi; Wu, Junwei; Liang, Xiao; Baker, Andrew P.; Qu, Deyang; Zhang, Hui; Zhang, Huayu; Zhang, Xinhe

2018-02-01

Carbon matrix (CM) derived from biomass is low cost and easily mass produced, showing great potential as sulfur host for lithium sulfur batteries. In this paper we report on a dihydrogen phosphate modified CM (PCM-650) prepared from luffa sponge (luffa acutangula) by phosphoric acid treatment. The phosphoric acid not only increases the surface area of the PCM-650, but also introduces dihydrogen phosphate onto PCM-650 (2.28 at% P). Sulfur impregnated (63.6 wt%) PCM-650/S, in comparison with samples with less dihydrogen phosphate LPCM-650/S, shows a significant performance improvement. XPS analysis is conducted for sulfur at different stages, including sulfur (undischarged), polysulfides (discharge to 2.1 V) and short chain sulfides (discharge to 1.7 V). The results consistently show chemical shifts for S2p in PCM-650, suggesting an enhanced adsorption effect. Furthermore, density functional theory (DFT) calculations is used to clarify the molecular binding: carbon/sulfur (0.86 eV), carbon/Li2S (0.3 eV), CH3-O-PO3H2/sulfur (1.24 eV), and CH3-O-PO3H2/Li2S (1.81 eV). It shows that dihydrogen phosphate group can significantly enhance the binding with sulfur and sulfide, consistent with XPS results. Consequently a CM functionalised with dihydrogen phosphate shows great potential as the sulfur host in a Li-S battery.

Preparation method and thermal properties of samarium and europium-doped alumino-phosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Sava, B.A., E-mail: savabogdanalexandru@yahoo.com [National Institute of Research and Development for Optoelectronics, Department for Optospintronics, 409 Atomistilor Street, P.O. Box MG – 5, RO-77125 Magurele (Romania); Elisa, M., E-mail: astatin18@yahoo.com [National Institute of Research and Development for Optoelectronics, Department for Optospintronics, 409 Atomistilor Street, P.O. Box MG – 5, RO-77125 Magurele (Romania); Boroica, L., E-mail: boroica_lucica@yahoo.com [National Institute for Lasers, Plasma and Radiation Physics, 77125 Magurele (Romania); Monteiro, R.C.C., E-mail: rcm@fct.unl.pt [Center of Materials Research/Institute for Nanostructures, Nanomodelling and Nanofabrication, (CENIMAT/I3N), Department of Materials Sciences, Faculty of Sciences and Technology, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

2013-12-01

Highlights: • Improved preparation method of rare-earth-doped phosphate glasses was done. • Working and annealing temperatures were lower than for undoped phosphate glass. • Doped glass viscosity is also lower and has quasi-linear variation with temperature. • Exothermic peak appears at about 555 °C and 685 °C, due to devitrification in glass. -- Abstract: The present work investigates alumino-phosphate glasses from Li{sub 2}O–BaO–Al{sub 2}O{sub 3}–La{sub 2}O{sub 3}–P{sub 2}O{sub 5} system containing Sm{sup 3+} and Eu{sup 3+} ions, prepared by two different ways: a wet raw materials mixing route followed by evaporation and melt-quenching, and by remelting of shards. The linear thermal expansion coefficient measured by dilatometry is identical for both rare-earth-doped phosphate glasses. Comparatively to undoped phosphate glass the linear thermal expansion coefficient increases with 2 × 10{sup −7} K{sup −1} when dopants are added. The characteristic temperatures very slowly decrease but can be considered constant with atomic weight, atomic number and f electrons number of the doping ions in the case of T{sub g} (vitreous transition temperature) and T{sub sr} (high annealing temperature) but slowly increase in the case of T{sub ir} (low annealing temperature–strain point) and very slowly increase, being practically constant in the case of T{sub D} (dilatometric softening temperature). Comparatively to undoped phosphate glass the characteristic temperatures of Sm and Eu-doped glasses present lower values. The higher values of electrical conductance for both doped glasses, comparatively to usual soda-lime-silicate glass, indicate a slightly reduced stability against water. The viscosity measurements, showed a quasi-linear variation with temperature the mean square deviation (R{sup 2}) being ranged between 0.872% and 0.996%. The viscosity of doped glasses comparatively to the undoped one is lower at the same temperature. Thermogravimetric

Formation of calcium phosphate layer on ceramics with different reactivities

International Nuclear Information System (INIS)

Ribeiro, C.; Rigo, E.C.S.; Sepulveda, P.; Bressiani, J.C.; Bressiani, A.H.A.

2004-01-01

Biphasic ceramic samples of different biological reactivity are prepared by using hydroxyapatite (HAp) and tricalcium phosphate (TCP) in various ratios. Different parameters for sintering in an air atmosphere furnace were defined after dilatometric studies. An increased densification with decreased TCP content was observed. The sintered bodies were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The dissolution kinetics and in vitro reactivity were investigated using simulated body fluid (SBF) at 37 deg. C for a maximum period of 3 weeks. The surfaces of the ceramics were analyzed by Fourier transform infrared spectroscopy (FTIR) and SEM in order to observe the formation of a calcium phosphate layer, which indicates the samples bioactivity. Dissolution in SBF demonstrated that layers with different kinetics on the samples surface were formed during the immersion period. The biphasic ceramics show bioactive behavior, even if the resorbable TCP is incorporated

Production of biomass/energy crops on phosphatic clay soils in central Florida

Energy Technology Data Exchange (ETDEWEB)

Stricker, J.A. [Univ. of Florida, Bartow, FL (United States); Prine, G.M.; Woodard, K.R. [Univ. of Florida, Gainesville, FL (United States); Anderson, D.L. [Univ. of Florida, Belle Glade, FL (United States); Shibles, D.B.; Riddle, T.C. [Mined Lands Agricultural Research/Demonstration Project, Bartow, FL (United States)

1993-12-31

Phosphatic clay is a byproduct of phosphate mining. Presently more than 40,470 ha have been created, most in central Florida, and about 810 ha are being added each year. Phosphatic clays have high fertility and high water holding capacity, reducing fertilization costs and producing high yields without irrigation. Based on 10 years of research, scientists have selected tall annual-regenerating perennial C-4 grasses as having the greatest potential for biomass production in Florida. The purpose of this work was to determine the feasibility of growing these tall perennial grasses for biomass on phosphatic clay. Elephantgrass, sugarcane and energycane, and erianthus were planted in duplicate replications on phosphatic clay soil in late August, 1986. yield was measured by one harvest in December or January each year for four years. Nitrogen fertilization included 112 kg ha{sup {minus}1} the first year followed by 134 kg ha{sup {minus}1} for the next three years. Nitrogen is the only supplemental nutrient needed to grow all tall grass crops on phosphatic clay. The average annual oven dry matter yield over the 4-yr period was 36.3 Mg ha{sup {minus}1} for PI 300086 elephantgrass, 45.2 for N51 elephantgrass, 42.5 for L79-1002 energycane, 49.0 for US72-1153 energycane, 49.7 for US78-1009 sugarcane, 52.2 for US56-9 sugarcane, 56.2 for CP72-1210 sugarcane, and 48.8 for 1K-7647 erianthus. More recent work has utilized domestic sewage sludge as a nitrogen source for the tall grasses. Preliminary sugar yields of selected sugarcane accessions & sweet sorghum were 4.7 Mg ha{sup {minus}1} for CP72-1210, 12.5 for US67-2022, 3.4 for US78-1009 and 1.3 Mg ha{sup {minus}1} for sweet sorghum. The high yields of the tall grasses grown on phosphatic clay with low inputs indicate a great potential for these crops as a source of renewable energy. A sustainable cropping system may be maintained by utilizing municipal sewage sludge as a nitrogen source with tall grasses on phosphatic clay.

