The influence of the sample introduction system on signals of different tin compounds in inductively coupled plasma-based techniques

The influence of the sample introduction system on the signals obtained with different tin compounds in inductively coupled plasma (ICP) based techniques, i.e., ICP atomic emission spectrometry (ICP–AES) and ICP mass spectrometry (ICP–MS) has been studied. Signals for test solutions prepared from four different tin compounds (i.e., tin tetrachloride, monobutyltin, dibutyltin and di-tert-butyltin) in different solvents (methanol 0.8% (w/w), i-propanol 0.8% (w/w) and various acid matrices) have been measured by ICP–AES and ICP–MS. The results demonstrate a noticeable influence of the volatility of the tin compounds on their signals measured with both techniques. Thus, in agreement with the compound volatility, the highest signals are obtained for tin tetrachloride followed by di-tert-butyltin/monobutyltin and dibutyltin. The sample introduction system exerts an important effect on the amount of solution loading the plasma and, hence, on the relative signals afforded by the tin compounds in ICP–based techniques. Thus, when working with a pneumatic concentric nebulizer, the use of spray chambers affording high solvent transport efficiency to the plasma (such as cyclonic and single pass) or high spray chamber temperatures is recommended to minimize the influence of the tin chemical compound. Nevertheless, even when using the conventional pneumatic nebulizer coupled to the best spray chamber design (i.e., a single pass spray chamber), signals obtained for di-tert-butyltin/monobutyltin and dibutyltin are still around 10% and 30% lower than the corresponding signal for tin tetrachloride, respectively. When operating with a pneumatic microconcentric nebulizer coupled to a 50 °C-thermostated cinnabar spray chamber, all studied organotin compounds provided similar emission signals although about 60% lower than those obtained for tin tetrachloride. The use of an ultrasonic nebulizer coupled to a desolvation device provides the largest differences in the emission signals, among all tested systems.

Isothermal (liquid + liquid) equilibrium data at T = 313.15 K and isobaric (vapor + liquid + liquid) equilibrium data at 101.3 kPa for the ternary system (water + 1-butanol + p-xylene)

The (vapor + liquid), (liquid + liquid) and (vapor + liquid + liquid) equilibria of the ternary system (water + 1-butanol + p-xylene) have been determined. (Water + 1-butanol + p-xylene) is a type 2 heterogeneous ternary system with partially miscible (water + 1-butanol) and (water + p-xylene) pairs. By contrast, (1-butanol + p-xylene) is totally miscible under atmospheric conditions. This paper examines the (vapor + liquid) equilibrium in both heterogeneous and homogeneous regions at 101.3 kPa of pressure. (Liquid + liquid) equilibrium data at T = 313.15 K have also been determined, and for comparison, the obtained experimental data have been calculated by means of several thermodynamic models: UNIQUAC, UNIFAC and NRTL. Some discrepancies were found between the (vapor + liquid + liquid) correlations; however, the models reproduced the (liquid + liquid) equilibrium data well. The obtained data reveal a ternary heterogeneous azeotrope with mole fraction composition: 0.686 water, 0.146 1-butanol and 0.168 p-xylene.

Optimal Design of a Hybrid Membrane System Combining Reverse and Forward Osmosis for Seawater Desalination

In this work we study Forward Osmosis (FO) as an emerging desalination technology, and its capability to replace totally or partially Reverse Osmosis (RO) in order to reduce the great amount of energy required in the current desalination plants. For this purpose, we propose a superstructure that includes both membrane based desalination technologies, allowing the selection of only one of the technologies or a combination of both of them seeking for the optimal configuration of the network. The optimization problem is solved for a seawater desalination plant with a given fresh water production. The results obtained show that the optimal solution combines both desalination technologies to reduce not only the energy consumption but also the total cost of the desalination process in comparison with the same plant but operating only with RO.

An Acyl-NHC Osmium Cooperative System: Coordination of Small Molecules and Heterolytic B–H and O–H Bond Activation

The hexahydride complex OsH6(PiPr3)2 (1) activates the C–OMe bond of 1-(2-methoxy-2-oxoethyl)-3-methylimidazolium chloride (2), in addition to promoting the direct metalation of the imidazolium group, to afford a five-coordinate OsCl(acyl-NHC)(PiPr3)2 (3) compound. The latter coordinates carbon monoxide, oxygen, and molecular hydrogen to give the corresponding carbonyl (4), dioxygen (5), and dihydrogen (6) derivatives. Complex 3 also promotes the heterolytic bond activation of pinacolborane (HBpin), using the acyl oxygen atom as a pendant Lewis base. The hydride ligand and the Bpin substituent of the Fischer-type carbene of the resulting complex 7 activate the O–H bond of alcohols and water. As a consequence, complex 3 is a metal ligand cooperating catalyst for the generation of molecular hydrogen, by means of both the alcoholysis and hydrolysis of pinacolborane, via the intermediates 7 and 6.

