Sulphide solubility in magma

Sulphide solubility in magma Abstract This essay aims to define the controls on sulphide solubility in magma, such as pressure, temperature and element activity. Chalcophile elements, elements of low abundance, form sulphide and arsenide minerals but are not stable at high temperatures of igneous crystallization. The relation of the processes of sulphide solubility against the relative outcomes for chalcophile elements will be looked into. Introduction Sulphur (or sulfur) is a natural substance; its elementary state is a crystalline solid of yellow colour. Sulphur is found in various forms, as mineral sulphides and sulphates, such as galena and cinnabar. Magmatic sulphide deposits with Nickel-Copper-Platinum-group elements are a result of segregation and concentration of liquid sulphide from mafic or ultramafic magma, and the screening of chalcophile elements into these deposits from the silicate magma. (A. J. Naldrett 2004) Due to the variation of sulphide deposits, it is convenient to relate the magmatic sulphide deposits to the bodies of mafic or ultramafic rock in terms of the composition of the magma associated with these rocks. It is then reasonable to investigate the geochemical and geophysical setting and the processes in which these deposits are formed. According to A. J. Naldrett, 2004, the key aspects in the creation of magmatic sulphide deposits are that the magma saturation in sulphide and segregation of the immiscible sulphide has to be concentrated locally with a sufficient amount of magma concentrating chalcophile elements to comprise ore of economic value. In conditions of normal mafic magma cooling and crystallization, no early segregation of liquid sulphides are noticed. This implies that the magma would have to be saturated in sulphide in the igneous body state. The assumption is that there is a process prior to the magmas extrusion from the ground, and final emplacement, where sulphide saturation is caused. The above assumption is reinforced due to the fact that most basaltic magmas, other than Mid Ocean Rig Basalts, have high contents of Platinum Group elements. The Controls The mantle has an estimated concentration of 300-1,000 parts per million (Sun 1982). This is believed to be the primary source of the sulphur carried in basaltic magmas. The solubility of sulphur is controlled by temperature, pressure, contents iron oxide and titanium oxide and their activity in the melt, oxygen and sulphur fugacity, the oxidation state of the melt and the mafic versus the felsic components in the melt. (Fincham Richardson 1954, Haughton et a. 1974, Shima Naldrett 1975, Buchanan Nolan 1979, Buchanan et al. 1983) These factors, or otherwise conditions, of sulphide solubility in the melt will be explored in order to record the effects of the controls of sulphur solubility against the deposits composition. Leaving the mantle, and entering the crust of the earth, the melts can either be intrusive or extrusive, yet the fundamental pressure temperature relation for sulphide solubility, from mantle to the crust in liquid state, remains the same. Pressure and temperature increase with depth; according to Marvrogenes and ONeil (1999), increased pressure presents a negative effect on a silicate melt, dissolving less sulphide. As pressure decreases and the melt reaches the surface, it ability to dissolve iron sulphide increases. Considering that the majority of melts leave the mantle unsaturated in sulphide, as they reach lower depths, while the pressure and temperature decrease, the sulphide saturation is not achieved; furthermore the temperature decrease can offset this relation, causing further decrease in sulphur solubility. (Buchanan and Nolan 1979) Exiting the mantle, sulphide segregation will occur after the silicates initiate crystallization. Therefore, the sulphides will be assorted with the silicate grain. The simultaneous crystallization, as a function of temperature and pressure conditions along with the composition of the liquid sulphide would produce a sulphide rich deposit (for nickel and copper dominant magmatic deposits against platinum group element magmatic deposits) only if an external factor could intervene. This factor, or condition, would reinforce the sulphide segregation, without further enhancing silicate crystallization. At isothermal conditions of 1200oC, Buchanan 1988, sulphur content in the silicate melt decreases with the increase of oxygen fugacity (fO2) at constant sulphur fugacity (fSÂ ­2). Furthermore, the study displays a correlation