Impact of endocrine hyperfunction and phosphate wasting on bone in McCune-Albright syndrome.

Science.gov (United States)

Lala, R; Matarazzo, P; Andreo, M; Defilippi, C; de Sanctis, C

2002-01-01

Skin dysplasia, as café-au-lait spots, bone fibrous dysplasia and peripheral endocrinopathies are the main clinical features of McCune-Albright syndrome (MAS). This illness is due to activating mutations of the Gsalpha protein and is spread with a mosaic pattern in affected tissues that consist of intermixed areas of normal and mutated cells. Peripheral endocrine secretion, free of hypothalamic pituitary control, is the hallmark of the endocrine syndromes: precocious puberty, Cushing's syndrome, hyperthyroidism and gigantism/acromegaly. In addition, phosphate wasting as hyperphosphaturia is often present. The impact of hormonal hypersecretion and phosphate loss on the bones of patients with MAS is poorly understood both in normal and fibrous bone tissue. As hypercortisolism and hyperthyroidism increase bone resorption, hyperestrogenism and growth hormone hypersecretion stimulate bone growth and mineralization, and phosphate wasting reduces bone mineral content. All these actions can be exerted at varying times and degrees in a single patient on lesional and non-lesional bones. Sonographic evidence of multiple diffused hyperechogenic spots in the testes of patients with MAS do not seem to be related to alterations in calcium-phosphate metabolism but rather to zonal dysplasia/hyperplasia of testicular tissue.

Impact of Phosphate, Potassium, Yeast Extract, and Trace Metals on Chitosan and Metabolite Production by Mucor indicus.

Science.gov (United States)

Safaei, Zahra; Karimi, Keikhosro; Zamani, Akram

2016-08-30

In this study the effects of phosphate, potassium, yeast extract, and trace metals on the growth of Mucor indicus and chitosan, chitin, and metabolite production by the fungus were investigated. Maximum yield of chitosan (0.32 g/g cell wall) was obtained in a phosphate-free medium. Reversely, cell growth and ethanol formation by the fungus were positively affected in the presence of phosphate. In a phosphate-free medium, the highest chitosan content (0.42 g/g cell wall) and cell growth (0.66 g/g sugar) were obtained at 2.5 g/L of KOH. Potassium concentration had no significant effect on ethanol and glycerol yields. The presence of trace metals significantly increased the chitosan yield at an optimal phosphate and potassium concentration (0.50 g/g cell wall). By contrast, production of ethanol by the fungus was negatively affected (0.33 g/g sugars). A remarkable increase in chitin and decrease in chitosan were observed in the absence of yeast extract and concentrations lower than 2 g/L. The maximum chitosan yield of 51% cell wall was obtained at 5 g/L of yeast extract when the medium contained no phosphate, 2.5 g/L KOH, and 1 mL/L trace metal solution.

Potato dextrose agar antifungal susceptibility testing for yeasts and molds: evaluation of phosphate effect on antifungal activity of CMT-3.

Science.gov (United States)

Liu, Yu; Tortora, George; Ryan, Maria E; Lee, Hsi-Ming; Golub, Lorne M

2002-05-01

The broth macrodilution method (BMM) for antifungal susceptibility testing, approved by the National Committee for Clinical Laboratory Standards (NCCLS), was found to have deficiencies in testing of the antifungal activity of a new type of antifungal agent, a nonantibacterial chemically modified tetracycline (CMT-3). The high content of phosphate in the medium was found to greatly increase the MICs of CMT-3. To avoid the interference of phosphate in the test, a new method using potato dextrose agar (PDA) as a culture medium was developed. Eight strains of fungi, including five American Type Culture Collection strains and three clinical isolates, were used to determine the MICs of amphotericin B and itraconazole with both the BMM and the PDA methods. The MICs of the two antifungal agents determined with the PDA method showed 99% agreement with those determined with the BMM method within 1 log(2) dilution. Similarly, the overall reproducibility of the MICs with the PDA method was above 97%. Three other antifungal agents, fluconazole, ketoconazole, and CMT-3, were also tested in parallel against yeasts and molds with both the BMM and the PDA methods. The MICs of fluconazole and ketoconazole determined with the PDA method showed 100% agreement within 1 log(2) dilution of those obtained with the BMM method. However, the MICs of CMT-3 determined with the BMM method were as high as 128 times those determined with the PDA method. The effect of phosphate on the antifungal activity of CMT-3 was evaluated by adding Na2HPO4 to PDA in the new method. It was found that the MIC of CMT-3 against a Penicillium sp. increased from 0.5 microg/ml (control) to 2.0 microg/ml when the added phosphate was used at a concentration of 0.8 mg/ml, indicating a strong interference of Na2HPO4 with the antifungal activity of CMT-3. Except for fluconazole, all the other antifungal agents demonstrated clear end points among the yeasts and molds tested. Nevertheless, with its high reproducibility

Synthesis and characterization of iron (II and III) phosphates by X-ray diffraction and Scanning Electron Microscopy of high vacuum

International Nuclear Information System (INIS)

Diaz F, J.C.; Solis M, L.; Garcia R, G.; Romero G, E.T.

2002-01-01

The XRD and Sem techniques for determining the mineralogical and structural composition of iron II and III phosphates have been used. The mineralogical and structural composition of the materials revealed that they are the ferrous phosphate and the ferric phosphate. The contribution of the synthesis and characterization of these phosphates is that they can be used as components in the geological barriers capable to avoiding the dispersion from the hazardous radioactive materials to the environment. (Author)

Plasma spheroidization and high temperature stability of lanthanum phosphate and its compatibility with molten uranium

International Nuclear Information System (INIS)

Ananthapadmanabhan, P.V.; Sreekumar, K.P.; Thiyagarajan, T.K.; Satpute, R.U.; Krishnan, K.; Kulkarni, N.K.; Kutty, T.R.G.

2009-01-01

Lanthanum phosphate has excellent thermal stability and corrosion resistance against many molten metals and other chemically corrosive environments. Lanthanum phosphate (LaPO 4 ) was synthesized from lanthanum oxalate by thermal dissociation of the oxalate to the oxide, followed by conversion to hydrated lanthanum phosphate (LaPO 4 .0.5H 2 O). Thermal treatment of LaPO 4 .0.5H 2 O above 773 K resulted in the irreversible transformation of the hydrated phase to the stable monazite phase. Thermal and chemical stability of monazite was studied by plasma spheroidization experiments using a DC thermal plasma reactor set up. Compatibility of monazite with molten uranium was studied by thermal analysis. Results showed that monazite is thermally stable up to its melting point and also is resistant towards attack by molten uranium. Adherent coatings of LaPO 4 could be deposited onto various substrates by atmospheric plasma spray technique

Molecular Dynamics Simulation of the Structure and Properties of Lithium Phosphate Glasses

Energy Technology Data Exchange (ETDEWEB)

Liang, J-J; Cygan, R.T.; Alam, T.M.

1999-07-09

A new forcefield model was developed for the computer simulation of phosphate materials that have many important applications in the electronics and biomedical industries. The model provides a fundamental basis for the evaluation of phosphate glass structure and thermodynamics. Molecular dynamics simulations of a series of lithium phosphate glass compositions were performed using the forcefield model. A high concentration of three-membered rings (P{sub 3}O{sub 3}) occurs in the glass of intermediate composition (0.2 Li{sub 2}O {center_dot} 0.8P{sub 2}O{sub 5}) that corresponds to the minimum in the glass transition temperature curve for the compositional series. Molecular orbital calculations of various phosphate ring clusters indicate an increasing stabilization of the phosphate ring structure going from two- to four-membered rings.

Interleaved MRI/MRS study of muscle perfusion, oxygenation and high energy phosphate metabolism in normal subjects and Becker's myopathic patients

International Nuclear Information System (INIS)

Toussaint, J.F.; Brillault-Salvat, C.; Giacomini, E.; Bloch, G.; Duboc, D.; Jehenson, P.