Influence of the Temperature on the Liquid–Liquid–Solid Equilibria of the Water + Ethanol + 1-Undecanol Ternary System

Liquid–liquid (L–L), solid–liquid (S–L), and solid–liquid–liquid (S–L–L) equilibrium data for the water–ethanol–1-undecanol ternary system have been determined experimentally at (275.15, 278.15, 281.15, 288.15, and 298.15) K and atmospheric pressure. Different shapes of the equilibrium diagrams have been observed depending on the temperature. A region with three phases (S–L–L) is present in the temperature range between (275.15 and 281.15) K. Above 288.15 K, only a L–L region is observed.

Liquid–Liquid Equilibria of Water + Ethanol + 1-Butyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)imide Ternary System: Measurements and Correlation at Different Temperatures

In this work authors present the experimental liquid–liquid equilibria (LLE) data of water + ethanol + 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([bmim][Tf2N]) system at different temperatures. The LLE of the system was obtained in the temperature range from 283.2 to 323.2 K. The nonrandom two liquid (NRTL) and universal quasichemical (UNIQUAC) models were used to correlate ternary systems. The equilibrium compositions were successfully correlated by the interaction parameters from both models, however UNIQUAC gave a more accurate correlation. Finally, a study about the solvent capability of ionic liquid was made in order to evaluate the possibility of separating the mixture formed by ethanol and water using that ionic liquid.

Isobaric vapor–liquid–liquid–solid equilibrium of the water + NaCl + 1-butanol system at 101.3 kPa

A mixture of water + NaCl + 1-butanol at 101.3 kPa is studied in order to determine the influence of salt on its experimental vapor–liquid–liquid–solid equilibrium. A detailed analysis of the evolution with temperature of the different equilibrium regions is carried out. The study is conducted at a constant pressure of 101.3 kPa in a recirculating still that has been modified by our research group. The changes in the 1-butanol/water composition ratio in the vapor phase that are provoked by the salt are studied as a function of equilibrium region. In addition, the mutual solubility of 1-butanol and water is assessed in the liquid–liquid and solid–liquid regions.

Gakara region, Burundi, 1994, Defense Mapping Agency (DMA) Series Z724, Sheet 4673-I (Raster Image)

This layer is a georeferenced raster image of the United States Defense Mapping Agency (DMA) Series Z724, Burundi, 1:50,000 Topographic Line Map (TLM) Series sheet map entitled: Gakara. Printed in: 1994. Covers portions of Gakara region, Burundi. Sheet: 4673-I. Edition statement: Ed. 1 - DMA. The image inside the map neatline is georeferenced to the surface of the earth and fit to World Geodetic System (1984) coordinates. All map collar information is also available as part of the raster image. Burundi 1:50:000 Series Z724 maps are in English and French (legends also include Rundi). Each source map in the series is printed in color at a scale of 1:50,000. Series source sheets were published in 1994-1995 by the United States Defense Mapping Agency, Hydrographic/Topographic Center. The source map was scanned and georeferenced for Harvard University's Center for Geographic Analysis' AfricaMap project by East View Cartographic. Individual TLM sheets covering Burundi (40 sheets in total) were selected from the TLM worldwide series. DMA Topographic Line Map series maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works of humans, such as roads, railroads, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 20 meters, with some sheets having supplemental meter contours, form lines, hachures, shading, and/or spot heights. Depths shown by bathymetric isolines. Please pay close attention to map collar information on projections, spheroid, compilation dates, legend information, and keys to grid numbering and other numbers which appear inside the neatline.

Bubanza region, Burundi, 1994, Defense Mapping Agency (DMA) Series Z724, Sheet 4674-I (Raster Image)

This layer is a georeferenced raster image of the United States Defense Mapping Agency (DMA) Series Z724, Burundi, 1:50,000 Topographic Line Map (TLM) Series sheet map entitled: Bubanza. Printed in: 1994. Covers portions of Bubanza region, Burundi. Sheet: 4674-I. Edition statement: Ed. 1 - DMA. The image inside the map neatline is georeferenced to the surface of the earth and fit to World Geodetic System (1984) coordinates. All map collar information is also available as part of the raster image. Burundi 1:50:000 Series Z724 maps are in English and French (legends also include Rundi). Each source map in the series is printed in color at a scale of 1:50,000. Series source sheets were published in 1994-1995 by the United States Defense Mapping Agency, Hydrographic/Topographic Center. The source map was scanned and georeferenced for Harvard University's Center for Geographic Analysis' AfricaMap project by East View Cartographic. Individual TLM sheets covering Burundi (40 sheets in total) were selected from the TLM worldwide series. DMA Topographic Line Map series maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works of humans, such as roads, railroads, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 20 meters, with some sheets having supplemental meter contours, form lines, hachures, shading, and/or spot heights. Depths shown by bathymetric isolines. Please pay close attention to map collar information on projections, spheroid, compilation dates, legend information, and keys to grid numbering and other numbers which appear inside the neatline.