between sulphur (wt % S2) content and iron oxide (FeO %), with a logarithmic increase on the field of saturation. On the other hand, the compositions of the melt in terms of the variation of content of iron oxides (FeO) or titanium dioxide (TiO2) diversify the ability of the melt to dissolve sulphide. The increase or decrease of oxide content in the melt is correlated to the sulphide solubility in the mixture. Oxidation is capable of causing the formation of an insoluble sulphide in the melt as a result of a reaction within the liquid between the soluble substances, usually without causing silicates crystallization. Oxygen and sulphur fugacity, and their relation to the pressure temperature setting, along with their ratio, are important factors for sulphide solubility. Induction of sulphur from an external source, and the felsification of a mafic magma are important causes of sulphide segregation. Silicate magma reacts with the sulphide liquid, resulting in the formation of the magmatic sulphide deposit. The ratio of reaction and the composition of both the sulphide liquid and the silicate magma , along with the controls on which the elements react are responsible for the final outcome. Buchanan 1988, determined the solubility of sulphur as a function of sulphur fugacity (fS2) in a basaltic melt containing 17 wt% iron monoxide (FeO) at a range of 1000 to 1400oC. Although the fugacity of oxygen and sulphur remain constant, the rate of increase of sulphur solubility drops from a factor of 10 times per 100oC at 1100oC, reduced to 3 times at 1400oC, implying that there is a threshold of maxima in sulphur saturation with temperature increase; the saturation is achieved in 1450oC. Hence, the actual sulphur content increases with temperature but decreases in rate, although with higher sulphur fugacity saturation is achieved at lower temperatures. The increase in sulphur content with increase temperature is reinforced by the experiments of Haughton et al 1974 and Shima and Naldrett 1975, for which, although the figures are of different nature for direct comparison, the fact remains that the sulphur content actually increases with temperature, making this a control of sulphu r solubility in the magmatic melt. The studies and experimental conditions on which pressure is investigated as a control in sulphur solubility are vast and vary on their conditions. The outcome of different studies such as Haung and Williams 1980 and Wendlandt 1982, indicate that under natural conditions increase in pressure has a negative effect on sulphur content. In contrast, the increase of FeO levels in the melt increase the sulphur solubility and this is confirmed by Mavrogenes and ONeil 1999, where the study of basaltic melts with 6-14 wt% FeO on pressures varying from 5-90 kilo bars and temperatures of 1400oC and 1800oC shows increase sulphur content at sulphide saturation with pressure. Sulphur can be found dissolved in an aqueous fluid. The sulphur content of the fluid is determined by its sulphur dioxide against hydrogen sulphide ratio (SO2:H2S). The ratio (Misra K.C. 1999) increases with increasing oxygen fugacity (fO2) of the initial magma before the start of second melting. Aqueous fluids originating from high oxygen fugacity magmas (I-type; high fO2) may contain large quantities of sulphur dioxide (SO2) as well as hydrogen sulphide (H2S). At lower temperatures on cooling hydrolysis of the SO2 (4SO2 + 4H2O = H2S + 3H2SO4) or its reaction with Fe2+ bearing minerals of the wallrocks (SO2 + 6FeO + H2O = H2S +3Fe2O3) increases the activity of H2S, causing precipitation of sulphide ore minerals from the metal-chloride complexes in the aqueous solution. On the other hand, aqueous fluids originating from low oxygen fugacity magmas (S-type; low fO2) may contain as much H2S as those derived from high oxygen fugacity, but because of lower oxygen fugacity they contain les s sulphur dioxide so the total amount of sulphur is smaller. Thus, aqueous fluids that separate from I-type magmas tend to produce Cu-Mo-Zn-Fe sulphide deposits, whereas fluids from S-type magmas generally precipitate smaller quantities of sulphides, mainly pyrrhotite, and correspondingly larger quantities of oxides, such as cassiterite (Burnham Ohmoto 1980). In either case, the precipitation of sulphides form metal-chloride complexes is accompanied by generation of HCl. The HCl and the H2SO4 produced by SO2 hydrolysis are consumed by acid alternation of aluminosilicate minerals in the wallrocks. (Misra K.C. 1999) Chalcophile Elements The partitioning of Chalcophile