1998-01-01

We present the first results of a study comparing patients suffering from Becker's myopathy and normal volunteers. We simultaneously assessed perfusion, oxygenation and high-energy phosphate metabolism using an interleaved NMR/NMRS approach. Muscle metabolism does not seem to differ in Becker's patients, except for myoglobin reoxygenation rates. (authors)

Boosting the pentose phosphate pathway restores cardiac progenitor cell availability in diabetes.

Science.gov (United States)

Katare, Rajesh; Oikawa, Atsuhiko; Cesselli, Daniela; Beltrami, Antonio P; Avolio, Elisa; Muthukrishnan, Deepti; Munasinghe, Pujika Emani; Angelini, Gianni; Emanueli, Costanza; Madeddu, Paolo

2013-01-01

Diabetes impinges upon mechanisms of cardiovascular repair. However, the biochemical adaptation of cardiac stem cells to sustained hyperglycaemia remains largely unknown. Here, we investigate the molecular targets of high glucose-induced damage in cardiac progenitor cells (CPCs) from murine and human hearts and attempt safeguarding CPC viability and function through reactivation of the pentose phosphate pathway. Type-1 diabetes was induced by streptozotocin. CPC abundance was determined by flow cytometry. Proliferating CPCs were identified in situ by immunostaining for the proliferation marker Ki67. Diabetic hearts showed marked reduction in CPC abundance and proliferation when compared with controls. Moreover, Sca-1(pos) CPCs isolated from hearts of diabetic mice displayed reduced activity of key enzymes of the pentose phosphate pathway, glucose-6-phosphate dehydrogenase (G6PD), and transketolase, increased levels of superoxide and advanced glucose end-products (AGE), and inhibition of the Akt/Pim-1/Bcl-2 signalling pathway. Similarly, culture of murine CPCs or human CD105(pos) progenitor cells in high glucose inhibits the pentose phosphate and pro-survival signalling pathways, leading to the activation of apoptosis. In vivo and in vitro supplementation with benfotiamine reactivates the pentose phosphate pathway and rescues CPC availability and function. This benefit is abrogated by either G6PD silencing by small interfering RNA (siRNA) or Akt inhibition by dominant-negative Akt. We provide new evidence of the negative impact of diabetes and high glucose on mechanisms controlling CPC redox state and survival. Boosting the pentose phosphate pathway might represent a novel mechanistic target for protection of CPC integrity.

Enhanced phosphate selectivity from wastewater using copper-loaded chelating resin functionalized with polyethylenimine.

Science.gov (United States)

An, Byungryul; Nam, Juhee; Choi, Jae-Woo; Hong, Seok-Won; Lee, Sang-Hyup

2013-11-01

In water and wastewater, phosphate is considered a critical contaminant due to cause algae blooms and eutrophication. To meet the stringent regulation of phosphate in water, a new commercial chelating resin functionalized with polyethylenimine was tested for phosphate removal by loading Cu(2+) and Fe(2+)/Fe(3+) to enhance selectivity for phosphate. Batch and column experiments showed that CR20-Cu exhibited high selectivity for phosphate over other strong anions such as sulfate. The average binary phosphate/nitrate and phosphate/sulfate factors for CR20-Cu were calculated to be 7.3 and 4.8, respectively, which were more than 0.97 and 0.22 for a commercial anion exchanger (AMP16). The optimal pH for the phosphate removal efficiency was determined to be 7. According to the fixed-bed column test, the breakthrough sequence for multiple ions was HPO4(2-)>SO4(2-)>NO3(-)>Cl(-). Saturated CR20-Cu can be regenerated using 4% NaCl at pH 7. More than 95% of the phosphate from CR20-Cu was recovered, and the phosphate uptake capacity for CR20-Cu was not reduced after 7 regeneration cycles. Copyright © 2013 Elsevier Inc. All rights reserved.

The structural response of gadolinium phosphate to pressure

Energy Technology Data Exchange (ETDEWEB)

Heffernan, Karina M. [Department of Geosciences, Virginia Tech, Blacksburg, VA 24061 (United States); Ross, Nancy L., E-mail: nross@vt.edu [Department of Geosciences, Virginia Tech, Blacksburg, VA 24061 (United States); Spencer, Elinor C. [Department of Geosciences, Virginia Tech, Blacksburg, VA 24061 (United States); Boatner, Lynn A. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2016-09-15

Accurate elastic constants for gadolinium phosphate (GdPO{sub 4}) have been measured by single-crystal high-pressure diffraction methods. The bulk modulus of GdPO{sub 4} determined under hydrostatic conditions, 128.1(8) GPa (K′=5.8(2)), is markedly different from that obtained with GdPO{sub 4} under non-hydrostatic conditions (160(2) GPa), which indicates the importance of shear stresses on the elastic response of this phosphate. High pressure Raman and diffraction analysis indicate that the PO{sub 4} tetrahedra behave as rigid units in response to pressure and that contraction of the GdPO{sub 4} structure is facilitated by bending/twisting of the Gd–O–P links that result in increased distortion in the GdO{sub 9} polyhedra. - Graphical abstract: A high-pressure single crystal diffraction study of GdPO{sub 4} with the monazite structure is presented. The elastic behaviour of rare-earth phosphates are believed to be sensitive to shear forces. The bulk modulus of GdPO{sub 4} measured under hydrostatic conditions is 128.1(8) GPa. Compression of the structure is facilitated by bending/twisting of the Gd−O−P links that result in increased distortion in the GdO{sub 9} polyhedra. Display Omitted - Highlights: • The elastic responses of rare-earth phosphates are sensitive to shear forces. • The bulk modulus of GdPO{sub 4} measured under hydrostatic conditions is 128.1(8) GPa. • Twisting of the inter-polyhedral links allows compression of the GdPO{sub 4} structure. • Changes to the GdO{sub 9} polyhedra occur in response to pressure (<7.0 GPa).

Availability of a P from phosphate rock, thermophosphate and trip superphosphate after different incubation periods

International Nuclear Information System (INIS)

Muraoka, T.; Boaretto, A.E.; Scivittaro, W.B.; Brasil, E.C.

2002-01-01

Patos phosphate rock, Yoorin thermophosphate and triple phosphate were mixed with a tropical acid soil (Haplic Ferralsol) and incubated for different periods (short term experiment 1: 0, 1 and 30 days, and long term experiment 2: 0, 1, 30, 60, 150 and 300 days). The experiments were started with the longest period in order to have all the periods ending at the same time when rice was sown. Soil samples were taken for available P determination through Bray 1 method. There was clear decrease in extractable P with increasing period of incubation, probably due to reversion reactions to form less soluble forms of P. In addition, the reversion reactions seemed to be a more intensive process than the dissolution process. The Yoorin thermophosphate, probably due to its alkaline nature and Si content, proved to be a superior agronomic P source by maintaining the same extractable P content during the whole incubation period. (author)

Phosphate enhances levan production in the endophytic bacterium Gluconacetobacter diazotrophicus Pal5

Science.gov (United States)

Idogawa, Nao; Amamoto, Ryuta; Murata, Kousaku; Kawai, Shigeyuki

2014-01-01

Gluconacetobacter diazotrophicus is a gram-negative and endophytic nitrogen-fixing bacterium that has several beneficial effects in host plants; thus, utilization of this bacterium as a biofertilizer in agriculture may be possible. G. diazotrophicus synthesizes levan, a D-fructofuranosyl polymer with β-(2→6) linkages, as an exopolysaccharide and the synthesized levan improves the stress tolerance of the bacterium. In this study, we found that phosphate enhances levan production by G. diazotrophicus Pal5, a wild type strain that showed a stronger mucous phenotype on solid medium containing 28 mM phosphate than on solid medium containing 7 mM phosphate. A G. diazotrophicus Pal5 levansucrase disruptant showed only a weak mucous phenotype regardless of the phosphate concentration, indicating that the mucous phenotype observed on 28 mM phosphate medium was caused by levan. To our knowledge, this is the first report of the effect of a high concentration of phosphate on exopolysaccharide production. PMID:24717418

Phosphate analysis of natural sausage casings preserved in brines with phosphate additives as inactivating agent - Method validation.