Bujumbura region, Burundi, 1994, Defense Mapping Agency (DMA) Series Z724, Sheet 4674-II (Raster Image)

This layer is a georeferenced raster image of the United States Defense Mapping Agency (DMA) Series Z724, Burundi, 1:50,000 Topographic Line Map (TLM) Series sheet map entitled: Bujumbura. Printed in: 1994. Covers portions of Bujumbura region, Burundi. Sheet: 4674-II. Edition statement: Ed. 1 - DMA. The image inside the map neatline is georeferenced to the surface of the earth and fit to World Geodetic System (1984) coordinates. All map collar information is also available as part of the raster image. Burundi 1:50:000 Series Z724 maps are in English and French (legends also include Rundi). Each source map in the series is printed in color at a scale of 1:50,000. Series source sheets were published in 1994-1995 by the United States Defense Mapping Agency, Hydrographic/Topographic Center. The source map was scanned and georeferenced for Harvard University's Center for Geographic Analysis' AfricaMap project by East View Cartographic. Individual TLM sheets covering Burundi (40 sheets in total) were selected from the TLM worldwide series. DMA Topographic Line Map series maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works of humans, such as roads, railroads, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 20 meters, with some sheets having supplemental meter contours, form lines, hachures, shading, and/or spot heights. Depths shown by bathymetric isolines. Please pay close attention to map collar information on projections, spheroid, compilation dates, legend information, and keys to grid numbering and other numbers which appear inside the neatline.

Butahana region, Burundi, 1994, Defense Mapping Agency (DMA) Series Z724, Sheet 4675-I (Raster Image)

This layer is a georeferenced raster image of the United States Defense Mapping Agency (DMA) Series Z724, Burundi, 1:50,000 Topographic Line Map (TLM) Series sheet map entitled: Butahana. Printed in: 1994. Covers portions of Butahana region, Burundi. Sheet: 4675-I. Edition statement: Ed. 1 - DMA. The image inside the map neatline is georeferenced to the surface of the earth and fit to World Geodetic System (1984) coordinates. All map collar information is also available as part of the raster image. Burundi 1:50:000 Series Z724 maps are in English and French (legends also include Rundi). Each source map in the series is printed in color at a scale of 1:50,000. Series source sheets were published in 1994-1995 by the United States Defense Mapping Agency, Hydrographic/Topographic Center. The source map was scanned and georeferenced for Harvard University's Center for Geographic Analysis' AfricaMap project by East View Cartographic. Individual TLM sheets covering Burundi (40 sheets in total) were selected from the TLM worldwide series. DMA Topographic Line Map series maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works of humans, such as roads, railroads, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 20 meters, with some sheets having supplemental meter contours, form lines, hachures, shading, and/or spot heights. Depths shown by bathymetric isolines. Please pay close attention to map collar information on projections, spheroid, compilation dates, legend information, and keys to grid numbering and other numbers which appear inside the neatline.

Ndora region, Burundi, 1994, Defense Mapping Agency (DMA) Series Z724, Sheet 4675-II (Raster Image)

This layer is a georeferenced raster image of the United States Defense Mapping Agency (DMA) Series Z724, Burundi, 1:50,000 Topographic Line Map (TLM) Series sheet map entitled: Ndora. Printed in: 1994. Covers portions of Ndora region, Burundi. Sheet: 4675-II. Edition statement: Ed. 1 - DMA. The image inside the map neatline is georeferenced to the surface of the earth and fit to World Geodetic System (1984) coordinates. All map collar information is also available as part of the raster image. Burundi 1:50:000 Series Z724 maps are in English and French (legends also include Rundi). Each source map in the series is printed in color at a scale of 1:50,000. Series source sheets were published in 1994-1995 by the United States Defense Mapping Agency, Hydrographic/Topographic Center. The source map was scanned and georeferenced for Harvard University's Center for Geographic Analysis' AfricaMap project by East View Cartographic. Individual TLM sheets covering Burundi (40 sheets in total) were selected from the TLM worldwide series. DMA Topographic Line Map series maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works of humans, such as roads, railroads, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 20 meters, with some sheets having supplemental meter contours, form lines, hachures, shading, and/or spot heights. Depths shown by bathymetric isolines. Please pay close attention to map collar information on projections, spheroid, compilation dates, legend information, and keys to grid numbering and other numbers which appear inside the neatline.