metal elements between sulphides and silicate metals are referred to as metals with low concentration, such as Nickel (Ni), Copper (Cu) and Colbat (Co) are exchanged with elements of higher concentration, like Iron (Fe). The Nernst coefficient of partitioning, arranged for iron substitution is the ratio of the products of the % (per cent) weights of the elements substituted. References Buchanan D. L. (1988). Development in Economic Geology Platinum-Group Element Exploration. Elsevier. ISBN 0444429581 Naldrett A. J. (2004). Magmatic Sulfide Deposits : Geology, Geochemistry and Exploration. Springer. ISBN 3540223177 Mungall J. E. (2005). Exploration for Platinum-Group Elements Deposits. Mineral Association of Canada. ISBN 0921294352 Misra K. C. (1999). Understanding Mineral Deposites. Kluwer Academic Publishers. ISBN 0045530092 Whitney J.A. (1989). Ore Deposition Associated with magmas. Society of Economic Geologists. ISBN 0961307439 Vaughan D. J. (1977) Mineral Chemistry of Metal Sulfides. Cambridge University Press. ISBN 0521214890

Inhumanity in Night Essay

Elie Wiesel’s Night is about what the Holocaust did, not just to the Jews, but also by extension, to humanity. People all over the world were devastated by this atrocious act, and there are still people today who have not overcome the effects. One example of the heinous acts of the Germans that stands out occurs at the end of the war, when Wiesel and the rest of the camp of Buna are being forced to transfer to Gleiwitz. This transfer is a long, arduous, and tiring journey for all who are involved. The weather is painfully cold, and snow fell heavily; the distance was greater than most people today will even dream of walking. The huge mass of people is often forced to run, and if one collapses, is injured, or simply can no longer bear the pain, they are shot or trampled without pity. An image that secures itself in Wiesel’s memory is that of the Rabbi Eliahou’s son leaving the Rabbi for dead. The father and son are running together when the father begins to grow t ired. As the Rabbi falls farther and farther behind his son, his son runs on, pretending not to see what is happening to his father. This spectacle causes Wiesel to think of what he would do if his father ever became as weak as the Rabbi did. He decides that he would never leave his father, even if staying with him would be the cause of his death. The German forces are so adept at breaking the spirits of the Jews that we can see the effects throughout Wiesel’s novel. Wiesel’s faith in God, above all other things, is strong at the onset of the novel, but grows weaker as it goes on. We see this when Wiesel’s father politely asks the gypsy where the lavoratories are. Not only does the gypsy not grace his father with a response, but he also delivers a blow to his head that sent him to the floor. Wiesel watches the entire exhibition, but does not even blink. He realizes that nothing, not even his faith in God, can save him from the physical punishment that would await him if he tried to counterattack the gypsy. If the gypsy’s attack had come just one day earlier, Wiesel probably would have struck back. However, the spiritual beating by the Germans had already begun. The incident that perhaps has the greatest effect on Wiesel is the hanging of the pipel. He is a young boy with an â€Å"innocent face† who is condemned to death because he is involved in a conspiracy that results in the destruction of a German building. When the time for the hanging approaches, the Lagerkapo refuses to kick out the chair, so SS officers are  assigned to do it. Unlike the necks of those he is hanged with, the young boy’s neck does not break when he falls, and he suffers for over half an hour. The suffering of the child is comparable to the suffering endured by many Jews during the Holocaust. He fought for his life, at times even seeing a bit of hope, only to be destroyed in the end. The Jews struggled for everything they had, from their possessions at the beginning, to their lives at the end. The result, however, was the same. At the end of the war, Wiesel looks into the mirror, and says he saw a â€Å"corpse.† This â€Å"corpse† is Wiesel’s body, but it has been robbed of its soul. This is similar to the loss suffered by people all over the world. Those not directly killed during the Holocaust were still alive physically, but their mind and spirit had long been dead. By the end of the w ar, Wiesel loses all of his faith in God and his fellow man, and this is the most difficult obstacle to overcome when he is released.