Science.gov (United States)

Wijnker, J J; Tjeerdsma-van Bokhoven, J L M; Veldhuizen, E J A

2009-01-01

Certain phosphates have been identified as suitable additives for the improvement of the microbial and mechanical properties of processed natural sausage casings. When mixed with NaCl (sodium chloride) and used under specific treatment and storage conditions, these phosphates are found to prevent the spread of foot-and-mouth disease and classical swine fever via treated casings. The commercially available Quantichrom™ phosphate assay kit has been evaluated as to whether it can serve as a reliable and low-tech method for routine analysis of casings treated with phosphate. The outcome of this study indicates that this particular assay kit has sufficient sensitivity to qualitatively determine the presence of phosphate in treated casings without interference of naturally occurring phosphate in salt used for brines in which casings are preserved.

31P-NMR differentiation between intracellular phosphate pools in Cosmarium (chlorophyta)

International Nuclear Information System (INIS)

Elgavish, A.; Elgavish, G.A.

1980-01-01

31 P nuclear magnetic resonance (NMR) spectroscopy of intact Cosmarium sp. cells is presented as a suitable tool for the differentiation of intracellular accumulation pools of polyphosphates. The cold trichloroacetic acid (TCA) insoluble fraction is shown to contain most of the total cellular phosphate in the phosphate rich Cosmarium cells. Moreover, evidence from a 31 P-NMR study and electron microscopic observations of cold TCA treated Cosmarium cells indicate that this fraction consists mostly of polyphosphates which seem to retain the native morphological structure observed in the untreated cells. The determination of orthophosphate in the hot water extract of Cosmarium cells did not measure the polyphosphate pools. Determination of total phosphorus content in the hot water extract rendered a value three times higher than the frequently used orthophosphate determination procedure. However, as revealed by the 31 P-NMR spectra and the chemical analyses of the extract and of the treated cells, even total phosphorus in the extract measured only 30% of the total cellular phosphorus. 31 P-NMR enabled the unequivocal chemical identification of the major phosphate compounds in the hot water extract (Surplus P) as orthophosphate and polyphosphates of about 10 phosphate units chainlength. More than 70% of the accumulation pool of polyphosphates was still in the cells after extraction. However, the electron microscopy study revealed that the native granular structure of polyphosphates had been destroyed by the hot water extraction procedure

Phosphate solubilization and multiple plant growth promoting ...

African Journals Online (AJOL)

Phosphate solubilizing efficiencies of the strains were analyzed using different insoluble phosphorus sources and the results show that most isolates released a substantial amount of soluble phosphate from tricalcium phosphate, rock phosphate and bone meal. Screening for multiple plant growth promoting attributes ...

High Content Screening: Understanding Cellular Pathway

International Nuclear Information System (INIS)

Mohamed Zaffar Ali Mohamed Amiroudine; Daryl Jesus Arapoc; Zainah Adam; Shafii Khamis

2015-01-01

High content screening (HCS) is the convergence between cell-based assays, high-resolution fluorescence imaging, phase-contrast imaging of fixed- or live-cell assays, tissues and small organisms. It has been widely adopted in the pharmaceutical and biotech industries for target identification and validation and as secondary screens to reveal potential toxicities or to elucidate a drugs mechanism of action. By using the ImageXpress® Micro XLS System HCS, the complex network of key players controlling proliferation and apoptosis can be reduced to several sentinel markers for analysis. Cell proliferation and apoptosis are two key areas in cell biology and drug discovery research. Understanding the signaling pathways in cell proliferation and apoptosis is important for new therapeutic discovery because the imbalance between these two events is predominant in the progression of many human diseases, including cancer. The DNA binding dye DAPI is used to determine the nuclear size and nuclear morphology as well as cell cycle phases by DNA content. Images together with MetaXpress® analysis results provide a convenient and easy to use solution to high volume image management. In particular, HCS platform is beginning to have an important impact on early drug discovery, basic research in systems cell biology, and is expected to play a role in personalized medicine or revealing off-target drug effects. (author)

Selective removal of phosphate for analysis of organic acids in complex samples.

Science.gov (United States)

Deshmukh, Sandeep; Frolov, Andrej; Marcillo, Andrea; Birkemeyer, Claudia

2015-04-03

Accurate quantitation of compounds in samples of biological origin is often hampered by matrix interferences one of which occurs in GC-MS analysis from the presence of highly abundant phosphate. Consequently, high concentrations of phosphate need to be removed before sample analysis. Within this context, we screened 17 anion exchange solid-phase extraction (SPE) materials for selective phosphate removal using different protocols to meet the challenge of simultaneous recovery of six common organic acids in aqueous samples prior to derivatization for GC-MS analysis. Up to 75% recovery was achieved for the most organic acids, only the low pKa tartaric and citric acids were badly recovered. Compared to the traditional approach of phosphate removal by precipitation, SPE had a broader compatibility with common detection methods and performed more selectively among the organic acids under investigation. Based on the results of this study, it is recommended that phosphate removal strategies during the analysis of biologically relevant small molecular weight organic acids consider the respective pKa of the anticipated analytes and the detection method of choice. Copyright © 2015 Elsevier B.V. All rights reserved.

Dependence of the phosphate sorption capacity on the aluminium and iron in Finnish soils

Directory of Open Access Journals (Sweden)

Armi Kaila

1963-12-01

Full Text Available An attempt was made to study to what extent the capacity of the more or less acid soils in Finland to sorb phosphate may be explained on the basis of their content of aluminium and iron. The indicator of the phosphate sorption capacity was calculated on the basis of the Freundlich adsorption isotherm according to the procedure proposed by TERÄSVUORI (8. The material consisted of 390 samples from cultivated and virgin soils representing both topsoils and subsoils. The indicator of the phosphate sorption capacity, the coefficient k, varied in the present material from 40 to 1510. The mean values (with the confidence limits at the 95 per cent level were for the 109 samples of sand and fine sand soils 290 ± 17, for the 103 samples of loam and silt soils 201 ± 24, for the 151 clay soils 308 ± 20, and for the 27 humus soils 236 ± 41. The total linear correlation coefficients between k and the soil pH, and its contents of organic carbon or clay were low or negligible in most of the soil groups. The correlation of k with the content of aluminium extracted by Tamm’s acid ammonium oxalate was fairly close in the clay soils (r = 0.84***, lower in the sand and fine sand soils (r = 0.77***, and in the loam and silt soils, and in the humus soils it was rather poor (r = 0.65*** and 0.63*** resp.. The elimination of the effect of the ammonium oxalate soluble iron decreased the correlation in the two latter groups quite markedly (to 0.32** and 0.37 resp., while the corresponding decrease in the coefficients for the former groups was less significant (to 0.64*** and 0.75*** resp.. The elimination of the effect of the ammonium oxalate soluble aluminium, on the other hand, decreased the correlation coefficients between k and the ammonium oxalate soluble iron in the sand and fine sand soils from 0.59*** to 0.26**, in the loam and silt soils from 0.73*** to 0.54***, in the clay soils from 0.70*** to 0.51***, and in the humus soils from 0.68*** to 0.49*. The

Eutrophication decrease: Phosphate adsorption processes in presence of nitrates.

