Polycyclic Aromatic Hydrocarbons (PAHs)

Polycyclic Aromatic Hydrocarbons (PAHs) Introduction Polycyclic aromatic hydrocarbons (PAHs) are made of two or more fused aromatic rings, where PAHs with two or three rings have low molecular weight and acute toxicity whereas PAHs with high molecular weight (4 or more rings) have shown high carcinogenic potential. These compounds are often products of incomplete combustion reactions where there is a lack of oxygen, there are two types of PAH; natural and anthropogenic which can be found in many different kinds of samples . However, the ratio of natural processes to anthropogenic processes is very low. PAHs can form due to a variety of anthropogenic sources the main one is believed to be atmospheric decomposition, other sources include thermal combustion processes, vehicular emissions and biomass burning [3]. PAHs caused from incomplete combustion reactions reach the sea via the atmosphere and rivers . Due to the causes listed above the United States Environmental Protection Agency (EPA) and other agencies formed regulations for the detection and monitoring of PAHs in the human environment, with new analytical methods being produced with better sensitivity and selectivity . Overall the EPA has selected sixteen PAHs as priority pollutants [4]. To verify different PAHs in seawater is difficult as the overall solubility of PAHs in water is low, and continues to decrease as molecular weight increases, the low solubility in turn effects the hydrophobic nature (between 3 and 8) and therefore the concentration of PAHs dissolved in seawater is very low . There are a variety of methods used to analyse the PAHs in seawater and other types of water. High Performance Liquid Chromatography (HPLC) is the most widely used analytical technique in analysing PAHs in seawater samples; in this document HPLC will be discussed along with other analytical methods such as Gas Chromatograph-Mass Spectrometer (GC-MS). This document focuses on data and results from the following papers: â€Å"Determination of polycyclic aromatic hydrocarbons in seawater by high-performance liquid chromatography with fluorescence detection following micelle-mediated preconcentration† V. Pino et al. â€Å"Polycyclic Aromatic Hydrocarbons in Water and Sediment of the Baltic Sea† â€Å"GC-MS Analysis of Total Petroleum Hydrocarbons and Polycyclic Aromatic Hydrocarbons in Seawater Samples after the North CapeOil Spill† Christopher M. Reddy and James G. Quinn Each paper will be individually introduced and the sample preparation, analytical method and any results significant to the separation will be discussed. The methods will then be compared, giving the advantages and disadvantages of each technique. â€Å"Determination of polycyclic aromatic hydrocarbons in seawater by high-performance liquid chromatography with fluorescence detection following micelle-mediated preconcentration† V. Pino et al. This paper looked at how non-ionic surfactant polyoxyethylene-10-lauryl ether (POLE) can be used for extraction of PAHs in seawater and compared cloud-point extraction (CPE)-HPLC and liquid-liquid extraction (LLE)-GC-MS. Sample Preparation The sample was prepared by shaking fuel-oil with natural seawater for one hour, and then allowed to settle and age overnight, until phase separation. The aqueous layer was removed and mixed with POLE until a final solution of 1% (w/v) was reached in the surfactant. Following this 3.0 ml of aliquots in the presence of the 1% surfactant solution dissolved in artificial seawater were administered to CPE. In order to test the reliability of the method used for preconcentration and separation of PAHs, the PAHs were analysed from spiked and un-spiked seawater samples. The method was evaluated by using LLE and GC-MS, overall determination was processed using the mass values which related to the molecular ions of the different PAHs . Analysis Once the two phases had been separated, 25 ÃŽ ¼l of the surfactant-rich phase was injected into the system. The HPLC method used in this instance to determine and separate the PAHs consisted of gradient