4th Gospel Revision Notes

Ethics EITHER 3 (a) (i) Examine the key ideas of one critique of the link between religion and morality. (18) (ii) To what extent does this critique effectively undermine the link between religion and morality? (12) (Total for Question 3(a) = 30 marks) OR (b) (i) Analyse the important features of either Deontology or Natural Moral Law. (18) (ii) To what extent is the selected theory persuasive? (12) (Total for Question 3(b) = 30 marks) EITHER 4 (a) (i) Examine the important concepts relating to justice and law and punishment. (18) (ii) Consider critically the extent to which subjectivism poses problems for these concepts. 12) (Total for Question 4(a) = 30 marks) OR (b) (i) Analyse the contribution made by emotivism to debates about ethical language. (18) (ii) To what extent do the problems of ethical language remain unsolved? (12) (Total for Question 4(b) = 30 marks) New Testament EITHER 17 (a) (i) Examine the religious significance of either the teachings of Jesus concerning the Kin gdom of God (Luke’s Gospel) or the teaching of the Prologue (Fourth Gospel). (18) (ii) To what extent are these teachings important for an understanding of the gospel? (12) (Total for Question 17(a) = 30 marks)OR (b) (i) ‘The gospel was written to reveal the nature of Jesus as the Christ. ’ Examine this claim regarding the purpose of either Luke’s Gospel or the Fourth Gospel. (18) (ii) To what extent may other purposes for the gospel be equally important? (12) (Total for Question 17(b) = 30 marks) EITHER 18 (a) (i) With reference to either Luke’s Gospel or the Fourth Gospel, examine the reasons why the religious and political authorities put Jesus to death. (18) (ii) To what extent was Pilate responsible for the death of Jesus? (12) (Total for Question 18(a) = 30 marks) OR b) (i) Examine the significance of the religious symbolism contained within the crucifixion narrative of either Luke’s Gospel or the Fourth Gospel. (18) (ii) To what extent does the resurrection narrative add to an understanding of the rest of the gospel? (12) (Total for Question 18(b) = 30 marks) Ethics EITHER 3 (a) (i) Analyse the important features of either Deontology or Virtue Ethics. (18) (ii) Consider critically how effective the selected theory may be as a guideline for moral living. (12) (Total for Question 3(a) = 30 marks) OR (b) (i) Examine the key ideas of Natural Moral Law. 18) (ii) To what extent do critiques of the link between religion and morality undermine the value of Natural Moral Law? (12) (Total for Question 3(b) = 30 marks) EITHER 4 (a) (i) Examine key ideas associated with either justice or law and punishment. (18) (ii) Evaluate the view that objectivity and relativism pose problems for the concept selected in part (i). (12) (Total for Question 4(a) = 30 marks) OR (b) (i) Examine the problems which scholars have identified regarding the use and meaning of ethical language. (18) (ii) To what extent may these problems be solved? 12) (Total for Question 4(b) = 30 marks) New Testament EITHER 17 (a) (i) Either examine the important features of Luke’s presentation of Jesus’ teaching on the Kingdom of God or examine the key ideas of the Prologue (Fourth Gospel). (18) (ii) Evaluate the claim that this teaching/these ideas are crucial to the meaning of the gospel. (12) (Total for Question 17(a) = 30 marks) OR (b) (i) ‘A careful reading of the gospel reveals the purpose the author had for writing it. ’ Examine this claim with reference to either Luke’s Gospel or the Fourth Gospel. 18) (ii) Evaluate the view that knowing the purpose of the gospel does not add to our understanding of its meaning. (12) (Total for Question 17(b) = 30 marks) EITHER 18 (a) (i) ‘It was the religious officials who were responsible for Jesus’ death; the political authorities had nothing to do with it. ’ Examine this claim with reference to either Luke’s Gospel or the Fourth Gospel . (18) (ii) Evaluate the view that conflict was crucial to the ministry of Jesus. (12) (Total for Question 18(a) = 30 marks) OR (b) (i) Analyse three examples of religious symbolism in the crucifixion narrative of either Luke’s Gospel or the Fourth Gospel. 