Science.gov (United States)

Boeykens, Susana P; Piol, M Natalia; Samudio Legal, Lisa; Saralegui, Andrea B; Vázquez, Cristina

2017-12-01

Eutrophication causes aquatic environment degradation as well as serious problems for different purposes of water uses. Phosphorus and nitrogen, mainly as phosphate and nitrate respectively, are considered responsible for eutrophication degradation. The focus of this work was the study of adsorption processes for decreasing phosphate and nitrate concentrations in bi-component aqueous systems. Dolomite and hydroxyapatite were selected as low-cost adsorbents. Obtained results showed that both adsorbents have high capacity for phosphate adsorption which the presence of nitrate does not modify. Hydroxyapatite proved to be the most efficient adsorbent, however, it showed a low percentage of desorption and few possibilities of reuse. Dolomite, on the other hand, allows a desorption of the adsorbed material that favours its reuse. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phosphate and phosphate fertilizer sector: structure and future prospects. [Uranium recovery

Energy Technology Data Exchange (ETDEWEB)

Zenaidi, B

1981-12-01

A statement of the past evolution of this sector's structure is given. Various prospective studies which have been made are reviewed and lead to the precision of the phosphate requirement in the year 2000 which is between 200 and 250 Mt. Only a small section p. 696-697 is devoted to recovery of uranium contained in phosphate and prospects in this field are given.

Consortium inoculum of five thermo-tolerant phosphate solubilizing Actinomycetes for multipurpose biofertilizer preparation.

Science.gov (United States)

Nandimath, Arusha P; Karad, Dilip D; Gupta, Shantikumar G; Kharat, Arun S

2017-10-01

Alkaline pH of the soil facilitates the conversion of phosphate present in phosphate fertilizer applied in the field to insoluble phosphate which is not available to plants. Problem of soluble phosphate deficiency arises, primarily due to needless use of phosphate fertilizer. We sought to biofertilizer with the thermo-tolerant phosphate solubilizing actinomycetes consortium that could convert insoluble phosphate to soluble phosphate at wider temperature range. In the present investigation consortium of five thermo-tolerant phosphate solubilizing actinomycetes was applied for preparation of inoculum to produce multipurpose bio-fertilizer. Phosphates solubilizing thermo-tolerant 32 actinomycetes strains were processed for identification with the use of PIBWIN software and were screened for phosphate solubilizing activity. Amongst these five actinomycetes were selected on the basis of their ability to produce cellulase, chitinase, pectinase, protease, lipase, amylase and phosphate solubilizing enzymes. Ability to produce these enzymes at 28°C and 50°C were examined. Biofertilizer was prepared by using agricultural waste as a raw material. While preparation of bio-fertilizer the pH decreased from 7.5 to 4.3 and temperature increased up to 74°C maximum at the end of 4 th week and in subsequent week it started to decline gradually till it reached around 50°C, which was found to be stable up to eighth week. This thermo-tolerant actinomycetes consortium released soluble phosphate of up to 46.7 μg ml -1 . As the mesophilic organisms die out at high temperature of composting hence thormo-tolerant actinomycetes would be the better substitute for preparation of phosphate solubilizing bio-fertilizer with added potential to degrade complex macromolecules in composting.

Equilibrium and kinetics of co-extraction of U(VI) and HNO3 using tri-n-butyl phosphate and tri-iso-amyl phosphate in paraffin

International Nuclear Information System (INIS)

Das, Diptendu; Juvekar, V.A.; Biswas, Sujoy; Roy, S.B.; Bhattacharya, R.

2014-01-01

Tri-n-butyl phosphate (TBP) is versatile solvent for recovery of actinides as it is cheaper and the extracted actinides can be stripped from the loaded organic phase using plain water. However there are inherent problems associated TBP such as i) formation of the third phase ii) high solubility in aqueous phase iii) radiolytic hydrolysis at high radiation environment and iv) high propensity for extraction of mineral acids. The last mentioned property makes it less suitable for liquid emulsion membrane (LEM) extraction where acid transport to the strip phase drastically reduces extraction efficiency. Therefore there is need to replace TBP with an extractant which has lesser propensity for acid extraction. Many researcher reported Tri-iso-amyl phosphate (TiAP) as an alternative extractant which can sustain high radiation environment without chemical/radiative degradation. However there are no studies available on co-extraction of U(VI) and mineral acids by TiAP. In this research paper equilibrium and kinetics of co-extraction of U(VI) and HNO 3 from nitric acid medium into a hydrocarbon phase (paraffin) using Tri n- butyl phosphate (TBP), Tri-iso-amyl phosphate (TiAP) has been studied. Relative rates of extraction of uranium(VI) and HNO 3 by TiAP and TBP were measured simultaneously using bulk-liquid membrane (BLM) system. Study reveals although TiAP is less efficient in extracting U(IV), than TBP, it transfers lesser quantity of nitric acid to organic phase. Hence TiAP is more suitable as a carrier for LEM extraction than TBP

Effect of added phosphate and type of cooking method on physico-chemical and sensory features of cooked lamb loins.

Science.gov (United States)

Roldán, Mar; Antequera, Teresa; Pérez-Palacios, Trinidad; Ruiz, Jorge

2014-05-01

This study evaluated the effect of brining with phosphates on the physico-chemical and sensory features of sous-vide and roasted cooked lamb. Lamb loins (n=48) were injected with either 10% w/w of distilled water or a solution containing 0.2% or 0.4% (w/v) of a mixture of phosphate salts. After injection, samples were either sous-vide cooked (12h-60°C) or oven roasted (180°C until 73°C of core temp.). Expressible moisture, cooking loss, instrumental color, pH, water holding capacity, instrumental texture and sensory properties were evaluated. Brining with phosphates led to lower cooking loss in both sous-vide and oven roasted samples, but only the former showed significantly higher moisture content. Phosphates increased instrumental hardness and shear force values in sous-vide samples, while this effect was not as evident in roasted ones. Toughness was reduced and juiciness was improved as a consequence of phosphate addition. Overall, injection of a phosphate solution appears as a potential procedure for improving sensory textural features of cooked lamb whole cuts. Copyright © 2014 Elsevier Ltd. All rights reserved.

Plasma spheroidization and high temperature stability of lanthanum phosphate and its compatibility with molten uranium

Energy Technology Data Exchange (ETDEWEB)

Ananthapadmanabhan, P.V. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)], E-mail: pvananth@barc.gov.in; Sreekumar, K.P.; Thiyagarajan, T.K.; Satpute, R.U. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Krishnan, K.; Kulkarni, N.K. [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kutty, T.R.G. [Radiometallurgy Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2009-01-15

Lanthanum phosphate has excellent thermal stability and corrosion resistance against many molten metals and other chemically corrosive environments. Lanthanum phosphate (LaPO{sub 4}) was synthesized from lanthanum oxalate by thermal dissociation of the oxalate to the oxide, followed by conversion to hydrated lanthanum phosphate (LaPO{sub 4}.0.5H{sub 2}O). Thermal treatment of LaPO{sub 4}.0.5H{sub 2}O above 773 K resulted in the irreversible transformation of the hydrated phase to the stable monazite phase. Thermal and chemical stability of monazite was studied by plasma spheroidization experiments using a DC thermal plasma reactor set up. Compatibility of monazite with molten uranium was studied by thermal analysis. Results showed that monazite is thermally stable up to its melting point and also is resistant towards attack by molten uranium. Adherent coatings of LaPO{sub 4} could be deposited onto various substrates by atmospheric plasma spray technique.

Long-term nitrate and phosphate loading of river water in the Upper ...

African Journals Online (AJOL)

High nitrate and phosphate concentrations were recorded directly downstream of residential, municipal and industrial areas suggesting that these were the major sources of the pollutants found in the river water. For example, phosphate concentration at 2 sites along Mukuvisi River (downstream of domestic and industrial ...

Overexpression, crystallization and preliminary X-ray crystallographic analysis of erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa.