elution with a fluorescence detector. The mobile phase was a mixture of acetonitrile and water with a linear gradient from 55 to 100% acetonitrile for 30 minutes and 100% acetonitrile for 10 minutes. The column used for the analysis was a reversed phase C18 column (Table 1) with a ÃŽ ¼Bondapak C18 guard column. Table 1: Vydac 201TP54 Reversed Phase C18Column Column length x internal diameter / mm 250 x 4.6 Particle size / ÃŽ ¼m 5 Pore size / Ã… 300 A flow rate of 1 ml / minute was used to elute the compounds. Results Each PAH gave an acceptable retention time with a relative standard deviation between 0.64 and 0.83%. The seawater contaminated with fuel-oil were analysed by both CPE-HPLC and LLE-GC-MS (Table 3). As can be seen the PAHs with fewer aromatic rings have similar results with both techniques where as the PAHs with more aromatic rings are different this could be due to the lower sensitivity in GC-MS. â€Å"Polycyclic Aromatic Hydrocarbons in Water and Sediment of the Baltic Sea† G.Witt During the years 1992 to 1994, 15 PAHs were analysed in seawater from the Baltic Sea during the different seasons. The method used is based on HPLC with fluorescence detection. Sample Preparation 156 seawater samples were collected from various depths, surface water (2-15m), bottom water (below the halocline) and surface micro layer (0-0.2 cm). The PAHs from the samples were separated and extracted via a HPLC column; three fractions were obtained using 9 ml pentane, 9 ml pentane/10% dichloromethane and 9 ml acetone as the eluents. The PAHs were contained into the second fraction and was evaporated down to 500 ÃŽ ¼l. Analysis The HPLC column used to separate the sample in to fractions was a MERCK LiChrospher Si 100-5 (Table 4) Table 4: MERCK LiChrospher Si 100-5 Column length x internal diameter / mm 250 x 4 Particle size / ÃŽ ¼l 5 Pore diameter / Ã… 60 Matrix Silica gel The column used in the analysis of the PAHs was a GROM PAH using gradient elution (Table 5). Table 5: GROM PAH Column length x internal diameter / mm 250 x 4 Eluents A) Water B) CAN Flow rate / ml min-1 1 Temperature /  °C 20 A fluorescence detector was used, along with a wavelength programme for optimal detection of all PAHs (Table 6). From the 16 PAHs listed as priority pollutants, acenaphthylene was the only one not detected as it does not show fluorescence activity. Results It was seen that there were a greater amount of lower molecular weight PAHs varying in concentration from 1 to 4.5 ng/L-1 in relation to higher molecular weight PAHs which remained below ng/L-1. The concentration of PAHs in different seasons was also compared, it was seen that autumn had the highest concentration this maybe because of low microbial degradation and photo-oxidation during the season; and summer had the lowest. During the winter months, the temperature of seawater is low which inhibits the microbial degradation of the PAHs. In spring the plankton are in abundance and thus cause a large amount of loose matter to be produced which may transfer the PAHs to the sea floor. This was mostly true for two/three ring PAHs, four to six rings however have a higher persistence to microbial degradation. The amount of PAHs in the surface micro layer was 2-13 times higher than that of the water below; this can be due to the atmospheric input . â€Å"GC-MS Analysis of Total Petroleum Hydrocarbons and Polycyclic Aromatic Hydrocarbons in Seawater Samples after the North CapeOil Spill† Christopher M. Reddy and James G. Quinn [6] GC-MS was used to measure PAHs in seawater samples after the North Cape oil spill. Sample Preparation The samples were spiked with internal standards which consisted of the following: 10 to 25 ÃŽ ¼g docosane and 2 ÃŽ ¼g each of naphthalene-d8, biphenyl-d10, acenaphthene-d10, anthracene-d10 and perylene-d12. After the samples were spiked they were shaken and extracted once with 100 ml methylene chloride and twice more with 100 ml of hexane. The organic extracts were then combined and rotary-evaporated to 1 ml while being solvent-exchanged into hexane. Following this the hexane extract was chromatographed and