Cibitoke region, Burundi, 1994, Defense Mapping Agency (DMA) Series Z724, Sheet 4675-III (Raster Image)

This layer is a georeferenced raster image of the United States Defense Mapping Agency (DMA) Series Z724, Burundi, 1:50,000 Topographic Line Map (TLM) Series sheet map entitled: Cibitoke. Printed in: 1994. Covers portions of Cibitoke region, Burundi. Sheet: 4675-III. Edition statement: Ed. 1 - DMA. The image inside the map neatline is georeferenced to the surface of the earth and fit to World Geodetic System (1984) coordinates. All map collar information is also available as part of the raster image. Burundi 1:50:000 Series Z724 maps are in English and French (legends also include Rundi). Each source map in the series is printed in color at a scale of 1:50,000. Series source sheets were published in 1994-1995 by the United States Defense Mapping Agency, Hydrographic/Topographic Center. The source map was scanned and georeferenced for Harvard University's Center for Geographic Analysis' AfricaMap project by East View Cartographic. Individual TLM sheets covering Burundi (40 sheets in total) were selected from the TLM worldwide series. DMA Topographic Line Map series maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works of humans, such as roads, railroads, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 20 meters, with some sheets having supplemental meter contours, form lines, hachures, shading, and/or spot heights. Depths shown by bathymetric isolines. Please pay close attention to map collar information on projections, spheroid, compilation dates, legend information, and keys to grid numbering and other numbers which appear inside the neatline.

Mabayi region, Burundi, 1994, Defense Mapping Agency (DMA) Series Z724, Sheet 4675-IV (Raster Image)

This layer is a georeferenced raster image of the United States Defense Mapping Agency (DMA) Series Z724, Burundi, 1:50,000 Topographic Line Map (TLM) Series sheet map entitled: Mabayi. Printed in: 1994. Covers portions of Mabayi region, Burundi. Sheet: 4675-IV. Edition statement: Ed. 1 - DMA. The image inside the map neatline is georeferenced to the surface of the earth and fit to World Geodetic System (1984) coordinates. All map collar information is also available as part of the raster image. Burundi 1:50:000 Series Z724 maps are in English and French (legends also include Rundi). Each source map in the series is printed in color at a scale of 1:50,000. Series source sheets were published in 1994-1995 by the United States Defense Mapping Agency, Hydrographic/Topographic Center. The source map was scanned and georeferenced for Harvard University's Center for Geographic Analysis' AfricaMap project by East View Cartographic. Individual TLM sheets covering Burundi (40 sheets in total) were selected from the TLM worldwide series. DMA Topographic Line Map series maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works of humans, such as roads, railroads, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 20 meters, with some sheets having supplemental meter contours, form lines, hachures, shading, and/or spot heights. Depths shown by bathymetric isolines. Please pay close attention to map collar information on projections, spheroid, compilation dates, legend information, and keys to grid numbering and other numbers which appear inside the neatline.

Mabanda region, Burundi, 1994, Defense Mapping Agency (DMA) Series Z724, Sheet 4772-II (Raster Image)

This layer is a georeferenced raster image of the United States Defense Mapping Agency (DMA) Series Z724, Burundi, 1:50,000 Topographic Line Map (TLM) Series sheet map entitled: Mabanda. Printed in: 1994. Covers portions of Mabanda region, Burundi. Sheet: 4772-II. Edition statement: Ed. 1 - DMA. The image inside the map neatline is georeferenced to the surface of the earth and fit to World Geodetic System (1984) coordinates. All map collar information is also available as part of the raster image. Burundi 1:50:000 Series Z724 maps are in English and French (legends also include Rundi). Each source map in the series is printed in color at a scale of 1:50,000. Series source sheets were published in 1994-1995 by the United States Defense Mapping Agency, Hydrographic/Topographic Center. The source map was scanned and georeferenced for Harvard University's Center for Geographic Analysis' AfricaMap project by East View Cartographic. Individual TLM sheets covering Burundi (40 sheets in total) were selected from the TLM worldwide series. DMA Topographic Line Map series maps are typical topographic maps portraying both natural and manmade features. They show and name works of nature, such as mountains, valleys, lakes, rivers, vegetation, etc. They also identify the principal works of humans, such as roads, railroads, boundaries, transmission lines, major buildings, etc. Relief is shown with standard contour intervals of 20 meters, with some sheets having supplemental meter contours, form lines, hachures, shading, and/or spot heights. Depths shown by bathymetric isolines. Please pay close attention to map collar information on projections, spheroid, compilation dates, legend information, and keys to grid numbering and other numbers which appear inside the neatline.