Science.gov (United States)

Ha, Jun Yong; Lee, Ji Hyun; Kim, Kyoung Hoon; Kim, Do Jin; Lee, Hyung Ho; Kim, Hye-Kyung; Yoon, Hye-Jin; Suh, Se Won

2006-02-01

The enzyme erythronate-4-phosphate dehydrogenase catalyses the conversion of erythronate-4-phosphate to 3-hydroxy-4-phospho-hydroxy-alpha-ketobutyrate. It belongs to the D-isomer-specific 2-hydroxyacid dehydrogenase family. It is essential for de novo biosynthesis of vitamin B6 (pyridoxine). Erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa, a homodimeric enzyme consisting of two identical 380-residue subunits, has been overexpressed in Escherichia coli with a C-terminal purification tag and crystallized at 297 K using 0.7 M ammonium dihydrogen phosphate, 0.4 M ammonium tartrate, 0.1 M sodium citrate pH 5.6 and 10 mM cupric chloride. X-ray diffraction data were collected to 2.20 A from a crystal grown in the presence of NADH. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 84.77, b = 101.28, c = 142.58 A. A dimeric molecule is present in the asymmetric unit, giving a crystal volume per protein weight (VM) of 3.64 A3 Da(-1) and a solvent content of 66%.

Selection and evaluation of phosphate-solubilizing bacteria from grapevine rhizospheres for use as biofertilizers

International Nuclear Information System (INIS)

Liu, M.; Liu, X.; Cheng, B.S.; Ma, X.L.; Lyu, X.; Zhao, X.; Ju, Y.; Min, Z.; Fang, Y.

2016-01-01

Phosphate-solubilizing bacteria (PSB) have the ability to solubilize insoluble phosphorus (P) and release soluble P. Extensive research has been performed with respect to PSB isolation from the rhizospheres of various plants, but little is known about the prevalence of PSB in the grapevine rhizosphere. In this study, we aimed to isolate and identify PSB from the grapevine rhizosphere in five vineyards of Northwest China, to characterize their plant-growth-promoting (PGP) traits, evaluate the effect of stress on their phosphate-solubilizing activity (PSA), and test their ability to stimulate the growth of Vitis vinifera L. cv. Cabernet Sauvignon. From the vineyard soils, 66 PSB isolates were screened, and 10 strains with high PSA were identified by 16S rRNA sequencing. Sequence analysis revealed that these 10 strains belonged to 4 genera and 5 species: Bacillus aryabhattai, B. megaterium, Klebsiella variicola, Stenotrophomonas rhizophila, and Enterobacter aerogenes. The selected PSB strains JY17 (B. aryabhattai) and JY22 (B. aryabhattai) were positive for multiple PGP traits, including nitrogen fixation and production of indole acetic acid (IAA), siderophores, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, chitinase, and protease. JY17 and JY22 showed strong PSA under stress conditions of high pH, high salt, and high temperature. Therefore, these two isolates can be used as biofertilizers in saline-alkaline soils. The inoculation with PSB significantly facilitated the growth of V. vinifera cv. Cabernet Sauvignon under greenhouse conditions. Use of these PSB as biofertilizers will increase the available P content in soils, minimize P-fertilizer application, reduce environmental pollution, and promote sustainable agriculture.

Selection and evaluation of phosphate-solubilizing bacteria from grapevine rhizospheres for use as biofertilizers

Energy Technology Data Exchange (ETDEWEB)

Liu, M.; Liu, X.; Cheng, B.S.; Ma, X.L.; Lyu, X.; Zhao, X.; Ju, Y.; Min, Z.; Fang, Y.

2016-07-01

Phosphate-solubilizing bacteria (PSB) have the ability to solubilize insoluble phosphorus (P) and release soluble P. Extensive research has been performed with respect to PSB isolation from the rhizospheres of various plants, but little is known about the prevalence of PSB in the grapevine rhizosphere. In this study, we aimed to isolate and identify PSB from the grapevine rhizosphere in five vineyards of Northwest China, to characterize their plant-growth-promoting (PGP) traits, evaluate the effect of stress on their phosphate-solubilizing activity (PSA), and test their ability to stimulate the growth of Vitis vinifera L. cv. Cabernet Sauvignon. From the vineyard soils, 66 PSB isolates were screened, and 10 strains with high PSA were identified by 16S rRNA sequencing. Sequence analysis revealed that these 10 strains belonged to 4 genera and 5 species: Bacillus aryabhattai, B. megaterium, Klebsiella variicola, Stenotrophomonas rhizophila, and Enterobacter aerogenes. The selected PSB strains JY17 (B. aryabhattai) and JY22 (B. aryabhattai) were positive for multiple PGP traits, including nitrogen fixation and production of indole acetic acid (IAA), siderophores, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, chitinase, and protease. JY17 and JY22 showed strong PSA under stress conditions of high pH, high salt, and high temperature. Therefore, these two isolates can be used as biofertilizers in saline-alkaline soils. The inoculation with PSB significantly facilitated the growth of V. vinifera cv. Cabernet Sauvignon under greenhouse conditions. Use of these PSB as biofertilizers will increase the available P content in soils, minimize P-fertilizer application, reduce environmental pollution, and promote sustainable agriculture.

Better prospects for phosphate production

Energy Technology Data Exchange (ETDEWEB)

1980-06-01

The extraction of uranium as a by product of phosphate production is discussed. Techniques being commercially developed are described. The trend towards the wet process, in which sulphuric acid is used to dissolve the phosphate, producing phosphoric acid, is also the preferred method for uranium recovery. Recovery from a wet process phosphoric acid stream, integrated with phosphate fertilizer manufacture, is becoming increasingly commercially viable for the production of yellow-cake.

The Oxygen Isotopic Composition of Phosphate: A Tracer for Phosphate Sources and Cycling

Energy Technology Data Exchange (ETDEWEB)

Mclaughlin, K. [Southern California Coastal Water Research Project, Costa Mesa, University of California, CA (United States); Young, M. B.; Paytan, A.; Kendall, C. [U.S. Geological Survey, University of California, CA (United States)

2013-05-15

Phosphorus (P) is a limiting macro-nutrient for primary productivity and anthropogenic P-loading to aquatic ecosystems is one of the leading causes of eutrophication in many ecosystems throughout the world. Because P has only one stable isotope, traditional isotope techniques are not possible for tracing sources and cycling of P in aquatic systems. However, much of the P in nature is bonded to four oxygen (O) atoms as orthophosphate (PO{sub 4}{sup 3-}). The P-O bonds in orthophosphate are strongly resistant to inorganic hydrolysis and do not exchange oxygen with water without biological mediation (enzyme-mediated recycling). Thus, the oxygen isotopic composition of dissolved inorganic phosphate ({delta}{sup 18}O{sub p}) may be used as a tracer for phosphate sources and cycling in aquatic ecosystems. Recently, several studies have been conducted utilizing {delta}{sup 18}O{sub p} as a tracer for phosphate sources and cycling in various aquatic environments. Specifically, work to date indicates that {delta}{sup 18}O{sub p} is useful for determining sources of phosphate to aquatic systems if these sources have unique isotopic signatures and phosphate cycling within the system is limited compared to input fluxes. In addition, because various processes imprint specific fractionation effects, the {delta}{sup 18}O{sub p} tracer can be utilized to determine the degree of phosphorous cycling and processing through the biomass. This chapter reviews several of these studies and discusses the potential to utilize the {delta}{sup 18}O{sub p} of phosphate in rivers and streams. (author)

Occurrence and functioning of phosphate solubilizing ...

African Journals Online (AJOL)

Occurrence and functioning of phosphate solubilizing microorganisms from oil palm tree ( Elaeis guineensis ) rhizosphere in Cameroon. ... While the use of soluble mineral phosphate fertilizers is the obvious best means to combat phosphate ... in order to improve agricultural production, using low inputs technology. Isolates ...