the first fraction (obtained by eluting with 20 ml of a 70/30 mixture of hexane/methylene chloride) containing the aromatic hydrocarbons was rotary-evaporated to a small volume (100 ÃŽ ¼l) and spiked with an external recovery standard (1.2 ÃŽ ¼g o-terphenyl in isooctane), and injected into the GC-MS detector. Analysis The PAHs were first extracted with methylene chloride and hexane and then fractionated via HPLC using silica gel. The analysis was done using a Hewlett-Packard 5890 Series II GC with a Hewlett-Packard 5971 mass selective detector. After the sample was injected, the compounds were separated using a 30m JW Scientific DB-XLB fused silica-capillary column (Table 7). Table 7:JW Scientific DB-XLB fused silica-capillary column Column length x internal diameter / mm 30,000 x 0.25 Film thickness / ÃŽ ¼m 0.25 Temperature limit /  °C 340-360 According to the website [7] this column has low polarity and is excellent for PAHs. The oven was set at 70 °C for 1.5 minutes, then ramped to 320 °C at 10 °C per minute, and then held for a further 10 minutes. The detector was run in selected-ion monitoring (SIM) mode for ions that have an m/z of 50 to 550, PAHs usually range between 128 and 234 m/z. Results A total of 54 seawater samples were collected and analysed were collected between day 4 and day 132 after the North Cape oil spill, results from a week after the oil spill showed that there were high concentration of PAHs, with the total sum coming too 115 ÃŽ ¼g L-1, these are some of the highest values for a marine oil spill. The relative percentage deviations for duplicate samples for total PAHs came to The use of other GC detectors such as GC flame ionisation detector which is widely used may not be suitable for the detection of PAHs as often lower limits of detection are needed, which is why GC-MS would be used. Comparison of analytical methods The most popular technique for the separation and determination of PAHs is HPLC however; a disadvantage of this is that gradient elution must be used opposed to isocratic elution due to the samples complexity. Other factors include that HPLC is expensive, and that it requires large amounts of solvent especially when gradient elution is used. The paper by V. Pino et al. and the paper by G. Witt both used HPLC reversed phase column with a fluorescence detector, however Pino et al. used a surfactant with a low retention time (POLE) which allowed for the determination of PAHs which were more polar. In Figure 2 the compounds eluted between ~7 and 40 minutes using the above method; whereas the method used by Witt produced a chromatogram (Figure 3) which shows the products eluted between ~7 and 23 minutes. The difference in retention times shows that the method used by Witt was more useful. However, the samples of seawater used for analysis by each paper were from different sources, Pino et al. does not state where the seawater samples were taken, while Witt took the sample from the Baltic Sea. Pino et al. only extracted 14 PAHs but Witt extracted all 16 PAHs listed by the EPA. From the data listed in Tables 2 and 6 it can be seen that there are comparable results such as Phenanthrene which eluted in 13.9 minutes for Pino et al. and 12.2 minutes for Witt, the emission wavelengths measured were identical at 370 nm and that the excitation wavelength only differed by 2 nm between Pino (248 nm) and Witt (246 nm). Overall, the HPLC methods used by both papers shows that it is a reliable method for determining PAHs in seawater, a fluorescence detector was used as the filters select the excitation and emission wavelengths and it reduces the complexity of the chromatogram which provides orthogonal information. Even though HPLC seems the most popular technique GC-MS is being used to analyse the PAHs after they have been separated by HPLC. This change could be because GC is faster than HPLC and that with a mass spectrometer (MS) detector it is possible to combine detection, quantification and identification. GC-MS is especially good for complex mixtures such as seawater where several analytes have similar retention times.