18) (ii) Evaluate the claim that the resurrection adds little to our understanding of the ministry of Jesus. (12) (Total for Question 18(b) = 30 marks) Ethics EITHER 3 (a) (i) Examine the important concepts of two critiques of the link between religion and morality (18) (ii) To what extent do these critiques succeed in weakening the link between religion and morality? (12) (Total for Question 3(a) = 30 marks) OR (b) (i) Analyse the key features of either Natural Moral Law or Virtue Ethics. (18) (ii) Evaluate the extent to which the selected theory can withstand criticism. (12) (Total for Question 3(b) = 30 marks)EITHER 4 (a) (i) Examine central ideas relating to justice and law and punishment. (18) (ii) To what extent does objectivity pose challenges for imposing punishment? (12) (Total for Question 4(a) = 30 marks) OR (b) (i) Analyse two problems raised by the use and meaning of ethical language. (18) (ii) Evaluate the view that these problems cannot be solved. (12) (Total for Question 4(b) = 30 marks) New Testament EITHER 17 (a) (i) Examine the key religious concepts of either the teachings of Jesus concerning the Kingdom of God (Luke’s Gospel) or the teaching of the Prologue (Fourth Gospel). 18) (ii) Evaluate the claim that these teachings lay down the primary themes of the gospel. (12) (Total for Question 17(a) = 30 marks) OR (b) (i) ‘The Gospel was written to make clear the identity of Jesus. ’ Examine this claim regarding the purpose of either Luke’s Gospel or the Fourth Gospel. (18) (ii) Evaluate the claim that there are also other important purposes for the gospel. (12) (Total for Question 17(b) = 30 marks) EITHER 18 (a) (i) With reference to either Luke’s Gos pel or the Fourth Gospel, examine the [pic][? ] |&'(*,. /@AGJKY[^_pqrs†¹ Zâ€Å" ¤?  ¬iaiaiaiaiaiOAa ·a ·?  ·aâ„ ¢? A†¦? {†¦A{A{A{†¦g†¦? u†°OJ[? ]QJ[? ]U[pic]^J[? ]mHnHu[pic]h? †ºOJ[? ]QJ[? ]contribution of both the religious and political authorities to the death of Jesus. (18) (ii) Consider critically the claim that it was Pilate who was responsible for the death of Jesus, not the Jewish leaders. (12) (Total for Question 18(a) = 30 marks) OR (b) (i) ‘The religious symbolism of the crucifixion narrative is vital to understanding the whole gospel. ’ Examine the meaning of this claim. (18) (ii) To what extent does the resurrection narrative enhance that understanding? (12) (Total for Question 18(b) = 30 marks)

Erectile Dysfunction Causes, Effects, And A Focus On...

Erectile Dysfunction: Causes, Effects, and a Focus on Treatments â€Å"Sex.† The media portrays sex to be easy, problem-less, and enjoyable all the time. Although this may be the case for some, for others, sex can be a serious struggle. Research shows that sexual dysfunction is common with 43% of women and 31% of men (DiMeo, 2006). In addition, around 10% of men aged 40 to 70 years old have complete erectile dysfunction, yet very few seek medical help (O’Leary, Barada, Costabile, 1996). Sexual dysfunction refers to a problem during any phase of the sexual response cycle that prevents the individual or couple from experiencing satisfaction from the sexual activity. The sexual response cycle has four phases: excitement, plateau, orgasm, and resolution. Sexual function is a very important part of one’s sexuality. Sex may be only one component of one’s life but it can affect many other facets of life, including confidence, identity, life satisfaction, and health. In addition, sexual dysfunction is frequently associ ated with a number of systemic illnesses and surgical treatments, thus it is important to address sexual dysfunctions. Sexual dysfunction is a topic that many people are hesitant and embarrassed to discuss (Barnes, 1991). Fortunately, most cases of sexual dysfunction are treatable, which is why it is important for people to share their concerns with their partner(s) and doctor(s). The three most common sexual dysfunctions for men are low desire (libido),Show MoreRelatedErectile Dysfunction And The Elderly Population1757 Words   |  8 PagesErectile Dysfunction, according to the American Sexual Health Association, is the inability to maintain an erection that is suitable for intercourse. It is a condition that can affect men of any age. Even though erectile dysfunction can affect men of all ages, it is most prevalent in the elderly population. Erectile dysfunction can be due to many issues such as psychological problems, heart disease, high blood pressure, Diabetes, Parkinsonâ⠂¬â„¢s disease, trauma from surgery related to prostate cancerRead MoreSexual Dysfunction Essay1057 Words   |  5 PagesA vast amount of men and women suffer from some type of sexual dysfunction. Researchers have identified a number of factors that may contribute to or perpetuate sexual dysfunction, including, but not limited to, performance anxiety. Performance anxiety is defined as an obsession about the adequate pleasing of one’s partner during the act of sexual intercourse. Rather than focusing on the pleasurable benefits that one can receive from intercourse, the individual experiencing performance anxiety isRead MoreCase