Effects of phosphate addition on methane fermentation in the batch and upflow anaerobic sludge blanket (UASB) reactors.

Science.gov (United States)

Suzuki, Sho; Shintani, Masaki; Sanchez, Zoe Kuizon; Kimura, Kohei; Numata, Mitsuru; Yamazoe, Atsushi; Kimbara, Kazuhide

2015-12-01

Ammonia inhibition of methane fermentation is one of the leading causes of failure of anaerobic digestion reactors. In a batch anaerobic digestion reactor with 429 mM NH3-N/L of ammonia, the addition of 25 mM phosphate resulted in an increase in methane production rate. Similar results were obtained with the addition of disodium phosphate in continuous anaerobic digestion using an upflow anaerobic sludge blanket (UASB) reactor. While methane content and production rate decreased in the presence of more than 143 mM NH3-N/L of ammonium chloride in UASB, the addition of 5 mM disodium phosphate suppressed ammonia inhibition at 214 mM NH3-N/L of ammonium chloride. The addition prevented acetate/propionate accumulation, which might be one of the effects of the phosphate on the ammonia inhibition. The effects on the microbial community in the UASB reactor was also assessed, which was composed of Bacteria involved in hydrolysis, acidogenesis, acetogenesis, and dehydrogenation, as well as Archaea carrying out methanogenesis. The change in the microbial community was observed by ammonia inhibition and the addition of phosphate. The change indicates that the suppression of ammonia inhibition by disodium phosphate addition could stimulate the activity of methanogens, reduce shift in bacterial community, and enhance hydrogen-producing bacteria. The addition of phosphate will be an important treatment for future studies of methane fermentation.

Shedding Light on Filovirus Infection with High-Content Imaging

Directory of Open Access Journals (Sweden)

Rekha G. Panchal

2012-08-01

Full Text Available Microscopy has been instrumental in the discovery and characterization of microorganisms. Major advances in high-throughput fluorescence microscopy and automated, high-content image analysis tools are paving the way to the systematic and quantitative study of the molecular properties of cellular systems, both at the population and at the single-cell level. High-Content Imaging (HCI has been used to characterize host-virus interactions in genome-wide reverse genetic screens and to identify novel cellular factors implicated in the binding, entry, replication and egress of several pathogenic viruses. Here we present an overview of the most significant applications of HCI in the context of the cell biology of filovirus infection. HCI assays have been recently implemented to quantitatively study filoviruses in cell culture, employing either infectious viruses in a BSL-4 environment or surrogate genetic systems in a BSL-2 environment. These assays are becoming instrumental for small molecule and siRNA screens aimed at the discovery of both cellular therapeutic targets and of compounds with anti-viral properties. We discuss the current practical constraints limiting the implementation of high-throughput biology in a BSL-4 environment, and propose possible solutions to safely perform high-content, high-throughput filovirus infection assays. Finally, we discuss possible novel applications of HCI in the context of filovirus research with particular emphasis on the identification of possible cellular biomarkers of virus infection.

Overexpression, crystallization and preliminary X-ray crystallographic analysis of erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa

Energy Technology Data Exchange (ETDEWEB)

Ha, Jun Yong; Lee, Ji Hyun; Kim, Kyoung Hoon; Kim, Do Jin; Lee, Hyung Ho; Kim, Hye-Kyung; Yoon, Hye-Jin; Suh, Se Won, E-mail: sewonsuh@snu.ac.kr [Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 151-742 (Korea, Republic of)

2006-02-01

Erythronate-4-phosphate dehydrogenase from P. aeruginosa was crystallized and X-ray diffraction data were collected to 2.20 Å resolution. The enzyme erythronate-4-phosphate dehydrogenase catalyses the conversion of erythronate-4-phosphate to 3-hydroxy-4-phospho-hydroxy-α-ketobutyrate. It belongs to the d-isomer-specific 2-hydroxyacid dehydrogenase family. It is essential for de novo biosynthesis of vitamin B{sub 6} (pyridoxine). Erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa, a homodimeric enzyme consisting of two identical 380-residue subunits, has been overexpressed in Escherichia coli with a C-terminal purification tag and crystallized at 297 K using 0.7 M ammonium dihydrogen phosphate, 0.4 M ammonium tartrate, 0.1 M sodium citrate pH 5.6 and 10 mM cupric chloride. X-ray diffraction data were collected to 2.20 Å from a crystal grown in the presence of NADH. The crystals belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 84.77, b = 101.28, c = 142.58 Å. A dimeric molecule is present in the asymmetric unit, giving a crystal volume per protein weight (V{sub M}) of 3.64 Å{sup 3} Da{sup −1} and a solvent content of 66%.

Overexpression, crystallization and preliminary X-ray crystallographic analysis of erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa

International Nuclear Information System (INIS)

Ha, Jun Yong; Lee, Ji Hyun; Kim, Kyoung Hoon; Kim, Do Jin; Lee, Hyung Ho; Kim, Hye-Kyung; Yoon, Hye-Jin; Suh, Se Won

2006-01-01

Erythronate-4-phosphate dehydrogenase from P. aeruginosa was crystallized and X-ray diffraction data were collected to 2.20 Å resolution. The enzyme erythronate-4-phosphate dehydrogenase catalyses the conversion of erythronate-4-phosphate to 3-hydroxy-4-phospho-hydroxy-α-ketobutyrate. It belongs to the d-isomer-specific 2-hydroxyacid dehydrogenase family. It is essential for de novo biosynthesis of vitamin B 6 (pyridoxine). Erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa, a homodimeric enzyme consisting of two identical 380-residue subunits, has been overexpressed in Escherichia coli with a C-terminal purification tag and crystallized at 297 K using 0.7 M ammonium dihydrogen phosphate, 0.4 M ammonium tartrate, 0.1 M sodium citrate pH 5.6 and 10 mM cupric chloride. X-ray diffraction data were collected to 2.20 Å from a crystal grown in the presence of NADH. The crystals belong to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 84.77, b = 101.28, c = 142.58 Å. A dimeric molecule is present in the asymmetric unit, giving a crystal volume per protein weight (V M ) of 3.64 Å 3 Da −1 and a solvent content of 66%

Effect of molybdate on phosphating of Nd-Fe-B magnets for corrosion protection

Directory of Open Access Journals (Sweden)

Adonis Marcelo Saliba-Silva

2005-06-01

Full Text Available Nd-Fe-B magnets are highly susceptible to corrosion and need protection against environment attack. The use of organic coatings is one of the main methods of corrosion protection of these materials. Data related to the effect of conversion coatings, such as phosphating, on corrosion performance of these magnets is still scarce. Studies about the effect of phosphating on the corrosion resistance of a commercial Nd-Fe-B sintered magnet indicated that it increases the corrosion resistance of these magnets, compared to non-phosphated magnets. In this study, the solution chemistry of a phosphating bath was altered with the addition of molybdate and its effect on the corrosion resistance of magnets investigated. Sintered magnet specimens were phosphated in solutions of 10 g/L NaH2PO4 (pH 3.8, either with or without molybdate [10-3 M MoO4(2-], to improve their corrosion resistance. The effect of phosphating time was also evaluated, and specimens were phosphated for 4 and 18 hours. To evaluate the corrosion performance of phosphated and unphosphated specimens, a corrosion test based on monitoring hydrogen evolution on the surface of the magnets was used. This technique revealed that the addition of molybdate to the phosphating solution improved the corrosion resistance of the magnets phosphated by immersion for short periods but had no beneficial effect if phosphated by immersion for longer periods.

on association of trialkyl phosphates

International Nuclear Information System (INIS)

Petkovic, D.M.; Maksimovic, Z.B.