The Acquisition Strategy Of Bankinter Marketing Essay

The Acquisition Strategy Of Bankinter Marketing Essay Bankinter is a small independent national bank, positioning itself as an innovative, multichannel, low-cost financial services provider. The bank uses various customer acquisition networks and distribution channels (brick-and-mortar branch, virtual banking and agents, telephone, internet). The firm realized that the Internet is a low-cost channel suitable for a smaller bank like itself, and launched its online site, e-bankinter.com in 1997, which ranked as the best online financial site in Spain. The Internet branch of the bank is called Branch 8700. In 2001, the Internet was the main source of entry of new consumers, so it was important part of the customer acquisition strategy of the firm. The Internet acquisition strategy of Bankinter was based on three channels: alliances, e-collaborators and 8700. I prepared a table to describe the advantages and disadvantages of the alliances and e-collaborators acquisition strategies. As from the table can be seen, the e-collaborator strategy was much more efficient in terms of acquiring new customers and it resulted in lower acquisition costs, so Bankinter decided to terminate the alliances with the portals and focused on e-collaborators. Alliances E-collaborators Pros High trafficked portals Co-branding High traffic sites Difficult to copy by competitors (customer-based CRM-system) Lower acquisition costs Higher number of new customers Cons Co-branding (brand was hidden, adaptation) High costs: Replication of systems Creation and maintenance costs Customer acquisition costs (promotion, advertising, fee/each customer acquired) Up-front annual fee Ease to copy by competitors Sites regardless of content No targeting High number of nonformalized customers Number of new customers/year 2000: ~5,000 clients 2001: 2,096 clients 2001: 43,433 clients 1st table: Pros and cons of the different Internet acquisition strategies of Bankinter The following table shows the performance of the three online channels in terms of new customers. The Branch 8700 acquires the most customers, followed by e-collaborators and alliances. The nonformalization rate is the highest in case of e-collaborators (76%, 33,003 clients). The acquisition rate is not only the highest in case of 8700 but this option has the lowest nonformalization rate (47%), as well. 8700 Alliances E-collaborators Total clients 68,175 2,096 43,433 Formalized clients (active) 35,859 1,015 10,430 Nonformalized clients 32,316 1,081 33,003 2nd table: Customer acquisition rate of the different acquisition strategies and channels at Bankinter 2) Which channel (8700, alliances, e-collaborators) performs better for the bank, and why? To analyze the performance of the three online channels, I computed the customer lifetime value for each channel. The excel tables containing the detailed analysis can be found in the Appendix. Due to the lack of information on interest rates, I used a 10 % interest rate in all scenarios to make the calculations transparent and the results easily comparable. I used two decimals at the calculations, except for the retention rates, where I used rounded numbers. When calculating the retention rates I used the first years retention rate as a base to calculate each years retention rate. I assumed a short-term and long-term period to show the results: 5 years and 10 years period also because at some scenarios the expected years in bank exceeds the 5 years period. By adding the first five years discounted values (including year 0 with the acquisition cost), or by adding the first ten years discounted values we arrive at the customer lifetime value. Based on the customer lifetime value, the 8700 is the best performing channel, because in this case the profitable clients have the highest customer lifetime value among the three scenarios. However, the customer lifetime value of the nonprofitable clients is also the highest in case of 8700, which means the highest costs. As there are only slight differences among the customer lifetime values of the nonprofitable clients of the three channels, it is less important. I mentioned in the previous part that the rate of the nonformalized and formalized customers is the best in case of 8700 (47% to 53%). Based on these calculations the 8700 is the best performing channel. E-collaborators is the second best option, as it has the second biggest customer lifetime value in case of profitable clients. 3) What (acquisition) strategy would you recommend to Bankinter? What actions should be taken by Ana Peralta? Bankinter is a multichannel bank known as the leader in online banking in its respective country. As both the traditional brick-and-mortar and online channels are essential for the bank, it should keep both focusing on the Internet branch. The brick-and-mortar channel still plays an important part, because of customer loyalty and cross-selling opportunities, as well as the high number of branch transactions (36% Exhibit 5). However, Bankinter could persuade customers to reduce the branch transactions and use Internet banking instead; it would result in lower transaction costs for the bank. Focusing on the Internet branch is also important because in 2001 it is the main source of entry, which means that it is an acquisition strategy of great relevance. Moreover, the Internet marketing campaign of the bank was successful, as the acquisition costs dropped and the number of new customers increased exponentially. I would suggest continuing the campaign, however changing some elements. Bankinter should focus on 8700 customers as their customer lifetime value is the highest. Among 8700 customers e-brokers and e-mortgage customers are the most valuable; Bankinter could try cross-selling to them. As for the other customers, finding new ways through introducing new services and attractive packages can help them turn into profitable clients. Drop alliances (as Bankinter did), and use e-collaborators instead. The problem with e-collaborators is the high number of nonformalized customers and the fact that the rate of the new customer acquisition strategy was correlated to the amount of incentives offered. By using the CRM system of the bank, it can recognize which marketing segments are the most valuable, and it enables the bank to use targeting. By using targeting in the e-collaborators channel Bankinter can attract more valuable customers. Finding the appropriate target groups also reduces the drawback of incentives. Bankinter should also find out what factors are behind the high number of nonformalization by conducting surveys, analyzing information on the nonformalized customers and the process itself. This way, they can introduce new services or alter their registration process.