Analysis Cialis Essay1608 Words   |  7 PagesTracy Rucker Marketing Mid-Term 2012 March 1, 2012 Product Team Cialis: Getting Ready to Market Brief Background Erectile dysfunction’ is the failure to achieve and maintain an erection sufficient for satisfactory sexual experience. It affects 150 million men globally. In March1998, Viagra (Sildenafil) was the first oral medication approved for use in ‘erectile dysfunction. Viagra had a very successful launch with a total of 600,000 prescriptions filled in the first month (April 1998), andRead MoreThe Drug Called Cialis And Its Effects On Erectile Dysfunction2966 Words   |  12 Pagescommercialize tadalafil (Cialis) as a treatment for ED (Erectile Dysfunction). The Eli Lilly and Company had made long strides in the drug industry as ICOS began to fall behind and in 2007, the Eli Lilly and Company bought the ICOS Corporation for 2.3 Billion dollars1. In December 2003, the Food and Drug Administration approved tadalafil as Cialis for sale in the United States1. This would make Cialis the third prescription drug pill to treat erectile dysfunction after Viagra and Levitra. In 1993,Read MoreSexual Dysfunction As A Side Effect Of Chronic Disease1675 Words   |  7 Pagesemotional problems that accompany the chronic disease (Ferrini, 2013 p. 358). The illness the individual is facing my cause them to feel tired, depressed, and uninterested in sexual activity. Intercourse and sexual relations may provide intimacy and relaxation, reduce isolation and depression, and help the person feel normal again (Karlen, 2002). Sexual dysfunction as a side effect of chronic disease has long been ignored in both research and clinical practice. Currently, the situation is changingRead MoreDiabetes Mellitus : An Autoimmune Disease And Affects The Body s Metabolism Of Carbohydrates1316 Words   |  6 Pagesor an autoimmune abnormality caused by an envi ronmental trigger. Essentially, the body’s pancreatic beta cells are destroyed, which in turn, inhibits the pancreas from either producing or secreting insulin. This caused a disarraying effect to all body systems. The cause of type 2 diabetes is said to be from an â€Å"imbalance between insulin sensitivity and insulin secretion† (Ralph A. DeFronzo). The pancreas is not producing adequate levels of insulin, seizing production of insulin or the insulin thatRead MoreThe Reality of the Vaginal Orgasm1226 Words   |  5 Pagessexual insecurity in the female counterpart. There are many factors that contribute to producing orgasms, and because of its multifaceted nature, there are also many factors that can disrupt the production of female orgasms. In this piece I will focus on reasons that contribute to this difference in frequency between men and women, which will include: why difficulty of the female orgasm is common, one of the most common sexual disorders amongst wo men, and why some women orgasm vaginally more oftenRead MoreSexual Roles And Sexual Performance1730 Words   |  7 Pagesconditions leads to erectile dysfunction. Physical stress increase, either at home or workplace is the main cause of inability to keep up a steady erection during sexual intercourse. The following are sexual performance problems experienced by people: 1. Delayed ejaculation-This is a state of achieving sexual climax in a given time frame between 5 to 30 minutes. The condition is known to affect sexual performance between both partners. When not properly addressed, the situation always causes a barrier inRead MoreThe Food And Drug Aspect Of Aphrodisiac1388 Words   |  6 Pagesduration of sexual activities (Sahoo et al. 2014). To some extent, some scientists also believe that the media involved sexual descriptions could trigger sexual desire through mental activities may also count as aphrodisiac. This paper will be mainly focus on the food and drug aspect of aphrodisiac. As many substances are considered to be aphrodisiac related, they are generally split into two categories—direct aphrodisiacs and indirect aphrodisiacs. Direct aphrodisiacs usually refer to many typesRead MoreLifestyle Drug Affecting Health : Obesity1694 Words   |  7 Pagesovercome sexual dysfunction. Whatever one may think about this: The consumption of alcohol, tobacco and illicit drugs is an everyday reality. They are consumed, although the associated health risks are known. With a congenital heart defect the dangers of consuming, however, are even greater. Background The distinction between a â€Å"real† drug and a lifestyle drug is out of focus and not least depending on the exact indication. For example, pharmaceutical apply against erectile dysfunction (ED) in patients