1976-01-01

The association constants of tri-n-butyl (TBP), tri-n-propyl (TPP) and triethyl phosphate (TEP) with chloroform, carbon tetrachloride and benzene were determined by dielectric constant, proton magnetic resonance and vapor pressure measurements. Correlation of the trialkyl phosphate-chloroform association constants, using the Hammett equation, showed their increase with the number of carbon atoms in the aliphatic radicals. The change of trialkyl phosphate reactivity with temperature was used to determine the thermodynamic quantities. (author)

Bio-treatment of phosphate from synthetic wastewater using ...

African Journals Online (AJOL)

In this study, the efficient phosphate utilizing isolates were used to remove phosphate from synthetic phosphate wastewater was tested using batch scale process. Hence the objective of the present study was to examine the efficiency of bacterial species individually for the removal of phosphate from synthetic phosphate ...

The radiological impact of the Belgian phosphate industry

Energy Technology Data Exchange (ETDEWEB)

Vanmarcke, H.; Paridaens, J. [Belgian Nuclear Research Centre, SCK.CEN, Boeretang 200, 2400 Mol (Belgium)

2006-07-01

The Belgian phosphate industry processes huge amounts of phosphate ore (1.5 to 2 Mton/year) for a wide range of applications, the most important being the production of phosphoric acid, fertilizers and cattle food. Marine phosphate ores show high specific activities of the natural uranium decay series (usually indicated by Ra-226) (e.g. 1200 to 1500 Bq/kg for Moroccan ore). Ores of magmatic origin generally contain less of the uranium and more of the thorium decay series (up to 500 Bq/kg). These radionuclides turn up in by-products, residues or product streams depending on the processing method and the acid used for the acidulation of the phosphate rock. Sulfuric acid is the most widely used, but also hydrochloric acid and nitric acid are applied in Belgium. For Flanders, the northern part of Belgium, we already have a clear idea of the production processes and waste streams. The five Flemish phosphate plants, from 1920 to 2000, handled 54 million ton of phosphate ore containing 65 TBq of radium-226 and 2.7 TBq of thorium- 232. The total surface area of the phosphogypsum and calcium fluoride sludge deposits amounts to almost 300 ha. There is also environmental contamination along two small rivers receiving the waste waters of the hydrochloric production process: the Winterbeek (> 200 ha) and the Grote Laak (12 ha). The data on the impact of the phosphate industry in the Walloon provinces in Belgium is less complete. A large plant produced in 2004 0.8 Mton of phosphogypsum, valorizing about 70 % of the gypsum in building materials (plaster, cement), in fertilizers, and in other products such as paper. The remainder was stored on a local disposal site. The radiological impact of the Belgian phosphate industry on the local population will be discussed. At present most contaminated areas are still recognizable as waste deposits and inaccessible to the population. However as gypsum deposits and other contaminated areas quickly blend in with the landscape, it is

Infrared-spectroscopy analysis of zinc phosphate and nickel and manganese modified zinc phosphate coatings on electrogalvanized steel

International Nuclear Information System (INIS)

Fernandes, Kirlene Salgado; Alvarenga, Evandro de Azevedo; Lins, Vanessa de Freitas Cunha

2011-01-01

Hopeite-type phosphate coatings in which zinc is partially replaced by other metals like manganese and nickel are of great interest for the automotive and home appliance industries. Such industries use phosphate conversion coatings on galvanized steels in association with cataphoretic electro painting. Zinc phosphates modified with manganese and nickel are isomorphic with the hopeite, and the phase identification using X-ray diffraction is difficult. In this paper, the phosphate coatings are identified using the Fourier transform infrared spectroscopy (FTIR). (author)

The distribution pattern of main and trace elements in phosphatic laterites from Pirocaua Plateau (MA)

International Nuclear Information System (INIS)

Siqueira, N.V.M. de.

1982-01-01

The phosphate-laterite of Pirocaua (state of Maranhao) was studied with basis on several lines of evidence, namely, structure of the deposit, mineral distribution, variations in chemical composition and chemistry of ground waters in the region. The distribution of elements during the formation of the deposit is interpreted and the conditioning factors analysed. Air and water samples were studied respectively by X-ray diffraction and atomic absorption spectroscopy. The results show that fluctuations of the hydrostatic level were important during the formation of the phosphate horizon. When the deposit was formed there was also a decrease of the activity of the silicic acid and a parallel increase of acidity towards the top of the cross-section studied. In these conditions, Fe sup(2+) migrated towards the top of the deposit and was precipitated as Fe sup(3+) in the oxidizing zone. Migration of phosphate was in part due to its affinities to clay minerals, in which mechanism ground water played a major role. Mass balance calculations indicate that of the parent-rock is a phyllite, it is necessary an extreme enrichment in P and Sr to give the composition of the phosphate horizon. With basis on these observations we conclude that: 1) the parent-rock must have contents of P and Sr higher than the average for phyllites; or 2) the phosphate has some other source. (author)

Application of Calcium Phosphate Materials in Dentistry

Directory of Open Access Journals (Sweden)

Jabr S. Al-Sanabani

2013-01-01

Full Text Available Calcium phosphate materials are similar to bone in composition and in having bioactive and osteoconductive properties. Calcium phosphate materials in different forms, as cements, composites, and coatings, are used in many medical and dental applications. This paper reviews the applications of these materials in dentistry. It presents a brief history, dental applications, and methods for improving their mechanical properties. Notable research is highlighted regarding (1 application of calcium phosphate into various fields in dentistry; (2 improving mechanical properties of calcium phosphate; (3 biomimetic process and functionally graded materials. This paper deals with most common types of the calcium phosphate materials such as hydroxyapatite and tricalcium phosphate which are currently used in dental and medical fields.

Thermochemical investigations on uranyl phosphates and arsenates

International Nuclear Information System (INIS)

Barten, H.

1986-11-01

The results are described of a study of the thermochemical stability of anhydrous uranyl phosphates and arsenates. A number of aspects of chemical technological importance are indicated in detail. The synthesized anhydrous uranyl phosphates and arsenates were very hygroscopic, so that experiments on these compounds had to be carried out under moisture-free conditions. Further characterisation of these compounds are given, including a study of their thermal stabilities and phase relations. The uranyl phosphates reduced reversibly at temperatures of the order of 1100 to 1600 0 C. This makes it possible to express their relative stabilities quantitatively, in terms of the oxygen pressures of the reduction reactions. The thermal decomposition of uranyl arsenates did not occur by reduction, as for the phosphates, but by giving off arsenic oxide vapour. The results of measurements of enthalpies of solution led to the determination of the enthalpies of formation, heat capacity and the standard entropies of the uranyl arsenates. The thermochemical functions at high-temperatures could consequently be calculated. Attention is paid to the possible formation of uranium arsenates, whose uranium has a valency lower than six, hitherto not reported in literature. It was not possible to prepare arsenates of tetravalent uranium. However, three new compounds were observed, one of these, UAsO 5 , was studied in some detail. (Auth.)

Chemical activation of gasification carbon residue for phosphate removal

Science.gov (United States)

Kilpimaa, Sari; Runtti, Hanna; Lassi, Ulla; Kuokkanen, Toivo

2012-05-01

Recycling of waste materials provides an economical and environmentally significant method to reduce the amount of waste. Bioash formed in the gasification process possesses a notable amount of unburned carbon and therefore it can be called a carbon residue. After chemical activation carbon residue could be use to replace activated carbon for example in wastewater purification processes. The effect of chemical activation process variables such as chemical agents and contact time in the chemical activation process were investigated. This study also explored the effectiveness of the chemically activated carbon residue for the removal of phosphate from an aqueous solution. The experimental adsorption study was performed in a batch reactor and the influence of adsorption time, initial phosphate concentration and pH was studied. Due to the carbon residue's low cost and high adsorption capacity, this type of waste has the potential to be utilised for the cost-effective removal of phosphate from wastewaters. Potential adsorbents could be prepared from these carbonaceous by-products and used as an adsorbent for phosphate removal.