Human Maturity in The Human Comedy by William Saroyan :: Maturity Mature Literature Essays

Human Maturity in The Human Comedy by William Saroyan William Saroyan's The Human Comedy, deals with ravages of life. Due to these trials, Homer is forced to mature. How he matures is a result of facing the challenges. Two very import themes that help homer mature are family and death. Homer represents the men of the house because he works and earns money for the family. For example, he goes to school until three o'clock, then goes to work until midnight. Going to school and working is very hard but it needs to be done for the family to survive. In addition, Homer needs to be both a father and a big brother for Ulysses. Homer loves and cares for Ulysses, and he teaches Ulysses about life, and physical appearance. Finally, Homer said, 'Any work that has to be done around here, men can do. Girls belong in homes, taking care of men.'; (Pg. 157) Homer is rewarded for being the man of the house by getting love and shelter from his family. Love is needed from the family to keep Homer supporting the family. Homer becomes mature by working, but looses his one and only childhood. Death is a very important theme, because delivering death messages is what made Homer mature. For example, Homer told his mother 'All of a sudden I feel different—not like I ever felt before.'; (Pg. 33) Delivering telegram message changed everything for Homer because he was no longer a child. Furthermore, delivering death telegrams made Homer sick. At the age of fourteen, when Homer had to deliver death messages, this made him realize that one day he is going to die himself. At the end when Homer realizes his brother's death, Homer said, 'What's a man supposed to do? I don't know who to hate. I don't know what to do.'; (Pg. 186) This showed being a teenager moreover a man, did not solve the problem about death.

Androgynous Characters in Thomas Hardys Novels Essay -- Biography Bio

Androgynous Characters in Thomas Hardy's Novels Androgyny may be defined as "a condition under which the characteristics of the sexes, and the human impulses expressed by men and women, are not rigidly assigned" (Heilbrun 10). In the midst of the Victorian Era, Thomas Hardy opposed conventional norms by creating androgynous characters such as Eustacia Vye, in The Return of the Native ; the title character in Tess of the d Urbervilles ; Sue Bridehead in Jude the Obscure ; and Marty South in The Woodlande rs. Hardy's women, possessing "prodigious energy, stunted opportunity, and a passion which challenges the entire, limiting world" (Heilbrun 70), often resemble men in actions and behavior. Eustacia Vye may be considered androgynous for her passion, rebelliousness, and refusal to accept the confines of Egdon. She exists in a state of untamed romantic emotion and fantasy, and has little concern for the effects of her actions. These characteristics of Eustacia make her less typical of women during the Victorian Era, but the scene in which her androgynous behavior is most evident...

othello Essay example -- essays research papers

jealousy In the play Othello, jealousy is shown to be very evident through the actions of the characters. Jealousy is an emotion that everyone shares, and it is ultimately responsible for the tragic ending of the play. Everyone feels jealous at certain times of their lives, and this feeling can cause people to do irrational things. This human emotion also shows people to be weak in the sense that they are never happy with what they have. Shakespeare shows through Othello, Iago, Roderigo, and Brabantio that jealousy is the most corrupt and destructive emotion. Othello is horribly jealous of what he thinks is going on between his wife and Cassio. This poisonous feeling turns Othello into a mad man and he strikes his wife. Jealousy causes people to act incredibly different. People that are almost always reserved and sincere can become crazy because of jealousy. Othello kills his wife because he feels that if he can’t have her, nobody can. This is a very selfish action that Othello takes. He determines his wife’s fatal fate just because he is jealous. People often think only for themselves when they are jealous. This shows humans to be selfish when their emotions are intense.   Ã‚  Ã‚  Ã‚  Ã‚  There is almost no worse feeling that being very jealous of someone or something. People will risk almost anything to get rid of this disastrous feeling. Jealously causes people to act irrationally and irresponsibly. This is a feeling that always comes up throughout everybody...

Chemalite Inc.

CHEMALITE, INC.   Financial Report| Period of January, 2003 1 to June 30, 2003 Financial report of Chemalite, Inc. for six months period ended June 30, 2003 is to include cash transaction, income statement and balance sheet. This report will also to include comment on Chemalite, Inc’s actual loss for the period. | In early 2003, Chemalite, Inc. was established by Bennett Alexander to market his invention, Chemalite,. During the first six months, Chemalite, Inc. was preparing for initial production and was still not ready for commercial phase. Chemalite, Inc. as setting up the plant by procuring needed legal entity, place, equipment and inventories. From those preparation activities, Chemalite, Inc. ’s summary of the cash for six months ended June 30, 2003 is: Chemalite, IncCash on June 30, 2003| $ 230,000 | By analyzing income statement, balance sheet and cash flow statement of Chemalite, Inc for period of first half of 2003, we find that the actual loss of Chemalite, Inc in that period is $7,500. This means that Mr. Larson’s comment on Chemalite’s loss of $145,000 is wrong, he calculated only cash position from January 2003 to June 2003, and he did not calculate other assets like patent, equipment and inventories. His comment is misleading and can influence other shareholders. My suggestion for Mr. Alexander is to do damage control by presenting this report to other shareholders.

Economic Growth Essay

There are different drivers of economic growth into country and research has to some extent also demonstrated that it can be associated with typical characteristics of the country too. Explaining economic growth through a relatively new theory of endogenous growth suggest that policy measures, if taken properly, can result into long term benefits for the country and that the country does not necessarily need to rely on the external or exogenous factors such as technological innovation. The neo-classical models of growth advocated that in order to attain a consistent long term economic growth, a consistent change into the technological advances such as new processes, new goods and new markets etc must take place. (Aghion et. al, 1998). It has always been believed that high investment and saving rates in any country tend to sustain high economic growth in that country and that coupled with relatively stable economic outlook, a higher saving rate can significantly result into greater economic growth because a larger pool of funds will be available to the firms, in the shape of household savings, that can be utilized to the best possible efficiency. It is also imperative to discuss here that the trends of saving markedly differ in developing as well as developed countries as developing countries tend to have high saving rates due to relatively smaller propensity to consume of the general masses. Since developing countries do no possess the strong manufacturing base therefore consumption tends to be relatively low as compared to the developed countries and people prefer to save rather than spend. (Aghevli, at. al, 1990) One of the most important aspects of economic growth is how the saving rates in a country shape and how they with respect to the different economic variables. However, over the period of time, research has also demonstrated that saving rates show a correlation with different economic variables in any given country. Though the same characteristics may be find over some regions however it is still believed that country’s individual characteristics such as demographics, rule of law, public finances, also show some relationship with the saving rates. It has been also successfully demonstrated that the saving rates are uneven across the countries confirming to the argument that saving rates respond to certain characteristics which may be typical of that country or region however in a study conducted by Hondroyiannis (2006) suggested that â€Å"A long-run saving function sensitive to dependency ratio, old dependency ratio, liquidity, public finances, real disposable income growth, real interest rate and inflation is found to exist†(Hondroyiannis,2006) in European countries. Thus, to some extent, it can be easily inferred that the saving rates in a particular country or a region show some related characteristics and tend to get affected by different so called country specific characteristics however the impact is in long run with little or no impact been witnessed on the short run saving rates within any country. One of the most interesting findings of the research also suggest that the government savings, in any particular country, are not particularly exogenous in nature and respond to the political as well as economic determinants of the country. (Edwards,1996). This cross country analysis conducted by Edwards strongly suggested that public savings in countries with higher degree of political instability are lower than the countries with relatively stable political situation at hand. References 1. Philippe Aghion, Peter Howitt, Maxine Brant-Collett, Cecilia Garcia-Penalosa (1998). Endogenous Growth Theory. New York: MIT Press. 694. 2. George Hondroyiannis. (2006). Private saving determinants in European countries: A panel cointegration approach . The Social Science Journal. 43 (4), 553-569 . 3. Sebastian Edwards. (1996). Why are Latin America’s Savings Rates So Low? An International Comparative Analysis. Journal of Development Economics,. 51 (1), 5-44. 4. Bijan B. Aghevli, James M. Boughton, Peter J. Montiel, Del Villanueva (1990). The Role of National Saving in the World Economy. New York: International Monetary Fund. 64.